Patent ID: 7601770

Claim:
A multi-functional admixture for concrete, said multi-functional admixture comprising Component A by 20-84 weight %, Component B by 15-79 weight % and Component C by 0.3-3 weight % such that their total will be 100 weight %, wherein: said Component A is one or more copolymers selected from a group consisting of graft copolymers and salts of copolymers, wherein the graft copolymers are obtained by a first process and a second process, and the salts of graft copolymers are obtained by said first process, said second process and a third process, said Component A having a structural unit shown by Formula 6; said first process is for obtaining copolymers with weight-average molecular weight of 10000-50000 by radical polymerization of a mixture of radical polymerizable monomers containing maleic anhydrides and monomers shown by Formula 1 by a total of 95 molar % or more at molar ratio of 50/50-70/30 in the absence of solvent; said second process is for obtaining graft copolymers by graft reaction of 100 weight parts of said copolymers obtained in said first process with 0.2-4 weight parts of polyether compounds shown by Formula 2; said third process is for obtaining salts of graft copolymers by partially or completely neutralizing said graft copolymers obtained in said second process with alkali metal hydroxide; said Component B is polypropyleneglycol monoalkyl ether shown by Formula 3; said Component C is organic phosphate shown by Formula 4 or Formula 5; Formula 1 is given by CH 2 ═CH—CH 2 —O—A 1 —O—R 1 ; Formula 2 is given by R 2 —O—A 2 —OH; Formula 3 is given by R 3 —O—A 3 —OH; Formula 4 is given by Formula 5 is given by Formula 6 is given by where: R 1 is methyl group or acetyl group; R 2 is aliphatic hydrocarbon group with 10-20 carbon atoms; A 1 is residual group obtained by removing all hydroxyl groups from polyethyleneglycol with polyoxyethylene group having 10-90 oxyethylene units in molecule; A 2 is residual group obtained by removing all hydroxyl groups from polyalkyleneglycol with polyoxyalkylene group having in molecule a total of 25-60 oxyethylene units and oxypropylene units; R 3 is alkyl group with 3-5 carbon atoms; A 3 is residual group obtained by removing all hydroxyl groups from (poly)propyleneglycol with (poly)oxypropylene group having in molecule only 2-4 oxypropylene units; R 4 and R 5 are each alkyl group with 8-18 carbon atoms; A 4 is (poly)oxypropylene group with 1-5 oxypropylene units; M is hydrogen atom or alkali metal; M 1 , M 2 , M 3 and M 4 are each hydrogen atom, alkali metal, alkali earth metal, ammonium or organic amine; and p, q and r are each an integer equal to or greater than 1.