EP2035462A1 - Method for producing aqueous polymer dispersions containing at least one lipophilic active substance and the use thereof - Google Patents

Abstract

The invention relates to a method for producing aqueous dispersions containing at least one lipophilic active substance by emulsion polymerization of ethylenically unsaturated monomers in an aqueous medium in the presence of at least one lipophilic active substance. The method according to the invention comprises the following steps: (i) emulsifying at least one lipophilic active substance having a water solubility of not more than 5 g/l (established at 25°C and 1013 mbar) and a melting point below 130°C, in an aqueous solution which contains at least one dispersion stabilizer, while producing an aqueous solution of the active substance with an average particle size of not more than 1000 nm, and (ii) subjecting a monomer composition which contains at least 80% of a neutral, monoethylenically unsaturated monomer that can be emulsified in water, in the aqueous dispersion of the active substance obtained in step (1), to an emulsion polymerization. The invention also relates to the use of the dispersions obtained according to the invention as sizing agents for paper, paperboard and cardboard, for finishing and stabilizing thermoplastic polymers, for material protection and crop protection.

Description

Process for the preparation of at least one lipophilic active substance-containing aqueous polymer dispersions and their use

description

The invention relates to a process for the preparation of at least one lipophilic active substance-containing aqueous polymer dispersions by emulsion polymerization of ethylenically unsaturated monomers in an aqueous medium in the presence of at least one lipophilic active ingredient and the use of the dispersions thus obtainable as sizing agents for paper, board and cardboard, for finishing and for stabilizing thermoplastic polymers, for material protection and crop protection.

In the technical language, active substances are generally understood to mean substances which, even in a low concentration, have the desired effect in the respectively intended application. In all cases, it is necessary to distribute a small amount of an active ingredient in a large amount of another substance or on a large area as evenly as possible. Thus, for example, so-called UV absorbers are used for the protection of materials such as polymers against the action of UV rays. Further examples of active substances are the sizing agents used for paper substances such as alkyldiketenes, alkenylsuccinic anhydrides and rosin size, as well as active ingredients for crop protection such as herbicides, fungicides, insecticides and growth regulators. These agents are lipophilic and therefore virtually insoluble in water. However, to apply them according to the desired purpose, they must be in finely divided form. There are several methods for using such products.

By way of example, UV absorber is thereby incorporated into a polymer by melting it and mixing the melt with the UV absorber under the action of shearing forces. On the other hand, sizing agents for paper, as well as lipophilic active ingredients for crop protection, are used in the form of a dilute aqueous dispersion. The dispersions are usually diluted with water to the respective application concentration shortly before use. The lipophilic active ingredients are present as emulsified or dispersed phase in a continuous aqueous phase. Such aqueous dispersions always contain a dispersion stabilizer which stabilizes the inherently metastable systems. Aqueous dispersions of lipophilic active substances can be prepared, for example, by two different polymerization processes, namely by the process of emulsion polymerization or miniemulsion polymerization.

So z. For example, JP-A 7-292009 discloses aqueous polymer dispersions which contain functional substances, in particular UV absorbers or epoxy resins. They are prepared by dissolving the functional substances in an unsaturated monomer, Emulsifying this solution in water in the presence of a surfactant to form a monomer emulsion having average particle sizes between 5 and 500 nm and polymerizing the miniemulsion in the presence of a free-radical initiator.

The aqueous dispersions containing the functional substances such as UV absorbers, epoxy resins, acrylic-based polymers, phenolic resins, unsaturated polyesters, phenol-based substances, and petroleum resins are used as a binder and as an additive for protective films.

WO-A 99/40123 discloses a process for preparing aqueous polymer dispersions whose dispersed polymer particles are an organic dye homogeneous, i. distributed molecularly dispersed. Such aqueous dispersions are prepared by miniemulsion polymerization by polymerizing ethylenically unsaturated monomers which contain an organic dye dissolved in the form of an oil-in-water emulsion in the presence of radical-forming polymerization initiators, wherein the disperse phase of the emulsion substantially of dye containing monomer droplets with a diameter <500 nm is formed. In an advantageous embodiment of the invention, monomer mixtures which contain crosslinking monomers are used in the polymerization. The polymer dispersions are sedimentation-stable. The dispersed particles have a mean particle diameter of 100 to 400 nm. They can be obtained from the aqueous dispersions using conventional drying methods. The dye-containing polymer dispersions are used, for example, for pigmenting high molecular weight organic and inorganic materials, for pigmenting printing inks and inks for ink-jet printing.

Further colorant-containing polymer dispersions whose colorant-containing polymer particles have an average particle diameter below 1000 nm are known from EP-A 1 191 041. Suitable colorants are, in addition to organic dyes, UV absorbers and optical brighteners. The dispersions are prepared by miniemulsion polymerization.

From DE-A 102 54 548 the use of finely divided, at least one UV absorber-containing polymer powder for the stabilization of polymers against the action of UV radiation is known. The polymer particles of the polymer powders have a particle size of 500 nm or below. They are prepared by miniemulsion polymerization and isolated from the aqueous dispersions.

From DE-A 102 48 879 alkyldiketenes containing aqueous polymer dispersions are known, which are obtainable by miniemulsion polymerization of hydrophobic monoethylenically unsaturated monomers in the presence of Alkyldiketenen. Correspondingly structured aqueous polymer dispersions containing alkenylsuccinic anhydrides Persimmons which are prepared by polymerizing hydrophobic monomers in the manner of a miniemulsion polymerization in the presence of alkenylsuccinic anhydrides and optionally additionally alkyldiketenes are known from WO-A 2005/070912. The dispersions are each used as sizing agents for paper, as water repellents for leather, natural and / or synthetic fibers and textiles.

A process for the emulsion polymerization of ethylenically unsaturated monomers containing at least one insecticide dissolved are known from US-A 3,400,093. In this method, initially emulsifying a solution of a substantially water-insoluble insecticide in at least one water-insoluble vinyl monomer in an aqueous solution containing at least one surfactant and then subjects this mixture to emulsion polymerization.

According to the process known from EP-A 0 875 544, polymer dispersions comprising, for example, UV absorbers can be prepared by dissolving at least one UV absorber in at least one ethylenically unsaturated monomer and then subjecting the solution to an emulsion polymerization in water which is a polymerization initiator and an emulsifier. The polymer particles may be composed of a single polymer or have a core / shell structure, where the UV absorber may be either in the core or in the shell of the polymer particle or both in the core and in the shell.

WO-A 01/10936 discloses particles with a core / shell structure in which the core comprises a polymer having a glass transition temperature T ₉ of below 40 ° C. and a polymerizable UV absorber, and preferably the shell a polymer of methyl acrylate, ethyl acrylate, ethyl methacrylate and / or methyl methacrylate. The polymer that forms the core of the particle may optionally be crosslinked. The polymer particles are prepared by emulsion polymerization. The UV absorber-containing polymer particles are used to make UV-absorbing polymer compositions.

WO-A 2006/015791 discloses a process for preparing aqueous active substance compositions of active substances which are sparingly soluble in water. The procedure comprises the following steps:

a) providing an aqueous suspension of solid active substance particles of at least one active ingredient having a water solubility of not more than 5 g / l at 25 ° C / 1013 mbar, containing no at least one surfactant to stabilize the dispersed Wirkstoffparti-, wherein the active ingredient particles in the suspension have an average particle size, determined by dynamic light scattering, of not more than 1200 nm, b) emulsion polymerization of a first monomer composition M1 in the aqueous suspension of the active ingredient, wherein the monomer composition M1 at least 95 wt .-%, based on their total weight, of at least one neutral, monoethylenically unsaturated monomer M 1.1 having a water solubility of not more than 30 g / l at 25 ° C / 1013 mbar, to obtain an aqueous dispersion of polymer-active substance particles, and c) emulsion polymerization of a second monomer composition M2 in an aqueous dispersion of the polymer active agent particles obtained in step b), wherein the monomer composition M2 at least 60 wt .-%, based on their total weight, of at least one neutral, monoethylenically unsaturated

Contains monomers M2.1 having a water solubility of not more than 30 g / l at 25 ° C / 1013 mbar.

In this context, active substances are understood to be substances which, even in low concentrations in an organism, cause a physiological reaction. Preferably, it is active ingredients for crop protection and for the protection of materials, eg. For example, herbicides, fungicides, insecticides, acaricides, nematicides, bactericides, growth regulators and other biocides.

The invention has for its object to provide a further process for the preparation of water-insoluble active ingredients containing aqueous dispersions available.

The object is achieved in accordance with the invention by a process for the preparation of aqueous polymer dispersions containing at least one lipophilic active agent by emulsion polymerization of ethylenically unsaturated monomers in aqueous medium in the presence of at least one lipophilic active ingredient, if (i) at least one lipophilic active ingredient having a water solubility of at most 5 g / l (determined at 25 ° C and 1013 mbar) and has a melting point below 130 ° C, in an aqueous solution containing at least one dispersion stabilizer, to form an aqueous dispersion of the active ingredient having an average particle size of at most 1000 emulsified and (ii) a monomer composition containing at least 80% by weight of a neutral, in

Water-emulsifiable monoethylenically unsaturated monomer containing, in the obtained according to (i) aqueous dispersion of the active ingredient of an emulsion polymerization.

Preferred is an embodiment of the method, wherein

(i) at least one lipophilic active substance having a water solubility of at most 5 g / l (determined at 25 ° C and 1013 mbar) and a melting point below 100 ° C, in an aqueous solution containing at least one dispersion stabilizer. emulsifier, to form an aqueous dispersion of the active ingredient having an average particle size of at most 500 nm and (ii) a monomer composition containing at least 80% by weight of a neutral, in

Water-emulsifiable monoethylenically unsaturated monomer containing, in the obtained according to (i) aqueous dispersion of the active ingredient of an emulsion polymerization.

The aqueous dispersion of the lipophilic active ingredient is produced particularly advantageously by emulsifying in step (i) a melt of at least one lipophilic active ingredient in an aqueous solution containing at least one dispersion stabilizer.

Suitable lipophilic active ingredients have a melting point or softening range which is below 130 ° C, preferably below 100 ° C. In principle, in process step (i) all lipophilic active substances can be used which have a

Water solubility of at most 5 g / l (determined at 25 ° C and 1013 mbar) and below a temperature of 130 ° C, preferably below 100 ° C melt or in liquid form. Examples of such active substances are alkyl- or alkenyldiketenes, alkenylsuccinic anhydrides, rosin size, UV absorbers, antistatics, antioxidants, antifogging agents, lubricants, colorants, tackifiers, waxes and crop protection agents. Preferably used active ingredients are alkyldiketenes, alkenylsuccinic anhydrides and resin size (rosin) and UV absorbers.

Suitable alkyldiketenes are preferably C ₄ - to C 22 -alkyl- or alkenyl-diketenes. They are prepared for example from the corresponding carboxylic acid chlorides by elimination of hydrogen chloride with tertiary amines. The diketenes which can be used according to the invention can carry saturated or unsaturated, branched or cyclic hydrocarbon radicals. Examples of such alkyldiketenes are tetradecyldiketen, Hexadecyldiketen, Octadecyldiketen, Dodosyldiketen, Palmityldike- ten, Oleyldiketen, Stearyldiketen and Behenyldiketen. Stearyldiketen, Palmityldiketen, Oleyldiketen, Behenyldiketen, Isostearyldiketen or mixtures of Alkyldiketenen eg mixtures of Behenyldiketen and Stearyldiketen or mixtures of Stearyldiketen and Palmityldiketen are preferably used.

