Patent ID: 7265168
Filing Date: 2007-09-04
Classification: C04B

Abstract:
1. A high-strength hydraulic cement composition comprising cement, fine aggregates, coarse aggregates, water and an admixture, said hydraulic cement composition containing water and said cement at a weight ratio of 20-40%, having a unit amount of water 120-185 kg/m 3 and containing 0.1-3.0 weight parts of said admixture per 100 weight parts of said cement, said admixture comprising one or more selected from the group consisting of reaction mixtures obtained by Process 1 and Process 2 and partially or completely neutralized substances of said reaction mixtures obtained by said Process 1, said Process 2 and also Process 3 wherein said Process 1 is a process of initiating a radical copolymerization process of a radical polymerizable monomer mixture containing maleic anhydride and a monomer shown by Formula 1 by 97 molar % or more at a molar ratio of 50/50-70/30 in a non-aqueous system in the presence of a non-aqueous radical initiator, said Process 2 is a process of stopping the radical copolymerization reaction initiated in said Process 1 in the midst of the reaction when the inversion rate of polymerization defined by {(TM−UM)/TM}×100 has become 50-90% by adding water to the reaction system and thereby obtaining a reaction mixture containing a copolymer thus produced and residual monomers, TM indicating the total weight of the radical polymerizable monomer mixture at the start of the radical polymerization reaction in said Process 1 and UM indicating the total weight of the residual monomers when the radical copolymerization reaction is stopped in said Process 2, said Process 3 is a process of partially or completely neutralizing the reaction mixture obtained in said Process 2 by one or two selected from the group consisting of alkali metal hydroxides, alkali earth metal hydroxides and amines, and said Formula 1 is given by CH 2 ═CH—CH 2 —O—A—O—R where R is methyl group, acetyl group or hydrogen atom and A is a residual group obtained by removing all hydroxyl groups from (poly)alkyleneglycol having (poly)oxyalkylene groups formed with 1-150 oxyethylene units or a total of 2-150 oxyethylene and oxypropylene units.