Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.


  1. Advanced Patent Search
Publication numberUS1962133 A
Publication typeGrant
Publication dateJun 12, 1934
Filing dateMay 18, 1933
Priority dateMay 18, 1933
Publication numberUS 1962133 A, US 1962133A, US-A-1962133, US1962133 A, US1962133A
InventorsBrooker Leslie G S, Staud Cyril J
Original AssigneeEastman Kodak Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Photographic emulsion containing certain disulphides as antifoggants
US 1962133 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)


N. Y.. a corporation of New York No Drawing. Application May 18, 1933,

' Serial N0. 671,720

3 Claims.

This invention relates to anti-fogging agents for photographic .amulsiohs, such as gelatinosilver-halide emulsions; and more particularly to the use of di-o-formylalkylaminodiphenyl- 5 disulphides for that purpose.

Some sensitizing dyes, while being powerful color sensitizers, have a fogging action upon photographic emulsions containing them. It is also well known that when development of photographic film is continued for protracted periods. or at temperatures above normal, fog is apt to result. 'Y

We have found that the harmful effects can be decreased by adding a small proportion of one 5 or more of the above disulphides tophotographic emulsions.

An object of our invention, therefore, is to provide photographic emulsions of enhanced stability. Other objects will hereinafter appear.

We have found that certain complex disulphides may be used for this purpose. For instance, di-of0rmylethylaminodiphenyldisulphide, which is obtained by the alkaline oxidation of benzothiazole ethiodi'de, is a powerful anti-foggant. Com- '5 pounds of this type have the structure '0 [111030 OHQED I g in which R equals an alkyl group.

When a solution containing 2 mg. of di-o-for mylethylaminodiphenyldisulphide, for instance, was added to 100 cc. of a fast negative emulsion the fog was materially reduced. This is merely illustrative of the use of these disulphides as anti-- 7 tenants and is not intended to limit our invention as it applies to the various known emulsions. The preparation of these disulphides is described in the literature and need not be repeated here. The disulphide is merely dissolved in alcohol and a solution containing approximately 1-8 mg. of the disulphide is added to cc. of any of the gelatino-silver-halide emulsions known to photographic experts (usually suitable sensitized as described in the prior art) and the emulsion coated upon a support in the usual way. I

What we claim as our invention and. desire to be secured by Letters Patent of the United States is:

1. A gelatino-silver-halide emulsion containing as an anti-foggant, a compound having the 4'0 general formula 8-- -g v (Isaac OHOND r i i in which R equals and alkyl group.

2. A gelatinosilver-halide emulsion containing di-o-formylethylanunodiphnyldisulphide as an 82 anti-togsant.

3. A photographic element coated with a gelatino-silver-halide emulsion containing as an antifoggant, a compound having the general formula a [Inqno OHQNI) i it o0 in which R equals an alkyl group.




Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2440110 *Oct 6, 1944Apr 20, 1948Gen Aniline & Film CorpStabilized silver halide emulsions
US2465149 *Apr 25, 1946Mar 22, 1949Gen Aniline & Film CorpTetrazolyl disulfides as stabilizing agents for silver-halide emulsions
US2759821 *Jun 4, 1952Aug 21, 1956Eastman Kodak CoX-ray film
US3397986 *Dec 29, 1964Aug 20, 1968Eastman Kodak CoPhotographic emulsion stabilized with bis (p-acylamidophenyl) disulfides
US3411917 *Apr 29, 1965Nov 19, 1968Eastman Kodak CoSensitization of silver halide emulsions with direct electrical current
US3779757 *Jan 11, 1972Dec 18, 1973Agfa Gevaert NvSilver complex diffusion transfer process utilizing an aromatic disulfide
US5217859 *Apr 16, 1992Jun 8, 1993Eastman Kodak CompanyAqueous, solid particle dispersions of dichalcogenides for photographic emulsions and coatings
US5219721 *Apr 16, 1992Jun 15, 1993Eastman Kodak CompanySilver halide photographic emulsions sensitized in the presence of organic dichalcogenides
US5364754 *Oct 29, 1992Nov 15, 1994Eastman Kodak CompanySilver halide photographic emulsions precipitated in the presence of organic dichalcogenides
US5759762 *May 30, 1997Jun 2, 1998Eastman Kodak CompanyHigh chloride emulsion with dimethylamine silver chloro-iodide and antifoggants
US6280922Mar 23, 2000Aug 28, 2001Eastman Kodak CompanyHigh chloride silver halide elements containing activated precursors to thiolic stabilizers
EP0201201A2 *Apr 4, 1986Nov 12, 1986EASTMAN KODAK COMPANY (a New Jersey corporation)Amido substituted divalent chalcogenide fog inhibiting agents for silver halide photography
EP0201201A3 *Apr 4, 1986Sep 21, 1988Eastman Kodak CompanyAmido substituted divalent chalcogenide fog inhibiting agents for silver halide photography
EP0775936A1Oct 28, 1996May 28, 1997Eastman Kodak CompanySilver halide photographic elements containing dioxide compounds as stabilizers
U.S. Classification430/611
International ClassificationG03C1/34
Cooperative ClassificationG03C1/346
European ClassificationG03C1/34S