ES368068A1 - Sequentially polymerized acrylic modifiers - Google Patents

Abstract

A particulate polymer obtained by conventional sequential aqueous emulsion or suspension techniques, with control of the initial particle size and of the later growth of new particles, comprises three stages (I) units of an alkyl-, alkoxyalkyl- or alkylthioalkyl acrylates together with units of a cross-linking polyethylenic monomer, (II) units of a monoalkenyl aromatic monomer and optionally together with units of a polyethylenic monomer, and (III) units of acrylateor methacrylate esters which may be halogen-substituted, (meth)acrylonitrile, or monoalkenyl aromatic monomers, the first stage polymer having an average particle diameter of at least 1500 A, the sequential copolymers may be mixed with other thermoplastic polymers, preferably vinyl chloride polymers. In examples the sequential emulsion polymerization of the following monomers is described, in some cases with incremental addition of ingredients, and with the usual emulsifiers and initiators:-(I) nbutyl-, 2-ethylhexyl-, decyl/octyl-,butoxyethyl-, ethoxyethyl-, octoxyethyl-, ethylthioethyl- and ethyl-acrylate and mixtures thereof together with 1,3-butylene-diacrylate or divinyl benzene, (II) styrene, -butylstyrene, chlorostyrene and vinyl toluene and mixtures thereof, together in some cases with divinyl benzene, and (III) methyl methacrylate, isobornyl methacrylate, ethyl acrylate, styrene, alphamethyl styrene, acrylonitrile, trichlorethyl methacrylate, benzyl methacrylate, and chloro- and -butylstyrene (in most cases mixtures thereof). Examples are given of compounding these polymers with chlorinated or normal polyvinyl chloride, styrene and methyl methacrylate polymers and copolymers thereof with an alkyl acrylate, acrylonitrile or alphamethylstyrene, and optionally TiO 2 and methyl methacrylate-isobornyl methacrylate copolymer.