Heat-sensitive recording materials containing high purity bis(4-hydroxyphenyl)sulfides
US5102858A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 1989 |
| Grant date | Apr 7, 1992 |
| Priority date | — |
| Expiry date | Jun 12, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C319/14
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.