DE102022114638A1 - HIGH MOLECULAR WEIGHT POLYMER DISPERSIONS - Google Patents

Abstract

The invention relates to processes for producing a polymer dispersion, to polymer dispersions and their use. The methods for preparing the polymer dispersion include the steps of providing a reaction mixture in an aqueous medium comprising a polymeric dispersant and a monomer composition comprising radically polymerizable monomers, and subjecting the monomer composition in the reaction mixture to radical polymerization to form a dispersed polymer synthesize so that the polymer dispersion is formed, wherein the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in a certain narrow range. These polymer dispersions are referred to as water-in-water (w/w) polymer dispersions.

Description

The invention relates to processes for producing a polymer dispersion, to polymer dispersions and their use. The methods for preparing the polymer dispersion include the steps of providing a reaction mixture in an aqueous medium comprising a polymeric dispersant and a monomer composition comprising radically polymerizable monomers, and subjecting the monomer composition in the reaction mixture to radical polymerization to form a dispersed polymer synthesize so that the polymer dispersion is formed, wherein the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in a certain narrow range. These polymer dispersions are referred to as water-in-water (w/w) polymer dispersions.

The water-in-water polymer dispersions are suitable as flocculants, drainage aids and retention aids in paper production and in other technical areas. To produce paper, an aqueous slurry of cellulose fibers is first produced that has a water content of more than 95% by weight. The finished paper sheet has a water content of less than 5 percent by weight. Drainage and retention are crucial steps in papermaking and are important for an efficient papermaking process. High-performance w/w polymer dispersions are a key factor in the papermaking process.

A known flocculant is a w/w polymer dispersion prepared by copolymerizing ethylenically unsaturated monomers in an aqueous system containing a polymeric dispersant, thereby forming a dispersion containing the polymeric dispersant and the synthesized copolymer. The US8476391B2 and the US7323510B2 are early publications of such w/w polymer dispersions. It is well known in this technical field that the addition of separately synthesized copolymers on the one hand and polymeric dispersants on the other hand results in products which have completely different properties than the w/w polymer dispersions disclosed in the above-mentioned patent documents. Copolymerization in a system containing the polymeric dispersant is necessary to obtain high performance flocculant products, for example for papermaking.

These circumstances make the production of the w/w polymer dispersions a multi-parameter system. The type of ethylenically unsaturated monomers, their ratio and the type of polymer dispersant are just a few parameters that influence the properties of the w/w polymer dispersion. Improving the properties of the end product of the w/w polymer dispersion has been the subject of numerous research and development attempts.

In addition to the properties of the final product of the W/W polymer dispersion, problems related to the manufacturing process itself were also identified. It was observed that some batches exhibited instabilities during the manufacturing process. Some dispersions begin to gel during the manufacturing process. In addition, some of the products show instabilities some time after the manufacturing process has been completed. Such instabilities are e.g. B. supported by changing temperatures during delivery to the customer.

The object underlying the invention is to provide a process for producing w/w polymer dispersions which has a high degree of stability during the manufacturing process and a high storage life under unfavorable conditions, such as. B. changing temperatures. In particular, the degree of stability refers to the ratio of batches with insufficient stability to batches with sufficient stability, which ratio should be equal to zero. The object underlying the invention is to eliminate these disadvantages.

1. A) Bereitstellen einer Reaktionsmischung in einem wässrigen Medium, umfassend
   1. a) ein polymeres Dispergiermittel und
   2. b) eine Monomerzusammensetzung, die radikalisch polymerisierbare Monomere umfasst, wobei die radikalisch polymerisierbaren Monomere aus der Gruppe ausgewählt sind, die aus einem oder mehreren nichtionischen ethylenisch ungesättigten Monomeren, einem kationischen ethylenisch ungesättigten Monomer und einem amphiphilen ethylenisch ungesättigten Monomer besteht;
2. B) Unterziehen der Monomerzusammensetzung in der Reaktionsmischung einer radikalischen Polymerisation, um ein dispergiertes Polymer zu synthetisieren und die Polymerdispersion zu bilden,

wobei das Verhältnis des polymeren Dispergiermittels zum dispergierten Polymer in der Polymerdispersion im Bereich von 0,65 : 1 bis 0,98 : 1, bevorzugt im Bereich von 0,7 : 1 bis 0,95 : 1, noch bevorzugter im Bereich von 0,72 : 1 bis weniger als 0,92 : 1, noch bevorzugter im Bereich von 0,74 : 1 bis 0,9 : 1, insbesondere im Bereich von 0,76 : 1 bis 0,88 : 1 liegt.The problems underlying the invention are solved by the subject matter of claim 1. Thus, according to a first aspect, the invention relates to a method for producing a polymer dispersion, comprising the steps

1. A) Providing a reaction mixture in an aqueous medium, comprising
   1. a) a polymeric dispersant and
   2. b) a monomer composition comprising radically polymerizable monomers, wherein the radically polymerizable monomers are selected from the group consisting of one or more nonionic ethylenically unsaturated monomers, a cationic ethylenically unsaturated monomer and an amphiphilic ethylenically unsaturated monomer;
2. B) subjecting the monomer composition in the reaction mixture to radical polymerization to synthesize a dispersed polymer and form the polymer dispersion,

wherein the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in the range of 0.65:1 to 0.98:1, preferably in the range of 0.7:1 to 0.95:1, even more preferably in the range of 0, 72:1 to less than 0.92:1, more preferably in the range of 0.74:1 to 0.9:1, in particular in the range of 0.76:1 to 0.88:1.

The process includes providing a reaction mixture containing the monomers to be copolymerized and a polymeric dispersant. The monomers are polymerized in an aqueous medium in the presence of the polymeric dispersant. According to the prior art, a polymer dispersion obtained by the process according to the invention cannot be obtained by subjecting the monomer composition to copolymerization and then adding the polymeric dispersant after the copolymerization. By using the process according to the invention, the polymer dispersion is given unique properties, the polymer dispersion representing the end product which comprises the copolymer obtained from the free-radically polymerizable monomers together with the polymeric dispersant.

It was surprisingly found that the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion, i.e. in the end product, plays an important role in the stability of the reaction mixture during polymerization. In particular, it has surprisingly been found that the above-mentioned narrow range improves the stability of the reaction mixture during polymerization and the stability of the final product, so that the shelf life is increased when the final product is exposed to unfavorable circumstances such as. B. is exposed to changing temperatures.

Although the ratio is determined in the final product, the manner in which the final product is obtained is advantageous in terms of the stability described above. The person skilled in the art knows that the said ratio in the end product is achieved, among other things, by adapting the amount of polymeric dispersant to the amount of copolymer that should be present in the end product. The way in which this ratio is set is exemplified in the examples below. The ratio of dispersant to dispersed phase is adjusted so that the resulting aqueous dispersion has a low viscosity and good stability. In addition, the ratio is also very important for the polymerization itself. If the ratio of dispersant and dispersed phase does not match, the torque during the reaction becomes extremely high and reaches such an extent that the polymerization has to be stopped.

In a preferred embodiment, the method is characterized in that step B is carried out by stirring while measuring the viscosity. Alternatively, the process is characterized in that step B is carried out by stirring and the viscosity during the polymerization is 1,800 mPas to 4,000 mPas, preferably 2,000 mPas to 3,600 mPas, more preferably 2,200 mPas to 3,400 mPas, measured with a Brookfield viscometer with spindle 4 at 20°C and an angular velocity of 10 rpm.

It is known to those skilled in the art that the product viscosity differs from the viscosity of the reaction mixture during the manufacturing process. This circumstance creates the problem that the viscosity can increase to such a value that the reaction has to be stopped. If the viscosity increases to a certain value during the manufacturing process, mixing is stopped. If the process is carried out in such a way that the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is within the narrow range according to the invention, safe implementation of the process is ensured.

The components are well distributed in the reaction mixture by stirring. When viscosity is monitored, the degree of stability can be observed. If the viscosity is outside the above ranges, especially if the viscosity is higher, gelling will be observed, resulting in a final product that does not have the required flocculant properties.

In a further preferred embodiment, the method is characterized in that step B is carried out by stirring while measuring the torque of a motor-driven agitator. Alternatively, the method is characterized in that step B is carried out by stirring and the torque of a motor-driven agitator is kept below 65 N/cm. If the torque ment is 65 N/cm or more, gel formation is observed, resulting in a final product that does not have the required flocculant properties.

1. i. ein nichtionisches Monomer der Formel (I)
   
   • , wobei
   • R¹ Wasserstoff oder Methyl bedeutet;
   • R² und R³ unabhängig voneinander Wasserstoff, C₁-C₅-Alkyl oder C₁-C₅-Hydroxyalkyl sind,
   • ii. ein kationisches Monomer der Formel (II)
     
   • , wobei
   • R¹ Wasserstoff oder Methyl bedeutet;
   • Z₁O, NH oder NR₄ ist, wobei R₄ C₁-C₄-Alkyl, vorzugsweise Methyl, bedeutet, und
   • Y eine der folgenden Bedeutungen hat
     
   • , wobei
   • Y₀ und Y₁ eine C₁-C₆-Alkylengruppe sind, gegebenenfalls substituiert mit einer oder mehreren Hydroxygruppen, vorzugsweise Ethylen oder Propylen, gegebenenfalls substituiert mit einer Hydroxygruppe;
   • Y₂, Y₃, Y₅, Y₆, Y₇ unabhängig voneinander jeweils C₁-C₆-Alkyl, vorzugsweise Methyl, bedeuten; und
   • Z^- ein Gegenion ist, vorzugsweise ein Halogen, Pseudohalogen, Acetat oder SO₄CH₃ ^-; und iii. ein amphiphiles Monomer der Formeln (III) oder (IV)
     
   • , wobei
   • Z₁O, NH, NR₄ ist, wobei R₄ C¹-C⁴-Alkyl, vorzugsweise Methyl, bedeutet,
   • R₁ Wasserstoff oder Methyl bedeutet,
   • R₈ eine C₁-C₆-Alkylengruppe ist, vorzugsweise Ethylen oder Propylen,
   • R₅ und R₆ unabhängig voneinander jeweils C1-C6-Alkyl sind, vorzugsweise Methyl,
   • R₇ ein C₈-C₃₂-Alkyl ist, gegebenenfalls substituiert mit einer oder mehreren Hydroxygruppen, vorzugsweise C₁₂-C₂₀-Alkyl, gegebenenfalls substituiert mit einer Hydroxygruppe, und
   • Z^- ein Gegenion ist, vorzugsweise ein Halogen, Pseudohalogen, Acetat oder SO₄CH₃ ^-; oder
     
   • ist, wobei
   • Z₁O, NH, NR₄ ist, wobei R₄ C₁-C₄-Alkyl, vorzugsweise Methyl bedeutet,
   • R₁ Wasserstoff oder Methyl bedeutet,
   • R₁₀ Wasserstoff, C₈-C₃₂-Alkyl, C₈-C₃₂-Aryl und/oder C₈-C₃₂-Aralkyl, vorzugsweise C₁₂-C₂₀-Alkyl bedeutet,
   • R₉ eine C₁-C₆-Alkylengruppe ist, vorzugsweise eine Ethylengruppe oder Propylengruppe, und n eine ganze Zahl zwischen 1 und 50, vorzugsweise zwischen 2 und 30, besonders bevorzugt zwischen 3 und 15, besonders bevorzugt zwischen 4 und 8 ist.

