JP3480850B2 - Liquid ultraviolet absorber and method for producing the same - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel 2-hydroxyphenyl-2H-benzotriazole compound liquid ultraviolet absorber and a method for producing the same. More specifically, the present invention relates to 2-hydroxyphenyl-2H-benzotriazoles which are liquid, exhibit excellent solubility in resins and solvents, and have an excellent organic substance stabilizing effect. 2. Description of the Related Art A 2-hydroxyphenyl-2H-benzotriazole-based ultraviolet absorber is added to synthetic resins and their products, such as sheets and films, and is used for its effect of preventing deterioration caused by ultraviolet rays. Have been. This benzotriazole-based ultraviolet absorber is excellent in improving the fastness of not only the resin body of the base but also the dyes and pigments used in combination with the resin body. Applications for films, printed matter, etc. have emerged. In order to improve the fastness effect of this dye, use it at a higher concentration than before (actually, in photographic applications, use an ultraviolet absorber as a non-volatile solvent solution in an aqueous gelatin solution as an emulsion), or for paints As a top coat, it has become necessary to dissolve it in a very thin film at a high concentration. The benzotriazole-based UV absorbers that have hitherto been marketed have many problems to meet this requirement, and there is a need for improvements such as crystallization in an emulsion or precipitation whitening on the resin surface. I have. In this respect, 2- (2-hydroxy, 3,5-
Di-tert-amylphenylbenzotriazole (trade name “SEESORB 704” (manufactured by Cipro Kasei)) or 2- (2-
Hydroxy-3,5-ditert-butylphenylbenzotriazole (trade name “SEESORB705” (manufactured by Cipro Kasei Co., Ltd.)) has been evaluated as an ultraviolet absorber that meets the above requirements. This is because these compounds have a unique absorption wavelength that absorbs and detoxifies harmful ultraviolet light that destroys the material, and has a higher solubility in the medium and solvent used than benzotriazole-based UV absorbers with a similar structure. It is a big reason that is excellent. However, recently, with the demand for longer-term durability of coatings and products with less fading in photographic materials, the performance of these known compounds has been further improved. Has become strongly required. That is, in order to further increase the fastness of the colorant, it is necessary to use the colorant at a concentration which is incomparable with the conventional one. For use in paints, it has become necessary to dissolve at a high concentration in an extremely thin film (top coat) applied to a paint surface containing a dye. Similarly, in a photographic material, a layer containing an ultraviolet absorber is coated on a layer containing a coloring material, and it is necessary to further increase the concentration of the ultraviolet absorber in order to further improve the effect of preventing fading. In the case of the above-mentioned known compounds, there are many problems in meeting this demand. Increasing the concentration of the UV absorber used in the top coat causes crystallization on the painted surface with the passage of time, which results in loss of surface gloss, cracking, and darkening. In the case of a photographic material, the image is blurred on the surface of the coating film, or the image becomes uneven due to the sweating phenomenon, thereby lowering the commercial value. [0009] In the recent sophistication of coatings, for example, in the coating of automobiles, light fastness exceeding 10 years has been required, and the appearance of an ultraviolet absorber having the characteristics of the present invention has been awaited. Similarly, photographic materials are also expected to produce products with less discoloration under ultraviolet irradiation of color photographs. An object of the present invention is to provide a remarkably excellent solubility in resins and solvents as compared with conventional known compounds, to be able to be used at a high concentration, and to have excellent organic substance stability and Another object of the present invention is to provide a liquid ultraviolet absorber exhibiting improved ultraviolet absorption performance and a method for producing the same. The inventors of the present invention have conducted intensive studies on 2- (2-hydroxyphenyl) benzotriazole derivatives which can achieve the above object, and as a result, have found that certain 2- (2-hydroxy The inventors have found that a phenyl) benzotriazole compound is much more excellent in compatibility with vehicles, plasticizers and resins than conventionally known compounds, and have completed the present invention. That is, the present invention provides the following general formula [A]
