Thermoplastic composition for setting bandages and a solventless process for the manufacture thereof
AssigneeTokyo Eizai Laboratory Co., Ltd.
InventorKoji Usukura
Life of this patent
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Abstract
The invention herein relates to a thermoplastic suitable for setting bandages and a solventless process for the manufacture of setting bandages therewith. The thermoplastic composition comprises a saturated linear polyester and a resin with low crystallizability and a low softening temperature. The setting bandage made according to this invention can be easily applied to injured parts of a body and the cast resulting therefrom is light, inert, waterproof, ventilative, rigid and shockproof. A method for the manufacture of said setting bandages without the use of solvents is also described in detail.
Claims12
An orthopedic setting bandage which comprises
- a thick, soft, woven or knit base fabric of natural or synthetic fibers impregnated with a thermoplastic composition comprising 60% to 80% by weight of a saturated linear polyester and 20% and 40% by weight of a resin having a low crystallinity and a low softening temperature which is selected from the group consisting of polyvinyl either, a copolymer of ethylene and vinylacetate, polyisoprene, polyisobutylmethacrylate, polyethylene, poly (4-hydroxyhexanoic acid) and poly (ethylene terephthalate-ethylene heptadiate) wherein,
- said composition impregnated base fabric will harden to a waterproof, strong, rigid, nonporous, nontacky structure upon being warmed to about 45.degree. C. and subsequently cooled.
A method for preparing a setting bandage without the use of solvents, which comprises:
- (a) forming a homogeneous thermoplastic composition by mixing 60% to 80% by weight of a saturated linear polyester and 20% to 40% by weight of a resin having a low crystallinity and a low softening temperature, which is selected from the group consisting of polyvinyl ether, a copolymer of ethylene and vinylacetate, polyisoprene, polyisobutylmethacrylate, polyethylene, poly (4-hydroxyhexanoic acid) and poly (ethylene terephthalate ethylene heptadiate);
- (b) heating the composition in a vessel to about 110.degree. C. until the composition is melted into a fluid with a viscosity of about 250,000 to 350,000 pois;
- (c) immersing a thick base fabric with large openings into the heated composition until a predetermined amount of composition per unit area of fabric impregnates or coats the fabric;
- (d) removing the fabric impregnated or coated with the composition from said vessel;
- (e) removing any excess composition from the fabric;
- (f) heating the fabric impregnated or coated with composition;
- (g) cooling the fabric coated or impregnated with composition.
Dependencies are inferred from the claim text.