US 5,124,445 A · Alkylaryl hydrophobically modified cellulose ethers

Abstract

Cellulose ethers are disclosed which have sufficient nonionic substitution to render them water soluble and which are further modified with a C.sub.10 to C.sub.24 long chain alkylaryl group in an amount between 0.2% by weight and the amount which makes them less than 1% by weight soluble in water. Hydroxyethylcellulose is a preferred water soluble cellulose ether for modification according to the invention. These products exhibit substantially improved viscosifying effects compared to their unmodified cellulose ether counterparts, and provide good leveling and sag resistance in latex paints. Preferred alkylaryl groups are nonylphenyl, dodecylphenyl, and dinonylphenyl. Included are cellulose ethers with spacer groups of various lengths between the alkylaryl group and the connecting group to the cellulose molecule.

Claims6

Dependent claims

A process for preparing an arylalkyl hydrophobically modified hydroxyethylcellulose with a hydroxyethyl Molar Substitution (M.S.) of 3.0 5.0 involves the steps:

(1) reacting hydroxyethylcellulose or a hydroxyethylcellulose precursor with a molecular weight 20,000 to 800,000 under alkaline conditions with from 0.25 to 2.0% by weight of an arylalkyl glycidyl ether comprising at least 14 carbon atoms at a temperature of at least 110.degree. C. for a least two hours in the presence of t-butyl alcohol;
(2) cooling the reaction mixture to at least 40.degree. C.;
(3) neutralizing the reaction mixture to a pH of 7-8;
(4) slurrying the reaction mixture in acetone;
and
(5) recovering a purified arylalkyl hydrophobically modified hydroxyethylcellulose.

3 more elements

Dependencies are inferred from the claim text.

Alkylaryl hydrophobically modified cellulose ethers

Life of this patent

Alkylaryl hydrophobically modified cellulose ethers

Life of this patent

Abstract

Claims6