COPOLYMER FOR CEMENT ADMIXTURES AND ITS PRODUCTION PROCESS AND USE

摘要

THE PRESENT INVENTION PROVIDES: A COPOLYMER FOR CEMENT ADMIXTURES WHICH DISPLAYS HIGH DISPERSIBILITY WITH A SMALL ADDING AMOUNT AND EXCELLENT DISPERSIBILITY PARTICULARLY EVEN IN A HIGH WATER REDUCING RATIO AREA, A CEMENT ADMIXTURE UTILIZING THE COPOLYMER, AND A CEMENT COMPOSITION, AND FURTHER, A PRODUCTION PROCESS FOR THE COPOLYMER. THE COPOLYMER FOR CEMENT ADMIXTURES COMPRISES: CONSTITUTIONAL UNIT (I) DERIVED FROM UNSATURATED POLYALKYLENE GLYCOL ETHER MONOMER (a) HAVING AN ALKENYL GROUP HAVING 5 CARBON ATOMS AND AN OXYALKYLENE GROUP HAVING 2 TO 18 CARBON ATOMS WITH AN AVERAGE ADDITION NUMBER OF MOLES OF THE OXYALKYLENE GROUPS TO BE IN THE RANGE OF 10 TO 300; AND CONSTITUTIONAL UNIT (II) DERIVED FROM UNSATURATED MONOCARBOXYLIC ACID MONOMER (b). THE CEMENT ADMIXTURE INCLUDES THE COPOLYMER FOR CEMENT ADMIXTURES AS AN ESSENTIAL COMPONENT, AND MAY FURTHER INCLUDE A DEFOAMING AGENT. THE CEMENT COMPOSITION INCLUDES THE COPOLYMER FOR CEMENT ADMIXTURES, AND CEMENT AS ESSENTIAL COMPONENTS. THE PRODUCTION PROCESS FOR THE COPOLYMER COMPRISES: COPOLYMERIZING COMONOMERS INCLUDING UNSATURATED POLYALKYLENE GLYCOL ETHER MONOMER (a) AND UNSATURATED MONOCARBOXYLIC MONOMER (b) AS ESSENTIAL COMPONENTS BY USE OF A CHAIN-TRANSFER AGENT, AND/OR ADJUSTING pH OF A RESULTANT REACTION MIXTURE TO NOT LESS THAN 5 AFTER THE COPOLYMERIZATION.