EP0306447A1 - Preparations comprising brightening agents of the dispersion type - Google Patents

Abstract

Dispersion brightener preparations are described which contain specific, water-insoluble aromatic or C14-C18 fatty alcohol auxiliaries which melt at from 40 ° C. to 200 ° C. The preparations are used to lighten coating slips for the coating of paper, cardboard, wood, foils, textiles, non-woven materials and building materials.

Description

The present invention relates to new solid and liquid dispersion brightener preparations, their preparation and their use for brightening coating slips, e.g. for the coating of paper, cardboard, wood, foils, textiles, non-woven materials and building materials.

It is known to optically lighten coating compositions for coating smooth surfaces by means of anionic compounds from the series of triazinylflavonic acid. However, this class of material only delivers good degrees of whiteness in coating slips that contain natural binders such as casein, starch, protein or gelatin.

For the coating slips in use today, the predominantly synthetic latex binders based on e.g. Containing copolymers of styrene-butadiene-acrylic acid esters or styrene-butyl acrylate, it has therefore been proposed to use dispersion brighteners in the presence of dispersants and, if appropriate, nonionic emulsifiers (GB-1294173, GB-1349934). The disadvantage of these processes is the low maximum whiteness that can be achieved and the strong dependence of the whiteness on the drying temperature.

Other proposed solutions were to improve the whitening effects by incorporating organic solvents (DE-A-2242597) and additional solubilizers (DE-A-2806195). In practice, however, these formulations can only be used to a limited extent, since explosive air mixtures can form during the evaporation of the solvents and the solvent vapors can lead to health hazards in operation and to environmental pollution.

It has now been found that preparations which, in addition to at least one dispersion brightener and at least one dispersant and / or emulsifier, optionally further additives and water, also contain at least one specific sches above 40 ° C to 200 ° C, preferably up to 120 ° C melting, water-insoluble aromatic or C₁₄-C₁₈ fatty alcoholic auxiliary or mixture of additives surprisingly do not show these disadvantages.

verwendet,
worin R₁ = -COOR, -COR, SO₂NHR, R oder OH, und
R₂ = H, -COOR, -COR, SO₂NHR oder R,
R₃ = H oder Phenylen,
mit R = gegebenenfalls mit C₁-C₈-Alkyl, C₃-C₈-Cycloalkyl oder Phenyl substituiertes C₁-C₈-Alkyl, C₃-C₈-Cycloalkyl oder Phenyl
bedeutet.Such auxiliaries are cetyl alcohol and especially compounds of the formula

used
wherein R₁ = -COOR, -COR, SO₂NHR, R or OH, and
R₂ = H, -COOR, -COR, SO₂NHR or R,
R₃ = H or phenylene,
with R = optionally substituted with C₁-C₈-alkyl, C₃-C₈-cycloalkyl or phenyl, C₁-C₈-alkyl, C₃-C₈-cycloalkyl or phenyl
means.

These are, for example, the following compounds: benzylphenyl ketone, salicylic acid phenyl ester, benzophenone, dibenzyl, p-benzyl biphenyl, benzenesulfanilide, 1-hydroxy-2-phenylnaphthoate, terephthalic acid diphenyl ester, terephthalic acid dimethyl ester and / or phthalic acid cyclo (PD) phthalate.

These auxiliaries are used in amounts of 0.1 to 150 parts, in particular in amounts of 1 to 100 parts and especially in amounts of 9 to 100 parts based on 1 part of dispersion brightener.

worin R₄ = Wasserstoff oder unabhängig voneinander C₁-C₆-Alkyl bedeutet.Water-insoluble or water-insoluble brighteners as described, for example, in DE-A-2806195 are used as dispersion brighteners, but dispersion brighteners from the class of coumarins and / or benzoxazoles, in particular benzoxazolylthiophenes, are preferably used. The dispersion brighteners are known. The brighteners and mixtures of brighteners of the formula are of particular interest

wherein R₄ = hydrogen or independently C₁-C₆ alkyl.

As dispersants and / or emulsifiers, the preparation according to the invention contains conventional anionic or cationic and / or nonionic emulsifiers and / or dispersants, preferably in amounts of 2-20%, in particular 5-10%, based on the sum of dispersion brighteners and auxiliaries.

