Pigment preparations useful for ink-jet printing

The present invention relates to a method for ink-jet printing with a printing ink containing a pigment preparation containing PA1 (a) water PA1 (b) a dispersing agent, and PA1 (c) at least one pigment consisting of a barbituric acid substituted by radicals containing methine or azo groups or a derivative thereof, preferably present as a salt or a complex, a solid solution, an inclusion compound, or an intercalation compound.

The invention relates to a method for ink-jet printing with a printing ink 
containing a pigment preparation and pigment preparations of specific 
organic pigments that are useful as printing inks for ink-jet printing. 
Aqueous printing inks for ink-jet printing based both on water-soluble 
organic dyestuffs and on organic colored pigments are known and are 
described in many publications. Compared with soluble dyestuffs, pigments 
generally produce an improved lightfastness in the resultant print-outs. 
However, it is also known that ink-jet prints of most pigments do not 
achieve the same brilliance as those of dyestuffs. Although the brilliance 
of the prints can be improved by use of a particularly high fine 
distribution of the pigment particles, this improvement is generally 
accompanied by a loss in lightfastness properties. Cf. Herbst, Hunger: 
Industrielle Organische Pigmente [Industrial Organic Pigments], VCM, 
Verlagsgesellschaft, Weinheim (1987), pages 135-136. 
According to European Patent Application 633,142 (U.S. Pat. No. 5,555,008), 
the brilliance can be improved, for example, by a suitable choice of 
additives for the inks or by a suitable choice of printing substrates, 
such as, for example, appropriately coated papers. The problem of 
providing both brilliant and light-fast pigments for ink-jet printing, 
however, has not yet been solved satisfactorily by the prior art methods. 
This applies particularly to the yellow color shade range. 
Despite the large number of publications, the above-mentioned object has 
not yet been satisfactorily achieved. Moreover, only a very few 
publications list examples of yellow pigments that are indeed suitable in 
principle in their lightfastness properties for conventional ink-jet 
printing, but which do not satisfy the lightfastness properties required 
for higher quality fields of ink-jet printing use, such as photographic 
image reproduction (photoreproduction, for example, for use outside or for 
display). E.g., European Patent Application 518,225 (U.S. Pat. No. 
5,221,334). 
SUMMARY OF THE INVENTION 
The present invention, therefore, relates to a method comprising ink-jet 
printing with a printing ink containing a pigment preparation comprising 
(a) water, 
(b) a dispersing agent, and 
(c) at least one pigment consisting of a barbituric acid substituted by 
radicals containing methine or azo groups or a derivative thereof, said 
pigment preferably being present as a salt or a complex, a solid solution, 
an inclusion compound, or an intercalation compound. 
In a particularly preferred embodiment, component (c) is one or more 
pigments having the formulas (I) to (III) or tautomeric forms thereof 
##STR1## 
wherein B is an isoindoline group having the formula 
##STR2## 
wherein the double bonds are linked respectively through the 1- and 
3-positions of the isoindoline group; 
A is a cyanomethylene group having the formula 
##STR3## 
Z.sup.1 to Z.sup.10 are independently O or NR.sup.10 ; R.sup.1, R.sup.2, 
R.sup.3, and R.sup.4 are independently hydrogen, alkyl (preferably C.sub.1 
-C.sub.6 alkyl), cycloalkyl (preferably C.sub.5 -C.sub.8 cycloalkyl), aryl 
(preferably phenyl or substituted phenyl), aralkyl (preferably (C.sub.6 
-C.sub.10 aryl)(C.sub.1 -C.sub.4 alkyl) such as benzyl or phenethyl), or 
heteroaryl; 
R.sup.5, R.sup.6, R.sup.7, and R.sup.8 are independently hydrogen, halogen 
(preferably F, Cl, or Br), C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 
alkoxy, or C.sub.6 -C.sub.10 aryloxy; 
R.sup.9 is an electron-withdrawing group; and 
R.sup.10 is hydrogen or cyano. 
DETAILED DESCRIPTION OF THE INVENTION 
Pigments of formula (I) are known, for example, from German 
Offenlegungsschrift 3,935,858 (U.S. Pat. No. 5,091,532), pigments of 
formula (II) are known, for example, from U.S. Pat. No. 5,177,209, and 
pigments of formula (III) are known, for example, from European Patent 
Application 74,515 (U.S. Pat. No. 4,628,082). 
As used herein, the term "alkyl" refers to straight or branched chain 
aliphatic hydrocarbon groups. Examples of the preferred C.sub.1 -C.sub.6 
alkyl groups are methyl, ethyl, propyl, butyl, pentyl, hexyl, and the 
isomeric forms thereof. The term "alkoxy" refers to straight or branched 
chain alkyl oxy groups. Examples of the preferred C.sub.1 -C.sub.6 alkoxy 
groups are methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, and the 
isomeric forms thereof. The term "cycloalkyl" refers to cycloaliphatic 
hydrocarbon groups. Examples of the preferred C.sub.5 -C.sub.7 cycloalkyl 
are cyclopentyl, cyclohexyl, and cycloheptyl. The term "aryl" refers to 
aromatic hydrocarbon groups, including aromatic hydrocarbon groups 
substituted with groups such as alkyl, alkoxy, halogen, hydroxy (including 
tautomeric oxo forms), alkoxycarbonyl, aryloxycarbonyl, cyano, and nitro 
groups. Examples of the preferred aryl groups are phenyl and substituted 
derivatives thereof. The term "aryloxy" refers to aromatic hydrocarbon 
groups attached through an oxygen atom. Examples of the preferred C.sub.6 
-C.sub.10 aryloxy groups are phenoxy and naphthoxy and derivatives thereof 
in which the aryl portion is substituted as described above for "aryl" 
groups. The term "aralkyl" (or, "arylalkyl") refers to alkyl groups 
bearing aryl group as substituents. Examples of the preferred (C.sub.6 
-C.sub.10 aryl)(C.sub.1 -C.sub.4 alkyl) groups are benzyl or phenethyl. 
