JPS62116181A - 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 providing a heat-sensitive color-developing layer containing a colorless or light-colored electron-donating dye precursor and an electron-accepting compound reacting with said precursor and developing a color, and by making a prescribed quantity of a specific compound contained in the heat-sensitive color-developing layer. CONSTITUTION:A compound expressed by a general formula I is contained in a quantity over 0.5wt% and below 20wt% of an electron-accepting compound in a heat-sensitive color-developing layer. In the formula I, R1 and R2 denote rings which may contain hydrogen atoms, alkyl and aryl or in which R1 and R2 may combine with each other and contain five to 7 members of hetero atoms; X denotes alkylene, aralkylene, alkenylene or allylene; R3 and R4 denote hydrogen atoms and alkyl; R5 and R6 denote hydrogen atoms, alkyl and acyl; and (n) denotes an integer.

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 utilized. 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 them are melted by heating and brought into contact with each other, and the coloring reaction that occurs is used to obtain records. These two-component color-forming heat-sensitive recording materials are ■-
It is a secondary color development and does not require development. ■The quality is close to that of regular paper. ■Easy to handle. It has advantages such as (1) high color density and (2) easy production of 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 field of facsimile, recorders, and printers has been remarkable in recent years. There was a strong desire to improve the pulse width, that is, the color development ability to develop color with sufficient density even with low thermal energy, that is, the thermal reactivity.
? No. 393, JP-A-59-67083, JP-A-60-
! ; Various attempts have been made as disclosed in No. t48gL/- and the like. However, as the thermal response is improved, the capri concentration in the white background tends to increase, which impairs the commercial value.
Special M Showa 5g-205796, Japanese Patent Publication Showa 5'9-/6
Various attempts have been made, as disclosed in No. 7297, etc., but 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, a compound represented by the following general formula CI) is added in an amount of 0.5% by weight or more of the electron-accepting compound at 20 ir.
This was achieved using a heat-sensitive recording material characterized by containing li% or less.

(1) In the formula, R1 and R2 are hydrogen atoms, number of carbon atoms is 1-1
The alkyl group and aryl group of 8 are preferred.

For example, methyl group, ethyl group, propyl group, 1so-
Propyl group, butyl group, t-butyl group, hexyl group, octyl group, benzyl group, phenethyl group, cetyl group, stearyl group, α-methylbenzyl group.

Alkyl groups branched in the α-position, such as an α-methylchlorobenzyl group, in particular an alkyl group 9 such as a t-butyl group.

[-Amyl group, t-hexyl group, t-octyl group.

A t-dodecyl group is preferred.

Furthermore, R1 and R2 are bonded to each other to form a pyrrolidine ring.

Piperidine ring 1 Morpholine ring, Isoquinoline ring.

A 5- to 7-membered ring that may contain a hetero atom such as an isoindole ring, penzazepine ring, azepine ring, phenothiazine ring, N-methylpiperazine ring, etc. may be formed. group, alkenylene group, and arylene group, and preferably a divalent group having 8 or less carbon atoms. R3 and R4 preferably represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, with methyl and ethyl groups being particularly preferred.

R5 is preferably a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an acyl group. n is preferably an integer of 10 or less,
In particular, it is preferably 8 or less.

The compound according to the present invention is present in an amount of 0.5% by weight or more2 based on the electron-accepting compound that reacts with the electron-donating dye precursor to develop color.
It is preferable to use it in an amount of less than 0% by weight. The amount of the compound according to the invention used is 0 relative to the electron-accepting compound.
．． If it is less than 5 ffif%, the effect of preventing soil burr is not observed and the burr of the thermosensitive recording material increases, and if it is more than 20% by weight, the thermoresponsiveness may deteriorate due to long-term storage of thermosensitive recordings or storage under high temperature and humidity. In any case, the commercial value as a heat-sensitive recording material is impaired and the purpose of the present invention cannot be achieved, especially when the content of 1% by weight or more and less than 18% by weight is colorless or light-colored electron used in the present invention. Examples of the donor dye precursor 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, triaryl methane compounds include 3.3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide (i.e., crystal violet 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-)+7chlorophenylleucoolamine, 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 benzoloucomethylene blue I, p-nitrobenzylleucomethylene blue, and the like.

