Process for the preparation of urethane resins and urethane resin compositions

摘要

A process for the preparation of urethane resins, which comprises the steps of: preparing a product(A) having a hydrolysable group directly bonded to 1-10 silicon atoms and having less than two secondary amino groups in one molecule; preparing a product(B) having a terminal isocyanate group in an amount 4% or less by weight of said product(B); and reacting said product(A) with said product(B) in proportions of at least 0.5 equivalent of the product(A) per free NCO group of said product(B). The process can readily give urethane resins which exhibit excellent storage stability and are enhanced in the degrees of freedom of physical properties of products of curing.