Abstract: Provided is a crystalline polyamide resin that can exhibit a high mechanical strength and electrical resistance in high temperature regions (in the neighborhood of 150° C.). This polyamide resin has the following: a dicarboxylic acid-derived component unit (a) that includes a component unit (a1) derived from terephthalic acid, naphthalenedicarboxylic acid, or cyclohexanedicarboxylic acid, at more than 20 mol % and up to and including 100 mol % with reference to the total number of moles of the dicarboxylic acid-derived component unit (a); and a diamine-derived component unit (b) that contains a component unit (b1) deriving from alkylenediamine having 4-18 carbon atoms and a component unit (b2) deriving from diamine given by formula (1).

Abstract: To provide: a semiaromatic polyamide which has excellent moldability, heat resistance, chemical resistance and mechanical characteristics; and a molded article of this semiaromatic polyamide. A semiaromatic polyamide (I) of the present invention contains 35-50% by mole of a structural unit derived from terephthalic acid [A], 25-40% by mole of a structural unit derived from isophthalic acid [B], 15-35% by mole of a structural unit derived from an aliphatic dicarboxylic acid [C] (provided that the total of [A], [B] and [C] is 100% by mole), and a structural unit derived from an aliphatic diamine [D] having 4-12 carbon atoms. The molar ratio ([A]/[B]) is from 65/35 to 50/50, and the molar ratio ([C]/[B]) is from 30/70 to 50/50. The melting enthalpy ([increment]H) of the semiaromatic polyamide (I) as determined by differential scanning calorimetry (DSC) is 20-40 mJ/mg, and the intrinsic viscosity of the semiaromatic polyamide (I) is 0.7-1.6 dl/g.

Abstract: To provide: a semiaromatic polyamide which has excellent moldability, heat resistance, chemical resistance and mechanical characteristics; and a molded article of this semiaromatic polyamide. A semiaromatic polyamide (I) of the present invention contains 35-50% by mole of a structural unit derived from terephthalic acid [A], 25-40% by mole of a structural unit derived from isophthalic acid [B], 15-35% by mole of a structural unit derived from an aliphatic dicarboxylic acid [C] (provided that the total of [A], [B] and [C] is 100% by mole), and a structural unit derived from an aliphatic diamine [D] having 4-12 carbon atoms. The molar ratio ([A]/[B]) is from 65/35 to 50/50, and the molar ratio ([C]/[B]) is from 30/70 to 50/50. The melting enthalpy ([increment]H) of the semiaromatic polyamide (I) as determined by differential scanning calorimetry (DSC) is 20-40 mJ/mg, and the intrinsic viscosity of the semiaromatic polyamide (I) is 0.7-1.6 dl/g.

Abstract: A process for producing a cyclic olefin random copolymer by copolymerizing ethylene with a specific cyclic olefin in the presence of a polymerization catalyst containing a transition metal catalyst component and a co-catalyst component, wherein in the process for producing a cyclic olefin random copolymer, at least one component of the transition metal catalyst component and the co-catalyst component is brought into contact with the cyclic olefin, and then brought into contact with the ethylene.