Pigment formulation based on CI Pigment Violet 23

Abstract

A pigment preparation comprising: a) as base pigment, CI Pigment Violet 23 of formula I, JPEG2025515961000017.jpg57170b) as pigment synergists, perylenetetracarboxylic diimide compounds of the general formula II containing at least one sulfonic acid group, JPEG2025515961000018.jpg51170 where: A is a divalent residue >NR 1 or >NR 2 -SO3 - X + and R 1 is a hydrogen atom or C1-C 30 - alkyl group, preferably C1-C 18 - an alkyl group, in particular a C1-C4-alkyl group, or an aryl group, preferably a phenyl group, in which the aryl group may be unsubstituted or mono- or polysubstituted by halogen, such as chlorine or bromine, by sulfo, by C1-C4-alkyl, such as methyl or ethyl, by C1-C4-alkoxy, such as methoxy or ethoxy, or by phenylazo, R 2 is an unbranched or branched C1-C6-alkylene radical, in particular ethylene or propylene, X + is NR 3 R 4 R 5 R 6+ and R 3 , R 4 , R 5 , R 6 is H, unbranched or branched C1-C 30 -alkyl, phenyl or phenyl-C1-C6-alkyl.

Description

[Technical field]

[0001] The present invention relates to a pigment formulation based on CI Pigment Violet 23, a process for producing it, and its uses. [Background technology]

[0002] In many cases, the organic pigments produced during synthesis or after finishing are not suitable for direct use as pigments in printing inks or printing ink concentrates: especially in systems containing a large amount of esters, difficulties such as insufficient wetting and flocculation of the pigments often occur, which results in the optimum color strength (tinting power), gloss, transparency and required purity not being achieved.

[0003] As a result, the viscosity often increases during storage, making further handling difficult or impossible, especially in printing ink concentrates.

[0004] In low viscosity formulations, poor pigment dispersion and wetting can lead to problems in further processing, especially settling.

[0005] Therefore, in order to improve the application properties of pigments, it is advantageous to add pigment synergists to the raw synthetic products or pre-finished products to produce pigment preparations which exhibit a significant improvement in quality compared to the corresponding base pigments.

[0006] EP 0 504 922 A1 discloses a pigment preparation containing: a) CI Pigment Violet 23 of general formula I as base pigment [ka] and b) as a pigment synergist, Dioxazine compounds of the general formula Ia [ka] During the ceremony Q represents an n-valent residue of a basic structure according to formula I; X ++ is H + , or M for m-valent metal cations m+ / m, or structure NR 1 R 2 R 3 R 4 represents an ammonium ion having the formula:

[0007] EP 486531 B1 describes perylene compounds containing sulfonic acid groups, in particular N-methyl-N-ethane-2-sulfonic acid-perylenetetracarboxylic acid diimides, and their use as fluorescent dyes, as colorants for coloring high molecular weight organic materials, and as pigment dispersants for base pigments of the azo, quinacridone and perylene compound classes in general and in particular. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] EP504922A1 [Patent Document 2] EP486531B1 Summary of the Invention [Problem to be solved by the invention]

[0009] The subject of the present invention is the further development of pigment formulations based on CI Pigment Violet 23 (PV23), with the aim to optimize the colorant properties, such as increased color strength, gloss and transparency, while at the same time improving the rheological properties towards Newtonian flow behavior and perfect storage stability. [Means for solving the problem]

[0010] This problem is solved by a pigment preparation which comprises: a) as a CI base pigment, Pigment Violet 23 of formula I, [ka] b) as pigment synergists, perylenetetracarboxylic diimide compounds of formula II containing at least one sulfonic acid group [ka] where: A is a divalent radical >NR 1 or >NR 2 -SO 3 - X + and R 1 is a hydrogen atom or C 1 -C 30 -Alkyl group, preferably C 1 -C 18 -Alkyl groups, especially C 1 -C 4 - an alkyl group or an aryl group, preferably a phenyl group, where the aryl group is unsubstituted or is substituted with a halogen, e.g., chlorine or bromine, sulfo, C 1 -C 4 -alkyl, e.g., methyl or ethyl, C 1 -C 4 - optionally mono- or polysubstituted by alkoxy, such as methoxy or ethoxy, or by phenylazo, such as mesitylyl, R 2 is unbranched or branched C 1 -C 6 - an alkylene group, in particular ethylene or propylene, X + is NR 3 R 4 R 5 R 6+ and R 3 , R 4 , R 5 , R 6 is H, unbranched or branched C 1 -C 30 -Alkyl, phenyl or phenyl-C 1 -C 6 -alkyl, for example benzyl.

