CA1138184A - Liquid crystal display element - Google Patents
Liquid crystal display elementInfo
- Publication number
- CA1138184A CA1138184A CA000373012A CA373012A CA1138184A CA 1138184 A CA1138184 A CA 1138184A CA 000373012 A CA000373012 A CA 000373012A CA 373012 A CA373012 A CA 373012A CA 1138184 A CA1138184 A CA 1138184A
- Authority
- CA
- Canada
- Prior art keywords
- liquid crystal
- element according
- type
- fluorenone
- electron acceptor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000004973 liquid crystal related substance Substances 0.000 title claims abstract description 130
- 239000000203 mixture Substances 0.000 claims abstract description 34
- -1 nitro-substituted 9-fluorenones Chemical class 0.000 claims abstract description 13
- JOERSAVCLPYNIZ-UHFFFAOYSA-N 2,4,5,7-tetranitrofluoren-9-one Chemical group O=C1C2=CC([N+]([O-])=O)=CC([N+]([O-])=O)=C2C2=C1C=C([N+](=O)[O-])C=C2[N+]([O-])=O JOERSAVCLPYNIZ-UHFFFAOYSA-N 0.000 claims description 6
- HDVGAFBXTXDYIB-UHFFFAOYSA-N 2,7-dinitrofluoren-9-one Chemical compound C1=C([N+]([O-])=O)C=C2C(=O)C3=CC([N+](=O)[O-])=CC=C3C2=C1 HDVGAFBXTXDYIB-UHFFFAOYSA-N 0.000 claims description 4
- NZNMSOFKMUBTKW-UHFFFAOYSA-N cyclohexanecarboxylic acid Chemical compound OC(=O)C1CCCCC1 NZNMSOFKMUBTKW-UHFFFAOYSA-N 0.000 claims description 4
- ZUOUZKKEUPVFJK-UHFFFAOYSA-N diphenyl Chemical compound C1=CC=CC=C1C1=CC=CC=C1 ZUOUZKKEUPVFJK-UHFFFAOYSA-N 0.000 claims description 4
- VHQGURIJMFPBKS-UHFFFAOYSA-N 2,4,7-trinitrofluoren-9-one Chemical group [O-][N+](=O)C1=CC([N+]([O-])=O)=C2C3=CC=C([N+](=O)[O-])C=C3C(=O)C2=C1 VHQGURIJMFPBKS-UHFFFAOYSA-N 0.000 claims description 3
- GLVSVKSIYXDZHY-UHFFFAOYSA-N 3-nitrofluoren-9-one Chemical group C1=CC=C2C3=CC([N+](=O)[O-])=CC=C3C(=O)C2=C1 GLVSVKSIYXDZHY-UHFFFAOYSA-N 0.000 claims description 3
- 239000002262 Schiff base Substances 0.000 claims description 3
- 150000004753 Schiff bases Chemical class 0.000 claims description 3
- DMBHHRLKUKUOEG-UHFFFAOYSA-N diphenylamine Chemical class C=1C=CC=CC=1NC1=CC=CC=C1 DMBHHRLKUKUOEG-UHFFFAOYSA-N 0.000 claims description 3
- YFORDJRKPMKUDA-UHFFFAOYSA-N 1,1'-biphenyl;cyclohexane Chemical compound C1CCCCC1.C1=CC=CC=C1C1=CC=CC=C1 YFORDJRKPMKUDA-UHFFFAOYSA-N 0.000 claims description 2
- CZPWVGJYEJSRLH-UHFFFAOYSA-N Pyrimidine Chemical compound C1=CN=CN=C1 CZPWVGJYEJSRLH-UHFFFAOYSA-N 0.000 claims description 2
- PJANXHGTPQOBST-VAWYXSNFSA-N Stilbene Natural products C=1C=CC=CC=1/C=C/C1=CC=CC=C1 PJANXHGTPQOBST-VAWYXSNFSA-N 0.000 claims description 2
- 125000005337 azoxy group Chemical group [N+]([O-])(=N*)* 0.000 claims description 2
- 235000010290 biphenyl Nutrition 0.000 claims description 2
- 239000004305 biphenyl Substances 0.000 claims description 2
- VZFUCHSFHOYXIS-UHFFFAOYSA-N cycloheptane carboxylic acid Natural products OC(=O)C1CCCCCC1 VZFUCHSFHOYXIS-UHFFFAOYSA-N 0.000 claims description 2
- QXFYBHYJBLQKSC-UHFFFAOYSA-N cyclohexane;1-cyclohexyl-2-phenylbenzene Chemical compound C1CCCCC1.C1CCCCC1C1=CC=CC=C1C1=CC=CC=C1 QXFYBHYJBLQKSC-UHFFFAOYSA-N 0.000 claims description 2
- IGARGHRYKHJQSM-UHFFFAOYSA-N cyclohexylbenzene Chemical compound C1CCCCC1C1=CC=CC=C1 IGARGHRYKHJQSM-UHFFFAOYSA-N 0.000 claims description 2
- PJANXHGTPQOBST-UHFFFAOYSA-N stilbene Chemical compound C=1C=CC=CC=1C=CC1=CC=CC=C1 PJANXHGTPQOBST-UHFFFAOYSA-N 0.000 claims description 2
- 235000021286 stilbenes Nutrition 0.000 claims description 2
- 239000000758 substrate Substances 0.000 claims description 2
- 239000002253 acid Substances 0.000 claims 1
- 150000002429 hydrazines Chemical class 0.000 claims 1
- 150000004986 phenylenediamines Chemical class 0.000 claims 1
- 239000011521 glass Substances 0.000 description 7
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 7
- 229910001887 tin oxide Inorganic materials 0.000 description 7
- 150000002148 esters Chemical class 0.000 description 6
- 125000001424 substituent group Chemical group 0.000 description 6
- FJUFINOZWSTZEZ-UHFFFAOYSA-N 5-butylcyclopenta-1,3-diene;iron(2+) Chemical compound [Fe+2].CCCCC1=CC=C[CH-]1.CCCCC1=CC=C[CH-]1 FJUFINOZWSTZEZ-UHFFFAOYSA-N 0.000 description 5
- 239000004988 Nematic liquid crystal Substances 0.000 description 5
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- FDRNXKXKFNHNCA-UHFFFAOYSA-N 4-(4-anilinophenyl)-n-phenylaniline Chemical compound C=1C=C(C=2C=CC(NC=3C=CC=CC=3)=CC=2)C=CC=1NC1=CC=CC=C1 FDRNXKXKFNHNCA-UHFFFAOYSA-N 0.000 description 3
- 210000004027 cell Anatomy 0.000 description 3
- IJVBYWCDGKXHKK-UHFFFAOYSA-N 1-n,1-n,2-n,2-n-tetraphenylbenzene-1,2-diamine Chemical compound C1=CC=CC=C1N(C=1C(=CC=CC=1)N(C=1C=CC=CC=1)C=1C=CC=CC=1)C1=CC=CC=C1 IJVBYWCDGKXHKK-UHFFFAOYSA-N 0.000 description 2
- ZXVONLUNISGICL-UHFFFAOYSA-N 4,6-dinitro-o-cresol Chemical group CC1=CC([N+]([O-])=O)=CC([N+]([O-])=O)=C1O ZXVONLUNISGICL-UHFFFAOYSA-N 0.000 description 2
- QIGBRXMKCJKVMJ-UHFFFAOYSA-N Hydroquinone Chemical compound OC1=CC=C(O)C=C1 QIGBRXMKCJKVMJ-UHFFFAOYSA-N 0.000 description 2
- 150000007942 carboxylates Chemical class 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000005486 organic electrolyte Substances 0.000 description 2
- FHCPAXDKURNIOZ-UHFFFAOYSA-N tetrathiafulvalene Chemical compound S1C=CSC1=C1SC=CS1 FHCPAXDKURNIOZ-UHFFFAOYSA-N 0.000 description 2
