JP2002226465A - CRYSTAL TRANSFORMATION COMPOSITION OF 2-(2'-HYDROXY-3',5'-DI- t-AMYLPHENYL)BENZOTRIAZOLE, METHOD FOR PRODUCING THE SAME AND ULTRAVIOLET LIGHT ABSORBENT USING THE SAME - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide crystal transformation composition of 2-(2'-hydroxy-3',5'-di- t-amylphenyl)benzotriazole not causing caking of powder, having good workability in using and being handleable, a method for producing the composition and an ultraviolet light absorbent using the composition. SOLUTION: This invention relates to a crystal transformation composition represented by the following formula (1), a method for producing the above composition and an ultraviolet light absorbent using the above composition. The crystal transformation composition comprises a crystal transformation (hereinafter referred to as crystal transformation I type) exhibiting peaks at angles (2θ) of diffraction of 5.5 deg., 10.4 deg., 11.0 deg., 14.3 deg., 16.5 deg., 17.8 deg. and 18.8 deg. in powdery X ray diffraction analysis by Cu-Kα beam and a crystal transformation (II type) exhibiting peaks at angles (2θ) of diffraction other than the above angles of diffraction and/or a crystal transformation (III type) exhibiting peaks at further other angles (2θ) of diffraction, and a content of the II type and/or the III type is <=0.3 wt.% based on that of the above I type crystal transformation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a modification of type I crystal
2- (2'-hydroxy-) having a content of the type-modified crystal and / or the type-III modified crystal of not more than 0.3% by weight.
The present invention relates to a 3 ', 5'-di-t-amylphenyl) benzotriazole crystal modified composition, a method for producing the composition, and an ultraviolet absorber using the composition.

[0002]

2. Description of the Related Art In recent years, with the increasing use of polymer products such as various plastics, synthetic rubbers, nylon fibers, and resin coatings, demands for additives such as flame retardants, antioxidants, and ultraviolet absorbers have increased. Has also increased. In particular, as polymer products are being differentiated and value-added, the use of UV absorbers has become an important issue in order to prevent polymer products from deteriorating phenomena such as cracks and discoloration due to UV rays. A stable supply of the agent is required.

[0003] 2- (2'-Hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole is generally used as an ultraviolet absorber for plastics, paints, oils, fibers and the like, and is manufactured by Tinuvin 328K (Ciba).
It is commercially available in the form of powders as Specialty (trade name), Seesorb 704 (trade name of Cipro Kasei), and KEMISORB 74 (trade name of Chemipro Kasei).

[0004] Commercially available 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole may be transported or stored depending on the storage conditions.
Local consolidation occurs and affects workability during powder handling. For this reason, it is desired to provide a powder that does not cause caking.

[0005] A method for producing 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole is disclosed in JP-A-2-134370, in which o-nitroazobenzenes are converted to a platinum catalyst and an organic amine. A method of catalytic hydrogenation in the presence of a catalyst, JP-A-7-228576, JP-A-7-228576
JP-A-228577 and JP-A-8-217762 disclose a method of reducing o-nitroazobenzenes with hydrogen in the presence of a hydrogenation catalyst and a basic substance poisoned with a sulfur compound, and a method disclosed in JP-A-2000-217762. JP-A-154180 discloses a method of reducing 2-phenylbenzotriazole-N-oxides with a hydrogenation catalyst and hydrogen in the presence of an acidic substance. There is no description of powder behavior or crystal transformation.

[0006] The above-mentioned consolidation phenomenon is due to heat, external force,
It is known to occur by reactions and phase transitions.
Further, as a method of preventing caking, coarsening by granulation is known. However, the desired shape differs depending on the application. Many of commercially available products are in the form of powder, and powders that do not solidify in powder form are desired.

It is generally known that a compound having a phase transition has a plurality of crystal modifications, and each crystal modification has various properties. It is known that physical properties are different. For example, JP-A-6-128195 and JP-A-6-72
No. 960 discloses the difference in bulk specific gravity, particle size distribution, and fluidity of powder for each crystal modification of the same compound. Obtaining the knowledge of crystal transformation as described above is important not only for the added value and quality improvement of the product, but also for understanding the behavior of the powder. Further, the X-ray diffraction method and the melting point measurement are practical methods for analyzing substances from the viewpoint of crystals, and are used in many fields such as discrimination of crystal transformation and development of functional new materials.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an easy-to-handle 2- (2'-hydroxy-3 ', 5'-di-t-type compound which does not cause powder compaction and has good workability during use. It is an object of the present invention to provide an amylphenyl) benzotriazole crystal modified composition, a method for producing the composition, and an ultraviolet absorber using the composition.

