JPS62259887A - Thermal recording material - Google Patents

Abstract

PURPOSE:To provide a thermal recording material capable of obtaining a high density color image even under low energy and reduced in background fog, by incorporating at least one kind of a heat-meltable substance represented by a specific formula and polyvinyl pyrrolidone in a thermal color forming layer. CONSTITUTION:A thermal color forming layer based on a colorless or light- colored electron donative dye precursor and an electron acceptive substance forming a color upon the reaction with said electron donative dye precursor is provided on a support and at least one kind of a heat-meltable substance represented by formula (I) or (II) and polyvinyl pyrrolidone are contained in said thermal color forming layer. Said heat-meltable substance pref. has m.p. of 70-150 deg.C and, concretely, beta-naphthylbenzyl ether (m.p., 105 deg.C), beta- naphthylbenzyl thioether (m.p., 87 deg.C) and 1,2-bisphenoxyethane (m.p., 97-98 deg.C) are designated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to a thermal recording paper, and more particularly to a thermosensitive recording paper that develops color by reacting with a normally colorless or light-colored electron-donating dye precursor and the electron-donating dye precursor. The present invention relates to a heat-sensitive recording material containing an electron-accepting substance.

(Prior art) So-called two-component heat-sensitive recording materials that utilize a color reaction between a colorless or light-colored electron-donating dye precursor and an electron-accepting compound are disclosed in Tokko Sho μyoichi/≠032 and Tokko Akihiro 3- ≠/6
It is disclosed in No. 0 etc.

Two-component color-forming heat-sensitive recording materials are produced by dispersing colorless or light-colored electron-donating dye precursors and electron-accepting additives in the form of fine particles, and mixing these with a binder, etc., to create two types of thermally reactive materials. The compound is isolated using a binder, etc., and then placed on a support, and one or both of them are melted by force and heat, and records are obtained by utilizing the color reaction that occurs when they come into contact. . These two-component color-forming heat-sensitive recording materials are ■-
Advantages include: secondary color development, no need for development; ■Paper quality is similar to ordinary paper; ■Easy handling; ■High color density; ■Easy to produce heat-sensitive recording materials with various color hues. It also has great utility value. For this reason, it is most commonly used as a heat-sensitive recording material.

In particular, the use of heat-sensitive recording materials in the fields of facsimiles, recorders, and printers has been remarkable in recent years. As its use in the field of facsimile has spread, recording speeds have been increased, but even for heat-sensitive recording materials, the ability to develop color with sufficient density even with short pulse widths, i.e., low thermal energy, has improved. There is a strong demand for improvement in thermal reactivity.For example, JP-A-67-≠
No. 7623 discloses that recording sensitivity can be improved by reducing the volume average particle size of the color former to λμ or less.

In addition, Tokukai Sho Zr-ir'y 3 No. 3, Tokukai Sho! Tart
Various attempts have been made to achieve the disclosed method, such as in No. 7013 and Japanese Unexamined Patent Publication No. 7013. However, as the thermal response is improved, the turnip IJ of the white background part tends to increase by 9 degrees, which impairs the commercial value. No., Tokukai Akira! Various attempts have been made to improve the fogging in white areas, although various attempts have been made to improve the fogging in white areas. Although it is effective, it has drawbacks such as a significant decrease in thermal response.

(Objective of the Invention) An object of the present invention is to obtain a heat-sensitive recording material which can provide a colored image with high density even at low energy and has less n1 background fog.

(Groove Bottom of the Invention) The object of the present invention is to provide a colorless or light-colored electron-donating dye precursor and an electron-accepting substance that develops color by reacting with the electron-donating dye precursor as main components on a support. In a heat-sensitive recording material provided with a heat-sensitive coloring layer, the following general formula (
1) or (n), and polyvinylpyrrolidone.

Ar 1-X-R1 (I) Ar 1-X-R2-X-Ar 2 (I
I) In the above formula, R1d is an aralkyl group, R2 has 2 carbon atoms
~IO alkylene group f, Ar1. Ar2 represents an aryl group, and X and Y represent oxygen, sulfur or CO2.

