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US 3,941,730 AGranted
Polyvinyl alcohol microgel precursor blends
AssigneeE. I. Du Pont de Nemours and Company
InventorJohn Carl Solenberger
Life of this patent
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AssigneeE. I. Du Pont de Nemours and Company
InventorJohn Carl Solenberger
Estimating the term…
Stable, fluid polyvinyl alcohol-containing microgels in water having a Brookfield viscosity of 1.15 to 1000 centipoises may be prepared more economically from a dry blend which comprises (A) a polymer mixture consisting of at least about 0.5% by weight of polyvinyl alcohol and one or more polysaccharide selected from the group consisting of up to about 99.5% by weight of starch and up to about 33% by weight of sodium carboxymethylcellulose, said polyvinyl alcohol having a Hoeppler viscosity of about 4 to 150 centipoises and having at least about 50 mole percent of the monomeric units present as vinyl alcohol units, (B) water-soluble, solid titanium salt of a hydroxy carboxylic acid of 2 to 10 carbon atoms in an amount which provides about 0.05 to 10 parts by weight of tetravalent titanium ions per 100 parts of polymer mixture, and (C) about 0.05 to 20 parts by weight of water-soluble, solid hydroxy carboxylic acid of 2 to 10 carbon atoms per 100 parts of polymer mixture.
A dry blend for forming a stable, fluid polyvinyl alcohol containing microgel in water having a Brookfield viscosity of 1.15 to 1000 centipoises which comprises (A) a polymer mixture consisting of at least about 0.5 percent by weight of polyvinyl alcohol and one or more polysaccharide selected from the group consisting of up to 99.5 percent by weight of starch and up to 33 percent by weight of sodium carboxymethylcellulose, said polyvinyl alcohol having a Hoeppler viscosity of 4 to 150 centipoises measured as a 4 percent aqueous solution at 20.degree.C. by the falling ball method and having at least 50 mole percent of the monomeric units present as vinyl alcohol units, (B) water-soluble, solid titanium salt of a hydroxy carboxylic acid of 2 to 10 carbon atoms in an amount which provides 0.05 to 10 parts by weight of tetravalent titanium ion per 100 parts of said polymer mixture, and (C) 0.05 to 20 parts by weight of water-soluble, solid hydroxy carboxylic acid of 2 to 10 carbon atoms per 100 parts of said polymer mixture.
Dependencies are inferred from the claim text.