WO2003031195A1

WO2003031195A1 - Thermal recording material

Info

Publication number: WO2003031195A1
Application number: PCT/JP2001/008592
Authority: WO
Inventors: Shoji Hizatate
Original assignee: Mitsubishi Paper Mills Limited
Priority date: 2001-09-28
Filing date: 2001-09-28
Publication date: 2003-04-17
Also published as: DE10197272T5; DE10197272B4

Abstract

A thermal recoding material which is excellent in heat response and storage stability of image areas and reduced in the deposition of dregs on a thermal head of a thermal printer. Specifically, a thermal recording material having a thermal recording layer containing both an electron-donating dye precursor which is colorless or colored palely under ordinary conditions and an electron-accepting developer which reacts with the dye precursor on heating to develop a color, characterized in that the thermal recording layer contains a specific diphenyl sulfone derivative, a specific amide derivative and a specific fluoran derivative with weight ratio of the diphenyl sulfone derivative to the amide derivative ranging from 2/1 to 1/2.

Description

Description Thermal recording material

Technical field

The present invention relates to a heat-sensitive recording material, which is particularly excellent in thermal responsiveness and image storability, and has a small amount of scum adhered to a thermal head of a heat-sensitive printer. As a result, printing trouble occurs even in long-distance printing. No heat-sensitive recording material. Background art

The heat-sensitive recording material is generally composed of a heat-sensitive material mainly composed of an electron-donating, usually colorless or pale-colored dye precursor on a support, and an electron-accepting developer, which reacts when heated to form a dye precursor. A recording layer is provided, and when heated with a thermal head, hot pen, laser light, etc., the dye precursor and the electron-accepting color developer react instantaneously to obtain a recorded image. Such thermosensitive recording materials can be recorded with relatively simple equipment, and have the advantages of easy maintenance, no noise, and other advantages.Measurement recorders, facsimile machines, printers, computer terminals It is used in a wide range of fields, such as vending machines for labels, labels, and ticketes.

Particularly in recent years, heat-sensitive recording materials have been used in financial-related recording paper, such as receipts for gas, water, and electricity bills, financial institution ATM usage statements, and various receipts.

In this way, the use and demand for thermal recording materials are not expected to expand in a wide variety of ways. In addition to the basic characteristics of high thermal response and color density, it is required that the amount of scum adhered to the thermal head is small. It is becoming.

That is, it is unacceptable that the thermal recording material used for the above-mentioned financial-related recording paper becomes unclear due to the adhesion of scum to the thermal head even when long-distance printing is continued. The above-mentioned portable printer using the meter reading paper is even more difficult because it is difficult to carry out maintenance work such as cleaning of the thermal head on the road.

Since it is difficult to improve the above characteristics only with the heat-sensitive recording layer, a protective layer that improves adhesion of scum to the thermal head and other characteristics is then replaced with a heat-sensitive recording layer. A method of forming the film on the substrate has been proposed in Japanese Patent Application Laid-Open Nos. 61-24989 and 62-515189.

However, even if this method is used, a thermal recording material with little adhesion of scum to the thermal head has not yet been obtained, and only the thermal recording layer is used to reduce energy and cost. There is still a need to improve the above characteristics.

In order to improve the heat responsiveness, a sensitizer is added as needed.增 Sensitives have the function of dissolving or encapsulating nearby dye precursors and electron-accepting developers when they are melted by the transferred thermal energy, thereby accelerating the color-forming reaction. Also, increasing the compatibility with an electron-accepting color developer is one means for increasing the sensitivity of a heat-sensitive recording material.

As this method, waxes are disclosed in JP-A-48-192331, naphthol derivatives are disclosed in JP-A-57-64593, and JP-A-60-56 is disclosed. No. 588 discloses an example in which diphenoxetanes are added. However, the addition of these sensitizers is accompanied by an increase in the amount of heat-fusible substances, and it is extremely difficult to reduce the amount of scum adhered to the thermal head.

Disclosure of the invention

An object of the present invention is to provide a heat-sensitive recording material which has basic characteristics such as high thermal response and color density, excellent image storability, and the amount of scum adhered to a thermal head of a thermal printer. To provide a heat-sensitive recording material having a small amount of heat.

As a result of intensive studies, the present inventors have invented a heat-sensitive recording material of the present invention which can solve the above-mentioned problems.

That is, the present invention provides a heat-sensitive recording layer having a heat-sensitive recording layer containing an electron-donating, usually colorless or pale-colored dye precursor, and an electron-accepting color developer that develops the dye precursor in response to heating. In the recording material, the heat-sensitive recording layer

General formula (1)

(1)

(In the formula, R ¹ and R ² may be the same or different, and each represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an aralkyl group, an aryl group or an arylslephonyl group;

m represents an integer of 1 to 3,

n represents an integer from 0 to 2)

A difluorosulfone derivative represented by

General formula (2)

A-I CO—— N

(2)

FT

(In the formula, A represents an alkyl group, an alkenyl group or an alkylamino group, and R ³ and R ⁴ may be the same or different, and each represents a hydrogen atom, an alkyl group, an alkenyl group, an aralkyl group, or an aryl group. Represents a group)

An amide derivative represented by

General formula (3)

(Wherein, R ⁵ and R ⁶ may be the same or different, and represent an alkyl group having 1 to 5 carbon atoms, a cyclohexyl group or an aryl group,

R ⁷ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a halogen atom,

R ⁸ represents a hydrogen atom, a methyl group or a halogen atom)

And a fluoran derivative represented by

And the weight ratio of the diphenyl sulfone derivative represented by the general formula (1) to the amide derivative represented by the general formula (2) (compound (1) compound (2)) is 21 to 1/2. The gist of the present invention is a heat-sensitive recording material characterized in that: In the heat-sensitive recording material of the present invention, the heat-sensitive recording layer is composed of ethylene daricol dimethacrylyl ether, 2-benzyloxynaphthalene, bis (4-methylbenzinole) oxalate, 1,2-bis (phenoxymethyl) benzene, p It can contain at least one other sensitizer selected from —acetotoluidine and 4— (4-methylphenoxy) biphenyl.

Further, in the heat-sensitive recording material of the present invention, the amide derivative represented by the general formula (2) in the heat-sensitive recording layer, ethylene glycol dimethatryl ether, 2-benzyloxynaphthalene, bis-oxalate (4 Weight ratio of other sensitizers selected from 1,2-bis (phenoxymethyl) benzene, p-acetotoluidine and 4- (4-methinolephenoxy) biphenyl (compound (2) and other sensitizers) Agent) is preferably in the range of 1/2 to 5: 1.

Further, in the heat-sensitive recording material of the present invention, the heat-sensitive recording layer comprises:

General formula (4)

,Ten

OR '

, 11

R ⁹ 0- -P- -0R ((4)

O

(Wherein, R ⁹ , R ^1G and R ¹¹ may be the same or different and each represents a hydrogen atom, an alkyl group, an alkyl group, an aryl group, an aralkyl group, an alkali metal, an alkaline earth metal, or a transition. Stands for metal or amine,

Any two groups selected from R ⁹ , R ^1G and R ¹¹ may be linked to each other to form a ring)

Can be contained.

General formula (5)

{Where R ¹² is General formula (6)

(In the formula, R ¹⁵ represents a cyclohexyl group, a fuel group or a tert-butyl group, and R ¹⁶ represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cyclohexyl group, a phenyl group or a tert-butynole group. Represent)

Represents a group represented by

R ¹³ represents a covalent bond or an alkylene group having 1 to 3 carbon atoms,

R ¹⁴ may contain a compound represented by a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or a group represented by R ¹² }.

General formula (7)

{Wherein, R ¹⁷ is a covalent bond, a C 8 anoalkylene group or

General formula (8)

20

CH COOR

(8)

20

CH C00R

(Wherein, R ²⁰ represents a 2,2,6,6-tetramethyl-14-piperidyl group or a 1,2,2,6,6-pentamethyl_4-piperidyl group)

Represents a group represented by

R ¹⁸ and R ¹⁹ may be the same or different and represent a 2,2,6,6-tetramethyl-4-piperidyl group or a 1,2,2,6,6-pentamethyl-4-piperidyl group. Can be contained.