In the above general formula, preferred examples of the aryl groups represented by Ar1 and Ar2 include phenyl group and naphthyl group.

Among the thermofusible substances represented by general formula (1) or (n), preferred are the following general formulas (1) and (II/)
Examples include compounds represented by n.

(In the formula, R3H represents a phenyl group, a benzyl group, and their lower alkyl or...rogen substituents, and R4 represents all monovalent groups, preferably an alkylene group or an alkylene group with a carbonyl group present.) - A polykylene group, an alkylene group having an unsaturated bond, and more preferably an alkylene group or an alkylene group having an ether bond.

X and Y represent oxygen, sulfur, or CO2. Zl, Z2
, Z3, Z1', Z2', and Z3' may be the same or different and represent a hydrogen atom, a halogen atom, an alkyloxycarbonyl group, or an aralkyloxycarbonyl group. )
The compounds of the general formulas (l[l) and (fV) have a melting point of 7o
The melting point is preferably 1rOuC or more and 1300C or less. Next, specific adducts and melting points are shown.

(1) β-naphthylbenzyl ether (mp, 10
(2) β-naphthylbenzylthioether (mp47°
C) f31/, 2-bisphenoxyethane (mp, Tahuta g 0C) (41/, 4'-bisphenoxybutane (mp, ri7-
TA J'C) (51/-7 dinoxy 2-(Hiro-methylphenoxy)
Ethane (mp, 1oo-iot 'c) (6) /-
Phenoxyco(≠-chlorophenoxy)ethane (m
p, 10/-102 °C) (7) l-phenoxyco(IA-iso-propylphenoxy)ethane (mp,
t'c) (13) / -7, Z / Kishi 2
- (4!-tert-butylphenoxy)ethane (m
p-taco-23°C) (9) l-7 dinoxy 2-(j
, IA-dimethylphenoxy)ethane (mp, /
00-/010C) αl/, J-bis-(≠-methoxyphenoxy)prono(mp, ♂ri-ri(7'C)C1) /-(
dermethylphenoxy)-2-(2-methylphenoxy)ethane (mp, J'j~♂6°C) (1 piece /-(4cm methylphenoxy)-λ-(3-
methylphenoxy)ethane (mp-tal~taco0C) (13/, G-bisphenoxyhexane (mp, rO0
C) C4)/-phenoxy-2-(≠-methoxyphenoxy)ethane (mp, 102-1011'C)C9l-7
Dinoxy J-(J-methoxyphenoxy)ethyl(m
p, Ir2~13 °C) α61/-7 dinoxy J-
(4!-fluorophenoxy)ethane (mp, taO
~23°C) C7)/-phenoxy-J-(4c-ethylphenoxy)ethane (mp, 10/°C) C8/, J-bis(λ-methylphenoxy)ethane7 (
mp,! 2~r j 'C) (L!J/, J-bis(μ-ethylphenoxy)pronomine (mp,
10'C) ■ l-phenoxyco (Hiro-n-
propylphenoxy)ethane (mp, taO~ri/'
C)01) /-phenoxy-p-(4c-ethylphenoxy)butane (mp, 10-1/'C) @/, 2
-bis(3-methylphenoxy)ethane (mp-taj'
C) (c) l-(dermethoxyphenoxy)-2-(co-methylphenoxy)ethane (mp-♂co~?3°C) 24)/-(≠-ethoxyphenoxy)-u-( J-chlorophenoxy)ethane (mp, !P/~3 °C) C) Si-<μmmethylphenylthio)-1-(4
C-ethoxyphenoxy)ethane (mp, J'ri-ri/
'C) C26)/-<'t-methoxyfuninylthio)-λ-(
≠-ethoxyphenoxy)ethane (mp-t7~rr0
c)! 7fJ/, 2-his(μm methylphenylthio)ethane (mp, I O'C) @ /, 2-bis(IA-methoxyphenylthio)
Ethane (mp, 1O1r~1100C) @ l, ≠-bis(≠-methoxyphenylthio)butane (mp, 102
~1036C) Gloss i,z-bis(≠-ethoxyphenylthio)ethane (mp-taO~ri10C) C31)'+λ-bis(≠-bromophenylthio)ethane (mp, /IJ ~/III' C) Q3t, u-bis(≠-bromophenylthio)butane (mp-tarr-P
ri0C) C33/, 2-bis(4/--butoxyphenylthio)
Etay (mp, 102-103 °C) (Foundation) 1.
2-bis(≠-chlorophenylthio)ethane (mp,
3 °C) (t) /, 2-bis(μ-n-propyloxyphenylthio)ethane ((yap, /// ~ 1ia0C) (to) /, 2-bis(≠-1so-i Lopyloxyphenylthio)ethane (mp, / /! A-/ /6
°C) at C3 /, 2-bis(≠-tert-butylphenylthio)ethane (mp, /07~/OJ”C)
p/-(44-methoxyphenoxy)-cophenylthioetay (mp, r2~tr3 °C) The above thermofusible substances can be used alone or in combination, and have sufficient thermal responsiveness. To obtain the electron-accepting compound, 1
It is preferable to use 0-200% by weight, and more preferably 20-20% by weight.

