FINELY DIVIDED, CATIONIC, AQUEOUS POLYMER DISPERSIONS, METHOD FOR THE PRODUCTION THEREOF, AND THE USE THEREOF

Abstract

Finely divided, cationic, aqueous polymer dispersions, method for the production thereof, and the use thereof The present invention relates to a finely divided, cationic, aqueous polymer dispersion which is obtainable by emulsion polymerisation of ethylenically unsaturated monomers in a continuous phase containing an aqueous liquid in which the emulsion polymerisation is carried out, in the presence of polymerisation initiators, of a combination of monomers comprising (a) from 0 to less than 60% by weight of at least one optionally substituted styrene, (b) from greater than 0 to 80% of at least one C.sub.1-C.sub.12-alkyl acrylate and/or at least one C.sub.1-C.sub.12-alkyl methacrylate, (c) from 0 to 10% by weight of at least one ethylenically unsaturated monomer comprising at least one acid group, (d) from 5 to 20% by weight of at least one ethylenically unsaturated monomer comprising a cationic group, and (e) from 0 to 50% by weight of at least one non-ionic ethylenically unsaturated monomer differing from (a), (b), (c), and (d), the sum of (a)+(b)+(c)+(d)+(e) being 100% by weight, and the aqueous liquid contains from 0 to 4% by weight based on the weight of the combination of monomers of at least one emulsifier, in which the emulsion polymerisation is carried out optionally in the presence of at least one terpene containing compound. Also claimed is a process or preparing the finely divided, cationic, aqueous polymer dispersion and the use of the finely divided, cationic, aqueous polymer dispersion for sizing paper, board and cardboard.

Claims

1. A finely divided, cationic, aqueous polymer dispersion which is obtained by emulsion polymerisation of ethylenically unsaturated monomers in a continuous phase containing an aqueous liquid in which the emulsion polymerisation is carried out, in the presence of polymerisation initiators, of a combination of monomers comprising (a) from 0 to less than 60% by weight of at least one optionally substituted styrene, (b) from greater than 0 to 80% of at least one C.sub.1-C.sub.12-alkyl acrylate and/or at least one C.sub.1-C.sub.12-alkyl methacrylate, (c) from 0 to 10% by weight of at least one ethylenically unsaturated monomer comprising at least one acid group, (d) from 5 to 20% by weight of at least one ethylenically unsaturated monomer comprising a cationic group, and (e) from 0 to 50% by weight of at least one non-ionic ethylenically unsaturated monomer differing from (a), (b), (c), and (d), the sum of (a)+(b)+(c)+(d)+(e) being 100% by weight, and the aqueous liquid contains from 0 to 4% by weight based on the weight of the combination of monomers of at least one emulsifier, in which the emulsion polymerisation is carried out optionally in the presence of at least one terpene containing compound.

2. The finely divided, cationic, aqueous polymer dispersion according to claim 1, wherein the emulsion polymerisation is of a combination of monomers comprising (a) from 10 to 50% by weight of styrene, (b) from 25 to 70% by weight of at least one C.sub.1-C.sub.12-alkyl acrylate and/or at least one C.sub.1-C.sub.12-alkyl methacrylate, (c) from 0 to 10% by weight of at least one ethylenically unsaturated monomer comprising at least one carboxylic acid group, (d) from 3 to less than 20% of at least one ethylenically unsaturated monomer comprising at least one quaternary ammonium group, (e) from 0 to 20% by weight of at least one non-ionic ethylenically unsaturated monomer differing from (a), (b), (c), and (d), the sum of (a)+(b)+(c)+(d) (e) being 100% by weight, and the aqueous liquid contains from 0.5 to 3.5% by weight based on the weight of the combination of monomers of at least one emulsifier, in which the emulsion polymerisation is carried out optionally in the presence of at least one terpene containing compound.

3. The finely divided, cationic, aqueous polymer dispersion according to claim 1, wherein the emulsion polymerisation is of a combination of monomers comprising (a) from 10 to 50% by weight of styrene, (b) from 25 to 70% by weight of at least one C.sub.1-C.sub.4-alkyl acrylate and/or at least one C.sub.1-C.sub.4-alkyl methacrylate, (c) from 0 to 10% by weight of acrylic acid or methacrylic acid, (d) from 5 to 15% of at least one ethylenically unsaturated monomer comprising at least one quaternary ammonium group, selected from the group consisting of a quaternary ammonium salt of dialkyl amino alkyl acrylate, a quaternary ammonium salt of dialkyl amino alkyl methacrylate and a quaternary ammonium salt of vinyl imidazole. (e) from 0 to 10% by weight of at least one non-ionic ethylenically unsaturated monomer differing from (a), (b), (c), and (d), the sum of (a)+(b)+(c)+(d)+(e) being 100% by weight, and the aqueous liquid contains from 0.5 to 3.5% by weight based on the weight of the combination of monomers of at least one emulsifier, in which the emulsion polymerisation is carried out optionally in the presence of at least one terpene containing compound.

