FR2538309A1 - REVERSIBLE THERMOSENSIBLE RECORDING MATERIAL - Google Patents

Abstract

Reversible heat-sensitive recording material comprised of a backing sheet coated with a composition containing a heat-sensitive coloring material. The thermosensitive coloring material comprises 3 components: A an organic chromatic compound which is an electron donor; B a compound chosen from certain phenols, carboxylic acids and metal salts, acid phosphoric esters and metal salts and triazoles, which reacts with component A to give the desired coloring, and C a compound chosen from certain monoalcohols and polyalcohols, esters, ketones, amides, sulfoxides and sulfones, which influence the color-to-color temperature range.

Description

25383 09

  The present invention relates to a recording material

  Reversible thermosensitive record It relates more specifically to a thermally sensitive recording material that can be used many times by exploiting the hysteresis properties of a chromogenic component, i.e. a recording material capable of register a positive image or a negative image by applying local cooling or heating,

  stably the recorded image if the recording material

  is maintained within a defined temperature range, but to erase the recording when desired, exposing the recording or recording material to a temperature

stronger or lower.

  Conventional-type heat-sensitive reversible recording materials which can be used repeatedly as described above exploit the heat-coloring properties of a metal complex salt such as Ag 2 Hg I 4 or Cu 2 Hg I 4 and a thermosensitive image-giving material (and which can repeatedly and reversibly assume a transparent state and a cloudy white state upon the application of heat); these materials comprise a gangue material consisting of a thermoplastic resin which contains in dispersion, according to a recent proposal which is the subject of the Japanese patent application published under No. 89992/82, a low molecular weight organic material. disadvantages, for example the contrast between an image portion and a bottom portion is low; 2 it is impossible to choose at will the temperature at which you want to keep the recording; 3 it is impossible to choose

  freely the color; there are other disadvantages.

  The present invention relates first of all to a

  reversible thermosensitive recording material without

described above.

  The reversible thermosensitive recording material according to the invention is characterized in that it contains, as a color component, a heat-stainable material which consists of a homogeneous melted mixture of at least one organic chromogenic donor compound. electrons selected from the group consisting of diarylphthalides, indolylphthalides, polyarycarbinols, leuco-auramines, acylauramines, arylauramines, lactams of Rhodamine B, indolines, spiropyrans and fluoran; B at least one compound selected from the group consisting of phenolic compounds containing 6 to 49 carbon atoms, metal salts of phenolics, C 7 -C 12 aromatic carboxylic acids, C 2 -C 7 aliphatic carboxylic acids 5, metal salts of C 2 -C 22 carboxylic acids, acidic phosphoric esters containing 1 to 44 carbon atoms, metal salts of acidic phosphoric esters, and triazoles containing from 2 to 24 carbon atoms; and C at least one compound selected from the group consisting of

  C 4 -C 31 aliphatic monoalcohols, the alicyclic monohydric alcohols are

  C 5 -C 10 groups, C 7 -C 9 aromatic monohydric alcohols, polyunsaturated

1> 7 9

  C 2 -C 6 alcohols, C 2 -C 22 carboxylic acid esters and

  C 1 -C 22 aliphatic monoalcohols, esters of monocarboxylic acid

  C 2 -C 22 and C 6 -C 18 phenols, the mono-

  C 2 -C 22 carboxylic acids and C 2 -C 6 polyhydric alcohols, esters of C 2 -C 12 polycarboxylic acids and aliphatic monoalcohols

  C 1 -C 22, C 5 -C 35 aliphatic ketones, aromatic ketones and the like.

  C 8 -C 13, C 2 -C 22 fatty acid amides, Nalkyl derivatives of fatty acid amides, C 8 -C 36 aliphatic ethers, C 12 -C 20 aromatic ethers, aliphatic acids

8 36 '2

  C 6 -C 22 monocarboxylic acids C 1 -C 18 thiols, sulphides

6 22> '1018

  at C 16 -C 89, C 16 -C 36 disulfides, C 2 -C 14 sulfoxides and C 4 -C 14 sulfones,

  as necessary components.

  Other features and advantages of the invention

  will be clearer from the detailed description given

  hereinafter with reference to the single figure of the accompanying drawing which is a graph showing the hysteresis properties of the color density variation caused by a temperature change of a heat-dyeing material used in the material

  reversible thermosensitive recording device according to the invention.

  With reference to this graph, on which the temperatures were plotted on the abscissa and the color density on the ordinate, it is found that the thermosensitive coloring material used in the invention gives rise to a phenomenon of hysteresis under the action of

  the variation of temperature (in abscissas), with coloring and decolo-

  In the graph of FIG. 1, the point A indicates the minimum temperature T 3 at which the thermosensitive coloring material changes to the fully discolored state, the point B indicates the staining density at the maximum temperature T at which the material takes its total color; at a temperature T 2 of the material, there is a colored state corresponding to the point C

  and a colorless state corresponding to point D The temperature region

  close to T 2, that is, the temperature region in which the colored state and the colorless state can coexist,

  temperature region in which records can be stored

  The length of the segment CD is a measure of the contrast between an image and a background and the length of the segment EF passing through the middle of the segment CD represents the temperature range which characterizes the importance of hysteresis Plus this

  interval is wide, and the easier it is to keep the record

  The applicant's experiences have shown that

  The above temperature range should be greater than 3 C and preferably greater than 80 C so that the recordings can, in practice, be maintained. The preferred temperature range is from 3 to 150 ° C or more preferably from 8 to 1000 ° C. C. The components of matter will now be described

  thermosensitive dye according to the invention.