Examples of anionic emulsifiers are:
Carboxylic acids and their salts, such as the sodium, potassium or ammonium salts of lauric, stearic or oleic acid, acylation products of aminocarboxylic acids and their salts, for example the sodium salt of oleoyl sarcoside. Sulphates such as fatty alcohol sulphates, eg lauryl sulphate and lorole sulphate, sulphates of hydroxy fatty acid esters, eg sulphated castor oil, of fatty acid hydroxyalkylamides, eg sulphated coconut fatty acid ethanol amide as well as sulphates of partially esterified or etherified polyhydroxy compounds such as sulphated oleic acid monoglycerate sulphate polyglycol ether sulfate, glycerol glycol sulfate, glycerol ether sulfate, and glycerol ether sulfate, as well Sulfonates such as primary and secondary alkyl sulfonates, for example C₁₂-C₁₆ paraffin sulfonic acids or their sodium salts, alkyl sulfonates with amide- or with ester-like acyl radicals such as oleyl methyl tauride and sulfonates of polycarboxylic esters such as di-iso-octyl sulfate succinate; furthermore those with aromatic groups such as alkylbenzene, for example dodecylbenzene, alkylnaphthalene, such as dibutylnaphthalene and alkylbenzimidazole, such as tetradecylbenzimidazole sulfonates.

Examples of nonionic emulsifiers are:
Esters and ethers of polyalcohols, such as alkyl polyglycol ethers, for example lauryl alcohol or oleyl alcohol, polyethylene glycol ethers, acyl polyglycol ethers such as oleic acid polyglycol ethers, alkylaryl polyglycol ethers such as the ethoxylation products of nonyl and dodecylphenol, acylated amino-alkanol polyglycol ethers, and also the known fatty acid amides, such as non-ionic amines, such as non-ionic amides, such as die amine acid amides, such as non-ionic amides, such as die amine ionides derived from sugars and their derivatives.

The anionic dispersants are the usual dispersants, for example condensation products of aromatic sulfonic acids with formaldehyde or lignin sulfonates, for example the compounds obtainable under the name sulfite waste liquor. However, naphthalene sulfonic acid / formaldehyde condensation products are particularly suitable. Mixtures of these dispersants can also be used.

Ethylene oxide adducts from the class of addition products of ethylene oxide with higher fatty acids, saturated or unsaturated fatty alcohols, mercaptans, fatty acid amides, fatty acid alkylolamides or fatty amines or alkylphenols or alkylthiophenols with at least 7 carbon atoms in the alkyl radical, and also ricinoleic acid esters or hydroxyabietyl alcohol may be mentioned as nonionic dispersants. Some of the ethylene oxide units can be replaced by other epoxides, e.g. Styrene oxide or, in particular, propylene oxide.

• a) Umsetzungsprodukte von gesättigten und/oder ungesättigten Fett­alkoholen mit 8 bis 20 C-Atomen, mit 20 bis 100 Mol Ethylenoxid pro Mol Alkohol;
• b) Umsetzungsprodukte von Alkylphenolen mit 7 bis 12 C-Atomen im Alkyl­rest mit 5 bis 20 Mol, vorzugsweise 8 bis 15 Mol, Ethylenoxid je Mol phenolische Hydroxylgruppe;
• c) Umsetzungsprodukte von gesättigten und/oder ungesättigten Fettaminen mit 8 bis 20 C-Atomen mit 5 bis 20 Mol Ethylenoxid je Mol Amin;
• d) Umsetzungsprodukte von gesättigten und/oder ungesättigten Fettsäuren mit 8 bis 20 C-Atomen mit 5 bis 20 Mol Ethylenoxid je Mol Fettsäure;
• e) ein Umsetzungsprodukt aus 1 Mol Ricinolsäureester und 15 Mol Ethylen­oxid;
• f) ein Umsetzungsprodukt aus 1 Mol Hydroxyabietylalkohol und 25 Mol Ethylenoxid.

The following are specifically mentioned as ethylene oxide adducts:

• a) reaction products of saturated and / or unsaturated fatty alcohols with 8 to 20 carbon atoms, with 20 to 100 moles of ethylene oxide per mole of alcohol;
• b) reaction products of alkylphenols with 7 to 12 carbon atoms in the alkyl radical with 5 to 20 moles, preferably 8 to 15 moles, of ethylene oxide per mole of phenolic hydroxyl group;
• c) reaction products of saturated and / or unsaturated fatty amines with 8 to 20 carbon atoms with 5 to 20 moles of ethylene oxide per mole of amine;
• d) reaction products of saturated and / or unsaturated fatty acids with 8 to 20 carbon atoms with 5 to 20 moles of ethylene oxide per mole of fatty acid;
• e) a reaction product of 1 mol of ricinoleic acid ester and 15 mol of ethylene oxide;
• f) a reaction product of 1 mol of hydroxyabietyl alcohol and 25 mol of ethylene oxide.