In a preferred process, the monomer composition comprises the radically polymerizable monomers selected from the group consisting of one or more of the following:

1. i. a nonionic monomer of the formula (I)
   
   • , where
   • R ¹ represents hydrogen or methyl;
   • R ² and R ³ are independently hydrogen, C ₁ -C ₅ alkyl or C ₁ -C ₅ hydroxyalkyl,
   • ii. a cationic monomer of the formula (II)
     
   • , where
   • R ¹ represents hydrogen or methyl;
   • Z ₁ is O, NH or NR ₄ , where R ₄ is C ₁ -C ₄ alkyl, preferably methyl, and
   • Y has one of the following meanings
     
   • , where
   • Y ₀ and Y ₁ are a C ₁ -C ₆ alkylene group, optionally substituted with one or more hydroxy groups, preferably ethylene or propylene, optionally substituted with a hydroxy group;
   • Y ₂ , Y ₃ , Y ₅ , Y ₆ , Y ₇ each independently represent C ₁ -C ₆ alkyl, preferably methyl; and
   • Z ^- is a counterion, preferably a halogen, pseudohalogen, acetate or SO ₄ CH ₃ ^- ; and iii. an amphiphilic monomer of the formulas (III) or (IV)
     
   • , where
   • Z ₁ is O, NH, NR ₄ , where R ₄ is C ¹ -C ⁴ alkyl, preferably methyl,
   • R ₁ means hydrogen or methyl,
   • R ₈ is a C ₁ -C ₆ alkylene group, preferably ethylene or propylene,
   • R ₅ and R ₆ are each independently C1-C6 alkyl, preferably methyl,
   • R ₇ is a C ₈ -C ₃₂ alkyl, optionally substituted with one or more hydroxy groups, preferably C ₁₂ -C ₂₀ alkyl, optionally substituted with a hydroxy group, and
   • Z ^- is a counterion, preferably a halogen, pseudohalogen, acetate or SO ₄ CH ₃ ^- ; or
     
   • is, where
   • Z ₁ is O, NH, NR ₄ , where R ₄ is C ₁ -C ₄ alkyl, preferably methyl,
   • R ₁ means hydrogen or methyl,
   • R ₁₀ is hydrogen, C ₈ -C ₃₂ alkyl, C ₈ -C ₃₂ aryl and/or C ₈ -C ₃₂ aralkyl, preferably C ₁₂ -C ₂₀ alkyl,
   • R ₉ is a C ₁ -C ₆ alkylene group, preferably an ethylene group or propylene group, and n is an integer between 1 and 50, preferably between 2 and 30, particularly preferably between 3 and 15, particularly preferably between 4 and 8.

In the context of the present invention, a cationic monomer is a monomer that permanently carries a positive charge, or the monomer carries a positive charge through protonation.

According to a preferred embodiment, one or more of the above under i. to iii. mentioned monomers are used as monomers in the monomer composition to be polymerized. A copolymer is preferably polymerized, i.e. two of the above under i. to iii. mentioned monomers are provided for the monomer composition to be polymerized. It is preferred that the monomer composition to be copolymerized is a monomer from point i. and a monomer from point ii. to be provided. In a preferred embodiment, the radically polymerizable monomers comprise a radically polymerizable nonionic monomer according to the general formula (I); and a radically polymerizable cationic monomer according to the general formula (II). These monomers are beneficial for solving the above-mentioned problems.

In a preferred embodiment, the process is characterized in that the monomer composition comprising the free-radically polymerizable monomers comprises at least the nonionic monomer of formula (I) selected from those in which R ₁ is hydrogen or methyl and R ₂ and R ₃ are both hydrogen, hydrogen and C ₁ -C ₃ alkyl, hydrogen and hydroxyethyl or both C ₁ -C ₃ alkyl, and/or comprises the cationic monomer of formula (II) selected from those in in which R ₁ is hydrogen or methyl and Z ₁ is O, NH or NR ₄ , where R ₄ is methyl, Y ₁ is C ₂ -C ₆ alkylene, preferably ethylene or propylene, Y ₅ , Y ₆ and Y ₇ are all methyl are and Z ^- is a halogen.

In a preferred embodiment, the radically polymerizable monomers comprise a radically polymerizable nonionic monomer according to the general formula (I), which is selected from the group consisting of (meth)acrylamide, N-methyl (meth)acrylamide, N,N-dimethyl (meth )acrylamide, N-ethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-methyl-N-ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide and N-hydroxyethyl(meth)acrylamide.

In a further preferred embodiment, the radically polymerizable monomers comprise a radically polymerizable cationic monomer according to the general formula (II), which is selected from the group consisting of trimethylammonium C ₂ -C ₆ alkyl (meth) acrylate halides and trimethy lambmonium C ₂ -C ₆ alkyl (meth) acrylamide halides. In a particularly preferred embodiment, the monomer composition comprises a radically polymerizable monomer which is (meth)acrylamide, together with a radically polymerizable monomer selected from trimethylammonium C ₂ -C ₆ alkyl (meth)acrylate halides, wherein it is in particular an acryloyloxyethyltrimethylammonium halide.

The choice of comonomers used in copolymerization can have an impact on the perfect ratio of polymeric dispersant to dispersed polymer in the polymer dispersion. The preferred comonomers used in the polymerization, together with the preferred ratio, result in favorable stability properties during and after the reaction.

Optionally, the monomer composition may further contain a crosslinker, preferably an ethylenically unsaturated crosslinker, and/or a hydrophobic monomer, preferably a hydrophobic (meth)acrylic acid C _{4 -18} alkyl ester, and/or an ethylenically unsaturated monomer.

In a preferred embodiment, the process is characterized in that the radically polymerizable monomers are selected from the non-ionic monomer of the formula (I) and/or the cationic monomer of the formula (II), the amount of the radically polymerizable monomers being selected from the non-ionic monomer of the formula (I) and/or the cationic monomer of the formula (II) are selected, is between 80 and less than 100% by weight, preferably 85 and 99% by weight, most preferably 90 and 95% by weight, based on the total amount of radically polymerizable monomers, the remainder being selected from the group consisting of any other ethylenically polymerizable monomer, a monomer of formula (III), a monomer of formula (IV) and a bifunctional ethylenically polymerizable monomer.

The sum of the values in% by weight does not have to be 100% by weight, since the monomer composition, i.e. in the reaction mixture, may contain further ethylenically unsaturated monomers (e), which must be taken into account when determining the total amount of monomers . However, the monomer composition preferably consists of the monomers (a) and (b), so that the sum of the two values in% by weight is 100% by weight, i.e. no further monomers are present.

1. (a) mindestens 5 Gew.-%, vorzugsweise mindestens 20 Gew.-% eines radikalisch polymerisierbaren nichtionischen Monomers der allgemeinen Formel (I);
2. (b) mindestens 5 Gew.-%, vorzugsweise mindestens 15 Gew.-%, weiter bevorzugt mindestens 20 Gew.-% oder 25 Gew.-%; vorzugsweise 10 bis 30 Gew.-%, oder 40 bis 60 Gew.-%, weiter bevorzugt 15 bis 25 Gew.-% oder 23 bis 32 Gew.-% oder 45 bis 55 Gew.-%, eines radikalisch polymerisierbaren kationischen Monomers gemäß der allgemeinen Formel (II);
3. (c) gegebenenfalls bis zu 1,25 Gew.-% eines vorzugsweise ethylenisch ungesättigten Vernetzers;
4. (d) gegebenenfalls bis zu 1,25 Gew.-% eines hydrophoben (Meth)acrylsäure-C4-18-Alkylesters; und
5. (e) gegebenenfalls weitere ethylenisch ungesättigte Monomere.

In a preferred embodiment, the monomer composition comprises

1. (a) at least 5% by weight, preferably at least 20% by weight, of a free-radically polymerizable nonionic monomer of the general formula (I);
2. (b) at least 5% by weight, preferably at least 15% by weight, more preferably at least 20% by weight or 25% by weight; preferably 10 to 30% by weight, or 40 to 60% by weight, more preferably 15 to 25% by weight or 23 to 32% by weight or 45 to 55% by weight, of a free-radically polymerizable cationic monomer the general formula (II);
3. (c) optionally up to 1.25% by weight of a preferably ethylenically unsaturated crosslinker;
4. (d) optionally up to 1.25% by weight of a hydrophobic (meth)acrylic acid C4-18 alkyl ester; and
5. (e) optionally further ethylenically unsaturated monomers.

Here too, the sum of the values in% by weight does not have to be 100% by weight, since further ethylenically unsaturated monomers (e) can be contained in the monomer composition, i.e. in the reaction mixture, which are used when determining the total amount of monomers must be taken into account. However, the monomer composition preferably consists of the monomers (a) and (b), so that the sum of the two values in% by weight is 100% by weight, i.e. no further monomers are present.

In the present application, all percentages relating to the monomer composition refer to the total amount of monomers.

According to the invention, the copolymerization is carried out in the presence of a polymeric dispersant.

In a preferred embodiment, the process is characterized in that the polymeric dispersant is selected from the group consisting of a cellulose derivative, polyvinyl acetate, starch, starch derivative, dextran, polyvinylpyrrolidone, polyvinylpyridine, polyethyleneimine, polyamine, polyvinylimidazole, polyvinylsuccinimide, polyvinyl-2-methylsuccinimide, Polyvinyl-1,3-oxazolidone-2, polyvinyl-2-methylimi dazoline, itaconic acid, (meth)acrylic acid, (meth)acrylic acid ester, (meth)acrylic acid amide; preferably a (meth)acryloylamidoalkyltrialkylammonium halide or a (meth)acryloxyalkyltrialkylammonium halide.

Preferably the polymeric dispersant is derived from one or more cationic monomers, most preferably from a single cationic monomer.

In a preferred embodiment, the polymeric dispersant is derived from one or more radically polymerizable, ethylenically unsaturated monomers.

ist, wobei
R¹ Wasserstoff oder Methyl bedeutet;
Z₁O, NH oder NR₄ ist, wobei R₄ C₁-C₄-Alkyl, vorzugsweise Methyl, bedeutet, und Y eines von

ist, wobei
Y₀ und Y₁ eine C₁-C₆-Alkylengruppe sind, gegebenenfalls substituiert mit einer oder mehreren Hydroxygruppen, vorzugsweise Ethylen oder Propylen, gegebenenfalls substituiert mit einer Hydroxygruppe;
Y₂, Y₃, Y₅, Y₆, Y₇ unabhängig voneinander jeweils C₁-C₆-Alkyl, vorzugsweise Methyl, bedeuten; und
Z^- ein Gegenion ist, vorzugsweise ein Halogen, Pseudohalogen, Acetat oder SO₄CH₃ ^-.In a further preferred embodiment, the process is characterized in that the polymeric dispersant is a homopolymer consisting of the cationic monomer of the formula (II)

is, where
R ¹ represents hydrogen or methyl;
Z ₁ is O, NH or NR ₄ , where R ₄ is C ₁ -C ₄ alkyl, preferably methyl, and Y is one of

is, where
Y ₀ and Y ₁ are a C ₁ -C ₆ alkylene group, optionally substituted with one or more hydroxy groups, preferably ethylene or propylene, optionally substituted with a hydroxy group;
Y ₂ , Y ₃ , Y ₅ , Y ₆ , Y ₇ each independently represent C ₁ -C ₆ alkyl, preferably methyl; and
Z ^- is a counterion, preferably a halogen, pseudohalogen, acetate or SO ₄ CH ₃ ^- .