  The electron donor chromatic organic compounds used as component A are, as indicated above, diarylphthalides, indolylphthalides, polyarylcarbinols,

  leuco-auramines, acylauramines, arylauramines, lac-

  Rhodamine B, indolines, spiropyrans and fluoranes. As practical examples of such compounds, mention may be made of the Violet Crystal lactone, the Malachite Green lactone, the Michler hydrol, the Violet crystal carbinol, the Malachite green carbinol and the N- (2,3-dichlorophenyl) leuco-auramine. N-benzoylauramine, Rhodamine B lactam, N-acetyl-auramine, N-phenyl-auramine, 2 (phenylimin-o-thylidene) -3,3-dimethyl

  indoline, N-3,3-trimethylindolinobenzospiropyran, 8-methoxy-

  N-3,3-trimethylindolinobenzospiropyran, 3-diethylamino-6-

  methyl-7-chlorofluorane, 3-diethylamino-7-methoxyfluorane,

  3-diethylamino-6-benzyloxyfluorane, 1,2-benzo-6-diethylamino-

  fluoran, 3,6-di-p-toluidino-4,5-dimethylfluorane-phenylhydro-

  zido-γ-lactam, 3-amino-5-methylfluorane, 2-methyl-3-amino-methyl-7-methylfluorane, 2,3-butylene-6-di-n-butylaminofluorane, 3diethylamino-7-anilinofluorane 3-diethylamino-7- (p-toluidino)

  fluoran, 7-acetamino-3-diethylaminofluorane, 2-bromo-6-cyclohexane

  hexyl-aminofluorane, -2,7-dichloro-3-methyl-6-n-butylaminofluorane, etc., preferably the lactone of Violet Crystal, the lactone of Green

  Malachite, 3-diethylamino-6-methyl-7-chlorofluorane, 3-diethyl-

  amino-7-methoxyfluorane, 3-diethylamino-6-benzyloxyfluorane,

  1,2-benzo-6-diethylaminofluorane, 3,6-di-p-toluidino-4,5-dimethyl-

  fluoran-phenylhydrazido-7-γ-lactam, 3-amino-5-methylfluorane,

  2-methyl-3-amino-6-methyl-7-methylfluorane, 2,3-butylene-6-di-n-

  butylarninofluorane, 3-diethylamino-7-anilino'fluorane, 3-

  diethylamino-7- (p-toluidino) fluoran, 7-acetamino-3-diethylamino-

  fluoran, 2-bromo-6-cyclohexylaminofluorane and 2,7-dichloro-

3-methyl-6-n-butylaminofluorane.

  The compounds used as Br component in the invention are, as mentioned above, C 6 -C -C phenol compounds, the metal salts of phinolic compounds,

  C 7-12 carboxylic aromatic acids of the aliphatic acids.

  C 2 -C 5 carboxylic acids, metal salts of carboxylic acid

  C 2 -C 22 acids, acidic phosphoric esters of C 1 -C 44, metal salts of acidic phosphoric esters and triazoles of

C 2-C 24.

  Among the phenolic compounds which can be used as component B are monophenols and polyphenols which can carry substituents such as an alkyl group, an aryl group, an acyl group, an alkoxycarbonyl group, a halogen atom, etc. As particular examples these phenol compounds include tert-butylphenol, nonylphenol, dodecylphenol, styrene phenol, 2,2-methylenebis (4-methyl-6-tertbutylphenol), naphtha Dl, 3-naphthol, monornethyl ether of hydroquinone,

  guaiacol, eugenol, lep-chlorophenol, p-bromophenol, o-chloro

  phenol, o-bromophenol, o-phenylphenol, p-phenylphenol,

  p- (p-chlorophenyl) phenol, o- (o-chlorophenyl) phenol, p-oxy-

  methyl benzoate, propyl p-oxybenzoate, propyl p-oxybenzoate, butyl p-oxybenzoate, octyl p-oxybenzoate,

  dodecyl p-oxybenzoate, 3-isopropylpyrocatechol, p-tert-

  butylpyrocatechol, 4,4-methyldiphenol, 4,4-thiobis (6-tert-

  butyl-3-methylphenol), 1,1-bis (4-hydroxyphenylcyclohexane, 4,4-butylidenebis (6-tert-butyl-3-methylphenol), bisphenol A, bisphenol S, 1,2-dioxynaphthalene, chlotopyrocatechol , bromopyrocatechol, 2,4-dihydroxybenzophenone, phenolphthalein, ocresolphthalein, methyl protocatechate>

  ethyl protocatechate, propyl protocatechate, the proto-

  octyl catechate, dodecyl protocatechate, 2,4,6 '-trioxy-

  methylbenzene, 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-trioxynaph-

  talene, tannic acid, a phenol-formaldehyde prodrug, etc., preferably tert-butylphenol, noihylphenol, dodecylphenol, pphenylphenol, p- (p-chlorophenyl) phenol, methyl p-oxybenzoate, p-phenylphenol, ethyloxybenzoate, propyl p-oxybenzoate,

  butyl p-oxybenzoate, octyl p-oxybenzoate, p-oxy-

  dodecyl benzoate, 4,4-methylthiophenol, 4,4-thiobis- (6-tert-

  butyl-3-methyl-enol), 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4-butylidenebis (6-tert-butyl-3-methylphenol), bisphenol A and bisphenol S.