In the thermal recording material of the present invention, the diphenylsulfone derivative represented by the general formula (1) is preferably 4,4′-dihydroxydiphenylsulfone. BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be described more specifically.

In the heat-sensitive recording material of the present invention, an electron-accepting head coloring agent which forms a part of the heat-sensitive recording layer and forms a dye precursor includes:

—General formula (1)

(1)

The diphenyl sulfone derivative represented by the following formula is used.

—In the general formula (1), R ¹ and R ² may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group, an arkeel group, an aralkyl group, an aryl group or an arylsulfonyl group. Here, examples of the halogen atom include chlorine, bromine, iodine, and fluorine. Examples of the alkyl group include a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, a linear or branched pentyl. And the like. Examples of the alkenyl group include a butyl group and an aryl group, and examples of the aralkyl group include a benzyl group and a phenethyl group. Examples of the aryl group include a phenyl group, a naphthyl group, and a 4-methylphenyl group. Examples of the arylsulfonyl group include a phenylsulfol group, a 4-methylphenylsulfonyl group, and a 2-methylphenylsolenoyl group. And so on.

Specific examples of the compound represented by the general formula (1), ^4, 4, one dihydric Doroki Siji Hue Nino less Honoré Hong, 2, 4 '- hydroxycarboxylic di Hue Nino less Honoré Hong, 4-arsenide mud Kishijifue Ninores norehon, 4-hydroxy-1 '4'-methinoresifeninoresnorehon, bis (3-arinoleic 4-hydroxypheninole) s / lehon, bis (3,5-jib mouth mo 4-hydroxyphenyl) Sulfone, bis (3,5-dichroic port _ 4-hydroxoxypheninole), ^ / hon, 3,4—hydroxydiffeninole sulfone, 3,4-di Human Dorokishi 4 'over-methyl diphenyl sulfone, 3, 4, 4, one tri ratio Dorokishi di Hue Nino less Honoré Hong, 3, 4, 3 4 ⁵ Tetorahi mud carboxymethyl di Hue Nino less Honoré Hong, 2, 3, 4 one tri ratio Dorokishijifu Examples thereof include enylsulfone and 4-hydroxy-13-phenylsulfo-diphenylphenylsulfone, but the compound represented by the general formula (1) is not limited thereto. These diphenylsulfone derivatives can be used alone or as a mixture of two or more, if necessary. According to the present invention, the amide derivative represented by the general formula (2) and the fluorane derivative represented by the general formula (3) are added to the thermosensitive recording layer together with the diphenylsulfone derivative represented by the general formula (1). And the weight ratio of the diphenyl sulfone derivative represented by the general formula (1) to the amide derivative represented by the general formula (2) (compound (1) / compound (2)) is 2Z By setting l to l2, higher thermal responsiveness is exhibited, and the amount of scum adhered to the thermal head of the thermal printer is small, and as a result, there is no printing failure even in long-distance printing. It can be used as recording material.

In the heat-sensitive recording material of the present invention, the amide derivative contained in the heat-sensitive recording layer plays a role as a sensitizer, and its chemical formula is represented by the general formula (2)

,Four

FT

A-I CO- -N

(2)

FT

It is represented by

Here, A in the general formula (2) represents an alkyl group, an alkenyl group or an alkylamino group, and examples of the alkyl group include long-chain alkyl groups having 12 to 22 carbon atoms. Examples of the alkenyl group include a long-chain alkenyl group having 12 to 22 carbon atoms. Examples of the alkylamino group include an amino group substituted with the above alkynole group. Further, the alkyl group or the alkylamino group may have a substituent such as an alkenyl group, an aryl group, an alkoxy group, a halogen atom, a hydroxyl group, an acyl group, an acyloxy group, and an acylamino group.

In the general formula (2), R ³ and R ⁴ may be the same or different and each represents a hydrogen atom, an alkyl group, a hydroxyalkyl group, an alkenyl group, an aralkyl group or an aryl group. A methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, a linear or branched pentyl group, a long-chain alkyl group having 12 to 22 carbon atoms. Groups. Examples of the above-mentioned hydroxyalkyl group include those in which the above-mentioned alkyl group is substituted with a hydroxyl group. Examples of the alkenyl group include a vinyl group, an aryl group, an oleyl group, and a cis-13-docosel group. Examples of the aralkyl group include a benzyl group and a phenethyl group. Examples of the aryl group include a phenyl group, a 4-methylphenyl group, and a naphthyl group. The alkyl group or aryl group may have a substituent such as an acyl group, an acyloxy group, or an acylamino group.

— Examples of the compound represented by the general formula (2) include lauric amide, palmitic amide, stearic amide, behenic amide, eric acid amide, N-panolemicyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl—12-hydroxystearic acid amide, N-oley ^ / — 12-hydroxyhydroxystearic acid amide, N-methylol stearic acid amide, N-methylol Behenic acid amide, methylenebisstearic acid amide, methylenebislauric acid amide, methylenebis (12-hydroxystearic acid amide), ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide Amide, ethylenebisisostearic acid amide, ethylenebis (12-hydroxystearic acid Amide), ethylenebisbehenic acid amide, hexamethylenebisstearic acid amide, hexamethylenebisbehenic acid amide, hexamethylenebis (12-hydroxy stearic acid amide), butylene bis stearin Acid amide, methylene bisoleic acid amide, ethylene bis oleic acid amide, ethylene bis erlic acid amide, hexamethylene bis oleic acid amide, 1,3-xylylene bis stearic acid amide, N— Butyl N'-stearyl urea, N-phenyl-N'-stearyl urea, N, Ν'-distearyl urea, and the like, but the compound represented by the general formula (2) is not limited thereto. These compounds can be used alone or in combination of two or more, if necessary.

Among the amide derivatives represented by the general formula (2), palmitic acid amide, stearic acid amide, behenic acid amide, 、 -methylol stearic acid amide, Tylene bisstearic acid amide is preferably used because of its excellent heat responsiveness.

Further, in the heat-sensitive recording material of the present invention, the electron-donating usually colorless to light-colored dye precursor constituting a part of the heat-sensitive recording layer includes:

General formula (3)

A fluoran derivative represented by the following formula is used.

In the general formula (3), R ⁵ and R ⁶ may be the same or different and each represents an alkyl group having 1 to 5 carbon atoms, a cyclohexyl group, an aryl group (such as a phenyl group), and R ⁷ is hydrogen. Represents an atom, methyl group, trifluoromethyl group or a halogen atom (chlorine, bromine, iodine, fluorine), and R ⁸ is a hydrogen atom, a methyl group or a halogen atom

(Chlorine, bromine, iodine, fluorine).

Examples of the compound represented by the general formula (3) include 3-dibutylamino-7- (2-chloroanilino) fluoran, 3-ethylethylamino-7- (2-chloroaylino) fluoran, and 3-ethylamino-6 —Methyl-7-anilinofluorane, 3-dibutylamino-6-methyl-7-anilinofluorane, 3-dipentylamino-6-methyl-7-anilinofluoran, 3- (N-ethyl-N— Tolyl) amino 6-methinole 7-anilinofluoran, 3- (N-ethyl-1N-trinole) amino-6-methyl-1 7- (4-toluidino) fluoran, 3-piperidino_6-methylinole 7-a Nilinofluoran, 3—Jetylamino-7— (4-12 Trois Nilino) Fluoran, 3— (N—Methyl-1-N—propyl) Amino-6—Methyl-7—Anylinofluoran, 3— (N—Ethyl N-isoamyl) amino-6-methyl-7-anilinofluoran, 3- (N-methyl-1-N-cyclohexyl) amino-6-methinole-1 7-anilinofluoran, 3- (N —Ethyru-N—tetrahydrofurfuryl) amino-6-methyl-7-α-linofluorane, 3-ethylethyl Minnow 7- (3-trifluoromethylarino) fluoran, 3-getylamino 6-chloro-17-anilinofluoran, and the like, and the compound represented by the general formula (3) The compounds are not limited to these, and these compounds can be used alone or in combination of two or more as necessary.

