ES330340A1 - Modifiers for vinyl halide polymers - Google Patents

Abstract

A sequentially emulsion polymerized acrylic polymer comprises (A) a cross-linked rubbery polymer which has a glass transition temperature not exceeding - 30 C. and which contains at least 80% by weight of mers derived from one or more alkyl acrylates having 3 to 8 carbon atoms in the alkyl group, (B) a crosslinked aromatic polymer which is attached to said rubbery polymer (A) and which contains at least 80% by weight of mers derived from at least one monovinyl aromatic compound, and (C) a hard polymer of monoethylenically unsaturated monomers which contains at least 80% by weight of mers derived from one or more alkyl methacrylates containing 1 to 4 carbon atoms in the alkyl group and which is attached to (A) and (B). The term " sequentially emulsion polymerized polymers " means homo- or copolymers which are prepared by the aqueous emulsion technique and in which successive monomer charges are polymerized in the presence of a preformed latex prepared from a prior monomer charge in the preceding stage, substantially no new additional and distinct particles being formed after the first stage of polymerization. The polymers may be incorporated into a composition comprising (I) a vinyl chloride polymer containing at least 60% by weight of vinyl chloride mers and (II) 1-50% by weight, based on the vinyl chloride polymer, of the acrylic polymer. In the examples polymers are prepared from n-butyl acrylate, methyl methacrylate, 1,3-butylene glycol dimethacrylate, 1,3-butylene diacrylate, 2-methoxyethyl acrylate, ethoxy-, propoxy-, isopropoxy-, butoxy-, hexoxy, 2-ethylhexoxy- and octoxyethyl acrylate, styrene and divinyl benzene aqueous sodium lauryl sulphate, glacial acetic acid, diisopropyl benzene hydroperoxide and sodium formaldehyde sulphoxylate. The polymers are compounded with P.V.C., a modifier, a fatty acid ester and stearic acid process lubricant and liquid organotin mercaptide stabilizer.