Further, the polyvinylpyrrolidone used in the present invention is used for the purpose of reducing the tenacity of the heat-sensitive recording material.

Polymerization K tit of polyvinylpyrrolidone used: r
.

~J, joo is preferred, more preferably /jo-
This is Jroo. Further, the amount used is preferably 5 to 200% by weight based on the electron-donating dye preconcentrator, and the more preferable amount is 10 to 10 weight percent.

Examples of the colorless to light-colored electron-donating dye precursor used in the present invention include triarylmethane compounds, diphenylmethane compounds, xanthine compounds, thiazine compounds, and spiropyran compounds. A specific example is Tokukaisho! ! Examples include those described in No. 27213.

To give some examples of these, triarylmethane compounds include 3.3-bis(p-dimethylaminophenyl)-J-dimethylaminophthalide (i.e., crystal violet lactone), 3゜3-bis( p-dimethylaminophenyl) phthalide, j-(p-dimethylaminophenyl)-! -(/,J-dimethylindol-3-yl)phthalide,! -(p-dimethylaminophenyl)-3
-(Cotatilindol-3-yl)phthalide, etc. Diphenylmethane compounds include p,+'-his-dimethylaminobenzhydrin, dilyl ether, N-
Halophenyl-leucoauramine, 1'J-J, μ,
j-trichlorophenylleucoolamine etc. 9. Examples of xanthine compounds include rhodamine-B-anilinolactam and rhodamine (p-nitrino)lactam 1.
2-(dibenzylamino)fluoran, nophenylamine-6-diethylamine-fluoran, J (o-
chloroanilino)-4-diethylaminofluorane, λ
-(3,≠-dichloroanilino)-6-diethylaminofluorane, co-anidino-3-methyl-6-pi includes lysinofluoran, cop-nyl-6-diethylaminofluorane, etc., and thiazine compounds include benzoleuco There are methylene blue, p-nitrobenzylleucomethylene blue, etc., and spiropyran compounds include 3-methyl-spiro-
dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, J,J'-cyclolosevirodinaphthopyran, 3
-benzylspiro-dinaphthopyran, 3-methyl-naphtho-(3-methoxy-benzo)-spiropyran, 3-propyl-spiro-dibenzobilane and the like. These may be used alone or in combination.

Among these, triarylmethane compounds (eg, crystal violet lactone) and xanthine-based electron-donating dye precursors are preferred because they contain less capri and give high color density.

Particularly preferred are the xanthine adducts represented by the following general formula (V).

In the general formula (V), the group n in the table for R1's, -R2 is preferably an alkyl group having 1 to IO carbon atoms, and even if it is straight chain or branched, The ring may have a ring shape, and M may also be a substituent. Also,! A ring containing a negative to 7-membered heteroatom may be round-bottomed.

