| 摘要 |
PROBLEM TO BE SOLVED: To provide a soft composition having a rubber hardness of 5 or less and yet heat resistance of at least 80 deg.C and excellent in vibration-proof proper ties and impact-absorbing properties and the like without employing a secondary means such as a plasticizer or the like which can be a factor of bleeding with time and to provide a novel self-adhesive material hardly suffering from deterio ration with time because the self-adhesive properties originate in the composition itself. SOLUTION: The soft composition composed of a novel polyurethane resin, excellent in heat resistance and having a rubber hardness of 5 or loss is obtained by reacting a polyol having a mol. wt. of 700-2,000 and bearing a terminal, primary hydroxy group or a polyol having a functionality of 3 and a mol.wt. of 6,000-8,000 and partially bearing a terminal, primary hydroxy group with a polyphenyl polymethylene polyisocyanate in an amount of less than the theoretical amount.
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