Preferably Y ₁ , Y ₂ and Y ₃ are identical, preferably methyl. In a preferred embodiment, Z ₁ is O or NH, Y ₀ is ethylene or propylene, R ₁ is hydrogen or methyl, and Y ₁ , Y ₂ and Y ₃ are methyl. The cationic monomer according to the general formula (II) can be an ester (Z ₁ = O), such as trimethylammonium ethyl (meth)acrylate (ADAME quat.). However, the cationic monomer according to the general formula (I) is preferably an amide (Z ₁ =NH), in particular trimethylammoniumpropylacrylamide (DIMAPA quat.).

Preferred radically polymerizable cationic monomers according to the general formula (II) are quaternized dialkylaminoalkyl (meth)acrylates or dialkylaminoalkyl (meth)acrylamides with 1 to 3 carbon atoms in the alkyl or alkylene groups, particularly preferably the methyl chloride-quaternized ammonium salt of dimethylaminomethyl (meth )acrylate, dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, diethylamino-methyl (meth)acrylate, diethylamino-ethyl (meth)acrylate, diethylamino-propyl (meth)acrylate, dimethylamino-methyl (meth)acrylamide, dimethylaminoEthyl( meth)acrylamide, dimethylamino-propyl (meth) acrylamide, diethylamino-methyl (meth) acrylamide, diethylamino-ethyl (meth) acrylamide, diethylamino-propyl (meth) acrylamide.

Quaternized dimethylaminoethyl acrylate and dimethylaminopropylacrylamide are particularly preferred. Quaternization can be done with dimethyl sulfate, diethyl sulfate, methyl chloride or ethyl chloride. In a preferred embodiment, the monomers are quaternized with methyl chloride.

In a preferred embodiment, the polymeric dispersant is a homopolymer of trimethylammonium propylacrylamide (DIMAPA quat).

Preferably, the polymeric dispersant is derived from a monomer composition containing a cationic monomer selected from the group consisting of (alk)acrylamidoalkyltrialkylammonium halides (e.g., trimethylammonium alkyl (meth)acrylamide halides), (alk)acryloyloxyalkyltrialkylammonium halides (e.g., trimethylammonium alkyl- (meth)acrylate halides), alkenyltrialkylammonium halides and dialkenyldialkylammonium halides (e.g. diallyldialkylammonium halides). More preferably, the polymeric dispersant is a cationic polymer derived from a monomer composition containing a cationic monomer selected from the group consisting of trimethylammonium alkyl (meth)acrylate halides, trimethylammonium alkyl (meth)acrylamide halides and diallyldialkyl ammonium halides. Preferably, the aforementioned cationic monomers contain 6 to 25 carbon atoms, more preferably 7 to 20 carbon atoms, most preferably 7 to 15 carbon atoms and especially 8 to 12 carbon atoms.

In a preferred embodiment, the polymeric dispersant is derived from a dialkenyl dialkylammonium halide, preferably a diallyldimethyl ammonium halide (DADMAC).

According to a preferred embodiment, the process is characterized in that the polymeric dispersant is a homopolymer of a (meth)acryloylamidopropyltrimethylammonium salt or a (meth)acryloyloxyethyltrimethylammonium salt.

In this application, the halide may be any acceptable halide such as chloride, bromide or iodide; the counterions of the salts may be any acceptable counterions such as halides, methosulfate, sulfate or others.

According to a preferred embodiment, the process is characterized in that the polymeric dispersant has a weight-average molecular weight Mw, determined by gel permeation chromatography (GPC), of 60,000 to 400,000 g/mol, preferably 70,000 to 350,000 g/mol, even more preferably 80,000 to less than 230,000, most preferably 85,000 to less than 150,000 g/mol.

The invention is particularly efficient if the process is characterized in that the total weight of the polymeric dispersant, based on the total weight of the polymer dispersion, is in the range of 10 to 28% by weight, preferably 12 to 26% by weight, more preferably 14 to 24% by weight, even more preferably 16 to 22% by weight.

According to a further embodiment, the process is characterized in that the total weight of the polymeric dispersant, based on the total weight of the polymer dispersion, is between 18 and 26% by weight, preferably 19 to 25% by weight. These preferred embodiments are particularly advantageous when the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in the range of 1:1 to 1:0.9.

In a preferred embodiment, the method is carried out by adding in step B) the reaction mixture successively or simultaneously at least a part of a predetermined amount of a redox initiator system which comprises an oxidizing agent and a reducing agent, at least a part of a predetermined amount of a first radical initiator and at least a part of a predetermined amount of a second radical initiator is added.

According to a preferred embodiment, the method comprises the step

C) reducing the residual monomer content by adding the remainder of the predetermined amount of the redox initiator system, the remainder of the predetermined amount of the first radical initiator and/or the remainder of the predetermined amount of the second radical initiator and/or a third radical initiator to the reaction mixture.

The addition of the initiators mentioned enables the monomer to be removed so that they have no adverse effects on the stability of the dispersion obtained.

According to a preferred embodiment, the process is characterized in that the charge density of the dispersed polymer is 5 to 40 mol%, preferably 8 to 35 mol%, more preferably 10 to 30 mol%, most preferably 12 to 28 mol% . While the charge density of the polymeric dispersant is preferably 100 mol%, that is, the polymeric dispersant is a 100 mol% polyelectrolyte, the dispersed polymer obtained by the copolymerization in step B) is partially one Polyelectrolyte. The charge density is calculated from the monomer components, whereby the number of monomer components that carry a formal charge per total number of monomer components results in the molar proportion of the charge density. The charge density is therefore calculated from the monomeric components of the dispersed polymer.

If the charge density is in the above-mentioned range, the positive effect in terms of stability and viscosity is increased. In particular, the combination of the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion and the charge density solves the problems mentioned above. Without being bound by theory, one might assume that the dispersibility of the polymeric dispersant depends on this ratio along with the charge density property.

1. a) ein polymeres Dispergiermittel und
2. b) ein dispergiertes Polymer, das von einer Monomerzusammensetzung abgeleitet ist, die radikalisch polymerisierbare Monomere umfasst, wobei die radikalisch polymerisierbaren Monomere aus der Gruppe ausgewählt sind, die aus einem oder mehreren nicht-ionischen ethylenisch ungesättigten Monomeren, einem kationischen ethylenisch ungesättigten Monomer und einem amphiphilen ethylenisch ungesättigten Monomer besteht;

wobei das Verhältnis des polymeren Dispergiermittels zu dem dispergierten Polymer in der Polymerdispersion im Bereich von 0,65 : 1 bis 0,98 : 1, bevorzugt im Bereich von 0,7 : 1 bis 0,95 : 1, noch bevorzugter im Bereich von 0,72 : 1 bis weniger als 0,92 : 1, noch bevorzugter im Bereich von 0,74 : 1 bis 0,9 : 1, insbesondere im Bereich von 0,76 : 1 bis 0,88 : 1 liegt.The objects on which the invention is based are further solved by the subject matter of claim 13. Thus, according to a second aspect, the invention relates to a polymer dispersion comprising

1. a) a polymeric dispersant and
2. b) a dispersed polymer derived from a monomer composition comprising radically polymerizable monomers, wherein the radically polymerizable monomers are selected from the group consisting of one or more nonionic ethylenically unsaturated monomers, a cationic ethylenically unsaturated monomer and an amphiphilic ethylenically unsaturated monomer;

wherein the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in the range of 0.65:1 to 0.98:1, preferably in the range of 0.7:1 to 0.95:1, more preferably in the range of 0 .72:1 to less than 0.92:1, more preferably in the range of 0.74:1 to 0.9:1, in particular in the range of 0.76:1 to 0.88:1.

1. A) Bereitstellen einer Reaktionsmischung in einem wässrigen Medium, umfassend
   1. a) ein polymeres Dispergiermittel und
   2. b) eine Monomerzusammensetzung, die radikalisch polymerisierbare Monomere umfasst, wobei die radikalisch polymerisierbaren Monomere aus der Gruppe ausgewählt sind, die aus einem oder mehreren nichtionischen ethylenisch ungesättigten Monomeren, einem kationischen ethylenisch ungesättigten Monomer und einem amphiphilen ethylenisch ungesättigten Monomer besteht;
2. B) Unterziehen der Monomerzusammensetzung in der Reaktionsmischung einer radikalischen Polymerisation, um ein dispergiertes Polymer zu synthetisieren und die Polymerdispersion zu bilden,

wobei das Verhältnis des polymeren Dispergiermittels zum dispergierten Polymer in der Polymerdispersion im Bereich von 0,65 : 1 bis 0,98 : 1, bevorzugt im Bereich von 0,7 : 1 bis 0,95 : 1, noch bevorzugter im Bereich von 0,72 : 1 bis weniger als 0,92 : 1, noch bevorzugter im Bereich von 0,74 : 1 bis 0,9 : 1, insbesondere im Bereich von 0,76 : 1 bis 0,88 : 1 liegt.The problems on which the invention is based are further solved by the subject matter of claim 14. Thus, according to a third aspect, the invention relates to a polymer dispersion obtained by a process for producing the polymer dispersion according to the invention, comprising the following steps

1. A) Providing a reaction mixture in an aqueous medium, comprising
   1. a) a polymeric dispersant and
   2. b) a monomer composition comprising radically polymerizable monomers, wherein the radically polymerizable monomers are selected from the group consisting of one or more nonionic ethylenically unsaturated monomers, a cationic ethylenically unsaturated monomer and an amphiphilic ethylenically unsaturated monomer;
2. B) subjecting the monomer composition in the reaction mixture to radical polymerization to synthesize a dispersed polymer and form the polymer dispersion,

wherein the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in the range of 0.65:1 to 0.98:1, preferably in the range of 0.7:1 to 0.95:1, even more preferably in the range of 0, 72:1 to less than 0.92:1, more preferably in the range of 0.74:1 to 0.9:1, in particular in the range of 0.76:1 to 0.88:1.

• - als Flockungshilfsmittel bei der Sedimentation, Flotation oder Filtration von Feststoffen
• - als Verdickungsmittel,
• - zur Kontrolle von Verunreinigungen,
• - als Trockenfestigkeitsmittel, Retentionsmittel oder Entwässerungshilfe bei der Papierherstellung.

The problems on which the invention is based are further solved by the subject matter of claim 15. According to a second aspect, the invention relates to the use of the polymer dispersion according to the invention

• - as a flocculant in the sedimentation, flotation or filtration of solids
• - as a thickener,
• - to control contamination,
• - as a dry strength agent, retention agent or drainage aid in paper production.

Features relating to preferred embodiments of the first aspect of the present invention and which are disclosed solely in relation to the first aspect of the invention also represent preferred embodiments of the second and third embodiments.