R3 is an aryl group, preferably an aryl group having 6 to 20 carbon atoms, and particularly preferably a phenyl group and a phenyl group carrying a substituent. As a substituent for the phenyl group, an alkyl group having /-/0 carbon atoms is preferable.

X is preferably an alkyl group having carbon atoms/-10 or a halogen atom.

Examples of these colorless to light-colored electron-donating dye precursors include, but are not limited to, the following compounds.

Ni-anilino-3-methyl-6-dimethylamine fluoran, ni-anilino-3-methyl-6-N-methyl-N
-Ethylamine fluorane, co-anilino J-methyl-j-N-methyl-N-(iso-propyl)aminofluorane, λ-anilino 3-methyl-AN-methyl-N- is antithylaminofluorane, λ- Anilino 3-
Methyl-6-N-methyl-N-cyclohexylaminofluorane, Ni-anilino-3-methyl-6-diethylaminofluorane, Ni-anilino-3-chloro≦-dimethylami/fluoran, Ni-anilino-3-methyl-A
-N-Ethyl-N-isoamylaminofluorane, -1-anilino-3-methyl-AN-methyl-N-isoamylaminofluorane, λ-anilino-3-chloro-6-
Dinitylaminofluorane, Nianilino-3-chloro-4-N-methyl-N-ethylaminofluorane, 2-
Anili/-3-chloro-4-N-methyl-N-(is
o-propyl)amine fluorane, l-anilino-3
-chloro-&-N-methyl-N-pentylaminofluorane, nianilino-3-chloro-,4-N-methyl-
N-cyclohexylaminofluorane, nianilino-
3-Methyl-6-N-ethyl-N- is nthylaminofluorane, nianilino-3-chloro-A-N-ethyl-
N-pentylaminofluorane, -2-(p-methylanilino)-3-methyl-6-panthylaminofluorane, '(p-methylanilino)-3-methyl-6-diethylaminofluorane, 2 (p-methyl Ayurinone
3-Methyl-A-N-methyl-N-dithylaminofluorane, -2-(p-methylanilino)-3-methyl-A
N-methyl-N-(iso-propyl)aminofluorane, λ-(p-methylanilino)-3-methyl-6
-N-methyl-N-panthylaminofluorane, ny(
p-methylanilino)-3-methyl-A-N-methyl-
N-cyclohexylaminofluorane, co-(p-methylanilino)-3-methyl-6-N-ethyl-N-cyclohexylaminofluorane, co-(p-methylanilino)-
3-chloro-6-panthylaminofluorane, 2(p-
methylanilino)-3-chloro-t-diethylaminofluorane, λ-(p-methylanilino)-3-chloro-
6-N-Methyl-N-ethylaminofluorane, ni(
p-methylanilino) -J-chloro-O-N-methyl-N-(iso-propyl)aminofluorane, -2-
(p-methylanilino)-3-chloro-A-N-methyl-N-cyclohexylamine fluorane, ni(p-methylanilino)-3-chloro-6-N-methyl-N-pentylaminofluorane, '(1 )-methylanilino)
-J-Chloro-6-N-ethyl-N-ethylaminofluorane, λ-anilino-3-methyl-t-N-methyl-N-7lylmethylaminofluorane, λ-anilino-3-ethyl-AN- There are methyl-N-furylmethylamine fluoranes, etc., which cannot be used alone, but can also be used in combination of λ or more to adjust color tone and prevent fading of colored images. good.

As an electron-accepting compound used in the invention, JP-A No. 1
Examples thereof include compounds exemplified in JP-A No. 1-/r7J-3 and JP-A No. 1-/R7J-3, and preferred examples include compounds of the following general formulas ('v1) to (X) containing precious stones.