Alkenyl succinic anhydrides are described in detail, for example, in US Pat. No. 3,102,064, EP-A 0 609 879 and EP-A 0 593 075. All alkenylsuccinic anhydrides which have hitherto been described in the literature as engine size agents for paper are also suitable according to the invention as active ingredient, either alone or in combination with alkyldiketenes. Suitable alkenylsuccinic anhydrides in the alkyl group contain an alkyl radical having at least 6 C atoms, preferably a C ₄ - to C 24 -olefin radical. Particularly preferred alkenyl succinic anhydrides contain 16 to 22, usually 16 to 18 C atoms in the alkenyl group. You can use linear, additionally contain unsaturated or branched alkenyl groups. Alkenylsuccinic anhydrides are accessible, for example, from α-olefins, which are first isomerized. In this case, a mixture of different isomers is obtained, which is then reacted with maleic anhydride in the manner of an ene reaction to succinic anhydrides. Alkenylsuccinic anhydrides are prepared according to EP-A 0 593 075 by reaction of propylene or n-butylene oligomers with maleic anhydride. Examples of this group of reactive sizing agents are decenylsuccinic anhydride, dodecenylsuccinic anhydride, octenylsuccinic anhydride and n-hexadecenylsuccinic anhydride. The individual isomeric succinic anhydrides can have different sizing effect. Thus, for example, 2- and 3-hexadecenylsuccinic anhydrides are not as effective as massing agents as the isomeric 4-, 5-, 6-, 7- and 8-hexadecenylsuccinic anhydrides.

Also included are rosin size (rosin) and derivatives derived therefrom, such as rosin size and maleic anhydride reaction products. The derivatives may be branched or unsaturated, e.g. For example, abietic acid.

Further suitable active substances are substances which are added, for example, to polymers in order to render them antistatic or fogging or to stabilize them against oxidation, exposure to UV rays, heat and / or light. Such stabilizers are commercial products. For example, UV absorbers under the trademark Uvinul ^® from BASF Aktiengesellschaft, Ludwigshafen, buys comparable. The eligible UV absorbers have a water solubility of at most 5 g / l (determined at 25 ° C and 1013 mbar). Under UV absorbers are known to UV-absorbing compounds that disable the absorbed radiation without radiation. UV absorbers absorb light of wavelength <400 nm and convert it into heat radiation. Examples of UV absorbers are derivatives of p-aminobenzoic acid, in particular their esters z. Ethyl 4-aminobenzoate and ethoxylated 4-aminobenzoic acid ethyl esters, salicylates, substituted cinnamates (cinnamates) such as octyl-p-methoxycinnamate or 4-isopentyl-4-methoxycinnamate, 2-phenylbenzimidazole-5-sulfonic acid and its salts. A particularly preferred UV absorber is 4-n-octyloxy-2-hydroxybenzophenone. Further examples of UV absorbers are derivatives of benzoxazoles, derivatives of benzotriazoles, benzylidene camphors, dibenzoylmethanes and 2- (2-hydroxyphenyl) -1, 3,5-triazines. UV absorbers are also described in the document Cosmetic Legislation, Vol.1, Cosmetic Products, European Commission 1999, pp. 64-66 and in lines 14 to 30 on page 6 of EP-A 1 191 041, to which reference is hereby made is taken. Also suitable as active ingredients are stabilizers and auxiliaries for organic polymers, in particular thermoplastic polymers. The stabilizers are compounds that are polymers against degradation upon exposure to Stabilize oxygen, light or heat. They are also referred to as antioxidants or as UV and light stabilizers, cf. Ullmanns, Encyclopedia of Industrial Chemistry, Vol. 3, 629-650 (ISBN-3-527-30385-5) and EP-A-1 1 10 999, page 2, line 29 to page 38, line 29. To this group Active ingredients also include flame retardants. With such stabilizers, virtually all organic polymers can be stabilized, cf. EP-A 1 1 10 999, page 38, line 30 to page 41, line 35. These references are incorporated by reference into the disclosure of the present invention. The stabilizers described in the EP application belong to the class of compounds of pyrazolones, organic phosphites or phosphonites, sterically hindered phenols and sterically hindered amines (stabilizers of the so-called HALS type, see Römpp, 10th edition, volume 5, pages 4206 -4207).

Examples of auxiliaries for polymers are substances which at least largely prevent the fogging of films and molded parts made of plastics, so-called antifogging agents. Commercial stabilizers and auxiliaries are sold under the trademarks Tinuvin ^® and Cyasorb ^® by Ciba and Tenox ^® from Eastman Kodak. Stabilizers and auxiliaries are described for example in Plastics Additives Handbook, 5th edition, Hanser Verlag, ISBN 1 -56990-295-X. Auxiliaries also include lubricants for polymers.

As active ingredients, it is also possible to use all colorants which have a melting point or softening range below 130 ° C. and a water solubility of at most 5 g / l (determined at 25 ° C. and 1013 mbar). Colorants are to be understood as meaning all customary dyes, optical brighteners, IR dyes and fluorescent dye substances. Examples of dyes can be found, for example, in DE-A 199 37 261, page 2, line 31 to page 8, line 27.

As active ingredients are also tackifiers and waxes into consideration. For the purposes of the present invention, waxes are understood as meaning the following compounds: fatty, fatty acids, fatty alcohols and fatty acid esters, in particular glycerides, sterols and sterol esters (squalene), waxes based on paraffin or olefin polymers (copolymers of ethylene and acrylic acid or of ethylene and dimethylaminopropyl methacrylate, maleic anhydride copolymers such as copolymers of styrene and maleic anhydride (MSA), copolymers of isobutene and MSA, copolymers of diisobutene and MSA, polyisobutylenes).

Further suitable active ingredients are agents for the protection of materials and pesticides, which in each case meet the abovementioned conditions (water solubility and melting point or softening range), eg. As herbicides, fungicides, insecticides, acaricides, nematicides, bactericides and growth regulators. Such agents are described, for example, in Ullmann's Encyclopedia of Industrial Chemistry, 5th Edition on CD-ROM, Wiley VCH 1997: Chapter Fungicides, Insect Control and Weed Confluence. trol and Compendium of Pesticide common names, https://www.hclrss.demon.co.uk./index.html .. Also elemental sulfur can be used according to the invention as an active ingredient.

The lipophilic active substances in question are dispersed in process step (i) in water. They are preferably first melted and then emulsified as a melt in water in the presence of a dispersion stabilizer. The emulsifier yaw of the active substances may for example be device by high-pressure emulsification in this known apparatus, by means of the action of ultrasound or by the action of strong shear forces, for example with the aid of an Ultra-Turrax ^®. During the emulsification process, the temperature of the system may be from 0 up to 130 ° C, preferably up to 100 ° C. Most often, the active ingredients are emulsified in the temperature range of 5 to 95 ° C in water containing a dispersion stabilizer. If one uses temperatures above 100 ° C, the emulsification step is carried out under elevated pressure in pressure-tight equipment. When emulsifying the temperature should be at least 5 ° C, preferably at least 10 ° C above the melting point or above the incipient softening range of the respective active ingredient. After emulsification, the resulting oil-in-water emulsion of the lipophilic active ingredient is cooled, usually to the respective ambient temperature, for example 10 to 30 ° C. In step (i), either an emulsion is obtained, if the melting point of the active ingredient is above the temperature of the system, or an aqueous dispersion, if the emulsified particles of the active ingredient are in the solid state.

The average diameter of the emulsified particles of the active ingredient is at most 1000 nm. It is usually in the range of 20 to 1000 nm, preferably 30 to 500 nm and in particular 40 to 200 nm. The particle sizes of the emulsified hydrophilic active ingredients indicated here are weight-average particle sizes. as they can be determined by dynamic light scattering. Methods for this purpose are familiar to the person skilled in the art, for example from H. Wiese in D. Distler, Aqueous Polymer Dispersions, Wiley-VCH 1999, Chapter 4.2.1, p 40ff and literature cited therein and H. Auweter, D. Horn, J. Colloid Interf , Be. 105 (1985) 399, D. Lie, D. Horn, Colloid Polym. Be. 269 (1991) 704 or H. Wiese, D. Horn, J. Chem. Phys. 94 (1991) 6429.

In order to obtain the most stable possible dispersion or emulsion of the active ingredient, step (i) is preferably carried out in the presence of at least one dispersion stabilizer. Most of the time you first dissolve a stabilizer in water and then add the molten drug. However, you can add the stabilizer only during emulsification or afterwards. The addition of the stabilizer can be carried out continuously, batchwise or all at once. A dispersion is obtained which contains, for example, 0.01 to 20% by weight, preferably 0.1 to 10% by weight and usually 0.2 to 5% by weight of at least one dispersion stabilizer. The content of active ingredient in the aqueous dispersion may be, for example, 1 to 60% by weight, preferably 2 to 50% by weight. It is usually in the range of 5 to 30% by weight. The weight ratio of active ingredient to dispersion stabilizer can be varied within a wide range. It is for example 100: 1 to 1: 2, preferably 50: 1 to 1: 1 and usually 20: 1 to 2: 1.

The dispersion stabilizer used is, for example, at least one cationic, anionic or nonionic surfactant, a protective colloid or a dispersant, or mixtures of surfactants and dispersants. Preference is given to mixtures of two or more dispersion stabilizers.

Suitable surfactants are, for example, all surfactants.

Examples of suitable nonionic surfactants are ethoxylated mono-, di- and tri-alkylphenols (degree of ethoxylation: 3 to 50, alkyl radical: C3-C12) and ethoxylated fatty alcohols (degree of ethoxylation: 3 to 80, alkyl radical: C8-C36).

Examples include the brands Lutensol ^® from BASF AG or the brands Triton ^® the

Union Carbide. Particularly preferred are ethoxylated linear fatty alcohols of the general formula

n-CχH ₂ x ₊ iO (CH ₂ CH ₂ O) y H,

where x are integers in the range of 10 to 24, preferably in the range of 12 to 20. The variable y preferably stands for integers in the range from 5 to 50, more preferably 8 to 40. Ethoxylated linear fatty alcohols are usually present as a mixture of different ethoxylated fatty alcohols with different degrees of ethoxylation. The variable y in the context of the present invention stands for the mean value (number average). Suitable nonionic surface-active substances are furthermore copolymers, in particular block copolymers of ethylene oxide and at least one C 3 -C 10 -alkylene oxide, eg. B. triblock copolymers of the formula

RO (CH ₂ CH ₂ O) yi- (BO) y ₂ - (AO) _m - (BO) y 3 - (CH ₂ CH ₂ O) y 4 R '.

where m is 0 or 1, A is a radical derived from an aliphatic, cycloaliphatic or aromatic diol, eg ethane-1, 2-diyl, propane-1,3-diyl, butane-1,4 -diyl, cyclohexane-1, 4-diyl, cyclohexane-1, 2-diyl or bis (cyclohexyl) methane-4,4'-diyl, B and B 'are independently propane-1, 2-diyl, butane-1 , 2-diyl or phenylethyl 4 independently of one another are from 2 to 100 and Y 2, Y 3 independently represent a number from 2 to 100, the sum y 1 + y 2 + y 3 + y 4 preferably being in the range from 20 to 400 , which corresponds to a number average molecular weight in the range of 1000 to 20,000. Preferably, A is ethane-1, 2-diyl, propane-1, 3-diyl or butane-1, 4-diyl. B is preferably propane-1,2-diyl. Suitable surface-active substances besides the nonionic surfactants are anionic and cationic surfactants. They can be used alone or as a mixture. The prerequisite for this, however, is that they are compatible with each other. This requirement applies, for example, to mixtures of one compound class in each case and to mixtures of nonionic and anionic surfactants and mixtures of nonionic and cationic surfactants. Examples of suitable surfactants are sodium lauryl sulfate, sodium dodecylsulfate, sodium hexadecylsulfate and sodium dioctylsulfosuccinate.