4. The finely divided, cationic, aqueous polymer dispersion according to claim 1, wherein the emulsion polymerisation is of a combination of monomers comprising (a) from 10 to 50% by weight of styrene, (b) from 25 to 70% by weight of at least one C.sub.1-C.sub.4-alkyl acrylate and/or at least one C.sub.1-C.sub.4-alkyl methacrylate, (c) from 1 to 10% by weight of acrylic acid or methacrylic acid, (d) from 5 to 15% of a quaternary ammonium salt of dimethyl amino ethyl acrylate. the sum of (a)+(b)+(c)+(d) being 100% by weight, and the aqueous liquid contains from 0.5 to 3.5% by weight based on the weight of the combination of monomers of at least one emulsifier, in which the emulsion polymerisation is carried out in the presence of at least 0.01% by weight based on the weight of the combination of components (a)+(b)+(c)+(d) of at least one terpene containing compound.

5. The finely divided, cationic, aqueous polymer dispersion according to claim 1, wherein the emulsion polymerisation is of a combination of monomers comprising (a) from 15 to 50% by weight of styrene, (b) from 35 to 70% by weight of at least one C.sub.1-C.sub.4-alkyl acrylate and/or at least one C.sub.1-C.sub.4-alkyl methacrylate, (d) from 5 to 15% of a quaternary ammonium salt of vinyl imidazole, optionally in combination with a quaternary ammonium salt of dimethyl amino ethyl acrylate. the sum of (a)+(b)+(d) being 100% by weight, and the aqueous liquid contains from 0.5 to 3.5% by weight based on the weight of the combination of monomers of at least one emulsifier, in which the emulsion polymerisation is carried out in the presence of at least 0.01% by weight based on the weight of the combination of components (a)+(b)+(d) of at least one terpene containing compound.

6. The finely divided, cationic, aqueous polymer dispersion according to claim 1, wherein the emulsifier is present and comprises a compound having the formula
R′—O—(CH.sub.2—CH.sub.2—O—).sub.xH in which R′ is an alkyl group of at least 12 carbon atoms, and x is at least 12.

7. The finely divided, cationic, aqueous polymer dispersion according to claim 1, wherein the emulsifier is present and comprises a polymerisable compound having the formula
R″(—O—CH.sub.2—CH.sub.2).sub.xM in which R″ is an alkyl group of at least one carbon atom, and M is a polymerisable moiety containing an ethylenically unsaturated group.

8. The finely divided, cationic, aqueous polymer dispersion according to claim 1, in which the terpene containing compound is present in an amount of from 0.01 to 5% by weight, based on the weight of the combination of components (a)+(b) (c) (d)+(e).

9. A process for the preparation of the finely divided, cationic, aqueous polymer dispersion according to claim 1, comprising emulsion polymerisation of ethylenically unsaturated monomers in a continuous phase containing an aqueous liquid in which the emulsion polymerisation is carried out, in the presence of polymerisation initiators, of a combination of monomers comprising (a) from 0 to less than 60% by weight of at least one optionally substituted styrene, (b) from greater than 0 to 80% of at least one C.sub.1-C.sub.12-alkyl acrylate and/or at least one C.sub.1-C.sub.12-alkyl methacrylate, (c) from 0 to 10% by weight of at least one ethylenically unsaturated monomer comprising at least one acid group, (d) from 5 to 20% by weight of at least one ethylenically unsaturated monomer comprising a cationic group, and (e) from 0 to 50% by weight of at least one non-ionic ethylenically unsaturated monomer differing from (a), (b), (c), and (d), the sum of (a)+(b)+(c)+(d)+(e) being 100% by weight, and the aqueous liquid contains from 0 to 4% by weight based on the weight of the combination of monomers of at least one emulsifier, in which the emulsion polymerisation is carried out optionally in the presence of at least one terpene containing compound.

