FI69477C - MASS- OCH YTLIMNINGSMEDEL FOER PAPPER SOM BASERAR SIG PAO FINFOERDELADE POLYMERDISPERSIONER VILKA INNEHAOLLER INPOLYMERISERADE KVAEVEHALTIGA MONOMER - Google Patents

Abstract

1. A finely divided polymer dispersion which contains polymerized units of nitrogen-containing monomers, and is obtained by a two-stage polymerization reaction, wherein, in the first polymerization stage, a low molecular weight prepolymer, which has a viscosity of from 1.06 to 1.40 (measured in an Ubbelohde viscometer) in a 1% strength solution of a mixture of 99 parts by weight of dimethyl formamide and 1 part by weight of glacial acetic acid at 20 degrees C, is prepared in a water-miscible solvent, which may contain up to 15% by weight of water, in the manner of a solution copolymerization from a monomer mixture which contains (a) per mole of a nitrogen-containing monomer of the formula see diagramm : EP0051144,P13,F1 or see diagramm : EP0051144,P13,F3 where A is O or NH, B is Cn H2n , n being from 1 to 8, R**1 and R**2 are each Cm H2m+1 , m being from 1 to 4, R**3 is H or CH3 , X4 **- is OH**- , Cl**- , Br**- or CH3 -OSO3 H**- , and R**4 is Cm H2m+1 , m being from 1 to 4, (b) 2.5 to 10 moles of at least one nonionic, hydrophobic, ethylenically unsaturated monomer which, if it is polymerized on its own, forms a hydrophobic polymer, (c) 0.5 to 1.5 moles of an ethylenically unsaturated carboxylic acid or maleic anhydride, and (d) 0 to 7 moles of a nonionic, hydrophilic, ethylenically unsaturated monomer, the solution of the prepolymer is diluted with water in a weight ratio of from 1:3 to 1:50 and, in the second polymerization stage, 1 to 32 parts by weight of at least one nonionic, hydrophobic, ethylenically unsaturated monomer, which is the same as monomer (b) of the prepolymer, are polymerized per part by weight of the solution polymer in this polymer solution in the manner of an emulsion polymerization in the presence of a usual amount of a water-soluble polymerization initiator.

Description

69477

The invention relates to paper pulp and surface sizing agents based on finely divided polymer dispersions containing nitrogen-containing monomers polymerized in a polymerized manner.

According to German patent application DE 25 48 393 10, sizing agents for pulp and surface sizing of paper based on anionic dispersion polymers are known, which are prepared in two steps. In the first step, 30-90% by weight of nonionic ethylenically unsaturated monomer is then polymerized in an aqueous solution with 70-10% by weight of ethylenically unsaturated C 1 -C 4 carboxylic acid according to a solution polymerization process. In this polymer solution, a solution copolymer is polymerized in an amount of 10 to 60% by weight; according to the emulsion polymerization process, 90-40% by weight of a mixture of ethylenically unsaturated copolymerizable raonomers, the monomers of which polymerize with each other to form hydrophobic copolymers having a glass transition temperature between +60 and -40 ° C. Dispersions with a high solids content and a relatively low viscosity are obtained. Alkalis-resistant adhesives are obtained from the dispersions, however, they only show sufficient shear strength in an alkaline medium for use in an adhesive press.

A process for the preparation of shear-strength copolymer aqueous dispersions obtained by copolymerization of ethylenically unsaturated compounds is known from German patent application DE 24 52 585, in which nitrogen-containing monomers also form a polymer. The polymerization takes place in two steps, in which the nitrogen-containing monomers are initially copolymerized in the aqueous phase with monomers containing carboxyl groups and then, optionally after the addition of low molecular weight emulsifiers 2 69477, the polymer solution is subjected to emulsion polymerization with non-polar monomers. Although these dispersions can be prepared without a conventional emulsifier in the second polymerization step, after that they have a lower LD value (light transmittance) and a lower stability compared to emulsifier-containing aqueous dispersions. The LD value is a measure of the particle size of the dispersion.

German patent application DE 24 54 397 discloses a process for preparing cationic copolymer aqueous dispersions 10, in which in the first polymerization step a copolymer is prepared in aqueous solution or dispersion having a K value, a molecular weight measure of 20-60% by weight, and containing 70-90% by weight of the copolymer. and / or (meth) acrylic acid ester and 10-30% by weight of monoolefinically unsaturated monomers having tertiary, protonated tertiary or quaternary nitrogen atoms, and then, in the second polymerization step, the polymerization is simultaneously copolymerized or copolymerized with diene, styrene and / or acrylonitrile and / or methyl ester of methacrylic acid and optionally small amounts of (-xi, /) -monoolefinically unsaturated carboxylic acids. The monomers are then selected so as to obtain a copolymer with a glass transition temperature of -15 to + 60 ° C.

The copolymer dispersions prepared by this method are used, for example, as surface coatings for paper, leather or textiles, as well as. as paper sizing agents. However, the effectiveness of these adhesives still needs to be improved.

It is an object of the invention to provide finely divided polymer aqueous dispersions which contain a nitrogen-containing monomer when polymerized and which are also very finely divided and durable without emulsifier.

According to the invention, the problem is solved by the addition of fine nitrogenous monomers polymerized

II

3 69477 prepared by a two-step polymerization and characterized in that in the first polymerization step a monomer mixture containing 5 a) per mole of the compound of the formula I and / or II is used. R1 "H ~ C = C-C-A-B-N" (I) Δ '-X' '. 2

R-3 "R

10 0 R1 + H ~ C = C-C-A-B-N ^ R2 X_ (II), Δ i \ 4

R3 R

15 R

in which formulas A = O, NH, B = CnH2n 'n * 20 R1, R2, R4 = = 1-4, R3 = H, CH3 and X "= OH, Cl", Br ", CH3-0SO3H, b) 2 , 5-10 moles of at least one nonionic, hydrophobic, ethylenically unsaturated monomer, c) 0.5-1.5 moles of ethylenically unsaturated carboxylic acid and d) 0-7 moles of nonionic, hydrophilic, ethylenically unsaturated monomer are prepared in a water-miscible solvent, may contain up to 15% by weight of water, the low molecular weight prepolymer according to the solution copolymerization method, the prepolymer solution is diluted with water in a weight ratio of 1: 3 to 1:50 and in the second polymerization step polymerized in this polymer solution, 1 part by weight of the solution polymer, 1-32 parts by weight part of at least one nonionic, ethylenically unsaturated monomer according to the emulsion polymerization process in the presence of conventional water-soluble amounts of polymeric stimulants.