Embodiments (A) to (H), which represent particularly preferred embodiments, are disclosed below by way of example.

(A)

1. A) Bereitstellen einer Reaktionsmischung in einem wässrigen Medium, umfassend
   1. a) ein polymeres Dispersionsmittel und
   2. b) eine Monomerzusammensetzung, die radikalisch polymerisierbare Monomere umfasst, wobei die radikalisch polymerisierbaren Monomere aus der Gruppe ausgewählt sind, die aus einem oder mehreren nichtionischen ethylenisch ungesättigten Monomeren, einem kationischen ethylenisch ungesättigten Monomer und einem amphiphilen ethylenisch ungesättigten Monomer besteht;
2. B) Unterziehen der Monomerzusammensetzung in der Reaktionsmischung einer radikalischen Polymerisation, um ein dispergiertes Polymer zu synthetisieren und die Polymerdispersion zu bilden,

wobei das Verhältnis des polymeren Dispergiermittels zu dem dispergierten Polymer in der Polymerdispersion im Bereich von 0,65 : 1 bis 0,98 : 1, bevorzugt im Bereich von 0,7 : 1 bis 0,95 : 1, noch bevorzugter im Bereich von 0,72 : 1 bis weniger als 0,92 : 1, noch bevorzugter im Bereich von 0,74 : 1 bis 0,9 : 1, insbesondere im Bereich von 0,76 : 1 bis 0. 88 : 1 liegt; wobei die Monomerzusammensetzung, die die radikalisch polymerisierbaren Monomere umfasst, mindestens das nichtionische Monomer der Formel (I) umfasst, das aus denjenigen ausgewählt ist, in denen R₁ Wasserstoff oder Methyl bedeutet und R₂ und R₃ beide Wasserstoff, Wasserstoff und C1-C3-Alkyl, Wasserstoff und Hydroxyethyl, oder beide C1-C3-Alkyl sind, und/oder das kationische Monomer der Formel (II) umfasst, das aus denjenigen ausgewählt ist, in denen R₁ Wasserstoff oder Methyl bedeutet und Z₁ O, NH oder NR₄ ist, wobei R₄ Methyl bedeutet, Y₁ C₂-C₆-Alkylen, vorzugsweise Ethylen oder Propylen ist, Y₅, Y₆ und Y₇ alle Methyl sind und Z^- ein Halogen ist.Process for producing a polymer dispersion, comprising the steps

1. A) Providing a reaction mixture in an aqueous medium, comprising
   1. a) a polymeric dispersant and
   2. b) a monomer composition comprising radically polymerizable monomers, wherein the radically polymerizable monomers are selected from the group consisting of one or more nonionic ethylenically unsaturated monomers, a cationic ethylenically unsaturated monomer and an amphiphilic ethylenically unsaturated monomer;
2. B) subjecting the monomer composition in the reaction mixture to radical polymerization to synthesize a dispersed polymer and form the polymer dispersion,

wherein the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in the range of 0.65:1 to 0.98:1, preferably in the range of 0.7:1 to 0.95:1, more preferably in the range of 0 .72:1 to less than 0.92:1, more preferably in the range of 0.74:1 to 0.9:1, in particular in the range of 0.76:1 to 0.88:1; wherein the monomer composition comprising the radically polymerizable monomers comprises at least the nonionic monomer of formula (I) selected from those in which R ₁ is hydrogen or methyl and R ₂ and R ₃ are both hydrogen, hydrogen and C1-C3 -alkyl, hydrogen and hydroxyethyl, or both are C1-C3 alkyl, and/or the cationic monomer of formula (II) selected from those in which R ₁ is hydrogen or methyl and Z ₁ is O, NH or NR ₄ is where R ₄ is methyl, Y ₁ is C ₂ -C ₆ alkylene, preferably ethylene or propylene, Y ₅ , Y ₆ and Y ₇ are all methyl and Z ^- is a halogen.

(B)

1. A) Bereitstellen einer Reaktionsmischung in einem wässrigen Medium, umfassend
   1. a) ein polymeres Dispersionsmittel und
   2. b) eine Monomerzusammensetzung, die radikalisch polymerisierbare Monomere umfasst, wobei die radikalisch polymerisierbaren Monomere aus der Gruppe ausgewählt sind, die aus einem oder mehreren nicht-ionischen ethylenisch ungesättigten Monomeren, einem kationischen ethylenisch ungesättigten Monomer und einem amphiphilen ethylenisch ungesättigten Monomer besteht;
2. B) Unterziehen der Monomerzusammensetzung in der Reaktionsmischung einer radikalischen Polymerisation, um ein dispergiertes Polymer zu synthetisieren und die Polymerdispersion zu bilden,

wobei das Verhältnis des polymeren Dispergiermittels zu dem dispergierten Polymer in der Polymerdispersion im Bereich von 0,65 : 1 bis 0,98 : 1, bevorzugt im Bereich von 0,7 : 1 bis 0,95 : 1, noch bevorzugter im Bereich von 0,72 : 1 bis weniger als 0,92 : 1, noch bevorzugter im Bereich von 0,74 : 1 bis 0,9 : 1, insbesondere im Bereich von 0,76 : 1 bis 0,88 : 1 liegt;
wobei die Monomerzusammensetzung, die die radikalisch polymerisierbaren Monomere umfasst, mindestens das nichtionische Monomer der Formel (I) umfasst, das aus denjenigen ausgewählt ist, in denen R₁ Wasserstoff oder Methyl bedeutet und R₂ und R₃ beide Wasserstoff, Wasserstoff und C₁-C₃-Alkyl, Wasserstoff und Hydroxyethyl sind, oder beide C₁-C₃-Alkyl sind, und/oder das kationische Monomer der Formel (II) ausgewählt ist aus denen, in denen R₁ Wasserstoff oder Methyl bedeutet und Z₁ O, NH oder NR₄ ist, wobei R₄ Methyl bedeutet, Y₁ C2-C6-Alkylen, vorzugsweise Ethylen oder Propylen ist, Y₅, Y₆ und Y₇ alle Methyl sind und Z^- ein Halogen ist,
und wobei das polymere Dispergiermittel ausgewählt ist aus der Gruppe bestehend aus einem Cellulosederivat, Polyvinylacetat, Stärke, Stärkederivat, Dextran, Polyvinylpyrrolidon, Polyvinylpyridin, Polyethylenimin, Polyamin, Polyvinylimidazol, Polyvinylsuccinimid, Polyvinyl-2-methylsuccinimid, Polyvinyl-1,3-oxazolidon-2, Polyvinyl-2-methylimidazolin, Itaconsäure, (Meth)acrylsäure, (Meth)acrylsäureester, (Meth)acrylsäureamid; vorzugsweise ein (Meth)acryloylamidoalkyltrialkylammoniumhalogenid oder ein
(Meth)acryloxyalkyltrialkylammoniumhalogenid ist.Process for producing a polymer dispersion, comprising the steps

1. A) Providing a reaction mixture in an aqueous medium, comprising
   1. a) a polymeric dispersant and
   2. b) a monomer composition comprising radically polymerizable monomers, wherein the radically polymerizable monomers are selected from the group consisting of one or more nonionic ethylenically unsaturated monomers, a cationic ethylenically unsaturated monomer and an amphiphilic ethylenically unsaturated monomer;
2. B) subjecting the monomer composition in the reaction mixture to radical polymerization to synthesize a dispersed polymer and form the polymer dispersion,

wherein the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in the range of 0.65:1 to 0.98:1, preferably in the range of 0.7:1 to 0.95:1, more preferably in the range of 0 .72:1 to less than 0.92:1, more preferably in the range of 0.74:1 to 0.9:1, in particular in the range of 0.76:1 to 0.88:1;
wherein the monomer composition comprising the radically polymerizable monomers comprises at least the nonionic monomer of formula (I) selected from those in which R ₁ is hydrogen or methyl and R ₂ and R ₃ are both hydrogen, hydrogen and C ₁ - are C ₃ alkyl, hydrogen and hydroxyethyl, or both are C ₁ -C ₃ alkyl, and/or the cationic monomer of formula (II) is selected from those in which R ₁ is hydrogen or methyl and Z _{1 is} O, NH or NR ₄ , where R ₄ is methyl, Y ₁ is C2-C6 alkylene, preferably ethylene or propylene, Y ₅ , Y ₆ and Y ₇ are all methyl and Z ^- is a halogen,
and wherein the polymeric dispersant is selected from the group consisting of a cellulose derivative, polyvinyl acetate, starch, starch derivative, dextran, polyvinylpyrrolidone, polyvinylpyridine, polyethyleneimine, polyamine, polyvinylimidazole, polyvinylsuccinimide, polyvinyl-2-methylsuccinimide, polyvinyl-1,3-oxazolidone-2 , Polyvinyl-2-methylimidazoline, itaconic acid, (meth)acrylic acid, (meth)acrylic acid ester, (meth)acrylic acid amide; preferably a (meth)acryloylamidoalkyltrialkylammonium halide or a
(Meth)acryloxyalkyltrialkylammonium halide is.

(C)

1. A) Bereitstellen einer Reaktionsmischung in einem wässrigen Medium, umfassend
   1. a) ein polymeres Dispersionsmittel und
   2. b) eine Monomerzusammensetzung, die radikalisch polymerisierbare Monomere umfasst, wobei die radikalisch polymerisierbaren Monomere aus der Gruppe ausgewählt sind, die aus einem oder mehreren nicht-ionischen ethylenisch ungesättigten Monomeren, einem kationischen ethylenisch ungesättigten Monomer und einem amphiphilen ethylenisch ungesättigten Monomer besteht;
2. B) Unterziehen der Monomerzusammensetzung in der Reaktionsmischung einer radikalischen Polymerisation, um ein dispergiertes Polymer zu synthetisieren und die Polymerdispersion zu bilden,

wobei das Verhältnis des polymeren Dispergiermittels zu dem dispergierten Polymer in der Polymerdispersion im Bereich von 0,65 : 1 bis 0,98 : 1, bevorzugt im Bereich von 0,7 : 1 bis 0,95 : 1, noch bevorzugter im Bereich von 0,72 : 1 bis weniger als 0,92 : 1, noch bevorzugter im Bereich von 0,74 : 1 bis 0,9 : 1, insbesondere im Bereich von 0,76 : 1 bis 0,88 : 1 liegt;
wobei die radikalisch polymerisierbaren Monomere ein radikalisch polymerisierbares nichtionisches Monomer gemäß der allgemeinen Formel (I), das ausgewählt ist aus der Gruppe bestehend aus (Meth)acrylamid, N-Methyl(meth)acrylamid, N,N-Dimethyl(meth)acrylamid, N-Ethyl(meth)acrylamid, N,N-Diethyl(meth)acrylamid, N-Methyl-N-ethyl(meth)acrylamid, N-Isopropyl(meth)acrylamid und N-Hydroxyethyl(meth)acrylamid und ein radikalisch polymerisierbares kationisches Monomer gemäß der allgemeinen Formel (II) umfassen, das ausgewählt ist aus der Gruppe bestehend aus Trimethylammonium-C2-C6-alkyl(meth)acrylathalogeniden und Trimethylammonium-C2-C6-alkyl(meth)acrylamidhalogeniden,
und wobei das polymere Dispergiermittel ein Homopolymer aus einem (Meth)acryloylamidopropyl-Trimethylammoniumsalz oder einem (Meth)acryloyl-Oxyethyl-Trimethylammoniumsalz ist.Process for producing a polymer dispersion, comprising the steps