Cheap! represents an integer of O to 3, R1 and R2 represent hydrogen, an alkyl group having carbon number/~r, or a cycloalkyl group in which R1 and R2 are bonded together. Also, R 2 ha, CO
OR' can also be used as an ester in the table, where R' represents an alkyl group of IO from the number of carbon atoms. Also, R is the number of carbon atoms/-f
A straight chain of '! ! c is a branched alkyl group or halogen atom. ) (In the formula, Y represents hydrogen, -CH3, -OH, the number of carbon atoms /, represents a linear or branched alkyl group of A, m, n are integers of θ to 3, Z is hydrogen, halogen, -
CH3 on the front page. ) (In the formula, R4n, a benzyl group, and a halogen atom represent a straight chain or branched alkyl group having carbon number/-r.) (In formula, R6 and R7 represent an alkyl group having carbon number/-r.

) (In the formula, R8 represents an alkylene group supporting an ether bond/-1.) Specific examples of compounds represented by the above general formulas (1 to (X)/B) include: 1. Corbis (Hiro'-Hydroxy phenyl)furopane, J,, 2-bis(μ'-hydroxyphenyl)pentane, co, corbis(Hiro'-hydroxy 7-J',
j'-') chlorophenyl) furonone, 1ll-bis(
μ′-hydroxyphenyl)cyclohexane, co, 2-
Bis(Hiro'-hydroxyphenyl)hexane, 1 liter
-bis(Hiro'-hydroxyphenyl)propane, 1.
/-bis<a/-hydroxyphenyl)butane,
/, /-his(4'/-hydroxyphenyl)hantan, 1. l-bis(≠′-hydroxyphenyl)hexane, 1. l-bis(tA/ -hydroxyphenyl)butane, /, /-bis(≠' -hydroxyphenyl)
-2-Methyl-pentane, l,l-bis(ri'-hydroxyphenyl)-λ-ethylhexane, l.

/-bis(<27-hydroxyphenyl)totican,!
, 3-bis(Hiro'-hydroxyphenyl)hantan,
/, 2-bis(μ′-hydroxyphenyl)ethane, 1
．． l-bis(Hiro'-hydroxyphenyl) sulfide, /, l-bis(Hiro'-hydroxyphenyl) sulfone, l,/-bis(μ'-hydroxyphenyl) ether, λ, z-his(≠'-hydroxy- J/,
zl -dichlorof:nyl)butane, j,! -Phenyl dihydroxybenzoate, λ, ta-dihydroxy≠'
-Me-f--Phenyl benzoate, co, ≠-dihydroquino≠'-phenyl chlorobenzoate, λ, ≠-dihydroxy-t-methylbenzoate phenyl, J, 4L, A-phenyl trihydroxybenzoate 1 .2,17L-dihydroxy-6, μ'-dimethylbenzoic acid uninylco, ≠
-Dihydroxy-6-methyl-Hiro'-phenyl chlorobenzoate, co,≠-benzyl dihydroxybenzoate, λ,
≠-dihydroxy-≠'-benzyl methylbenzoate, co-, Hiro-dihydroxy-Hiro'-benzyl chlorobenzoate,
≠-benzyl dihydroxy-6-methylbenzoate,
2.41°A-benzyl 1-hydroxybenzoate, 2.
Hiro-dihydroxy-6, Hiro'-benzyl dimethylbenzoate, Co, Hiro-dihydroxy-t-methyl-≠'-benzyl chlorobenzoate, ≠-hydroxybenzoic acid monothyl ester, Hiro-hydroxybenzoic acid propyl ester, Hiro-
Hydroxybenzoic acid isopropyl ester, ≠-hydroxybenzoic acid benzyl ester, ≠-hydroxybenzoic acid--2-ethylhexyl ester, ≠-hydroxy-μ'-chlorobenzoic acid benzyl ester, μm hydroxy-μ'-methylbenzoic acid benzyl ester, ≠-Hydroxy-j'-ethylbenzoate henzilnistil, 3-
Hydroxy-m-dimethyl phthalate, 3-hydroxy-
Diethyl m-phthalate, methylethyl 3-hydroxy-m-phthalate, dibutyl 3-hydroxy-m-phthalate, dimethyl 3-hydroxy-0-phthalate, diethyl 3-hydroxy-〇-phthalate, methyl-bis (Hiro-hydroxyphenyl)acetate, 1so-butyl-bis(
≠-Hydroxyph:nyl)acetate, etc.

