To obtain a composition which can be packed by means of a relatively simple pump and can give a seal having excellent watertightness even under high water pressure by including an amorphous poly-α-olefin, a polybutene and a carbon black having a specified specific surface area.
This composition comprises 30-60 pts.wt. amorphous poly-α-olefin (e.g. amorphous propylene/ethylene copolymer, amorphous propylene/butene-1 copolymer, amorphous propylene/ethylene/butene-1 terpolymer or amorphous propylene/pentene-1 copolymer) having a degree of crystallinity of 2 wt.% or below and a melt viscosity (at 190°C) of 400-9,000 cP, 10-60 pts.wt. polybutene having a kinematic viscosity (at 100°C) of 50-1,000 cP, desirably 100-600 cP, 5-30 pts.wt. carbon black having a specific surface area of 600-1,200 m2/g, desirably 800-1,100 m2/g and a volume resistivity of 102 to 105 Ω cm and optionally 10-40 pts.wt. terpene resin having a softening point of 100-130°C.
KAMIBAYASHI HIROYUKI
TAZAKI MARI
KATO HIROSHI
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