JP2000178276A - New trisbenzotriazole compound and heat-sensitive record medium containing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new trisbenzotriazole having an ultraviolet absorbing ability. SOLUTION: This compound is shown by formula I (X and Y are each H, an 1-8C alkyl, 1-6C alkoxy or halogen), e.g. 2,4,6-tris-[4-(2H-benzotriazole-2-yl)-3- hydroxyphenoxy]-1,3,5-triazine. A compound of formula I is obtained by dissolving a dihydroxyphenylbenzotriazole compound and cyanuric chloride in the molar ratio of 3 to 1 into an aromatic hydrocarbon solvent of e.g. pseudocumene or mesitylene and by reacting it under heating and mixing conditions at reflux for several minutes to several hours under coexistence with an inorganic alkali compound of e.g. sodium carbonate. A compound of formula I is high in ultraviolet absorbing ability and also excellent in high-temperature stability apart from the conventional ultraviolet absorbing agent, and the recording paper using the compound provides each of recording section and texture section with good light-resistant property, thus resulting in neither change in color nor damage in appearances even when stored for a long time by exposure to sunshine at high temperatures.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel trisbenzotriazole compound having a high ultraviolet absorbing ability, and further relates to a thermosensitive recording material using the compound as an ultraviolet absorber.

[0002]

2. Description of the Related Art In a thermosensitive recording system, a thermosensitive recording layer mainly comprising an electron-donating usually colorless or pale-color dye precursor and an electron-accepting developer is provided on a support. By heating with a pen, laser light, or the like, the dye precursor and the developer are instantaneously reacted to obtain a recorded image. Japanese Patent Publication Nos. 43-4160 and 45-1
No. 4039, for example. Such a thermosensitive recording medium does not require development and fixing, and a very clear image can be obtained with a relatively simple apparatus. Also, the equipment is relatively inexpensive,
It has the advantages of being compact, easy to maintain, and no noise generation.
It is used in a wide range of fields, such as measurement recorders, labels, and ticket vending machines.

As one use of the heat-sensitive recording material, it has been increasingly used in recent years for various heading labels, display media such as posters, and the like. However, since this type of thermosensitive recording medium has low stability to light and heat, if the thermosensitive recording medium is exposed to room light or sunlight for a long period of time or is exposed to high temperatures, the background will turn yellow and the appearance will change. And the stability of the recorded image is impaired, and as a result, the product image of the thermal recording medium is significantly impaired.

[0004] In order to solve these problems, conventionally, for the purpose of preventing yellowing due to light on the background of a thermal recording medium,
A method of adding a finely pulverized ultraviolet absorbent to a heat-sensitive recording layer or a protective layer (Japanese Patent Laid-Open Nos. 50-104650 and 55-104).
55891, 55-93492, 58
No. 87093). But,
If the heat-sensitive recording layer contains a finely pulverized ultraviolet absorber, if sufficient light resistance is to be obtained, the absorption efficiency and shielding efficiency of ultraviolet light are poor, so a large amount of the ultraviolet absorber is added to compensate for this defect. There is a need. Therefore, when such a heat-sensitive recording medium is placed in a high-temperature environment, it causes background fog, or has a new defect such as a decrease in recording density,
There is a disadvantage that the performance as a thermal recording medium is impaired.

[0005] Further, even if the protective layer contains a finely pulverized ultraviolet absorber, if it is a conventionally proposed ultraviolet absorber, these compounds have a relatively low melting point. The heating of the thermal head easily dissolves the ultraviolet absorber, causing scum and sticking, and causing a problem that the thermal head is stained by printing for a long time. In addition, the function of the protective layer is lost because the ultraviolet absorber is eluted from the protective layer due to the influence of the plasticizer, oils and fats, etc., and as a result, the storage stability of the recorded image is reduced.

A method of adding a water-soluble compound by introducing a sodium sulfonate group into an ultraviolet absorber is added to the heat-sensitive recording layer and / or the protective layer.
No. 8 has been proposed. However, in this method, the introduction of the sodium sulfonate group has a problem of adversely affecting the pH and the liquid properties of the prescription system, and also has a problem such as coloring of the background, and a bad influence on the heat-sensitive head, which is practical. It is hard to say.

In addition, Japanese Patent Application Laid-Open No. 5-155134 discloses that a microencapsulated ultraviolet absorber is added to a protective layer to obtain a heat-sensitive recording material having excellent storage stability and light resistance. I have. However, in this method, it is necessary to microencapsulate the ultraviolet absorber, and it is necessary to make the microcapsules finer in order to increase the ultraviolet absorption efficiency, but there is a limit to the minimum value in terms of synthesis. Therefore, in order to develop sufficient light resistance, the required amount of the microcapsules enclosing the ultraviolet absorber increases, which leads to an increase in cost. In addition, the microcapsules containing the ultraviolet absorber contain heat,
Since the film must be stable against pressure, the film thickness must be increased, which also causes an increase in cost.

Recently, a heat-sensitive recording material using an ultraviolet absorbent obtained by polymerizing an ultraviolet absorbing benzotriazole molecule or a benzophenone molecule has been disclosed in Japanese Patent Laid-Open No. Hei 7-31489.
4, JP-A-9-221487, JP-A-9-26818
3, JP-A-9-314496, JP-A-10-7177
0, and Japanese Patent Laid-Open No. 10-36371. However, even with the compounds described in these patents,
The effect of improving scum and sticking is not yet sufficient.

