DK155188B - PROCEDURE FOR CONDITIONING ORGANIC PIGMENTS IN GRINDING IN WATER IN THE PRESENT OF A GRINDING AID - Google Patents

Description

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DK 155188 B

Organic pigments, which in their preparation appear in coarse crystalline form, must usually be subjected to post-treatment or so-called conditioning to obtain a useful and colorfully valuable pigment form. In the after-treatment or conditioning, in particular with regard to color strength, an optimal particle size must be obtained. A known method for the finishing or conditioning of organic pigments is grinding in water. However, when milled in wet milling equipment, the pigment crystals are subjected to 10 high compressive and impact forces. Thereby, not only does the comminution of the crystals occur, but also, depending on the nature of the pigment, a more or less powerful reagglomeration. This leads to pigments with poor dispersibility and thus to color faint stains.

15 Various auxiliaries are known which can be added during the milling process, for example. to reduce the reagglomeration of the pigment particles. From e.g. Thus, in U.S. Patent No. 381,781, it is known to enhance the color power and improve certain pigment properties by treating organic crude pigments by grinding with a binder in the presence of grinding aid. Polyols, polyol ethers and esters are used, chlorinated derivatives of these polyols as well as mixtures of the polyols and their derivatives.

U.S. Patent No. 3,046,282 also discloses a process for treating crude pigments by grinding crude copper phthalocyanine pigments in the presence of 2-methyl-2,4-pentanediol as a grinding aid, thereby providing an improvement in texture in particular. and the color strength of the pigments thus treated in the application, especially in inks. However, in all 30 exemplary embodiments of U.S. Pat. No. 3,046,282, this specific adjuvant is used in large quantities, in all cases in larger quantities than the pigment to be treated.

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However, these grinding aids have various disadvantages. Thus, e.g. used in uneconomically large quantities, requires a long grinding time, is only suitable for certain pigments, or can only be very difficult to remove and regenerate.

It has been found that by using certain 1,2-dihydroxy compounds as grinding aid pigments with very good dispersibility are obtained without the disadvantages mentioned above. In addition, depending on the pigment and its use, it may be advantageous to use water-insoluble dihydroxy-. compounds and to leave them in the pigment or pigment mixture. Namely, the 1,2-dihydroxy compounds act as texture protection agents.

Accordingly, the invention relates to a method for conditioning organic pigments by grinding in water and in the presence of a grinding aid, and the method according to the invention is characterized in that, as grinding aid, an unsubstituted or phenyl-substituted aliphatic or cycloaliphatic 1,2- dihydroxy compound having 6-30 carbon atoms in amounts of 0.05-25% by weight, based on the pigment or pigment mixture to be formed.

Examples of suitable 1,2-dihydroxy compounds may be mentioned hexanediol- (1,2), heptanediol- (1,2), octanediol- (1,2), 25 nonanediol- (1,2), decanediol- (1, 2), undecanediol- (1,2), do-decanediol- (1,2), tridecanediol- (1,2), tetradecanediol- (1,2), pentadecanediol- (1,2), hexadecanediol- (1, 2), heptadecanediol- (1.2), octadecanediol- (1,2), nonandecanediol- (1,2), icosanediol- (1,2), hemicosanediol- (1,2), docosanediol- (1,2) , pentacosanediol- (1,2), triacontanediol- (1,2), 1-phenylethanediol- (1,2), 2-phenyl-propanediol- (1,2), cyclohexanediol- (1,2) ), cycloheptanediol- (1,2) or mixtures thereof.

The process of the invention preferably uses unsubstituted aliphatic 1,2-dihydroxy compound, especially with 6-18 carbon atoms. It is particularly preferred to use

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The hexanediol (1,2), octanediol (1,2), dodecanediol (1,2) and hexadecanediol (1,2), (1,2) dihydroxy compounds are preferably used in amounts of 0.5 20% by weight, based on the pigment or pigment mixture to be ground.

Organic pigments which can be conditioned by the process of the invention are, for example, pigments of perylene, phthalocyanine, perinone, quinacridone, quino-phthalon, isoindolinone, isoindoline, dioxazine, anthraquinone, thioindigo, azo, methine or azomethine series.