Mixtures of the ethylene oxide adducts according to a) to f) with one another can also be used. These mixtures are obtained by mixing individual reaction products or directly by ethoxylating a mixture of the compounds on which the adducts are based. An ethoxylated nonylphenol is preferably used.

Quaternary fatty amine polyglycol ethers, for example, are suitable as cationic dispersants.

The preparation can also contain 45-95% water, preservatives and defoamers. However, the solid preparations are preferred.

The preparations according to the invention are prepared by simply mixing or dry grinding the components or by melting the dispersion brightener and the auxiliary, if appropriate in the presence of dispersants and / or emulsifiers, allowing them to solidify and then, if appropriate, dry-grinding or, if appropriate, wet-grinding in the presence of dispersants and / or emulsifiers will.

The preparations according to the invention are suitable for lightening the coating slips usually used in the paper industry, specifically for lightening unpigmented, but in particular pigmented coating slips. These known coating slips contain, inter alia, binders. Plastic dispersions based on copolymers of butadiene-styrene, acrylonitrile-butadiene-styrene, acrylic acid esters, ethylene-vinyl chloride and ethylene-vinyl acetate; Homopolymers, such as polyvinyl chloride, polyvinylidene chloride, polyethylene and polyvinyl acetate or polyurethanes. A preferred binder consists of styrene-butyl acrylate or styrene-butadiene-acrylic acid mixed polymers. Further polymer latices are described, for example, in US Pat. Nos. 3,265,654, 3,657,174, 3,547,899 and 3,240,740. The preparation according to the invention is incorporated into these binders, for example by means of melt emulsification.

Aluminum silicates such as china clay and kaolin, barium sulfate, satin white, titanium dioxide or calcium carbonate (chalk) are usually used to pigment the coating slips.

Recipes of such known coating slips for paper are, for example, in JP Casey "Pulp and Paper"; Chemistry and Chemical Technology, 2nd Ed. Vol. III, pp. 1648-1649 and in Mc Graw-Hill "Pulp and Paper Manufacture", 2nd and 5th Ed. Vol. II, p. 497.

The coating slips according to the invention preferably contain 30 to 70% of a white pigment. The binder is preferably used in an amount sufficient that the dry content of polymeric compound is 1 to 30 percent by weight, preferably 5 to 25 percent by weight, of the white pigment. The amount of the brightener preparation according to the invention is calculated in such a way that the dispersion brightener is present in amounts of 0.001 to 1 percent by weight, in particular 0.01 to 0.55 percent by weight, based on the white pigment.

The coating slip according to the invention can be produced by mixing the components in any order at temperatures from 10 to 100 ° C., preferably 20 to 80 ° C. The components here also include the usual auxiliaries that can be used to regulate the rheological properties such as viscosity or water retention capacity of the coating slips. Such tools are e.g. natural binders such as starch, casein, protein or gelatin, cellulose ethers such as carboxyalkyl cellulose or hydroxyalkyl cellulose, alginic acid, alginates, polyethylene oxide or polyethylene oxide alkyl ethers, copolymers of ethylene oxide and propylene oxide, polyvinyl alcohol, polyvinyl pyrrolidone, water-soluble condensation products of formaldehyde with urea or melamine, polyphosphate salts or polyphosphates.

The coating slip according to the invention can be used to coat paper, wood, foils such as e.g. Polypropylene, polyethylene, polyester, cellulose, cellulose triacetate, textiles, non-woven materials and suitable building materials such as Wallpaper, room cladding, plastic covers can be used. Use on paper and cardboard and photo paper is particularly preferred.

The coating slip can be applied to the substrate by any conventional method, for example using an air knife, a doctor knife, a brush, a roller, a squeegee or a stick, followed by coating with, for example, infrared dryers and / or hot air dryers at paper surface temperatures in the range of 70 up to 200 ° C, preferably 90 to 130 ° C, to a residual moisture content of 3-6%. Comparably high degrees of whiteness are thus achieved even at low drying temperatures.