Among the compounds represented by the above general formula (3), 3-dibutylamino-6-methyl-7-anilinofluoran, 3-getylamino-6-methyl-7-α-linofunoleolane, 3- (N-ethyl) 1-N-isoamyl) amino-6-methyl-1 7-anilinov 4 ^ orane, 3- (N-methyl-N-cyclohexinole) amino-6-methylenol 7-anilinofluoran, 3-dibutylamino-7 (2-chloroayurino) Fluorane and 3-dipentylamine 6-methyl-7-α-linolefluoran are preferably used.

In the heat-sensitive recording material of the present invention, the weight ratio (compound (1) / compound (2)) of the diphenylsulfone derivative represented by the general formula (1) to the amide derivative represented by the general formula (2) is 2 A range of 1 to 12 is preferred. If the proportion of the diphenyl sulfone derivative represented by the general formula (1) exceeds the above range, good thermal responsiveness cannot be obtained. The concentration decreases. In the heat-sensitive recording material of the present invention, the heat-sensitive recording layer may be provided, if necessary, with ethylene glycol dimetha tolyl ether, 2-benzyloxynaphthalene, bis (4-methylinobenzyl) oxalate, 1,2-bis (phenoxy). It can contain a compound selected from benzene, ρ-acetotoluidine and 4- (4-methinolephenoxy) biphenyl. These compounds can be used alone or in combination of two or more. By using these compounds, a thermosensitive recording material having even higher thermal responsiveness can be obtained. The reason is considered to be that these compounds further improve the compatibility between the dye precursor and the electron-accepting developer.

In the present invention, the amide derivative represented by the general formula (2), ethylene glycol dimetha tolyl ether, 2-benzyloxynaphthalene, bis (4-methylbenzinole) oxalate, 1,2-bis (phenoxymethyl) The weight ratio (compound (2) and other sensitizers) to other sensitizers selected from benzene and 4- (4-methylphenoxy) biphenyl is preferably in the range of 1: 2 to 5: 1. Expressed by the general formula (2) If the proportion of the amide derivative to be used is outside the above range, good thermal responsiveness cannot be obtained. Further, in the heat-sensitive recording material of the present invention, if necessary, the heat-sensitive recording layer may have the general formula (4)

OR, 1'0

R ⁹ 0—— P—— OR, 1 "1 (4)

0

By adding the phosphoric acid ester derivative represented by the formula, the storage stability of the image area with respect to temperature is further improved, and a heat-sensitive recording material having excellent thermal response can be obtained.

In the general formula (4), R ⁹ , R ¹⁰ and R ¹¹ may be the same or different, and each represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkali metal, an alkaline earth metal, Represents a transition metal or an amine, and examples of the alkyl group include a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, and a linear or branched pentyl group. Examples of the alkenyl group include a vinyl group, an aryl group, and an oleyl group. Examples of the aryl group include a phenyl group, a naphthyl group, a 4-tert-butylphenylamine, and a 4,6-di-tert- group. Butylphenyl group, 4-chlorophenyl group, 4-benzyloxyphenyl group, 3,5-di-tert-butyl-4-hydroxyphenyl group and the like. Benzyl group, phenethyl group and the like. Examples of the alkali metal include Li, Na, and K. Examples of the alkaline earth metal include Βa and Ca. Examples of the transition metal include Zn, Fe, and the like. Examples of the amine include a substituted ammonium group such as an ammonium group or an alkyl-substituted ammonium group.

Examples of the esterhenol phosphate derivative represented by the general formula (4) include trifenyl phosphate, dipheninolephosphate, bis (4-tert-butynolephenine) phosphate, and bis (4,6-di-tert-butynolephene). Nore) Phosphate, Bis (4-chloropheninole) Phosphate, Bis (pentinoleoxypheninole) phosphate, 2,2'-methylenebis (4,6-di-tert-butylphenyl) Phosphate, dimethinoleoxyphosphate, getinoleoxyphosphate, bis (3,5-di-tert-butyl-14-hydroxyphenophosphate) phosphate, 3,5-di-tert-butinoresipheninophosphate, bis ( 4 tert-butylphenyl phosphate, bis (4,6-di-tert-butylphenyl) phosphate, bis (4-chlorophenylphenyl) phosphate, bis (benzyl / reoxyphenyl) phosphate, 2,2-methylenebis (4 , 6-di-tert-butylpheninole) phosphate, dimethyloxyphosphate, getyloxyphosphate, ethynole (3,5-di-tert-butylinole 4-hydroxoxyphene / phosphate), 2,2'-methylenebis (4, 6-di-tert-butynole phenyl) phosphate Sodium salt, 2,2, -methylenebis (4,6-di-tert-butylpheninole) phosphate canolesum salt, 2,2'-methylenbis (4,6-di-tert-butynolepheninole) phosphate zinc salt , 2,2,1-methylenebis (4,6-di-tert-butynolepheninole) phosphate amm-pium salt, and the like, and these can be used alone or in combination of two or more.

Among the phosphoric ester derivatives represented by the above general formula (4), 2,2′-methylenebis (4,6-di-tert-butylpheninole) phosphate and 2,2′-methylenebis (4,6-di A sodium salt of (i-tert-butynolefenisole) phosphate is preferably used.

—The phosphoric ester derivative represented by the general formula (4) is preferably contained in an amount of 1 to 30% by weight, more preferably 3 to 10% by weight, based on the electron-accepting developer. preferable.

—When the content of the phosphoric ester derivative represented by the general formula (4) is less than 1% by weight based on the electron-accepting developer, the effect of improving the image storability is small. It inhibits the contact between the reactive dye precursor and the electron-accepting developer, and tends to cause a decrease in thermal responsiveness.

In the heat-sensitive recording material of the present invention, if necessary, a general formula (5)

{Where R ¹² is

General formula (6)

(In the formula, R ¹⁵ represents a cyclohexyl group, a phenyl group or a tert-butyl group, and R ¹⁶ represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cyclohexyl group, a phenyl group or a tert-butyl group. Represent)

Represents a group represented by

R ¹⁴ represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or a group represented by R ¹² ), whereby the storage stability of the image area with respect to temperature can be improved. An improved thermosensitive recording material can be obtained.

In the formula (6) in the general formula (5), the alkyl group having 1 to 8 carbon atoms as R ¹⁶ is preferably a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. In the general formula (5), the alkylene group having 1 to 3 carbon atoms as R ¹³ is preferably a methylene group, an ethylene group, or a propylene group, and the alkyl group having 1 to 8 carbon atoms as R ¹⁴ is a methyl group, Preferred are an ethyl group, a propyl group, a butyl group and a pentyl group.