The term "heteroaryl" refers to aromatic groups, preferably five- or 
six-membered aromatic groups, having one or more ring heteroatoms, such as 
nitrogen, oxygen, and sulfur, and fused ring analogs thereof. The term 
"heteroaryl" also refers to heteroaryl groups further substituted with 
hydroxy (including tautomeric oxo forms), halogen, alkyl, alkoxy, 
alkoxycarbonyl, or aryloxycarbonyl. 
The group R.sup.9 preferably represents a group in which the Hammett 
substituent constant .sigma. (para) is greater than zero. A corresponding 
list of Hammett substituent constants can be found, for example, in Sykes, 
Reaktionsmechanismen der organischen Chemie [Reaction Mechanisms of 
Organic Chemistry], 9th edition, Weinheim VCM Verlagsgesellschaft, 1988, 
or can be determined by known methods. Examples of suitable 
electron-withdrawing groups include --CN, --COOH and esters and amides 
thereof, aldehyde and ketone carbonyl, --SO.sub.3 H and esters and amides 
thereof, --NO.sub.2, --NO, --ONO, halogen, ammonium groups, aryl, and 
heteroaryl. 
Preferred pigments of formula (I) are symmetric isoindoline pigments 
corresponding to formula (IV) 
##STR4## 
wherein R.sup.11 is hydrogen, C.sub.1 -C.sub.6 alkyl, or phenyl. 
Especially preferred pigments of formula (I) correspond to formula (IV) in 
which R.sup.11 is hydrogen. 
Preferred pigments of formula (II) are asymmetric isoindoline pigments 
corresponding to formula (V) 
##STR5## 
wherein R.sup.9 is --CN, aminocarbonyl or aminocarbonyl substituted with 
C.sub.1 -C.sub.6 alkyl, C.sub.5 -C.sub.7 cycloalkyl, aralkyl (preferably 
(C.sub.6 -C.sub.10 aryl)(C.sub.1 -C.sub.4 alkyl)), or C.sub.6 -C.sub.10 
-aryl) (more preferably --CONHCH.sub.3), C.sub.1 -C.sub.6 alkoxycarbonyl, 
C.sub.6 -C.sub.10 aryloxycarbonyl, or heteroaryl such as heteroaryl groups 
having the formulas (VI) or (VII) 
##STR6## 
wherein R.sup.13 and R.sup.14 are independently hydrogen, halogen 
(preferably Cl, Br, or F), C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 
alkoxy, or C.sub.1 -C.sub.6 alkoxycarbonyl, or R.sup.13 and R.sup.14 
together form a fused-on benzene ring, 
G is O, S, NH, or N(C.sub.1 -C.sub.4 alkyl), and 
R.sup.12 is hydrogen, C.sub.1 -C.sub.6 alkyl, or phenyl. 
Especially preferred pigments of formula (V) are those in which R.sup.9 is 
--CONHCH.sub.3 and R.sup.12 has the above-mentioned meaning, particularly 
pigments in which R.sup.9 is --CONHCH.sub.3 and R.sup.12 is hydrogen. 
Preferred pigments are salts, complexes, inclusion compounds, solid 
solutions, and intercalation compounds corresponding to the pigments of 
formula (III). Such pigments are known, for example, from European Patent 
Application 74,515 (U.S. Pat. No. 4,628,082). Preferred salts and 
complexes of the compounds of the formula (III) are the salts and 
complexes of the corresponding mono-, di-, tri-, and tetra-anions with the 
metals Li, Cs, Mg, Cd, Co, Al, Cr, Sn, and Pb, and most preferably with 
the metals Na, K, Ca, Sr, Ba, Zn, Fe, Ni, Cu, and Mn. The nickel salts and 
complexes and solid solutions and intercalation and inclusion compounds 
thereof are of particular importance. An inclusion compound, intercalation 
compound, or solid solution of a salt or a complex of azobarbituric acid 
(particularly of the azobarbituric acid-nickel 1:1 complex) is 
particularly preferred. 
The included compound is preferably a cyclic or acyclic organic compound, 
preferably a carboxamide or sulfonamide, urea or substituted urea, or a 
heterocyclic compound, especially 2,4,6-triamino-1,3,5-triazine, 
acetoguanamine, or benzoguanamine. 
Preferred pigments of formula (III) correspond to pigments of formulas 
(VIII) and (IX) 
##STR7## 
especially as their inclusion compounds or intercalation compounds, where 
2,4,6-triamino-1,3,5-triazine, acetoguanamine, and benzoguanamine are 
preferred as the included compound. 
Particularly preferred pigments of formulas (I) to (III) and mixtures 
thereof are those of which the prints cover the color shade range which, 
in the coloristic sense, can preferably be described by the color shade 
value range h, as determined with the parameters of the CIELAB system 
(1976), from 80 to 100.degree. (preferably from 85 to 100.degree.). CIELAB 
system (1976) is the calorimetric classification system described, for 
example, by A. Brockes et al. in "Farbmessung in der Textilindustrie" 
["Color Measurement in the Textile Industry"], JSSN 0722-0391, 1986 
Mitteilungen flir die Farbstoffe verarbeitende Industrie [Communications 
for the Dyestuffs Processing Industry], volume 24. 
Dispersing agents in the context of this invention are understood as 
meaning substances which stabilize the pigment particles in their finely 
particulate form in aqueous media. The term "finely particulate" is 
preferably understood as meaning a fine division of 0.001 to 5 .mu.m 
(preferably 0.005 to 1 .mu.m and more preferably 0.005 to 0.5 .mu.m). 
Suitable dispersing agents can be anionic, cationic, amphoteric, or 
nonionic. 
Suitable anionic dispersing agents include condensation products of 
aromatic sulfonic acids with formaldehyde, such as condensation products 
of formaldehyde and alkylnaphthalenesulfonic acids or of formaldehyde, 
naphthalenesulfonic acids, and/or benzenesulfonic acids, and condensation 
products of optionally substituted phenol with formaldehyde and sodium 
bisulfite. Dispersing agents from the group consisting of sulfosuccinic 
acid esters and alkylbenzenesulfonates are also suitable. 
