EP0043790A1 - Process for increasing or improving the whitening effect during the optical brightening of coating compositions - Google Patents

Abstract

A process is disclosed for obtaining coating compositions of improved whiteness for coating paper or cardboard using fluorescent whitening agents of the bis-triazinylaminostilbene-2,2'-disulfonic acid series, which process comprises adding to the coating compositions, in addition to the respective fluorescent whitening agent, an acid phosphoric acid ester of an oxyalkylated fatty amine of the formula <IMAGE> (1) or an alkali metal salt, ammonium salt or amine salt thereof, wherein R is an aliphatic hydrocarbon radical of 8 to 22 carbon atoms, Y1 and Y2 are both hydrogen, or one of Y1 and Y2 is hydrogen and the other is methyl, X is the acid radical of phosphoric acid, the acid hydrogen atoms of which radical can be replaced by alkali metal ions, ammonium ions or amine salt ions, and m and n are integers, the sum of which is 2 to 30. To the coating compositions can also be added organic solubilizers, non-ionic or anionic surfactants and/or polar organic compounds. Coating compositions which contain the above fluorescent whitening agents and assistants are also disclosed.

Description

The present invention relates to a method for increasing or improving the white effect in the optical brightening of coating slips for the coating of paper or cardboard with the aid of brighteners of the bis-triazinylaminostilbene-2,2'-disulfonic acid series and optically brightened coating slips and with these coating slips coated paper or cardboard.

Brighteners from the class of bis-triazinylaminostilbene-2,2'-disulfonic acids are also suitable for lightening paper. When lightening coating slips, however, problems arise depending on the brightener and depending on the composition of the coating slip, so that either insufficient white effects are obtained or that some brighteners are out of the question for application in certain coating slips. Especially at higher brightener concentrations, there is often a sharp decrease in the degree of whiteness instead of an increase in whiteness, which often also results in a greening of the coating slip. This undesirable effect occurs in some of the brighteners mentioned, particularly in the case of coating slips with artificial binders.

Efforts have already been made to deal with the difficulties described. So the prank was mass added solubilizers, especially polyethylene glycol. With some brighteners this measure brings a certain increase in effect, with other brighteners it fails. In addition, if effect increases are achieved, these are often insufficient.

Furthermore, the addition of surfactants (see GB-PS 1 294 173) or of amide-formaldehyde resins (see DE-OS 22 29 872) was proposed in the lightening of the coating slips. Brightenings are then obtained, but they do not meet the requirements regarding whiteness. Otherwise, these measures can only be applied in coating slips with synthetic binders, but not for the technically important mixtures of natural and synthetic binders.

DE-OSes 28 06 194 and 28 06 195 disclose coating compositions to which a dispersion brightener, but also bis-triazinylaminostilbene-2,2'-disulfonic acid brightener, mixed with water, an organic liquid boiling above 150 ° C, e.g. Triethyl phosphate, trioctyl phosphate, tricresyl phosphate or trichloroethyl phosphate, and a solubilizer, e.g. a non-ionic emulsifier is added. This method is mainly suitable for dispersion brighteners. In addition, the use of relatively expensive, high-boiling organic solvents is not advantageous for various reasons.

It was an object of the present invention to find a process which does not have the disadvantages described, which leads to higher whitening effects, especially when bis-triazinylaminostilbene-2,2'-disulfonic acid brighteners are used in coating slips, which leads to higher whitener concentrations Frequent greening eliminated and the use of some brighteners of the above To enable class in coating slips that were previously considered unsuitable for this application.

This object was surprisingly achieved by adding an acidic phosphoric acid ester of a fatty amine oxalkylation product of the formula (1) below to the coating slip in addition to the brightener. This measure significantly improves the whiteness of the lightened coating slips, in particular at higher brightener concentrations, and the undesired greening is avoided. In contrast to the usual lightening of coating slips with bis-triazinylaminostilbene-2,2'-disulfonic acid brighteners, the degree of whiteness increases practically linearly with the logarithm of the increasing brightener concentration, so that very high degrees of whiteness can be achieved.

oder dessen Alkalimetall-, Ammonium- oder Aminsalz einverleibt, worin R einen aliphatischen Kohlenwasserstoffrest mit 8 - 22 C-Atomen, ^y ₁ und Y₂ beide Wasserstoff oder eines dieser beiden Symbole Wasserstoff und das andere Methyl,X den Säurerest der Phosphorsäure, wobei die sauren Wasserstoffatome dieses Restes durch Alkalimetall-, Ammonium- oder Aminsalzionen ersetzt sein können, und m und n ganze Zahlen bedeuten, wobei die Summe n + m zwischen 2 und 30 liegt.The process for increasing or improving the white effect in the optical brightening of coating slips for the coating of paper or cardboard with the aid of brighteners of the bis-triazinylamino-stilbene-2,2'-disulfonic acid series is now characterized in that the coating slips are next to the respective brightener an acidic phosphoric acid ester of a fatty amine oxalkylation product of the formula.

or incorporates its alkali metal, ammonium or amine salt, in which R is an aliphatic hydrocarbon radical having 8-22 carbon atoms, ^y ₁ and Y ₂ both hydrogen or one of these two symbols hydrogen and the other methyl, X the acid radical of phosphoric acid, the acidic hydrogen atoms of this residue can be replaced by alkali metal, ammonium or amine salt ions, and m and n are integers, the sum n + m being between 2 and 30.

worin R' einen Alkyl- oder Alkenylrest mit 10 bis 18 C-Atomen, X' den Säurerest der Phosphorsäure, wobei die sauren Wasserstoffatome dieses Restes auch durch Alkalimetall- oder Ammoniumionen ersetzt sein können und n' und m' ganze Zahlen bedeuten, wobei die Summe n' + m' zwischen 4 und 20 liegt.In auxiliaries of the formula (1) used in the process according to the invention, the aliphatic radical R preferably denotes an alkyl or alkenyl radical (branched or unbranched) having 10 to 18 carbon atoms. Auxiliaries which can preferably be used correspond to the formula

wherein R 'is an alkyl or alkenyl radical having 10 to 18 carbon atoms, X' the acid radical of phosphoric acid, the acidic hydrogen atoms of this radical can also be replaced by alkali metal or ammonium ions and n 'and m' are integers, the Sum n '+ m' is between 4 and 20.