As a spiropyran compound, 3-methyl-spiro-
dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3.3'-cyclolose bilodinaphthopyran,
3-Benzylspiro-dinaphthopyran, 3-methyl-naphtho-(3-methoxybenzo)-spiropyran, 3-
Examples include propyl-spiro-dibenzopyran. These may be used alone or in combination.

Among these, electron-donating dye precursors such as triarylmethane compounds (eg, crystal violet lactone) and xanthene compounds are preferred because they cause less fog and provide high color density.

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

In the general formula (II), the groups represented by R1 and R2 are preferably alkyl groups having 1 to 10 carbon atoms,
Whether it's a straight chain or 8-branched.

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

R3 represents an aryl group, preferably an aryl group having 6 to 20 carbon atoms, and particularly preferably a phenyl group and a phenyl group having a substituent. 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 to light-colored electron-donating dye precursors include, but are not limited to, the following compounds.

2-anilino-3-methyl-6-pentylaminofluorane, 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-pentylaminofluorane, 2-anilino- 3-methyl-6
-N-ethyl-N-isoamylaminofluorane, 2-
Anilino-3-methyl-6-N-methyl-N-isoamylaminofluorane, 2-anilino-3-chloro-6-
ethylaminofluorane, 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
-Cyclohe xylaminofluorane, 2-anilino-
3-Methyl-6-N-ethyl-N-pentylaminofluorane, 2-anilino-3-tacolo 6-N-ethyl-
N = pentylaminofluorane, 2-(p-methylanilino)-3-methyl-6-pentylaminofluorane,
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, 2-(p-methylanilino)-3-chloro-6-pentylaminofluorane, 2-
(p-methylanilino)-3-chloro-6-dinithylaminofluorane, 2-(p-methylanilino)-3-chloro-6-N-methyl-N-dithylaminofluorane.

2-(p-methylanilino)-3-chloro-6-N-methyl-N (iso-propyl)aminofluorane,
2-(p-methylanili/)-3-chloro-6-N-methyl-N-cyclohexylaminofluorane, 2-(p-
-methylanilino)-3-chloro-6-N-methyl-N
-Pentylaminofluorane, 2-(p-methylanilino)-3-chloro-6-N-ethyl-N-pentylaminofluorane, 2-anilino-3-methyl-6-N-methyl-N-furylmethylamino There are fluorane, 2-anilino-3-ethyl-6-N-methyl-N-furylmethylaminofluorane, etc., and these can be used alone, but they are useful for improving one-color gvj and preventing fading of colored images. For this purpose, two or more types may be mixed and used.

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 the following general formulas (III) to (■).

The compounds represented are preferred.

R+ represents an integer of 0 to 3, and R1 and R2 are hydrogen.

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

R2 may also be an ester represented by -COOR' (Ro represents an alkyl group having 1 to 10 carbon atoms, and R represents a straight chain or branched alkyl group having 1 to 8 carbon atoms, or a halogen represents an atom.) (In the formula, Y is hydrogen,
-CH, -OH, Rs represents a straight chain or branched alkyl group having 1 to 6 carbon atoms, m and n are integers of θ to 3,
Z represents hydrogen, halogen, -CH. ) (In the formula, R4 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 R-7 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 (II[) to (■) are as follows.

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

1.1-bis(4′-hydroxyphenyl)cyclohexane, 2.2-bis(4′-hydroxyphenyl)
Hexane, 1. l-bis(4'-hydroxyphenyl)propane, 1,1-bis(4'-hydroxyphenyl)butane, i,i-bis(4'-hydroxyphenyl)pentane, 1,1-bis(4'-hydroxyphenyl) ) hexane, 1,1-bis(4°-hydroxyphenyl)hebutane.

1.1-bis(4°-hydroxyphenyl)-2-methyl-pentane, l, 1-bis(4°-hydroxyphenyl)-2-ethyl-hexane, l.

l-bis(4゛　-hydroxyphenyl)dodecane.

