Ppg Industries, Inc.

Ppg Industries Ohio, Inc.

Earl M Gorton

Ronald D Olinger

Tommy G Taylor

John D Driskill

Randall M Hall

Robert E McGreevy

Domenick V Amato

Robert W Kline

Polychloroethylene, e.g., trichioroethylene and perchloroethylene, is stabilized with a stabilizing amount of a stable free radical stabilizer, e.g., a material having the 2,2,6,6-tetra(lower alkyl)-1-piperidinyloxy-yl free radical group, such as 2,2,6,6-tetramethyl-4-hydroxy-1-piperidinyloxy, or the 2,2,5,5-tetra(lower alkyl)pyrrolidinyloxy group, such as 2,2,5,5-tetramethyl pyrrolidinyloxy. Stable free radical stabilizer is removed from a polychloroethylene composition containing same by contacting the composition with silica, e.g., precipitated silica.

Stabilized polychloroethylenes

Describes a stabilized trans-1,2-dichloroethylene composition having a low concentration of aliphatic aldehyde hydrazone, optionally in combination with an epoxide. The aliphatic aldehyde hydrazone was found to be more efficient than commercially used hydroquinone monomethylether (HQMME) in preventing the isomeric transformation of trans-1,2-dichloroethylene to cis-1,2-dichloroethylene during storage. Also described is a process for cleaning the surface of an article with the stabilized 1,2-dichloroethylene composition.

Storage stabilized 1,2-dichloroethylene compositions

Vinylidene chloride is stabilized with free radical stabilizer having at least one 2,2,6,6-tetra(lower alkyl)-1-piperidinyloxy-yl free radical group.

Stabilization of vinylidene chloride

Describes nonflammable organic solvent compositions comprising 1,2-dichloroethylene and a halocarbon different than 1,2-dichloroethylene. The 1,2-dichloroethylene consists essentially of trans-1,2-dichloroethylene, cis-1,2-dichloroethylene and mixtures thereof; preferably a major amount of trans-1,2-dichloroethylene; and in particular at least 99% by weight of trans-1,2-dichloroethylene, based on the total weight of 1,2-dichloroethylene. The halocarbon is selected from the group consisting of 1,1,1,3,3,3-hexafluoroisopropanol, perfluoro-tert-butyl alcohol, 1,1,2,3,3-pentafluoropropane, 1-bromo-2-chloro-1,1,2-trifluoroethane, 1,2-dichloro-1,1,2,3,3,3-hexafluoropropane and mixtures thereof.

Nonflammable organic solvent compositions

One stereoisomer of 1,2-dichloroethene is isomerized to the other stereoisomer in the liquid phase and in the presence of free radical initiator.

Method for isomerizing 1,2-dichloroethene

Tetrachloroethylene is obtained by the vapor phase reaction of carbon tetrachloride in the presence of elemental hydrogen and a barium chloride catalyst at a temperature of at least 500.degree. C.

Process for making tetrachloroethylene

Methylchloroform containing ferric chloride and quaternary ammonium halide is distilled without significant decomposition.

Growing community of inventors

Sulphur, LA, United States of America

Earl M Gorton