JPS62116182A - Heat-sensitive recording material - Google Patents

Abstract

PURPOSE:To obtain a color image of high density even with low energy and to eliminate the decrease of heat responsiveness and the increase of base fogging even at high temperature and humidity or in long-term storage, by making two kinds of prescribed compounds contained in a heat-sensitive color-developing layer which contains an electron-accepting compound reacting with a colorless or light-colored electron- donating dye precursor. CONSTITUTION:Each one kind or more of compounds expressed by formulas I-VI and compounds expressed by formulas VII-XII is contained in a heat-sensitive color- developing layer. R1 and R2 in the formula I denote hydrogen atoms, and R3 denotes a hydrogen atom radical. X in the formulas I and IV denotes an alkylene radical in which the number of carbon atoms is 1-18. R in the formulas II and VI denotes an alkyl radical in which the number of carbon atoms is 1-18. A and B in the formula III denote an alkylene radical in which the number of carbon atoms is 1-12. Mark (n) in the formulas III and V denotes an integer of 12 or less. R1-R4 in the formulas VII-XI denote low-rank alkyl or a halogen substituent in an aryl radical, R5 and R6 an alkyl radical, and R7 hydrogen. R4' in the formula IX denotes hydrogen. R8 in the formula XII denotes a bivalent radical. X, Y, Z, X', Y' and Z' denote hydrogen atoms. A denotes O or S.

Description

Detailed Description of the Invention (Field of Application of the Invention) The present invention relates to a heat-sensitive recording material, and more particularly to a heat-sensitive recording material that utilizes a color reaction between a colorless or light-colored electron-donating dye precursor and an electron-accepting compound. Concerning recording materials.

(Prior art) A color reaction between a colorless or light-colored electron-donating dye precursor and an electron-accepting compound was used. The so-called two-component heat-sensitive recording material is disclosed in Japanese Patent Publication No. 14039/1983.

It is disclosed in Japanese Patent Publication No. 43-4160.

Two-component color-forming heat-sensitive recording materials are produced by dispersing a colorless or light-colored electron-donating dye precursor and an electron-accepting compound in the form of fine particles, and then mixing these with a binder, etc. to bind these two types of heat-reactive compounds. One or both of the materials are coated on a support so as to be isolated by heat, and one or both of them are melted and grafted together, and the resulting coloring reaction is used to obtain records. The material of these two-component color-forming thermosensitive recording materials is ■-
It is a secondary color development and does not require development. 0 Paper quality is similar to regular paper; ■Easy to handle. It has the advantages of (1) high color density, (2) ease of producing heat-sensitive recording materials with various color hues, and 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 was a strong demand for improvement in heat index 2, and Japanese Patent Application Laid-open No. 6; g-/ and 7393, No. 39-670i8, and No. 60 of
-&? Various attempts have been made as disclosed in F.G. However, as the thermal response is improved, the fog density on the white background tends to increase, which impairs the commercial value. -2o-! ;'Kwodo issue, Tokukai Sho, t?
-76q2'; Although various attempts have been made as disclosed in No. 7, etc., none of them have been sufficiently effective in improving fogging in white background areas.

Although it is effective in improving fogging, 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 color image with high density even with low energy, and to be able to obtain a color image with high density even under high temperature and humidity conditions.

To obtain a heat-sensitive recording material that exhibits no decrease in thermal responsiveness and no increase in burr even when stored for a long period of time.

(Structure of the Invention) The object of the present invention is to provide a heat-sensitive recording material having a heat-sensitive coloring layer containing a colorless or light-colored electron-donating dye precursor and an electron-accepting compound that reacts with the electron-donating dye precursor to develop color. In the heat-sensitive coloring layer, at least one compound represented by the following general formulas (I) to (Vl) and the general formula (■)
This was achieved by simultaneously containing at least one of the compounds represented by (XI).

The compounds represented by (1) to (VI) according to the present invention are as follows.

However, with these disclosed methods, not only the storage stability of the printed image is insufficient, but also the thermal responsiveness of the heat-sensitive recording material decreases when the heat-sensitive recording material is stored at high temperature or under high humidity, resulting in poor quality of the product. It loses value. Therefore, as shown in the present invention, at least one or more of the compounds represented by the formulas (■) to (X■) are simultaneously added to at least one or more of the compounds represented by the formulas (1) to (VI). When included in the coloring layer,
It has been discovered that not only the above-mentioned drawbacks are improved, but also that the increase in the density of soil burr is significantly reduced compared to when one or both of them are not contained in the heat-sensitive coloring layer, leading to the filing of the present invention.