Compounds of the formula (2) in which n '+ m' is 6 to 8 are particularly preferably used, in particular those in which R 'is the lauryl radical (C ₁₂ H ₂₅ ). The number 8 is then particularly advantageous for the sum n '+ m'.

In general, the radical R need not have a certain number of carbon atoms, but it can also be a mixture of hydrocarbon chains of different lengths, as is the case with many fatty amines derived from natural fats. A preferred residue of this type is the hydrocarbon residue of tallow fatty amine. In formula (1), Y and Y _{2 are} preferably hydrogen.

The acid component of the ester of formula (1) is phosphoric acid. X is therefore the rest of the phosphoric acid. the terminal OH groups of the ethylene oxide or propylene oxide chains can be completely or only partially esterified. According to the degree of esterification, the the number of acidic hydrogen atoms in the phosphoric acid residue X is not an integral number. These acidic hydrogen atoms can also be replaced by alkali metal, ammonium or amine salt ions, so that the residue X is in salt form. However, the radical X is preferably in its acidic form.

Depending on the degree of esterification, possible boundary structures of the compounds of the formula (1) would be, for example, the following (for ^Y ₁ = Y ₂ = ^H ) ^:

eingesetzt, worin M Wasserstoff, ein Alkalimetall-, Ammonium- oder Aminsalzion, R₁ und R₂ NH₂, NH-CH₃, NH-C₂H₅, N(CH₃)₂, N(C₂H₅)₂, NH-CH₂-CH₂-OH, NH-CH₂ -CH₂-CH₂-OH, N(CH₂-CH₂-OH)₂, N(CH₂-CH₂-CH₂-OH)₂, N(CH₃)(CH₂-CH₂-OH), NH-CH₂-CH₂-O-CH₂-CH₂-OH, NH-CH₂-CH₂-SO₂ M, OH, OCH₃, OCH(CH₃)₂, O-CH₂-CH₂-O-CH₃,

SCH₃, SO₃M

bedeuten.Bis-triazinylaminostilbene-2,2'-disulphonic acid brighteners which are used according to the invention for the optical brightening of coating slips are, in particular, those of the formula

used, in which M is hydrogen, an alkali metal, ammonium or amine salt ion, R ₁ and R ₂ NH ₂ , NH-CH ₃ , NH-C ₂ H ₅ , N (CH ₃ ) ₂ , N (C ₂ H ₅ ) ₂ , NH-CH ₂ -CH ₂ -OH, NH-CH ₂ -CH ₂ -CH ₂ -OH, N (CH ₂ -CH ₂ -OH) ₂ , N (CH ₂ -CH ₂ -CH ₂ -OH) ₂ , N (CH ₃ ) (CH ₂ -CH ₂ -OH) , NH-CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -OH, NH-CH ₂ -CH ₂ -SO ₂ M, OH, OCH ₃ , OCH (CH ₃ ) ₂ , O-CH ₂ -CH ₂ -O-CH ₃ ,

SCH ₃ , SO ₃ M

mean.

worin R₁ -NHCH₂CH₂OH, -N(CH₂CH₂OH)₂,-N(CH₂CH₃)₂ oder

oder

und M' Wasserstoff oder ein Alkalimetallion, ein Ammonium-, Diäthanolammonium- oder Triäthanolammoniumion bedeuten.A brightener of the formula is preferably used

wherein R ₁ -NHCH ₂ CH ₂ OH, -N (CH ₂ CH ₂ OH) ₂ , -N (CH ₂ CH ₃ ) ₂ or

or

and M 'is hydrogen or an alkali metal ion, an ammonium, diethanolammonium or triethanolammonium ion.

The sulfo groups -S0 ₃ M in the compounds of formula (3) can be in free form (M = H) or in salt form. M then denotes an alkali metal ion, in particular a sodium or potassium ion, an ammonium ion or an amine salt ion, for example a primary one or secondary alkyl amines, where the alkyl group (s) can be substituted by halogen, hydroxy (eg ethanolamine, diethanolamine, triethanolamine) or alkoxy or a cyclic amine, eg a piperidine, pyrrolidine, piperazine or morpholine.

The acidic hydrogen atoms in the phosphoric acid residue X of the compounds of formula (1) or (2) can optionally be replaced by the same ions as defined for M above. The rest X is then in salt form.

In addition to the brighteners and auxiliaries of the formula (1), it may often be expedient to incorporate further substances into the coating slips which either bring about a further improvement in effect or which have a positive effect on the properties of the coating slip in another way. Non-ionic or anionic surfactants, organic solubilizers and / or certain organic polar compounds can be considered as such additional aids.

• Niedere einwertige Alkohole, mehrwertige Alkohole, Aetheralkohole, nicht zu hochmolekulare Polyglykole oder Carbonsäureamide. Beispiele solcher Lösungsmittel sind Propanol, Isopropanol, Aethylenglykol, Propylenglykol, Butylenglykol, Glycerin, Aethylenglykolmonomethyl-, monoäthyl-, -monopropyl- oder -monobutyläther, Dipropylenglykol, Formamid, Dimethylformamid, Dimethylacetamid und N-Methylpyrrolidon. Bevorzugt sind hierbei Aethyl-englykol und Polyäthylenglykole. Weiters kommen Amine wie Triäthanolamin und andere wässerlösliche polare Verbindungen wie Dimethylsulfoxid, Dimethylmethanphosphonat, Dimethylsulfon, Sulfolan (=Tetrahydrothio- phen-l,l-dioxid), Aethylen- oder Propylencarbonat sowie Harnstoff oder substituierte Harnstoffe, beispielsweise Tetramethylharnstoff , in Betracht.

The following can be used as organic solubilizers and polar organic compounds:

• Lower monohydric alcohols, polyhydric alcohols, ether alcohols, not too high molecular weight polyglycols or carboxamides. Examples of such solvents are propanol, isopropanol, ethylene glycol, propylene glycol, butylene glycol, glycerin, ethylene glycol monomethyl, monoethyl, monopropyl or monobutyl ether, dipropylene glycol, formamide, dimethylformamide, dimethylacetamide and N-methylpyrrolidone. Ethylene-glycol and polyethylene glycols are preferred. Amines such as triethanolamine and other water-soluble polar compounds such as dimethyl sulfoxide, dimethyl methane phosphonate, dimethyl sulfone, sulfolane (= tetrahydrothiophene-l, l-dioxide), ethylene or propylene carbonate and urea or substituted ureas, for example tetramethyl urea, are also suitable.