10 The pigments of the phthalocyanine, methine or azomethine series can use both the metal-free pigments and the metal complexes. Furthermore, it is also possible to use pigment mixtures.

The process according to the invention is particularly suitable for conditioning pigments of the perylene, azo, isoindoline or isoindolinone series, primarily of pigments which have a strong tendency for agglomeration under the influence of mechanical forces such as compressive forces, e.g. . diazocondensation pigment C.I. Pigment brown 23, diazocondensation pigment 20 C.I. Pigment red 220, anthraquinoid pigment C.I. Pigment yellow 147 and diazocondensation pigment C.I. Pigment red 166.

As apparatus for use in the method of the invention, any apparatus which allows the pigment and carrier in a liquid medium to be subjected to intense mechanical force effects can be used. Such devices are known in large numbers. For example, they are based on the generation of large velocity gradients in a liquid medium or a sudden change of direction or in particular on the bias or mutual friction of grinding bodies, such as metal, glass or porcelain spheres, synthetic granules or grains which are set in motion at rotating the container or even more efficiently by oscillation or stirring means such as e.g. at glass bead mills.

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The grinding temperature is not critical within technically sensible limits. Conveniently, the milling is carried out at temperatures between 5 and 90 ° C, preferably at 15-70 ° C.

Although the pigment suspension to be ground is generally neutral, in some cases it may be advantageous to adjust the pigment suspension to a pH value in the acidic or basic range.

In addition to the 1,2 1,2-dihydroxy compounds used in the invention, additives which have a favorable effect on the application properties of the milled pigments, such as e.g. texture protection agents. Such additives may be added in amounts of 0.05 to 25, preferably 1 to 15% by weight, based on the pigment or pigment mixture to be ground.

Suitable texture preservatives are, for example, fatty acids having at least 12 carbon atoms such as stearic acid or behenic acid, their amides, salts or esters such as magnesium stearate, zinc stearate, aluminum stearate or magnesium behenate, and further quaternary ammonium compounds such as tri- (C -alkylbenzylammonium salts, in addition to plasticizers, such as epoxidized soybean oil, waxes such as polyethylene wax, resin acids such as abietic acid, rosin soap, hydrogenated or dimerized rosin, C2-2 c-Lg "Paraffin indi-2b sulfonic acids, alkyl, .

Preferred texture preservatives are lauryl or stearylamine, stearic acid, amides, salts or esters thereof, epoxidized soybean oil, waxes or resin acids.

As a rule, the process of the invention is carried out in the absence of organic solvents. However, smaller amounts of organic solvents can be accepted, provided they do not adversely affect the process.

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In the process of the invention, pigment, 1,2-dihydroxy compound, water and any additives 5 can be added to the grinding apparatus at the same time or in succession. The mixture is ground until the pigment or pigment mixture is in the desired covering or more transparent form. Depending on the grinding equipment, pigment and additives, the grinding usually lasts from 1 Π '1/4 to 72 hours. The required grinding time can easily be determined from time to time.

The processing of the mixture can be carried out in the usual manner by filtering out the pigment suspension, removing the additives which do not remain in the pigment, and drying. Water-insoluble 1,2-dihydroxy compounds can again be removed by washing the filter cake with an organic solvent such as ethanol and water-soluble 1,2-dihydroxy compounds such as hexanediol (1,2) by washing the filter cake with water. Although not necessary, depending on the pigment and its use, it may be advantageous to use water-insoluble 1,2-dihydroxy compounds and to leave them in the pigment or pigment mixture. Namely, the 1,2-dihydroxy compounds act as texture protectors and can prevent reagglomeration of the pigment particles by their further processing. In all cases, the presence of a 1,2-dihydroxy compound in the milled pigment or pigment mixture has a favorable influence on the dispersibility. For the drying of the pigments, the conventional apparatus such as vacuum dryers or circulating air dryers, vane dryers, vortex dryers or freeze dryers, and sprayers can be used.

In some cases, it is possible in the process of the invention to comminute pigment crystals such that particles having a specific property are formed. Thus, for example, from very coarse crystalline pigments, which also exhibit high refractive indices, one can directly prepare

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6 pigments which, due to the size of the grain formed, the distribution of the grain size and a high number of isometric particles have a high coating capacity, thereby eliminating the finishing which must be carried out by other methods to obtain such particles.

