JPH01263076A - Thermal recording material - Google Patents

Abstract

PURPOSE:To enhance age stability and color forming properties, by incorporating a benzoic acid derivative having a substd. allyloxyl group at an ortho position. CONSTITUTION:A benzoic acid derivative having a substd. allyloxyl group at an ortho position is incorporated, in a recording material utilizing color development upon contact of an electron-donative colorless dye with an electron- acceptive compound. The benzoic acid derivative preferably has a melting point of 40-170 deg.C, from the viewpoints of age stability and sensitivity of the recording material as a thermal recording material. The solubility of the acid derivative is preferably not more than 1%, because the derivative is used after being finely dispersed to a particle diameter of 3mum or below. The acid derivative may be emulsified or dispersed after dissolving it with the electron-acceptive compound, and may be dispersed by grinding after it is melted and cooled. In the case of melting the acid derivative by heating, the heating temperature is preferably 120-180 deg.C. In this way, a thermal recording material can be obtained which has satisfactory developed color density and color forming sensitivity and excellent age stability.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application of the Invention The present invention relates to a recording material, and particularly to a heat-sensitive recording material with improved stability over time and color development.

<Prior Art> Recording materials using electron-donating colorless dyes and electron-accepting compounds are already well known as pressure-sensitive paper, thermal paper, photosensitive pressure-sensitive paper, and electrically conductive thermal paper. For example UK%FF, 2
/≠otithiro, US hour hand≠+, r o.

! λ, Same I/L Hiro 36 Octopus O1 Special Public Show 60-23 Octopus 2
, JP-A-17-/79136, AO-/23jJ-t
, 2θ-7, 23, j7, etc.

The characteristics that a heat-sensitive recording material should have are (1) sufficient color density, (2) no color development during storage before use, and (3) fastness of the color material after color development. (4) Appropriate color hue and suitability for copying machines (5)
) A high S/N ratio, and (6) sufficient chemical resistance of the coloring body, etc., but it is currently not possible to obtain a product that completely satisfies these requirements.

Especially in recent years, with the speeding up of thermal recording systems, the above (1)
Research is being carried out intensively.

As a method, the melting point of the electron-accepting compound itself is /2
00C or less, using an organic acid and a phenolic compound together as an electron acceptor, or using a polyvalent metal salt of a compound having an alcoholic hydroxyl group, hydroxyethylcellulose and maleic anhydride. To use a copolymer, add waxes, thioacetanilide, phthalonitrile, acetamide, di-β-naphthyl-p-phenylenediamine, 1Iit
Nitrogen-containing universal compounds such as alidisamide, aceto-m-acid anilide, diphenylamine, penzamide, carbazole, etc. or 2,3-dirr+-tributane, ≠
, Adding esters as sensitizers with heat-fusible substances such as μ'-dimethylbiphenyl, or carbones such as dimethyl phthalate, diphenyl phthalate, dimethyl terephthalate, etc., and adding hindered phenols. Things are being tried.

However, heat-sensitive recording materials produced using these methods are insufficient in color density and color sensitivity.

<Object of the Invention> Accordingly, an object of the present invention is to provide a heat-sensitive recording material which has sufficient color density and color development sensitivity and has excellent stability over time.

<Structure of the Invention> The object of the present invention is to provide a recording material that utilizes color development due to contact between an electron-donating colorless dye and an electron-accepting compound, which contains a benzoic acid conductor having a substituted allyloxy group at the ortho position. Eri was achieved in recording materials featuring features.

Among the benzoic acid conductors according to the present invention, the following general formula fI)
The one represented by is preferable.

In the above formula, R1s R2, R3, R4 are hydrogen atoms, alkyl groups or aryl groups, R5, R6, R7R8 are hydrogen atoms, alkyl groups, aryl groups, nitro groups, cyano groups,
A halogen atom, an alkoxy group, an aryloxy group, an acyl group, or an acylamino group, or aS and R6, R6 and R7, or R7 and RsVX, each bonding to represent an aromatic ring, and M is a hydrogen atom. , an alkyl group or a metal of valence n (an integer from/to n).

In addition, an alkyl group represents a saturated, unsaturated or cycloalkyl group, and these include a substituent such as an aryl group, an alkoxy group, an aryloxy group, an acyloxy group, a halogen atom, an acylamino group, an aminocarbonyl group, or a cyano group. You may do so.