As a result of the use of the preparations or auxiliaries according to the invention, the coatings obtained are distinguished by an optimal distribution of the dispersion brighteners over the entire surface and a consequent increase in the white level and high light fastness.

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

Example 1:

wird mit den in Tabelle 1 angegebenen Teilen der Komponenten bei Raumtemperatur während 15 Stunden in einer Glasperlenrührmühle (Glas­perlendurchmesser 2 mm) in Gegenwart von Wasser gemahlen.The brightener of the formula

is ground with the parts of the components listed in Table 1 at room temperature for 15 hours in a glass bead mixer (glass bead diameter 2 mm) in the presence of water.

Example 2

The brightener according to Example 1 is melted together with the components and parts shown in Table 2, dry-ground after cooling and then dispersed according to Example 1 in water. Table 1 Prep no. Share tools Parts brightener acc. example 1 Naphthalenesulfonic acid / formaldehyde Nonylphenol (35 AeO) 1.1 90 PDCH 10th 5% 1.2 90 PDCH 10th 10% 1.3 90 PDCH 10th 10% 1.4 85 PDCH 15 10% 1.5 90 benzophenone 10th 10% 1.6 90 dibenzyl 10th 10% 1.7 90 benzylphenyl ketone 10th 10% The homogeneous dispersions obtained are pourable and stable in storage. The percentages in Table 1 relate to the total dry matter of brightener and auxiliary Prep no. Share tools Parts brightener Naphthalenesulfonic acid / formaldehyde Nonylphenol (35 AeO) 2.1 90 PDCH 10th 5% 2.2 90 PDCH 10th 10% 2.3 90 PDCH 10th 5% 2.4 90 PDCH 10th 10% 2.5 85 PDCH 15 10% 2.6 80 PDCH 20th 10% 2.7 90 benzophenone 10th 10% The homogeneous dispersions obtained are pourable and stable in storage. The percentages in Table 2 relate to the total dry matter of brightener and auxiliary.

Example 3: a) Preparation of the coating slip

700 g of a commercially available kaolin pigment and 300 g of a commercially available calcium carbonate pigment are dispersed with 385 g of water, 5 g of a dispersant based on sodium salt of a polycarboxylic acid at a pH of about 9 and under the action of strong shear forces. 240 g of a commercially available 50% polymer dispersion based on styrene-butyl acrylate copolymer Acronal S 320 D from BASF) and one of the brightener dispersion described in Examples 1 to 2 are added to the resulting pigment dispersion and stirred. The brightener is used at 0.3%, based on the amount of pigment used. The coating color is then adjusted to a solids content of 50% by dilution with water.

b) Application of the paper coating

The coat is applied to wood-free coating paper with the help of a hand squeegee and acid-glued using the usual methods, so that the coat weight after drying with the help of an IR radiator is approx. 15 g per m². The residual moisture still present after this drying is approx. 2%.

c) Whiteness determination

The whiteness of the coating is determined according to "Ciba-Geigy whiteness", as described in "Status of the instrumental whiteness assessment with special consideration of the lighting", textile finishing 5/1983, pp. 157-162. The degree of whiteness of the preparations 1.1 to 2.7 is given in Table 3. Table 3 example Preparation no. Ciba-Geigy whiteness 1 1.1 116.0 1.2 118.0 1.3 109.0 1.4 101.2 1.5 68.5 1.6 92.3 1.7 109.1 2nd 2.1 127.5 2.2 124.6 2.3 112.8 2.4 112.0 2.5 111.1 2.6 103.7 2.7 96.8

Example 4:

A coating slip without additive, but with 0.3% of the brightener according to Example 1 and the dispersants mentioned in Table 4 is prepared and applied analogously to the procedure used in Example 3 (preparations 4.1 to 4.4). The results of the whiteness measurement are compared in Table 4 to those corresponding preparations from Example 2. Table 4 Prep no. Naphthalenesulfonic acid / formaldehyde Nonylphenol (35 AeO) Ciba-Geigy whiteness Prep no. in% based on the brightener) 4.1 5% 62.2 127.5 2.1 4.2 10% 59.5 124.6 2.2 4.3 5% 75.3 112.8 2.3 4.4 10% 73.7 112.0 2.4

Example 5:

• a) The brightener of the formula (1) is melted together with the components and parts shown in Table 5 and, after cooling, dry-milled.
• b) The solid, powdery preparation obtained in this way is introduced into a 90 ° C. solution of 9% aqueous polyvinyl alcohol (Mowiol 4-98 from Hoechst) and melt-emulsified by application of shear forces. Then so much of this aqueous formulation is stirred with the pigment dispersion according to Example 3a) that the coating color formed contains 0.4% polyvinyl alcohol based on the amount of pigment. The use of brighteners is 0.3% or 0.1% based on the amount of pigment used.