Ligninsulfonates, for example, those which are obtained by the sulfite or 
kraft process, are also particularly suitable. Such compounds are 
preferably products that are partly hydrolyzed, oxidized, propoxylated, 
sulfonated, sulfomethylated, or desulfonated and fractionated by known 
processes, for example, according to molecular weight or according to the 
degree of sulfonation. Mixtures of sulfite and kraft ligninsulfonates also 
have a good dispersing action. Ligninsulfonates having an average 
molecular weight of between 1000 and 100,000, a content of active 
ligninsulfonate of at least 80%, and preferably a low polyvalent cation 
content are particularly suitable. The degree of sulfonation can vary 
within wide limits. 
Suitable nonionic dispersing agents include reaction products of alkylene 
oxides with alkylatable compounds, such as fatty alcohols, fatty amines, 
fatty acids, phenols, alkylphenols, arylalkylphenols (for example, 
styrene-phenol condensates), carboxamides, and resin acids. Such compounds 
include ethylene oxide adducts obtained as reaction products of ethylene 
oxide with 
a) saturated and/or unsaturated fatty alcohols having 6 to 20 C atoms, or 
b) alkylphenols having 4 to 12 carbon atoms in the alkyl group, or 
c) saturated and/or unsaturated fatty amines having 14 to 20 carbon atoms, 
or 
d) saturated and/or unsaturated fatty acids having 14 to 20 carbon atoms, 
or 
e) hydrogenated and/or non-hydrogenated resin acids. 
Suitable ethylene oxide adducts include the alkylatable compounds mentioned 
under a) to e) with 5 to 120 mol (preferably 5 to 100, more preferably 5 
to 100, and more preferably 5 to 60, and most preferably 5 to 30 mol) of 
ethylene oxide. 
Suitable dispersing agents also include mixtures, some of which are 
disclosed in German application 195 35 246, of 
(I) alkoxylation products of at least one styrene-phenol condensate, said 
alkoxylation products having formula (X) 
##STR8## 
wherein R.sup.15 is hydrogen or C.sub.1 -C.sub.4 alkyl, 
R.sup.16 is hydrogen or CH.sub.3, 
R.sup.17 is hydrogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, 
C.sub.1 -C.sub.4 alkoxycarbonyl, or phenyl, 
m is a number from 1 to 4, 
n is a number from 6 to 120, and 
R.sup.18 is independently for each --(CH.sub.2 --CHR.sup.18 --O)-- unit 
hydrogen, CH.sub.3, or phenyl, with the proviso that either (i) 0 to 60% 
of the total R.sup.18 is CH.sub.3 and 40 to 100% of the total R.sup.18 is 
hydrogen or (ii) 0 to 60% of the total R.sup.18 is phenyl and 40 to 100% 
of the total R.sup.18 is hydrogen, and 
(II) esters of such alkoxylation products (X), said esters having formula 
(XI) 
##STR9## 
wherein R.sup.15', R.sup.16', R.sup.17', R.sup.18', m', and n' are 
defined in the same manner as, but independently from, R.sup.15, R.sup.16, 
R.sup.17, R.sup.18, m, and n, respectively, 
X is --SO.sub.3.sup.-, --SO.sub.2.sup.-, --PO.sub.3.sup.2-, or 
--CO--(R.sup.19)--COO.sup.-, 
cat is a cation selected from the group consisting of H.sup.+, Li.sup.+, 
Na.sup.+, K.sup.+, NH.sub.4.sup.+, and HO--CH.sub.2 CH.sub.2 
--NH.sub.3.sup.+ with the proviso that two cat must present if X is 
--PO.sub.3.sup.2-, and 
R.sup.19 is a divalent aliphatic or aromatic group (preferably C.sub.1 
-C.sub.4 alkylene, particularly ethylene, C.sub.2 -C.sub.4 monounsaturated 
group, particularly acetylene, or optionally substituted phenylene, 
particularly orthophenylene, optionally substituted with C.sub.1 -C.sub.4 
alkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 alkoxycarbonyl, or 
phenyl). 
Mixtures containing compounds of formulas (X) and (XI) are known, for 
example, from German application 19,535,246. 
The present invention further relates to novel embodiments of the compounds 
of the formula (XI) in which X is a group having the formula 
--CO--(R.sup.19)--COO.sup.- and R.sup.15', R.sup.16', R.sup.17', 
R.sup.18', R.sup.19', cat, m', and n' have the above-mentioned meanings. 
The present invention also relates to a process for the preparation of the 
novel compounds of the formula (XI) according to the invention comprising 
reacting (1) a corresponding compound of formula (X) in which R.sup.15, 
R.sup.16, R.sup.17, R.sup.18, m, and n have the same meaning as the 
corresponding groups R.sup.15', R.sup.16', R.sup.17', R.sup.18', m', and 
n', respectively, with (2) dicarboxylic acids of formula (XII) 
EQU HOOC--(R.sup.19)--COOH (XII) 
or derivatives thereof (preferably anhydrides thereof) wherein R.sup.19 has 
the above-mentioned meaning. 
Corresponding reactions can be carried out analogously to the process 
disclosed in German application 19,535,246. 
To prepare esters of the formula (XI) which are important according to the 
invention, the oxyalkylation products of the formula (X) are reacted with 
polybasic oxygen acids or derivatives thereof. Derivatives of such oxygen 
acids are, for example, their acid anhydrides, acid halides, acid esters 
or acid amides. Important examples of such acids or derivatives thereof 
are: chlorosulphonic acid, amidosulphonic acid, sulphamic acid, phosphorus 
pentoxide or phosphorus oxytrichloride. The esterification reactions are 
carried out in a manner known to the expert; these reactions result in 
monoesters of the alkoxylation products (X) mentioned, which, if an acid 
derivative has been used as the starting substance, can be converted into 
the free acid or the salts of such half-esters of the formula (XI) by 
water, an alkali metal hydroxyide or monoethanolamine. 
