Patent ID: 6140401
Filing Date: 2000-10-31
Classification: C08J,C08K

Abstract:
A process for stabilizing a polyvinyl chloride-containing composition used in the production of semi-rigid and flexible films, said process comprising:(i) providing a polyvinyl chloride-containing composition;(ii) providing a stabilizer composition comprising:(a) at least one inorganic component in an amount of from about 0.03 to about 3 parts by weight per 100 parts by weight of polyvinyl chloride, wherein the at least one inorganic component is selected from the group consisting of:(a1) synthetic, crystalline, fine-particle sodium aluminosilicates containing from about 7 to about 25% by weight of bound water, wherein the sodium aluminosilicates, in water-free form, correspond to the general formula (I):0.7-1.1 Na.sub.2 O.Al.sub.2 O.sub.3.1.3-5 SiO.sub.2 (I)(a2) hydrotalcites of the general formula (II):Mg.sub.1-x Al.sub.x (OH).sub.2 A.sub.x/n.sup.n-.mH.sub.2 O (II)wherein 0<x<0.5, m is a positive number and A.sup.n- represents an anion having a valency of from 1 to 3;(a3) basic calcium/aluminum hydroxyphosphites of the general formula (III):Ca.sub.z Al.sub.2 (OH).sub.2(z+2) HPO.sub.3.pH.sub.2 O (III)wherein z represents a number of from 2 to 8 and p represents a number of from 0 to 12;(b) at least one zinc salt in a weight ratio of zinc to component (a) of from about 0.02:1 to about 0.25:1, wherein the at least one zinc salt is selected from the group consisting of zinc salts of monocarboxylic acids having from about 6 to about 36 carbon atoms, zinc salts of dicarboxylic acids having from about 6 to about 10 carbon atoms, zinc salts of benzoic acid, and zinc salts of C.sub.1-4 -substituted benzoic acid; and(c) at least one component selected from (c1) calcium salts of saturated linear monocarboxylic acids having from 16 to 22 carbon atoms in an amount of 0.1 to 0.2 parts by weight per 100 parts by weight of polyvinyl chloride, and (c2) magnesium salts of saturated linear monocarboxylic acids having from 16 to 22 carbon atoms in an amount of 0.1 to 0.4 parts by weight per 100 parts by weight of polyvinyl chloride; and(iii) combining the polyvinyl chloride-containing composition and the stabilizer composition prior to using the polyvinyl chloride-containing composition in the production of semi-rigid and flexible films.