- KGYHDKQBNLIFKF-UHFFFAOYSA-N (4-propylphenyl) 4-hexanoyloxybenzoate Chemical compound C1=CC(OC(=O)CCCCC)=CC=C1C(=O)OC1=CC=C(CCC)C=C1 KGYHDKQBNLIFKF-UHFFFAOYSA-N 0.000 description 1
- GEYOCULIXLDCMW-UHFFFAOYSA-N 1,2-phenylenediamine Chemical compound NC1=CC=CC=C1N GEYOCULIXLDCMW-UHFFFAOYSA-N 0.000 description 1
- LGDAXDNJFXVZHI-UHFFFAOYSA-N 2,5-dinitrofluoren-9-one Chemical compound C1=CC([N+]([O-])=O)=C2C3=CC=C([N+](=O)[O-])C=C3C(=O)C2=C1 LGDAXDNJFXVZHI-UHFFFAOYSA-N 0.000 description 1
- XHBAHYMCKJTKJV-UHFFFAOYSA-N 2,6-dinitrofluoren-9-one Chemical compound C1=C([N+]([O-])=O)C=C2C3=CC=C([N+](=O)[O-])C=C3C(=O)C2=C1 XHBAHYMCKJTKJV-UHFFFAOYSA-N 0.000 description 1
- LDXJRKWFNNFDSA-UHFFFAOYSA-N 2-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)-1-[4-[2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidin-5-yl]piperazin-1-yl]ethanone Chemical group C1CN(CC2=NNN=C21)CC(=O)N3CCN(CC3)C4=CN=C(N=C4)NCC5=CC(=CC=C5)OC(F)(F)F LDXJRKWFNNFDSA-UHFFFAOYSA-N 0.000 description 1
- WZFUQSJFWNHZHM-UHFFFAOYSA-N 2-[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]piperazin-1-yl]-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethanone Chemical group C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)N1CCN(CC1)CC(=O)N1CC2=C(CC1)NN=N2 WZFUQSJFWNHZHM-UHFFFAOYSA-N 0.000 description 1
- RVIJNTKQXPLWET-UHFFFAOYSA-N 4-hexanoyloxy-2-(4-pentylphenyl)benzoic acid Chemical compound CCCCCC(=O)OC1=CC=C(C(O)=O)C(C=2C=CC(CCCCC)=CC=2)=C1 RVIJNTKQXPLWET-UHFFFAOYSA-N 0.000 description 1
- RHWPJRFUMRXNTE-UHFFFAOYSA-N 4-methoxy-4-pentylcyclohexa-1,5-diene-1-carboxylic acid Chemical compound CCCCCC1(OC)CC=C(C(O)=O)C=C1 RHWPJRFUMRXNTE-UHFFFAOYSA-N 0.000 description 1
- 229920002799 BoPET Polymers 0.000 description 1
- FERIUCNNQQJTOY-UHFFFAOYSA-M Butyrate Chemical compound CCCC([O-])=O FERIUCNNQQJTOY-UHFFFAOYSA-M 0.000 description 1
- FERIUCNNQQJTOY-UHFFFAOYSA-N Butyric acid Natural products CCCC(O)=O FERIUCNNQQJTOY-UHFFFAOYSA-N 0.000 description 1
- VHPINAOCEXULFE-PFXMMIRDSA-N C(CCCC)[C@@H]1CC[C@H](CC1)C=1C(=C(C=CC=1)C1=CC=CC=C1)[C@@H]1CC[C@H](CC1)CCC Chemical group C(CCCC)[C@@H]1CC[C@H](CC1)C=1C(=C(C=CC=1)C1=CC=CC=C1)[C@@H]1CC[C@H](CC1)CCC VHPINAOCEXULFE-PFXMMIRDSA-N 0.000 description 1
- OXBRRUNAAVNTOZ-SHTZXODSSA-N C1C[C@@H](CCC)CC[C@@H]1C1=CC=C(OCC)C=C1 Chemical compound C1C[C@@H](CCC)CC[C@@H]1C1=CC=C(OCC)C=C1 OXBRRUNAAVNTOZ-SHTZXODSSA-N 0.000 description 1
- BPVJENLMEMWFBW-QAQDUYKDSA-N CCCCOc1ccc(cc1)[C@H]1CC[C@H](CCC)CC1 Chemical compound CCCCOc1ccc(cc1)[C@H]1CC[C@H](CCC)CC1 BPVJENLMEMWFBW-QAQDUYKDSA-N 0.000 description 1
- 239000005041 Mylar™ Substances 0.000 description 1
- NIPNSKYNPDTRPC-UHFFFAOYSA-N N-[2-oxo-2-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical group O=C(CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 NIPNSKYNPDTRPC-UHFFFAOYSA-N 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 210000002858 crystal cell Anatomy 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 230000003028 elevating effect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- YLQWCDOCJODRMT-UHFFFAOYSA-N fluoren-9-one Chemical compound C1=CC=C2C(=O)C3=CC=CC=C3C2=C1 YLQWCDOCJODRMT-UHFFFAOYSA-N 0.000 description 1
- 229910003437 indium oxide Inorganic materials 0.000 description 1
- PJXISJQVUVHSOJ-UHFFFAOYSA-N indium(iii) oxide Chemical compound [O-2].[O-2].[O-2].[In+3].[In+3] PJXISJQVUVHSOJ-UHFFFAOYSA-N 0.000 description 1
- 239000011244 liquid electrolyte Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 125000000956 methoxy group Chemical group [H]C([H])([H])O* 0.000 description 1
- 239000011368 organic material Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- FCJSHPDYVMKCHI-UHFFFAOYSA-N phenyl benzoate Chemical compound C=1C=CC=CC=1C(=O)OC1=CC=CC=C1 FCJSHPDYVMKCHI-UHFFFAOYSA-N 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- JRMUNVKIHCOMHV-UHFFFAOYSA-M tetrabutylammonium bromide Chemical compound [Br-].CCCC[N+](CCCC)(CCCC)CCCC JRMUNVKIHCOMHV-UHFFFAOYSA-M 0.000 description 1
- STOSPPMGXZPHKP-UHFFFAOYSA-N tetrachlorohydroquinone Chemical compound OC1=C(Cl)C(Cl)=C(O)C(Cl)=C1Cl STOSPPMGXZPHKP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K19/00—Liquid crystal materials
- C09K19/52—Liquid crystal materials characterised by components which are not liquid crystals, e.g. additives with special physical aspect: solvents, solid particles
- C09K19/58—Dopants or charge transfer agents
- C09K19/582—Electrically active dopants, e.g. charge transfer agents
- C09K19/584—Electrically active dopants, e.g. charge transfer agents having a condensed ring system; macrocyclic compounds
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K19/00—Liquid crystal materials
- C09K19/52—Liquid crystal materials characterised by components which are not liquid crystals, e.g. additives with special physical aspect: solvents, solid particles
- C09K19/58—Dopants or charge transfer agents
Abstract
Abstract of the Disclosure A liquid crystal display element utilizing dynamic scattering uses a liquid crystal composition comprising a liquid crystal and charge transfer complex. The charge transfer complex contains nitro-substituted 9-fluorenones as the electron acceptor.