[0009]

SUMMARY OF THE INVENTION The first aspect of the present invention is that Cu-
In the powder X-ray diffraction analysis using Kα ray, the diffraction angle (2
θ) 5.5 °, 10.4 °, 11.0 °, 14.3 °,
Diffraction angles (2θ) of 5.6 ° and 7.3 ° with respect to crystal modifications showing peaks at 16.5 °, 17.8 ° and 18.8 ° (hereinafter, this crystal modification may be referred to as type I). , 9.4 °,
10.5 °, 13.0 °, 13.7 °, 16.0 °, 1
Crystal modification showing diffraction peaks at 6.4 °, 18.3 °, and 18.7 ° (this crystal modification may be hereinafter referred to as type II)
And / or diffraction angles (2θ) 5.5 °, 7.3 °, 1
0.6 °, 13.0 °, 14.1 °, 14.9 °, 1
5.7 °, 16.4 °, 17.2 °, 25.1 °, 2
The content of the crystal modification which shows a diffraction peak at 6.7 ° (hereinafter, this crystal modification is sometimes referred to as type III) is 0.3% by weight.
The present invention relates to the following modified crystalline 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole represented by the following formula (1).

Embedded image

A second aspect of the present invention is to obtain 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole by recrystallization in the presence of a soluble solvent at a temperature lower than 70 ° C. 2. The method according to claim 1, wherein the obtained crystals are dried at a temperature lower than 70 ° C. under normal pressure or reduced pressure.
The present invention relates to a method for producing a (2'-hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole crystal modified composition.

A third aspect of the present invention is the second aspect of the present invention.
The present invention relates to an ultraviolet absorbent containing a (2'-hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole crystal modified composition.

In order to achieve the above-mentioned object, the present inventors considered the cause of the consolidation of commercially available 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole. Diligently studied. First, for the consolidated part and the non-consolidated part, the residual amount of impurities, the transmittance-sensing type melting point measurement value (Mettler fully automatic melting point measuring device FP-62, heating rate 0.2 ° C./min) and A comparison was made between the Cu-Kα ray powder X-ray diffraction analyzes, but no difference was found. Next, in order to know the behavior of the powder due to heat in detail, a differential scanning calorimeter (TA Instrument 2920 DSC, heating rate 2.0 ° C./mi)
n, hereinafter referred to as DSC).
The melting point peak of the unconsolidated portion was 1 at 79 to 82 ° C.
In contrast to having a book, the consolidated portion obtained a finding having a melting point peak of 85 to 88 ° C. in addition to a melting point peak of 79 to 82 ° C. At this time, the melting point peak at 79 to 82 ° C. and 8
The ratio of the heat of fusion to the melting point peak at 5-88 ° C. is 98.5.
(79-82 ° C): 1.5 (85-88 ° C).

The inventors of the present invention have conducted a study on obtaining a powder which does not cause caking, which is the object of the present invention, and have studied a cause showing a plurality of melting points. Under certain conditions, we found that caking occurs. For example, a solidified portion is obtained from a powder dried at around 75 ° C., and the DSC measurement result of the solidified portion of the powder indicates that
It has two melting peaks at 9-82 ° C and 85-88 ° C,
It showed the same behavior as the solidified part of the commercial product. At this time, the ratio of the heat of fusion between the melting point peak at 79 to 82 ° C and the melting point peak at 85 to 88 ° C was 95.0 (79 to 82 ° C): 5.
0 (85-88 ° C).

