CA2234714A1 - Water based inks containing near infrared fluorophores - Google Patents

Abstract

The present invention provides inks which contain a near infrared fluorophoric compound incorporated into a water-dissipatable polyester backbone. The inks of the present invention are preferably colorless or "invisible" but could be made slightly colored if desirable. Specifically, the inks of the present invention comprise: (A) between 1 and 10 weight percent of at least one waterdissipatable polyester having from 0.1 ppm by weight to 10 % by weight of a thermally stable near infrared fluorophoric compound copolymerized therein; (B) between 5 and 75 weight percent of at least aliphatic humectant; (C) between 0 and 15 weight percent of at least one lower aliphatic alcohol of no more than 3 carbon atoms; (D) water and optionally up to 2 weight percent of one or more additives; wherein the weight percentages of components A-D equal 100 %.

Description

CA 02234714 1998-04-1~
W O 97/15634 PCTrUS96/16635 Water Based Inks Containinq Near Infrared Fluorophores Field of the Invention This invention relates to aqueous ink formulations suitable for ink jet printing, both by drop-on-demand (DOD) and continuous printing methods, and which contain sulfopolyesters~amides having near infrared fluorophores copolymerized therein.

Backqround of the Invention It is desirable to provide intelligible markings that are virtually invisible to the human eye on the surface of articles for identification, authentication, sorting, etc. U.S. Patents 5,093,147; 5,336,714 disclose using certain near infrared fluorescent compounds having ~in;~l light absorption of radiation in the visible range 400-700 nanometers (nm) and strong light absorption in the near infrared region 700-900 nm with accompanying fluorescence to produce fluorescent radiation of wavelengths longer than the wavelength of excitation. However, aqueous ink formulations suitable for ink jet printing are not disclosed and markings produced from those compounds do not have adequate stability to sunlight~ultraviolet (W) light to permit practical marking speeds required for suitable intelligible markings.
The polymeric compositions used in U.S. Patent 5,336,714 are unique in that the near infrared fluorophores (NIRF's) are copolymerized therein and thus are not extractable, exudable, sublimable or leachable from the polymeric composition. The phthalocyanines and naphthalocyanines mentioned therein are unique in that they provide improved W light stability over the known cyanine laser dyes used in U.S. Patent 5,093,147.
However, U.S. Patent 5,336,714 provides no help in formulating an aqueous based ink suitable for ink jet CA 02234714 1998-04-1~

printing using the polymeric compositions containing the copolymerized NIRF compound.
U.S. Patent 4,540,595 provides an ink which fluoresces in the near infrared and which is used to mark documents such as bank checks for automatic identification. The dyes used are phenoxazines (e.g.
3,7-bis(diethylamino) phenoxazonium nitrate is the preferred fluorescent material) which impart blue color to the marked substrate and thus are not invisible.
certain inorganic rare earth compounds typified by neodymium (Nd), erbium (Er) and ytterbium (Yb) have been used to impart fluorescent markings that can be activated in the infrared to data cards (U.S.
4,202,491). Inks prepared from the insoluble rare earth metals are prone to clogging ink jet nozzles causing poor print start-up and thus, in general, are not practical.
In U.S. 5,093,147 inks are disclosed which are useful for printing infrared fluorescent invisible markings on the surface of an article using certain known polymethine (cyanine) laser dyes. The dyes used, however, have the disadvantage of fading or decomposing upon brief exposure times to ultraviolet light, thus rendering the marking method inferior.
Certain 16,17-dialkoxyviolanthrones (also called dibenzanthrones) are known (U.S. Patent 3,630,941) to be useful as infrared fluorescent markers when solubilized in various substrates, although they are not fluorescent in the solid state. These high molecular weight compounds have essentially no water solubility and thus have no utility for formulation of water based inks for ink jet printing. Furthermore, these compounds have significant absorption of light having wavelengths below 700 nanometers and therefore do not usually provide invisible markings.

CA 02234714 1998-04-1~
W O 97/15634 PCT~US96/16635 Japanese Laid-Open Patent Application: Hei3-79683 discloses ink formulations containing infrared absorbing naphthalocyanine compounds useful for printing barcodes and for identifying documents to prevent falsification and forgery. Various meltable waxes and thermoplastic resins are used as vehicles in combination with alcohols and aromatic hydrocarbons to produce non-aqueous inks.
The high molecular weight naphthalocyanine compounds have essentially no water solubility and are not useful for formulating a~ueous inks for ink jet printing directly. The marking method mentioned in this application does not utilize fluorescence of the naphthalocyanines when exposed to infrared radiation, but relies merely on absorption of infrared radiation.
U.S. 5,336,714 discloses aqueous coating compositions cont~;n;ng 20 weight percent to 35 weight percent of a water-dissipatable sulfopolyester having 0.1 ppm by weight to 10% by weight of a thermally stable near infrared fluorophoric compound copolymerized therein dispersed in water (65-80 weight percent). The ink formulation disclosed (Example 7) was suitable for coating substrates such as paper with drawdown rods, but is not suitable for ink jet printing because of plugging or clogging of the jets.
n~r~TpTION OF T~E lNv~llON
This invention relates to an aqueous ink composition suitable for use in ink jet printing comprising:
A. between 1 and 10 weight percent of at least one water-dissipatable polyester comprising:
(i) monomer residues of at least one dicarboxylic acid;
(ii) 4 to 25 mole percent, based on the total of all acid, hydroxy and amino equivalents, of CA 0 2 2 3 4 7 1 4 1 9 9 8 - b 4 - 1 ~
,~/f///~ ~ os ~e~6 63~

~onomer residue.s o~ a~ leas~ one dl~unc~ional ~ul~onomsr contai~ing at least one sulfona~e ~r~up bond~d to an aromat_c ring where-~the Functional groups ~re hy~roxy ~ c~rPox~
carboxylate ester or amino;
~iii) monomer re~idues of ~ least ~ne diol or a mixture o~ diol a~d ~ d;~ine; an~
optlonally, ~iv~ m~nomer residues of at ~east one lC di~u~ct~ onal m~ncmer r~ac~ant sele~ea ~om hydroxycarboxylic aclds, ~mlno car~ox~lLc acids ~nd amino~lkan~ls p~vide~ _h~ leas~ 2~ per~n~ of the gro~ps li~ci~s the mcn~meric un'ts are ester link~ge~; szi~ wate~-di~sipata~1~ polyester ha~in~ ~rom 0.1 ppm ~y wei~h~ ~o a~ by weight o~ a thermally stabl e n~ar ~ n~rare~
Cluoro~horic ~o~pound co-~alently ~our.d ~o ~he p~lyes~er;
s. ~etween 5 an~ 75 w~ight pexcent of at leas' on~
binder or aL~ pha'cic h~mectant;
~. ~etwean ~ ard 15 weight percent o~ at: least onE~
lo~er alipha. ic alcohol of no msr~ than 3 carbo~.
~L~ ams, ~ _ D~ ~ate~ and op~ion~}ly up to 2 sreight perc~nt af one-or sn~re addl~ives;
~5 wherein the weight perce~.tages ~e ~a~ed ~n t:~le tatal . wei~ht~: o$ component~; A--~ .
In a pre~erre~l em}: oA ~ m~nt, c:omponan I A is ~ water--dissipatz~3~1e ~ op~lyester and component ~iii) compri~e~ ( a3 at lea~t 15 male percent, ~ on the 3 0 ~o~al ~le p~rcent of diol ~onome~ ~e~siduQ~3, of ~ diol -~ having ~he ~o--mula H(OCH2C~z~OH~ wher~ n is ~ t~ 20, or ~s) o .1 to 1Q~ tha~ 15 :~ole percent, ~as~d on the total mol~ percent o~ diol ~on~mer residues or diol and diamine r~idu~s o~ a poly ~et~.ylene gl ycol) hav~ ns the formula Hl0CH2CEI2)nOEI, wh~re n is 2 to 5C0, provided AMEND'.D SHEET

' '"' -~J~CA 02234714 1998-04-15 that the mole percent o~ ~Uch re&i~u~c is inversely praportional to the va lue o~ n .
The ~ter dissipat~ble ~lyester5 are any p~iyes~ars which are ca~ahle o~ f orming ~lec:~ro~ta~ically staP~3.ize~ colloid.~ havin~ particle ~:izes between 2QO and 85~ A in diametl3r. Prefe~-abl~ the polyesters are water clis~ patable sul~op~ly~ster~fa~ides u~e!~ which ~re d~sc::ri~ed in U ~ S . Pat~nt 5, 3 3 6, 7 ~4 A
Th~ cornp;~i tions of the pre5ent in~tent~ on ~ay ~e ~o u~ed for a wids v~riety of prin~3r applications whic~
c~n utili~e wa~r base~ s.
~or e7~ample, an in3c coripo~ition u~ie~ or dro~on--de~and ~E~OD) ink ~t printing t~La the piezo~lec,ric impulse method compris~s:
h . betweRn 1 and 10 we ig~t perce~t o~ said at lea~ one w2ter~issipa~-abl~ polyester ha~ring fr~
O.1 ppm ~y weig~t to 109~ by weig~t of~ a ther~ally stable n~ar in~ra_ed ~luorophori~ com}?ound ccvalently bound tc~ the poly~ster;
~o BA ~e~w~en 45 and 75 we~ght pe~-cent of ~aid at ie;~t sn~ ~indsr or ~umectant;
c. ~tween 2 and ~5 w~ight perc~nt of at 1e~st or~e l~wer alc~ol;
o; ~e ~ween ~ . o 1 and o . ~ G weight percent c~ a~

2~ lea~:~ one cor~o~ion inhihitcr;
- E . ~etween O . O1 an~l O . 3~ weight pe--cent c:~ at lea~:t one ~io~ld~;
F. water, whe-ein th~ t~eight percent~ges a~ P2~;ed cn thQ total welghts of compon~n_~ A--~.

