DE3347171A1 - REVERSIBLE HEAT SENSITIVE RECORDING MATERIAL - Google Patents

Description

Reversible thermosensitive recording material

The invention relates to a reversible thermosensitive recording material. It affects in particular a thermosensitive recording material comprising can be used repeatedly by making use of the hysteresis property of a chromogenic component makes, i.e. that one creates a positive image with the material or a negative image through application can record from local cold or heat and maintain the recording stably, by placing the recording material in a defined Temperature range and then, if desired, the recording can be easily deleted by removing the recording or exposing the recording material to a higher or lower temperature.

Usual reversible thermosensitive recording materials which can be used repeatedly in the above-mentioned manner include a reversible thermosensitive recording material which makes use of the heat discoloration properties of _{a metal complex salt such as Ag 3 HgI 4} or Cu "HgI., And a thermosensitive image-displaying material (which reversibly changes its transparent state and a white cloudy state due to the

10 application of heat) from a matrix material of a thermoplastic resin and an organic low molecular weight, in the matrix material dispersed material as disclosed in Japanese Patent Publication (unexamined) 89 992/82

15 is written. However, these materials have the following Disadvantage:

(1) the contrast between the recorded part and the background part is low,

(2) a desired selection for recording Preservation temperature door is impossible, and

(3) a free choice of color is impossible. 25th

The main aim of the invention is to provide a reversible thermosensitive To provide recording material without the aforementioned disadvantages.

The invention relates to a reversible thermosensitive recording material used as

chromogenic components of a heat discoloring material from a homogeneous fused mixture of:

5 (A) at least one electron donating chromatic organic compound selected from Diarylphthaliden, Indolylphthaliden, Polyarylcarbinolen, Leuco auramines, acylauramines, arylauramines, Rhodamine B-lactams, indolines, spiropyrans and 10 fluorans,

(B) at least one compound selected from phenolic compounds having 6 to 49 carbon atoms, the

Metal salts of phenolic compounds, aromatic carboxylic acids with 7 to 12 carbon atoms, aliphatic Carboxylic acids with 2 to 5 carbon atoms, metal salts of carboxylic acids with 2 to 22 carbon atoms, acidic phosphoric acid esters with 1 to 44 carbon atoms, the metal salts

of acidic phosphoric acid esters and triazole compounds with 2 to 24 carbon atoms, and

(C) at least one compound selected from aliphatic monohydric alcohols having 4 to 31 carbon atoms, alicyclic monohydric alcohols with 5 to 10 carbon atoms, aromatic monohydric alcohols Alcohols with 7 to 9 carbon atoms, polyhydric alcohols with 2 to 6 carbon atoms

atoms, ester compounds of monocarboxylic acids with 2 to 22 carbon atoms and aliphatic monohydric alcohols with 1 to 22 carbon atoms

men, Esterverbinduhgen of monocarboxylic acids with 2 to 22 carbon atoms and phenols with 6 to 18 carbon atoms / ester compounds of monocarboxylic acids with 2 to 22 carbon atoms and polyhydric alcohols with 2 to 6 carbon atoms, ester compounds of polycarboxylic acids with 2 to 12 carbon atoms and aliphatic monohydric alcohols with 1 to 22 carbon atoms, aliphatic ketones with 5 to 35 'carbon IQ atoms, aromatic ketones with 8 to 13 carbon atoms, Fatty acid amides with 2 to 22 carbon atoms, the N-alkyl-substituted compounds of fatty acid amides, aliphatic ethers with 8 to 36 carbon atoms, aromatic ethers with Ί5 12 to 20 carbon atoms, aliphatic monocarboxylic acids with 6 to 22 carbon atoms, thiols with 10 to 18 carbon atoms, sulfides with 16 to 89 carbon atoms, disulfides with 16 to 36 carbon atoms, sulfoxides with 2 to 14 carbon atoms and sulfons with 4 to 14 carbon atoms as necessary components.

Fig. 1 is a diagram showing

the hysteresis curve of the change in color density caused by a change in temperature

of the heat discoloring material used in the reversible thermosensitive recording material is used according to the invention, where on the abscissa the temperature and on the ordi

nate the color density are given.

As shown in Fig. 1, the heat discoloring material according to the invention exhibits a hysteresis phenomenon caused by temperature change (on the abscissa) and including repetition of coloration and discoloration. In Fig. 1, A is a point which shows the density at a minimum temperature T_ at which the heat-discoloring material has a completely achromatized state and B is a point which shows the density at the maximum temperature T ₁ at which the heat-discoloring material has the fully colored state and at a temperature T ~ of the heat-discoloring material, two phases of a colored state, point C, and an achromatic state, point D, exist together. The temperature range in the vicinity of T ₂ , that is, the temperature range at which the colored state and the achromatic state coexist, is a temperature range at which the record on the heat-sensitive recording material .20 according to the invention can be preserved. The length of the line CD is a measure and indicates the contrast between a recording and the background, and the length of the line EF, which passes through the midpoint of the lines CD, is a temperature width or temperature range which indicates the extent of the hysteresis The wider this width is, the easier it is to keep the record. Investigations by the inventors have shown that the aforementioned temperature range should be wider than 3 ^° C., and preferably wider than 8 ^° C. for convenience of keeping the record necessary reasons

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preferred range for this temperature range is 3 to 150 ^° C. and even more preferably 8 to 100 ^° C.

The components making up the heat discoloring material according to the present invention are as follows described in detail.

The electron donating chromatic organic compounds used as component (A) are diarylphthalide, indolylphthalide, polyarylcarbinole, Leukoauramine, Acylauramine, Arylauramine, Rhodamine B-lactams, indolines, spiropyrans and fluorans.