Description
1~381~34 Liquid crystal display element This invention relates to a liquid crystal display element based on a liquid crystal composition of the dynamic scattering type.
When impressed with voltage, a composition including a liquid c~ystal indicating negative dielectric anisotropy whose conductivity is elevated by the addition of an organic electrolyte like a quarternary ammonium salt, for example, tetrabutyl-ammonium bromide gives rise to dynamic scattering (DS).
Many liquid crystal display elements are manufactured by utilizing the above-mentioned phenomenon. Where A.C.
voltage is impressed, the conventional DS type liquid crystal display element can indeed indicate a stable display function. Where, however, D.C. voltage is impressed, the liquid crystal and electrolyte of the prior art DS type liquid crystal display element are deteriorated electrochemically, resulting in the possibility that the display element will lose a required display function even during an operation of several hours to several days. Particularly, a Schiff base liquid crystal generally used as a type indicating negative dielectric anisotropy is unstable chemically as well as electrochemically when impressed with D.C.
voltage, and is found unadapted to be actuated by D.C.
voltage.
q~
113818~
In recent years, attemps have been made to apply a liquid crystal display element to the display of an image from the standpoint of rendering a display apparatus thin and compact, and minimizing power consumption. For such application, the display element has to indicate gray scale, and also the number of picture elements has to be increased. In this case, a display system comprising a switching circuit for each picture element has the advantages that the display of gray scale is made easier than in the time sharing drive (matrix drive) display system, and crosstalks are suppressed. However, application of D.C. power required for the above-mentioned display system of the switching circuit driving type leads to the deterioration of a liquid crystal and a decline in the image display f~nction.
Therefore, the stability of a liquid crystal is an important factor in ensuring the life of a DS type liquid crystal display element capable of being actuated by D.C. voltage.
In this connection, it is reported in Appl. Phys.
Lett 21. 142 (1972), A.I. Baise et al that threshold voltage for dynamic scattering can be effectively reduced by mixing a liquid crystal with an electron acceptor alone as a conductivity-elevating agent in the sense that a nonionic material is added to a liquid crystal instead of the above-mentioned ionic organic electrolyte. In this case, too, however, a liquid crystal tends to lose a required display function even during an operation of several hours - to several days. This event is assumed to result from the fact that a charge transfer complex is formed between a liquid crystal and an electron acceptor added thereto, and impression of D.C. voltage causes the liquid crystal to be electrochemically deteriorated on an electrode.
11381~34 To the best of our knowledge, no conductivity-elevating agent has been developed to date which imparts a sufficiently high conductivity to a liquid crystal composition for dynamic scattering and extends the life of any kind of liquid crystal composition.
It is accordingly the object of this invention to provide a liquid crystal display element which is adapted to be actuated by D.C. voltage, can effectively utilize dynamic scattering and be operated over a long period of time with a prominent display function.
With a liquid crystal display element according to this invention, the liquid crystal composition commprises a liquid crystal and a charge transfer complex formed of an electron acceptor and electron donor, said electron acceptor being at least one nitro-substituted 9-fluorenone expressed by the general structural formula:
1l ( NO2 ~ NO~ )n ~A) where m and n are each an integer of 0 to 4, and m plus n are an integer of 1 to 4.
As is well known to those skilled in the art, a liquid crystal composition according to this invention is filled between a pair of electrode substrates, at least one of which is transparent.
Where a liquid crystal is blended in accordance with this invention with a charge transfer complex whose electron acceptor is at least one nitro-substituted 9-fluorenone (Formula (A)), then a display element can be provided which sustains a prominent display function by dynamic scattering even when actuated by D.C. voltage.
As described above, a liquid crystal composition used with a liquid crystal display element according to this invention contains a charge transfer complex whose electron acceptor is at least one nitro-substituted 9-fluorenone of Formula (A). This nitro-substituted 9-fluorenone may be a mononitro substituent (m+n=l), S a dinitro substituent (m+n=2), trinitro substituent (m+n=3) or tetranitro substituent (m+n=4).
The mononitro substituent includes 3-nitro-9-fluorenone. The dinitro substituent includes 2,5-,
When impressed with voltage, a composition including a liquid c~ystal indicating negative dielectric anisotropy whose conductivity is elevated by the addition of an organic electrolyte like a quarternary ammonium salt, for example, tetrabutyl-ammonium bromide gives rise to dynamic scattering (DS).
Many liquid crystal display elements are manufactured by utilizing the above-mentioned phenomenon. Where A.C.
voltage is impressed, the conventional DS type liquid crystal display element can indeed indicate a stable display function. Where, however, D.C. voltage is impressed, the liquid crystal and electrolyte of the prior art DS type liquid crystal display element are deteriorated electrochemically, resulting in the possibility that the display element will lose a required display function even during an operation of several hours to several days. Particularly, a Schiff base liquid crystal generally used as a type indicating negative dielectric anisotropy is unstable chemically as well as electrochemically when impressed with D.C.
voltage, and is found unadapted to be actuated by D.C.
voltage.
q~
113818~
In recent years, attemps have been made to apply a liquid crystal display element to the display of an image from the standpoint of rendering a display apparatus thin and compact, and minimizing power consumption. For such application, the display element has to indicate gray scale, and also the number of picture elements has to be increased. In this case, a display system comprising a switching circuit for each picture element has the advantages that the display of gray scale is made easier than in the time sharing drive (matrix drive) display system, and crosstalks are suppressed. However, application of D.C. power required for the above-mentioned display system of the switching circuit driving type leads to the deterioration of a liquid crystal and a decline in the image display f~nction.
Therefore, the stability of a liquid crystal is an important factor in ensuring the life of a DS type liquid crystal display element capable of being actuated by D.C. voltage.
In this connection, it is reported in Appl. Phys.
Lett 21. 142 (1972), A.I. Baise et al that threshold voltage for dynamic scattering can be effectively reduced by mixing a liquid crystal with an electron acceptor alone as a conductivity-elevating agent in the sense that a nonionic material is added to a liquid crystal instead of the above-mentioned ionic organic electrolyte. In this case, too, however, a liquid crystal tends to lose a required display function even during an operation of several hours - to several days. This event is assumed to result from the fact that a charge transfer complex is formed between a liquid crystal and an electron acceptor added thereto, and impression of D.C. voltage causes the liquid crystal to be electrochemically deteriorated on an electrode.
11381~34 To the best of our knowledge, no conductivity-elevating agent has been developed to date which imparts a sufficiently high conductivity to a liquid crystal composition for dynamic scattering and extends the life of any kind of liquid crystal composition.
It is accordingly the object of this invention to provide a liquid crystal display element which is adapted to be actuated by D.C. voltage, can effectively utilize dynamic scattering and be operated over a long period of time with a prominent display function.
With a liquid crystal display element according to this invention, the liquid crystal composition commprises a liquid crystal and a charge transfer complex formed of an electron acceptor and electron donor, said electron acceptor being at least one nitro-substituted 9-fluorenone expressed by the general structural formula:
1l ( NO2 ~ NO~ )n ~A) where m and n are each an integer of 0 to 4, and m plus n are an integer of 1 to 4.
As is well known to those skilled in the art, a liquid crystal composition according to this invention is filled between a pair of electrode substrates, at least one of which is transparent.
Where a liquid crystal is blended in accordance with this invention with a charge transfer complex whose electron acceptor is at least one nitro-substituted 9-fluorenone (Formula (A)), then a display element can be provided which sustains a prominent display function by dynamic scattering even when actuated by D.C. voltage.