3 G ~o~h~r pre~rred inlc GompoC~ t_on p2~ticu.~ ~rl~
U~ Ul f or drzp--on~demand ~ DOl~ e~ printing Yi~ t;he C~O--called bu~le ~et method c~pri~Q;
A. i~etween 1 and lO welgh~ percent ~f 5aicl ~
least: one water--dissipa~al~le polyester having ~om ~.1 pp~ ~y weigh~ tc~ lO~ by weight of a t~ermally AMENDED SHEEJ

~s ~ ; CA o i 2 3 4 7 1 4 1 9 9 8 - 0 4 - 1 ~

g~;able ne~r ~ nfrare~ f 3 uorophoric compounc3 co~ralently h~u~d t:o the polyester;
B . b~w~en 2 0 and 6 0 weight per~ent o~ ~t least ~ne huIne~tant;
C. Petwe~n 0 ~ 50 and 1. 5 weight p~rcent o~ at lea~t on~ surf ace ACtiVe agent, r). ~etween C'f . Ot and 0 . 5 weight percent cf at lf3ast one c~rrosioJl ~ nhibitar;
E. bei:w~en 0 . 01 2nd 0. 3 wei~h~ percent o~ at least lo one kio~de;
F. water, wh~rei~ t~se we ~ht ~excentages are ~sed on the t~a } wei~ht~2 o~ comporlen'cs A--F .
A preferr~d ink composit~ 3n p~rticularly use~ul for ccntinuous ink jet printing us ng -_he cci~ex ink--~et imaging system ¢,Scitex Digit21 Prirlting, Inc. f D~ton, C~hio 45420--4035 ) comprises:
. ketwsen 1 and 10 we~ ght perc:ent Cf said at le~st c~ne wa' er~i~sipat:able polyester h~in~ ~r~
0.1 pp~ }~y weight t~ ; by w~ight of a th~r~ally 7 0 ~2t~ble nea-- ln~ra~-ed ~luo~ophoric compo~md cc~ 1er~tly ~ound t~ _he ~ly~ ~r;
B. ~e~ween~ 4 ~n~ 8 wei~:sht percent o~ ~;aid a~ leas~
t~n~ humectant, C. hetween ~ ~ 35 ~nd ~ . 6~ weight perce~ ~ at least one ~face active ~ge~;;
between.O.~5 ~nd 1.25 wei~ht per~ent o~ at lea~t one defo~ming agent;
E. ~tween o.o1 and 0.50 weight pe~c~nt of at ieast one corr~sion in~i~itor;
F. ~et-~een 0.~1 an~ 0.3 weight percent Qf at least ~ne ~iocid~; ~
~. water, wherein wei~ht percentag~s of A through G e~ual loo~.
~inally, a preferred ink co~po~ition for single ~5 n~2~1e contin~ous ink jet printer~ ~uch as the Codebox - A~.N~~~ SHE~T
-r~ r ~ ~A 02i347l4 l998-04-l5 ~ 7 ~
c.
2, suppl~ed ky A:~j et , DC~;~ino A~ e~ , Inc ~, Gurnee , Il.
6 0~3 1, compr~ se~:
A. ~etween 1 an~ 10 woight percen~ a4 at leas'c one water~issi~atable ~lye&ter h~V~ ro~ 0 .1 ppm by weigh~ to lC% by weight ~f~ a t~ermally ~;~able near inf_ar~d ~uorophoric compoun;:~ co~ralentl~ boun~ ' o the p41y8st~r;
B . ~etween 3 0 anc~ 50 weiç~ht percent o~ ~t least one hur~ect~n~;
0 C. be~ween 5 and ~ 5 wei~ht percent o~ said ~t l east on e 13wer al iphat i c a lct~ho 1;
D. be~wee~ tt . ol ~nd O. S0 welgh~ pe-cen~ o~
lea~t one corrosion inhi}~i'cor;
~ ~ ~ett~reen ~ . ol and 0 . 3 0 welg~t percsnt o~ at le~t ~ne biocide;
F. wa' er, w~rein ~he percentages o' A thro~gh F
e~u~l ~ 00~
The i?olyestert3 o~ co~ponent A are prefer~bly sulf~pclye~er and or sull~opo~yes~oramides. The we~er--~ ~sipat~ble pol~ner , wi~ou~ the ne2r infrared ~ l~Lore~cent compo~nds incorporated therein, are deccr~bed ~n U.S. P~ten~ Nu;nber. 3,734,~74; 3,77~,gg3; -~,sa~ o; ~,5~6,00a; 4,233,1g~; and 4~435,Z20.
She ~re~erred near in~rared fluore~cent comp~,ds us~ul i~ .he pr~ctice of the ~nvention ar~ ~elected fro~ ~ne ~_~sses of phthalocyanin2s, naphthalocyani~e~
an~ ~gua~alr-e6 'derivati~e~ c~ sgu2~ic aci~) ~nd correspond to F:~rsQuIae II, III an~ :~V;

_ [p~] n ~Nc~
(X~~m ~X~R)~
(II) ~III~

,. .

A~JIENDED SHE'tT

W O 97/15634 PCT~US96/16635 1~ - CH ~ R2 .~ CH3 ~ CH3~ICH3~.=.
~ ~CH=-~ ~--CH=-~

IV
wherein Pc and Nc represent the phthalocyanine and naphthalocyanine moieties of Formulae IIa and IIIa, Phthalocyanine 2,3-Naphthalocyanine ~ ~ ~.
1l 1 1 1 N~ ~ = ~N N~

ll l l ll ll l l ll IIa IIIa respectively, covalently bonded to hydrogen or to various metals, halometals, organometallic groups, and oxymetals including AlCl, AlBr, AlF, AlOH, AlOR5, AlSR5, Fe, Ge(OR6)2, GaCl, GaBr, GaF, GaOR5, GaSR6, Pb, InCl, Mg Mn, SiC12, SiF2, SnC12, Sn(OR6)2, Si(OR6)2, ( 6)2 Si(SR6)2 and Zn, I L ~ ~CA 02234714 1998-04-1~

wherein k5 ~nCI R6 are ~el~cted ~rom hydrogen, a ~ ~:yl, aryl, aroyl, heteroaryl, lower alkanoyl, tri~luoroace~y}, groups Gf ~h~ ~ormulae ~7 ~R7 ~Z7 ~R7 7 ~R~
O --~ --R , --~OR8, --'l i--R~ i~R 8 ~ ~-~8 ' ~ 8 ~ 8 an~l R~ ~re indepen~en~ly seiecte~ Lrom a 1 ky~, phenyl or phenyl subs~itutsd wit~ lower al~cy~, low~
alkoxy or halo~en7 X i5 selecteci f~o~ GXy~en~ ~ul~ur, s~ler.ium, telluriu~
c~r a group c~ the for~.~ul~ N--R1Q~ Where1r, :R~O is hydroge~, cycloalXyl, alky~ ~cy , alkylsul~onyl, o~
~3 aryl o~ Rlo and R ta~en together ~orm an al~phatic ~r aron~atic -in~ w~-h the nitr~en ato~ to whic~ they cre a~tached;

Y is selected rom ~lkyl, aryl, ha I oqen or hydrogen;
r~ selac' c& frGm ~ns~ t2d ~r sub~ uted c-l,;yl, b alkenyl~ al~ynyl, ~5 ~7 - C3-~C8 cy~loalkyl, aryl, heteroaryl, alkylene ~ g ~r ~8 ~7 alkylene - Si-~oR~; or bRS
-~X-R~m is alkyl~ul~onyl8mino, aryl~ onyla~inr~, or a grcup sel~t~d ~ro~ the formulae -X~2H~O)~ , A~EN~Ei~ SHEET

-- ~0 ~7 ~7 ~7 ~7 --~n--R8 ~ ~Ra ~ R8 1 or --~i~R~, ~g ~R~3 ~9 tSR~3 wherein R is hy~rogen or R as def'ined 2~0~re; ~ i5 an integer o~ fra~ 1--4 i 15 c1r ~wo - ~x~ m groups can be taken together to ~or~
di~ralent substituents cJ f the ~or~ula l~A
,X

w~r~in eacr~ Xl is independer.tly select~d from ~}~ ~s--or --N--Rlo and A is seles;:ted ~ro~ ethylene; proFylene i .rimethy~ ene; a~d such grGups ~ubstit~ed with Cl--C4 alkyl, C;~C4 alko~y, aryl and cycloalXyl; 1, Z--phenylen~
an~l 1, 2 phenylene containing 1--3 su~stitue~ts se.lec_ed f~rom Cl--C~; ~lkyl, Cl--C4 alXoxy or halos~en;

