Process for producing aqueous polyacrylamide solutions by polymerizing an aqueous solution comprising at least acrylamide thereby obtaining an aqueous polyacrylamide gel and dissolving said aqueous polyacrylamide gel in water, wherein the process is carried out in a modular, relocatable plant. The plant preferably is deployed at a location at which aqueous polyacrylamide solutions are used, for example on an oilfield or in a mining area.

Process for producing aqueous polyacrylamide solutions by polymerizing an aqueous solution comprising at least acrylamide thereby obtaining an aqueous polyacrylamide gel and dissolving said aqueous polyacrylamide gel in water, wherein the process is carried out in a modular, relocatable plant. The plant preferably is deployed at a location at which aqueous polyacrylamide solutions are used, for example on an oilfield or in a mining area.

The invention relates to an aqueous polymer dispersion and its preparation. The dispersion comprises a styrene acrylate polymer, which is obtainable by free-radical polymerisation of 1-90 weight-% of monomer (a), which comprises at least one optionally substituted styrene; 10-99 weight-% of monomer (b), which comprises at least one alkyl (meth)acrylate, and 0-9 weight-% of monomer (c), which comprises at least one ethylenically unsaturated monomer, which is different from monomer (b). The polymerisation is conducted in a polymerisation medium comprising a cationic prepolymer, which is obtainable by free radical polymerisation of at least 10-55 weight-% of a monomer (i), which comprises at least one ethylenically unsaturated quaternary and/or tertiary amine, 35-90 weight-% of a monomer (ii), which comprises at least one optionally substituted styrene, and 0-55 weight-% of a monomer (iii), which comprises at least one alkyl (meth)acrylate. The oligomer content in the polymer dispersion is ≤1.4 weight-%, calculated from the dry polymer content.

The invention relates to an aqueous polymer dispersion and its preparation. The dispersion comprises a styrene acrylate polymer, which is obtainable by free-radical polymerisation of 1-90 weight-% of monomer (a), which comprises at least one optionally substituted styrene; 10-99 weight-% of monomer (b), which comprises at least one alkyl (meth)acrylate, and 0-9 weight-% of monomer (c), which comprises at least one ethylenically unsaturated monomer, which is different from monomer (b). The polymerisation is conducted in a polymerisation medium comprising a cationic prepolymer, which is obtainable by free radical polymerisation of at least 10-55 weight-% of a monomer (i), which comprises at least one ethylenically unsaturated quaternary and/or tertiary amine, 35-90 weight-% of a monomer (ii), which comprises at least one optionally substituted styrene, and 0-55 weight-% of a monomer (iii), which comprises at least one alkyl (meth)acrylate. The oligomer content in the polymer dispersion is ≤1.4 weight-%, calculated from the dry polymer content.

The present disclosure relates to a preparation method for a super absorbent polymer film. Specifically, it relates to a preparation method for a new type of super absorbent polymer film, which is thin and exhibits excellent absorption performance while having excellent flexibility and mechanical properties. In addition, the super absorbent polymer film is free from scattering or leaking, and does not require an auxiliary substance such as pulp, so that products can be made thinner and the manufacturing process and costs may be reduced.

A method for producing a fluoropolymer powder including (A1) adding, to a fluoropolymer aqueous dispersion obtained by polymerization using a carboxylic acid type hydrocarbon surfactant, and an acid to adjust a pH to 4.0 or less and cause coagulation to thereby obtain a wet fluoropolymer powder containing a fluorine-containing compound represented by the following general formula (1A), and (B1) heat-treating the wet fluoropolymer powder at a temperature higher than 150° C. and lower than 240° C.: General Formula (1A): H—(CF.sub.2).sub.m—COOH wherein m is 3 to 19.

A method for producing a fluoropolymer powder including (A1) adding, to a fluoropolymer aqueous dispersion obtained by polymerization using a carboxylic acid type hydrocarbon surfactant, and an acid to adjust a pH to 4.0 or less and cause coagulation to thereby obtain a wet fluoropolymer powder containing a fluorine-containing compound represented by the following general formula (1A), and (B1) heat-treating the wet fluoropolymer powder at a temperature higher than 150° C. and lower than 240° C.: General Formula (1A): H—(CF.sub.2).sub.m—COOH wherein m is 3 to 19.

A method for producing a crosslinking polymer gel, the method including polymerizing a monomer composition containing at least one (meth)acrylic acid compound selected from the group consisting of (meth)acrylic acid and a salt thereof and benzaldehyde to obtain a crosslinking polymer gel, in which a centrifuge retention capacity of crosslinking polymer particles obtained by coarsely crushing, drying, and pulverizing the crosslinking polymer gel is 60 g/g or more. A monomer composition for obtaining a crosslinking polymer gel, the monomer composition containing at least one (meth)acrylic acid compound selected from the group consisting of (meth)acrylic acid and a salt thereof, and benzaldehyde, in which a centrifuge retention capacity of crosslinking polymer particles obtained by coarsely crushing, drying, and pulverizing the crosslinking polymer gel is 60 g/g or more.

A production method of water-absorbent resin particles is disclosed, the method including: preparing a monomer aqueous solution containing an ethylenically unsaturated monomer and silica; polymerizing the ethylenically unsaturated monomer in the monomer aqueous solution by an aqueous solution polymerization method to obtain a hydrogel-like polymer; and coarsely crushing the hydrogel-like polymer, in which a concentration of the silica in the monomer aqueous solution is 0.02 to 4.0 ppm.

A production method of water-absorbent resin particles is disclosed, the method including: preparing a monomer aqueous solution containing an ethylenically unsaturated monomer and silica; polymerizing the ethylenically unsaturated monomer in the monomer aqueous solution by an aqueous solution polymerization method to obtain a hydrogel-like polymer; and coarsely crushing the hydrogel-like polymer, in which a concentration of the silica in the monomer aqueous solution is 0.02 to 4.0 ppm.