10. A sizing agent comprising the finely divided, cationic, aqueous polymer dispersions according to claim 1.

Description

EXAMPLES

[0084] The percentage data in the examples are percent by weight, unless evident otherwise from the context.

[0085] The particle sizes were determined by means of a high performance particle sizer (HPPS) from Malvern using an He—Ne laser (633 nm) at a scattering angle of 173°.

Example 1

[0086] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 16.25 g (80% by weight) of Dimethylaminoethyl acrylate methyl chloride, 1.00 g (100% by weight) of Bisomer® M PEG 350 MA (Methoxypolyethylene glycol 350 methacrylate), available from GEO Specialty Chemicals, and 240.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 36.00 g of Styrene, 48.00 g of tert-Butyl acrylate, 0.50 g of Terpinolene (90% by weight) and 2.00 g (100% by weight) of Acrylic acid was also fed over 150 min. At the end of the initiator feed the batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25% by weight and a particle size of 125 nm was obtained.

Example 2

[0087] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 16.25 g (80% by weight) of Dimethylaminoethyl acrylate methyl chloride, 3.00 g (100% by weight) of Bisomer® M PEG 350 MA (Methoxypolyethylene glycol 350 methacrylate), available from GEO Specialty Chemicals, and 240.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 34.00 g of Styrene, 48.00 g of tert-Butyl acrylate, 0.50 g of Terpinolene (90% by weight) and 2.00 g (100% by weight) of Acrylic acid was also fed over 150 min. At the end of the initiator feed the batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25% by weight and a particle size of 104 nm was obtained.

Example 3

[0088] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 20.00 g (50% by weight) of 1-Vinylimidazole dimethyl sulfate quaternary salt, 5.00 g (20% by weight) of emulsifier Lutensol® AT 25, available from BASF SE, and 120.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 40.00 g of Styrene, 40.00 g of tert-Butyl acrylate, 10.00 g of n-Butyl acrylate, 0.50 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-di-ethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25% by weight and a particle size of 93 nm was obtained.

Example 4

[0089] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 20.00 g (50% by weight) of 1-Vinylimidazole dimethyl sulfate quaternary salt, 5.00 g (20% by weight) of emulsifier Lutensol® AT 25, available from BASF SE, and 120.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 40.00 g of Styrene, 50.00 g of tert-Butyl acrylate, 0.50 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-di-ethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25% by weight and a particle size of 96 nm was obtained.

Example 5

[0090] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 30.00 g (50% by weight) of 1-Vinylimidazole dimethyl sulfate quaternary salt, 5.00 g (20% by weight) of emulsifier Lutensol® AT 25, available from BASF SE, and 120.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 35.00 g of Styrene, 50.00 g of tert-Butyl acrylate, 0.50 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-di-ethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25% by weight and a particle size of 82 nm was obtained.

Example 6

[0091] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 24.00 g (50% by weight) of 1-Vinylimidazole dimethyl sulfate quaternary salt, 5.00 g (20% by weight) of emulsifier Lutensol AT 25 and 120.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 38.00 g of Styrene, 50.00 g of tert-Butyl acrylate, 0.56 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten I-SC (sodium-di-ethyl-hexyl-sulfosuccinate) and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25% by weight and a particle size of 89 nm was obtained.

Example 7

[0092] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 12.00 g (50% by weight) of 1-Vinylimidazole dimethyl sulfate quaternary salt, 5.00 g (80% by weight) of Dimethylaminoethyl acrylate methyl chloride, 5.00 g (20% by weight) of emulsifier Lutensol® AT 25, available from BASF SE, and 120.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 40.00 g of Styrene, 50.00 g of tert-Butyl acrylate, 0.56 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-diethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25% by weight and a particle size of 75 nm was obtained.

Example 8

[0093] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 16.00 g (50% by weight) of 1-Vinylimidazole dimethyl sulfate quaternary salt, 2.50 g (80% by weight) of Dimethylaminoethyl acrylate methyl chloride, 5.00 g (20% by weight) of emulsifier Lutensol® AT 25, available from BASF SE, and 120.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 40.00 g of Styrene, 40.00 g of tert-Butyl acrylate, 10.00 g of n-Butyl acrylate, 0.56 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-di-ethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25% by weight and a particle size of 88 nm was obtained.

