Preparation of pigments based on CI 23 violet pigment

Abstract

A pigment formulation comprising (a) CI Violet 23 pigment of formula (I) as a base pigment, (b) a perylenetetracarboxylic diimide compound containing at least one sulfo group and of general formula (II) as a pigment synergist, wherein: A is a divalent radical >NR1 or >N-R2-SO3-X+, R1 is a hydrogen atom or a C1-C30 alkyl group, preferably a C1-C18 alkyl group and especially a C1-C4 alkyl group, or an aryl group, preferably phenyl, wherein the aryl group may be unsubstituted or mono- or polysubstituted by halogen such as chlorine or bromine, sulfo, C1-C4 alkyl such as methyl or ethyl, C1-C4 alkoxy such as methoxy or ethoxy, or phenylazo, R2 is a linear or branched C1-C6 alkylene group, especially ethylene or propylene, X+ is NR3R4R5R6+ with R3, R4, R5, R6 = H, unbranched or branched C1-C30 alkyl, phenyl or C1-C6 phenylalkyl.

Description

[0001] The present invention relates to pigment preparations based on CI pigment violet 23, methods for their production and their use.

[0002] The organic pigments obtained during their synthesis or after finishing are often unsuitable for direct use in pigmenting printing inks or printing ink concentrates. Difficulties often arise, such as insufficient pigment wetting and flocculation, especially in ester-rich systems, which prevents the achievement of optimal color strength, gloss, transparency, and the required fineness.

[0003] Viscosity increases often occur during storage, which, especially in the case of printing ink concentrates, make further handling difficult or impossible.

[0004] In low-viscosity settings, insufficiently dispersed and wetted pigments can also cause problems during further processing; in particular, this can easily lead to sedimentation problems.

[0005] In order to improve the application-related properties of pigments, it is therefore advantageous to produce pigment preparations by adding pigment synergists to the crude synthesis product or pre-finished product, which show a significant increase in quality compared to the corresponding base pigment.

[0006] EP 0 504 922 A1 discloses pigment preparations containing a) CI Pigment Violet 23 of formula I as base pigment and b) a dioxazine compound of the general formula a1a Q[SO 3 -< X +< ] n (a1a), wherein Q represents an n-valent residue of the basic structure according to formula I; X +< represents H +< or the equivalent M m+< / m of an m-valent metal cation or an ammonium ion with the structure N +< R 1< R 2< R 3< R 4<, as pigment synergists.

[0007] EP 486 531 B1 describes perylene compounds containing sulfonic acid groups, specifically N-methyl-N-ethane-2-sulfonic acid perylenetetracarboxylic acid diimide, and their use as fluorescent dyes, as colorants for pigmenting high-molecular-weight organic materials, and generally as pigment dispersants for base pigments from the class of azo, quinacridone, and especially perylene compounds. EP 0 937 724 A1 also describes pigment preparations containing perylene compounds and an organic base pigment.

[0008] The object of the present invention is the further development of pigment preparations based on CI Pigment Violet 23 (PV23). The aim is to optimize the coloristic properties, such as increasing color strength, gloss and transparency, while simultaneously improving the rheological properties towards Newtonian flow behavior and excellent storage stability.

[0009] The problem is solved by pigment preparations containing a) CI Pigment Violet 23 of formula I as base pigment, b) a perylenetetracarboxylic acid diimide compound of general formula II containing at least one sulfonic acid group as a pigment synergist wherein: A a bivalent residue >NR 1< or >NR 2< -SO 3 -< X +< R 1< a hydrogen atom or a C 1 -C 30 alkyl group, preferably a C 1 -C 18 alkyl and in particular a C 1 -C 4 alkyl group, or an aryl group, preferably phenyl, wherein the aryl group may be unsubstituted or may be singly or multiply substituted by halogen such as chlorine or bromine, sulfo, C 1 -C 4 alkyl such as methyl or ethyl, C 1 -C 4 alkoxy such as methoxy or ethoxy, or phenylalozo, for example mesitylyl, R 2< a straight-chain or branched C 1 -C 6 alkylene group, in particular ethylene or propylene, X +< NR 3< R 4< R 5< R 6+< with R 3< , R 4< , R 5< , R 6< H, unbranched or branched C1-C30 alkyl, phenyl or phenyl-C1-C6 alkyl, for example benzyl.