Rl and ~2 ~re ~ndepend~n~ly se~ected from hyd2-ogE~n, l~wer alkyl~ lower 21koxy, halogen, aryloxy, lower alkylt~io" ~ry ~ , low~r ~lkylsuli~onyl, ~r~ls~lr~nyl;
l~we~ alkylsul~onylamino, arylsul~cnylamin~, ~_ycloalkyls~lf~onyla~ina, ca~boxy, unsubstitute~l zn~
cu~stitu~ed carbamoyl an~l ~ul~asn;:~yl, lower ;~lic~xycarbonyl, hydrox~J, lc~w~r a~i~anc~yloscy, ~7 ~R7 T7 f~7 ~& ~ Sr~OR8, ~ R8, or --~f i~?~3;
d~g ~g ~P~g :R3 and R4 are i ndependently se~ ec~f~d :~om hydroqen, ~o t ow~r alkyl, alkenyl or aryl; n is an ~nL eger from O--12;
nl i~ an integ~r ~rom 0--~4, ~n is an intege~ from ~l~aEN~ SHEET

CA 02234714 1998-04-1~

ml is an integer from 0-16, provided that the sums of n+m and n1+m1 are 16 and 24, respectively.
In a preferred embodiment of this aspect of the present invention m is from 4 to 12; ml is from 0-8;
provided that in the definitions of the substituents (Y)n, (Y)nl and (-X-R)ml that these substituents are not present when n, n1 and ml are zero, respectively.
Substituents (X-R)m and (Y)n are present in compounds IIa on the peripheral carbon atoms, i.e. in positions 1, 2, 3, 4, 8, 9, 10, 11, 15, 16, 17, 18, 22, 23, 24, 25 and substituents (X-R)m1 and (Y)n1 are present on the peripheral carbon atoms of III, i.e. in positions 1, 2, 3, 4, 5, 9, 10, 11, 12, 13, 14, 18, 19, 20, 21, 22, 23, 27, 28, 29, 30, 31, 32 and 36.
Preferably the near infrared fluorescing compound is covalently bonded to a moeity selected from the groups consisting of AlCl, AlBr, AlF, AlOH, AlOR5, AlSR5, Ge(OR6)2, GaCl, GaBr, GaF, GaOR5, GaSR6,, Mg, SiC12~ SiF2~ sncl2, Sn(OR6)2, Si(oR6)2, Sn(SR6)2, Si(SR6)2, and Zn.
Phthalocyanines and naphthalocyanines are the preferred near infrared fluorophores, particularly where stability to W light or sunlight is desirable.
In the above definitions, the term alkyl is used to designate a straight or branched chained hydrocarbon radical cont~;n;ng 1-12 carbons.
In the terms lower alkyl, lower alkoxy, lower alkyl-thio, lower alkoxycarbonyl, lower alkanoyl and lower alkanoyloxy the alkyl portion of the groups contains l-6 carbons and may be a straight or branched chain.
The term "cycloalkyl" is used to represent a cyclic aliphatic hydrocarbon radical containing 3-8 carbons, preferably 5 to 7 carbons.
The alkyl and lower alkyl portions of the previously defined groups may contain as further CA 02234714 1998-04-1~
W O 97/1~634 PCT~US96/16635 substituents one or more groups selected from hydroxy, halogen, carboxy, cyano, Cl-C4-alkoxy, aryl, C1-C4-alkylthio, arylthio, aryloxy, Cl-C4-alkoxycarbonyl or Cl-C4-alkanoyloxy.
The term "aryl" includes carbocyclic aromatic radicals containing 6-18 carbons, preferably phenyl and naphthyl, and such radicals substituted with one or more substituents selected from lower alkyl, lower alkoxy, halogen, lower alkylthio, N(lower alkyl)2, trifluro-methyl, carboxy, lower alkoxycarbonyl, hydroxy, lower alkanoylamino, lower alkylsulfonylamino, arylsulfonyl-amino, cycloalkylsulfonylamino, lower alkanoyloxy, cyano, phenyl, phenylthio and phenoxy.
The term "heteroaryl" is used to represent mono or bicyclic hetero aromatic radicals containing at least one "hetero" atom selected from oxygen, sulfur and nitrogen or a combination of these atoms. Examples of suitable heteroaryl groups include: thiazolyl, benzo-thiazolyl, pyrazolyl, pyrrolyl, thienyl, furyl, thia-diazolyl, oxadiazolyl, benzoxazolyl, benzimidazolyl, pyridyl, pyrimidinyl and triazolyl. These heteroaryl radicals may contain the same substituents listed above as possible substituents for the aryl radicals. The term triazolyl also includes structure V and mixed 25 isomers thereof, "N-N ~ 11 ~C ~ CH
(V) wherein R11 is hydrogen or selected from lower alkyl and lower alkyl substituted with one or two groups selected from hydroxy, halogen, carboxy, lower alkoxy, aryl, cyano, cycloalkyl, lower alkanoyloxy or lower alkoxy-carbonyl.

CA 02234714 1998-04-1~

W O 97/15634 PCTrUS96/16635 The terms "alkenyl and alkynyl" are used to denote aliphatic hydrocarbon moiety having 3--8carbons and contA; n; ng at least one carbon--carbon double bond and one carbon-carbon triple bond, respectively.
The term halogen is used to include bromine, chlorine, fluorine and iodine.
The term "substituted alkyl" is used to denote a straight or branched chain hydrocarbon radical contA;n;ng 1-12 carbon atoms and containing as substituents 1 or 2 groups selected from hydroxy, halogen, carboxy, cyano, Cl-C4 alkoxy, aryl, C1-C4 alkylthio, arylthio, aryloxy, C1-C4 alkoxycarbonyl, or Cl-C4 alkanoyloxy.
The term "substituted carbamoyl" is used to denote a radical having the formula -CONR12R13, wherein Rl2 and R13 are selected from unsubstituted or substituted alkyl, alkenyl, alkynyl, cycloalkyl, aryl, or heteroaryl.
The term "substituted sulfamoyl" is used to denote a radical having the formula -SO2NR12R13' wherein R12 an R13 are as defined above.
The term "alkylene" refers to a divalent Cl-C12 aliphatic hydrocarbon moiety, either straight or branched-chain, and either unsubstituted or substituted with one or more groups selected from lower alkoxy, halogen, aryl, or aryloxy.
The term "acyl" refers to a group of the formula R~C(O)-O-, wherein R~ is preferably a Cl-C10 alkyl moiety. The term "alkyl sulfonyl" refers to a group of the formula R~S02--,wherein R~ is as defined for acyl.
Preferred -X-R groups include those listed in Table I below.

Wo 97/15634 PCT~US96/16635 EXEMPI~RY -X-R Groups -X-R -X-R

-~CH3 ~S~

.~ ~.
-OC4Hg-n -S- '!~ !

-~C(CH3)3 -S-~ CH3 ~C12H25 n S

SC8H17 n -S-~ 3CH3 CA 022347l4 l998-04-l~

TABLE 1 (Continued) EXEMPLARY -X-R Groups _ -X-R
--OCH2CH(C2H5)C4H9-n -S-.~ ~.-CO2CH3 -OCH2CH=CH2 ~ - ~ 3 -OCH2CH=CH-CH3 ~ _ ~ 3 -SCH2C6H5 -Se-~~

-SCH2CH(OH)CH2OH OCH2C6H4 4 COOH

-OCH2CeCH -OC H -4-CH2COOH

N( 2 5)2 -ocH2cH2co2cH3 -NHC6H5 -ocH2cH2ococH3 N( H3) 6 5 6 5 -N(C2H4OH)2 ~C6H4 4 Cl ,_, NHC6Hll ,~ ~.
~ _.

W O 97/15634 PCT~US96/16635 T ~ LE 1 (Continued) EXE ~ ~ RY -X-R Groups -X-R -X-R
-O

~ ~ . .
-N ~ ~ ~
~ ~ .=.
. _ . . .