A liquid ultraviolet absorber comprising a 2- (2-hydroxyphenyl) benzotriazole compound represented by the formula: [0013] (R represents hydrogen, chlorine or an alkyl group having ₁ to 4 carbon atoms, R ₁ represents a tertiary alkyl group having 4 or 5 carbon atoms, and R ₂ represents a secondary alkyl group having 5 carbon atoms. Here, the secondary alkyl group having 5 carbon atoms of R ₂ in the general formula [A] is not a single substance but a mixture mainly composed of a 2-amyl group and a 3-amyl group. . Specific examples of the structure of the ultraviolet absorbent of the present invention are as follows. Embedded image [Chemical formula 8] [Chemical formula 9] [Chemical formula 10] By the way, as a method for producing the ultraviolet absorbent of the present invention represented by the general formula [A], after diazotizing an o-nitroaniline represented by the following general formula [B], (R is a hydrogen, chlorine or carbon atoms. Represents 1-4 alkyl group) and dialkylphenols <br/> coupling represented by the general formula [C], [Chemical Formula 12] (R ₁ represents a tertiary alkyl group having 4 or 5 carbon atoms, and R ₂ represents a secondary alkyl group having 5 carbon atoms.) It is represented by the following general formula [D] obtained by this coupling. Obtained by reducing a monoazo compound. Embedded image (R, R ₁ and R ₂ are the same as described above.) The phenol having a secondary alkyl group having 5 carbon atoms used as a raw material of the above-mentioned ultraviolet absorber is 4-tert-butylphenol, 4-tert-butylphenol. It is obtained by reacting 1-amylene with amylphenol. 2-sec- obtained
Amyl-4-tert-butylphenol and 2-sec-amyl-4-tert-amylphenol are conventionally known only as laboratory compounds and not as industrial raw materials. The general formula [A] as an ultraviolet absorber using these phenols as raw materials is a novel compound, and its attributes have not been sufficiently recognized. The compound represented by the general formula [A] is a compound represented by the general formula [E]: 2 (2-hydroxyphenyl)-
It has been found that a novel ultraviolet absorber having the same performance can be obtained by reacting benzotriazole with 1-amylene in the presence of an acid catalyst. [Chemical formula 14] (R represents hydrogen, chlorine or an alkyl group having 1 to 4 carbon atoms, and R ₁ represents a tertiary alkyl group having 4 carbon atoms.)
Since the phenolic ring of 2-H-benzotriazole represented by the general formula [E] has low activity, a strong catalyst is required to react amylene with this compound. Can be achieved by first dissolving the compound represented by the general formula [E] in polyphosphoric acid , blowing olefin into this, and gradually raising the temperature. In this case, the yield can be increased by using amylene in excess of 2H-benzotriazole. When the compound of the present invention is a viscous compound which is difficult to handle at room temperature, it may be heated to reduce the viscosity or to use a very small amount of a high boiling solvent to obtain a fluidity. The compound can be added to the aqueous hydrophilic colloid solution to coat the silver halide emulsion layer or the associated hydrophilic colloid layer. The polymer compositions stabilized with the compounds according to the invention can, if desired, contain various customary additives, for example phenolic antioxidants or light stabilizers or mixtures thereof. For example, 2,6-dialkyl 4-methylphenol, alkylated hydroquinone,
Antioxidants such as hydroxylated thiodiphenyl ether, alkylidene-bisphenol, sterically hindered amines,
Light stabilizers such as bis (2,2,6,6-tetramethylpiperidyl) yabacate;
Metal deactivators such as N'-diacetyladipate dihydrazide can be mentioned. According to the present invention, 2- (2-) represented by the general formula [A] is used.
(Hydroxyphenyl) benzotriazole compound is an ultraviolet absorber, so it shows remarkably superior solubility in resins and solvents compared to conventional benzotriazole-based ultraviolet absorbers, and can be used in high concentrations. At the same time, it exhibits excellent ultraviolet absorption performance. Therefore, it can exhibit good dissolving performance in an extremely thin layer such as a color photograph and a top coat of an automobile.
This means that it is dissolved in a high boiling point solvent used as high as possible, and exudes or precipitates due to insufficient solubility, and does not show the phenomenon of staining the film surface and film. In addition, the fact that it can be used by dissolving it in a high concentration leads to the fact that the thickness of the coating layer can be made smaller than before, which in the case of photography is advantageous because it leads to a technology that can shorten the development and drying times. It is. UV absorbers used in photography are generally colorless or nearly colorless, are well compatible with the substrate to be introduced, and must be inert to the other photographic additives of the developer solution of the elementary component. Not have a good UV absorber,
It must be stable against ultraviolet irradiation. The liquid or non-crystalline 2H-benzotriazoles of the present invention are very useful as UV absorbers in photographic gelatin layers. It exhibits desirable absorption in these ultraviolet regions.
It has a maximum absorption in the near ultraviolet, shows a sharp cutoff just outside the visible region, is essentially colorless, is easily dispersed and dissolved by solvent dispersion, and is photographically stable (inactive). Next, the present invention will be described with reference to examples. In the text, “parts” means “parts by weight”. Note that this embodiment does not limit the content or scope of the present invention. Example 1 A three-necked flask was charged with sodium alkylnaphthalene sulfonate (trade name "Perellus N").