In principle, oxyalkylation products of the formula (X) can be employed in 
addition to half-esters (XI), oxyalkylation products other than those 
according to (X) being used as starting substances to form the half-esters 
(XI). In the formulas (X) and (XI), this is expressed by the substituents 
and the indices in (XI) in each case carrying an apostrophe ('). 
Preferably, however, half-esters (XI) which are derived from oxyalkylation 
products (X) in which, instead of R.sup.15', R.sup.16', R.sup.17', 
R.sup.18', m' and n', the corresponding radicals and indices R.sup.15, 
R.sup.16, R.sup.17, R.sup.18, m and n thus occur, are used. Such mixtures 
of (X) and (XI) can be prepared by leaving out a portion of the 
oxyalkylation product which is constituent X and esterifying another 
portion of (X) in the manner mentioned to give (XI), if appropriate 
neutralizing the product and then mixing the two contents. It is of course 
also possible, and is an advantageous variant, to react an alkoxylation 
product (X) with less than the stoichiometric amount of acid or acid 
derivative and thus automatically to obtain a mixture of constituents (X) 
and (XI). 
The particularly preferred compounds of the formula (XI) can be obtained by 
reaction of compounds of the corresponding formula (X) with succinic, 
maleic, or phthalic anhydride. 
The present invention also relates to mixtures comprising at least one 
compound of the formula (XI), wherein X is a group having the formula 
--CO--(R.sup.19)--COO.sup.- and R.sup.19 has the above-mentioned meaning, 
and at least one compound of formula (X). 
Such mixtures according to the invention preferably contain 5 to 99% by 
weight of compound (XI) and 1 to 95% by weight of compound (X). 
The invention also relates to the surfactant mixtures, which are not 
disclosed in unpublished German application 19,535,246, comprising a 
compound of the formula (X) and a compound of the formula (XI) wherein 
R.sup.15, R.sup.16, R.sup.17, R.sup.18, R.sup.15', R.sup.16', R.sup.17', 
R.sup.18', n, m, n', and m' have the above-mentioned meanings, and X 
represents --SO.sub.3.sup.-, --SO.sub.2.sup.-, or --PO.sub.3.sup.2-, 
excluding those mixtures in which n or n' is a number equal to or less 
than 3 or m or m' is a number from 6 to 100. 
The compounds of the formula (XI) in the broadest meaning and their 
mixtures with the compounds of the formula (X) on which they are based 
are, moreover, outstandingly suitable as dispersing agents for stabilizing 
even pigments other than those mentioned herein for ink-jet printing inks. 
Suitable pigments in this connection include, for example, carbon blacks 
(particularly acidic to alkaline carbon blacks from the group consisting 
of furnace or gas carbon blacks and chemically or physically modified or 
after-treated carbon blacks), inorganic pigments, such as zinc sulfides, 
ultramarine, iron oxides, cobalt blue, and chromium oxide pigments, finely 
particulate oxide pigments, such as silicon dioxide, titanium dioxide, 
nickel oxides, chromium/antimony/titanium dioxides, and aluminum oxide, 
and finely particulate metals, such as copper, iron, or aluminum, and 
organic colored pigments, such as those of the azo, diazo, polyazo, 
anthraquinone, and thioindigo series, as well as other polycyclic pigments 
such as phthalocyanine, quinacridone, dioxazine, isoindolinone, 
naphthalenetetracarboxylic acid, and perylene and perylenetetracarboxylic 
acid pigments, and pigments of the perinone, indigoid, thioindigoid, and 
diketopyrrolopyrrole series, metal complex pigments of azo, azomethine, or 
methine dyestuffs, or laked dyestuffs, such as Ca, Mg, and Al lakes of 
dyestuffs containing sulfonic acid groups and/or carboxylic acid groups. 
Possible polymeric dispersing agents include water-soluble and 
water-emulsifiable types, for example, homopolymers and copolymers, such 
as random or block copolymers. 
Particularly preferred dispersing agents are polymeric dispersing agents, 
such as, for example, AB, BAB, and ABC block copolymers. In AB or BAB 
block copolymers, the A segment is a hydrophobic homopolymer or copolymer 
that ensures bonding to the pigment and the B block is a hydrophilic 
homopolymer or copolymer or a salt thereof that ensures dispersion of the 
pigment in the aqueous medium. Such polymeric dispersing agents and their 
synthesis are known, for example, from European Patent Applications 
518,225 and 556,649 (U.S. Pat. No. 5,221,334). 
Dispersing agents are preferably used in the pigment preparation in an 
amount of 0.1 to 100% by weight (preferably 0.5 to 60% by weight), based 
on the pigment employed. 
In a preferred embodiment, the pigment preparation used according to the 
invention comprises 
(a) 10 to 98% by weight (preferably 30 to 98% by weight) of water, 
(b) 0.1 to 100% by weight (preferably 0.5 to 60% by weight), based on the 
pigment employed, of dispersing agent, and 
(c) 0.2 to 60% by weight (preferably 0.2 to 20% by weight, more preferably 
0.2 to 20% by weight, and most preferably 0.2 to 10% by weight) of at 
least one pigment having the formulas (I) to (III). 
The pigment preparations used according to the invention can, of course, 
also contain further additives in addition to components (a), (b) and (c). 
Suitable optional further additives are the additives customary for 
printing inks for ink-jet printing. 
Thus, for example, organic solvents can be present as a further component 
(d). Water-soluble organic solvents are particularly suitable. Those 
having a solubility of greater than 0.5 g/100 g of water are preferred. 
Suitable organic solvents include aliphatic C.sub.1 -C.sub.4 alcohols, such 
as methanol, ethanol, isopropyl alcohol, n-propanol, n-butanol, isobutyl 
alcohol, or tert-butyl alcohol; aliphatic ketones, such as acetone, methyl 
ethyl ketone, methyl isobutyl ketone, or diacetone alcohol; polyols, such 
as ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, 
triethylene glycol, trimethylolpropane, polyethylene glycols having an 
average molecular weight of 100 to 4000 g/mol (preferably 400 to 1500 
g/mol), or glycerol; and monohydroxy ethers, preferably monohydroxyalkyl 
ethers (more preferably mono(C.sub.1 -C.sub.4 alkyl) glycol ethers), such 
as ethylene glycol monoalkyl or monomethyl ethers, diethylene glycol 
monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol 
monobutyl ether, dipropylene glycol monoethyl ether, thiodiglycol, or 
triethylene glycol monomethyl ether or monoethyl ether; as well as 
2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethylpyrrolidone, 
N-vinylpyrrolidone, 1,3-dimethylimidazolidone, dimethylacetamide, and 
dimethylformamide. 