Incidentally, the aryl group represents a phenyl group, a caftylated group, or a heterocyclic group, and these include an alkyl group, a human group, an alkoxy group, an aryloxy group, a halogen atom, a CI group, a cyano group, and a substituted carbamoyl group. , substituted sulfamoyl group, substituted amine group, substituted oxycarbonyl group,
It may have a substituent such as a substituted oxysulfonyl group, an alkylthio group, an arylsulfonyl group, or a phenyl group.

In the above formula, among the substituents represented by R1, R2, R3, and R4, a hydrogen atom, an alkyl group having from / to r carbon atoms, and an aryl group having from 72 carbon atoms are preferable.

Examples of R1.tt2, R3, and R4 include a hydrogen atom, an ethyl group, an ethyl group, a butyl thread, and a phenyl group.

In the above formula, among the substituents represented by R5, R6, R7, R8'''c, hydrogen atoms, alkyl groups having 7 to 1 carbon atoms, aryl groups having 6 to 72 carbon atoms, chlorine atoms, carbon An alkoxy group with a number of atoms of 1 or 20, an acyl group with a number of carbon atoms of 1 to /r, or an acylamino group with a carbon atom of !!/may be /f are feminine.

R5, R6, R7, R8 are hydrogen atoms, methyl groups,
Ethyl group, t-butyl group, t-amyl group, t-dodecyl group, cyclohexyl group, benzyl group, α-methylbenzyl group, phenyl group, ix atom, methoxy group, methoxy group, phenoxyethoxy group, acetyl group, acetamino group etc. can be mentioned.

Or R5 and R6, R6 and R7 or R7 and R2H
It is preferable that they are bonded to each other to form a benzene ring.

Among the substituents represented by M in the above formula, a hydrogen atom, an alkyl group having 1 to t carbon atoms, or a metal having an atom f111im (m is an integer from λ to 3) is preferable.

M is a hydrogen atom, an ethyl group, an ethyl group, a butyl group,
Examples include zinc, nickel, aluminium, calcium, and magnesium.

The benzoic acid e5 conductor used in the present invention has a melting point≠θ~770 from the viewpoint of stability over time and sensitivity as a heat-sensitive recording material.
℃ is preferable, and 60 to 300℃ is particularly preferable.

These should be used finely dispersed to a particle size of 3μ or less, so
The solubility in water is preferably 100% or less, particularly 0 or 100% or less.

Further, these may be emulsified and dispersed after being previously dissolved together with the electron-accepting compound, or may be pulverized and dispersed after being melted and cooled.

When thermally melting, it is preferable to heat immediately to 72086 or more and 1ro0c or less.

Here, an example of synthesis of the benzoic acid derivative according to the present invention will be shown.

<Synthesis example> Koshinkabaloxybenzoic acid In a three-necked flask equipped with a stirrer, 0.1M of methyl salicylate and 0.1M of sulfuric acid carbonate were added. /IM, dimethylacetamide jO1 was weighed, and 0.10j M of syncamyl chloride was slowly added dropwise while stirring at an internal temperature of jO°C. After finishing under tA, set the internal temperature to 1000-! Raise the temperature with ≠ and continue the reaction for ≠ time.

After the reaction is complete, the contents are poured into ice water and the precipitated crystals are collected by filtration. The obtained crystals were dissolved in Oml of ethanol, and mixed with 20% caustic soda water o, r while stirring at an internal temperature of j'0 C.
Slowly drip M. After the dropwise addition is completed, the temperature is raised and the reaction is continued for 7 hours under reflux conditions. After the reaction is complete, pour the contents into ice water and make the solution acidic with concentrated hydrochloric acid. Crystals will precipitate. The target product is recrystallized from methanol and the melting point/1
Crystals of O-10C were obtained.

Specific examples of benzoic acid derivatives according to the present invention are shown below, but the present invention is not limited thereto.