Examples of the hindered phenol compound represented by the general formula (5) include 1,1,2,2-tetrakis (5-cyclohexyl-14-hydroxy-2-methylphenole) ethane and 1,1 , 2,2-Tetrakis (3-phenyl-hydroxy-4,4-hydroxyphenyl) ethane, 1,1,2,2-Tetrakis (3-tert-butyl-14-hydroxyphenyl) ethane, 1,1, 3-tris (3-cyclohexyl 4-hydroxy benzoyl) butane, 1,1,3-tris (5-cyclohexynole 4-hydr) 1,2,3-methylhexyl-2-butane, 1,1,3-tris (3-cyclohexyl-4-hydroxy-5-methynolephenyl) butane, 1,1,3-tris (3- 4-phenol-1-butane, 1,1,3-tris (5-phenyl-4-hydroxy-2-methylphenyl) butane, 1,1,3-tris (3-tert-butyl-4) -Hydroxyphenyl) butane, 1,1,3-tris (5-tert-butynole-1-hydroxy-4-methinolephen-2-ole) butane, 1,1,3,3-tetrakis (5-cyclohexyl 4-) Hydroxy-1-methylphenyl propane, 1,1,3,3-tetrakis (3-cyclohexyl 4-hydroxyphenyl) propane, 1,1,5,5-tetrakis (5-cyclohexyl) 4-Hydroxy-1- (2-methylphenyl) pentane, 1, 1,3,3-tetrakis (3-cyclohexynole-14-hydroxyphenole) pentane, 1,1,3,3-tetrakis (3-phenylenole-4-hydroxyphenyl) propane, 1, 1, 3, 3- tetrakis (5- Fueeru one 4- arsenide Dorokishi 2- methylphenyl) Puronoヽ⁰ emissions, 1, 1, 3, 3- tetrakis (3-tert-butyl one 4-arsenide Dorokishifue sulfonyl) propane, 1 ,! _, 3,3-tetrakis (5-tert-butyl-14-hydroxy-12-methylphenyl) propane, and the like, but the compound represented by the general formula (5) is not limited thereto. These compounds can be used alone or in combination of two or more, if necessary. Among the hindered phenol derivatives represented by the above general formula (5), in particular, 1,1,3-tris (5-cyclohexyl-4-hydroxy-12-methylphenyl) butane, 1,1,3-tris- (3-tert-butyl-4-hydroxy-1-methylphenyl) butane and the like are particularly preferable since they have a large effect of improving the heat-resistant storage stability of the color image portion.

The hindered fuanol derivative represented by the general formula (5) is preferably contained in an amount of 1 to 30% by weight, more preferably 3 to 10% by weight, based on the electron-accepting developer.

If the hindered phenol derivative represented by the general formula (5) is less than 1% by weight of the electron-accepting developer, the effect on the improvement of image preservability is small. Inhibits contact between the dye precursor and the electron-accepting developer, It tends to cause a decrease in responsiveness.

Further, in the heat-sensitive recording material of the present invention, the heat-sensitive recording layer may optionally contain a general formula

(7)

{Wherein, R ¹⁷ is a covalent bond, an alkylene group having 1 to 8 carbon atoms or

General formula (8)

20

CH COOR

(8)

20

CH COOR

(Wherein, R ²⁰ represents a 2,2,6,6-tetramethyl-1-piperidyl group or a 1,2,2,6,6-pentamethyl-4-piperidyl group)

Wherein R ¹⁸ and R ¹⁹ may be the same or different and each represents a 2,2,6,6-tetramethyl-14-piperidyl group or 1,2,2,6,6-pentamethyl- 4- represents a piperidyl group}

By containing a hindered amine derivative represented by the formula (1), a heat-sensitive recording material having improved storage stability of an image portion with respect to temperature can be obtained.

Examples of the hindered amine derivative represented by the general formula (7) include bis (2,2,6,6,1-tetramethyl-14-piperidyl) sebacate, and bis (2,2,6,6) succinate. , —Tetramethyl-1-4-piperidyl) ester, butane-1 1,2,3,4-tetracarboxylic acid-tetrakis (1,2,2,6,6-pentamethinole (4-piberidi / le)) ester, butane-1 1,2,3,4-tetranorenoleic acid monotetrax (2,2,6,6-tetramethyl (4-piberidyl)) ester, etc., and the compound represented by the general formula (7) The compounds are not limited to these, and these compounds can be used alone or in combination of two or more as necessary.

Among the hinderdamine derivatives represented by the general formula (7), 1,2,3,4-Tetrakisolenoic acid-tetrakis (1,2,2,6,6-pentamethyl (4-piberidyl)) ester and butane mono 1,2,3,4-tetracarboxylic acid tetrakis (2 2,2,6,6-tetramethyl (4-piperidyl)) ester is particularly preferable because it has a large effect of improving the heat-resistant storage stability of the color image area.

The hinderdamine derivative represented by the general formula (7) is preferably contained in an amount of 1 to 30% by weight, more preferably 3 to 10% by weight, based on the electron-accepting developer.

When the hinderdamine derivative represented by the general formula (7) is less than 1% by weight based on the electron-accepting developer, the effect of improving the image storability is small. It hinders contact between the dye precursor and the electron-accepting color developer and tends to cause a decrease in thermal responsiveness.

The heat-sensitive recording material of the present invention comprises, as essential components, an electron-donating, usually colorless or pale-colored dye precursor, an electron-accepting color developer, and an amide derivative as a photosensitive agent, and after dispersing them in a binder. The dye precursor and the electron-accepting developer instantly react with each other by applying a thermal recording layer by applying it on a support and heating it with a thermal head, hot pen, laser light, etc. Is what you get. Further, a pigment, a binder, an antioxidant, an anti-sticking agent and the like are added to the heat-sensitive recording layer as needed. In the heat-sensitive recording material of the present invention, the heat-sensitive recording layer contains the fluoran derivative represented by the general formula (3) as a dye precursor, but the general formula (3) is not impaired in the effect of the present invention. A dye precursor other than the compound represented by the formula (1) can be used together with the dye precursor represented by the general formula (3), which is an essential component. As these dye precursors, those commonly used in heat-sensitive recording materials and pressure-sensitive recording materials can be used, but are not limited thereto.

Examples of the dye precursor other than the compound represented by the general formula (3) are as follows. That is,

(1) Triaryl methane compound; 3,3-bis (p-dimethylaminophenyl) -16-dimethylaminophthalide (crystal violet lactone), 3,3-bis (p-dimethylaminophenol) Enyl) phthalide, 3- (p-dimethylaminophenyl) -3- (1,2-dimethylindole-3-yl) phthalide, 3- (p 3-Dimethylaminophenyl) 3- (2-methylindole-3-yl) phthalide, 3- (p-dimethylaminophenyl) 1-3- (2-phenylindole-3-yl) phthalide , 3,3-bis (1,2-dimethylindole-3-yl) -1-5-dimethylaminophthalide, 3,3-bis (1,2-dimethylindone-l-yl) -1 6- Dimethylaminophthalide, 3,3-bis (9-ethylcarbazole-13-yl) 15-Dimethylaminophthalide, 3,3-bis (2-phenylindole-13_) 1) 5-dimethylaminophthalide, 3-p-dimethylaminophenyl 1-3- (1-methylpyrroyl-2-yl) -16-dimethinoleaminophthalide, etc.

(2) diphenylmethane compounds; 4,4'-bis (dimethylaminophenyl) benzhydrinolebenzinoleatenole, N-cyclopheninoleleuco auramine, N-2,4,5-triclonophenolerole Such as co-olamine,

(3) Xanthene compounds; rhodamine B-anilinolactam, rhodamine B-p-chloroaurynolactam, 3-getylamino-7-dibenzylaminofluoran, 3-getylamino-7-octylaminofluoran, 3-getylaminon 7-Pheninolephnoleorane, 3-Jetinoleamino-l 7-Chlorophlorenolane, 3-Jetylamino 6-Chloro 7-Methylfluoran, 3-Jetylaminol 7- (3,4-Dichloroa-lino) fluoran, 3 — (N-ethyl-N-tolyl) amino-6-methyl-7-phenethylfluoran

(4) thiazine-based compounds such as benzoinoleurocomethylene methylene, p-nitrobenzoinoleurocomethylene methylene

(5) Spiro compounds; 3-methylspirodinaphthovirane, 3-ethylspirodinaphthovirane, 3,3,1-dichlorospirodinaphtopyran, 3-benzylspirodinaphthovirane, 3-methylnaphtho (3-methoxybenzo) spiropyran, 3 1-propyl spirobenzopyran, etc.

Are examples of dye precursors other than the compound represented by the general formula (3). These dye precursors can be used alone or as a mixture of two or more, if necessary.