-OC H -O(CH CH O) H

-OC H -4-COOH -S(CH CH O) H

-SC H -4-COOH -O(CH CH O) H

-OC H -3,5-diCOOH-O(CH CH O) CH

--OCH --3,5--diCOCH--O(CHCH O) C H

-SC H -2-COOH -NH(CH CH O) H

CA 02234714 1998-04-1~
W O 97/15634 PCT~US96/16635 TABLE 1 (Continued) EXEMPLARY -X-R Groups -X-R -X-R
s -oC H -4-C H OH

-oC H -4-OC H OH

In the compounds above, it should be recognized that the structures must bear at least one polyester reactive group to allow the compound to be incorporated into the polymeric composition and to be bound by covalent bonds.
The water-dissipatable polymers, without the near infrared fluorescent compounds incorporated therein, are described in U.S. Patents 3,734,874; 3,779,993;
3,828,010; 3,546,008; 4,233,196; and 4,335,220, incorporated herein by reference.
The polymers of the present invention are, for the most part, water-dispersible because they form electrostatically-stabilized colloids when mixed with water. The colloid particle size varies with the polymer composition but has been shown by light diffraction studies and transmission electron microscopy (on fresh films) to be mostly 200-800 ~ in diameter.
The aqueous colloid dispersions exhibit a minimum precipitation of solid material with time, in the temperature range of 0.1-99.9~C because the relationship between the particle densities and viscosities (very similar to those of water when concentrations are less than 30 weight percent) are such that thermal energy ; r ~ l ~~ ~ 'CA 022347i4 1998-04-15 erpres~ed a~ Bro~nia~. mo~ion is sufficient to keep t~Le particles ~;uspende,d in water.
T~e water~ispersible ~polyesters have ~n inhere~nt vi5c05ity o~ at leas~ 0.1 dI~fg, prefer~bly 0.2~~--0.38 dL~g~ when de'~ermin~c~ at 25~~ using 0.2~ g polymer per lO0 n~l o~ a solvent con~ist:ing of 6C parts by welght phenol and 40 parts }:~y Weight ~etrachlor~
eth~ ~e .
The 3ulfonat~containin~, w~ter~i~persi~le, line~r lC po'ymer~ thus c~pr~e pc~lyes' ers, includiQ~ p~lyes~er--am~ de~, cons ~ sting Gf rcpeati:~, alter~atin~ res ~ dues o~
( 1) one or ~ore dicar~oxylic ~clds ~nd ~2; or,e o~ ~nore diols or a com~3in~?tl0n o~ Ol ~ or ~nore c~iols ~nd on~ ar m~re ~iarr.ines w~e~e, in ~he preceding ;lefln~ n, the mol~ percentaes are bas~d on 100 mole percan~
di~ar~ox~lic acid residue~; anc~ 100 mole perce~t diol or diol ar.d c3.iamine residue~. P~lternati~ly, ~he polyme_s m~Ly include re:sidue~ r.omt~r~3 ha~rin~3 mixeâ
f~-lcl ional ity ~uch aB hy~Lroxycarboxylic aci~
arainocarb_xylLc ~cids and--or aminoa}~ca~ols. ~he nea--infrared f louropho~ic ~ compoun~ls c~n thus ;~
in~,_rpo_ated into -~e poly~si er, so lcmg as the ~ has one f ~r prefex~ two , polyester reac _ive group6 ~ ~ . g .;
hyd=oxy, car~oxy, ~tc. ) prese~st. When t:ow polye~r er 2, ~eaoti~e gr~ups ~re prer2ent the near in~ra~ed ~luorophorLr- co~pounds may be co~p~lym~r~ ~ed intc t;~e pG lye~ter.
The residu~-s ~ c~mponent (i) may be de~ived ~om one or ~ore dic~rboxylic acids or their e~ter-~o ~ ing deri~a~ives ~uch aC dialkyl e~ers~ Pis(hydrox~ralkyl~
e~t~r~, ~i~ c~ori~es or, in 30~ ca~eQ~ a ~ ydrides.
The sulf~t~ group a~ camponent (ii) may b~ an al~ali mstal sul~onic galt ~uch ~ lithium, po~a~sium or, preferably, sodiu~ sulfonat~ groups, or an a~unoniu~ ~r su~stitu~ed a~unonium sulfoni~te.

DED SHEET

v~ CA 02234714 1998-04-15 - 18~ -T~e prefer~d water_~ sper~ible pc~lymers have an inherent ~iscosity ~f 0. ~8 to o . 3~ d~ and are co~nprised of: i7 ~A/IENDED SHEET

CA 02234714 1998-04-1~

W O 97/15634 PCT~US96/16635 (i) diacid monomer residues comprising 75 to 84 mole ~ percent isophthalic acid monomer residues and 16 to 25 mole percent 5-sodiosulfoisophthalic acid monomer residues; and (ii) diol monomer residues comprising 45 to 60 mole percent diethylene glycol monomer residues and 40 to 55 mole percent ethylene glycol, 1,4-cyclohexanedimethanol monomer residues or mixtures thereof.
Specific embodiments of these water-dispersible polymers are available from Eastman Chemical Company, in the form of pellets (EASTMAN AQ 29S Polymer, EASTMAN 38S
Polymer and EASTMAN 55S Polymer) and in the form of aqueous dispersions (EASTMAN AQ 29D Polymer, EASTMAN 38D
Polymer and EASTMAN 55D Polymer). These polyesters have been shown to disperse in water due to the presence of 5-sodiosulfoisophthalic acid residues.
Preferably, the water dispersible polyester above contains some poly(ethylene glycol) to aid in its water dispersibility. When some poly(ethylene glycol) is used, the content of the sulfomonomer can be lower, which aids in flexibility of formulating the polyester.
The water dispersibility of the polyester is related to the weight percent of poly(ethylene glycol) and mole percent of sulfomonomer. Therefore, if the content of either is relatively low, the other should be relatively high to maintain adequate dispersibility.
The poly(ethylene glycol) need not be present in the initial reaction charge, because poly(ethylene glycol) may form in situ from decomposition products and be incorporated into the polyester chain. It is well known, for example, that diethylene glycol is formed in situ in such reactions.
In the preferred form of the present invention, the polyester contains repeating units of a poly(ethylene CA 02234714 1998-04-1~

glycol) of the formula H--(OCH2--CH2) n-- OH wherein n is an integer of 2 to 500. The value of n is preferably from between 2 to 20. The values of n and the mole percent of poly(ethylene glycol) in the polyester, if used, are adjusted such that the mole percent of poly(ethylene glycol) within the stated range is inversely proportional to the quantity of n within the stated ranges. Thus, when the mole percent is high, the value of n is low. On the other hand, if the mole percent is low, the value of n is high. It is apparent, therefore, that the weight percent (product of mole percent and molecular weight) of the poly(ethylene glycol) is an important consideration because the water dissipatability of the copolyester decreases as the weight percent poly(ethylene glycol) in the copolyester decreases. For example, if the weight of poly~ethylene glycol) is too low, the water dissipatability of the copolyester may be inadequate. Furthermore, the weight percent of poly(ethylene glycol) is preferably adjusted such that it is inversely proportional to the mole percent of the difunctional sulfomonomer because the water dissipatability of the copolyester is a function of both the mole percent sulfomonomer and the weight percent polyethylene glycol.
Examples of suitable poly(ethylene glycols) include relatively high molecular weight polyethylene glycols, some of which are available commercially under the designation CARBOWAX, a product of Union Carbide.
Diethylene glycol is also especially suitable.
Other useful glycols for preparing copolyesters include aliphatic, alicyclic and arylalkyl glycols.
Examples of these glycols include ethylene glycol;
propylene glycol; 1,3-propanediol; 2,4-dimethyl-2-ethylhexane-1,3-diol; 2,2-dimethyl-1,3-propanediol; 2-ethyl-2-butyl-1,3-propanediol; 2-ethyl-2-isobutyl-1,3-CA 02234714 1998-04-1~

W O 97/15634 PCT~US96/16635 propanediol; 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2,4-trimethyl-1,6-hexanediol; thiodiethanol. 1,2-cyclohexanedimethanol, 1,3-cyclohexandimethanol; 1,4-cyclohexanedimethanol;
2,2,4,4-tetramethyl-1,3-cyclobutanediol; and p-xylylenediol.
The dicarboxylic acid component of the polyesters are preferably selected from aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic dicarboxylic acids, or mixtures of two or more of these acids. Examples of such dicarboxylic acids, include succinic; glutaric; adipic; azelaic; sebacic; 1,4-cyclohexanedicarboxylic; phthalic; terephthalic and isophthalic acid. Terephthalic acid and isophthalic acid are preferred as the carboxylic acid component of the polyester.
It should be understood that use of the corresponding acid anhydrides, esters, and acid chlorides of these acids is included in the term "dicarboxylic acid."
The difunctional sulfomonomer component of the polyester may advantageously be a dicarboxylic acid or an ester thereof containing a metal sulfonate group, a glycol containing a metal sulfonate group or a hydroxy acid containing a metal sulfonate group. The metal ion of the sulfonate salt may be Na+, Li+, K+ and the like.
When a monovalent alkali metal ion is used, the resulting polyesters are less readily dissipated by cold water and more readily dissipated by hot water. When a divalent or a trivalent metal ion is used the resulting polyesters are not ordinarily easily dissipated by cold water but are more readily dissipated in hot water. It is possible to prepare the polyester using, for example, a sodium sulfonate salt and latex and by ion-exchange replace this ion with a different ion, and thus alter CA 02234714 1998-04-1~

the characteristics of the polymer. The difunctional monomer component may also be referred ~o the difunctional sulfomonomer and is further described herein below.
Advantageous difunctional sulfomonomer components are those wherein the sulfonate salt group is attached to an aromatic acid nucleus such as benzene, naphthalene, diphenyl, oxydiphenyl, sulfonyldiphenyl or methylenediphenyl nucleus. Preferred results are obtained through the use of sulfophthalic acid, sulfoterephthalic acid, sulfoisophthalic acid, 4--sulfonaphthalene--2,7--dicarboxylic acid, and their esters.
Particularly superior results are achieved when the difunctional sulfomonomer component is 5-sodiosulfo-isophthalic acid or its esters, and the glycol is a mixture of ethylene glycol or l,4-cyclohexanedimethanol with diethylene glycol.
Component B is a humectant or binder and includes any is water soluble and has a viscosity sufficient to provide to the ink the desired properties for the printer and substrate. Examples of suitable humectants and binders include ethylene glycol, propylene glycol, butanediol, glycerol, polyethylene glycols of the formula H--(OCH2--CH2)n--OHhaving a Mn of between 200 and 10,000; poly(ethylene glycol) methyl ethers having an Mn of 250 to 5,000; polyvinyl alcohols, polyvinylpyridines, and polyvinylpyrrolidones and mixtures thereof.
Preferably said humectant is selected from ethylene glycol, propylene glycol, butanediol, glycerol, polyethylene glycols of the formula H--(OCH2--CH2) n--OH
wherein n is 2 to 6 and mixtures thereof.
The term lower aliphatic alcohol is used to include methanol, ethanol, n-propanol, isopropanol, ethylene glycol mono Cl-C2 alkyl ethers and mixtures of these.

