WO1981001757A1 - Color imaging system - Google Patents
Color imaging system Download PDFInfo
- Publication number
- WO1981001757A1 WO1981001757A1 PCT/US1980/001506 US8001506W WO8101757A1 WO 1981001757 A1 WO1981001757 A1 WO 1981001757A1 US 8001506 W US8001506 W US 8001506W WO 8101757 A1 WO8101757 A1 WO 8101757A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- dye
- nitrate
- imageable layer
- present
- binder
- Prior art date
Links
- 238000003384 imaging method Methods 0.000 title abstract description 25
- 239000011230 binding agent Substances 0.000 claims abstract description 30
- 150000002823 nitrates Chemical class 0.000 claims abstract description 27
- -1 silver halide Chemical class 0.000 claims abstract description 11
- 239000000975 dye Substances 0.000 claims description 106
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 claims description 41
- 150000003839 salts Chemical class 0.000 claims description 24
- 230000003287 optical effect Effects 0.000 claims description 18
- 239000002253 acid Substances 0.000 claims description 17
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 10
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 8
- 229910017604 nitric acid Inorganic materials 0.000 claims description 8
- 239000007800 oxidant agent Substances 0.000 claims description 8
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 6
- 238000001228 spectrum Methods 0.000 claims description 5
- WZKXBGJNNCGHIC-UHFFFAOYSA-N Leucomalachite green Chemical compound C1=CC(N(C)C)=CC=C1C(C=1C=CC(=CC=1)N(C)C)C1=CC=CC=C1 WZKXBGJNNCGHIC-UHFFFAOYSA-N 0.000 claims description 4
- 229910052782 aluminium Inorganic materials 0.000 claims description 4
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 4
- 229910052759 nickel Inorganic materials 0.000 claims description 4
- 150000002989 phenols Chemical class 0.000 claims description 4
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 3
- OAZWDJGLIYNYMU-UHFFFAOYSA-N Leucocrystal Violet Chemical class C1=CC(N(C)C)=CC=C1C(C=1C=CC(=CC=1)N(C)C)C1=CC=C(N(C)C)C=C1 OAZWDJGLIYNYMU-UHFFFAOYSA-N 0.000 claims description 3
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 3
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 3
- 229910052793 cadmium Inorganic materials 0.000 claims description 3
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 claims description 3
- 229910052804 chromium Inorganic materials 0.000 claims description 3
- 239000011651 chromium Substances 0.000 claims description 3
- 229910017052 cobalt Inorganic materials 0.000 claims description 3
- 239000010941 cobalt Substances 0.000 claims description 3
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 3
- 229910052802 copper Inorganic materials 0.000 claims description 3
- 239000010949 copper Substances 0.000 claims description 3
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 229910052749 magnesium Inorganic materials 0.000 claims description 3
- 239000011777 magnesium Substances 0.000 claims description 3
- 150000004893 oxazines Chemical class 0.000 claims description 3
- 150000004897 thiazines Chemical class 0.000 claims description 3
- 150000003732 xanthenes Chemical class 0.000 claims description 3
- 229910052725 zinc Inorganic materials 0.000 claims description 3
- 239000011701 zinc Substances 0.000 claims description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 2
- 229910052688 Gadolinium Inorganic materials 0.000 claims description 2
- 229940051880 analgesics and antipyretics pyrazolones Drugs 0.000 claims description 2
- 150000004056 anthraquinones Chemical class 0.000 claims description 2
- 229910052791 calcium Inorganic materials 0.000 claims description 2
- 239000011575 calcium Substances 0.000 claims description 2
- UIWYJDYFSGRHKR-UHFFFAOYSA-N gadolinium atom Chemical compound [Gd] UIWYJDYFSGRHKR-UHFFFAOYSA-N 0.000 claims description 2
- 125000001434 methanylylidene group Chemical group [H]C#[*] 0.000 claims description 2
- JEXVQSWXXUJEMA-UHFFFAOYSA-N pyrazol-3-one Chemical class O=C1C=CN=N1 JEXVQSWXXUJEMA-UHFFFAOYSA-N 0.000 claims description 2
- 229910001960 metal nitrate Inorganic materials 0.000 claims 4
- ZSLUVFAKFWKJRC-IGMARMGPSA-N 232Th Chemical compound [232Th] ZSLUVFAKFWKJRC-IGMARMGPSA-N 0.000 claims 1
- 229910052776 Thorium Inorganic materials 0.000 claims 1
- 229910052797 bismuth Inorganic materials 0.000 claims 1
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 claims 1
- 229910052746 lanthanum Inorganic materials 0.000 claims 1
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 claims 1
- 239000000463 material Substances 0.000 abstract description 17
- 229910052709 silver Inorganic materials 0.000 abstract description 10
- 239000004332 silver Substances 0.000 abstract description 10
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 abstract description 5
- 230000000630 rising effect Effects 0.000 abstract 1
- 238000001931 thermography Methods 0.000 abstract 1
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 39
- 239000000243 solution Substances 0.000 description 28
- 229910002651 NO3 Inorganic materials 0.000 description 22
- 238000011161 development Methods 0.000 description 15
- 238000007254 oxidation reaction Methods 0.000 description 14
- XNGIFLGASWRNHJ-UHFFFAOYSA-N phthalic acid Chemical compound OC(=O)C1=CC=CC=C1C(O)=O XNGIFLGASWRNHJ-UHFFFAOYSA-N 0.000 description 14
- 230000003647 oxidation Effects 0.000 description 13
- 238000010276 construction Methods 0.000 description 12
- 239000004615 ingredient Substances 0.000 description 12
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 10
- 239000011248 coating agent Substances 0.000 description 10
- 238000000576 coating method Methods 0.000 description 10
- 238000010438 heat treatment Methods 0.000 description 9
- 229920005989 resin Polymers 0.000 description 9
- 239000011347 resin Substances 0.000 description 9
- 230000002378 acidificating effect Effects 0.000 description 8
- 239000000203 mixture Substances 0.000 description 8
- 230000009467 reduction Effects 0.000 description 8
- 150000002500 ions Chemical class 0.000 description 7
- 230000001590 oxidative effect Effects 0.000 description 7
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 6
- MFUVDXOKPBAHMC-UHFFFAOYSA-N magnesium;dinitrate;hexahydrate Chemical compound O.O.O.O.O.O.[Mg+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O MFUVDXOKPBAHMC-UHFFFAOYSA-N 0.000 description 6
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 6
- 238000002835 absorbance Methods 0.000 description 5
- 239000004480 active ingredient Substances 0.000 description 5
- AOPCKOPZYFFEDA-UHFFFAOYSA-N nickel(2+);dinitrate;hexahydrate Chemical compound O.O.O.O.O.O.[Ni+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O AOPCKOPZYFFEDA-UHFFFAOYSA-N 0.000 description 5
- CIWBSHSKHKDKBQ-JLAZNSOCSA-N Ascorbic acid Chemical compound OC[C@H](O)[C@H]1OC(=O)C(O)=C1O CIWBSHSKHKDKBQ-JLAZNSOCSA-N 0.000 description 4
- NTIZESTWPVYFNL-UHFFFAOYSA-N Methyl isobutyl ketone Chemical compound CC(C)CC(C)=O NTIZESTWPVYFNL-UHFFFAOYSA-N 0.000 description 4
- UIHCLUNTQKBZGK-UHFFFAOYSA-N Methyl isobutyl ketone Natural products CCC(C)C(C)=O UIHCLUNTQKBZGK-UHFFFAOYSA-N 0.000 description 4
- 150000007513 acids Chemical class 0.000 description 4
- 230000003466 anti-cipated effect Effects 0.000 description 4
- 239000007844 bleaching agent Substances 0.000 description 4
- 150000001768 cations Chemical class 0.000 description 4
- 229920002301 cellulose acetate Polymers 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 229940043265 methyl isobutyl ketone Drugs 0.000 description 4
- 229920000728 polyester Polymers 0.000 description 4
- FGIUAXJPYTZDNR-UHFFFAOYSA-N potassium nitrate Chemical compound [K+].[O-][N+]([O-])=O FGIUAXJPYTZDNR-UHFFFAOYSA-N 0.000 description 4
- 230000005855 radiation Effects 0.000 description 4
- PAWQVTBBRAZDMG-UHFFFAOYSA-N 2-(3-bromo-2-fluorophenyl)acetic acid Chemical compound OC(=O)CC1=CC=CC(Br)=C1F PAWQVTBBRAZDMG-UHFFFAOYSA-N 0.000 description 3
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 3
- XNDZQQSKSQTQQD-UHFFFAOYSA-N 3-methylcyclohex-2-en-1-ol Chemical compound CC1=CC(O)CCC1 XNDZQQSKSQTQQD-UHFFFAOYSA-N 0.000 description 3
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 3
- 230000002411 adverse Effects 0.000 description 3
- 238000004061 bleaching Methods 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 238000004042 decolorization Methods 0.000 description 3
- 239000012954 diazonium Substances 0.000 description 3
- 150000001989 diazonium salts Chemical class 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 230000005012 migration Effects 0.000 description 3
- 238000013508 migration Methods 0.000 description 3
- 150000007524 organic acids Chemical class 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- 229910001961 silver nitrate Inorganic materials 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- XTEGARKTQYYJKE-UHFFFAOYSA-M Chlorate Chemical compound [O-]Cl(=O)=O XTEGARKTQYYJKE-UHFFFAOYSA-M 0.000 description 2
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 239000003963 antioxidant agent Substances 0.000 description 2
- 235000006708 antioxidants Nutrition 0.000 description 2
- 239000002216 antistatic agent Substances 0.000 description 2
- 235000010323 ascorbic acid Nutrition 0.000 description 2
- 229960005070 ascorbic acid Drugs 0.000 description 2
- 239000011668 ascorbic acid Substances 0.000 description 2
- IWOUKMZUPDVPGQ-UHFFFAOYSA-N barium nitrate Chemical compound [Ba+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O IWOUKMZUPDVPGQ-UHFFFAOYSA-N 0.000 description 2
- 230000004888 barrier function Effects 0.000 description 2
- FBXVOTBTGXARNA-UHFFFAOYSA-N bismuth;trinitrate;pentahydrate Chemical compound O.O.O.O.O.[Bi+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O FBXVOTBTGXARNA-UHFFFAOYSA-N 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- PHFQLYPOURZARY-UHFFFAOYSA-N chromium trinitrate Chemical compound [Cr+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O PHFQLYPOURZARY-UHFFFAOYSA-N 0.000 description 2
- QGUAJWGNOXCYJF-UHFFFAOYSA-N cobalt dinitrate hexahydrate Chemical compound O.O.O.O.O.O.[Co+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O QGUAJWGNOXCYJF-UHFFFAOYSA-N 0.000 description 2
- 150000001875 compounds Chemical group 0.000 description 2