1. A) Providing a reaction mixture in an aqueous medium, comprising
   1. a) a polymeric dispersant and
   2. b) a monomer composition comprising radically polymerizable monomers, wherein the radically polymerizable monomers are selected from the group consisting of one or more nonionic ethylenically unsaturated monomers, a cationic ethylenically unsaturated monomer and an amphiphilic ethylenically unsaturated monomer;
2. B) subjecting the monomer composition in the reaction mixture to radical polymerization to synthesize a dispersed polymer and form the polymer dispersion,

wherein the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in the range of 0.65:1 to 0.98:1, preferably in the range of 0.7:1 to 0.95:1, more preferably in the range of 0 .72:1 to less than 0.92:1, more preferably in the range of 0.74:1 to 0.9:1, in particular in the range of 0.76:1 to 0.88:1;
where the radically polymerizable monomers are a radically polymerizable nonionic monomer according to the general formula (I), which is selected from the group consisting of (meth)acrylamide, N-methyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N -Ethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N-methyl-N-ethyl (meth)acrylamide, N-isopropyl (meth)acrylamide and N-hydroxyethyl (meth)acrylamide and a radically polymerizable cationic monomer according to the general formula (II), which is selected from the group consisting of trimethylammonium C2-C6 alkyl (meth) acrylate halides and trimethyl ammonium C2-C6 alkyl (meth) acrylamide halides,
and wherein the polymeric dispersant is a homopolymer of a (meth)acryloylamidopropyl trimethyl ammonium salt or a (meth)acryloyl oxyethyl trimethyl ammonium salt.

(D)

1. A) Bereitstellen einer Reaktionsmischung in einem wässrigen Medium, umfassend
   1. a) ein polymeres Dispersionsmittel und
   2. b) eine Monomerzusammensetzung, die radikalisch polymerisierbare Monomere umfasst, wobei die radikalisch polymerisierbaren Monomere aus der Gruppe ausgewählt sind, die aus einem oder mehreren nichtionischen ethylenisch ungesättigten Monomeren, einem kationischen ethylenisch ungesättigten Monomer und einem amphiphilen ethylenisch ungesättigten Monomer besteht;
2. B) Unterziehen der Monomerzusammensetzung in der Reaktionsmischung einer radikalischen Polymerisation, um ein dispergiertes Polymer zu synthetisieren und die Polymerdispersion zu bilden,

wobei das Verhältnis des polymeren Dispergiermittels zu dem dispergierten Polymer in der Polymerdispersion im Bereich von 0,65 : 1 bis 0,98 : 1, bevorzugt im Bereich von 0,7 : 1 bis 0,95 : 1, noch bevorzugter im Bereich von 0,72 : 1 bis weniger als 0,92 : 1, noch bevorzugter im Bereich von 0,74 : 1 bis 0,9 : 1, insbesondere im Bereich von 0,76 : 1 bis 0,88 : 1 liegt; wobei die Monomerzusammensetzung ein radikalisch polymerisierbares Monomer, bei dem es sich um (Meth)acrylamid handelt, zusammen mit einem radikalisch polymerisierbaren Monomer, das aus Trimethylammonium-C2-C6-alkyl(meth)acrylathalogeniden ausgewählt ist, wobei es sich vorzugsweise um ein Acryloyloxyethyltrimethylammoniumhalogenid handelt, umfasst,
und wobei das polymere Dispergiermittel ein Homopolymer aus einem (Meth)acryloylamidopropyltrimethylammoniumsalz oder einem (Meth)acryloyloxyethyltrimethylammoniumsalz ist.A process for producing a polymer dispersion, comprising the following steps

1. A) Providing a reaction mixture in an aqueous medium, comprising
   1. a) a polymeric dispersant and
   2. b) a monomer composition comprising radically polymerizable monomers, wherein the radically polymerizable monomers are selected from the group consisting of one or more nonionic ethylenically unsaturated monomers, a cationic ethylenically unsaturated monomer and an amphiphilic ethylenically unsaturated monomer;
2. B) subjecting the monomer composition in the reaction mixture to radical polymerization to synthesize a dispersed polymer and form the polymer dispersion,

wherein the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in the range of 0.65:1 to 0.98:1, preferably in the range of 0.7:1 to 0.95:1, more preferably in the range of 0 .72:1 to less than 0.92:1, more preferably in the range of 0.74:1 to 0.9:1, in particular in the range of 0.76:1 to 0.88:1; wherein the monomer composition is a radically polymerizable monomer which is (meth)acrylamide together with a radically polymerizable monomer selected from trimethylammonium C2-C6 alkyl (meth)acrylate halides, which is preferably an acryloyloxyethyltrimethylammonium halide , includes,
and wherein the polymeric dispersant is a homopolymer of a (meth)acryloylamidopropyltrimethylammonium salt or a (meth)acryloyloxyethyltrimethylammonium salt.

(E)

1. A) Bereitstellen einer Reaktionsmischung in einem wässrigen Medium, umfassend
   1. a) ein polymeres Dispersionsmittel und
   2. b) eine Monomerzusammensetzung, die radikalisch polymerisierbare Monomere umfasst, wobei die radikalisch polymerisierbaren Monomere aus der Gruppe ausgewählt sind, die aus einem oder mehreren nichtionischen ethylenisch ungesättigten Monomeren, einem kationischen ethylenisch ungesättigten Monomer und einem amphiphilen ethylenisch ungesättigten Monomer besteht;
2. B) Unterziehen der Monomerzusammensetzung in der Reaktionsmischung einer radikalischen Polymerisation, um ein dispergiertes Polymer zu synthetisieren und die Polymerdispersion zu bilden,

wobei das Verhältnis des polymeren Dispergiermittels zu dem dispergierten Polymer in der Polymerdispersion im Bereich von 0,65 : 1 bis 0,98 : 1, bevorzugt im Bereich von 0,7 : 1 bis 0,95 : 1, noch bevorzugter im Bereich von 0,72 : 1 bis weniger als 0,92 : 1, noch bevorzugter im Bereich von 0,74 : 1 bis 0,9 : 1, insbesondere im Bereich von 0,76 : 1 bis 0,88 : 1 liegt; wobei die radikalisch polymerisierbaren Monomere ein radikalisch polymerisierbares nichtionisches Monomer gemäß der allgemeinen Formel (I), das ausgewählt ist aus der Gruppe bestehend aus (Meth)acrylamid, N-Methyl(meth)acrylamid, N,N-Dimethyl(meth)acrylamid, N-Ethyl(meth)acrylamid, N,N-Diethyl(meth)acrylamid, N-Methyl-N-ethyl(meth)acrylamid, N-Isopropyl(meth)acrylamid und N-Hydroxyethyl(meth)acrylamid und ein radikalisch polymerisierbares kationisches Monomer gemäß der allgemeinen Formel (II) umfassen, das ausgewählt ist aus der Gruppe bestehend aus Trimethylammonium-C2-C6-alkyl(meth)-acrylathalogeniden und Trimethylammonium-C2-C6-alkyl(meth)acrylamidhalogeniden,
wobei das polymere Dispergiermittel ein Homopolymer aus einem (Meth)acryloylamido-propyl-Trimethylammoniumsalz oder einem (Meth)acryloyl-Oxyethyl-Trimethylammoniumsalz ist,
wobei Schritt B durch Rühren durchgeführt wird und die Viskosität während der Polymerisation 1.800 mPas bis 4.000 mPas, vorzugsweise 2.000 mPas bis 3.600 mPas, noch bevorzugter 2.200 mPas bis 3.400 mPas beträgt, gemessen mit einem Brookfield-Viskosimeter mit Spindel 4 bei 20°C und einer Winkelgeschwindigkeit von 10 U/min.Process for producing a polymer dispersion, comprising the steps

1. A) Providing a reaction mixture in an aqueous medium, comprising
   1. a) a polymeric dispersant and
   2. b) a monomer composition comprising radically polymerizable monomers, wherein the radically polymerizable monomers are selected from the group consisting of one or more nonionic ethylenically unsaturated monomers, a cationic ethylenically unsaturated monomer and an amphiphilic ethylenically unsaturated monomer;
2. B) subjecting the monomer composition in the reaction mixture to radical polymerization to synthesize a dispersed polymer and form the polymer dispersion,

wherein the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in the range of 0.65:1 to 0.98:1, preferably in the range of 0.7:1 to 0.95:1, more preferably in the range of 0 .72:1 to less than 0.92:1, more preferably in the range of 0.74:1 to 0.9:1, in particular in the range of 0.76:1 to 0.88:1; where the radically polymerizable monomers are a radically polymerizable nonionic monomer according to the general formula (I), which is selected from the group consisting of (meth)acrylamide, N-methyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N -Ethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N-methyl-N-ethyl (meth)acrylamide, N-isopropyl (meth)acrylamide and N-hydroxyethyl (meth)acrylamide and a radically polymerizable cationic monomer according to the general formula (II), which is selected from the group consisting of trimethylammonium C2-C6 alkyl (meth) acrylate halides and trimethylammonium C2-C6 alkyl (meth) acrylamide halides,
wherein the polymeric dispersant is a homopolymer of a (meth)acryloylamido-propyl-trimethylammonium salt or a (meth)acryloyl-oxyethyl-trimethylammonium salt,
wherein step B is carried out by stirring and the viscosity during the polymerization is 1,800 mPas to 4,000 mPas, preferably 2,000 mPas to 3,600 mPas, more preferably 2,200 mPas to 3,400 mPas, measured with a Brookfield viscometer with spindle 4 at 20 ° C and a Angular speed of 10 rpm.