4 · 69477

The small molecule prepolymer prepared in the first polymerization step contains as component (a) at least one nitrogen-containing monomer having an amino and / or quaternary amino group.

The compounds of formula I are generally referred to as cationic monomers and the compounds of formula I as basic monomers. Also, the basic ethylenically unsaturated mono-mers include acrylic acid and methacrylic acid esters of amino alcohols, e.g. dietyyliaminodietyyliakrylaat 10-acetate, diethylaminoethyl methacrylate, acrylate-Dimethylaminopropyl, dimetyyliaminopropyylimetakrylaatti, dibutyy-liaminopropyyliakrylaatti, dibutyyliaminopropyylimetakry-methacrylate, dimetyyliaminoneopentyyliakrylaatti, derivatives containing amino groups akryyliaraidin or methacrylamide, such as 15 akryyliamidodimetyylipropyyliamiini and methacrylamidodimethylpropylamine.

The quaternary compounds of the formula II are obtained by reacting the basic monomers of the formula I with known quaternizing agents, for example benzyl chloride, ethyl chloride, butyl bromide, dimethyl sulphate and diethyl sulphate. These monomers lose their basic nature when quaternized.

The monomers used to prepare the prepolymer of group (b) are nonionic, hydrophobic, ethylenically unsaturated compounds. These are monomers which are not significantly soluble in water and which form hydrophobic polymers. Such monomers include, for example, vinyl aromatic monomers such as styrene and substituted styrenes such as methylstyrene or ethylstyrene, ethylenically unsaturated C 1 -C 4 mono- and dicarboxylic acids and monohydric alcohols having 1 to 18, preferably 4 to 12 carbon atoms. carboxylic acid esters, nitriles of said carboxylic acids 35 and vinyl esters of aliphatic carboxylic acids of 1 to 12 carbon atoms, alkyl esters of 2 to 10 carbon atoms

(I

69477 nit, preferably those with a double bond at the chain end, such as ethylene or diolefins, especially butadiene and isoprene. Of this monomer group, it is preferable to use styrene, acrylic acid ester, methacrylic acid-5 ester, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl propionate and butadiene. Particularly preferred compounds are methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, ethyl hexyl acrylate, lauryl acrylate and corresponding methacrylic acid esters.

It is self-evident that mixtures of said monomers can also be used, e.g. mixtures of styrene and ethylhexyl acrylate, styrene and n- or isobutyl acrylate, styrene, isobutyl acrylate and acrylonitrile or vinyl isobutyl. This group of monomers is not ionizable and forms hydrophobic polymers alone during polymerization, i. polymers that are insoluble in water. The monomers of the prepolymer group (b) are included, in a ratio of 1 mole to the monomers of group (a), in a monomer mixture of 2.5 to 10, preferably 3 to 8 moles.

Ethylenically unsaturated carboxylic acids are used as monomers of group (c). These monomer groups are mainly C 1 -C 4 mono-25 and dicarboxylic acids, e.g. acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, styrenecarboxylic acids and esters of maleic acid halides having 1 to 8 carbon atoms. It is preferred to use acrylic acid and methacrylic acid.

The monomer mixture contains 0.5 to 1.5, preferably 0.7 to 1.4, moles of the monomers of group (c) in a ratio of 1 mole.

Suitable monomers (d) for modifying the properties of the prepolymer include non-ionic, hydrophilic, ethylenically unsaturated monomers, e.g. methylol acrylamide, N-methylol methacrylamide, and N-methylol acrylamides etherified with monohydric C 1 -C 6 alcohols and N-methylol methacrylamides. The monomer mixture contains 1 to 7 moles of the group (a) monomers, preferably 0 to 3 moles of the group (d) monomers.

Said monomers are polymerized in a water-miscible organic solvent, which may contain up to 15% by weight of water, to a low molecular weight product. In a preferred embodiment of the process according to the invention, the solvent should dissolve the monomers as well as the copolymer formed in the first-stage prepolymerization into a homogeneous solution.

As the solvent, for example, formic acid, acetic acid, propionic acid, alcohols such as methanol, ethanol and isopropanol and ketones such as acetone and methyl ethyl ketone or amides such as dimethylformamide are used.

Solvent mixtures can also be used, e.g. mixtures of acetic acid and dimethylformamide, acetic acid and isopropanol. Mixtures of acetic acid and acetone are particularly preferred because the polymerization initiator is most often added to the reaction mixture dissolved in acetone. In the case where alcohols, ketones or amides are used as the solvent, it is necessary to neutralize the basic monomers. It is preferred not to use acetic acid as a solvent and to work without larger amounts of water.

In the first polymerization step, amphoteric solution copolymers are prepared. Amphoteric mixed polymers contain monomers of group (a) and group (c) in stoichiometric proportions or excess monomers of group (c). The weight ratio of hydrophobic (group (b) monomers) components in the prepolymer to hydrophilic (group (a), (c) and (d) monomers)) components is preferably between 2: 1 and 7: 1. The preparation of the prepolymer of the first stage of polymerization takes place at temperatures of 20-160, 7 69477, preferably 60-140 ° C. A small molecule, statistical copolymer having a degree of polymerization of 5 to 100, preferably 10 to 50, is prepared. The viscosities of these low molecular weight prepolymers in a 1% solution of a mixture of 99 parts by weight of dimethylformamide and 1 part by weight of glacial acetic acid at 20 ° C are between 1.06 and 1.40. measured with a viscometer).