The coating color thus obtained is adjusted to a solids content of 50% by dilution with water, applied in accordance with Example 3b) and the degree of whiteness is determined in accordance with Example 3c). The degrees of whiteness are shown in Table 5. Table 5 Prep no. Share tools Parts brightener Emulsifier ²⁾ 100% dry content Whiteness with 0.3% brightener ¹⁾ 5.0 without without without 41 5.1 100 PDCH 1 5% emulsifier ³⁾ 151 5.2 100 2nd 5% emulsifier ³⁾ 138 5.3 100 10th 5% emulsifier ³⁾ 112 5.4 100 20th 5% emulsifier ³⁾ 91 5.5 100 100 5% emulsifier ³⁾ 63 5.6 100 benzophenone 1 5% emulsifier ³⁾ 124 5.7 100 2nd 5% emulsifier ³⁾ 127 5.8 100 10th 5% emulsifier ³⁾ 106 5.9 100 20th 5% emulsifier ³⁾ 93 5.10 100 100 5% emulsifier ³⁾ 65 5.11 100 cetyl alcohol 1 5% emulsifier ³⁾ 144 5.12 100 2nd 5% emulsifier ³⁾ 146 5.13 100 10th 5% emulsifier ³⁾ 95 5.14 100 phenyl salicylates 1 5% emulsifier ³⁾ 139 5.15 100 2nd 5% emulsifier ³⁾ 117 5.16 100 10th 5% emulsifier ³⁾ 72 5.17 100 PDCH 10th 5% emulsifier ⁴⁾ 101 5.18 100 10th 5% emulsifier ⁵⁾ 113 5.19 100 10th 5% emulsifier ⁶⁾ 85 1) based on the amount of pigment used 2) based on the total dry substance of brighteners and auxiliaries 3) ethoxylated hydroxyabietyl alcohol with 200 moles of ethylene oxide (EO) + 1% 1,6-hexamethylene diisocyanate 4) Polyoxyethylene sorbitan monostearate / sorbitan monostearate 1: 1 5) ethoxylated stearyl alcohol with 35 moles of EO 6) ethoxylated stearylamine with 2 moles of EO

Example 6:

und den in Tabelle 6 angegebenen Komponenten und Teilen hergestellt. Diese Präparate werden gemäss Beispiel 5b) weiterverarbeitet. Die Weissgrade sind Tabelle 6 zu entnehmen. Tabelle 6 Präp. Nr. Teile Hilfsmittel Teile Aufheller Emulgator ²⁾ 100 % Trockengehalt CG-Weissgrad bei 0,1 % Aufhellereinsatz ¹⁾ 6.1 90 PDCH 10 Aufheller(1) 5 % Emulgator ³⁾ 96 6.2 90 PDCH 10 Aufheller(2) 5 % Emulgator ³⁾ 96 6.3 90 PDCH 10 Aufheller(3) 5 % Emulgator ³⁾ 85 6.4 90 PDCH 10 Aufheller(4) 5 % Emulgator ³⁾ 83 6.5 90 PDCH 10 Aufheller(5) 5 % Emulgator ³⁾ 96 6.6 90 PDCH 5 Aufheller (1) 5 % Emulgator ³⁾ 90 5 Aufheller (6) 6.7 90 PDCH 2,5 Aufheller(1) 5 % Emulgator ³⁾ 96 2,5 Aufheller(2) 2,5 Aufheller(4) 2,5 Aufheller(6) 1) bezogen auf die eingesetzte Menge Pigment 2) bezogen auf die Summe an Trockensubstanz von Aufhellern und Hilfsmittel 3) ethoxylierter Hydroxyabietylalkohol mit 200 Mol Ethylenoxid (EO) + 1 % 1,6-Hexamethylendiisocyanat According to Example 5a, solid preparations with a brightener each of the formula