In the general formulas (I) to (VI), R1 and R2 represent a hydrogen atom or an alkyl group, preferably hydrogen or an alkyl group having 1 to 4 carbon atoms. R3 represents a hydrogen atom, an alkyl group, or an acyl group, preferably a water atom,
An acyl group having 1 to 10 carbon atoms is preferable.

In formulas (1) and (IV), X has 1 to 1 carbon atoms
8 represents an alkylene group.

In formulas (II) and (VT), R has 1 to 1 carbon atoms.
represents an alkyl group having 18 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 12 carbon atoms,
It may be partially substituted with an alkyl group or a hydroxyl group, and in this case, 3,5-di-t-butyl-4-hydroxyphenyl group is preferred.

In formula (III), A and B each have 1 to 12 carbon atoms.
represents an alkylene group, an alkynylene group having 2 to 12 carbon atoms, or an alkynylene group having 2 to 12 carbon atoms.

In formulas ([) and (V), n represents an integer of 12 or less.

In formulas (■) to (XI), R5 to R4 are each preferably a phenyl group, a benzyl group, or a lower alkyl or halogen-substituted product thereof, R,,R.

are each preferably an alkyl group having 12 to 24 carbon atoms, and R7 is preferably hydrogen or a phenyl group.

Further, when the phenyl group or benzyl group represented by R8-R4 in general formulas (■) to 01) is substituted with a lower alkyl group, the number of carbon atoms is 1 or more and 8 or less, preferably 1 or more and 3 or less. When substituted with a halogen atom, fluorine is preferred. Further, in formula 2 (IX), R4'' represents hydrogen or a hydroxyl group.

In the formula zZ゛(X U), I R1 represents a divalent group, preferably an alkylene group, an alkylene group having a carbonyl group, an alkylene group having a halogen atom, an alkylene group having an unsaturated bond, and more preferably an alkylene group. , indicates an alkylene group with an ether bond.

Further, x, y, z, x', y'', and Z' may be the same or different and represent a hydrogen atom, a halogen atom, an alkyloxycarbonyl group, or an aralkyloxycarbonyl group, and A represents 0 or S.

The compounds of the general formulas (■) to (XII) have a melting point of 70°C
The melting point is preferably 80°C or higher and 130°C or lower, and more preferably 80°C or higher and 130°C or lower. in particular.

Benzyl p-benzyloxybenzoate (mp, 119°C
), β-naphthylbenzyl ether (mp, 105°C)
, stearic acid amide (mp, 108°C), palmimic acid amide (mp, 103°C), N-phenylniaric acid amide (rnp, 96'C), N-stearylurea (mp, 110°C).

β-naphthoic acid phenyl ester (mp, 92°C), 1
-Hydroxy-2-naphthoic acid phenyl ester (mp
, 92°C), β-naphthol<p-chlorobenzyl)ether (mp, 115°C).

β-naphthol (p-methylbenzyl) ether (mp
, 96°C), α-naphthylbenzyl ether (mp, 7
6°C), 1,4-butanediol-p-methylphenyl ether (mp, 93°C).

1.4-propanediol-p-methylphenyl ether (mp, 93°C), 1.4-butanediol-p-isopropylphenyl ether (mp, 79°C), 1.4
-butadanediol-pt-octylphenyl ether (mp, 99°C).

2-phenoxy-1-p-tolyl-oxy-ethane (m
p, 104°C), l-phenoxy-2-(4-ethylphenoxy)ethane (mp, 106°C), 1-phenoxy-2-(4-chlorophenoxy)ethane (mp, 77°C)
), 1,4-butanediol phenyl ether (mp,
98℃) diethylene glycol-bis(4-methoxy-
Phenyl) ether (mp, 101°C) 1 and the like.

The compounds represented by the general formulas (I) to (VI) according to the present invention are used in an amount of 0.5% by weight to less than 40% by weight based on the electron-accepting compound that reacts with the electron-donating dye precursor to develop color. It is preferable to use the additive amount.

The amount of the compound represented by the general formulas (I) to (V[) according to the present invention is 0.5f[ff] with respect to the electron-accepting compound.
If it is less than i%, the effect of preventing soil burr is not observed and causes an increase in soil burr in the heat-sensitive recording material.