25583 09

  Among the metal salts of the phenolic compounds mentioned above, mention will be made of metal salts such as sodium, potassium, lithium, calcium, zinc, zirconium, aluminum, magnesium, nickel, cobalt, tin, copper, iron, vanadium, titanium, lead, molybdenum, etc. Examples of C 7 -C 12 aromatic carboxylic acids and of C 2 -C 5 aliphatic carboxylic acids which can be used as component B are maleic acid, fumaric acid, benzoic acid, toluic acid, p-tert-butylbenzotc acid,

  chlorobenzoic acid, bromobenzoic acid, ethoxybenzic acid

  zoic acid, gallic acid, naphthoic acid, phthalic acid,

  naphthalenedicarboxylic acid, acetic acid, propionic acid and

  butyric acid, valeric acid, etc., preferably benzoic acid, tolulic acid, p-tert-butylbenzotc acid,

  chlorobenzotc acid, bromobenzotc acid, ethoxybenzic acid

  zoic, butyric acid, valeric acid.

  Metal salts of C 2 -C 22 carboxylic acids

  components B are, inter alia, metal salts,

  Examples of monocarboxylic and polycarboxylic acids include, in particular, metal salts such as sodium, potassium, lithium, calcium, zinc, zirconium, aluminum, magnesium, nickel, cobalt, tin, copper, iron, vanadium, titanium, lead, molybdenum, etc., acetic acid, propionic, butyric, caprotque, caprylic, capric, lauric, myristic, palmitic, stearic, isostearic, behenic,

  crotonic, oleic, elaldic, linoleic, linolenic, monochlor

  monobromoacetic, monofluoroacetic, glycolic, hydroxy-

  propionic, hydroxybutyric, ricinoleic, 1,2-hydroxystearic, lactic, pyruvic, oxalic, malonic, succinic, adipic, sebacic, malic, tartaric, valeric, maleic, fumaric,

  naphthenic, benzene, tolutyl, phenylacetic, p-tert-butylbene

  zoic, cinnamic, chlorobenzoic, bromobenzoic, ethoxybenzotc,

  mandelic, protocatechic, vanillic, resorcinic, dioxybenzoic

  zoic, dioxychlorobenzoic, gallic, naphthoic, hydroxynaphthoic, phthalic, as well as monoethyl ester of phthalic acid

  or naphthalenedicarboxylic acid, mono-

  methyl of napitalenedicarboxylic acid, trimeric acid

  lithic acid, pyromellitic acid, etc., preferably the metal salts (for example sodium, potassium, lithium, calcium, zinc and nickel) butyric acid, caprotque, caprylic, capric, lauric, myristic, palmitic, stearic, isostearic, oleic, elafdic, linoleic, succinic, adipic, sebacic, malic, benzoic, tolulic, p-tert-butylbenzoic,

  chlorobenzoic, bromobenzoic and ethoxybenzoic.

  Examples of acidic C 1 -C 44 phosphoric esters which can be used in component B are those which have an ester group such as an alkyl group, a branched alkyl group, an alkenyl group, an alkynyl group or a cycloalkyl group, aryl group, etc. and the derivatives of these groups The preferred ester groups are alkyl, branched alkyl, cycloalkyl and aryl groups. These acidic phosphoric esters are monoesters and diesters or mixtures of these esters. under the name acid phosphate a mixture of monoester and

diester.

  Particular examples of acidic phosphoric esters are methyl acid phosphate, ethyl acid phosphate, n-propyl acid phosphate, acideden-butyl phosphate, ethylhexyl acid phosphate, n-octyl acid phosphate and the like. isodecyl acid phosphate, n-decyl acid phosphate, lauryl acid phosphate, myristyl acid phosphate,

  cetyl acid phosphate, stearyl acid phosphate, phos-

  acidic phase of docosyl, oleyl acid phosphate, phosphate

  2-chloroethyl acid, the acid phosphate of 2,3-dibromo-2,3-di-

  chloropropyl, dichloropropyl acid phosphate, cyclohexyl acid phosphate, phenyl acid phosphate, otolyl acid phosphate, 2,3-xylyl acid phosphate, dibutyl acid phosphate, mesityl acid phosphate, acid phosphate of naphthyl, 2-naphthyl acid phosphate, anthryl acid phosphate, benzyl acid phosphate, phenethyl acid phosphate, styryl acid phosphate, cinnamyl acid phosphate, triethyl acid phosphate, phenyl and methyl phosphate, phenyl ethyl phosphate, phenyl and n-propyl phosphate, phenyl and n-butyl phosphate, phenyl and noctyl phosphate, phenyl phosphate and lauryl, phenyl phosphate and cyclohexyl,

  phenyl and 2,3-xylyl phosphate, cyclohexyl phosphate,

  hexyl and stearyl, cyclohexyl and cetyl phosphate, dimethyl phosphate, diethyl phosphate, di-npropyl phosphate, di-n-butyl phosphate, di-n-hexyl phosphate, phosphate di (2-ethylhexyl), di-n-decyl phosphate, dilauryl phosphate, dimyristyl phosphate, dicetyl phosphate, distearyl phosphate, phosphate

  dibenyl, diphenyl phosphate, dicyclo

  hexyl, di-o-tolyl phosphate, bis (diphenyl)