The low molecular weight amphoteric prepolymers are in principle prepared by methods known per se by polymerization in the presence of large amounts of control agents (concentrations 0.1-15% by weight, control agents are e.g. It is particularly advantageous to use high concentrations of initiator-15, e.g. 1 mole of initiator per 17 to 160 moles of monomer to be polymerized. The degradation rate of the initiator is between -4 and 10 mol / sec. These initiators are soluble in an organic, water-miscible solvent. Particularly relevant in this case are azoisobutyric acid dinitrile, tert-butyl perbenzoate, benzoyl peroxide, tert-butyl hydroperoxide and hydrogen peroxide in the presence of iron salts. In this way, copolymer solutions are obtained which contain 20 to 70, preferably 30 to 65% by weight of small molecule prepolymer in solution.

During the first polymerization step, the copolymer solution is diluted with water in a weight ratio of 1: 3 to 1:50. In the event that no acid is used, the solution should be acidified. Due to the basic amino groups or quaternary ammonium groups contained in the polymer, it is soluble in water. The concentration of the solution polymer in the water-diluted solution is between 2 and 25% by weight. An aqueous solution of the polymer, from which the organic solvent can optionally be distilled off, serves as a precursor for the second polymerization step, in which nonionic hydrophobic ethylenically unsaturated monomers are polymerized primarily according to an emulsion polymerization process.

In an amount of 1 part by weight of the solution polymer, 1 to 4 parts by weight of a nonionic, hydrophobic ethylenically unsaturated monomer or a mixture of this monomer group is used. For this purpose, those monomers which were marked as belonging to group (b) in connection with the preparation of the first-stage prepolymer come into question. Preferred from this group are styrene, C4-C8 alkyl acrylates and methacrylates, such as butyl ester of acrylic acid and methacrylic acid, hex-10 acrylates and 2-ethylhexyl acrylates, acrylonitrile, methacrylonitrile, methacrylonitrile, vinyl nitrile,

The emulsion polymerization takes place in the temperature range of 40 to 160, preferably 60 to 100, using conventional amounts of water-soluble polymerization initiators. The upper limit of these initiators is 4% by weight, based on the monomers to be polymerized. Suitable initiators for use in emulsion polymerization include, for example, organic peroxides, hydroperoxides, hydrogen peroxides and inorganic peroxides, and redox systems, e.g., hydrogen peroxide / ascorbic acid or tert-butyl hydroxide / ascorbic acid. In the second polymerization step, the monomers are introduced into the polymerization batch either undiluted or in the form of an aqueous emulsion. For emulsifying the monomers in water, for example, a part of the aqueous solution of the prepolymer of the first polymerization step or also conventional emulsifiers can be used. The second stage emulsion polymerization is preferably carried out without conventional emulsifiers. However, up to 30% by weight of emulsifiers, based on the amount of first and second stage polymers, can be used in addition. Conventional emulsifiers have little effect on the particle size of the dispersion according to the invention. Suitable emulsifiers for use in the polymerization include products obtained by ethoxylation of phenol or phenol derivatives. Such emulsifiers contain from 4 to 30 moles of ethylene oxide each

II

9 69477 per mole of phenol. In addition, cationic and amphoteric emulsifiers are suitable, for example dimethyl-C12H24 fatty alkylbenzylammonium chloride or a compound of the formula C16H25 "CONH" (CH2J3_N + <CH3) 2-CH2-COO-.

It is self-evident that it is also possible to use mixtures of nonionic and anionic emulsifiers. Emulsifiers can also be added to the dispersion after the second stage emulsion polymerization to modify the properties of the dispersion. Depending on the amount of dispersed polymers, the emulsifier or emulsifier mixture is used in an amount of 0.05 to 3% by weight.

The pH of the reaction mixture is adjusted to 2-5 in the second polymerization step.

According to the two-step polymerization process, polymer dispersions containing finely divided nitrogen-containing monomers polymerized with a particle size of between 25 and 250 nm are obtained. This range of particle sizes is thus below the range of polymer dispersions obtained, for example, according to the method described in German Patent Application Publication No. 24 52 585. One measure of the particle size of a dispersion is the LD value.

The determination of the LD (light transmittance) is performed by measuring the wavelength with light at 546 nm from a 0.01% aqueous dispersion solution in a cuvette with a side length of 2.5 cm. The particle diameter can be calculated from this using the "Mie theory" (cf. B. Verner, M. Bärta, B. Sedläcek, Tables of Scattering Functions for Spherical Particles, 30 Prague 1976, Edice Marco, Rada D-DATA, SVAZEK Dl).

Films made from dried amphoteric dispersions are clearly more water resistant than films made from correspondingly prepared cationic dispersions. The films have good adhesion to glass and metals. Amphospheric dispersions, in the absence of quaternary amino compounds, have a pH-dependent region where they coagulate (isoelectric point). At low or relatively high pH, the dispersions are stable. The isoelectric point with respect to the monomers of group (a) :( c) can be transferred in the solution copolymer by 5 to 2 pH units. It is at about pH 8 when the ratio of monomer (a) :( c) is 1.

The dispersions according to the invention can be used in a number of applications, e.g. in the layering or impregnation of paper and building materials, and as pulp and surface adhesives for paper.

In surface sizing of paper, the total polymer concentration of the dispersion according to the invention is adjusted by adding water to the preparation solutions to a commonly used concentration, e.g. 0.03-3.0% by weight. The amount of copolymer generally used for sizing purposes is generally between 0.2 and 1.5, preferably between 0.3 and 0.8% by weight, based on the fiber content. When making preparation solutions, dispersions containing 10-50% by weight of solids are diluted with water. The preparation solutions may also contain adjuvants, for example starch, colorants and wax emulsions. The dispersions according to the invention can also be used as pulp adhesives. They are then effective as adhesives over the entire acidic pH range.

