The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 29, 1992
Filed:
Apr. 10, 1991
Akira Onoe, Hyogo, JP;
Masao Kawamura, Hyogo, JP;
Kunioki Kato, Hyogo, JP;
Tomiharu Amitani, Hyogo, JP;
Makoto Sato, Hyogo, JP;
Tsuyoshi Morishita, Hyogo, JP;
Seitetsu Kagaku Co., Ltd., Hyogo, JP;
Abstract
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.