Patent GB-1436362-A (GB)
Title: Resin laminate structures
IPC: C08J5/00
Filed: 1973-08-20
Abstract: 1436362 Resin laminates; extrusion and blow moulding TOYO SEIKAN KAISHA Ltd 20 Aug 1973 [20 Aug 1972 7 July 1973] 39249/73 Headings B5N B5A and B5B [Also in Division B2]  A laminate comprises:- (A) at least one layer comprising a crystalline, film-forming polyolefin, and (B) at least one layer comprising a saponified ethylene-vinyl ester copolymer having an ethylene content of 25 to 50 mol per cent and a degree of saponification of at least 96%, said laminate comprising at least one (A) layer which satisfies the following conditions: (i) said A layer is bonded directly to a (B) layer and (ii) at least one of said (A) layer and said (B) layer to which it is bonded contains a thermoplastic polymer containing 120 to 1400 mini-equivalents of carbonyl groups per 100 g. of the thermoplastic polymer, said thermoplastic polymer being present in said (A) layer in an amount of 5 to 100 parts by weight per 100 parts by weight of the polyolefin in said (A) layer or in said (B) layer in an amount of 5 to 100 parts by weight of the saponified copolymer in said (B) layer. In a preferred embodiment, layer (A) comprises a crystalline, film-forming polyolefine and layer (B) comprises a blend of (a) the saponified ethylene-vinyl ester copolymer and (b) the thermoplastic polymer, the average content (X) of the saponified copolymer in layer (B) being 50 to 95% by weight of the total weight of (a) and (b), the average content of the thermoplastic polymer in layer (B) being 5 to 50% by weight of the total weight of (a) and (b), said layer (B) having a stratified structure in the polymers (a) and (b) are distributed substantially uniformly along the length and breadth of the layer (B) but non-uniformly through its thickness, in such a manner that the concentration of the saponified copolymer in the region of layer (B) adjacent to the polyolefine layer (A) is 0 to 0À95X. The laminate may comprise:- (1) outer layers each comprising a blend of the polyolefine with the thermoplastic polymer sandwiching an inner layer comprising the saponified copolymer or (2) outer layers each comprising the polyolefine sandwiching an inner layer comprising a blend of the saponified copolymer and the thermoplastic polymer. The laminate may be made by extrusion, the layers being combined in a die or after extrusion, in an alternative method the laminate is made by extrusion coating. The polyolefine may be a homo- or copolymer of an olefine of the formula where R is hydrogen or a C 1  to C 4  alkyl group, e.g. polyethylene, polypropylene an ethylenepropylene copolymer, polybutene-1 and polypentene, specified comonomers for polymerization with an olefine being vinyl chloride, vinyl acetate, acrylic acid, methacrylic acid and esters of acrylic or methacrylic acid. The carbonyl group containing thermoplastic polymer may be a polyacrylic or polymethacrylic ester, an ethylene/acrylic acid copolymer, an acrylate/acrylic acid copolymer, an ethylene/ acrylate/acrylic acid copolymer, an ethylene/ acrylic acid copolymer, a styrene/methacrylate/ acrylic acid copolymer, an acrylate/vinyl chloride copolymer, a methacrylate/vinyl chloride copolymer, a stryene/methacrylate/butadiene copolymer, a methacrylate/acrylonitrile copolymer, polyvinyl acetate, polyvinyl propionate, an ethylene/vinyl acetate copolymer, an acrylate/vinyl acetate copolymer, a vinyl chloride/vinyl acetate copolymer, an ionomeric resin, a maleic anhydride/vinyl ether copolymer, a maleic anhydride/vinyl chloride copolymer, an ethylene/maleic anhydride copolymer, a maleic anhydride modified polypropylene, a polyamide (many of which are listed) a polyester, e.g. polyethylene adipate, polyethylene sebacate, polyethyleneterephthalate, polytetramethylene isophthalate and polyethylene terephthalate / isophthalate, polyhexamethylene urea, polyheptamethylene urea, polyundecamethylene urea, polynonamethylene urea, polytetramethylene hexamethylene urethane, polyhexamethylenetetramethylene urethane, polyp-xylene glycol biscarbonate, poly-dihydroxydiphenyl-methane carbonate, polydihydroxydiphenyl-ethane carbonate, poly - dihydroxyphenyl - 2, - propane carbonate and polydihydroxy diphenyl-1,1-ethane carbonate. The saponified ethylene-vinyl ester may be derived from a copolymer of ethylene with vinyl acetate, vinyl formate, vinyl propionate or vinyl acetate and propylene or butene-1. The resin layers may comprise ultra-violet absorbents, stabilizers, anti-oxidants, pigments, dyes and anti-static agents. The examples describe the formation of laminates by co-extrusion and the blow moulding of the laminates to form bottles. Relationships between extrusion conditions and flow parameters are given.