[0010] The pigment preparations according to the invention are characterized by high color strength, high gloss, high transparency, very good rheological properties, and very good compatibility with ester-rich solvent mixtures.

[0011] The suitability of the perylenetetracarboxylic acid diimide compound of general formula II containing the sulfonic acid group as a pigment synergist for CI Pigment Violet 23 was very surprising due to the large structural difference between dioxazine compounds such as PV23 on the one hand and perylene compounds on the other.

[0012] In a preferred pigment preparation, R1 in formula II is methyl and R2 is C2-alkylene. The ammonium salt of N-methyl-N-ethane-2-sulfonic acid perylenetetracarboxylic acid diimide is particularly preferred.

[0013] In another preferred pigment preparation, R 3< is hexadecyl and R 4< is , R 5< and R 6< is methyl.

[0014] In another preferred pigment preparation, R 3< and R 4< are hexadecyl and / or octadecyl, as well as R 5< and R 6< methyl.

[0015] The pigment synergist of general formula II is preferably prepared from a corresponding perylenetetracarboxylic acid diimide compound of general formula III containing at least one sulfonic acid group. wherein M< H< , a metal cation or the equivalent M m< , of an m-valent metal cation, and a corresponding ammonium halide compound NR 3< R 4< R 5< R 6< Hal -< is generated in the pigment preparation itself. The preferred halide is the chloride.

[0016] Suitable metal cations M< or M< are Li<, Na<, K<, Mg<, Ca<, Sr<, Ba<, Mn<, Cu<, Ni<, Cd<, Co<, Zn<, Fe<, Al3+, Cr3+, or Fe<. Na< and K< are preferred.

[0017] The claimed pigment preparations can be prepared in various ways. According to the invention, the synergists can be added to the base pigment during the preparation process as an aqueous or aqueous-solvent suspension of the individual components or their mixture, as a moist press cake before drying, or as an already dry powder. a) the moist press cake of the base pigment, b) as part of a fine distribution process of the coarse-crystalline raw pigment, such as b1) dry milling with and without salt, b2) wet milling with or without solvent, c) the already finely divided raw pigment before, during or after a subsequent solvent finish treatment, d) during mechanical mixing in the dry state, such as of ground synergists with the pigment powder, and finally e) only when the pigment is incorporated into the intended application medium.

[0018] According to the invention, dry and wet milling are considered preferred techniques for producing the pigment preparations. The addition of the pigment synergists can be carried out, for example, during dry milling of the crude pigment with or without additional milling aids on a roller or vibratory mill, or during wet milling of the crude pigment in aqueous, aqueous-organic, or organic milling media on a vibratory, roller, or bead mill. The application of the synergists before, during, or after the printing finish for the underlying pigment in aqueous or aqueous-organic media has also proven to be reliable.

[0019] The amounts of pigment synergists b) to be added to the base pigment a) in the production of the pigment preparations according to this invention are not limited to a specific maximum value, provided that the desired pigment quality is not negatively affected, but in general a content of 0.1 to 30 wt.%, in particular of 0.5 to 5 wt.% of the individual synergist, calculated on the respective pigment weight, is suitable.

[0020] The claimed pigment preparations may contain, in addition to pigment a) and pigment synergists b), other components such as surfactants, resins or anti-dust agents.

[0021] Pigment preparations within the meaning of the present invention therefore consist essentially of a) 99.5 to 70 wt.% base pigment of formula I, b) 0.5 to 30 wt.% of the pigment synergist of formula II, c) 0 to 5 wt.% of a non-ionic surfactant, and d) 0 to 5 wt.% of common additives, where the proportions of the respective components are based on the total weight (100%) of the preparation.

[0022] Pigment preparations based on CI Pigment Violet 23 with excellent coloristic and rheological properties can be easily produced by first wet-milling the PV 23 crude pigment, which is formed in a coarse-crystalline state during the drying of the moist press cake from pigment synthesis, in a liquid medium on a stirred ball mill in the presence of the pigment synergist until a desired degree of fineness of the resulting pigment particles is achieved. The resulting milled material suspension is then subjected directly, or, in the case of intermediate isolation, after its reabsorption in a liquid, to a standard finishing treatment at elevated temperature with the involvement of organic solvents. The pigment synergists can be added at any time during the two previously defined treatment steps.The measures taken according to the claimed method for formulating the base pigment of formula I combine fine distribution and finish in a simple and elegant way.