As described above, a liquid crystal composition used with a liquid crystal display element according to this invention contains a charge transfer complex whose electron acceptor is at least one nitro-substituted 9-fluorenone of Formula (A). This nitro-substituted 9-fluorenone may be a mononitro substituent (m+n=l), S a dinitro substituent (m+n=2), trinitro substituent (m+n=3) or tetranitro substituent (m+n=4).
The mononitro substituent includes 3-nitro-9-fluorenone. The dinitro substituent includes 2,5-,
2,6- and 2,7-dinitro-9-fluorenones. The trinitro substituent includes 2,4,7-trinitro-9-fluorenone.
The tetranitro substituent includes 2,4,5,7-tetranitro-9-fluorenone. This last mentioned 2,4,5,7-tetranitro-9-fluorenone is most preferred.
An electron donor which can be coupled with the electron acceptor (in the molar ratio of 1:1) to constitute the chargé transfer complex may be of any type, provided it well serves the purpose.
The electron donor includes, for example, metallocene deviatives such as di-n-butylferrocene;
phenylenediamine deviatives such as N,N,N',N'-tetraphenyl phenylenediamine; diphenylamine deviatives such as diphenyl benzidine; hydroquinone deviatives such as tetrachlorohydroquinone; tetrathiafulvalene deviatives such as tetrathiafulvalene; hydrazine deviatives such as 1,1-diphenyl-2-pycryl hydrazine.
Liquid crystals used with a liquid crystal display element according to this invention are not critical and any suitable type of them can be used. The liquid crystal includes:
(1) Cyclohexane carboxylic acid ester type liquid crystals such as:
C3H7 --~3-- C -- --~-- OC2H5 ~: ' 1~3818~
C3H7 - ~ - C - 0 - ~ - oC4Hg C4H9 - ~ ICl ~
C4Hg ~ C - 0 - ~ - 0C2H5 ~ 11 0 ~ - C6Hl3 C5Hll - ~ - C - 0 - ~ - OCN3 O
C4H9 - ~ - C - 0 - ~ - CSHll C4H9 - ~ - C - 0 - ~ - C6H13 (2) Cyclohexyl biphenyl cyclohexane type liquid crystals such as:
C5H11 ~ ~ ~ ~ 3 7
The tetranitro substituent includes 2,4,5,7-tetranitro-9-fluorenone. This last mentioned 2,4,5,7-tetranitro-9-fluorenone is most preferred.
An electron donor which can be coupled with the electron acceptor (in the molar ratio of 1:1) to constitute the chargé transfer complex may be of any type, provided it well serves the purpose.
The electron donor includes, for example, metallocene deviatives such as di-n-butylferrocene;
phenylenediamine deviatives such as N,N,N',N'-tetraphenyl phenylenediamine; diphenylamine deviatives such as diphenyl benzidine; hydroquinone deviatives such as tetrachlorohydroquinone; tetrathiafulvalene deviatives such as tetrathiafulvalene; hydrazine deviatives such as 1,1-diphenyl-2-pycryl hydrazine.
Liquid crystals used with a liquid crystal display element according to this invention are not critical and any suitable type of them can be used. The liquid crystal includes:
(1) Cyclohexane carboxylic acid ester type liquid crystals such as:
C3H7 --~3-- C -- --~-- OC2H5 ~: ' 1~3818~
C3H7 - ~ - C - 0 - ~ - oC4Hg C4H9 - ~ ICl ~
C4Hg ~ C - 0 - ~ - 0C2H5 ~ 11 0 ~ - C6Hl3 C5Hll - ~ - C - 0 - ~ - OCN3 O
C4H9 - ~ - C - 0 - ~ - CSHll C4H9 - ~ - C - 0 - ~ - C6H13 (2) Cyclohexyl biphenyl cyclohexane type liquid crystals such as:
C5H11 ~ ~ ~ ~ 3 7
(3) Phenyl ester type liquid crystals such as:
C6H13 ~ 11 ~
C3H70 - ~ - ~C - 0 - ~ C5Hll 1138~14 C5HllCOO ~ - ICl - o - ~ - C3H7 C5HllCOO --~-- ICI -- o --~)-- C5Hll
C6H13 ~ 11 ~
C3H70 - ~ - ~C - 0 - ~ C5Hll 1138~14 C5HllCOO ~ - ICl - o - ~ - C3H7 C5HllCOO --~-- ICI -- o --~)-- C5Hll
(4) Dialkyl benzoic acid phenyl ester type liquid crystals such as:
C 5 H 1 1 ~ ICl ~ .
C5Hll - ~ - ICl - O - ~ - CH3 o C3H7 ~ ICl ~ 7 15
C 5 H 1 1 ~ ICl ~ .
C5Hll - ~ - ICl - O - ~ - CH3 o C3H7 ~ ICl ~ 7 15
(5) Phenyl cyclohexane type liquid crystals such as:
C3H7 --~--~-- C2H5 C3H7 - ~ - ~ - OC4Hg C3H7 - ~ _ ~ _ O _ ICl C3H7 C3H7 - ~ - ~ - ICl - o - ~ - C3H7 1138~84 Cl O ~ - C3H7 ~ - ~ - C - - ~ C3 7
C3H7 --~--~-- C2H5 C3H7 - ~ - ~ - OC4Hg C3H7 - ~ _ ~ _ O _ ICl C3H7 C3H7 - ~ - ~ - ICl - o - ~ - C3H7 1138~84 Cl O ~ - C3H7 ~ - ~ - C - - ~ C3 7
(6) Biphenyl cyclohexane type liquid crystals such as:
C 5H ~ >-- C 2H 5
C 5H ~ >-- C 2H 5
(7) Biphenyl type liquid crystals such as:
C2H50 --~--~-- C5Hll C6H130 - ~ - ~ C5Hll
C2H50 --~--~-- C5Hll C6H130 - ~ - ~ C5Hll
(8) Azoxy type liquid crystals such as:
o i ~ O CO--C5Hll C6H13 ~ - N = N - ~ O 4 9
o i ~ O CO--C5Hll C6H13 ~ - N = N - ~ O 4 9
(9) Schiff base type liquid crystals such as:
CH30 - ~ - CH = N - ~ - C4H9 C2H5 - ~ - CH = N - ~ - C4H9
CH30 - ~ - CH = N - ~ - C4H9 C2H5 - ~ - CH = N - ~ - C4H9
(10) Azo type liquid crystals such as:
C4H9 - ~ - N = N - ~ - O - CO - O - C4Hg C2H5 - ~ - N - N - ~ _ o - CO - C5Hll C5Hll - ~ - N = N - ~ OCH3
C4H9 - ~ - N = N - ~ - O - CO - O - C4Hg C2H5 - ~ - N - N - ~ _ o - CO - C5Hll C5Hll - ~ - N = N - ~ OCH3
(11) Stilbene type liquid crystals such as:
C2H5 - ~ - CH = CH - ~ - C2H5 C2H5 - ~ - CH = CH - ~ - C4H9 C2H5 - ~ - CCQ = CH - ~ - C4H9 C2H5 - ~ - CH = CCQ - ~ - C4H9 C2H5 - ~ - CH = CCQ - ~ - C8H17 C2H5 - ~ - CH = CCQ - ~ - CH2 - CH(CH3) - c4H9 1138~34 g
C2H5 - ~ - CH = CH - ~ - C2H5 C2H5 - ~ - CH = CH - ~ - C4H9 C2H5 - ~ - CCQ = CH - ~ - C4H9 C2H5 - ~ - CH = CCQ - ~ - C4H9 C2H5 - ~ - CH = CCQ - ~ - C8H17 C2H5 - ~ - CH = CCQ - ~ - CH2 - CH(CH3) - c4H9 1138~34 g
(12) Pyrimidine type liquid crystals such as:
{ N ~ oC6H13 It is possible to use a mixture of two or more of the above listed liquid crystals.