) λ-allyloxybenzoic acid (2), 2-(λ-guthynyloxy)benzoic acid (3)
, 2-cincamyloxybenzoic acid (4) co-allyloxy-monochlorobenzoic acid (5) -2-allyloxy-yo-methylbenzoic acid (6) 2-allyloxy-j-
Methoxybenzoic acid (7) J-allyloxy-! -Phenylbenzoic acid (8) 2-cincamyloxy-! −
Phenylbenzoic acid (9), 2-allyloxy-! -Acetylbenzoic acid (10) x-allyloxy-! -Nitrobenzoic acid 0
υ Co(2-methylallyloxyJbenzoic acid α) λ
-Methyl cinnamyloxyconaphthoic acid f43) J-Allyloxyconaphthoic acid q(a) 3-Cinnamyloxyconaphthoic acid Q5)
Zinc salt of medium example (1) 061 Nickel salt of specific example (3) 117) Zinc salt of specific example 11 (7) U (to)! r-(p-(α-methylbenzyl)-α-
Methylbenzyl”-2-allyloxybenzoic acid (19!
,! '-Methylenebis(2-allyloxy)benzoic acid ■ j , j'-(amprobiritenebis(2-allyloxy)benzoic acid As the colorless dye according to the present invention, triphenylmethane phthalide compounds which are already well known are used. , a fluoran compound, a phenonaazine compound, an indolyl 7-thallide compound, a leuco auramine compound, a rhodamine lactam thread compound, a triphenylmethane compound, a triazene thread compound, a spiropyran thread compound, a fluoran compound, etc. It will be done.

Regarding these, for example, specific examples of phthalides are US reissue special FF23.0, US pin 3. Hirori/, /l/
, same 3. μri/, //λ, same 3. ψP/, //l, same 3
．． jOri, /741. A specific example of fluorans is 3.62
≠, 107, 3,627.71r7, 3. t'l/
, 0//, same J, Hiro A2.8'2r, same 3. tl/, 3
ri01 same 3. Octopus 0, jlo, same 3. ri J'P, j
7/, direction≠, λko≦, ri12, specific examples of subirojibirans are 3.77/, ♂or, pyridine-based pyrazines are the same 3
, 77j, u211, same 3. r! 3,11. ri, ≠,
dμ6.3/za, fluorenesμ Tokugansho &/-, 2hiroQ
It is described in Riniri etc.

For example, some fluoranes can be expressed by the following formula.

In the formula, R9 to R12 represent a hydrogen atom, an alkyl group, an aryl group, or an acyl group, and in addition to these, a halogen atom, an alkyl group, an aryl group, a Peter symbol, an acyl group, an alkoxy group, an aryloxy group, a substituted amino group, a ) R13 to R17 may be substituted with o group, cyano group, etc. R13 to R17 are hydrogen atoms, alkyl groups, aryl groups,
Indicates a group selected from an acyl group, a halogen atom, a nitrokoto, an acyl group, an aryloxy group, an alkoxy group, a nido-oi, a carbamoyl group, an amino group, an acyloxy group, a cyano group, etc. may be further substituted with.

Also %R9 and R10~R9 and R17%R13 and R14,R
14 and R12, R11 and atS are mutually bonded, and! It may form a 6- to 6-membered ring.

R9, RIO are alkyl groups, all, R16, R17 are hydrogen atoms, R13, R14, 'C is particularly preferred.

Y represents an oxygen atom or a sulfur atom. 2 represents C or H. These may form a bis body via R9, R11 or R16.

Specific sequences include, for example, λ-aniIJ/-J-mef-z-diethylaminofluorane, 2-anilino-3-mef&-cyclohexylmethylaminofluorane 1.2-p-ri00anilino-3 -Methyl-t-diethylaminofluorane, 2
-anilino-3-methyl-A-dioctylaminofluorane, no-anilino-3-chloro-o-diethylaminofluoran, pyridine blue, 2-anilino-3-methyl-A-diisobutylaminofluorane, λ-phenyl-6- ethylaminofluorane, no-anilino-3
-Mesol-2-~-Etherhein amyl aminofluorane, λ-anilino 3-methyl-6-dinithylamino-7-methylfluoran, co-anilino 3-methoxy 3-diptylaminofluorane, 2-〇-chloroanilino B-dibutyl abanofluorane, 2-p-chloroanilino-3-fluorane A-N-ethyl N-ia 7
Mylaminofluorane, No-0-Chloroanilino-O-
p-Butylanilinofluorane, λ-anilino 3-pentadecyl-4-diethylaminofluorane, λ-anilino 3-ether-2-dibutylaminofluorane, co-anilino 3-methyl-Hiro'.

! '-Dichlorofluorane, 2-o-toluidino-3-
Methyl-6-diitubrobylaminohiro'.