401 again! If the amount is more than 1%, the thermal responsiveness will be greatly reduced if the thermosensitive recording material is stored for a long time or stored under high temperature and humidity, and both of these will impair the commercial value as a thermosensitive recording material and will not defeat the purpose of the present invention.

The compounds of formulas (■) to (X■) may be used in combination.9 In order to obtain the effects of the present invention, it is preferable to use 10 to 200% by weight of the electron-accepting compound. A more preferable usage amount is 20-150j! I amount%.

77' 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. Specific examples include those described in JP-A No. 55-27253 and the like.

To illustrate some of these, triarylmethane compounds include 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide (i.e., crystal bioleft lactone), 3,3-bis (p-dimethylaminophenyl)phthalide, 3-(p-dimethylaminophenyl)-3-(1,3-dimethylindol-3-yl)phthalide+3-(p-dimethylaminophenyl)-
Examples include 3-(2-methylindol-3-yl)phthalide.

As a diphenylmethane compound, 4,4°-bis-
Dimethylaminobenzhydrin benzyl ether, N-
Halophenyl-leucoauramine.

N-2,4,5-)lichlorophenylleucoolamine, etc.

As xanthine compounds, rhodamine-B-anilinolactam, rhodamine (p-nitrino)lactam, 2
-(dibenzylamino)fluoran, 2-phenylamino-6-dinithylaminofluoran, 2-(o-chloroanilino)-6-dinithylaminofluoran, 2-
Examples include (3,4-dichloroanilino)-6-dinithylaminofluorane, 2-anilino-3-methyl-6-piperidinofluorane, and 2-phenyl-6-dinithylaminofluorane.

Examples of thiazine compounds include benzoleicomethylene blue and p-nitrobenzylleucomethylene blue.

As a spiropyran compound, 3-methyl-spiro-
dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3.3°-cyclolose bilodinaphthopyran, 3
-benzylspiro-dinaphthopyran, 3-methyl-naphtho-(3-methoxy-benzo)-spiropyran, 3-propyl-spiro-dibenzopyran and the like. These may be used alone or in combination.

Among them, electron-donating dye precursors of triarylmethane compounds (eg, crystal bioleft lactone) and xanthine compounds have a small amount of capri, and many give high color density (preferably).

More preferred are xanthine compounds represented by the following general formula (XIII).

In the general formula (Xllll), the groups represented by R1 and R2 are preferably alkyl groups having 1 to 10 carbon atoms, and may be linear or monobranched.

It may form a ring, may further have a substituent, or may form a ring containing a 5- to 7-membered heteroatom.

R3 represents an aryl group, preferably an aryl group having 6 to 20 carbon atoms, particularly preferably a phenyl group and a phenyl group having a substituent, and as a substituent for the phenyl group, an alkyl group having 1 to 10 carbon atoms is preferable. .

X is an alkyl group having 1 to 10 carbon atoms.

A halogen atom is preferred.

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

2-7nilino-3-methyl-6-dimethylaminofluorane, 2-anilino-3-methyl-6-N-methyl-N
-ditylaminofluorane, 2-anilino-3-methyl-6-N-methyl-N-(iso-propyl)aminofluorane, 2-anilino-3-methyl-6-N-methyl-N-pentylamino Fluoran, 2-anilino-3-
Methyl-6-N-methyl-N-cyclohexylaminofluorane, 2-anilino-3-methyl-6-dinithylaminofluorane, 2-anilino-3-chloro-6-dimethylaminofluorane, 2-anilino -3-methyl-6
-N-ethyl-N-isoamylaminofluorane, 2-
Anilino-3-methyl-6-N-methyl-N-isoamylaminofluorane, 2-anilino-3-chloro-6-
Dinitylaminofluorane, 2-anilino-3-chloro-6-N-methyl-N-ethylaminofluorane.