Practical examples of these compounds are

Crystal violet lactone, malachite green lactone, Michler's Hydrol, crystal violet carbinol, malachite green carbinol, N- (2,3-dichlorophenyl) leukoauramine, N-benzoylauramine, Rhodamine B-lactam, N-Acetylauramine, N-Phenylauramine, 2- (phenyliminoethylidene) -3,3-dimethylindoline, N-3,3-Trimethylindolinbenzspiropyran, 8-Methoxy-N-3,3-trimethylindolinbenzspiropyran, 3-diethylamino-6-methyl-7-chlorofluorane, 3-diethylamino-7-methoxyfluoran, 3-diethylamino-6-benzyloxyfluoran, 1,2-benz-6-diethylaminofluoran, 3,6-di-p-toluidino-4,5-dimethylfluorane

25 "phenylhydrazido - ^ - lactam, 3-amino-5-methylfluorane,

2-methyl-3-amino-6-methyl-7-methylfluoran, 2,3-butylene-6-di-n-butylaminofluoran, S-diethylamino-V-anilinofluoran, 3-diethylamino-7- (p-toluidino) fluoran , 7-acetamido-3-diethylaminofluoran, 2 ^u bromo-6-cyclo-

30 hexylaminofluorane, 2,7-dichloro-3-methyl-6-n-butyl-

aminofluoran etc., and preferably crystal violet lactone,

Bf * OO. β β '

OB O β β <♦ ·

«Θ · © ο · ft β * β

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Malachite green lactone, S-fluoran, S-diethylamino - ^ - methoxyfluorane, 3-diethylamino-6-benzyloxyfluorane, 1,2-Benz-6-diethylaminofluoran, 3,6-Di-p-toluidino-4,5-dimethylfluoranphenylhydrazido-gf-lactam, 3-amino-5-methylfluorane, 2-methyl-3-amino-6-methyl-7-methylfluorane, 2,3-butylene-6-di-n-butylaminofluorane, S-Diethylamino - ^ - anilinofluoran, S-Diethylamino -? - (p-toluidino) fluoran, 7-acetamido-3-diethylaminofluoran, 2-bromo-6-cyclohexylaminofluoran and 2,7-dichloro-3-methyl-6-n-butylaminofluoran.

The compounds used as component (B) according to the invention are phenolic compounds with 6 to 49 carbon atoms, metal salts of phenolic compounds, aromatic carboxylic acids with 7 to 12 Carbon atoms, aliphatic carboxylic acids with 2 to 5 carbon atoms, metal salts of carboxylic acids with 2 to 22 carbon atoms, acidic phosphoric acid esters with 1 to 44 carbon atoms, metal salts of acidic phosphoric acid esters and triazole compounds with 2 to 24 carbon atoms.

Suitable phenolic compounds of the compounds of component (B) include monophenols and polyphenols an which may be substituted by an alkyl group, an aryl group, an acyl group, a Alkoxycarbonyl group, a halogen atom etc. Practical examples of such phenolic compounds are t-butylphenol, Nonylphenol, dodecylphenol, styrenated phenol, 2,2-methylenebis (4-methyl-6-t-butylphenol), 06-naphthol,

ß-naphthol, hydroquinone monomethyl ether, guaiacol, Eugenol, p-chlorophenol, p-bromophenol, o-chlorophenol, o-bromophenol, o-phenylphenol, p-phenylphenol, p- (p-chloropheny1) phenol, o- (o-chloropheny1) phenol, methyl p-oxybenzoate, Ethyl p-oxybenzoate, propyl p-oxybenzoate, Butyl p-oxybenzoate, octyl p-oxybenzoate, dodecyl poxybenzoate, 3-isopropylcatechol, p-t-butylcatechol, 4,4-methyldiphenol, 4,4-thiobis (6-t-butyl-3-methylphenol ), 1,1-bis (4-hydroxyphenyl) eyelohexane, 4,4-butylidenebis (6-t-butyl-3-methylphenol), Bisphenol A, bisphenol S, 1,2-dioxynaphthalene, chlorocatechol, Bromocatechol, 2,4-dihydroxybenzophenone, phenolphthalein, o-cresolphthalein, methyl protocatechuate, ethyl protocatechuate, Propyl protocatechuate, octyl protocatechuate,

15 dodecyl protocatechuate, 2,4,6-trioxymethylbenzene,

2,3,4-trioxyethylbenzene, methyl gallate, ethyl gallate, propyl gallate, butyl gallate, hexyl gallate, octyl gallate, dodecyl gallate, cetyl gallate, stearyl gallate, 2,3,5-trioxynaphthalene, tannic acid, phenol-formaldehyde prepolymer, etc., and preferably , Nonylphenol, dpdecylphenol, p-phenylphenol, p- (p-chlorophenyl) phenol, methyl p-oxybenzoate, ethyl poxybenzoate, propyl p-oxybenzoate, butyl p-oxybenzoate, octyl p-ox ² benzoate, dodecyl p-oxybenzoate, 4,4-methyl-

25 "diphenol, 4,4-thiobis (6-t-butyl-3-methy! Phenol),

1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4-butylidenebis (6-t-butyl-3-methylphenol), Bisphenol A and Bisphenol S.

30 metal salts of the aforementioned phenol compounds

close salts of pheno! compounds with metals,

α β am

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such as sodium, potassium, lithium, calcium, zinc, zirconium, aluminum, magnesium, nickel, cobalt, tin, copper, iron, vanadium, titanium, lead, molybdenum etc.
| 5

Examples of aromatic carboxylic acids having 7 to 12 carbon atoms and aliphatic carboxylic acids having 2 to 5 carbon atoms in the compounds of component (B) include maleic acid, fumaric acid, Benzoic acid, toluic acid, p-t-buty! Benzoic acid, chlorobenzoic acid, Bromobenzoic acid, ethoxybenzoic acid, gallic acid, naphthoic acid, phthalic acid, naphthalenedicarboxylic acid, Acetic acid, propionic acid, butyric acid, valeric acid etc., whereby benzoic acid, toluic acid, p-t-Buty! benzoic acid, chlorobenzoic acid, bromobenzoic acid, Ethoxybenzoic acid, butyric acid and valeric acid are preferred.