In the heat-sensitive recording material of the present invention, the heat-sensitive recording layer is mainly used for coloring the dye precursor. As the electron accepting color developer, together with the compound represented by the general formula (1), an electron accepting color developer other than the compound represented by the general formula (1) is used as long as the effects of the present invention are not impaired. You can also. As these electron-accepting color developers, acidic substances commonly used for heat-sensitive recording materials and pressure-sensitive recording materials are used, but are not limited thereto. Examples of these electron-accepting color developing agents include phenol derivatives, aromatic carboxylic acid derivatives, N, N ⁷ -diarylthiourea derivatives, arylsulfonylurea derivatives, and polyvalent metal salts such as a dumbbell salt of an organic compound. be able to. Examples of electron-accepting developers other than the compound represented by the above general formula (1) include 4-hydroxy-4'-isopropoxydiphenylsulfone and 4-hydroxy-14'-benzyloxydiphenyl. Sulfone, 4-hydroxy-4'-propoxydiphenolenoleshon, 4-hydroxy-4'-benzenesolephoninole 1,2,4-bis (ρ-hydroxypheninole) propane, 1,1-bis (p-hydroxypheninole) pentane, 1-bis (p-hydroxypheninole) 1,1-bis (p-hydroxyphenyl) hexane, 1,1-bis (p-hydroxyphenyl) cyclohexane, 2,2-bis (p-hydroxy) (Shifen-2-ole) propane, 2,2-bis (p-hydroxyphenyl) hexane, 1,1-bis (p-hydroxyphenyl) 1-2-ethynolehexane, 2,2-bis (3-chloro) Mouth 4-Hydroxyphenyl) propane, 1,1-bis (p-hydroxyphenyl) 1 1-Fu-leutan, 1,3-zy [2- (p-hydroxyphenyl) 1-2-propynole] benzene, 1,3-di-1- [2- (3,4-dihydroxyphenole) -2-propyl] benzene, 1,4-zy [2- (p-hydroxyphenyl) 1-2-propynole] benzene, 4, 4'-Hydroxydiphenylenolate, 3,3'-Dichloro-4,4'-hydroxydiphenylenolesulfide, 2,2-bis (4-Hydroxyphenyl) acetate, 2,2'- Bis (4-Head Droxifeneinole) Vinegar Butylate, 4,4'-thiobis (2-tert-butyl-5-methylphenol), 4-hydroxydimethylphthalate, benzyl gallate, stearyl gallate, N, N'-diphenylthiourea, 4,4'- Bis (3- (4-methylphenylsulfonyl) perido) diphenylenomethane, N— (4-methylphenylsulfonyl) — Ν '— pheninoleurea,-(4-Methinolepheninolenesolenohonore)-N' — (3— (4-Methylphenylsulfonyloxy) phenyl) urea, salicylanilide, 5_ salicylanilide , Salicylic acid, 3,5-di-tert-butylsalicylic acid, 3,5-diα-methylbenzylsalicylic acid, 4- [2 '-(4-methoxyphenoxy) ethyloxy] salicylic acid or metal salt of these salicylic acid derivatives And the like.

In the heat-sensitive recording material of the present invention, a compound represented by the general formula (2) and, if necessary, other heat-fusible compounds as a heat-fusible sensitizer in the heat-sensitive recording layer. Can be contained within a range that does not impair the effect of the above. The other heat-fusible compound preferably has a melting point of 60 to 180 ° C, more preferably a melting point of 80 to 140 ° C.

Specific examples of such heat-fusible compounds include synthetic waxes such as paraffin wax, microcrystalline wax, polyethylene wax, and carnauba wax, and natural waxes, bis (4-methoxyphenyl) ether, 2,2 ' —Ethyl compounds such as bis (4-methoxyphenoxy) getyl ether, 1,2-bis (3-methynolef enoxy) ethane, naphthyl ether derivatives, anthryl ether derivatives, aliphatic ethers, dipheninole adipate, Estenole compounds such as dibenzyl oxalate, di (4-chlorobenzyl) oxalate, diphenyl carbonate, dimethyl terephthalate, dibenzyl terephthalate, phenyl benzenesulfonate, 4-acetylacetophenone, m-terpheninole, 4 1 Benzinolebiphenyl, ⁴ 1 Known heat-fusible compounds such as acetinolebiphenyl, biphenyl derivatives such as 4-arinoleoxybipheninole, bis (4-aryloxyphenyl) sulfone, acetoacetate anilide, and fatty acid anilides The compounds include, but are not limited to, compounds, and may be used alone or as a mixture of two or more, if necessary. In the heat-sensitive recording material of the present invention, pigments used in the heat-sensitive recording layer include kieselguhr, talc, kaolin, calcined kaolin, calcium carbonate, magnesium carbonate, titanium oxide, zinc oxide, silicon oxide, aluminum hydroxide, and urea. Inorganic and organic pigments such as formalin resin.

Further, in the heat-sensitive recording material of the present invention, the binder used in the heat-sensitive recording layer Te is, starches, human de Loki Chez chill cellulose, methyl Se Honoré loin, carboxymethyl sheet cellulose, gelatin, casein, polyvinyl - alcohol, denatured polyvinyl alkenyl alcohol, sodium polyacrylate, acrylic acid Ami de / ^/ acrylic acid ester le co Water solubility of polymers, terpolymers of acrylamide / acrylic acid ester / methacrylic acid, alkali salts of styrene / maleic anhydride copolymer, and salts of ethylene Z maleic anhydride copolymer Binders, polyacetate butyl, polyurethane, polyacrylate, styrene-butadiene copolymer, atarilonitrile / butadiene copolymer, methyl acrylate / butadiene copolymer, ethylene z-butyl acetate copolymer latex, etc. No.

Other additives include higher fatty acid metal salts such as zinc stearate and calcium stearate, paraffin, paraffin oxide, polyethylene, polyethylene oxide, stearic acid amide, custard for the purpose of preventing abrasion of the heating print head or preventing stating. Waxes such as wax, dispersants such as sodium octylsulfosuccinate, ultraviolet absorbers such as benzophenone and benzotriazole, surfactants and fluorescent dyes can be added as necessary. In monkey.

As the support used in the heat-sensitive recording material of the present invention, paper is mainly used.1 Non-woven fabric, plastic film, synthetic paper, metal foil, etc., or a composite sheet combining these can be used as necessary. . In addition, a single-layer or multiple-layer overcoat layer is provided to protect the heat-sensitive recording layer, and a single-layer or multiple layers of an undercoat layer made of pigment or resin are provided between the heat-sensitive recording layer and the support. Various known techniques in the production of heat-sensitive recording materials can be used.

The coating amount of the heat-sensitive recording layer is determined by the amount of dye precursor and an electron accepting color developing agent is a color-forming component, usually, the coating weight of the dye precursor is 0. 1~1. O g / m 2 Appropriate. The amount of the electron-accepting developer is usually preferably in the range of 5 to 500% by weight, particularly preferably in the range of 20 to 400% by weight, based on the dye precursor.

Example

Next, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto. Not something. The “parts” and “%” used in the examples are all based on weight, and the coating amounts are absolutely dry coating amounts.

(1) Preparation of thermal coating liquid

Preparation of a liquid dispersion>

Dispersions A to S were prepared by the following method.

Dispersion A>

4,4'-Dihydroxydiphenephone 200 g was dispersed in a mixture of 200 g of a 10% aqueous solution of a sulfonated polybutyl alcohol and 600 g of water, and the average particle size was 1.0 with a bead mill. / Xm to obtain a dispersion A. <Dispersion B>

4-Hydroxy-1 4'-isopropoxydiphenylenolesnorefone 200 g was dispersed in a mixture of 200% aqueous 10% sulfone group-modified polyvinyl alcohol and 600 g of water, and the average particle size was 1. The mixture was pulverized to 0 μπι to obtain a dispersion Β.

200 g of 3-dibutylamino-6-methyl-17-anilinofluoran was dispersed in a mixture of 200 g of a 10% aqueous solution of sulfonated polyvinyl alcohol and 600 g of water. Then, the mixture was pulverized to 0 / im to obtain a dispersion C.