Examples of cationic surfactants are quaternary alkylammonium salts, alkylbenzylammonium salts, such as dimethyl-C 2 - to cis-alkylbenzylammonium chlorides, primary, secondary and tertiary fatty amine salts, quaternary amidoamine compounds, alkylpyridinium salts, alkylimidazolinium salts and alkyloxazolinium salts.

Particularly preferred are anionic surfactants, such as. B. with sulfuric acid esterified (optionally alkoxylated) alcohols, which are usually used in neutralized with alkali lye form. Further customary emulsifiers are, for example, sodium alkyl sulfonates, sodium alkyl sulfates, such as, for example, sodium. For example, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, sulfosuccinic. Furthermore, esters of phosphoric acid or of phosphorous acid as well as aliphatic or aromatic carboxylic acids can also be used as anionic emulsifiers. Common emulsifiers are well described in the literature, see, for example, M. Ash, I. Ash, Handbook of Industrial Surfactants, Third Edition, Synapse Information Resources Inc.

Also suitable as dispersion stabilizer are condensates of naphthalenesulfonic acid and formaldehyde, amphiphilic polymers or nanoparticles of water-insoluble organic polymers or water-insoluble inorganic compounds (Pickering effect). Stabilizers of this type are z. B. nanoscale silica and alumina.

Amphiphilic polymers having an average molecular weight M _w of, for example, 1000 to 100 000 can also be used as a dispersion stabilizer. Examples of amphiphilic polymers are copolymers comprising units of

(a) hydrophobic monoethylenically unsaturated monomers and

(B) monoethylenically unsaturated carboxylic acids, monoethylenically unsaturated sulfonic acids, monoethylenically unsaturated phosphonic acids or mixtures thereof and / or basic monomers

contain. Suitable hydrophobic monoethylenically unsaturated monomers for preparing the amphiphilic polymers are, for example

Styrene, methylstyrene, ethylstyrene, acrylonitrile, methacrylonitrile, C 2 - to cis-olefins, esters of monoethylenically unsaturated C 3 - to C 8 -carboxylic acids and monohydric alcohols, vinyl alkyl ethers, vinyl esters or mixtures thereof. Isobutene, diisobutene, styrene and acrylic esters such as ethyl acrylate, isopropyl acrylate, n-butyl acrylate and sec-butyl acrylate are preferably used from this group of monomers.

The amphiphilic copolymers are preferably contained as hydrophilic monomers

(b) acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid,

Vinylsulfonic acid, 2-acrylamidomethylpropanesulfonic acid, acrylamido-propane-3-sulfonic acid, 3-sulfopropyl acrylate, 3-sulfopropyl methacrylate, styrenesulfonic acid, vinylphosphonic acid or mixtures thereof in copolymerized form. The acidic monomers may be in the form of the free acids or in partially or completely neutralized form.

Other suitable hydrophilic monomers are basic monomers. They can be polymerized with the hydrophobic monomers (a) alone or in admixture with the acidic monomers mentioned above. When mixtures of basic and acidic monomers are used, amphoteric copolymers are formed, which are anionically or cationically charged, depending on the molar ratio of the copolymerized acidic to basic monomers.

Basic monomers are, for example, di-C 1 to C ₂ -alkylamino-C ₂ to C ₄ -alkyl (meth) acrylates or diallyldimethylammonium chloride. The basic monomers may be in the form of the free bases, the salts with organic or inorganic acids or in the form quaternized with alkyl halides. The salt formation or the quaternization, at which the basic monomers become cationic, can be partial or complete. Examples of such compounds are dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, dimethylaminopropyl methacrylate, dimethylaminopropyl acrylate, diethylaminopropyl methacrylate, diethylaminopropyl acrylate and / or dimethylaminoethylacrylamide, dimethylaminoethylmethacrylamide, dimethylaminopropylacrylamide, dimethylaminopropylmethacrylamide and / or diallyldimethylammonium chloride.

If the amphiphilic copolymers in the form of the free acid are not sufficiently water-soluble, they are used in the form of water-soluble salts, for example using the corresponding alkali metal, alkaline earth metal and ammonium salts. These salts are prepared, for example, by partial or complete neutralization of the free acid groups of the amphiphilic copolymers with bases, e.g. B. For neutralization, sodium hydroxide solution, potassium hydroxide solution, magnesium oxide, ammonia or amines such as triethanolamine, ethanolamine, morpholine, triethylamine or butylamine are used. Preferably, the acid groups of the amphiphilic copolymers are neutralized with ammonia or sodium hydroxide solution. By contrast, the water solubility of basic monomers or of copolymers which contain such monomers in copolymerized form can be increased by partial or complete neutralization with a mineral acid such as hydrochloric acid or sulfuric acid or by addition of an organic acid such as acetic acid or p-toluenesulfonic acid. The molecular weight of the amphiphilic copolymers is for example 1000 to 100,000 and is preferably in the range of 1500 to 10,000. The acid numbers of the amphiphilic copolymers are, for example, 50 to 500, preferably 150 to 350 mg KOH / g of polymer.

Particularly preferred are such amphiphilic copolymers, the

95 to 45 wt .-% isobutene, diisobutene, styrene or mixtures thereof and

5 to 55 wt .-% acrylic acid, methacrylic acid, maleic acid, half ester of maleic acid or mixtures thereof in copolymerized form. Copolymers are particularly preferably used as dispersion stabilizer, the

(a) 45 to 80% by weight of styrene,

(b) 55 to 20% by weight of acrylic acid and optionally

(c) additional monomers

incorporated in copolymerized form. If appropriate, the copolymers may contain polymerized units of maleic monoesters as further monomers (c). Such copolymers are obtainable, for example, by copolymerizing copolymers of styrene, diisobutene or isobutene or mixtures thereof with maleic anhydride in the absence of water and reacting the copolymers with alcohols after the polymerization, with from 5 to 50 per mole of anhydride groups in the copolymer Mol% of a monohydric alcohol. Suitable alcohols are, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol and tert-butanol. However, it is also possible to react the anhydride groups of the copolymers with polyhydric alcohols, such as glycol or glycerol. However, the reaction is only carried out to the extent that only one OH group of the polyhydric alcohol reacts with the anhydride group. If the anhydride groups of the copolymers are not completely reacted with alcohols, the ring opening of the non-reacted with alcohols anhydride groups by addition of water.

Other suitable dispersion stabilizers are, for example, commercially available polymers of monoethylenically unsaturated acids and also graft polymers of N-vinylformamide on polyalkylene glycols, which are described, for example, in WO-A 96/34903. be written. The grafted vinylformamide units may optionally be hydrolyzed. The proportion of grafted vinylformamide units is preferably 20 to 40 wt .-%, based on polyalkylene glycol. Polyethylene glycols having molecular weights of 2,000 to 10,000 are preferably used.

Also suitable as a dispersion stabilizer zwitterionic polyalkylenepolyamines and zwitterionic polyethyleneimines into consideration. Such compounds are known for example from EP-B 0 1 12 592. They are obtainable, for example, by first alkoxylating a polyalkylene polyamine or polyethyleneimine, eg. With ethylene oxide, propylene oxide and / or butylene oxide and the alkoxylation products are then quaternized, e.g. with methyl bromide or dimethyl sulfate and the quaternized, alkoxylated products then sulfated with chlorosulfonic acid or sulfur trioxide. The molecular weight of the zwitterionic polyalkylenepolyamines is, for example, 1000 to 9000, preferably 1500 to 7500. The zwitterionic polyethyleneimines preferably have molecular weights in the range from 1500 to 7500 daltons.

Further suitable dispersion stabilizers are protective colloids. They generally have average molecular weights M _w of above 500, preferably of more than 1000. Examples of protective colloids are polyvinyl alcohols, cellulose derivatives such as carboxymethyl cellulose, polyvinylpyrrolidone, polyethylene glycols, graft polymers of vinyl acetate and / or vinyl propionate on polyethylene glycols, with one or both sides Alkyl, carboxyl or amino groups end-capped polyethylene glycols, polydiallyldimethylammonium chlorides and / or polysaccharides such as in particular water-soluble starches, starch derivatives and proteins. Such products are described, for example, in Römpp, Chemie Lexikon 9th Edition, Volume 5, page 3569 or in Houben-Weyl, Methods of Organic Chemistry, 4th Edition, Volume 14/2, Chapter IV Conversion of Cellulose and Starch of E. Husemann and R. Werner, pages 862-915 and in Ullmann's Encyclopedia for Industrial Chemistry, 6th edition, volume 28, pages 533 ff under polysaccharides.

Also suitable, for example, all types of water-soluble starch, eg. For example, both amylose and amylopectin, native starches, hydrophobically or hydrophilically modified starches, anionic starches, cationically modified starches, maltodextrins, degraded starches, wherein the starch degradation, for example, can be made oxidatively, thermally, hydrolytically or enzymatically and wherein for the starch degradation both native as well as modified starches can be used. Other suitable protective colloids are dextrins and crosslinked water-soluble starches which are water-swellable.

The protective colloid used is preferably native, water-soluble starches which, for example, can be converted into a water-soluble form by means of starch digestion, and anionically modified starches such as oxidized potato starch. Particular preference is given to anionically modified starches corresponding to a molecular were subjected to weight reduction. The molecular weight degradation is preferably carried out enzymatically. The average molecular weight M _{w of} the degraded starches is, for example, 500 to 100,000, preferably 1,000 to 30,000. The degraded starches have, for example, an intrinsic viscosity [η] of 0.04 to 0.5 dl / g. Such starches are described, for example, in EP-B 0 257 412 and in EP-B 0 276 770. If protective colloids are used in the polymerization, the amounts used are, for example, from 0.5 to 50, in particular from 5 to 40,% by weight, usually from 10 to 30,% by weight, based on the monomers used in the polymerization.