  methyl), bis (triphenylmethyl) phosphate, phosphate

  di (2,3-xylyl), dibenzyl phosphate, dihydrogen phosphate,

  naphthyl), ete, 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 and n-butyl phosphate, phenyl and n-octyl phosphate, phenyl and lauryl phosphate, phenyl and 2,3xylyl phosphate, cyclohexyl and stearyl phosphate, cyclohexyl and cetyl phosphate, di-n butyl, din-hexyl phosphate, di (2-ethylhexyl) phosphate, di-n-decyl phosphate, dilauryl phosphate, dimyristyl phosphate, dicetyl phosphate, distearyl phosphate, dibhenyl phosphate, diphenyl phosphate, dicyclohexyl phosphate e and di-o-tolyl phosphate Metal salts of acidic phosphoric esters

  are, among others, metal salts such as sodium, potassium

  sium, lithium, calcium, zinc, zirconium, aluminum, magnesium, nickel, cobalt, tin, copper, iron, vanadium, titanium, lead, molybdenum, etc. esters

  phosphoric acids mentioned above.

  As particular examples of C 2 -C 24 triagoles which can be used in component B according to the invention,

  1,2,3-triazole, 4 (5) -hydroxy-1,2,3-triazole, 5 (6) -

  1,2,3-methylbenzotriazole, 5-chloro-1,2,3-benzotriazole, 7-nitro-1,2,3-benzotriazole, 4-benzoylamino-1,2,3-benzotriazole,

  4-hydroxy-1,2,3-benzotriazole, naphtho-1,2,3-triazole, 5,5 '-

  bis (1,2,3-benzotriazole), 1,2,3-benzotriazole-4-sulfooctylamide, etc.

  The compounds used as component C according to

  According to the invention, C 4 -C 31 aliphatic monohydric alcohols, C 5 -C 10 alicyclic monohydric alcohols, C 7 -C 9 aromatic monoalcohols, polyalcohols are mentioned as described above.

  C 2 -C 6, C 2 -C 22 monocarboxylic acid esters and mono-

  aliphatic C 1 -C 22 alcohols, esters of these mono-

  carboxylic acids and C 6 -C 18 phenols, esters of the same monocarboxylic acids and C 2 -C 6 polyalcohols, esters of C 2 -C 12 polycarboxylic acids and C 1 -C 22 aliphatic monoalcohols of the aliphatic ketones. C 5 -C 35 'aromatic C 8 -C 13 ketones, C 2 -C 22 fatty acid amides, N-alkylated fatty acid amides, C 8 -C 36 aliphatic ethers. ; of the

  C 12 -C 20 aromatic ethers, aliphatic monocarboxylic acids,

  C 6 -C 22 boxyls C 1 -C 18 thiols C 16 -C 89 sulfides, C 16 -C 36 disulfides, C 2 -C 14 sulfoxides and C 4 -C 14 sulfones Examples of alcohols which can be used in component C are monoalcohols, polyalcohols and their derivatives. As particular examples of these alcohols, mention may be made of noctyl, n-nonyl, n-decyl, n-lauryl and n- myristyl,

  n-cetyl, n-stearyl, n-dicosyl, n-docosylic, n-melissyl

  isocetyl, isostearyl, isodocosylic, oleyl, cyclohexanol, cyclopentanol, benzyl alcohol, alcohol

  cinnamic, ethylene glycol, diethylene glycol, triethylene

  glycol, polyethylene glycol, propylene glycol, butylene

  glycol, hexylene glycol, cyclohexane-4-diol, trimethylol-

  propane, 1,2,6-hexanetrol, pentaerythritol, sorbitol, mannitol, etc., preferably n-octyl, n-nonyl, necyl, n-lauryl, r-myristyl, n-cetyl, n-alcohols. stearyl, ndicosylic, n-docosylic, isostearyl, isodocosyl and benzyl. As practical examples of esters which can be used in component C, mention may be made of 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 laurste, myristyl laurate, cetyl laurate, stearyl laurate, methyl myristate, ethyl myristate, butyl myristate, hexyl myristate, octyl myristate, lauryl myristate, mnyristyl myristate, cetyl myristate, staryl myristate, methyl palmitate, ethyl palmitate, butyl palmitate, palmitate hexyl, octyl palmitate, lauryl palmitate, myristyl palmitate, cetyl palmitate, stearyl palmitate e, methyl stearate, ethyl stearate, butyl stearate, hexyl stearate, octyl stearate, lauryl stiarate, myristyl stearate, cetyl stearate, stearyl stearate, methyl behenate, ethyl behenate, propyl behenate, butyl behenate, ethyl benzoate, butyl benzoate, amyl benzoate, phenyl benzoate, ethyl acetyl acetate, 1 methyl oleate, butyl oleate, butyl acrylate, digthyl oxalate, dibutyl oxalate, diethyl malonate> dibutyl rmanolate,

  dibutyl tartrate, dibutyl sebacate, dibutyl sebacate,

  methyl, dibutyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl fumarate, diethyl maleate, dibutyl maleate, triethyl citrate, 12-hydroxy-stearic acid triglyceride, castor oil, methyl ester

  dioxystearic acid, the methyl ester of 12-hydroxy-

  stearic acid, etc., preferably amyl acetate, octyl acetate, butyl propionate, octyl propionate, phenyl propionate, ethyl caproate, amyl caproate, caprylate ethyl acrylate, 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, myristate of octyl, lauryl myristate, myristyl myristate, cetyl myristate, stearyl myristate, methyl palmitate, ethyl palmitate, butyl palmitate, hexyl palmitate, palmitate octyl, lauryl palmitate, myristyl palmitate, cetyl palmitate, stearyl palmitate, methyl stearate, stearate ethyl, 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 benzoate

of phenyl.