As described above, the provision of light resistance to a heat-sensitive recording medium using an ultraviolet absorber has been performed for a long time, but at present, a satisfactory method has not been developed.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel trisbenzotriazole compound having an ultraviolet absorbing ability and excellent heat resistance of a recording portion and a background portion without impairing the basic performance of a heat-sensitive recording material. Another object of the present invention is to provide a thermosensitive recording medium which is excellent in recording running property and further excellent in image storability such as plasticizer resistance, oil resistance and solvent resistance.

[0011]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, have developed a trisbenzotriazole compound represented by the following general formula (1).

[0012]

Embedded image (1) wherein X and Y each represent a hydrogen atom or an alkyl group of C1 to C8, an alkoxy group of C1 to C6, or a halogen atom, and among them, a hydrogen atom or C1
-C4 alkyl groups are preferred.

The present inventors use the trisbenzotriazole compound represented by the above general formula (1) as an ultraviolet absorber in a thermosensitive recording medium applying a color development reaction between an electron donating compound and an electron accepting compound. As a result, it has been found that a heat-sensitive recording material having excellent light resistance in the recording portion and yellowing resistance in the background portion can be obtained. In addition, when the trisbenzotriazole compound of the present invention was used, there was a problem when using an existing ultraviolet absorber, the background fog when incorporated into the recording layer, and the fog when incorporated into the protective layer. The present invention has been found that deterioration of recording running property and deterioration of plasticizer resistance and the like due to occurrence of sticking and the like can be prevented.

The reason is considered to be that the trisbenzotriazole compound of the present invention has a high melting point without impairing the ultraviolet absorption of the benzotriazole compound, and thus does not easily melt even when the thermal head is heated. . Therefore, the thermosensitive recording medium containing the compound of the present invention can completely suppress the generation of scum sticking. Further, the trisbenzotriazole compound of the present invention has a very low solubility in general organic solvents. For this reason, there is an advantage that the present compound does not elute from the protective layer even when the thermosensitive recording medium containing the compound of the present invention in the protective layer comes into contact with a plasticizer, oils or the like.

Although it is not clear why the trisbenzotriazole compound of the present invention has a high melting point and low solubility in general organic solvents, the benzotriazole compound of the present invention is synthesized from resorcinol as a raw material, and is generally used. It is thought that the melting point is higher than that of benzotriazole-based UV absorbers made from alkylphenols that are used as raw materials, and the solubility in organic solvents is low. It is considered that the solubility in organic solvents is further reduced. Therefore, it is considered that the thermosensitive recording medium using the trisbenzotriazole compound of the present invention has no occurrence of sticky sticking and has excellent image storability such as plasticizer resistance as compared with the existing ultraviolet absorber. Can be

Further, the present inventors have found that a thermosensitive recording medium using the trisbenzotriazole compound of the present invention has higher whiteness than a thermosensitive recording medium using an existing ultraviolet absorber. . In general, existing ultraviolet absorbers are often colored yellow, and the whiteness of the heat-sensitive recording medium is reduced. On the other hand, the trisbenzotriazole compound of the present invention has a high whiteness itself, so that the whiteness does not decrease even when it is contained in a thermosensitive recording medium. Does not degrade the image.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the trisbenzotriazole compound of the present invention and a thermosensitive recording medium containing the same will be described in detail. First, a method for producing the trisbenzotriazole compound represented by the above general formula (1) of the present invention will be described. The trisbenzotriazole compound represented by the general formula (1) of the present invention can be synthesized by a conventionally known method. That is, a dihydroxyphenylbenzotriazole compound represented by the following general formula (2) and cyanuric chloride are dissolved in an aromatic hydrocarbon solvent such as pseudocumene or mesitylene at a molar ratio of 3: 1, and an inorganic alkali compound such as sodium carbonate is dissolved. Can be synthesized by heating and stirring under reflux for several minutes to several hours.

[0018]

Embedded image (2) wherein X and Y each represent a hydrogen atom, an alkyl group of C1 to C8, an alkoxy group of C1 to C6, or a halogen atom. The dihydroxyphenylbenzotriazole compound represented by the general formula (2), which is used as a raw material in the present invention, is a known compound (O. Fogl et al., J. Macromol. Sci-Chem., A20 (3) , 309-320
(1983), Macromol. Chem., 185 , 2497-2509 (1984), etc.)
Can be synthesized.

The following compounds are exemplified as specific examples of the trisbenzotriazole compound represented by the above general formula (1) of the present invention, but the present invention is not limited thereto, and two or more of these compounds may be used. You may mix and use.

2,4,6-tris- (4- (2H-benzotriazol-2-yl) -3-hydroxyphenoxy) -1,3,5-triazine, 2,4,6-tris-
(4- (2H-benzotriazol-2-yl) -3-
(Hydroxy-6-methylphenoxy) -1,3,5-triazine, 2,4,6-tris- (4- (2H-benzotriazol-2-yl) -3-hydroxy-6-t-
Butylphenoxy) -1,3,5-triazine, 2,
4,6-tris- (4- (2H-benzotriazole-
2-yl) -3-hydroxy-6-t-octylphenoxy) -1,3,5-triazine, 2,4,6-tris- (4- (5-chloro-2H-benzotriazole-2)
-Yl) -3-hydroxyphenoxy) -1,3,5-
Triazine, 2,4,6-tris- (4- (5-methoxy-2H-benzotriazol-2-yl) -3-hydroxyphenoxy) -1,3,5-triazine, 2,
4,6-tris- (4- (5-n-hexyl-2H-benzotriazol-2-yl) -3-hydroxyphenoxy) -1,3,5-triazine, 2,4,6-tris- (4 -(5-phenyl-2H-benzotriazole-
2-yl) -3-hydroxyphenoxy) -1,3,5
-Triazine, 2,4,6-tris- (4- (5-benzyl-2H-benzotriazol-2-yl) -3-hydroxyphenoxy) -1,3,5-triazine,
4,6-tris- (4- (5-chloro-2H-benzotriazol-2-yl) -3-hydroxy-6-methylphenoxy) -1,3,5-triazine, 2,4,6-
Tris- (4- (5-methyl-2H-benzotriazol-2-yl) -3-hydroxy-6-chlorophenoxy) -1,3,5-triazine and the like. In particular,
From the viewpoint of light resistance and heat resistance, 2,4,6-tris- (4
-(2H-benzotriazol-2-yl) -3-hydroxyphenoxy) -1,3,5-triazine is preferred.