In addition, as the compound of general formula (X), specifically, etc. are listed.

Preferred examples other than the electron-accepting compounds represented by the above formula (■'l~(
/ +≠-bis-p-hydroxycumylbenzene%/
I≠-bis-m-hydromodicumylbenzene, /, 3-
Bis-p-hydroxycumylbenzene, /, 3--m-
Hydroxycumylbenzene, /l≠-bis-〇-hydroxycumylbenzene, /l Hiro-bis-p-hydroxy-α-methylbenzylbenzene, l,3-bis-p-hydroxy-α-methylbenzylbenzene, etc. n.

In addition, as salicylic acid derivatives, 3. ! -di-alpha-methylbenzylosalicylic acid, 3. ! -G is monobutylsalicylic acid, 3-α,α-dimethylbenzylsalicylic acid II
- Salicylic acids such as n-pentadecylsalicylic acid, or polyvalent metal salts thereof (zinc and aluminum salts are particularly preferred), and p-phenylphenol,
3. Examples include, but are not limited to, phenols such as j-diphenylphenol and cumylphenol.

The above electron-accepting compound is the electron-donating dye (2), (3)
It is preferable to use 0-100M amount, and more preferably ioo-rooM amount.

Water-soluble bangu is added to the recording layer of the 1z thermal recording material of the present invention. As these binders (1,2j0
Against the water of C! Compounds that dissolve at least % by weight are preferred, and specific examples include polyvinyl alcohol, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, tenbun-gashi (including modified starch), gelatin, gum arabic, casein, styrene-maleic anhydride copolymer-i6. Hydrolyzate, ethylene-maleic anhydride copolymer hydrolyzate, inbutylene-maleic anhydride copolymer hydrolyzate, carboxy-modified polyvinyl alcohol, polyacrylamide, saponified copolymer of vinyl acetate and polyacrylic acid etc. are listed.

These binders can also be used as dispersants for finely dispersing electron-donating dyes, electron-accepting compounds, thermofusible substances, and compounds according to the invention.

Furthermore, if necessary, pigments, water-insoluble binders, metal soaps, waxes, surfactants, etc. may all be added to the recording layer of the heat-sensitive recording material of the present invention.

Examples of pigments used include zinc oxide, carunium carbonate, barium sulfate, titanium oxide, lithopone, talc, waxite, kaolin, aluminum hydroxide, silicate, amorphous silicate, etc. Preferred are 6'-7 calcium, kaolin, surface-treated amorphous silica, and aluminum hydroxide.

As water-insoluble binders, synthetic rubber latex or base resin emulsion is generally used, styrene-butadiene rubber latex, acrylonitrile-butadiene rubber latex-methyl acrylate-butadiene rubber latex, vinyl acetate emulsion. etc. are used. In order to prevent fogging of the heat-sensitive recording material, the amount of surfactant used in the rubber latex or emulsion is preferably as small as possible, so-called soap-free rubber latex or emulsion is preferred.

As the metal soap, higher fatty acid metal salts are used, and emulsions of zinc stearate, calcium stearate, aluminum stearate, etc. are used.

Ha, /1 as wax! Emulsions such as rough-in wax, microcrystalline wax, carnauba wax, methylols dearoamide, polyethylene wax, and polyethylene wax are used.

Examples of the surfactant include sulfosuccinic acid-based alkali metal salts and fluorine-containing surfactants.

In the heat-sensitive recording material according to the present invention, it is preferable that the heat-sensitive coloring layer contains a compound that prevents color fading in order to prevent the printed image from fading and to harden the generated image.

Phenol derivatives, especially hindered phenol compounds, are effective as anti-fading agents. Examples of preferable anti-fading agents include those represented by the following general formulas (XI) to (XIV).
Here are some compounds.

