Patents by Inventor John Douglas Ballantine

John Douglas Ballantine has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

Production of hardened gelatin layers by the addition of quaternary carbamoyl pyridinium compounds

Patent number: 4014862

Abstract: The present invention relates to the production of hardened gelatin layers by means of quaternary carbamoyl pyridinium compounds. Preferably this method is used for the hardening of silver halide photographic material.

Type: Grant

Filed: July 6, 1973

Date of Patent: March 29, 1977

Assignee: Ilford Limited

Inventors: John Douglas Ballantine, Norman Alfred Smith
Method of producing a hardened gelatin layer using aqueous solution of a 2-halogeno pyridinium compound

Patent number: 3951940

Abstract: This invention relates to the hardening of gelatin layers. The gelatin is heated with an aqueous solution of a 2-halogeno pyridinium compound.

Type: Grant

Filed: September 30, 1974

Date of Patent: April 20, 1976

Assignee: Ciba-Geigy AG

Inventors: John Douglas Ballantine, Norman Alfred Smith

Production of hardened gelatin layers by the addition of quaternary carbamoyl pyridinium compounds

Method of producing a hardened gelatin layer using aqueous solution of a 2-halogeno pyridinium compound