# US 5,703,006 A · Thermosensitive recording medium

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

- Number: US 5,703,006 A
- Document ID: US5703006A
- Status: Granted
- Kind: A
- Application number: 08/584,355
- Filed: 1996-01-11
- Granted: 1997-12-30
- Earliest claimed: 1995-01-12
- Assignees: Ricoh Company, Ltd.
- Inventors: Yasutomo Mori; Motoi Orihara; Kunihiko Hada; Shuji Miyamoto
- Web page: https://patentgrep.com/patent/US5703006A

## CPC

- B41M 5/3375: {Non-macromolecular compounds}
- B41M 5/3335: {Compounds containing phenolic or carboxylic acid groups or metal salts thereof}
- B41M 5/3336: {Sulfur compounds, e.g. sulfones, sulfides, sulfonamides}
- 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)

## Abstract

A thermosensitive recording medium is disclosed which includes a support, and a thermosensitive color-developing layer formed on the support and containing a leuco dye having a melting point of at least 200.degree. C. and a color developer having a melting point of at least 180.degree..

## Claims

### Claim 1

A thermosensitive recording medium comprising a support, and a thermosensitive color-developing layer formed on said support and containing a leuco dye having a melting point of at least 200.degree. C. a color developer having a melting point of at least 180.degree. C., and an image stabilizing agent having a melting point of at least 200.degree. C.;
wherein said image stabilizing agent is an organic compound selected from the group consisting of bis(3,5-dibromo-4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)sulfone, dodecanedio-bis{(2-hydroxybenzoyl)hydrazide}, sodium salt of di(2,4,6-tri-t-butylphenyl)hydrogenphosphate, 3-(2-hydroxybenzoylamino)-1-H-1,2,4-triazine, 1,3,5-tris (4-hydroxy-3,5-di-t-butylbenzyl)isocyanuric acid and 1,1-bis (2-methyl-4-hydroxy-5-t-butylphenyl)butanebis(3,5-dibromo-4-hydroxyphenyl) sulfone.

### Claim 2 (depends on 1)

A thermosensitive recording medium as claimed in claim 1, further comprising a heat insulating layer provided between said support and said color-developing layer and containing a filler in the form of empty beads having an outside diameter of 0.1-10 .mu.m and an inside diameter which is at least 30% of said outside diameter.

### Claim 3 (depends on 2)

A thermosensitive recording medium as claimed in claim 2, wherein said heat insulating layer contains a filler in the form of empty beads having an outside diameter of 1-5 .mu.m and an inside diameter which is at least 30% of the outside diameter.

### Claim 4 (depends on 1)

A thermosensitive recording medium as claimed in claim 1, wherein said leuco dye is 3-(N-ethyl-p-toluidino)-6-methyl-7-anilinofluoran and said color developer is 2,4'-dihydroxyphenylsulfone.

### Claim 5 (depends on 1)

A thermosensitive recording medium as claimed in claim 1, wherein said leuco dye is 3-diethylamino-6-methyl-7-o-chloroanilinofluoran or 3-piperidino-6-methyl-7-anilinofluoran.

### Claim 6 (depends on 1)

A thermosensitive recording medium as claimed in claim 1, wherein said thermosensitive color-developing layer further comprises a second leuco dye having a melting point lower than 200.degree. C. selected from the group consisting of triallylmethane dyes, diphenylmethane dyes, thiazine dyes, spiro dyes, lactam dyes, fluoran dyes, and mixtures thereof.

### Claim 7 (depends on 1)

The thermosensitive recording medium as claimed in claim 1, wherein said thermosensitive color-developing layer further comprises a second color developer having a melting point lower than 180.degree. C. selected from the group consisting of phenol compounds, hydroxylbenzophenone compounds, aromatic esters having a phenolic hydroxyl group, phenol novolak resins, polyphenols, aromatic carboxylic acids, 4-hydroxydiphenyl sulfone compounds, sulfides, organic acidic compounds, salts of phenol compounds, salts of hydroxybenzophenone compounds, salts of aromatic esters having a phenolic hydroxyl group, and mixtures thereof.