Of the abovementioned polymeric dispersion stabilizers, preference is given to using at least one protective colloid selected from the group consisting of polyvinyl alcohols, polyvinylpyrrolidones, polyacrylic acid, polyalkylene glycols, polyalkylene glycols, polydiallyl dimethylammonium chlorides, water-soluble starches, water-soluble starches, capped on one or both sides with alkyl, carboxyl or amino groups Starch derivatives and water-soluble proteins. Particularly preferred dispersion stabilizers are degraded native starches, cationic starches, mixtures of cationic starch and a surfactant and mixtures of a surfactant and at least one dispersant of a condensate of naphthalenesulfonic acid and formaldehyde and / or at least one of the abovementioned protective colloids. The condensates of naphthalenesulfonic acid and formaldehyde may optionally be modified by condensing urea. Particularly preferred dispersion stabilizers are mixtures of an anionic surfactant and at least one dispersant of a condensate of naphthalenesulfonic acid and formaldehyde or at least one protective colloid.

In step (ii) of the process according to the invention, a monomer composition containing at least 80% by weight of a neutral, water-emulsifiable, monoethylenically unsaturated monomer is subjected to emulsion polymerization in the aqueous dispersion of the active ingredient obtained according to step (i). Water-emulsifiable monomers are understood as meaning those monomers which do not completely dissolve in water and form an emulsion together with water. These monomers have for example a water solubility of at most 90 g / l, preferably at most 60 g / l (in each case determined at 25 ° C and 1013 mbar). In particular, the water solubility of these monomers under the given conditions is 0.01 to 40 g / l and especially 0.1 to 30 g / l.

To stabilize the subsequent emulsion polymerization, the stabilizing systems listed above (surfactants and dispersants, water-soluble or water-dispersible polymers and starches) may also be used. They may be charged or separated into the reaction mixture with the monomers or added together. The monomer composition comprises (a) at least 80% by weight, based on the total amount of the monomers, preferably at least 95% by weight and especially at least 99.9% by weight of neutral, monoethylenically unsaturated monomers which are emulsifiable in water. Suitable monomers are, for example, vinylaromatic monomers such as styrene, α-methylstyrene, tert-butylstyrene and vinyltoluene, esters of α, β-monoethylenically unsaturated mono- and dicarboxylic acids having 3 to 8 and in particular 3 or 4 C atoms with C 1 -C 6 -alkanols or with Cs-Cs-cycloalkanols, in particular the esters of acrylic acid, methacrylic acid, crotonic acid, the diesters of maleic acid, fumaric acid and itaconic acid and particularly preferably the esters of acrylic acid with C 1 to C 10 alkanols (= d-bis -do Alkyl acrylates) such as ethyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate and 3-propylheptyl acrylate and the esters of methacrylic acid with C 1 to C 10 alkanols such as ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert Butyl methacrylate, n-hexyl methacrylate and the like. Suitable monomers of this type are also vinyl and allyl esters of saturated aliphatic carboxylic acids having 1 to 18 carbon atoms, for example vinyl acetate, vinyl propionate and the vinyl esters of Versatic® acids (vinyl versatates), vinyl halides such as vinyl chloride and vinylidene chloride and C2-C6 olefins such as ethylene , Propene, 1-butene and n-hexene. Preferred monomers are vinylaromatic monomers, C 2 -C 8 -alkyl acrylates, in particular C 2 -C 8 -alkyl acrylates, especially tert-butyl acrylate, and C 2 -C 18 -alkyl methacrylates and in particular C 2 -C 4 -alkyl methacrylates.

In particular, at least 70% by weight of the monomer composition of group (a) used in the emulsion polymerization is selected from vinyl aromatic monomers, in particular styrene, esters of methacrylic acid with C 2 -C 4 -alkanols and tert-butyl acrylate. Particularly preferred monomers of this type are vinylaromatic monomers, especially styrene, and mixtures of vinylaromatic monomers with the abovementioned C 2 -C 5 -alkyl acrylates and / or C 2 -C 4 -alkyl methacrylates, in particular those mixtures with a proportion of vinylaromatics of at least 60% by weight. %, based on the total amount of monomers.

The monomer composition may further contain up to 20% by weight, based on the total weight of the monomers, of one or more monoethylenically unsaturated monomers (b) other than the monomers of group (a). The proportion of monomers (b) in the total amount of monomers is preferably 15% by weight, in particular up to 5% by weight. However, the monomers (b) are used only in amounts such that the resulting polymers are insoluble in water, so that dispersions are always obtained.

The monomers (b) include in particular monoethylenically unsaturated monomers containing at least one acid group such as a sulfonic acid, a phosphonic acid or have one or two carboxyl groups and the salts of these monomers, in particular the alkali metal salts, for. As the sodium or potassium salts and ammonium salts. This group of monomers (b) includes ethylenically unsaturated sulfonic acids, in particular vinylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-acryloxyethanesulfonic acid, 2-methacryloxyethanesulfonic acid, 3-acryloxy and

Methacryloxypropanesulfonic acid, vinyl benzene sulfonic acid and salts thereof, ethylenically unsaturated phosphonic acids such as vinylphosphonic acid and Vinylphosphonsäuredi- methylester and its salts and α, ß-ethylenically unsaturated C3-Cs-monocarboxylic and C ₄ -CS- dicarboxylic acids, especially acrylic acid, methacrylic acid, crotonic acid, maleic acid, Fumaric acid and itaconic acid. The proportion of monomers having acid groups is often not more than 20 wt .-%, preferably not more than 15 wt .-%, z. B. 0.1 to 15 wt .-% and in particular 0.5 to 10 wt .-%, based on the total amount of the monomers constitute.

The monomers of group (b) furthermore include monoethylenically unsaturated, neutral monomers such as the amides of the abovementioned ethylenically unsaturated carboxylic acids, in particular acrylamide and methacrylamide, hydroxyalkyl esters of the abovementioned α, β-ethylenically unsaturated Ca-Cs monocarboxylic acids and the C ₄ -Cs Dicarboxylic acids, in particular 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2- and 3-hydroxypropyl acrylate, 2- and 3-hydroxypropyl methacrylate, esters of the abovementioned monoethylenically unsaturated mono- and dicarboxylic acids with C ₂ -C 4 -alkylene glycols, in particular the esters of these carboxylic acids with polyethylene glycol - Kol or alkyl-polyethylene glycols, wherein the (alkyl) polyethylene glycol radical usually has a molecular weight in the range of 100 to 3000. The monomers (b) furthermore include N-vinylamides, such as N-vinylformamide, N-vinylpyrrolidone, N-vinylformamide.

Vinylimidazole and N-vinylcaprolactam. The proportion of these monomers is chosen so that the resulting polymers are insoluble in water. It is preferably not more than 20 wt .-%, and in particular not more than 10 wt .-%, z. B. 0.1 to 10 and in particular 0.5 to 5 wt .-%, based on the total amount of Monome ren.

The monomers of group (b) furthermore include monoethylenically unsaturated monomers which have at least one cationic group and / or at least one amino group which can be protonated in the aqueous medium, a quaternary ammonium group, a protonatable imino group or a quaternized imino group. Examples of monomers having a protonatable imino group are N-vinylimidazole and N-vinylpyridines. Examples of monomers having a quaternized imino group are N-alkylvinylpyridinium salts and N-alkyl-N'-vinylimidazolinium salts such as N-methyl-N'-vinylimidazolinium chloride or metosulphate. Among these monomers, in particular the monomers of general formula I are preferred

wherein R ^{1 is} hydrogen or C ¹ -C ⁴ -alkyl, in particular hydrogen or methyl,

R ² , R ³ independently of one another are C ¹ -C ⁴ -alkyl, in particular methyl, and

R ^{4 is} hydrogen or C 1 -C ₄ -alkyl, in particular hydrogen or methyl,

Y is oxygen, NH or NR ⁵ with R ⁵ = C 1 -C ₄ -alkyl,

A is C ₂ -C ₈ alkylene, e.g. B. 1, 2-ethanediyl, 1, 2- or 1, 3-propanediyl, 1, 4-butanediyl or 2-methyl-1, 2-propanediyl, which is optionally interrupted by 1, 2 or 3 not adjacent be oxygen atoms, stands and

X- for an anion equivalent, e.g. B. CH, HSO ₄ -, ^1/4 SO ₄ ^{2 "or} CH ₃ OSO ^_3" etc. is,

and for Y = H, the free bases of the monomers of the formula I.

Examples of such monomers are 2- (N, N-dimethylamino) ethyl acrylate, 2- (N, N-dimethylamino) ethyl methacrylate, 2- (N, N-dimethylamino) ethylacrylamide,

3- (N, N-dimethylamino) propylacrylamide, 3- (N, N-dimethylamino) propylmethacrylamide,

2- (N, N-dimethylamino) ethyl methacrylamide,

2- (N, N, N-trimethylammonium) ethyl acrylate chloride,

2- (N, N, N-trimethyl ammonium) ethyl methacrylate chloride, 2- (N, N, N-trimethyl ammonium) ethyl methacrylamide chloride,

3- (N, N, N-trimethylammonium) propyl acrylamide chloride,

3- (N, N, N-trimethylammonium) propyl methacrylamide chloride,

2- (N, N, N-trimethylammonium) ethylacrylamide chloride, and the corresponding Me sulfates and sulfates.

In another embodiment, the monomers forming the polymer include

(b) at least one cationic monomer. The proportion of cationic monomers is then advantageously from 0.1 to 20% by weight, in particular from 0.5 to 10% by weight, and particularly preferably from 1 to 7% by weight, based on the total amount of the monomers.

The polymers may optionally contain a further group of monomers (c) in copolymerized form, which can usually be used as crosslinking agent in an emulsion polymerization. However, the proportion of monomers (c) which have two or more ethylenically unsaturated double bonds usually makes up not more than 10% by weight, usually not more than 5% by weight, in particular not more than 2% by weight. , z. B. 0.01 to 2 wt .-% and in particular 0.05 to 1, 5 wt .-%, based on the total amount of monomers. Examples of crosslinkers are butanediol diacrylate, butanediol dimethacrylate, hexanediol diacrylate, hexanediol dimethacrylate, glycol dicorylate, glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, diacrylates and dimethacrylates of alkoxylated dihydric alcohols, divinylurea and / or conjugated diolefins such as butadiene or isoprene.

Depending on the application, the monomers of group (c) may also include so-called functional monomers, i. Monomers which, in addition to a polymerizable C =C double bond, also have a reactive functional group, for example an oxirane group, a reactive carbonyl group, e.g. an acetoacetato group, an isocyanate group, an N-hydroxymethyl group, an N-alkoxy-methyl group, a trialkylsilyl group, a trialkoxysilyl group or other nucleophile-reactive group.

Furthermore, it has proven to be advantageous if the monomer composition is selected such that the resulting polymer has a glass transition temperature of at least 0, preferably at least 10 ° C, in particular in the range of 20 to 130 ° C.

To prepare polymers having such a glass transition temperature, for example, the monomers (a) are selected in the monomer mixture so that they correspond to a polymer 1 having a theoretical glass transition temperature according to Fox T _g (Fox) of at least 50 ° C. According to Fox (TG Fox, Bull. Am. Phys Soc. (Ser. II) 1, 123 [1956] and Ullmann's Encyclopedia of Industrial Chemistry, Weinheim (1980), pp 17-18) applies to the glass transition temperature of not or weakly cross-linked copolymers at high molecular weights in a good approximation

1 X ¹ X ² Xn

9 'g' g 'g

where X ¹ , X ² X ^π mean the mass fractions of the monomers 1, 2 n and T ₉ ¹ , T ₉ ² T _g ⁿ the glass transition temperatures of each of only one of the monomers 1, 2 n constructed polymers in degrees Kelvin. The latter are z. For example, Ullmann's Encyclopedia of Industrial Chemistry, VCH, Weinheim, Vol. A 21 (1992) p. 169, or J. Brandrup, EH Immergut, Polymer Handbook 3rd Ed., J. Wiley, New York 1989.