3.3-bis(4′-hydroxyphenyl)pentane,
1,2-bis(4°-hydroxyphenyl)ethane,
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'-chlorobenzoic acid Phenyl, 2,4-dihydroxy-6
-Phenyl methylbenzoate, phenyl 2.4.6-dolihydroxybenzoate, 2.4-dihydroxy-6,4°
-Phenyl 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, Benzyl 2,4-dihydroxy-6,4゜-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 84-Hydroxybenzoic acid-2-ethylhexyl ester, 4-hydroxy-41-chlorobenzoic acid benzyl ester, 4-
hydroxy-4°-methylbenzoic acid benzyl ester,
4-Hydroxy-4°-ethylbenzoic acid benzyl ester, dimethyl 3-hydroxy-m-phthalate.

Diethyl 3-hydroxy-m-phthalate, methylethyl 3-hydroxy-m-phthalate, 3-hydroxy-m-phthalate
dibutyl phthalate, dimethyl 3-hydroxy-〇-phthalate, diethyl 3-hydroxy-〇-7thalate, methyl-bis(4-hydroxyphenyl) aceter), 1so
-butyl-bis(4-hydroxyphenyl)acetate and the like.

Moreover, as a compound of general formula (■), J! Physically.

etc. can be mentioned.

Preferred examples other than the electron-accepting compounds represented by the above formulas (III) to (■) are as follows.

Specific examples of bis-hydroxycumylbenzene or euhydroxy-α-methylbenzylbenzene include 1
,4-bis-p-hydroxycumylbenzene, l,4-
Bis-m-hydroxycumylbenzene, 1,3-bis-
p-hydroxycumylbenzene, 1.3-m-hydroxycumylbenzene, 1.4-bis-m-hydroxycumylbenzene, 1.4-bis-p-hydroxy-α-methylbenzylbenzene, 1. Examples include 3-bis-p-hydroxy-α-methylbenzylbenzene, and examples of salicylic acid derivatives include 3.5-diα-methylbenzylosalicylic acid, 3.5-di-t-butylsalicylic acid, and 3-α , α-dimethylbenzylsalicylic acid 4-n-
Salicylic acids such as pentadecyl salicylic acid, or polyvalent metal salts thereof (zinc and aluminum salts are particularly preferred), and others such as p-phenylphenol, 3.5-
Examples include, but are not limited to, phenols such as diphenylphenol and cumylphenol.

The above electron-accepting compound is an electron-donating dye precursor.
It is preferable to use 0 to 800% by weight, more preferably 100 to 500f[31%, and may be used alone or in combination of two or more types.

In the heat-sensitive recording material according to the present invention, a heat-fusible substance can be contained in the heat-sensitive coloring layer in order to improve its heat responsiveness.

As an example of a preferable thermofusible substance, the following general formula (■) ~
Examples include compounds represented by (X I[I).

Rs NHCONHz (X I)R
hC0NH-Rt (XII) In the formula, R3 to R4 each represent a phenyl group, a benzyl group, and a lower alkyl or halogen substituted product thereof, and R
s and Rh each represent an alkyl group having 12 to 24 carbon atoms, and R1 represents hydrogen or a phenyl group.

In addition, when the phenyl group or benzyl group represented by R1-R4 in general formulas (■) to (Xn) is substituted with a lower alkyl group, the number of carbon atoms is 1 or more and 8 or less, preferably 1.
The above is 3 or less. When substituted with a halogen atom, fluorine is preferred. Further, in formula 2 (X), R41 represents hydrogen or a hydroxyl group.

(XIII) In the formula, R6 is 2! iiH represents a group 9 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, more preferably an alkylene group or an alkylene group having an ether bond.

Also, X, Y, Z, X', Y', and Z' may be the same or different (hydrogen atom, halogen atom, etc.).

It represents an alkyloxycarbonyl group or an aralkyloxycarbonyl group, and A represents O or S.

The compounds of the general formulas (■) to (X I[[) have a melting point of 7
The melting point is preferably 0°C or higher and 150°C or lower, and more preferably 80°C or higher and 130°C or lower. in particular.

Benzyl p-benzyloxybenzoate Cmp, 119°C
), β-naphthylbenzyl ether (mp, 105°C)
, stearic acid amide (mp, 108°C), palmitic acid amide (mp, 103°C), N-phenylniaric acid amide (mp, 96”C), N-stearylic acid urine = (m
p, 110°C).