! '-dimethylaminofluorane, co-anilino 3-
Ethyl-4-N-ethyl-N-(:/7mylaminofluorane, 2-anilino-3-methyl-4-N-ethyl-
N-1-Hyricylzolobylaminofluorane, λ-anilino-3-chloro-2-Heeguruheisoamylaminofluorane, rhodamine-B-anilinolactam, rhodamine(p-nitroanilino)lactam, rhodamine B( p-chloroanilino)lactam, co-anilino 6-diethylaminofluoranato.

Some examples of other colorless dyes include triarylmethane compounds such as 3,3-bis(p-dimethylaminophenyl-6-dimethylaminophthalide (i.e., crystal violet lactone), (There are p-dimethylaminophenyl fumelide, etc., and diphenylmethane thread compounds include ≠ R7,1-bis-dimethylaminobenzhydrin benzyl ether, hehalophenyl leukoolamine, N-2,≠,!- Examples of thiazine-based compounds include benzoylleucomethylene blue and p-nitrobenzoylleucomethylene blue; examples of spiro-based compounds include 3-methyl-spiro-dinaphthopyran and 3-ethyloose billow. Dikaftvilan, 3.3'
-Dicalose biro dicaftobilane, 3-pendylsubirone capftobilan, 3-methyl-cut-(3-methoxy-benzo)spiropyran, 3-propyl-spiro-dibenzobilan, etc., and two or more of them are used in combination. This is desirable.

Electron-accepting compounds that provide color upon contact with colorless dyes include inorganic and lv organic Lewis and Brønsted acids. For example, compounds containing T that exhibit acidity such as phenolic hydroxyl, carboxyl group, imide group, etc.
Alternatively, metal complexes are useful. For example, phenol visiting conductors, salicylic acid derivatives, metal salts of aromatic carboxylic acids, acid clay, bentonite, novolac a1 fat, metal-treated novolac resins, such as 2-rioo-4t phenylphenol, 2,2-bis(Hiro-hydroxy) phenyl)propane, Hiro, ≠′-isobrohyritenebis(2-
Methylphenol), /, /-bis-(J-chloro-guhydroxyphenyl)cyclohexane, z, r-bis(3-chloro-guhydroxyphenyl)-3-methylbutane, Hiroshi, lLt/-Secondary-inoc tylidene diphenol, Hiro, ≠'-5ee-butylidenephenol, ≠-cyanophenylphenol, ≠'-isopentylidene diphenol, ≠, Hiro'-methylcyclohexylidene diphenol, /, Hiro-bisu Hiro' -hydroxycumylbenzene, /, 4t-bis-Hiro'-hydroxybenzoylbenzene, +, p'-thiobis (J, G-
methylphenol), ≠, Hiro'-dihydroxydiphenyl sulfone, phloroglycin monobenzenether, ≠-hydroxybenzophenone, 2. Hiro-dihydroxy≠'-butoxybenzophenone, 3.3'-methylenebis-≠-hydroxybenzoic acid benzyl ester, polyvinylphenol,! , Ko', 4t.