Further, the applicant's Japanese Patent Application No. 2000-393.
No. 432 and Japanese Patent Application No. 2000-393654.
By heat-treating (2'-hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole at 70 ° C. or more, a type II crystal modification and a type III crystal modification are obtained, and the melting point is 85 to 85. From the finding of a single peak at 88 ° C., it was noticed that the behavior of this melting point was similar to the properties found in a compound having a crystalline polymorph. Accordingly, Japanese Patent Application No. 2000-343432 and Japanese Patent Application No.
Cu-K obtained by the synthesis method of No. 00-393654
The diffraction angle (2θ ±
0.1 °) 5.6 °, 7.3 °, 9.4 °, 10.5
°, 13.0 °, 13.7 °, 16.0 °, 16.4
Type II crystal transformation having diffraction peaks at °, 18.3 °, 18.7 ° and diffraction angles (2θ) 5.5 °, 7.3 °, 1
0.6 °, 13.0 °, 14.1 °, 14.9 °, 1
5.7 °, 16.4 °, 17.2 °, 25.1 °, 2
The result of mixing the commercially available product with the type III crystal modification having a diffraction peak at 6.7 ° and performing a DSC measurement shows that the D
Since it is consistent with the result of SC measurement,
It was clarified that the type II and / or type III crystal modifications were contained.

As a result of further studies, the present inventors have found that the cause of consolidation is due to the inclusion of type II crystal transformation and / or type III crystal transformation, and the content of the novel crystal modification in the consolidated powder. Can be clarified by DSC measurement, and the content of the type II crystal transformation and / or the type III crystal transformation is 0.3% by weight or less, preferably 0.1% by weight with respect to the type I crystal transformation.
The following compositions have been found not to cause caking and have led to the solution of the problem.

A composition having a content of the type II crystal modification and / or the type III crystal modification relative to the type I crystal modification of 0.3% by weight or less is 2- (2'-hydroxy-3 ', 5' −
It is obtained by recrystallizing (di-t-amylphenyl) benzotriazole at a temperature lower than 70 ° C. in the presence of a soluble solvent, and performing a drying operation at a temperature lower than 70 ° C. The content of the type II crystal modification and the content of the type III crystal modification included in the type I crystal modification were determined by preparing a calibration curve based on the calorific value of fusion measured by DSC in the single crystal modification.

That is, according to the present invention, 2- (2'-
(Hydroxy-3 ′, 5′-di-t-amylphenyl) benzotriazole is recrystallized at a temperature lower than 70 ° C. in the presence of a soluble solvent, and the obtained crystals are cooled at a normal pressure or a pressure lower than 70 ° C. By drying at a temperature, preferably at 20 to 60 ° C., the content of the type II crystal modification of which the content of the type II crystal modification and / or the type III crystal modification is 0.3% by weight or less is 2- (2 '-Hydroxy-3', 5'-di-t
-Amylphenyl) benzotriazole crystal modified composition is obtained.

The Form II Crystal Modification and / or III of the Invention
2- (2'-hydroxy-3 ', 5'-) whose main component is a type I crystal modification having a content of the type crystal modification of 0.3% by weight or less.
Examples of the soluble solvent used to obtain the crystalline modified composition of (di-t-amylphenyl) benzotriazole include methanol, ethanol, isopropyl alcohol, n-propanol, isobutanol, n-butanol, cyclohexanol, ethylene glycol, and propylene glycol. Such as alcohols, dioxane, tetrahydrofuran, dibutyl ether, ethyl isoamyl ether,
Ethers such as ethylphenyl ether, n-pentane, n-hexane, n-heptane, n-octane, n-
Decane, 3-ethylhexane, cyclohexane, methylcyclohexane, toluene, ethylbenzene, cumene,
o-cymene, p-cymene, m-cymene, o-xylene,
m-xylene, p-xylene, t-butylbenzene, 1
-Butyl-4-methylbenzene, 1-butyl-2-methylbenzene, 1,2,3-trimethylbenzene, 1,
Hydrocarbons such as 2,4-trimethylbenzene, 1,3,5-trimethylbenzene, 1,2,4,5-tetramethylbenzene, carboxylic esters such as ethyl acetate, butyl acetate and ethyl propionate, acetone , Methyl ethyl ketone, methyl isobutyl ketone, etc., chloroform, methylene chloride, carbon tetrachloride, 1,2
Organic halides such as -dichloroethane, chlorobenzene, o-dichlorobenzene, dimethyldimethylformamide, dimethylacetamide, quinoline, triethylamine, n-butylamine, and 2-methylpyrrolidone; it can. It can also be used by mixing water.

The amount of the solvent used and the mixing ratio are 2- (2'-
(Hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole is an amount necessary to crystallize at a temperature lower than 70 ° C, and is not particularly limited.
Naturally, the crystallization yield is greatly affected by the solubility.

