Aqueous polymeric methyl methacrylate compositions for coating cement products and methods for coating such products

Claim 1

A PROCESS FOR PREPARING A COATED CEMENT PRODUCT WHICH COMPRISES APPLYING TO A FORMED BUT UNCURED, HEATED, ASBESTOS-CEMENT COMPOSITION A COATING OF AN AQUEOUS DISPERSION CONTAINING (A) A LINEAR COPOLYYMER OF (A) 85 TO 99.75% BY WEOGHT OF METHYL METHACRYLATE, AND (B) ABOUT 1/4 TO 15% BY WEIGHT OF AT LEAST ONE OTHER COPOLYMERIZABLE MONOETHYLENICALLY UNSATURATED MONOMER SELECTED FROM THE GROUP CONSISTING OF ESTERS OF ACRYLIC ACID WITH AN ALCOHOL HAVING 1 TO 18 CARBON ATOMS AND HYDROPHILIC MONOMERS SELECTED FROM THE GROUP CONSISTING OF ACRYLIC ACID, METHACRYLIC ACID, ITACONIC ACID, ACRYLAMIDE, METHACRYLAMIDE, BETA-HYDROXYETHYL ACRYLATE, BETA-HYDROXYETHLY VINYL ETHER, BETA-AMINOETHYL ACRYLATE, BETA-N,N-DIMETHYLAMINOETHYL ACRYLATE, THE TOTAL AMOUNT OF HYDROPHILIC MONOMER BEING NOT OVER 2% BY WEIGHT, BASED ON THE ENTIRE WEIGHT OF MONOMERS, AND (B) 20 TO 60% BY WEIGHT, BASED ON THE WEIGHT OF THE COPOLYMER, OF AN ORGANIC SOLVENT FOR THE COPOLYMER HAVING A BOILING POINT IN THE RANGE FROM 150* TO 255*C., THE POLYMER CONTENT OF THE ABOVE-MENTIONED DISPERSION CONSISTING EXCLUSIVE OF LINEAR COPOLYMERIC MATERIAL AS DEFINED IN (A) HEREIN THE AMOUNT OF THE SOLVENT BEING AT LEAST SUFFICIENT TO CAUSE FILM-FORMATION OF COPOLYMER IN THE COATING MERELY ON DRYING AT A TEMPERATURE BELOW 100*C., AND THE TEMPERATURE OF THE ASBESTOS-CEMENT COMPOSITION AT THE TIME OF APPLICATION OF THE COATING BEING SUFFICIENTLY HIGH TO CAUSE THE COATING TO RAPIDLY DRY TO TACK-FREE CONDITION, AND THEN CURING THE TACK-FREE COATED CEMENT COMPOSITIONS WHILE STACKED ON ONE ANOTHER.