Back to results
US 4,897,274 AGranted
Multi-layer highly moisture and gas permeable packaging film
AssigneeW. R. Grace & Co.
InventorsGiovanni Candida, Luigi Perazzo
Life of this patent
Estimating the term…
Abstract
A multi-layer highly moisture and gas permeable packaging film comprising a core layer of a butadiene-styrene copolymer with a styrene content of 60 to 80% by weight and at least two outer layers having heat sealable and gas permeability properties.
Claims5
A multilayer high permeability packaging film comprising:
- (a) two layers comprising a polymeric resin selected from the group consisting of
- (i) very low density polyethylene with a comonomer content of from 10% to 22% by weight of the very low density polyethylene, said comonomer selected from the group consisting of C.sub.4 --, C.sub.6 -- and C.sub.8 -alpha-n-olefins,
- (ii) polybutylene and copolymers thereof,
- (iii) poly-4-methyl-pentene-1,
- (iv) polyethylene terephthalate glycol,
- (v) polyether,
- (vi) polyurethanes, and
- (vii) elastomeric copolyesters;
- and
- (b) a third layer disposed between the two layers and comprising butadiene-styrene copolymer with a styrene content of from 60% to 80% by weight of the copolymer.
7 more elements
A multilayer high permeability packaging film comprising
- (a) two layers comprising a polymeric resin selected from the group consisting of
- (i) very low density polyethylene with a comonomer content of from 10% to 22% by weight of the very low density polyethylene, said comonomer selected from the group consisting of C.sub.4 --, C.sub.6 -- and C.sub.8 -alpha-n-olefins,
- (ii) polybutylene and copolymers thereof,
- (iii) poly-4-methyl-pentene-1,
- (iv) polyethylene terephthalate glycol,
- (v) polyether,
- (vi) polyurethanes,
- (vii) elastomeric copolyesters, and
- (viii) ethylene vinyl acetate copolymer;
- (b) a third layer disposed between the two layers and comprising butadiene-styrene copolymer with a styrene content of from 60% to 80% by weight of the copolymer;
- and
- (c) an additional layer between the third layer and at least one of the two layers, the additional layer comprising a polymeric material selected from the group consisting of
- (i) ethylene vinyl acetate copolymer with a vinyl acetate content of 8 to 28% by weight,
- (ii) very low density polyethylene containing a comonomer selected from the group consisting of C.sub.4 --, C.sub.6 -- and C.sub.8 -alpha-n-olefins in an amount of 10% to 20% by weight of the very low density polyethylene,
- (iii) polybutylene and its copolymers,
- (iv) poly-4-methyl-pentene-1,
- (v) polyethylene terephthalate glycol,
- (vi) polyether,
- (vii) polyurethane,
- (viii) elastomeric copolyesters,
- (ix) adhesive modified ethylene vinyl acetate copolymer resins, and
- (x) ionomeric resins.
19 more elements
Dependencies are inferred from the claim text.