Next, application of the thus obtained trisbenzotriazole compound to a thermosensitive recording medium will be described. The thermosensitive recording medium is usually obtained by providing a thermosensitive recording layer containing an electron donating compound and an electron accepting compound on a support. In the present invention, in addition to the thermosensitive recording layer, a protective layer containing a water-soluble or water-dispersible binder as a main component, an intermediate layer between the thermosensitive recording layer and the protective layer, a support and a thermosensitive recording layer on the thermosensitive recording layer. A laminated structure in which an undercoat layer containing a filler and a binder as main components, a back coat layer made of water or a binder on the back of the support, and the like can be provided. These layer configurations may be appropriately combined according to the required quality, and a known technique usually used in the field of thermal recording can be applied.
The thermosensitive recording medium of the present invention is characterized in that at least one of these contains at least one trisbenzotriazole compound represented by the general formula (1) as an ultraviolet absorber. By using this trisbenzotriazole compound, the light resistance of the recording portion and the background portion of the thermosensitive recording medium is remarkably improved. However, in particular, in terms of ultraviolet absorption efficiency and shielding efficiency, a protective layer is formed on the thermosensitive recording layer. Is desirably provided in the protective layer.

Further, due to the high-temperature stability of the trisbenzotriazole compound of the present invention, stable recording traveling properties can be obtained without sticking or head residue due to melting during recording with a thermal head. Further, even when the trisbenzotriazole compound of the present invention is blended in the heat-sensitive recording layer, the background fog of the recording portion under a high-temperature environment is extremely small. Moreover, since it hardly dissolves in plasticizers, oils, organic solvents, etc., when used for the protective layer, even if the protective layer surface comes into contact with these organic solvents, the barrier function is reduced due to the elution of the ultraviolet absorber. And an excellent effect of improving image storability can be obtained.

When the trisbenzotriazole compound of the present invention is used in a thermosensitive recording medium, the average particle size is preferably 2 μm or less, more preferably 0.5 μm or less, in order to obtain a desired effect. . The average particle size is 0.
When the thickness is 5 μm or less, not only the ultraviolet absorption efficiency is remarkably improved, but also when contained in the protective layer, the recorded image is hardly concealed, so that a clear recorded image can be obtained.

As a method for reducing the average particle size of the trisbenzotriazole compound to 2 μm or less, generally, water is used as a dispersion medium, and additives such as a dispersant and an antifoaming agent are added as necessary. , An attritor, a sand mill or the like, and a method using a stirrer / pulverizer. Among them, a sand mill type pulverizer is desirable, and the average particle size of the dispersion medium is preferably 1 mm or less.

The trisbenzotriazole compound of the present invention can be used in combination with other known ultraviolet absorbers as long as the desired effect is not impaired. Nickel bis (octylphenyl) sulfide, [2,2 ′
-Thiobis (4-tert-octylphenolate)]
UV stabilizers such as -n-butylamine nickel, nickel complex-3,5'-di-tert-butyl-4-hydroxybenzyl-phosphate monoethylate, nickel dibutyl dithiocarbamate, benzoate type quencher, and bis (2 It is also preferable to use a hindered amine light stabilizer such as (2,6,6-tetramethyl-4-piperidyl) sebacate.

In the present invention, examples of a thermal recording system utilizing a color development reaction between an electron-donating compound and an electron-accepting compound include, for example, a combination of a dye precursor and a color developer, a combination of a diazonium salt and a coupler, iron and the like. Examples of the combination of a transition element and a chelate compound, a combination of an aromatic isocyanate compound and an imino compound, and the like, but the combination of a dye precursor and a developer is excellent in color density and recording sensitivity. A heat-sensitive recording material utilizing a color development reaction between a dye precursor and a color developer will be described in detail.

As the dye precursor used in the present invention, various known compounds can be used. These may be used alone or in combination of two or more, and are selected depending on the application and required characteristics. Specific examples include, but are not limited to, the following compounds.

