| 摘要 |
PROBLEM TO BE SOLVED: To obtain a lightweight polyurethane elastomer capable of being relatively easily controlled in elasticity, strengths, harness, etc., by reacting two specified polyols with a polyisocyanate in the presence of a weight-reducing agent. SOLUTION: A mixture comprising 1mol of an at least trifunctional polyol and 1-3mol of a difunctional polyol and having a molecular weight of 1,500-10,000 is mixed with a polyisocyanate in an OH/NCO molar ratio of 1-1.5. The obtained mixture is mixed with 1-4wt.% weight-reducing agent comprising microballoons having a particle diameter of 10-30μm, optionally 10-70wt.% phosphorus flame retardant such as triphenyl phosphate or tricreasyl phosphate and 10-70wt.% plasticizer such as tri-2-ethylhexyl phosphate. The resulting mixture is poured into a preheated mold and cured by reaction.
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