  As particular examples of ketones that can be used in component C, mention will be made of diethyl ketone, ethyl butyl ketone, methyl hexyl ketone, mesityl oxide, cyclohexanone,

  methylcyclohexanone, acetophenone, propiophenone, benzo

  phenone, 2,4-pentanedione, acetonylacetone, diacetone alcohol> ketone wax, etc., preferably diethylketone, ethylbutylketone, methylhexylketone, cyclohexanone, and benzophenone. As particular examples of ethers which may be used in component C, mention may be made of butyl ether, hexyl ether, benzyl and diisopropyl ether, diphenyl ether,

  dioxane, ethylene glycol dibutyl ether, dibutyl ether,

  diethylene glycol, ethylene glycol diethyl ether, diethylene glycol diethyl ether, ethylene glycol diphenyl ether, ethylene glycol monophenyl ether, etc.

  preferably diphenyl ether, ethylene dibutyl ether,

  glycol, diethylene glycol dibutyl ether, diethyl ether

  ethylene glycol, and the ethylene glycol diphenyl ether.

  Among the amides which can be used in component C are acetamide, propionamide, butyramide, caprylic amide, caprylic amide, capric amide, lauric amide, myristic amide palmitic amide, stearic amide, behenic amide, oleic amide, erucic amide, beuzamide, caprotic anilide, caprylic anilide, capric anilide, lauric anilide, anilide myristic, palmitic anilide, stearic anilide, behenic anilide, oleic anilide, erucic anilide, caproic acid N-methylamide, caprylic acid N-methylamide, N-methylamide, capric acid, lauric acid N-methylamide, myristic acid N-methylamide, palmitic acid N-methylamide, stearic acid N-methylamide, N-methylamide behenic acid, N-methylamide of oleic acid, N-methylamide of erucic acid,

  N-ethylamide of lauric acid, N-ethylamide of myrys

  tick, palmitic acid N-ethylamide, N-ethylamide

  stearic acid, N-ethylamide of oleic acid, N-butyl-

  amide of lauric acid, myristic acid, palmar acid,

  mitic acid, stearic acid or oleic acid, lauric acid N-octylamide, myristic acid, palmitic acid, stearic acid or oleic acid, N lauric acid, myristic acid, palmitic acid, stearic acid or oleic acid, distearic amide, dipalmitic amide, dimyristic amide, dilauric amide, dioleic amide, tristearic amide, tripalmitic amide, trimyristic amide, trilauric amide, trioleic amide, succinic amide, adipic amide, glutaric amide, malonic amide, azelaic acid, maleic amide, N-methylamide of succinic acid, adipic acid, glutaric acid, malonic acid or azelaic acid, N acetamide, adipic acid, glutaric acid, malonic acid or azela acid, N-butylamide, succinic acid, adipic acid, glutaric acid or malonic acid, N-octylamide of adipic acid, N-dodecylamide of adipic acid, etc., preferably butyric amide, caprotic amide, caprylic amide, capric amide, lauric amide, myristic amide, palmitic amide, stearic amide, behenic amide, benzamide, caprotic anilide, caprylic anilide, capric anilide, lauric anilide, anilide myristic, palmitic anilide, stearic anilide, behenic anilide, succinic amide, adipic amide, glutaric amide and malonic amide. As particular examples of C 6 -C 7 aliphatic carboxylic acids Suitable for use in component C are caproic, caprylic, capric, lauric, myristic, palmitic, stearic, arachidic, behenic, lignoceric, cerotic, montanic, melissic, isomyristic, isopalmitic,

  isostearic, oleic, alkaline, linoleic, linolenic,

  stearic, arachidonic, 2-oxylauric, 2-oxymyristic, 2-oxypal-

  mitic, 2-oxystearic, 3-oxystearic, 12-hydroxystearic, ricinoleic, 2-bromolauric, 2-bromomyristic, 2-bromopalmitic,

  2-bromostearic, 18-bromostearic, 2-chlorostearic, 18-chloro

  stearic, dioxypalmitic, dioxystearic, 3-ethyl-3-lauryl-3-oxy

  propionic, 2-methyl-3-oxystearic, 2-cetostearic, 2-carboxylate

  the monoethyl ester of azelaic acid, the mono-

  butyl or monooctylic acid of azelaic acid, the monoethyl ester of sebacic acid, the monobutyl ester of sebacic acid, the monoctyl ester of sebacic acid, the monolauryl ester of sebacic acid, 1,12-dodecamethylene dicarboxylic acid,

  1,14-tetradecamethylene-dicarboxylic acid, 1,16-hexadecarboxylic acid,

  camethylene-dicarboxylic acid, dimer acids, etc., preferably caprylic acid, caprylic acid, capric acid, lauric acid, myristic acid,

  palmitic, stearic, behenic, 12-hydroxystearic, 2-bromolau-

  2-bromomyristic, 2-bromopalmitic, 2-bromostearic,

  18-Bromostearic, 2-chlorostearic and 18-chlorostearic.

