Thermoplastic polyester polyurethanes
AssigneeThe Upjohn Company
InventorsHenry W. Bonk, Richard W. Oertel
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Abstract
Novel thermoplastic polyester polyurethanes are disclosed which are obtained by reacting a polyester diol, a difunctional extender, a methylenebis(phenyl isocyanate), and from about 0.0025 mole to about 0.03 mole per equivalent of isocyanate of a monocarbodiimide product derived from a methylenebis(phenyl isocyanate) or the corresponding uretidinedioneimine adduct thereof with said latter methylenebis(phenyl isocyanate). The polyester polyurethanes are characterized by a combination of thermoplasticity, extremely good hydrolytic stability which cannot be diminished by solvent action, good physical properties, particularly tensile strength and elongation, and enhanced clarity of molded articles.
Claims9
In a thermoplastic polyester polyurethane prepared from a polyester diol, a difunctional extender, and methylenebis(phenyl isocyanate) the improvement which comprises employing a methylenebis(phenyl isocyanate) which contains from about 0.0025 mole to about 0.03 mole per equivalent of isocyanate of (i) a monocarbodiimide product derived from a methylenebis(phenyl isocyanate) or (ii) the corresponding uretidinedioneimine adduct formed by said monocarbodiimide with said methylenebis(phenyl isocyante).
A thermoplastic polyurethane prepared from:
- (a) a blend comprising from about 50 to about 95 equivalent percent of 4,4'-methylenebis(phenyl isocyanate) and the remaining 5 to 50 equivalent percent being 4,4'-methylenebis(phenyl isocyanate) containing from about 0.05 mole to about 0.06 mole per equivalent of said latter isocyanate of (i) the monocarbodiimide product derived from said 4,4'-methylenebis(phenyl isocyanate), or (ii) the corresponding uretidinedioneimine adduct formed by said monocarbodiimide with said 4,4'-methylenebis(phenyl isocyanate),
- (b) a polyalkylene ester diol,
- (c) an aliphatic straight chain diol having from
- two to six carbon atoms, inclusive,
- wherein the equivalent proportions of (b) to (c) is within the range of from about 1:1 to 1:12 and the overall ratio of equivalents of isocyanate to equivalents of active hydrogen materials is within the range of 0.95:1 to 1.10:1.
Dependencies are inferred from the claim text.