JPH11147880A - Novel bisbenzotriazole compound and heat-sensitizing recording body containing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject compound being an ultraviolet-absorbing compound that is useful as a heat-sensitive recording body showing excellent light resistance of its images and exposed parts and record-running properties. SOLUTION: This compound is represented by formula I [W is an imino, 0; Y is H, a 1-6C alkyl, R1 CO (R1 is a 1-6C alkyl, aryl); Z is H, a 1-6C alkyl or alkoxy, a (2-7C acyl-containing) amino, a halogen], typically 4,4'-bis(4-(2H- benzotriazol-2-yl)-3-hydroxyphenoxycarbonylamino)diphenyl-methane. The compound of the formula I is prepared by reaction of two molar equivalent amount of a triazole of formula II (W' is an amino or hydroxyl group) with one molar equivalent amount of 4,4'-diphenylmethane diisocyanate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel bisbenzotriazole compound and a thermosensitive recording medium containing the compound.

[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-colored dye precursor and an electron-accepting developer is provided on a support, and this is provided with a thermal head,
By heating with a hot pen, laser light, or the like, the dye precursor and the developer are instantaneously reacted to obtain a recorded image.
It is disclosed in, for example, JP-A-14039. Such thermosensitive recording paper has the advantages of being able to record with a relatively simple device, being easy to maintain, and having no noise.It has a measuring recorder, facsimile, printer, computer terminal, It is used in a wide range of fields such as labels and ticket vending machines.

[0003] As one application of the heat-sensitive recording paper, in recent years, it has been often used for various heading labels, display media such as posters, and the like. In these applications, the thermal recording paper is often exposed to room light or sunlight for a long period of time, and as a result, the background of the thermal recording paper yellows or the stability of the recorded image is impaired. As a result, the product image is significantly impaired.

In order to solve these problems, a method of adding a finely pulverized ultraviolet absorber to a heat-sensitive recording layer or a protective layer in a conventional heat-sensitive recording paper (Japanese Patent Laid-Open No. 50-1078).
No. 4650, No. 55-55891, No. 55-
93492, 58-87093, etc.). However, finely crushed UV absorbers have poor absorption efficiency of UV rays, failing to provide a sufficient effect.Additionally, increasing the amount of UV absorbers causes new flaws, such as background fogging or reduced recording density. At present, however, it has not been possible to obtain sufficiently satisfactory light fastness as a result. In addition, if the protective layer contains a finely pulverized ultraviolet absorber, the ultraviolet absorber elutes due to the influence of a plasticizer or oils and the like, losing the function of the protective layer, and as a result, the preservability of the recorded image is reduced. Resulting in.

Further, a compound which is made water-soluble by introducing a sodium sulfonate group into an ultraviolet absorber is used as a heat-sensitive layer and / or
A method of adding it to the protective layer is proposed in Japanese Patent Publication No. 61-57198. However, in this method, the introduction of a sodium sulfonate group has an adverse effect on the pH and liquidity of the prescription system, and also has a problem such as coloring of the background and an adverse effect on a heat-sensitive head. 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. However, this method requires microencapsulation of an ultraviolet absorber, and although it is superior to a finely pulverized product, the dispersibility of the ultraviolet absorber is lower than the dispersion at the molecular level, and the ultraviolet absorption efficiency becomes poor. The amount added has to be large.

[0006]

As described above, it has been practiced for a long time to impart light fastness to heat-sensitive recording paper using an ultraviolet absorber, but a satisfactory method has not yet been developed. is the current situation. Accordingly, an object of the present invention is to obtain a novel ultraviolet absorbent, and to provide a thermosensitive recording medium which is excellent in light resistance of an image and a background portion using the ultraviolet absorbent, and which is excellent in recording running property. .