a/f trahydroxydiphenylsulfone, Hiro-dimethyl hydroxyphthalate, ≠-isobutyl hydroxy7benzoate, Ko, Hiro, Hiro'-trihydroxyco'-benzyloxydiphenylsulfone/,! -His-p-hydroxy/phenylpentane, 73-Bis-p-hydroxyphenoxyhexane, Guhitomixyam, @Tolyl Froate, Hiro-Hydroquine benzoic eα-phenylbenzyl ester, m-xylylenebisguyhydroxybenzoic acid ester, II -Phenethyl hydroxybenzoate, ≠-hydroxybenzoic acid H-p-cumylbenzyl, ≠-hydroxybenzoic acid henzyl ester, ≠-hydroxybenzoic acid henzyl ester, ≠-hydroxybenzoic acid em-
Fluorobenzyl ester, Hiro"T'-Loki'/ Benzoic acid-cumyl ester, ≠, Hiro'-Hydroquine-rl
, 2/-digtylphenyl sulfone, β-7 enetelorse 1J*-1, nka ε oleorseinate, orselic acid-o-chlorophene, noquinethyl ester,! ,
! '-methylenebisu2. Hiro-Dipydihydroxybenzoic acid benzyl ester phenylphenoxyethyl orselinate, m-7 dinylphenoxyethyl orselinate, 2,41-dihydroxybenzoic acid-β
-J'-t-i Chiru Hiro'-Hydroxyphenoxyethyl ester, bisphenol A bis p-hydroxybenzoic acid ester, terβ-p-methoxyphenoquinethoquine-2-hydroquine benzoic acid, λ,4L-dihydroxybenzoic acid 7
Benzoic acid p-methylbenzyl ether, Ko-dihydroquine benzoic acid β-phenoquine ethyl ester,
2,1LL-dihydroxy-6-methylbenzoic acid 0-
Methyl benzyl ester, bis-gu-hydroxyphenylacetic acid phenoxyethyl ester, ≠, ≠'-diacetyldiphenylthiourea, 3-7enyl salicylic acid, r
-p-α-Methylbenzyl-α-methylbenzylsalicylic acid, terp-methoxyphenoxyethoxysalicylic acid, j-phenoxyethoxysalicylic acid, terp-benzyl-α-methylbenzylsalicylic acid, 3-xylyl-! Aromatic carboxylic acids such as -(α,α-dimethylbenzyl)salicylic acid, 3゜terdi(α-methylbenzyl)salicylic acid, 2-hydroxy-/-α-ethylbenzyl-3-caftoeic acid, J,r-di- Organic color developer series such as 7-lylopentadienyl salicylic acid, para-phenylphenol-formalin resin, and Nato's phenolic resin. Complexes of zinc rhodan and molybdic acid, such as imidazole complex of zinc rhodan, λ-phenylimidazole complex, picoline complex, copendylimidazole complex, penzimitasole H form, ! , ,y-dimethyl-/-7enyl J-Hira:/')-j-one complex, l-phenyl-2-methyl-3-benzyl-3-virasorin-!
-one complex, /-phenyl-comethyl-3-(,2
-ethylhexyl) -3-hira:/ phosphorus-r-one complex% '-phenyl-2-methyl-3-isopropyl-3-pyrazolin-j-one complex, /-phenyl-,
2,3-Dibenzyl-Hilathorin! -one complex, 1-
Phenyl-2-benzyl-3-methyl-virazoline!
-one complexes, β-diketone molygdate complexes, for example, ligands include acetylacetone, benzoylacetone, thenoyltrifluoroacetone, acetylacetylacetone, EDTA, ethyl benzoylacetate, bipyridyl, oxine, and the like. Furthermore, these organic color developers, such as zinc, magnesium, albanium, calcium, etc.
Salts with polyvalent metals such as Particularly preferred is the case where one or more of bisphenol lj4 or its derivatives, salicylic acid derivatives, and zinc salts are used.

When specific compounds of the formula, colorless dyes, and electron-accepting compounds are applied to recording materials, they are used in the form of fine dispersions or fine droplets as described above.

When used in thermal paper, the compound of the present invention, the colorless dye, and the electron-accepting compound are 3μ or less in the dispersion medium,
Preferably μ/,! It is used after being crushed and dispersed to a particle size of μ or less. As a dispersion medium, an aqueous solution of a water-soluble polymer having a concentration of about 9% O, C to 10% is generally used, and dispersion is carried out using a ball mill, a sand mill, a horizontal sand mill, an attritor, or a colloid iA/%.

The ratio of the colorless dye to the electron-accepting compound used is from /:10 to /:0. Preferably between /, and even /:! to 2:3 is particularly preferred.

i:o to the compound of the invention to the electron accepting compound.

From l/;/! Preferably between.

In this case, it is preferable to use aromatic ethers, esters and/or aliphatic amides or ureides in combination.

