Patent PT-75262-B (PT)
Title: Process for preparing aqueous dispersions of plastic synthetic materials useful for the manufacture of hot cross-linking coatings
IPC: C08F2/22
Filed: 1982-07-15
Abstract: 1. Claims for the Contracting states : BE, CH, DE, FR, GB, IT, LI, LU, NL, SE An aqueous plastics dispersion based on a copolymer of an acrylic monomer, a vinyl monomer and a functional monomer capable of crosslinking, containing at least one emulsifier consisting of a fluorinated surfactant, which dispersion is obtained by a radically initated emulsion copolymerization of a monomer mixture containing I) 20 to 80% by weight of a "hardening" component A from the group comprising methacrylic acid ester, the homopolymer of which has a glass transition temperature TG above + 50 degrees C, styrene, vinyltoluene or vinylxylene, or mixtures of these components, the aromatic vinyl monomer contributing not more than 50% by weight to the total amount of all monomers, II) 20 to 80% by weight of a "plasticizing" component B from the group comprising acrylic acid ester or methacrylic acid ester, the homopolymer of which has a glass transition temperature TG below + 50 degrees C, or mixtures of these components, III) in each case relative to the total of A + B = 100, 1) 3 to 18% by weight of a monoolefinic unsaturated monomer having a hydroxyl group and 2) 0,5 to 10% by weight of an alpha-, beta- unsaturated monocarboxylic acid and/or an unsaturated dicarboxylic acid, characterized in that the copolymerization was carried out in the pressence of an anionic fluorinated surfactant having a perfluoroalkyl radical of 2 to 20 C atoms or a perfluoroaralkyl radical of 7 to 30 C atoms as the emulsifier or as a component of the mixture of emulsifiers, and the particle diameters of the resulting dispersion copolymer are in the range of from 0,05 to 0,2 mu m. 1. Claims for the Contracting state : AT A process for the preparation of an aqueous plastics dispersion by copolymerization of a) 20 to 80% by weight of an ester of methacrylic acid, the homopolymer of which has a glass temperature TG above + 50 degrees C, or styrene, vinyltoluene or vinylxylene, or a mixture of these monomers, the aromatic monomer contributing not more than 50% by weight to the total amount of all monomers, as the hardening component, b) 20 to 80% by weight of an ester of acrylic acid or of methacrylic acid, the homopolymer of which has a glass temperature TG below + 50 degrees C, or a mixture of these monomers, as the plasticizing component, c) in each case relative to the total of A + B = 100, 1) 3 to 18% by weight of a monoolefinic unsaturated monomer having a hydroxyl group and 2) 0,5 to 10% by weight of an alpha-, beta- unsaturated monocarboxylic acid and/or an unsaturated dicarboxylic acid, in an aqueous medium in the presence of a radical-forming initiator and an emulsifier or a mixture of several emulsifiers, characterized in that the copolymerization is carried out in the presence of an anionic fluorinated surfactant having a perfluoralkyl radical of 2 to 20 C atoms or a perfluoraoaralkyl radical of 7 to 30 C atoms as the emulsifier or as a component of the mixture of emulsifier, and the particle diameters of the resulting dispersion copolymer are in the range of from 0.05 to 0.2 mu m.