| abstract |
PURPOSE: To provide the titled composition exhibiting high dynamic modulus after vulcanization, and having excellent moldability, by compounding a solid rubber such as natural rubber, a specific liquid diene rubber, a masked polyisocyanate, and a novolac-type (modified) phenolic resin. n CONSTITUTION: The objective composition is prepared by compounding (A) 100pts.wt. of rubber components composed of (i) 70W95pts. of a solid rubber selected from natural rubber, polyisoprene rubber, polybutadiene rubber, and styrene-butadiene copolymer rubber and (ii) 30W5pts. of a liquid diene rubber having functional groups at the molecular terminals or in the molecule, with (B) a masked polyisocyanate and (D) 5W25pts. of a novolac-type phenolic resin and/ or a novolac-type modified phenolic resin. The ratio of the isocyanate equivalent in the component (C) to the functional group equivalent in the component (B) is adjusted to 0.5W2.0. n EFFECT: Excellent breaking properties. n COPYRIGHT: (C)1982,JPO&Japio |