DE10150895A1 - Polymer dispersion containing vinylamide copolymers, useful for paper coating compositions containing a new type of binder for fixing pigment to the paper - Google Patents

Abstract

The addition of a (co)polymer B, comprising an N-vinylcarboxamide, to a polymer dispersion, the bonding force of this binder in a paper coating composition is increased, and the optical brightener in the paper coating composition is extremely strongly activated. Polymer dispersions containing: (i) a (co) polymer A with at least one main monomer selected from 1-20C alkyl (meth)acrylate, vinyl ester from up to 20C carboxylic acid, up to 20C vinyl aromatics, ethylenically unsaturated nitrile, vinyl halide, vinyl ether or 1-10C allyl ethers containing alcohols and aliphatic 2-8C hydrocarbons and 1 or two double bonds included by polymerization (sic); and (ii) at least one N-vinylcarboxyic acid amide in polymerized form containing (co)polymer B. Independent claims are included for: (1) a paper coating composition containing the polymer dispersion; and (2) a process for preparation of the polymer dispersion by mixing a dispersion of (co)polymer A with (co)polymer B, its dispersion, solution, suspension, or emulsion, and a brightener, its solution, or suspension.

Description

The invention relates to paper coating slips, which a new Contain binders, these binders, papers, which with the Paper coating slips are coated and the printing of Papers coated with these coating slips.

Paper coating slips essentially consist of one white pigment, dispersants, optical brighteners, polymeric binders and additives, which the rheological Properties of the coating color and the properties of the surface of the coated paper in the desired way. Such Additives are often referred to as "cobinders". The The main task of the Cobinder is to increase the effectiveness of the optical brightener. Through the binder, the pigments pinned on paper and the cohesion in the preserved Coating guaranteed.

The binders used in paper coating slips are it is usually styrene / butadiene copolymers or else Acrylic copolymers. For example, dispersions of (Co) polymers are used, which in varying amounts of acrylic acid, Acrylic acid ester, acrylonitrile, styrene, butadiene, vinyl acetate and Contain ethylene in copolymerized form, e.g. B. (Co) polymers from acrylic ester and styrene, styrene and butadiene, vinyl acetate and Ethylene or vinyl acetate.

Exemplary paper coating slips are, for example, in WO 97/00776 described.

The main task of the binders is to Pigment particles are distributed evenly and finely to the base paper bind that they are in the processing of the paper, in particular when Print, do not peel off the paper. The binders wear in general itself not to the desired increase in Whiteness of the paper, which is one of the main goals, that aimed at by coating paper with coating slips becomes.

Obtained by coating with paper coating slips Base papers have a smooth, uniform white surface.

The coating of paper with paper coating slips is well known nowadays, see e.g. B. "The Essential Guide to Aqueous Coating of Paper and Board ", T. W. R. Dean (ed.), Published by the Paper Industry Technical Association (PITA), 1997.

An increase in the whiteness of the coated paper can be caused by a Variety of different measures can be achieved for example by using a raw paper with the highest possible Whiteness, which in turn is whiter as possible Starting materials can be obtained. Another very important one Measure is the selection of white pigments for the Paper coating slip.

The measures mentioned to increase the whiteness alone are sufficient in many cases, today's consumer demands on Not white of the paper. That is why the coating slip is usually used so - called "whitener" (fluorescent or Phosphorescent dyes) or "optical brighteners". It refers to dye-like, fluorescent compounds that the for short-wave ultraviolet light not visible to human eye absorb and emit as longer-wave blue light, which gives the human eye a higher whiteness and so on the whiteness is increased.

However, the use of optical brighteners only leads to desired success if this in the finished coating of the Paper in an optimal structure, conformation and distribution available. To achieve this, the paper coating slip polymeric compounds added that have the effect of optical Reinforce brighteners and as "activator", "carrier" or "Carrier" are called. An important function of the beginning Cobinder in coating colors mentioned is hers brightening activating effect.

Suitable cobinder can be water-soluble polymers, e.g. B. Polyvinyl alcohol, carboxymethyl cellulose, anionic or non-ionic degraded starches, casein, soy protein and Use (meth) acrylic acid-acrylate copolymers (see e.g. K.P. Kreutzer, basic processes of paper production 2: interface processes when using chemical auxiliaries, H.-G. Völkel and R. Grenz (Ed.), Munich: PTS Munich, 2000, PTS manuscript: PTS-GPE-SE 2031-2).

However, the activation of the optical brightener is not included all water-soluble polymers possible. So it succeeds. B. not, with certain polysaccharides, e.g. B. dextran, or with anionic polyacrylamides, their use because of their low Price and their good workability would be aimed at activate optical brightener. On the contrary, has been for a long time known that water-soluble polymers, the cationic Contain groups, especially amino or ammonium groups, such. B. Polyamine / epichlorohydrin or polyamidoamine / epichlorohydrin resins, Polyamines or polyethyleneimines, not just not the whitener amplify, but even deactivate, so that it becomes a The brightening is deleted (K. P. Kreutzer, op. Cit., Pp. 8-22).

From the German patent application with the file number 100 55 592.6 it is known that N-vinylformamide in polymerized form (Co) polymers containing a strength-increasing and show brightening-enhancing effects if they are independent of the binder incorporated into the coating slip as a cobinder. You are there regarding strength increase and brightener reinforcement, especially if both properties are required at the same time, significantly more effective than the usual cobinder.

DE-A 197 27 503 describes polymer dispersions for Manufacture of paper coating slips known as N-vinylformamide contain polymerized monomer component. This Polymer dispersions are made by those for the manufacture main monomers commonly used in polymer dispersions, such as As acrylic esters, styrene, acrylonitrile, butadiene, and. Ä., on a polymer containing N-vinylformamide, which acts as a graft base serves to be graft polymerized. An individual adaptation to The needs of different customers is only different Change in the entire polymerization recipe and process possible and therefore logistically and technically difficult to carry out. The polymer dispersions obtained in this way also have no effect Reinforcement of the optical brighteners in the coating slip.

The present invention was based on the object Paper coating slips with improved properties with regard to Whiteness increase and at the same time with regard to increasing the binding power to make available without being in the coating slip as additional components an amplifier for the optical Work in brightener.

• a) mindestens ein Hauptmonomer, ausgewählt aus der Gruppe umfassend C₁ bis C₂₀-Alkyl(meth)acrylate, Vinylester von bis zu 20 C-Atome enthaltenden Carbonsäuren, Vinylaromaten mit bis zu 20 C-Atomen, ethylenisch ungesättigte Nitrile, Vinylhalogenide, Vinylether oder Allylether von 1 bis 10 C-Atome enthaltenden Alkoholen und aliphatische Kohlenwasserstoffe mit 2 bis 8 C-Atomen und 1 oder 2 Doppelbindungen, einpolymerisiert enthaltendes (Co)polymer A und
• b) mindestens ein N-Vinylcarbonsäureamid in einpolymerisierter Form enthaltendes (Co)polymer B.

The object was achieved by containing polymer dispersions

• a) at least one main monomer selected from the group comprising C ₁ to C ₂₀ alkyl (meth) acrylates, vinyl esters of carboxylic acids containing up to 20 C atoms, vinyl aromatics with up to 20 C atoms, ethylenically unsaturated nitriles, vinyl halides, vinyl ethers or allyl ethers of alcohols containing 1 to 10 carbon atoms and aliphatic hydrocarbons with 2 to 8 carbon atoms and 1 or 2 double bonds, copolymerized containing (co) polymer A and
• b) at least one (co) polymer B containing polymerized N-vinylcarboxamide.

• 1. 30 bis 100 Gew.-% sogenannter Hauptmonomere,
• 2. 0 bis 40 Gew.-% sogenannter Nebenmonomere und
• 3. 0 bis 30 Gew.-% sogenannter Hilfsmonomere, wobei die Summe immer 100 Gew.-% ergibt.

The (co) polymers A generally act as binders in the finished paper coating slips and are structured, for example, as follows:

• 1. 30 to 100% by weight of so-called main monomers,
• 2. 0 to 40% by weight of so-called secondary monomers and
• 3. 0 to 30% by weight of so-called auxiliary monomers, the total always giving 100% by weight.

• 1. 50 bis 99,5 Gew.-% Hauptmonomere
• 2. 0,5 bis 30 Gew.-% Nebenmonomere und
• 3. 0 bis 20 Gew.-% Hilfsmonomere.

The (co) polymer A is preferably composed of

• 1. 50 to 99.5% by weight of main monomers
• 2. 0.5 to 30 wt .-% secondary monomers and
• 3. 0 to 20% by weight of auxiliary monomers.

• 1. 60 bis 99 Gew.-% Hauptmonomere
• 2. 1 bis 20 Gew.-% Nebenpolymere und
• 3. 0 bis 20 Gew.-% Hilfsmonomere.

The (co) polymer A is very particularly preferably composed of

• 1. 60 to 99% by weight of main monomers
• 2. 1 to 20% by weight of secondary polymers and
• 3. 0 to 20% by weight of auxiliary monomers.

The term (co) polymer is used in this document for polymer and Copolymer used.

