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:
Jun. 16, 1981
Filed:
Nov. 21, 1979
Chemische Werke Huls Aktiengesellschaft, Marl, DE;
Abstract
A process for preparing coating powders based on polylaurolactam for the vitrification coating process beginning with polylaurolactam granulates obtained by polymerizing laurolactam under internal pressure in the presence of 2 to 10% by wt. of water and 0.3 to 0.7% by wt. of phosphoric acid at temperatures between 265.degree. and 300.degree. C., in the absence of chain stabilizers, and which have a relative viscosity of between 1.50 and 1.80. After precooling to temperatures between -50.degree. and 0.degree. C., the granulates are ground and then graded. Extraction with methanol or ethanol is carried out prior to grinding or grading. Pigments are added to the monomerous laurolactam or to the polylaurolactam in the molten state prior to granulation. The powders are especially well suited to manufacture colored powders by the dry-blend process.