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. 26, 1979
Filed:
Sep. 01, 1978
Ehrenfried Loock, Wilhelmshaven, DE;
Olympia Werke AG, Wilhelmshaven, DE;
Abstract
An aqueous black ink for a writing process in which ink is transferred in droplets onto a print carrier. The ink comprises 25-42 g./l. of the direct Diamine Blue 6B, extra high concentration; 14-22 g./l. of the direct dye Diamine Scarlet 4BS, extra concentration; 290-430 ml./l. of formamide; 32-48 ml./l. of 90% diethanolamine, 24-60 g./l. of citric acid, a water-soluble and organic soluble disinfectant, and balance essentially water. A process for producing such an ink comprises the steps of mixing both dyes together; introducing the mixture at room temperature in incremental portions into the formamide and stirring until the dyes are substantially completely dissolved. Undissolved salts are removed from the mixture. Diethanolamine and distilled water are introduced under agitation into the mixture. The pH is adjusted to about 6 to 8 with citric acid and disinfectant is added. The mixture is filtered under vacuum and then gases are withdrawn by treating the mixture under a vacuum.