The use of the dispersions according to the invention as surface adhesives takes place in a manner known per se, i. most often in the case of starch or synthetic dry reinforcing agents, in which case the preparation solution is usually introduced into the paper by means of an adhesive press. Of course, it is also possible to apply the preparation solution to the paper webs by spraying or dipping or, for example, by means of a water scraper. The paper treated with the preparation solution is dried immediately after treatment. The gluing is already completely formed after the paper web has dried.

The parts shown in the examples are parts by weight, the percentages of 35 to 35 are also calculated according to the weight of the substances. The degree of sizing of the papers was determined by means of a Cobb value of 11 69477 in accordance with DIN 53 132 and the residence time in the ink in minutes until 50% permeability was achieved by means of a standard ink in accordance with DIN 53 126. To test the sizing effect of the dispersions according to the invention, two different grades of test paper were used. Test paper A had the following composition: 50% bleached sulphite cellulose 50% bleached sulphate cellulose 25% kaolin, based on the amount of dry cellulose 10 2% alum, based on the amount of dry paper

Paperi B

50% bleached sulphite cellulose 50% bleached sulphate cellulose 25% kaolin, 4% alum based on dry cellulose 15, alum based on dry paper The test papers were in the form of an adhesive tower with a basis weight of 70 g / m 2; the degree of grinding was 25 ° SR and the ash content was 14%. The preparation solutions contained, if not mentioned, 1.5 g / l of copolymer in each case, based on the solids content of the dispersions, and 60 g of oxidatively decomposed starch. The uptake of the dye solution was 90% of the dry paper in all cases.

25 Example 1

In a mixing tank, 60 parts of acetic acid, 60 parts (5.77 mol) of styrene and 33 parts (1.94 mol) of dimethylaminopropylmethacrylamide and 15 parts (2.08 mol) of acrylic acid were mixed with 1 part of azoisobutyric acid dinitrile and heated to 85 °. C. After preheating the reactants for 1/2 hour at 85 ° C, a solution of 1.25 parts of azoisobutyric acid dinitrile in 5 parts of acetone was added over 1 hour and the temperature of the reaction mixture was maintained at 85-90 ° C. After a further 30 minutes, the first polymerization step was complete.

A homogeneous polymer solution was obtained which was dissolved in --- - f: 12 69477 590 parts of water to give a clear joint and heated to 85 ° C. After the addition of 20 parts of 6% hydrogen peroxide and 0.04 parts of FeSO 4 .7H 2 O, a mixture of 80 parts of 6% hydrogen peroxide and 126 parts of 5 isobutyl acrylate and 66 parts of styrene was added separately to the 2nd polymerization step over 2 hours. During the second stage polymerization, the temperature was 84-87 ° C. It was maintained for an additional 1 hour after the addition of monomer and initiator.

The result was a finely divided dispersion with a solids content of 32% and an LD value of 98. The dispersion was used as a paper sizing agent. Test paper A was then given a Cobb value of 21 and an ink residence time of 23 minutes and test paper B a Cobb value of 21 and an ink residence time of 13 minutes.

15 Example 2

In a mixing tank, 60 parts of acetic acid, 60 parts (5.77 mol) of styrene, 33 parts (1.94 mol) of dimethylaminopropylmethacrylamide, 15 parts (2.08 mol) of acrylic acid and 1 part of azoisobutyric acid dinitrile were mixed and heated to 20 ° C. . After the monomer mixture was preheated for 1/2 hour at 85 ° C, a solution of 1 part azoisobutyric acid dinitrile and 5 parts acetone was added over 1 hour. Thirty minutes after the addition of the initiator, the prepolymer solution was dissolved in 25,300 parts of water to a homogeneous solution. The solution was heated to 85 ° C and then a redox initiator consisting of 20 parts of 6% hydrogen peroxide solution and 0.04 parts of FeSO 4 .7H 2 O was added. Within 2 hours, 80 parts of 6% hydrogen peroxide and another emulsion consisting of 126 parts of isobutyl acrylate, 66 parts of styrene and 3 parts of dimethyldodecylbenzylammonium chloride (emulsifier) in 300 parts of emulsifier are added to a solution heated to 85 ° C in 2 separate vessels. of water. In the subsequent polymerization, the temperature of the reaction mixture was maintained at 85 ° C for 1 hour after the addition of the monomer was complete. A finely divided aqueous dispersion with a solids content of 30.3% and an LD value of 99 was obtained.

Example 3

In a mixing tank, 60 parts of acetic acid, 5 parts of 60.77 mol (5.77 mol) of styrene, 33 parts (1.94 mol) of dimethylaminopropylmethacrylamide, 15 parts (2.08 mol) of acrylic acid and 1 part of azoisobutyric acid dinitrile were mixed and heated to 85 ° C. . After the mixture was kept at 85 ° C for 30 minutes, a solution of 1.25 parts of azoisobutyric acid dinitrile and 5 parts of acetone was added over 1 hour. Thirty minutes after the addition of the initiator solution, the prepolymer was dissolved in 440 parts of water to a homogeneous solution (prepolymer viscosity, = 1.14).

tre1. 40 parts of the prepolymer solution were removed from the tank and used as an emulsifier in the preparation of the emulsion feed for the 2nd polymerization step. The remainder of the prepolymer solution remained in the mixing tank and was heated to 85 ° C.

After the addition of 20 parts of a 6% hydrogen peroxide solution and 0.04 parts of FeSO 4, 2 separate feeds were introduced over a period of 2 hours, namely 80 parts of 6% hydrogen peroxide and an emulsion consisting of 126 parts of iso-butyl acrylate and 66 parts of styrene in 300 parts of water and 40 parts of prepolymer solution. One hour after the end of the ini-25 initiator and monomer addition, a fine dispersion with a solids content of 26.5% and an LD value of 99 was obtained.