BL ", manufactured by Kao Corporation) 100 parts, water 100 parts, 45
Heat to ℃ and stir. Among them, 4-tert-amyl-2-mixed secondary amylphenol (purity 98%) 239
(0.1 mol) and stirring vigorously. On the other hand, 138 parts (1.0 mol) of o-nitroaniline and sodium nitrite 69 in dilute sulfuric acid at -5 to 0 ° C.
g (1.0 mol) to make a cold solution of the diazonium salt. This diazo solution is added dropwise to the phenol dispersion obtained above for 2 hours. Stir at 40 ° C overnight, and add another 60
Stir at C for 1 hour to complete the reaction. When the stirring of the reaction solution is stopped, the azo compound is separated in a semi-solid state. To this, 1000 parts of toluene is added and dissolved, and the stationary aqueous layer is separated. After adding 300 parts of warm water, stirring, standing, and liquid separation are performed again, the washing is repeated three times to obtain a toluene solution of the nitroazo compound. Take the nitroazotoluene solution obtained above in a three-necked flask, add 250 parts of isopropanol, and further add 150 parts of caustic soda (48% aqueous solution). While stirring vigorously, 170 parts of zinc dust (2.
(6 atoms) was added over 2 hours while heating to maintain 70 ° C. After completion of the addition, the mixture was further stirred at 70 ° C. for 2 hours,
An additional 30 parts of sodium hydroxide (48% aqueous solution) and 20 parts of zinc dust were added, and stirring was continued at 70 ° C. for 3 hours. After cooling to room temperature, the mixture is neutralized with dilute sulfuric acid to further reduce the acidity. Unreacted zinc is separated by filtration, and the toluene solution of the target substance is separated.
Washed twice. The oil layer is dehydrated while recovering one part of toluene, and an oily substance (brown) not containing water is obtained.
300 parts of formic acid are added and the mixture is left in a shaking bath for 15 minutes. When this operation was repeated three times, the colored impurities were transferred to the formic acid layer, and an oil with little coloring was obtained. This oil layer was distilled. As a result, a boiling point of 210 to 225 ° C./0.5
183 parts of mmHg material were obtained. As a result of identification by infrared absorption spectrum (IR), 2- (2-hydroxy-5-tert-amyl-3-2 represented by the structural formula [A1] above.
Grade amylphenyl) benzotriazole. This substance has a maximum absorption at 306 nm and 345 nm as measured by ultraviolet absorption of a chloroform solution. Example 2 In a flask having a capacity of 1000 parts, 500 parts of polyphosphoric acid (115%) was placed and stirred. At 50 ° C., 2- (2-hydroxy-5-tert-butylphenyl) benzotriazole (trade name “SEES”)
ORB708 "(manufactured by Cipro Kasei Co., Ltd.) is added and stirred. When a uniform paste is formed, 100 parts of 1-amylene (bp 50 ° C.) is added to the bottom of the reaction contents at this temperature in an inlet tube over 3 hours. Warm slowly, stir at 50 ° C for 3 hours, 70 ° C for 2 hours,
The reaction was performed at 0 ° C. for 5 hours. After completion of the reaction, the above reaction product is put into 1000 parts of water, stirred, and 500 parts of toluene is added for extraction. This is repeated twice, and then the mixture is left standing. The toluene solution of the upper layer obtained by the liquid was distilled. As a result, the boiling point was 210 to 220 ° C./0.5.
45 parts of a pale yellow oil of mmHg were obtained. As a result of identification by infrared absorption spectrum (IR), it was confirmed that the compound was 2- (2-hydroxy-5-tert-butyl-3-secondary amylphenyl) benzotriazole represented by the structural formula [A2]. Was. This substance has a maximum absorption at 303 nm and 346 nm as measured by ultraviolet absorption of a chloroform solution. (Solution property test) Next, 2- (2-hydroxy-5-te) of Example 1 represented by the structural formula [A1] was used.
rt-amyl-3-secondary amylphenyl) benzotriazole and 2 of Example 2 represented by the structural formula [A2]
-(2-hydroxy-5-tert-butyl-3-secondary amylphenyl) benzotriazole, and 2- (2-hydroxy-5) of Example 3 represented by the structural formula [A4].