(In the formula, R1fl is a branched alkyl group having 3 to t carbon atoms, R2 is hydrogen or a branched alkyl group having 3 to r carbon atoms, R3 is hydrogen or an alkyl group having 7 to 3 carbon atoms, and R4 is hydrogen. or an alkyl group having carbon number/-7, R5, R5, R7 are hydrogen or an alkyl group having carbon number 1 to 3, R8 is hydrogen or an alkyl group having carbon number/, f. (In the formula, R1, R3 are A branched alkyl group having 3 to t carbon atoms, R2 and R4 represent an alkyl group having a carbon number/~t, tyrene group represents a cyclohexylene group, and n is O~
An integer of 3, R5 and R6 are hydrogen or an alkyl group representing the number of carbon atoms. ) (In the formula, R1% R4 is a branched alkyl group having 3 to .r carbon atoms, and R2, R3, R5, and R6 are hydrogen or an alkyl group having 1 to 1 carbon atoms.

m is an integer of O to 3, R7 and R8 are hydrogen or an alkyl group having carbon number/-f, or '
ri Represents a cyclic pentamethylene group formed by bonding R7 and R8. ) Hill 2 (In the formula, R1s R2 is a branched alkyl group having 3 to 1 carbon atoms, ZH-NH-1-0 (CH21n- (where n is /-
j represents all integers), i represents l-represents an integer. However, when i=l, W is an alkyl group with carbon number /~/r, and R4 of i=co is hydrogen if
c represents an alkyl group having carbon number/-J', and j represents an integer of or. When 1%J=3, W is →C-Rs (where R5 represents hydrogen or an alkyl group of carbon number/-r), and when i=≠, W is 10-Kinshishiwacho. ) Representative examples of the phenol derivatives represented by the above general formulas (XI) to (XIV) are shown below.

(As a phenol derivative with the general formula (M), l,/, 3-tris(comethyl-≠-hydroxy-j
-tert-butylphenyl)butane, l.

1.3-) Lis(2-ethyludahydroxyj-
tert-butylphenyl)butane, /, /.

3-tris(3,j-di-tert-butyl≠-hydroxyphenyl)butane, /, /, J-)lis(comethyl-≠-hydroxy-j-tert-butylphenyl)propane, etc. are released.

(The phenol derivatives represented by the R3 general formula (XI[) include co, λ'-methylene-bis(4-tert-butyl-Hiro-methylphenol), J, 2'-methylene-bis(
Examples include A-tert-7''f-ethylphenol).

(C) As the phenol derivative represented by the general formula (XI), ≠, ≠'-butylidene bis(A-tert-butyl-
3-methylphenol) 4(, 4('-thio-bis(3-methyl-+-tert-butylphenol)).

(D) Examples of the phenol derivative represented by the general formula (XIV)* include Bu.

The usage amount of the phenol compound represented by the general formulas (Xi to (XIV)) is preferably 7 to 200% by weight based on the electron-accepting compound, and the preferred usage amount may vary from 5 to 10% by weight. be.

The coating solution is applied to a support such as neutral paper, high-quality paper, or plastic film and dried. When preparing the coating liquid tvi, all the ash contents may be simultaneously mixed and pulverized from the beginning, or they may be combined in an appropriate combination and mixed after pulverization and dispersion separately.

(Embodiments of the invention) Examples of the invention are shown below, but the invention is not limited to these.
It's not something you can do.

Example 1 Co-anilino 3-methyl-6-N-methyl-N-cyclohexylaminofluoran iot, λ-anilino 3-chloro 6-diethylaminofluoran l09f1001 j% polyvinyl alcohol (clan PVA -10r) Dispersion with an aqueous solution was carried out overnight in a vacuum mill to give a volume average particle diameter of 3 μm or less. .

As an electron-accepting compound, λ, -2-bis(p-hydroxyphenyl)propane 20? The particles were dispersed in a ball mill overnight with a 5% polyvinyl alcohol aqueous solution of f100t to have a volume average particle size of 3 μm or less.