Incidentally, the glass transition temperature T ₉ is understood to mean the "midpoint temperature" determined by differential thermal analysis (DSC) according to ASTM D 3418-82 (see Ullmann's Encyclopedia of Industrial Chemistry, 5th Edition, Volume A 21, VCH Weinheim). Heim 1992, p 169 and Zosel, paint and varnish 82 (1976), pp 125-134, see also DIN 53765).

The polymerization of the monomers takes place by the method of emulsion polymerization, i. the monomers to be polymerized are present in the polymerization mixture as an aqueous emulsion. For this purpose, they can be added in bulk or in the form of an aqueous emulsion to the dispersion of the active ingredient prepared in step (i). The monomers are preferably used in the form of an aqueous emulsion. To stabilize the monomer emulsions, the same compounds are used, which are used as dispersion stabilizer in process step (i) for the preparation of the aqueous dispersions of active compounds, eg. B. anionic surfactants, water-soluble starch, preferably anionic starch and protective colloids.

The monomers can be initially charged in the reactor before the start of the polymerization or added under polymerization conditions in one or more portions or continuously to the aqueous dispersion of at least one active ingredient prepared in step (i). For example, the main amount of the monomers, in particular at least 80% and particularly preferably the total amount in the polymerization vessel together with the dispersion of the active ingredient according to (i) and immediately after the polymerization start by adding a polymerization initiator. According to another variant of the method, the aqueous dispersion of at least one active ingredient prepared in process step (i) is initially introduced in the polymerization reactor, then at least 50%, preferably 100%, of the monomers are mixed in the form of an aqueous emulsion, the reactants are continuously mixed and dosed only after a residence time from 1 to 120 minutes, preferably 5 to 60 minutes after addition of the monomer emulsion, at least one polymerization initiator and polymerizing the monomers. During the mixing (before adding the polymerization initiator), the reaction mixture is preferably heated to the polymerization temperature.

A further process variant consists in first of all a part (eg 10 to 25%) of the aqueous dispersion of the active ingredient prepared according to process step (i) and a part (eg 5 to 25%) of the monomers or the monomer emulsion in the polymerization reactor, the polymerization starts by adding an initiator and the remaining aqueous dispersion of the active ingredient and the remaining amount of monomers or monomer emulsion continuously or in portions fed to the reactor and the polymerization of the monomers to an end. The polymerization initiator in this process variant, for example, partially or completely charged together with the dispersion of the active ingredient in the reactor or dosed separately from the dosage of the dispersion of the active ingredient and the monomers in the reactor. The starters which are suitable for the emulsion polymerization in step (ii) are, in principle, all polymerization initiators which are suitable and usually used for emulsion polymerization and which initiate free-radical polymerization of ethylenically unsaturated monomers. These include, for example, azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis [2-methyl-N - (2-hydroxyethyl) propionamide, 1,1 'Azobis (1-cyclohexanecarbonitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (N, N'-dimethyleneisobutyroamidine) dihydrochloride, and 2,2'-azobis (2-amidinopropane ) dihydrochloride, organic or inorganic peroxides such as diacetyl peroxide, di-tert-butyl peroxide, diamyl peroxide, dioctanoyl peroxide, didecanoyl peroxide, dilauroyl peroxide, dibenzoyl peroxide, bis (o-toluyl) peroxide, succinyl peroxide, tert-butyl peracetate, tert-butyl permaleinate tert-butyl perisobutyrate, tert-butyl perpivalate, tert-butyl peroctoate, tert-butylperneodecanoate, tert-butyl perbenzoate, tert-butyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, tert-butyl peroxy-2-ethylhexanoate and diisopropyl peroxydicarbamate; , Salts of peroxodisulfuric acid and redox initiator systems.

The polymerization in step (ii) is preferably carried out using a redox initiator system, in particular a redox initiator system containing as oxidizing agent a salt of peroxodisulfuric acid, hydrogen peroxide or an organic peroxide such as tert-butyl hydroperoxide. As the reducing agent, the redox initiator systems preferably contain a sulfur compound, which is especially selected from sodium hydrogen sulfite, sodium hydroxymethanesulfinate and the bisulfite adduct of acetone. Further suitable reducing agents are phosphorus-containing compounds such as phosphorous acid, hypophosphites and phosphinates, as well as hydrazine or hydrazine hydrate and ascorbic acid. Furthermore, redox initiator systems may contain addition of small amounts of redox metal salts, such as iron salts, vanadium salts, copper salts, chromium salts or manganese salts, for example the redox initiator system ascorbic acid / iron (II) sulfate / sodium peroxodisulfate. Particularly preferred redox initiator systems are acetone bisulfite adduct / organic hydroperoxide such as tert-butyl hydroperoxide; Sodium disulfite (Na 2 S 2 O) / organic hydroperoxide such as tertiary

butyl hydroperoxide; Sodium hydroxymethanesulfinate / organic hydroperoxide such as tert-butyl hydroperoxide; and ascorbic acid / hydrogen peroxide.

The initiator is usually employed in an amount of 0.02 to 2% by weight and in particular 0.05 to 1.5% by weight, based on the amount of the monomers. The optimum amount of initiator naturally depends on the initiator system used and can be determined by the person skilled in the art in routine experiments. The initiator may be partially or completely charged in the reaction vessel. In most cases, a portion of the amount of initiator is introduced together with a portion of the monomer emulsion and the remaining initiator is added continuously or batchwise together with the monomers but separately therefrom. Pressure and temperature are of minor importance for carrying out the polymerization of the monomers. The temperature naturally depends on the initiator system used. The optimum polymerization temperature can be determined by a person skilled in the art with the aid of routine experiments. Usually, the polymerization temperature is in the range of 0 to 110 ° C, often in the range of 30 to 95 ° C. The polymerization is usually carried out at normal pressure or ambient pressure. But it can also at elevated pressure, z. B. to 10 bar or at reduced pressure z. B. at 20 to 900 mbar, but usually be carried out at> 800 mbar. The polymerization time in step (ii) is preferably 1 to 120 minutes, in particular 2 to 90 minutes and more preferably 3 to 60 minutes, wherein longer or shorter polymerization times are possible.

In step (ii), the polymerization is preferably carried out under the so-called "starved conditions", ie conditions which allow only little or no formation of empty micelles and thus the formation of drug-free polymer particles only so little more surface-active substance is added so that the active-substance particles are wetted by the water-insoluble monomers and stabilized in the aqueous phase, so that no measurable proportions of stabilized droplets of monomers are present in the reaction mixture in which polymerization can take place. and the surface-active substances contained in the polymerization mixture serve essentially for wetting the surface of the active substance particles and for transporting the monomers (a) through the continuous aqueous phase.

If, in step (ii), a dispersion stabilizer is added to stabilize the resulting emulsion polymers, it is preferable to dose at least one further surfactant in an amount of, for example, up to 5% by weight, e.g. 0.1 to 5 wt .-%, based on the monomers to be polymerized. In addition to the nonionic surface-active substances, anionic emulsifiers, eg. As alkyl sulfates, alkyl sulfonates, alkylarylsulfonates, alkyl ether sulfates, alkylaryl ether sulfates, anionic starch, sulfosuccinates such as sulfosuccinic and sulfosuccinic and sulfosuccinic and alkyl ether and further cationic emulsifiers into consideration, which are also used in step (i).

In a preferred embodiment of the invention, the emulsion polymerization of the monomers is carried out in the presence of the dispersion of an active ingredient prepared in step (i) and, in addition, for example up to 20% by weight, usually up to 10% by weight, based on the total Dispersion, a cationically or anionically modified starch. Of course, it is possible to add to the polymerization mixture in step (ii) further additives which are customary in emulsion polymerization, for example glycols, polyethylene glycols, buffer / pH regulators, molecular weight regulators and chain transfer inhibitors. In order to modify the properties of the polymers, the emulsion polymerization can optionally be carried out in the presence of at least one polymerization regulator. Examples of polymerization regulators are organic compounds which contain sulfur in bonded form, such as dodecylmercaptan, thiodiglycol, ethylthioethanol, di-n-butylsulfide, di-n-octylsulfide, diphenylsulfide, diisopropyl disulfide, 2-mercaptoethanol, 1,3-mercaptopropanol, 3-mercaptopropane-1,2-diol, 1,4-mercapto-butanol, thioglycolic acid, 3-mercaptopropionic acid, mercaptosuccinic acid, thioacetic acid and thiourea, aldehydes such as formaldehyde, acetaldehyde and propionaldehyde, organic acids such as formic acid, sodium formate or ammonium formate, alcohols such as in particular isopropanol and phosphorus compounds such as sodium hypophosphite. If one uses a regulator in the polymerization, the amount used in each case, for example, 0.01 to 5, preferably 0.1 to 1 wt .-%, based on the monomers used in the polymerization. Polymerization regulators and crosslinkers can be used together in the polymerization. This can be used, for example, to control the rheology of the resulting polymer dispersions.

After step (ii), an aqueous polymer / active substance dispersion is obtained, the active substance particles of the originally provided active substance suspension being at least partially enveloped by the water-insoluble polymer formed from the monomers. There are observed no measurable or only extremely small proportions of agglomerates, which are usually less than 2 wt .-%, preferably less than 0.2 wt .-%, based on the solids contained in the dispersion.

In a further step, it is possible to subject the aqueous polymer dispersions obtainable according to (ii), which contain at least one type of active ingredient particles, optionally in a further process step (iii), to additional emulsion polymerization in order to vary the properties of the polymer particles. In this case, it is possible to polymerize another monomer or another mixture of monomers onto the dispersed polymer particles, so that particles having a core / shell structure are formed. The shell of such structures may be uncrosslinked or preferably crosslinked. For the emulsion polymerization in step (iii), all information given for the emulsion polymerization in step (ii) applies. For example, if step (iii) is carried out, the weight ratio of polymer in the core to polymer in the shell is 10: 1 to 1: 5, preferably 5: 1 to 1: 1.

In process step (ii), the monomers are preferably employed in an amount such that the weight ratio of active ingredient to monomers is in the range from 10: 1 to 1:50, in particular from 5: 1 to 1:30 and particularly preferably in the range from 2: 1 to 1: 20 lies. However, the aqueous dispersions containing active ingredients prepared by the process according to the invention may optionally be subjected to purification operations such as filtration. Furthermore, it is possible to isolate the dispersed, at least one active substance-containing particles from the dispersion, for. B. by spray drying. The at least one active substance-containing aqueous dispersions prepared by the process according to the invention or the polymer powders containing them, for example by spray-drying, comprising at least one active substance can be used directly for the application which is predetermined on the basis of the respective active substance contained therein. They are used, for example, as sizing agents for paper, paperboard and cardboard, for equipping and stabilizing thermoplastic polymers, for the protection of materials and for crop protection.