[0011] The pigment preparations according to the invention exhibit high tinctorial strength, high gloss, high transparency, very good rheological properties and very good compatibility with ester-rich solvent mixtures.

[0012] It was quite surprising that the sulfonic acid group-containing perylene tetracarboxylic diimide compounds of the general formula II showed good suitability as pigment synergists for CI Pigment Violet 23, because of the large structural difference between dioxazine compounds such as PV23 on the one hand and perylene compounds on the other hand.

[0013] In a preferred pigment formulation, in formula II, R 1 is methyl, R 2 is C 2 -alkylene. Particularly preferred is the ammonium salt of N-methyl-N-ethane-2-sulfonic acid-perylenetetracarboxylic acid diimide.

[0014] In another preferred pigment formulation, R 3 is hexadecyl, and R 4 , R 5 and R 6 is methyl.

[0015] In a further preferred pigment formulation, R 3 and R 4 is hexadecyl and / or octadecyl, R 5 and R 6 is methyl.

[0016] The pigment synergist of general formula II preferably contains at least one sulfonic acid group and is a corresponding perylenetetracarboxylic diimide compound of general formula III [ka] In the formula, M + H + , metal cation, or m-valent metal cation equivalent M m+ / m, And, The corresponding ammonium halide compound NR 3 R 4 R 5 R 6+ Hal - In the pigment preparations, the preferred halide is the chloride.

[0017] Suitable metal cations M + or M m+ Li + , Na + , K + , Mg 2+ , Ca 2+ , Sr 2+ , B.A. 2+ , Mn 2+ , Cu 2+ , Ni 2+ , Cd 2+ , Co 2+ , Zn 2+ , Fe 2+ , Al 3+ , Cr 3+ or Fe 3 It is. + and K. + is preferred.

[0018] The claimed pigment preparations can be prepared in various ways. Thus, according to the invention, the synergist can be added to the base pigment during the preparation process, as an aqueous or aqueous-solvent-containing suspension of the individual components or their mixtures, as a water-moist presscake before drying or as an already dried powder, in particular a) a wet presscake of the base pigment, b) As part of the fine distribution process of the crude crystalline pigment raw material, for example, the following steps are carried out: b1) Dry grinding with or without salt, b2) Wet grinding with or without solvent; c) Pigments that are already finely divided raw materials, before, during or after a subsequent solvent finishing treatment; d) in the case of dry mechanical mixing, e.g. mixing of finely divided synergists with pigment powders, and finally e) Only if the pigment is incorporated into the intended application medium.

[0019] The preferred technique for producing the pigment preparation according to the present invention is dry and wet grinding.The addition of pigment synergist can be carried out during the dry grinding of the raw pigment, for example on a roller or vibratory mill, with or without additional grinding aid, or during the wet grinding of the raw pigment in aqueous, aqueous-organic or organic grinding medium, on a vibratory mill, roller or ball mill.The use of synergist for the pigment of the lower layer in aqueous or aqueous-organic medium before, during or after print finishing has also proven reliable.

[0020] The amount of pigment synergist b) added to the base pigment a) in the production of the pigment preparation according to the invention is not limited in the direction of a particular maximum value, provided that the desired pigment quality is not adversely affected thereby, but is generally calculated on the basis of the respective pigment weight and takes into account contents of 0.1 to 30% by weight, in particular 0.5 to 5% by weight, of the individual synergist.

[0021] In addition to the pigment a) and the pigment synergist b), the claimed pigment preparations can also contain other ingredients such as surfactants, resins or antidust agents.

[0022] A pigment preparation within the scope of the present invention therefore essentially consists of: a) 99.5 to 70% by weight of a base pigment of formula I, b) 0.5 to 30% by weight of a synergist of formula II, c) 0 to 5% by mass of a nonionic surfactant, and d) 0 to 5% by weight of customary additives; Here, the percentage of each component is based on the total weight (100%) of the formulation.