2-anilino-3-chloro-6-N-methyl-N-(i
so-propyl)aminofluorane, 2-anilino-3
-chloro-6-N-methyl-N-pentylaminofluorane, 2-anilino-3-chloro-6-N-methyl-N
-cyclohexylaminofluorane, 2-anilino-3
-Methyl-6-N-ethyl-N-pentylaminofluorane, 2-anilino-3-chloro-6N-ethyl-N-
Pentylaminofluorane, 2-(p-methylanilino)-3-methyl-6-dimethylaminofluorane, 2-
(p-methylanilino)-3-methyl-6-dinithylaminofluorane, 2-(p-methylanilino)
-3-Methyl-6-N-methyl-N-ethylaminofluorane, 2-(p-methylanilino)-3-methyl-6
-N-methyl-N-(iso-propyl)aminofluorane, 2-(p-methylanilino)-3-methyl-6-
N-methyl-N-pentylaminofluorane, 2-(p
-methylanilino)-3-methyl-6-N-methyl-N
-Cyclohexylaminofluorane, 2-(p-methylanilino)-3-methyl-6-N-ethyl-N-pentylaminofluorane 22-(p-methylanilino)-
3-chloro-6-dimethylaminofluorane, 2-(p
-methylanilino)-3-chloro-6-dinithylaminofluorane, 2-(p-methylanilino)-3-chloro-6-N-methyl-N-ethylaminofluorane.

2-(p-methylanilino)-3-chloro-6-N-methyl-N-(iso-propyl)aminofluorane, 2
-(p-methylanilino)-3-chloro-6-N-methyl-N-cyclohexylaminofluorane, 2-(p-
methylanilino)-3=chloro-6-N-methyl-N-
Pentylaminofluorane, 2-(p-methylanilino)-3-chloro6-N-ethyl-N-pentylaminofluorane, 2-anilino-3-methyl-6-N-methyl-N-furylmethylaminofluorane , 2-anilino-3-ethyl-6-N-methyl-N-furylmethylaminofluorane, etc., and these can be used alone, but in order to adjust the color tone and prevent fading of the colored image, You may use a mixture of more than one species.

Examples of electron-accepting compounds used in the present invention include:

JP-A-58-187393, JP-A-59-67083
Examples include compounds exemplified by No.

Preferred examples include compounds represented by the following general formulas (XI'/) to (X■).

represents an integer of O to 3, and R1 and R2 are hydrogen.

Or an alkyl group having 1 to 8 carbon atoms, or a cycloalkyl group formed by bonding R1 and R2.

Further, R2 may be an ester represented by -COOR', and Ro represents an alkyl group having 1 to 10 carbon atoms.
Further, R represents a straight chain or branched alkyl group having 1 to 8 carbon atoms or a halogen atom. )CH Y (wherein, Y represents hydrogen, -CH,, -OH +R3 represents a straight chain or branched alkyl group having 1 to 6 carbon atoms, m,
n is an integer from O to 3, Z is hydrogen, halogen, CHs
(In the formula, R1 represents a benzyl group, a halogen atom, or a linear or branched alkyl group having 1 to 8 carbon atoms.) (In the formula, R6 and R7 represent an alkyl group having 1 to 8 carbon atoms. ,
(In the formula, R8 represents an alkylene group having 1 to 5 ether bonds.) Specific examples of the compounds represented by the above general formulas (Xr/) to (X■) are as follows.

2.2-bis(4′-hydroxyphenyl)propane,
2.2-bis(4′-hydroxyphenyl)pentane, 2.2-bis(4′-hydroxy-3″, 5°-
dichlorophenyl)propane.

1.1-bis(4′-hydroxyphenyl)cyclohexane, 2,2-bis(4′-hydroxyphenyl)hexane, l,1-bis(4′-hydroxyphenyl)
Propane, 1,1-bis(4'-hydroxyphenyl)butane, 1,1-bis(4'-hydroxyphenyl)pentane, 1,1-bis(4'-hydroxyphenyl)hexane, 1,1-bis(4'-hydroxyphenyl) °-Hydroxyphenyl)hebutane.

1.1-bis(4゛-hydroxyphenyl)-2-methyl-pentane, 1.1-bis(4゛-hydroxyphenyl)-2-dithylhexane, 1゜1-bis(4゛-
Hydroxyphenyl) dodecane.

3.3-bis(4′-hydroxyphenyl)pentane,
1.2-bis(4“-hydroxyphenyl)ethane 5
1.1-bis(4°-hydroxyphenyl) sulfide, 1.1-bis(4°-hydroxyphenyl) sulfone, 1.1-bis(4′-hydroxyphenyl)ether, 2.2-bis(4′- -Hydroxy-3°,5'-dichlorophenyl)butane, phenyl 2,4-dihydroxybenzoate, phenyl 2,4-dihydroxy-4'-methyl-benzoate, 2,4-dihydroxy-4"
-Phenyl chlorobenzoate, 2,4-dihydroxy-6
-Phenyl methylbenzoate, phenyl 2,4.6-dolihydroxybenzoate, phenyl 2,4-dihydroxy-6,4'-dimethylbenzoate.