The Form II Crystal Modification and / or III of the Invention
2- (2'-hydroxy-3 ', 5'-) whose main component is a type I crystal modification having a content of the type crystal modification of 0.3% by weight or less.
The drying conditions for obtaining the di-t-amylphenyl) benzotriazole crystal modified composition include hot air drying such as a fluidized drying apparatus and heat transfer drying such as a vacuum drying apparatus.
A method of drying at a temperature lower than 70 ° C., preferably at 20 to 60 ° C., may be mentioned.

The II-form and III-form modifications are described in Japanese Patent Application Nos. 2000-393432 and 2000-39.
2- (2'-hydroxy-) as described in US Pat.
3 ', 5'-Di-t-amylphenyl) benzotriazole can be obtained as powder or flake-like crystals by heat treatment under appropriate conditions.

That is, the type II crystal transformation is described in Japanese Patent Application
As described in -393432, 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole is used in the absence of a solvent or in the presence of a sparingly soluble solvent at 70 to 70%.
It can be obtained by heating and stirring at 79 ° C, preferably in the range of 76 ° C to 79 ° C. Form I crystal modification is 79-
The resulting Form II crystal modification has a melting point of 86-88 ° C, while having a melting point of 82 ° C. Examples of the poorly soluble solvent used to obtain the type II crystal modification include water and alcohols such as methanol, ethanol, isopropyl alcohol, n-propanol, isobutanol, n-butanol, cyclohexanol, ethylene glycol and propylene glycol, and dioxane. Ethers such as tetrahydrofuran, dibutyl ether, ethyl isoamyl ether and ethyl phenyl ether, n-pentane, n-hexane, n-heptane, n-octane, n-
Decane, 3-ethylhexane, cyclohexane, methylcyclohexane, toluene, ethylbenzene, cumene,
o-cymene, p-cymene, m-cymene, o-xylene,
m-xylene, p-xylene, t-butylbenzene, 1
-Butyl-4-methylbenzene, 1-butyl-2-methylbenzene, 1,2,3-trimethylbenzene, 1,
Hydrocarbons such as 2,4-trimethylbenzene, 1,3,5-trimethylbenzene, 1,2,4,5-tetramethylbenzene, carboxylic esters such as ethyl acetate, butyl acetate and ethyl propionate, acetone , Methyl ethyl ketone, methyl isobutyl ketone, etc., chloroform, methylene chloride, carbon tetrachloride, 1,2
Organic halides such as dichloroethane, chlorobenzene, o-dichlorobenzene, dimethylformamide,
Dimethylacetamide, quinoline, triethylamine,
One type of nitrogen-containing compounds such as n-butylamine and 2-methylpyrrolidone, or a mixed solvent is used.

Further, as described in Japanese Patent Application No. 2000-393654, the crystal modification of the type III crystal modification can be carried out using 2- (2'-
(Hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole in the absence of a solvent or in the presence of a poorly soluble solvent
It is obtained as a powder or flake-like crystal by heat melting and solidifying at a temperature higher than 79 ° C. The Form I crystal modification has a melting point of 79-82 ° C, while the resulting II
The Form I crystal modification has a melting point of 85-87 ° C. Examples of the poorly soluble solvent used to obtain the type III crystal modification include water and alcohols such as methanol, ethanol, isopropyl alcohol, n-propanol, isobutanol, n-butanol, cyclohexanol, ethylene glycol and propylene glycol, dioxane , Tetrahydrofuran, dibutyl ether, ethyl isoamyl ether, ethers such as ethyl phenyl ether,
n-pentane, n-hexane, n-heptane, n-octane, n-decane, 3-ethylhexane, cyclohexane, methylcyclohexane, toluene, ethylbenzene, cumene, o-cymene, p-cymene, m-cymene, o
-Xylene, m-xylene, p-xylene, t-butylbenzene, 1-butyl-4-methylbenzene, 1-butyl-2-methylbenzene, 1,2,3-trimethylbenzene, 1,2,4-trimethyl Benzene, 1,3,5-
Hydrocarbons such as trimethylbenzene, 1,2,4,5-tetramethylbenzene, carboxylic esters such as ethyl acetate, butyl acetate and ethyl propionate; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; chloroform; Organic halides such as methylene chloride, carbon tetrachloride, 1,2-dichloroethane, chlorobenzene and o-dichlorobenzene, and nitrogen-containing compounds such as dimethylformamide, dimethylacetamide, quinoline, triethylamine, n-butylamine and 2-methylpyrrolidone One type or a mixed solvent may be used.

