Abstract: A composition for production of cover packing, comprising: (A) a blocked isocyanate, (B) an active hydrogen group-containing compound having average two or more functional groups, (C) an organic substance powder having an average particle diameter of 40 to 250 &mgr;m, and (D) an inorganic substance powder having an average particle diameter of less than 40 &mgr;m; and a method for production of cover packing using the composition. With this composition which is a one-pack type, curable composition, no apparatus for mixing the main material and the curing agent is required; by heating, dissociation of blocking agent and completion of reaction are allowed to take place simultaneously; and a cover packing superior in mechanical strength, etc. can be formed.

Abstract: A composition for production of cover packing, comprising:

Abstract: Polymers of C4 olefins having a viscosity of 15 to 35 centistokes at 100.degree. F show improved performance as cosmetic oils, in comparison with squalane. These polymers are prepared by polymerizing (a) isobutylene by itself, or (b) C4 hydrocarbon olefin containing a mixture of at least two of isobutylene, 1-butene, 2-butene and butadiene, using a catalyst; then removing high molecular weight and low molecular weight compounds by distillation; hydrogenating the remainder of the polymerization product; removing carbonyl compounds therefrom if necessary and further purifying the resultant polymer by steam distillation or treating same with activated carbon or solvent extraction, to deodorize same.