A charge transfer complex whose electron acceptor is nitro-substituted 9-fluorenone of Formula (A) is added to a liquid crystal in an amount sufficient to give rise to dynamic scattering in the liquid crystal.
This amount is generally 0.1 to 5% by weight based on the weight of a liquid crystal, but is not limited thereto.
The liquid crystal together with the charge transfer complex are filled and sealed according to the A conventional metho~d in a space formed by a spacer made of e.g., Mylar~ between a pair of opposed electrodes, at least one of the electrodes being transparent, for example, glass base plates prepared by depositing indium oxide, tin oxide or the like thereon to provide a display element.
The charge transfer complex used with a liquid crystal display element of this invention is well compatible with a liquid crystal and easily provides the liquid crystal with a sufficiently high conductivity for the generation of dynamic scattering. Impression of D.C. voltage on a liquid crystal composition containing such charge transfer complex causes oxidation and reduction to take place easily and reversibly in the liquid crystal over a long period of time. Therefore, the liquid crystal element of the invention stably maintains the desired display function for a long time.
The above-mentioned advantageous effect is realized only by mixing a liquid crystal with a charge transfer complex whose electron acceptor is the nitro-substituted f~ ~ m ,g~
9-fluorenone of Formula (A). Where the electron acceptor of nitro-substituted 9-fluorenone alone is added to a liquid crystal, then the liquid crystal is not fully increased in conductivity though dynamic 5 scattering takes place. Moreover, in this case the liquid crystal indicates a low contrast, has a short life when actuated by D.C. volgtage and gives rise to wide current variations when supplied with power.
Where the electron donor alone is added to a liquid crystal, then a liquid crystal element can not have a sufficiently high conductivity to produce dynamic scattering. Where the electron acceptor alone is added to a liquid crystal, a charge transfer complex is formed between the liquid crystal and electron acceptor, indeed elevating the conductivity of the resultant liquid crystal element to a certain extent.
In this case, however, it is assumed that charge transfer repeatedly takes place between the liquid crystal and the electrode assembly, deteriorating the liquid crystal by electrochemical reaction and shortening the life of the liquid crystal element when actuated by D.C. voltage. Further where the electron donor alone is added to a liquid crystal, it is supposed that since a liquid crystal generally has a low capacity to accept electrons, a charge transfer complex is not formed between the liquid crystal and electron donor;
and the addition of the electron donor only has the same action as that of a nonionic organic material, failing to increase the conductivity of the liquid crystal.
This invention will be more fully understood from the following examples.
Example 1 3 parts by weight of 4-ethoxyphenyl-trans-4-butylcyclohexyl carboxylate, 3 parts by weight of 4-pentoxyphenyl-trans-4-pentylcyclohexyl carboxylate, 1 part by weight of 4-propylphenyl-4-hexanoyloxybenzoate, :
.
1 part by weight of 4-pentylphenyl-4-hexanoyloxybenzoate and 2 parts by weight of 4-methoxybenzylidene-4'-butylaniline were mixed to provide a mixed liquid crystal. This mixed liquid crystal had conductivity of lO-ll (Qcm~l) or less, and a nematic liquid crystal temperature range of 0 to 63C. The above-mentioned liquid crystal was mixed with 2~ by weight of a charge transfer complex whose electron donor was di-n-butylferrocene and whose electron acceptor was 3-nitro-9-fluorenone to prepare a liquid crystal composition. This liquid crystal composition had a conductivity of 1.5 x 10 10 (Qcm 1). The liquid crystal composition was filled between a pair of glass electrode plates on which a layer of tin oxide was thermally deposited to provide a liquid crystal cell (element).
The liquid crystal element thus formed was actuated by impression of D.C. voltage of 6 V or more.
Then dynamic scattering appeared with the formation of a white turbit region, indicating that the liquid crystal element had a display function. For determination of an effective life, the liquid crystal display element was impressed with D.C. voltage of 15 V
and held in a thermostat at 60C to check changes in the current value and external appearance of the display element. After voltage was introduced through the display element continuously for 5,000 hours, the edge portions of the electrode assembly were slightly deteriorated, but little change was recognized in the current value. The display element was shown to produce full dynamic scattering. Tests carried out under the above-mentioned forced condition$ showed that when applied under the ordinary conditions at normal temperature, the above-mentioned liquid crystal display element of this invention was assumed to have an effective life of about three years or more.
For better understanding of the present invention, - 1138.1~4 description is now given of the following controls.
Control 1 -A liquid crystal composition was prepared by mixing the mixed liquid crystal of Example 1 with 1.0% by weight of an electron donor formed of di-n-butylferrocene. The liquid crystal composition thus prepared had a conductivity of 1.2 x 10-11 (Qcm~l).
The liquid crystal composition was filled between a pair of glass electrode plates on which a layer of tin oxide was thermally deposited to provide a liquid crystal display element. When actuated by a D.C. voltage of 60 V or more, said display element showed slight dynamic scattering, proving that it was necessary to apply considerably high voltage for the full actuation of said display element.
As described above, the object of this invention cannot be attained in Controls 1 and 2. In other words, the individual application of the electron acceptor and donor used in this invention does not give a full effect.
Example 2 3 parts by weight of 4-trans-(4-propyl)cyclohexylphenyl butyrate, 2 parts by weight of trans-4-propyl(4-ethoxyphenyl)cyclohexane, 2 parts by weight of 4-methoxybenzylidene-4'-butylaniline, 2 parts by weight of 4-ethoxybenzylidene-4'-butylaniline, and 1 part by weight of trans-4-pentylcyclohexyl-(trans-4-propylcyclohexyl)biphenyl were blended together to provide a mixed liquid crystal. This mixed liquid crystal had a conductivity of 10-11 (Qcm 1) or less, and a nematic liquid crystal temperature range of -10 to 56C.
The mixed liquid crystal was blended with 2.0% by weight of a charge transfer complex whose electron donor was di-n-butylferrocene and whose electron acceptor was 2,7-dinitro-9-fluorenone to prepare a liquid crystal ' 11381~4
{ N ~ oC6H13 It is possible to use a mixture of two or more of the above listed liquid crystals.
A charge transfer complex whose electron acceptor is nitro-substituted 9-fluorenone of Formula (A) is added to a liquid crystal in an amount sufficient to give rise to dynamic scattering in the liquid crystal.
This amount is generally 0.1 to 5% by weight based on the weight of a liquid crystal, but is not limited thereto.
The liquid crystal together with the charge transfer complex are filled and sealed according to the A conventional metho~d in a space formed by a spacer made of e.g., Mylar~ between a pair of opposed electrodes, at least one of the electrodes being transparent, for example, glass base plates prepared by depositing indium oxide, tin oxide or the like thereon to provide a display element.
The charge transfer complex used with a liquid crystal display element of this invention is well compatible with a liquid crystal and easily provides the liquid crystal with a sufficiently high conductivity for the generation of dynamic scattering. Impression of D.C. voltage on a liquid crystal composition containing such charge transfer complex causes oxidation and reduction to take place easily and reversibly in the liquid crystal over a long period of time. Therefore, the liquid crystal element of the invention stably maintains the desired display function for a long time.
The above-mentioned advantageous effect is realized only by mixing a liquid crystal with a charge transfer complex whose electron acceptor is the nitro-substituted f~ ~ m ,g~
9-fluorenone of Formula (A). Where the electron acceptor of nitro-substituted 9-fluorenone alone is added to a liquid crystal, then the liquid crystal is not fully increased in conductivity though dynamic 5 scattering takes place. Moreover, in this case the liquid crystal indicates a low contrast, has a short life when actuated by D.C. volgtage and gives rise to wide current variations when supplied with power.