[0007]

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

[0008]

Embedded image

Wherein W is an imino group or an oxygen atom, Y is a hydrogen atom, an alkyl group of C1 to C6, or R1CO, and R1 is an alkyl or aryl group of C1 to C6. Z is a hydrogen atom, C1 to
An alkyl group up to C6, an alkoxy group up to C1 to C6, an amino group optionally having an acyl group up to C2 to C7, or a halogen atom. ]

The bisbenzotriazole compound represented by the general formula (1) is characterized by having a structure in which a benzotriazole compound exhibiting ultraviolet absorbing properties is bonded with 4,4'-diphenylmethane diisocyanate (hereinafter referred to as MDI). The present inventors have found that by using such a compound, it is possible to obtain a heat-sensitive recording material which is excellent in light fastness of an image and yellowing resistance of a white paper portion and excellent in recording running property, and has reached the present invention.

Conventional UV absorbers have a low melting point of the substance,
When it was contained in the protective layer, there was a problem of adhesion of scum to the thermal head. On the other hand, the novel bisbenzotriazole compound of the present invention has a very high melting point as compared with a simple benzotriazole compound, so that the adhesion of scum to the thermal head can be reduced. It is known that the compound synthesized from MDI has a very high melting point and high crystallinity, but the bisbenzotriazole compound of the present invention has a high melting point without impairing the ultraviolet absorption of the benzotriazole compound. Is a successful one. Further, when it is contained in the thermosensitive recording medium, it is possible to maintain a sufficient recording density without adversely affecting various characteristics of the thermosensitive recording medium.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the bisbenzotriazole compound of the present invention and a thermosensitive recording medium containing the same will be described in detail. First, a method for producing a novel bisbenzotriazole compound represented by the above general formula (1) of the present invention will be described.

The benzotriazole compound used as a raw material in the present invention is represented by the following general formula (2).

[0014]

Embedded image

Wherein W 'is an amino group or a hydroxyl group, Y is a hydrogen atom, an alkyl group of C1 to C6, or R1CO, and R1 is an alkyl group or an aryl group of C1 to C6. Z is a hydrogen atom, C1 to
An alkyl group up to C6, an alkoxy group up to C1 to C6, an amino group optionally having an acyl group up to C2 to C7, or a halogen atom. ]

The synthesis of these benzotriazole compounds has been known for a long time, and is described, for example, in O. Fogl et al., J. Macro.
mol.Sci-Chem., A20 (3), 309-320 (1983), Macromol. Che
m., 185, 2497-2509 (1984). The benzotriazole compound of the general formula (2) used in the present invention can be synthesized in the same manner.

Next, the compound of the present invention can be synthesized as follows. Two molar equivalents of the benzotriazole compound of the general formula (2) and 1 molar equivalent of MDI were obtained by a conventionally known method (for example, a method described in New Experimental Chemistry Lecture 14, Reaction of Organic Compounds and Synthesis (III) p. By using the compound, a desired bisbenzotriazole compound can be synthesized. Specifically, a benzotriazole compound dissolved in an inert solvent such as acetone or THF is mixed with M
DI is mixed under an atmosphere of an inert gas (e.g., argon, nitrogen, etc.) and heated and stirred for several minutes to several hours.
The desired bisbenzotriazole compound can be synthesized. At this time, if a small amount of a base (for example, a basic compound such as pyridine) is used as a catalyst, the above reaction proceeds rapidly. The MDI used in the present invention is very easily and inexpensively available because it is industrially produced in large quantities as a paint, an adhesive, or a raw material for polyurethane. Also, the production can be performed at a high yield without requiring any special equipment. Therefore, there is an advantage that the production cost of the ultraviolet absorbent of the present invention is very low. In addition, the difference in reactivity between the two hydroxyl groups present in the benzotriazole compound used as a raw material is described as follows.
Since the hydroxyl group at the 4-position is stabilized by the nitrogen atom of the triazole ring and the hydrogen bond, the reactivity is very low, and the reactivity of the hydroxyl group at the 4-position is high. Therefore, in the case of a benzotriazole compound having a hydroxyl group at the 2-position and 4-position, the reaction proceeds selectively without protecting the 2-position hydroxyl group only.