W O 97/lS634 PCTrUS96/1663 Various additives may also be added. Suitable additives include surfactants, surface active agents, defoaming agents, corrosion inhibitors and biocides.
Preferred surface active agents or surfactants are the nonionic types containing polyalkylene oxide moieties. A particularly preferred type of nonionic surfactant is obtained by ethoxylating acetylenic diols, such as ethoxylated tetramethyl decynediol (Surfynol 465, provided by Air Products and Chemicals, Inc., Allentown, PA 18195).
The activity of the surfactant may be controlled by addition of a defoaming agent or defoamer. A preferred defoamer is comprised of a mixture of tetramethyldecynediol and propylene glycol (Surfynol 104 PG, provided by Air Products and Chemicals, Inc., Allentown, PA 18195).
The term biocide is used to describe various antifungal compounds used to prevent or control the growth of various fungi upon prolonged standing of the ink compositions. A preferred biocide is 1,2-benzisothiazolin-3-one (Proxel~ GXL, ICI Americas Inc., Wilmington, Delaware 19897).
Corrosion inhibitors are added to the ink formulations to inhibit or reduce corrosion of the metal parts, particularly the nozzles~orifices, of the ink jet printers. A preferred class of corrosion inhibitors are the lH-benzotriazoles and lH-benzotriazole itself is the preferred corrosion inhibitor (Cobratec 99, PMC
Specialties, Cincinatti, OH).
This invention provides aqueous ink formulations for ink jet printing of invisible, intelligible near infrared fluorescent markings which overcome the deficiencies of the prior inks. The inks of the present invention are especially useful for printing invisible markings such as bar codes on various porous or semi-CA 02234714 1998-04-1~

porous substrates, such as paper or paper products, where subsequent detection or identification are desired. The invisible markings may be on a white or colored background.
The inks and markings generated therefrom have the valuable property of being fluorescent when exposed to infrared radiation. The emitted light is detected by a near infrared radiation detector, thus allowing the invisible "marking" or "tagging" of items to which the film forming polymeric composition has been applied.
Based on the prior art, it is surprising that sulfopolyesters~amides containing copolymerized near infrared fluorophores can be used to formulate suitable inks for ink jet printing which have good stability and which can be used for marking or tagging various substrates for identification~authentication purposes.
This result was particularly surprising because monomeric near infrared fluorophores formulated into solvent based inks lost much of the absorption at the desired wavelength because of apparent aggregation which shifts the wavelength of maximum absorption of the aggregated dye signi~icantly to lower values. The aggregated dye has greatly reduced luminescence properties.
The following examples illustrate further the practice of the invention. The inherent viscosities specified herein are determined at 25~C, using 0.5 g of polymer per 100 mL of a solvent consisting of 60 weight percent phenol and 40 weight percent tetrachloroethane.
The weight average molecular weight (Mw) and num~er average molecular weight (Mn) values referred to herein are determined by gel permeation chromatography (gpc).

CA 0 2 2 3 4 i l 4 1 9 9 8 - 0 4 - 1 5 r l 1 ~ ~ J ' ~ J~ f L

~xam~l~
~ ompo~ents I-VII w~r~ ~ded to ~ 500 mL roun~
botto~ flask which wa~ ~itte~ with a v~cu~m ~utlet, s~irre~, ccndsnsate takeo~ and nitrogen inlet.
I B1.77 ~ ~0.421 m~ dimethyl ~sophthalate II z4.~ 0.0~37 ~ di~Qthyl 5-sodios~l~oiso~h~alate ~IT 44.1t g ~0.415 m) diethylene glycol IV 34.07 q ~0.236 m) 1,4-cyclohexaned~methanol ~ O.75 g ~.0088 m) anhydrous sodi~m acstate VI -0~ ppm ~i catalyst as titanium isopropoxide VII 0.28 q ~3.6 x lo 4~) in~rare~ ~luoreco2nt compaund - NcSi~OH)2 ~Whee'er, et al.~
. J.A.C.S. Vol. ~0~, ~. 24, 1984, pp 7~4 74103 (Nc = naphthalocyanine) . The ~lask ~d c~nten.~ wer~ _m~ers~d in a Bel~o~
metal b~th at 2 0~~C ~nd s~irred for 1~0 hour wlth a nitrogen sweep cve~ the reaction mixture. T~e bath temp~rature was in~~eased to 22Q~C o~er 5 ~inutes and ~eld at z2~oc f~r 2.0 hours~ ~o co~pl2~e the p~lyc~den~a~ior, the temp~at~ sf the rea~ti~n ~i~1re w~s inor~ase. to 2s~oc, vacuum was zpplied to ~ower ~e ~ressure ~o 6~.~5 ~f~2 ~0.5 mm '~g', and h~ati~ at ~5~C continued fGr 20 ~inut~s~ The re~ulti~g pQlymer, which wa~ ground ~sing a Wi~ey ~ill ~o pa~ through ~ 2 ~m s~re~n, has an inherent Y~isco~i~y ~I .V. ~ ~C n.27S, z weight average ~Mw~ molecuiar weight of 14 t ~7, a number ~vexag~ ~Mn) ~olecular we~ght of ~,8~8, ~ polyd~persi~y (MwfMn) of 3.86, a gla~
30 ~ransitioh t~mperature ~Tg~ o~ 4~4~C and contain~ abo~t ~2 weigh~ per~nt ~2~0~ ppm) o~ the near infrared flucrop~ore (NIR~, ~xam~
~ port~ion (loO g) o~ the water dis~ipatable sulfo -35 c~nlaining pol~ester of Exa~.ple 1 was ~dded portionw~se hi'i~ kD SHEET

CA 02234714 1998-04-1~
W O 97/15634 PCT~US96/16635 to distilled water (250 mL) at 95~C with stirring. The mixture was stirred until dispersion of the polymer was completed and then cooled. Total weight of the aqueous dispersion which contained about 29% by weight of the water--dissipatable sulfo--containing polyester having about 2,000 ppm of NIRF reacted therein was 343 g.

rn~le 3 Near infrared fluorophore PcAl~ C6H3--3,5--diC02CH3 (0.7 g, 9. 36 X 10--4m) (Example 29 of U.S. Patent 5,397,819) was combined with components I--VI of Example 1 above and reacted to produce the condensation polymer exactly as described in Example 1. ~he water-dissipatable sulfo--cont~; ning polyester thus produced contained about O .596 by weight (5,000 ppm) of the NIRF
compound copolymerized therein and was ground in a Wiley mill to pass through a 2 mm screen. The polymer has an I.V. of 0.293, a Tg of 52.6~C, a Mw of 16,244, a Mn of 4,510 and a polydispersity of 3. 60.

~mple 4 A portion (100 g) of the polymer of Example 3 was added portionwise to distilled water (250 mL) at 95--100~C with stirring. The mixture was stirred until dispersion was completed and then cooled. Total weight of the aqueous dispersion which contained about 30% by weight of the water-dissipatable sulfo-containing polyester having about 5,000 ppm of NIRF reacted therein was 337.5 g, Example 5 Example 1 was repeated using 0.14 g (1.8 X 10 4m) of the same infrared fluorescent compound - NcSi(OH)2 -to give a polymer which contained about 0.1 weight percent (1,000 ppm) of the near infrared fluorophore.

CA 02234714 1998-04-1~

W O 97/15634 PCT~US96/16635 The polymer has an I.V. of 0.268, a Tg of 49.2~C, a Mw of 15,092, a Mn of 6,582, and a polydispersity of 2.29.

- ~Am~le 6 A portion (110 g) of the polymer of Example 5 was added portionwise to distilled water (275 mL) at 95-100~C with stirring. The mixture was stirred until dispersion was completed and then cooled. Total weight of the aqueous dispersion which contained about 30% by weight of the water-dissipatable sulfo-containing polyester having about 1,000 ppm of NIRF reacted therein was 365.5 g.

~~le 7 Example 1 was repeated using 0.7 g (9.0 X 10-4m) of the same infrared fluorescent compound -NcSi(OH)2 - to give a polymer which contained about 0.5 weight percent (5,000 ppm) of the near infrared fluorophore. The polymer has an I.V. of 0.288, a Tg of 51.0~C, a Mw of 16,372, a Mn of 4,643, and a polydispersity of 3.52.