Mixture of the solvents mentioned above are also possible. 
The amount of the organic solvent is preferably 1 to 40% by weight (more 
preferably 2 to 20% by weight), based on the pigment preparations. The 
amount of water and organic solvent is preferably 20 to 99% by weight 
(more preferably 30 to 97% by weight), based on the pigment preparations. 
The pigment preparation can also contain agents for adjusting the viscosity 
of the ink, such as polyvinyl alcohol, polyvinyl pyrrolidone, 
methylcellulose, and other known agents, if they do not adversely affect 
the stability of the printing ink, the printing properties, and the drying 
properties on paper. 
In addition to the components mentioned above, the pigment preparations 
used according to the invention as printing inks can also contain 0 to 15% 
by weight (preferably 0.5 to 10% by weight), based on the ink, of a 
surface-active agent. These surface-active agents can in principle be 
employed, for example, for regulating the surface tension of the ink, as 
well as for preventing dripping or leaking at the jet discharge surface of 
the printing head, and for adjusting the wetting and drying properties of 
the ink on various types of substrates (e.g., papers). Such surface-active 
agents are known in the form of commercially available products. It is 
important to choose surface-active agents that do not impair the stability 
of the pigment preparation or the printing head materials used. 
The pigment preparation used according to the invention can also contain 
further ionic and nonionic auxiliaries. If the dispersing agent contains 
ionic groups, these auxiliaries should preferably be nonionic or have the 
same ionic character. 
The pigment preparations used according to the invention can in principle 
also contain preservatives, light stabilizers, further surfactants and, if 
appropriate, pH regulators. 
Examples of pH regulators are NaOH, ammonia, aminomethylpropanol, and 
N,N-dimethylaminoethanol. 
Examples of preservatives are methyl- and chloromethyl-isothiazolin-3-one, 
benzisothiazolin-3-one, and mixtures thereof. 
Examples of light stabilizers are UV absorbers. 
The invention also relates to pigment preparations comprising 
(a) water, 
(b) a dispersing agent, 
(c) at least one pigment consisting of a barbituric acid substituted by 
radicals containing methine or azo groups or a derivative thereof, said 
pigments preferably being present as a salt or a complex, a solid 
solution, an inclusion compound, or an intercalation compound (preferably 
a pigment of formulas (I) to (III)), and 
(d) at least one organic solvent selected from the group consisting of: 
aliphatic C.sub.1 -C.sub.4 alcohols (such as methanol, ethanol, isopropyl 
alcohol, n-propanol, n-butanol, isobutyl alcohol, or tert-butyl alcohol), 
aliphatic ketones (such as acetone, methyl ethyl ketone, methyl isobutyl 
ketone, or diacetone alcohol), polyols (such as ethylene glycol, propylene 
glycol, butylene glycol, diethylene glycol, triethylene glycol, 
trimethylolpropane, polyethylene glycol having an average molecular weight 
of 100 to 4000 g/mol (preferably 400 to 1500 g/mol), or glycerol), 
monohydroxy ethers (preferably monohydroxyalkyl ethers, more preferably 
mono(C.sub.1 -C.sub.4 alkyl)glycol ethers, such as ethylene glycol 
monoalkyl or monomethyl ethers, diethylene glycol monomethyl ether, 
diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, 
dipropylene glycol monoethyl ether, thiodiglycol, or triethylene glycol 
monomethyl ether or monoethyl ether), 2-pyrrolidone, 
N-methyl-2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, 
1,3-dimethylimidazolidone, dimethylacetamide, and dimethylformamide. 
The preferred embodiments of the individual components correspond to those 
mentioned above. 
The invention further relates to pigment preparations comprising 
(a') water, 
(b') a compound of the formula (XI) wherein X is 
--CO--(R.sup.19)--COO.sup.- and the other groups have the meanings given 
above, and 
(c') a pigment. 
Pigment preparations that optionally contain the compound of formula (XI) 
as a mixture with a corresponding compound of formula (X) are preferred, 
the preferred amounts corresponding to those of component (b) of the above 
pigment preparation. 
The preferred embodiments of component (c') and, where appropriate, an 
organic solvent of component (d'), correspond to the embodiments of 
components (c) and (d) of the pigment preparations described above. 
The methods of use also correspond to those set out above, preferably as a 
printing ink for ink-jet printing as described above. 
The invention further relates to preparation of the pigment preparations of 
the invention that are useful as printing inks for ink-jet printing 
wherein at least one pigment of formulas (I) to (III) is homogenized and 
subjected to wet comminution with a dispersing agent and, if appropriate, 
further additives. 
In general, the pigment is thoroughly blended (i.e., introduced and 
homogenized) in powder form or in the form of the water-moist presscake 
together with some of the dispersing agent and water (preferably deionized 
water) to give a homogeneous ground suspension using, for example, a 
stirred vat, dissolver, or similar unit, if appropriate after a 
precomminution. 
The ground suspension can also contain fractions of low-boiling solvents 
(having a boiling point less than 150.degree. C.), which can be discharged 
by evaporation in the course of the subsequent fine grinding. However, the 
ground suspension can also contain fractions of higher-boiling solvents or 
further additives such as described above, for example, grinding 
auxiliaries or defoaming or wetting agents. 
The wet comminution includes both the precomminution and the fine grinding. 
Here, the pigment concentration of the suspension is preferably above the 
desired concentration of the finished pigment preparation or printing ink. 