Main monomers a1) are selected from C ₁ to C ₂₀ alkyl (meth) acrylates, vinyl esters of carboxylic acids containing up to 20 C atoms, vinyl aromatics with up to 20 C atoms, ethylenically unsaturated nitriles, vinyl halides, vinyl ethers or allyl ethers of 1 alcohols containing up to 10 carbon atoms, aliphatic hydrocarbons having 2 to 8 carbon atoms and 1 or 2 double bonds or mixtures of these monomers.

As alkyl (meth) acrylates to name z. B. (Meth) acrylic acid alkyl ester with a C ₁ -C ₁₀ alkyl radical, such as methyl methacrylate, ethyl methacrylate, methyl acrylate, n-butyl acrylate, n-octyl acrylate, ethyl acrylate and 2-ethylhexyl acrylate.

In this document, (meth) acrylic acid is used for acrylic acid and Methacrylic acid used.

In particular, mixtures of the (meth) acrylic acid alkyl esters suitable.

Vinyl esters of carboxylic acids with 1 to 20 carbon atoms are e.g. B. Vinyl laurate, stearate, vinyl propionate, vinyl versatic acid and preferably vinyl acetate.

As vinyl aromatic compounds come vinyl toluene α and p-methylstyrene, α-butylstyrene, 4-n-butylstyrene, 4-n-decylstyrene and preferably styrene.

Examples of nitriles are acrylonitrile and methacrylonitrile.

The vinyl halides are substituted with chlorine, fluorine or bromine ethylenically unsaturated compounds, preferably vinyl chloride and Vinylidene chloride.

Examples of vinyl ethers include B. vinyl methyl ether, Vinyl ethyl ether or vinyl isobutyl ether. Vinyl ethers of 1 are preferred alcohols containing up to 4 carbon atoms.

As hydrocarbons with 2 to 8 carbon atoms and one or two olefinic double bonds are butadiene, isoprene and Called chloroprene, ethylene and propylene.

Preferred main monomers are the C ₁ to C ₁₀ alkyl acrylates and methacrylates, in particular C ₁ to C ₈ alkyl acrylates and methacrylates, the acrylates being particularly preferred in each case.

Particularly preferred main monomers are styrene, butadiene, Acrylonitrile, vinyl acetate, methyl acrylate, methyl methacrylate, Ethyl acrylate, n-butyl acrylate, n-hexyl acrylate, octyl acrylate and 2-ethylhexyl acrylate and mixtures of these monomers.

The (co) polymer A is preferably a (co) polymer based on acrylate, ie that the (co) polymer is composed of at least 60% by weight of C ₁ -C ₂₀ alkyl (meth) acrylates or mixtures thereof with vinyl aromatics such mixtures of alkyl (meth) acrylates and styrene are particularly preferred. Mixtures of alkyl (meth) acrylates, acrylonitrile and styrene are also preferred.

A (co) polymer based on butadiene is also preferred, d. H. at least 60% by weight of the (co) polymer from butadiene or mixtures thereof with vinyl aromatics, especially mixtures of butadiene and styrene are preferred. Farther mixtures of butadiene, acrylonitrile and styrene are preferred.

As secondary monomers a2), monomers with carboxylic acid, Sulfonic acid or phosphonic acid groups and their derivatives. Carboxylic acid groups are preferred. May be mentioned for. B. acrylic acid, Methacrylic acid, itaconic acid, maleic acid or fumaric acid or Maleic anhydride.

Also suitable as secondary monomers are polymers with at least one copolymerizable, ethylenically unsaturated group, a number average molecular weight M _n of 500 to 50,000 g / mol and at least one carboxylic acid group (hereinafter referred to as ethylenically unsaturated polymer). The content of ethylenically unsaturated groups and carboxylic acid groups relates to the content per polymer chain. The ethylenically unsaturated polymer preferably contains one or two, particularly preferably one, ethylenically unsaturated group. The or one (if more than one) ethylenically unsaturated group is particularly preferably in the terminal position in the respective polymer chain. In particular, the ethylenically unsaturated group is an acrylic or methacrylic group, preferably a methacrylic group.

The ethylenically unsaturated polymer preferably contains more than 2, particularly preferably more than 4, very particularly preferred more than 8 carboxylic acid groups.

The ethylenically unsaturated polymer is preferably made of Radically polymerizable compounds built up, for example from the monomers referred to here as main monomers a1) or (Meth) acrylic acid, and correspondingly available through radical Polymerization of these compounds.

The ethylenically unsaturated polymer preferably consists of at least 50% by weight, particularly preferably 80% by weight, of C ₁ -C ₁₀ alkyl (meth) acrylates, (meth) acrylic acid and mixtures thereof.

The ethylenically unsaturated is very particularly preferably Polymer at least 50% by weight, in particular at least 80% by weight from acrylic acid or methacrylic acid. Methacrylic acid is preferred.

The average molecular weight Mn of the ethylenically unsaturated polymer is preferably 800 to 20,000, particularly preferably 1,000 up to 10,000 g / mol.

Mn is determined by gel permeation chromatography (Polyacrylic acid standard and water as eluent).

The ethylenically unsaturated polymer is preferred prepared by radical polymerization in the presence of a Transition metal complex as a molecular weight regulator, e.g. B. one Kobaltchelatkomplexes. This process is called catalytic chain transfer polymerization (CCT) known and z. B. in WO 95/04767 described.

Mentioned as secondary monomers are also (meth) acrylamide or hydroxyl group-containing monomers, in particular C ₁ -C ₁₀ hydroxyalkyl (meth) acrylates, such as. B. 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, 2- or 3-hydroxypropyl acrylate or 4-hydroxybutyl vinyl ether.

Coming as auxiliary monomers a3) Phenyloxyethyl glycol mono (meth) acrylate, glydidyl acrylate, glycidyl methacrylate Amino (meth) acrylates such as 2-aminoethyl (meth) acrylate and N-vinylformamide into consideration.

Crosslinking monomers, such as, for. B. Trimethylolpropane triacrylate, pentaerythritol tetraacrylate, 1,3-propanediol diacrylate, neopentyl glycol diacrylate, 1,4-butanediol diacrylate or ethylene glycol diacrylate.

The glass transition temperature of (co) polymer A is preferred below 50 ° C, in particular it is -40 to + 50 ° C, especially preferably -20 to + 30 ° C and very particularly preferably -10 to + 25 ° C and especially -5 to + 20 ° C.

The glass transition temperature of a polymer can be decreased usual methods such as differential thermal analysis or differential Scanning calorimetry (see, for example, ASTM 3418/82, so-called "midpoint temperature ").

• 1. 30 bis 100 Gew.-% mindestens eines N-Vinylcarbonsäureamids,
• 2. 0 bis 20 Gew.-% mindestens eines wasserlöslichen kationischen Monomers,
• 3. 0 bis 40 Gew.-% Acrylsäure oder Methacrylsäure und/oder deren Salze oder Gemische davon und
• 4. 0 bis 30 Gew.-% mindestens eines weiteren Vinylmonomers,

wobei die Summe immer 100 Gew.-% ergibt. The (co) polymers B in the polymer dispersion according to the invention generally act as cobinder in the finished paper coating slip and are generally composed as follows:

• 1. 30 to 100% by weight of at least one N-vinylcarboxamide,
• 2. 0 to 20% by weight of at least one water-soluble cationic monomer,
• 3. 0 to 40 wt .-% acrylic acid or methacrylic acid and / or their salts or mixtures thereof and
• 4. 0 to 30% by weight of at least one further vinyl monomer,

the sum always being 100% by weight.

• 1. 35 bis 100 Gew.-% mindestens eines N-Vinylcarbonsäureamids,
• 2. 0 bis 10 Gew.-% mindestens eines wasserlöslichen kationischen Fr Monomers,
• 3. 0 bis 30 Gew.-% Acrylsäure oder Methacrylsäure und/oder deren Salze oder Gemische davon und
• 4. 0 bis 25 Gew.-% mindestens eines weiteren Vinylmonomers,

wobei die Summe immer 100 Gew.-% ergibt. Preferred (co) polymer B are composed as follows:

• 1. 35 to 100% by weight of at least one N-vinylcarboxamide,
• 2. 0 to 10% by weight of at least one water-soluble cationic Fr monomer,
• 3. 0 to 30% by weight of acrylic acid or methacrylic acid and / or their salts or mixtures thereof and
• 4. 0 to 25% by weight of at least one further vinyl monomer,

the sum always being 100% by weight.

• 1. 50 bis 100 Gew.-% mindestens eines N-Vinylcarbonsäureamids,
• 2. 0 bis 5 Gew.-% mindestens eines wasserlöslichen kationischen Monomers,
• 3. 0 bis 20 Gew.-% Acrylsäure oder Methacrylsäure und/oder deren Salze oder Gemische davon und
• 4. 0 bis 25 Gew.-% mindestens eines weiteren Vinylmonomers,
  wobei die Summe immer 100 Gew.-% ergibt.

(Co) polymer B, which are composed as follows, are particularly preferred:

• 1. 50 to 100% by weight of at least one N-vinylcarboxamide,
• 2. 0 to 5% by weight of at least one water-soluble cationic monomer,
• 3. 0 to 20% by weight of acrylic acid or methacrylic acid and / or their salts or mixtures thereof and
• 4. 0 to 25% by weight of at least one further vinyl monomer,
  the sum always being 100% by weight.

