NBR composition and sealing rubber material

摘要

Providing an NBR composition substantially free of containment of an insolubilized substance-generating causative substance so as to prevent generation of an insolubilized substance due to extraction by a fuel while which composition is excellent in ozone resistance, ejectability from kneader, and which composition realizes a first compression set and a second compression set which are both 46% or less. An NBR composition including a polymer obtained by mixing an acrylonitrile-butadiene rubber (NBR) with polyvinyl chloride (PVC), wherein the NBR composition is obtained without blending an insolubilized substance-generating causative substance, or, in case of blending, by blending an insolubilized substance-generating causative substance at an upper limit of 0.15 parts by weight or less, into 100 parts by weight of the polymer having a PVC content of 15.70 to 17.50 wt %.

主权项

1. A sealing rubber material obtained by cross-linkingly molding an acrylonitrile-butadiene rubber (NBR) composition by using sulfur as a vulcanizing agent;
wherein the NBR composition comprises a polymer obtained by mixing an NBR with polyvinyl chloride; wherein the NBR composition is obtained by blending an insolubilized substance-generating causative substance within a limit of 0 to 0.15 parts by weight, into 100 parts by weight of the polymer having a PVC content of 15.70 to 17.50 wt %; and wherein the insolubilized substance-generating causative substance is a wax component and/or stearic acid.