Paul R Jarvi

US Patent:

47283653, Mar 1, 1988

Filed:

Aug 11, 1986

Appl. No.:

6/895176

Inventors:

Paul Jarvi - Orange CT

Assignee:

Mitchell Bradford International Corp. - Milford CT

International Classification:

C23C 2200
C23C 2248

US Classification:

106 105

Abstract:

A room temperature black coating for ferrous metal is formed in a solution based on selenium dioxide, an inorganic copper salt and an organic acid. The solution virtually eliminates the formation of a selenium iron precipitate which results from conventional blackening agents in which an inorganic acid such as phosphoric, sulfuric, nitric or hydrochloric acid is used. Further, the virtual elimination of the precipitate produces the additional benefit that the user needs handle and ultimately dispose of only an insignificant amount of toxic selenium iron or selenium phosphate compound materials.

US Patent:

47894091, Dec 6, 1988

Filed:

Dec 5, 1986

Appl. No.:

6/938552

Inventors:

Paul R. Jarvi - Orange CT

Assignee:

Mitchell Bradford International Corp. - Milford CT

International Classification:

C23C 2258

US Classification:

148 624

Abstract:

A black conversion coating for substrates contains sodium thiosulfate, nickel sulfate (pentahydrate), zinc sulfate (monohydrate), and sodium fluoborate. The coating comes in a powdered formulation in which the sodium thiosulfate, nickel sulfate, zinc sulfate, and sodium fluoborate comprise, respectively, 54%, 30%, 15% and 1% by weight of the formulation. The powdered matter is mixed with water at a concentration of 30-60 grams per liter of water. The coating is applied at a liquid temperature of 160. degree. -180. degree. F.