Example 4

In a mixing tank, 60 parts of glacial acetic acid, 60 parts (5.77 mol) of styrene, 33 parts (1.94 mol) of dimethylaminopropylmethacrylamide, 15 parts (2.08 mol) of acrylic acid and 3 parts of azoisobutyric acid dinitrile were mixed and heated to 85 ° C: a. After 30 minutes, 6 parts of azoisobutyric acid dinitrile were added over 1 hour. After a further 30 minutes, the prepolymer was dissolved in 590 parts of water and the solution was heated to 85 ° C. Then 20 parts of 14 69477 6% hydrogen peroxide solution and 0.04 parts of FeSO 2 .7H 2 O were added.

Over 2 hours, 2 separate vessels, one with 80 parts of 6% aqueous hydrogen peroxide and the other with a mixture of 126 parts of 5 isobutyl acrylate and 66 parts of styrene were added continuously and evenly. After reacting for one hour, a fine dispersion with a solids content of 30.8% and an LD value of 99 was obtained.

Example 5

In a mixing tank, 60 parts of acetic acid, 10 parts of (5.77 mol) of styrene, 21 parts (1.94 mol) of dimethylaminopropylmethacrylamide, 11 parts (2.08 mol) of acrylic acid and 3 parts of azoisobutyric acid dinitrile were mixed and heated to 85 ° C: C. After 30 minutes, 6 parts of azoisobutyric acid dinitrile were added over 1 hour. After a further 30 minutes, the prepolymer was dissolved in 590 parts of water and heated to 85 ° C. Then 20 parts of a 6% hydrogen peroxide solution and 0.04 parts of FeSO 4 4.7H 2 O were added.

Within 2 hours, 2 parts from 6 different equipments, one with 80 parts of 6% hydrogen peroxide as initiator and the other with a mixture of 99 parts of isobutyl acrylate and 99 parts of styrene were added uniformly. After one hour of reaction, a fine dispersion with a solids content of 28.5% and an LD value of 99 was obtained.

Example 6 In a mixing tank, 60 parts of acetic acid, 33 parts (2.58 mol) of butyl acrylate, 33 parts (3.17 mol) of styrene, 18 parts (1.06 mol) of dimethylaminopropylmethacrylamide, 9 parts (1.25 mol) of acrylic acid were mixed , 9 parts (1.27 mol) of acrylamide and 3 parts of azoisobutyric acid dinitrile 30 and heated to 85 ° C. After 35 minutes, the addition of 6 parts of azoisobutyric acid dinitrile was started. The addition of initiator was completed after 1 hour. Thirty minutes after the end of the stimulant addition, the prepolymer was dissolved in 590 parts of water to a homogeneous solution with heating to 35-85 ° C. Then 20 parts of 6% aqueous hydrogen peroxide and 0.04 parts of FeSO 4 -7H 2 O were added. Subsequently, 80 parts of a 6% aqueous solution of hydrogen peroxide and a second mixture of 156 parts of acrylonitrile and 36 parts of isobutyl acrylate were added over a period of 2 hours from separate feed tanks. The mixture was then heated at 85 ° C for an additional 1 hour to effect the reaction. A dispersion with a solids content of 30.5% and an LD value of 95 was obtained.

Example 7

In a mixing tank, 60 parts of acetic acid, 60 parts (5.77 mol) of styrene, 33 parts (1.94 mol) of dimethylaminopropylmethacrylamide, 15 parts (2.08 mol) of acrylic acid, 1 part of azoisobutyric acid dinitrile and 2 parts (0, 22 mol) thioglycolic acid and heated to 85 ° C. This temperature was maintained for 30 minutes and then a solution of 1.25 parts of azoisobutyric acid dinitrile, 2 parts of thioglycolic acid in 5 parts of acetone was added continuously over 1 hour, 30 minutes after the end of the addition of the latter solution was added 590 parts of the prepolymer. water and the mixture was heated to 85 ° C and stirred at this temperature for 20 parts of a 6% aqueous hydrogen peroxide solution and 0.04 parts of FeSO 4. Then, in a second polymerization step, 80 parts of a 6% aqueous hydrogen peroxide solution and a mixture of 126 parts of isobutyl 25 acrylate and 66 parts of styrene were added uniformly over 2 hours. After one hour of reaction, a dispersion with an LD value of 99 and a solids content of 30.6% was obtained.

Example 8

In a mixing tank, 60 parts of acetic acid, 30 parts (5.77 mol) of styrene, 33 parts (1.94 mol) of dimethylaminopropylmethacrylamide, 15 parts (2.08 mol) of acrylic acid, 2 parts of thioglycolic acid (as a control agent) and 1 part of azoisobutyric acid dinitrile and heated to 85 ° C. The mixture was kept at 85 ° C for 30 minutes and then stirred for 1 hour with a solution of 1.25 parts of azoisobutyric acid dinitrile in 2 parts of thioglycolic acid - _____ - · 1, ..

16 69477 * · and 5 parts acetone. Thirty minutes after the addition of the latter solution, the prepolymer was dissolved in 590 parts of water, and at 85 ° C was mixed with 20 parts of 6% aqueous hydrogen peroxide solution, 1.5 parts of 5 thioglycolic acid and 0.04 part of FeSO 4 H 2 O. To the second polymerization step, 80 parts of a 6% aqueous hydrogen peroxide solution and a mixture of 126 parts of isobutyl acrylate and 66 parts of styrene were then added uniformly over 2 hours from separate storage tanks.

After the addition of monomer and excipient was complete, the reaction mixture was heated at 85 ° C for an additional 1 hour. A dispersion with an LD value of 99 and a solids content of 30.4% was obtained.