For example, aqueous dispersions containing alkyl diketene or alkenylsuccinic anhydride as active ingredient, as well as rosin size-containing aqueous dispersions, are sizing agents for paper, paperboard and cardboard. They can be used both as surface sizing agent and as sizing agent in the quantities customary for the known active compounds. The application is preferred as a surface sizing agent. In particular, dispersions containing as active ingredient at least one alkyldiketene are used as surface sizing agents for paper, board and cardboard.

The dispersions prepared according to the invention can be processed with all process methods suitable for surface sizing. The polymer dispersions can, for example, be applied to the surface of the paper to be glued using a size press, a film press or a gate-roll applicator. For the application, the dispersion is usually added to the size press liquor in an amount of 0.05 to 3% by weight, based on solid substance, and depends on the desired degree of sizing of the papers to be finished. In addition, the size press fleet may contain other substances such. As starch, pigments, optical brighteners, biocides, solidifiers for paper, fixing agents, defoamers, retention aids, and / or dehydrating agents. The amounts of polymer to be applied to the surface of paper products, for example, be 0.005 to 1, 0 g / m ^2, preferably 0.01 to 0.5 g / m ^2.

Dispersions containing as active ingredient at least one UV absorber or the polymer powders obtainable from the aqueous dispersions by spray-drying are used to stabilize thermoplastic polymers against the action of UV radiation. They are incorporated, for example, in thermoplastic polymers such as polyethylene, polypropylene, polyamide, polyacrylonitrile, polycarbonate, polyvinyl chloride or polyester. For this purpose, for example, amounts of at least one UV absorber-containing polymer of 0.1 to 3, preferably 0.5 to 2 are needed Wt .-%. In order to stabilize a thermoplastic polymer against UV exposure, it is possible, for example, to melt the polymer first in an extruder, an aqueous dispersion prepared by the process according to the invention, to the polymer particles of which at least one UV absorber adheres or a polymer powder , the Z. B. is obtainable by spray-drying from the aqueous dispersion, incorporated into the melt of a thermoplastic polymer. The finely divided, at least one UV absorber-containing polymer is distributed evenly in the melt of the thermoplastic material. The mixture is usually processed into a granulate from which one then produces, for example, films which are protected against the action of UV radiation.

The percentages in the examples are by weight unless otherwise indicated in the context. The particle sizes were determined using a High Performance Particle Sizer (HPPS) from Malvern using a He-Ne laser (633 nm) at a scattering angle of 173 °.

example 1

(i) Dispersion - stearyldiketene dispersion A

Sulfonate 120 g stearyidiketene, 871, 3 g of demineralized water, 12 g Natriumdocecylsul- and 7.6 g of a condensation product of naphthalenesulfonic acid and formaldehyde (Tamol ^® NNP) were mixed and heated to a temperature of 85 ° C. Once this temperature was reached, the mixture with the aid of an Ultraturrax ^® apparatus at 6000 rpm within 5 minutes was pre-emulsified and then emulsified (bar APV Gaulin LAB 40, 600) at 80 ° C three times with a homogenizer, and rapidly cooled to room temperature. A finely divided aqueous dispersion of stearyl diketene having an average particle size distribution of 144 nm was obtained.

(ii) emulsion polymerization

In a two liter reactor equipped with an anchor stirrer and apparatus for working under inert gas atmosphere, 430 g of the above-described stearyldiketene dispersion A was charged, heated to a temperature of 85 ° C and charged with 0.75 g of a 10 % aqueous solution of iron (II) sulfate heptahydrate added. At this temperature 34.53 g of an 18% strength aqueous hydrogen peroxide solution and 167.26 g of a mixture of 33.93 g of completely deionized water, 0.14 g of emulsifier K 30 (40th) were metered in two separate feeds over a period of 120 minutes % aqueous solution of a mixture of the Na salts of alkanesulfonates having an average chain length of C15), 93.24 g of styrene and 39.96 g of n-butyl acrylate in the reactor. Thereafter, the mixture was stirred for 90 minutes at 85 ° C, cooled to 50 ° C, 9.25 g of t-butyl hydroperoxide and stirred for 15 minutes at 50 ° C. After cooling to room temperature (20 ° C) was obtained a finely divided dispersion having an average particle size distribution of 157 nm and a solids content of 29.6%.

(iii) Emulsion Polymerization In a two-liter reactor equipped with an anchor stirrer and an apparatus for working under inert gas atmosphere, 0.67 g of calcium acetate hydrate (25% in water), 52.96 g of an oxidized potato starch were added and 0.21 g of an α-amylase (1% in water) mixed with 108.36 g of completely deionized water. The mixture was heated with stirring to 85 ° C and treated with another 1. 89 g of α-amylase. After 30 minutes, the enzymatic degradation was stopped with 2.8 g of glacial acetic acid, and 0.56 g of iron (II) sulfate heptahydrate and 326 g of the stearyldiketene dispersion A described under (i) were added.

In two separate feeds over a period of 120 minutes, 26.13 g of an 18% aqueous hydrogen peroxide solution and 134.02 g of a mixture of 33.12 g of completely demineralized water, 0.10 g of emulsifier K 30 (40% aqueous Solution of a mixture of the Na salts of alkanesulfonates having an average chain length of C15), 70.56 g of styrene and 30.24 g of n-butyl acrylate in the reactor. Thereafter, the mixture was stirred for 90 minutes at 85 ° C, cooled to 50 ° C, 9.25 g of t-butyl hydroperoxide and stirred for 15 minutes at 50 ° C. After cooling to room temperature (20 ° C) gave a finely divided dispersion having an average particle size distribution of 131 nm and a solids content of 26.5%.

Example 2

(i) preparing an aqueous dispersion of a UV absorber (Uvinul ^® 3008) 5.18 parts of 4-n-Octoyloxy-2-hydroxy-benzophenone (Uvinul ^® 3008) were placed in a 60 ° C hot solution of 0.86 parts Dowfax ^® 2A1 (30% aqueous solution) in 37.1 parts of water. Hielscher ultrasonic sonotrode UP 400S emulsified for 120 minutes. After cooling in an ice bath, an aqueous dispersion of the UV absorber having an average particle size distribution of 282 nm was obtained. The dispersion was still highly fluid even after storage for several days at room temperature.

(ii) emulsion polymerization

431.9 g of the dispersion of a UV absorber obtained according to (i) were introduced into a 2 l reactor and brought to an internal temperature of 85 ° C. At this temperature, a solution of 0.74 part of iron (II) sulfate heptahydrate as a 10% aqueous solution (addition 1) was then added first. At the same time 34.53 parts of 18% hydrogen peroxide and a stirred mixture of 23.93 parts of deionized water, 0.14 parts of emulsifier K 30 (40% aqueous solution of an anionic surfactant), 93.2 g of styrene and 40 g n-butyl acrylate within 120 minutes in the reactor. After completion of the feed, the reaction mixture was postpolymerized for 30 minutes. To deodorize the mixture was then added to 9.25 g of tert-butyl hydroperoxide as a 10% aqueous solution and the reaction mixture was stirred for 15 minutes at 85 ° C on. After completion of deodorization, it was allowed to cool to room temperature. The solids content of the dispersion was 26.5%. The dispersion was then cooled to room temperature and the dispersion was filtered through a 500 μm filter and then through a 125 μm filter to remove the coagulum. The amount of coagulum separated was 10 g. The mean particle size of the dispersed particles was 514 nm.

Example 3

(i) Dispersion - stearyldiketene B 300 g stearyldiketene, 700 g of demineralized water, 18.2 g of 10-fold Ci3 ethoxylated oxo alcohol and 21, 4 g of a condensate of naphthalenesulfonic sulfonic acid and formaldehyde (Tamol ^® NNP) were mixed and heated to a temperature of 85 ° C. Once this temperature was reached, the mixture using a UltraTurrax® ^® apparatus at 6000 rpm was pre-emulsified within 5 minutes. The mixture was then emulsified at 80 ° C. three times with a homogenizer (APV Gaulin LAB 40, 600 bar) and the emulsion was rapidly cooled to room temperature. This gave a finely divided aqueous dispersion of stearydiketene having an average particle size distribution of 167 nm and a solids content of 31, 9%.

(ii) emulsion polymerization

In a two liter reactor equipped with an anchor stirrer and an inert gas atmosphere device, 0.67 g of calcium acetate hydrate (25% in water), 52.96 g of a cationized potato starch (DS value = 0.048, FG = 90%) and 0.21 g of an α-amylase (1% in water) mixed with 108.36 g of fully deionized water. The mixture was heated with stirring to 85 ° C and treated with another 1. 89 g of α-amylase. After 30 minutes, the enzymatic degradation was stopped with 2.8 g of glacial acetic acid, and 0.56 g of iron (II) sulfate heptahydrate and 326 g of the stearyldiketene dispersion B described under (i) were added.

In two separate feeds over a period of 120 minutes, 26.13 g of an 18% aqueous hydrogen peroxide solution and a mixture of 33.12 g of completely demineralized water, 0.10 g of emulsifier K 30 (40% aqueous solution of a mixture the Na salts of alkanesulfonates having an average chain length of C15), 70.56 g of styrene and 30.24 g of n-butyl acrylate in the reactor. Thereafter, the mixture was stirred for 90 minutes at 85 ° C, cooled to 50 ° C, 9.25 g of t-butyl hydroperoxide and stirred for 15 minutes at 50 ° C. After cooling to Room temperature (20 ° C) gave a finely divided dispersion having an average particle size distribution of 143 nm and a solids content of 26.5%.

Example 4

(i) Dispersion - stearyl diketene dispersion C

200 g stearyldiketene, 800 g of demineralized water, 60.4 g of a Oleylaminetho- xylates (Lipamin ^® OK, FG 40%) and 68.5 g of a maltodextrin starch (average Molmas- se Mw about 10,000 Da) were mixed and applied to a Temperature of 85 ° C heated. After this temperature was reached, the mixture with the aid of a UltraTur- was rax ^® device pre-emulsified at 6000 rpm over 5 minutes, then emulsified at a temperature of 80 ° C three times with a homogenizer (APV Gaulin LAB 40, 600 bar) and fast cooled to room temperature. This gave a finely divided aqueous dispersion of stearyl diketene having an average particle size of 185 nm and a solids content of 24.1%.

(ii) emulsion polymerization

In a two-liter reactor equipped with an anchor stirrer and an inert gas atmosphere device, 0.67 g of calcium acetate hydrate (25% in water), 52.96 g of cationized corn starch (DS) were added. Value of 0.045, FG = 78%), and 0.21 g of an α-amylase (1% in water) mixed with 108.36 g of fully deionized water. The mixture was heated with stirring to 85 ° C and treated with another 1. 89 g of α-amylase. After 30 minutes, the enzymatic degradation was stopped with 2.8 g of glacial acetic acid, and 0.56 g of iron (II) sulfate heptahydrate and 195 g of the stearyldiketene dispersion C were added. This was followed by 26.13 g of an 18% hydrogen peroxide solution over a period of 120 min. added. At the same time, a monomer feed consisting of 33.1 g of demineralized water, 0.32 g of emulsifier K 30 (40% aqueous solution of a mixture of the Na salts of alkanesulfonates with an average chain length of C15), 1.0 g of t - Dodecylmercaptan, 63 g of styrene, 12.6 g of 2-ethylhexyl acrylate and 25.2 g of t-butyl acrylate started and also added over 120 min. The mixture was post-polymerized for 30 minutes and then cooled to 50 ° C. 7.6 g of tert-butyl hydroperoxide (10%) were then added and the reaction mixture was cooled to room temperature. There was obtained a finely divided polymer dispersion having a solids content of 33.2%. The mean particle size was 154 nm.

