Other

Polaroid Corporation

Bsg, Inc.

Jerome L Reid

J Michael Grasshoff

Pauline Do

A photochromic material adapted for coating light transmissive materials. The photochromic material contains photosensitive silver halide crystals having dimensions in the range of approximately 50 Angstroms to 800 Angstroms. The silver halide crystals are surface doped with copper ions and another sensitizer selected from mild reducing agents, thioethers, or sulfur-bearing ions and are treated with an agent to accelerate the forward reaction and control the reverse reaction. The accelerants are ions selected from the group consisting of cobalt, chromium, manganese, magnesium, and rare earth metals such as cerium, samarium and europium. The agent for controlling the reverse reaction is one that confers electrical conductivity on the material and while to this end glycerol containing a high concentration of metal ions, methane sulfonic acid and benzyltrimethyl ammonium chloride are useful, the preferred agent is phosphoric acid. The crystals are dispersed in one or more protective polymers that do not irreversibly bind halogen.

Photochromic polymer membrane

A photochromic material adapted for coating light transmissive materials. The photochromic material contains photosensitive silver halide crystals having dimensions in the range of approximately 50 Angstroms to 800 Angstroms. The silver halide crystals are surface doped with copper ions and another sensitizer selected from mild reducing agents or sulfur-bearing ions. The crystals are dispersed in a protective polymer that does not irreversibly bind halogen.

Photochromic emulsion

Photochromic polymeric membrane

Polymeric derivatives of tetrazole-5-thiols are useful in conjunction with photosensitive silver halide elements as interlayers to provide interimage control, as dispersants for dye image-forming materials or as silver scavengers.

Photographic uses of polyvinyl-phenylmercapto-tetrazoles

Novel polymeric derivatives of tetrazole-5-thiols and their metal and ammonium salts, and the preparation of such compounds which are useful as gelatin thickeners or in their production, are disclosed.

Growing community of inventors

Wayland, MA, United States of America

Jerome L Reid