Process for the preparation of polyisocyanate prepolymers and polyurethanes having high temperature performance and low hysteresis
AssigneeAir Products and Chemicals, Inc.
InventorsWilliam E. Starner, Jeremiah P. Casey, Barton Milligan, Susan M. Clift
Life of this patent
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Abstract
This invention relates to a polyisocyanate prepolymer for polyurethane/urea elastomer synthesis and to the resulting elastomer. The prepolymer is formed by reacting toluenediisocyanate with a long chain polyol under conditions such that essentially a 2:1 adduct is formed. Excess toluenediisocyanate is removed prior to forming the elastomer.
Claims16
In a process for producing a reaction product comprising a prepolymer suited for producing polyurethane/urea elastomers, wherein toluenediisocyanate is reacted with a long chain polyol to produce a prepolymer and the prepolymer reacted with an aromatic diamine, to form a polyurethane/urea elastomer, the improvement for producing such prepolymer and for enhancing physical properties in the resulting polyurethane/urea elastomer which comprises:
- (a) reacting an isomer of 2,4- or 2,6-toluene diisocyanate with a long chain diol at a temperature from about 0.degree. to 90.degree. C. and at a mole ratio of toluenediisocyanate to long chain diol from 4 to 20:1 to form a prepolymer such that at least about 90% of such prepolymer consists of a prepolymer of two moles toluenediisocyanate per mole of long chain diol;
- and
- (b) removing unreacted toluenediisocyanate from the reaction product comprising prepolymer to a level of less than about 0.15%.
A toluenediisocyanate end-capped prepolymer reaction product formed by the reaction of 2,4-toluenediisocyanate or 2,6-toluenediisocyanate, or mixtures thereof, and a long chain diol wherein at least 90% of the prepolymer consists of a prepolymer of 2 moles reacted toluenediisocyanate per mole of long chain diol and;
- further, said prepolymer reaction product having an unreacted toluenediisocyanate content of less than about 0.15% by weight of said prepolymer reaction product.
Dependencies are inferred from the claim text.