Patent ID: 6451880
Filing Date: 2002-09-17
Classification: C04B,C08K

Abstract:
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 â€ƒwhere A is â€ƒwherein 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; â€œaâ€  represents 0 or 1; â€œbâ€  represents an integer from 0 to 50; â€œcâ€  represents an integer from 0 to 150; â€œdâ€  represents an integer from 0 to 50; â€œeâ€  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.