[0024]

EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited by these.

The DSC measurement method is based on TA Instruments 2
Using a 920 type DSC, the sample amount was 1 to 3 mg, the furnace atmosphere was a nitrogen gas flow of 50 ml / min, and the heating rate was 2.0 ° C.
/ Min. Claims and Examples, the content of each of the type II and type III in the type I in the comparative example,
It was measured using this method.

The melting point was measured by using a Mettler fully automatic melting point measuring apparatus FP-62 at a heating rate of 0.2 ° C./min (no offset correction).

The powder X-ray diffraction analysis using Cu-Kα ray is as follows.
Using TFD-18 kw manufactured by Mac Science, anti-cathode Cu-Kα (1.5405 °), 40 kV-50 mA,
The scanning was performed at a scanning speed of 2.000 ° / min. The X-ray diffraction method is a practical method for analyzing a substance from the viewpoint of a crystal, and is used in many fields such as development of a new functional material. Further, the diffraction angles determined by powder X-ray diffraction analysis are identical with an error of about ± 0.1 ° in the case of the same crystal type, so that the difference in crystal transformation is clearly shown.

The solidification was evaluated by using a DX400 manufactured by Yamato Scientific Co., Ltd.
After storage at 30 ° C. for 30 days, the presence or absence of caking was observed.

Example 1 330 g (0.898 mol) of 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole-N-oxide was placed in a 1000 ml four-necked flask.
3.0 g of 5% palladium carbon, toluene: 2-propanol: water (mixed at a volume ratio of 10: 2: 1) 60
0 ml and oxalic acid dihydrate 10 g (0.08 mo
l) was charged and hydrogen was blown in while stirring at 30 to 40 ° C. The reaction was performed for 15 hours while supplementing the amount of absorbed hydrogen. After completion of the reaction, the hydrogenation catalyst was filtered off. [A part of the filtrate was quantified by HPLC, and the yield of 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole was determined. Was 99.0%. After removing residual acidic substances in the solvent layer by washing with water, the solvent and the like are distilled off,
The crude 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole was obtained as a solid. Methanol 400 as a crystallization solvent in the solid
Then, 10 ml of toluene and 10 ml of toluene were added and dissolved by heating under stirring. Crystals were precipitated at 68 ° C., cooled to room temperature, and filtered. The crystals separated by filtration are reduced to 10 torr under reduced pressure at 65 ° C.
To give a pale yellow crystalline powder in a yield of 98%. Even if the obtained crystals were stored at 40 ° C. for 30 days, they did not solidify. As shown in Table 1 and FIG. 1, the heat of fusion ratio obtained by DSC measurement (the ratio of the heat of fusion between the melting peak of type I and the melting peak of type II was 99.74: 0.26) was obtained. The mixing ratio of the type II crystal modification included in the type I crystal modification of the resulting crystal was 0.09% by weight.

The melting point of the obtained crystal was 81.
At 0 to 81.6 ° C, it was the same as the unconsolidated part of the commercial product. The results of powder X-ray diffraction analysis of the obtained crystals by Cu-Kα radiation showed that the diffraction angle (2θ) was 5.5 °,
0.4 °, 11.0 °, 14.3 °, 16.5 °, 1
It was the same type I crystal modification as the unconsolidated portion of the commercial product shown in FIG. 2 having strong peaks at 7.8 ° and 18.8 °. In the powder X-ray diffraction analysis, depending on the particle size of the crystal,
Since the detection intensity of the diffraction peak changes, it cannot be said with certainty, but if the type I or II does not contain around 20% of the type II, the clear diffraction peak of the type II or III will not be obtained. No detection is possible, and when the type II is about 0.3% as in this example, the diffraction pattern is the same as that of the type I 100%.