In the process of the invention, it is also possible to produce very fine crystalline pigments, since the presence of a 1,2-dihydroxy compound prevents a reagglomeration of the fine pigment particles frequently observed by intensive grinding. Even when the 1,2-dihydroxy compound ice cream is not removed during the work-up, extremely color-transparent translucent stains are obtained with the fine crystalline pigments thus produced.

When, after grinding, the 1,2-dihydroxy compound remains in the pigment or pigment mixture, regardless of the amount, an excellent compatibility between the 1,2-dihydroxy compound and the substrate to be stained is observed. Furthermore, there is no deterioration in the properties of the pigmented substrate, e.g. heat, weather, light and migration authenticity.

Pigments made by the process of the invention are suitable for pigmentation of high molecular weight organic matter, e.g. cellulose ethers and esters such as ethyl cellulose, acetyl cellulose, nitrocellulose, polyamides or polyurethanes or polyesters, natural resins or synthetic resins, especially urea and melamine formaldehyde resins, alkyd resins, phenoplasts, polyolefins, polyolefins, polyolefins, polyolefins, polyolefins . polyvinyl chloride, polyacrylonitrile, polyacrylic acid esters, thermoplastic or curable acrylic resins, rubber, casein, silicone and silicone resins or mixtures thereof. Said high molecular weight compounds may exist as plastic masses, melts or in the form of spinning solutions, lacquers or inks. Depending on the application, it is advantageous to use the pigments as toner or in the form of preparations.

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The high molecular weight organic matter stained with pigments conditioned by the process of the invention is characterized by very pure and uniform shades, high color strength and high gloss, high light and weather resistance and high heat resistance.

The invention is further illustrated in the following examples in which parts by weight and percentages are by weight, unless otherwise stated.

Example 1.

8.1 parts of coarse crystalline, needle-shaped perylenetetracarboxylic acid dianhydride, and 0.9 parts of dodecanediol (1,2) are ground together in a 500 volume beaker in 40 parts water with 90 parts sand (Ottawa sand having a diameter of 2- 3 mm) and a nylon disc stirrer at a stirring rate of 2000 15 rpm without external cooling for 3 1/2 hours. The sand is isolated from the milled pigment suspension, then washed with water and filtered. The press cake is dried at 70-80 ° C in a vacuum drying cabinet, after which the dry material is pulverized. You get 8 parts approx. 10% dodecanediol (1,2) -contained 20-perylenetetracarboxylic acid dianhydride pigment, which is dyed in a soft PVC roll film, gives color-rich red colorings of excellent authenticity.

The conditioned pigment contains a large number of particles with isometric particle shape, which is largely due to the high coverage power.

Example 2.

8.1 parts of coarse crystalline, needle-shaped perylenetetracarboxylic acid bis- (3,5-dimethylphenyl) imide in the γ modification prepared according to Example 1 of European Patent Application No. 23,191 and 0.9 parts of octanediol (1.2) ground in a beaker with a volume of 500 parts by volume in 40 parts of water with 90 parts by volume of sand (Ottawa sand with a diameter of 2-3 mm) and a

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8 nylon disc tubes with a stirring speed of 2000 rpm. without external cooling for 5 hours. The sand is removed from the milled pigment suspension and then washed with water and filtered. The press cake is dried at 70-80 ° C in a vacuum drying cabinet and the dry material pulverized. 8.0 parts of conditioned perylenetetracarboxylic acid bis (3,5-dimethylphenyl) imide pigment are obtained, which are colored in lacquers and plastics to give color-rich, bluish-red stains with excellent authenticity. The pigment thus conditioned contains a large number of particles with isometric particle shape, which is largely responsible for the high tire force.

