Patent ID: 6034208
Filing Date: 2000-03-07
Classification: C08F,C08G

Abstract:
A copolymer useful as a cement additive obtained by(a) oxyalkylating an initiator molecule selected from the group consisting of hydroxyalkyl acrylates, hydroxyalkyl methacrylates, and monounsaturated monocarboxylic acids with an alkylene oxide in the presence of an effective amount of a double metal cyanide complex catalyst under conditions effective to form a well-defined unsaturated macromonomer having a terminal hydroxyl functionality and not more than substantially one initiator molecule per unsaturated macromonomer molecule; and(b) copolymerizing the unsaturated macromonomer with at least one comonomer which is ethylenically unsaturated and has at least one carboxylic acid-based group selected from free carboxylic acids, carboxylic acid salts, hydroxyalkyl esters of carboxylic acids, and carboxylic acid anhydrides.