(1) Triarylmethane compound 3,3'-bis (4-dimethylaminophenyl) -6
Dimethylaminophthalide <trade name: crystal violet lactone, CVL>, 3- (4-dimethylamino-
2-methylphenyl) -3- (4-dimethylaminophenyl) phthalide, 3,3′-bis (2- (4-dimethylaminophenyl) -2- (4-methoxyphenyl) ethenyl) -4,5,6 , 7-Tetrachlorophthalide <NI
R-Black>, 3,3′-bis (4-dimethylaminophenyl) phthalide <MGL>, 3- (4-dimethylaminophenyl) -3- (1,2-dimethylindol-3-yl) phthalide, 3 -(4-dimethylaminophenyl) -3- (2-phenylindol-3-yl) phthalide, 3,3'-bis (4-ethylcarbazole-3
-Yl) -3-dimethylaminophthalide, 3,3'-bis (1-ethyl-2-methylindol-3-yl) phthalide <indolyl red>, 3,3'-bis (2-phenylindole- 3-yl) -5-dimethylaminophthalide, tris (4-dimethylaminophenyl) methane <LCV> and the like. (2) Diphenylmethane compounds 4,4-bis (dimethylamino) benzhydrin benzyl ether, N-halophenyl-leuco auramine, N
-2,4,5-trichlorophenylleuco auramine and the like. (3) Xanthene compound rhodamine B-anilinolactam, 3-diethylamino-7-dibenzylaminofluoran, 3-diethylamino-7-butylaminofluoran, 3-diethylamino-7-anilinofluoran <Green-2 >, 3-diethylamino-7- (2-chloroanilino) fluoran, 3-dibutylamino-7- (2-chloroanilino)
Fluoran <TH-107>, 3-diethylamino-7
-(3-trifluoromethylanilino) fluoran <B
rack-100>, 3-diethylamino-6-methyl-7-anilinofluoran <ODB>, 3-dibutylamino-6-methyl-7-anilinofluoran <ODB-
2>, 3-piperidino-6-methyl-7-anilinofluoran, 3- (N-isoamyl-N-ethylamino)-
6-methyl-7-anilinofluoran <S-205>,
3- (N-ethyl-N-tolylamino) -6-methyl-
7-anilinofluoran, 3- (N-cyclohexyl-
N-methylamino) -6-methyl-7-anilinofluoran <PSD-150>, 3-diethylamino-6-chloro-7- (β-ethoxyethylamino) fluoran,
3-diethylamino-6-chloro-7- (γ-chloropropylamino) fluoran, 3-cyclohexylamino-6-chlorofluoran <OR-55>, 3-diethylamino-6-chloro-7-anilinofluoran, 3-
(N-cyclohexyl-N-methylamino) -6-methyl-7-anilinofluoran, 3-diethylamino-7
-Phenylfluoran and the like. (4) Thiazine-based compounds Benzoyl leucomethylene blue, p-nitrobenzoyl leucomethylene blue and the like can be mentioned. (5) Spiro compounds 3-methylspirodinaphthopyran, 3-ethylspirodinaphthopyran, 3-benzylspirodinaphthopyran, 3
-Methylnaphtho- (6'-methoxybenzo) spiropyran; (6) Pentadiene compound 1,1,5,5-tetrakis (4-dimethylaminophenyl) -3-methoxy-1,4-pentadiene,
1,5,5-tetrakis (4-dimethylaminophenyl) -1,4-pentadiene and the like can be mentioned.

Next, as a developer used in the present invention, activated clay, attapulgite, colloidal silica,
Inorganic acidic substances such as aluminum silicate, benzyl 4-hydroxybenzoate, ethyl 4-hydroxybenzoate,
4-hydroxybenzoic acid esters such as normal propyl hydroxybenzoate, isopropyl 4-hydroxybenzoate, butyl 4-hydroxybenzoate, dimethyl 4-hydroxyphthalate, diisopropyl 4-hydroxyphthalate, dibenzyl 4-hydroxyphthalate, 4-hydroxyphthalic acid diesters such as 4-hydroxyphthalic acid dihexyl; phthalic acid monoesters such as monobenzyl phthalate, monocyclohexyl phthalate, monophenyl phthalate, and monomethylphenyl phthalate; bis (4 -Hydroxy-
3-tert-butyl-6-methylphenyl) sulfide,
Bishydroxyphenyl sulfides such as bis (4-hydroxy-2,5-dimethylphenyl) sulfide and bis (4-hydroxy-5-ethyl-2-methylphenyl) sulfide; 3,4-bisphenol A;
Bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane <bisphenol A>, bis (4-hydroxyphenyl) methane <bisphenol F>, 2,2-bis (4-hydroxyphenyl) Hexane, tetramethylbisphenol A, 1,1
-Bis (4-hydroxyphenyl) -1-phenylethane, 1,4-bis (2- (4-hydroxyphenyl) propyl) benzene, 1,3-bis (2- (4-hydroxyphenyl) propyl) benzene, 1,4-bis (4
-Hydroxyphenyl) cyclohexane, 2,2'-bis- (4-hydroxy-3-isopropylphenyl) propane, 1,4-bis (1- (4- (2- (4-hydroxyphenyl) -2-propyl) Bisphenols such as phenyl) ethyl) benzene, 4-hydroxy-4 ′
-Isopropoxydiphenyl sulfone <D-8>, 4-
Hydroxy-4′-methoxydiphenylsulfone, 4-
4-hydroxyphenylarylsulfones such as hydroxy-4′-normalpropoxydiphenylsulfone, bis (4-hydroxyphenyl) sulfone <bisphenol S>, tetramethylbisphenol S, bis (3-ethyl-4-hydroxyphenyl) sulfone, Bis (3-propyl-4-hydroxyphenyl) sulfone, bis (3-isopropyl-4-hydroxyphenyl) sulfone, bis (3-tert-butyl-4-hydroxy-6-methylphenyl) sulfone, bis (3-chloro Bishydroxyphenylsulfones such as -4-hydroxyphenyl) sulfone, bis (3-bromo-4-hydroxyphenyl) sulfone, 2-hydroxyphenyl-4′-hydroxyphenylsulfone, 4-hydroxybenzenesulfonate, and 4-hydrido 4-hydroxyphenylarylsulfonates such as xylphenyl-p-tolylsulfonate, 4-hydroxyphenyl-p-chlorobenzenesulfonate, benzyl 4-hydroxybenzoyloxybenzoate, ethyl 4-hydroxybenzoyloxybenzoate, 4-hydroxy 4-hydroxybenzoyloxybenzoates such as normal propyl benzoyloxybenzoate, isopropyl 4-hydroxybenzoyloxybenzoate, butyl 4-hydroxybenzoyloxybenzoate, 2,4-dihydroxybenzophenone, α, α′-bis- Benzophenones such as (3-methyl-4-hydroxyphenyl) -m-diisopropylbenzophenone and 2,3,4,4'-tetrahydroxybenzophenone, N-stearyl-p-amido Phenol, 4-hydroxy salicylic anilide,
4,4′-dihydroxydiphenyl ether, n-butylbis (hydroxyphenyl) acetate, α, α ′,
α "-tris (4-hydroxyphenyl) -1,3,5
-Triisopropylbenzene, stearyl gallate,
4,4'-thiobis (6-t-butyl-m-cresol), 2,2-bis (3-allyl-4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxy- 3-methylphenyl) sulfide, p-tert-butylphenol, p
-Phenylphenol, p-benzylphenol, 1
Phenolic compounds such as naphthol and 2-naphthol, thiourea compounds such as N, N'-di-m-chlorophenylthiourea, benzoic acid, p-tert-butylbenzoic acid, trichlorobenzoic acid, 3-sec-butyl- 4-hydroxybenzoic acid, 3-cyclohexyl-4-hydroxybenzoic acid, 3,5-dimethyl-4-hydroxybenzoic acid, terephthalic acid, salicylic acid, 3-isopropylsalicylic acid, 3-tert-butylsalicylic acid, 4- (2- (P
-Methoxyphenoxy) ethyloxy) salicylic acid, 4
Aromatic carboxylic acids such as-(3- (p-tolylsulfonyl) propyloxy) salicylic acid, 5- (p- (2- (p-methoxyphenoxy) ethoxy) cumyl) salicylic acid, and zinc of these aromatic carboxylic acids; Organic acids such as salts with polyvalent metals such as magnesium, aluminum, calcium, titanium, manganese, tin and nickel, and antipyrine complexes of zinc thiocyanate and composite zinc salts of terephthalaldehyde acid and other aromatic carboxylic acids Substances and the like. These may be used in combination of two or more.