~nle 8 A portion (100 g) of the polymer of Example 7 was added portionwise to distilled water (250 mL) at 90-95~C
with stirring. The mixture was stirred until dispersion was completed and then cooled. Total weight of the aqueous dispersion which contained about 30% by weight of the water-dissipatable sulfo-cont~;ning polyester having about 5,000 ppm of NIRF reacted therein was 334.6 g.

le 9 Components I-VII were added to a 500 mL round bottom flask which was fitted with a vacuum outlet stirrer, condensate takeoff and nitrogen inlet.

CA 02234714 1998-04-1~
W O 97/15634 PCT~US96/16635 I 116.78 g (0.602 m) dimethyl isophthalate II 35.40 g (0.120 m) dimethyl 5-sodiosulfoisophthalate III 63.07 g (0.595 m) diethylene glycol IV 48.68 g (0.338 m) 1,4-cyclohexanedimethanol) V 0.98 g (0.120 m) anhydrous sodium acetate VI 75 ppm Ti catalyst as titanium isopropoxide VII 0.40 g (5.3 X 10-4m) infrared fluorescent compound - PcAl-OC6H3-3,5-di-C02CH3 (Pc =
phthalocyanine)[Compound of Example 29 of U.S. Patent 5,397,819]
The flask and contents were immersed in a Belmont metal bath at 200~C and stirred for 1.0 hour with a nitrogen sweep over the reaction mixture. The bath 15 temperature was increased to 220~C over 5 minutes and held at 220~C for 2.0 hours. The polycondensation was completed by increasing the bath temperature to about 2 50~, applying vacuum snd reducing the pressure to 0.1 mm Hg and heating for 15 minutes. The resulting 20 polymer, which was ground using a Wiley mill to pass through a 2 mm screen, has an I.V. of 0.271, a weight average (Mw) molecular weight of 14,458, a number average (Mn) molecular weight of 7,162, a polydispersity of 2.0, a glass transition temperature (Tg) of 48.8~C, 25 and contains about 0.2 weight percent (2,000 ppm) of the near infrared fluorophore.

~mnle 10 A portion (150 g) of the water-dissipatable sulfo-30 containing polyester of Example 9 was added to distilled water (375 mL) or 95-100~C with stirring until dispersion of the polymer was completed and then the mixture was cooled. The total weight of the aqueous dispersion which contained about 29% by weight of the CA 02234714 1998-04-1~
W O 97/15634 PCT~US96/16635 water-dissipatable sulfo-cont~;ning polyester having about 2,000 ppm of NIRF reacted therein was 514.7 g.

- ~x~m~le 11 A mixture of 2(3), 11(12), 20(21), 29(30)-tetra-t-butylNcAlCl (5.0 g, 0.005 m) (Product of Example 34 of U.S. Patent 5,397,819), dimethyl 5-hydroxyisophthalate (1.05 g, 0.005 m) (Aldrich) and pyridine (200 mL) was heated and stirred at reflux for a total of 55 hours.
After cooling the reaction mixture was drowned into water (500 mL). The product, 2(3), 11(12), 20(21), 29(30)-tetra-t-butyl-NcAl-OC6H3-3,5-diCO2CH3, was collected by filtration, washed with water and air dried (yield - 4.9 g).
~m~le 12 Components I-VI of Example 9 were combined with the near infrared fluorophore of Example 11 above (0.4 g, 3.4 X 10-4m) and the polymerization reaction carried out exactly as described as in Example 9. The water-dissipatable sulfo-polyester thus prepared contains about 2,000 ppm of the NIRF compound and has an I.V. of 0.27, a Tg of 49.9~C, a weight average molecular weight (Mw) of 13,986, a number average molecular weight (Mn) of 4,088 and a polydispersity of 3.42.

Exam~le 13 A portion (150 g) of the polymer of Example 12 was added portionwise with stirring to distilled water (375 mL) at 95-lOO~C. Stirring was continued until dispersion of polymer was completed and then the mixture was allowed to cool. Total weight of the aqueous dispersion which contained about 29.6% by weight of polymer was 507.5 g.

CA 02234714 1998-04-1~
W O 97/15634 PCT~US96/16635 ~nle 17 Preparation of 780 nm NIRF Ink for Continuous Ink ~et Printing Components I-VII were combined to produce a NIRF
ink containing about 120 ppm of the near infrared fluorophore by mixing in a Cowles dissolver for 25 minutes using moderate shear.

Component Parts I 8.00 parts aqueous solution from Example 16 which contained 29.0% by weight of sulfopolyester containing 5,000 ppm NcSi(OH)2 residue II 6.80 parts propylene glycol III 84. 30 parts deionized water IV 0.50 parts Surfynol 465 surfactant (an ethoxylated tetramethyl decynediol surfactant (Air Products and Chemicals, Inc.) V 0.25 parts Surfynol 104 PG defoaming agent (a mixture of tetramethyl decynediol and propylene glycol (Air Products and Chemicals, Inc.) VI 0.10 parts Proxel~ GXL (30 wt % in water) biocide (ICI Americas, Inc.) VII 0.05 parts corrosion inhibitor t50% by weight solution of lH-benzotriazole (PMC
Specialties) in propylene glycol]
100.00 parts The composition thus produced was vacuum filtered in series through a depth filter (extra thick glass fiber filter), Versapor 3000 (3~), Versapor 1200 (1.2~), and Versapor 800 (0.8~) from Gelman Sciences. The ink thus produced had a viscosity of 1.0 centipoise, a pH of CA 02234714 1998-04-1~

Example 14 Components I-VI of Example 9 above were combined with the near infrared fluorophore 2(3), 9tlO), 16(17), 23(24)-tetraphenoxy-Pc-Si(OC6H4-4-CO2CH3)2 (0.4 g, 3.3 X
10-4m) (Example 24 of U.S. Patent 5,397,819) and the polymerization reaction carried out exactly as described in Example 9. The water-dissipatable sulfo-polyester thus prepared contains about 0.2~ by weight (2,000 ppm) of the NIRF compound and has an I.V. of O.24, a Tg of 49.5~C, a weight average molecular weight (Mw) of 13,591, a number average molecular weight (Mn) of 4,391 and a polydispersity of 3.1.

Exam~le 15 A portion (150 g) of the polymer of Example 14 was added portionwise with stirring to distilled water (375 mL) at 95-100~C. Stirring was continued until dispersion of polymer was completed and then the mixture was cooled. Total weight of the aqueous dispersion which contained about 29.7% by weight of the polymer was 505 g.

~ample 16 One hundred and fifty grams of water-dissipatable sulfo-containing polyester, which contained about 5,000 ppm of near infrared fluorophore NcSi(OH)2 reacted therein, were prepared exactly as described in Example 7 above and added portionwise to distilled water (375 mL) at 95-100~C with stirring. The mixture was stirred until dispersion of the polymer was completed and then allowed to cool. Total weight of the aqueous dispersion which contained about 30% by weight of the polymer was 512.8 g.

W O 97/15634 PCT~US96/1663 6.72, a conductivity of 437 micro mhos, an average particle size of 0.018 micron (~), a surface tension of 30.53 dynes~cm. Using the Scitex 5100 ink jet printer (Scitex Digital Printing, Inc., Dayton, OH 45420--4099), invisible code 39 barcodes were printed on plain white paper at high speed.

Exam~le 18 Lower Viscosity Ink 10An ink having a surface tension of 27.88 dynes~cm and a conductivity of 517 micro mhos was prepared exactly as described in Example 17 except using 6.00 parts Component II, 84.35 parts Component III, 1.00 part Component IV and o. 50 part Component V and was used 15successfully to print invisible bar codes as described in Example 17.

Example 19 Preparation of 680 nm NIRF Ink for Ink Jet Continuous Printing Components I-VII were combined to produce a NIRF
ink containing about 120 ppm of the near infrared fluorophore by mixing in a Cowles dissolver~blender for 22 minutes using moderate shear and then filtered as described in Example 17.

Component Parts I 20.0 parts aqueous solution from Example 10 which contained 29.0% by weight of sulfopolymer containing 2,000 ppm PcAlOC6H3--3,5--diC02CH3 residue II 6.00 parts propylene glycol III 73.10 parts deionized water IV 0.50 partS Surfynol 465 V 0.25 partS Surfynol 104 PG

CA 022347l4 l998-04-l~
W O 97/15634 PCT~US96/16635 VI 0.10 parts Proxel~!9 GXL (30% in water) VII 0.05 parts corrosion inhibitor [50% by weight solution of lH-benzotriazole in propylene glycol]
100.00 parts The ink thus prepared had a viscosity of 1.01 cps, a surface tension of 32.97 dynes~cm, a conductivity of 513 micro mhos, an average particle size of 0. 015~*, a pH
10 of 6.90 and an absorption -X;~l (~max) at 679 nm in the visible~near infrared light absorption spectrum as determined using an ACS Sensor II Spectrophotometer (Applied Color Systems). Bar codes were successfully printed on plain white paper as described in Example 17.

~;~mnle 20 An ink similar to that of Example 19, but having a surface tension of 27.68 dynes~cm and a conductivity of 502 micro mhos was prepared as in Example 19 except 20 using 8.00 parts of aqueous solution from Example 4 which contained 30% of sulfopolyester containing 5,000 ppm PcAlOC6H3--3,5--diCO2CH3 for Component I, 84.35 parts Component III, 1.00 part Component IV, and 0. 50 part Component V. Successful printing of bar codes on plain 25 white paper was carried out as in Example 17.