Example 9 In a mixing tank equipped with a reflux condenser, 60 parts (5.77 mol) of styrene, 33 parts (1.94 mol) of dimethylaminopropylmethacrylamide, 15 parts (2.08 mol) of acrylic acid, 60 parts of acetic acid and 9 parts of tertiary acid were mixed. butyl perbenzoate and heated to 120 ° C. After heating at 120 ° C for 2 hours, the mixture was cooled to 85 ° C and the Phase 1 prepolymer was dissolved in 590 parts of water. The polymerization of step 2 was then carried out at 85 ° C. To the prepolymer solution was added 0.04 parts of FeSO 4> 4.7H 2 O, and 100 parts of a 6% hydrogen peroxide solution and a mixture of 126 parts of isobutyl acrylate and 66 parts of styrene were passed uniformly over 2 hours from 2 separate storage vessels. The post-polymerization and the main polymerization were performed at 85 ° C. A finely divided dispersion was obtained with a solids content of 32% and an LD value of 99.

Example 10 A mixture of 20 parts (1.92 mol) of styrene, 7 parts (0.41 mol) of dimethylaminopropylmethacrylamide, 3.5 parts (0.486 mol) of acrylic acid and 10 parts of acetic acid was pumped for 1 hour into a kettle heated to 90 ° C by a pump. . Simultaneously and likewise within 1 hour, 17 parts of azoisobutyric acid dinitrile and 10 parts of acetic acid were added by means of a second dosing apparatus. The mixture was heated at 90 ° C for 30 minutes and then dissolved in 180 parts of water. Then, 0.01 part of 5 ferrous sulfate was added and a mixture of 32 parts of styrene and 32 parts of isobutyl acrylate was polymerized at 85 ° C, which was added separately with 33 parts of 6% hydrogen peroxide solution over 2 hours continuously to the prepolymer. After 1 hour of post-polymerization at 10 to 85 ° C, a fine dispersion with a solids content of 31.4% and an LD value of 99 was obtained.

Examples 11-16

A mixture of 20 parts of 15 (1.02 mol) of styrene, 20 parts of acetic acid, 7 parts (0.41 mol) of dimethylaminopropylmethacrylamide and 3.5 parts (0.486 mol) of acrylic acid was prepared in each case and heated to the various temperatures shown in Table 1. then 0.3 part of azoisobutyric acid dinitrile was added. Within the time "t" minute shown in Table 1, the portions of Table 1 were then added to the initiator, azoisobutyric acid dinitrile as a 20% acetone solution. In each case, 30 minutes after the end of the catalyst addition, 180 parts of water and 0.01 part of ferrous sulfate were added. The mixture was then heated to 85 ° C and served as a collection vessel for the second polymerization step, in which a mixture of 32 parts of styrene and 32 parts of isobutyl acrylate was polymerized for 2 hours, adding 33 parts of 6% aqueous hydrogen peroxide solution simultaneously and continuously. The post-30 polymerization took place at 85 ° C for 1 hour. In each case, finely divided dispersions were obtained, the solids contents and LD values of which are shown in Table 1.

69477 5 18

table 1

Eg T ° C Initiative-Duration-Solid-LD-market time t '' Irel. concentration value _share_ (min) _ 11 90 0.4 30 1.153 30.9 96 12 90 0.4 45 1.157 31.6 96 13 100 0.4 30 1.137 30.5 98 14 110 0.8 30 1.114 30.1 99 10 15 110 0.8 30 1.119 30.5 99 16 115 0.8 30 1.11 30.2 98

To determine the r-values shown in the table, the aqueous prepolymer solution was lyophilized at -18 ° C.

15 g of this product were then dissolved in 10 ml of a mixture of 99 parts by weight of dimethylformamide and 1 part by weight of glacial acetic acid, and the measurement was carried out at 20 ° C.

Example 17

In a mixing tank, 60 parts of glacial acetic acid, 60 parts (5.77 mol) of styrene, 33 parts (1.93 mol) of diethylaminoethyl acrylate and 15 parts of acrylic acid (2.08 mol) were mixed with 3 parts of azoisobutyronitrile and heated to 85 ° C. After 30 minutes, 6 parts of azoisobutyronitrile were added over 1 hour. After a further 30 minutes, the prepolymer (25 ° C = 1/13) was relied on 590 parts of H 2 O and the solution was heated to 85 ° C. Then 20 parts of a 6% hydrogen peroxide solution and 0.04 parts of FeSO 2 .7H 2 O were added.

Over 2 hours, 80 parts of a 6% hydrogen peroxide solution and a mixture of 66 parts of styrene and 126 parts of isobutyl acrylate were added uniformly. After one hour of post-reaction, a fine dispersion with a solids content of 30.8% and an LD value of 87 was obtained.

Example 18 In a mixing tank, 60 parts of glacial acetic acid, 51.5 parts (0.5 mol) of styrene, 17 parts of butyl acrylate, 19 69477 (0.13 mol), 27.5 parts (0.34 mol) of dimethylaminoneopentyl acrylate, 12 parts of (0.167 mol) of acrylic acid and 3 parts of azoisobutyric acid dinitrile and was heated to 85 ° C. After 30 minutes, 6 parts of 5-azoisobutyronitrile were added over 30 minutes. After a further 30 minutes, the prepolymer was dissolved in 590 parts of water. Then 20 parts of 6% hydrogen peroxide and 0.04 parts of FeSO 4 .71 ^ 0: 3 were added. Within 2 hours, a mixture of 96 parts of isobutyl acrylate, 96 parts of styrene and 80 parts of 6% hydrogen peroxide was introduced simultaneously and uniformly at 85 ° C. After one hour of post-reaction, a fine dispersion with a solids content of 29% and an LD value of 99 was obtained.

