Abstract A coated polyester film suitable for producing polyester/polyolefin laminates consists of biaxially oriented poly(ethylene terephthalate) film coated with a cross-linked styrene copolymer by deposition from an aqueous coating composition which comprises (A) a copolymer containing 50-75 mol % of styrene units and 25-50 mole % of comonomer units providing carboxylic groups (10-50 mole %) and alkyl carboxylate groups (20-50 mole %) and (B) a melamine/formaldehyde cross-linking agent. The styrene copolymer (A) is preferably a water-soluble copolymer of styrene and maleic anhydride partially converted into butyl ester and partially neutralized with ammonia, and the cross-linking agent (B) is conveniently hexamethoxymethylmelamine. The polyolefin layer in the laminates produced may in particular be of low-density polyethylene.
Coated polyester film which consists of biaxially oriented poly(ethylene terephthalate) film coated with a cross-linked styrene polymer which is deposited from an aqueous coating composition comprising: (A) 100 parts by weight of a copolymer of: (i) 50-75 mole % of styrene units which may be alpha- and/or ring-substituted with methyl or halogen; (ii) 25-50 mole % of comonomer units selected from units of acrylic, methacrylic, itaconic and maleic acids, alkyl half-esters of itaconic and maleic acids, alkyl acrylates and methacrylates and dialkyl maleates; the comonomer units being such as to provide the copolymer with 10-50 mole % of carboxylic groups which may be present as salts and 20-50 mole % of alkyl carboxylate groups in which the alkyl groups may each have up to 10 carbon atoms; (B) 10-20 parts by weight of cross-linking agent selected from condensation products of formaldehyde and melamine and said condensation products having hydroxyl groups converted into methoxy, ethoxy, propoxy or butoxy groups.
Claim 2
Dependent Claim
158 words
Coated polyester film which consists of biaxially oriented poly(ethylene terephthalate) film coated with a cross-linked styrene polymer which is deposited from an aqueous coating composition comprising: (A) 100 parts by weight of a copolymer of: (i) 50-75 mole % of styrene units which may be alpha- and/or ring-substituted with methyl or halogen; (ii) 25-50 mole % of comonomer units selected from units of acrylic, methacrylic, itaconic and maleic acids, alkyl half-esters of itaconic and maleic acids, alkyl acrylates and methacrylates and dialkyl maleates; the comonomer units being such as to provide the copolymer with 10-50 mole % of carboxylic groups which may be present as salts and 20-50 mole % of alkyl carboxylate groups in which the alkyl groups may each have up to 10 carbon atoms; (B) 10-20 parts by weight of cross-linking agent selected from condensation products of formaldehyde and melamine and said condensation products having hydroxyl groups converted into methoxy, ethoxy, propoxy or butoxy groups.
Claim 3
Dependent Claim
43 words
Coated polyester film according to claim 1 in which (A) is a water-soluble copolymer of 50-75 mole % of styrene units and 25-50 mole % of units of maleic anhydride which have been partially converted into butyl ester and partially neutralized with ammonia.
Claim 4
Dependent Claim
23 words
Coated polyester film according to claim 1 in which (B) is hexamethoxymethylmelamine or melamine-formaldehyde condensate having a methoxymethyl-methylol ratio of at least 1:2.
Claim 5
Dependent Claim
31 words
Polyester/polyolefin laminate which consists of coated polyester film as claimed in claim 1 overcoated with a layer of polyethylene or of ethylene copolymer containing up to 10 mole % of comonomer.
Claim 6
Dependent Claim
13 words
Polyester/polyolefin laminate according to claim 4 in which the polyolefin is low-density polyethylene.