Examples of metal salts of carboxylic acid having 2 to 22 carbon atoms in the compounds of the component (B) include metal salts of monocarboxylic acids and polycarboxylic acids. Useful examples for such salts are the metal salts (of sodium, potassium, lithium, calcium, zinc, zirconium, aluminum, "Magnesium, nickel, cobalt, tin, copper, iron, vanadium, titanium, lead, molybdenum etc.), salts of acetic acid, Propionic acid, butyric acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, Stearic acid, isostearic acid, behenic acid, crotonic acid, oleic acid, elaidic acid, linoleic acid, linolenic acid, Monochloroacetic acid, monobromoacetic acid,

U <Φ

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Monofluoroacetic acid, glycolic acid, hydroxypropionic acid, Hydroxybutyric acid, ricinoleic acid, 1,2-hydroxy stearic acid, Lactic acid, pyruvic acid, oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, malic acid, 5 tartaric acid, valeric acid, maleic acid, fumaric acid, naphthenic acid, benzoic acid, toluic acid, phenylacetic acid, p-t-Buty! benzoic acid, cinnamic acid, chlorobenzoic acid, bromobenzoic acid, ethoxybenzoic acid, mandelic acid, Protocatechuric acid, vanillic acid, resorcic acid,

10 dioxybenzoic acid, dioxychlorobenzoic acid, gallic acid, Naphthalic acid, hydroxynaphthalic acid, phthalic acid, phthalic acid monoethyl ester, naphthalenedicarboxylic acid, Naphthalenedicarboxylic acid monomethyl ester, trimellitic acid, Pyromellitic acid, etc., and preferably the metal salts

(of sodium, potassium, lithium, calcium, zinc and

Nickel), salts of butyric acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, Stearic acid, isostearic acid, oleic acid, elaidic acid, linoleic acid, succinic acid, adipic acid, sebum acid

cic acid, malic acid, benzoic acid, toluic acid, p-t-buty! benzoic acid, Chlorobenzoic acid, bromobenzoic acid and ethoxybenzoic acid.

Examples of acidic phosphoric acid esters having 1 to 44 "carbon atoms among the compounds of the component (B) are acidic phosphoric ester compounds having an ester group such as an alkyl group, a branched alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group etc., as well as the derivatives of these groups. the

preferred ester groups are alkyl groups, branched ones

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Alkyl groups, cycloalkyl groups and aryl groups. Examples for acidic phosphoric ester compounds include monoesters and diesters or mixtures of these Ester a. In the following practical examples, a mixture of the monomer and the diester is used referred to as an acid phosphate.

Practical examples of the acidic phosphorus ester compounds are methyl acid phosphate, ethyl acid Phosphate, n-propyl acid phosphate, n-butyl acid phosphate, 2-ethylhexyl acid phosphate, n-octyl acid Phosphate, isodecyl acid phosphate, n-decyl acid phosphate, lauryl acid phosphate, myristyl acid Phosphate, cetyl acid phosphate, stearyl acid Phosphate, docosyl acid phosphate, oleyl acid phosphate, 2-chloroethyl acid phosphate, 2,3-Dibromo-2,3-dichloropropyl acid phosphate, dichloropropyl acid Phosphate, cyclohexyl acid phosphate, phenyl acid phosphate, o-tolyl acid phosphate, 2,3-xylyl acid phosphate, p-cumenyl acid phosphate, Mesityl Acid. Phosphate, 1-naphthyl acid phosphate, 2-naphthyl acid phosphate, 1-anthryl acid phosphate, Benzylic acid phosphate, phenethyl acid phosphate, styryl acid phosphate, cinnamon acid phosphate, "Triethyl acid phosphate, phenyl methyl phosphate, phenyl n-propyl phosphate, Phenyl n-butyl phosphate, phenyl noctyl phosphate, Phenyl lauryl phosphate, phenyl cyclohexyl phosphate, phenyl 2,3-xylyl phosphate, cyclohexyl stearyl phosphate, Cyclohexyl cetyl phosphate, dimethyl phosphate, Diethyl phosphate, di-n-propyl phosphate, di-n-butyl phosphate, Di-η-hexy! Phosphate, di (2-ethylhexyl) phosphate,

Di-n-decyl phosphate, dilauryl phosphate, dimyristyl phosphate, Dicetyl phosphate, distearyl phosphate, dibehenyl phosphate, diphenyl phosphate, dicyclohexyl phosphate, Di-o-tolyl phosphate, bis (diphenylmethyl) phosphate, bis (triphenylmethyl) phosphate, Di (2,3-xyIyI) phosphate, dibenzyl phosphate, di (1-naphthy1) phosphate etc., and preferably 2-ethylhexyl acid phosphate, n-octyl acid Phosphate, isodecyl acid phosphate, n-decyl acid phosphate, lauryl acid phosphate, myristyl acid Phosphate, Cetyl Acid Phosphate, Stearyl Acid Phosphate, Docosyl Acid Phosphate, Cyclohexyl Acid Phosphate, phenyl acid phosphate, o-tolyl acid phosphate, phenyl n-butyl phosphate, phenyl n-octyl phosphate / Phenyl lauryl phosphate, phenyl 2,3-xylyl phosphate, cyclohexyl stearyl phosphate, cyclohexyl cetyl phosphate, Di-n-buty! Phosphate, di-n-hexyl phosphate, di (2-ethylhexyl) phosphate, Di-n-decyl phosphate, dilauryl phosphate, dimyristyl phosphate, dicetyl phosphate, distearyl phosphate, Dibehenyl phosphate, diphenyl phosphate, dicyclohexyl

20 phosphate and di-o-tolyl phosphate.

Examples of metal salts of acidic phosphoric acid esters include metal salts (of sodium, potassium, Lithium, calcium, zinc, zirconium, aluminum, magne-25 sium, nickel, cobalt, tin, copper, iron, vanadium, Titanium, lead, molybdenum, etc.) of the aforementioned phosphoric acid ester compounds.

Examples of triazole compounds having 2 to 24 carbon atoms among the compounds of the component (B) are 1,2,3-triazole, 4 (5) -hydroxy-1,2,3-triazole,

5 (6) -Methyl-1,2,3-benzotriazole, 5-chloro ~ 1,2,3-benzotriazole, 7-nitro-1,2,3-benzonitrazole, 4-benzoylamino-1,2,3-benzotriazole, 4-hydroxy-1,2,3-benzotriazole, naphtho-1,2,3-triazole, 5,5'-bis (1,2,3-benzotriazole),

5 1,2,3-Benzotriazole-4-sulfooctylamide etc ..