  As particular examples of thiols usable in component C, mention may be made of n-decylmercaptan, n-dodecylmercaptan, n-myristylmercaptan, n-cetylmercaptan, n-stearylmercaptan, isododecylmercaptan, isomyristylmercaptan, isocetylmercaptan, dodecylbenzylmercaptan and the like. . As particular examples of sulphides usable in component C, mention will be made of the sulphides of di-n-octyl, di-n-nonyl,

  di-n-decyl, di-n-dodecyl, di-n-myristyl, di-n-cetyl, di-n-decyl

  stearyl, di-tert-dodecyl, octyldodecyl, diphenyl, dibenzyl, ditolyl, diethylphenyl, or 4,4-dichlorophenyl, thiopropionate

  of dilauryl, distearyl thiodipropionate, penta-

  erythritol of tetra (laurylthiopropionic) acid, pentaerythritol ester of tetra (stearylthiopropionic acid), etc., of

  di-n-octyl sulphides, di-n-nonyl sulphides, di-n-

  decyl, di-n-dodecyl, di-n-myristyl, di-n-cetyl, di-n-stearyl, di-tert-dodecyl, octyldodecyl, diphenyl

or dibenzyl-.

  As particular examples of disulfides usable in

  component C will be mentioned disulphides di-n-decyl, di-n-

  dodecyl, di-n-myristyl, di-n-cetyl, di-n stearyl,

  diphenyl, dibenzyl, ditolyl, dinaphthyl, 4,4-

  dichlorodiphenyl, etc., preferably di-n-decyl, din-dodecyl, di-n-myristyl, di-n-cetyl, di-n-stearyl sulfides.

and diphenyl.

  As particular examples of sulfoxides which can be used in component C, mention will be made of dimethylsulfoxide and diethyl sulfoxide.

  tetramethylenesulphoxide, diphenylsulfoxide, dibenzylsulphonyl

  oxide, etc., preferably diphenyl sulfoxide and dibenzyl sulphoxide.

sulfoxide.

  As particular examples of sulfones which may be used in component C, mention may be made of ethylsulfone, dibutylsulfone, methylphenylsulphone, diphenylsulfone, ditolylsulfone and the like.

  dibutylphenylsulfone, dibenzyl sulfone, 4,4-dichlorodiphenyl-

  sulfone, etc., preferably diphenylsulfone, ditol 1 sulfone,

  dibutyltolylsulfone and dibenzylsulfone.

  The thermosensitive coloring material used in the invention is obtained by mixing the 3 components A, B and C defined above in relative proportions of 1: 0.1 to 50: 1 to 800 by weight, preferably 1: 1 to 20: 10 to 400 and more preferably 1: 2 to 15: 20 to 200, and melting the mixture by

  heating at a temperature of 50 to 150 C, preferably 80 to -

 C, until homogeneous.

  Component A is used in the invention to provide the desired coloring to the heat-sensitive material, component B serves to cause reversible staining by reaction with component A and component C serves to control the temperature and heat sensitivity of the material. the above reaction The extent of the hysteresis of the thermosensitive dyestuff according to the invention between the coloration and the discoloration depends on the

  the nature of each of the components described above but the

  relative mixing requirements between these components also

  a decisive factor In general, the temperature range

  The degree of discoloration is close to the melting point of the component C in a negative direction, a thermally sensitive dyestuff will be obtained.

  with the desired range of fade and tempera-

  color retention pattern using a combination

  suitable compounds having different melting points.

  As indicated above, the material according to the invention

  tion, from the point of view of its coloration, the phenomenon of hystdresis as a function of the temperature as represented

  in the graph in Figure 1: it can therefore undergo color-

  Repeated bleaching and discoloration, but when a phosphoric acid ester or a metal salt of such an ester is used as the component, the curve takes on a shape corresponding to a rotation of 180 relative to the CD axis. other words, the material is colored at high temperatures and discolored at low temperatures. The reversible thermosensitive recording material according to the invention is prepared by melting the above temperature-dependent coloring material by heating and applying the coated melt composition in an amount of about 1 to 50 g. m 2 on the surface of a carrier sheet such as a sheet of paper, a plastic film, a fabric or a metal sheet, preferably a sheet of paper or a film of plastic material, or by encapsulating the material whose coloring is a function of temperature in microcapsules of diameter less than 30 μm, preferably 1 μm, by a well-known encapsulation technique (for example the coacervation technique described in US Pat. No. 2,800,457 and 3,116,206, the interfacial polymerization technique described in U.S. Patent Nos. 3,429,827 and 3,167,602 and the in situ polymerization technique. described in British Patent No. 989,264, etc.), then dispersing

  microcapsules obtained in a resin solution, an emulsion

  resin or such a mixture and applying the coated composition to the surface of a carrier sheet as described above. Suitable techniques for applying the coating composition to the surface of the sheet of support are the bar-coating technique, the screen-printing technique, the engraving technique, the technique

  flexographic printing and offset printing technique.

  The examples which follow illustrate the invention without, however, limiting its scope; in these examples, the indications of parts and percentages are by weight unless otherwise indicated.

Example l.

  A molten homogenous composition is formed by heating at about 1000 ° C. 4 g of Violet Crystal lactone, 20 g of bisphenol A-30 and 100 g of myristyl alcohol and applying the melted composition uniformly over a fiber-free paper. of wood (high quality paper); a recording sheet is thus obtained which is heated to 450 ° C., at which temperature it is white; a rubber relief cooled to 15 ° C. is pressed onto the recording sheet at room temperature (270 ° C.):

  positive blue image When the leaf is kept at rest

  24 hours at room temperature from 25 to 30 C, the image remains stable.

  But when you heat the sheet with the blue image evenly

  at 40 C, the image disappears and we once again obtain a single surface

  formally white These training and erasing operations

  image can be made of repeated material.

