# US 5,350,634 A · Thermochromic composition

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- Number: US 5,350,634 A
- Document ID: US5350634A
- Status: Granted
- Kind: A
- Application number: 08/103,674
- Filed: 1993-08-10
- Granted: 1994-09-27
- Earliest claimed: 1992-09-08
- Assignees: Sakura Color Products Corporation
- Inventors: Masaaki Sumii; Fumiko Sakai; Yasuyuki Yoshimura
- Web page: https://patentgrep.com/patent/US5350634A

## CPC

- B41M 5/284: {Organic thermochromic compounds}
- Y10T 428/2985: Solid-walled microcapsule from synthetic polymer
- 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)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A thermochromic composition which comprises (1) an electron-donating chromogenic organic compound, (2) an electron-accepting compound, and (3) at least one desensitizer selected from among diphenylamine derivatives of-the following formulas: ##STR1## wherein R.sup.1 and R.sup.2 each independently is H, an alkyl group containing 1 to 22 carbon atoms, ##STR2## (in which R.sup.3 and R.sup.4 each independently is H, an alkyl group containing 1 to 4 carbon atoms). A thermochromic composition which comprises (1) an electron-donating chromogenic organic compound, (2) an electron-accepting compound, (3) at least one desensitizer selected from among diphenylamine derivatives mentioned above, and (4) a thermochromic transition temperature modifier. A thermochromic composition which comprises one of the thermochromic compositions mentioned above as enclosed in microcapsule.

## Claims

### Claim 1

A thermochromic composition which comprises:
(1) an electron-donating chromogenic organic compound,
(2) an electron-accepting compound, and
(3) at least one desensitizer selected from among diphenylamine derivatives of the following formula: ##STR9## wherein R.sup.1 and R.sup.2 each independently is H, an alkyl group containing 1 to 22 carbon atoms, ##STR10## in which R.sup.3 and R.sup.4 each independently is H, an alkyl group containing 1 to 4 carbon atoms.

### Claim 2 (depends on 1)

A thermochromic composition as claimed in claim 1, wherein said desensitizer is a diphenylamine derivative having a molecular weight within the range of 169 to 900.

### Claim 3 (depends on 1)

A thermochromic composition as claimed in claim 1, wherein said desensitizer is a diphenylamine derivative having a melting point within the range of 50.degree. C. to 300.degree. C.

### Claim 4 (depends on 1)

A thermochromic composition as claimed in claim 1, wherein said desensitizer comprises at least one diphenylamine derivative selected from the group consisting of diphenylamine, 4,4'-dimethyl diphenylamine, 4,4'-diethyl diphenylamine, 4,4'-dipropyl diphenylamine, 4,4'-dibutyl diphenylamine, 4,4'-diisopropyl diphenylamine, 4,4'-dicapryl diphenylamine, 4,4'-dilauryl diphenylamine, 4,4'-dimyristyl diphenylamine, 4,4'-dicetyl diphenylamine, 4,4'-distearyl diphenylamine, 4,4'-dioctyl diphenylamine, 4,4'-bis(.alpha.,.alpha.-dimethylbenzyl) diphenylamine, 4,4'-bis(.alpha.,.alpha.-diethylbenzyl) diphenylamine, 4,4'-bis(.alpha.,.alpha.-dipropylbenzyl) diphenylamine, and 4,4'-bis(.alpha.,.alpha.-diebutylbenzyl) diphenylamine.

### Claim 5 (depends on 1)

A thermochromic composition as claimed in claim 1, wherein said electron-donating chromogenic organic compound comprises at least one compound selected from the group consisting of diarylphthalides, polyarylcarbinols, leucoauramines, rhodamine B lactams, indolines, spiropyrans, and fluorans.

### Claim 6 (depends on 1)

A thermochromic composition as claimed in claim 1, wherein said electron-donating chromogenic organic compound comprises at least one compound selected from the group consisting of crystal violet lactone, malachite green lactone, 3-(4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl) phthalide, Michler's hydrol, crystal violet carbinol, malachite green carbinol, N-(2,3-dichlorophenyl) leucoauramine, N-benzoylauramine, N-acetylauramine, N-phenylauramine, rhodamine B lactam, 2-(phenyliminoethylidene) 3,3-dimethylindoline, N-3,3-trimethylindolinobenzospiropyran, 8-methoxy-N-3,3-trimethylindolinobenzospiropyran, 3-diethylamino-6-methyl-7-chlorofluoran, 3-diethylamino-7-methoxyfluoran, 3-diethylamino-6-benzyloxyfluoran, 3-amino-5-methylfluoran, 2-methyl-3-amino-6,7-dimethylfluoran, 2-bromo-6-cyclohexylaminofluoran, 2-(o-chlorophenylamino)-6-dibutylaminofluoran, 1,3-dimethyl-6-diethylaminofluoran, 3,6-diphenylaminofluoran, 9-(diethylamino)-spiro(12H-benzoxanthene-12,1'(3'H)-isobenzofluoran)-3'-on e, 2-(N-phenyl-N-methylamino)-6-(N-ethyl-N-phenylamino)fluoran, 3-diethylamino-6-methyl-7-chlorofluoran, and 3-diethylaminobenzo(a)-fluoran.