Usually, in a thermosensitive recording medium, a sensitizer is used for the purpose of improving the sensitivity. In the thermosensitive recording medium of the present invention, a sensitizer can be added to the thermosensitive recording layer according to the purpose. Specific examples are shown below, but the present invention is not limited thereto, and two or more of them may be used in combination.

Stearic acid amide, methoxycarbonyl-N-stearic acid benzamide, N-benzoylstearic acid amide, N-eicosanoic acid amide, ethylenebisstearic acid amide, behenic acid amide, methylenebisstearic acid amide, methylolamide, N-methylolamide Methylol stearamide, dibenzyl terephthalate, dimethyl terephthalate, dioctyl terephthalate, benzyl p-benzyloxybenzoate, 1-hydroxy-2-
Phenyl naphthoate, dibenzyl oxalate, oxalic acid
Di-p-methylbenzyl, di-p-chlorobenzyl oxalate, 2-naphthylbenzyl ether, m-terphenyl, p-benzylbiphenyl, tolylbiphenyl ether, di (p-methoxyphenoxyethyl) ether,
1,2-di (3-methylphenoxy) ethane, 1,2-
Di (4-methylphenoxy) ethane, 1,2-di (4-
Methoxyphenoxy) ethane, 1,2-di (4-chlorophenoxy) ethane, 1,2-diphenoxyethane, 1,
-(4-methoxyphenoxy) -2- (2-methylphenoxy) ethane, p-methylthiophenylbenzyl ether, 1,4-di (phenylthio) butane, p-acetotoluidide, p-acetophenethidide, N-acetoacetyl -P-toluidine, di (-biphenylethoxy) benzene, p-di (vinyloxyethoxy) benzene, 1
-Isopropylphenyl-2-phenylethane and the like. These sensitizers are usually used in an amount of 0.1 to 10 parts by weight based on 1 part by weight of the dye precursor.

Further, in the heat-sensitive recording material of the present invention, a storage stabilizer can be used for stabilization during storage. Specific examples of the storage stabilizer include 1,1,3-tris (2
-Methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane, 4,
4'-butylidenebis (2-tert-butyl-5-methylphenol), 4,4'-thiobis (2-tert-butyl-5-methylphenol), 2,2'-thiobis (6-
hindered phenol compounds such as tert-butyl-4-methylphenol) and 2,2′-methylenebis (6-tert-butyl-4-methylphenol), 4-benzyloxy-4 ′-(2-methylglycidyloxy) diphenyl Sulfone, sodium 2,2′-methylenebis (4,6-di-tert-butylphenyl) phosphate and the like. These storage stabilizers are usually dye precursor 1
0.1 to 10 parts by weight per part by weight is used.