Example 2

  A homogeneous melted composition is formed by heating

  at about 100 ° C a mixture of 6 g of 3-diethylamino-7,8-benzo

  fluorane (ECOC (1)), 16 g of the zinc salt of bisphenol A, 50 g of

  cyclododecanol and 50 g of cetyl alcohol.

  melted in a uniform coating on coated paper and then laminated onto the sheet a polypropylene film 20 μm thick; a recording sheet is thus obtained, which is uniformly cooled, and the whole surface takes on a pink color; the sheet is kept at 5 ° C. When writing on the sheet with a pen whose tip is heated to about 50 ° C., a white negative image is obtained with a high contrast with the bottom

  pink; the image can be stored for the desired time.

  When the sheet is heated to 50 ° C., its entire surface becomes white; it is allowed to cool to 25 C and is written again with a pen whose tip is cooled to about 10 C: a positive pink image is obtained with high contrast with the bottom

  white This image can be stored for the desired time.

  As in the previous case, the formation and the suppression of the positive image as the negative image can be repeated

as often as we want.

  Table 1 below provides information on

  relative items as: recording materials of Examples 3 to 8, including the components used, the relative proportions, the recording temperature, the storage temperature of the images, the erasing temperature and the coloring obtained in

each case.

  The recording materials of these examples were prepared as described in Example 1 with the components

* listed in Table 1.

TA BLEAU I

  1 Composition of the heat-sensitive material Component B

4,4 '-Thiobis (6-t-butyl-3-

  Methyl Phenol) (16 g) octyl ester of oxybenzoic acid (16 g)

4, 4 '-Thiobis (6-t-butyl-3-

  methylphenol) (20 g) -chloro-11,2,3-benzotriazole (16 g) acid phosphide of 2,3 xylyl (15 g)

1,1-Bis (4-hydroxyphenyl) -

  Cyclohexane (15 g) * Partposant AT ECQO (2) (6 g) ECOC (3) (6 g) ECOC (6) (6 g) ECOC C 7) (6 g) Component C Myristyl alcohol (50 g) butane tetralauryl tetrachlorate (50 g) Trilaurine (100 g) Magnesium alcohol (50 g) Myristyl caprate (50 g) Laurone (100 g) Cetyl alcohol (100 g) Diphenyl sulphide (100 g) Tempera ture T 1 (black) ) (ros e) o red (vermilion) (b lanc) (green) C and (coloring T 2 (b lanc) 1 45 k (b / c) 1 (white) (white) (dark red, (white) Note ECOC tump

ECOC (1)

ECQO (2)

ECOC (3)

ECOC (4)

ECOC (5)

ECOC (6)

ECOC (7)

  3-dieth I and T compound are those represented on the gtaphique of

1 2 3

  Chromatic organic donor Ylamino-7,8-benzofluorane electron Figure 6 '- (Cyclo-xyliethylamino) -3'-methyl-2' - (phenylamino) spiro lisobenzofuran 1 (3H) 39 '- (911) xanheen-3-one 3,3-bis (1-ethyl-2-methyl-1H-indol-3-yl) -1 (311) isobenzofuranone 3-chlouro-6: cyclohexylanofluorane 3-diethylamino -6-mnéthyl-7-clhlorofluorane

  2 '-bis (phenylmethyl) aminoinol-3'-methyl-6' - (diethylamino) spirolisobenzofuran-1 (31), 99- (91-1) -

  xanthene D-3-one 3-diethylamino-5-methyl-7-dibenzylaminofluorane Exenp on

ECOC (4)

ECOC (1)

ECOC (5)

  (4 g) (4 g) (6 g). A Co & A Ir 1

Example 9

  A homogeneous melt is formed by heating at 120 ° C.

  about a mixture of 6 g of 2'-l (4-n-butylphenyl) -aminol-3'-methyl-

  6 '- (diethylamino) -spirolisobenzofuran-1 (3H), 9' - (9H) xanthenel-3

  one (ECOC (8)), 15 g of bisphenol S, 60 g of stearyl alcohol and g of trimyristin is encapsulated-this mixture by a technique

  Well-known coacervation method is then dispersed.

  capsules containing the thermosensitive coloring material in a

  vehicle composed of 200 g of an emulsion of an ethylene-

  vinyl acetate (solids content: 50%, minimum film formation temperature: OC), 40 g of sodium alginate and 80 g of water and this dispersion is coated uniformly over a polyester film of 25 jm thick on

  which is then applied in rolling a film of poly-

  propylene 20 microns thick; we thus obtain a sheet of paper

  gistreuse. When an image is formed on this sheet by means of a heat-recording thermal head and maintained on a plate heated to 400 ° C., a high-contrast black-and-white negative image is obtained which can be Stably stored for the desired time When the sheet of the hot plate is passed through a zone heated to 60 C and then in a zone cooled to -10 C, an inverted image is obtained by means of a thermal head. ; the sheet is kept on a hot plate: a positive image is obtained in white and black with high contrast

  which can be kept for the desired duration. The training cycle

  image, image preservation and image

  the image can be repeated many times.