[0023] Pigment Preparations By first wet-grinding the PV23 raw pigment in the coarse crystalline state during drying of the wet press cake resulting from the pigment synthesis in a liquid medium in the presence of a pigment synergist on a stirred ball mill until the desired degree of fine distribution of the resulting pigment particles is achieved, and the ground suspension obtained here can then, in the case of intermediate isolation after reabsorption into liquid, be directly subjected to a conventional finishing treatment at high temperature involving organic solvents, to produce in a convenient manner a pigment preparation based on CI Pigment Violet 23 with excellent coloristic and rheological properties, where the pigment synergist can be added at any time in the course of the two process steps defined above. In the process adopted according to the claimed method for formulating the base pigment of formula I, fine distribution and finishing are combined in a simple and elegant manner.

[0024] The production of these pigment preparations according to the invention requires high grinding efficiency, which is achieved by using stirred ball mills of special design in conjunction with the observance of the specified grinding and finishing conditions. Stirred ball mills designed for discontinuous or continuous operation, with cylindrical or hollow cylindrical grinding chambers of horizontal or vertical design, capable of operating with a specific power density of at least 2.5 kW per liter of grinding chamber and with a peripheral speed of the stirrer of at least 12 m per second, are suitable for grinding with the required efficiency. The energy released by the stirrer per unit of time is transferred to the material to be ground in the form of heat, as grinding work and as frictional energy. In order to dissipate this large amount of heat without problems, design considerations must ensure that the ratio of the grinding chamber to the grinding chamber surface (cooling surface) is as small as possible.

[0025] Balls made of zirconium oxide, zirconium mixed oxide, aluminum oxide or quartz with a diameter of ≦1 mm are used as grinding media, balls with a diameter of 0.2-1 mm, preferably 0.3-0.5 mm.

[0026] When using a continuous stirred ball mill for fine distribution, the grinding media is preferably separated from the material to be ground by centrifugation, so that the separating device does not substantially come into contact with the grinding media, thus preventing most clogging. The stirred ball mill is operated with a high degree of filling of the grinding media. In a continuous stirred ball mill, the grinding chamber is substantially completely filled with grinding media.

[0027] The pigment concentration in the mill is ≦about 40% by weight, typically 10-35% by weight, preferably 10-20% by weight. The milling is carried out in a medium of aqueous, aqueous / organic or organic solvent type, preferably in the alkaline or neutral pH range. In addition to the liquid phase and the raw pigment, the milling may contain pigment dispersants, surfactants and other additives. The residence time of the milling in the stirred ball mill depends on the required fineness, but is generally 10-60 minutes, preferably 10-45 minutes, preferably 10-30 minutes. The milling is carried out at a temperature in the range of 0° C. to 100° C., preferably 10° C. to 60° C., preferably 20° C. to 50° C.

[0028] The liquid grinding media used is water; water-miscible C 1 -C 4 -alkanols, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol or isobutanol; cyclic alkanols, such as cyclohexanol; C 1 -C 6 dialkyl ketones, such as acetone, diethyl ketone, methyl isobutyl ketone or methyl ethyl ketone; ethers and glycol ethers, such as methyl glycol, ethyl glycol, butyl glycol, ethyl diglycol or methoxybutanol; aliphatic acid amides, such as formamide or dimethylformamide; formamide or dimethylformamide; cyclic carboxylic acid amides, such as N-methylpyrrolidone, valero- and caprolactam; heterocyclic bases, such as pyridine, morpholine or picolines; as well as mixtures of these solvents with water; in particular aqueous solutions of isobutanol, such as 5% isobutanol.

[0029] The pigment synergists can be added all at once or in several portions. They can be added before, during or after grinding, but also before, during or after finishing. The most suitable time must be determined in advance by preliminary tests. The addition can be made in the dry state, in the form of a moist presscake or as an aqueous or aqueous-solvent-containing suspension of the individual components or their mixtures.

[0030] The invention also relates to the use of the pigment preparation for pigmenting high molecular weight organic materials of natural or synthetic origin in the form of plastic masses, melts, spinning solutions, lacquers, paints or printing inks.

[0031] Preferred is the use in pigmented (colored) printing inks based on nitrocellulose, in particular in gravure and flexographic inks for packaging based on nitrocellulose. In addition to pure NC inks, PU, ​​PA, PVB and CAB binder systems are also used, as well as in combination with NC concentrates for the production of blended printing inks.

