Hydrophobic pigment modification
AssigneesRohm and Haas Company, The Regents of the University of California
InventorsJames C. Bohling, Alexander Katz, Manish Mishra, Clayton J. Radke, Antony K. Van Dyk
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Abstract
The present invention is a composition comprising an aqueous dispersion of metal oxide pigment particles coated with a polymer comprising structural units of an alkyltrihydroxysilane or a salt thereof and a dialkyldihydroxysilane or a salt thereof. The composition of the present invention provides hydrophobicity to pigment particles, thereby imparting water resistance, and allows for high loadings of pigment in water without increased viscosity.
Claims10
A composition comprising an aqueous dispersion of metal oxide pigment particles coated with an organosilane polymer comprising structural units of an alkyltrihydroxysilane or a salt thereof and a dialkyldihydroxysilane or a salt thereof, wherein a mole:mole ratio of structural units of alkyltrihydroxysilane or a salt thereof to dialkyldihydroxysilane or a salt thereof is in a range of 99.9:1 to 50:50, and wherein the aqueous dispersion has a pH in the range of from 7.5 to 12.
A method for preparing an aqueous dispersion of hydrophobically modified pigment particles comprising the step of contacting, in the presence of water and at a pH of from 7.5-12, metal oxide pigment particles with an alkyltrihydroxysilane or a salt thereof and a dialkyldihydroxysilane or a salt thereof where a mole:mole ratio of units of the alkyltrihydroxysilane or a salt thereof to dialkyldihydroxysilane or a salt thereof is in a range of 99.0 to 50:50.
Dependencies are inferred from the claim text.