### Claim 7 (depends on 1)

A thermochromic composition as claimed in claim 1, wherein said electron-accepting compound comprises at least one compound selected from the group consisting of phenols, phenol resins, metal phenolates, aromatic carboxylic acids, aliphatic carboxylic acids containing 2 to 5 carbon atoms, metal salts of carboxylic acids, acid phosphoric esters, metal salts of acid phosphoric esters, triazole compounds, thiourea, diphenylthiourea, di-o-toluoylthiourea halohydrins, and benzothiazoles.

### Claim 8 (depends on 7)

A thermochromic composition as claimed in claim 7, wherein said electron-accepting compound comprises at least one compound selected from the group consisting of bisphenol A, p-phenylphenol, dodecylphenol, o-bromophenol, ethyl p-hydroxybenzoate, methyl gallate, sodium phenolate, potassium phenolate, lithium phenolate, calcium phenolate, zinc phenolate, aluminum phenolate, magnesium phenolate, nickel phenolate, cobalt phenolate, tin phenolate, copper phenolate, iron phenolate, titanium phenolate, lead phenolate, molybdenum phenolate, phthalic acid, benzoic acid, acetic acid, propionic acid, sodium oleate, zinc salicylate, nickel benzoate, 1,2,3-triazole, 1,2,3-benzotriazole, thiourea, diphenylthiourea, and di-o-toluoylthiourea.

### Claim 9

A thermochromic composition which comprises:
(1) an electron-donating chromogenic organic compound,
(2) an electron-accepting compound,
(3) at least one desensitizer selected from among diphenylamine derivatives of the following formula: ##STR11## wherein R.sup.1 and R.sup.2 each independently is H, an alkyl group containing 1 to 22 carbon atoms, ##STR12## in which R.sup.3 and R.sup.4 each independently is H, an alkyl group containing 1 to 4 carbon atoms, and
(4) a thermochromic transition temperature modifier.

### Claim 10 (depends on 9)

A thermochromic composition as claimed in claim 9, wherein said desensitizer is a diphenylamine derivative having a molecular weight within the range of 169 to 900.

### Claim 11 (depends on 9)

A thermochromic composition as claimed in claim 9, wherein said desensitizer is a diphenylamine derivative having a melting point within the range of -50.degree. C. to 300.degree. C.

### Claim 12 (depends on 9)

A thermochromic composition as claimed in claim 9, wherein said desensitizer comprises at least one diphenylamine derivative selected from the group consisting of diphenylamine, 4,4'-dimethyl diphenylamine, 4,4'-diethyl diphenylamine, 4,4'-dipropyl diphenylamine, 4,4'-dibutyl diphenylamine, 4,4'-diisopropyl diphenylamine, 4,4'-dicapryl diphenylamine, 4,4'-dilauryl diphenylamine, 4,4'-dimyristyl diphenylamine, 4,4'-dicetyl diphenylamine, 4,4'-distearyl diphenylamine, 4,4'-dioctyl diphenylamine, 4,4'-bis(.alpha.,.alpha.-dimethylbenzyl) diphenylamine, 4,4'-bis(.alpha.,.alpha.-diethylbenzyl) diphenylamine, 4,4'-bis(.alpha.,.alpha.-dipropylbenzyl) diphenylamine and 4,4'-bis(.alpha.,.alpha.-diebutylbenzyl) diphenylamine.

### Claim 13 (depends on 9)

A thermochromic composition as claimed in claim 9, wherein said thermochromic transition temperature modifier comprises at least one compound selected from the group consisting of alcohols, esters, ketones, ethers, acid amides, fatty acids, aromatic hydrocarbons, thiols, sulfides, disulfides, sulfoxides, sulfones, azomethines, and fatty acid primary amine salts.