- SXTLQDJHRPXDSB-UHFFFAOYSA-N copper;dinitrate;trihydrate Chemical compound O.O.O.[Cu+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O SXTLQDJHRPXDSB-UHFFFAOYSA-N 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 229940093915 gynecological organic acid Drugs 0.000 description 2
- 235000019239 indanthrene blue RS Nutrition 0.000 description 2
- UHOKSCJSTAHBSO-UHFFFAOYSA-N indanthrone blue Chemical compound C1=CC=C2C(=O)C3=CC=C4NC5=C6C(=O)C7=CC=CC=C7C(=O)C6=CC=C5NC4=C3C(=O)C2=C1 UHOKSCJSTAHBSO-UHFFFAOYSA-N 0.000 description 2
- ICIWUVCWSCSTAQ-UHFFFAOYSA-M iodate Chemical compound [O-]I(=O)=O ICIWUVCWSCSTAQ-UHFFFAOYSA-M 0.000 description 2
- SZQUEWJRBJDHSM-UHFFFAOYSA-N iron(3+);trinitrate;nonahydrate Chemical compound O.O.O.O.O.O.O.O.O.[Fe+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O SZQUEWJRBJDHSM-UHFFFAOYSA-N 0.000 description 2
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 2
- 239000000314 lubricant Substances 0.000 description 2
- FDZZZRQASAIRJF-UHFFFAOYSA-M malachite green Chemical compound [Cl-].C1=CC(N(C)C)=CC=C1C(C=1C=CC=CC=1)=C1C=CC(=[N+](C)C)C=C1 FDZZZRQASAIRJF-UHFFFAOYSA-M 0.000 description 2
- 229940107698 malachite green Drugs 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 235000005985 organic acids Nutrition 0.000 description 2
- 229940082615 organic nitrates used in cardiac disease Drugs 0.000 description 2
- CMCWWLVWPDLCRM-UHFFFAOYSA-N phenidone Chemical compound N1C(=O)CCN1C1=CC=CC=C1 CMCWWLVWPDLCRM-UHFFFAOYSA-N 0.000 description 2
- KJFMBFZCATUALV-UHFFFAOYSA-N phenolphthalein Chemical compound C1=CC(O)=CC=C1C1(C=2C=CC(O)=CC=2)C2=CC=CC=C2C(=O)O1 KJFMBFZCATUALV-UHFFFAOYSA-N 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 229920002037 poly(vinyl butyral) polymer Polymers 0.000 description 2
- 235000010333 potassium nitrate Nutrition 0.000 description 2
- 239000004323 potassium nitrate Substances 0.000 description 2
- VWDWKYIASSYTQR-UHFFFAOYSA-N sodium nitrate Chemical compound [Na+].[O-][N+]([O-])=O VWDWKYIASSYTQR-UHFFFAOYSA-N 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 239000004094 surface-active agent Substances 0.000 description 2
- VAVIMIAZQDNXID-UHFFFAOYSA-N thorium(4+);tetranitrate;tetrahydrate Chemical compound O.O.O.O.[Th+4].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O VAVIMIAZQDNXID-UHFFFAOYSA-N 0.000 description 2
- 229920002554 vinyl polymer Polymers 0.000 description 2
- BNGXYYYYKUGPPF-UHFFFAOYSA-M (3-methylphenyl)methyl-triphenylphosphanium;chloride Chemical compound [Cl-].CC1=CC=CC(C[P+](C=2C=CC=CC=2)(C=2C=CC=CC=2)C=2C=CC=CC=2)=C1 BNGXYYYYKUGPPF-UHFFFAOYSA-M 0.000 description 1
- XIOUDVJTOYVRTB-UHFFFAOYSA-N 1-(1-adamantyl)-3-aminothiourea Chemical compound C1C(C2)CC3CC2CC1(NC(=S)NN)C3 XIOUDVJTOYVRTB-UHFFFAOYSA-N 0.000 description 1
- 125000004066 1-hydroxyethyl group Chemical group [H]OC([H])([*])C([H])([H])[H] 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 108010010803 Gelatin Proteins 0.000 description 1
- 229920000084 Gum arabic Polymers 0.000 description 1
- IOVCWXUNBOPUCH-UHFFFAOYSA-M Nitrite anion Chemical compound [O-]N=O IOVCWXUNBOPUCH-UHFFFAOYSA-M 0.000 description 1
- 206010034960 Photophobia Diseases 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- 229910006069 SO3H Inorganic materials 0.000 description 1
- 241000978776 Senegalia senegal Species 0.000 description 1
- FOIXSVOLVBLSDH-UHFFFAOYSA-N Silver ion Chemical compound [Ag+] FOIXSVOLVBLSDH-UHFFFAOYSA-N 0.000 description 1
- 241000907663 Siproeta stelenes Species 0.000 description 1
- OCBFFGCSTGGPSQ-UHFFFAOYSA-N [CH2]CC Chemical group [CH2]CC OCBFFGCSTGGPSQ-UHFFFAOYSA-N 0.000 description 1
- 239000000205 acacia gum Substances 0.000 description 1
- 235000010489 acacia gum Nutrition 0.000 description 1
- 150000001241 acetals Chemical class 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
- RMRFFCXPLWYOOY-UHFFFAOYSA-N allyl radical Chemical group [CH2]C=C RMRFFCXPLWYOOY-UHFFFAOYSA-N 0.000 description 1
- OSYLPIYJUCCMTQ-UHFFFAOYSA-O azanium;cerium(3+);nitrate Chemical compound [NH4+].[Ce+3].[O-][N+]([O-])=O OSYLPIYJUCCMTQ-UHFFFAOYSA-O 0.000 description 1
- 125000000649 benzylidene group Chemical group [H]C(=[*])C1=C([H])C([H])=C([H])C([H])=C1[H] 0.000 description 1
- QOYRNHQSZSCVOW-UHFFFAOYSA-N cadmium nitrate tetrahydrate Chemical compound O.O.O.O.[Cd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O QOYRNHQSZSCVOW-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000012822 chemical development Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 150000001844 chromium Chemical class 0.000 description 1
- GVHCUJZTWMCYJM-UHFFFAOYSA-N chromium(3+);trinitrate;nonahydrate Chemical compound O.O.O.O.O.O.O.O.O.[Cr+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O GVHCUJZTWMCYJM-UHFFFAOYSA-N 0.000 description 1
- 239000008199 coating composition Substances 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 125000000664 diazo group Chemical group [N-]=[N+]=[*] 0.000 description 1
- ZOMNIUBKTOKEHS-UHFFFAOYSA-L dimercury dichloride Chemical class Cl[Hg][Hg]Cl ZOMNIUBKTOKEHS-UHFFFAOYSA-L 0.000 description 1
- 125000002147 dimethylamino group Chemical group [H]C([H])([H])N(*)C([H])([H])[H] 0.000 description 1
- 125000000816 ethylene group Chemical group [H]C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- NBVXSUQYWXRMNV-UHFFFAOYSA-N fluoromethane Chemical compound FC NBVXSUQYWXRMNV-UHFFFAOYSA-N 0.000 description 1
- 239000008273 gelatin Substances 0.000 description 1
- 229920000159 gelatin Polymers 0.000 description 1
- 235000019322 gelatine Nutrition 0.000 description 1
- 235000011852 gelatine desserts Nutrition 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 150000002366 halogen compounds Chemical class 0.000 description 1
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
- GPRLSGONYQIRFK-UHFFFAOYSA-N hydron Chemical compound [H+] GPRLSGONYQIRFK-UHFFFAOYSA-N 0.000 description 1
- FGSLWIKEHNEHLX-UHFFFAOYSA-N lanthanum(3+) trinitrate nonahydrate Chemical compound O.O.O.O.O.O.O.O.O.[N+](=O)([O-])[O-].[La+3].[N+](=O)([O-])[O-].[N+](=O)([O-])[O-] FGSLWIKEHNEHLX-UHFFFAOYSA-N 0.000 description 1
- 239000011133 lead Substances 0.000 description 1
- 208000013469 light sensitivity Diseases 0.000 description 1
- 159000000003 magnesium salts Chemical group 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- DZVCFNFOPIZQKX-LTHRDKTGSA-M merocyanine Chemical compound [Na+].O=C1N(CCCC)C(=O)N(CCCC)C(=O)C1=C\C=C\C=C/1N(CCCS([O-])(=O)=O)C2=CC=CC=C2O\1 DZVCFNFOPIZQKX-LTHRDKTGSA-M 0.000 description 1
- 125000000956 methoxy group Chemical group [H]C([H])([H])O* 0.000 description 1
- 125000002816 methylsulfanyl group Chemical group [H]C([H])([H])S[*] 0.000 description 1
- 108700009872 mild silver Proteins 0.000 description 1
- 150000007522 mineralic acids Chemical class 0.000 description 1
- 150000004780 naphthols Chemical class 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- LFLZOWIFJOBEPN-UHFFFAOYSA-N nitrate, nitrate Chemical class O[N+]([O-])=O.O[N+]([O-])=O LFLZOWIFJOBEPN-UHFFFAOYSA-N 0.000 description 1
- UJVRJBAUJYZFIX-UHFFFAOYSA-N nitric acid;oxozirconium Chemical compound [Zr]=O.O[N+]([O-])=O.O[N+]([O-])=O UJVRJBAUJYZFIX-UHFFFAOYSA-N 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 150000004690 nonahydrates Chemical class 0.000 description 1
- VLTRZXGMWDSKGL-UHFFFAOYSA-M perchlorate Inorganic materials [O-]Cl(=O)(=O)=O VLTRZXGMWDSKGL-UHFFFAOYSA-M 0.000 description 1
- VLTRZXGMWDSKGL-UHFFFAOYSA-N perchloric acid Chemical compound OCl(=O)(=O)=O VLTRZXGMWDSKGL-UHFFFAOYSA-N 0.000 description 1
- KHIWWQKSHDUIBK-UHFFFAOYSA-N periodic acid Chemical compound OI(=O)(=O)=O KHIWWQKSHDUIBK-UHFFFAOYSA-N 0.000 description 1
- JRKICGRDRMAZLK-UHFFFAOYSA-L peroxydisulfate Chemical compound [O-]S(=O)(=O)OOS([O-])(=O)=O JRKICGRDRMAZLK-UHFFFAOYSA-L 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 229920000058 polyacrylate Polymers 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920006267 polyester film Polymers 0.000 description 1
- 229920000139 polyethylene terephthalate Polymers 0.000 description 1
- 239000005020 polyethylene terephthalate Substances 0.000 description 1
- 239000002952 polymeric resin Substances 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- XAEFZNCEHLXOMS-UHFFFAOYSA-M potassium benzoate Chemical compound [K+].[O-]C(=O)C1=CC=CC=C1 XAEFZNCEHLXOMS-UHFFFAOYSA-M 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- XLABPPWWFVQMBZ-UHFFFAOYSA-O pyridin-1-ium;nitrate Chemical compound [O-][N+]([O-])=O.C1=CC=[NH+]C=C1 XLABPPWWFVQMBZ-UHFFFAOYSA-O 0.000 description 1
- 150000003242 quaternary ammonium salts Chemical class 0.000 description 1
- AQRYNYUOKMNDDV-UHFFFAOYSA-M silver behenate Chemical compound [Ag+].CCCCCCCCCCCCCCCCCCCCCC([O-])=O AQRYNYUOKMNDDV-UHFFFAOYSA-M 0.000 description 1
- 235000010344 sodium nitrate Nutrition 0.000 description 1
- 239000004317 sodium nitrate Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 239000012086 standard solution Substances 0.000 description 1
- 125000001424 substituent group Chemical group 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 239000004634 thermosetting polymer Substances 0.000 description 1
- 239000004416 thermosoftening plastic Substances 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
- B41M5/00—Duplicating or marking methods; Sheet materials for use therein
- B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
- B41M5/30—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers
- B41M5/32—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers one component being a heavy metal compound, e.g. lead or iron
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
- B41M5/00—Duplicating or marking methods; Sheet materials for use therein
- B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
- B41M5/30—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers
- B41M5/323—Organic colour formers, e.g. leuco dyes
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
- G03C1/00—Photosensitive materials
- G03C1/494—Silver salt compositions other than silver halide emulsions; Photothermographic systems ; Thermographic systems using noble metal compounds
- G03C1/498—Photothermographic systems, e.g. dry silver
- G03C1/4989—Photothermographic systems, e.g. dry silver characterised by a thermal imaging step, with or without exposure to light, e.g. with a thermal head, using a laser
Definitions
- a layer comprising 1) an oxidizing ion and 2) leuco dye or bleachable dye in a binder is useful as either an imaging layer or as a heat-bleachable antihalation layer.
