Abstract: A polished-piece holder capable of preventing a polished piece from taking scratches, being increased in wear resistance, thickness accuracy, warpage resistance and dimensional stability, and preventing a deterioration in polishing accuracy. The polished-piece holder includes a core layer and a wear-resistant surface layer laminated on at least one of front and rear surfaces of the core layer. The core layer is constituted of at least one thermosetting resin impregnated fibrous layer and the surface layer is likewise constituted of a thermosetting resin impregnated fibrous layer. The thermosetting resin impregnated fibrous layer constituting the surface layer is subject to heating and pressurizing, to thereby provide a prepreg wherein a nonwoven aramid fiber substrate is impregnated with thermosetting resin.

Abstract: A polished-piece holder capable of preventing a polished piece from taking scratches, being increased in wear resistance, thickness accuracy, warpage resistance and dimensional stability, and preventing a deterioration in polishing accuracy. The polished-piece holder includes a core layer and a wear-resistant surface layer laminated on at least one of front and rear surfaces of the core layer. The core layer is constituted of at least one thermosetting resin impregnated fibrous layer and the surface layer is likewise constituted of a thermosetting resin impregnated fibrous layer. The thermosetting resin impregnated fibrous layer constituting the surface layer is subject to heating and pressurizing, to thereby provide a prepreg wherein a nonwoven aramid fiber substrate is impregnated with thermosetting resin.

Abstract: Disclosed is a heat insulating plate including a plurality of superposed, heat-resisting, synthetic paper sheets integrally bonded with each other, and one or more metal films interposed between adjacent two of the plurality of synthetic paper sheets.

Abstract: A process for the preparation of a copper phthalocyanine pigment, which comprises dry grinding crude copper phthalocyanine, treating the dry ground crude copper phthalocyanine with an aqueous solution of a mineral acid under such conditions of acid concentration and temperature as not to transform the .beta. form contained in the ground crude copper phthalocyanine into the .alpha. one to thereby carry out the pigmentation and removing the mineral acid from the resulting mixture.