### Claim 14 (depends on 9)

A thermochromic composition as claimed in claim 9, wherein said thermochromic transition temperature modifier comprises at least one compound selected from the group consisting of n-cetyl alcohol, n-octyl alcohol, cyclohexanol, hexylene glycol, ethyl myristate, stearyl laurate, dioctyl phthalate, methyl hexyl ketone, benzophenone, stearone, butyl ether, diphenyl ether, distearyl ether, oleamide, stearamide, N-octyl lauramide, caproanilide, lauric acid, stearic acid, 2-hydroxymyristic acid, isopropylbenzene, dodecylbenzene, biphenyl, trimethylbiphenyl, diphenylethane, dibenzyltoluene, propylnaphthalene, butyltetralin, n-decylmercaptan, n-myristylmercaptan, n-stearylmercaptan, isocetylmercaptan, dodecylbenzylmercaptan, di-n-octyl sulfide, di-n-decyl sulfide, diphenyl sulfide, diethylphenyl sulfide, dilauryl thiodipropionate, di-n-octyl disulfide, di-n-decyl disulfide, diphenyl disulfide, dinaphthyl disulfide, diethyl sulfoxide, tetramethylene sulfoxide, diphenyl sulfoxide, diethyl sulfone, dibutyl sulfone, diphenyl sulfone, dibenzyl sulfone, benzylidenelaurylamine, p-methoxybenzylidenelaurylamine, benzylidene-p-anisidine, stearylamine oleate, myristylamine stearate, and stearylamine behenate.

### Claim 15 (depends on 9)

A thermochromic composition as claimed in claim 9, wherein said electron-donating chromogenic organic compound comprises at least one compound selected from the group consisting of diarylphthalides, polyarylcarbinols, leucoauramines, rhodamine B lactams, indolines, spiropyrans, and fluorans.

### Claim 16 (depends on 9)

A thermochromic composition as claimed in claim 9, wherein said electron-donating chromogenic organic compound comprises at least one compound selected from the group consisting of crystal violet lactone, malachite green lactone, 3-(4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)phthalide, Michler's hydrol, crystal violet carbinol, malachite green carbinol, N-(2,3-dichlorophenyl)leucoauramine, N-benzoylauramine, acetylauramine, N-phenylauramine, rhodamine B lactam, 2-(phenyliminoethylidene) 3,3-dimethylindoline, N-3,3-trimethylindolinobenzospiropyran, 8-methoxy-N-3,3-trimethylindolinobenzospiropyran, 3-diethylamino-6-methyl-7-chlorofluoran, 3-diethylamino-7-methoxyfluoran, 3-diethylamino-6-benzyloxyfluoran, 3-amino-5-methylfluoran, 2-methyl-3-amino-6,7-dimethylfluoran, 2-bromo-6-cyclohexylaminofluoran, 2-(o-chlorophenylamino)-6-dibutylaminofluoran, 1,3-dimethyl-6-diethylaminofluoran, 3,6-diphenylaminofluoran, 9-(diethylamino)-spiro(12H-benzoxanthene-12,1'(3'H)-isobenzofluoran)-3'-on e, 2-(N-phenyl-N-methylamino)-6-(N-ethyl-N-phenylamino)fluoran, 3-diethylamino-6-methyl-7-chlorofluoran, and 3-diethylaminobenzo(a)-fluoran.

### Claim 17 (depends on 9)

A thermochromic composition as claimed in claim 9, wherein said electron-accepting compound comprises at least one compound selected from the group consisting of phenols, phenol resins, metal phenolates, aromatic carboxylic acids, aliphatic carboxylic acids containing 2 to 5 carbon atoms, metal salts of carboxylic acids, acid phosphoric esters, metal salts of acid phosphoric esters, triazole compounds, thiourea, diphenylthiourea, di-o-toluoylthiourea halohydrins, and benzothiazoles.

### Claim 18 (depends on 9)

A thermochromic composition as claimed in claim 9, wherein said electron-accepting compound comprises at least one compound selected from the group consisting of bisphenol A, p-phenylphenol, dodecylphenol, o-bromophenol, ethyl p-hydroxybenzoate, methyl gallate, sodium phenolate, potassium phenolate, lithium phenolate, calcium phenolate, zinc phenolate, aluminum phenolate, magnesium phenolate, nickel phenolate, cobalt phenolate, tin phenolate, copper phenolate, iron phenolate, titanium phenolate, lead phenolate, molybdenum phenolate, phthalic acid, benzoic acid, acetic acid, propionic acid, sodium oleate, zinc salicylate, nickel benzoate, 1,2,3-triazole, 1,2,3-benzotriazole, thiourea, diphenylthiourea, and di-o-toluoylthiourea.

### Claim 19 (depends on 1)

A microencapsulated thermochromic composition which comprises the thermochromic composition of claim 1 enclosed within a microcapsule.
