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:
Oct. 05, 1999
Filed:
Mar. 12, 1998
Robert B Login, Simpsonville, SC (US);
Calvin McIntosh Wicker, Jr, Spartanburg, SC (US);
Otto Bella, Tryon, NC (US);
Sybron Chemicals, Inc., Birmingham, NJ (US);
Abstract
A process for dying materials containing natural or synthetic polyamides is disclosed. The process includes immersing the materials to be dyed in a dye bath containing an acid dye. The pH of the dye bath is initially at a level that substantially inhibits the dye from being absorbed by the polymer. In accordance with the present invention, however, an acid producing composition is added to the bath which gradually reduces the pH of the bath and allows for uniform diffusion of the dye into the polymer. The acid producing composition of the present invention is a maleate ester, which, in one embodiment, is the reaction product of maleic acid or maleic anhydride and a glycol.