Compounds of component (C) according to the invention are used are aliphatic monohydric alcohols having 4 to 31 carbon atoms, alicyclic monohydric alcohols with 5 to 10 carbon atoms, aromatic monohydric alcohols with 7 to 9 carbon atoms, polyhydric alcohols with 2 to 6 carbon atoms, ester compounds of monocarboxylic acids with 2 to 22 carbon atoms and aliphatic monohydric alcohols having 1 to 22 carbon atoms, ester compounds of monocarboxylic acids with phenols with 6 to 18 carbon atoms, ester compounds of monocarboxylic acids with polyhydric alcohols with 2 to 6 carbon atoms, ester compounds of polycarboxylic acids with 2 to 12 carbon atoms and aliphatic monohydric alcohols with 1 to 22 carbon atoms, aliphatic ketones with 5 to 35 carbon atoms, aromatic ketones with 8 to 13 carbon atoms, Fatty acid amides with 2 to 22 carbon atoms, "N-alkyl-substituted compounds of fatty acid amides, aliphatic ethers with 8 to 36 carbon atoms, aromatic ethers with 12 to 20 carbon atoms, aliphatic monocarboxylic acids with 6 to 22 carbon atoms, thiols with 10 to 18 carbon atoms, sulfides with 16 to 89 carbon atoms, disulfides with up to 16 to 36 carbon atoms, sulfoxides with 2 to 14 carbon atoms and sulfones having 4 to 14 carbon atoms.

Examples of alcohols of the compounds of component (C) include monohydric alcohols, polyhydric alcohols Alcohols and their derivatives. Practical examples of such alcohols are n-octyl alcohol, n-nonyl alcohol, n-decyl alcohol, n-lauryl alcohol, n-myristyl alcohol, n-cetyl alcohol, n-stearyl alcohol, n-eicosyl alcohol, n-docosyl alcohol, n-melissyl alcohol, isocetyl alcohol, Isostearyl alcohol, isodocosyl alcohol, oleyl alcohol, cyclohexanol, cyclopentanol, benzyl alcohol

10 hol, cinnamon alcohol, ethylene glycol, diethylene glycol,

Triethylene glycol, polyethylene glycol, propylene glycol, Butylene glycol, hexylene glycol, cyclohexane-1,4-diol, Trimethylolpropane, 1,2,6-hexanetriol, pentaerythritol, Sorbitol, mannitol etc., preferably n-octyl alcohol, n-nony alcohol, n-decyl alcohol, n-lauryl alcohol, n-myristyl alcohol, n-cetyl alcohol, n-stearyl alcohol, n-eicosyl alcohol, n-docosyl alcohol, isostearyl alcohol, Isodocosyl alcohol and benzyl alcohol.

Practical examples of esters as compounds of component (C) are amyl acetate, octyl acetate, butyl propionate, Octyl propionate, phenyl propionate, ethyl caproate, amyl caproate, ethyl caprylate, amyl caprylate, ethyl caprate, Amyl caprate, octyl caprate, methyl laurate, ethyl laurate, "butyl laurate, hexyl laurate, octyl laurate, dodecyl laurate, Myristyl laurate, cetyl laurate, stearyl laurate, methyl myristate, ethyl myristate, butyl myristate, hexyl myristate, Octyl myristate, lauryl myristate, myristyl myristate, cetyl myristate, Stearyl myristate, methyl palmitate, ethyl palmitate, Ethyl palmitate, butyl palmitate, hexyl palmitate, octyl palmitate, Lauryl palmitate, myristyl palmitate, cetyl palmitate,

Stearyl palmitate, methyl stearate, ethyl stearate, butyl stearate, Hexyl stearate, octyl stearate, lauryl stearate, myristyl stearate, cetyl stearate, stearyl stearate, methyl behenate, Ethyl behenate, propyl behenate, butyl behenate, Ethyl benzoate, butyl benzoate, amyl benzoate, phenyl benzoate, Ethyl acetoacetate, methyl oleate, butyl oleate, butyl acrylate, Diethyl oxalate, dibutyl oxalate, diethyl malonate, Dibutyl malonate, dibutyl tartrate, dibutyl sebacate, Dimethyl sebacate, dimethyl phthalate, dibutyl phthalate / Dioctyl phthalate, dibutyl fumarate, diethyl maleate, dibutyl maleate, Triethyl citrate, 12-hydroxystearic acid triglyceride, castor oil, dioxystearic acid methyl ester, 12-hydroxystearic acid methyl ester etc., and preferably amyl acetate, octyl acetate, butyl propionate, octyl propionate

15 nat, phenylpropionate, ethylcaproate, amylcaproate,

Ethyl caprylate, amyl caprylate, ethyl caprate, amyl caprate, Octyl caprate, methyl laurate, ethyl laurate, butyl laurate, hexyl laurate, octyl laurate, dodecyl laurate, myristyl laurate, Cetyl laurate, stearyl laurate, methyl myristate, ethyl myristate, butyl myristate, hexyl myristate, octyl myristate, Lauryl myristate, myristyl myristate, cetyl myristate, Stearyl myristate, methyl palmitate, ethyl palmitate, Butyl palmitate, hexyl palmitate, octyl palmitate, Lauryl palmitate, myristyl palmitate, cetyl palmitate, "Stearyl palmitate, methyl stearate, ethyl stearate, butyl stearate, Hexyl stearate, octyl stearate, lauryl stearate, myristyl stearate, cetyl stearate, stearyl stearate, methyl behenate, Ethyl behenate, propyl behenate, butyl behenate, ethyl benzoate, butyl benzoate, amyl benzoate and phenyl

30 benzoate.

Practical examples of ketones as compounds of component (C) are diethyl ketone, ethyl butyl ketone, Methylhexyl ketone, mesityl oxide, cyclohexanone, methylcyclohexanone, Acetophenone, propiophenone, benzophenone, 2,4-pentanedione, acetonylacetone, diacetone alcohol, ketone wax etc., and preferably diethyl ketone, ethyl butyl ketone, methyl hexyl ketone, cyclohexanone and benzophenone.

