Abstract: Provided is an optical molding material comprising a cyclic polyolefin resin having a glass transition temperature (Tg) of 120° C. to 170° C., wherein the melt viscosity of the resin at 260° C. is 5,000 to 50,000 poises as measured at a shear rate of 10 sec−1 and 200 to 1,000 poises at a shear rate of 10,000 sec−1, and the melt viscosity of the resin at 320° C. is 500 to 5,000 poises at a shear rate of 10 sec−1 and 100 to 800 poises at a shear rate of 10,000 sec−1. An optical molding material comprising a cyclic polyolefin resin, an optical molded product and an optical disk substrate, wherein a variation range of retardation of the resin is within ±10% of the retardation at 590 nm when the wavelength is changed from 400 nm to 830 nm, are provided. The material is molded into, for example, the optical disk substrate.

Abstract: A polyamide resin composition comprising: (a) 100 parts by weight of a polyamide; (b) from about 1 part to about 80 parts by weight of an aromatic polyamide fiber; (c) from about 3 parts to about 80 parts by weight of a polytetrafluoroethylene; and (d) from about 1 part to about 20 parts by weight of high-density polyethylene is disclosed. The polyamide resin composition can be molded into sliding members, like bearings, bushings and slide rails, that demonstrate excellent mechanical and physical properties, like low frictional force, low self-abrasion, and low abrasion to metals.