[0032] The present invention also relates to the use of the pigment preparation for pigmenting a colour filter. EXAMPLES

[0033] The following examples will explain the invention in more detail. example Testing pigments in NC-alcohol-gravure printing with increased pigment concentration Pigments commonly used in nitrocellulose-based packaging gravure and flexographic inks were tested as follows.

[0034] Preparation of dispersions using a shaker First, prepare a mixed solvent of 98% ethanol and 2.0% ethyl alkoxide by mass. Prepare one standard and one sample as follows, and disperse them on a shaker at 660 rpm for 45 minutes.

[0035] After being dispersed with a shaker, the concentrated ink is passed through a sieve into a plastic cup and the balls are separated.

[0036] [Table 1]

[0037] Gloss and Transparency Measurement The ink is prepared as follows: 15 g of the dispersion concentrate and 0.75 g of Solvenon PM (1-methoxy 2-propanol) are weighed into a 150 ml plastic beaker and shaken for 3 minutes in a "Disperser DAS 200K".

[0038] Type and sample concentrated colours are applied side by side, as streak-free as possible, to Leneta WF White (glossy) and Leneta WF Black Barred (transparent) test papers using a KCC Doctor Blade applicator (12 μm wet film thickness).

[0039] The judgement is done visually. It is important that the evaluation of transparency is done in a non-glossy state.

[0040] [Table 2]

[0041] Determining flow time The viscosity is measured in the concentrated printing ink without "Solvenon PM". This requires a minimum of 50 g of printing ink concentrate. The dispersion concentrate is preheated in a water bath at 23°C for 60 minutes.

[0042] The prepared printing ink concentrate is measured in an appropriately selected Zahn-Cup using a Cup Timer 243T (electronic measuring device for flow times) as follows:

[0043] Preparation of blended printing ink for colorimetric determination 5.0g concentrated printing ink (see above) 45.0g Varnish 1 (NC alcohol varnish)

[0044] For colorimetric determination, the concentrated pigment is mixed with NC blend varnish to adjust the pigment content to 2%. Under this condition, the absorption and reflectance ratio of the mixed ink is suitable for colorimetric measurement using a spectrophotometer.

[0045] The type and sample printing inks are applied side by side on Apco II / II test paper A white with a KCC doctor blade applicator level 7, weight bar 2. The above mentioned drawdowns are measured and evaluated at two different measuring positions using a spectrophotometer with 3.7% gloss removal, using a template, to determine the colorimetric properties (color strength, hue, purity) according to CIELAB.

[0046] Testing the compatibility of printing ink concentrates when diluted with ethyl acetate The printing ink concentrate is weighed into a 150 ml PE beaker with a plug-in lid. A solvent mixture consisting of 50% by weight ethanol and 50% by weight ethyl acetate is added while stirring and shaken by hand.

[0047] [Table 3]

[0048] Warm the ester-stable ink diluted in the solvent mixture for 60 min in a water bath (23 °C). A visual evaluation of the printing inks for ester compatibility was then performed as follows: -Changes in viscosity (low, medium, high) -Lump formation -phase separation

[0049] The formulated ester stable inks are measured after 24 hours to determine viscosity, thixotropy, and flow behavior using a rotational viscometer (cone and plate configuration).

[0050] Microscopic assessment of flocculation stability: Ester Stability The flocculation stability of the ink is evaluated using a microscope at 110x magnification. It is rated from 1 (poor) to 5 (very good).

[0051] evaluation The color properties are evaluated visually and colorimetrically according to the CIELAB formula (DINISO 18314-2).

[0052] Printing ink (blending): Drawdown on APCO II / II Papier A: Colorimetric determination of color intensity, hue (dH) and chroma (dC).

[0053] [Table 4]

[0054] Example 1 A test equivalent to Example 4 was carried out using 2.62 g of HPP-additive (89.6%) and 4.85 g of Arquad 16-29 (29%).

[0055] Example 2 A test equivalent to Example 4 was carried out using 2.36 g of HPP-additive (89.6%), 4.37 g of Arquad 16-29 (29%), and 0.35 g of Solsperse 5000S.