As the bisbenzotriazole compound represented by the general formula (1), specifically, 4,4'-bis (4
-(2H-benzotriazol-2-yl) -3-hydroxyphenoxycarbonylamino) diphenylmethane, 4,4'-bis (4- (5-chloro-2H-benzotriazol-2-yl) -3-hydroxyphenoxycarbonyl Amino) diphenylmethane, 4,4′-bis (4- (5-methoxy-2H-benzotriazole-2)
-Yl) -3-hydroxyphenoxycarbonylamino) diphenylmethane, 4,4'-bis (4- (5-methyl-2H-benzotriazol-2-yl) -3-hydroxyphenoxycarbonylamino) diphenylmethane, 4,4 ' -Bis (4- (5-bromo-2H-benzotriazol-2-yl) -3-hydroxyphenoxycarbonylamino) diphenylmethane, 4,4'-bis (4- (5-diacetylamino-2H-benzotriazole-2) -Yl) -3-hydroxyphenoxycarbonylamino) diphenylmethane, 4,4'-bis (2-acetyl-4- (2H-benzotriazol-2-yl)
-5-hydroxyphenoxycarbonylamino) diphenylmethane, 4,4'-bis (2-benzoyl-4-
(2H-benzotriazol-2-yl) -5-hydroxyphenoxycarbonylamino) diphenylmethane,
4,4'-bis (2-methyl-4- (2H-benzotriazol-2-yl) -3-hydroxyphenoxycarbonylamino) diphenylmethane, 4,4'-bis (4
-(2H-benzotriazol-2-yl) -3-hydroxyphenylaminocarbonylamino) diphenylmethane, 4,4'-bis (4- (5-chloro-2H-benzotriazol-2-yl) -3-hydroxyphenyl Aminocarbonylamino) diphenylmethane, 4,4 ′
-Bis (4- (5-methoxy-2H-benzotriazol-2-yl) -3-hydroxyphenylaminocarbonylamino) diphenylmethane, 4,4'-bis (4-
(5-methyl-2H-benzotriazol-2-yl)
-3-hydroxyphenylaminocarbonylamino) diphenylmethane, 4,4'-bis (4- (5-bromo-
2H-benzotriazol-2-yl) -3-hydroxyphenylaminocarbonylamino) diphenylmethane, 4,4′-bis (4- (5-diacetylamino-2)
H-benzotriazol-2-yl) -3-hydroxyphenylaminocarbonylamino) diphenylmethane and the like. Among them, 4,4′-bis (4- (2H-benzotriazole-) is particularly preferable in terms of light resistance and reactivity.
2-yl) -3-hydroxyphenoxycarbonylamino) diphenylmethane is preferred.

Next, the application of the novel bisbenzotriazole compound thus obtained 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 coloring 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 the thermosensitive coloring layer on the thermosensitive coloring layer. It is possible to adopt a laminated structure in which an under layer mainly containing a filler and a binder is provided between the color forming layer and the like. These layer configurations may be appropriately combined according to the required quality performance, and a known technique usually used in the thermal recording field can be applied. The heat-sensitive recording medium of the present invention contains the above-mentioned bisbenzotriazole compound of the present invention as an ultraviolet absorber in at least one of these layers. Particularly, from the viewpoint of ultraviolet absorption, it is desirable to provide a protective layer and to include the protective layer in the protective layer.

When the bisbenzotriazole compound of the present invention is used for a heat-sensitive recording medium, the average particle diameter is preferably 2 μm or less, particularly preferably 0.1 μm or less, in order to obtain a desired effect.
More preferably, it is 5 μm or less. 0.5μ average particle size
When it is less than m, not only the ultraviolet absorption efficiency is remarkably improved, but also a clear recorded image can be obtained without containing the recorded image when it is contained in the protective layer.