[0023] The production of these pigment preparations according to the invention requires a high grinding efficiency, which is achieved by using a special embodiment of the stirred ball mill in conjunction with adherence to specified grinding and finishing conditions. Stirred ball mills designed for discontinuous or continuous operation, with a cylindrical or hollow cylindrical grinding chamber in a horizontal or vertical configuration, are suitable for grinding with the required efficiency. These mills can be operated with a specific power density of over 2.5 kW per liter of grinding chamber and have a peripheral speed of over 12 m per second. The energy delivered by the agitator per unit time is transferred to the material being ground as comminution work and as frictional energy in the form of heat.To ensure the trouble-free dissipation of this large amount of heat, the ratio of grinding chamber to grinding chamber surface (cooling surface) must be kept as small as possible through design measures.

[0024] The grinding media consists of spheres made of zirconium oxide, zirconium mixed oxide, aluminum oxide or quartz with a diameter ≤ 1 mm; those with a diameter of 0.2 to 1 mm, preferably 0.3 to 0.5 mm, are advantageously used.

[0025] When using continuous stirred ball mills for fine dispersal, the separation of the grinding media from the material being ground is preferably achieved by centrifugal separation, so that the separating devices are practically never in contact with the grinding media, thus largely preventing clogging. The stirred ball mills are operated with a high degree of media filling. In continuous stirred ball mills, the grinding chamber is practically completely filled with grinding media.

[0026] The pigment concentration in the milled material should be ≤ 40 wt.%, generally 10 to 35 wt.%, and preferably between 10 and 20 wt.%. Milling is carried out in aqueous, aqueous / organic, or organic solvent-type media, preferably in the alkaline or neutral pH range. In addition to the liquid phase and the crude pigment, the milled material may contain pigment dispersants, surfactants, and other additives. The residence time of the milled material in the stirred ball mill is generally between 10 and 60 minutes, depending on the required fineness; it is expediently 10 to 45 minutes, preferably 10 to 30 minutes. Milling is carried out at temperatures in the range of 0° to 100°C, expediently between 10° and 60°C, and preferably between 20° and 50°C.

[0027] Suitable liquid grinding media include water; water-miscible C1-C4 alkanols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, or isobutanol; cyclic alkanols such as cyclohexanol; C1-C6 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 amides such as formamide or dimethylformamide; cyclic carboxylic amides such as N-methylpyrrolidone, valero- and caprolactam; heterocyclic bases such as pyridine, morpholine, or picoline; as well as dimethyl sulfoxide or mixtures of these solvents with water; in particular, a solution of isobutanol in water, e.g., 5% isobutanol, is preferred.

[0028] The pigment synergists can be added all at once or in several portions; they can be added before, during, or after milling, as well as before, during, or after finishing. The most suitable time must be determined beforehand through preliminary trials. The addition can take place in a dry state, as a moist press cake, or as an aqueous or aqueous-solvent suspension of the individual components or a mixture thereof.

[0029] The invention also relates to the use of the pigment preparations for pigmenting high molecular weight organic materials of natural or synthetic origin in the form of plastic masses, melts, spinning solutions, varnishes, paints or printing inks.

[0030] The preferred application is for pigmenting (coloring) nitrocellulose-based printing inks, especially gravure and flexographic packaging inks. In addition to pure NC inks, PU, ​​PA, PVB, and CAB binder systems are also used, as well as their combination with NC concentrates for the production of blended printing inks.

[0031] The invention also relates to the use of the pigment preparations for pigmenting color filters.

[0032] The invention is explained in more detail by the following examples. Examples Testing of pigments in NC alcohol gravure printing at increased pigment concentration

[0033] Pigments used primarily in nitrocellulose-based gravure and flexographic packaging printing inks are tested as follows. Production of a shaking machine friction device

[0034] First, a solvent mixture of 98 wt% ethanol and 2.0 wt% ethyl acetate is prepared. A color is then prepared from both the standard and the sample(s) as follows: and dispersed using a shaking machine at 660 rpm for 45 minutes.

