Ultraviolet absorber aqueous composition

Abstract

To provide an ultraviolet absorber aqueous composition which is excellent in transparency and sufficiently blocks ultraviolet rays, and a coating composition using the same.SOLUTION: An ultraviolet absorber aqueous composition is an aqueous composition in which at least an ultraviolet absorber and a dispersant are present in an aqueous medium, wherein the ultraviolet absorber is a benzotriazole-based ultraviolet absorber, and a polyoxyalkylene derivative is contained.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an ultraviolet absorber composition, a method for producing the same, and a method for producing a coating composition.

Background Art

[0002] Benzotriazole-based ultraviolet absorbers are known for their excellent properties such as ultraviolet absorption performance and light stability, and have been widely used. In particular, 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-tert-octylphenol] (also known as bisoctrizole) is known as an ultraviolet absorber that can absorb up to long wavelengths, but it is an organic compound and is generally used in a molecular state dissolved in a volatile organic solvent or the like. However, since there are concerns about the environmental and human impacts of volatile organic solvents, the use of aqueous solvents is desired, but bisoctrizole is insoluble in water. Therefore, methods for dispersing the compound in water have been reported (Patent Documents 1, 2, 3, 4, 5). By dispersing in water, an aqueous solvent can be used, eliminating the need to use an organic solvent. Moreover, since it is in a dispersed state and not dissolved, the light resistance of the ultraviolet absorber itself is improved. Also, since the absorption increases up to longer wavelengths in the dispersed state compared to the dissolved state, the amount of ultraviolet absorber used can be reduced. Therefore, it is expected that the range of applicable products will expand to aqueous paints, sol-gel coating liquids, in-line coating liquids, etc. Furthermore, by making it a water dispersion, it can be processed into a paint form or a film form. In particular, by making it a transparent dispersion, wide application to products that require light resistance and transparency, such as fiber materials, inks, and cosmetics, can be expected.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, according to the study by the present inventor, it has been found that it is difficult to improve the visible light transmittance while sufficiently cutting ultraviolet rays in the dispersion liquids disclosed in these conventionally known documents. Specifically, among the above-mentioned documents, in Patent Documents 1 to 3, when the transmittance in the ultraviolet region (200 nm to 380 nm) is 0.0%, the transmittance of visible light (600 nm) exceeding 25% (the numerical value when the concentration of the ultraviolet absorber is 0.00982%) could not be obtained. Therefore, it was difficult to apply it to applications that require higher transparency than the above report, such as glass coating.

[0005] Also, in Patent Documents 4 and 5, a high transmittance is maintained through a long manufacturing process, and it cannot be said that the production efficiency is high due to the long manufacturing process. Therefore, there has been a demand for a dispersion composition that maintains a high transmittance and has a high production efficiency with a short manufacturing process.

Means for Solving the Problems

[0006] The present inventor repeated studies to solve the above problems. As a result, it was found that by using a specific ultraviolet absorber and dispersing it while containing a polyoxyalkylene derivative which is a surfactant, the transmittance can be improved in a shorter time than before. That is, it is a dispersion liquid in which a specific bisoctrizole-related compound is dispersed in water and contains a polyoxyalkylene derivative.

[0007] That is, the present invention is (1) An aqueous composition in which at least an ultraviolet absorber and a dispersant are present in an aqueous medium, wherein the ultraviolet absorber is a benzotriazole-based ultraviolet absorber and contains a polyoxyalkylene derivative, and which is characterized as an aqueous ultraviolet absorber composition. (2) The aqueous ultraviolet absorber composition according to (1) above, wherein the benzotriazole-based ultraviolet absorber is a compound represented by the following general formula (I). General formula (I)

Chemical formula

[0008] (4) The ultraviolet absorber aqueous composition according to any one of (1) to (3) above, characterized in that the dispersant is one or more compounds selected from acrylic copolymers of controlled polymerization. (5) In the compound of general formula (I), The ultraviolet absorber aqueous composition according to any one of (1) to (4) above, characterized in that R1 is chlorine and R2 is tert-octyl. (6) A method for producing a coating composition, characterized in that the ultraviolet absorber aqueous composition according to any one of (1) to (5) above is further mixed with a resin component and liquefied for coating. is as follows.

Advantages of the Invention

[0009] According to the present invention, an ultraviolet absorber composition capable of improving the visible light transmittance while sufficiently cutting off ultraviolet rays and a coating composition using the same can be obtained.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0011] Hereinafter, the present invention will be described in detail. 〔Ultraviolet Absorbing Compound〕 1. Structure of Ultraviolet Absorbing Compound In the present invention, a benzotriazole-based ultraviolet absorber is used as the ultraviolet absorber. The benzotriazole-based ultraviolet absorber is a compound having a benzotriazole skeleton. Among these benzotriazole-based ultraviolet absorbers, in particular, the ultraviolet absorbing compound represented by the following general formula (1) is preferable.

[0012] General formula (1)

Chemical formula

[0013] In the formula, R1 and R 1' may be the same as or different from each other, and are a hydrogen atom, a halogen atom, a nitro group, a cyano group, a perfluoroalkyl group having 1 to 12 carbon atoms, an R3SO- group or an R3O2- group.

[0014] R2 and R 2' may be the same as or different from each other, and are an alkyl group having 1 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms substituted by a CO2H group, a phenyl group, a phenylalkyl group containing 1 to 4 carbon atoms in the alkyl part, or a cycloalkyl group having 5 to 8 carbon atoms. Preferably, it is an alkyl group having 1 to 12 carbon atoms.