and the components and parts specified in Table 6. These preparations are processed according to Example 5b). The degrees of whiteness are shown in Table 6. Table 6 Prep no. Share tools Parts brightener Emulsifier ²⁾ 100% dry content CG whiteness with 0.1% brightener ¹⁾ 6.1 90 PDCH 10 brighteners (1) 5% emulsifier ³⁾ 96 6.2 90 PDCH 10 brighteners (2) 5% emulsifier ³⁾ 96 6.3 90 PDCH 10 brighteners (3) 5% emulsifier ³⁾ 85 6.4 90 PDCH 10 brighteners (4) 5% emulsifier ³⁾ 83 6.5 90 PDCH 10 brighteners (5) 5% emulsifier ³⁾ 96 6.6 90 PDCH 5 brighteners (1) 5% emulsifier ³⁾ 90 5 brighteners (6) 6.7 90 PDCH 2.5 brighteners (1) 5% emulsifier ³⁾ 96 2.5 brighteners (2) 2.5 brighteners (4) 2.5 brighteners (6) 1) based on the amount of pigment used 2) based on the total dry substance of brighteners and auxiliaries 3) ethoxylated hydroxyabietyl alcohol with 200 moles of ethylene oxide (EO) + 1% 1,6-hexamethylene diisocyanate

Claims (14)

1. Preparation containing at least one dispersion brightener, at least one dispersant and / or emulsifier characterized by a content of at least one melting above 40 ° C to 200 ° C, water-insoluble aromatic or C₁₄-C₁₈ fatty alcoholic auxiliaries or mixture of auxiliaries. 2. Preparation according to claim 1, the auxiliary compounds of the formula

contains
where R₁ = -COOR, -COR, SO₂NHR, or R or OH,
R₂ = H, -COOR, -COR, SO₂NHR or R,
R₃ = H or phenylene,
with R = optionally substituted with C₁-C₈-alkyl, C₃-C₈-cycloalkyl or phenyl, C₁-C₈-alkyl, C₃-C₈-cycloalkyl or phenyl
means. 3. Preparation according to claim 2, which contains as an aid benzylphenyl ketone, salicylic acid phenyl ester, benzophenone, dibenzyl, p-benzyl biphenyl, benzenesulfanilide, 1-hydroxy-2-phenylnaphthoate, terephthalic acid diphenyl ester, terephthalic acid dimethyl ester or cetyl ethyl alcohol, or cetyl alcohol. 4. Preparation according to claim 1 containing 0.1-150 parts of the auxiliary or auxiliary mixture, based on 1 part of dispersion brightener, and 2-20% of dispersant and / or emulsifier, based on the sum of dispersion brightener and auxiliary. 5. Preparation according to claim 4, which contains 1-100 parts of auxiliaries based on 1 part of brightener. 6. A preparation according to claim 1, which contains dispersion brighteners from the class of coumarins and / or benzoxazoles. 7. Preparation according to claim 6, which as a dispersion brightener is a compound or mixture of compounds of the formula

contains
wherein R₄ = hydrogen or independently C₁-C₆ alkyl. 8. A preparation according to claim 6, which as a dispersion brightener is a compound of the formula

contains. 9. A preparation according to claim 7, which contains dicyclohexyl phthalate as an auxiliary. 10. A process for the preparation of the preparations mentioned in claim 1 to, characterized in that the dispersion brightener and the auxiliary material are melted together, allowed to solidify and then dry-ground, the dispersants and / or emulsifiers being melted or added subsequently during dry grinding or, if appropriate, a subsequent wet grinding will. 11. Use of the preparations mentioned in one of claims 1 to 9 for the optical brightening of coating slips for the coating of paper, cardboard, foils, textiles, wood, non-woven materials and building materials. 12. Use of the preparations mentioned in one of claims 1 to 9 for the optical brightening of coating slips for the coating of paper, photographic paper and cardboard. 13. Aqueous coating slip containing white pigments, synthetic binders, at least one dispersion brightener, at least one dispersant and / or emulsifier and at least one water-insoluble aromatic or C₁₄-C₁₈ fatty alcoholic auxiliary or auxiliary mixture which melts at 40 ° C. to 200 ° C. 14. A process for the preparation of the coating slip mentioned in claim 13, characterized in that the components are mixed or melt-emulsified in any order at temperatures from 10 ° C to 150 ° C.