(F)

1. A) Bereitstellen einer Reaktionsmischung in einem wässrigen Medium, umfassend
   1. a) ein polymeres Dispersionsmittel und
   2. b) eine Monomerzusammensetzung, die radikalisch polymerisierbare Monomere umfasst, wobei die radikalisch polymerisierbaren Monomere aus der Gruppe ausgewählt sind, die aus einem oder mehreren nichtionischen ethylenisch ungesättigten Monomeren, einem kationischen ethylenisch ungesättigten Monomer und einem amphiphilen ethylenisch ungesättigten Monomer besteht;
2. B) Unterziehen der Monomerzusammensetzung in der Reaktionsmischung einer radikalischen Polymerisation, um ein dispergiertes Polymer zu synthetisieren und die Polymerdispersion zu bilden,

wobei das Verhältnis des polymeren Dispergiermittels zu dem dispergierten Polymer in der Polymerdispersion im Bereich von 0,65 : 1 bis 0,98 : 1, bevorzugt im Bereich von 0,7 : 1 bis 0,95 : 1, noch bevorzugter im Bereich von 0,72 : 1 bis weniger als 0,92 : 1, noch bevorzugter im Bereich von 0,74 : 1 bis 0,9 : 1, insbesondere im Bereich von 0,76 : 1 bis 0,88 : 1 liegt; wobei die radikalisch polymerisierbaren Monomere ein radikalisch polymerisierbares nichtionisches Monomer gemäß der allgemeinen Formel (I) umfassen, das ausgewählt ist aus der Gruppe bestehend aus (Meth)acrylamid, N-Methyl(meth)acrylamid, N,N-Dimethyl(meth)acrylamid, N-Ethyl(meth)acrylamid, N,N-Diethyl(meth)acrylamid, N-Methyl-N-ethyl(meth)acrylamid, N-Isopropyl(meth)acrylamid und N-Hydroxyethyl(meth)acrylamid und ein radikalisch polymerisierbares kationisches Monomer gemäß der allgemeinen Formel (II), das ausgewählt ist aus der Gruppe bestehend aus Trimethylammonium-C2-C6-alkyl(meth)acrylathalogeniden und Trimethylammonium-C2-C6-alkyl(meth)acrylamid-halogeniden,
wobei das polymere Dispergiermittel ein Homopolymer aus einem (Meth)acryloylamido-propyl-Trimethylammoniumsalz oder einem (Meth)acryloyl-Oxyethyl-Trimethylammoniumsalz ist,
wobei die Ladungsdichte des dispergierten Polymers 5 bis 40 Mol-%, vorzugsweise 8 bis 35 Mol-%, noch bevorzugter 10 bis 30 Mol-%, am meisten bevorzugt 12 bis 28 Mol-% beträgt.Process for producing a polymer dispersion, comprising the steps

1. A) Providing a reaction mixture in an aqueous medium, comprising
   1. a) a polymeric dispersant and
   2. b) a monomer composition comprising radically polymerizable monomers, wherein the radically polymerizable monomers are selected from the group consisting of one or more nonionic ethylenically unsaturated monomers, a cationic ethylenically unsaturated monomer and an amphiphilic ethylenically unsaturated monomer;
2. B) subjecting the monomer composition in the reaction mixture to radical polymerization to synthesize a dispersed polymer and form the polymer dispersion,

wherein the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in the range of 0.65:1 to 0.98:1, preferably in the range of 0.7:1 to 0.95:1, more preferably in the range of 0 .72:1 to less than 0.92:1, more preferably in the range of 0.74:1 to 0.9:1, in particular in the range of 0.76:1 to 0.88:1; wherein the radically polymerizable monomers comprise a radically polymerizable nonionic monomer according to the general formula (I), which is selected from the group consisting of (meth)acrylamide, N-methyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-ethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-methyl-N-ethyl (meth) acrylamide, N-isopropyl (meth) acrylamide and N-hydroxyethyl (meth) acrylamide and a radically polymerizable cationic Monomer according to the general formula (II), which is selected from the group consisting of trimethylammonium C2-C6 alkyl (meth) acrylate halides and trimethyl ammonium C2-C6 alkyl (meth) acrylamide halides,
wherein the polymeric dispersant is a homopolymer of a (meth)acryloylamido-propyl-trimethylammonium salt or a (meth)acryloyl-oxyethyl-trimethylammonium salt,
wherein the charge density of the dispersed polymer is 5 to 40 mol%, preferably 8 to 35 mol%, more preferably 10 to 30 mol%, most preferably 12 to 28 mol%.

(G)

1. A) Bereitstellen einer Reaktionsmischung in einem wässrigen Medium, umfassend
   1. a) ein polymeres Dispersionsmittel und
   2. b) eine Monomerzusammensetzung, die radikalisch polymerisierbare Monomere umfasst, wobei die radikalisch polymerisierbaren Monomere aus der Gruppe ausgewählt sind, die aus einem oder mehreren nichtionischen ethylenisch ungesättigten Monomeren, einem kationischen ethylenisch ungesättigten Monomer und einem amphiphilen ethylenisch ungesättigten Monomer besteht;
2. B) Unterziehen der Monomerzusammensetzung in der Reaktionsmischung einer radikalischen Polymerisation, um ein dispergiertes Polymer zu synthetisieren und die Polymerdispersion zu bilden,

wobei das Verhältnis des polymeren Dispergiermittels zu dem dispergierten Polymer in der Polymerdispersion im Bereich von 0,65 : 1 bis 0,98 : 1, bevorzugt im Bereich von 0,7 : 1 bis 0,95 : 1, noch bevorzugter im Bereich von 0,72 : 1 bis weniger als 0,92 : 1, noch bevorzugter im Bereich von 0,74 : 1 bis 0,9 : 1, insbesondere im Bereich von 0,76 : 1 bis 0,88 : 1 liegt; wobei die radikalisch polymerisierbaren Monomere ein radikalisch polymerisierbares nichtionisches Monomer gemäß der allgemeinen Formel (I), das ausgewählt ist aus der Gruppe bestehend aus (Meth)acrylamid, N-Methyl(meth)acrylamid, N,N-Dimethyl(meth)acrylamid, N-Ethyl(meth)acrylamid, N,N-Diethyl(meth)acrylamid, N-Methyl-N-ethyl(meth)acrylamid, N-Isopropyl(meth)acrylamid und N-Hydroxyethyl(meth)acrylamid und ein radikalisch polymerisierbares kationisches Monomer gemäß der allgemeinen Formel (II) umfassen, das ausgewählt ist aus der Gruppe bestehend aus Trimethylammonium-C2-C6-alkyl(meth)acrylathalogeniden und Trimethylammonium-C2-C6-alkyl(meth)acrylamidhalogeniden,
wobei das polymere Dispergiermittel ein Homopolymer aus einem
(Meth)acryloylamidopropyl-Trimethylammoniumsalz oder einem (Meth)acryloyl-Oxyethyl-Trimethylammoniumsalz ist,
wobei die Ladungsdichte des dispergierten Polymers 5 bis 40 Mol-%, vorzugsweise 8 bis 35 Mol-%, noch bevorzugter 10 bis 30 Mol-%, am meisten bevorzugt 12 bis 28 Mol-% beträgt, und wobei Schritt B durch Rühren durchgeführt wird und die Viskosität während der Polymerisation 1.800 mPas bis 4.000 mPas, vorzugsweise 2.000 mPas bis 3.600 mPas, besonders bevorzugt 2.200 mPas bis 3.400 mPas, gemessen mit einem Brookfield-Viskosimeter mit Spindel 4 bei 20°C und einer Winkelgeschwindigkeit von 10 U/min, beträgt.Process for producing a polymer dispersion, comprising the steps

1. A) Providing a reaction mixture in an aqueous medium, comprising
   1. a) a polymeric dispersant and
   2. b) a monomer composition comprising radically polymerizable monomers, wherein the radically polymerizable monomers are selected from the group consisting of one or more nonionic ethylenically unsaturated monomers, a cationic ethylenically unsaturated monomer and an amphiphilic ethylenically unsaturated monomer;
2. B) subjecting the monomer composition in the reaction mixture to radical polymerization to synthesize a dispersed polymer and form the polymer dispersion,

wherein the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in the range of 0.65:1 to 0.98:1, preferably in the range of 0.7:1 to 0.95:1, more preferably in the range of 0 .72:1 to less than 0.92:1, more preferably in the range of 0.74:1 to 0.9:1, in particular in the range of 0.76:1 to 0.88:1; where the radically polymerizable monomers are a radically polymerizable nonionic monomer according to the general formula (I), which is selected from the group consisting of (meth)acrylamide, N-methyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N -Ethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N-methyl-N-ethyl (meth)acrylamide, N-isopropyl (meth)acrylamide and N-hydroxyethyl (meth)acrylamide and a radically polymerizable cationic monomer according to the general formula (II), which is selected from the group consisting of trimethylammonium C2-C6 alkyl (meth) acrylate halides and trimethyl ammonium C2-C6 alkyl (meth) acrylamide halides,
wherein the polymeric dispersant is a homopolymer of a
(Meth) acryloylamidopropyl trimethyl ammonium salt or a (meth) acryloyl oxyethyl trimethyl ammonium salt,
wherein the charge density of the dispersed polymer is 5 to 40 mol%, preferably 8 to 35 mol%, more preferably 10 to 30 mol%, most preferably 12 to 28 mol%, and wherein step B is carried out by stirring and the viscosity during the polymerization is 1,800 mPas to 4,000 mPas, preferably 2,000 mPas to 3,600 mPas, particularly preferably 2,200 mPas to 3,400 mPas, measured with a Brookfield viscometer with spindle 4 at 20 ° C and an angular velocity of 10 rpm.

(H)

1. A) Bereitstellen einer Reaktionsmischung in einem wässrigen Medium, umfassend
   1. a) ein polymeres Dispersionsmittel und
   2. b) eine Monomerzusammensetzung, die radikalisch polymerisierbare Monomere umfasst, wobei die radikalisch polymerisierbaren Monomere aus der Gruppe ausgewählt sind, die aus einem oder mehreren nichtionischen ethylenisch ungesättigten Monomeren, einem kationischen ethylenisch ungesättigten Monomer und einem amphiphilen ethylenisch ungesättigten Monomer besteht;

Process for producing a polymer dispersion, comprising the steps

1. A) Providing a reaction mixture in an aqueous medium, comprising
   1. a) a polymeric dispersant and
   2. b) a monomer composition comprising radically polymerizable monomers, wherein the radically polymerizable monomers are selected from the group consisting of one or more nonionic ethylenically unsaturated monomers, a cationic ethylenically unsaturated monomer and an amphiphilic ethylenically unsaturated monomer;

B) subjecting the monomer composition in the reaction mixture to radical polymerization to synthesize a dispersed polymer and form the polymer dispersion,
wherein the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in the range of 0.76:1 to 0.88:1;
where the radically polymerizable monomers are a radically polymerizable nonionic monomer according to the general formula (I), which is selected from the group consisting of (meth)acrylamide, N-methyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N -Ethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N-methyl-N-ethyl (meth)acrylamide, N-isopropyl (meth)acrylamide and N-hydroxyethyl (meth)acrylamide and a radically polymerizable cationic monomer according to the general formula (II), which is selected from the group consisting of trimethylammonium C2-C6 alkyl (meth) acrylate halides and trimethyl ammonium C2-C6 alkyl (meth) acrylamide halides,
wherein the polymeric dispersant is a homopolymer of a
(Meth) acryloylamidopropyl trimethyl ammonium salt or a (meth) acryloyl oxyethyl trimethyl ammonium salt,
where the charge density of the dispersed polymer is 12 to 28 mol%,
and wherein step B is carried out by stirring and the viscosity during polymerization is 2,000 mPas to 3,600 mPas, measured with a Brookfield viscometer with spindle 4 at 20 ° C and an angular velocity of 10 rpm.

EXAMPLES

• Die Viskosität des Produkts wird wie folgt gemessen:
  • Das Produkt ist direkt für die Messung zu verwenden. Die Spindel Nr. 5 wird langsam in das Produkt eingetaucht und die Viskosität mit einem Brookfield RVT-Viskosimeter bei 10 U/min bestimmt. Die Messung wird beendet, wenn der Messwert über einen Zeitraum von 30 Sekunden konstant bleibt.

The test methods used are described in detail below:

• The viscosity of the product is measured as follows:
  • The product is to be used directly for measurement. The No. 5 spindle is slowly immersed in the product and the viscosity is determined with a Brookfield RVT viscometer at 10 rpm. The measurement is stopped when the measured value remains constant over a period of 30 seconds.