Disperse 200 g of 3-getylamino-6-chloro-7- (2-ethyloxyshethylamino) fluoran in a mixture of 200 g of 10% sulfonate-modified polybutyl alcohol aqueous solution and 600 g of water. The mixture was pulverized with a single mill to an average particle size of 1.0 / 1 m to obtain a dispersion D.

Ku Dispersion E>

100 g of stearic acid amide was dispersed in a mixture of 100 g of a 10% aqueous solution of sulfonated polyvinyl alcohol and 800 g of water, and crushed with a bead mill until the average particle size became 5.0 / m. Dispersion E was obtained.

<Dispersion F> Disperse 200 g of 2-benzyl / reoxynaphthalene in a mixture of 200 g of 10% sulfonate-modified polybutyl alcohol aqueous solution and 600 g of water, and pulverize with a bead mill until the average particle size becomes 1.0 / xm. A dispersion F was obtained.

Dispersion G>

200 g of ethylene glycol dimethatryl ether is dispersed in a mixture of 200 g of an aqueous solution of 10% sulfonated polybutyl alcohol and 600 g of water, and ground with a bead mill until the average particle size becomes 1.0 / m. Thus, a dispersion G was obtained.

Disperse 200 g of bis (4-methylbenzyl) oxalate in a mixture of 200 g of a 10% aqueous solution of sulfonated polyvinyl alcohol and 600 g of water until the average particle size becomes 1.0 m using a bead mill. The mixture was ground to obtain a dispersion H.

Disperse 200 g of 1,2-bis (phenoxymethyl) benzene in a mixture of 200 g of a 10% aqueous solution of sulfonate-modified polyvinyl alcohol and 600 g of water, and use a bead mill to reduce the average particle size to 1.0 μm. By pulverizing, a dispersion I was obtained. <Dispersion J>

200 g of p-acetotoluidine is dispersed in a mixture of 200 g of a 10% sulfonate-modified aqueous polyvinyl alcohol solution and 600 g of water, and the mixture is ground by a bead mill until the average particle size becomes 1.0 μπ, and dispersed. Liquid J was obtained.

200 g of 4- (4-methylphenoxy) biphenyl is dispersed in a mixture of 200 g of a 10% sulfonate-modified aqueous polybutyl alcohol solution and 600 g of water, and the average particle size is 1.0 with a bead mill. Grinding until μιη was obtained to obtain dispersion K.

Dispersion L>

Disperse 200 g of 4-acetinorebiphenyl in a mixture of 200 g of an aqueous solution of 10% sulfone group-modified polyvinyl alcohol and 600 g of water, and the average particle size becomes 1.0 μπι with a bead mill. To obtain a dispersion L.

分散〉

2,2'-methylenebis (4,6-di-tert-butynolephenyl) phosphe 200 g of sodium salt was dispersed in a mixture of 200 g of 10% sulfone-modified polyvinyl alcohol aqueous solution and 600 g of water, and ground with a bead mill until the average particle size became 1.0 μπι. Got M.

Disperse 200 g of 1,1,3-tris (2-methyl-14-hydroxy-5-cyclohexylphenyl) butane in a mixture of 200 g of 10% aqueous solution of sulfonated polybutyl alcohol and 600 g of water Then, the mixture was pulverized with a bead mill until the average particle diameter became 1.0 μm, to obtain a dispersion N.

Dispersion o>

200 g of 1,2,3,4-tetracarboxylic acid-tetrakis (1,2,2,6,6-pentamethyl (4-piperidyl)) ester of butane was added to 200 g of a 10% aqueous solution of sulfonate-modified polybutyl alcohol and water. The dispersion was dispersed in 600 g of the mixed solution, and pulverized by a bead mill until the average particle size became 1.0 // m, to obtain a dispersion O. Dispersion P>

200 g of aluminum hydroxide was dispersed in 800 g of a 0.5% aqueous solution of sodium polyacrynolate and stirred with a homomixer for 10 minutes to obtain a dispersion P.

Dispersion Q>

Disperse 200 g of 2,4'-dihydroxydiphenyl-snorrephone in a mixture of 200 g of a 10% aqueous solution of sulfonated polybutyl alcohol and 600 g of water until the average particle size becomes 1.0 μm using a bead mill. By pulverizing, a dispersion Q was obtained. <Dispersion R>

3- (N-ethyl-N-isoamyl) amino-6-methyl-7-anilinofluorane 200 g was dispersed in a mixture of 200 g of a 10% aqueous solution of sulfonated polybutyl alcohol and 600 g of water. The dispersion R was obtained by pulverizing until the diameter became 1.0 m.

Dispersion S>

200 g of 3-dipentylamino-6-methyl-7-anilinofluoran was dispersed in a mixture of 200 g of a 10% aqueous solution of sulfonated polybutyl alcohol and 600 g of water. Pulverize to a diameter of 1.0 / zm and disperse Liquid s was obtained.

Table 1 shows the types, compound names, concentrations and particle sizes of the main components of the dispersions A to S.

(Hereinafter the margin)

Name Type Compound Concentration% Particle Size tm Dispersion A Developer 4,4 Dihydroxydiphenenolesnolephone 20 1.0 Dispersion B Developer 4-Hydroxy 4'isopropoxydiphenyl sulfone 201.0 Dispersion C Dye 3-Dibutylamino-6-methyl 7-anilinofluoran 20 1.0 Dispersion D Dye 3 Jetinoleamino-1 6 Clos 7 _ (2-Ethyloxshetylamino) Fluoran 20 1.0 Dispersion E 增Sensitizer Stearic acid amide 10 5.0 Dispersion F 增 Sensitizer 2-benzinoleoxynaphthalene 20 1.0 Dispersion G 增 Sensitizer Ethylene glycol dimetha trilinoleether 20 1.0 Dispersion H 增 Sensitive bismuth oxalate (4- Methyl benzyl) 20 1.0 to

Dispersion I 增 Sensitive 1,2 _bis (phenoxymethinole) benzene 20 1.0 Dispersion J 增 Sensitive p-acetotoluidine 20 1.0 Dispersion K 增 Sensitive 41- (4-methylphenoxy) bihue 20 1.0 Dispersion L L Sensitizer 4-Acetinolebiphenyl 20 1.0 Dispersion M Δ, ― Narenos 4- ― tert-Noah / Lenoenole;

Additives Rum salt 20 1.0 Dispersion N 1, 1, 3 tris ~ 7-tenor 1 4 c

Additive 20 1.0 Dispersion o 丄, Q, "" = 7? "7 7 '3 / Ε¾ Ar -τ ^,-, 9 D c, O

Additive Methyl (4-piperidyl)) Esthenol 20 1.0 Dispersion P Pigment Aluminum hydroxide 20

Dispersion Q Developer 2,4'-Dihydroxydiphenylenolesnorephone 20 1.0 Dispersion R Dye 3— (N-ethyl-N-isoamyl) amino-6-methyl 7-anilinofluorane 20 1.0 Dispersion S dye 3-dipentylamino 6-methyl-1 7-anilinofluoran 20 1.0

Example 1

(1) Preparation of thermal coating liquid

The dispersions prepared above and other dispersions and aqueous solutions were mixed in the proportions shown below, water was added so that the coating solution concentration was 15%, and the mixture was sufficiently stirred to prepare a heat-sensitive coating solution. .

Dispersion A 60 parts

Dispersion C 30 parts

Dispersion E 60 parts

Dispersion P 100 parts

25% aqueous dispersion of 40% zinc stearate

272 parts of 10% polybutyl alcohol aqueous solution

300 parts of water

(2) Preparation of thermal coated paper

A coating solution having the following composition was applied to a high-quality paper having a basis weight of 40 g / m ^{2 so} that the solid content was 9 g / m ² , and dried to prepare a heat-sensitive coated paper.