In the thermal recording medium of the present invention, specific examples of the binder used for each layer include starches, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, gum arabic, polyvinyl alcohol, carboxy-modified polyvinyl alcohol, Acetyl group-modified polyvinyl alcohol, silicon-modified polyvinyl alcohol, isobutylene-
Water-soluble binders such as maleic anhydride copolymer alkaline salt, styrene-maleic anhydride copolymer alkaline salt, ethylene-maleic anhydride copolymer alkaline salt, styrene-acrylic acid copolymer alkaline salt, and styrene-butadiene copolymer Latexes such as polymers, acrylonitrile-butadiene copolymers, methyl acrylate-butadiene copolymers, and water-dispersible binders such as urea resins, melamine resins, amide resins, and polyurethane resins. At least one of these binders is used in the range of 15 to 80% by weight based on the total solid content of the heat-sensitive recording layer, protective layer, intermediate layer, or undercoat layer.

As the filler, activated clay, clay,
Inorganic fillers such as calcined clay, diatomaceous earth, talc, kaolin, calcined kaolin, calcium carbonate, magnesium carbonate, barium carbonate, titanium oxide, zinc oxide, silicon oxide, aluminum hydroxide, urea-formalin resin, polystyrene resin, phenol resin, etc. Organic fillers are used.

A heat-fusible substance may be added for the purpose of preventing head abrasion and sticking. Examples include beeswax, animal waxes such as shellac wax,
Vegetable waxes such as carnauba wax, mineral waxes such as montan wax, petroleum waxes such as microcrystalline wax, higher fatty acid polyhydric alcohol esters, higher fatty acid amides such as stearamide, zinc stearate,
Metal salts of higher fatty acids such as calcium stearate, higher amines, condensates of fatty acids and amines, condensates of aromatic and amine, synthetic paraffin, chlorinated paraffin, paraffin oxide, higher linear glycol, 3,4-epoxyhexahydrophthale Synthetic wax such as dialkyl acid, polyethylene, polyethylene oxide and the like.

Further, a dispersant such as sodium dioctyl sulfosuccinate, a surfactant, an antifoaming agent, a fluorescent whitening agent,
Waterproofing agents, lubricants and the like are utilized as desired.

As the support in the heat-sensitive recording medium of the present invention, paper such as high-quality paper, medium-quality paper, and coated paper is mainly used, and various non-woven fabrics, plastic films, synthetic papers, metal foils, and the like are used. A combined sheet or the like is optionally used.

Using the various materials described above, the thermosensitive recording medium of the present invention can be manufactured by a conventionally known method. The method for preparing the coating solution for each layer of the thermosensitive recording medium is not particularly limited.Generally, water is used as a dispersion medium, and in addition to the trisbenzotriazole of the present invention, a binder and a filler, if necessary, a filler, a lubricant, and the like are added. It is prepared by mixing and stirring. In the case of a heat-sensitive recording layer, the adjustment is performed by adding a dye precursor and a color developer.

The dye precursor and the developer are separately pulverized and dispersed in an aqueous system with a sand grinder, an attritor, a ball mill or the like, and then mixed to obtain an aqueous paint. A method of obtaining a water-based paint after microencapsulating any of the agents is known. The use ratio of the dye precursor and the developer is appropriately selected depending on the type of the dye precursor and the developer to be used, and is not particularly limited. Generally, 1 to 50 parts by weight based on 1 part by weight of the dye precursor is used. Parts by weight, preferably 2 to 10
Approximately parts by weight of developer are used.

When the trisbenzotriazole compound of the present invention is contained in at least one of a heat-sensitive recording layer, a protective layer, an intermediate layer and an undercoat layer, it is 1 to 50% by weight, preferably 10 to 50% by weight, based on the total solid content of each layer. Preferably it is present in the range of 40% by weight. When the amount of such a compound is less than 1% by weight based on the total solid content, the light resistance in the recording portion and the background portion is remarkably reduced, and when the amount is more than 50% by weight, the viscosity of the paint over time becomes severe and the coating aptitude becomes poor. Inferior. When it is contained in the protective layer, if it exceeds 50% by weight, the film-forming property of the protective layer is reduced, and the image storability of the recording part is significantly reduced.

The method of forming each layer of the thermosensitive recording medium is not particularly limited, and air knife coating, buriba blade coating, pure blade coating,
Rod blade coating, short dwell coating, curtain coating, die coating, and the like can be appropriately selected. For example, after coating the coating solution for the heat-sensitive recording layer on the support and drying, the coating solution for the protective layer is further coated with the coating solution for the heat-sensitive recording layer. It is formed by a method such as coating and drying. Further, the coating amount of the heat-sensitive recording layer coating liquid is 2 to 12 g by dry weight.
/ M ² , preferably about 3 to 10 g / m ² , and the coating amount of the coating solution for the intermediate layer or the protective layer is 0.1 to 15 by dry weight.
g / m ² approximately, it is preferably adjusted in the range of about 0.5~7g / m ^2.

The heat-sensitive recording medium of the present invention can be provided with a back coat layer on the back side of the support, if necessary, to further improve the storability. Furthermore, after each layer is formed, it is subjected to a smoothing treatment such as super calendaring, or a pressure-sensitive adhesive is applied to the rear surface of the heat-sensitive recording material to process the pressure-sensitive adhesive label. Various known techniques in the field of heat-sensitive recording material production, such as providing a recording layer, can be added according to the application.

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to specific embodiments. However, the present invention is not limited to this embodiment. In the examples, “parts” and “%” indicate “parts by weight” and “% by weight”, respectively, unless otherwise specified.