• In ein 400-ml-Becherglas werden 323,0 ± 0,1 g demineralisiertes Wasser eingewogen. Dann werden 17,0 ± 0,1 g des Produkts unter Rühren bei 300 U/min zugegeben (22 ± 3°C). Die Auflösungszeit beträgt 60 Minuten bei 300 ± 10 U/min. Danach muss die Lösung 5 min ruhen. Nun wird die Spindel Nr. 2 langsam eingetaucht und die Viskosität mit einem Brookfield-RFT-Viskosimeter bei 10 U/min bestimmt. Die Messung wird beendet, wenn der Messwert 30 Sekunden lang konstant bleibt.

The viscosity of the solution is measured in DI water and determined as follows:

• 323.0 ± 0.1 g of demineralized water are weighed into a 400 ml beaker. Then 17.0 ± 0.1 g of the product are added while stirring at 300 rpm (22 ± 3 ° C). The dissolution time is 60 minutes at 300 ± 10 rpm. The solution must then rest for 5 minutes. Now spindle No. 2 is slowly immersed and the viscosity is determined with a Brookfield RFT viscometer at 10 rpm. The measurement will stop when the reading remains constant for 30 seconds.

• In ein 400-ml-Becherglas werden 289,0 ± 0,1 g demineralisiertes Wasser eingewogen. Dann werden 17,0 ± 0,1 g des Produkts unter Rühren bei 300 U/min zugegeben (22 ± 3°C). Die Auflösungszeit beträgt 45 Minuten bei 300 ± 10 U/min. und dann werden 34,0 ± 0,1 g NaCl zugegeben. Die Lösung wird weitere 15 min gerührt. Danach muss die Lösung 5 min ruhen. Nun wird die Spindel Nr. 1 langsam eingetaucht und die Viskosität mit einem Brookfield RVT-Viskosimeter bei 10 U/min bestimmt. Die Messung wird beendet, wenn der Messwert über einen Zeitraum von 30 Sekunden konstant bleibt.

The salt viscosity is measured in a 10% NaCl solution and determined as follows:

• 289.0 ± 0.1 g of demineralized water are weighed into a 400 ml beaker. Then 17.0 ± 0.1 g of the product are added while stirring at 300 rpm (22 ± 3 ° C). The dissolution time is 45 minutes at 300 ± 10 rpm. and then 34.0 ± 0.1 g of NaCl are added. The solution is stirred for another 15 minutes. The solution must then rest for 5 minutes. Now spindle No. 1 is slowly immersed and the viscosity is determined with a Brookfield RVT viscometer at 10 rpm. The measurement is stopped when the measured value remains constant over a period of 30 seconds.

1. (a) 100 ± 0,1 g der Dispersion werden in ein Zentrifugationsröhrchen eingewogen. Das Röhrchen wird in eine Laborzentrifuge (Hermle Z300) gestellt und 1 Stunde lang bei 4000 U/min zentrifugiert. Anschließend wird der flüssige Teil der Probe innerhalb von 3 Minuten ausgephast und das Sediment im Zentrifugenröhrchen wird gewogen. Ein höheres Sediment bedeutet eine geringere Phasenstabilität.
2. (b) Die Probe wird 3 Tage lang bei 40°C im Trockenschrank gelagert. Das Aussehen wird visuell kontrolliert.

Stability is determined using two different methods: (a) centrifugation and (b) oven test. The tests are carried out as follows:

1. (a) 100 ± 0.1 g of the dispersion are weighed into a centrifugation tube. The tube is placed in a laboratory centrifuge (Hermle Z300) and centrifuged at 4000 rpm for 1 hour. The liquid part of the sample is then phased out within 3 minutes and the sediment in the centrifuge tube is weighed. Higher sediment means lower phase stability.
2. (b) The sample is stored in a drying cabinet at 40°C for 3 days. The appearance is checked visually.

The molar mass is measured using gel permeation chromatography (SEC, also called GPC). The measurement is carried out in particular to determine the molecular weight of the dispersant. Molecular weights are characterized by aqueous SEC using pullulan standards for calibration.

Sample preparation:

The samples are diluted with the eluent (polymer make-down in a volumetric flask) and filtered through a 1µm filter (M&N) (using a syringe) before injection.

If the device is equipped with an autosampler, the solution is filtered through a 1µm filter into a vial. Parameters used: Device: SEC (Agilent) Pillar: Novema 3000 (PSS) Detector: R.I Eluent: 1.5% by weight formic acid in water Flow rate: 1 ml/min Calibration standards: Pullulan with different Mw

The following examples further illustrate the invention but are not to be construed as limiting its scope.

Example 1: Synthesis of a low molecular weight polymeric dispersant:

First, 294.06 g of water, 666.7 g of acryloylamidopropyltrimethylammonium chloride (DIMAPA quat.) (60% by weight) and sulfuric acid (50% by weight) were added to adjust the pH to 5.0 ± 0.2 Weighed out 2 liter container. The monomer solution was then purged with nitrogen while stirring for 30 minutes. The aqueous solution was then heated to 60 °C and 2-mercaptoethanol and V-50 (2,2'-azobis(2-amidinopropane) dihydrochloride) were added. After Tmax was reached, two further portions of the initiator (V-50) were added to the product at 10-minute intervals to burn off the residual monomer. The product was stirred at 85 °C for 2 hours. The aqueous end product was then cooled to 30°C. The dispersants were provided in 40% by weight aqueous solutions.

• - Viskosität des Produkts [mPas]: 110-180
• - pH-Wert (unverdünnt): 4.9-5.3
• - Gesamtfeststoffgehalt [%]: 40-43
• - MwSEC [g/mol]: 70000-110000

Specifications:

• - Product viscosity [mPas]: 110-180
• - pH value (undiluted): 4.9-5.3
• - Total solids content [%]: 40-43
• - MwSEC [g/mol]: 70000-110000

The Mw is adjusted by varying the chain transfer agent 2-mercaptoethanol (2-ME).

Example 2: Synthesis of a polymer dispersion (charge density of the dispersed polymer 15 mol%)

In a batch process (batch size 1,000 kg), acrylamide and acryloyloxyethyltrimethylammonium chloride (ADAME quat.) were polymerized in an aqueous solution in the presence of homopolyacryloylamidopropyltrimethylammonium chloride (polymeric dispersant). The water phase was prepared at 200 rpm.

First, 206.90 kg of soft water, 261.80 kg of bio-acrylamide (49% by weight), 77.20 kg of acryloyl-oxyethyl-trimethylammonium chloride (ADAME quat) (80% by weight), 412.50 kg of polymers Dispersant from Example 1, 10.00 kg of ammonium sulfate and 0.20 kg of Trilon C were added to the reaction container. The pH was adjusted to pH 5.0±0.2 with approximately 0.10 kg of sulfuric acid (50%). The vessel was heated to 30 °C and evacuated five times before venting with nitrogen. The initiator composition was added at a negative pressure of 0.5 bar and maximum stirrer speed. Initiation began at 22±1°C with the addition of 0.34 kg V-50 in 3.05 kg soft water, 0.025 kg sodium persulfate in 0.47 kg soft water, 0.014 kg sodium bisulfite in 0.27 kg soft water and 0.003 kg t-butyl hydroperoxide (70%) in 1 kg soft water. The vessel was then ventilated again with nitrogen. After reaching the maximum temperature, a solution of 0.17 kg V-50 in 1.53 kg soft water was added to reduce the monomer content. After a one-hour post-reaction time, the product was cooled to a temperature below 40 °C. Then 8.30 kg of citric acid and 0.82 kg of the biocide Acticide SPX were added and the product was cooled to a temperature below 30 ° C. Table 1: Dry DP-742*1) [%] 16.5 Active ingredients [%] 19.0 Batch hMw [% by weight] 32.5 Total charge [wt.%] 68.6 *1) Polymer from Example 1, calculated as dry content

• - Produktviskosität [mPas]: <6000
• - Viskosität der Lösung [mPas]: 400-2000
• - Salz-Viskosität [mPas]: 400-700
• - Rest Acrylamid [ppm]: <95
• - pH-Wert (unverdünnt): 3-4

Specifications:

• - Product viscosity [mPas]: <6000
• - Viscosity of the solution [mPas]: 400-2000
• - Salt viscosity [mPas]: 400-700
• - Residual acrylamide [ppm]: <95
• - pH value (undiluted): 3-4

• Das Verhältnis Dispergiermittel zu dispergierter Phase wird so eingestellt, dass die resultierende wässrige Dispersion eine niedrige Viskosität und gute Stabilität aufweist. Darüber hinaus ist das Verhältnis auch für die Polymerisation selbst sehr wichtig. Wenn das Verhältnis von Dispergiermittel und dispergierter Phase nicht zueinander passt, ist das Drehmoment während der Reaktion extrem hoch. Die extrem hohe Viskosität kann zu einer Unterbrechung des Rührwerks/der Rührmaschine führen.

The influence of the ratio of dispersant to dispersed phase is analyzed below:

• The ratio of dispersant to dispersed phase is adjusted so that the resulting aqueous dispersion has a low viscosity and good stability. In addition, the ratio is also very important for the polymerization itself. If the ratio of dispersant and dispersed phase does not match, the torque during the reaction will be extremely high. The extremely high viscosity can lead to a breakdown of the agitator/mixer.

• Das Prozessprofil hängt von der Rezeptur und anderen Parametern ab. Insbesondere das Verhältnis von Dispergiermittel zu dispergierter Phase ist ein wichtiger Parameter. 1 zeigt den Temperatur- und Drehmomentverlauf über die Zeit der laufenden Reaktion. Der Temperatur- und Drehmomentverlauf über der Zeit wurde in Beispiel 2 ermittelt. Es zeigt ein typisches Verhalten im Sinne der Erfindung: Das Drehmoment wird stets unter 65 N/cm gehalten.

High viscosity/torque during polymerization:

• The process profile depends on the recipe and other parameters. In particular, the ratio of dispersant to dispersed phase is an important parameter. 1 shows the temperature and torque curve over the time of the ongoing reaction. The temperature and torque curve over time was determined in Example 2. It shows typical behavior in the sense of the invention: The torque is always kept below 65 N/cm.

2 shows a reaction profile of a reaction in which the ratio of polymeric dispersant to dispersed polymer is 0.658 for the dispersion with 15 mol% charge density. The torque value increases quickly and after just over 10 minutes reaches a value that is outside an acceptable range. The same applies to the reaction with regard to the in 3 reaction profile shown. For this reaction the ratio is 0.92. The 2 and 3 show reactions carried out by a process that does not fall within the scope of the invention.

The stability of the dispersion also depends on the ratio of dispersant to dispersed phase. The most important factor related to stability is the viscosity parameter. If the dispersion is prepared using an unsuitable ratio of dispersant and dispersed phase, the viscosity increases significantly and even gels.

4 shows a dispersion prepared by a process in which the ratio is 0.76: 1 to 0.88: 1. The dispersion is homogeneous. The dispersions in 5 are manufactured using a process in which the ratio is less than 0.7, whereupon the visual appearance varies from one batch to another. The dispersions are inhomogeneous.