The desired end concentration of pigment is preferably established only 
after wet comminution. After precomminution, grinding takes place to the 
desired particle fine division of 0.001 to 5 .mu.m (preferably 0.005 to 1 
.mu.m). Possible units for this grinding step include, for example, 
kneaders, roll mills, kneading screws, ball mills, rotor-stator mills, 
dissolvers, corundum disc mills, vibratory mills, and, particularly, 
high-speed, continuously, or discontinuously charged stirred ball mills 
containing grinding bodies having a diameter of 0.1 to 2 mm. Suitable 
grinding bodies can be made of glass, ceramic, or metal (for example, 
steel). The grinding temperature is preferably in the range from 0 to 
250.degree. C., but is generally room temperature, especially below the 
turbidity point of the dispersing agent of component (b) and of the 
optional surface-active agent. 
In a similarly preferred procedure, the grinding can be carried out partly 
or completely in a high pressure homogenizer or in a so-called jet 
disperser (known from German application 19,536,845, which has not 
previously been published), which means that the content of abraded 
grinding-body material in the suspension or the release of soluble 
substances from the grinding bodies (for example, ions from glass bodies) 
can be minimized or avoided completely. 
The resultant pigment preparation can diluted by mixing into and 
homogenized in water in a known manner with any remaining amounts of 
dispersing agent and any further additives and adjusting to the desired 
final pigment concentration or color strength of the preparation or 
printing ink. If appropriate, some of the dispersing agent can also be 
added, for example, to avoid reagglomeration of fine pigment particles in 
the dilution. 
A process for preparing the pigment preparations in which sufficient 
dispersing agent for stabilization is provided during the grinding step 
for preparation of the pigment concentrate is of particular advantage. 
Thereafter, or after dilution with water, a dispersing agent in solution 
that is not adsorbed on the pigment and/or excess surface-active agents 
are preferably removed and the desired pigment preparation is then 
established by adding the remaining portions of the pigment preparati on. 
A process for removing dispersing agent in solution includes, for example, 
centrifugation of the suspension and subsequent decanting of the 
supernatant. 
Other additives, such as polyurethane polymers or acrylic polymers, can 
also be added to improve waterfastness, if appropriate. Such additives can 
be both water-soluble and water-emulsifiable in nature or can be soluble 
in one of the components contained in (d). 
In a preferred procedure, mixing and homogenization of the pigment 
preparations are carried out using a jet disperser or high pressure 
homogenizer in order to suppress the formation of foam and to avoid 
possible reagglomeration. 
The desired pigment preparations are adjusted during preparation to the 
desired viscosity, color strength, color shade, density, and surface 
tension of the ink. 
Before using the pigment preparations as printing inks, the inks are 
subjected to fine filtration, if appropriate, for example, by means of 1 
to 5 .mu.m membrane or glass filters. 
The physical properties of the inks are generally adjusted to the use in 
customary ink-jet printers, where the surface tension should be between 20 
and 70 mN/m and the viscosity should be less than 20 mPa.multidot.s 
(preferably 0.5 to 10 mPa.multidot.s). 
Printing inks prepared and used according to the invention, when used as a 
printing ink in ink-jet printing, print with excellent lightfastness and 
brilliance, and also have as advantages outstanding dispersion and storage 
stability in a wide temperature range, no so-called coagulation or 
clogging or blocking in the printing head, high fastness to water and 
migration of the prints on various substrates (for example, wood-free 
paper, medium quality paper, sized and coated paper, polymeric films, and 
transparent films for overhead projection), and no bleeding in 
multicolored printing, even when used together with dyestuff inks or other 
pigmented inks. 
The pigment preparations described above can be used as printing inks for 
ink-jet printing. 
Ink-jet printing is known and is in general carried out by introducing the 
printing ink into a receiving vessel of an ink-jet printing head and 
spraying it onto the substrate in small droplets. Ejection of the ink in 
droplet form is preferably effected by a piezoelectric crystal, a heated 
cannula (bubble-jet or thermal-jet process), or mechanical increase in the 
pressure, with pressure being exerted on the ink system and ink drops thus 
being flung out. During this operation, the droplets from one or more 
small nozzles are propelled at the substrate, such as paper, wood, 
textiles, plastic, or metal, in a controlled manner. The individual 
droplets are collected on the substrate as written symbols or graphic 
patterns by electronic control. 
A process in which tiny volumes are brought in the form of drops onto a 
substrate by means of electrostatic deflection from an inkjet is also 
possible. 
The following examples further illustrate details for the process of this 
invention. The invention, which is set forth in the foregoing disclosure, 
is not to be limited either in spirit or scope by these examples. Those 
skilled in the art will readily understand that known variations of the 
conditions of the following procedures can be used. Unless otherwise 
noted, all temperatures are degrees Celsius and all parts and percentages 
are parts by weight and percentages by weight, respectively.

EXAMPLES 
Example 1 
Preparation of a Particularly Preferred Inclusion Compound of the Pigment 
of Formula (IX) 
25 g of benzenesulfonic acid hydrazide, 200 ml of water, 20 ml of 10 N 
hydrochloric acid, and 1.25 g of a condensation product of stearic acid 
with taurine were stirred for 30 minutes. After 60 g of ice were added, 34 
ml of an aqueous sodium nitrite solution having a content of 30 g of 
sodium nitrite per 100 ml of solution were added dropwise over a period of 
about 30 minutes. The mixture was stirred for 30 minutes while an excess 
of nitrite was maintained. The excess nitrite was destroyed with a small 
amount of amidosulfonic acid and the mixture was neutralized with about 5 
ml of 10 N sodium hydroxide solution. An emulsion of benzenesulfonic acid 
azide was obtained. 
38.2 g of barbituric acid were added to the emulsion thus prepared, after 
which the mixture was stirred for 10 minutes and the pH was adjusted to 8 
with about 33 ml of 10 N sodium hydroxide solution. The resultant mixture 
was stirred at 50.degree. C. for 2 hours, subsequently adjusted to pH 4.8 
with 3 ml of acetic acid and about 14 ml of 10 N hydrochloric acid, and 
heated at 70.degree. C. for a further 1 hour and at 80.degree. C. for 3 
hours. A suspension of the sodium salt of azobarbituric acid was obtained, 
and about 22 g of the benzenesulfonic acid amide formed as a by-product 
were also additionally present in dissolved form. 