In order to keep the average particle size of the bisbenzotriazole compound at 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. There are methods using a stirring / pulverizer such as a sand mill, etc., and this is achieved by pulverization into fine particles by those methods. Among them, a sand mill type pulverizer is desirable, and the average particle size of the dispersion medium is 1 m.
m or less is preferable.

The bisbenzotriazole 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 , 2,6,6-tetramethyl-4-piperidyl) sebacate and the like.

In the present invention, examples of the thermal recording system utilizing a color development reaction between an electron donating compound and an electron accepting compound include a combination of a leuco dye and a developer, a combination of a diazonium salt and a coupler, and a combination of iron and the like. Examples include a combination of a transition element and a chelate compound, and a combination of an aromatic isocyanate compound and an imino compound. A combination of a leuco dye and a color developer is preferable because of excellent color density and recording sensitivity. Hereinafter, a thermosensitive recording medium utilizing a color development reaction between a leuco dye and a color developer will be described in detail.

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

(1) Triarylmethane compound 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (crystal violet lactone), 3- (p-dimethylaminophenyl) -3-
(1,2-dimethylindol-3-yl) phthalide,
3- (p-dimethylaminophenyl) -3- (2-phenylindol-3-yl) phthalide, 3,3-bis-
(P-ethylcarbazol-3-yl) -3-dimethylaminophthalide, 3,3-bis- (2-phenylindol-3-yl) -6-dimethylaminophthalide and the like.

(2) Diphenylmethane compounds 4,4-bis-dimethylaminobenzhydryl benzyl ether, N-halophenyl-leuco auramine, N-
2,4,5-trichlorophenyl leuco auramine and the like.

(3) Xanthene compounds Rhodamine B-anilinolactam, 3-diethylamino-7-dibenzylaminofluoran, 3-diethylamino-7-butylaminofluoran, 3-diethylamino-7- (2-chloroanilino) Fluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3-
Piperidino-6-methyl-7-anilinofluoran, 3
-Ethyltolylamino-6-methyl-7-anilinofluoran, 3-cyclohexylmethylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6
Chloro-7- (β-ethoxyethyl) aminofluoran, 3-diethylamino-6-chloro-7- (γ-chloropropyl) aminofluoran, 3-diethylamino-
6-chloro-7-anilinofluoran, 3-N-cyclohexyl-N-methylamino-6-methyl-7-anilinofluoran, 3-diethylamino-7-phenylfluoran, 3- (N-isoamyl- N-ethylamino)-
6-methyl-7-anilinofluoran, 3-dibutylamino-6-methyl-7-anilinofluoran and the like.

(4) Thiazine compounds Benzoyl leucomethylene blue, p-nitrobenzoyl leucomethylene blue and the like can be mentioned.

(5) Spiro compounds 3-methyl-spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3-benzyl-spiro-dinaphthopyran, 3-methylnaphtho- (6'-methoxybenzo) -spiropyran and the like. .

Next, as a developer, benzyl parahydroxybenzoate, dimethyl hydroxyphthalate, 2,4-dihydroxybenzophenone, N-stearyl-p-aminophenol, 3,4-bisphenol A, 4-hydroxy Salicylanilide, 4,4'-dihydroxydiphenyl ether, 4,4'-ethylidenebisphenol, 4,4'-diisopropylidenediphenol (bisphenol A), 4,4 '-(1-methylpentylidene) bisphenol, tetramethyl Bisphenol A, 4,4 ′-(α-methylbenzylidene) bisphenol, 4,4 ′-(p-phenylenediisopropylidene) bisphenol, 4,4 ′-[(1,3-phenylenebis- (1-methylethylidene) )] Bisphenol, 4,4'-cyclohexyl Denbisphenol,
2,2′-bis- (4-hydroxy-3-isopropylphenyl) propane, α, α′-bis- (3-methyl-
4-hydroxyphenyl) -m-diisopropylbenzophenone, n-butylbis (hydroxyphenyl) acetate, α, α ′, α ″ -tris (4-hydroxyphenyl) -1,3,5-triisopropylbenzene, 4,
4 '-[1- [4- [1- (4-hydroxyphenyl)
-1-methylethyl] phenyl] ethylidene] bisphenol, stearyl gallate, 2,3,4,4'-tetrahydroxybenzophenone, 4-hydroxy-4'-
Isopropoxydiphenyl sulfone, 2,2-bis (4,4′-hydroxyphenyl) sulfone, 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, tetramethylbisphenol S and the like can be mentioned.