As a thermofusible substance, uninvented β-naphthylbenzyl ether was dispersed in a ball mill overnight with 100 ft of 5% polyvinyl alcohol water bath solution to give a volume particle size of 3 μm or less. /, /, J-Tris (
2-Methyl-guhydroxy-j-tert-butylphenyl)butane λot2iooy was dispersed in a ball mill overnight with a 5% polyvinyl alcohol aqueous solution to give a volume average particle size of 3 μm or less.

The pigment is calcium carbonate (manufactured by Shiraishi Kogyo, Univer-70)
)10? Sodium hexametaphosphate O0j bath solution/40
? It was used after being dispersed with a homogenizer. Each of the dispersions prepared as above was mixed with the electron-donating dye before the main body dispersion. , electron-accepting compound 10? , thermofusible substance dispersion! ? , anti-fading agent dispersion 2? , 22 tons of pigment dispersion were mixed, and an emulsion of 27 tons of zinc stearate was mixed with 39.10% polyvinylpyrrolidone (polymerization degree 3).
60) Aqueous solution λ,! ? was saturated to obtain a coating liquid.

The thus obtained coating liquid was applied onto a high-quality paper with a basis weight of 7rrL2 using a wire spar to give a dry coating weight of 71/m2, and dried for 2 minutes with the jOoC open to obtain a heat-sensitive recording material.

Example 2 A coating liquid was prepared in exactly the same manner as in Example 1 except that the thermofusible substance i/-phuninoquinoxy-goo-ethyl phenoxybutane was used to obtain a heat-sensitive recording material.

Example 3 In Example 1, one of the electron-donating dye precursors, 2-anilino-3-methyl-6-N-iso-amyl- A coating liquid was prepared in the same manner except that N-ethylaminofluorane was used and the heat-fusible material *w7.2-bis(≠-methoxyphenylthio)ethane was used to prepare a heat-sensitive recording material.

Comparative Examples 1 and 2 A heat-sensitive recording material was obtained by preparing a coating liquid in the same manner as in Example 1.3 except that the thermofusible substance and polyvinylpyrrolidone were removed.

Comparative Example 3 A coating liquid was prepared in the same manner as in Example 1, except that polyvinylpyrrolidone t was omitted, and a heat-sensitive recording material was prepared. Obtained.

Performance comparisons were made for the heat-sensitive recording materials prepared in Examples and Comparative Examples.

Thermal responsiveness is determined by Matsushita Electric Transmission ■High-speed facsimile IJUF-ta 2
Copy the Imaging Electronics Engineers of Japan test chart A3 and measure its density using a Macbeth RD-T♂ type densitometer.

``Wei'' Heat resistance (6
00C130%RH), moisture resistance (Hiroo'c, 70%
After storing an uncolored heat-sensitive recording material and a heat-sensitive recording material colored by the above method under RHL conditions for 2≠ hours, the fog density of the white background area, the density of the colored area, and the density of the sample that developed color after storage were measured. Gold was measured using a Macbeth RD-Tit type densitometer.

The storage stability of the density of the colored part was expressed as (density after storage/density immediately after color development) x 100 (expressed as %).

The test results are shown in Table 1, and it can be seen that the present invention is superior in terms of soil strength and thermal response.

Claims (1)

[Scope of Claims] A thermosensitive coloring layer is provided on a support, the main components of which are a colorless or light-colored electron-donating dye precursor and an electron-accepting substance that develops color by reacting with the electron-donating dye precursor. In the heat-sensitive recording material, the following general formula (I) or (II) is present in the heat-sensitive coloring layer.
1. A heat-sensitive recording material comprising at least one thermofusible substance represented by: and polyvinylpyrrolidone. Ar_1-X-R_1(I) Ar_1-X-R_2-X-Ar_2(II) In the above formula, R
_1 is an alkyl group, R_2 is an alkylene group having 2 to 10 carbon atoms, Ar_1 and Ar_2 are aryl groups, X, Y
represents oxygen, sulfur or CO_2.