Patent ID: 6716896
Filing Date: 2004-04-06
Classification: C04B,C07C,C08F,C08G

Abstract:
A method for the production of a polycarboxylic acid type copolymer for the use in a cement dispersant which comprises reacting by the esterification of an alcohol represented by the formula (1):R1O(R2O)nHâ€ƒâ€ƒ(1) wherein R1 represents a hydrocarbon group of 1 to 30 carbon atoms, R2O represents an oxyalkylene group of 2 to 18 carbon atoms, providing that the repeating units, R2O, may be the same or different and that when the R2O's are in the form of a mixture of two or more species, the repeating units, R2O, may be added either in a block form or in a random form, and n represents an average addition mol number of oxyalkylene groups and is in the range of 1 to 300, with (meth)acrylic acid while causing an antigelling agent to act on a distillate, to obtain an alkoxy polyalkylene glycol mono(meth)acrylic acid type monomer (a), and copolymerizing 5 to 98% by weight of said alkoxy polyalkylene glycol mono(meth)acrylic acid type monomer (a), 95 to 2% by weight of a (meth)acrylic acid type monomer (b) represented by the following formula (2): wherein R3 represents a hydrogen atom or a methyl group, and M1 represents a hydrogen atom, a monovalent metal element, a divalent metal element, an ammonium group, or an organic amine group,and 0 to 50% by weight of a monomer (c) copolymerizable with the monomers mentioned above, providing that the total amount of the monomers (a), (b), and (c) be 100% by weight.