Nicca Chemical Co., Ltd.

Yoshihiro Sasada

Masahiro Makino

Mikihiko Kurose

Masaaki Hosoda

Hajime Saito

High purity 2,4'-dihydroxydiphenylsulfones useful as developers for thermal recording paper can be produced efficiently and with high selectivity by reacting one or more phenols and sulfuric acid in the presence as of at least one of phosphonic acid, phosphinic acid and salts thereof, in the absence of a solvent or in the presence of an aromatic hydrocarbon solvent having a boiling point at atmospheric pressure of 130.degree. to 200.degree. C., and then purifying the thus-produced crude 2,4'-dihydroxydiphenylsulfones using a mixed solvent containing (1) 5 to 20 weight % of at least one lower aliphatic alcohol and 95 to 80 weight % of at least one aromatic hydrocarbon which does not contain halogen, (2) 10 to 40 weight % of at least one ketone and 90 to 60 weight % of at least one aromatic hydrocarbon which does not contain halogen or (3) 10 to 40 weight % of at least one ester of acetic acid and 90 to 60 weight % of at least one aromatic hydrocarbon which does not contain halogen.

Method of producing A 2,4'-dihydroxydiphenylsulfone

A germicidal and fungicidal agent can solve the problems of conventional germicidal and fungicidal agents comprising quaternary ammonium salts or amphoteric surface active agents that fungicidal activity is insufficient and metals such as parts of medical instruments are corroded. Furthermore, it has higher germicidal and fungicidal activity against Gram-negative bacteria and filamentous fungi than benzalkonium chloride and excellent safety for human health. It is advantageously applied as a disinfectant for medical uses, a disinfectant for environment, a germicidal and fungicidal agent for fibers, a germicidal and fungicidal agent for cycling cooling water and the like. It has excellent resistance against discoloration, heat resistance, corrosion preventing property and compatibility with anionic surface active agents and can be used for providing all kinds of fibers with the germicidal and fungicidal activity to replace silicone type quaternary ammonium salts. The germicidal and fungicidal agent comprises quaternary ammonium salts having three alkyl or alkenyl groups connected to the nitrogen, an oxyalkylene group or its oligomer connected to the nitrogen and a counter ion which is an anion of a carboxylic acid, an ion of an alkyl ester of phosphoric acid or an ion of a polyoxyalkylenealkylether ester of phosphoric acid. A germicidal and fungicidal method utilizes the germicidal and fungicidal agent described above.

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Takefu, Japan

Yoshihiro Sasada