Thermoplastic and elastomeric polyurethane products - by reacting quasi-isocyanate and quasi-hydroxylated prepolymers

摘要

Polyurethane prodts. are prepd. by reacting (I) an isocyanate prepolymer prepd. from (a) 3-12, esp. 4-6, moles diisocyanate having an ave. mol.wt. of 100-500, pref. 150-300, and (b) 1 mole diol having a mol.wt. of 500-4500, pref. 500-2500, and (II) a hydroxylated prepolymer prepd. from (a) an isocyanate prepolymer prepd. from 1.8-2.5 moles diisocyanate having a mol.wt. of 100-500, and 1 mole diol having a mol.wt. of 500-4500, and (b) a diol having a mol. wt. of 60-250, esp. 60-128. The amt. of (IIb) is 4-17 moles per mole of diol used for the prepn. of (IIa), and the reaction mixt. has an isocyanate no. of 100-115, esp. 101-105. The prodts. may be solid or microcellular, thermoplastic or elastomeric. Wide range of applications, e.g., adhesives, coatings, packaging, mouldings, and footwear.