Examt~le 21 An ink was prepared exactly as described in Example 19 except 20.00 parts of aqueous solution from Example 30 13, which contained 29. 6% by weight of sulfopolyester containing 2,000 ppm of NIRF compound [2(3), 11(12), 20(21), 20(21), 29(30)-- tetra--t--butyl--NcAl~ C6H3--3,5--diC02CH3] was used for Component I.

CA 02234714 1998-04-1~

Examt~le 22 An ink was prepared exactly as described in Example 19 except 20.0 parts of aqueous solution from Example 15, which contained 29.7% by weight of sulfopolyester continaing 2,000 ppm of NIRF compound [2 (3), 9(1O), 16(17), 23(24)-- tetraphenoxy-- PcSi (OC6H4--4--CO2CH3)2] was used for Component I.

Exam~le 2 3 Preparation of 780 nm NIRF Ink for Single Nozzle Continuous Ink Jet Printing Components I-VI were combined to produce a NIRF ink containing about 120 ppm of the near infrared fluorophore by mixing in a Cowles dissolver~blender for 25 minutes using moderate shear and then vacuum filtered in series through a depth filter (extra thick glass fiber filter), Versapor 3000 (3~), Versapor 1200 (1.2~u) from Gelman Sciences).

20 Component Parts I 8.00 parts aqueous solution from Example 16 which contained 29.0% by weight of sulfopolyester containing 5,000 ppm NcSi(OH)2 residue II 41.00 parts propylene glycol III 41.90 parts deionized water IV 9.00 parts n-propyl alcohol V 0.05 part Proxel~ GXL (30% in water) biocide VI 0.05 parts corrosion inhibitor (50~
solution of lH-benzotriazole in propylene glycol) 100.00 parts CA 022347l4 l998-04-l~
W O 97/15634 PCT~US96/16635 The ink thus produced had a viscosity of 5.0 cps, a surface tension of 34.5 dynes~cm a conductivity of 123 micro mhos and was used successfully to print on plain white paper using a Domino Codebox 2 Printer (Domino Amjet, Inc., Gurnee, IL 60031) to provide invisible markings.

Exam~le 24 Preparation of Drop-On-Demand Bubble Jet Ink (670 nm) Components I-VI were mixed using a Cowles dissolver~blender for 25 minutes with moderate shear to provide a NIRF ink containing about 120 ppm of the near infrared fluorophore.

Component Parts 8.00 parts aqueous solution from Example 4 which contained 30.0% by weight of sulfopolyester containing 5,000 ppm PcAl--~ C6H3--3~5--diC02CH3 residue II 45.00 parts propylene glycol III 45. 85 parts deionized water IV 1.00 part Surfynol 465 V 0.10 parts Proxel~!9 GXL (30% in water) VI 0.05 parts corrosion inhibitor (50%
solution of lH-benzotriazole in propylene glycol) 100.00 parts The ink composition thus prepared had a viscosity of 5.0 cps and was successfully used to print bar codes (Code 39) on plain white paper using a drop--on--demand, bubble jet printer Kodak Diconix 180Si Printer (Eastman Kodak C~~ -ny, Rochester, New York 4650) to produce invisible markings.

CA 022347l4 l998-04-l~
W 097/15634 PCT~US96/16635 ~mnle 25 Preparation of Drop--On--Demand Bubble Jet Ink (780 nm) An ink was prepared and used for printing invisible bar codes exactly as described in Example 24, except Component I was 8.00 parts of aqueous solution from Example 8 which contained 30.096 by weight of sulfopolyester containing 5,000 NcSi(OH)2. The ink had a viscosity of 4. 5 cps.

~s~mnle 26 Preparation of Drop-On-Demand Piezoelectric Impulse Jet Ink Components I-V were combined to produce a NIRF ink containing about 180 ppm of the near infrared fluorophore by mixing at medium shear for 10 minutes and then filtering by gravity.

Component Parts I 30.0 parts aqueous solution from Example 2 which contained 29.0% by weight of sulfopolyester containing 2,000 ppm NcSi(OH) 2 residue II 65.00 parts propylene glycol III 4. 85 parts n--propanol IV 0.10 parts Proxel~l9 GXL (30% in water) V 0.05 parts corrosion inhibitor (50%
solution of lH-benzotriazole in propylene glycol) 100.00 parts The ink thus produced had a viscosity of 19.5 cps, a surface tension of 36.63 dynes~cm and was useful for jet CA 022347l4 l998-04-l~
W O 97/15634 PCT~US96/16635 printing invisible markings using the drop-on-demand piezoelectric impulse method.

Example 27 Preparation of Drop--On--Demand Piezoelectric Impulse Jet Ink Components I-VII were combined to produce a NIRF
ink containing about 180 ppm of the near infrared fluorophore by mixing at medium shear for 10 minutes and then filtering by gravity.

Component Parts 30.0 parts aqueous solution from Example 2 which contained 29.0% by weight of sulfopolyester containing 2,000 ppm NiSi(OH)2 residue II 50.00 parts propylene glycol III 10.00 parts glycerine IV 4.85 parts deionized water V 5.00 parts n-propanol VI 0.10 parts Proxel~ GXL (30 wt % in water) VII 0.05 parts corrosion inhibitor [50%
solution of lH-benzotriazole in propylene glycol~
100.00 parts The ink thus produced had a viscosity of 18.0 cps, a surface tension of 37.04 dynes~cm and was useful for printing invisible marking using the drop-on-demand piezoelectric impulse ink jet method.
The viscosities reported in above examples were measured in centipose(s) units, cp (cps) using a Shell Cup #2 Viscometer (Morcross Corporation, 255 Newtonville Ave., Newton, MA 02158). The surface tension values were measured in dynes~cm using a Surface Force Analyzer -~A 02i34il4 lsss-04-l5 o SFA--211 ~Ca~n Instrument, Inc., 16Z~7 ~o~lth Car~enita Rd., Cerritu6, CA gO701~. ~he ~Yer~g~ par~ le &i~es were mea~ure~ ~n ~ ro~5 (~ a ~icrctrac--U~ fine ~artict e Analyzer Model ~230~ 00~ ad? ~nd ~lorthrup 5 Co. Sunneytown Pi~, North t~a}es, PA 1~454 and the conductanc.~ was m~a?3ured in micro ~hos using a YSI Mo~el 3 2 Con~uct~nce Meter ~Yell~w~Sprin~ Inc~umen~ Co ., In~., Scient~ f~c Division, Yellow ~prings, O~ 45387).

~les ~ an~ ~c~nparat~ Y~ ExamPles The ink compcsltions listed in T~ble 2 kelow were made via the proc~dure o~ ~x2Lm~1~ 24 havir.g 2S, ~ 0~ anc~
20~c by we~ht ~R~ c~ontainlnq polymex.
Ta~le C~mpon~nt ' ~ Pol ~ ~r Exam ?~e # 28 2 Comp 1 Co~p 2 prcp"lene 42.60 32.5Q 15.00 1~50 ~lycol NIR~ .70 ;3.40 5G.OO 66.7 Sur yno.... 465 _.0~ -.00 ~.30 l,OO
DL wate: ~9. 5 .2.95 33.~5 30.&5 Co~r~sion Q.O 0.05 O. a5 o. 05 Inhibitor G t 50%) Proxel GX1 O.~O O.lO O.1 C.lG
~30~) Tctal 1GO.OO 100.C;O 1~0.0~ 100.00 Vi~co~ity ~2 14.5 15~5 l5.O l~.O
shell cup in sQc~onds ~
o~ty 4.7 5.5 5.0 5.0 (cps~
35 Eight Kcdak ~iconix 180 S~ pr~nthead~ were ~ill~d with the inks lis~ed in Table 1 ~tW~ printhe~d~ were charged with ~ch ink;. Each print head was Fut int~ t~e Xodak ~icon_x l~O S~ p~in~e~ ~t tk~ ti~ int~rv~ls specl~ied ~n ~able 3, be}ow. Prin~ing was conducted at 20~
~8CF) ~nd ~5~ relati~e h~.~ y. T~e print heads were AMENDED SHEET

CA 02234714 1998-04-1~
W O 97/15634 PCT~US96/16635 stored at 68~F and 65~ relative humidity when not in use. If the printhead did not print the printhead was primed by pushing the ink bladder until ink passed through the jets. The printhead was then wiped clean S with a lint free cloth and start up was attempted again.
The results are shown in Table 3, below.
Table 3 Ex # % 1st 3 10 20 34 Polymer hr days days days days :n Ink ,8 ,~. 4 4 4 4 4 ,8 .~; 4 4 4 ~ 4 _ 0 ~ ~ ~ 4 ,0~, 4 ~ 4 comp -5~i Comp ~5~, 4 Comp .'0~, 0 ~ 0 0 0 Comp 2 ;0~; o o O 0 0 0 - Very poor; clogged orifices; no jets printing 1 - poor; clogged orifice; won't print even with multiple priming (>3); >1 jet not printing 2 - fair; all jets print after priming 3X
3 - good; all jets print after 1-2 priming 4 - excellent; no priming necessary Inks having compositions similar to those disclosed in U.S. 5,3 36, 714 were not printable at any time interval. The ink jet orifices were clogged and could not be corrected by priming. However, surprisingly the inks of the present invention displayed excellent printability over the entire test period. Even though the inks of the present invention contain greatly reduced amounts of the NIRF (between about 1~100 to 1~2 as compared to U.S. 5,336,714) the inks still produce a detectible fluorescent signal.