• Anlagerungsprodukte von Alkylenoxiden, insbesondere von Aethylenoxid, an höhere Fettsäuren, Fettsäureamide, aliphatische Alkohole, Mercaptane oder Amine, an Alkylphenole oder Alkylthiophenole, deren Alkylreste mindestens 7 Kohlenstoffatome aufweisen oder an Phenylphenole wie z.B. Polyglykol- (monoalkyl-phenyl)-äther, deren Alkylgruppe 8 bis 12 Kohlenstoffatome aufweist, mit mindestens 8 gegebenenfalls substituierten Glykoleinheiten, wie Decaäthylenglykolmono-octoyl-phenyläther oder das Umsetzungsprodukt von Monononylphenol mit 5 bis 35 Molen Aethylenoxid; Blockpolymere aus Aethylenoxid und höheren Alkylenoxiden, wie z.B. Propylenoxid oder Butylenoxid; nichtionogene Ester der Anlagerungsprodukte von Alkylenoxiden, wie z.B. der tertiäre Phosphorsäureester des Anlagerungsproduktes von 40 Molen Aethylenoxid an Monononylphenol; Ester von Polyalkoholen, insbesondere Monoglyceride von Fettsäuren mit 12 bis 18 Kohlenstoffatomen, z.B. die Monoglyceride der Laurin-, Stearin- oder Oelsäure; N-acylierte Alkanolamine des gleichen Typs wie bei den Sulfaten dieser Verbindungen erwähnt (siehe unten), so z.B. die N,N-Bis-(w -hydroxyalkyl)-amide-der unter dem Sammelbegriff "Cocosölfettsäuren" zusammengefassten Säuregemische, vor allem N,N-Bis-(ß-hydroxyäthyl)- oder N,N-Bis-(y-hydroxypropyl)-amide, ferner die Anlagerungsprodukte von Aethylenoxid an diese N-acylierten Alkanolamine; Reaktionsprodukte von höheren Fettsäuren mit einem Alkanolamin, wobei das Molverhältnis Alkanolamin zu Fettsäure grösser als 1, z.B. 2, ist. Als Fettsäuren kommen vor allem solche mit 8 bis 18 Kohlenstoffatomen sowie die als Cocosölfettsäuren bezeichneten Gemische, als Alkanolamine insbesondere Diäthanolamin, in Betracht.

Examples of nonionic surfactants that can be used are:

• Addition products of alkylene oxides, in particular of ethylene oxide, with higher fatty acids, fatty acid amides, aliphatic alcohols, mercaptans or amines, with alkylphenols or alkylthiophenols whose alkyl radicals have at least 7 carbon atoms or with phenylphenols such as polyglycol (monoalkylphenyl) ether, the alkyl group 8 has up to 12 carbon atoms, with at least 8 optionally substituted glycol units, such as decaethylene glycol mono-octoyl phenyl ether or the reaction product of monononylphenol with 5 to 35 moles of ethylene oxide; Block polymers of ethylene oxide and higher alkylene oxides, such as propylene oxide or butylene oxide; nonionic esters of the adducts of alkylene oxides, such as, for example, the tertiary phosphoric acid esters of the adducts of 40 moles of ethylene oxide with monononylphenol; Esters of polyalcohols, especially monoglycerides of fatty acids with 12 to 18 carbon atoms, for example the monoglycerides of lauric, stearic or oleic acid; N-acylated alkanolamines of the same type as mentioned for the sulfates of these compounds (see below), for example the N, N-bis (w -hydroxyalkyl) amides - the acid mixtures summarized under the collective term "coconut oil fatty acids", especially N, N-bis- (ß-hydroxyethyl) - or N, N-bis- (y-hydroxypropyl) -amides, also the addition products of ethylene oxide with these N-acylated alkanolamines; Reaction products of higher fatty acids with an alkanolamine, the molar ratio of alkanolamine to fatty acid being greater than 1, for example 2. Suitable fatty acids are, in particular, those having 8 to 18 carbon atoms and the mixtures referred to as coconut oil fatty acids, and in particular diethanolamine as alkanolamines.

• Sulfatierte Alkylenoxidaddukte, insbesondere sulfatierte Aethylenoxidaddukte, wie sulfatierte Anlagerungsprodukte von 1 bis 40 Mol Aethylenoxid 'an Fettsäureamide, Mercaptane oder Amine, besonders aber an Fettsäuren, aliphatische Alkohole oder Alkylphenole mit 8 bis 20 Kohlenstoffatomen in der Alkylkette, z.B. an Stearinsäure, Oelsäure, Laurylalkohol, Myristylalkohol, Stearylalkohol, Oleylalkohol, Octylphenol oder Nonylphenol. Anstelle der Sulfate können auch die Ester anderer mehrwertiger Säuren eingesetzt werden. Hierher gehören z.B. die primären und sekundären Ester der Phosphorsäure sowie die Halbester der Sulfobernsteinsäure; Sulfate N-acylierter Alkanolamine, z.B. die sulfatierten Amide von Capryl-, Pelargon-, Caprin-, Laurin-, Myristin- oder Stearinsäure oder von durch Alkylphenoxygruppen substituierten niederen Fettsäuren, wie Octyl- oder Nonylphenoxyessigsäure, mit Mono- oder Bis-hydroxyalkylaminen, wie β-Hydroxyäthylamin, y-Hydroxypropylamin, β,γ-Dihydroxy- propylamin, Bis-(ß-hydroxyäthyl)-amin oder mit N-Alkyl-N-hydroxyalkylaminen, wie N-Methyl- bzw. N-Aethyl-N-(ß-hydroxyäthyl)-amin; Sulfatierte veresterte Polyoxyverbindungen, z.B. sulfatierte partiell veresterte mehrwertige Alkohole, wie das Natriumsalz des sulfatierten Monoglycerids der Palmitinsäure.