The molecular weight of the (co) polymers B that can be used is not limited. (Co) polymers B are preferred K values between 20 and 110, with K values between 30 and 90 are particularly preferred.

According to Fikentscher, the K values in this document are 0.5% by weight aqueous saline solution measured at 25 ° C.

Preferred N-vinylcarboxamides b1) are those of the formula (I).

In formula I, R ¹ and R ² independently of one another denote hydrogen or C ₁ to C ₂₀ alkyl, it being possible for the alkyl radical to be straight-chain or branched.

R ¹ and R ² are preferably independently of one another hydrogen or C ₁ to C ₁₀ alkyl, particularly preferably hydrogen or C ₁ to C ₄ alkyl, very particularly preferably hydrogen or methyl and in particular hydrogen.

R ¹ and R ² can also together form a straight-chain or branched chain containing 2 to 8 carbon atoms, preferably a 3 to 6 and particularly preferably a 3 to 5 carbon atom-containing chain. Optionally, one or more carbon atoms can be replaced by heteroatoms, such as. As oxygen, nitrogen or sulfur, may be replaced.

Examples of the radicals R ¹ and R ² are methyl, ethyl, iso-propyl, n-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, n-hexyl, n-heptyl, 2-ethylhexyl, n-octyl, n-decyl, n-undecyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl or n-eicosyl.

Examples of radicals R ¹ and R ² which together form a chain are 1,2-ethylene, 1,2-propylene, 1,3-propylene, 2-methyl-1,3-propylene, 2-ethyl-1, 3-propylene, 1,4-butylene, 1,5-pentylene, 2-methyl-1,5-pentylene, 1,6-hexylene or 3-oxa-1,5-pentylene.

Examples of such N-vinylcarboxamides of the formula (I) are N-vinylformamide, N-vinylacetamide, N-vinylpropionic acid amide, N-vinylbutyric acid amide, N-vinylisobutyric acid amide, N-vinyl-2-ethylhexanoic acid amide, N-vinyl decanoic acid amide, N-vinyl dodecanoic acid amide, N-vinyl stearic acid amide, N-methyl-N-vinyl formamide, N- Methyl-N-vinyl acetamide, N-methyl-N-vinyl propionic acid amide, N-methyl-N-Vinylbuttersäureamid, N-methyl-N-vinylisobutyric acid amide, N-methyl-N-vinyl-2-ethylhexanoic acid amide, N-methyl-N-vinyl decanoic acid amide, N-methyl-N-vinyl dodecanoic acid amide, N-methyl-N-vinylstearic acid amide, N-ethyl-N-vinylformamide, N-ethyl-N-vinyl acetamide, N-ethyl-N-vinyl propionic acid amide, N-ethyl-N-vinylbutyric acid amide, N-ethyl-N-vinylisobutyric acid amide, N-ethyl-N-vinyl 2-ethylhexanoic acid amide, N-ethyl-N-vinyl decanoic acid amide, N-ethyl N-vinyl dodecanoic acid amide, N-ethyl-N-vinyl stearic acid amide, N-iso- Propyl-N-vinylformamide, N-iso-propyl-N-vinyl acetamide, N-iso- Propyl-N-Vinylpropionsäureamid, N-iso-propyl-N-vinylbutyric acid amide, N-iso-propyl-N-vinylisobutyric acid amide, N-iso-propyl-N-vinyl-2-ethylhexanoic acid amide, N-iso-propyl-N-vinyl decanoic acid amide, N-isopropyl-N-Vinyldodekansäureamid, N-iso-propyl-N-vinylstearic acid amide, N-n-butyl-N-vinylformamide, N-n-butyl-N-vinyl acetamide, N-n-butyl-N-vinyl propionic acid amide, N-n-butyl-N-vinylbutyric acid amide, N-n-butyl-N-vinylisobutyric acid amide, N-n-butyl-N-vinyl-2-ethylhexanoic acid amide, N-n-butyl-N-vinyl decanoic acid amide, N-n-butyl-N-Vinyldodekansäureamid, N-n-butyl-N-vinyl stearic acid amide, N-vinyl pyrrolidone or N-vinyl caprolactam.

Preferred are N-vinylformamide, N-vinyl acetamide, N-methyl-N-vinylformamide, N-methyl-N-vinylacetamide, N-vinylpyrrolidone or N- Vinylcaprolactam, particularly preferred is N-vinylformamide.

The water-soluble cationic monomer b2) can be cationic Groups such as B. ammonium, sulfonium or phosphonium groups, and at least one copolymerizable, ethylenically unsaturated Group bearing monomers such as Diallyldimethylammonium chloride, diallyldimethylammonium methosulfate, N- (2-tri- methylammonium) ethyl acrylamide methosulfate or N-2- (ethyl-dimethyl) ammoniumethyl methacrylamide ethosulfate or mixtures thereof copolymerize with the N-vinylcarboxamide b1), e.g. B. in EP-B1 464 043 described, and thus receives cationic Copolymers B.

As monomers of the monoethylenically unsaturated carboxylic acids b3) with 3 to 8 carbon atoms and their water-soluble salts Monomers come into consideration, for example: acrylic acid, Methacrylic acid, dimethylacrylic acid, ethacrylic acid, maleic acid, Citraconic acid, methylene malonic acid, allylacetic acid, vinyl acetic acid, Crotonic acid, fumaric acid, mesaconic acid and itaconic acid. From this Group of monomers is preferably used acrylic acid, Methacrylic acid, maleic acid or mixtures of the above Carboxylic acids, especially mixtures of acrylic acid and Maleic acid or mixtures of acrylic acid and methacrylic acid. This Monomers or mixtures thereof can either be in the form of the free Carboxylic acids or partially or completely, with ammonium, Alkali or alkaline earth metal ions, such as. B. ammonium, Trimethylammonium, triethylammonium, tris- (2-hydroxyethyl) ammonium, Bis (2-hydroxyethyl) ammonium, mono (2-hydroxyethyl) ammonium, Trimethylbenzylammonium, sodium, potassium, magnesium, calcium or Barium, neutralized form used in the copolymerization become. Copolymerizing b1) with these monomers leads to anionic (co) polymers B.

Also nonionic copolymers B of N-vinylcarboxamides with other vinyl monomers b4) can in the invention Polymer dispersions are used. To do this, the same Monomers used as the main monomers a1) in the (Co) polymers A are described.

The preparation of the polymers of N-vinylformamide as they are (Co) polymer B can be used has long been known see e.g. B. EP-B1 71 050.

A common, but not the only method of making the previously mentioned (co) polymers, preferably the (Co) polymers B, is the radical (co) polymerization in a solution or diluent.

The radical (co) polymerization of the monomers takes place for example in aqueous solution in the presence of Polymerization initiators that under polymerization conditions into radicals disintegrated. The (co) polymerization can be carried out in a wide range Temperature range, possibly under reduced or else under elevated pressure usually at temperatures up to 100 ° C be made. The pH of the reaction mixture will usually set in the range of 4 to 10.

However, the (co) polymerization can also be carried out in a different way, to the skilled worker be carried out in a known manner, e.g. B. as a solution, Precipitation, water-in-oil emulsion or reverse Suspension.

The monomer is thereby using free radical polymerization initiators, e.g. B. peroxides, such as dibenzoyl peroxide or hydrogen peroxide, persulfates, such as sodium, potassium and ammonium persulfate or peroxosulfate, hydroperoxides, such as tert-butyl hydroperoxide or peroxyacetic acid, redox initiators, such as H ₂ O ₂ / ascorbic acid, or radical-decomposing azo compounds, such as 2 , 2'-azobis (isobutyronitrile), 2,2'-azobis (2-amidinopropane) hydrochloride or 4,4'-azobis (4'-cyanopentanoic acid) (co) polymerized.

So-called are particularly suitable Reduction-Oxygen (Red-Ox) initiator systems.

The Red-Ox initiator systems usually consist of at least one inorganic reducing agent and an inorganic or organic oxidizing agent.

The oxidation component is e.g. B. the already initiators mentioned above.

The reduction components are e.g. B. um Alkali metal salts of sulfurous acid, such as. B. sodium sulfite, Sodium hydrogen sulfite, alkali salts of disulfuric acid such as Sodium disulfite, bisulfite addition compounds more aliphatic Aldehydes and ketones such as acetone bisulfite or reducing agents such as Hydroxymethanesulfinic acid and its salts, or ascorbic acid. The Red-Ox initiator systems can be more soluble when used Metal compounds, their metallic component in several Severity levels can occur.

Common red-ox initiator systems are e.g. B. Ascorbic acid / iron (II) sulfate / sodium peroxodisulfate, tert-butyl hydroperoxide / sodium disulfite, tert-butyl hydroperoxide / sodium hydroxymethanesulfinate. The individual components, e.g. B. the Reduction component, can also be mixtures z. B. a mixture of the Sodium salt of hydroxymethanesulfinic acid and sodium disulfite.

The monomers mentioned are mostly in the form of aqueous solutions or dispersion used, the lower concentration by the amount of water acceptable in the (co) polymerization and the upper concentration by solubility respectively The dispersibility of the compound in question was determined in water is. The concentration is generally 0.1 to 30% by weight, preferably 0.5 to 20% by weight, particularly preferably 1.0 to 10% by weight, based on the solution or dispersion 10-80% by weight, preferably 10-70% by weight and particularly preferably 20 up to 60% by weight.