- the antihalation layer is particularly useful in photothermographic systems where the development temperature acts to oxidize the leuco dye or bleach the dye.
- the present invention may be practiced in any polymeric binder system having the necessary active ingredients therein.
- These ingredients comprise leuco dyes or bleachable dyes and a non-dye-reactive nitrate salt.
- the active agents may also include any material which supplies hydrogen ion, such as an acidic material, and in particular an acid.
- a binder material containing these ingredients can be colorized or decolorized locally by heating portions of the binder layer or generally decolorized by heating the entire layer. The presence of an acidic material accelerates the decolorization phenomenum.
- the three required components are the dye (leuco or bleachable), the nitrate salt, and the polymeric binder.
- the Binder Any polymeric binder may be used in the practice of the present invention.
- the pH of the resin has been found to affect only the speed of the discolorizing effect. If the speed is not important, any resin may be used.
- Such resins as polyvinyl acetals, polyesters, polyvinyl resins, polyvinyl pyrolidone, polyesters, polycarbonates, polyamides, polyvinyl butyral, polyacrylates, cellulose esters, copolymers and blends of these classes of resins, and others have been used with particular success.
- Natural polymeric materials such as gelatin and gum arabic may also be used. Where the proportions and activities of dyes and nitrate ion require a particular developing time and temperature, the resin should be able to withstand those conditions.
- the polymer not decompose or lose its structural integrity at 200°F (93°C) for 30 seconds, and more preferred that it not decompose or lose its structural integrity at 260°F (127°C) for 30 seconds and most preferred that it withstand 290°F (144°C) for 60 seconds.
- Nitrate Salt Nitrate salts are themselves well known. They may be supplied as various compounds forms, but are preferably provided as a metal salt, and most preferably provided as a hydrated metal salt.
- oxidizing ions which are ordinarily good oxidizing ions such as nitrite, chlorate, iodate, perchlorate, periodate, and persulfate do not provide comparable results.
- the composition are satisfactory.
- metal salts, acid salts, mixtures of acids and salts, and other means of supplying the ion are useful.
- nitrates of zinc, cadmium, potassium, calcium, zirconyl, nickel, aluminum, chromium, iron, copper, magnesium, lead, and cobalt, ammonium nitrate, and cerous ammonium nitrate have been used.
- the nitrate salt component of the present invention must be present in a form within the imaging layer so that HNO 3 , NO, NO 2 , or N 2 O 4 will be provided within the layer when it is heated to a temperature no greater than 200°C for 60 seconds and preferably no greater than 160°C for 60 or most preferably 30 seconds. This may be accomplished with many different types of salts, both organic and inorganic, and in variously different types of constructions.
- the most convenient way of providing such thermal oxidant providing nitrate salts is to provide a hydrated nitrate salt such as aluminum nitrate nonahydrate (Al(NO 3 ) 2 .9H 2 O).
- This salt when heated in a binder, will generate HNO 3 , NO, NO 2 and/or N 2 O 4 in various amounts.
- the binder should not be at such a high pH that the liberated nitric acid would be profely neutralized as this would adversely affect the oxidizing capability of the system. It is not essential that a completely acidic or neutral pH environment be provided, but pH levels above 8.5 may in many cases completely prevent oxidation. It is therefore desired that the nitrate salt containing layer have an acidic environment such as a pH less than 7.5, preferably equal to or less than 7.0, and more preferably equal to or less than 6.5.
- non-hydrated salts in layers having a pH less than 7.5, and preferably in an acidic environment are also capable of providing HNO 3 , NO, NO 2 , and/or N 2 O 4 in sufficient quantities to provide the oxidizing capability necessary for practice of the present invention.
- Ammonium nitrate for example, does not enable good oxidation in the present invention in a layer having a pH of 8.0 or higher, but when a moderate strength organic acid such as phthalic acid is added to lower the pH to below 7.0, a quite acceptable imaging system is provided.
- organic salts in non-alkaline environments are also quite useful in the practice of the present invention.
- nitrated quaternary ammonium salts such as guanadinium nitrate work quite well in acid environments, but will not provide any useful image at alkaline pH levels of 8.0 or higher.
- the alkaline environment causes any oxidizing agent (e.g., HNO 3 , NO, NO 2 and/or N 2 O 4 ) which is liberated from the nitrate salt to be preferentially reacted with hydroxy ions or other neutralizing moieties so as to prevent oxidation of the dyes.
- any oxidizing agent e.g., HNO 3 , NO, NO 2 and/or N 2 O 4
- One other consideration should be given in the selection of the nitrate salt and that is the choice of a salt in which the cation is non-reactive with the dye.
- Non-reactive salts are defined in the practice of the present invention as those salts the cations of which do not spontaneously oxidize the dyes that they are associated with at room temperature. This may be readily determined in a number of fashions.
- the dye and a non-nitrate (preferably halide) salt of the cation may be codissolved in a solution. If the salt oxidizes the dye spontaneously (within two minutes) at room temperature, it is a reactive salt.
- Such salts as silver nitrate, in which the cation is itself a strong oxidizing agent, is a reactive salt. Cerric nitrate is also reactive, while hydrated cerrous nitrate is not.
- Preferred salts are the hydrated metal salts such as nickel nitrate hexahydrate, magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, ferric nitrate nonahydrate, cupric nitrate trihydrate, zinc nitrate hexahydrate, cadmium nitrate tetrahydrate, bismuth nitrate pentahydrate, thorium nitrate tetrahydrate, cobalt nitrate hexahydrate, gadolinium or lanthanum nitrate nonahydrate, mixtures of these hydrated nitrates and the like.
- Nonhydrated or organic nitrates may be admixed therewith.
- Organic nitrates are also quite useful in the practice of the present invention. These nitrates are usually in the form of quaternary nitrogen containing compounds such as guanadinium nitrate, pyridinium nitrate, and the like. Nitrated dyes will also be useful, but again, they must be used in an environment which will not neutralize any liberated HNO 3 , NO, NO 2 , and/or N 2 O 4 .
- nitrate ion per mole of dye It is preferred to have at least 0.10 moles of nitrate ion per mole of dye. It is more preferred to have at least 0.30 or 0.50 moles of ion per mole of dye. Even amounts of from 1.0 to 100 moles of nitrate ion per mole of dye have been found useful. With dyes having relatively higher oxidation potentials, more nitrate is desirable.
- leuco dyes as defined herein
- dyes are useful in the present invention. With some constructions it may be desirable to select dyes which have an oxidation potential of less than or equal to +1.0.
- the dyes may be selected from any class of dyes.
- These classes include but are not limited to 1) methines, 2) indamines, 3) anthraquinones, 4) triarylmethanes, 5) benzylidenes, 6) monoazos, 7) oxazines, 8) azines, 9) thiazines, 10) xanthenes, 11) indigoids, 12) oxonols, 13) cyanines, 14) merocyanines, 15) phenols, 16) naphthols, 17) pyrazolones, and others, of which most are classified by the Colour Index System.
- oxidation potentials is well known to the ordinarily skilled artisan.
- the measurements in the present invention are taken by measuring the voltage and current transferred between a carbon and a platinum electrode through the appropriate solution.
- 0.1 M lithium chloride in anhydrous methanol with 1 to 10 millimoles/liter of the appropriate dye was the standard solution used in the measurements given herein with a saturated calomel electrode.
- Leuco dyes are colorless dyes which when subjected to an oxidation reaction form a colored dye. These leuco dyes are well known in the art (e.g.. The Theory of the Photographic Process, 3rd Ed., Mees and James, pp. 283-4, 390-1, Macmillion Co., N.Y.; and Light-Sensitive Systems, Kosar, pp. 367, 370-380, 406 (1965) Wiley and Sons, Inc., N.Y. ) and U.S. Patent 3,974,147.
- leuco malachite blue leuco malachite blue
- leuco malachite green leuco crystal violet
- 1(2-(1,3,3-trimethylindolyl))-2-(p-morpholinyl ⁇ henyl)ethene Only those leuco dyes which can be converted to colored dyes by oxidation are useful in the practice of the present invention. Acid or base sensitive dyes such as phenolphthalein are not useful in the present invention unless they are also oxidizable to a colored state. Indicator dyes would only form transient images or would be too sensitive to changes in the environment.
- the leuco dye should be present as at least 0.3% by weight of the binder, preferably as at least 1% by weight of the binder, and most preferably as from 2 to 10% or more by weight of the binder.
- the proportions of nitrate salt and leuco dye should be such that on heating the layer at 260°F (127°C) for 30 seconds there is at least an optical density of 0.2 obtained, although with a mechanical viewing of the image or heating to a higher temperature, a lower optical density is useful.
- the relative proportion of nitrate ion to dye may vary. As a general rule, at least 0.1 moles of nitrate ion per mole of dye is desirable in the practice of the present invention. At least 0.3 or 0.5 moles of nitrate per mole of dye is more preferred, and at least 0.7 or 0.9 moles of nitrate per mole of dye is most preferred.
- the binder prior to imaging so that at least 15% of incident radiation (including ultraviolet and infrared) in a 50 nm range would be absorbed through a 0.5 mm layer of binder and dye. Preferably at least 75% of the incident radiation in a 20 nm range would be absorbed. These ranges must of course be chosen within the spectral absorption region of the particular dye, but such absorption in any portion of the spectra is useful. In terms of weight percentages, it would be preferred to have at least 0.30% by weight of dye as compared to the binder. Preferably, at least 0.50% by weight of dye to binder is desired and most preferably there should be at least 1% by weight of dye to binder in the layer up to 10% or more.
