Polyamide Composition Containing Ionomer
AssigneeE. I. Du Pont de Nemours and Company
InventorsRichard T. Chou, Herbert Vernon Bendler
Life of this patent
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Abstract
Disclosed is a composition comprising polyamide comprising nylon-6 and optionally nylon-6,66, nylon-66, nylon-610, nylon-612, nylon-11, nylon-12 and an ionomer comprising an ethylene carboxylic acid copolymer, wherein 30 to 90% of the total carboxylic acid functionalities are neutralized to salts with a mixture of zinc cations and cations of a second metal selected from Group 1 of the Periodic Table of the Elements wherein the salts comprise from 20 to 90% equivalents of zinc. Articles prepared from the composition have improved salt stress crack resistance when exposed to zinc chloride solutions.
Claims22
A shaped article in the form of an extruded profile comprising a blend composition comprising:
- (a) about 50 to about 75 weight % of polyamide comprising nylon-6 and optionally up to 40 weight %, based on the total polyamide component, of nylon-6,66, nylon-66, nylon-610, nylon-612, nylon-11, nylon-12 or mixtures thereof;
- (b) about 25 to about 50 weight % of an ionomer, wherein the ionomer comprises at least one copolymer comprising copolymerized comonomers of ethylene, 3 to 20 weight % of at least one α,β-unsaturated C3-C8 monocarboxylic acid, and 0 to 30 weight % of alkyl acrylate or alkyl methacrylate;
- and 30 to 90% of the total carboxylic acid functionalities are neutralized to salts with a mixture of zinc cations and sodium or lithium cations, wherein the salts comprise from 20 to 90 % equivalents of zinc.
A method for improving the salt stress crack behavior of a polyamide composition, comprising
- (a) providing a polyamide composition comprising nylon-6 and optionally up to 40 weight %, based on the total polyamide component, of nylon-6,66, nylon-66, nylon-610, nylon-612, nylon-11, nylon-12 or mixtures thereof;
- (b) melt blending the polyamide with an ionomer comprising at least one copolymer comprising copolymerized comonomers of ethylene, 3 to 20 weight % of at least one α,β-unsaturated C3-C8 monocarboxylic acid, and 0 to 30 weight % of alkyl acrylate or alkyl methacrylate;
- and 30 to 90% of the total carboxylic acid functionalities are neutralized to salts with a mixture of zinc cations and sodium or lithium cations, wherein the salts comprise from 20 to 90% equivalents of zinc;
- to provide a molten blend composition comprising about 50 to about 75 weight % of the polyamide and about 25 to about 50 weight % of the ionomer;
- (c) shaping the molten blend composition into a defined shape;
- (d) allowing the shaped molten blend composition to cool, thereby providing a shaped article;
- wherein the salt stress crack behavior of the blend composition when tested according to ASTM D1693 is characterized by standard test plaques that exhibit fewer cracks than comparison test plaques consisting essentially of the polyamide composition of (a) when exposed to 50% aqueous zinc chloride solution at about 20 to about 25° C. for at least 24 hours.
Dependencies are inferred from the claim text.