Example 19 In a mixing tank, 60 parts of formic acid, 60 parts (5.77 mol) of styrene, 33 parts (1.94 mol) of dimethylaminopropyl methacrylate and 15 parts (2.08 mol) of acrylic acid and 9 parts of azoisobutyronitrile were mixed and heated to 85 ° C. . The mixture warmed to 100 ° C. After 2 hours, 540 parts of water, 20 parts of 6% hydrogen peroxide and 0.04 parts of FeSO 4 .7 → 0: 3 were added. A mixture of 96 parts of isobutyl acrylate and 96 parts of styrene was then introduced simultaneously and evenly, and 80 parts of 6% hydrogen peroxide were fed separately. After 25 hours of post-reaction, a dispersion with a solids content of 31.7% and an LD value of 97 was obtained.

Example 20

In a mixing tank, 40 parts of formic acid, 40 parts (3.85 mol) of styrene, 22 parts (1.29 mol) of dimethylaminopropyl methacrylate and 10 parts (1.39 mol) of acrylic acid and 9.6 parts of azoisobutyronitrile were mixed and heated to 85 ° C. The mixture spontaneously warmed to 101 ° C. After 1 hour, it was dissolved in 540 parts of water and 20 parts of 6% hydrogen peroxide and 0.04 parts of 35 FeSO 4 were added. At 85 ° C, a mixture of 140 - - · ti 20 6 9 4 7 7 parts of isobutyl acrylate and 79 parts of styrene was added simultaneously and uniformly to the mixture, together with 80 parts of 6% hydrogen peroxide. The hour-long post-reaction resulted in a dispersion with a solids content of 30.9% and an LD value of 93 · 5. Preparation of reference dispersions according to DE 24 52 585

Reference dispersion 1

To the mixing tank were introduced 235 parts of water, 4 parts of dimethyl-C 1-4 fatty alkylalkylaminomethyl chloride · 6.7 parts of acetic acid and 0.02 parts of ferrous sulphate and heated to 85 ° C. Then 8 parts of 3% were added: A mixture of 12.5 parts (0.73 mol) of diethylaminoethyl acrylate and 1.8 parts (0.25 mol) of acrylic acid was then added and the mixture was heated for 15 minutes at 85 [deg.] C. The polymerization step 2 was then pumped. continuously for 4 hours a mixture of 40 parts of butyl acrylate and 46 parts of acrylonitrile and 32 parts of a 3% aqueous solution of hydrogen peroxide in the second storage tank was maintained at 85 [deg.] C. for a further 90 minutes after the addition of the mono-20 merre. 25% and LD value 81.

Reference dispersion 2

To the mixing tank were added 227 parts of water, 20 parts of acetic acid, 6.6 parts of 6% hydrogen peroxide solution and 0.02 parts of ferrous sulfate and heated to 85 ° C. 12.5 parts (0.735 mol) of dimethylaminopropylmethacrylamide and 5 parts (0.69 mol) of acrylic acid were then introduced over a period of 3 minutes. The prepolymerization ended after 30 minutes. A mixture of 28.5 parts of styrene and 54 parts of isobutyl acrylate and 27 parts of a 5% hydrogen peroxide solution were then simultaneously pumped uniformly over 1 hour into the prepolymer solution heated to 85 ° C. During the post-reaction, the mixture was kept at 85 ° C for another 2 hours.

35 A 26.5% aqueous dispersion with an LD value of 11 was obtained.

21 69477

Reference dispersion 3

According to the instructions for Reference Dispersion 2, a similar prepolymer was prepared, however, in Step 2, a mixture of 40 parts of 5-butyl acrylate and 46 parts of acrylonitrile was used for emulsion polymerization. Simultaneously with the monomer feed, 27 parts of a 6% aqueous hydrogen peroxide solution were pumped in within 2 hours. The after-reaction lasted for 2 hours at 85 ° C. A dispersion with an LD value of 60 was obtained.

10 Reference dispersion 4

In a mixing tank, 60 parts of glacial acetic acid, 58 parts (5.57 mol) of styrene, 33 parts (1.94 mol) of dimethylaminopropylmethacrylamide and 26 parts (2.03 mol) of butyl acrylate were mixed with 3 parts of azoisobutyronitrile and heated to 85 ° C. After 30 minutes, 6 parts of azoisobutyronitrile were added over 30 minutes. After a further 60 minutes, the prepolymer was dissolved in 540 parts of water, mixed with 20 parts of 6% hydrogen peroxide solution and 0.04 parts of FeSO 4 .71 → 0: 3. At 85 ° C, a mixture of 126 parts of isobutyronitrile and 66 parts of styrene was added simultaneously and uniformly at 85 ° C, together with 80 parts of 6% hydrogen peroxide. The one hour post-reaction resulted in a dispersion with a solids content of 29.1% and an LD value of 99 · 25 Reference dispersion 5

In a mixing tank, 60 parts of glacial acetic acid, 66 parts (6.35 mol) of styrene, 25 parts (1.47 mol) of dimethylaminopropylmethacrylamide, 17 parts (2.0 mol) of methyl acrylate and 3 parts of azoisobutyronitrile were mixed and heated to 85 ° C: C. After 30 minutes, 6 parts of azoisobutyronitrile were added over 30 minutes. After a further 60 minutes, the mixture was dissolved in 540 parts of T 2 O and 20 parts of 6% hydrogen peroxide and 0.04 parts of FeSO 4, 7H 2 O were introduced. At 85 [deg.] C., a mixture of 35,126 parts of isobutyl acrylate and 66 parts of styrene and then 80 parts of 6% of hydrogen peroxide were then added simultaneously and evenly.

__ - ΊΓ. ____ 22 6 9 4 7 7

The one hour post-reaction resulted in a dispersion with a solids content of 31.1% and an LD value of 99.