Phenyl 2,4-dihydroxy-6-methyl-4°-chlorobenzoate, benzyl 2,4-dihydroxybenzoate, benzyl 2,4-dihydroxy-4°-methylbenzoate, 2,4-dihydroxy-4°- Benzyl chlorobenzoate, benzyl 2,4-dihydroxy-6-methylbenzoate, benzyl 2,4゜6-dolihydroxybenzoate, 2,4-dihydroxy-6,4゜-benzyl dimethylbenzoate, 2,4- dihydroxy-6-methyl-4
゛-Benzyl chlorobenzoate, 4-hydroxybenzoic acid ethyl ester, 4-hydroxybenzoic acid propyl ester, 4-hydroxybenzoic acid isopropyl ester,
4-Hydroxybenzoic acid benzyl ester, 4-hydroxybenzoic acid-2-ethylhexyl ester, 4-hydroxy-4'-chlorobenzoic acid benzyl ester, 4
-Hydroxy-4'-methylbenzoic acid benzyl ester, 4-hydroxy-41-ethylbenzoic acid, alpha benzyl ester, dimethyl 3-hydroxy-m-phthalate.

Diethyl 3-hydroxy-m-phthalate, methylethyl 3-hydroxy-m-phthalate, 3-hydroxy-m-phthalate
Diptyl phthalate, dimethyl 3-hydroxy-0-phthalate, diethyl 3-hydroxy-〇-phthalate, methyl-bis(4-hydroxyphenyl) acetate, 1so
-butyl-bis(4-hydroxyphenyl)acetate and the like.

Further, specific examples of the compound of general formula (X■) include:

etc. can be mentioned.

Preferred examples other than the electron-accepting compounds represented by the above formulas (XfV) to (X■) include:

Specific examples of bis-hydroxycumylbenzene or bis-hydroxy-α-methylbenzylbenzene include 1
．． 4-bis-p-hydroxycumylbenzene, 1.4-
Bis-m-hydroxycumylbenzene, 1,3-bis-
p-hydroxycumylbenzene, 1.3-m-hydroxycumylbenzene, 1,4-bis-low hydroxycumylbenzene, 1.4-bis-p-hydroxy-α-methylbenzylbenzene, l, 3- Examples include bis-p-hydroxy-α-methylbenzylbenzene, and salicylic acid derivatives include 3,5-di-α-methylbenzyl-salicylic acid, 3,5-di-t-butylsalicylic acid, 3-α, α-dimethylbenzylsalicylic acid 4-n
- Salicylic acids such as pentadecyl salicylic acid, or polyvalent total salts thereof (zinc and aluminum salts are particularly preferred)
etc., and other p-phenylphenol, 3.5
- Phenols such as diphenylphenol and cumylphenol can be mentioned, but are not limited to these.

The electron-accepting compound described above is the 5 of the electron-donating dye precursor.
It is preferable to use 0 to 800% by weight, and more preferably 100 to 500% by weight. A water-soluble binder is added to the recording layer of the heat-sensitive recording material. These binders are preferably compounds that dissolve 5% by weight or more in water at 25°C, and specific examples include polyvinyl alcohol, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, starches (including modified starches), gelatin, and Arabica. rubber.

Casein, styrene-maleic anhydride copolymer hydrolyzate 1. Ethylene-maleic anhydride copolymer hydrolyzate 1
．． inbutylene-anhydrous maleic shark copolymer hydrolyzate,
Examples include carboxy-modified polyvinyl alcohol, polyacrylamide, and saponified copolymers of vinyl acetate and polyacrylic acid.

These binders are electron-donating dye precursors.

It may also be used as a dispersant for the fine dispersion of electron-accepting compounds, thermofusible substances and compounds according to the invention.

Furthermore, if necessary, B group, water-insoluble binder, metal soap, wax, surfactant, etc. are added to the recording layer of the heat-sensitive recording material of the present invention.

Pigments include zinc oxide, calcium carbonate, barium sulfate, titanium oxide, lithopone, talc, waxite, kaolin, aluminum hydroxide, and silica.