Practical examples of ethers as compounds of component (C) are butyl ether, hexyl ether, diisopropylbenzyl ether, Diphenyl ether, dioxane, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, ethylene glycol diethyl ether, Diethylene glycol diethyl ether, ethylene glycol diphenyl ether, ethylene glycol monophenyl ether etc., and preferably diphenyl ether ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, ethylene glycol diethyl ether and ethylene glycol diphenyl ether.

Practical examples of acid amide compounds as Compounds of component (C) are acetamide, propionic acid amide, butyric acid amide, caproic acid amide, caprylic acid amide, Capric acid amide, lauric acid amide, myristic acid amide, Palmitic acid amide, stearic acid amide, behenic acid amide, oleic acid amide, erucic acid amide, benzamide, Caproic anilide, caprylic anilide, capric acid anilide, lauric acid anilide, myristic acid anilide, Palmitic anilide, stearic anilide, behenic anilide, oleic anilide, erucic anilide, caproic acid-N-methylamide, Caprylic acid-N-methylamide, capric acid-N-methylamide, Lauric acid-N-methylamide, myristic acid-N-methylamide, Palmitic acid-N-methylamide,

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Stearic acid-N-methylamide, behenic acid-N-methylamide, Oleic acid-N-methylamide, erucic acid-N-methylamide, lauric acid-N-ethylamide, Myristic acid-N-ethylamide, palmitic acid-N-ethylamide, Stearic acid-N-ethylamide, oleic acid-N-ethylamide, Lauric acid-N-butylamide, myristic acid-N-butylamide, Palmitic acid-N-butylamide, stearic acid-N-butylamide, oleic acid-N-butylamide, lauric acid-N-octylamide, Myristic acid-N-octylamide, palmitic acid-N-octylamide, Stearic acid-N-octylamide, oleic acid-N-octylamide, Lauric acid-N-dodecylamide, myristic acid-N-dodecylamide, Palmitic acid-N-dodecylamide, stearic acid-N-dodecylamide, oleic acid-N-dodecylamide, distearic acid amide, Dipalmitic acid amide, dimyristic acid amide, dilauric acid amide, Dioleic acid amide, tristearic acid amide, Tripalmitic acid amide, trimyristic acid amide, trilauric acid amide, Trioleic acid amide, succinic acid amide, adipic acid amide, Glutaric acid amide, malonic acid amide, azelaic acid amide, Maleic acid amide, succinic acid-N-methyl * - amide, adipic acid-N-methylamide, glutaric acid-N-methylamide, Malonic acid-N-methylanud, azelaic acid-N-methylamide, Succinic acid-N-ethylamide, adipic acid-N-ethylamide, Glutaric acid-N-ethylamide, malonic acid-N-ethylamide, Azelaic acid-N-ethylamide, succinic acid-N-butylamide, Adipic acid-N-butylamide, glutaric acid-N-butylamide, malonic acid-N-butylamide, Adipic acid-N-octylamide, adipic acid-N-dodecylamide etc., and preferably butyric acid amide, Caproic acid amide, caprylic acid amide, capric acid amide, Lauric acid amide, myristic acid amide, palmitic acid amide, Stearic acid amide, behenic acid amide, benzamide, caproic acid anilide, Caprylic anilide, capric acid anilide, lauric acid anilide, myristic acid anilide, palmitic acid anilide,

-'22 -

Stearic acid anilide, behenic acid anilide, succinic acid amide, Adipic acid amide, glutaric acid amide and malonic acid amide.

Practical examples of aliphatic carboxylic acids having 6 to 22 carbon atoms as compounds of Component (C) are caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, Stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, melissa acid, isomyristic acid, Isopalmitic acid, isostearic acid, oleic acid, elaidic acid, linoleic acid, linolenic acid, eleostearic acid, Arachidonic acid, 2-oxylauric acid, 2-oxymyristic acid, 2-oxypalmitic acid, 2-oxystearic acid, 3-oxy-stearic acid, 12-hydroxystearic acid, ricinoleic acid, 2-bromo lauric acid, 2-bromomyristic acid, 2-bromopalmitic acid, 2-bromostearic acid, 18-bromostearic acid, 2-chlorostearic acid, 18-chlorostearic acid, dioxypalmitic acid, Dioxystearic acid, 3-ethyl-3-lauryl-3-oxy-

20 propionic acid, 2-methyl-3-ox ^ stearic acid, 2-keto

stearic acid, -2-ketopalmitic acid, A2elaic acid monoethyl ester, Azelaic acid monobutyl ester, azelaic acid monooctyl ester, Sebacic acid monoethyl ester, sebacic acid monobutyl ester, sebacic acid monooctyl ester, Monolauryl sebacate, 1,12-dodecamethylenedi-. carboxylic acid, 1,14-tetradecamethylene dicarboxylic acid, 1,16-hexadecamethylene dicarboxylic acid, dimer acid etc., and preferably caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, Behenic acid, 12-hydroxystearic acid, 2-bromolauric acid, 2-bromomyristic acid, 2-bromopalmitic acid,

WHEEL ORIGINAL

2-bromostearic acid, 18-bromostearic acid, 2-chlorostearic acid and 18-chlorostearic acid.

Practical examples of thiols as compounds of component (C) are n-decyl mercaptan, n-dodecyl mercaptan, n-myristyl mercaptan, n-cetyl mercaptan, n-stearyl mercaptan, Isododecyl mercaptan, isomyristyl mercaptan, isocetyl mercaptan, dodecylbenzyl mercaptan Etc

Practical examples of sulfides as compounds of component (C) are di-n-octyl sulfide, di-n-nonyl sulfide, di-n-decyl sulfide, di-n-dodecyl sulfide, di-n-myristyl sulfide, di-n-cetyl sulfide, di- n-stearyl sulphide, di-t-dodecyl sulphide, octyldodecyl sulphide, diphenyl sulphide, dibenzyl sulphide, ditolyl sulphide, diethylphenyl sulphide, 4,4-dichlorodiphenyl sulphide, dilaurylthiopropionate, penta-propionate, pentropionic acid, penta-propionic acid, p-tetra-thio-propionate, tetra-propionic acid, tetra-pyrityl, and distearylthio-propionate, preferably tetra-pyrityl, tetra-thio-propionate, tetra-propionic acid, tetra-pyrityl, etc. , Di-n-nonyl sulfide, di-n-decyl sulfide, di-n-dodecyl sulfide, di-n-myristyl sulfide, di-n-cetyl sulfide, di-n-stearyl sulfide, di-t-dodecyl sulfide, octyldodecyl sulfide, diphenyl sulfide and dibyl sulfide .

