Patent ID: 8317918
Filing Date: 2012-11-27
Classification: C04B

Abstract:
1. A method for controlling air in hydratable cementitious compositions, comprising: introducing to a cementitous binder (A) at least one agent operative to entrain air in a hydratable cementitious composition, said at least one agent comprising a higher trialkanolamine, a lignosulfonate, a naphthalene sulfonate, a melamine sulfonate, an oxyalkylene-containing superplasticizer, an oxyalkylene-containing shrinkage reducing agent, or mixture thereof; (B) a polypropoxylated polyalkylene polyamine defoamer formed by alkoxylating a polyalkylene polyamine with ethylene oxide, propylene oxide, or mixture thereof, wherein the amount of ethylene oxide groups is in the range of 0%-40% based on total weight of polyethers, and the amount of polypropylene oxide groups is in the range of 60%-100% based on total weight of polyethers, the molar ratio of propylene oxide to ethylene oxide being greater than 1, said polypropoxylated polyalkylene polyamine defoamer having a structure represented by Formula (1) or salt thereof, or combination of said defoamer and salt thereof, wherein each of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , and R 7 independently represents a hydrogen, C 1 -C 4 alkyl group, —CH 2 —OH, or -(AO) x —R 8 , wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , and R 7 represents -(AO) x —R 8 and wherein AO represents propylene oxide (“PO”) or a mixture of PO and ethylene oxide (“EO”) wherein the molar ratio of PO to EO is at least 100:0 to 100:90; “x” represents an integer of 4 to 100; and R 8 represents hydrogen or an alkyl group; “n” represents an integer of 0 to 100; and wherein, if “n” is 0 then the amount of EO is less than 10% by weight based on total weight of said polypropoxylated polyalkylene polyamine defoamer; and (C) The ratio of component A to component B is in the range of 5 to 100 by dry weight.