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AssigneeThe Upjohn Company
InventorsHenry W. Bonk, Tilak M. Shah
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Polyurethane polyether-based elastomers are described which are thermoplastic, recyclable and have increased high temperature resistance which permits fabrication by injection molding. The elastomers are the product of reaction of 4,4'-methylenebis(phenyl isocyanate), a particular group of polypropylene oxide-polyethylene oxide block copolymers and an extender [straight chain aliphatic diols C.sub.2-6 or the bis(2-hydroxyethyl ether) of hydroquinone or resorcinol]. The block copolymers have at least 50 percent primary hydroxyl groups, a pH in the range of 4.5 to 9, a content of alkali metal ion less than 25 ppm and a molecular weight of 1000 to 3000. The minimum ethylene oxide (E.O.) residue content (percent by weight) of the polyether for any molecular weight (M.W.) is governed by the equation: ##EQU1## In a particularly preferred embodiment the elastomers are prepared by replacing up to 25 percent by equivalents of the extender by certain diols (polyethylene glycols up to 1500 M.W. preferred).
A thermoplastic, recyclable polyurethane elastomer which is the product of reaction of
A thermoplastic, recyclable, polyurethane elastomer which is the product of reaction of:
A thermoplastic, recyclable, polyurethane elastomer according to claim 7 wherein up to 25% of the 1,4-butanediol is replaced by an equivalent amount of dipropylene glycol.
A thermoplastic, recyclable, polyurethane elastomer which is the product of reaction of:
A thermally stable polyurethane elastomer which is a reaction product of (a) a poly(oxypropylene)-poly(oxyethylene) glycol of molecular weight from about 1000 to about 3000 and containing 15 to 50% by weight of oxyethylene groups (b) methylenebis(4-phenylisocyanate) and (c) 1,4-butanediol;
A thermally stable polyurethane elastomer as in claim 13 in which the molecular weight of (a) is about 2000 and the oxyethylene group content is 30-45%.
Dependencies are inferred from the claim text.