METHOD FOR PRODUCING AN AQUEOUS POLYMER DISPERSION FROM A VINYL AROMATIC COMPOUND AND A CONJUGATED ALIPHATIC DIENE

• Main Authors: LAWRENZ DIRK, CIMPEANU CARMEN-ELENA
• Format: Patent
• Language: Chinese; English
• Published: 21.01.2022
• Subjects: ADHESIVES; CHEMICAL PAINT OR INK REMOVERS; CHEMISTRY; COATING COMPOSITIONS, e.g. PAINTS, VARNISHES ORLACQUERS; COMPOSITIONS BASED THEREON; CORRECTING FLUIDS; DYES; FILLING PASTES; INKS; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; ORGANIC MACROMOLECULAR COMPOUNDS; PAINTS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; POLISHES; THEIR PREPARATION OR CHEMICAL WORKING-UP; USE OF MATERIALS THEREFOR; WOODSTAINS

The invention relates to a method for producing an aqueous polymer dispersion by radically initiated aqueous emulsion polymerization, in which in an aqueous medium comprising (a) 40 to 75 parts by weight of at least one vinyl aromatic compound, (b) 24.9 - 59.9 parts by weight of at least one conjugated aliphatic diene, (c) 0.1 to 10 parts by weight of at least one monomer containing acid groups and (d) 0 to 20 parts by weight of at least one other monoethylenically unsaturated monomer, the total sum of the monomers (a) to (d) totalling up to 100 parts by weight, is polymerized according to a monomer feed process, with the proviso that monomers and emulsifier are continuously metered, following a period P1, when 15 to 30% of the total metering time of the monomers has elapsed and 15 to 30% by weight of the total amount of the monomers are metered, the metering rate of the emulsifier for a period P2, which lasts at most 30 minutes, is increased to up to 100 times the average metering rate of the emulsifier of t