[0035] After dispersion in the shaking machine, the color concentrates are poured through a sieve into a plastic cup to separate the spheres. Table 1: Composition of the printing ink concentrate pigment Pigment concentration [%] Amount of pigment [g] NC varnish (25% 75% ethanol) [g] Solvent mixture (98% ethanol / 2% ethyl acetate) [g] Pigment concentration for color measurement [%] Tooth cup (mm) **( see note) PV23 22 22,00 40,00 38,00 2,2 3 (Pigment:Binder = 1:0.45) Determination of gloss and transparency

[0036] The printing ink is produced as follows: 15 g of dispersing concentrate and 0.75 g of Solvenon PM (1-Methoxy 2-Propanol) are weighed into a 150 ml plastic cup, then shaken for 3 minutes in the "Disperser DAS 200 K".

[0037] The color concentrates of type and sample are applied side by side to test paper Leneta WF white (gloss) and Leneta WF with black bar (transparency) using the KCC doctor blade applicator (wet film thickness 12 µm) as streak-free as possible.

[0038] The assessment is visual. It is important that the transparency is assessed while eliminating glare. Table 2: Rating scale for transparency Visual rating level Visual deviation about like / = / track 1 something 2 noticeably 3 transparent (tra) clearly 4 covering (de) significant 5 significant 6 Determination of the run-out time

[0039] The viscosity is determined using printing ink concentrates without "Solvenone PM". A minimum quantity of 50 g of printing ink concentrate is required. The dispersing concentrates should first be tempered in a water bath at 23°C for 60 minutes.

[0040] The tempered printing ink concentrate is measured as follows using the appropriately selected toothed cup dispensing cup with the Cup Timer 243T (electronic measuring device for dispensing time). Production of blended printing inks for colorimetric determination

[0041] 5,0 g Printing ink concentrate (see above) 45,0 g Varnish 1 (NC alcohol blend varnish)

[0042] For colorimetric determination, the pigment concentrate is mixed with NC blending varnish to adjust the pigment content to 2%. Under these conditions, the ratio of absorption to reflection of the blended printing ink is favorable for colorimetric measurement using a spectrophotometer.

[0043] The printing inks of type and sample are applied side by side onto Apco II / II white test paper A using the KCC doctor blade applicator, stage 7, with weight and rod no. 2, ensuring streak-free application. To determine the coloristic properties according to CIELAB (color intensity, hue, and purity), the draw-downs described above are measured and evaluated at two different measuring positions using a template and a spectrophotometer with a 3.7% gloss reduction. Testing the compatibility of printing ink concentrates when diluted with ethyl acetate

[0044] The printing ink concentrates are weighed into a 150 ml PE cup with a snap-on lid. A solvent mixture consisting of 50 wt% ethanol and 50 wt% ethyl acetate is added while stirring and shaken by hand. Table 3: Composition of ester stability dyes pigment Printing ink concentrate (22% pigment) [g] Solvent mixture (ethanol: ethyl acetate 1:1) [g] Pigment concentration of ester stability colors [%] Tooth cup (mm) PV23 Hostaperm-Violet P-RL 70,00 30,00 15,4 2

[0045] The ester stability paints, diluted with the solvent mixture, are tempered in a water bath (23°C) for 60 minutes.

[0046] The next step is always a visual assessment of the printing inks regarding ester compatibility, as follows: Viscosity change (low, medium or high viscosity), clumping, phase separation Determination of the run-on time:

[0047] The tempered ester stability printing inks are measured after 24 h to determine viscosity, thixotropy and flow behavior using a rotational viscometer (cone-plate arrangement). Microscopic assessment of flocculation stability:

[0048] Assess the flocculation stability of ester-based printing inks using a microscope at 110x magnification. Rating scale from 1 (poor) to 5 (very good). Evaluation

[0049] The evaluation of the color properties is carried out visually and colorimetrically according to the CIELAB formula (DIN ISO 18314-2). Printing ink (cut off):

[0050] Drawdown on APCO II / II paper A: Colorimetric determination of color intensity, hue (dH), chroma (dC). Table 4: Components used Trade name CAS No. Chemical name Manufacturer form Arquad 16-29 203-928-6 Hexadecyltrimethylammonium chloride Akzo Nobel 29% in water Modifier#3C 28901-96-4 copper phthalocyanine monosulfonic acid Heubach moist press cake Genamin DSAP 92129-33-4 Di-C 16 - 18 alkyldimethylammonium chloride Clariant 90% Prills HPP additive 135934-43-9 N-Methy-N-ethane-2-sulfonic acid perylenetetracarboxylic acid diimide Heubach dry powder Solsperse 5000S 70750-63-9 Monosulfonated copper phthalocyanine dioctadecyldimethylammonium salt Lubrizole dry powder AQ-SO 3 Na*H 2 O 153277-35-1 Anthraquinone-2-sulfonic acid, sodium salt Sigma-Aldrich dry powder Example 1