Example 2 The same operation as in Example 1 was carried out to give 2- (2'-hydroxy-
The crude 3 ', 5'-di-t-amylphenyl) benzotriazole was obtained as a solid. To this solid, 50 ml of toluene and 300 ml of isopropyl alcohol were added as crystallization solvents, dissolved at 70 ° C., recrystallized, and filtered. The obtained crystals were heated at 60 ° C. under a reduced pressure of 10 torr.
And 303.0 g (96.0% yield) of a slightly yellow crystalline powder of 2- (2'-hydroxy-3 ', 5'-di-
(t-Amylphenyl) benzotriazole was obtained. Even if the obtained crystal was stored at 40 ° C. for 30 days, it did not solidify. As shown in Table 1, the crystals obtained from the heat of fusion ratio by DSC measurement (the ratio of the heat of fusion between the melting peak of type I and the melting peak of type II was 99.85: 0.15) The mixing ratio of the type II crystal modification included in the type I crystal modification was 0.05% by weight.

The melting point of the obtained crystal was 81.
At 0 to 81.6 ° C, it was the same as the unconsolidated part of the commercial product. The results of powder X-ray diffraction analysis of the obtained crystals by Cu-Kα radiation showed that the diffraction angle (2θ) was 5.5 °,
0.4 °, 11.0 °, 14.3 °, 16.5 °, 1
It was the same type I crystal modification as the unconsolidated portion of the commercial product having strong peaks at 7.8 ° and 18.8 °.

Example 3 The same operation as in Example 1 was carried out to give 2- (2'-hydroxy-
The crude 3 ', 5'-di-t-amylphenyl) benzotriazole was obtained as a solid. As a crystallization solvent, 50 ml of toluene, 400 ml of methanol,
After adding 10 ml of water and dissolving at 70 ° C., recrystallization was performed and filtration was performed. The obtained crystals were subjected to 68 ° C. under reduced pressure of 10 torr.
And 303.0 g (96.0% yield) of a slightly yellow crystalline powder of 2- (2'-hydroxy-3 ', 5'-di-
(t-Amylphenyl) benzotriazole was obtained. Even if the obtained crystal was stored at 40 ° C. for 30 days, it did not solidify. As shown in Table 1, the mixing ratio of the type II crystal modification included in the type I crystal modification of the crystal obtained from the calorific value of fusion measured by DSC was 0.2% by weight.

The melting point of the obtained crystal was 81.
At 0 to 81.6 ° C, it was the same as the unconsolidated part of the commercial product. The results of powder X-ray diffraction analysis of the obtained crystals by Cu-Kα radiation showed that the diffraction angle (2θ) was 5.5 °,
0.4 °, 11.0 °, 14.3 °, 16.5 °, 1
It was the same type I crystal modification as the unconsolidated portion of the commercial product having strong peaks at 7.8 ° and 18.8 °.

COMPARATIVE EXAMPLE 1 The crystals obtained by recrystallization were treated under reduced pressure of 10 torr for 7 hours.
Except for drying at 5 ° C., the same operation as in Example 2 was carried out to obtain 303.0 g (yield 96.0%) of 2- (2′-hydroxy-3 ′, 5 ′) of a slightly yellow crystalline powder. -Di-t-amylphenyl) benzotriazole was obtained. The obtained crystals were stored at 40 ° C. for 30 days and consolidated. As shown in Table 1 and FIG. 3, the ratio of the heat of fusion of the solidified portion by DSC measurement (the ratio of the heat of fusion of the melting peak of type I to the melting peak of type II was 97.94: 2.06). ), The mixing ratio of the type II crystal modification included in the type I crystal modification was 0.7% by weight.

As a result of measuring the melting point of the consolidated portion,
At 0 to 81.6 ° C, it was the same as the unconsolidated part of the commercial product. Further, Cu-K of the solidified portion of the obtained crystal was
The result of powder X-ray diffraction analysis using α-rays is the diffraction angle (2θ)
5.5 °, 10.4 °, 11.0 °, 14.3 °, 1
It was the same type I crystal modification as the unconsolidated portion of the commercial product having strong peaks at 6.5 °, 17.8 °, and 18.8 °.

Reference Example 1 In a 500 ml four-necked flask, 2- (2'-hydroxy-
50.0 g of 3 ', 5'-t-amylphenyl) benzotriazole and 400 ml of a 40% methanol aqueous solution were charged and stirred at 79 ° C for 10 hours. After cooling to room temperature, the mixture was filtered and dried to obtain 49.9 g of white crystals. The melting point of the obtained crystal was 86 ° C. Cu-Kα of the obtained crystal
The result of the powder X-ray diffraction analysis by X-ray is shown in FIG.
Diffraction angles (2θ) 5.6 °, 7.3 °, 9.4 °, 10.
5 °, 13.0 °, 13.7 °, 16.0 °, 16.4
Strong diffraction peaks at °, 18.3 ° and 18.7 °
It was a type II crystal modification. The sample of Reference Example I was Type II 1
00%.