The following Table 2 shows the result of the physical parameters depending on the ratio of dispersant to dispersed phase. Some dispersion batches of the dispersion according to the invention were prepared with different ratios - below 0.6, between 0.6 and 1 and above 1. The table summarizes the results. There is only a small window for a sensible ratio of dispersant to dispersed phase. The charge density can play a role as a further parameter with regard to the physical parameters of the dispersion. Table 2: Execution pAPTAC dispersant ^d [%] Dispersed phase [%] Ratio of dispersant to dispersed phase Product viscosity [mPas] ^a Torque [N/cm] ^b Sediment centrifuge [%] ^c Store at 40°C PC8915 10.5 19.0 0.553 65 N/cm torque, reaction stopped after 5 min, gelatinous 12.5 19.0 0.658 65 N/cm torque, reaction stopped after 10 min, gelatinous 14.5 19.0 0.763 2400 30 17 OK 15.5 19.0 0.816 2800 31 13 OK 16.5 19.0 0.868 3200 27 12 OK 18.0 19.0 0.947 gel 31 Jelly-like after cooling 20.0 19.0 1,053 65 N/cm torque, reaction stopped after 40 min, gelatinous e ^a 20°C, spindle 4, speed 10 ^b Torque @ laboratory mixer IKA Power Control, max. 65 N/cm ^c 20°C, laboratory centrifuge Hermle Z300, 1 h @ 4000 rpm ^d Polyacryloylamidopropyltrimethylammonium chloride

6 shows the appearance of a batch at the time of stopping (stopping the agitator) due to a highly viscous, jelly-like texture. It can be observed from the shaft of the agitator that the reacting composition rises up the shaft without flowing downward due to gravity. The texture of the composition is such that the reaction is disturbed.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 8476391 B2 [0003]
• US 7323510 B2 [0003]

Claims (15)

Process for producing a polymer dispersion, comprising the steps A) Providing a reaction mixture in an aqueous medium, comprising a) a polymeric dispersant and b) a monomer composition comprising radically polymerizable monomers, wherein the radically polymerizable monomers are selected from the group consisting of one or more nonionic ethylenically unsaturated monomers, a cationic ethylenically unsaturated monomer and an amphiphilic ethylenically unsaturated monomer; B) subjecting the monomer composition in the reaction mixture to radical polymerization to synthesize a dispersed polymer and form the polymer dispersion, wherein the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in the range of 0.65: 1 to 0.98: 1, preferably in the range from 0.7:1 to 0.95:1, more preferably in the range from 0.72:1 to less than 0.92:1, even more preferably in the range from 0.74:1 to 0, 9: 1, in particular in the range from 0.76: 1 to 0.88: 1. Procedure according to Claim 1 , characterized in that step B is carried out by stirring while measuring the viscosity, or characterized in that step B is carried out by stirring and the viscosity during the polymerization is 1,800 mPas to 4,000 mPas, preferably 2,000 mPas to 3,600 mPas, particularly preferably 2,200 mPas up to 3,400 mPas, measured with a Brookfield viscometer with spindle 4 at 20 ° C and an angular velocity of 10 rpm. Procedure according to Claim 1 or Claim 2 , characterized in that step B is carried out by stirring while measuring the torque of a motor-driven stirrer, or characterized in that step B is carried out by stirring and the torque of a motor-driven stirrer is kept below 65 N/cm. Procedure according to one of the Claims 1 until 3 , characterized in that the monomer composition comprising the radically polymerizable monomers is selected from the group consisting of one or more of the following: i. a nonionic monomer of the formula (I)

, where R ¹ represents hydrogen or methyl; R ² and R ³ are independently hydrogen, C1-C5 alkyl or C1-C5 hydroxyalkyl, ii. a cationic monomer of the formula (II)

, where R ¹ represents hydrogen or methyl; Z ₁ is O, NH or NR ₄ , where R ₄ is C1-C4 alkyl, preferably methyl, and Y has one of the following meanings

, where Y ₀ and Y ₁ are a C1-C6 alkylene group, optionally substituted with one or more hydroxy groups, preferably ethylene or propylene, optionally substituted with a hydroxy group; Y ₂ , Y ₃ , Y ₅ , Y ₆ , Y ₇ each independently represent C1-C6 alkyl, preferably methyl; and Z ^- is a counterion, preferably a halogen, pseudohalogen, acetate or SO ₄ CH ₃ ^- ; and iii. an amphiphilic monomer of the formulas (III) or (IV)

, where Z ₁ is O, NH, NR ₄ , where R ₄ is C1-C4 alkyl, preferably methyl, R ₁ is hydrogen or methyl, R ₈ is a C1-C6 alkylene group, preferably ethylene or propylene, R ₅ and R ₆ are independently each C1-C6 alkyl, preferably methyl, R7 is a C8-C32 alkyl, optionally substituted with one or more hydroxy groups, preferably C12-C20 alkyl, optionally substituted with a hydroxy group, and Z ^- a Counterion is, preferably a halogen, pseudohalogen, acetate or SO ₄ CH ₃ ^- ; or

, where Z ₁ is O, NH, NR ₄ , where R ₄ is C1-C4 alkyl, preferably methyl, R ₁ is hydrogen or methyl, R ₁₀ is hydrogen, C8-C32 alkyl, C8-C32 aryl and/or C8-C32 aralkyl, preferably C12-C20 alkyl, R ₉ is a C1-C6 alkylene group, preferably an ethylene group or propylene group, and n is an integer between 1 and 50, preferably between 2 and 30, more preferably between 3 and 15, most preferably between 4 and 8. Procedure according to one of the Claims 1 until 4 , characterized in that the monomer composition containing the radically polymerizable monomers at least the nonionic monomer of formula (I) selected from those in which R ₁ is hydrogen or methyl and R ₂ and R ₃ are both hydrogen, hydrogen and C1-C3 alkyl, hydrogen and hydroxyethyl or both are C1-C3 alkyl, and/or contains the cationic monomer of formula (II) selected from those in which R ₁ is hydrogen or methyl and Z _{1 is} O, NH or NR ₄ , where R ₄ is methyl, Y ₁ is C2-C6 alkylene, preferably ethylene or propylene, Y ₅ , Y ₆ and Y ₇ are all methyl and Z ^- is a halogen. Procedure according to one of the Claims 1 until 5 , characterized in that the free-radically polymerizable monomers are selected from the non-ionic monomer of the formula (I) and/or the cationic monomer of the formula (II), the amount of the free-radically polymerizable monomers being selected from the non-ionic monomer of the formula ( I) and/or the cationic monomer of the formula (II), is between 80 and less than 100% by weight, preferably 85 and 99% by weight, am most preferably 90 and 95% by weight, based on the total amount of radically polymerizable monomers, the remainder being selected from the group consisting of any other ethylenically polymerizable monomer, a monomer of the formula (III), a monomer of the formula ( IV) and a difunctional ethylenically polymerizable monomer. Procedure according to one of the Claims 1 until 6 , characterized in that the polymeric dispersant is selected from the group consisting of a cellulose derivative, polyvinyl acetate, starch, starch derivative, dextran, polyvinylpyrrolidone, polyvinylpyridine, polyethyleneimine, polyamine, polyvinylimidazole, polyvinylsuccinimide, polyvinyl-2-methylsuccinimide, polyvinyl-1,3- oxazolidone-2, polyvinyl-2-methylimidazoline, itaconic acid, (meth)acrylic acid, (meth)acrylic acid ester, (meth)acrylic acid amide; is preferably a (meth)acryloylamidoalkyltrialkylammonium halide or a (meth)acryloxyalkyltrialkylammonium halide. Procedure according to one of the Claims 1 until 7 , characterized in that the polymeric dispersant is a homopolymer consisting of the cationic monomer of formula (II)

is, where R ₁ represents hydrogen or methyl; Z ₁ is O, NH or NR ₄ , where R ₄ is C1-C4 alkyl, preferably methyl, and Y is one of

is, where Y ₀ and Y ₁ are a C1-C6 alkylene group, optionally substituted with one or more hydroxy groups, preferably ethylene or propylene, optionally substituted with a hydroxy group; Y ₂ , Y ₃ , Y ₅ , Y ₆ , Y ₇ each independently represent C1-C6 alkyl, preferably methyl; and Z ^- is a counterion, preferably a halogen, pseudohalogen, acetate or SO ₄ CH ₃ ^- . Procedure according to one of the Claims 1 until 8th , characterized in that the polymeric dispersant is a homopolymer of a (meth)acryloylamidopropyltrimethylammonium salt or a (meth)acryloyloxyethyltrimethylammonium salt. Procedure according to one of the Claims 1 until 9 , characterized in that the total weight of the polymeric dispersant, based on the total weight of the polymer dispersion, is in the range from 10 to 28% by weight, preferably 12 to 26% by weight, more preferably 14 to 24% by weight, even further preferably 16 to 22% by weight. and/or characterized in that the total weight of the polymeric dispersant, based on the total weight of the polymer dispersion, is between 18 and 26% by weight, preferably 19 to 25% by weight, when the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in the range from 1: 1 to 1: 0.9. Procedure according to one of the Claims 1 until 10 , characterized in that the method comprises the step C) reducing the residual monomer content by adding the remainder of the predetermined amount of the redox initiator system, the remainder of the predetermined amount of the first radical initiator and / or the remainder of the predetermined amount of the second radical initiator and / or a third radical initiator to the reaction mixture. Procedure according to one of the Claims 1 until 11 , characterized in that the charge density of the dispersed polymer is 5 to 40 mol%, preferably 8 to 35 mol%, more preferably 10 to 30 mol%, most preferably 12 to 28 mol%. Polymer dispersion comprising a) a polymeric dispersant and b) a dispersed polymer derived from a monomer composition comprising radically polymerizable monomers, wherein the radically polymerizable monomers are selected from the group consisting of one or more nonionic ethylenically unsaturated monomers, a cationic ethylenically unsaturated monomer and an amphiphilic ethylenically unsaturated monomer; wherein the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in the range of 0.65:1 to 0.98:1, preferably in the range of 0.7:1 to 0.95:1, more preferably in the range of 0 .72:1 to less than 0.92:1, more preferably in the range of 0.74:1 to 0.9:1, in particular in the range of 0.76:1 to 0.88:1. Polymer dispersion obtained by a process for producing the polymer dispersion according to one of Claims 1 until 12 , comprising the steps A) providing a reaction mixture in an aqueous medium, comprising a) a polymeric dispersant and b) a monomer composition which comprises radically polymerizable monomers, the radically polymerizable monomers being selected from the group consisting of one or more non- ionic ethylenically unsaturated monomers, a cationic ethylenically unsaturated monomer and an amphiphilic ethylenically unsaturated monomer; B) subjecting the monomer composition in the reaction mixture to radical polymerization to synthesize a dispersed polymer and form the polymer dispersion, wherein the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in the range of 0.65:1 to 0.98: 1, preferably in the range from 0.7:1 to 0.95:1, more preferably in the range from 0.72:1 to less than 0.92:1, even more preferably in the range from 0.74:1 to 0, 9: 1, in particular in the range from 0.76: 1 to 0.88: 1. Use of the polymer dispersion after Claim 13 or Claim 14 - as a flocculant in sedimentation, flotation or filtration of solids - as a thickener, - to control contamination, - as a dry strength agent, retention agent or drainage aid in papermaking.

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