[0051] Perform the procedure analogously to Example 4 using 2.62 g of HPP additive (89.6%) and 4.85 g of Arquad 16-29 (29%). Example 2

[0052] Procedure analogous to Example 4 using 2.36 g HPP additive (89.6%), 4.37 g Arquad 16-29 (29%) and 0.35 g Solsperse 5000S. Example 3 Addition of an additive component before grinding

[0053] In a Drais DCP SF12 stirred ball mill (manufacturer: Draiswerke GmbH, Mannheim), filled with 3522 g of zirconium oxide beads with a diameter of 0.35–0.45 mm as grinding media, 560 g of raw pigment (Pigment Violet 23) and 15.72 g of HPP additive (89.6%), suspended in a mixture of 3430 g water and 10.0 g of 33% sodium hydroxide solution, are placed and milled for 52 minutes at a speed of 1470 rpm, a throughput of 600 ml / min, and a power input of 4 kW at 35°C. Then, 17.17 g of Genamin DSAP (90%) are added and the mixture is stirred for one hour at 25°C.

[0054] For the finishing step, 500 g of the resulting pearl mill suspension are adjusted to a pH of 6.5 by adding formic acid, mixed with 150 g of 85% aqueous isobutanol, and stirred for 5 hours at 25°C. The mixture is then heated to 130°C in an autoclave, held at this temperature for 5 hours, and the isobutanol is distilled off azeotropically by heating to 100°C. After cooling to 60°C, the resulting pigment is isolated by filtration of the aqueous suspension, washed with demineralized water to a conductivity of < 100 µS, and dried at 80°C. Example 4 Variant: Addition of additive components after finishing

[0055] In a Drais DCP SF12 type stirred ball mill (manufacturer: Draiswerke GmbH, Mannheim), which is filled with 3522 g of zirconium oxide beads with a diameter of 0.35 - 0.45 mm as grinding media, 560 g of raw pigment (Pigment Violet 23), suspended in a mixture of 3311 g water and 129 g sodium hydroxide solution 33%, are placed and ground in it at a speed of 1470 rpm, a throughput of 600 ml / min and a power input of 4 kW at 35°C for 52 minutes.

[0056] For the finishing step, 500 g of the resulting pearl mill suspension are adjusted to a pH of 6.5 by adding formic acid, mixed with 150 g of aqueous isobutanol (85%), and stirred for 5 hours at 25°C. The mixture is then heated to 130°C in an autoclave, held at this temperature for 5 hours, and the isobutanol is distilled off azeotropically by heating to 100°C. After cooling to 60°C, the distillation residue is mixed with 1.96 g of HPP additive (89.6%), and after stirring for one hour, 2.15 g of Genamin DSAP (90%) are added, followed by a final 2 hours of stirring at 60°C. The pigment obtained in this way is isolated by filtration of the aqueous suspension, washed with demineralized water to a conductivity < 100 µS and dried at 80°C.

[0057] The same result can also be achieved by adding a pre-prepared mixture of the two additive components to isopropanol / water. Example 5 Variant: Addition of additive components before finishing

[0058] In a Drais DCP SF12 stirred ball mill (manufacturer: Draiswerke GmbH, Mannheim), filled with 3522 g of zirconium oxide beads with a diameter of 0.35–0.45 mm as grinding media, 560 g of raw pigment (Pigment Violet 23), suspended in a mixture of 3311 g water and 129 g of 33% sodium hydroxide solution, are placed and milled for 52 minutes at a speed of 1470 rpm, a throughput of 600 ml / min, and a power input of 4 kW at 35°C. After milling, the mixture is stirred for 1 hour at 25°C.

