Polyester resin synthesis from isophthalic acid and diol - in presence of metal catalyst and small amt. of protonic acid, useful as soln. adhesive

摘要

Synthesis of polyester resin (I) contg. repeating units derived from isophthalic acid (IPA) comprises reacting at least one dicarboxylic acid (one must be IPA), or its diester with at least one diol in the presence of (a) a metal catalyst and (b) a Bronsted acid (A) with pKa at least about 2.5. The new feature is that reaction is in presence of 1-49.9 ppm (A), the amt. of (A) being related to the wt. of (I) being made. Reaction is in presence of 2-20 (5-10) ppm of (A). USE/ADVANTAGE - (I) is dissolved in solvent to produce soln. adhesives which remain free of turbidity (caused by cyclic oligomeric by-products) during long term storage.