| 摘要 |
Articles comprising multilayer coextruded films having polyester and polyamide layers adhered with a copolymer of polyester and a sulfonic acid or its derivative, having high oxygen barrier properties and temperature resistance that are capable of being heated to 425° F. in a conventional oven are disclosed. The articles are packages, such as bags, pouches, and casings that are particularly useful for packaging and cooking foodstuffs such as meat, poultry, seafood and the like. |
| 主权项 |
1. An article comprising a coextruded multilayer film wherein the film comprises a sulfonic acid-containing polyester layer in direct contact with a polyamide layer and with a sealant layer, the film optionally also comprising a barrier layer;
wherein the sulfonic acid-containing polyester is a sulfonic acid-containing copolymer consisting of units of sulfobenzenedicarboxylic acid, terephthalic acid, optionally other diacids selected from the group consisting of succinic acid, adipic acid, azelaic acid, sebacic acid, glutaric acid, 1,10-decanedicarboxylic acid, phthalic acid, isophthalic acid and dodecanedioic acid, ethylene glycol and optionally one or more other diols selected from the group consisting of propylene glycol, methoxypolyalkylene glycol, neopentyl glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, diethylene glycol, polyethylene glycol and cyclohexane dimethanol, or a blend of a polyester and the sulfonic acid-containing copolymer; the polyester in the blend is polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, or combinations of two or more thereof; the sulfobenzenedicarboxylic acid is sulfobenzenedicarboxylic acid, a salt of the acid, an ester of the acid, an ester of the salt of the acid, or combinations of two or more thereof; and the barrier layer is at least one polymer including ethylene/vinyl alcohol copolymer, polyamide, polyvinylidene chloride, polyalkylene carbonate, or combinations of two or more thereof; wherein the sulfonic acid-containing polyester comprises from 0.01 to 5 mol % of the sulfobenzenedicarboxylic acid, and wherein the film can withstand submersion in water at 100° C. for 12 hours; the sealant layer is an outer layer and is polyester having a Tg below 65° C.; the film has a free shrink at 185° F. of at least 10% in one or both of the machine and transverse directions; and the film can withstand exposure to cooking conditions at 425° F. for 3 hours. |