The amount of initiators is generally 0.1 to 10 wt .-%, preferably 0.5 to 5 wt .-%, based on the (co) polymerizing monomers. There can also be several different ones Initiators are used in (co) polymerization.

As a solvent or diluent such. B. water, alcohols, such as methanol, ethanol, n- or iso-propanol, n- or iso-butanol, or ketones, such as acetone, ethyl methyl ketone, diethyl ketone or iso- Butyl methyl ketone serve.

Optionally, the (co) polymerization in the presence of Polymerization regulators, such as hydroxylammonium salts, chlorinated hydrocarbons and thio compounds, such as. B. tert-butyl mercaptan, ethyl thioglycolate, mercaptoe thynol, mercaptopropyltrimethoxysilane, dodecylmercaptan, tert.- Dodecyl mercaptan or alkali metal hypophosphites become. In the (co) polymerization, these regulators, e.g. B. in Amounts from 0 to 0.8 parts by weight, based on 100 parts by weight of the to (co) polymerizing monomers, are used by the the molecular weight of the resulting (co) polymer is reduced.

In the emulsion polymerization, ionic and / or nonionic emulsifiers and / or protective colloids or stabilizers can be used as surface-active compounds.

Depending on the polymerization conditions, (Co) polymerization (co) polymers of a different Molecular weight. (Co) polymers B with a high K value, e.g. B. above 80, are preferably by (co) polymerizing the N-vinyl carboxamides made in water. (Co) polymers with a high K value, for example by (co) polymerizing the monomers in the form of the reverse Suspension polymerization or by (co) polymerizing the Monomers using the water-in-oil polymerization process.

In the process of reverse suspension polymerization as well Water-in-oil polymerization is used as the oil phase saturated hydrocarbons, for example hexane, heptane, Cyclohexane, decalin or aromatic hydrocarbons, such as benzene, Toluene, xylene and cumene. The ratio of oil phase to aqueous Phase is in the reverse suspension polymerization for example 10: 1 to 1:10.

(Co) polymer B with a low K value, e.g. B. below 80, is obtained when the (co) polymerization in the presence of Polymerisation regulators or in a solvent, that regulates the (co) polymerization, e.g. B. alcohols, such as methanol, Ethanol, n- or iso-propanol, or ketones, such as acetone, Ethyl methyl ketone, diethyl ketone or iso-butyl methyl ketone.

Correspondingly low K values can still be obtained using the usual methods, d. H. Use larger amounts of Polymerization initiator or use of polymerization regulators or Combinations of the measures mentioned.

The N-vinylcarboxamides, for example of the formula (I) and especially N-vinylformamide, in copolymerized form containing (co) polymers B according to the invention both in partially or completely split as well as in non-split Form are used. A degree of hydrolysis is preferred Carboxylic acid group between 0 and 30 mol%, particularly preferred between 0 and 20 mol% and very particularly preferably between 0 and 10 mol%, based on those contained in the (co) polymer N-carboxamide units. The way of splitting off the carboxylic acid or formyl group is not limited, it can for example in the presence of acid or base, cleavage in the presence of bases, such as, for example, is preferred Sodium hydroxide, potassium hydroxide, alkaline earth metal hydroxides, Ammonia or amines. It can by partial hydrolysis, for. B. one (Meth) acrylates and N-alkyl-N-vinylcarboxamides in copolymerized form containing copolymer, amphoteric (co) polymers arise.

Cationic polymers are particularly easy to obtain from N-vinylformamide in that homopolymers of N-vinylformamide with defined amounts of acid or base hydrolytically to the desired degree of hydrolysis splits, as in EP-B1 071 050 described. The resultant on the polymer chain Amino groups are more or less protonated depending on the pH of the solution AND give the polymer a more or less cationic character.

If, after the (co) polymerization, the If the carboxylic acid group is desired, this can be done, for example, in water be performed.

The carboxylic acid group is split off in the hydrolysis at Temperatures in the range of 20 to 200, preferably 40 to 180 ° C, in the presence of acids or bases. The hydrolysis in The presence of acids or bases is particularly preferred in the Temperature range from 70 to 90 ° C carried out.

Per carboxylic acid group equivalent in poly-N-vinylcarboxamide one needs about 0.05 to 1.5 for the acid hydrolysis Equivalents of an acid, such as hydrochloric acid, hydrobromic acid, Phosphoric acid, sulfuric acid. The pH in acid hydrolysis is in the range from 2 to 0, preferably from 1 to 0. The Hydrolysis of N-vinylformamide is much faster than that of (Co) polymers of other N-vinylcarboxamides, such as. B. of N-methyl-N-vinylformamide, and can therefore be more gentle Conditions, d. H. at lower temperatures and without a high one Excess acids.

In addition, the hydrolysis of the carboxylic acid groups Poly-N-vinylcarboxamides also in an alkaline medium perform, e.g. B. in the pH range from 11 to 14. This pH will preferably by adding alkali metal bases, such as. B. Sodium hydroxide solution or potassium hydroxide solution set. However, it is also possible Use ammonia, amines and / or alkaline earth metal bases. For the alkaline hydrolysis uses 0.05 to 1.5, preferably 0.4 up to 1.0 equivalents of a base.

The cleavage can also take place at high temperatures, for example above 100 ° C, preferably 120 to 180 ° C, particularly preferably 140 to 160 ° C in the presence of a solvent, e.g. B. water, without acid or base. This is preferred for Conditions performed above the critical point, for example with supercritical water.

In hydrolysis, i.e. H. the carboxylic acid group is dissolved in water Presence of acids or bases from the Cleaving off poly-N-vinylcarboxamide gives carboxylic acid as a by-product, for example formic acid or its salts.

The solutions available in this way can be processed in the process of the invention are used, the hydrolysis or solvolysis products can also be separated off become.

To separate the solutions obtained, for example, with Ion exchangers treated. The one from the hydrolysis products separated residue can then be used according to the invention.

The water solubility of those which can be used according to the invention (Co) polymer B, which copolymerizes N-vinylcarboxamides contain, at 20 ° C is usually at least 1 wt .-% up to complete solubility.

The (co) polymers A and B differ, for example in that the (co) polymer B contains at least 30% by weight contains an N-vinyl carboxamide, but the (co) polymer A to to 30 wt .-% N-vinylformamide.

Furthermore, the (co) polymer A is preferably via a Emulsion polymerization available, while the (co) polymer B is preferred is obtainable by solution polymerization.

• a) mindestens ein (Co)polymer A, das mindestens ein Hauptmonomer, ausgewählt aus der Gruppe Styrol, Butadien und (Meth)acrylsäureester in einpolymerisierter Form enthält und
• b) mindestens ein N-Vinylcarbonsäureamid in einpolymerisierter Form enthaltendes (Co)polymer B.

Such polymer dispersions according to the invention containing are preferred

• a) at least one (co) polymer A, which contains at least one main monomer selected from the group styrene, butadiene and (meth) acrylic acid ester in polymerized form and
• b) at least one (co) polymer B containing polymerized N-vinylcarboxamide.

Polymer dispersions which are particularly preferred are those in (Co) polymer B at least one N-vinylcarboxamide of the formula (I) contain copolymerized.

Polymer dispersions which are particularly preferred are those in (Co) polymer B N-vinylformamide copolymerized.

Of course, several different (co) polymers can also be used A and / or B can be used, for example 2 or 3.

Furthermore, the polymer dispersion of the invention Contain post additives known to those skilled in the art, for example Polyanions such as B. polyacrylic acid, the partially or can be completely neutralized, biocides etc.

• a) mindestens einen optischen Aufheller C.

The present invention furthermore relates to those polymer dispersions mentioned above which additionally contain

• a) at least one optical brightener C.

The optical brightener C used in the polymer dispersions can be used are not limited. For example brighteners such as those used in Ullmann's can be used Encyclopedia of Industrial Chemistry, Sixth Edition, 2000 Electronic Release, OPTICAL BRIGHTENERS - Chemistry of Technical Products are described.