In the heat-sensitive recording material of the present invention, the water-soluble binder used for each layer includes starches, hydroxyethylcellulose, methylcellulose, carboxymethylcellulose, gelatin, casein, polyvinyl alcohol, modified polyvinyl alcohol, styrene-maleic anhydride. Water dispersibility of latexes such as acid copolymers, water-soluble binders such as ethylene-maleic anhydride copolymers, styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, and methyl acrylate-butadiene copolymers Binders and the like. At least one of these water-soluble binders is used in a range of 15 to 80% by weight based on the total solid content of the heat-sensitive recording layer or the protective layer. Various crosslinking agents can be used to increase the water resistance of the film.

As the pigment, diatomaceous earth, talc, kaolin, calcined kaolin, calcium carbonate, magnesium carbonate, titanium oxide, zinc oxide, silicon oxide, aluminum hydroxide, urea-formalin resin and the like are used. In addition, for the purpose of preventing head abrasion and sticking, zinc stearate, higher fatty acid metal salts such as calcium stearate, wax such as paraffin, paraffin oxide, polyethylene, polyethylene oxide, stearic acid amide, caster wax, Examples of the sensitizer include parabenzyl bisphenyl, esters of hydroxynaphthoic acid, various oxalates such as stearamide, tribenzylamine, naphthalene derivatives, dibenzyl terephthalate, and bis (paramethylbenzyl) oxalate. Further, a dispersant such as sodium dioctyl sulfosuccinate, a surfactant,
A fluorescent dye or the like is added as desired. Paper is mainly used as the substrate in the thermal recording medium of the present invention, and various nonwoven fabrics, plastic films, synthetic papers, metal foils and the like, or composite sheets obtained by combining these are arbitrarily 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 liquid for each layer of the thermosensitive recording medium is not particularly limited, and generally water is used as a dispersion medium, and in addition to the bisbenzotriazole compound of the present invention, a binder and a pigment to be added as necessary. It is prepared by mixing and stirring a lubricant and the like. In the case of a thermosensitive coloring layer, adjustment is made by adding a basic dye and a color developer. The basic dye and the developer are separately pulverized and dispersed in an aqueous system using a sand grinder, an attritor, a ball mill, or the like, and then a method of obtaining a paint by mixing, or any of the basic dye and the developer is used. A method of obtaining a water-based paint after microencapsulation is known. The use ratio of the basic dye and the developer is appropriately selected depending on the type of the basic dye and the developer to be used and is not particularly limited, but is generally 1 to 50 parts by weight based on 1 part by weight of the basic dye. Parts by weight, preferably 2
A developer of about 10 to 10 parts by weight is used.

The bisbenzotriazole compound of the present invention is used in an amount of 1 to the total solid content of each layer such as a heat-sensitive recording layer and a protective layer.
Preferably, it is present in the range of from 50 to 50% by weight, especially from 10 to 40% by weight. When the amount of such a compound is less than 1% by weight relative to the total solid content, the light resistance of a recorded image and a white paper portion is remarkably reduced. . When contained in the protective layer,
If it exceeds 50% by weight, the film-forming property of the protective layer is reduced, and the chemical resistance of the recorded image is significantly reduced.

The method for 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 a coating solution for a heat-sensitive coloring layer on a support and drying, a coating solution for a protective layer is further coated with a coating solution for a heat-sensitive coloring 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 protective layer coating liquid is about 0.1 to 20 g / m ^{2 on a} dry weight basis.
Preferably, it is adjusted in the range of about 0.5 to 10 g / 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, a smoothing treatment such as super calendaring is performed, or an adhesive treatment is performed on the back surface of the thermosensitive recording material to form an adhesive label, a magnetic thermosensitive recording layer, a printing coating layer, and a thermal transfer thermosensitive layer. Various known techniques in the heat-sensitive recording field, such as providing a recording layer, can be added according to the application.