Example 9

[0094] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 16.00 g (50% by weight) of 1-Vinylimidazole dimethyl sulfate quaternary salt, 2.50 g (80% by weight) of Dimethylaminoethyl acrylate methyl chloride, 5.00 g (20% by weight) of emulsifier Lutensol® AT 25, available from BASF SE, and 120.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 40.00 g of Styrene, 30.00 g of tert-Butyl acrylate, 20.00 g of n-Butyl acrylate, 0.56 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-di-ethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 26% by weight and a particle size of 95 nm was obtained.

Example 10

[0095] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 10.00 g (50% by weight) of 1-Vinylimidazole dimethyl sulfate quaternary salt, 12.50 g (80% by weight) of Dimethylaminoethyl acrylate methyl chloride, 5.00 g (20% by weight) of emulsifier Lutensol® AT 25, available from BASF SE, and 120.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 40.00 g of Styrene, 30.00 g of tert-Butyl acrylate, 15.00 g of n-Butyl acrylate, 0.56 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-di-ethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25% by weight and a particle size of 97 nm was obtained.

Example 11

[0096] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 16.25 g (80% by weight) of Dimethylaminoethyl acrylate methyl chloride, 1.25 g (80% by weight) of the monomer Plex® 6954-0, available from Evonik, and 130.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 30.00 g of Styrene, 50.00 g of tert-Butyl acrylate, 6.00 g of Acrylic acid, 0.56 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-di-ethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25% by weight and a particle size of 115 nm was obtained.

Example 12

[0097] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 26.00 g (50% by weight) of 1-Vinylimidazole dimethyl sulfate quaternary salt, 5.00 g (20% by weight) of emulsifier Lutensol® AT 50, available from BASF SE, and 120.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 37.00 g of Styrene, 50.00 g of tert-Butyl acrylate, 0.56 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-di-ethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25% by weight and a particle size of 83 nm was obtained.

Example 13

[0098] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 26.00 g (50% by weight) of 1-Vinylimidazole dimethyl sulfate quaternary salt, 5.00 g (20% by weight) of emulsifier Lutensol® AT 80, available from BASF SE, and 120.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 37.00 g of Styrene, 50.00 g of tert-Butyl acrylate, 0.56 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-di-ethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 24% by weight and a particle size of 80 nm was obtained.

Example 14

[0099] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 26.00 g (50% by weight) of 1-Vinylimidazole dimethyl sulfate quaternary salt, 1.00 g (100% by weight) of Bisomer® MPEG 350 MA (Methoxypolyethylene glycol 350 methacrylate), available from GEO Specialty Chemicals, and 125.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 36.00 g of Styrene, 50.00 g of tert-Butyl acrylate, 0.56 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-di-ethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 24.5% by weight and a particle size of 202 nm was obtained.

Example 15

[0100] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 11.25 g (80% by weight) of Dimethylaminoethyl acrylate methyl chloride, 15.00 g (20% by weight) of emulsifier Lutensol® AT 18, available from BASF SE, and 120.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 35.00 g of Styrene, 51.00 g of tert-Butyl acrylate, 5.00 g of Acrylic acid, 0.56 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-di-ethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25.6% by weight and a particle size of 86 nm was obtained.

Example 16

[0101] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 5.00 g (100% by weight) of Acetic acid, 26.00 g (50% by weight) of 1-Vinylimidazole dimethyl sulfate quaternary salt, 5.00 g (20% by weight) of emulsifier Lutensol® AT 25, available from BASF SE, and 120.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 37.00 g of Styrene, 50.00 g of tert-Butyl acrylate, 0.56 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-di-ethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25% by weight and a particle size of 80 nm was obtained.

Example 17

[0102] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 5.00 g (100% by weight) of Formic acid, 26.00 g (50% by weight) of 1-Vinylimidazole dimethyl sulfate quaternary salt, 5.00 g (20% by weight) of emulsifier Lutensol® AT 25, available from BASF SE, and 120.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 37.00 g of Styrene, 50.00 g of tert-Butyl acrylate, 0.56 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-di-ethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 24.7% by weight and a particle size of 87 nm was obtained.

Example 18

[0103] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Formic acid, 26.00 g (50% by weight) of 1-Vinylimidazole dimethyl sulfate quaternary salt, 5.00 g (20% by weight) of emulsifier Lutensol® AT 25, available from BASF SE, 120.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 37.00 g of Styrene, 50.00 g of tert-Butyl acrylate, 0.56 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-di-ethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 24.5% by weight and a particle size of 89 nm was obtained.