[0059] For the finishing step, 500 g of the resulting pearl mill suspension are adjusted to a pH of 6.5 by adding formic acid, 1.96 g of HPP additive (89.6%) is added, and the mixture is stirred for 1 hour at 25°C. Then, 2.15 g of Genamin DSAP (90%) is added and the mixture is stirred again for 1 hour at 25°C. Next, 150 g of aqueous isobutanol (85%) is added and the mixture is stirred for 5 hours at 25°C. The mixture is then heated in an autoclave to 130°C, held at this temperature for 5 hours, and the isobutanol is distilled off by heating to 100°C at the azeotropic transition. After cooling to 60°C, the pigment thus obtained is isolated by filtration of the aqueous suspension, washed with demineralized water to a conductivity < 100 µS and dried at 80°C. Comparison example V2

[0060] Procedure analogous to example 4, but immediate reprocessing without additives. Comparison example V3

[0061] Procedure analogous to Example 4 using 11.22 g Modifier#3C (22.3%) and 4.21 g Arquad 16-29 (29%); Modifier#3C is used as an aqueous suspension neutralized with dilute sodium hydroxide solution. Comparison example V4

[0062] The procedure is carried out analogously to Example 3 using 28 g of Solsperse 5000S instead of the HPP additive; the addition of Genamin DSAP is omitted in this embodiment. Comparison example V5

[0063] Perform the procedure analogously to Example 4 using 2.12 g of anthraquinone-2-sodium sulfonate hydrate (97%) and 6.92 g of Arquad 16-29 (29%). Comparison example V6

[0064] Procedure analogous to Example 4, but without the addition of Genamin DSAP. In visual coloristic testing, the 2.2% pigment drawdown is both redder (6 redder) and duller (2 duller) compared to the reference example V1. Table 5 Transparency, gloss, viscosity Concentrate 22% Example Transparency (tra = more transparent) Gloss 60° Standard Gloss 60° Example Viscosity D = 5 s -1< Viscosity D = 10 s -1< Viscosity D = 30 s -1< Viscosity D = 60 s -1< [Pa•s] V1 reference --- --- 12,19 7,93 0,61 0,55 Hostaperm Violet P-RL standard V2 5 tra 44,2 95,5 1,04 0,67 0,34 0,28 No additives 1 5 tra 67,5 105,3 8,30 5,15 1,14 0,86 Arquad 16-29 | HPP additive V3 5 tra 64,3 97,7 9,89 5,00 0,82 0,68 Arquad 16-29 | Modifier#3C V4 5 tra 65,2 97,0 5,25 3,51 0,68 0,55 Solsperse 5000S V5 5 tra 68,2 97,5 4,13 3,12 0,56 0,48 Arquad 16-29 | AQ-SO3H V6 2 de 68,5 75,9 1,95 1,54 0,86 0,59 HPP additive 2 5 tra 72,0 101,6 5,42 3,54 0,82 0,64 Arquad 16-29 | HPP additive Solsperse 5000S 3 5 tra 69,6 97,2 2,94 1,88 0,57 0,44 Genamin DSAP | HPP additive 4 5 tra 58,0 81,0 1,98 1,38 0,45 0,36 Genamin DSAP | HPP additive 5 5 tra 58,0 83,0 1,64 1,16 0,41 0,33 Genamin DSAP | HPP additive *) According to DIN 67530, gloss is measured at a measuring angle of 60° for gloss levels between 10 and 70 gloss units (medium gloss), and at a measuring angle of 20° for high gloss levels >70 gloss units. In the examples listed here, all measured values ​​are in the >80 range, in contrast to the standard, which falls within the medium gloss range. To ensure a uniform evaluation of the gloss level and better comparability between the standard and the examples, the gloss angle for the measurements of the examples was retained at 60°, deviating from the standard. Table 6 Results of the coloristic test 2.2% Pigment Drawdown Example Color intensity [%] dH dC V1 100 reference reference Hostaperm Violet P-RL V2 106 3,67 1,99 no additives 1 100 3,09 -0,9 Arquad 16-29 | HPP additive V3 100 0,75 -0,28 Arquad 16-29 | Modifier#3C V4 101 0,87 0,30 Solsperse 5000S V5 101 2,22 0,82 Arquad 16-29 + AQ-SO3H V6 101 2,54 -0,77 HPP additive 2 102 3,68 0,16 Arquad 16-29 | HPP additive Solsperse 5000S 3 101 3,84 0,39 Genamin DSAP | HPP additive 4 100 2,92 -0,68 Genamin DSAP | HPP additive 5 100 2,88 -0,61 Genamin DSAP | HPP additive Table 7 Ester compatibility Flocculation: 5 = perfect / no flocculation; 1 = totally flocculated pigment Flocculation stability After 24 hours (23°C) Additive Viscosity D = 5 s -1< Viscosity D = 10 s -1< Viscosity D = 30 s -1< Viscosity D = 60 s -1< [Pa•s] V1 3 0,15 0,16 0,13 0,10 Hostaperm Violet P-RL V2 without additives 1 4 0,48 0,41 0,24 0,15 Arquad 16-29 | HPP additive V3 4 2,33 1,22 0,46 0,24 Arquad 16-29 | Modifier#3C V4 2 0,44 0,34 0,19 0,13 Solsperse 5000S V5 1 3,80 2,02 0,60 0,36 Arquad 16-29 + AQ-SO3H 2 5 0,16 0,13 0,09 0,08 Arquad 16-29 | HPP additive Solsperse 5000S 3 5 0,22 0,18 0,11 0,09 Genamin DSAP | HPP additive 4 5 1,19 0,09 0,08 0,06 Genamin DSAP | HPP additive 5 5 0,19 0,19 0,14 0,10 Genamin DSAP | HPP additive

