| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a reclaimed rubber, which is reclaimed from used tires, hoses, scrap materials produced from a rubber molding step, etc., and in which rubber particles are finely dispersed and which has high modulus of elasticity, strengths, elongation and good surface quality by simultaneously applying heat and shearing force to a composite vulcanized rubber comprising at least two rubbers to simultaneously effecting fine dispersion and reclamation. SOLUTION: To apply heat for reclaiming a composite vulcanized rubber, that temperature, at which the sulfur crosslinkages of the constituent rubber can be cleaved, is desirable, and a temperature high enough to cause the cleavage of the main chain of the rubber molecule is not desirable. In particular, it is in the range from 180 to 350 deg.C and is selected according to the type of the rubber used and the magnitude of shearing force. The shearing force applied for the reclamation is desirably 150 kg/cm<2> . The optimal shearing force depends on the type of the rubber used. The apparatus for applying shearing force is exemplified by a twin-screw extruder. The obtained reclaimed rubber is then compounded with a vulcanizing agent, and the obtained compound is suitably subjected to e.g. molding to form a fresh rubber molding.</p> |
