The Dow Chemical Company

Kenneth R Meath

William H Keskey

Kent B McReynolds

Donald M Blake

Cast ceiling tile requires a particular rheology of its wet formulation for the dried tile to have a desired aesthetic appearance. The use of a latex binder rather than starch for cast ceiling tiles imparts the necessary rheological properties to the wet ceiling tile formulation. The tile is prepared by blending mineral wool with a premixture of water, latex, and filler, said premixture having a sharp yield point when measured with a recording Brookfield Viscometer. The latex is an alkali-swellable latex comprising (i) a C.sub.3 -C.sub.8 .alpha.,.beta.-ethylenically unsaturated carboxylic acid monomer in an amount from about 15 to about 60 weight percent based on the weight of the monomers in the cpolymers; (ii) at least one of a copolymerizable nonionic vinyl monomer in an amount from about 45 to about 30 weight percent based on the weight of the monomers in the copolymer and (iii) an additional late feed of nonionic vinyl monomer in an amount from about 10 to about 40 weight percent based on the weight of the monomers in the copolymer.

Cast ceiling tiles containing latexes as binders

Cast ceiling tile requires a particular rheology of its wet formulation for the dried tile to have a desired aesthetic appearance. The use of a latex binder rather than starch for cast ceiling tiles imparts the necessary rheological properties to the wet ceiling tile formulation. The tile is prepared by blending mineral wool with a premixture of water, latex, and filler, said premixture having a sharp yield point when measured with a recording Brookfield Viscometer. The latex is an alkali-swellable latex comprising (i) a C.sub.3 -C.sub.8 .alpha.,.beta.-ethylenically unsaturated carboxylic acid monomer in an amount from about 15 to about 60 weight percent based on the weight of the monomers in the copolymer; (ii) at least one of a copolymerizable nonionic vinyl monomer in an amount from about 45 to about 30 weight percent based on the weight of the monomers in the copolymer and (iii) an additional late feed of nonionic vinyl monomer in an amount from about 10 to about 40 weight percent based on the weight of the monomers in the copolymer.

Latexes as binders for cast ceiling tiles

Compositions comprising asbestos fibers and blends of at least two latexes wherein the solids in the blended latexes comprise (A) from 5 to 40 parts by weight of a carboxylated copolymer comprising 10 to 25 parts by weight of methacrylic acid and correspondingly 90 to 75 parts by weight of at least one unsaturated carboxylic acid ester of the formula CH.sub.2 .dbd.C(R.sub.2)COOR.sub.1, wherein R.sub.1 is an alkyl group containing 1 to 8 carbon atoms and R.sub.2 is hydrogen or methyl and (B) 95 to 60 parts by weight of at least one synthetic rubber. The binder composition employed in this invention provides asbestos sheets having utility in flooring felts and gasket materials having relatively little change in elongation at room temperature, at 350.degree. F. and after soaking in dioctylphthalate.

Growing community of inventors

Midland, MI, United States of America

Kenneth R Meath