Suitable optical brighteners C belong, for example, to the group of distyrylbenzenes, for example cyano-substituted 1,4-distyrylbenzenes with cyano groups in positions 2 'and 3 "[CAS Reg. No. 79026-03-2], or in positions 2' and 2" [13001-38-2], 3 'and 3 "[36755-00-7], 3' and 4" [79026-02-1] and 4 'and 4 "[13001-40-6], or amphoteric compounds , such as [84196-71-4], each in the 2 'and 2 "position one group

-O- (CH ₂ ) ₂ -N ⁺ (C ₂ H ₅ ) ₂ -CH ₂ COO ^-

contribute to the group of distyrylbiphenyls, for example 4,4'-di (2-sulfostyryl) biphenyl disodium salt [27344-41-8], 4,4'-di (3-sulfostyryl) biphenyl disodium salt [51119-63-2], 4,4'-di (4-chloro-3-sulfostyryl) biphenyl disodium salt [42380-62-1], 4,4'-di (6-chloro-3-sulfostyryl) biphenyl disodium salt [60477-28-3], 4,4'-di (2-methoxystyryl) biphenyl [40470-68-6] or a 4,4'-di (styryl) biphenyl, which is a group in position 2 on the styryl radical

-O- (CH ₂ ) ₂ -N ⁺ (CH ₃ ) (C ₂ H ₅ ) ₂ .CH ₃ OSO ₃ ^-

carries [72796-88-4] to the group of divinyl stilbenes, for example 4,4'-di (ethoxycarbonylvinyl) stilbene [60683-03-6] or 4,4'-di (cyanovinyl) stilbene [60682-87-3] , to the group of triazinylaminostilbenes, e.g. B. 1,3,5-triazinyl derivatives of 4,4'-diaminostilbene-2,2'-disulfonic acid, such as anilino derivatives which carry the following radicals on the triazine rings in position 3: a methoxy radical (CAS Reg. [3426- 43-5]), aminomethyl [35632-99-6], ethylamino [24565-13-7], hydroxyethylamino [12224-16-7], N-hydroxyethyl-N-methylamino [13863-31-5], bis- (Hydroxyethyl) amino [4193-55-9], morpholino [16090-02-1], phenylamino [133-66-4], N-2-aminocarbonylethyl-N-2-hydroxyethylamino [68444-86-0] or as Anilinosulfonic acid derivatives which each have the following residues in position 3 on the triazine rings: N-hydroxyethylamino and, in addition, a sulfonic acid group in position 3 on the anilino group in position 5 of the triazine ring (CAS Reg. No. [61968-74-9]), N -Bis (hydroxyethyl) amino and a sulfonic acid group in position 3 on the anilino group (CAS Reg. No. [12224-02-1]), N-bis (2-hydroxypropyl) amino and a sulfonic acid group in position on the anilino group 4 (CAS Reg. No. [9954 9-42-5]), N-bis (hydroxyethyl) amino and additionally a sulfonic acid group in position 4 on the anilino group (CAS RegNr. [16470-24-9]), N-hydroxyethyl-N-methylamino and in addition to the anilino group a sulfonic acid group in position 4 (CAS Reg. No. [74228-28-7]), diethylamino and additionally to the anilino group Sulphonic acid groups in positions 2 and 5 (CAS Reg. No. [83512-97-4]), N-bis (hydroxyethyl) amino and additionally on the anilino group sulphonic acid groups in positions 2 and 5 (CAS Reg. [76482-78-5 ]), or morpholino groups and additionally on the anilino group sulfonic acid groups in positions 2 and 5 (CAS Reg. [55585-28-9]), or to the group of stilbenyl-2H-triazoles, e.g. B. stilbenyl-2H-naphtho [1,2-d] triazoles such as the sodium salt of 4- (2H-naphtho [1,2-d] triazol-2-yl) stilbene-2-sulfonic acid [6416-68-8] or those which carry a sulfonic acid at position 6 on the naphthol ring and at position 2 of the stilbene structure [2583-80-4], or carry a cyano group at position 2 and a chlorine group at position 4 '[5516-20-1] or z. B. bis (1,2,3-triazol-2-yl) stilbene, such as. B. 4,4'-bis (4-phenyl-1,2,3-triazol-2-yl) stilbene-2,2'-disulfonic acid dipotassium salt [52237-03-3] or 4,4'-bis (4th - (4'-sulfophenyl) -1,2,3-triazol-2-yl) stilbene-2,2'-disulfonic acid tetrasodium salt [61968-72-7], or to the group of benzoxazoles, e.g. B. stilbenylbenzoxazoles, for example 5,7-dimethyl-2- (4'-phenylstilben-4-yl) benzoxazole [40704-04-9], 5-methyl-2- (4 '- (4 "-methoxycarbonyl) -phenylstilbene -4-yl) benzoxazole [18039-18-4] or those which carry other heterocycles in the 4 "position, such as, for. B. [64893-28-3], or bis (benzoxazole), e.g. B. ethylene, thiophene, naphthylene, phenylethylene or stilbene-bridged bis-benzoxazoles, such as those with the CAS numbers [1041-00-5], [2866-43-5], [7128-64-5], [5089-22-5], [1552-46-1], [1533-45-5] or [5242-49-9].

Furans, Benzo [b] furane and Benzimidazoles, such as. B. bis (benzo [b] furan-2-yl) biphenyls, for example, sulfonated 4,4'-bis (benzo [b] furan-2-yl) biphenyls or cationic benzimidazoles, for example 2,5-di (1-methylbenzimidazol-2-yl) furan [4751-43-3], [72829-17-5], [74878-56-1], [74878-48-1] or [66371-25-3], or 1,3-diphenyl-2-pyrazoline, z. B. 1- (4-amidosulfonylphenyl) -3- (4-chlorophenyl) -2-pyrazoline, [2744-49-2], [60650-43-3], [3656-22-2], [27441-70-9], [32020-25-0], [61931-42-8] or [81209-71-4], as well as tertiary and quaternary amine salts of 1,3-diphenyl-2-pyrazoline derivatives, e.g. B. [106359-93-7], [85154-08-1], [42952-22-7], [63310-12-3], [12270-54-1] or [36086-26-7], as well as coumarins, such as. B. 7-diethylamino-4-methylcoumarin [91-44-1] and [6025-18-9], [19683-09-1], [3333-62-8], [63660-99-1], [26867-94-7] or [52725-14-1] and naphthalimides, such as. B. 4-acetylamino-N- (n-butyl) naphthalimide [3353-99-9], 4-methoxy-N-methylnaphthalimide [3271-05-4], [3271-05-4], [22330-48-9], [25826-31-7], [26848-65-7] or [60317-11-5] and 1,3,5-triazin-2-yl Derivatives, for example (4,6-dimethoxy-1,3,5-triazin-2-yl) pyrene [3271-22-5] or 4,4'-di (4,6-diphenyl-1,3,5-triazin-2-yl) stilbene [6888-33-1].

4,4'-distyrylbiphenyl derivatives or Stilbene derivatives with up to 6, particularly preferably with 2, 4 or 6 Sulfonic acid groups are used, are preferred the Blankophor® brands from Bayer AG, particularly preferred are Blankophor® P, PUL and Blankophor® PSG, are preferred also the Tinopal® brands from Ciba Specialty Chemicals, particularly preferred Tinopal® MC liquid, Tinopal® ABP-Z liquid, Tinopal® SPP-Z liquid and Tinopal® SK-B liquid and more the Leukophor® brands from Clariant AG are preferred, particularly preferred Leukophor® APN, UO, NS or SHR.

Of course, several different optical ones can also be used Brighteners are used, for example two, three or four, however, preferably only one is used.

The invention furthermore relates to the use of mentioned polymer dispersions in paper coating slips and in their Manufacture, especially the use as a binder in Paper coatings.

The invention furthermore relates to paper coating slips, containing a polymer dispersion according to the invention, as described above is described.

It is surprising that the addition of (Co) polymers B for polymer dispersion the binding power of this binder is significantly increased in a paper stock. Further It is surprising to the skilled person that the so obtained new binders at the same time the optical brighteners in the Paper coating slip can be activated extremely strongly. It is also unexpected and surprising that cationic Copolymers of vinyl formamide in the new binder for Coatings of the invention may be included, although the Polymer dispersions practically always have an anionic character have and consequently by forming polymer complexes Intolerance, such as B. precipitate formation, should come. Even more surprising and completely unexpected is that too Binder, the cationic copolymers of n-Vinylcarbonsäureamid contain, contrary to the statement by K. P. Kreutzer, a. a. O., Page 8-22, also the optical brighteners in the Activate paper coating and sometimes even its effect amplify more than the corresponding nonionic Polyvinylformamides.

An advantage of the coating slips according to the invention is that that in their manufacture a process step in the Paper mill, namely the incorporation of the cobinder into the coating slip by using the polymer dispersions according to the invention can be omitted. This is not just for the paper mill Time savings associated, but also a reduction in logistical Expenses. In general, the manufacturers of coated Paper the individual components of the coating slips of different suppliers. An important advantage of Coatings according to the invention is that the paper mill is a Chemical has to work less into the coating slip, and thus on a supplier, an order process, a Incoming inspection, a storage container, a dosing system, etc. s. w. dispense can. In case of quality problems with the coating slip there is one when using the coating slip according to the invention Variable less in question as a possible cause of the problems can come.

Another advantage of the coating slips according to the invention is for the paper manufacturer that handling chemicals, even if it is relatively harmless polymers, for Supplier is relocated. The paper industry understands itself as a technical industry and usually endeavors to To keep handling chemicals as low as possible and for that as few personnel trained in handling chemicals as possible employ. The new binders and coating slips according to the invention.

The used for the coating slips according to the invention Polymer dispersions also have the advantage that they are easily after the individual needs of the paper manufacturer from in Large-scale quantities of polymer dispersions produced by simple Mix after polymerization and before delivery to the Paper mill can be manufactured.

The amount of (co) polymer A and B used in the Contain polymer dispersions for the coating slips according to the invention is based on the requirements of the paper manufacturer regarding the strength and whiteness of the paper coating. The Quantity also depends on the viscosity of the new one Binder (polymer dispersion) by adding the (co) polymer B gets.

Based on 100 parts of (co) polymer A the polymer dispersion can the proportion of (co) polymer B1 to 50 parts. A range from 2 to 25 parts of (co) polymer B is preferred per 100 parts of (co) polymer A, with 5 to 20 parts in particular are preferred. 5 to 15 parts are very particularly preferred.

