Optionally reinforced polyamide composition containing ionomer
AssigneeE. I. Du Pont de Nemours and Company
InventorsRichard T. Chou, Jennifer L. Thompson, Herbert Vernon Bendler
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Abstract
Disclosed is a composition comprising a polyamide composition comprising nylon-66 or nylon 66/6T, and optionally nylon-6, nylon-610, nylon-612, nylon-11, nylon-12, an ionomer composition comprising at least one ethylene acid copolymer wherein 30 to 90% of the total 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; and optionally reinforcing filler. Articles prepared from the composition exhibit improved calcium chloride salt stress crack resistance over polyamide compositions not containing the ionomer.
Claims25
A composition comprising
- (a) about 60 to about 80 weight % %, based on the total weight of (a)+(b), of polyamide composition comprising nylon-66, nylon-6/66 or nylon 66/6T, and optionally up to 40 weight %, based on the total polyamide composition, of nylon-6, nylon-610, nylon-612, nylon-11, nylon-12 or mixtures thereof;
- (b) about 20 to about 40 weight %, based on the total weight of (a)+(b), of an ionomer composition, wherein the ionomer composition comprises at least one copolymer comprising copolymerized units of ethylene, 3 to 20 weight % of copolymerized units of at least one α,β-unsaturated C3-C8 monocarboxylic acid and 0 to 30 weight % of copolymerized units of alkyl acrylate or alkyl methacrylate;
- and 30 to 90% of the total monocarboxylic 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;
- and optionally
- (c) reinforcing filler in the range of 0.1 to about 50 weight % of the total weight of (a), (b) and (c).
A method for improving the salt stress crack behavior of a polyamide composition, comprising
- (a) providing a polyamide composition comprising nylon-66, nylon-6/66 or nylon 66/6T, and optionally up to 40 weight %, based on the total polyamide component, of nylon-6, 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 units of ethylene, 3 to 20 weight % of copolymerized units of at least one α,β-unsaturated C3-C8 monocarboxylic acid and 0 to 30 weight % of copolymerized units of alkyl acrylate or alkyl methacrylate;
- and 30 to 90% of the total monocarboxylic 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 60 to about 80 weight % of the polyamide and about 20 to about 40 weight % of the ionomer;
- (c) optionally blending in reinforcing filler in the range of about 0.1 to about 50 weight % of the total weight of polyamide, ionomer and filler;
- (d) shaping the molten blend composition into a defined shape;
- (e) 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 prepared from a similar composition that does not contain the ionomer when exposed to 50% aqueous calcium chloride solution at about 80° C. for at least 24 hours.
Dependencies are inferred from the claim text.