Practical examples of disulfides as compounds of component (C) are di-n-decyl disulfide, di-ndodecyl disulfide, Di-n-myristyl disulfide, di-n-cetyl disulfide, Di-n-stearyl disulfide, diphenyl disulfide, Dibenzyl disulfide, ditolyl disulfide, dinaphthyl disulfide, 4,4-dichlorodiphenyl disulfide etc., and preferably

Di-n-decyl disulfide, di-n-dodecyl disulfide, di-n-myristyl disulfide, Di-n-cetyl disulfide, di-n-stearyl disulfide and diphenyl disulfide.

Practical examples of sulfoxides as compounds of component (C) are dimethyl sulfoxides, diethyl sulfoxide, Tetramethylene sulfoxide, diphenyl sulfoxide, dibenzyl sulfoxide, etc., and preferably diphenyl sulfoxide and dibenzyl sulfoxide.

Practical examples of sulfones as compounds of component (C) are diethyl sulfone, dibutyl sulfone, Methylphenyl sulfone, diphenyl sulfone, ditolyl sulfone, Dibutylphenyl sulfone, dibenzyl sulfone, 4,4-dichlorodi-

15 phenyl sulfone etc., and preferably diphenyl sulfone,

Ditolyl sulfone, dibutyl phenyl sulfone and dibenzyl sulfone.

The heat discoloring materials used in the present invention are obtained by adding the aforementioned three components (A), (B) and (C) in a mixing ratio of 1: 0.1 to 50: 1 to (on the by weight), and preferably 1: 1 to 20: 10 to 400, and especially from 1: 2 to 15: 20 to 200, and the mixture sjchmilzt by passing it to a temperature of 50 to 15O ⁰ C and preferably 80 to 120 ⁰ C melts to form a homogeneous fused mixture.

The component (A) used in the present invention is 30 for determining the color of that which is discolored with heat Material determines the component (B)

BATH ORIGINAL

--25 -

causes the coloration to be reversible by reacting with the component (A), and the component (C) is to determine the temperature and heat sensitivity in the aforementioned reaction responsible. The extent of the hysteresis character of the inventive, discolored in the heat Materials for staining and achromatization depend on the type of the aforementioned components however, the mixing ratio of these compounds is a dominant factor. In general the discoloration temperature range is close to the melting point of component (C) and consequently a heat discoloring material having a desired discoloration temperature range is obtained and a color retention temperature range by using a suitable combination of compounds with the correspondingly different melting points are used.

As already mentioned, a heat decolorizing material * according to the invention shows the hysteresis phenomenon Relationship to. Temperature change as shown in the graph of FIG. 1 to thereby repeatedly to achieve a coloration and decolorization (achromatization), but if the acidic phosphoric acid ester or a metal salt thereof is used as component (B), the graphic representation assumes a shape in which it is rotated 180 degrees with respect to the CD line as an axis. With In other words, this means that the material which is discolored when heated is in a colored state in place of the higher temperature and in one

--26 -

achromatic state is located at a point of lower temperature.

The reversible heat-sensitive recording material is obtained by melting the aforementioned heat-discoloring material by heating and then applying the melted composition in an amount of about 1 to 50 g / m ² to the surface of a base sheet of paper, plastic sheet, cloth , a metal foil, but preferably a paper or a plastic film, or by applying the material, which changes color in the heat, in microcapsules with a diameter of less than 30 μm and preferably 1 to 10 μm by known encapsulation methods

15 encapsulated (e.g. by coacervation according to üS-PSen

2,800,457 and 3,116,206, by interfacial phase polymerization according to US Pat. Nos. 3,429,827 and 3,167,602 or by in situ polymerization according to GB-PS 989 264 etc.), whereupon the microcapsules thus obtained are then placed in a resin solution, a resin emulsion or a mixture thereof dispersed and the coating composition thus obtained applies to the surface of the aforementioned base sheet. Suitable coating methods for application the coating composition on a base sheet consist of a coating process, a screen printing process, an engraving process, a flexographic one Printing method or an offset printing method.

The following examples describe the invention. 30th

WHEEL ORIGINAL

• _# : y . ·: * :. · ..; .; 334717I

--27 -

example 1

4 g of crystal violet lactone, 20 g of bisphenol A and 100 g of myristyl alcohol were ^{melted to a homogeneous melt by heating to 100 °} C. and this melt was evenly applied to wood-free paper (high-grade paper) to form a recording sheet. The recording sheet was heated to 45 ° C, wherein the ■ coating layer was transferred into a white state and then give a blue positive image of the recording sheet was measured using a rubber relief, which was cooled to 15 ⁰ C, pressed at room temperature (27 ⁰ C), clear emerged. If the recording sheet was left to stand for 24 hours at room temperature of 25 to 30 ^° C., the image remained stable.

If the recording sheet with the blue image was ^{heated uniformly to 40 °} C., then the image disappeared and a uniform white surface was obtained. This aforementioned formation and elimination of the image

20 could be carried out repeatedly.

Example 2

A mixture of 6 g of 3-diethylamino-7,8-benzofluoran (ECOC (1)), 16 g of the zinc salt of bisphenol A, 50 g cyclododecanol and 50 g of cetyl alcohol was heated to about 100 ⁰ C and ER- to a uniform melt

30 melted. The melted composition was

evenly applied to a coated paper

■ ..., = BaQ ORIGINAL

-'28 -

and then a polypropylene film was laminated to a thickness of 20 µm to form a recording sheet. The recording sheet thus prepared was uniformly cooled to 1O ⁰ C, whereby the entire surface pink discolored, and then at 25 ⁰ C allowed to stand. If you wrote on the sheet with a hot spring a letter, then formed at the point, which was approximately maintained at 5O ⁰ C, a white negative image with high contrast with a pink background and this image could be maintained for a desired period.