[0037]

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.

<Production of bisbenzotriazole compound of the present invention> Example 1 5.0 g of 2- (2 ', 4'-dihydroxyphenyl) benzotriazole and MDI2 were placed in a three-necked flask equipped with a reflux condenser. 0.5 g was charged and the inside was replaced with argon. 60m anhydrous acetone in it
1 and 10 drops of anhydrous pyridine. The mixture was stirred at room temperature until the inside of the system became a homogeneous solution, and then heated to the reflux temperature of acetone. Stirring was continued for 6 hours. After completion of the reaction, the resulting precipitate was filtered off, recrystallized from acetone and purified, and 4,4'-bis (4- (2H-benzotriazol-2-yl) -3-hydroxyphenoxycarbonylamino) diphenylmethane was purified. 6.7 g of pale yellow solid
(95% yield). The analysis results of the synthesized bisbenzotriazole compound are shown below.

NMR spectrum QE300 FT-NMR Spectrometer (manufactured by General Electric)
It measured using. The results are shown in FIG. The spectrum data and their assignments are shown below. ¹ H-NMR (DMSO-d6, TMS)

[0040]

Embedded image

Δ3.9 (2H, brs, Ph-CH _2-
Ph), 6.9 (2H, dd, J = 2 Hz, 9 Hz,
−CH =, H ₄ ), 7.1 (2H, d, J = 2 Hz, −)
_{CH =, H 3), 7.2} (4H, d, J = 8Hz, -C
_{H =, H 7), 7.4} (4H, d, J = 8Hz, -CH
=, H ₆ ), 7.5 (4H, dd, J = 3 Hz, 7H)
_{z, -CH =, H 1)} , 7.8 (2H, d, J = 9H
_{z, -CH =, H 5)} , 8.0 (4H, dd, J = 3
_{Hz, 7Hz, -CH =, H} 2), 10.3 (2H,
brs, NH), 10.8 (2H, brs, OH)
ppm ¹³ C-NMR (DMSO-d6, TMS)

[0042]

Embedded image

Δ 111.0 (-CH =, C ₆ ), 113.1 (-CH =, C ₈ ), 117.
9 (-CH =, C ₁ ), 118.7 (> C =, C ₄ ), 124.9 (> C =, C ₁₃ ), 126.0 (-
CH =, C ₉ ), 127.2 (-CH =, C ₁₂ ), 129.0 (-CH =, C ₂ ), 136.1 (> C
=, C ₁₀ ), 136.3 (> C =, C ₃ ), 143.6 (-CH =, C ₁₁ ), 151.0 (> C =,
C ₅ ), 151.7 (> C =, C ₇ ), 152.0 (CONH) ppm

The ultraviolet absorption spectrum was measured using a UV-3100 Spectrometer (manufactured by Shimadzu Corporation). The results are shown in FIG. Maximum absorption wavelength is 299n
m (molar extinction coefficient 2.84 × 10 ⁴ lcm ^-1 mol ^-1 )
Met.

The infrared absorption spectrum was measured using a Magna 850 IR Spectrometer (Nicolet). The results are shown in FIG. The spectrum data is shown below. IR (KBr) 3377 (OH), 3288 (NH), 3111, 3057, 1758 (C = O),
1734 (C = O), 1711 (C = O), 1601, 1567, 1534, 1500, 144
6, 1413, 1383, 1346, 1306, 1279, 1261, 1215,1200,
1158, 1129, 1072, 1012, 973, 809, 746, 693 cm ^-1

Melting point: 208-210 ° C. (decomposition)