A suspension prepared in this manner was heated at 95.degree. C. to 
100.degree. C. and the solid was collected by suction filtration and 
washed with about 1 liter of boiling, hot water in several portions. A 
presscake of the sodium salt of azobarbituric acid was obtained. 
The presscake thus prepared was stirred with 500 ml of water. A solution of 
34.5 gof NiCl.sub.2. 6 H.sub.2 O and 13 g of anhydrous sodium acetate in 
100 ml of water was added dropwise at 80.degree. C. over a period of about 
5 minutes. The mixture was stirred at 80.degree. C. for 1 hour, 42 g of 
melamine were added, the mixture was stirred at 80.degree. C. for a 
further 1 hour and at 95.degree. C. for 2 hours, and the still hot solid 
was subsequently collected by suction filtration and washed with hot 
water. 
A water-moist pigment presseake having a dry substance content of 42.6% by 
weight was obtained. 
Examples 2 to 4 
Preparation of Pigment Preparations 
Example 2 
To 
______________________________________ 
89.9 parts 
of the moist presscake of the pigment 
according to formula (IX) prepared according to Example 1, 
having a dry substance content of 42.6%, 
______________________________________ 
were added 
______________________________________ 
6.9 parts of a naphthalenesulfonic acid condensation product 
(TAMOL .RTM. NN 9401, BASF AG) and 
3.2 parts of deionized water 
______________________________________ 
and the mixture was homogenized by means of a dissolver. The pH of the 
suspension was 5.5. Thereafter, the suspension was introduced into an 
open, discontinuously operated 1 liter stirred ball mill (manufactured by 
Sussmeyer, Brussels) and ground with zirconium oxide beads (diameter 0.4 
to 0.6 mm), with cooling, over a period of 3 hours. The resultant aqueous 
pigment concentrate was formulated to a pigment concentration of 35% with 
______________________________________ 
0.1 part of a preservative (benzisothiazolin-3-one) 
and deionized water. 
______________________________________ 
The pigment preparation had excellent flow properties and an excellent 
stability of the suspension during storage for 3 months at room 
temperature and 50.degree. C. Aqueous dilutions of this preparation down 
to a pigment concentration of 2% were also stable. The composition is 
shown in Table 1. 
Example 3 
______________________________________ 
22 parts 
of the dried pigment according to formula (V) in 
which R.sup.9 is CONHCH.sub.3 and R.sup.12 is H, prepared 
according 
to Example 10 of U.S. Pat. No. 5,177,209, and 
8.8 parts 
of a liginsulfonate (ULTRAZINE .RTM. NA, Lignotech, 
Dusseldorf) 
______________________________________ 
were beaten and homogenized in 
______________________________________ 
69.2 parts of deionized water 
______________________________________ 
using a dissolver. 
Thereafter, grinding was carried out as described in Example 2. The pigment 
concentrate thus obtained was formulated to a pigment concentration of 20% 
with 
______________________________________ 
0.1 part 
of the same preservative as in Example 2 and 
deionized water, and the pH was brought to 8 by means of 
dilute sulfuric acid. The preparation also had excellent 
stability and flow properties. The composition is shown 
in Table 1. 
______________________________________ 
Example 4 
To 
______________________________________ 
90.9 parts 
of the most presscake of the pigment according to 
formula (IV) in which R.sup.11 is H, prepared according 
to Example 8 of German Offenlegungsschrift 
3,935,858, having a dry substance content of 40.4%, 
______________________________________ 
were added 
______________________________________ 
1.8 parts of a dispersing agent mixture of alkoxylation 
products according to formula (X) and (XI) having a 
composition of 51% of formula (X) in which 
R.sup.15 is CH.sub.3, R.sup.16, R.sup.17, and R.sup.18 are H, 
m is 2.8, and n is 50 and 49% 
of formula (XI) in which R.sup.15' is CH.sub.3, R.sup.16', 
R.sup.17', and R.sup.18' are H, m' i 2.8, n' is 50, 
X is SO.sub.3.sup.-, and cat is NH.sub.4.sup.+, and 
7.3 parts of deionized water, and 
______________________________________ 
the mixture was homogenized by means of a dissolver. The pH was adjusted to 
7.0 by means of dilute sodium hydroxide solution. Thereafter, the 
suspension was ground as described in Example 2 and the pigment 
concentrate thus obtained was formulated to a pigment concentration of 30% 
with 
______________________________________ 
0.1 part of the same preservative as in Example 2 and 
deionized water. 
______________________________________ 
The composition is shown in Table 1. 
TABLE 1 
______________________________________ 
Compositions for Example 2 to 4 (values in percent by weight 
based on the pigment concentrate) 
Components Components Examples 
(general) (specific) 2 3 4 
______________________________________ 
Water Deionized water 
58.6 71.9 68.43 
Dispersing agent 
ULTRAZINE .RTM. NA 
-- 8.0 
-- 
6.3TAMOL .RTM. NN 9401 
-- -- 
-- Dispersing agent mixture 
-- 
1.47 
Pigments Pigment according to 
35 -- 
-- 
formula (IX) (dry) 
--ment according to 
20 -- 
formula (V) (dry) 
--t according to 
-- 30 
formula (IV) (dry) 
Further additives 
Preservative 0.11 
0.1 
Properties pH 8.0 6.5 
6.9 
&lt;0.2mum particle size* 
&lt;0.2 
&lt;0.2 
(.mu.m) 
______________________________________ 
*Determined from the particle size distribution (weightaverage) 
[Measurement apparatus: disc centrifuge type DCP .RTM. 1000 from 
Brookhaven 
Examples 5 to 7 
Application Examples 
The pigment preparations according to Examples 2 to 4 were each formulated 
to a pigment concentration of 4% by weight using deionized water and 
org,anic solvents for use as printing inks for ink-jet printing. The 
compositions of the pigment preparations to be used as printing inks were 
each chosen to give printing inks having viscosities in the range of 3 to 
5 mPa.multidot.s. 