<Production of trisbenzotriazole compound of the present invention> [Synthesis Example 1] 2,4,6-tris- (4- (2H-benzotriazol-2-yl) -3-hydroxyphenoxy) -1,
Synthesis of 3,5-triazine In a three-necked flask equipped with a reflux tube, 2- (2,4
-Dihydroxyphenyl) -2H-benzotriazole
A mixture of 4.54 g (20 mmol), 1.23 g (6.67 mmol) of cyanuric chloride, 2.12 g (20 mmol) of anhydrous sodium carbonate, and 16.5 g of 1,2,4-trimethylbenzene was heated and stirred at 170 ^° C. for 3 hours.
Then, when cooled to room temperature, a pale yellow solid was deposited. It was filtered and washed with water and trimethylbenzene. After drying it, 2,4,6-tris- (4- (2
H-benzotriazol-2-yl) -3-hydroxyphenoxy) -1,3,5-triazine as a pale yellow solid
2.79 g (55% yield) was obtained. The analysis results of the synthesized trisbenzotriazole compound are shown below. 330-335 ^o C (decomp.) Infrared absorption spectrum (KBr, cm ^-1 ) 3443 (OH), 3114, 3069, 1606, 1577, 1563, 1526, 149
9, 1447, 1371, 1364, 1277, 1258, 1225, 1170, 1132,
971, 867, 808, 743, 687 NMR spectrum ¹ H-NMR (DMSO-d ₆ , TMS, δ ppm) 7.0 (dd, 3H, J = 1.4 Hz, 7.7 Hz), 7.1 (dd, 3H, J = 1.4 H)
z, 5.3Hz), 7.4-7.6 (m, 6H), 7.8-8.3 (m, 9H), 10.9-11.
0 (m, 3H) mass spectrometry (FAB-MS (m / z)) 757 [M + H] ⁺ ultraviolet absorption spectrum λmax (DMSO) = 289 nm (ε = 3.52 X 10 ⁴ lcm ^-1 mol ^-1 )

<Manufacture of thermosensitive recording medium> [Example 1] Liquid A (developer dispersion liquid) 4-hydroxy-4'-isopropoxydiphenyl sulfone 6.0 parts 10% aqueous solution of polyvinyl alcohol 20.0 parts Water 17 0.0 part A mixture of the above composition was ground with a sand grinder to an average particle size of 1 micron. Liquid B (dye dispersion liquid) 2,4-dimethyl-6-[(4-dimethylamino) anilino] fluoran 3.0 parts 10% aqueous solution of polyvinyl alcohol 5.0 parts Water 2.0 parts Mixture of the above compositions Was ground to an average particle size of 1 micron with a sand grinder. Subsequently, the dispersion liquid was mixed at the following ratio to obtain a coating liquid. Solution A 43.0 parts Solution B 10.0 parts Kaolin clay 30% dispersion 10.0 parts Each of the above coating solutions is applied to one surface of a support of 50 g / m ² .
The coating was dried at 0 g / m ² to form a heat-sensitive recording layer. Formation of protective layer (containing UV absorber) Liquid C (UV absorber dispersion) 2,4,6-tris- (4- (2H-benzotriazol-2-yl) -3-hydroxyphenoxy) -1 3,3,5-Triazine 3.0 parts 10% aqueous solution of polyvinyl alcohol 5.0 parts Water 2.0 parts A mixture of the above compositions was ground with a sand grinder to an average particle diameter of 1 micron. Subsequently, the dispersion liquid was mixed at the following ratio to obtain a coating liquid. 10% aqueous polyvinyl alcohol solution 26.2 parts Aluminum hydroxide (50% dispersion) 6.0 parts Liquid C 10.0 parts Dilution water 48.1 parts Fluorescent dye 25% aqueous solution 0.1 parts Thermal recording of each of the above coating liquids After coating and drying on the layer so that the coating amount was 3.0 g / m ² , a super calender treatment was performed to obtain a heat-sensitive recording material.

Example 2 Formation of Thermal Recording Layer (Containing Ultraviolet Absorber) Solution A (Developer Dispersion) 4-Hydroxy-4′-isopropoxydiphenyl sulfone 6.0 parts 10% aqueous solution of polyvinyl alcohol 20. 0 parts Water 17.0 parts A mixture of the above compositions was ground with a sand grinder to an average particle size of 1 micron. Liquid B (dye dispersion liquid) 2,4-dimethyl-6-[(4-dimethylamino) anilino] fluoran 3.0 parts 10% aqueous solution of polyvinyl alcohol 5.0 parts Water 2.0 parts Mixture of the above compositions Was ground to an average particle size of 1 micron with a sand grinder. Liquid C (ultraviolet absorbent dispersion) 2,4,6-tris- (4- (2H-benzotriazol-2-yl) -3-hydroxyphenoxy) -1,3,5-triazine 3.0 parts 10% aqueous solution of polyvinyl alcohol 5.0 parts Water 2.0 parts A mixture of the above compositions was ground with a sand grinder to an average particle size of 1 micron. Subsequently, the dispersion liquid was mixed at the following ratio to obtain a coating liquid. Liquid A 43.0 parts Liquid B 10.0 parts Liquid C 10.0 parts Kaolin clay 30% dispersion 10.0 parts Each of the above coating liquids is applied on one surface of a 50 g / m ² support.
The coating was dried at 0 g / m ² to form a heat-sensitive recording layer. Formation of protective layer A dispersion was mixed at the following ratio to obtain a coating liquid. 10% aqueous polyvinyl alcohol solution 60.0 parts Aluminum hydroxide (50% dispersion) 50.0 parts Zinc stearate 10.0 parts Dilution water 50.0 parts Fluorescent dye 25% aqueous solution 0.5 parts Heat-sensitive each coating solution After coating and drying to a coating amount of 3.0 g / m ² on the recording layer, a super calender treatment was performed to obtain a thermosensitive recording medium.