Amorphous silica and the like are used, but light calcium carbonate, kaolin, surface-treated amorphous silica, and aluminum hydroxide are preferable.

As the water-insoluble binder, 2-synthetic rubber latex or 2-synthetic resin emulsion is generally used, and 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 heat-sensitive recording materials, the amount of surfactant used in the rubber latex or emulsion should be as small as possible, and so-called soap-free rubber latex or emulsion are preferred.

Higher fatty acid metal salts are used as gold and ha soaps.

Emulsicone of zinc stearate, calcium stearate, aluminum stearate, etc. are used.

Waxes include paraffin wax, microcrystalline wax, and carnauba wax.

Emulsicons such as methylol stearamide, polyethylene wax, polystyrene wax, etc. are used.

As the surfactant, sulfosuccinic acid-based alkali metal salts, fluorine-containing surfactants, etc. are used.

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 compounds represented by the following general formulas (XIX) to (XXn).

(In the formula, R1 is a branched alkyl group having 3 to 1 carbon atoms, R2 is hydrogen or a branched alkyl group having 3 to 3 carbon atoms, R1 is hydrogen or an alkyl group having 1 to 3 carbon atoms, R4): Hydrogen or) i carbon number/-r alkyluminum.

R5, Rs, R, represents hydrogen or an alkyl group having 1 to 3 carbon atoms, and R8 represents hydrogen or an alkyl group having a carbon number of /-r. , R2, R4 represent an alkyl group with carbon number/~r, represents an ethylene group or cyclohexylene group, n is a mourning number of O~3, R5%R6 represents hydrogen or an alkyl group with carbon number/~trJ5 (In the formula, Ri and R4 are branched alkyl groups having a radical number of 3 to g, and R2, R3, Rs, and Ra are hydrogen or an alkyl group having a carbon number of 1 to g@.

C R.

m is an integer of θ to 3, R7 and R8 are hydrogen or an alkyl group having 7 to 1r carbon atoms, or the ring formed by bonding R7 and R8 represents an tametelene group. ) (In the formula, R1 and R2 are branched alkyl groups having 3 or more carbon atoms, Z is -NH-1-0(CH2)!1- (where n is /
~ j ), i takes /~μ time T0 However, when i-7, W represents an alkyl group with carbon number/~it, and when i-2, W represents S, O
, +C-)j'e (where R3 and R4 are hydrogen or alkyl i having 1-♂ carbon atoms.

j is an integer from 0 to jr. ), i-3, W is:>C-R5 (where R5 is hydrogen or the number of carbon atoms/-r
), i-≠, 1 and W represents -C-'Y. ) Representative examples of the phenol derivatives represented by the above general f:, 0qX) to (XXI+) are shown below.

(A) As the phenol derivative represented by the general formula (XIX), 1.1.3-tris(2-nonal-μm hydroxy-5
-tert-butylphninyl)butane, l.

/,3-)1,1s(niethyl-μmhydroxy-5
-tert-buterphninyl)butane, /, /.

j-1-11su (3,!-G-tert-Butyl-Hiroshi-
hydroxyfninyl)butane, /, /, 3-tris(2
Examples include -methyl-hiro-hydroxy-j-tert-)'tylfuninyl)propane.

(B) As the phenol derivative represented by the general formula (XX), 2,2'-methylene-bis(A-tert-butyl-≠
-methylphenol), X, λ'-methylenebis(A
-tert-butyl-Hiro-ether phenol) and the like.

(C)-, as the phenol derivative represented by the general formula (XXI), u, IA'-butylidene-bis(A-tert-butyl-3-methylphenol)g, tA'-thio-bis(3-methyl -1r-tert-butylphenol).

(D)-8 Examples of the phenol derivative represented by formula (XXI) include 1 and qi.

The amount of the phenol compound represented by the general formulas (XIX) to (XX・W) used is /-2 with respect to the electron-accepting compound.
It is preferable to use 00 heavy fchi, and who is the more preferable user? ~! O heavy i-chi.

(Embodiments of the Invention) Examples are shown above, but the present invention is not limited thereto. In the examples, unless otherwise specified, it represents 1% by weight.

Thermal response is Fujitsu's high-speed facsimile FF-2000
1 page a of the Institute of Electronics Engineers Test Chart No. 3 was copied, and its concentration was measured using a Macbeth Co., Ltd. RD-918 model densitometer.