- the bleachable dyes which have been specificall shown to work in the present invention include but are not limited to the following:
- R 2 C 2 H 5 ; C 7 H 15 ; (CH 2 ) 5 COOH ; C 8 H 17 ; CH 2 CH 2 ⁇ ; or
- R 3 H ; C 2 H 5 O ; or Cl
- R 4 C 2 H 5 ; or CH 2 CH 2 C 6 H 5 wherein
- R 1 H ; or -CN
- R 5 -C 2 H 5 ; -CH 2 CH-CH 2 or -C 7 H 15
- R 3 -CH 3 ; or -C 2 H 5
- R 1 -C 2 H 5 ; --(CH 2 ) 2 OH ; - ⁇ CH 2 ) 2 COOH ; -CH 2 COOH ; or -(CH 2 ) 3 SO 3
- R 2 -C 2 H 5 ; -(CH 2 ) 2 OH ; -(CH 2 ) 2 COOH ; -CH 2 COOH ; or -CH 3
- R. H ; -CH 3 ; -SCH 3 ; or -C 2 H 5
- R 4 H ; -CH 3 ; -Br ; or -N(C 2 H 5 ) 2
- R 5 H ; -CH 3 ; or -Br
- R 3 H ; Br wherein
- R 1 S ;
- R 1 -CH 3 ; or CH 3 O-
- R 2 -C 2 H 5 ; or -C 7 H 15
- R 3 H ; -OH ; or -NHC 2 H 5
- R 1 H ; -CH 3 ; or -C 2 H 5
- R 2 H ; -C 2 H 5 ; or -CH 2 COOH
- R 1 H ; -N(CH 3 ) 2
- R 2 H ; -Cl
- the bleachable dyes of the present invention are preferably colored, that is, having absorbance in the visible portion of the electromagnetic spectrum (approximately 400 to 700 nm), but may also be colorless, having absorbance only or predominately in the infrared (700 to 1100 nm) or ultraviolet (310 to 400 nm) portions of the electromagnetic spectrum.
- the images where colorless dyes are used must then be viewed through a filter, by an ultraviolet sensitive apparatus, or by some enhancement technique.
- bleachable dye present in the layers of this invention so that an optical density of at least 0.1 in the visible portions of the spectrum is obtained or at least 5% of incident colorless light (including ultraviolet or infrared) is absorbed. It is preferred that an optical density of at least .0.5 or 0.8 be obtained and most preferably that there be sufficient dye so that an optical density of at least 1.0 be obtained in the layer.
- colorless dyes e.g., ultraviolet and infrared absorbing dyes
- the proportions of nitrate ion and dye should be such that on heating the layer at 260°F (127°C) for 30 seconds there is at least a 20% reduction in optical density, although with a mechanical viewing of the image, a lower reduction in optical density is useful.
- the relative proportion of nitrate ion to dye may vary. As a general rule, at least 0.1 moles of nitrate ion per mole of dye is desirable in the practice of the present invention. At least 0.3 or 0.5 moles of nitrate per mole of dye is more preferred, and at least 0.7 or 0.9 moles of nitrate per mole of dye is most preferred.
- decolorizable layers of the present invention are used as antihalation layers, particularly with thermally developable imaging materials, more than a 20% reduction in optical density is usually desirable. At least 50% or 60% is preferred and at least 90% or 95% reduction in optical density is most preferred. These reductions can be measured at the development temperatures for the imaging materials, e.g., 127°C for 30 seconds or 155°C for 45 seconds.
- the acids optionally useful in the present invention are acids as generally known to the skilled chemist.
- Organic acids are preferred, but inorganic acids (generally in relatively smaller concentrations) are also useful.
- Organic acids having carboxylic groups are more preferred.
- the acid may be present in a ratio of from 0 . to 10 times the amount of the nitrate ion. More preferably it is present .in amounts from 0.2 to 2.0 times the amount of nitrate ion.
- temperatures should, of course, not be used during manufacture which would completely oxidize decolorize the layer.
- Some colorization or decolorization is tolerable, with the initial dye concentrations chosen so as to allow for anticipated color changes. It is preferred, however, that little or no dye be formed or decolorized during forming or coating so that more standardized layers can be formed.
- the coating or forming temperature can be varied.
- the drying temperature could be 280°F (138°C) and it would not be desirable for the layer to lose 20% of its optical density at the drying temperature in less than 4-5 minutes, although it would be tolerable by correspondingly increasing the amount of dye.
- the preferred limitation of at least 20% reduction in optical density or absorbance of colorless light at 127°C for 30 seconds is based on the assumption of a development temperature of 127°C. For an anticipated higher or lower development temperature, the 20% reduction in optical density or absorbance should occur at that development temperature within a reasonable period of time.
- a reasonable development temperature range is between 180°F (82°C) and 380°F (193°C) and a reasonable dwell time is between 5 seconds and 5 minutes, preferably at between 220°F (105°C) and 350°F (167°C) and for 10 to 180 seconds, with the longer times most likely associated with the lower development temperatures. Therefore, all of the absorbance characteristics are applicable to the generally useful development range of 82°C to 193°C.
- Photothermographic imaging materials are well known in the art in various and sundry forms. Silver reduction systems (e.g., as disclosed in U.S. Patent. No. 3,457,075 and 3,849,049), thermal diazonium salt systems (e.g., as described in U.S.
- Patent No, 3,754,916), and others are examples of these systems.
- Typical constructions of these photothermographic systems will comprise one or two layers which constitute a photothermographic imaging system coated over a base.
- the support base is transparent, the heatbleachable layer of the present invention may be coated either between the imaging layers and the base or on the backside of the base. If coated between the base and the imaging layer, .it is desirable to minimize competing reactions. This can be done, for example, by selecting polymers and solvent systems for the various layers which will not promote migration between the layers.
- the heat-bleachable layer must be between the imaging layers and the base. This would, of course, also be true if there were more than one imaging layer. All of this will be more thoroughly understood by consideration of the following examples: Examples 1-13 A three component system of the present invention was evaluated by using nickel nitrate hexahydrate, phthalic acid and a merocyanine dye of the formula
- the dye was provided as a solution of 0.8 g dye/100 ml of a solvent comprising 50/50 volume proportions of methanol and N-methylpyrollidone. Three different concentrations of each ingredient were used. These ingredients were added to 2.5 g methanol and 12.5 g of a 10% by weight solids solution of polyvinylbutyral (as a binder) and methanol. The solutions were coated at 0.076 mm thickness on a polyester backing then dried for 3 minutes at 70°C. Maximum optical density (D max ) readings were taken. The coated sheets were then heated at 127°C for 30 seconds and the final maximum optical density (D f ) measured. The difference between D max and D f is the change in optical density ( ⁇ D) . The concentrations of materials and results appear in Table I.
- Example 14 bleached from medium blue to pale yellow, 15 became a lighter purple, and 16 became a light yellow. This shows that in the absence of an acid environment, greater concentrations of nitrate are desirable for more complete bleaching.
- Examples 17-24 show the wide variety of acids which can be used in the construction and indicates that the acid functionality is not dependent upon the structure of the acid. All constructions were identical to those of Examples 14-16 except that 5.5 ml of dye and 0.05 g of nickel nitrate hexahydrate were used. The sheets were heated at 127°C for 30 seconds in an inert fluorocarbon bath. All sheets were initially a medium blue.
- Example 25 This example demonstrates the use of the heat decolorizable layer as an antihalation backing for a photothermographic film.
- a solution was prepared by dissolving 8 g of magnesium nitrate hexahydrate and 12 g of phthalic acid in 75 g of methanol. This was broken down into aliquots of 3 g of solution, to which were added 4 ml of dye solution containing 0.15 g of malachite green and 0.05 g of crystal violet in 10 ml of a 50/50 volume solution of methanol and N-methylpyrolidone.
- Crystal violet has an oxidation potential greater than +1.0 and has the structure:
- Acid malachite green also used in the practice of the present invention, has the same structure except that one of the dimethylamine groups has been replaced by a hydrogen atom.
- a photothermographic film with the antihalation backing was exposed at the same time as the sample without the backing to artificial daylight through a continuous step wedge. Both examples were then developed at 127oC for 30 seconds.
- the antihalation backing bleached to a pale yellow.
- the effect of the antihalation layer was obvious to the untrained eye. Image flare was significantly reduced.
- Example 26 The antihalation backing of the previous example was coated on transparent polyester film and dried at 70°C.
- the colored film was thermographically exposed imagewise in a thermographic copier ("Secretary" Copier by 3M).
- the film bleached in an area corresponding to the image on the original.
- This demonstrates the use of the films as an image producing element which, for example, could be used as a transparency for overhead projector.
- the imaging materials have excellent shelf life. They may set for months at ambient conditions and in room light without any deterioration in properties, to the degree that the dyes themselves are light stable. They are inexpensive to make and have a broad range of utility.
- Examples 27-39 Examples 1-13 were repeated for each of the following nitrate salts: Aluminum nitrate, nonahydrate, cobalt nitrate hexahydrate, zirconyl nitrate, eerie ammonium nitrate, barium nitrate, cupric nitrate trihydrate, silver nitrate, chromium nitrate nonahydrate, thorium nitrate tetrahydrate, bismuth nitrate pentahydrate, ferric nitrate nonahydrate, sodium nitrate and potassium nitrate. These systems also showed decolorizing effects.
- the multivalent salts tended to be significantly better than the monovalent salts, except that silver nitrate performed as well as many of the multivalent salts because of the oxidizing ability of the silver ion.
- the imaging layers of the present invention may contain various materials in combination with the essential ingredients of the present invention.
- lubricants e.g., ascorbic acid, hindered phenols, phenidone, etc. in amounts that would not prevent oxidation of the dyes when heated
- surfactants e.g., ascorbic acid, hindered phenols, phenidone, etc. in amounts that would not prevent oxidation of the dyes when heated
- surfactants e.g., antistatic agents, mild oxidizing agents in addition to the nitrate, and brighteners may be used without adversely affecting practice of the invention.
- the imaging layers of the present invention must allow reactive association of the active ingredients in order to enable imaging. That is, the individual ingredients may not be separated by impenetrable barriers within the layer, as with dispersed immiscible phases.
- the active ingredients are homogeneously mixed (e.g., a molecular mixture of ingredients) within the layer. They may be individually maintained in heat softenable binders which are dispersed or mixed within the layer and which soften upon heating to allow migration of ingredients, but this would require a longer development time.
- light sensitive or radiation sensitive components such as silver halide, photolabile halogen compounds, diazonium salts, or photooxidant compounds are not essential for the practice of the present invention.
- the preferred construction of the present invention is not light sensitive. That is, if the element were exposed to light in an imagewise manner prior to thermal development of the entire sheet, there would be no dramatic differential image formed. As almost all dyes fade or bleach with prolonged exposure to light, light insensitivity for the element must be defined as stated above, with the exposure being less than that capable of photobleaching the dye itself.