Claims

1. Pigment formulation comprising a) C. I. Pigment Violet 23 of the formula I as base pigment, b) a perylenetetracarboximide compound that contains at least one sulfo group and is of the general formula II as pigment synergist in which: A is a bivalent >NR1 or >N-R2-SO3-X+ radical R1 is a hydrogen atom or a C1-C30-alkyl group, preferably a C1-C18-alkyl and especially a C1-C4-alkyl group, or an aryl group, preferably phenyl, where the aryl group may be unsubstituted or mono- or polysubstituted by halogen such as chlorine or bromine, sulfo, C1-C4-alkyl such as methyl or ethyl, C1-C4-alkoxy such as methoxy or ethoxy, or phenylazo, R2 is a straight chain or branched C1-C6-alkylene group, especially ethylene or propylene, X+ is NR3R4R5R6+ where R3, R4, R5, R6 are H, unbranched or branched C1-C30-alkyl, phenyl or phenyl-C1-C6-alkyl.

2. Pigment formulation according to Claim 1, characterized in that R1 is methyl and R2 is C2-alkylene.

3. Pigment formulation according to Claim 1 or 2, characterized in that R3 is hexadecyl and R4, R5 and R6 are methyl.

4. Pigment formulation according to Claim 1 or 2, characterized in that R3 and R4 are hexadecyl and / or octadecyl and R5 and R6 are methyl.

5. Pigment formulation according to any of Claims 1 to 4, characterized in that the compound of the general formula II is produced in the pigment formulation from a perylenetetracarboximide compound that contains at least one sulfo group and is of the general formula III in which M+ is H+, a metal cation or the equivalent Mm+ / m of an m-valent metal cation, and an appropriate ammonium halide compound NR3R4R5R6+ Hal-.

6. Pigment formulations according to any of Claims 1 to 5, comprising a) 99.5% to 70% by weight of base pigment of the formula I, b) 0.5% to 30% by weight of the synergist of the formula II, c) 0% to 5% by weight of a nonionic surfactant, and d) 0% to 5% by weight of customary additives, where the proportions of the respective components are based on the total weight of the formulation.

7. Process for producing the pigment formulation according to any of Claims 1 to 6, characterized in that the surface structure of the base pigment a) is coated uniformly with a pigment synergist b).

8. Process according to Claim 7, characterized in that the pigment synergist b) is added to the coarsely crystalline crude base pigment a) on fine distribution thereof in the course of a dry grinding or wet grinding operation.

9. Process according to Claim 7, characterized in that the pigment synergist b) is added to the water-moist presscake of the base pigment a).

10. Process 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. Process according to Claim 7, characterized in that the pigment synergist b) in the dry state is mixed mechanically with the finely divided base pigment a).

12. Use of the pigment formulations according to any of Claims 1 to 6 for pigmenting high molecular weight organic materials of natural or synthetic origin in the form of plastic masses, melts, spinning solutions, varnishes, paints or printing inks.

13. Use according to Claim 12 for pigmenting (colouring) nitrocellulose-based printing inks.

14. Use of the pigment formulations according to any of Claims 1 to 6 for pigmenting colour filters.