The storage stability of heat-sensitive recording materials at high temperature and humidity is determined by heat resistance (7
0℃, 30XRH), moisture resistance (50℃, 90XRH)
) After storing the uncolored heat-sensitive recording material and the heat-sensitive recording material colored by the above method under the above conditions for 24 hours, the fog density of the white background area 2 the density of the colored area before and after storage, and the density of the sample that developed color after storage were measured using a Macbeth RD-918 type densitometer.

1. What is the storage stability of the density of the colored part?

(Concentration after storage 10 concentration immediately after color development) x 100 (% display)
It was shown in

Table 1 shows one compound according to the present invention used in Examples and Comparative Examples.

Table 2 shows the materials used for the heat-sensitive coloring layer according to the present invention.

20 g each of the electron-donating dye precursor, electron-accepting compound, and anti-fading agent were dispersed in a ball mill overnight with 100 g of 5% polyvinyl alcohol (Kuraray PVA-105) aqueous solution to give a volume average particle size of 3 μ or less. .

Pigment: 80g of sodium hexametaphosphate 0.5% solution 1
Each dispersion prepared as above was used by dispersing with 60g using a homogenizer.

Electron-donating dye precursor dispersion 5g, electron-accepting compound dispersion 10g, anti-color dispersion 2g, pigment dispersion 22g
Mix in the following proportions, and then add 3 g of 21% stearin mini-lead emulsion and 2% di(2-ethylhexyl).
- 5 g of sodium sulfosuccinate aqueous solution was added to obtain a mother liquor.

To this mother liquor was added 20 g of the compound according to the invention shown in Table 1.
, 100g of 5% polyvinyl alcohol (Kuraray PV
A-105) A dispersion liquid that was dispersed with an aqueous solution in a ball mill overnight to have a volume average particle diameter of 3 μm or less was mixed in the proportions shown in Table 183 to obtain a coating liquid.

The coating solution thus obtained was coated on a high-quality paper of 5 tsubo (R) 50 g/m with a wire bar to a dry coating weight of 7 g/m, and dried in an oven at 50° C. to obtain a heat-sensitive recording material.

(Comparative Examples 1 to 10) A thermosensitive coloring layer was obtained in the same manner as in the example except that the components were added in the proportions shown in Table 4.

Table 5 shows the test results of Examples and Comparative Examples.

(Table 1) (Continued from Table 1) (Continued from Table 1) (Continued from Table 1) (Table 3) (Table 4)

Claims (1)

[Scope of Claims] A thermosensitive recording material having a thermosensitive coloring layer containing a colorless or light-colored electron-donating dye precursor and an electron-accepting compound that reacts with the electron-donating dye precursor to form a color, the thermosensitive coloring layer It is characterized by simultaneously containing at least one or more of the compounds represented by the following general formulas (I) to (VI) and at least one or more of the compounds represented by the general formulas (VII) to (XII). A heat-sensitive recording material. ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (I) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (III) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ( IV) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(V) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(VI) (In the general formula, R1 and R2 represent a hydrogen atom or an alkyl group, and R3 represents a hydrogen atom or Represents an alkyl group or an acyl group.In formulas (I) and (IV), X has 1 carbon atom.
~18 represents an alkylene group. In formulas (II) and (VI), R has 1 to 18 carbon atoms
represents an alkyl group, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 12 carbon atoms. It may be partially substituted with an alkyl group or a hydroxyl group. In formula (III), A and B represent an alkylene group having 1 to 12 carbon atoms, an alkenylene group having 2 to 12 carbon atoms, or an alkynylene group having 2 to 12 carbon atoms. In formulas (III) and (V), n represents an integer of 12 or less. ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(VII) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(VIII) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(IX) R_5NHCONH_2(X) R_4CONH-R_7(X I ) In general formulas (VII) to (X I), R_1 to R_4 each represent an aryl group and a lower alkyl or halogen substituted product of the aryl group, R_5 and R_6 each represent an alkyl group, and R_7 represents hydrogen or an aryl group. show. Further, in formula (IX), R_4' represents hydrogen or a hydroxyl group. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (XII) In the formula (XII), R_3 represents a divalent group. In addition, X, Y, Z, X', Y', and Z' may be the same or different and represent a hydrogen atom, a halogen atom, an alkyloxycarbonyl group, an aralkyloxycarbonyl group,
A represents O or S.