Then, the recording sheet to 5O ⁰ C was heated to the entire surface and subsequently form white

closing the sheet was cooled to 25 ⁰ C and if you wrote a letter followed by a cold-pen, then returned at the point, which was maintained at about 10 ⁰ C, a pink positive image with high contrast and white background. This image could be maintained for a desired time. As previously mentioned, the formation and elimination of both the positive and the negative image can be repeated as often as desired.

The conditions for the recording materials according to Examples 3 to 8, including the components used, the composition ratio, the recording temperature, the storage temperature for the images and the erasing temperature, and the

Thirty colors that are formed are shown in Table 1.

RAn

• »Ik * m 41

- 29 -

The recording material became the same In the manner of Example 1 using the components shown in Table 1.

Tabel

example
No.

Composition that discolors when heated

Component (A)

ECOC (2) (6 g)

4th ECOC (3) (6 G) 5 ECOC
ECOC (4)
(D (4th
(4th 6th ECOC (5) (6 G) 7th ECOC (6) (6 G)

ECOC (7) (6 g)

Component (B)

4,4'-thiobis (6-t-butyl-3-methylphenol) (16 g)

Octyl p-oxybenzoate (16 g)

4,4'-thiobis (6-tbuty1-3-methyI-phenol) (20 g)

5-chloro-l, 2, J * benzotriazole (16 g)

2,3-xylyl acid phosphate (15 g)

1,1-bis (4-hydroxyphenyl) cyclohexane (15 g)

Component (C)

Myristyl alcohol
(50 g) butanetetracarboxylic acid tetralauryl ester (50 g)

Trilaurin (100 g)

Myristyl alcohol (50 g) myristyl caprate (50 g)

Lauron (100 g)

Cetyl alcohol (100 g)

Diphenyl sulfide (100 g) temperature ( ⁰ C) and (color)

0
(black) 20th 35
(White) 5
(pink) 25th 45
(White) 0
(Red) 15th 30th
(White) 40
(vermilion) 58 70
(White) 25th
(White) 40 60
(dark
Red) 30th
(green) 45 65
(White)

ANNOTATION:

T, R ₂ and T ₃ are shown in the graph of FIG.
5

ECOC: electron donating chromatic organic

link

ECOC (1): 3-diethylamino-7,8-benzofluorane ECOC (2): 6 WCyclohexylmethylamino) -3 ^l · - · Inethyl-2'-0 (phenylamino) -spiro / isobenzofuran-1 (3H), 9'-

(9H) -xanthen7-3-one
ECOC (3): 3,3-bis (1-ethyl-2-methyl-1H-indol-3-yl) -1 (3H)

isobenzofuranone

ECOC (4): S-chloro-δ-cyclohexylaminofluoran ECOC (5): S-diethylamino-e-methyl-T-chlorofluorane

ECOC (6): 2 ^I - / bis (phenylmethyl) amino7-3' ^l-methyl-6 - (diethylamino) spiro / isobenzofuran-1 (3H), 9 '- (9H) -xanthen7-3-one

ECOC (7): S-Diethylamino-S-methyl-T-dibenzylaminofluoran

25 Example 9

A mixture of 6 g of 2 '- / T4-n-butylphenyl) -amino? - 3'-methyl-6' - (diethylamino) -spiro / isobenzofuran-1 (3H), 9 '- (9H) xanthene7-3- on (ECOC (8)), 15 g of bisphenol S, 60 g of stearyl alcohol and 40 g of trimyristine were ^{melted by heating to 120 0} C, whereby a

3347Ί7Ί

-'32 -

homogeneous molten mixture was obtained / which was encapsulated by a known coacervation method. 80 g of the microcapsules containing the heat-discoloring material were dispersed in a carrier of 200 g of ethylene-vinyl acetate copolymer emulsion (solids ^{content 50%, lowest film-forming temperature O 0} C) / 40 g of sodium alginate and 80 g of water and the dispersion was dispersed on a Polyester film of 25 μm thickness was evenly applied and a polypropylene film with a thickness of 20 μm was laminated thereon to form a recording sheet.

If you take a picture on the surface with a thermal head

drawing sheet and then immediately placed it on a hot plate ^{kept at 40 °} C., a black and white negative image with high contrast appeared and the image could be retained for any time. Then, was sent as the recording sheet from the heat plate through a heating zone of 60 ⁰ C and then through a cooling zone of 10 ⁰ C, was then recorded by a thermal head, a reverse image and the recording sheet was held on a hot plate to give a black and white obtained a positive high-contrast image and it was possible to keep this image for a desired time. The cycle of image formation, image retention and image elimination could be repeated as often as desired.

--33 -

Example 10

A mixture of 5 g of 6 '- (diethylamino) -2' - / cyclohexyl (phenylmethyl) amino7-spiro / ~ isobenzofuran-1 (3H), 9 '- (9H) xanthen7-3-one (ECOC (9)), 15 g of zinc benzoate and 100 g of di-n-hexyl ketone was melted by heating to about 100 ⁰ C to give a homogeneous molten mixture and this was encapsulated in known manner by coacervation.

Then 80 g of the microcapsule containing the heat-discoloring material were placed in a carrier made of 200 g of a styrene-maleic acid copolymer (molecular weight about 8,000, acid number 170 to 185), 20 g of 80% aqueous ammonia and 40 g of water and the dispersion was coated on wood-free paper (high grade paper) to form a recording sheet. The recording sheet was then heated again to 3O ⁰ C, whereby the entire surface was white and then a letter with a cold spring has been recorded thereon * and the site which was maintained at 0 ° .C at a temperature range of 10 to 15 ⁰ C, gave a green positive image with high contrast and a white background, which image could be retained for any period of time. Was the recording sheet then reheated to 3O ⁰ C, the entire sheet was white, where you could repeat the recording and erasing process as often.