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

β-Naphthol Cp-methylbenzyl)ether (m
p, 96°C) l α-naphthylbenzyl ether (mp
, 76°C), 1.4-butanediol-p-methylphenyl ether (mp, 93°C) 11.4-propanediol-p-methylphenyl ether (mp, 93°C)
), 1,4-butanediol-p-isopropylphenyl ether (mp, 79°C), 1,4-butanediol-p-t-octylphenyl ether (mp, 99°C)
.

2-phenoxy-1-p-)lyluoxyethane (m
p, 104°C), 1-phenoxy-2-(4-ditylphenoxy)ethane (mp, 106°C), l-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 thermofusible substances may be used alone or in combination in order to obtain sufficient thermal responsiveness.

It is preferably used in an amount of 10 to 200% by weight, more preferably 20 to 15% by weight based on the electron accepting compound.
It is 0% by weight.

A water-soluble binder is added to the recording layer of the heat-sensitive recording material of the present invention. These binders are preferably compounds that dissolve 5% by weight or more in water at 25°C, and specific examples include polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, starch i9 (including f starch), gelatin, gum arabic.

Casein, styrene-maleic anhydride copolymer hydrolyzate 1. Ethylene-maleic anhydride copolymer hydrolyzate 1
．． B. Sobutylene-maleic anhydride copolymer hydrolyzate, carboxy-modified polyvinyl alcohol, polyacrylamide, and acid compounds of vinyl acetate and polyacrylic acid copolymers.

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.

In addition, if necessary, one of the inventions! ! 5. Notes on thermal recording materials
In LN, fl additive, water-insoluble binder, metal soap,
Add wax, surfactant, etc.

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, 1 synthetic rubber latex or 9 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, it is better to use as little surfactant as possible in rubber latex or emulsion A, and so-called soap-free rubber latex or emulsion is preferred.

Higher fatty acid metal salts are used for Zenkureishinami.

Zinc stearate, calcium stearate, emulsilon of aluminum stearate, etc. are used.

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

Emulsions of methylolstearamide, 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.

As an anti-fading agent, phenol derivatives, especially hindered phenol compounds, are effective. Preferred examples of anti-discoloration compounds include compounds represented by the following general formulas (XV) to (X■).

(In the formula, R1 is a branched alkyl group having 3 to r carbon atoms.

R1 is hydrogen or a branched alkyl group having 3 to g carbon atoms, R3 is hydrogen or an alkyl group having 3 to 3 carbon atoms, R4) is hydrogen or an alkyl group having 3 to 3 carbon atoms, R5, Rs, and Rt are Hydrogen or an alkyl group having 1 to 3 carbon atoms; R8 represents hydrogen or an alkyl group having 1 to 3 carbon atoms; ) kL2 R4 (In the formula, R1 and R3 represent a branched alkyl group having 3 to 1 carbon atoms, R2 and R4 represent an alkyl group having a carbon number/-J', and Rs X is S, 0, so2.s2, (-C-)n and cyclo represent an telene group or a cyclohexylene group.

n is an integer of 0 to 3; Rs and R6 represent hydrogen or an alkyl group having 7 to 2 carbon atoms; ) In the c formula, Rt and R4 are branched alkyl groups having 3 to +r carbon atoms, and R2*R3% R5-Rs are hydrogen or an alkyl group having 1 to +r carbon atoms.

R-cho Ward m is an integer from 0 to 3.

R7, R, is hydrogen or an alkyl group having a carbon number of /~, or a cyclic group formed by bonding R and Ra is an tametherene group. ) (Length: R2 is a branched alkyl group having 3 to 1 carbon atoms, 2 is -NH-1-0(CH2)n- (where n is /~
j is an integer →, i is an integer with l-≠.
, +C-)j (where R3, R.

R4 is hydrogen or an alkyl group having carbon number/-r.

j is θ~! Divide the number of layers of r. ), when i-J.

W is >C-R5 (where Rs is hydrogen or carbon li/
-4 represents an alkyl group), when i-4, W represents 10-. ) Representative examples of the phenol derivatives represented by the above general formulas (XV') to (X■) are shown below.

(A) The phenol derivative represented by the general formula (XV) is 1,/,3-)lis(2-menal-Hydroxy-3
-teτt-)゛thyl7ynyl)butane, l.