(iii) emulsion polymerization

In a two-liter reactor equipped with an anchor stirrer and a device for working under an inert gas atmosphere, 240 g of the stearyldiketene dispersion C were introduced, heated to a temperature of 85 ° C and 0.75 g of a 10 % aqueous solution of iron (II) sulfate heptahydrate added. at This temperature was metered in two separate feeds over a period of 120 minutes 34.53 g of an 18% aqueous hydrogen peroxide solution and 167.26 g of a mixture of 33.93 g of completely deionized water, 0.14 g emulsifier K 30 (40%). aqueous solution of a mixture of Na salts of alkanesulfonates having an average chain length of C15), 93.24 g of styrene and 39.96 g of n-butyl acrylate in the reactor. Thereafter, the mixture was stirred for 90 minutes at 85 ° C, cooled to 50 ° C, 9.25 g of t-butyl hydroperoxide and stirred for 15 minutes at 50 ° C. After cooling to room temperature (20 ° C) gave a finely divided dispersion having an average particle size distribution of 201 nm and a solids content of 28.1%.

Example 5

(i) Dispersion - stearyldiketene dispersion D

300 g stearyldiketene, 700 g of demineralized water, 75 g of a Oleylaminethoxy- lates (FG = 40%, Lipamin ^® OK) and 28 g of a teilhydrophobierten and crosslinked polyethylenimine (FG = 25%; see. EP 081 1091 B1, Example 7) were mixed and heated to a temperature of 85 ° C. After this temperature was reached, the mixture with the aid of an Ultraturrax ^® apparatus at 6000 rpm was pre-emulsified within 5 minutes, then at a temperature of 80 ° C three times with a homogenizer (APV Gaulin LAB 40, bar 600) emulsified and rapidly to room temperature cooled. This gave a finely divided aqueous dispersion of Stearyldiketen with an average particle size of 135 nm and a solids content of 31, 3%.

(ii) emulsion polymerization

In a 2 l flat-section flask with stirrer and internal temperature measurement, 31.9 g of a cationized potato starch (DS value = 0.48, FG = 90%) were introduced. With stirring, 180 g of demineralized water, 1.52 g of α-amylase (1%) and 0.8 g of calcium acetate hydrate (25%) were added. The mixture was heated to 85 ° C, a further 8 g of α-amylase (1%) was added and stirred for 23 min at this temperature. Thereafter, 4.0 g of glacial acetic acid and 0.8 g of iron (II) sulfate heptahydrate (10%) were added and then 4.0 g of an 18% hydrogen peroxide solution within 12 min.

Then started a monomer feed consisting of 120 g of demineralized water, 0.15 g of emulsifier K 30 (40% aqueous solution of a mixture of Na salt of alkanesulfonates having an average chain length of C15), 71, 4 g of acrylonitrile and 58.1 g n-butyl acrylate and 144 g of Stearyldiketendispersion D. The feed time of the monomer feed was 165 min. At the same time started a feed of 16 g of 5% hydrogen peroxide solution over a period of 36 min and after its completion, a feed of 28 g of 5% hydrogen peroxide solution over a period of 180 min. There were another 60 min. stirred at 85 ° C, then Tere 4 g of 5% hydrogen peroxide solution was added over a period of 10 min and cooled to 30 ° C. Then, 0.31 g of Rongalit C ^® gave (40%) and 5.73 g t-butyl hydroperoxide (10% strength) are added and the reaction was stirred an additional 30 min. A finely divided polymer dispersion having a solids content of 29.2% and an average particle size of 195 nm was obtained.

(iii) emulsion polymerization

In a 2I flat-bottomed flask with stirrer and internal temperature measurement, 90 g

Glacial acetic acid and 4 g of acrylic acid submitted. At a temperature of 105 ° C with stirring (270 rpm) via two separate feeds a) the initiator mixture consisting of 7.06 g tert-butyl peroctoate dissolved in 14.54 g of isopropanol within 60 min and b) the monomer mixture consisting of 124 g of styrene and 52 g of dimethylaminoethyl acrylate added within 45 min. After completion of the feeds was stirred for a further hour at 105 ° C and cooled to 95 ° C. At this temperature, 620 g of hot demineralised water (about 85 ° C) were added and cooled to 85 ° C.

Then (10%) (40%) was added 1, 2 g of iron (II) sulfate heptahydrate and 2 g of Rongalit C ^® and it is then left 16 g of a 5% strength hydrogen peroxide solution within 30 min run. Thereafter started a monomer feed consisting of on the one hand 44 g of styrene and 176 g of tert-butyl acrylate and on the other hand, an inlet of 400 g of stearyldiketene D each with a feed time of 120 min .. At the same time started a feed of 64 g of a 5% hydrogen peroxide solution over a period of 150 min. The mixture was after completion of the feeds 60 min. postpolymerized and then cooled to 50 ° C. Then 2 g Rongalit C ^® gave (40% strength), it was stirred for a further 30 min, gave an additional 2 g of Rongalit C ^® (40%) while cooling it thereafter at 30 ° C from. This gave a finely divided polymer dispersion having a solids content of 30.7% and an LD value (0.1%) of 50%. The mean particle size was 122 nm.

(iv) emulsion polymerization

91 g of glacial acetic acid and 4.5 g of acrylic acid were placed in a 2 l flat-section flask with stirrer and internal temperature measurement. At a temperature of 105 ° C with stirring (270 rpm) via two separate feeds a) the initiator mixture consisting of 7.94 g of tert-butyl peroctoate dissolved in 16.36 g of isopropanol within 60 min. and b) the monomer mixture consisting of 140 g of styrene and 60 g of dimethylaminopropyl methacrylamide within 45 min. added. After completion of the feeds was stirred for a further hour at 105 ° C and cooled to 95 ° C. At this temperature, 860 grams of hot demineralized water (about 85 ° C) was added and cooled to 85 ° C. At this temperature, 300 g of the stearyldiketene dispersion D was added. Then (10%) (40%) was 1, 35 g of iron (II) sulfate heptahydrate and 2.2 g Rongalit C ^® and it is then left 18 g of a 5% strength hydrogen peroxide solution within 30 min run , Thereafter started a monomer feed consisting of 50 g of styrene and 197 g of tert-butyl acrylate with a feed time of 120 min. At the same time, a feed of 72 g of a 5% strength hydrogen peroxide solution was started over a period of 150 minutes. The mixture was polymerized after completion of the feeds for 60 minutes and then cooled to 50 ° C. Then 2.2 g Rongalit ^® C gave (40% strength), stirring it for another 30 minutes, gave an additional 2.2 g Rongalit ^® C (40% strength) and cooled it to 30 ° C after starting. This gave a finely divided polymer dispersion having a solids content of 30.8% and an LT value (0.1%) of 43%. The mean particle size was 139 nm.

Example 6

(i) Dispersion - isostearyl diketene dispersion E

120 g of isostearyl diketene, 871, 3 g of completely desalted water, 8 g of sodium dodecylsulfonate and 7.6 g of a condensation product of naphthalenesulfonic acid and formaldehyde (Tamol® NNP) were mixed and heated to a temperature of 55 ° C. As soon as this temperature was reached, the mixture with the aid of an Ultraturrax ^® apparatus at 6000 rpm was pre-emulsified within 5 minutes and then emulsified at 80 ° C three times with a homogenizer (APV Gaulin LAB 40, 300 bar) and rapidly cooled to room temperature , A finely divided aqueous dispersion of isostearyl diketene having an average particle size distribution of 198 nm and a solids content of 12.4% was obtained.

(ii) emulsion polymerization

In a 2I flat ground flask with stirrer and internal temperature measurement were

50.3 g of an oxidized potato starch (FG = 78%) submitted. With stirring, 360 grams of demineralized water and 0.9 grams of calcium acetate hydrate (25%) were added. The mixture was heated to 85 ° C, 1, 6 g of an α-amylase (1%) was added and stirred for 18 min at this temperature. Thereafter, 8.0 g of glacial acetic acid and 2.3 g of iron (II) sulfate heptahydrate (10%) and then within 10 min 4 g of a 5% hydrogen peroxide solution. 143.3 g of isostearyl diketene emulsion E were added.

Then, a monomer feed consisting of 33 g of demineralized water, 0.18 g of emulsifier K 30 (40% aqueous solution of a mixture of the Na salt of alkanesulfonates having an average chain length of C15) was started, 58.4 g of styrene, 29.2 g n-butyl acrylate and 29.2 g of tert-butyl acrylate. The feed time was 90 min. At the same time, a feed of 40 g of 5% hydrogen peroxide solution was started over a period of 120 minutes. The mixture was postpolymerized for 30 minutes and then cooled to 65 ° C. Subsequently, 4 g of t-butyl hydroperoxide (10% strength) were added to the postpolymerization, and the reaction mixture was stirred for 40 minutes and then cooled to 30 ° C. There was obtained a finely divided polymer dispersion having a solids content of 21, 2%. The mean particle size was 174 nm.

Example 7

(i) Dispersion - alkenylsuccinic acid dispersion F

80 g of alkenyl succinic anhydride, 871, 3 g of demineralized water, 8 g sodium umdocecylsulfonat and 7.6 g of a condensation product of naphthalenesulfonic acid and formaldehyde (Tamol ^® NNP) were mixed, and the mixture was determined by means of an Ultraturrax ^® apparatus at 6000 rpm within pre-emulsified for 5 minutes and then emulsified three times with a homogenizer (APV Gaulin LAB 40, 300 bar). A finely divided aqueous dispersion of alkenylsuccinic anhydride having an average particle size distribution of 301 nm and a solids content of 8.4% was obtained.

(ii) emulsion polymerization

In a two liter reactor equipped with an anchor stirrer and an inert gas atmosphere device, 0.67 g of calcium acetate hydrate (25% in water), 52.96 g of a cationized potato starch (DS value = 0.048, FG = 90%) and 0.21 g of an α-amylase (1% in water) mixed with 108.36 g of fully deionized water. The mixture was stirred up

Heated to 85 ° C and treated with a further 1. 89 g of α-amylase. After 30 minutes, the enzymatic degradation was stopped with 2.8 g of glacial acetic acid, and 0.56 g of iron (II) sulfate heptahydrate and 326 g of the alkenylsuccinic anhydride dispersion F described under (i) were added.