The following can be used as anionic surfactants:

• Sulphated alkylene oxide adducts, especially sulphated ethylene oxide adducts, such as sulphated addition products of 1 to 40 moles of ethylene oxide with fatty acid amides, mercaptans or amines, but especially with fatty acids, aliphatic alcohols or alkylphenols with 8 to 20 carbon atoms in the alkyl chain, for example with stearic acid, oleic acid, lauryl alcohol, Myristyl alcohol, stearyl alcohol, oleyl alcohol, octylphenol or nonylphenol. Instead of the sulfates, the esters of other polyvalent acids can also be used. This subheading includes, for example, the primary and secondary esters of phosphoric acid and the half esters of sulfosuccinic acid; Sulfates of N-acylated alkanolamines, for example the sulfated amides of caprylic, pelargonic, capric, lauric, myristic or stearic acid or of lower fatty acids substituted by alkylphenoxy groups, such as octyl or nonylphenoxyacetic acid, with mono- or bis-hydroxyalkylamines, such as β-hydroxyethylamine, y-hydroxypropylamine, β, γ-dihydroxy propylamine, bis (ß-hydroxyethyl) amine or with N-alkyl-N-hydroxyalkylamines, such as N-methyl- or N-ethyl-N- (ß -hydroxyethyl) amine; Sulfated esterified polyoxy compounds, for example sulfated partially esterified polyhydric alcohols, such as the sodium salt of the sulfated monoglyceride of palmitic acid.

worin die allgemeinen Symbole wie in Formel (1) definiert sind, mit Phosphorsäure, Phosphorpentoxid oder einem Halogenid der Phosphorsäure erhalten werden. Bevorzugt ist die Umsetzung mit Phosphorpentoxid. Die Veresterung erfolgt zweckmässig durch einfaches Vermischen der Reaktionspartner unter Erwärmen, z.B. auf 50 - 100°C. Die sauren Ester können, falls erwünscht, in die entsprechenden Salze (Alkalimetall-, Ammonium- oder Aminsalze) übergeführt werden, z.B. in üblicher Weise durch Zugabe der entsprechenden Basen, z.B. Ammoniak, Monoäthanolamin, Triäthanolamin, Alkalimetallhydroxide.The acidic phosphoric acid esters of fatty amine oxalkylation products of the formula (1) used in the process according to the invention are known and can be obtained simply by esterification of a fatty amine oxalkylation product of the formula

wherein the general symbols as defined in formula (1) can be obtained with phosphoric acid, phosphorus pentoxide or a halide of phosphoric acid. The reaction with phosphorus pentoxide is preferred. The esterification is conveniently carried out by simply mixing the reactants with heating, for example to 50-100 ° C. If desired, the acidic esters can be converted into the corresponding salts (alkali metal, ammonium or amine salts), for example in a conventional manner by adding the corresponding bases, for example ammonia, monoethanolamine, triethanolamine, alkali metal hydroxides.

worin n"+ m" die Zahl 8 ist und X einen sauren Phosphorsäurerest bedeutet, kann wie folgt vorgegangen werden: 914,6 g der Verbindung der Formel

worin n"+ m = 8, werden bei Raumtemperatur in einem Kolben vorgelegt und unter Rühren mit einem Wasser/Eisbad auf 18°C gekühlt. Dann werden 80,94 g Phosphorpentoxid schnell zugegeben. Nach Entfernung des Kühlbades steigt die Temperatur der gelblichen Suspension auf Raumtemperatur an. Nun wird mit einem Oelbad innerhalb 2 Stunden auf 40°C und anschliessend innerhalb weiterer 2 Stunden auf 60°C erwärmt. Es wird noch eine Stunde bei 60°C gerührt. Das erhaltene Produkt der Formel (6) ist bei Raumtemperatur ein gelbes, gut giessbares Gel. Die analogen Verbindungen der Formeln (6a), (6b), (6c) und (6d) (siehe Beispiele) werden ebenfalls nach der obigen Vorschrift erhalten.For the preparation of the compound of the formula

where n "+ m" is the number 8 and X is an acidic phosphoric acid residue, can be carried out as follows: 914.6 g of the compound of the formula

where n "+ m = 8, are placed in a flask at room temperature and cooled with stirring with a water / ice bath to 18 ° C. 80.94 g of phosphorus pentoxide are then added rapidly. After the cooling bath has been removed, the temperature of the yellowish suspension rises The mixture is then heated with an oil bath to 40 ° C. in the course of 2 hours and then to 60 ° C. in the course of a further 2 hours, and the mixture is stirred for another hour at 60 ° C. The product of the formula (6) obtained is at room temperature yellow, easily pourable gel. The analogous compounds of the formulas (6a), (6b), (6c) and (6d) (see examples) are also obtained according to the above procedure.

The addition products of the formula (5) are known and can be prepared in a known manner by adding 2 to 30 mol of ethylene oxide or propylene oxide to an aliphatic amine having a hydrocarbon radical of 8 to 22 carbon atoms.

The process according to the invention is expediently carried out in such a way that, for example, the brightener, an acidic phosphoric acid ester of a fatty amine oxalkylation product of the formula (1) and, if appropriate, one or more of the above-mentioned additional auxiliaries, individually and for the respective coating liquor which is prepared in the customary manner mixed in in any order and finely divided therein, for example at temperatures between 10 and 150 ° C. Alternatively, the whitening agent can also be mixed with an acidic phosphoric acid ester of a fatty amine oxalkylation product of the formula (1) and optionally with one or more of the above-mentioned additional auxiliaries, advantageously with the addition of water, before the addition to the coating liquor, and the whitening agent preparation obtained can then, are added to the coating liquor as described above. The finished coating slip can then be used to coat paper or cardboard with conventional coating apparatus, for example with an air knife, a doctor blade, a brush, a roller, a doctor blade, a rod or another coating apparatus customary in the paper industry.

The amount of compound of the formula (1) used in the process according to the invention can vary within wide limits. Even at a ratio of brightener to compound of the formula (1) of 1: 0 ₉ 5, positive effects are observed. This ratio is preferably 1: 1 to 1: 5, in particular 1: 1 to 1: 3. With a ratio of 1: 2, particularly good effects are achieved. It would also be entirely possible to use more compound of the formula (1) than corresponds to the ratio 1: 5; however, this is both out In practice, it is not practical for economic reasons or because of the associated influence on the consistency of the coating slip. The amount of optional aids (surfactants, solubilizers, polar compounds) can vary within wide limits. The ratio of brightener to these aids can be between 1: 0.1 to 1:10, depending on the type of aid used (see also examples).

The amount of brightener that is added to the coating slips is within the normal range in the paper industry. For example, amounts between 1 g and 50 g / 1 coating liquor are considered, preferably those between 4 and 20 g / l. As already mentioned, the method according to the invention also allows brightener concentrations higher than they are usually used (e.g. 4 to 8 g / l). Without the addition of compounds of the formula (I), for example at concentrations of more than 10 g of brightener per liter, there is often already a drop in whiteness or severe greening. On the other hand, when compounds of the formula (1) are added according to the invention, this effect is eliminated: with an increasing brightener concentration, the attainable degree of whiteness also increases.