Based on 100 parts of (co) polymer A the polymer dispersion can the proportion of optical brightener 0 to 10, preferably 0.1 to 8 and particularly preferably 0.5 to 5 parts.

The preparation of the polymer dispersions according to the invention for the Coatings of the invention are done by mixing one Dispersion of a (co) polymer A with a (co) polymer B, its dispersion, solution, suspension or emulsion, according to the for the production of mixtures of known liquids of the technique. Of course, the (co) polymeric B can also as solids or gels in a dispersion of the (co) polymeric A be incorporated.

The optical brightener can be used as a solid, as a solution, for example in water, or as a suspension in the polymer dispersion be entered, preferably as a solution. It is irrelevant whether it is added before or after components A and / or B. you the optical brightener can also initially with components B mix and mix these with the polymer dispersion unite. It makes sense to carry out the optimal trials Determine mixing order and mixing method.

The mixtures can be produced continuously or done discontinuously and is not limited. Does that happen Production batchwise, so you can either (co) polymer B, its dispersion, solution, suspension or emulsion for Give dispersion of (co) polymer A or the dispersion of (Co) polymer A to (co) polymer B, its dispersion, solution, Suspension or emulsion.

The smaller component is preferred given larger quantities.

The optical brightener or its is particularly preferred Mix with component B as the last substance in the mixture from the (co) polymers A and B or B and A or into the Polymer dispersion A.

The (co) polymeric B are preferably present as solutions in one suitable solvents, especially water.

It does not matter which way the mixture will be produced. Possible production routes are known to the person skilled in the art.

The mixture is preferred with vigorous mixing, such as z. B. stirring, pumping or the like.

It is also irrelevant in which way the used Dispersions have been obtained, or whether these are Primary dispersions, in which the (co) polymerization of the base monomers takes place directly in the liquid phase, or around Secondary dispersions, in which prefabricated polymers in one separate process step are dispersed.

The polymer dispersions of the invention are usually with Polymer contents (sum (co) polymer A and B) of 15 to 75% by weight, preferably produced from 20 to 60 wt .-%.

The viscosity of the polymer dispersion is usually 100 to 1500 mPas (measured according to the Brookfield method at 20 rpm and 20 ° C according to DIN 53019), preferably 100 to 1300 and especially preferably 150 to 1200 mPas, or 50 to 1000 mPas (measured according to the Brookfield method at 100 rpm and 20 ° C), preferably 50 to 750 and particularly preferably 100 to 600 mPas.

The paper coating slips according to the invention contain the new one Binder preferably in amounts of 1 to 30, especially 5 up to 15 parts by weight, based on the pigment content of the Paper coating slips, one being below the amount of the binder Understands total content of (co) polymers A and B.

The coating slips according to the invention are processed completely analogous to the processing of coating colors according to the state of the art Technology, e.g. B. according to "The Essential Guide to Aqueous Coating of Paper and Board ", T.W.R. Dean (ed.), Published by the Paper Industry Technical Association (PITA), 1997 or "Counselor for the use of BASF products in paper and Cardboard coating shop ", BASF Aktiengesellschaft, D-6700 Ludwigshafen, Federal Republic of Germany, B 376d, 09.77.

The optical brighteners that are used in conjunction with the coating slips according to the invention can not be used limited.

For example, the optical brighteners mentioned above be used.

For example, such brighteners can be used as they are in Ullmann's Encyclopedia of Industrial Chemistry, Sixth Edition, 2000 Electronic Release, OPTICAL BRIGHTENERS - Chemistry of Technical Products are described. They can preferably there listed 4,4'-distyrylbiphenyl derivatives or stilbene derivatives, the with up to 6, particularly preferably with 2, 4 or 6 Sulphonic acid groups are used, are particularly preferred the Blankophor® brands from Bayer AG, especially Blankophor® P, PUL and Blankophor® PSG are preferred, in particular the Tinopal® brands from Ciba are also preferred Specialty Chemicals, most preferably Tinopal® MC liquid, Tinopal® ABP-Z liquid, Tinopal® SPP-Z liquid and Tinopal® SK-B liquid and still particularly preferred are Leukophor® brands from Clariant AG, most preferably Leukophor® APN, UO, NS or SHR.

Usually 0.2 to 2 parts by weight of optical are given Brightener per 100 parts by weight of pigment in the coating slip.

Are such for the production of the paper coating slips Polymer dispersions used, the optical brightener C included, so it makes sense not to use another brightener To give paper coating slip.

The pigments which can be used in the coating slips according to the invention are also not limited. For example, satin white (Calcium sulfoaluminate), calcium carbonate in ground or precipitated form, barium sulfate in ground or precipitated form, kaolin (clay), calcined clay, talc, Zinc oxide, silicates, or organic pigments, e.g. B. plastics in Particle shape can be used.

The paper coating slips can continue, for. B. dispersant contain. Suitable dispersants are polyanions, for example of polyphosphoric acids or of polyacrylic acids (Polysalts), which are usually present in amounts of 0.1 to 3% by weight. parts, based on the amount of pigment, are included.

According to the invention, the coating slip according to the invention a cobinder can also be added. Come as a cobinder in addition to the (co) polymers B or N-vinylformamide copolymerized (co) polymers, as in German Patent application with the file number 100 55 592.6 described, the State-of-the-art cobinder, e.g. B. polyvinyl alcohol, Carboxymethyl cellulose, anionic or nonionic degraded Starches, casein, soy protein and (Meth) acrylic acid-acrylate copolymers in question.

The Cobinder is usually given the same to the five times the amount of the optical brightener for the coating slip, i.e. 0.2 up to 10 parts by weight, preferably 0.5 to 8 and particularly preferably 1 to 5 parts by weight based on 100 parts by weight of pigment.

It has now surprisingly been found that the presence of new binders in the coating colors according to the invention also Effectiveness of additional cobinder in terms of reinforcement of the optical brightener is improved. This doesn't just apply to the conventional cobinder such as polyvinyl alcohol, Carboxymethyl cellulose or acrylic acid-acrylic ester copolymers, but especially for (co) polymers B, such as those used for the production of new binders for the coating slips according to the invention be used. It can be the same Act (co) polymers B, which are already with the polymer dispersion for the new binders were mixed. But it can also be another (Co) polymer of N-vinylcarboxamide as an additional Cobinder can be used.

If necessary, a thickener can be added. As Thickeners come alongside radical (co) polymerized ones (Co) polymers customary organic and inorganic thickeners such as Hydroxymethyl cellulose or bentonite.

The paper coating slips can still be known to those skilled in the art Components included. Consider z. B. Flow aids, wetting aids for the pigments etc.

To produce the paper coating slip, the components in known manner mixed.

The application amount of the paper coating slip to the substrate to be coated can be chosen as desired, as a rule the application amount is 5 to 25 g / m ² , preferably 7 to 20 g / m ² and particularly preferably 9 to 15 g / m ² .

The line can be on one or both sides on paper or cardboard can be applied and one, two or more strokes can be applied in succession.

The paper stick masses are mostly aqueous Paper coatings. The water content can vary depending on the desired Viscosity or flow properties can be set.

The water content in the paper coating slip is usually to 25 to 75% by weight, based on the total paper coating slip (including water).

The paper coating slips according to the invention are suitable for Coating z. B. of paper or cardboard. The paper coating slip can then be applied to the surfaces to be coated using customary methods Paper or cardboard can be applied (see Ullmann's Encyclopedia der Technische Chemie, 4th edition, vol. 17, pp. 603 ff).

The coated with a paper coating slip according to the invention Papers are also the subject of the present invention.

The coated with the paper coating slips according to the invention Papers, cardboard or boxes can be printed using standard printing processes, z. B. offset, letterpress or gravure printing or modern Digital printing processes such as B. laser printing or ink jet used become.

The following examples are intended to illustrate the invention without it but restrict to these examples.

In this document, as "parts",% and ppm are, if not different indicated, "parts by weight",% by weight and ppm by weight understood.

example 1

In 192 parts of a 50% dispersion of a copolymer the main monomers styrene, butadiene and acrylonitrile (Styronal® D 610 from BASF Aktiengesellschaft) 30 parts of one 20% aqueous solution of a homopolymer of N-vinylformamide, in which 5% of the formamido groups are split by hydrolysis were mixed in with the K value 30. The binder obtained has a viscosity of 330 mPa.s (Brookfield, 20 U / min) or 198 mPa.s (Brookfield, 100 rpm). It can be used to manufacture the coating slips according to the invention can be used.

Example 2

In 192 parts of a 50% dispersion of a copolymer the main monomers butyl acrylate and styrene (Acronal® S 504 der BASF Aktiengesellschaft) 30 parts of a 20% aqueous solution of a homopolymer of N-vinylformamide, 5% of the formamido groups have been cleaved by hydrolysis, mixed with the K value 30. The binder obtained has one Viscosity of 170 mPa.s (Brookfield, 20 rpm) or 108 mPa.s (Brookfield, 100 rpm). It can be used to manufacture the coating slips according to the invention can be used.

