Method of making flowable alkaline thiosulfate/alkaline sulfite and the product thereof
USRE35795E · kind E · reissue
Assignee
Inventors
Key dates
| Filing date | Jul 5, 1996 |
| Grant date | May 12, 1998 |
| Priority date | — |
| Expiry date | Jul 5, 2016 |
Classification
- Technology area (CPC —)General
Abstract
A method for making flowable alkaline thiosulfate, flowable alkaline sulfite, or a combination of the two, by blending an alkaline thiosulfate, an alkaline sulfite, or a combination of the two, with an alkali metal ..arylsulfonate.formaldehyde.!. .Iadd.arylsulfonate.cndot.formaldehyde .Iaddend.in an amount effective to render the alkaline thiosulfate, the alkaline sulfite, or the combination freely flowable, and the product of this method. It has been found that the product of this method, such as freely flowable ammonium thiosulfate powder mixture, can be stored in a freely flowable condition for extended periods of time and can be dissolved into solution readily to form a clear non-turbid solution. The freely flowable ammonium thiosulfate powdered mixture of the present invention is particularly useful as a photographic fixative and bleach fixative for processing photographic elements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.