The PVC constituent and the electric wire cable null degree of polymerization

摘要

PROBLEM TO BE SOLVED: To obtain a protective layer for an electric wire or cable which can be easily processed and can be easily torn and removed without using a special tool by forming the layer from a PVC compsn. prepd. by compounding and kneading a low-degree of polymn. straight PVC having a specified degree of polymn. or lower, a medium-degree of polymn. straight PVC having a specified degree of polymn. or higher. and necessary additives in a specified ratio of the former PVC to the latter. ;SOLUTION: A straight PVC having a degree of polymn. of 600 or lower in an amt. of 30% or higher, a straight PVC having a degree of polymn. of 800 or higher in an amt. of 40% or higher, and necessary additives are mixed and kneaded, and the resultant compsn. is formed into the objective protective layer. If necessary, the compsn. may further contain a crosslinked PVC. An electric wire or cable is produced by covering a plurality of cores in one bundle with the compsn. and covering the external surface of the resultant product with a sheath. A filler in an amt. of 80-160 pts.wt. based on 100 pts.wt. PVC is incorporated as one of the additive into the compsn. Thus obtd. electric wire or cable can be easily freed from the protective layer in the laying work without causing the degradation in strengths.;COPYRIGHT: (C)1998,JPO