The Dow Chemical Company

Dalton C MacWilliams

H Nelson Beck

James R Wirt

Charles J McDonald

Yohannes Chonde

William E Cohrs

The present invention provides for a process for preparing hollow polymer latexes by a one stage emulsion polymerization. The first step invloves introducing an effective amount of a first charge of a organic phase to an aqueous phase. The first charge of the organic phase comprises monomer which is vertually insoluble in the aqeuous phase and an inert-nonpolymerizable hydrocarbon. The polymer formed from polymerizing the monomer is virtually insoluble in the hydrocarbon, the hydrocarbon is virtually insoluble in the aqueous phase and the monomer is miscible with the hydrocarbon. The monomer is polymerized to produce a low molecular weight polymer such that the low molecular weight polymer will phase separate from the organic phase and conentrates at the surface of the introduced organic phase forming a low molecular weight polymer phase. The second step involves introducing a second charge of the organic phase to the aqeuous phase, wherein the second charge of the organic phase comprises a crosslinking monomer. The crosslinking monomer is polymerized with the low molecular weight polymer to produce a hollow polymer latex particle.

Method for preparing hollow latexes

Methods for impregnating the pores of at least partially dried wood with a phosphorus nitride, particularly P.sub.3 N.sub.5, to provide flame resistance are described. Preferably liquid slurries of the phosphorus nitride are impregnated into the exposed pores of the wood using pressure or preferably a partial vacuum in a confined space which removes air from the pores and allows the slurry to impregnate the wood. The liquid is then removed from the wood.

Method for imparting flame resistance to wood surfaces

A method and compositions for imparting flame resistance to exposed surfaces of wood by impregnating the wood with dimethyl(oxiranylmethyl)phosphonate (DMOMP) and a catalyst and then reacting wood surfaces with the DMOMP is described. The catalysts are preferably Lewis acids or Lewis bases. The resulting treated wood products are useful in applications where flame resistance is important.

Method for imparting flame resistance to wood using dimethyl

A method for imparting flame resistance to exposed surfaces of wood by impregnating and reacting wood surfaces with dimethyl(oxiranylmethyl)phosphonate (DMOMP) is described. The resulting treated wood products are useful in applications where flame resistance is important.

Method for imparting flame resistance to wood using

Water-soluble salts of low-molecular weight polyacrylic acids function synergistically with inorganic salts to obtain superior reduction of water demand of dispersed inorganic solids. The disclosed invention is particularly adapted for use in the wet-grinding process for preparing portland cement.

Aqueous suspensions

Water-soluble copolymers prepared from styrene and maleic anhydride and the water-soluble salts and partial esters thereof function synergistically with inorganic salts to obtain superior reduction of water demand of dispersed inorganic solids. The disclosed invention is particularly adapted for use in the wet-grinding process for preparing portland cement.

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Alamo, CA, United States of America

Dalton C MacWilliams