ES357823A1 - Aromatic polyester based moulding compositions - Google Patents

Abstract

A moulding composition comprises (a) a linear saturated polyester of an aromatic dicarboxylic acid and an aliphatic or cycloaliphatic diol (b) a copolymer of ethylene with an ester of acrylic, methacrylic or ethacrylic acid and an aliphatic alcohol, and (c) an ionic copolymer of an [alpha]-olefin or styrene, a mono-, di- or tri-valent salt of an [alpha],#-unsaturated carboxylic acid and, possibly, an [alpha],#- unsaturated acid and/or ester thereof. The copolymers (b) and (c) are each present in an amount of at least 0À01% by weight of the moulding composition and the total amount of copolymers (b) and (c) is 0À05 to 25% by weight of the moulding composition. The components (a), (b) and (c) may be mixed together in powder or molten form and the polyesters may be aftercondensed during or after the mixing process. The moulding composition may be coated with paraffin wax or other wax. Specified polyesters are polyethylene terephthalate which may also contain the residues of isophthalic acid, 2 : 6- naphthalenedicarboxylic acid, adipic acid, 1 : 4- butanediol or neopentylene glycol and polycyclohexane - l : 4 - dimethylol terephthalate. The copolymer (b) may be a random or graft copolymer and preferably has a molecular weight of above 2000 (e.g. 50,000-150,000). The ionic copolymer (c) may also be a random or graft copolymer and preferably has a molecular weight of above 5000. The metal component of copolymer (c) may be as described in Canadian Specification 674,595 (viz. Na, K, Li, Cs, Ag, Hg, Cu, Be, Mg, Ca, Sr, Ba, Cu, Cd, Sn, Pb, Fe, Co, Ni, Zn, Al, Sc or Y). Examples describe compositions of polyethylene terephthalate (particle size 100-750Á), a copolymer of ethylene and ethyl acrylate and a copolymer of ethylene and methacrylic acid neutralized with sodium ions.