Example 3

In 192 parts of a 50% dispersion of a copolymer the main monomers butyl acrylate and styrene (Acronal® 5360 D der BASF Aktiengesellschaft) 30 parts of a 20% aqueous solution of a homopolymer of N-vinylformamide, 5% of the formamido groups have been cleaved by hydrolysis, mixed with the K value 50. The binder obtained has one Viscosity of 1150 mPa.s (Brookfield, 20 rpm) or 572 mPa.s (Brookfield, 100 rpm). It can be used to manufacture the coating slips according to the invention can be used.

Example 4

In 192 parts of a 50% dispersion of a copolymer the main monomers styrene and butadiene (Styronal® D 610 from the company BASF Aktiengesellschaft) 30 parts of a 20% aqueous Solution of a homopolymer of N-vinylformamide with the K value 50 mixed in. The binder obtained has a viscosity of 350 mPa.s (Brookfield, 20 rpm) or 212 mPa.s (Brookfield, 100 rpm). It can be used to manufacture the invention Coatings can be used.

Examples 1 to 4 show that commercially available Dispersions, as are usually used as binders in Paper coating slips are used by mixing with nonionic and cationic (co) polymers of N-vinylformamide stable, new binders can be produced.

Example 5

A paper coating slip is produced by intensively mixing 360 parts of a 77.7% suspension of calcium carbonate (Hydrocarb® 90 from Plüss-Staufer AG), 160 parts of a 75% suspension of coating kaolin (Amazon® 88 from Kaolin International ), 74 parts of the binder from Example 4, 4 parts of a 50% solution of an optical brightener (Blankophor® PSG from Bayer AG) and 42.3 parts of water. This coating slip is applied with a solids content of 68.4% by weight to a sized wood-free paper with a basis weight of 70 g / m ² , which contains optical brighteners, to a coat weight of 15 g / m ² , dried and then satinized. This coating slip according to the invention is compared in Table 1 with the comparative examples.

Table 2 shows the same coating slip on one unsized and not lightened paper with the Comparative examples compared.

The lightening of the paper was determined according to DIN 53 145, Part 2.

The CIE whiteness of the paper was measured according to ISO 2469.

The color density when determining the dry pick resistance according to IGT (ISO 3 783) with the specified Lorilleux color at 85 cm / s was determined with the Gretag densitometer.

The color density when determining wet pick resistance according to IGT with the specified Lorilleux color was with the Gretag Densitometer determined.

Comparative Example 1

A paper coating slip is made by intensive Mix 360 parts of a 77.7% suspension of Calcium carbonate (Hydrocarb® 90 from Plüss-Staufer AG), 160 parts a 75% suspension of spreadable kaolin (Amazon® 88 from the company Kaolin International), 64 parts of a 50% dispersion of a Copolymer of the main monomers styrene and butadiene (Styronal® D 610 from BASF Aktiengesellschaft), 20 parts of one 10% solution of carboxymethyl cellulose (CMC 7L2T from the company Hercules GmbH), 4 parts of a 50% solution of an optical Brighteners (Blankophor® PSG from Bayer AG) and 32.3 parts Water.

Comparative Example 2

A paper coating slip is produced by intensively mixing 360 parts of a 77.7% suspension of calcium carbonate (Hydrocarb® 90 from Plüss-Staufer AG), 160 parts of a 75% suspension of coating kaolin (Amazon® 88 from Kaolin International ), 64 parts of a 50% dispersion of a copolymer of the main monomers styrene and butadiene (Styronal® D 610 from BASF Aktiengesellschaft), 10 parts of a 20% aqueous solution of a homopolymer of N-vinylformamide with a K value of 50 , 4 parts of a 50% solution of an optical brightener (Blankophor® PSG from Bayer AG) and 42.3 parts of water. Table 1 Base paper: wood-free, sized, with optical brightener

Table 2 Base paper: wood-free, unsized, with optical brightener

Tables 1 and 2 show that the invention Spreading Example 5, which contains the new binder, in almost all properties is significantly better than a classic Spreading material Comparative Example 1 with the cobinder Carboxymethylcellulose. It is also at least as good as the coating slip Comparative Example 2, in which the (co) polymer of N-vinylformamide is not present in the binder, but as a cobinder is added separately.

Example 6

7.5 parts of a 40% aqueous solution of a homopolymer of N-vinylformamide with the K value are in 96 parts of a 50% strength dispersion of a copolymer of the main monomers styrene and butadiene (Styronal® D 610 from BASF Aktiengesellschaft) 30 mixed in. The binder obtained has a viscosity of 495 mPa.s (Brookfield, 20 rpm) or 272 mPa.s (Brookfield, 100 rpm). It intensely with 537 parts of a 78.2% suspension of calcium carbonate (Hydrocarb® 90 from Plüss-Staufer AG), 241 parts of a 74.8% suspension of coating kaolin (Amazon® 88 from Kaolin International), 6 parts of a 50% solution of an optical brightener (Blankophor® PSG from Bayer AG), 12 parts of a 25% solution of a cobinder based on acrylic acid / acrylic ester (Acrosol® C 50 L from BASF Aktiengesellschaft) and 80, 9 parts of water mixed. This coating slip according to the invention is applied with a solids content of 67.2% by weight to a glued wood-free paper with a basis weight of 70 g / m ² , which contains optical brighteners, to a coat weight of 15 g / m ² , dried and then satinized , The properties of the coating slip and the paper coated with it can be found in Table 3. The properties of the coating of a wood-free, unsized, brightener-free paper can be found in Table 4.

Example 7

7.5 parts of a 40% aqueous solution of a homopolymer of N-vinylformamide with the K value are in 96 parts of a 50% strength dispersion of a copolymer of the main monomers styrene and butadiene (Styronal® D 610 from BASF Aktiengesellschaft) 30 mixed in. The binder obtained has a viscosity of 495 mPa.s (Brookfield, 20 rpm) or 272 mPa.s (Brookfield, 100 rpm). It intensely with 537 parts of a 78.2% suspension of calcium carbonate (Hydrocarb® 90 from Plüss-Staufer AG), 241 parts of a 74.8% suspension of coating kaolin (Amazon® 88 from Kaolin International), 6 parts of a 50% solution of an optical brightener (Blankophor® PSG from Bayer AG), 30 parts of a 10% solution of carboxymethyl cellulose (CMC 7L2T from Hercules GmbH) and 62.9 parts of water mixed. This coating slip according to the invention is applied with a solids content of 67.3% by weight to a sized wood-free paper with a basis weight of 70 g / m ² , which contains optical brighteners, to a coat weight of 15 g / m ² , dried and then satinized , The properties of the coating slip and the paper coated with it can be found in Table 3. The properties of the coating of a wood-free, unsized, brightener-free paper can be found in Table 4.

Example 8

7.5 parts of a 40% aqueous solution of a homopolymer of N-vinylformamide with the K value are in 96 parts of a 50% strength dispersion of a copolymer of the main monomers styrene and butadiene (Styronal® D 610 from BASF Aktiengesellschaft) 30 mixed in. The binder obtained has a viscosity of 495 mPa.s (Brookfield, 20 rpm) or 272 mPa.s (Brookfield, 100 rpm). It intensifies with 537 parts of a 78.2% suspension of calcium carbonate (Hydrocarb® 90 from Plüss-Staufer AG), 241 parts of a 74.8% suspension of coating kaolin Amazon® 88 from Kaolin International, 6 Parts of a 50% solution of an optical brightener (Blankophor® PSG from Bayer AG), 14.9 parts of a 20.2% solution of a homopolymer of N-vinylformamide with a K value of 90 and 78.0 parts of water mixed , This coating slip according to the invention is applied with a solids content of 67.1% by weight to a glued wood-free paper with a basis weight of 70 g / m ² , which contains optical brighteners, to a coat weight of 15 g / m ² , dried and then satinized , The properties of the coating slip and the paper coated with it can be found in Table 3. The properties of the coating of a wood-free, unsized, brightener-free paper can be found in Table 4.

Comparative Example 3

A paper coating slip is made by intensive Mix 537 parts of a 78.2% suspension of Calcium carbonate (Hydrocarb® 90 from Plüss-Staufer AG), 241 parts a 74.8% suspension of coating kaolin (Amazon® 88 der Kaolin International), 96 parts of a 50% dispersion a copolymer of the main monomers styrene and butadiene (Styronal® D 610 from BASF Aktiengesellschaft), 6 parts a 50% solution of an optical brightener (Blankophor® PSG from Bayer AG), 12 parts of a 25% solution of one Cobinders based on acrylic acid / acrylic ester (Acrosol® C 50 L of BASF Aktiengesellschaft) and 83.9 parts of water.

Comparative Example 4

A paper coating slip is produced by intensive mixing of 537 parts of a 78.2% suspension of calcium carbonate (Hydrocarb® 90 from Plüss-Staufer AG), 241 parts of a 74.8% suspension of coating kaolin (Amazon® 88 from the company Kaolin International), 96 parts of a 50% dispersion of a copolymer of the main monomers styrene and butadiene (Styronal® D 610 from BASF Aktiengesellschaft), 6 parts of a 50% solution of an optical brightener (Blankophor® PSG from Bayer AG ), 30 parts of a 10% solution of carboxymethyl cellulose (CMC 7L2T from Hercules GmbH) and 65.9 parts of water. Table 3 Base paper: wood-free, sized, with optical brightener

Table 4 Base paper: wood-free, unsized, without optical brightener

From the values in Tables 3 and 4 it can be seen that the Coatings from Examples 6, 7 and 8, which are non-ionic Polymer of N-vinylformamide contained in the binder, in Presence of additional cobinder much better Develop properties as classic coating colors that only Cobinder included (Comparative Examples 3 and 4).

