# US 5,705,452 A · Sulfonyl compound and thermal-sensitive recording medium using the same

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,705,452 A
- Document ID: US5705452A
- Status: Granted
- Kind: A
- Application number: 08/540,722
- Filed: 1995-10-11
- Granted: 1998-01-06
- Earliest claimed: 1994-10-14
- Assignees: Sanko Haihatsu Kagaku Kenkyusho
- Inventors: Toranosuke Saito; Shigeru Oda; Eiji Kawabata
- Web page: https://patentgrep.com/patent/US5705452A

## CPC

- B41M 5/3336: {Sulfur compounds, e.g. sulfones, sulfides, sulfonamides}
- C07C 317/22: with sulfone or sulfoxide groups bound to carbon atoms of six-membered aromatic rings of the carbon skeleton
- B41M: PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING, (correction of typographical errors B41J; processes for applying transfer pictures or the like B44C1/16; fluid media for correction of typographical errors by coating C09D10/00; printing textiles D06P)
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

A thermal recording medium comprising a as a developer a sulfonyl compound represented by general formula (1) or a polyvalent metal salt thereof. ##STR1## where X represents H or a lower alkyl group, R.sub.1, R.sub.2 and R.sub.3 represent H, halogen atom, a hydroxyl group, a lower alkyl group or a cycloalkyl group, R.sub.4, R.sub.5 and R.sub.6 represent H, halogen atom, a lower alkyl group or a cycloalkyl group, and R.sub.7 represents H or ##STR2## where R.sub.4, R.sub.5 and R.sub.6 are as defined above. The thermal recording medium has a high sensitivity and a lower background blush during storage, and also has excellent stability against heating, moisture and plasticizer.

## Claims

### Claim 1

A thermal recording medium comprising a substrate and a thermal developer layer containing therein a developer using a developing reaction of an electron donative basic dye precursor and an electron receptive developer, said developer comprising at least one selected from the sulfonyl compounds represented by general formula (1) and the polyvalent metal salts thereof: ##STR11## where X represents a hydrogen atom or a lower alkyl group, R.sub.1, R.sub.2 and R.sub.3, which may be equal or different, represent a hydrogen atom, a hydroxyl group, a lower alkyl group or a cycloalkyl group, R.sub.4, R.sub.5 and R.sub.6, which may be equal or different, represent a hydrogen atom, halogen atom, a lower alkyl group or a cycloalkyl group, and R.sub.7, represents a hydrogen atom or ##STR12## where R.sub.4, R.sub.5 and R.sub.6 are defined above.

### Claim 2

A thermal recording medium, comprised of a substrate and a thermal developer layer using a developing reaction of an electron donative basic dye precursor and an electron receptive developer, said developer comprising at least one selected from the sulfonyl compounds represented by general formula (1) and the polyvalent metal salts thereof: ##STR13## where X represents a hydrogen atom or a lower alkyl group, R.sub.1, R.sub.2 and R.sub.3, which may be equal or different, represent a hydrogen atom, a hydroxyl group, a lower alkyl group or a cycloalkyl group, R.sub.4, R.sub.5 and R.sub.6, which may be equal or different, represent a hydrogen atom, halogen atom, a lower alkyl group or a cycloalkyl group, and R.sub.7 represents a hydrogen atom or ##STR14## where R.sub.4, R.sub.5 and R.sub.6 are defined above, and at least one selected from the diphenyl derivatives represented by general formula (2) below: ##STR15## wherein R.sub.8 and R.sub.9, which may be equal or different, represent a hydrogen atom, a lower alkyl group or a lower alkylene group, and R.sub.10 represents a hydrogen atom or straight or branched lower alkyl group, Y represents sulfonyl group, a lower alkylene group or a lower alkylidene group, and n represents 0 or 1.