Abstract:
The present invention which provides antifoaming agents for the paper industry, based on oil-in-water emulsions, in which the oil phase accounts for from 5 to 50% by weight of the emulsion if the oil phase of the emulsions contains (a) an alcohol of not less than 12 carbon atoms, fatty esters of alcohols of not less than 22 carbon atoms and C1-C36-carboxylic acids, distillation residues which are obtainable in the preparation of alcohols having a relatively large number of carbon atoms by the oxo synthesis or by the Ziegler method and which may furthermore be alkoxylated, a mixture of the stated compounds and (b) optionally a fatty ester of a C12-C22-carboxylic acid with a monohydric to trihydric C1-C18-alcohol and, (c) optionally a hydrocarbon having a boiling point above 200° C. or a fatty acid of 12 to 22 carbon atoms, in combination with from 1 to 80% by weight of component (d) comprising (d1) polyglyceryl esters which are obtainable by not less than 20% esterification of a polyglycerol mixture of from 0 to 10% by weight of monoglycerol, from 15 to 40% by weight of diglycerol, from 30 to 55% by weight of triglycerol, from 10 to 25% by weight of tetraglycerol, from 0 to 15% by weight of pentaglycerol, from 0 to 10% by weight of hexaglycerol and from 0 to 5% by weight of polyglycerols having higher degrees of condensation with one or more fatty acids of 12 to 36 carbon atoms; and (d2) C18-C30 alkyl behenate. The antifoaming agents can be used for preventing foam in pulp cooking, in the beating of paper stock, in papermaking and in the dispersing of pigments for papermaking. Further, the anti-foaming agents can be used for preventing foam in paper stocks.
Abstract:
The invention relates to finely divided starch-containing polymer dispersions, which can be obtained by the radically initiated emulsion polymerization of ethylenically unsaturated monomers in the presence of at least one redox initiator and starch, wherein the ethylenically unsaturated monomers used are (a) 30 to 60% by weight of at least one optionally substituted styrol, (b) 1 to 60% by weight of at least one acrylic acid-C 1 -C 12 -alkyl ester and/or methacrylic acid-C 1 -C 12 -alkyl ester, (c) 0 to 10% by weight of at least one other ethylenically unsaturated copolymerizable monomer, and the starch used is (d) 15 to 40% by weight of at least one degraded starch having a molar mass M w of 1000 to 65000 g/mol, wherein the sum (a) + (b) + (c) + (d) = 100% and relates to the total solid matter content, and wherein the polymerization is carried out in the presence of at least 0.01% by weight, relative to the monomers used, of at least one terpene-containing polymerization regulator. The invention further relates to a method for producing the finely divided starch-containing polymer dispersions by means of the emulsion polymerization of monomers (a), (b) and (c) using redox initiators in the presence of (d) degraded starch and at least 0.01% by weight, relative to the monomers used, of at least one terpene-containing polymerization regulator, and to the use of the finely divided starch-containing polymer dispersions as a sizing agent for paper, paperboard and cardboard.
Abstract:
The invention relates to fine-particle, cationic, aqueous polymer dispersions, which can be obtained by emulsion polymerization of ethylenically unsaturated monomers in an aqueous solution of a cationic prepolymer as a dispersant, wherein first the cationic prepolymer is produced in a solution polymerization in a solvent partially or completely miscible with water in the presence of polymerization initiators by polymerizing (a) 15 to 40 wt% of a mixture of at least two different (meth)acrylate esters, each having an amino group and/or quaternary ammonium group, and/or (meth)acrylamides, each carrying an amino group and/or quaternary ammonium group, (b) 40 to 85 wt% of at least one optionally substituted styrene, (c) 0.5 to 5 wt% of at least one ethylenically unsaturated monomer containing acid groups, and (d) 0 to 20 wt% of at least one non-ionic, ethylenically unsaturated monomer different from (b), wherein the sum of (a) + (b)+ (c) + (d) = 100 wt%, the solution/dispersion of the prepolymer is then mixed with water, and subsequently in the aqueous solution of the prepolymer an emulsion polymerization of a monomer mixture of (i) 0 to 29 wt% of at least one optionally substituted styrene, (ii) 50 to 100 wt% of at least one C 1 to C 18 (methy)acrylate ester, (iii) 0 to 30 wt% of at least one vinyl ester of linear or branched C 1 -C 30 carboxylic acids, and (iv) 0 to 30 wt% of at least one non-ionic, ethylenically unsaturated monomer different from (i), (ii), and (iii), wherein the sum of (i) + (ii) + (iii) + (iv) = 100 wt%, is carried out in the presence of polymerization initiators, and the solution polymerization and/or emulsion polymerization is carried out in the presence of 0 to 10 wt% of at least one polymerization regulator.
Abstract:
A finely divided, cationic or amphoteric, aqueous polymer dispersion which is obtainable by emulsion polymerisation of ethylenically unsaturated monomers in the presence of a cationic or amphoteric protective colloid, wherein first the cationic or amphoteric protective colloid is prepared by polymerising a monomer blend in the presence of at least one first polymerisation initiator in an organic solvent, and is carried out in a pressurised reactor at a pressure of at least 1720 kPa and at a temperature of at least 150°C, which monomer blend comprises at least one ethylenically unsaturated monomer carrying an amine group,, to provide a resin, then combining the resin, with an acid and water, to form the cationic or amphoteric protective colloid, thereafter carrying out an emulsion polymerisation by introducing a monomer mixture into an aqueous medium containing said cationic or amphoteric protective colloid and at least one second polymerisation initiator, wherein said monomer mixture comprises at least one ethylenically unsaturated water insoluble monomer. The composition is useful as a sizing agent for paper.