Seitetsu Kagaku Co., Ltd.

Akira Onoe

Masao Kawamura

Kunioki Kato

Makoto Sato

Tsuyoshi Morishita

Masato Yoshikawa

Tomiharu Amitani

Tadaaki Nishi

Hirokazu Kagano

Kenzo Kobayashi

In a process of producing high purity bis(4-hydroxyphenyl)sulfides which comprises reacting phenols with sulfur dichloride in an organic solvent, the improvement comprising: reacting the phenols with sulfur dichloride in a nonpolar organic solvent; removing partly or wholly the nonpolar organic solvent after the reaction; adding a polar organic solvent to the reaction mixture to dissolve the reaction mixture therein at elevated temperatures; and crystallizing out the high purity bis(4-hydroxyphenyl)sulfides. There is further provided a high performance heat-sensitive recording material which comprises high purity bis(4-hydroxy-3-methylphenyl)sulfide thus prepared and having a melting point in the range of from 123.9.degree. C. to 124.9.degree. C. as a developer and a fluoran compound as a color former.

Process of producing high purity bis(4-hydroxyphenyl)sulfides and

In a process of producing high purity bis(4-hydroxyphenyl) sulfides which comprises reacting phenols with sulfur dichloride in organic solvents, the improvement comprising: reacting the phenols with sulfur dichloride in nonpolar organic solvents; removing partly or wholly the nonpolar organic solvents after the reaction; adding polar organic solvents to the reaction mixture to dissolve the reaction mixture therein at elevated temperatures; and crystallizing out the high purity bis(4-hydroxyphenyl)sulfides. There is further provided a high performance heat-sensitive recording material which comprises high purity bis(4-hydroxy-3-methylphenyl)sulfide thus prepared and having a melting point in the range of from 123.9.degree. C. to 124.9.degree. C. as a developer and a fluoran compound as a color former.

Heat-sensitive recording materials containing high purity

A method of producing alkali metal benzenesulfinates having the general formula of ##STR1## wherein M represents Na or K, which comprises: reacting nitrophenylphenyl sulfones having the general formula of ##STR2## wherein n is an integer of 1 or 2, with alkali metal thiophenolates having the general formula of ##STR3## in solvents. The reaction produces also nitrophenylphenyl sulfides as by-products in equimolar amounts to the alkali metal benzenesulfinates, and the oxidation of the sulfides provides the starting nitrophenylphenyl sulfones. A method of producing the nitrophenylphenyl sulfones is also provided wherein the sulfides are oxidized with hydrogen peroxide in the presence both of water-soluble tungstates or molybdates and of phase transfer catalysts in a two-phase heterogeneous solvent.

Method of producing alkali metal benzenesulfinates

A process for producing polythiobisphenols which comprises: reacting a phenol having the general formula ##STR1## wherein each R independently represents a hydrogen, a halogen or an alkyl, with sulfur monochloride in a polar organic solvent in the presence of a nitrogen-containing organic compound as a catalyst which is selected from the group consisting of tertiary amines, quaternary ammoniums, alkylated acid amides and heteroaromatic compounds, in amounts of about 1-30% by weight based on the amount of the phenol used. As a catalyst, bromine or an alkali metal halide is also usable. A novel process for producing mercaptophenols by the hydrogenolysis of polythiobisphenols in the presence of a nickel catalyst is also disclosed. Raney nickel catalyst which is in advance poisoned with an organosulfur compound in which the sulfur atom has unshared electron pairs is especially effective as a catalyst.

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Hyogo, Japan

Akira Onoe