Patent ID: 6264739
Filing Date: 2001-07-24
Classification: C04B

Abstract:
A method for improving the foam-stability of a plaster composition which comprises adding a copolymer prepared by copolymerizing a monomer (a) represented by the following formula (A) with a monomer (b) selected from the group consisting of the compounds represented by the following formula (B) and those represented by the following formula (C) to a plaster composition: ##STR7##wherein R.sub.1 and R.sub.2 may be the same or different from each other and each represents a hydrogen atom or a methyl group; ml is an integer of 0 to 300; AO represents an oxyalkylene group having 2 to 3 carbon atoms; n is a number of 2 to 300; and X represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, ##STR8##wherein R.sub.3, R.sub.4 and R.sub.5 may be the same or different from one another and each represents a hydrogen atom, a methyl group or a group represented by the formula: (CH.sub.2).sub.m2 COOM.sub.2 (wherein m2 is an integer of 0 to 2; and M2 represents a hydrogen atom, an alkali metal atom, 1/2 an alkaline earth metal atom, an ammonium group, an alkylammonium group or a substituted alkylammonium group); and M1 represents a hydrogen atom, an alkali metal atom, 1/2 an alkaline earth metal atom, an ammonium group, an alkylammonium group or a substituted alkylammonium group, and ##STR9##wherein R.sub.6 represents a hydrogen atom or a methyl group; and Y represents a hydrogen atom, an alkali metal atom, 1/2 an alkaline earth metal atom, an ammonium group, an alkylammonium group or a substituted alkylammonium group.