Abstract: A polishing sheet which can improve waviness at a face of a material to be polished and which has a long life is provided. The polishing pad 1 has a polyurethane sheet 2 made of polyurethane resin. The polyurethane sheet 2 has a polishing layer which is disposed inside a surface layer and which is allowed to wear away by polishing and whose thickness is larger than a thickness of the surface layer. The polishing layer has an approximately uniform foam structure in a direction of the thickness of the polishing sheet 2 by being formed foams whose space volume is larger than that of foams formed at the surface layer and which are communicated so as to form a network by continuous holes.

Abstract: The present invention provides a polishing pad whose unevenness in thickness hardly occurs and whose life can be improved. A polishing pad 1 is provided with a polyurethane sheet 2. Foams 3 having lengths of about ½ of the length of the polyurethane sheet 2 in its thickness direction and elongated foams 4 having lengths of at least 70% of the length of the polyurethane sheet 2 in the thickness direction are formed in the polyurethane sheet 2. The foams 3 and the elongated foams 4 are opened by buffing processing so that opened pores 5 and opened pores 6 are formed at a polishing face P, respectively. Regarding the opened pores 5, 6, the total number of opened pores having opened pore diameters falling in a range of from 30 to 50 ?m occupies at least 50% of the number of all opened pores. The total number of the opened pores 5, 6 per 1 mm2 of the polishing face P is set in a range of from 50 to 100.

Abstract: A polishing sheet which can improve waviness at a face of a material to be polished and which has a long life is provided. The polishing pad 1 has a polyurethane sheet 2 made of polyurethane resin. The polyurethane sheet 2 has a polishing layer which is disposed inside a surface layer and which is allowed to wear away by polishing and whose thickness is larger than a thickness of the surface layer. The polishing layer has an approximately uniform foam structure in a direction of the thickness of the polishing sheet 2 by being formed foams whose space volume is larger than that of foams formed at the surface layer and which are communicated so as to form a network by continuous holes.

Abstract: The present invention provides a polishing pad whose unevenness in thickness hardly occurs and whose life can be improved. A polishing pad 1 is provided with a polyurethane sheet 2. Foams 3 having lengths of about ½ of the length of the polyurethane sheet 2 in its thickness direction and elongated foams 4 having lengths of at least 70% of the length of the polyurethane sheet 2 in the thickness direction are formed in the polyurethane sheet 2. The foams 3 and the elongated foams 4 are opened by buffing processing so that opened pores 5 and opened pores 6 are formed at a polishing face P, respectively. Regarding the opened pores 5, 6, the total number of opened pores having opened pore diameters falling in a range of from 30 to 50 ?m occupies at least 50% of the number of all opened pores. The total number of the opened pores 5, 6 per 1 mm2 of the polishing face P is set in a range of from 50 to 100.

Abstract: A polishing sheet which can improve waviness at a face of a material to be polished and which has a long life is provided. The polishing pad 1 has a polyurethane sheet 2 made of polyurethane resin. The polyurethane sheet 2 has a polishing layer which is disposed inside a surface layer and which is allowed to wear away by polishing and whose thickness is larger than a thickness of the surface layer. The polishing layer has an approximately uniform foam structure in a direction of the thickness of the polishing sheet 2 by being formed foams whose space volume is larger than that of foams formed at the surface layer and which are communicated so as to form a network by continuous holes whose diameter is smaller than that of the space volume of the foams formed at the polishing layer.