Where the electron donor alone is added to a liquid crystal, then a liquid crystal element can not have a sufficiently high conductivity to produce dynamic scattering. Where the electron acceptor alone is added to a liquid crystal, a charge transfer complex is formed between the liquid crystal and electron acceptor, indeed elevating the conductivity of the resultant liquid crystal element to a certain extent.
In this case, however, it is assumed that charge transfer repeatedly takes place between the liquid crystal and the electrode assembly, deteriorating the liquid crystal by electrochemical reaction and shortening the life of the liquid crystal element when actuated by D.C. voltage. Further where the electron donor alone is added to a liquid crystal, it is supposed that since a liquid crystal generally has a low capacity to accept electrons, a charge transfer complex is not formed between the liquid crystal and electron donor;
and the addition of the electron donor only has the same action as that of a nonionic organic material, failing to increase the conductivity of the liquid crystal.
This invention will be more fully understood from the following examples.
Example 1 3 parts by weight of 4-ethoxyphenyl-trans-4-butylcyclohexyl carboxylate, 3 parts by weight of 4-pentoxyphenyl-trans-4-pentylcyclohexyl carboxylate, 1 part by weight of 4-propylphenyl-4-hexanoyloxybenzoate, :
.
1 part by weight of 4-pentylphenyl-4-hexanoyloxybenzoate and 2 parts by weight of 4-methoxybenzylidene-4'-butylaniline were mixed to provide a mixed liquid crystal. This mixed liquid crystal had conductivity of lO-ll (Qcm~l) or less, and a nematic liquid crystal temperature range of 0 to 63C. The above-mentioned liquid crystal was mixed with 2~ by weight of a charge transfer complex whose electron donor was di-n-butylferrocene and whose electron acceptor was 3-nitro-9-fluorenone to prepare a liquid crystal composition. This liquid crystal composition had a conductivity of 1.5 x 10 10 (Qcm 1). The liquid crystal composition was filled between a pair of glass electrode plates on which a layer of tin oxide was thermally deposited to provide a liquid crystal cell (element).
The liquid crystal element thus formed was actuated by impression of D.C. voltage of 6 V or more.
Then dynamic scattering appeared with the formation of a white turbit region, indicating that the liquid crystal element had a display function. For determination of an effective life, the liquid crystal display element was impressed with D.C. voltage of 15 V
and held in a thermostat at 60C to check changes in the current value and external appearance of the display element. After voltage was introduced through the display element continuously for 5,000 hours, the edge portions of the electrode assembly were slightly deteriorated, but little change was recognized in the current value. The display element was shown to produce full dynamic scattering. Tests carried out under the above-mentioned forced condition$ showed that when applied under the ordinary conditions at normal temperature, the above-mentioned liquid crystal display element of this invention was assumed to have an effective life of about three years or more.
For better understanding of the present invention, - 1138.1~4 description is now given of the following controls.
Control 1 -A liquid crystal composition was prepared by mixing the mixed liquid crystal of Example 1 with 1.0% by weight of an electron donor formed of di-n-butylferrocene. The liquid crystal composition thus prepared had a conductivity of 1.2 x 10-11 (Qcm~l).
The liquid crystal composition was filled between a pair of glass electrode plates on which a layer of tin oxide was thermally deposited to provide a liquid crystal display element. When actuated by a D.C. voltage of 60 V or more, said display element showed slight dynamic scattering, proving that it was necessary to apply considerably high voltage for the full actuation of said display element.
As described above, the object of this invention cannot be attained in Controls 1 and 2. In other words, the individual application of the electron acceptor and donor used in this invention does not give a full effect.
Example 2 3 parts by weight of 4-trans-(4-propyl)cyclohexylphenyl butyrate, 2 parts by weight of trans-4-propyl(4-ethoxyphenyl)cyclohexane, 2 parts by weight of 4-methoxybenzylidene-4'-butylaniline, 2 parts by weight of 4-ethoxybenzylidene-4'-butylaniline, and 1 part by weight of trans-4-pentylcyclohexyl-(trans-4-propylcyclohexyl)biphenyl were blended together to provide a mixed liquid crystal. This mixed liquid crystal had a conductivity of 10-11 (Qcm 1) or less, and a nematic liquid crystal temperature range of -10 to 56C.
The mixed liquid crystal was blended with 2.0% by weight of a charge transfer complex whose electron donor was di-n-butylferrocene and whose electron acceptor was 2,7-dinitro-9-fluorenone to prepare a liquid crystal ' 11381~4
- 13 -composition. This liquid crystal composition had a conductivity of 2 x 10-1 tQcm 1). The liquid crystal composition thus prepared was filled between a pair of glass electrode plates on which a layer of tin oxide was thermally deposited to constitute a liquid crystal display cell (element). When impressed with a D.C.
voltage of 6 V or more, the liquid crystal display element thus prepared gave rise to dynamic scattering with the formation of a white turbit region, proving to have a display function. For determination of an effective life, the liquid crystal display element was impressed with D.C. voltage of 15 V and held in a thermostat at 60C to check changes in the current value and external appearance of the display element.
After voltage was introduced through the display element continuousl'y for 5,000 hours, the edge portions of the electrode assembly were slightly deteriorated, but little change was recognized in the current value.
The display element was shown to give rise to full dynamic scattering. Tests carried out under the above-mentioned forced conditions showed that when applied under the ordinary conditions at normal temperature, the above-mentioned liquid crystal display element embodying this invention was assumed to have an effective life of about three years or more.
Experiments were made under substantially the same conditions as described above, except that 2,7-dinitro-9-fluorenone used as an electron acceptor was replaced by 2,5-dinitro-9-fluorenone or 2,6-dinitro-9-fluorenone. Still the same results were ensured as in the first-mentioned experiment of Example 2.
Example 3 2 parts by weight of 4-trans-propylcyclohexane carboxylic acid-4'-ethoxyphenyl ester, 2 parts by weight of 4-trans-pentylcyclohexane carboxylic acid-4'pentoxyphenyl ester, 3 parts by weight of 1138~
voltage of 6 V or more, the liquid crystal display element thus prepared gave rise to dynamic scattering with the formation of a white turbit region, proving to have a display function. For determination of an effective life, the liquid crystal display element was impressed with D.C. voltage of 15 V and held in a thermostat at 60C to check changes in the current value and external appearance of the display element.
After voltage was introduced through the display element continuousl'y for 5,000 hours, the edge portions of the electrode assembly were slightly deteriorated, but little change was recognized in the current value.
The display element was shown to give rise to full dynamic scattering. Tests carried out under the above-mentioned forced conditions showed that when applied under the ordinary conditions at normal temperature, the above-mentioned liquid crystal display element embodying this invention was assumed to have an effective life of about three years or more.
Experiments were made under substantially the same conditions as described above, except that 2,7-dinitro-9-fluorenone used as an electron acceptor was replaced by 2,5-dinitro-9-fluorenone or 2,6-dinitro-9-fluorenone. Still the same results were ensured as in the first-mentioned experiment of Example 2.