<Manufacture of thermosensitive recording medium> [Example 2] Liquid A (developer dispersion liquid) 4-hydroxy-4'-isopropoxydiphenyl sulfone 6.0 parts 10% aqueous polyvinyl alcohol solution 18.8 parts Water 11 .2 parts 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 2.0 parts 10% aqueous polyvinyl alcohol solution 4.6 parts Water 2.6 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 36.0 parts Solution B 9.2 parts Kaolin clay 50% dispersion 12.0 parts Amount of each of the above coating solutions applied to one surface of a 50 g / m ² support 6.
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) UV absorber synthesized in Example 1 12.0 parts 10% aqueous polyvinyl alcohol solution 6.7 parts Water 21.3 parts Of the composition was ground to an average particle diameter of 1 micron with a sand grinder. Subsequently, the dispersion liquid 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 C solution 20.0 parts Dilution water 50.0 parts Fluorescent dye 25% aqueous solution 0.5 parts Each of the above coating liquids was coated on the heat-sensitive recording layer so as to have a coating amount of 4.0 g / m ² and dried, and then subjected to a super calender treatment to obtain a heat-sensitive recording material.

Example 3 Formation of Thermal Recording Layer Liquid A (Developer Dispersion) 4-hydroxy-4′-isopropoxydiphenyl sulfone 6.0 parts 10% aqueous polyvinyl alcohol solution 18.8 parts water 11.2 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 2.0 parts 10% aqueous polyvinyl alcohol solution 4.6 parts Water 2.6 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 36.0 parts Solution B 9.2 parts Kaolin clay 50% dispersion 12.0 parts Amount of each of the above coating solutions applied to one surface of a 50 g / m ² support 6.
The coating was dried at 0 g / m ² to form a heat-sensitive recording layer.

Formation of Intermediate Layer (Containing Ultraviolet Absorber) Liquid C (Ultraviolet Absorber Dispersion) Ultraviolet absorber synthesized in Example 1 12.0 parts 10% aqueous polyvinyl alcohol solution 6.7 parts Water 21.3 parts Of the above composition was ground by a sand grinder to an average particle diameter of 1 micron to obtain a coating liquid. 50 g of this coating liquid
/ M ² was coated on one side of the support at a coating amount of 2.0 g / m ² and dried to form an intermediate layer.

Formation of protective layer 10% aqueous solution of polyvinyl alcohol 60.0 parts Aluminum hydroxide (50% dispersion) 50.0 parts Zinc stearate 10.0 parts Dilution water 50.0 parts 25% aqueous solution of fluorescent dye 0.5 Part Each of the above coating liquids was applied and dried on the heat-sensitive recording layer so as to have a coating amount of 4.0 g / m ² , and then subjected to a super calender treatment to obtain a heat-sensitive recording material.

[Example 4] Formation of heat-sensitive recording layer (containing ultraviolet absorber) Liquid A (developer dispersion liquid) 4-hydroxy-4'-isopropoxydiphenylsulfone 6.0 parts 10% aqueous solution of polyvinyl alcohol 8 parts Water 11.2 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 2.0 parts 10% aqueous polyvinyl alcohol solution 4.6 parts Water 2.6 parts Mixture of the above compositions Was ground to an average particle size of 1 micron with a sand grinder. Liquid C (UV absorber dispersion) UV absorber synthesized in Example 1 12.0 parts 10% aqueous solution of polyvinyl alcohol 6.7 parts Water 21.3 parts Average particle diameter of a mixture of the above compositions with a sand grinder Milled to 1 micron. Subsequently, the dispersion liquid was mixed at the following ratio to obtain a coating liquid. Liquid A 36.0 parts Liquid B 9.2 parts Liquid C 20.0 parts Kaolin clay 50% dispersion liquid 12.0 parts Amount of each of the above coating liquids applied to one surface of a 50 g / m ² support 6.
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 on the recording layer to a coating amount of 4.0 g / m ² , a super calender treatment was performed to obtain a heat-sensitive recording material.