Example 3

In a beaker of 300 volumes, 13.0 parts of brown diazo condensation pigment C.I. Pigment brown 23, 1.7 parts dodecanediol (1.2), 0.3 parts stearylamine and 0.3 parts stearic acid in 130 parts water with stirring to 70 ° C. After stirring for approx. For 15 minutes, the suspension is cooled to 20-25 ° C, then it is poured into a glass bead mill 20 with a volume of 500 volumes. The pigment dispersion is diluted with water to 140 parts, and 400 parts of glass spheres of 3.4-4.0 mm in diameter are added, after which the suspension is ground at 30-35 ° C for 5 1/2 hours and after the grinding is completed the suspension is adjusted to pH 7.0. The pigment suspension is isolated from the glass beads which are washed afterwards with some water and then filtered. The press cake is washed with water and dried at 70-80 ° C in a vacuum drying cabinet. You get 13.0 parts of brown pigment, which, when incorporated into soft PVC roll films, gives transparent, very colorful, brown stains with 30 excellent authenticity. The pigment thus conditioned is extremely well dispersed in the plastic mass, despite the fine particulate form.

Example 4

By analogy to the procedure described in Example 2, however, instead of the perylenetetracarboxylic acid bis- (3,5-dimethylphenyl) imide, the orange isoindoline is used.

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9 pigment prepared according to Example 51 of DE patent 2,814,526 and carrying out the grinding for 20 hours instead of 5 hours, a pigment is prepared which is incorporated into lacquers and plastics. Available in very rich and color-5 strong orange colors with excellent authenticity. The pigment thus conditioned contains a large number of particles having isometric particle shape.

Example 5

In a 300-volume beaker, 13.0 parts of coarse 10 crystalline diazocondensation pigment C.I. Pigment red 220, 1.8 parts dodecanediol (1.2) and 0.2 parts hexadecanediol-1,2) in 130 parts of water with stirring to 70 ° C. After approx. After stirring for 15 minutes, the suspension is cooled to 20-30 ° C and then poured into a glass bead mill with a volume of 15,500 volumes. The pigment suspension is diluted with water to 140 parts, and 400 parts of glass balls with a diameter of 3.5-4.0 mm are added and the suspension is ground for 2 3/4 hours at 30-35 ° C. The glass beads are removed from the pigment suspension, then washed with water and filtered.

The press cake is dried at 70-80 ° C in a vacuum drying cabinet and 13.3 parts of red pigment are obtained, which after powdering in satisfactory dispersion gives transparent bright red colors by incorporation in plastics and varnishes.

Example 6

In a glass bead mill with a volume of 500 volumes, 13.5 parts of coarse crystalline diazocondensation pigment C.I. Pigment red 166, 1.5 parts dodecanediol (1.2) and 130 parts water. 400 parts of glass spheres with a diameter of 3.5-4.0 mm are added to the pigment suspension, which is ground at 30-35 ° C for 12 hours at a stirring speed of 320 rpm.

The pigment suspension is isolated from the glass beads which are washed with water and then filtered. The press cake is washed with water and dried at 70-80 ° C in a vacuum drying cabinet. You get 14.1 parts approx. 10% dodecanediol (1,2) -containing pigment which after incorporation can be satisfactorily incorporated

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10 dispersibility in plastics and lacquers and gives very color brightness and much more transparent red colors to the starting form.

Example 7

5 in a glass bead mill with a volume of 500 volumes is stirred 13.5 parts of coarse crystalline nickel azomethine complex prepared according to Example 27 in EP patent application no.

36.835, 1.5 parts octanediol (1.2) and 125 parts water. To the suspension are added 400 parts of glass spheres with a diameter of 10 3.5-4.0 mm and grinding is carried out at 30-35 ° C for 9 hours with a stirring speed of 320 rpm. The suspension is isolated from the glass beads which are washed with water and then filtered. Octanediol (1,2) is washed from the press cake with methanol and the press cake is dried at 70-80 ° C in a vacuum drying cabinet. You get 13 parts yellow-red pigment, which is more transparent and has a higher color strength compared to the starting product. By incorporating in burn-in varnishes you get yellow-red stains with excellent lightness and weathering.

Example 8.

The procedure is the same as described in Example 7, but instead of using octanediol (1,2), hexanediol (1,2) is used and the press cake is washed with water instead of methanol, and 12 is obtained. 8 parts yellow-red pigment with similar good properties.

Example 9.