Reference Example 2 In a 500 ml four-necked flask, 2- (2'-hydroxy-
50.0 g of 3 ', 5'-di-t-amylphenyl) benzotriazole was charged, melted at 80 to 90 ° C, and cooled and solidified at room temperature to obtain flake crystals. Then, the mixture was pulverized with an automatic mortar to obtain a white powder. The melting point of the obtained crystal is
85 ° C. As a result of the powder X-ray diffraction analysis of the obtained crystal by Cu-Kα ray, as shown in FIG.
θ) 5.5 °, 7.3 °, 10.6 °, 13.0 °, 1
4.1 °, 14.9 °, 15.7 °, 16.4 °, 1
It was a type III crystal modification having strong diffraction peaks at 7.2 °, 25.1 °, and 26.7 °. The reference example 2 is I
Type II 100%.

[0039]

[Table 1]

[0040]

As shown in the Examples and Table 1, the difference between the solidified part and the non-solidified part cannot be confirmed by powder X-ray diffraction analysis and melting point measurement. The content of the type II crystal modification and / or the type III crystal modification can be confirmed, clearly showing the relationship between the content and the consolidation. According to the invention, the Form II crystal modification and / or III
The composition having a content of the type crystal modification of 0.3% by weight or less
It is clear that it is advantageous for powder handling without caking.

[Brief description of the drawings]

FIG. 1 is a DSC chart of the crystal-modified composition of the present invention obtained in Example 1.

FIG. 2 is an X-ray diffraction pattern of a type I crystal modification which is a known crystal modification of a commercially available product.

FIG. 3 is a DSC chart of a crystal modification composition obtained by mixing the type I crystal modification and the type II crystal modification obtained in Comparative Example 1.

FIG. 4 is an X-ray diffraction pattern of a type II crystal modification obtained in Example 3.

FIG. 5 is an X-ray diffraction pattern of a type III crystal modification obtained in Reference Example 1.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshinori Omae 1-3-3 Higashikawasaki-cho, Chuo-ku, Kobe-city, Hyogo Prefecture Inside Chemipro Kasei Co., Ltd. (72) Inventor Yuichi Kaneko 1 Higashikawasaki-cho, Chuo-ku, Kobe-shi, Hyogo Prefecture Chome 3-3 Cemipro Kasei Co., Ltd.

Claims (3)

[Claims] 1. In a powder X-ray diffraction analysis using Cu-Kα ray, diffraction angles (2θ) are 5.5 °, 10.4 °, and 11.
0 °, 14.3 °, 16.5 °, 17.8 °, 18.8
With respect to a crystal modification showing a peak at ° (this crystal modification may be hereinafter referred to as type I), the diffraction angle (2θ) is 5.6 °,
7.3 °, 9.4 °, 10.5 °, 13.0 °, 13.
7 °, 16.0 °, 16.4 °, 18.3 °, 18.7
Crystal transformation showing a diffraction peak at ° (this crystal transformation is referred to as II
And / or diffraction angle (2θ)
5.5 °, 7.3 °, 10.6 °, 13.0 °, 14.
1 °, 14.9 °, 15.7 °, 16.4 °, 17.2
It is represented by the following formula (1) in which the content of a crystal modification showing diffraction peaks at °, 25.1 °, and 26.7 ° (hereinafter, this crystal modification is sometimes referred to as type III) is 0.3% by weight or less. 2- (2'-Hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole crystal modified composition. Embedded image 2. 2- (2'-hydroxy-3 ', 5'-
Recrystallizing (di-t-amylphenyl) benzotriazole in the presence of a soluble solvent at a temperature lower than 70 ° C., and drying the obtained crystal at a normal pressure or under a reduced pressure at a temperature lower than 70 ° C. Item 2. The process for producing a crystal modified composition of 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole according to Item 1. 3. An ultraviolet absorbent comprising the crystalline 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole modified composition according to claim 1.