Comparative Example 1 A thermosensitive recording medium was produced in the same manner as in Example 2 except that the above-mentioned ultraviolet absorber was not used.

Comparative Example 2 Instead of the above-mentioned ultraviolet absorber, 5-chloro-2- (3-tert.butyl-2-hydroxy-5-methylphenyl) benzotriazole was used. A heat-sensitive recording medium was produced in the same manner as in the above.

Table 1 shows the results of quality performance tests performed on the thermal recording media obtained in the above Examples and Comparative Examples. Color development: UBI EasyCoder IIE (UBI) 270mj / mm ²
Was recorded with a Macbeth densitometer. Light fastness: The heat-sensitive recording medium printed under the above conditions was treated with a xenon lamp weather meter for 24 hours, and the density of the color-developed portion and the background portion was measured with a Macbeth densitometer. (Irradiance 67W / m ² , Integrated irradiance 5348kj / m ² ) Head residue: UBI EasyCoder
After recording at IIE (manufactured by UBI) at 450 mj / mm ² , the degree of dirt (head residue) on the thermal head was visually evaluated as follows. Evaluation criteria ◎: No head residue. ：: There is slight head residue, but there is no practical problem. ×: Many head residue.

[0057]

[Table 1]

[0058]

As described above, it can be said that the bisbenzotriazole compound represented by the general formula (1) of the present invention overcomes the drawbacks of the existing ultraviolet absorber and provides new advantages. Also, synthesis and purification can be performed very easily, which is industrially advantageous. The heat-sensitive recording material using the novel bisbenzotriazole compound of the present invention has excellent light fastness in the recording portion and the background portion, and does not discolor even when stored for a long time under sunlight or high temperature. Is not impaired. Further, adhesion of the head scum during recording is suppressed, and the recording traveling property is also good, so that the thermosensitive recording medium is extremely useful.

[Brief description of the drawings]

FIG. 1 is a proton NMR spectrum of the compound of the present invention.

FIG. 2 is an ultraviolet absorption spectrum of the compound of the present invention.

FIG. 3 is an infrared absorption spectrum of the compound of the present invention.

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 2, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

Embedded image Wherein W represents any one of -NH- and -O- , Y represents a hydrogen atom, an alkyl group of C1 to C6, or R1CO, and R1 represents an alkyl group or an aryl group of C1 to C6. Z represents a hydrogen atom, an alkyl group of C1 to C6, an alkoxy group of C1 to C6, an amino group which may have an acyl group of C2 to C7, or a halogen atom. ]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

Wherein W is any of -NH- and -O- , Y is a hydrogen atom, an alkyl group of C1 to C6, or R1CO, and R1 is an alkyl group of C1 to C6 or An aryl group; Z is a hydrogen atom;
An alkyl group up to C6, an alkoxy group up to C1 to C6, an amino group optionally having an acyl group up to C2 to C7, or a halogen atom. ]

Claims (5)

[Claims] 1. A novel bisbenzotriazole compound represented by the following general formula (1). Embedded image Wherein W represents an imino group, an oxygen atom, Y represents a hydrogen atom, an alkyl group of C1 to C6, or R1CO, and R1 represents an alkyl group or an aryl group of C1 to C6; Z is a hydrogen atom, an alkyl group of C1 to C6, an alkoxy group of C1 to C6, C2 to C7
Or an amino group which may have an acyl group, or a halogen atom. ] 2. A bisbenzotriazole compound according to claim 1, wherein W represents an oxygen atom. 3. A bisbenzotriazole compound according to claim 2, wherein Y is a hydrogen atom and Z is a hydrogen atom. 4. A heat-sensitive recording material utilizing a color development reaction between an electron-donating compound and an electron-accepting compound, wherein at least one of the bisbenzotriazole compounds represented by the general formula (1) according to claim 1 is used as an ultraviolet absorber. A heat-sensitive recording material comprising: 5. The heat-sensitive recording material according to claim 4, comprising the bisbenzotriazole compound according to claim 3 as an ultraviolet absorber.