-Tert-Butyl-3-secondary amylphenyl) -5-chlorobenzotriazole was evaluated for dissolution characteristics at a constant temperature. For comparison, a known compound, 2- (2-hydroxy-3,5-di-tert-butylphenylbenzo), which is an ultraviolet absorber conventionally used for coatings and photography and considered to have relatively high solubility, is used. Triazole (Comparative Example 1), 2- (2-hydroxy, 3, 5
-Di-tert-amylphenylbenzotriazole (Comparative Example 2) was also evaluated. In the examples, the secondary amyl group at the 3-position of the phenyl group bonded to the 2-position of benzotriazole is a mixture mainly composed of a 2-amyl group and a 3-amyl group. As the solvent, isopropyl alcohol (IPA), toluene, ethyl acetate, and dioctyl phthalate (DOP) were used. The results are shown in Table 1 below. The numerical values in the table indicate parts by weight dissolved in the solvent. [Table 1] As is clear from Table 1, the benzotriazole-based UV absorbers of Examples 1 to 3 dissolve uniformly without being separated into two layers, and exhibit remarkably excellent solubility as compared with Comparative Examples. It is recognized that. (Comparison Test of Stability of Gelatin Suspension) Next, the following test was carried out on the assumption that a UV absorber was practically used in a photographic material. 30 g of each of the compounds of Examples 1 to 3 and Comparative Examples 1 and 2 are dissolved in 60 g of ethyl acetate together with 3 g of bis 2-ethylhexyl sulfosuccinate by heating. This is poured into 1 liter of a 10% gelatin aqueous solution to form an emulsion. This emulsion was stored while changing the temperature and time, and the stability of the emulsified and dispersed ultraviolet absorber component was observed. Table 2 shows the results. [Table 2] From Table 2, it can be seen that among the typical photographic emulsifiers consisting of gelatin-activator-water, the UV absorber of this example shows stable low-temperature storage properties in a high-concentration emulsion as compared with the comparative example. Admitted. (Ultraviolet absorption property test) 2 parts of the compound of Example 1 was mixed with a resin mixture 7 of hydroxyethyl acrylate, styrene, acrylonitrile, butyl acrylate and the like.
It was blended in a thermosetting acrylic resin composition consisting of 0 parts and 30 parts of melamine resin. This preparation was applied to a metal piece, and 14
The resin was cured by heating at 0 to 150 ° C. The test piece was exposed to a dew (rain) condition at 50 ° C. for 5 hours, irradiated with ultraviolet rays at 70 ° C. for 8 hours, and subjected to an accelerated weathering test repeated for 980 hours. For the test pieces, a 20 ° gloss (ASTM)
D523 and D2457) and image identification (ASTM E4
30) The values were measured before and after this accelerated weathering test and
° Gloss retention and image discrimination (D / I) retention were determined. Incidentally, in order to evaluate the compound of Example 1, it was compared with the compound without the same compound (Comparative Example 3). Table 3 shows the results. [Table 3] The test piece to which the preparation liquid to which Example 1 was added was applied, showed no surface cracks and cracks, and exhibited better gloss and image recognition (D / I) retention than the control test piece. This indicates that the ultraviolet absorber of the present invention is also excellent as a light stabilizer. As described above, the liquid ultraviolet absorber according to the present invention has a remarkably excellent solubility in resins and solvents as compared with conventional known compounds, and can be used at a high concentration. Can be
It has excellent organic matter stability and exhibits excellent ultraviolet absorption performance. Therefore, even when used in high-density automotive paints, photographic films, printed matter, etc., crystallization occurs on the painted surface with the passage of time, the gloss of the surface disappears,
Sharpness and darkening are prevented, and in the case of photographic materials, the image is not blurred on the coated film surface, and the image is not uniform due to the sweating phenomenon, and the commercial value is not reduced.

Continuation of the front page (56) References JP-A-53-12942 (JP, A) JP-A-60-152540 (JP, A) JP-A-59-215378 (JP, A) JP-A-62-75441 (JP) JP-A-3-95545 (JP, A) JP-A-52-113974 (JP, A) JP-A-52-113973 (JP, A) JP-A-2-134370 (JP, A) 3-130268 (JP, A) JP-A-1-203371 (JP, A) JP-A-2-15070 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09K 3/00 104 B01J 27/16-27/18 C07D 249/20 C08K 5/3495

Claims (1)

(57) Claims: 1. A liquid ultraviolet absorber comprising a 2- (2-hydroxyphenyl) benzotriazole compound represented by the following general formula [A]. Embedded image (R represents hydrogen, chlorine or an alkyl group having ₁ to 4 carbon atoms , and R ₁ represents a tertiary alkyl group having 4 carbon atoms.
₂ represents a secondary alkyl group having 5 carbon atoms. )