Example 3 Liquid A (Developer Dispersion) 4-Hydroxy-4′-isopropoxydiphenylsulfone 6.0 parts 10% aqueous polyvinyl alcohol solution 20.0 parts Water 17.0 parts The above composition Was mixed with a sand grinder to an average particle size of 1 micron. Liquid B (dye dispersion liquid) 2,4-dimethyl-6-[(4-dimethylamino) anilino] fluoran 3.0 parts 10% aqueous solution of polyvinyl alcohol 5.0 parts Water 2.0 parts Mixture of the above compositions Was ground to an average particle size of 1 micron with a sand grinder. Subsequently, the dispersion liquid was mixed at the following ratio to obtain a coating liquid. Solution A 43.0 parts Solution B 10.0 parts Kaolin clay 30% dispersion 10.0 parts Each of the above coating solutions is applied to one surface of a support of 50 g / m ² .
The coating was dried at 0 g / m ² to form a heat-sensitive recording layer. Formation of Intermediate Layer (Containing UV Absorber) The dispersion liquid was mixed at the following ratio to obtain a coating liquid. 2,4,6-tris- (4- (2H-benzotriazol-2-yl) -3-hydroxyphenoxy) -1,3,5-triazine 3.0 parts 10% aqueous solution of polyvinyl alcohol 5.0 parts Water 2.0 parts A mixture of the above composition was ground with a sand grinder to an average particle size of 1 micron. This coating liquid was applied onto the heat-sensitive recording layer so as to have a coating amount of 3.0 g / m ² and dried to form an intermediate layer. Formation of protective layer A dispersion was mixed at the following ratio to obtain a coating liquid. 10% aqueous polyvinyl alcohol solution 60.0 parts Aluminum hydroxide (50% dispersion) 50.0 parts Zinc stearate 10.0 parts Dilution water 50.0 parts Fluorescent dye 25% aqueous solution 0.5 parts Heat-sensitive each coating solution After coating and drying to a coating amount of 3.0 g / m ² on the recording layer, a super calender treatment was performed to obtain a thermosensitive recording medium.

Comparative Example 1 A thermosensitive recording medium was produced in the same manner as in Example 1 except that the above-mentioned ultraviolet absorbent was not used. [Comparative Example 2] Instead of the above-mentioned ultraviolet absorber, an existing ultraviolet absorber, 2,2'-methylenebis [6- (2H-
Benzotriazol-2-yl) -4- (1,1,3,
[3-tetramethylbutylphenol], and a thermosensitive recording medium was produced in the same manner as in Example 1 except for the above.

Tables 1 and 2 show the results of quality performance tests performed on the thermal recording media obtained in the above Examples and Comparative Examples.
Shown in Whiteness: Measured with a blue filter using a Hunter whiteness meter. Color development: UBI EasyCoder 201 IIE (by UBI) 0.26mj / d
The image density recorded by ot was measured with a Macbeth densitometer amber filter. Light fastness: The heat-sensitive recording medium printed under the above conditions was treated with a xenon lamp weather meter for 24 hours, and then the densities of the recording portion and the background portion were measured with a Macbeth densitometer amber filter. (Irradiance 67W / m ² , Integrated irradiance 5348kj / m ² ) Head scum: UBI EasyCoder
After recording at 201 IIE (manufactured by UBI) at 0.41 mj / dot, the degree of dirt (head residue) on the thermal head was visually evaluated as follows. Evaluation criteria A: No head residue at all. ：: There is some head residue, but there is no practical problem. ×: Many head scum. Plasticizer resistance test: A heat-sensitive recording medium printed under the above conditions was applied to a vinyl chloride film (Mitsubishi Resin Co., Ltd.
0G), allowed to stand at room temperature for 24 hours, and measured the density of the recording portion with a Macbeth densitometer.

[0050]

[Table 1] Table 1

[0051]

[Table 2] Table 2

[0052]

The trisbenzotriazole compound represented by the general formula (1) of the present invention has a new advantage of high-temperature stability, which is not present in existing ultraviolet absorbers, in addition to its own high ultraviolet absorption ability. Can be said to have been given. In addition, synthesis and purification can be performed very easily, and it is industrially useful. And, the thermosensitive recording medium using the trisbenzotriazole compound of the present invention,
It is excellent in light resistance of the recording portion and the background portion, does not discolor even when stored for a long time in sunlight or under high temperature, and its appearance is not impaired. In addition, the head scum adhesion during recording is suppressed, the recording running property is good, and the image storability such as plasticizer resistance is also excellent.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Reiji Ohashi 5-2-1-1, Oji, Kita-ku, Tokyo Nippon Paper Industries Central Research Laboratory F-term (reference) 2H026 AA21 DD08 DD09 DD15 DD45 DD46 4C050 AA01 AA07 BB01 CC02 EE03 FF05 GG01 HH01

Claims (3)

[Claims] 1. A novel trisbenzotriazole compound represented by the following general formula (1). Embedded image (1) However, X and Y represent a hydrogen atom, an alkyl group of C1 to C8, an alkoxy group of C1 to C6, or a halogen atom. 2. Trisbenzotriazole according to claim 1, which is 2,4,6-tris- (4- (2H-benzotriazol-2-yl) -3-hydroxyphenoxy) -1,3,5-triazine. Compound. 3. The trisbenzotriazole according to claim 1 or 2, wherein the thermosensitive recording medium has a thermosensitive recording layer containing an electron-donating compound and an electron-accepting compound as main components on a support. A heat-sensitive recording material comprising at least one compound.