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:
Sep. 13, 1983
Filed:
Feb. 18, 1982
Applicant:
Inventor:
Dieter Cornelius, Darmstadt, DE;
Assignee:
Cassella Aktiengesellschaft, Frankfurt, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C09B / ; D06P / ;
U.S. Cl.
CPC ...
8652 ; 8918 ; 8924 ; 260134 ; 544 35 ; 544 36 ;
Abstract
New sulphur dyestuffs are prepared by reacting sulphur with a 4-hydroxydiphenylamine of the formula ##STR1## wherein R and R.sup.1 denote hydrogen or alkyl having 1 to 4 carbon atoms and the nucleus A has at least one free ortho-position in relation to the imino group, in a first stage at an elevated temperature to form a thiazine compound which is then sulphurized in a second stage in a water-soluble solvent at an elevated temperature to produce the sulphur dyestuff, and wherein a molar ratio of first stage reactants of 1:(2 to 2.4) between the 4-hydroxydiphenylamine compound and sulphur is maintained.