Example 19

[0104] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 26.00 g (50% by weight) of 1-Vinylimidazole dimethyl sulfate quaternary salt, 5.00 g (20% by weight) of emulsifier Lutensol® AT 25, available from BASF SE, and 120.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 37.00 g of Styrene, 50.00 g of tert-Butyl acrylate, 0.56 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-di-ethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25% by weight and a particle size of 82 nm was obtained.

Example 20

[0105] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 16.25 g (80% by weight) of Dimethylaminoethyl acrylate methyl chloride, 1.00 g (100% by weight) of Bisomer® M PEG 350 MA (Methoxypolyethylene glycol 350 methacrylate), available from GEO Specialty Chemicals, and 135.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 30.00 g of Styrene, 50.00 g of tert-Butyl acrylate, 6.00 g of Acrylic acid, 0.56 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-di-ethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25% by weight and a particle size of 133 nm was obtained.

Example 21

[0106] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 11.25 g (80% by weight) of Dimethylaminoethyl acrylate methyl chloride, 1.00 g (100% by weight) of Bisomer® M PEG 350 MA (Methoxypolyethylene glycol 350 methacrylate), available from GEO Specialty Chemicals, and 135.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 34.00 g of Styrene, 51.00 g of tert-Butyl acrylate, 5.00 g of Acrylic acid, 0.56 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-di-ethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25% by weight and a particle size of 101 nm was obtained.

Example 22

[0107] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 16.25 g (80% by weight) of Dimethylaminoethyl acrylate methyl chloride, 2.00 g (100% by weight) of Bisomer® M PEG 350 MA (Methoxypolyethylene glycol 350 methacrylate), available from GEO Specialty Chemicals, and 240.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 15.00 g of Styrene, 48.00 g of tert-Butyl acrylate, 6.00 g of Acrylic acid, 9.00 g of Methyl acrylate, 7.00 g of Methyl methacrylate and 0.50 g of Terpinolene (90% by weight) was also fed over 150 min. At the end of the initiator feed the batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25% by weight and a particle size of 101 nm was obtained.

Example 23

[0108] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 16.25 g (80% by weight) of Dimethylaminoethyl acrylate methyl chloride, 2.00 g (100% by weight) of Bisomer® M PEG 350 MA (Methoxypolyethylene glycol 350 methacrylate), available from GEO Specialty Chemicals, and 240.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 17.00 g of Styrene, 48.00 g of tert-Butyl acrylate, 4.00 g of Acrylic acid, 9.00 g of Methyl acrylate, 7.00 g of Methyl methacrylate and 0.50 g of Terpinolene (90% by weight) was also fed over 150 min. At the end of the initiator feed the batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25% by weight and a particle size of 95 nm was obtained.

Example 24

[0109] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 10.00 g (50% by weight) of 1-Vinylimidazole dimethyl sulfate quaternary salt, 15.00 g (20% by weight) of emulsifier Lutensol® AT 25, available from BASF

[0110] SE, and 120.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 45.00 g of Styrene, 50.00 g of tert-Butyl acrylate, 0.56 g of Terpinolene (90% by weight), 0.26 g (58% by weight) of emulsifier Lumiten® I-SC (sodium-di-ethyl-hexyl-sulfosuccinate), available from BASF SE, and 90.00 g demineralised water was also fed over 150 min. At the end of the initiator feed 10.00 g demineralized water were added to the reactor. The batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25.4% by weight and a particle size of 116 nm was obtained.

Example 25

[0111] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 10.00 g (100% by weight) of Acetic acid, 21.25 g (80% by weight) of Dimethylaminoethyl acrylate methyl chloride, 2.00 g (100% by weight) of Bisomer® M PEG 350 MA (Methoxypolyethylene glycol 350 methacrylate), available from GEO Specialty Chemicals, and 240.00 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.40 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently the feed of 48.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 31.00 g of Styrene, 48.00 g of tert-Butyl acrylate, 2.00 g of Acrylic acid and 0.50 g of Terpinolene (90% by weight) was also fed over 150 min. At the end of the initiator feed the batch was further stirred for 60 min (post polymerisation) and then cooled down to the room temperature. A finely divided polymer dispersion having a solids content of 25% by weight and a particle size of 96 nm was obtained.

