| 摘要 |
PROBLEM TO BE SOLVED: To obtain a flexible polyurethane foam compound desirably used to form a seal material excellent in ozone resistance and recovery from deformation by mixing a major proportion of a polyol with a major proportion of an isocyanate and a crosslinking agent. SOLUTION: This compound is prepared by mixing 100 pts.wt. polyol (A) with 20-100 pts.wt. isocyanate (B) such as tolylene diisocyanate, 0.1-10 pts.wt. crosslinking agent (C), 0-15 pts.wt. blowing agent such as water, 0.5-20 pts.wt. ozone aging resister such as phenyl-1-naphthylamine, etc., and gives a flexible urethane foam by foaming, curing, and crosslinking. This foam shows an increase in air permeability of at most 100 cc/cm2/sec and a tensile strength retentivity of at least 60% after 504 hr exposure in an ozone aging test. Component A is exemplified by a polyether polyol or polyester polyol having a number- average molecular weight of 1,000-10,000 and an OH value of 20-100. Component C is exemplified by trimethylolpropane or 1,4-butanediol having a molecular weight of 50-500 and a functionality of 2-10.
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