100 parts of calcined kaolin

24 parts of 50% styrene butadiene latex aqueous dispersion

200 parts of water

(3) Preparation of thermal recording material

The thermal coating liquid prepared in (1) is coated on the thermal coating paper prepared in (2) so that the solid content becomes 4 g / m ^2, and dried to obtain a thermal recording material. Produced.

Example 2

A heat-sensitive recording material was obtained in the same manner as in Example 1 except that the addition ratio of the dispersion E in Example 1 was changed from 60 parts to 120 parts.

Example 3

A heat-sensitive recording material was obtained in the same manner as in Example 1 except that the addition ratio of the dispersion E in Example 1 was changed from 60 parts to 240 parts.

Example 4

The addition ratio of Dispersion E of Example 1 was changed from 60 parts to 100 parts, and Dispersion F Was obtained in the same manner as in Example 1 except that 50 parts of was added.

Example 5

A heat-sensitive recording material was obtained in the same manner as in Example 1 except that the addition ratio of the dispersion E in Example 1 was changed from 60 parts to 100 parts, and that 50 parts of the dispersion G was added.

Example 6

A heat-sensitive recording material was obtained in the same manner as in Example 1 except that the addition ratio of the dispersion E in Example 1 was changed from 60 parts to 100 parts, and that the dispersion H was added to 50 parts. .

Example 7

A heat-sensitive recording material was obtained in the same manner as in Example 1, except that the addition ratio of the dispersion E in Example 1 was changed from 60 parts to 100 parts, and 50 parts of the dispersion I was added.

Example 8

A heat-sensitive recording material was obtained in the same manner as in Example 1, except that the addition ratio of the dispersion E in Example 1 was changed from 60 parts to 100 parts, and 50 parts of the dispersion J was added.

Example 9

A heat-sensitive recording material was obtained in the same manner as in Example 1 except that the addition ratio of the dispersion E in Example 1 was changed from 60 parts to 100 parts, and the dispersion K was added to 50 parts. .

Example 10

A heat-sensitive recording material was obtained in the same manner as in Example 1, except that 70 parts of Dispersion F was added in the preparation of the coating solution for forming a heat-sensitive recording layer in Example 1.

Example 1 1

A heat-sensitive recording material was obtained in the same manner as in Example 1 except that the addition ratio of the dispersion E in Example 1 was changed from 60 parts to 80 parts, and the dispersion F was added with 60 parts of kneaded.

Example 1 2

A heat-sensitive recording material was obtained in the same manner as in Example 1 except that the addition ratio of the dispersion E in Example 1 was changed from 60 parts to 160 parts, and that 20 parts of the dispersion F was added.

Example 13

A heat-sensitive recording material was obtained in the same manner as in Example 1 except that the addition ratio of the dispersion E in Example 1 was changed from 60 parts to 180 parts, and that the dispersion F was added with 10 parts of kneading. .

Example 14 A heat-sensitive recording material was obtained in the same manner as in Example 1 except that the addition ratio of the dispersion E in Example 1 was changed from 60 parts to 200 parts, and the dispersion J was added with 50 parts of kneaded. .

Example 15

A heat-sensitive recording material was obtained in the same manner as in Example 1 except that the addition ratio of the dispersion E in Example 1 was changed from 60 parts to 100 parts, and 100 parts of the dispersion J was added. .

Example 16

The heat sensitivity was the same as in Example 1 except that the addition ratio of the dispersion E in Example 1 was changed from 60 parts to 100 parts, and 50 parts of the dispersion F and 3 parts of the dispersion M were added. The recording material was obtained.

Example 17

In the same manner as in Example 1 except that the addition ratio of the dispersion E in Example 1 was changed from 60 parts to 100 parts, and 50 parts of the dispersion F and 3 parts of the dispersion N were added. Thus, a heat-sensitive recording material was obtained.

Example 18

The heat sensitivity was the same as in Example 1 except that the addition ratio of the dispersion E in Example 1 was changed from 60 parts to 100 parts, and 50 parts of the dispersion F and 3 parts of the dispersion O were added. The recording material was obtained.

Example 19

Example 1 was repeated except that the addition ratio of the dispersion E was changed from 60 parts to 100 parts, and that 50 parts of the dispersion F, 3 parts of the dispersion M, and 3 parts of the dispersion N were added. A heat-sensitive recording material was obtained in the same manner as in Example 1.

Example 20

Example 1 was repeated except that the addition ratio of the dispersion E was changed from 60 parts to 100 parts, and that 50 parts of the dispersion F, 3 parts of the dispersion M, and 3 parts of the dispersion O were added. A heat-sensitive recording material was obtained in the same manner as in Example 1.

Example 2 1

Example 1 was repeated except that the addition ratio of dispersion E was changed from 60 parts to 100 parts, and dispersion F was 50 parts, dispersion N was 3 parts, and dispersion O was 3 parts. A heat-sensitive recording material was obtained in the same manner as in Example 1. Example 22

A heat-sensitive recording material was obtained in the same manner as in Example 4 except that the addition ratio of the dispersion A in Example 4 was changed from 60 parts to 50 parts, and that 10 parts of the dispersion Q was added.

Example 2 3

A heat-sensitive recording material was obtained in the same manner as in Example 5, except that the addition ratio of the dispersion C in Example 5 was changed from 30 parts to 20 parts, and that 10 parts of the dispersion R was added.

Example 2 4

A thermosensitive recording material was obtained in the same manner as in Example 7, except that Dispersion C in Example 7 was replaced with Dispersion S.

Comparative Example 1

A heat-sensitive recording material was obtained in the same manner as in Example 1 except that the addition ratio of the dispersion E in Example 1 was changed from 60 parts to 40 parts.

Comparative Example 2

A heat-sensitive recording material was obtained in the same manner as in Example 1, except that the addition ratio of the dispersion E in Example 1 was changed from 60 parts to 300 parts.

Comparative Example 3

A heat-sensitive recording material was obtained in the same manner as in Example 1, except that Dispersion E of Example 1 was replaced with Dispersion F.

Comparative Example 4

A thermosensitive recording material was obtained in the same manner as in Example 1, except that Dispersion E of Example 1 was replaced with Dispersion G.

Comparative Example 5

A thermosensitive recording material was obtained in the same manner as in Example 1, except that Dispersion E of Example 1 was replaced with Dispersion H.

Comparative Example 6

A heat-sensitive recording material was obtained in the same manner as in Example 1, except that Dispersion E of Example 1 was replaced with Dispersion I.

Comparative Example 7

The heat sensitivity was the same as in Example 1 except that Dispersion E of Example 1 was replaced with Dispersion J. A recording material was obtained.

Comparative Example 8

A heat-sensitive recording material was obtained in the same manner as in Example 1 except that Dispersion E of Example 1 was replaced with Dispersion K.

Comparative Example 9

A heat-sensitive recording material was obtained in the same manner as in Example 1, except that Dispersion E of Example 1 was replaced with Dispersion L.

Comparative Example 10

A thermosensitive recording material was obtained in the same manner as in Example 2 except that Dispersion A of Example 1 was replaced with Dispersion B.

Comparative Example 1 1

A heat-sensitive recording material was obtained in the same manner as in Example 2 except that Dispersion C of Example 1 was replaced with Dispersion D.

Comparative Example 1 2

A thermosensitive recording material was obtained in the same manner as in Example 4, except that Dispersion C of Example 1 was replaced with Dispersion D.

Comparative Example 1 3

A heat-sensitive recording material was obtained in the same manner as in Example ⁴ except that Dispersion A of Example 4 was replaced with Dispersion B.

Comparative Example 1 4

A heat-sensitive recording material was obtained in the same manner as in Example 5, except that Dispersion A in Example 5 was replaced with Dispersion B.

Comparative Example 15

A thermosensitive recording material was obtained in the same manner as in Example 6, except that Dispersion A in Example 6 was replaced with Dispersion B.