Example 10

  A homogeneous melt is formed by heating to 100 ° C

  about a mixture of 5 g of 6 '- (diethylamino) -2'-cyclohexyl (phenyl)

  methyl) aminol-spirolisobenzofuran-1 (3H), 9 '- (9H) xanthenal-3-one (ECOC (9)), 15 g of zinc benzoate and 100 g of di-n-hexylketone are encapsulated Melted by a well known technique of coacervation 80 g of the microcapsules containing the thermosensitive coloring material are then dispersed in a vehicle composed of 200 g of a styrene-maleic acid copolymer (molecular weight about 8,000, acid number 170 to 185). ), 20 g of 28% ammonia and 40 g of water and the coating is applied to paper without wood fibers (high quality paper); thus, a recording sheet is formed which is heated to 30 ° C. which gives an entirely white surface; written on this surface using a feather whose tip is maintained at 00 C, in a

  temperature range of 10 to 150 ° C., a positive image is obtained.

  High green contrast with the white background which can be stored for the desired time. If the leaf is heated to 30 ° C, the whole leaf will turn white; we can repeat many

  times the registration and erasure operations.

  Thus, the reversible thermosensitive recording material according to the invention has the characteristics of giving a desired coloration with the desired temperatures for recording, image preservation and erasure by a correct choice of the composition of the composition. staining material

  thermosensitive material used to prepare the recording material

  istration; these characteristics had never previously been obtained with conventional recording materials of the same type. A recording material whose image can be conserved at normal temperature is particularly of great interest. Similarly, the contrast between an image and a background being expressed by the difference in brightness (corresponding to the lon

  section of the graph of Figure 1) with a lumi-

  10 for pure white and O for deep black, the contrast that can be achieved with a conventional recording material (with yellow-to-orange color variation) based on a complex metal salt such as Ag 2 Hg I 4 is about 1.0 to 1.1 while the contrast that can be achieved with the recording material according to the invention reaches 6.5 to 7.0 for black on a white background, about 5.0 for blue on white background and about

4.0 for the red on a white background.

  Of course, the heat recording material

  reversible sensitive material according to the invention can be used as a thermosensitive recording material for imaging formations and eliminations but it can also be used as

  thermosensitive material indicative of temperature.

  Also, the reversible thermosensitive recording material can be used as a writing board with which a combination of a cooling nib and a heating eraser or a combination of a heating plume and a cooling eraser is used. the recording material according to the invention can also be used as a toy, for example in the form of a writing board that can be used in the bath by exploiting the temperature difference between the hot water and the water cold In addition, the recording material

  according to the invention can be used in a recording device

very laser light.

  The possibility of making a colored design appear at will and making it disappear at will makes it possible to use the reversible thermosensitive recording material according to the invention in fields such as personal ornaments, clothing, etc., for example under the in the form of neckties, undershirts, sportswear, blouses, gloves, ski wear, etc., and in decorations such as ribbons,

  flowers, wall covering papers, curtains, etc.

  It is clear that the invention is in no way limited to the preferred embodiments described above as examples and that one skilled in the art can make modifications thereto.

  without leaving the frame.

Claims (4)

  A reversible thermosensitive recording material comprising a support sheet on the surface of which a coating composition containing, as a   chromogenic component, a substance whose coloring is thermo-   and which consists of a homogeneous, fused composition comprising: A an electron-donating chromogenic organic compound selected from the group consisting of diarylphthalides, indolylphthalides, polyarylcarbinols, leuco-auramines, acylauramines, arylauramines, lactams Rhodamine B, indolines, spiropyrans and fluoranes; B a compound selected from the group consisting of C 6 -C 49 phenolic compounds, metal salts of these phenolic compounds, C 7 -C 12 aromatic carboxylic acids, C 2 -C 5 aliphatic carboxylic acids, metal salts of C 2 -C 22 carboxylic acids, C 1 -C 44 acidic phosphoric esters, metal salts of these acidic phosphoric esters, and C 2 -C 24 triazoles; C a compound selected from the group consisting of C 4 -C 31 aliphatic monoalcohols, C 5 -C 1 alicyclic monohydric alcohols, C 7 -C 9 aromatic monoalcohols, polyalcohols 10 '7 9   at C 2 -C 6, esters of monocarboxylic acids in C 2 -C 22 and   C 1 -C 22 aliphatic monoalcohols, esters of monocarboxylic acid   C 2 -C 22 and C 6 -C 18 phenols, the esters of   C 2 -C 22 carboxylic acids and C 2 -C 6 polyhydric alcohols, esters of C 2 -C 12 polycarboxylic acids and aliphatic monoalcohols   C 1 -C 22 aliphatic C 5 -C 35 ketones, aromatic ketones and the like.   C -C 13 ticks, C 2 -C 22 fatty acid amides, Nalkyl derivatives of fatty acid amides, C 8 -C 36 aliphatic ethers, 6   C 12 -C 20 aromatic ethers, monohydric aliphatic acids,   C 6 -C 22 carboxylic acids, C 13 -C 18 thiols, C 16 -C 89 sulfides, C 16 -C 36 disulfides, C 2 -C 14 sulfoxides and C 4 -C 8 sulfonates. 14, the components A, B and C being present in relative proportions by weight of 1: 0.1 to 50: 1 to 800 O staining-thermosensitive material giving rise to a discolouration phenomenon with hysteresis in a range of temperature above 3 C.   Reversible thermosensitive recording material according to claim 1, characterized in that the coating composition consists of the heat-sensitive coloring material   contained in microcapsules with a diameter of 30 μm or less   even scattered in a vehicle.   A reversible thermosensitive recording material according to claim 1 or 2, characterized in that on the layer of the coating composition a substantially transparent layer is formed. 4 Reversible thermosensitive recording material   according to claim 1, characterized in that the material of -   thermosensitive coloration gives rise to a phenomenon of   discoloration with hysteresis in a temperature range greater than 8 C.