26.13 g of an 18% strength aqueous hydrogen peroxide solution and 134.02 g of a mixture of 33.12 g of completely demineralized water, 0.10 g of emulsifier K 30 (40% strength by weight) were metered in two separate feeds over a period of 120 minutes aqueous solution of a mixture of the Na salts of alkanesulfonates having a mean chain length of C15), 70.56 g of styrene and 30.24 g of n-butyl acrylate in the reactor. Thereafter, the mixture was stirred for a further 90 minutes at 75 ° C, cooled to 50 ° C, 9.25 g of t-butyl hydroperoxide and stirred for 15 minutes at 50 ° C. After cooling to room temperature (20 ° C) gave a finely divided dispersion having an average particle size distribution of 131 nm and a solids content of 24.5%. Example 8

(i) Dispersion - oleyldiketene dispersion G

120 g of oleyl diketene, 871, 3 g of completely desalted water, 8 g of sodium docecylsulfonate and 7.6 g of a condensation product of naphthalenesulfonic acid and formaldehyde (Tamol® NNP) were mixed and heated to a temperature of 55 ° C. Once this temperature was reached, the mixture was pre-emulsified using an UltraTurrax® device at 6000 rpm within 5 minutes and then emulsified at 80 ° C three times with a homogenizer (APV Gaulin LAB 40, 300 bar) and rapidly cooled to room temperature. A finely divided aqueous dispersion of oleyl diketene having an average particle size distribution of 231 nm and a solids content of 12.4% was obtained.

(ii) Emulsion Polymerization In a two liter reactor equipped with an anchor stirrer and an inert gas atmosphere device, 0.67 g of calcium acetate hydrate (25% in water), 52.96 g of a cationized potato starch was added (DS value = 0.048, FG = 90%) and 0.21 g of an α-amylase (1% in water) mixed with 108.36 g of fully deionized water. The mixture was heated with stirring to 85 ° C and treated with another 1. 89 g of α-amylase. After 30 minutes, the enzymatic degradation was stopped with 2.8 g of glacial acetic acid, and 0.56 g of iron (II) sulfate heptahydrate and 326 g of the oleyldiketene dispersion G described under (i) were added.

One dosed in two separate inlets over a period of 120 minutes

26.13 g of an 18% aqueous hydrogen peroxide solution and 134.02 g of a mixture of 33.12 g of completely demineralized water, 0.10 g of emulsifier K 30 (40% aqueous solution of a mixture of the Na salts of alkanesulfonates with a medium Chain length of C15), 70.56 g of styrene and 30.24 g of n-butyl acrylate in the reactor. Thereafter, the mixture was stirred for 90 minutes at 85 ° C, cooled to 50 ° C, 9.25 g of t-butyl hydroperoxide and stirred for 15 minutes at 50 ° C. After cooling to room temperature (20 ° C) gave a finely divided dispersion having an average particle size distribution of 138 nm and a solids content of 26.5%.

Example 9

(i) Dispersion - Wax Dispersion H

120 g of a wax mixture of montanic acid wax and Montanester (mp. 68-78 ° C, Luwax ^® LG), 871, 3 g of demineralized water, 16 g Natriumdocecylsulfonat and 12.4 g of a condensation product of naphthalenesulfonic acid and formaldehyde (Tamol ^® NNP) were mixed and heated to a temperature of 85 ° C. Once this Temperature was reached, the mixture was pre-emulsified using an UltraTurrax ^® device at 6000 rpm within 5 minutes and then emulsified at 90 ° C three times with a homogenizer (APV Gaulin LAB 40, 300 bar) and cooled quickly to room temperature. This gave a finely divided aqueous wax dispersion having an average particle size distribution of 296 nm and a solids content of 1 1, 9%.

(ii) emulsion polymerization

In a two-liter reactor equipped with an anchor stirrer and a device for working under an inert gas atmosphere, 430 g of the wax dispersion H were introduced and heated to a temperature of 85 ° C. At this temperature, metered in two separate feeds over a period of 150 minutes 23.2 g of a 7% aqueous sodium peroxodisulfate solution and a mixture of 33 g of completely deionized water, 2.6 g of sodium dodecylbenzylsulfonate (15%) and 133 g of styrene in the reactor. Thereafter, the mixture was stirred for 90 minutes at 85 ° C, cooled to 50 ° C, 9.25 g of t-butyl hydroperoxide and stirred for 15 minutes at 50 ° C. After cooling to room temperature, a dispersion having an average particle size distribution of 340 nm and a solids content of 29.7% was obtained.

Example 10

(i) Dispersion - wax dispersion I 120 g of a polyether wax having a melting range 47-51 ° C (Luwax ^® V), 871, 3 g of demineralized water, 16 g sodium dodecyl sulfate and 12.4 g of a condensation product of naphthalenesulfonic acid and formaldehyde (Tamol ^® NNP ) were mixed and heated to a temperature of 65 ° C. Once this temperature was reached, the mixture with the aid of an Ultraturrax ^® apparatus at 6000 rpm within 5 minutes was pre-emulsified and then emulsified (bar APV Gaulin LAB 40, 300) at 85 ° C three times with a homogenizer, and rapidly cooled to room temperature. This gave a finely divided aqueous wax dispersion having an average particle size distribution of 265 nm and a solids content of 12.1%.

(ii) emulsion polymerization

In a two-liter reactor equipped with an anchor stirrer and an apparatus for working under an inert gas atmosphere, 300 g of the wax dispersion I were introduced, heated to a temperature of 90 ° C. At this temperature, metered in two separate feeds over a period of 150 minutes 23.2 g of a 7% aqueous Natriumperoxodisufatlösung and within 120 min. a mixture of 30 g of fully deionized water, 2.5 g of sodium dodecylbenzylsulfonate (15%) and 120 g of methyl methacrylate in the reactor. After that The mixture was stirred for 60 minutes at 90 ° C, cooled to 50 ° C, 9.25 g of t-butyl hydroperoxide and stirred for 15 minutes at 50 ° C. After cooling to room temperature, a dispersion having an average particle size distribution of 340 nm and a solids content of 31.0% was obtained.

Test Methods

The sizing degree was determined according to CobbδO according to DIN EN 20 535. The HST value was determined according to the Hercules Sizing Test according to Tappi Standard T 530. The Inkschwimmzeit was carried out according to DIN 53 126 with a Papierprüfinte blue. The toner adhesion was carried out with an IGT tester according to the regulation EN 12 283.

Application testing as a surface sizing agent

An anionically modified potato starch was dissolved by heating at 95 ° C for 30 minutes. Subsequently, the starch solution was added to the polymer dispersion to be tested, and diluted with water, so that in the finished mixture, a starch concentration of 8% was present. The mixture of starch solution and polymer dispersion was then applied by means of a size press to a wood-free, unsized paper having a grammage of 80 g / m ² at a temperature of 55 ° C. The preparation uptake was in the range of 50-60%. Subsequently, the papers thus treated were dried by means of contact drying at 90 ° C, air-conditioned for 24 h at 50% humidity and then subjected to the tests indicated above.

For comparison with the prior art, in addition, a commercially available watery dispersion of sizing agents (Basoplast ^® 400DS) was based on a styrene / butyl acrylate polymer tested (Comparative Example 1). The solids content of the dispersion was 24.9%, the particle size distribution 101 nm.

The results obtained in the tests are given in the table. table

Claims

claims

1. A process for the preparation of at least one lipophilic active substance-containing aqueous polymer dispersions by emulsion polymerization of ethylenically unsaturated monomers in an aqueous medium in the presence of at least one lipophilic active ingredient, characterized in that

(i) at least one lipophilic active substance having a water solubility of at most 5 g / l (determined at 25 ° C. and 1013 mbar) and a melting point below 130 ° C., in an aqueous solution containing at least one dispersion stabilizer, emulsifying to form an aqueous dispersion of the active ingredient having an average particle size of at most 1000 nm; and (ii) a monomer composition containing at least 80% by weight of a neutral, water-emulsifiable monoethylenically unsaturated monomer in which (i) aqueous dispersion of the active ingredient of an emulsion polymerization.

2. The method according to claim 1, characterized in that one

(I) at least one lipophilic active ingredient having a water solubility of at most 5 g / l (determined at 25 ° C and 1013 mbar) and a melting point below 100 ° C, in an aqueous solution containing at least one dispersion stabilizer, with formation an aqueous dispersion of the active substance with an average particle size of at most

500 nm emulsified and

(ii) subjecting a monomer composition containing at least 80% by weight of a neutral, water-emulsifiable monoethylenically unsaturated monomer to emulsion polymerization in the aqueous dispersion of the active ingredient obtained according to (i).

3. The method according to claim 1 or 2, characterized in that emulsifying in step (i) a melt of at least one lipophilic active ingredient in an aqueous solution containing at least one dispersion stabilizer.

4. The method according to any one of claims 1 to 3, characterized in that as lipophilic active ingredient AI kyldiketene, Alkenylbernsteinsäureanhydride, resin glue, UV absorber, antistatic agents, antioxidants, anti-fogging agents, lubricants, colorants, tackifiers, waxes, agents for the protection of materials and Pflan - uses zenschutzmittel.

5. The method according to any one of claims 1 to 4, characterized in that one uses as a dispersion stabilizer at least one cationic, anionic or nonionic surfactant, a protective colloid and / or a dispersant.

6. The method according to any one of claims 1 to 5, characterized in that is used as a dispersion stabilizer condensates of naphthalenesulfonic acid and formaldehyde, amphiphilic polymers and / or nanoparticles of organic polymers or inorganic compounds.

7. The method according to any one of claims 1 to 6, characterized in that as a dispersion stabilizer at least one protective colloid from the group of polyvinyl alcohols, polyvinylpyrrolidones, polyacrylic acid, polyalkylene glycols, one or both sides with alkyl, carboxyl or amino groups endgruppenver closed polyalkylene glycols, Polydiallyldimethylammoniumchloride, water-soluble starches, water-soluble starch derivatives and / or water-soluble proteins.

8. The method according to any one of claims 1 to 7, characterized in that one uses as a dispersion stabilizer, a mixture of a surfactant and at least one dispersant of a condensate of naphthalenesulfonic acid and formaldehyde and / or at least one protective colloid.

9. The method according to any one of claims 1 to 8, characterized in that one uses as a dispersion stabilizer, a mixture of an anionic surfactant and at least one dispersant of a condensate of naphthalenesulfonic acid and formaldehyde or at least one protective colloid.

10. The method according to any one of claims 1 to 9, characterized in that one uses a degraded starch as a dispersion stabilizer.

1 1. A method according to any one of claims 1 to 10, characterized in that one uses the dispersion stabilizers in an amount of 0.01 to 20 wt .-%, based on the dispersion.

12. The method according to any one of claims 1 to 1 1, characterized in that one uses the active ingredients in an amount of 1 to 60 wt .-%, based on the dispersion.

13. Use of the dispersions obtainable according to claims 1 to 12 as sizing agents for paper, board and cardboard, for equipping and for stabilizing thermoplastic polymers, for the protection of materials and plant protection.

14. Use according to claim 13, characterized in that one uses dispersions containing as active ingredient at least alkyl diketene, at least one alkenylsuccinic anhydride and / or at least one resin size, as a mass and surface sizing agent for paper, cardboard and cardboard.

15. Use according to claim 14, characterized in that dispersions containing as active ingredient at least one Alkyldiketen used as surface sizing agent for paper, cardboard and cardboard.

16. Use according to claim 13, characterized in that one uses dispersions containing as active ingredient at least one UV absorber, or the polymer powder obtainable from the aqueous dispersions by spray drying for the stabilization of thermoplastic polymers against the action of UV radiation.