Workability and board life in masonry mortar and method for obtaining same
AssigneeW. R. Grace & Co.-Conn.
InventorLeslie A. Jardine
Life of this patent
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Abstract
Improved workability and board life in masonry mortar is achieved through the use of an alkali soluble emulsion polymer and a low molecular weight, water-soluble humectant comprising a polymer having oxyalkylene groups, polyhydric groups, or a mixture thereof. The humectant in combination with a pH-sensitive polymer which provides significant advantages over the polymer alone. Preferably, the molecular weight of the humectant is approximately 2500 or lower. Exemplary masonry mortar compositions and methods for modifying them are also disclosed.
Claims27
An additive for improving workability and boardlife in masonry mortar, comprising:
- an alkali soluble emulsion polymer having two or more polymer stages wherein:
- (A) at least one of said polymer stages is an ionically-soluble polymer, the ionically-soluble polymer being polymerized from a monomer mixture comprising:
- (a) about 0.1 to about 55% by weight hydrophobic monomer having the formula
- where A is
- wherein R1 and R5 independently represent a (C1-C30) alkyl group, (C1-C30) alkyl-substituted phenyl ring, or a sorbitan fatty ester;
- R2, R3 and R4 independently represent hydrogen or (C1-C10) alkyl, aryl or alkylaryl group;
- “a” represents 0 or 1;
- “b” represents an integer from 0 to 50;
- “c” represents an integer from 0 to 150;
- “d” represents an integer from 0 to 50;
- “e” represents an integer equal to or greater than 1, and X represents a group containing at least one ethylenic double bond;
- (b) about 10 to about 69% by weight of (C3-C30) ethylenically-unsaturated, ionizable monomer, and
- (c) about 0.1 to about 90% by weight nonionic (C2-C30) ethylenically-unsaturated monomer, and
- (d) 0 to about 10% by weight multi-functional compounds;
- (B) the ionically-soluble polymer is physically or chemically attached to the polymer particle such that, upon neutralizing the ionically-soluble polymer with base or acid, at least a portion of said ionically-soluble polymer remains attached to the remainder of the polymer particle;
- and
- (C) the ionically-soluble polymer comprises from about 1% to about 99% by weight of the polymer particle;
- and
- said additive further comprising, in addition to said alkali-soluble emulsion polymer, a water-soluble humectant having a molecular weight of 100-2500 and comprising a polyoxyalkyene glycol, a polyoxyalkylene adduct of polyols, a polyvinyl alcohol, a hydroxy-modified cellulose ether, or mixture thereof.
Dependencies are inferred from the claim text.