The inks were prepared by mixing and stirring the pigment preparations of 
Examples 2 to 4 with the required amount of water and other additives, 
such as 20 organic solvents, in a glass container. Thereafter, ultrasonic 
treatment was carried out for 1 minute, preservative was added and, if 
appropriate, the pH was adjusted using dilute NaOH. The composition of the 
pigment preparations used as printing, inks are shown in Table 2. 
The pigment preparations were filtered through a 1.2 .mu.m filter, before 
printing, in order to remove from the suspension any abraded grinding 
material and coarse content present. 
TABLE 2 
______________________________________ 
Composition and properties of the preparations used as printing inks 
(values in percent by weight based on the compositions) 
Examples 
5 6 7 
______________________________________ 
Deionized water (%) 
79.0 70.4 77.1 
Polyethylene glycol (%) 
4.0 
4.0 
4.0 
(Molecular weight 
400 g/mol) 
2-Pyrrolidone (%) 
3.9 
3.9 
Isopropyl alcohol (%) 
1.5 
1.5 
1.5 
Pigment concentrate (%) 
according to Example 2 
11.4 
-- -- 
according to Example 3 
-- 20 -- 
according to Example 4 
-- -- 13.3 
Preservative (%) 0.2 
0.2 
0.2 
pH 8.0 6.7 
7.5 
Surface tension (mN/m) 
&gt;30 
&gt;30 
&gt;30 
Maximum particle size (.mu.m) 
&lt;0.2 &lt;0.2 
&lt;0.2 
(disc centrifuge) 
______________________________________ 
Properties of the Pigment Preparations According to Examples 5 to 7 Used as 
Printing Inks 
Prints were produced on a commercially available ink-jet printer from 
Hewlett Packard (HP DESKJET.RTM. 1600 C) using a cleaned cartridge. The 
printing inks could be used for printing without problems and gave 
brilliant printed images of high color strength and good contrast. 
Lightfastness of the prints on various substrates was carried out using the 
Xenon Test 450.RTM. (apparatus from Heraeus) and, when compared with the 
similarly exposed blue scale (DIN 54004), gave the results shown in Table 
3: The prints also showed a good fastness to water and text marker. 
TABLE 3 
______________________________________ 
Lightfastness ratings for Examples 5 to 7 
Lightfastness rating* on the substrate 
Printing 
Normal 
ink paper 
Glossy paper 
Coated film 
HP special 
according 
AGFA .RTM. 
(HP-C (HP-C 3828A/ 
paper 
to 701 
3831A .RTM.) 
32-A .RTM.) 
(HP-516342 .RTM.) 
______________________________________ 
Example 5 
7-8 6-7 7 7-8 
Example 6 
not tested 
Example 7 
7 
______________________________________ 
*Scale ranging from 8 (corresponding to no loss in color) to 1 
(corresponding to complete loss in color) 
Example 8 
Preparation of a Dispersing Agent According to Formula (XI) 
In a 2 liter stirred apparatus purged with nitrogen were sequentially added 
1500 g (0.9 mol) of tristyrylphenyloxyethylate emulsifier of formula (X) 
##STR10## 
wherein m is 2.7, n is 29, and R.sup.15, R.sup.16, R.sup.17, and R.sup.18 
are each H, having a statistical chain length of about 29 EO units (melted 
at 90.degree. C.), and 
90.1 g (0.9 mol) of succinic anhydride at 90 to 100.degree. C. 
The mixture was subsequently stirred under a weak stream of nitrogen at 
100.degree. C. for 2 hours and then at 150.degree. C. for 3 hours, during 
which time the initially creamy white mass became thinner and slightly 
brownish liquid. The mixture was cooled to 100.degree. C. and filtered 
over a G-2 glass frit, thereby giving 1,480 g of a viscous, slightly 
cloudy brownish liquid having the following properties: 
______________________________________ 
pH at 1% strength in completely 
4.6 
desalinated water 
Turbidity point at 1% strength in 
94-96.degree. C. 
completely desalinated water 
Solidification point about 25.degree. C. 
Acid number (mg KOH/g) 29.5 
______________________________________ 
The mixture thus obtained contained more than 90% of a dicarboxylic acid 
half-ester according to formula (XI). 
Example 9 
______________________________________ 
4.3 parts 
of the dispersing agent mixture described in Example 
______________________________________ 
8 
were melted at 80.degree. C. and added to 
______________________________________ 
7.9 parts of deionized water and 
______________________________________ 
dissolved completely. The solution was then introduced into 
______________________________________ 
87.8 parts 
of a water-moist presscake of Colour Index Pigment Red 122 
having a dry substance content of 31.9%, and 
______________________________________ 
the mixture was precomminuted and homogenized by means of a dissolver. 
During this operation the pH of the suspension was adjusted to 8.0 using 
dilute sodium hydroxide solution. Thereafter, grinding was carried out as 
described in Example 2. The resultant aqueous pigment preparation was 
formulated to a pigment concentration of 25% with 
______________________________________ 
0.1 part 
of a preservative (benzisothiazolin-3-one) and deionized 
______________________________________ 
water. 
This preparation had very good flow properties and an excellent suspension 
stability during storage for three months at both room temperature and 
50.degree. C. 
The preparation thus obtained was diluted to a pigment concentration of 4% 
for use as a printing ink for ink-jet printing. The composition and 
properties of the printing ink were chosen as follows: 
______________________________________ 
Deionized water 69% 
Polyethylene glycol (molecular weight: 800 g/mol) 
10% 
25% strength pigment preparation described above 
16% 
2-pyrrolidone 5% 
pH 
7.2 
Surface tension &gt;30 
mN/m 
Maximum particle size (disc centrifuge) 
&lt;0.2 .mu.m 
______________________________________ 
The printing ink could be used for printing without problems on a 
commercially available ink-jet printer (analogously to Examples 5 to 7) 
and gave printed images having high color strength and high brilliance, as 
well as good fastness to water and text marker.