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:
Mar. 20, 1990
Filed:
Jan. 06, 1989
John J McLafferty, Hicksville, NY (US);
Sue L Wang, Flushing, NY (US);
Ruco Polymer Corporation, Hicksville, NY (US);
Abstract
The present disclosure is concerned with catalyzing the reactivity of carboxyl group bearing polyesters such as terephthalic acid, isophthalic acid, neophentyl glycol based polyesters which are suitable for use in powder coating formulations with epoxide compounds. An enhanced uniformity of catalysis is obtained without a degradation of color by adding 1-methyl imidazole to a liquid melt of the polyester. In a preferred embodiment between 0.03 and 0.3 weight percent of the 1-methyl imidazole is added to a molten polyester which has an acid number between 10 and 100, a 200.degree. C. I.C.I. cone and plate viscosity between 20 and 70 Poise, and a DSC determined glass transition temperature of at least about 40.degree. C. when the polyester is at a sufficiently elevated temperature to have I.C.I. plate and cone viscosity of less than about 70 Poise. A particularly advantageous powder coating composition results when such a polyester is combined with an at least difunctional epoxy compound such as triglycidyl isocyanurate (TGIC) at an epoxy to carboxyl ratio of between about 0.9 to 1.4 extrusion mixing.