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:
Aug. 30, 1977
Filed:
Oct. 17, 1975
Raymond A Plepys, Lake Jackson, TX (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
Novel copolymer resins having the repeating unit ##STR1## WHEREIN EACH R is independently alkyl of 1 to about 10 carbon atoms or halogen, z is oxygen or sulfur, the dashed line is an optional chemical bond, the group represented by z taken with the dashed line represents dibenzofuran and dibenzothiophene moieties, or mixtures thereof, each R' is hydrogen or ##STR2## wherein each R' is a hydrocarbon or substituted hydrocarbon radical of from 2 to about 11 carbon atoms, n averages about 3-10, each m is 0-2 and p and q are each 0 or 1 with the proviso that the sum of p and q has an average value of 0.1-1.0 and there is an average of at least one carboxyl group per polymer molecule, are prepared by reacting a mixture comprising a hydroxymethylated diphenylether-formaldehyde copolymer with an anhydride of the formula ##STR3## wherein R' is a hydrocarbon or substituted hydrocarbon radical of from 2 to about 11 carbon atoms, at a temperature between about 120.degree. and about 170.degree. C. The copolymer resins form stable aqueous solutions in the presence of base which, when heated in the presence of a water-soluble curing agent, such as hexamethoxymethylmelamine, yield glossy, flexible and impact-, solvent-, and water-resistant films.