- a coating composition comprising 2.0 grams phthalic acid, 0.3 grams crystal violet, 12.3 grams acetone, 15.4 grams N-methylpyrrolidone, 150 grams of 30% by weight solutions of polyvinylidine chloride in tetrahydrofuran (5%) and methylethylketone (65%) and 0.17 grams of quanidine and nitric acid in equal molar proportions was coated at 75 microns wet thickness on polyester base and dried for three minutes at 75°C. Imagewise heating for forty seconds at 290°F (143°C) provided an image with a D min of 0.17 and a D max of -0.86.
- Example 41 Each and every one of the dye structures listed above with Roman numerals was found to thermally imaging by bleaching in one of the following systems.
- the first system tried was 3 ml of a dye solution formed by dissolving 0.1 g dye in 10 ml of a N-methylpyrolidone/methanol (50/50 volume). To this was added 0.05 g of Ni(NO 3 ) 2 .6H 2 O and 0.05 g of phthalic. acid in 2.5 g methanol. This was then combined with 12.5 g of a resin solution comprising 10% by weight cellulose acetate, 10% methylisobutyl ketone, and 80% acetone.
- Example 42 A coating solution was prepared by dissolving 8g of magnesium nitrate hexahydrate and 12g of phthalic acid in 75g of methanol.
- Example 43-46 Example 42 was repeated except that the magnesium salt was replaced with equimolar (based on nitrate ion) proportions of aluminum nitrate nonahydrate, nickel nitrate hexahydrate, chromium nitrate nonaydrate, and potassium nitrate (the last with 0.5g of glycerol added to the first solution).
- the nickel, aluminum, and chromium salts showed similar results with D max values in excess of 0.9.
- the potassium salt produced a much weaker, but visible image.
- Example 47-49 Example 42 was repeated except that the leuco malachite green was replaced by equal molar amounts of leuco crystal violet, 1(2-(1,3,3-trimethylindolyl))-2- (p-mor ⁇ holinylphenyl)ethene, and the leuco dye
- Example 42 Upon development as in Example 42, violet, red and pale blue images were respectively formed in each of the colorizable systems.
- the imaging layers of the present invention may contain various materials in combination with the essential ingredients of the present invention.
- lubricants e.g., ascorbic acid, hindered phenols, phenidone, etc. in amounts that would not prevent oxidation of the dyes when heated
- surfactants e.g., ascorbic acid, hindered phenols, phenidone, etc. in amounts that would not prevent oxidation of the dyes when heated
- surfactants e.g., antistatic agents, mild oxidizing agents in addition to the nitrate, and brighteners may be used without adversely affecting practice of the invention.
- the imaging layers of the present invention must allow reactive association of the active ingredients in order to enable imaging. That is, the individual ingredients may not be separated by impenetrable barriers within the layer, as with dispersed immiscible phases.
- the active ingredients are homogeneously mixed (e.g., a molecular mixture of ingredients) within the layer. They may be individually maintained in heat softenable binders which are dispersed or nixed within the layer and which soften upon heating to allow migration of ingredients, but this would require a longer development time.
Abstract
The cost of conventional silver halide imaging technology has increased dramatically with the rising cost of silver. It would therefore be desirable to remove the silver from such imaging materials. Many replacement systems for silver tend to be complex without providing equivalent sensitometric results to silver halide systems. A novel imaging system comprising a binder containing nitrate salt and a leuco dye or bleachable dye has been found to be an effective thermographic imaging system.
Description
COLOR IMAGING SYSTEM
Field of the Invention A layer comprising 1) an oxidizing ion and 2) leuco dye or bleachable dye in a binder is useful as either an imaging layer or as a heat-bleachable antihalation layer. The antihalation layer is particularly useful in photothermographic systems where the development temperature acts to oxidize the leuco dye or bleach the dye.
Summary of the Invention
The present invention may be practiced in any polymeric binder system having the necessary active ingredients therein. These ingredients comprise leuco dyes or bleachable dyes and a non-dye-reactive nitrate salt. The active agents may also include any material which supplies hydrogen ion, such as an acidic material, and in particular an acid. A binder material containing these ingredients can be colorized or decolorized locally by heating portions of the binder layer or generally decolorized by heating the entire layer. The presence of an acidic material accelerates the decolorization phenomenum.
Detailed Description of the Invention There are a minimum of three components to the present invention, and four components to the preferred construction of the present invention. The three required components are the dye (leuco or bleachable), the nitrate salt, and the polymeric binder.
The Binder Any polymeric binder may be used in the practice of the present invention. The pH of the resin has been found to affect only the speed of the discolorizing effect. If the speed is not important, any resin may be
used. Organic polymeric resins, preferably thermoplastic although thermoset resins may be used, are generally preferred. Where speed is more important, either the more acidic resins should be used or an acid should be added to the system to decrease the pH and increase the rate of oxidation or decolorizing. Such resins as polyvinyl acetals, polyesters, polyvinyl resins, polyvinyl pyrolidone, polyesters, polycarbonates, polyamides, polyvinyl butyral, polyacrylates, cellulose esters, copolymers and blends of these classes of resins, and others have been used with particular success. Natural polymeric materials such as gelatin and gum arabic may also be used. Where the proportions and activities of dyes and nitrate ion require a particular developing time and temperature, the resin should be able to withstand those conditions. Generally it is preferred that the polymer not decompose or lose its structural integrity at 200°F (93°C) for 30 seconds, and more preferred that it not decompose or lose its structural integrity at 260°F (127°C) for 30 seconds and most preferred that it withstand 290°F (144°C) for 60 seconds.
Beyond these minimal requirements, there is no criticality in the selection of a binder. In fact, even transparency and translucency are not required, although they are desirable. Where, for example, the polymer with the bleachable dye is itself an opaque white, the thermally treated area will become white and the non-treated areas will remain the color of the dye. The binder serves a number of additionally important purposes in the constructions of the present invention. The imageable materials are protected from ambient conditions such as moisture. The consistency of the coating and its image quality are improved. The durability of the final image is also significantly improved.
The Nitrate Salt Nitrate salts are themselves well known. They may be supplied as various compounds forms, but are preferably provided as a metal salt, and most preferably provided as a hydrated metal salt. Other ions which are ordinarily good oxidizing ions such as nitrite, chlorate, iodate, perchlorate, periodate, and persulfate do not provide comparable results. Extremely active oxidizing agents, such as iodate, even used in relatively smaller proportions to prevent complete and immediate oxidation or decolorization of dyes do not perform nearly as well as nitrate ion compositions. The performance of nitrate is so far superior to any other ion that it is apparently unique in the practice of the present invention. While some of the better oxidizing ions other than nitrate can only produce modest differences between the maximum optical density (Dmax) and the minimum optical density (Dmin) or produce high Dmin values even in their best constructions, the better constructions with nitrate ions can have a Dmax in excess of 1.0 and a Dmin below 0.10.
Most means of supplying the nitrate ion into, the composition are satisfactory. E.g., metal salts, acid salts, mixtures of acids and salts, and other means of supplying the ion are useful. For example, nitrates of zinc, cadmium, potassium, calcium, zirconyl, nickel, aluminum, chromium, iron, copper, magnesium, lead, and cobalt, ammonium nitrate, and cerous ammonium nitrate have been used.
The nitrate salt component of the present invention must be present in a form within the imaging layer so that HNO3, NO, NO2, or N2O4 will be provided within the layer when it is heated to a temperature no greater than 200°C for 60 seconds and preferably no greater than 160°C for 60 or most preferably 30 seconds. This may be accomplished with many different types of salts, both organic and inorganic, and in variously different types of constructions.
The most convenient way of providing such thermal oxidant providing nitrate salts is to provide a hydrated nitrate salt such as aluminum nitrate nonahydrate (Al(NO3)2.9H2O). This salt, when heated in a binder, will generate HNO3, NO, NO2 and/or N2O4 in various amounts. The binder should not be at such a high pH that the liberated nitric acid would be imediately neutralized as this would adversely affect the oxidizing capability of the system. It is not essential that a completely acidic or neutral pH environment be provided, but pH levels above 8.5 may in many cases completely prevent oxidation. It is therefore desired that the nitrate salt containing layer have an acidic environment such as a pH less than 7.5, preferably equal to or less than 7.0, and more preferably equal to or less than 6.5.
In addition to hydrated nitrate salts, non-hydrated salts in layers having a pH less than 7.5, and preferably in an acidic environment are also capable of providing HNO3, NO, NO2, and/or N2O4 in sufficient quantities to provide the oxidizing capability necessary for practice of the present invention. Ammonium nitrate, for example, does not enable good oxidation in the present invention in a layer having a pH of 8.0 or higher, but when a moderate strength organic acid such as phthalic acid is added to lower the pH to below 7.0, a quite acceptable imaging system is provided.
Beside the inorganic types of salts generally described above, organic salts in non-alkaline environments are also quite useful in the practice of the present invention. In particular, nitrated quaternary ammonium salts such as guanadinium nitrate work quite well in acid environments, but will not provide any useful image at alkaline pH levels of 8.0 or higher.
It is believed that the alkaline environment causes any oxidizing agent (e.g., HNO3, NO, NO2 and/or N2O4) which is liberated from the nitrate salt to be preferentially reacted with hydroxy ions or other
neutralizing moieties so as to prevent oxidation of the dyes. For this reason it is preferred to have the environment of the nitrate salt acidic, effectively at a pH no greater than 7.0 and more preferably less than 6.5. One other consideration should be given in the selection of the nitrate salt and that is the choice of a salt in which the cation is non-reactive with the dye. Non-reactive salts are defined in the practice of the present invention as those salts the cations of which do not spontaneously oxidize the dyes that they are associated with at room temperature. This may be readily determined in a number of fashions. For example, the dye and a non-nitrate (preferably halide) salt of the cation may be codissolved in a solution. If the salt oxidizes the dye spontaneously (within two minutes) at room temperature, it is a reactive salt. Such salts as silver nitrate, in which the cation is itself a strong oxidizing agent, is a reactive salt. Cerric nitrate is also reactive, while hydrated cerrous nitrate is not. Preferred salts are the hydrated metal salts such as nickel nitrate hexahydrate, magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, ferric nitrate nonahydrate, cupric nitrate trihydrate, zinc nitrate hexahydrate, cadmium nitrate tetrahydrate, bismuth nitrate pentahydrate, thorium nitrate tetrahydrate, cobalt nitrate hexahydrate, gadolinium or lanthanum nitrate nonahydrate, mixtures of these hydrated nitrates and the like. Nonhydrated or organic nitrates may be admixed therewith. Organic nitrates are also quite useful in the practice of the present invention. These nitrates are usually in the form of quaternary nitrogen containing compounds such as guanadinium nitrate, pyridinium nitrate, and the like. Nitrated dyes will also be useful, but again, they must be used in an environment which will not neutralize any liberated HNO3, NO, NO2, and/or N2O4.
