Abstract: A hot-melt adhesive composition containing, (A) per 10 to 80 parts by weight of a base polymer, (B) 10 to 80 parts by weight of a stickiness-imparting agent which is a copolymer of a particular styrene-type monomer and a particular indene-type monomer, the molar ratio of the indene-type monomer to the styrene-type monomer being from 99/1 to 30/70, and the weight average molecular weight of said copolymer being from 300 to 5000. The hot-melt adhesive composition exhibits excellent heat-resistant adhesiveness and heat-resistant creeping property, and has a low-molecular weight and exhibits good hue.

Abstract: A process for the production of a cycloolefin-based random copolymer, which comprises:(A) copolymerizing (a) ethylene and (b) at least one cycloolefin,(B) in the presence of a catalyst comprising a vanadium compound soluble in a mixed solvent described below and an organoaluminum compound.(C) in a mixed solvent comprising (a) a hydrocarbon-based solvent having a solubility parameter (.delta. value) of not less than 7.7 (cal/cm.sup.3).sup.1/2 and (b) a hydrocarbon-based solvent having a solubility parameter (.delta. value) of not more than 7.5 (cal/cm.sup.3).sup.1/2, the mixed solvent having a volume ratio (a)/(b) of 90/10 to 50/50. The said process permits the production of a copolymer in a higher concentration when copolymers having an identical molecular weight to that of conventional copolymers are produced, and permits the production of a copolymer having a higher molecular weight when copolymers are produced in an identical concentration to that of conventional copolymers.

Abstract: Compositions comprising (A) cycloolefin random copolymer containing an ethylene component, and a cycloolefin component represented by the general formula [I] or [II] and having an intrinsic viscosity of 0.05-10 dl/g as measured at 135.degree. C. in decalin and a softening temperature (TMA) not lower than 70.degree. C., and (B) a cycloolefin random copolymer containing an ethylene component, and a cycloolefin component represented by the general formula [I] or [II] and having an intrinsic viscosity of 0.01-5 dl/g as measured at 135.degree. C. in decalin and a softening temperature (TMA) of below 70.degree. C., the weight ratio of said (A) component/(B) component ranging from 100/0.1 to 100/10.The composition is particularly useful for molding an information recording base board.

Abstract: A power transmission apparatus comprises first and second rotary devices rotatable with respect to each other, a sealed chamber hermetically formed between the first and second rotary devices and filled with viscous fluid, first and second resistance devices disposed within the sealed chamber and respectively rotatable together with the first and second rotary devices to transmit torque therebetween by the shearing resistance of the viscous fluid, and a third device for controlling the pressure within the sealed chamber in accordance with the running state of an object provided with the power transmitting apparatus.