PURPOSE: To obtain the surface of a glass plate which is little in undulation, and shallow and little in a flaw and a microcrack through a little quantity of polishing by specifying the hardness of a high hardness layer which functions as a surface layer for polishing and has an impregated abrasive grain.
CONSTITUTION: A glass plate polishing pad has a soft layer 3 stuck to a high hardness layer 1 through a pressure sensitive adhesive double coated tape. The hardness of the high hardness layer 1 is set up to be more than Hs 90 in a hardness test (A type) prescribed by JIS:K6301. In addition, the hardness of the soft layer 3 serving as the backside of the high hardness layer 1 is set up to be less than 80 in a hardness test prescribed by JIS:S6050. The thickness of the high hardness layer 1 and of the soft layer 3 is set up to be 0.5 to 3mm or preferably 0.8 to 1.5mm, and the above thickness is desirable for the glass plate polishing pad to deform according to an irregular shape having a cycle larger than 50mm and not to deform according to the irregular shape having a small cycle being about 3 to 30mm.
TAKAKUSA TOSHIHARU