Comparative Example 16

A thermosensitive recording material was obtained in the same manner as in Example 7, except that Dispersion A of Example 7 was replaced with Dispersion B.

Comparative Example 1 7 A thermosensitive recording material was obtained in the same manner as in Example 8, except that Dispersion A of Example 8 was replaced with Dispersion B.

Comparative Example 1 8

A heat-sensitive recording material was obtained in the same manner as in Example 9, except that Dispersion A in Example 9 was replaced with Dispersion B.

The main components of the heat-sensitive coating solutions prepared in Examples 1 to 24 and Comparative Examples 1 to 18 are shown in Tables 2, 3 and 4, and 5, respectively.

(Hereinafter the margin)

Table 2 t

* Weight ratio of developer of general formula (1) to sensitizer of general formula (2)

Table 3

CO CO

Table 4 ^

Table 5

The heat-sensitive recording materials prepared in the above Examples and Comparative Examples were calendered so that the Beck smoothness of the heat-sensitive coated surface was 400 to 500 seconds, and the following evaluation was performed. Tables 6 and 7 show the results of the evaluation. The evaluation method is as follows.

[Thermal response test]

A printing test was performed using an Okura Electric Facsimile Tester TH-PMD. Using a thermal head with a dot density of 8 dots / mm and a head resistance of 185 Ω, a head voltage of 12 V and a pulse width of 1. Oms ec are used for printing, and the color density is determined by Macbeth RD-918. It was measured with a reflection densitometer. Table 1 shows the evaluation results. Practical density of 1.05 or higher at 1.0 ms e c is required.

[Heat resistance test of image area]

The density of the thermosensitive recording material printed at 1.0 ms ec and the unprinted background after being stored at 60 ° C for 24 hours was used to evaluate the thermal response characteristics. It was measured with a type 18 reflection densitometer. Table 1 shows the evaluation results.

[Dust adhesion test]

Using the G3 thermal facsimile machine (KX-PW3TA, manufactured by Matsushita Electric), the No. 3 facsimile test chart of the Institute of Image Electronics Engineers of Japan was sent, and the resulting thermosensitive recording material was used.

After continuous printing at 20 km, the thermal head and the state of printing were visually observed. The evaluation criteria followed the following indices.

5: No scum adhesion was observed, and no print scum was observed.

4: Adhesion of scum is hardly observed, and no print scum is observed.

3: Adhesion is observed, but no print blur is observed.

2: Adhesion of scum was observed, and slight print scumming due to this was also observed. 1: Adhesion of scum is observed in large quantities, and severe printing scumming due to this is also observed. Table 6

* Larger numbers indicate less scum adherence. Table 7

* The smaller the number, the more scum adheres. As is clear from Tables 6 and 7, the thermal recording materials of Examples 1 to 24 were compared with the thermal recording materials of Comparative Examples 1 to 18. Excellent in properties. That is, the thermal responsiveness and the heat resistance of the image portion are 1.10 to 1.38 and 0.98 to 1.32 in the example, respectively, whereas the thermal response and the heat resistance of the image portion are 0.98 to 1.32 in the comparative example. 25 and 0.73 to 1.09 The example is superior to the comparative example. Furthermore, when comparing the adhesion of scum, in the examples, all the ranks were 3 or higher (mostly ranks 4 or 5) and the scum adhesion was small. There is a lot of sticking and it is not practical. From the above, the heat-sensitive recording materials of the examples were highly evaluated in all of the thermal responsiveness, the heat resistance, and the anti-scum adhesion property, and were highly practical. In particular, the heat-sensitive recording materials of Examples 16 to 23 had good property balance and high overall evaluation.

Industrial applicability

As apparent from Tables 4 and 5, the heat-sensitive recording material of the present invention containing a specific diphenylsulfone derivative, a specific amide derivative and a specific fluoran derivative as essential components in the heat-sensitive recording layer, It is excellent in responsiveness and image storability, and the amount of scum adhered to the thermal head of the thermal printer is small. As a result, printing trouble does not occur even in long-distance printing. In addition, by including a specific ester / resin phosphate derivative, a hindered phenol / resin derivative, a specific hindered amine derivative, etc. in the heat-sensitive recording layer, the balance between the thermal responsiveness and the storage characteristics of the image area is further improved. And a heat-sensitive recording material can be obtained.

Claims

The scope of the claims

1. A heat-sensitive recording material having a heat-sensitive recording layer containing an electron-donating, usually colorless or pale-colored dye precursor, and an electron-accepting head coloring agent that reacts upon heating to form a dye precursor; The recording layer is

General formula (1)

m represents an integer of 1 to 3,

η represents an integer from 0 to 2)

A diphenylsulfone derivative represented by

~ General formula (2)

(In the formula, A represents an alkyl group, an alkenyl group or an alkylamino group, and R ³ and R ⁴ may be the same or different and each represents a hydrogen atom, an alkyl group, an alkenyl group, an aralkyl group or an aryl group. Represents)

An amide derivative represented by

—General formula (3)

R ⁷ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a halogen atom, and R ⁸ represents a hydrogen atom, a methyl group or a halogen atom)

And a fluoran derivative represented by

And the weight ratio (compound (1) compound (2)) of the difuunyl sulfone derivative represented by the general formula (1) to the amide derivative represented by the general formula (2) is 2Z1 to Thermal recording material characterized in that it is 1/2.

2. The thermosensitive recording layer is composed of ethylene glycol dimetha tolyl ether, 2-benzyloxynaphthalene, bis (4-methylbenzyl) oxalate, 1,2_bis (phenoxymethinole) benzene, p-acetoto ^^ idine and 2. The heat-sensitive recording material according to claim 1, comprising at least one compound selected from mono (4-methylphenoxy) biphenyl.

3. An amide derivative represented by the general formula (2), ethylene glycol dimethatryl ether, 2-benzyloxynaphthalene, bis (4-methylbenzyl) oxalate, 1,2-bis (phenoxymethyl) benzene, The weight ratio to the other sensitizer selected from p-acetotoluidine and 4- (4-methylphenoxy) biphenyl (compound (2) Z and other sensitizers) is in the range of 1-2Ζ to 5Ζ1. Item 2. The heat-sensitive recording material according to Item 2.

4. The thermal recording layer

—General formula (4) OR 10

R ^90- P-11

-OR (4)

O

(Wherein, R ⁹ , R ^1Q and R ¹¹ may be the same or different and each represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkali metal, an alkali earth metal, a transition metal or Represents

Any two groups selected from R ⁹ , R ^1Q and R ¹¹ may be linked to each other to form a ring.

The heat-sensitive recording material according to any one of claims 1 to 3, comprising a compound represented by the following formula: 5. The thermal recording layer

General formula (5)

{Where R ¹² is

General formula (6)

(In the formula, R ¹⁵ represents a cyclohexyl group, a fuel group or a tert-butyl group, and R ¹⁶ represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cyclohexyl group, a phenyl group or a tert-butyl group. Represent)

Represents a group represented by

R ¹⁴ represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or a group represented by R ¹² ). The thermosensitive recording material according to any one of claims 1 to 4, wherein 6. The thermal recording layer General formula (7)

In the formula, R ¹⁷ is a covalent bond, an alkylene group having 8 carbon atoms, or

General formula (8)

CH C00R 20

(8)

CH COOR ²⁰

(Wherein, R ²⁰ represents a 2,2,6,6-tetramethyl-1-piperidinole group or a 1,2,2,6,6-pentamethyl-14-piperidyl group)

Represents a group represented by

R ¹⁸ and R ¹⁹ may be the same or different and represent a 2,2,6,6-tetramethyl-4-piperidyl group or a 1,2,2,6,6-pentamethyl-14-piperidyl group}

The heat-sensitive recording material according to any one of claims 1 to 5, comprising a compound represented by the following formula: 7. The heat-sensitive recording material according to any one of claims 1 to 6, wherein the diphenylsulfone derivative represented by the general formula (1) is 4,4'dihydroxydiphenylsulfone.