Abstract: [1] A ?-phellandrene polymer which is a polymerization product of ?-phellandrene. [2] The ?-phellandrene polymer comprising ?-phellandrene units represented by chemical formulae (I-1), (I-2), (II-1) and (II-2), a total amount of the ?-phellandrene units being 50% by mass or more. [3] The ?-phellandrene polymer, which has a number average molecular weight Mn of 40,000 or more. [4] The ?-phellandrene polymer, wherein at least a part of olefinic carbon-carbon double bonds thereof are hydrogenated. [5] The ?-phellandrene polymer, which has a glass transition temperature of 80° C. or more.

Abstract: [1] A ?-phellandrene polymer which is a polymerization product of ?-phellandrene. [2] The ?-phellandrene polymer comprising ?-phellandrene units represented by chemical formulae (I-1), (I-2), (II-1) and (II-2), a total amount of the ?-phellandrene units being 50% by mass or more. [3] The ?-phellandrene polymer, which has a number average molecular weight Mn of 40,000 or more. [4] The ?-phellandrene polymer, wherein at least a part of olefinic carbon-carbon double bonds thereof are hydrogenated. [5] The ?-phellandrene polymer, which has a glass transition temperature of 80° C. or more.

Abstract: It is an object of the present invention to provide a release film which is superior in the flexibility at high temperature, the conformability to circuit patterns, the heat resistance, the releasing property and the non-contaminative property, and easily discarded after use. The present invention relates to a release film, which is used in a manufacturing process of a printed-circuit board, a flexible printed-circuit board or a multilayer printed-circuit board, having a layer comprising a resin composition comprising a resin having a polar group in a main chain as a matrix and having a halogen content of 5% by weight or less on at least one surface.

Abstract: It is an object of the present invention to provide a release film which is superior in the flexibility at high temperature, the conformability to circuit patterns, the heat resistance, the releasing property and the non-contaminative property, and easily discarded after use. The present invention relates to a release film, which is used in a manufacturing process of a printed-circuit board, a flexible printed-circuit board or a multilayer printed-circuit board, having a layer comprising a resin composition comprising a resin having a polar group in a main chain as a matrix and having a halogen content of 5% by weight or less on at least one surface.

Abstract: A resin foamed product is formed of a resin, and closed cells dispersed in the resin. The resin with the closed cells therein has a shape-recoverable property at an ambient temperature, a closed cell rate higher than 30% and a compression permanent set lower than 10%. Thus, when contraction takes place in the resin with the closed cells, after a predetermined time has passed without providing an outer stimulation to the resin, a shape of the resin foamed product formed of the resin with the closed cells is automatically recovered at least in one direction without equally expanding in all directions.