Hart Chemical Limited

National Starch and Chemical Investment Holding Corporation

Texaco Chemical Company

Huntsman Petrochemical Corporation

Huntsman Corporation

Brigitte H Licht

Ratana Kanluen

Rajeev Farwaha

Frederick S Schell

Martin Menard

Roger T Bentley

Clarke A Boyce

This invention presents a series of polyfunctional polymers useful as deinking agents. The polymers, which generally have molecular weights in the 2,000-100,000 range, can be used to effectively separate and remove ink in a variety of deinking processes, including flotation, wash, and mechanical, resulting in fibers of superior brightness.

Polyfunctional polymers as deinking agents

Wet adhesion properties comparable or superior to all-acrylic latexes for vinyl acetate copolymers and other low cost polymers, such as EVA-vinyl chloride copolymers, is achieved by blending a minor proportion, usually about 5 to 15%, of a small particle size copolymer containing copolymerized wet adhesion monomer which is a cyclic ureido. Very low quantities of the wet adhesion monomer, less than 0.25 wt% of total monomers, only are required to achieve excellent results.

Vinyl acetate polymer with wet adhesion

Vinyl monomers are polymerized in high yield to water-soluble polymers or copolymers by free radical polymerization of an aqueous reaction mixture containing the vinyl monomer(s), an UV-activated photoinitiator and a heat-activated chemical initiator. The polymerization is initially carried out by exposing the monomer mixture to UV radiation to activate the photoinitiator and then is carried out under the influence of free radicals produced by the chemical initiator.

Polymerization process

A novel low foaming non-ionic surfactant having good wetting properties has a molecular weight of about 1700 to about 2300 and the formula:

Low foaming surfactant

The water dispersibility of water-soluble vinyl polymers, for example, polyacrylamides, is improved by incorporating a suitable surfactant in the monomer mixture from which the polymer is formed. The polymerization is effected by an initial phase of ultraviolet radiation-induced free radical polymerization until the monomer mix achieves the temperature at which chemically-induced free radical polymerization commences and then a terminal phase of chemically-induced free radical polymerization.

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Burlington, Canada

Brigitte H Licht