Cement admixture product having improved rheological properties and process of forming same
AssigneeW. R. Grace & Co.-Conn.
InventorsAhmad Arfaei, David C. Darwin, Ellis M. Gartner, Byong-Wa Chun, Hideo Koyata, Lawrence L. Kuo
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Abstract
The present invention is directed to an imidized polycarboxylic acid polymer useful as a cement admixture, to improved cement compositions containing said polymer and to a process of forming the same.
Claims10
An imidized acrylic polymer composed of units represented by the structural formulae:
- ##STR3## wherein each R independently represents hydrogen atom or a methyl (CH.sub.3 --) group;
- R' represents a (i) hydrogen atom, (ii) a C.sub.2 -C.sub.10 oxyalkylene group represented by (BO).sub.n R" in which O represents an oxygen atom, B represents a C.sub.2 -C.sub.10 alkylene group or mixtures thereof, R" represents a C.sub.1 -C.sub.10 alkyl and n represents an integer of from 1-200, or (iii) mixtures thereof;
- A represents a C.sub.1 -C.sub.10 alkyl group, R', an alkali metal cation or mixtures thereof;
- NR'" represents a heterocyclic group of which N is a part thereof;
- and a, b, c, and d are numerical values representing molar percentage of the polymers structure such that a is a value of about 50 to 70;
- the sum of c+d is a value of from about 2 to about 10;
- and b is a remainder value of {100-(a+c+d+e)};
- and e is a value greater than 0 and up to or equal to 10.
A polymer product useful as a cement admixture, said product formed according to the process comprising contacting (i) a polymer having functional groups selected from carboxylic acid groups, their C.sub.1 -C.sub.10 alkyl esters or mixtures thereof, wherein said functional groups are positioned pendant alpha-beta, alpha-gamma or both from the polymer backbone chain, with (ii) an amine selected from ammonia or a primary amine of the formula
- H.sub.2 N(BO).sub.n R"
- wherein O represents oxygen atom, B represents a C.sub.2 -C.sub.10 alkylene group or mixtures thereof, R" represents a C.sub.1 -C.sub.10 alkyl group, and n represents an integer of 1 to 200;
- maintaining said reaction mixture at a temperature of from 60.degree. C. to 250.degree. C. at atmospheric or reduced atmospheric pressure for a time of from 1 to 8 hours while removing water from the reaction mixture;
- and cooling and recovering the formed imidized polymer product.
Dependencies are inferred from the claim text.