Claims (16)

WE CLAIM:

1. An ink composition comprising:
A. between 1 and 10 weight percent of least one water-dissipatable polyester comprising:
(i) monomer residues of at least one dicarboxylic acid;
(ii) 4 to 25 mole percent, based on the total of all acid, hydroxy and amino equivalents, of monomer residues of at least one difunctional sulfomonomer containing at least one sulfonate group bonded to an aromatic ring where the functional groups are hydroxy, carboxyl, carboxylate ester or amino;
(iii) monomer residues of at least one diol or a mixture of diol and a diamine; and optionally, (iv) monomer residues of at least one difunctional monomer reactant selected from hydroxycarboxylic acids, amino carboxylic acids and aminoalkanols;
provided that at least 20 percent of the groups linking the monomeric units are ester linkages; said water-dissipatable polyester having from 0.1 ppm by weight to 10% by weight of a thermally stable near infrared fluorophoric compound covalently bound to the polyester;
B. between 5 and 75 weight percent of at least one aliphatic humectant or binder;
C . between 0 and 15 weight percent of at least one lower aliphatic alcohol of no more than 3 carbon atoms;
D. water and optionally up to 2 weight percent of one or more additives;
wherein the weight percentages of components A-D equal 100%.

2. The composition of claim 1 wherein said water-dissipatable polyester is a sulfopolyester and wherein the diol of component (iii), based upon 100 mole% diol comprises (a) at least 15 mole percent of a diol having the formula H(OCH2CH2)nOH, where n is 2 to 20, or (b) 0.1 to less than 15 mole percent of a poly(ethylene glycol) having the formula H(OCH2CH2)nOH, where n is 2 to 500, provided that the mole percent of said poly(ethylene glycol) is inversely proportional to the value of n.

3. The composition of claim 1 comprising:
A. said water dissipatible polyester;
B. between 45 and 75 weight percent of said humectant or binder;
C. between 2 and 15 weight percent of said lower aliphatic alcohol;
D. water; between 0.01 and 0.50 weight percent of at least one corrosion inhibitor; and between 0.01 and 0.30 weight percent of at least one biocide.

4 . The composition or Claim 1 further comprising A. said water-dissipatable polyester;
B. between 20 and 60 weight percent of said humectant;
C. between 0.50 and 1.5 weight percent of at least one surface active agent;
D. water; between 0.01 and 0.5 weight percent of at least one corrosion inhibitor;
between 0.01 and 0.3 weight percent of at least one biocide.

5. The ink composition of claim 1 comprising A. said water-dissipatable polyester;

B. between 4 and 8 weight percent of said humectant;
C. between 0.35 and 0.65 weight percent of at least one surface active agents;
D. water; between 0.75 and 1.25 weight percent of at least one defoaming agent; between 0.01 and 0.50 weight percent of at least one corrosion inhibitor;
between 0.01 and 0.3 weight percent of at least one biocide.

6. The ink composition of claim 1 comprising A. said water-dissipatable polyester;
B. between 30 and 50 weight percent of said at least one humectant;
C. between 5 and 15 weight percent of said at least one alcohol;
D. water; between 0.01 and 0.50 weight percent of at least one corrosion inhibitor; between 0.01 and 0.30 weight percent of at least one biocide.

7. The ink composition of claim 1 wherein said humectant is selected from the group consisting of ethylene glycol, propylene glycol, butanediol, glycerol, polyethylene glycols of the formula H-(OCH2-CH2)n-OH having a Mn of between 200 and 10,000; poly(ethylene glycol) methyl ethers having an Mn of 250 to 5,000; polyvinyl alcohols, polyvinylpyridines, and polyvinylpyrrolidones and mixtures thereof.

8. The ink composition of claim 1 wherein said humectant is selected from the group consisting of ethylene glycol, propylene glycol, butanediol, glycerol, polyethylene glycols of the formula H-(OCH2-CH2)n-OH wherein n is 2 to 6 and mixtures thereof.

9. The composition of claim 1, wherein the near infrared flourescing compound is selected from the classes of phthalocyanines, 2,3-naphthalocyanines and squaraines and correspond to Formulae II, III and IV:

wherein Pc and Nc represent the phthalocyanine and 2,3-naphthalocyanine moieties of Formulae IIa and IIIa, respectively, covalently bonded to a moeity selected from hydrogen, various metals, halometals, organometallic groups, and oxymetals selected from a group consisting of hydrogen, AlCl, AlBr, AlF, AlOH, AlOR5, AlSR5, Fe, Ge(OR6)2, GaCl, GaBr, GaF, GaOR5, GaSr5, InCl, Mg, Mn, SiCl2, SiF2, SnCl2, Sn(OR6)2, Si(OR6)2, Sn(SR6)2, Si(SR6)2 and Zn.
wherein R5 and R6 are selected from hydrogen, alkyl, aryl, aroyl, heteroaryl, lower alkanoyl, trifluoroacetyl or groups of the formulae or R7, R8 and R9 are independently selected from alkyl, phenyl or phenyl substituted with lower alkyl, lower alkoxy or halogen;

X is selected from oxygen, sulfur, selenium, tellurium or a group of the formula -N-R10, wherein R10 is hydrogen, cycloalkyl, alkyl, acyl, alkyl-sulfonyl, or aryl or R10 and R taken together form an aliphatic or aromatic ring with the nitrogen atom to which they are attached;

Y is selected from alkyl, aryl, halogen or hydrogen;

R is selected from unsubstituted or substituted alkyl, alkenyl, alkynyl, C3-C8 cycloalkyl, aryl, heteroaryl, or ; or -(X-R)m is alkylsulfonylamino, arylsulfonylamino, or a group selected from the formulae -X(C2H4O)zR', , , , or , wherein R' is hydrogen or R as defined above; Z is an integer of from 1-4;
or two -(X-R)m groups can be taken together to form divalent substituents of the formula wherein each X1 is independently selected from -O- , -S-, or -N-R10 and A is selected from ethylene;
propylene; trimethylene; and said groups substituted with C1-C4 alkyl, C1-C4 alkoxy, aryl and cycloalkyl; 1, 2 -phenylene and 1, 2-phenylene containing 1-3 substituents selected from C1-C4 alkyl, C1-C4 alkoxy or halogen;

R1 and R2 are independently selected from hydrogen, lower alkyl, lower alkoxy, halogen, aryloxy, lower alkylthio, arylthio, lower alkylsulfonyl;
aryl-sulfonyl; lower alkylsulfonylamino, arylsulfonyl-amino, cycloalkylsulfonylamino, carboxy, unsubstituted and substituted carbamoyl and sulfamoyl, lower alkoxycarbonyl, hydroxy, lower alkanoyloxy, ' ~ or R3 and R4 are independently selected from hydrogen, lower alkyl, alkenyl or aryl; n is an integer from 0-12; n1 is an integer from 0-24, m is an integer from 4-16; m1 is an integer from 0-16; provided that the sums of n+m and n1+m1 are 16 and 24, respectively, provided that at least one polyester reactive group is present.

10. The composition of claim 9, wherein the near infrared fluorescing compound is a squaraine compound of Formula IV, wherein R1 and R2 are independently carboxy or lower alkoxycarbonyl.

11. The ink composition of claim 9 wherein said near infrared fluorophore is selected from the group consisting of phthalocyanines of formula II, naphthalocyanines of formula III and mixtures thereof.

12. The composition of claim 9, wherein the near infrared fluorescing compound is a 2,3-naphthalocyanine compound of Formula III, wherein Y
is hydrogen, n1 is 24, and m1 is 0.

13. The composition of claim 11, wherein the near infrared fluorescing compound is a 2,3-naphthalocyanine compound of Formula III, wherein the naphthalocyanine moiety is bonded to SiC12, Si(OH)2, or Si(OR6)2-

14. The composition of claim 11, wherein the near infrared fluorescing compound is a phthalocyanine compound of Formula II, wherein X is oxygen, R is aryl, Y is hydrogen, m is 4, and n is 12; and wherein the phthalocyanine moiety is bonded to AlCl, AlOH, AlOCOCF3, AlOR5, SiCl2, Si(OH)2, or Si(OR6)2.

15. The ink composition of claim 9 wherein said near infrared fluorescing compound is covalently bonded to a moeity selected from hydrogen, AlCl, AlBr, AlF, AlOH, AlOR5, AlSR5, Ge(OR6)2, GaCl, GaBr, GaF, GaOR5, GaSr5, Mg, SiCl2, SiF2, SnCl2, Sn(OR6)2, Si(OR6)2, Sn(SR6)2, Si(SR6)2 and Zn.

16. A method for invisibly marking an article comprising applying to said article an ink composition of Claims 1-15.