It is preferred to have at least 0.10 moles of nitrate ion per mole of dye. It is more preferred to have
at least 0.30 or 0.50 moles of ion per mole of dye. Even amounts of from 1.0 to 100 moles of nitrate ion per mole of dye have been found useful. With dyes having relatively higher oxidation potentials, more nitrate is desirable.
Dyes
It is believed that essentially all leuco dyes (as defined herein) and dyes are useful in the present invention. With some constructions it may be desirable to select dyes which have an oxidation potential of less than or equal to +1.0. The dyes may be selected from any class of dyes. These classes include but are not limited to 1) methines, 2) indamines, 3) anthraquinones, 4) triarylmethanes, 5) benzylidenes, 6) monoazos, 7) oxazines, 8) azines, 9) thiazines, 10) xanthenes, 11) indigoids, 12) oxonols, 13) cyanines, 14) merocyanines, 15) phenols, 16) naphthols, 17) pyrazolones, and others, of which most are classified by the Colour Index System.
The measurement of oxidation potentials is well known to the ordinarily skilled artisan. The measurements in the present invention are taken by measuring the voltage and current transferred between a carbon and a platinum electrode through the appropriate solution. 0.1 M lithium chloride in anhydrous methanol with 1 to 10 millimoles/liter of the appropriate dye was the standard solution used in the measurements given herein with a saturated calomel electrode.
Leuco dyes are colorless dyes which when subjected to an oxidation reaction form a colored dye. These leuco dyes are well known in the art (e.g.. The Theory of the Photographic Process, 3rd Ed., Mees and James, pp. 283-4, 390-1, Macmillion Co., N.Y.; and Light-Sensitive Systems, Kosar, pp. 367, 370-380, 406 (1965) Wiley and Sons, Inc., N.Y. ) and U.S. Patent 3,974,147. Amongst the known leuco dyes are leuco malachite blue, leuco malachite green, leuco crystal violet, and 1(2-(1,3,3-trimethylindolyl))-2-(p-morpholinyl
ρhenyl)ethene. Only those leuco dyes which can be converted to colored dyes by oxidation are useful in the practice of the present invention. Acid or base sensitive dyes such as phenolphthalein are not useful in the present invention unless they are also oxidizable to a colored state. Indicator dyes would only form transient images or would be too sensitive to changes in the environment.
The leuco dye should be present as at least 0.3% by weight of the binder, preferably as at least 1% by weight of the binder, and most preferably as from 2 to 10% or more by weight of the binder.
The proportions of nitrate salt and leuco dye should be such that on heating the layer at 260°F (127°C) for 30 seconds there is at least an optical density of 0.2 obtained, although with a mechanical viewing of the image or heating to a higher temperature, a lower optical density is useful. Depending upon the relative ease of colorizing the particular dye selected, the relative proportion of nitrate ion to dye may vary. As a general rule, at least 0.1 moles of nitrate ion per mole of dye is desirable in the practice of the present invention. At least 0.3 or 0.5 moles of nitrate per mole of dye is more preferred, and at least 0.7 or 0.9 moles of nitrate per mole of dye is most preferred. It is preferred to have sufficient bleachable dye in the binder prior to imaging so that at least 15% of incident radiation (including ultraviolet and infrared) in a 50 nm range would be absorbed through a 0.5 mm layer of binder and dye. Preferably at least 75% of the incident radiation in a 20 nm range would be absorbed. These ranges must of course be chosen within the spectral absorption region of the particular dye, but such absorption in any portion of the spectra is useful. In terms of weight percentages, it would be preferred to have at least 0.30% by weight of dye as compared to the binder. Preferably, at least 0.50% by weight of dye to binder is desired and most preferably there should be at least 1% by
weight of dye to binder in the layer up to 10% or more.
The bleachable dyes which have been specificall shown to work in the present invention include but are not limited to the following:
R2 = C2H5 ; C7H15 ; (CH2)5COOH ; C8H17 ; CH2CH2∅ ; or
CH2COOH
R1 = H ; or -CN
R2 = CN ; or -SO2CF3 = R3
R1 = =S ; XII
R2 = H ; CH3 = R3
R4 = C2H5 ; CH2CH=CH2 or CH2CH2CO2C2H5
R5 = -C2H5 ; -CH2CH-CH2 or -C7H15
R6 = -CH2COOH ; -CH2CH=CH2 ; or -(CH2)2SO3H
R1 = -C2H5 -C7H15 or -CH2CH=CH2
R 2 = =S ; or =C(CN)2
R3 = -CH3 ; or -C2H5
R2 = -C2H5 ; -(CH2)2OH ; -(CH2)2COOH ; -CH2COOH ; or -CH3
R. = H ; -CH3 ; -SCH3 ; or -C2H5
R4 = H ; -CH3 ; -Br ; or -N(C2H5)2
R5 = H ; -CH3 ; or -Br
R1 = H ; Cl
XXIII
wherein
R1 = S ;
R1 = -CH3 ; or CH3O-
R3 = H ; -OH ; or -NHC2H5
Indlgoids
R 1 = H ; -CH3 ; or -C2H5 R2 = H ; -C2H5 ; or -CH2 COOH
R3 = =S ; or =CHNO2
Xanthenes
Azines
Oxazines
R2 = H ; -Cl
Indarnines
These examples are not intended to represent the limits of the present invention. Any dye, and particularly those having an oxidation potential of +1.0 or less, may work in the present invention. The substituent groups and dye structure are unimportant.
The bleachable dyes of the present invention are preferably colored, that is, having absorbance in the visible portion of the electromagnetic spectrum (approximately 400 to 700 nm), but may also be colorless, having absorbance only or predominately in the infrared (700 to 1100 nm) or ultraviolet (310 to 400 nm) portions of the electromagnetic spectrum. The images where colorless dyes are used, must then be viewed through a filter, by an ultraviolet sensitive apparatus, or by some enhancement technique.
There should be sufficient bleachable dye present in the layers of this invention so that an optical density of at least 0.1 in the visible portions of the spectrum is obtained or at least 5% of incident colorless light (including ultraviolet or infrared) is absorbed. It is preferred that an optical density of at least .0.5 or 0.8 be obtained and most preferably that there be sufficient dye so that an optical density of at least 1.0 be obtained in the layer. With colorless dyes (e.g., ultraviolet and infrared absorbing dyes), it is preferred that at least 20% or 40% of incident radiation be absorbed and most preferably that at least 60% or 90% of the incident colorless light within a 20 nm range be absorbed. The proportions of nitrate ion and dye should be such that on heating the layer at 260°F (127°C) for 30 seconds there is at least a 20% reduction in optical density, although with a mechanical viewing of the image, a lower reduction in optical density is useful. Depending upon the relative ease of decolorizing the particular dye selected, the relative proportion of nitrate ion to dye may vary. As a general rule, at least 0.1 moles of nitrate ion per mole of dye is desirable in the practice of the present invention. At least 0.3 or 0.5 moles of nitrate per mole of dye is more preferred, and at least 0.7 or 0.9 moles of nitrate per mole of dye is most preferred. Where the decolorizable layers of the present invention are used as antihalation layers, particularly
with thermally developable imaging materials, more than a 20% reduction in optical density is usually desirable. At least 50% or 60% is preferred and at least 90% or 95% reduction in optical density is most preferred. These reductions can be measured at the development temperatures for the imaging materials, e.g., 127°C for 30 seconds or 155°C for 45 seconds.
The acids optionally useful in the present invention are acids as generally known to the skilled chemist. Organic acids are preferred, but inorganic acids (generally in relatively smaller concentrations) are also useful. Organic acids having carboxylic groups are more preferred. The acid may be present in a ratio of from 0 . to 10 times the amount of the nitrate ion. More preferably it is present .in amounts from 0.2 to 2.0 times the amount of nitrate ion.
In forming the dye layers or coating of the dye layers onto a substrate, temperatures should, of course, not be used during manufacture which would completely oxidize decolorize the layer. Some colorization or decolorization is tolerable, with the initial dye concentrations chosen so as to allow for anticipated color changes. It is preferred, however, that little or no dye be formed or decolorized during forming or coating so that more standardized layers can be formed. Depending on the anticipated development temperature, the coating or forming temperature can be varied. Therefore, if the anticipated development temperature were, for example, 350°F (167°C) the drying temperature could be 280°F (138°C) and it would not be desirable for the layer to lose 20% of its optical density at the drying temperature in less than 4-5 minutes, although it would be tolerable by correspondingly increasing the amount of dye. Thus the preferred limitation of at least 20% reduction in optical density or absorbance of colorless light at 127°C for 30 seconds is based on the assumption of a development temperature of 127°C. For an anticipated higher or lower
development temperature, the 20% reduction in optical density or absorbance should occur at that development temperature within a reasonable period of time. A reasonable development temperature range is between 180°F (82°C) and 380°F (193°C) and a reasonable dwell time is between 5 seconds and 5 minutes, preferably at between 220°F (105°C) and 350°F (167°C) and for 10 to 180 seconds, with the longer times most likely associated with the lower development temperatures. Therefore, all of the absorbance characteristics are applicable to the generally useful development range of 82°C to 193°C. Photothermographic imaging materials are well known in the art in various and sundry forms. Silver reduction systems (e.g., as disclosed in U.S. Patent. No. 3,457,075 and 3,849,049), thermal diazonium salt systems (e.g., as described in U.S. Patent No, 3,754,916), and others are examples of these systems. Typical constructions of these photothermographic systems will comprise one or two layers which constitute a photothermographic imaging system coated over a base. If the support base is transparent, the heatbleachable layer of the present invention may be coated either between the imaging layers and the base or on the backside of the base. If coated between the base and the imaging layer, .it is desirable to minimize competing reactions. This can be done, for example, by selecting polymers and solvent systems for the various layers which will not promote migration between the layers. When the base is opaque, the heat-bleachable layer must be between the imaging layers and the base. This would, of course, also be true if there were more than one imaging layer. All of this will be more thoroughly understood by consideration of the following examples:
Examples 1-13 A three component system of the present invention was evaluated by using nickel nitrate hexahydrate, phthalic acid and a merocyanine dye of the formula
The dye was provided as a solution of 0.8 g dye/100 ml of a solvent comprising 50/50 volume proportions of methanol and N-methylpyrollidone. Three different concentrations of each ingredient were used. These ingredients were added to 2.5 g methanol and 12.5 g of a 10% by weight solids solution of polyvinylbutyral (as a binder) and methanol. The solutions were coated at 0.076 mm thickness on a polyester backing then dried for 3 minutes at 70°C. Maximum optical density (Dmax) readings were taken. The coated sheets were then heated at 127°C for 30 seconds and the final maximum optical density (Df) measured. The difference between Dmax and Df is the change in optical density (Δ D) . The concentrations of materials and results appear in Table I.