Example 26

[0112] In a ground-joint 2 l flask equipped with stirrer and internal temperature measurement, 15.00 g (100% by weight) of Acetic acid, 30.00 g (50% by weight) of 1-Vinylimidazole dimethyl sulfate quaternary salt, 1.50 g (20% by weight) of emulsifier Lutensol® AT 25, available from BASF SE, and 97.50 g demineralized water were added to the charge and heated up to 85° C. under stirring. Then 0.60 g (10% by weight) Iron (II) sulfate heptahydrate solution in water was added. Subsequently a feed of 72.00 g (5% by weight) hydrogen peroxide solution (initiator) was started and fed over 180 min. Concomitantly a mixture of 60.00 g of Styrene, 60.00 g of tert-Butyl acrylate, 15.00 g of n-Butyl acylate and 0.83 g of Terpinolene (90% by weight) was also fed over 150 min. At the end of the initiator feed 15.00 g demineralized water were added and the batch was further stirred for 30 min (post poymerisation) and then within 30 min the polymerization mixture was cooled down to 50° C. Afterwards 3.00 g (10% by weight) of t-Butyl hydroperoxyde were added, followed by 30 min post polymerisation. Then the polymerisation mixture was cooled down further to the room temperature. A finely divided polymer dispersion having a solids content of 43% by weight and a particle size of 178 nm was obtained.

[0113] Testing of performance characteristics of polymer dispersions obtained according to the examples and the comparative example.

[0114] The pH stability tests were carried out by adding a solution of NaOH (25% wt) up to pH>7. The samples which are stable (during the pH adjustment no coagulation can be observed) are beeing stored at 25° C. for 1 h. The dispersion is then pH stable, when it is not affected after this treatment—no coagulum can be observed.

Performance Testing of Polymer Dispersions:

[0115] To test the surface-sizing effect in use, the inventive dispersions and the comparative dispersions were applied by means of a laboratory size press to the test paper (100% reclaimed paper, 80 g/m2 basis weight, unsized). The aqueous solution of a degraded corn starch was adjusted to the desired concentration. The dispersions to be tested were then added to the starch solution such that the size press liquor comprised 60 g/l of a degraded corn starch, 0.3-0.5 g/l of the dispersions (see Table 1) and 2 g/L of Polyaluminum chloride (Sachtoklar® 39 available from Sachtleben Wasser Chemie).

[0116] The sizing effect of the dispersions 1 to 26 obtained as described in Examples 1 to 26 and Comparative example 1 was then determined by surface application to the unsized test paper. To this end, the paper was passed twice through the size press, an average weight increase of about 65% being achieved.

[0117] The surface-sized papers were dried on a drying cylinder at 90° C. The papers were subsequently stored overnight in a conditioned room (23° C., 50% relative humidity) before the degree of sizing was determined.

[0118] To determine the degree of sizing of the surface-sized papers, the Cobb60 and Cobb120 values were determined according to DIN 53 132. The Cobb60 value is defined as the water absorption of the paper sheet in g/m2 after contact with water and a contact time of 60 s (or 120 s in the case of the Cobb120 value). The lower the Cobb value, the better the sizing effect of the dispersion used.

[0119] The sizing and stability results are shown in Table 1.

TABLE-US-00001 TABLE 1 Cobb values - permanent cationic dispersions Cobb 60-Value Cobb 120-Value [g/m.sup.2] [g/m.sup.2] Stable Dose dispersion at 0.3 0.4 0.5 0.5 pH = 7 @25° C. Comparative 43 30 22 32 No Example 1 Basoplast ® 285S Example 1 44 38 30 62 Yes Example 2 39 34 30 45 Yes Example 3 40 35 24 33 yes Example 4 45 39 26 39 yes Example 5 60 33 28 49 yes Example 6 52 34 29 36 yes Example 7 34 29 26 44 yes Example 8 39 33 27 47 yes Example 9 59 32 24 63 yes Example 10 53 44 32 61 yes Example 11 92 40 37 91 yes Example 12 34 33 31 49 yes Example 13 39 36 30 54 yes Example 14 56 38 33 74 yes Example 15 50 48 40 52 yes Example 16 39 32 24 47 yes Example 17 49 40 32 64 yes Example 18 59 36 27 54 yes Example 19 50 34 24 50 yes Example 20 42 40 39 92 yes Example 21 52 46 40 76 yes Example 22 58 42 37 75 yes Example 23 48 32 31 55 yes Example 24 53 30 28 66 yes Example 25 40 37 33 48 Yes Example 26 36 30 26 57 Yes