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:
Jan. 31, 1984
Filed:
Jul. 10, 1981
Applicant:
Inventors:
Richard L Cournoyer, Waltham, MA (US);
James W Foley, Andover, MA (US);
Assignee:
Polaroid Corporation, Cambridge, MA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
549394 ;
Abstract
In one embodiment, the present invention is concerned with novel xanthene compounds selected from those of the formulae ##STR1## wherein each R.sup.1 the same or different is alkyl, each R.sup.2 the same or different is an electron-withdrawing group having a positive sigma value greater than 0.6, X is ##STR2## wherein R.sup.3 is alkyl, Y is an electron-withdrawing group, n is 0 or 1 and A is an anion. In another embodiment, the present invention is concerned with photographic products and processes employing these xanthene compounds, e.g., as photographic light-screening dyes.