Example 9

7.5 parts of a 40% aqueous solution of a homopolymer of N-vinylformamide with the K value are in 96 parts of a 50% strength dispersion of a copolymer of the main monomers styrene and butadiene (Styronal® D 610 from BASF Aktiengesellschaft) 30, in which 3.3% of the formamido groups were cleaved by hydrolysis. The binder obtained has a viscosity of 800 mPa.s (Brookfield, 20 rpm) or 411 mPa.s (Brookfield, 100 rpm). It intensely with 537 parts of a 78.2% suspension of calcium carbonate (Hydrocarb® 90 from Plüss-Staufer AG), 241 parts of a 74.8% suspension of coating kaolin (Amazon® 88 from Kaolin International), 6 parts of a 50% solution of an optical brightener (Blankophor® PSG from Bayer AG), 30 parts of a 10% solution of carboxymethyl cellulose (CMC 7L2T from Hercules GmbH) and 62.9 parts of water mixed. This coating slip according to the invention is applied with a solids content of 67.3% by weight to a sized wood-free paper with a basis weight of 70 g / m ² , which contains optical brighteners, to a coat weight of 15 g / m ² , dried and then satinized , The properties of the coating slip and the paper coated with it can be found in Table 5. The properties of the coating of a wood-free unsized, brightener-free paper can be found in Table 6.

Example 10

7.5 parts of a 40% aqueous solution of a homopolymer of N-vinylformamide with the K value are in 96 parts of a 50% strength dispersion of a copolymer of the main monomers styrene and butadiene (Styronal® D 610 from BASF Aktiengesellschaft) 30, in which 3.3% of the formamido groups were cleaved by hydrolysis. The binder obtained has a viscosity of 800 mPa.s (Brookfield, 20 rpm) or 411 mPa.s (Brookfield, 100 rpm). It intensely with 537 parts of a 78.2% suspension of calcium carbonate (Hydrocarb® 90 from Plüss-Staufer AG), 241 parts of a 74.8% suspension of coating kaolin (Amazon® 88 from Kaolin International), 6 parts of a 50% solution of an optical brightener (Blankophor® PSG from Bayer AG), 14.9 parts of a 20.2% solution of a homopolymer of N-vinylformamide with a K value of 90 and 78.0 parts of water mixed. This coating slip according to the invention is applied with a solids content of 67.1% by weight to a glued wood-free paper with a basis weight of 70 g / m ² , which contains optical brighteners, to a coat weight of 15 g / m ² , dried and then satinized , The properties of the coating slip and the paper coated with it can be found in Table 5. The properties of the coating of a wood-free unsized, brightener-free paper can be found in Table 6.

Example 11

6.0 parts of a 50% aqueous solution of a homopolymer of N-vinylformamide with the K value are in 96 parts of a 50% strength dispersion of a copolymer of the main monomers styrene and butadiene (Styronal® D 610 from BASF Aktiengesellschaft) 15, in which 5.4% of the formamido groups were cleaved by hydrolysis. The binder obtained has a viscosity of 230 mPa.s (Brookfield, 20 U / min) or 150 mPa.s (Brookfield, 100 U / min). It intensely with 537 parts of a 78.2% suspension of calcium carbonate (Hydrocarb® 90 from Plüss-Staufer AG), 241 parts of a 74.8% suspension of coating kaolin (Amazon® 88 from Kaolin International), 6 parts of a 50% solution of an optical brightener (Blankophor® PSG from Bayer AG), 30 parts of a 10% solution of carboxymethyl cellulose (CMC 7L2T from Hercules GmbH) and 64.4 parts of water mixed. This coating slip according to the invention is applied with a solids content of 67.3% by weight to a sized wood-free paper with a basis weight of 70 g / m ² , which contains optical brighteners, to a coat weight of 15 g / m ² , dried and then satinized , The properties of the coating slip and the paper coated with it can be found in Table 5. The properties of the coating of a wood-free unsized, brightener-free paper can be found in Table 6.

Example 12

6.0 parts of a 50% aqueous solution of a homopolymer of N-vinylformamide with the K value are in 96 parts of a 50% strength dispersion of a copolymer of the main monomers styrene and butadiene (Styronal® D 610 from BASF Aktiengesellschaft) 15, in which 5.4% of the formamido groups were cleaved by hydrolysis. The binder obtained has a viscosity of 230 mPa.s (Brookfield, 20 U / min) or 150 mPa.s (Brookfield, 100 U / min). It intensely with 537 parts of a 78.2% suspension of calcium carbonate (Hydrocarb® 90 from Plüss-Staufer AG), 241 parts of a 74.8% suspension of coating kaolin (Amazon® 88 from Kaolin International), 6 parts of a 50% solution of an optical brightener (Blankophor® PSG from Bayer AG), 14.9 parts of a 20.2% solution of a homopolymer of N-vinylformamide with a K value of 90 and 79.5 parts of water mixed. This coating slip according to the invention is applied with a solids content of 67.3% by weight to a sized wood-free paper with a basis weight of 70 g / m ² , which contains optical brighteners, to a coat weight of 15 g / m ² , dried and then satinized , The properties of the coating slip and the paper coated with it can be found in Table 5. The properties of the coating of a wood-free unsized, brightener-free paper can be found in Table 6.

The values in Tables 5 and 6 show that the coating slips from Examples 9, 10, 11 and 12, which contain cationic (co) polymers of different molecular weights of N-vinylformamide in the binder, develop significantly better properties in the presence of additional cobinder than Classic coating colors which only contain carboxymethyl cellulose (comparative example 4) as cobinder. Table 5 Base paper: wood-free, sized, with optical brightener

Table 6 Base paper: wood-free, unsized, without optical brightener

Example 13

To 20 parts of a 50% dispersion of a copolymer of the main monomers styrene, butadiene and acrylonitrile (Styronal® PR 8727 from BASF Aktiengesellschaft), 8 parts of a 10% solution of a polyvinylformamide with a K value of 40 and 0 are added with vigorous stirring. 7 parts of a commercial optical brightener (Blankophor® PUL from Bayer AG). From the binder obtained in this way and from 80 parts of a coating carbonate (Hydrocarb® 90 from the company of Plüss-Staufer AG), 20 parts of a coating kaolin (Amazon® 88 from Kaolin International), 0.1 part of a polyacrylate (polysalt S from BASF Aktiengesellschaft), 0.5 part carboxymethyl cellulose (CMC 7L2T from Hercules Inc.) and 0.7 part of a commercially available dispersion of calcium stearate (Nopcote® C 104 from Nopco Paper Technology) and water, a paper coating slip with a water content is prepared from 32% ago. This coating slip is applied on both sides to a wood-free base paper on a modern coating machine using a bent blade at a speed of 1500 m / min, so that 18 g / m ^{2 of} dry coating remain on each side. After calendering on a super calender, the paper has a whiteness of 111.9 CIE white points.

This example 13 shows that according to the Invention Process also a mixture of a polymer dispersion, a a polymer containing copolymerized vinyl carboxamide and an optical brightener an effective binder manufacture and in a coating slip for paper coating can process.

Claims (11)

1. Polymer dispersions containing a) at least one main monomer selected from the group comprising C ₁ to C ₂₀ alkyl (meth) acrylates, vinyl esters of carboxylic acids containing up to 20 C atoms, vinyl aromatics with up to 20 C atoms, ethylenically unsaturated nitriles, vinyl halides, vinyl ethers or allyl ethers of alcohols containing 1 to 10 carbon atoms and aliphatic hydrocarbons with 2 to 8 carbon atoms and 1 or 2 double bonds, copolymerized containing (co) polymer A and b) at least one (co) polymer B containing polymerized N-vinylcarboxamide. 2. Polymer dispersion according to claim 1, containing a) at least one (co) polymer A, which contains at least one main monomer selected from the group styrene, butadiene and (meth) acrylic acid ester in polymerized form and b) at least one (co) polymer B containing polymerized N-vinylcarboxamide. 3. Polymer dispersion according to one of the preceding claims, characterized in that the (co) polymer B is N-vinylformamide polymerized contains. 4. Polymer dispersion according to one of the preceding claims, additionally containing a) at least one optical brightener C. 5. Paper coating slip containing a polymer dispersion according to any of the preceding claims. 6. A method for producing a polymer dispersion according to a of claims 1 to 4, characterized in that one Dispersion of a (co) polymer A with a (co) polymer B, its dispersion, solution, suspension or emulsion, and optionally an optical brightener, its solution or Suspension, mixed. 7. Polymer dispersion, obtainable by one Dispersion of a (co) polymer A with a (co) polymer B, the Dispersion, solution, suspension or emulsion mixed. 8. A process for producing a paper coating slip, thereby characterized in that a polymer dispersion according to a of claims 1 to 4 with further paper typical Aids mixed. 9. Use of a polymer dispersion according to one of the claims 1 to 4 in paper coating slips. 10. Paper, coated with one of the paper coating slips after Claim 5. 11. Use of paper according to claim 10 in one Printing process.