As already mentioned, the reversible according to the invention, heat-sensitive recording sheet the

- ■ • 34 -

A property that a recording material having a desired color and a desired recording, image-maintaining and image-erasing temperature can be obtained by selecting the composition for the heat-decolorizing material used in the recording material. This was not possible with the previously known recording materials of a similar type. In particular, the recording material which has an image keeping temperature in a normal temperature range has high utility. If the contrast between a recording or an image and a background is expressed by the brightness difference (corresponding to the length of the line CD in the graph of FIG. 1), so that the brightness of pure white is indicated by 10 and deep black by 0 Then the contrast for a conventional recording material (yellow-orange color change) using a metal complex _{salt Ag 3 HgI 4 is} approximately 1.0 to 1.1, while the contrast of the recording material according to the invention is 6.5 to 7.0 as black with a white background and around 5.0 in blue with a white background and around 4.0 in red with a white background.

The reversible heat-sensitive one of the present invention Recording material can of course be used as a thermosensitive recording material are used, which gives the possibility of recordings

30 and repeat deletions and can also be used as a

thermosensitive recording material for heat indicators

--35 -

be used.

The heat-sensitive recording material of the present invention Can also be used as a writing tablet, taking a cooling pen and a heat extinguisher or use a combination of a heated spring and a cold extinguisher. You can still do that recording material according to the invention also as a Use toys, e.g. you can use a writing surface use in a bath, taking into account the temperature difference between warm water and cold water · uses. Finally, you can the invention Recording material also as a recording material apply for laser light.

Since a color image can be changed repeatedly, taking advantage of the property of being reversible heat-sensitive recording material according to Invention, the invention can also be used in the field of personal jewelry, clothing etc., such as ties, T-shirts, blouses, gloves, ski equipment etc., and also as decoration material for flowers, wallpaper, curtains etc.

BATH ORIGINAL

3t.

- blank page -

Claims (3)

hoffmann "." vain «" partner " PATENT AND LAWYERS PATENTANWÄLTE DIPL.-ΙΝΘ. W. EITLE. DR. RER. NAT. K. HOFFMANN · DIPL-INa. W. LEHN DIPL.-1N3. K. FOCHSLE ■ DR. RER. NAT. B. HANSEN. DR. RER. NAT. H ₁ -A. BRAUNS DIPL.-ING. K. GORG DIPL.-INa. K. KOHLMANN · LAWYER A. NETTE 39 650 o / wa _mm A _mm PILOT INK CO., LTD., NAGOYA-SHI / JAPAN Reversible thermosensitive recording material PATENT CLAIMS Reversible thermosensitive recording material a sheet substrate having a coating composition applied to its surface which contains as a chromogenic component a material which discolors when exposed to heat, the is composed of a homogeneous fused composition of: (A) an electron donating chromatic organic compound selected from DiaryIphthaliden, Indolylphthaliden, Polyarylcarbinolen, Leuco auramines, acylauramines, arylauramines, Rhodamine B-lactams, indolines, spiropyrans and fluorans, ARABELLA STREET 4. D-8OOO MÜNOHEN 81 · TELEFON CO 89} 911Ο 87 · TELEX Β-29Ο1Θ CPATHEJ · TELECOPIER 9183! (B) a compound selected from phenolic compounds having 6 to 49 carbon atoms, the Metal salts of phenolic compounds, aromatic 'Carboxylic acids with 7 to 12 carbon atoms, aliphatic Carboxylic acids with 2 to 5 carbon atoms, metal salts of carboxylic acids with 2 to 22 carbon atoms, acidic phosphoric acid esters with 1 to 44 carbon atoms, the metal salts of the acidic phosphoric acid esters and triazole compounds having 2 to 24 carbon atoms, and (C) a compound selected from aliphatic monohydric alcohols having 4 to 31 carbon atoms, alicyclic monohydric alcohols with 5 to 10 carbon atoms, aromatic monohydric alcohols with 7 to 9 carbon atoms, polyhydric alcohols with 2 to 6 carbon atoms, ester compounds of monocarboxylic acids with 2 to 22 carbon atoms and aliphatic monohydric alcohols with 1 to 22 carbon atoms, Ester compounds of monocarboxylic acids with 2 to 22 carbon atoms and phenols with 6 to 18 carbon atoms, ester compounds of monocarboxylic acids with 2 to 22 carbon atoms and polyhydric alcohols with 2 to 6 carbon atoms, ester compounds of polycarboxylic acids with 2 to 12 carbon atoms and aliphatic monohydric alcohols with 1 to 22 carbon atoms, aliphatic ketones with 5 to 35 carbon atoms, aromatic ketones with 8 to 13 carbon atoms, Fatty acid amides with 2 to 22 carbon atoms, the N-alkyl-substituted compounds e · of fatty acid amides, aliphatic ethers with 8 to 36 carbon atoms, aromatic ethers with 12 to 20 carbon atoms, aliphatic monocarboxylic acids with 6 to 22 carbon atoms, thiols with 10 to 18 carbon atoms, sulfides with 16 to 89 carbon atoms, disulfides with 16 to 36 carbon atoms, sulfoxides with 2 to 14 carbon atoms and sulfons with 4 to 14 Carbon atoms, wherein (A), (B) and (C) are in a weight ratio in the range of 1: 0.1 to 50: 1 to 800, and the heat-discoloring material has coloring-color-erasing hysteresis. in a temperature range of wider than 3 ⁰ C shows. 2. Reversible thermosensitive recording material according to claim 1, characterized in that the coating composition tion is in such a Ferm that the material, which changes color when heated, is in microcapsules with a diameter of 30 μια or less and the microcapsules are dispersed in a carrier. 3. Reversible thermosensitive recording material according to claims 1 or 2, characterized in that on the layer from the coating composition an essentially 30 chen transparent layer is formed. BATH ORIGINAL - "4 - A reversible thermosensitive recording material according to claim 1, characterized in that the heat-coloring of the material has a Dye Farblösch- · hysteresis in a temperature range of wider than 8 ⁰ C.