Examples of aromatic ethers or esters include penzylokicuna 7-talene, di-m-tolyloxyethane, β
-phenoxyethoxyanisole, /-phenoxy-2
-p-ethylphenoxyethane, bis(p-methoxyphenoquine)ethoxymethane, bis-β-(p-methoxyphenoxy)ethyl ether, /-methylphenoquine-
1-ethylphenoxyethane, /-tolyloxy-1-
p-methylphenoxyethane, l,2-diphenoxyethane, /, Hiro-diphenoxybutane, bis-β-(p-
Ethoxyphenoxine ethyl ether, /-7dinoxy-2-p-chlorophenoxyethane, /-p-metherphenoxycop'-fluorophenoxyethane,
l, 2-bis-p-methoxyphenylthioethoxyethane, l-phenoxy-J-p-methoxy7phenylthioegluether, /, Corbis-p-methoxyphenylthioethane, /-tolyloxy-2-p-methoxyphenylthio Ethane, β-7thyl p-methylphenoxyacetate, β-f7thyl p-methoxy7phenoxyacetate, p-methoxyphenyl-p'-methoxyphenoxyacetate, β-phenoxyethyl-6phthyl (
2)-oxyacetate, β-p-chlorophenoxyethyl-caftyl-(2)-oxyacetate, β-p-
Methylphenoki7ethernaphthyl(2)-oxyacetate, β-caftyl-(2)-oxyethylbenzyl carbonate, ditolyl carbonate, ≠-ethoxy/-methoxyphthalene, l-hydroxy-2-naphthoic acid phenyl ester , /-benzylox7benzoic acid benzyl ester, phenylbenzoate, bis-β-
p-Methquinphenoxy/ethyl carbonate, β-phenoxyethoxybenzoic acid butyramide, β-caftylthiobenzyl ether, ethylene glycol-bis-caftyl-(2)-oxyacetate, /, ≠-gutanediolubis-butyramide xyacetate, Korg toxy, benzyl caphtoate, guaryloxybiphenyl,
/-caftyl(2)-oxycophenoquine propane and the like.

Amide compounds include stearic acid amide, methylene bis stearamide, stearyl urea, cyclohexyl urea, stearic acid anisidide, benzoylstearylamine, phenoxyacetobenzylamide, phenylacetylbenzylamide, butoxyethylbenzylamide, and furoic benzyl. It is particularly effective to use amide, etc. in combination with the above-mentioned ethers.

These are used in finely dispersed form at the same time as the colorless dye or at the same time as the electron-accepting compound. In particular, it is preferable to disperse them at the same time as the colorless dye from the viewpoint of preventing capri. The amount of these to be used is added at a heavy electric ratio of 0% or more and 300% or less, especially 10% or more l! Q% or less is preferable.

Historically, in the present invention, μ particle size is 0. / to 10μ pigments such as kaolin, calcined kaolin, Merck, calcium carbonate, aluminum hydroxide, magnesium hydroxide, calcined gypsum, mineral, magnesium carbonate, zinc oxide, aluminum, barium carbonate, barium sulfate, mica, microballoon, It is preferable to use urea-formalin filler, polyethylene particles, cellulose filler, etc.

Furthermore, it is also preferable to use hindered phenol in combination.

Hindered phenol refers to a phenol derivative in which at least % of one or more of the 2 or 6 positions is substituted with a branched alkyl group, such as l.

l-bis(2-methyl-ψ-hydroxy-s-butylphenyl)butane, 7.3-tris(3-methyl-Hiro-hydroxy-r-t-butylphenyl)butane, bis(2-hydroquine) -3-1-phthyl-j-methylphenyl)methane, bis(comethyl-Hiro-hydroxy-j-1-7'' tylphenyl) sulfide, and the like.

Examples of ultraviolet absorbers include cinnamic acid derivatives, benzophenone derivatives, benzotriazolyl phenol derivatives, etc., such as glutyl α-cyano-β-phenylaceta, 0-benzotriazolylpheno-/L/, O-benzo Triazolyl-p-chlorophenol, 0-benzotriazolyl-λ, ≠-dibutylphenol, 0-bensothoIJ
7:,'IJ loop-chlorophenol, etc. Alternatively, a small amount of a hindered amine compound called LALS can also be used in combination.

These materials are also detailed in the watches mentioned above.

Additives are further added to the coating liquid thus obtained in order to meet various requirements.

An example of an additive is to disperse an oil-absorbing substance such as a polyurea filler in a binder and leave it at ℃ in order to prevent the recording head from becoming dirty during recording, and also to improve the originality of the head V. Therefore, metal soap etc. should be added. Therefore, in addition to colorless dyes and electron-accepting compounds that contribute to color development, waxes, antistatic agents, ultraviolet absorbers, antifoaming agents, conductive agents, fluorescent dyes, surfactants, etc. are used in combination. Then, the recording material is constituted.

Waxes include paraffin wax, carboxy-modified paraffin wax, polyethylene wax,
Examples include higher fatty acid esters.