The process according to the invention is suitable for the optical brightening of the coating slips usually used in the paper industry, specifically of unpigmented, but in particular pigmented coating slips. These coating slips contain a polymeric binder, an inorganic pigment (in the case of pigmented coating slips) and optionally other additives such as e.g. Waxes, dispersants, wetting agents or other surface-active agents, viscosity regulators, antifoams, lubricants, plasticizers and / or preservatives.

The usual polymeric adhesive-binder systems used in the paper industry come in as polymeric binders Consider. For example, any of the known, modified, or converted starches, such as oxidized, hydrolyzed, or hydroxyethylated starches, can be used. In addition to the different types and types of starch, other natural or synthetic polymeric binder systems can be used alone or particularly in the case of synthetic polymeric binders in combination with one another. Plastic dispersions based on copolymers of butadiene-styrene, acrylonitrile-butadiene-styrene, acrylic acid esters, ethylene-vinyl chloride and ethylene-vinyl acetate; or based on homopolymers such as polyvinyl chloride, polyvinylidene chloride, polyethylene, polyvinylpyrrolidone, polyvinyl alcohol and polyvinyl acetate, and polyurethanes are suitable as binders for the coating slips to be lightened in the process according to the invention. Further degraded starch, alginates, carboxymethyl cellulose, proteins (eg gelatin, casein, soy protein) etc. can be used as binders.

For example, aluminum-magnesium silicates (china clay), calcium carbonate, CaSO ₄ can be used as white pigments. 10H ₂ 0 (satin white), aluminum silicates and hydroxides, barium sulfate (Blancfix) or titanium dioxide or mixtures of such pigments. In addition, for the purpose of eliminating undesirable traces of metal (for example Fe (III)), the wash liquors can contain metal-binding agents such as, for example, water-soluble poly- or metaphosphates and polycarboxylic acid salts.

To obtain good flow properties, an alkaline coating liquor is used for the pigment coat. The alkaline reaction is expediently set with ammonia or with NaOH or KOH or with Na or K carbonates or borates or mixtures thereof.

Examples of suitable wetting agents are unsulphated or sulphated higher alkanol or alkylphenol polyglycol ethers with an 8 to 14 carbon atom having alkyl radical with 1 to 20 ethylene oxide groups can be used.

Recipes of such known coating slips to be lightened by the process according to the invention are described, for example, in JP Casey, "Pulp and Paper"; Chemistry and Chemical Technology, ^2nd Ed, Vol. III, p. 1648-1649 and in Mc Graw-Hill, "Pulp and Paper. Manufacture", ^2nd Ed., Vol. II, p. 497.

The present invention further relates to the coating slips lightened by the process according to the invention, that is to say an optical brightener of the bis-triazinylaminostilbene-2,2'-disulphonic acid series, preferably one of the formula (2), in particular one of the formula (3) and an acidic phosphoric acid ester of a fatty aminoxalkylation product of formula (1), preferably one of formula (2).

In addition to the optical brightener and the acidic phosphoric acid ester of a fatty amine oxalkylation product, the coating slips according to the invention can additionally contain nonionic or anionic surfactants, organic solubilizers and / or polar organic compounds, for example as organic solubilizers, hydrophilic organic solvents, for example lower monohydric alcohols, polyhydric alcohols, Ether alcohols, glycols, polyglycols, glycol and polyglycol ethers, amides and / or amines or as a polar organic compound dimethyl sulfoxide, dimethyl sulfone, ethylene or propylene carbonate and / or urea, or nonionic surfactants such as adducts of alkylene oxides with higher fatty acids, fatty acid amides, aliphatic alcohols Mercaptans or amines, on alkylphenols, alkylthiophenols or phenylphenols, block polymers of ethylene oxides and higher alkylene oxides, nonionic esters of the adducts of alkylene oxides, esters of polyalcohols, N-acyl ized alkanolamines and their analgesic products with ethylene oxide and reaction products from higher fatty acids with an alkanolamine and / or as anionic surfactants alkylene oxide adducts with sulfate or other acid residues, sulfates of N-acylated alkanolamines and sulfated esterified polyoxy compounds.

Finally, the present invention relates to paper and cardboard coated with coating compositions according to the invention (as described above).

In the following examples, parts and percent are always parts by weight and percent by weight, unless stated otherwise.

Example 1:

• a) 100 g of starch ("Paperol R 10") and 950 ml of demineralized water are heated to 80 ° C. in the course of 10-15 minutes in a 2 liter beaker and then stirred at 80-85 ° C. for 15 minutes. A slightly cloudy, gray, colloidal solution is obtained. The mixture is then cooled to about 40 ° C., 50 ml of 4-nonylphenol 1:25 ethoxylated with 9.7 mol of ethylene oxide are added, and the mixture is made up to about 1000 ml with demineralized water and shaken briefly. Then with conc. Ammonia adjusted a pH of 8 - 9.
• b) 15 ml of the starch liquor obtained according to a) are mixed with 5 ml of a brightener solution, which consists of 11.6 g of the optical brightener of the formula
  
  20 g of the acidic phosphoric acid ester of a fatty amine oxalkylation product of the formula (6), 10 g of a 4-nonylphenol ethoxylated with 9.7 mol of ethylene oxide, 15 g of ethylene glycol, 18 g of polyethylene glycol 300 and 25.4 g of water. The mass obtained is homogeneously mixed on a magnetic stirrer.
• c) After a waiting time of approx. 20 minutes, the coating slip obtained in b) is stirred again and strips of coating base paper thus prepared are coated in the customary manner. In this way a paper is obtained whose whiteness is significantly higher than that of a comparison paper which is coated with a coating liquor which does not contain any compound of the formula (6).

