The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 29, 1990
Filed:
Jul. 21, 1988
Miroslav Chmelir, Krefeld, DE;
Chemische Fabrik Stockhausen GmbH, Krefeld, DE;
Abstract
The invention concerns a method of preparing homopolymers or copolymers that are water-soluble or swell up in water and have a low residual monomer content by treating them with at least one compound that can react with the monomer's double bond. The homopolymer or copolymer in the swollen form and in the form of a gel or in the form of a solution is treated with a compound, such as for example ammonia, an ammonium salt, an alkylamine and/or one of their salts or a hydroxylamine and/or their salts, that can react with the monomer's double bond and contains nitrogen or with a compound, such as a hydrogen halide, an acetoacetate, or a malonate, that contains an active hydrogen atom, or with a compound, such as bromosuccinimide, pyridinium bromide, or dioxane perbromide, that contains bromine and allows bromine to attach to the double bond, or with a compound, such as a permanganate, a bichromate, a chromate, selenium dioxide, or ozone, that can oxidize the double bond, or with a compound, such as an alkali sulfite or ammonium sulfite, an alkali or ammonium hydrogen sulfite or disulfite, or a thio compound, that contains sulphur, subsequent to which the resulting polymer gel or polymer solution is dried at an elevated temperature.