Moisture-curing polyurethane hot-melt adhesive composition

TLDR: In this paper, a polyester polyol having a number-average molecular weight of 1,000-8,000 is compounded with 0.1-5 wt.% tertiary amine and 20-5,000 ppm of a phosphoric acid ester.

Abstract: PROBLEM TO BE SOLVED: To obtain an adhesive composition exhibiting excellent initial tack and good heat resistance and storage stability by reacting a mixture prepared by compounding a polyester polyol having a specified molecular weight with a specified amount of a tertiary amine and a specified amount of a phosphoric acid ester with an excess of an organic isocyanate compound. SOLUTION: A polyester polyol having a number-average molecular weight of 1,000-8,000 is compounded with 0.1-5 wt.% tertiary amine and 20-5,000 ppm of a phosphoric acid ester. The polyester polyol and the organic isocyanate compound are not particularly limited. The tertiary amine used may be a monoamine such as tripropylamine or tributylamine or a polyamine such as tetramethyl-1,2-diaminoethane, or tetramethylhexamethylenediamine. The phosphoric acid ester used is exemplified by trioctyl phosphate, tridecyl phosphate, or triphenyl phosphate. The ratio of the number of the NCO groups to that of the OH groups in the urethane formation reaction is desirably 1.3-5.0.