Examples of the metal soap include higher fatty acid polyvalent metal salts, ie, zinc stearate, zinc oleate, and the like.

These are dispersed and applied in a binder.

Water-soluble binders include polyvinyl alcohol, hydroxyethylcellulose, hydroxypropylcellulose, epichlorohydrin-modified polyamide, maleic anhydride copolymer, acrylic acid copolymer, modified polyacrylamide, starch fat conductor, casein, gelatin, etc. can be given. It is also possible to add a water resistant agent (gelling agent, crosslinking agent) to these binders, or to add an emulsion of a hydrophobic polymer such as styrene-butadiene latex or acrylic resin emulsion.

Furthermore, for the purpose of imparting coating, coating surface, and chemical resistance,
A layer consisting of a water-soluble polymeric compound such as polyvinyl alcohol, hydroxyethyl starch or epoxy-modified polyacrylamide and a gelling agent (hard axe) 2 can also be provided.

The coating fluid is most commonly applied onto base paper, acid-free paper, wood-free paper or synthetic paper, preferably acid-free paper coated with a white pigment such as synthetic calcium carbonate.

In this case, it is preferable to use a pigment and a thermoplastic or thermofusible material in combination.

Generally, the coating amount is about λ to lOg/m2 in terms of solid content.

When used for thermal paper, OLSλ2 Kottri,
Same, 2iiorrtt, Tokko Akira! Various types of cores described in J-20/Hiroshi λ etc. can be used.

Alternatively, operations such as preheating, humidity control, or stretching of coated paper may be added prior to recording.

(Examples of the Invention) Examples are shown below, but the present invention is not limited only to these examples.

Example 1 (1) Preparation of sample 1 Co-anilino 3-methyl-AN-ethyl-n-propylaminofluorane 2 fl, , 2-anilino-3
-Chloro-4-diethylaminofluorane 2! Each of the samples was dispersed with an aqueous solution of 3.5 polyvinyl alcohol (2000% polyvinyl alcohol, 1000 degree of polymerization) to an average particle diameter of 2 using a sand mill.

10,000, bisphenol / 3j; l,) 4 body example rot (3)
Compound B, β-p-ethelphenoxy-α-phenoxyemene B, was melted in /J'00C and then dispersed in a 3% polyvinyl alcohol aqueous solution jOg and 4 in a ball mill overnight. length, /, /, 3-tris-2'-methyl-
Hiro'-hydroxy-yo'-1-butylphenylbumene 0
．． /jl! Disperse with Tivoli vinyl alcohol aqueous solution 209 all day and night.

After mixing this well, Georgia Caorinco O, fine particle silica 6,! Add i+ and disperse well, then paraffin wax emulsion! 4L of O% dispersion (Chukyo Yushi 7A Sol #1za) was mixed to prepare a coating liquid.

The support used was neutral paper having a basis weight of RO97m and coated with synthetic carbon carbide and benzyloxykafta L/7 at a ratio of r g/m 2 at a weight ratio of 20:/(wt).

The coating solution was coated onto this support so that the solid coating amount was 527 m2, and after drying at 0c for 1 minute, it was applied with a super calender at a linear pressure of 1r OKgW/Cm to obtain a coated paper.

The obtained recording material had no fog during raw storage, and its stability over time was significantly poor.

The colored image obtained by heating the coated paper with 7mm 7mm was clear black and showed good resistance to chemicals and sunlight.

Example 2.3 The compound of Example 4 (3) of Example 1 was converted into Example A (131
[Example 2], β-p-etherphenoxy-α-phenoxyethane of Example 1 was replaced with the compound [Example 2].

A coating liquid was obtained in the same manner except that β'-bis-p-methoxyphenoxy7ethyl ether was used instead of ethyl ether (Run 3J). This coating liquid is coated with synthetic fine charcoal (Brilliant IR) on neutral paper.
The binder is carboxy-modified SBR/, 1g7m
It was coated on high-quality paper with a coating of 2.

When color was developed according to the method of Example 1, a clear black image was obtained, and the reflection densities were both o and s' or higher.

The black image was clear and showed no discoloration or fading even when exposed to oil or sunlight.

Claims (1)

[Claims] A heat-sensitive recording material that utilizes color development due to contact between an electron-donating colorless dye and an electron-accepting compound, which is characterized by containing a benzoic acid conductor having a substituted allyloxy group at the ortho position.