Filled hydrolyzable copolymer compositions resistant to premature crosslinking
AssigneeQuantum Chemical Corporation
InventorsCraig C. Meverden, Robert L. Silverman
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Abstract
Improved filled silane copolymer compositions resistant to premature crosslinking during compounding and storage but which are readily hydrolyzed and undergo cure in the presence of silanol condensation catalyst are provided. The compositions are comprised of random copolymers of ethylene and vinyltriethoxysilane and contain relatively high levels of particulate fillers. Rubbery ethylene copolymers are included with the silane copolymer to produce compositions with superior physical properties. The invention also relates to the method of crosslinking these compositions by combining the filled silane copolymer compositions with a second component which has a silanol condensation catalyst dispersed in a polymer resin.
Claims28
A filled, pelletized hydrolyzable silane copolymer composition consisting essentially of:
- (a) 20 to 94 weight percent random ethylene-vinyltriethoxysilane copolymer having a melt index from 0.1 to 50 and from 0.1 to 20 weight percent copolymerized vinyltriethoxysilane;
- (b) 5 to 70 weight percent rubber ethylene copolymer having a melt index from 0.1 to 100 and less than about 30% crystallinity selected from the group consisting of ethylene-vinyl acetate copolymer, ethylene-alkyl acrylate copolymer, and ethylene-.alpha.-olefin copolymer;
- and
- (c) 1 to 70 weight percent particulate filler;
- said filled, pelletized composition retaining at least 70% of the original melt index upon storage under ambient conditions for six months in the absence of a silanol condensation catalyst but capable of being crosslinked by the action of water in the presence of a silanol condensation catalyst to a tensile strength greater than 1800 psi and elongation greater than 250 percent.
A process for crosslinking a filled hydrolyzable silane copolymer composition comprising:
- (1) combining (a) a first component containing 20 to 94 weight percent random ethylene-vinyltriethoxysilane copolymer having a melt index from 0.1 to 50 and from 0.1 to 20 weight percent vinyltriethoxysilane copolymerized, 5 to 70 weight percent rubbery ethylene copolymer having a melt index from 0.1 to 100 and crystallinity less than about 30% selected from the group consisting of ethylene-vinyl acetate copolymer, ethylene-alkyl acrylate copolymer, and ethylene-.alpha.-olefin copolymer, and 1 to 70 weight percent particulate filler and (b) a second component comprising an olefin polymer and 0.25 to 10 weight percent silanol condensation catalyst, based on the weight of the olefin polymer;
- (2) processing the mixture of (a) and (b) to produce a homogenous blend;
- (3) extruding the homogeneous blend to form an extruded article;
- and
- (4) contacting the extruded article with moisture to effect crosslinking.
Dependencies are inferred from the claim text.