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, 1988
Filed:
May. 29, 1987
Edward J Marx, Houston, TX (US);
Shell Oil Company, Houston, TX (US);
Abstract
A phenolic curing agent for epoxy resin powder coatings is prepared by combining (a) a linear phenolic hydroxyl-terminated resin having a weight per phenolic within the range of about 650 to about 8,000, preferably about 850 to about 950, (b) a dihydric phenol present in an amount such that the weight per hydroxyl of the mixture of (a) and (b) is within the range of about 240 to about 280, and (c) at least about 2 weight percent, based on the weight of the composition, of an imidazole cure accelerator. The described imidazole-accelerated curing agent is less susceptible to melting point depression and to sintering with storage than conventional imidazole-containing phenolic curing agents. The dihydric phenol-terminated epoxy resin is preferably prepared by reacting a dihydric phenol with a linear diepoxy resin in the presence of a phosphonium halide catalyst so as to produce a phenolic hydroxyl-terminated resin having a weight per hydroxyl within the range of about 650 to about 8,000.