Example 2: 100 g of starch ("Paperol R 10") and 950 ml of demineralized water are heated to 80 ° C. in the course of 10-15 minutes in a 2.1 beaker and then stirred at 80-85 ° C. for 15 minutes. A slightly cloudy, gray, colloidal solution is obtained, to which 7.5 g of the acidic phosphoric acid ester of a fatty amine oxyalkylation product of the formula (6) are added. The mixture is then cooled to about 40 ° C., 50 ml of 4-nonylphenol 1:25 ethoxylated with 9.7 mol of ethylene oxide are added, and the mixture is made up to about 1000 ml with demineralized water and shaken briefly. Then with conc. Ammonia adjusted a pH of 8-9.

b) 15 ml of the starch liquor obtained according to a) are mixed with 5 ml of a brightener solution which contains 11.6 g of the brightener of the formula (10) in 88.4 g of water. The mass obtained is homogeneously mixed on a magnetic stirrer.

c) After a waiting time of about 20 minutes, the coating slip obtained in b) is stirred again and strips of coating base paper prepared with it are coated in the usual way. In this way a paper is obtained whose whiteness is significantly higher than that a comparison paper coated with a coating liquor which contains no compound of formula (6).

ein, so erhält man Papier mit ähnlich hohem Weissgrad.Example 3: If Example 1 is repeated, but instead of the brightener of the formula (10), the corresponding amount of a brightener of the following formulas is used:

, paper with a similarly high degree of whiteness is obtained.

Example 4: If example 2 is repeated, but instead of using the brightener of the formula (10), the corresponding amount of a brightener of the formula (11), (12), (13), (14) or (15) is used, the result is Paper with a similar degree of whiteness.

• A) 20 g der Verbindung der Formel (6) 11,6 g des Aufhellers der Formel (10) 15 g Aethylenglykol 53,4 g Wasser;
• B) 10 g der Verbindung der Formel (6) 5,8 g des Aufhellers der Formel (10) 9 g Polyäthylenglykol 300 25,2 g Wasser;
• C) 10 g der Verbindung der Formel (6) 5,8 g des Aufhellers der Formel (10) 5 g eines mit 9.7 Mol Aethylenoxid äthoxylierten 4-Nonylphenols 29,2 g Wasser;
• D) 10 g der Verbindung der Formel (6) 5,8 g des Aufhellers der Formel (10) 5 g eines mit 9,7 Mol Aethylenoxid äthoxylierten 4-Nonylphenols 7,5 g Aethylenglykol 21,7 g Wasser;
• E) 10 g der Verbindung der Formel (6) 5,8 g des Aufhellers der Formel (10) 7,5 g Aethylenglykol 9 g Polyäthylenglykol 300 17,7 g Wasser

Example 5: 5 ml of the following brightener solutions are added to 15 ml of a starch liquor obtained according to Example la):

• A) 20 g of the compound of the formula (6) 11.6 g of the brightener of the formula (10) 15 g of ethylene glycol 53.4 g of water;
• B) 10 g of the compound of the formula (6) 5.8 g of the brightener of the formula (10) 9 g of polyethylene glycol 300 25.2 g of water;
• C) 10 g of the compound of the formula (6) 5.8 g of the brightener of the formula (10) 5 g of a 4-nonylphenol ethoxylated with 9.7 mol of ethylene oxide and 29.2 g of water;
• D) 10 g of the compound of the formula (6) 5.8 g of the brightener of the formula (10) 5 g of a 4-nonylphenol ethoxylated with 9.7 mol of ethylene oxide 7.5 g of ethylene glycol and 21.7 g of water;
• E) 10 g of the compound of formula (6) 5.8 g of the brightener of formula (10) 7.5 g of ethylene glycol 9 g of polyethylene glycol 300 17.7 g of water

The coating slip is finished and the paper is coated as described in Examples 1b) and 1c). In each case paper with a high degree of whiteness is obtained, which is considerably higher than that which is achieved with the individual brightener formulations A) to E), but without the compound of the formula (6).

If you replace the brightener of the formula (10) in the brightener solutions A) to E) with appropriate amounts of brightener of the formula (11), (12), (13), (14) or (15), you come to paper similarly high degree of whiteness.

The individual components listed in the brightener solutions A) to E) can also be added individually and in any order to the coating slip, and similar results are then obtained.

• A) 30 g der Verbindung der Formel (6) 16,7 g des Aufhellers der Formel
  
  und 53,3 g Wasser;
• B) 30 g der Verbindung der Formel (6) 16,7 g des Aufhellers der Formel (10a) 9 g Harnstoff 44,3 g Wasser;
• C) 30 g der Verbindung der Formel (6) 16,9 g des Aufhellers der Formel
  
  und 53,1 g Wasser,
• D) 30 g der Verbindung der Formel
  
  worin n''' + m''' die Zahl 12 ist und X wie in Formel (6) definiert ist, 16,9 g des Aufhellers der Formel (10b) 53,1 g Wasser;
• E) 30 g der Verbindung der Formel
  
  worin n^1V + m^1V die Zahl 20 ist und X wie in Formel (6) definiert ist, 16,9 g des Aufhellers der Formel (10b) 53,1 g Wasser;
• F) 30 g der Verbindung der Formel
  
  worin n" + m" die Zahl 8 ist, X wie in Formel (6) definiert ist und R₁ den Kohlenwasserstoffrest des Talgfettamins bedeutet, 16,9 g des Aufhellers der Formel (lOb) 53,1 g Wasser.

Example 6: 5 ml of the following brightener solutions are added to 15 ml of a starch liquor obtained according to Example la)

• A) 30 g of the compound of formula (6) 16.7 g of the brightener of the formula
  
  and 53.3 g water;
• B) 30 g of the compound of formula (6) 16.7 g of the brightener of formula (10a) 9 g of urea 44.3 g of water;
• C) 30 g of the compound of formula (6) 16.9 g of the brightener of the formula
  
  and 53.1 g of water,
• D) 30 g of the compound of the formula
  
  where n '''+m''' is the number 12 and X is as defined in formula (6), 16.9 g of the brightener of formula (10b) 53.1 g of water;
• E) 30 g of the compound of the formula
  
  wherein n ^1V + m ^{1V is} 20 and X is as defined in formula (6), 16.9 g of the brightener of formula (10b) 53.1 g of water;
• F) 30 g of the compound of the formula
  
  where n "+ m" is the number 8, X is as defined in formula (6) and R _{1 is} the hydrocarbon residue of tallow fatty amine, 16.9 g of the brightener of formula (10b) 53.1 g of water.

The coating slip is finished and the paper is coated as described in Examples 1b) and 1c). You get paper with a high degree of whiteness, which is significantly higher than that. with the individual brightener formulations A) to F), but without a compound of the formula (6), (6a), (6b) or (6c).

If the brightener of the formula (10a) or (10b) in the brightener solutions A) to F) is replaced by corresponding amounts of brightener of the formula (11), (12), (13), (14) or (15), see above one comes with paper similarly high whiteness.