Examples 14-16 These examples evaluate the benefits of an acidic environment of the bleaching or decolorizing of the present invention. For this example, a dye of the structure
was used in a solution having 0.8 g dyes/100 ml of solvent comprising a 50/50 volume solution of methanol and N-methyl-pyrolidone. The coating solutions were as follows:
The acid was phthalic acid, the nitrate was nickel nitrate hexahydrate. The coating solution was prepared, coated, and dried as in Example 1, then heated for thirty seconds at 260°F (127°C). Example 14 bleached from medium blue to pale yellow, 15 became a lighter purple, and 16 became a light yellow. This shows that in the absence of an acid environment, greater concentrations of nitrate are desirable for more complete bleaching.
Examples 17-24 These examples show the wide variety of acids which can be used in the construction and indicates that the acid functionality is not dependent upon the structure
of the acid. All constructions were identical to those of Examples 14-16 except that 5.5 ml of dye and 0.05 g of nickel nitrate hexahydrate were used. The sheets were heated at 127°C for 30 seconds in an inert fluorocarbon bath. All sheets were initially a medium blue.
Example 25 This example demonstrates the use of the heat decolorizable layer as an antihalation backing for a photothermographic film.
A solution was prepared by dissolving 8 g of magnesium nitrate hexahydrate and 12 g of phthalic acid in 75 g of methanol. This was broken down into aliquots of 3 g of solution, to which were added 4 ml of dye solution containing 0.15 g of malachite green and 0.05 g of crystal violet in 10 ml of a 50/50 volume solution of methanol and N-methylpyrolidone.
Acid malachite green, also used in the practice of the present invention, has the same structure except that one of the dimethylamine groups has been replaced by a hydrogen atom.
To the dye and nitrate containing solution was added 12.5 g of a solution of 15% by weight cellulose acetate, 10% methylisobutylketone, 10% methanol, and 65% acetone. The final solution was coated onto the backside of a commercially available photothermographic film'(3M Dry Silver Film Type 8220) which comprises a transparent backing having an imageable layer thereon comprised of silver halide in catalytic proximity to silver behenate in a binder with a mild silver reducing agent. These materials are well described in U.S. Patent No. 3,475,075. The coating thickness was 3 mils and was dried for 3 minutes at 70°C. A photothermographic film with the antihalation backing was exposed at the same time as the sample without the backing to artificial daylight through a continuous step wedge. Both examples were then developed at 127ºC for 30 seconds. The antihalation backing bleached to a pale yellow. The effect of the antihalation layer was obvious to the untrained eye. Image flare was significantly reduced.
Example 26 The antihalation backing of the previous example was coated on transparent polyester film and dried at 70°C. The colored film was thermographically exposed imagewise in a thermographic copier ("Secretary" Copier by 3M). The film bleached in an area corresponding to the
image on the original. This demonstrates the use of the films as an image producing element which, for example, could be used as a transparency for overhead projector. There are a number of features of the present invention which should be noted. The imaging materials have excellent shelf life. They may set for months at ambient conditions and in room light without any deterioration in properties, to the degree that the dyes themselves are light stable. They are inexpensive to make and have a broad range of utility. No light sensitive materials need be present in the system and no external chemistry need be applied in order to develop an image. The absence of photosensitive and even thermally sensitive materials (except for whatever gives the present invention its thermally developable properties) is particularly noteworthy. No silver halides or diazonium salts are needed for light sensitivity and there is no need for the external application of toners. The present system is remarkable in its simplicity. The present system is light insensitive in that exposure to light does not sensitize or desensitize the construction to any form of thermal or chemical development. That is, if the imageable layer of the present invention is exposed to light in an imagewise fashion then generally heated or generally exposed to a reducing agent, there will be no image formed corresponding to the light exposure. This is true even when the layer is laminated to a light sensitive substrate.
Examples 27-39 Examples 1-13 were repeated for each of the following nitrate salts: Aluminum nitrate, nonahydrate, cobalt nitrate hexahydrate, zirconyl nitrate, eerie ammonium nitrate, barium nitrate, cupric nitrate trihydrate, silver nitrate, chromium nitrate nonahydrate, thorium nitrate tetrahydrate, bismuth nitrate pentahydrate, ferric nitrate nonahydrate, sodium nitrate and potassium nitrate. These systems also showed
decolorizing effects. The multivalent salts tended to be significantly better than the monovalent salts, except that silver nitrate performed as well as many of the multivalent salts because of the oxidizing ability of the silver ion.
The imaging layers of the present invention may contain various materials in combination with the essential ingredients of the present invention. For example, lubricants, coating aids, antioxidants (e.g., ascorbic acid, hindered phenols, phenidone, etc. in amounts that would not prevent oxidation of the dyes when heated), surfactants, antistatic agents, mild oxidizing agents in addition to the nitrate, and brighteners may be used without adversely affecting practice of the invention.
The imaging layers of the present invention must allow reactive association of the active ingredients in order to enable imaging. That is, the individual ingredients may not be separated by impenetrable barriers within the layer, as with dispersed immiscible phases.
Generally, the active ingredients are homogeneously mixed (e.g., a molecular mixture of ingredients) within the layer. They may be individually maintained in heat softenable binders which are dispersed or mixed within the layer and which soften upon heating to allow migration of ingredients, but this would require a longer development time.
As can be seen from the constructions of the examples, light sensitive or radiation sensitive components such as silver halide, photolabile halogen compounds, diazonium salts, or photooxidant compounds are not essential for the practice of the present invention. In fact, the preferred construction of the present invention is not light sensitive. That is, if the element were exposed to light in an imagewise manner prior to thermal development of the entire sheet, there would be no dramatic differential image formed. As almost all dyes
fade or bleach with prolonged exposure to light, light insensitivity for the element must be defined as stated above, with the exposure being less than that capable of photobleaching the dye itself.
Example 40
A coating composition comprising 2.0 grams phthalic acid, 0.3 grams crystal violet, 12.3 grams acetone, 15.4 grams N-methylpyrrolidone, 150 grams of 30% by weight solutions of polyvinylidine chloride in tetrahydrofuran (5%) and methylethylketone (65%) and 0.17 grams of quanidine and nitric acid in equal molar proportions was coated at 75 microns wet thickness on polyester base and dried for three minutes at 75°C. Imagewise heating for forty seconds at 290°F (143°C) provided an image with a Dmin of 0.17 and a Dmax of -0.86.
Example 41 Each and every one of the dye structures listed above with Roman numerals was found to thermally imaging by bleaching in one of the following systems. The first system tried was 3 ml of a dye solution formed by dissolving 0.1 g dye in 10 ml of a N-methylpyrolidone/methanol (50/50 volume). To this was added 0.05 g of Ni(NO3)2.6H2O and 0.05 g of phthalic. acid in 2.5 g methanol. This was then combined with 12.5 g of a resin solution comprising 10% by weight cellulose acetate, 10% methylisobutyl ketone, and 80% acetone. If the dye did not bleach well when heated in this air dried composition, the proportions were varied by increasing the amount of Ni(NO3)2.6H2O and phthalic acid to 0.20 g each, increasing the cellulose acetate to 20% and the methylisobutyl ketone to 20% in the resin solution, while reducing the acetone to 60% in the resin solution. All of the dyes were shown thermally bleach in an imagewise fashion in this manner.
Example 42 A coating solution was prepared by dissolving 8g of magnesium nitrate hexahydrate and 12g of phthalic acid in 75g of methanol. To a 3g aliquot of this solution was added 4 ml of a dye solution containing 0.20g of leuco malachite green in 10 ml of a 50/50 volume solution of methanol and N-methylpyrolidone. To this leuco dye and nitrate solution was added 12.5g of a solution of 15% by' weight cellulose acetate, 10% methylisobutylketone, 10% methanol, and 65% acetone. This was coated onto clear polyethyleneterephthalate and dried below 90°C for ten minutes. Upon imagewise heating to 127ºC for thirty seconds, an image was produced with a Dmax of about 1.0 and a low Dmin.
Examples 43-46 Example 42 was repeated except that the magnesium salt was replaced with equimolar (based on nitrate ion) proportions of aluminum nitrate nonahydrate, nickel nitrate hexahydrate, chromium nitrate nonaydrate, and potassium nitrate (the last with 0.5g of glycerol added to the first solution). After development as in Example 42, the nickel, aluminum, and chromium salts showed similar results with Dmax values in excess of 0.9. The potassium salt produced a much weaker, but visible image.
Examples 47-49 Example 42 was repeated except that the leuco malachite green was replaced by equal molar amounts of leuco crystal violet, 1(2-(1,3,3-trimethylindolyl))-2- (p-morρholinylphenyl)ethene, and the leuco dye
Upon development as in Example 42, violet, red and pale blue images were respectively formed in each of the colorizable systems.
The imaging layers of the present invention may contain various materials in combination with the essential ingredients of the present invention. For example, lubricants, coating aids, antioxidants (e.g., ascorbic acid, hindered phenols, phenidone, etc. in amounts that would not prevent oxidation of the dyes when heated), surfactants, antistatic agents, mild oxidizing agents in addition to the nitrate, and brighteners may be used without adversely affecting practice of the invention.
The imaging layers of the present invention must allow reactive association of the active ingredients in order to enable imaging. That is, the individual ingredients may not be separated by impenetrable barriers within the layer, as with dispersed immiscible phases. Generally, the active ingredients are homogeneously mixed (e.g., a molecular mixture of ingredients) within the layer. They may be individually maintained in heat softenable binders which are dispersed or nixed within the layer and which soften upon heating to allow migration of ingredients, but this would require a longer development time.
Claims
1. An imageable layer comprising a polymeric binder, and within said binder 1) a leuco dye or bleachable dye, and 2) a nitrate salt, and said nitrate ion being present in a ratio of at least 0.1 moles/mole of dye, said nitrate salt in said binder being capable of liberating a sufficient quantity of an oxidizing agent selected from the class consisting of HNO3 , NO, NO2, and N2O4 when heated to 200°C for 60 seconds to oxidize said bleachable dye to a different color or colorless state or oxidized said leuco dye to a colored state.
2. The imageable layer of claim 1 wherein there is a bleachable dye present in a concentration of dye sufficient to provide an optical density of at least 0.7 in the visible region of the electromagnetic spectrum, the ratio of the moles of nitrate ion to moles of dye is at least 0.5, and said nitrate salt in said binder is capable of liberating said sufficient quantity of oxidizing agent when heated to 160°C for 60 seconds to oxidize said bleachable dye to a different color or colorless state.
3. The imageable layer of claim 2 wherein an acid is also present within said binder.
4. The imageable layer of claim 3 wherein the pH of said imageable layer is less than 7.0.
5. The imageable layer of claims 3 or 4 wherein said nitrate ion comprises a metal nitrate salt.
6. The imageable layer of claims 3 or 4 wherein said nitrate ion comprises a hydrated metal nitrate salt.
7. The imageable layer of claims 3 or 4 wherein said nitrate salt is a hydrated salt of one of the group consisting of zinc, cadmium, nickel, aluminum, iron, copper, magnesium, chromium, cobalt, bismuth, lanthanum, gadolinium, and thorium.
