Process of producing high purity bis(4-hydroxyphenyl) sulfides and heat-sensitive recording materials contaning the same.

摘要

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 tempertures; 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 DEG C to 124.9 DEG C as a developer and a fluoran compound as a color former.