The individual components listed in the brightener solutions A) to F) can also be added individually and in any order to the coating slip, and similar results are then obtained.

• Example 7: A. To 15 ml of a starch liquor obtained according to Example la) are added 1.1 g of the brightener of the formula (15), 0.85 g of the acid ester of the formula (6) and 3 g of water. The mass obtained is homogeneously mixed on a magnetic stirrer.
• B. 15 ml of a starch liquor obtained according to Example la) are mixed with 1.1 g of the brightener of the formula (15), 0.51 g of the acidic ester of the formula (6c) and 3.4 g of water. The mass obtained is homogeneously mixed on a magnetic stirrer.
• C. Process B is repeated, but instead of the acidic ester of the formula (6c), the same amount of an ester of the formula (6a) is used.
• D. Process B is repeated, but instead of the acidic ester of the formula (6c), the same amount of an ester of the formula (6b) is used.

After a waiting time of about 20 minutes, the coating slips obtained in accordance with A to D are stirred again and strips of coating base paper prepared therewith are coated in the customary manner. In this way, papers are obtained whose whiteness is significantly higher than that of a comparison paper which is coated with a coating liquor which contains no acidic ester of the formula (6), (6a), (6b) or (6c).

Example 8:

• a) 150 ml of an aqueous plastic dispersion of a copolymer of acrylic acid ester and styrene (free from plasticizers and solvents), 100 ml of sodium salt of a polycarboxylic acid (solution 1:50), 500 ml of China Clay Dinkie A and 50 ml of one with stirring 9.7 mol of ethylene oxide athoxylated 4-nonylphenol (solution 1:25) in 600 ml of water. The mixture is stirred until a homogeneous coating liquor is obtained. The pigmented coating liquor thus produced is sieved (nickel sieve), deaerated and freed from coarser impurities.
• b) 15 ml of the pigment coating liquor obtained according to a) are mixed with 5 ml of a brightener solution which consists of 11.6 g of the brightener of the formula (10), 20 g of the acidic phosphoric acid ester of a fatty amine oxyalkylation product of the formula (6), 10 g of a with 9.7 mol of ethylene oxide ethoxylated 4-nonylphenol, 15 g of ethylene glycol, 18 g of polyethylene glycol 300 and 25.4 g of water. The mass obtained is homogeneously mixed on a magnetic stirrer.
• c) After a waiting time of approx. 20 minutes, the coating slip obtained in b) is stirred again and strips of coating base paper thus prepared are coated in the customary manner. In this way a paper is obtained whose whiteness is significantly higher than that of a comparison paper which is coated with a coating liquor which does not contain any compound of the formula (6).

Example 9:

• a) With stirring, 14 g of the compound of formula (6), 150 ml of an aqueous plastic dispersion of a copolymer of acrylic ester and styrene (free from plasticizers and solvents), 100 ml of sodium salt of a polycarboxylic acid (solution 1:50), 500 ml of China Clay Dinkie A and 50 ml one with 9.7 mol ethylene oxide ethoxylated 4-nonylphenol (solution 1:25) in 600 ml of water. The mixture is stirred until a homogeneous coating liquor is obtained. The pigmented coating liquor thus produced is sieved (nickel sieve), deaerated and freed from coarser impurities.
• b) 5 ml of a brightener solution containing 11.6 g of the brightener of the formula (10) in 88.4 g of water are added to 15 ml of the egg whisking liquor obtained according to a). The mass obtained is homogeneously mixed on a magnetic stirrer.
• c) After a waiting time of approx. 20 minutes, the coating slip obtained according to b) is stirred again and strips of coating base paper prepared therewith are coated in the customary manner. In this way, a paper is obtained whose whiteness is significantly higher than that of a comparison paper which is coated with a coating liquor which contains no compound of the formula (6).

Example 10: If Example 8 is repeated, but instead of the brightener of the formula (10), the corresponding amount of a brightener of the formula (11), (12), (13), (14) or (15) is used, paper is also obtained similarly high degree of whiteness.

Example 11: If Example 9 is repeated, but instead of using the brightener of the formula (10), the corresponding amount of a brightener of the formula (11), (12), (13), (14) or (15) is used, the result is Paper with a similarly high degree of whiteness.

Example 12: 5 ml of the brightener solutions A) to E) defined in Example 5 are added to 15 ml of a pigment coating liquor obtained according to Example 8a). The coating slip is finished and the paper is coated as described in Examples 8b) and 8c). You get paper with a high degree of whiteness, which is much higher than that with the individual brighteners formulations A) to E), but without a compound of formula (6).

If you replace the brightener of the formula (10) in the brightener solutions A) to E) with appropriate amounts of brightener of the formula (11), (12), (13), (14) or (15), you come to paper similarly high degree of whiteness.

Example 13:

• a) 600 ml of demineralized water, 10 ml of conc. Ammonia and 35 g casein are placed in a 2 liter beaker and heated to 70 ° C within 10 minutes with stirring. The mixture is stirred at 70-75 ° C. for a further 15 minutes. A cloudy, sand-colored, colloidal solution is obtained. The casein solution cooled to 30 ° C. is added to a mixture of 50 ml of the sodium salt of a polycarboxylic acid (aqueous solution 1:50) and 400 g of china clay SPS. The mixture obtained is slowly stirred for 3 minutes. The stirrer is then switched off and the pigment which may be adhering to the wall is scraped off with a scraper. The mixture is then slowly stirred again for 2 minutes. Then 3 ml of conc. Ammonia and 80 ml of styrene-butadiene latex were added and the mixture was slowly stirred for a further 3 minutes. Finally, 50 ml of a 4-nonylphenol (1:25) ethoxylated with 9.7 mol of ethylene oxide are added and the mixture is stirred again for about 15 seconds.
  The fleet thus produced is vented through a nickel sieve and freed from agglomerates and coarser impurities. Then the mass is placed in a 1 liter Erlenmayer flask and adjusted to a weight of 1260 g per liter with deionized water.
• b) 15 ml of the art print coating liquor obtained according to a) are mixed with 5 ml of a brightener solution which consists of 11.6 g of the brightener of the formula (10), 20 g of the acidic phosphoric acid ester of a fatty amine oxyalkylation product of the formula (6), 10 g of a with 9.7 moles Ethylene oxide is ethoxylated 4-nonylphenol, 15 g of ethylene glycol, 18 g of polyethylene glycol 300 and 25.4 g of water. The mass obtained is homogeneously mixed on a magnetic stirrer.
• c) After a waiting time of approx. 20 minutes, the coating slip obtained in b) is stirred again and strips of coating base paper thus prepared are coated in the customary manner. In this way a paper is obtained whose whiteness is significantly higher than that of a comparison paper which is coated with a coating liquor which does not contain any compound of the formula (6).