8. The imageable layer of claims 3, 4 or 5 which is light insensitive and wherein said dye is selected from, the group of dyes consisting of methines, indamines, anthraquinones, triarylmethanes, monoazos, oxazines, azines, thiazines, xanthenes, indigoids, cyanines, merocyanines, phenols, napthols, and pyrazolones and said nitrate salt is a hydrated metal nitrate salt.
9. The imageable layer of claim 1 wherein said leuco dye is present as at least 0.3% by weight of the binder, and the nitrate ion is present in a ratio to said leuco dye of at least 0.5 moles nitrate ion/mole of leuco dye.
10. The imageable layer of claim 1 wherein said nitrate ion is present as a metal nitrate salt.
11. The imageable layer of claim 9 wherein said leuco dye is selected from the class of leuco crystal violet, leuco malachite green, and 1(2-(1,3,3- trimethylindolyl))-2-(p-morpholinylpheny)-ethene.
12. The imageable layer of claim 9 wherein said nitrate salt is present as a hydrated nitrate salt of zinc, cadmium, calcium, zyrconyl, nickel, aluminum, chromium, iron, copper, magnesium, and cobalt.
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP81500296A JPS56501480A (en) | 1979-12-07 | 1980-11-10 | |
DE8181900104T DE3070044D1 (en) | 1979-12-07 | 1980-11-10 | Color imaging system |
BR8008959A BR8008959A (en) | 1979-12-07 | 1980-11-10 | COLOR PICTURE FORMER SYSTEM |
AT81900104T ATE11460T1 (en) | 1979-12-07 | 1980-11-10 | COLOR PHOTOGRAPHIC IMAGING SYSTEM. |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10119779A | 1979-12-07 | 1979-12-07 | |
US10114479A | 1979-12-07 | 1979-12-07 | |
US101144 | 1979-12-07 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1981001757A1 true WO1981001757A1 (en) | 1981-06-25 |
Family
ID=26797946
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1980/001506 WO1981001757A1 (en) | 1979-12-07 | 1980-11-10 | Color imaging system |
Country Status (9)
Country | Link |
---|---|
EP (1) | EP0041540B1 (en) |
JP (1) | JPS56501480A (en) |
AT (1) | ATE11460T1 (en) |
AU (1) | AU543071B2 (en) |
BR (1) | BR8008959A (en) |
DE (1) | DE3070044D1 (en) |
IT (1) | IT1148239B (en) |
MX (1) | MX157192A (en) |
WO (1) | WO1981001757A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0055111A2 (en) * | 1980-12-22 | 1982-06-30 | Minnesota Mining And Manufacturing Company | Black image from a thermographic imaging system |
EP0159874A2 (en) * | 1984-04-16 | 1985-10-30 | Minnesota Mining And Manufacturing Company | Prevention of spotting in thermal imaging compositions |
EP0181085A1 (en) * | 1984-10-01 | 1986-05-14 | Minnesota Mining And Manufacturing Company | Stabilized leuco phenazine dyes and their use in an imaging system |
US4889932A (en) * | 1984-10-01 | 1989-12-26 | Minnesota Mining And Manufacturing Company | Stabilized leuco phenazine dyes and their use in an imaging system |
EP0646628A1 (en) * | 1993-09-27 | 1995-04-05 | Minnesota Mining And Manufacturing Company | Spectrally sensitized silver halide photographic elements |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4386154A (en) * | 1981-03-26 | 1983-05-31 | Minnesota Mining And Manufacturing Company | Visible light sensitive, thermally developable imaging systems |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2324060A (en) * | 1940-10-09 | 1943-07-13 | Eastman Kodak Co | Photographic copying paper |
US2756144A (en) * | 1951-04-25 | 1956-07-24 | Brown Allen Chemicals Inc | Photochemical multicolor printing of textile and the like |
US2880153A (en) * | 1957-01-28 | 1959-03-31 | American Viscose Corp | Photopolymerization process |
US3300314A (en) * | 1963-02-01 | 1967-01-24 | Eastman Kodak Co | Nonsilver, light-sensitive photographic elements |
US3595657A (en) * | 1968-10-03 | 1971-07-27 | Little Inc A | Non-silver direct positive dye bleachout system using indigoid dyes and colorless activators |
US3595655A (en) * | 1968-10-03 | 1971-07-27 | Little Inc A | Non-silver direct positive dyes bleachout system using polymethine dyes and colorless activators |
US3801319A (en) * | 1972-06-21 | 1974-04-02 | Xerox Corp | Imaging method utilizing chemical reactivities of photoexcited states of aromatic hydroxy compounds |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3460964A (en) * | 1964-11-19 | 1969-08-12 | Eastman Kodak Co | Heat-sensitive recording element and composition |
JPS5143786B2 (en) * | 1972-12-23 | 1976-11-24 | ||
JPS6010781B2 (en) * | 1977-06-22 | 1985-03-20 | 潤三 下飯坂 | Quasi-static heavy liquid sorting method and equipment |
-
1980
- 1980-11-10 AT AT81900104T patent/ATE11460T1/en not_active IP Right Cessation
- 1980-11-10 JP JP81500296A patent/JPS56501480A/ja active Pending
- 1980-11-10 WO PCT/US1980/001506 patent/WO1981001757A1/en active IP Right Grant
- 1980-11-10 DE DE8181900104T patent/DE3070044D1/en not_active Expired
- 1980-11-10 BR BR8008959A patent/BR8008959A/en not_active IP Right Cessation
- 1980-11-10 EP EP81900104A patent/EP0041540B1/en not_active Expired
- 1980-11-10 AU AU66445/81A patent/AU543071B2/en not_active Ceased
- 1980-12-05 MX MX185070A patent/MX157192A/en unknown
- 1980-12-05 IT IT50318/80A patent/IT1148239B/en active
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2324060A (en) * | 1940-10-09 | 1943-07-13 | Eastman Kodak Co | Photographic copying paper |
US2756144A (en) * | 1951-04-25 | 1956-07-24 | Brown Allen Chemicals Inc | Photochemical multicolor printing of textile and the like |
US2880153A (en) * | 1957-01-28 | 1959-03-31 | American Viscose Corp | Photopolymerization process |
US3300314A (en) * | 1963-02-01 | 1967-01-24 | Eastman Kodak Co | Nonsilver, light-sensitive photographic elements |
US3595657A (en) * | 1968-10-03 | 1971-07-27 | Little Inc A | Non-silver direct positive dye bleachout system using indigoid dyes and colorless activators |
US3595655A (en) * | 1968-10-03 | 1971-07-27 | Little Inc A | Non-silver direct positive dyes bleachout system using polymethine dyes and colorless activators |
US3801319A (en) * | 1972-06-21 | 1974-04-02 | Xerox Corp | Imaging method utilizing chemical reactivities of photoexcited states of aromatic hydroxy compounds |
Non-Patent Citations (1)
Title |
---|
N, Light-Sensitive Systems, August 1965 (JOHN WILEY & SONS, Inc., New York/London/Sydney) JEROME KOSAR, pages 187 and 193 * |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0055111A2 (en) * | 1980-12-22 | 1982-06-30 | Minnesota Mining And Manufacturing Company | Black image from a thermographic imaging system |
EP0055111A3 (en) * | 1980-12-22 | 1983-01-05 | Minnesota Mining And Manufacturing Company | Black image from a thermographic imaging system |
EP0159874A2 (en) * | 1984-04-16 | 1985-10-30 | Minnesota Mining And Manufacturing Company | Prevention of spotting in thermal imaging compositions |
EP0159874A3 (en) * | 1984-04-16 | 1986-06-04 | Minnesota Mining And Manufacturing Company | Prevention of spotting in thermal imaging compositions |
EP0181085A1 (en) * | 1984-10-01 | 1986-05-14 | Minnesota Mining And Manufacturing Company | Stabilized leuco phenazine dyes and their use in an imaging system |
US4647525A (en) * | 1984-10-01 | 1987-03-03 | Minnesota Mining And Manufacturing Company | Stabilized leuco phenazine dyes and their use in an imaging system |
US4889932A (en) * | 1984-10-01 | 1989-12-26 | Minnesota Mining And Manufacturing Company | Stabilized leuco phenazine dyes and their use in an imaging system |
EP0646628A1 (en) * | 1993-09-27 | 1995-04-05 | Minnesota Mining And Manufacturing Company | Spectrally sensitized silver halide photographic elements |
US5422236A (en) * | 1993-09-27 | 1995-06-06 | Minnesota Mining And Manufacturing Company | Spectrally sensitized silver halide photographic elements |
Also Published As
Publication number | Publication date |
---|---|
ATE11460T1 (en) | 1985-02-15 |
AU543071B2 (en) | 1985-03-28 |
EP0041540A1 (en) | 1981-12-16 |
JPS56501480A (en) | 1981-10-15 |
MX157192A (en) | 1988-11-03 |
AU6644581A (en) | 1981-07-06 |
DE3070044D1 (en) | 1985-03-07 |
BR8008959A (en) | 1981-10-20 |
IT8050318A0 (en) | 1980-12-05 |
IT1148239B (en) | 1986-11-26 |
EP0041540A4 (en) | 1982-03-29 |
EP0041540B1 (en) | 1985-01-23 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4336323A (en) | Decolorizable imaging system | |
US4373020A (en) | Decolorizable imaging system | |
US4370401A (en) | Light sensitive, thermally developable imaging system | |
US4379835A (en) | Black image from a thermographic imaging system | |
US5055373A (en) | Multicolor recording material | |
DE3215485C2 (en) | ||
US5153105A (en) | Thermally developable light sensitive imageable layers containing photobleachable dyes | |
US4395484A (en) | Roomlight-stable ultraviolet-response photothermographic imaging material | |
EP0067638A2 (en) | Image enhancement of photothermographic elements | |
US4386154A (en) | Visible light sensitive, thermally developable imaging systems | |
US4196002A (en) | Photothermographic element containing heat sensitive dye materials | |
US3871887A (en) | Photothermographic composition, element and process | |
US4670374A (en) | Photothermographic accelerators for leuco diazine, oxazine, and thiazine dyes | |
GB2042750A (en) | Thermal silver-dye bleach process and sheet materials therefor | |
US4460677A (en) | Visible light sensitive, thermally developable imaging systems | |
AU543071B2 (en) | Color imaging system | |
US4423139A (en) | Stabilizer combination for dye oxidation | |
DE2822495C2 (en) | Photographic recording material | |
US4587211A (en) | Photothermographic stabilizers for syringaldazine leuco dyes | |
EP0041571B1 (en) | Light sensitive, thermally developable imaging system | |
EP0302610A2 (en) | Light sensitive element | |
US3526506A (en) | Heat reactive,light desensitizing compositions | |
CA1154992A (en) | Decolorizable imaging system including a bleachable or leuco dye and a nitrate salt | |
JPS6332177B2 (en) | ||
JPS6145548B2 (en) |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Designated state(s): AU BR JP |
|
AL | Designated countries for regional patents |
Designated state(s): AT CH DE FR GB NL SE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1981900104 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 1981900104 Country of ref document: EP |
|
WWG | Wipo information: grant in national office |
Ref document number: 1981900104 Country of ref document: EP |