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US 4,692,379 AGranted
Heat sealable film and method for its preparation
AssigneeMobil Oil Corporation
InventorsJay K. Keung, Kevin M. Donovan, Ricardo Balloni
Life of this patent
Estimating the term…
Abstract
An oriented, heat sealable polymer film laminate possessing a low coefficient of friction, good receptivity for water-based coatings and good optical clarity and a method for manufacturing such a laminate are provided.
Claims22
An oriented, heat sealable polymer film laminate possessing a low coefficient of friction, good receptivity for water-based coatings and good optical clarity which comprises:
- (a) an upper heat sealable, water-based coating-receiving layer coextensively adherent to the upper surface of a core layer (b), said upper layer (a) being formed from a polymer selected from the group consisting of ethylene-propylene-butene-1 terpolymer, ethylene-propylene random copolymer and blends thereof, said polymer being compounded with an anti-blocking effective amount of anti-blocking agent but being substantially devoid of silicone oil, the exposed surface of upper layer (a) being coated with a coefficient of friction-reducing amount of silicone oil transferred to said surface through contact with a silicone oil coating present upon the exposed surface of a lower heat sealable surface layer (c);
- (b) a core layer derived from an isotactic polypropylene;
- and,
- (c) a lower heat sealable layer coextensively adherent to the lower surface of core layer (b), said lower layer (c) being formed from a polymer selected from the group consisting of ethylene-propylene-butene-1 terpolymer, ethylene-propylene random copolymer and blends thereof, said polymer being compounded with an anti-blocking effective amount of anti-blocking agent and a quantity of silicone oil such that a coefficient of friction-reducing amount thereof will be present on the exposed surface of layer (c) as well as the exposed surface of layer (a) following mutual contact of said surfaces.
1 more element
The method of making a polymer laminate which comprises:
- (1) providing the upper major surface of a core layer (b) derived from an isotactic polypropylene with a coextensive heat sealable, water-based coating-receiving layer (a) formed from a polymer selected from the group consisting of ethylene-propylene-butene-1 terpolymer, ethylene-propylene random copolymer and blends thereof, said polymer being compounded with an anti-blocking effective amount of anti-blocking agent but being substantially devoid of silicone oil;
- (2) providing the lower major surface of core layer (b) with a coextensive heat sealable surface layer (c) formed from a polymer selected from the group consisting of ethylene-propylene-butene-1 terpolymer, ethylene-propylene random copolymer and blends thereof, said polymer being compounded with an anti-blocking effective amount of anti-blocking agent and a quantity of silicone oil such that a coefficient of friction-reducing amount thereof will be present on the exposed surface of layer (c) as well as the exposed surface of layer (a) following mutual contact of said surfaces;
- and
- (3) contacting the exposed surface of layer (c) with the exposed surface of layer (a) such that a coefficient of friction-reducing amount of silicone oil is transferred from the exposed surface of layer (c) to the exposed surface of layer (a).
1 more element
Dependencies are inferred from the claim text.