Example 14: Example 13 is repeated, but 14 g of the compound of the formula (6) were additionally added in the preparation of the art print coating slip according to Example 13a). 15 ml of the coating slip otherwise prepared as described in Example 13a) are then mixed with 5 ml of a Brightener solution added, which consists of 11.6 g of the brightener of the formula (10) and 88.4 g of water. Further workup is carried out as described in Example 13. A paper with a significantly higher degree of whiteness than that obtained by coating with an appropriate coating liquor which does not contain the compound of the formula (6) is likewise obtained.

In Examples 13 and 14, instead of the brightener of formula (10), those of formula (11), (12), (13), (14) and (15): can be used with equal success.

Replacing the acidic ester of formula (6) with one of formula (6a), (6b) or (6c) in the procedures of Examples 8 to 14 also gives well-lightened paper which has a higher degree of whiteness than Paper that is coated with a coating liquor that does not contain such an acid ester.

Claims (11)

1. A method for increasing or improving the white effect in the optical brightening of coating slips for the coating of paper or cardboard using brighteners of the bis-triazinylamino-stilbene-2,2'-disulfonic acid series, characterized in that the coating slips in addition to the each brightener an acidic phosphoric acid ester of a fatty amine oxalkylation product of the formula

or incorporates its alkali metal, ammonium or amine salt, in which R is an aliphatic hydrocarbon radical having 8-22 carbon atoms, Y ₁ and Y ₂ both hydrogen or one of these two symbols hydrogen and the other methyl, X the acid radical of phosphoric acid, the acidic hydrogen atoms of this radical can be replaced by alkali metal, ammonium or amine salt ions, and m and n are integers, the sum n + m being between 2 and 30. 2. The method according to claim 1, characterized in that one of the formula as the acidic phosphoric acid ester of a fatty amine oxalkylation product

uses, wherein R 'is an alkyl or alkenyl radical having 10 to 18 carbon atoms, preferably the lauryl radical or the hydrocarbon radical of tallow fatty amine, X' the acid radical of phosphoric acid, where the acidic hydrogen atoms of this radical can also be replaced by alkali metal or ammonium ions, and n 'and m' are integers, where: the sum n '+ m' is between 4 and 20, in particular between 6 and 8. 3. The method according to claim 1, characterized in that one of the formula as a brightener

wherein R ₁ and R ₂ NH ₂ , NH-CH ₃ , NH-C ₂ H ₅ , ^N ( ^CH ₃ ) ₂ , N (C ₂ H ₅ ) ₂ , NH-CH ₂ -CH ₂ -OH, NH-CE ₂ -CH ₂ -CH ₂ -OH, N (CH ₂ -CH ₂ -OH) ₂ , N (CH ₂ -CH ₂ -CH ₂ -OH) ₂ , N (CH3) (CH2-CH2-OH) NH-CH2 -CH2-O-CH2-CH2-OH, NH-CH2-CH ₂ -SO ₃ M, OH, OCH ₃ , OCH (CH ₃ ) ₂ , O-CH ₂ -CH ₂ -2-O-CH ₃ ,

SCH ₃ , SO ₃ M

and M represents hydrogen, an alkali metal, ammonium or amine salt ion, preferably of the formula

used, wherein R ₁ -NHCH ₂ CH ₂ OH, -N (CH ₂ CH ₂ OH) ₂ , -N (CH ₂ CH ₃ ) ₂ der

or

and M 'is hydrogen or an alkali metal ion, an ammonium, diethanolammonium or triethanolammonium ion. 4. The method according to any one of claims 1 to 3, characterized in that in addition to the brightener and acidic phosphoric acid ester of a fatty amine oxalkylation product, nonionic or anionic surfactants, organic solubilizers and / or polar organic compounds are added. 5. The method according to claim 4, characterized in that one as a solubilizer hydrophilic organic solvents such as lower monohydric alcohols, polyhydric alcohols, ether alcohols, glycols, polyglycols, glycol and polyglycol ethers, amides, amines and / or as polar organic compounds dimethyl sulfoxide, dimethyl methane phosphonate , Dimethyl sulfone, sulfolane, ethylene or propylene carbonate and urea or substituted ureas are added. 6. The method according to claim 4, characterized in that addition products of alkylene oxides to higher fatty acids, fatty acid amides, aliphatic alcohols, mercaptans or amines, to alkylphenols, alkylthiophenols or phenylphenols, block polymers of ethylene oxides and higher alkylene oxides, nonionic esters of the addition products of as nonionic surfactants Alkylene oxides, esters of polyalcohols, N-acylated alkanolamines and their addition products with ethylene oxide and reaction products from higher fatty acids with an alkanolamine and / or alkylene oxide adducts with sulfate or other acid residues, sulfates of N-acylated alkanolamines and sulfated esterified polyoxy compounds are added as anionic surfactants. 7. The method according to any one of claims 1 to 6, characterized in that the brightener is mixed with the acidic phosphoric acid ester of a fatty amine oxalkylation product and optionally with optional auxiliaries defined in claims 4 to 6 and optionally water and this mixture is incorporated into the coating slip. 8. The method according to any one of claims 1 to 6, characterized in that the brightener, the acidic phosphoric acid ester of a fatty amine oxalkylation product and optionally the optional auxiliaries defined in claims 4 to 6 are incorporated independently of the coating slip. 9. Optically lightened coating slip for the coating of paper and cardboard, containing an optical brightener of the bis-triazinylaminostilbene-2,2'-disulfonic acid series, preferably one of the formula (3), in particular one of the formula (4) and an acidic phosphoric acid ester a fatty amine oxyalkylation product of the formula (1), preferably one of the formula (2). 10. coating slip according to claim 9, which, in addition to the optical brightener and the acidic phosphoric acid ester of a fatty amine oxalkylation product, nonionic or anionic surfactants, preferably those defined in claim 6, organic solubilizers and / or polar organic compounds, preferably those which claim 5 are defined. 11. Paper or cardboard coated with a coating slip defined in claim 9 or 10.