Example 3 2 parts by weight of 4-trans-propylcyclohexane carboxylic acid-4'-ethoxyphenyl ester, 2 parts by weight of 4-trans-pentylcyclohexane carboxylic acid-4'pentoxyphenyl ester, 3 parts by weight of 1138~
- 14 -4-transbutylcyclohexane carboxylic acid-4'-hexylphenyl ester, and 3 parts by weight of 4-methoxybenzylidene-4'-butylaniline were blended together to provide a mixed liquid crystal. This mixed liquid crystal had a conductivity of 10-11 (Qcm~l) or less and a nematic liquid crystal temperature range of -10 to 53C.
The mixed liquid crystal was blended with 1.0~ by weight of a charge transfer complex whose electron donor was di-n-butylferrocene and whose electron acceptor was 2,4,7-trinitro-9-fluorenone to prepare a liquid crystal composition. This liquid crystal composition had a conductivity of 2 x 10-1 (Qcm~l). The liquid crystal composition was filled between a pair of glass electrode plates on which a layer of tin oxide was thermally deposited to prepare a liquid crystal display cell (element). When impressed with a D.C. voltage of 6 V or more, the display element produced dynamic scattering with the formation of a white turbit region, proving to have a display function. For determination of an effective life, the liquid crystal display element was impressed with D.C. voltage of 15 V and held in a thermostat at 60C to check changes in the current value and external appearance of the display element. After voltage was introduced through the display element continuously for 5,000 hours, the edge portions of the electrode assembly were slightly deteriorated, but little change was observed in the current value. The display element was shown to produce sufficient dynamic scattering. Tests carried out under the above-mentioned forced conditions showed that when applied under the ordinary conditions at normal temperature, the above-mentioned liquid crystal display element embodying this invention supposedly had an effective life of about three years or more.
Example 4 1 part by weight of 4-trans-butylcyclohexane ~, ' ~.
1138~34
The mixed liquid crystal was blended with 1.0~ by weight of a charge transfer complex whose electron donor was di-n-butylferrocene and whose electron acceptor was 2,4,7-trinitro-9-fluorenone to prepare a liquid crystal composition. This liquid crystal composition had a conductivity of 2 x 10-1 (Qcm~l). The liquid crystal composition was filled between a pair of glass electrode plates on which a layer of tin oxide was thermally deposited to prepare a liquid crystal display cell (element). When impressed with a D.C. voltage of 6 V or more, the display element produced dynamic scattering with the formation of a white turbit region, proving to have a display function. For determination of an effective life, the liquid crystal display element was impressed with D.C. voltage of 15 V and held in a thermostat at 60C to check changes in the current value and external appearance of the display element. After voltage was introduced through the display element continuously for 5,000 hours, the edge portions of the electrode assembly were slightly deteriorated, but little change was observed in the current value. The display element was shown to produce sufficient dynamic scattering. Tests carried out under the above-mentioned forced conditions showed that when applied under the ordinary conditions at normal temperature, the above-mentioned liquid crystal display element embodying this invention supposedly had an effective life of about three years or more.
Example 4 1 part by weight of 4-trans-butylcyclohexane ~, ' ~.
1138~34
- 15 -carboxylic acid-4'-ethoxyphenyl ester, 1 part by weight of 4-trans-butylcyclohexane carboxylic acid-4'-hexyloxyphenyl ester and 1 part by weight of 4-trans-pentylcyclohexane carboxylic acid-4'-methoxyphenyl ester were mixed together. The mixture(which had a conductivity of 10-11 (Qcm~l) or less) was blended with 1.0% by weight of a charge transfer complex whose electron donor was dibutylferrocene and whose electron acceptor was 2,4,5,7-tetranitro-9-fluorenone to provide a liquid crystal composition.This liquid crystal composition had a conductivity of 2 x 10-1 ~cm~l) or less. The composition was filled between a pair of glass electrode plates on which a layer of tin oxide was thermally deposited to prepare a liquid crystal display cell (element). When impressed with a D.C. voltage of 6 V or more, the display element gave rise to dynamic scattering with the formation of a white turbit region, proving to have a sufficient display function. For evaluation of an effective life, the display element was impressed with D.C. voltage of 15 V and held in a thermostat at 60C to check changes in the current value and external appearance of the display element. After voltage was introduced through the display element continuously for 5,000 hours, the edge portions of the electrode assembly were slightly deteriorated, but noticeable changes were not observed in the current value, proving that the display element was shown to produce sufficient dynamic scattering.
From the results of accelerated tests at 60C, the display element assumed to have an effective life of about three years or more at a lower temperature.
Example 5 22.5% by weight of trans-4-propyl-(4-butoxyphenyl)cyclohexane, 27% by weight of trans-4-pentyl-(4-ethylbiphenyl)-cyclohexane, 27% by weight of 4-pentyl-4-methoxybenzoate, 13.5% by weight of , . :
. .
From the results of accelerated tests at 60C, the display element assumed to have an effective life of about three years or more at a lower temperature.
Example 5 22.5% by weight of trans-4-propyl-(4-butoxyphenyl)cyclohexane, 27% by weight of trans-4-pentyl-(4-ethylbiphenyl)-cyclohexane, 27% by weight of 4-pentyl-4-methoxybenzoate, 13.5% by weight of , . :
. .
- 16 -2-cyano-4-heptylpheny-4'-pentyl-4-biphenyl carboxylate, and 10% by weight of 4-methoxybenzylidene-4'-butylaniline were mixed together to provide a liquid crystal. This mixed crystal had a conductivity of lO ll (Qcm~l) or less and a nematic liquid crystal temperature range of -12 to 71C. The mixed liquid crystal was blended with l~ by weight of a charge transfer complex whose electron donor was formed of N,N'-diphenylbenzidine and whose electron acceptor was formed of 2,4,5,7-tetranitro-9-fluorenone to prepare a liquid crystal composition. This composition indicated substantially the same properties as those of the composition of Example 1, thereby attaining the object of this invention.
Where N,N'-diphenylbenzidine used as an electron donor was replaced by, for example, N,N,N',N'-tetraphenyl phenylenediamine, it was possible to obtain the same result as the liquid crystal display element of the above Examples.
Control 2 A liquid crystal composition was prepared by mixing the mixed liquid crystal of Example S with 1.0% by weight of an electron acceptor formed of 2,4,5,7-tetranitro-9-fluorenone. The liquid crystal composition thus prepared had a conductivity of 5 x lO-ll (Qcm~l). The liquid crystal composition was filled between a pair of glass electrode plates on which a layer of tin oxide was thermally deposited to provide a liquid crystal display element. When actuated even by a D.C. voltage of 6 V or more, this display element did not give rise to such dynamic scattering as was observed in the liquid crystal display element of Example 5. When D.C. voltage of 12 V was applied, dynamic scattering was observed for the first time.
Even at this time, the display element of Control 2 had a low display function, making it necessary to ~138~84
Where N,N'-diphenylbenzidine used as an electron donor was replaced by, for example, N,N,N',N'-tetraphenyl phenylenediamine, it was possible to obtain the same result as the liquid crystal display element of the above Examples.
Control 2 A liquid crystal composition was prepared by mixing the mixed liquid crystal of Example S with 1.0% by weight of an electron acceptor formed of 2,4,5,7-tetranitro-9-fluorenone. The liquid crystal composition thus prepared had a conductivity of 5 x lO-ll (Qcm~l). The liquid crystal composition was filled between a pair of glass electrode plates on which a layer of tin oxide was thermally deposited to provide a liquid crystal display element. When actuated even by a D.C. voltage of 6 V or more, this display element did not give rise to such dynamic scattering as was observed in the liquid crystal display element of Example 5. When D.C. voltage of 12 V was applied, dynamic scattering was observed for the first time.