[0056] example Addition of additive ingredients before grinding 560 g of raw pigment (Pigment Violet 23) and 15.72 g of HPP-additive (89.6%) suspended in a mixture of 3430 g of water and 10.0 g of 33% aqueous caustic soda solution are added to a ball mill Drais DCP SF12 (manufacturer: Draiswerke GmbH, Mannheim) filled with 3522 g of zirconium oxide beads with a diameter of 0.35-0.45 mm as grinding medium, and grind for 52 minutes at a rotation speed of 1470 rpm, a throughput of 600 ml / min, an input power of 4 kW, and 35 ° C. Then 17.17 g of Genamin DSAP (90%) is added and stirred for 1 hour at 25 ° C.

[0057] For finishing, 500 g of the resulting pearl mill suspension are adjusted to a pH of 6.5 by adding formic acid, 150 g of an aqueous solution of isobutanol (85%) are added and the mixture is stirred for 5 hours at 25° C. The mixture is then heated to 130° C. in an autoclave and kept at this temperature for 5 hours, after which the isobutanol is azeotropically removed by heating to its transition point of 100° C. After cooling to 60° C., the pigment thus obtained is isolated by filtration of the aqueous suspension, washed with demineralized water to a conductivity of <100 μS and dried at 80° C.

[0058] Example 4 Various additions of post-finish additive ingredients 560 g of raw pigment (Pigment Violet 23) suspended in a mixture of 3311 g of water and 129 g of 33% caustic soda was added to a Drais DCP SF12 stirred ball mill (manufacturer: Draiswerke GmbH, Mannheim) filled with 3522 g of zirconium oxide beads with a diameter of 0.35 to 0.45 mm as a grinding medium, and ground for 52 minutes at a rotation speed of 1470 rpm, a throughput of 600 ml / min, an input power of 4 kW, and 35°C.

[0059] For the finishing, 500 g of the resulting pearl mill suspension are adjusted to a pH of 6.5 by adding formic acid, 150 g of an aqueous solution of isobutanol (85%) are added and the mixture is stirred for 5 hours at 25°C. The mixture is then heated to 130°C in an autoclave and kept at this temperature for 5 hours, after which it is heated at the transition point to 100°C in order to azeotropically remove the isobutanol. After cooling to 60°C, 1.96 g of HPP-additive (89.6%) are added to the distillation residue and after stirring for 1 hour, 2.15 g of Genamin DSAP (90%) are added and stirred for a further 2 hours at 60°C. The pigment thus obtained is isolated by filtration of the aqueous suspension, washed with demineralized water to a conductivity of <100 μS and dried at 80°C.

[0060] The same results are obtained by adding a pre-prepared mixture of the two additive components in isopropanol / water.

[0061] Example 5 Various additions of additive ingredients before finishing 560 g of raw pigment (Pigment Violet 23) suspended in a mixture of 3311 g of water and 129 g of 33% aqueous sodium hydroxide solution is added to a stirred ball mill of the Drais DCP SF12 type (manufacturer: Draiswerke GmBH, Mannheim) filled with 3522 g of zirconium oxide beads with a diameter of 35 to 0.45 mm as grinding medium, and grind for 52 minutes at 35 ° C. at a rotation speed of 140 rpm, a throughput of 600 ml / min, and an input power of 4 kW. After grinding is completed, the mixture is stirred for 1 hour at 25 ° C.

[0062] For finishing, 500 g of the obtained pearl mill suspension are adjusted to a pH of 6.5 by adding formic acid, 1.96 g of HPP-additive (89.6%) are added, stirred for 1 hour at 25°C, then 2.15 g of Genamin DSAP (90%) are added and stirred again for 1 hour at 25°C. 150 g of an aqueous solution of isobutanol (85%) are then added and stirred for 5 hours at 25°C. The mixture is then heated to 130°C in an autoclave and kept at this temperature for 5 hours, after which the isobutanol is azeotropically removed by heating to 100°C at the transition point. After cooling to 60°C, the pigment thus obtained is isolated by filtration of the aqueous suspension, washed with demineralized water to a conductivity of <100 μS and dried at 80°C.

[0063] Comparative Example V2 As in Example 4, but without additives and with immediate treatment.

[0064] Comparative example V3 Repeat as in Example 4 using 11.22 g of Modifier #3C (22.3%) and 4.21 g of Arquad 16-29 (29%). Modifier #3C is used as an aqueous suspension neutralized with dilute aqueous sodium hydroxide.

