# US 9,040,065 B2 · Preparation of polyacrylates by emulsion polymerization > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,040,065 B2 - Document ID: US9040065B2 - Status: Granted - Kind: B2 - Application number: 13/489,932 - Filed: 2012-06-06 - Published: 2012-12-13 - Granted: 2015-05-26 - Earliest claimed: 2011-06-07 - Assignees: BASF SE - Applicants: Maximilian Angel; Peter Hossel - Inventors: Maximilian Angel; Peter Hossel - Web page: https://patentgrep.com/patent/US9040065B2 ## CPC - C08F 2/22: Emulsion polymerisation - A61K 8/8152: {Homopolymers or copolymers of esters, e.g. (meth)acrylic acid esters; Compositions of derivatives of such polymers} - A61K 8/8158: {Homopolymers or copolymers of amides or imides, e.g. (meth) acrylamide; Compositions of derivatives of such polymers} - A61Q 5/06: Preparations for styling the hair, e.g. by temporary shaping or colouring - C08F 220/1802: {C2-(meth)acrylate, e.g. ethyl (meth)acrylate} - A61K 2800/48: Thickener, Thickening system - A61Q 5/006: {Antidandruff preparations} - A61Q 5/02: Preparations for cleaning the hair - A61Q 5/10: Preparations for permanently dyeing the hair - A61Q 5/12: Preparations containing hair conditioners - C08F 220/286: {and containing polyethylene oxide in the alcohol moiety, e.g. methoxy polyethylene glycol (meth)acrylate} - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS - A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D) - A61Q: SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS ## Abstract The present invention relates to a process for the preparation of polymers comprising carboxyl groups by emulsion polymerization and the use of the polymers obtainable by this process, for example as thickeners. Moreover, the invention relates to thickener dispersions obtainable by the process and to the use thereof for modifying the rheology of paper coating slips, textile printing pastes, drugs, cosmetic preparations, detergents, cleansing compositions, or foods. ## Claims ### Claim 1 A process for the preparation of polymers, the polymers comprising in a polymerized-in form, a. M1a+M2a=30 to 70% by weight of an ester of (meth)acrylic acid with a C1-C4-alcohol; b. M1b+M2b=30 to 70% by weight of (meth)acrylic acid; c. M1c+M2c=0.1 to 20% by weight of monomer substituted with at least one C8-C30-radical; and M1d+M2d=0 to 20% by weight of monomers different from a) to c), the process comprising emulsion polymerization with a first polymerization stage followed by a second polymerization stage, wherein the first polymerization stage includes i) providing an initial charge comprising the monomer part amounts M1a, M1b, M1c, and M1d, water, and optionally a surface-active agent, to form a first monomer mixture; ii) heating the first monomer mixture (i) to a temperature in the range of about 30 to 120° C.; and iii) adding a polymerization initiator to form a first reaction mixture, and wherein the second polymerization stage includes iv) adding the monomer part amounts M2a, M2b, M2c, and M2d to the first reaction mixture (iii) to form a second reaction mixture; and v) after-treatment of the second reaction mixture (iv), wherein M1b/M1a≧0.4 and M1b/M1a