Even at this time, the display element of Control 2 had a low display function, making it necessary to ~138~84
- 17 -impress a voltage of 40 V or more in order to provide a sufficiently distinct contrast. Where the life of this control display element was determined under the same conditions as in Example 5, the electrode assembly was colored after introduction of only 25 hours, and bubbles appeared in the display section. Determination was made of a point (NI point) at which the nematic liquid crystal of the liquid crystal material was transferred to an isotropic liquid. The point indicated a decrease of 15C from the initial temperature. This means that addition of the electron acceptor alone of Control 2 results in the deterioration of a liquid crystal when impressed with D.C. voltage.
Claims (15)
1. A dynamic scattering type liquid crystal display element adapted to be actuated by D.C. voltage, comprising:
a pair of electrode substrates forming a space therebetween, at least one of which is transparent;
a liquid crystal composition filled in said space, said composition comprising a liquid crystal, and a charge transfer complex formed of an electron acceptor and electron donor, said electron acceptor being at least one nitro-substituted 9-fluorenone expressed by the general formula where m and n are each an integer of 0 to 4, and m plus n are an integer of 1 to 4.
a pair of electrode substrates forming a space therebetween, at least one of which is transparent;
a liquid crystal composition filled in said space, said composition comprising a liquid crystal, and a charge transfer complex formed of an electron acceptor and electron donor, said electron acceptor being at least one nitro-substituted 9-fluorenone expressed by the general formula where m and n are each an integer of 0 to 4, and m plus n are an integer of 1 to 4.
2. The element according to claim 1, wherein m+n is 1.
3. The element according to claim 2, wherein the electron acceptor is 3-nitro-9-fluorenone.
4. The element according to claim 1, wherein m+n is 2.
5. The element according to claim 4, wherein the electron acceptor is 2,5-, 2,6- or 2,7-dinitro-9-fluorenone.
6. The element according to claim 1, wherein m+n is 3.
7. The element according to claim 6, wherein the electron acceptor is 2,4,7-trinitro-9-fluorenone.
8. The element according to claim 1, wherein m+n is 4.
9. The element according to claim 8, wherein the electron acceptor is 2,4,5,7-tetranitro-9-fluorenone.
10. The element according to claim 1, wherein the electron donor is selected from the group consisting of metallocene derivatives, phenylenediamine derivatives, diphenylamine derivatives, hydroquinone derivatives tetrathiafulvalene derivatives and hydrazine derivatives.
11. The element according to claim 10, wherein the electron donor is dibutylferrocene.
12. The element according to claim 1, wherein the charge transfer complex is present in an amount sufficient to produce dynamic scattering in the liquid crystal.
13. The element according to claim 12, wherein the charge transfer complex is present in an amount of 0.1 to 5% by weight based on the weight of the liquid crystal.
14. The element according to claim 12, wherein the liquid crystal is at least one member selected from the group consisting of cyclohexane carboxylic acid ester type, cyclohexyl biphenyl cyclohexane type, phenyl ester type, phenyl cyclohexane type, biphenyl cyclohexane type, biphenyl type, azoxy type, Schiff base type, azo type, stilbene type and pyrimidine type liquid crystals.
15. The element according to claim 14, wherein the phenyl ester type is dialkylbenzoic acid phenyl ester.
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4468380A JPS56141378A (en) | 1980-04-07 | 1980-04-07 | Liquid crystal display element |
JP44683/80 | 1980-04-07 | ||
JP3873/81 | 1981-01-16 | ||
JP387381A JPS57119975A (en) | 1981-01-16 | 1981-01-16 | Liquid crystal display element |
Publications (1)
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CA1138184A true CA1138184A (en) | 1982-12-28 |
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CA000373012A Expired CA1138184A (en) | 1980-04-07 | 1981-03-13 | Liquid crystal display element |
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US (1) | US4366080A (en) |
EP (1) | EP0037902B1 (en) |
AU (1) | AU526448B2 (en) |
CA (1) | CA1138184A (en) |
DE (1) | DE3174833D1 (en) |
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Publication number | Priority date | Publication date | Assignee | Title |
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JPS5871979A (en) * | 1981-10-26 | 1983-04-28 | Alps Electric Co Ltd | Liquid crystal mixture |
EP0106175B1 (en) * | 1982-09-30 | 1988-12-07 | Showa Denko Kabushiki Kaisha | Electrically conductive liquid crystalline substance and polymer |
US5283676A (en) * | 1991-05-13 | 1994-02-01 | Hughes-Jvc Technology Corporation | Liquid crystal light valve |
EP0606858B1 (en) * | 1993-01-11 | 2000-04-26 | Chisso Corporation | Liquid crystal compositions and liquid crystal display devices |
Family Cites Families (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3838059A (en) * | 1972-02-22 | 1974-09-24 | Hughes Aircraft Co | Liquid crystal composition |
US3963311A (en) * | 1972-02-23 | 1976-06-15 | Hoffmann-La Roche Inc. | Liquid crystal esters |
US3814700A (en) * | 1972-08-03 | 1974-06-04 | Ibm | Method for controllably varying the electrical properties of nematic liquids and dopants therefor |
US3975285A (en) * | 1972-10-30 | 1976-08-17 | Hodogaya Chemical Co., Ltd. | Liquid crystal composition |
JPS5347795B2 (en) * | 1973-01-19 | 1978-12-23 | ||
US3932298A (en) * | 1973-07-19 | 1976-01-13 | Temple University | Nematic liquid crystals with charge-transfer acceptors as dopants |
DE2441296C3 (en) * | 1973-08-31 | 1978-11-02 | Dai Nippon Toryo K.K., Osaka (Japan) | Nematic liquid crystal compositions and their use |
US3979020A (en) * | 1973-11-30 | 1976-09-07 | Braber Robert J | Article dispensing container |
GB1459046A (en) * | 1974-03-15 | 1976-12-22 | Secr Defence | Liquid crystal devices |
FR2266541B1 (en) * | 1974-04-05 | 1979-10-19 | Anvar | |
US4066570A (en) * | 1974-10-25 | 1978-01-03 | Hoffman-La Roche Inc. | Phenyl-pyrimidines |
US4066569A (en) * | 1975-12-30 | 1978-01-03 | Hughes Aircraft Company | Dopants for dynamic scattering liquid crystals |
US4113647A (en) * | 1976-08-13 | 1978-09-12 | The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland | Liquid crystalline materials |
DE2636684C3 (en) * | 1976-08-14 | 1980-06-19 | Merck Patent Gmbh, 6100 Darmstadt | Phenylcyclohexane derivatives and their use in liquid-crystalline dielectrics |
US4064919A (en) * | 1976-11-22 | 1977-12-27 | Rca Corporation | Method of filling dynamic scattering liquid crystal devices |
DE2702598C2 (en) * | 1977-01-22 | 1984-10-25 | Merck Patent Gmbh, 6100 Darmstadt | Cyclohexylcyclohexanes and dielectrics containing them |
-
1981
- 1981-03-09 US US06/242,030 patent/US4366080A/en not_active Expired - Fee Related
- 1981-03-10 EP EP81101767A patent/EP0037902B1/en not_active Expired
- 1981-03-10 DE DE8181101767T patent/DE3174833D1/en not_active Expired
- 1981-03-13 AU AU68369/81A patent/AU526448B2/en not_active Ceased
- 1981-03-13 CA CA000373012A patent/CA1138184A/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
AU6836981A (en) | 1981-10-15 |
AU526448B2 (en) | 1983-01-13 |
EP0037902A1 (en) | 1981-10-21 |
EP0037902B1 (en) | 1986-06-18 |
DE3174833D1 (en) | 1986-07-24 |
US4366080A (en) | 1982-12-28 |
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