[0065] Comparative Example V4 As in Example 3, but 28 g of Solsperse 5000S was used instead of the HPP-additive; in this embodiment there is no addition of Genamin DSAP.

[0066] Comparative Example V5 The same procedure as in Example 4 is carried out using 2.12 g (97%) of sodium anthraquinone-2-sulfonate hydrate and 6.92 g (29%) of Arquad 16-2.

[0067] Comparative example V6 As in Example 4, but without the addition of Genamin DSAP. The 2.2% pigment drawdown is redder (6 redder) and duller (2 duller) in the visual shade test compared to Reference Example V1.

[0068] [Table 5]

[0069] [Table 6]

[0070] [Table 7]

Claims

1. A pigment preparation comprising: a) as base pigment, C.I. Pigment Violet 23 of formula I, 【Chemistry 1】 b) as pigment synergists, perylenetetracarboxylic diimide compounds of the general formula II containing at least one sulfonic acid group, 【Chemistry 2】 Where: A is a divalent residue >NR １ Or > N-R ２ -SO ３ － X ＋ and R １ is a hydrogen atom or C １ -C ３０ - an alkyl group, preferably C １ -C １８ -Alkyl groups, especially C １ -C ４ an alkyl or aryl group, preferably a phenyl group, wherein the aryl group is unsubstituted or substituted with halogen, e.g., chlorine or bromine, sulfo, C １ -C ４ - alkyl, for example methyl or ethyl, C １ -C ４ - optionally mono- or polysubstituted by alkoxy, for example methoxy or ethoxy, or by phenylazo, R ２ is a linear or branched chain C １ -C ６ an alkylene group, in particular ethylene or propylene, X ＋ is N.R. ３ R ４ R ５ R ６＋ and R ３ , R ４ , R ５ , R ６ is H, unbranched or branched C １ -C ３０ -alkyl, phenyl or phenyl-C １ -C ６ - alkyl.

2. R １ is methyl, R ２ is C ２ 2. The pigment preparation according to claim 1, characterized in that:

3. R ３ is hexadecyl, R ４ , R ５ and R ６ 3. The pigment preparation according to claim 1, wherein is methyl.

4. R ３ and R ４ is hexadecyl and / or octadecyl, R ５ and R ６ 3. The pigment preparation according to claim 1, wherein is methyl.

5. The compound of general formula II is a perylene tetracarboxylic diimide compound of general formula III containing at least one sulfonic acid group. 【Chemistry 3】 (In the formula, M ＋ Is H ＋ , a metal cation, or an equivalent M of a metal cation with a valence of m ｍ＋ / m) And, The corresponding ammonium halide compound NR ３ R ４ R ５ R ６＋ Hal － 5. The pigment preparation according to claim 1 , wherein the pigment preparation is produced from

6. a) 99.5 to 70% by weight of a base pigment of formula I, b) 0.5 to 30% by weight of a synergist of formula II, c) 0 to 5% by weight of a nonionic surfactant, and d) 0 to 5% by weight of customary additives, (wherein the percentage of each ingredient is based on the total weight of the formulation) 6. The pigment preparation according to claim 1 , comprising:

7. 7. A process for producing a pigment preparation according to claim 1, characterized in that the surface structure of the base pigment a) is uniformly coated with the pigment synergist b).

8. 8. The process according to claim 7, characterized in that the pigment synergist b) is added to the coarsely crystalline raw material-based pigment a) during its micronization in the course of dry or wet grinding.

9. 8. The method according to claim 7, characterized in that the pigment synergist b) is added to the water-wet presscake of the base pigment a).

10. 8. The method according to claim 7, characterized in that the pigment synergist b) is added to the finely divided base pigment a) in the course of a solvent finishing treatment.

11. 8. The method according to claim 7, characterized in that the pigment synergist b) is mechanically mixed in the dry state with the finely divided base pigment a).

12. 7. Use of a pigment preparation according to any one of claims 1 to 6 for pigmenting high molecular weight organic materials of natural or synthetic origin in the form of plastic materials, melts, spinning solutions, lacquers, paints or printing inks.

13. 13. Use according to claim 12 for pigmenting (colouring) printing inks based on nitrocellulose.

14. 7. Use of a pigment preparation according to any one of claims 1 to 6 for pigmenting colour filters.

Images