To proceed in the same manner as described in Example 7, however, instead of the pigment described, the coarse crystalline anthraguinone pigment C.I. Pigment yellow 147 and instead of 1.5 parts of octanediol- (1,2) a mixture 30 of 1.2 parts of dodecanediol- (1,2) and 0.3 parts of octanediol- (1,2) to give a yellowish pigment tones, which with satisfactory dispersibility are incorporated into lacquers and synthetic fabrics and, in relation to the initial form, provide much cleaner, more transparent and more color-rich, yellow stains with 35 extremely good authenticity.

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Example 10.

11 180 parts crude isoindolinone pigment C.I. Pigment yellow 110 and 20 parts of dodecanediol (1.2) are stirred in 1500 parts of water in a beaker, then heated to 70 ° C with stirring and cooled to 30-35 ° C after 15 minutes. Dilute the pigment suspension with water to a total weight of 1800 parts. The pigment suspension is intensively milled at 30-35 ° C for 3 hours in a Dyno mill, type KDL, from the company Willy A. Bachofen, Basel, equipped with a steel grinding container of 600 volumes filled with 480-510 volumes glass balls with a diameter of 1 mm, at a stirring speed of 3000 rpm. and a pump speed of 30 rpm. The pigment suspension is separated from the glass beads, which are washed with 500 parts of water. Filtration is carried out, the press cake is washed with 1000 parts of water, dried in a vacuum cabinet of 70-80 ° C, and the pigment is pulverized in an Osterizer mixer. You get 190 parts of yellow pigment tones containing approx. 10% dodecanediol- (1,2), which when incorporated into lacquers and plastics gives very transparent 20 stains with greater color strength than the initial form. Despite the great fineness of the milled pigment, it has excellent dispersibility in the application media.

Example 11.

a) In a beaker, 80 parts of dodecanediol (1,2) are heated to 25 ° C and melted. With stirring is added at 80-100 ° C

20 parts of polyethylene-polyvinyl acetate polymer "AC-Copolymer 400" (from Allied Chemical) and the mixture is stirred at ca. 100 ° C. Thereby a clear melt is formed which is then cooled to 0 ° C, thereby solidifying. The 30 solidified mixture of dodecanediol (1,2) and "AC-Copolymer 400" thus formed is pulverized in an Osterizer mixer and pressed through a metal screen having a mesh width of 1 mm. The mixture is now available as a white powder.

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12 b) Proceed in the same manner as described in Example 10, however, instead of using 10 parts of dodecanediol (lf2), 20 parts of the white powder prepared according to example 10a) consisting of 80% dodecanediol (1.2) ) and 20% "AC-Copolymer 400" and grinding for 2 1/2 hours instead of 3 hours to give a yellow pigment with equally good properties.

Example 12.

One proceeds in the same manner as described in Example 6, however, instead of C.I. Pigment red 166 uses a co-crystalline perylenetetra-carboxylic acid N, Ν'-dimethylimide pigment directly obtained by the synthesis and grinds for 9 hours instead of 12 hours to give a burgundy pigment which, when incorporated into plastics and varnishes, gives strongly covering stains with excellent authenticity.

Example 13

The procedure is similar to that described in Example 6, but instead of C.I. Pigment red 166 uses the coarse crystalline perinone pigment formed directly in the synthesis 20 C.I. Pigment orange 43 and grinding for 7 hours instead of 12 hours to give a pigment which, when incorporated into plastics and lacquers in relation to the starting product, gives substantially cleaner stains with greater color strength.

Example 14.

The procedure is similar to that described in Example 6, but instead of C.I. Pigment red 166 uses the synthesis dioxazine pigment C.I. Pigment violet 37 and grinding for 9 hours instead of 30 12 hours to give a cleaner, violet pigment with greater color strength, which can be incorporated in plastics, varnishes and inks very well.

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Example 15

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The procedure is similar to that described in Example 6, but instead of C.I. Pigment red 166 uses the synthetic guinacridone C.I. Pigment red 5,122 and grinding for 10 hours instead of 12 hours, giving a very well-dispersible blue-red pigment with greater color strength and with excellent authenticity in relation to the starting product.

Example 16.

The procedure is similar to that described in Example 6, but instead of C.I. Pigment red 166 uses a tetrachlorothioindigopigment obtained directly in the synthesis and grinds for 6 hours instead of 12 hours to give a purer 15 violet pigment with greater color strength which can be very well incorporated in plastics, varnishes and inks.

