Abstract: A cooling medium and a cooling device for optical equipment using the same, which cooling medium has a refractive index in a specific range, hardly causes the problem to dissolve or swell plastic lens and other component parts, and is flame retardant. The cooling medium comprises a cyclic aliphatic hydrocarbon having at least one cross linkage and has a flash point of 120° C. or above and a melting point of −20° C. or below. The space between a pair of transparent optical members of a cooling device for optical equipment, is filled with the cooling medium.

Abstract: Disclosed is a traction drive fluid which comprises (A) one or more than two compounds selected from the group consisting of saturated polycyclic hydrocarbon compounds represented by the formulae: wherein R1 and R2 are each independently hydrogen or a methyl group, provided that the case where both R1 and R2 are a methyl group at the same time is excluded, and R3 and R4 are each independently hydrogen or a methyl group; wherein R5 and R6 are each independently hydrogen or a methyl group, provided that the case where both R5 and R6 are a methyl group at the same time is excluded, R7 and R8 are each independently hydrogen or a methyl group; and wherein R9, R10 and R11 are each independently hydrogen or a methyl group.

Abstract: The present invention provides a process for producing alkylidenenorbornenes by reacting C.sub.4 -C.sub.6 acyclic conjugated dienes with cyclopentadiene, dicyclopentadiene, or a methyl- or dimethyl-substituted derivative thereof in the presence of a catalyst derivative composed of:(A) a titanium-containing compound, and(B) at least one metallic reducing agent containing the group IA, IIA or IIIA metals in the periodic table.