Reference dispersion 6 (example according to DE 24 54 397) 5 145 parts of acetone were allowed to flow under reflux at 60 [deg.] C. for 8 hours under cooling with 190 parts (18.2 mol) of styrene, 10 parts (0.78 mol) of n-butyl acrylate 60 parts (3.8 mol) of dimethylaminoethyl methacrylate, 30 parts of formic acid and 30 parts of a 20% acetone solution of t-butyl perpivalate. At the end of the polymerization, the mixture was diluted with 1000 parts of water. To 440 parts of the solution was added 370 parts of water. After heating to 85 ° C, 5 parts of a 50% hydrogen peroxide solution were added, followed over 4 hours by a mixture of 125 parts of 2-ethylhexyl acrylate and 154 parts of 15 styrene, and at the same time a further 15 parts of a 50% aqueous hydrogen peroxide solution. Two hours after the completion of the raono-mer addition, the mixture was cooled. A dispersion with a solids content of 30.3% and an LD value of 42 is obtained.

Reference dispersion 7 145 parts of acetone were allowed to reflux for 8 hours at 60 [deg.] C. 190 parts (18.2 mol) of styrene, 10 parts (0.78 mol) of n-butyl acrylate, 60 parts (3.5 mol) of dimethylaminopropylmethacrylamide, 25 parts of formic acid and 20 parts of a 20% acetone solution of t-butyl peripalate. After completion of the polymerization, it was diluted with 1000 parts of water. To 440 parts of the solution was added 370 parts of water. After heating to 85 ° C, 5 parts of a 50% hydrogen peroxide solution were added, followed by a 4-hour mixture of 125 parts of 2-ethylhexyl acrylate and 154 parts of styrene, and at the same time a further 15 parts of a 50% hydrogen peroxide solution. Two hours after the end of the monomer addition, the mixture was cooled.

A dispersion with a solids content of 30.6% 35 and an LD value of 41 was obtained.

23 69477

The LD values of the reference dispersions 2 and 3 are so small that these dispersions show insufficient sizing values when used as paper surface sizing agents. The polymer dispersions described in the examples were tested as paper-5 sizing agents according to the instructions given above. The results are summarized in Table 2 and compared with the results of the respective surface sizing agents obtained from Reference Dispersions 1, 4, 5, 6 and 7.

10 Table 2

Use of the dispersions according to the invention as a surface sizing agent

Example Paper A In Ink Paper B In Ink _Cobb_time_Cobb_time_ 1 21 23 21 13 15 2 22 18 22 12 3 19 25 21 10 4 21 14 20 17 5 21 16 22 18 7 22 15 23 12 20 8 22 18 22 17 9 24 19 23 17 10 19 30 23 40

Reference variance 25 1 35 3 37 2 4 95 0 87 0,5 5 93 0 80 0,5 6 76 1 7 59 1 30

Compared to the dispersions according to the invention tested, the reference dispersion 1 according to DE 24 52 585 is inferior, while the purely cationic reference dispersions 4 and 5 are substantially inferior. The reference dispersions 35 6 and 7 are also inferior, only higher concentrations gave better sizing values.

24 69477

The dispersions are also useful as a pulp sizing agent for paper, in which case the sizing agent is added to the paper material before the sheet is formed. The experiments tested two different paper grades.

5 The starting materials used in the manufacture of papers C and D had the following compositions:

Paper C: 100% sulfite cellulose, 30% CaCl 2 based on dry sulfite cellulose, 0.3% / based on dry paper, copolymer of acrylamide and acrylic acid, 35 ° SR; 80 g / m 2; alunaton; 12% ash (as CaCO3).

Paper D: 50% waste paper, 50% corrugated board? 2 80 g / m; alunaton.

Table 3 15 Use of the dispersions according to Examples 1-10 as a paper sizing agent

Eg Cons. Paper C Ink Paper D Ink _% _ Cobb_Cobb_ 1 0.75 27 60 25 25 yn 1.0 22 60 22 40 1.75 19 60 20 60 4 0.75 26 60 28 24 1.0 23 60 24 47 5 0.75 33 60 25 60 1.0 25 60 20 60 6 0.75 50 30 72 10 1.0 36 60 35 50 7 0.75 32 45 38 25 8 0.75 28 27 28 20

Reference variance 30 1 1.0 156 0 151 0 4 0.75 58 30 68 9 1.0 34 60 35 15 1.75 27 60 28 45 5 0.75 192 2 45 20 1.0 40 30 34 55 35 1.75 30 30 26 60 6 1.0 44 45 7 1.0 95 10 25 6 9 4 7 7

Also in mass sizing, the dispersions according to the invention tested are clearly better than the reference dispersions studied.

Claims (3)

26 69477 Paper pulp and sizing agents based on finely divided polymer dispersions containing nitrogen-containing monomers in poly-5 formulation, prepared by two-step polymerization, characterized in that in the first polymerization step a monomer mixture containing a) or one mole of formula I and II according to 10 compounds O R1 II HC = CCABN (I) R3 XR2 15 0 / R1 + HC = CCABN-R2 X ~ (II), 2 '3 \ 4 RR _ 20 in which formulas A = O, NH, VV * 2n' n * L-8 R3, r2, r4 = CnH2n + 1. m = 1-4, R = H, CH 3 and X "= OH, Cl, Br, CH 3 -SO 3 H, b) 2.5-10 moles of at least one nonionic, hydrophobic, ethylenically unsaturated monomer, c) 0.5 -1.5 moles of ethylenically unsaturated carboxylic acid and d) 0-7 moles of nonionic, hydrophilic, ethylenically unsaturated monomer are prepared in a water-miscible solvent which may contain up to 15% by weight of water, a low molecular weight prepolymer in a weight ratio of 1: 3 to 1:50 and in the second polymerization step in this polymer solution, 1 part by weight of a solution polymer, 1 to 32 parts by weight of at least one nonionic, ethylenically unsaturated monomer are polymerized according to an emulsion polymerization method. Pulp and surface sizing agents according to Claim 1, characterized in that the first polymerizes In this step, acetic acid is used as the water-miscible solvent. Pulp and surface sizing agents according to Claims 1 and 2, characterized in that the second-stage polymerization is carried out without conventional emulsifiers. 69477 28