Example 17

The procedure is similar to that described in Example 6, but instead of C.I. Pigment red 166 uses crude β-20 Cu-phthalocyanine pigment and grinds for 6 hours instead of 12 hours to give a blue pigment that has greater color strength than the starting form and which can be incorporated with excellent dispersibility in plastics.

Example 18.

You proceed in the same manner as described in Example 6, but instead of C.I. Pigment 166 uses a pigment mixture consisting of 50% isoindolinone pigment C.I. Pigment yellow 110 and 50% diazocondensation pigment C.I. Pigment brown 23 and grind for 3 hours instead of 12 30 hours, after which, after incorporation in plastics or varnishes, yellowish-brown stains are obtained with excellent heat, light and weathering.

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Example 19.

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The procedure is similar to that described in Example 9, however, instead of the mixture of 1.2 parts of dodecanediol (1,2) and 0.3 parts of octanediol (1,2), 1.5 parts of hexane are used. 5 decanediol- (1,2) to give a yellow pigment toner with similar good properties.

Example 20

A mixture of 130 parts of 8 mm diameter steatite balls, 47.5 parts of alkyd melamine burn-in paint consisting of 15 60 parts of Beckosol® 27-320 (60% Si xylene, Reichold Chemie AG), 36 parts of "Super-Beckamine" ® 13-501 (50%, Reichold Chemie AG), 2 parts xylene and 2 parts ethylene glycol monomethyl ether and 2.5 parts of the metal complex pigment prepared according to Example 7 are dispersed in a 200 ml glass bottle with 20 swirl closures for 120 hours on a rotary shaker. After removal of the steatite beads, 2.4 parts of the thus-dispersed whole-tone mixture, 6.0 parts of titanium dioxide "Kronos" ® RN 59 (Kronos Titan GmbH) and 24.0 parts of the alkyd melamine burn-in coating described above are mixed, then the mixture is sprayed onto aluminum plate and then roast for 30 minutes at 130 ° C. You get yellowish-red stains with excellent authenticity.

Example 21.

A mixture of 1.0 parts of the pigment prepared according to Example 6, 1.0 part antioxidant "Irganox" 1010 (CIBA

Geigy AG) and 1000.0 parts of polyethylene HD granular "Vestolen" ® A 60-16 (Hiils) are premixed for 15 minutes in a glass bottle on a rotary shaker table. Then, the mixture is extruded in two passages on a single screw extruder and then the granulate thus formed is sprayed onto an injection molding machine (Allround Aarburg 200) at 220 ° C for plates which are post-pressed for 5 minutes at 180 ° C. The press plates show bright red shades of color with excellent authenticity.

Claims (10)

10 PATENT REQUIREMENTS. A process for conditioning organic pigments by grinding in water and in the presence of a grinding aid, characterized in that as a grinding aid, an unsubstituted or phenyl-substituted aliphatic or cycloaliphatic 1,2-dihydroxy compound having 6-30 carbon atoms is used, 05-25% by weight, based on the pigment or pigment mixture / to be ground. Process according to claim 1, characterized in that an unsubstituted aliphatic 1,2-dihydroxy compound is used. Process according to claim 1, characterized in that a 1,2-dihydroxy compound having 6-18 carbon atoms is used. Process according to claim 1, characterized in that hexanediol- (1,2), octanediol- (1,2), dodecanediol- (1,2) or hexadecanediol- (1,2) are used. Process according to claim 1, characterized in that the 1,2-dihydroxy compound is used in amounts of 0.5 to 20% by weight, based on the pigment or pigment mixture to be ground. DK 1551 88 B Process according to claim 1, characterized in that, in addition to the 1,2-dihydroxy compound, a texture protection agent is used. Process according to claim 6, characterized in that lauryl or stearylamine, stearic acid, amides, salts or esters thereof, epoxidized soybean oil, waxes or resin acids are used as texture protection agents. Process according to claim 1, characterized in that the milling is carried out at 15-70 ° C. Process according to claim 1, characterized in that the pigment to be ground belongs to the perylene, azo, isoindoline or isoindolinone series. Process according to claim 1, characterized in that the pigment to be ground has a strong tendency for agglomeration under the influence of mechanical forces.