/,3-)lis(2-ether-μmhydroxy--e-
tert-butylphenyl)butane, /, /.

3-tris(3,!-di-tert-butyl-hydroxyphenyl)butane,! , /, 3-tris(2-methyl-≠-hydroxy, 1-tert-butylphenyl)propane, etc. fL% (B) General formula (XV
The phenol derivatives represented by I) include co, λ'-methylenebis(A-tert-butyl-≠
-methylfunol), 2. ．． 2'-methylene-bis(
Examples include A-tert-bunarubutsu-eterfe/-ru).

(C) As a phenol derivative represented by the general formula (X■), q,≠'-butylidene-bis(,4-1ert-butyl-3-methylphenol)4c, lA'-thio-bis(
3-methyl-1,-tert-butylphenol).

(D) As a phenol derivative represented by the general formula (nX).

13u etc. can be mentioned.

The amount of the phenol compound represented by the general formulas (XV) to (X■) used is 7 to 200% relative to the electron-accepting compound.
It is preferable to use it for patients with heavy T. larvae, and the more preferable fecal amount is 5 to 30% by weight.

(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
One stroke using ? [The Subsidiary Society Test Chart Toru 3 was copied and its concentration was measured using a Macbeth RD-918 model 1 degree meter.

J at high temperature and humidity! ! The storage stability of the thermal recording material is heat resistance (70℃, 30:RH), humidity resistance (50℃, 90:RH),
RH) Under the conditions, an uncolored heat-sensitive recording material and a heat-repellent Et! that was colored by the above method. After storing the material for 24 hours, the density of the Capri density 1 coloring part on a white background iπ before and after storage, and the density of the sample that was colored after storage were measured using Macbeth RD-91.
It was measured using a type 8 densitometer.

Note that the density of the coloring area should be preserved.

(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 1) (Note) The symbol at the top of Table 1 is the general formula (1) in the text.
) represents the symbol inside.

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

20g each of electron-donating dye precursor, electron-accepting compound, thermoplastic substance, and anti-fading agent.

100g of 5% polyvinyl alcohol (Kuraray PVA-
105) The particles were dispersed with an aqueous solution in a ball mill overnight to make the volume average particle size 3μ or less. 80g of the pigment was dispersed with a homogenizer along with 160g of a 0.5% sodium hexametaphosphate solution, and each dispersion prepared as above was used.

Electron-donating dye precursor dispersion *5 g, electron-accepting compound dispersion 10 g, thermofusible substance dispersion 5 g, anti-fading dispersion 2 g, pigment dispersion 22 g were mixed, and further
A mother liquor was obtained by adding 3 g of a 1% zinc stearate emulsion and 5 g of a 2% aqueous solution of sodium di(2-ethylhexyl)-sulfosuccinate.

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 size of 3 μm or less was mixed in the proportions shown in Table 3 to obtain a coating liquid.

The coating liquid thus obtained was applied onto high-quality paper with a grammage weight of 50 g/m using a wire bar so that the dry coating amount was 1 g/rd, and was dried in an oven at 50°C to obtain a heat-sensitive recording material. .

(Comparative Examples 1 to 11) Thermosensitive coloring layers were obtained in the same manner as in Examples 1 to 11 except that the compound according to the present invention was not added.

(Comparative Examples 12 to 23) In Examples σ111 to 11, the compound according to the present invention was
A thermosensitive coloring layer was obtained in the same manner as in Examples 1 to 11, except that the components were added in the proportions shown in the table.

Table 5 shows the test results of Example and Comparison 11.

(Table 3) (Continuation of Table 3)

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 A heat-sensitive recording material characterized in that it contains a compound represented by the following general formula (I) in an amount of 0.5% by weight or more and less than 20% by weight of an electron-accepting compound. (I) In the formula, R1 and R2 represent a hydrogen atom, an alkyl group, an aryl group, or a ring in which R1 and R2 are bonded to each other and may contain a 5- to 7-membered heteroatom. X represents an alkylene group, an aralkylene group, an alkenylene group, or an arylene group. R3 and R4 represent a hydrogen atom or an alkyl group, and R5 and R6 represent a hydrogen atom, an alkyl group or an acyl group. Further, n represents an integer.