[0015] R3 is an alkyl group having 1 to 20 carbon atoms, a hydroxyalkyl group having 2 to 20 carbon atoms, an alkyl group substituted by an alkoxycarbonyl group having 2 to 9 carbon atoms, an alkenyl group having 3 to 18 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, a phenylalkyl group having 7 to 15 carbon atoms, an aryl group having 6 to 10 carbon atoms or the aryl group substituted by one or two alkyl groups having 1 to 4 carbon atoms, or a 1,1,2,2-tetrahydroperfluoroalkyl group (the perfluoroalkyl part of this group consists of 6 to 16 carbon atoms). R1 and R 1' are preferably a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a halogen group. More preferably, they are a hydrogen atom or a halogen group. Most preferably, it is a chlorine atom.

[0016] R2 and R 2' are preferably alkyl groups having 1 to 12 carbon atoms. Most preferably, both R2 and R 2' are the following groups.

[0017] [Chemical formula]

[0018] These compounds themselves are known, and commercially available products can be used. In addition, they can be produced and used by the production methods of various benzotriazole compounds known conventionally. Generally, after producing a benzotriazole compound from raw material phenols, methods such as dimerization of the benzotriazole with aldehydes can be mentioned. For example, they can also be produced by the methods described in Japanese Patent No. 3223377, German Patent No. 1,670,951, etc.

[0019] 2. Glass transition point of the ultraviolet absorbing compound The ultraviolet absorbing compound used in the present invention preferably has a glass transition point of 35°C or higher, more preferably 60°C or higher, and most preferably 67°C. If it is too low, the heat of dispersion during dispersion will cause it to exceed the glass transition point, making it impossible to maintain crystallinity and difficult for dispersion to proceed. For this reason, the particle size becomes large and the transparency decreases.

[0020] 3. Melting point of the ultraviolet absorbing compound The ultraviolet absorbing compound used in the present invention preferably has a melting point of 150°C or higher, more preferably 190°C or higher, and most preferably 205°C or higher. If the melting point is too low, the glass transition point also tends to be low, and the above problems occur.

[0021] The melting point and the glass transition point are values measured by DSC. More specifically, it is by the method described in JIS standard K-7121-1987 "Method for Measuring Transition Temperature of Plastics".

[0022] Molecular weight of the ultraviolet absorber The ultraviolet-absorbing compound used in the present invention preferably has a molecular weight of 400 to 2,500, more preferably 650 to 750, and most preferably 727.76. When the molecular weight is lower than 400, the melting point and glass transition point tend to be low, and when it is larger than 2,500, there is a tendency that crystallization becomes difficult and problems such as inability to disperse occur.

[0023] 〔Surfactant〕 In the present invention, a specific surfactant is contained. That is, a polyoxyalkylene derivative is contained as the surfactant. A polyoxyalkylene derivative is a compound having a polyoxyalkylene skeleton, and examples thereof include polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene derivatives, ethylene oxide-propylene oxide block copolymers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene alkylamines, acetylene glycols, and ethylene glycol adducts of acetylene glycols.

[0024] Particularly preferred surfactants are polyoxyalkylene derivatives having an HLB of 9 to 16, preferably 11 to 15, and most preferably 13.2, having 1 to 3 benzyl groups, which may be bonded to any part of the phenyl ether ring, and the hydrophilic group may contain ethylene oxide or propylene oxide, and may contain -SO3NH4, -PO3H2 or other ionic groups at the ends of ethylene oxide or propylene oxide.

[0025] As commercial products, Kao's Emulgen A-60, Emulgen A-90, Emulgen B-66, Toho Chemical's TS1500, TS2000, TS2600, Clariant's Emulsogen TS160, Dispersing agent LFH, LFES, Nippon Emulsifier's Newcol 704, 706, 707, 708, 709, 710, 711, 712, 714, 714(80), 719, 610, 610(80), 2604, 2607, 2609, 2614, 707-F, 710-F, 714-F, 2608-F, 2600-FB, 2616-F, 3612-FA, 707-SF, 707-SFC, 707-SN, 714-SF, 714-SN, 723-SF, 740-SF, 780-SF, 2607-SF, 2614-SF, Takemoto Oil & Fat's New Calgen C-150, C-173, C-200, C-314, CP-50, CP-80, CP-120, CP-15-200, Pionin D-6112, D-6512, D-6414, DTD-51, Miyoshi Oil & Fat's Trimine CB#32, Daiichi Kogyo Seiyaku's Hitenol NF-13, Pricerf AL, Neugen EA-87, EA-137, EA-157, EA-167, EA-177 can be used. Most preferably, it is Emulgen B66.

[0026] [Polymeric dispersant] Furthermore, in addition to the above surfactants, a polymeric dispersant may be used in combination. Preferred polymeric dispersants include acrylic copolymers of controlled polymerization. As commercial products, BYK Chemie's Disperbyk-190, 2010, 2012, 2013, 2015, 2055, 2060, 2061, 2096 can be used. Preferably, Disperbyk-190, 2015, and most preferably Disperbyk-2015 are preferred because they have high compatibility with the surfactants used in combination and the dispersibility is improved compared to the case of using surfactants alone.

[0027] [Dispersion medium] In the present invention, at least each of the above components is dispersed in water. When a dispersion medium other than water is contained, there may be a problem that the ultraviolet absorber is dissolved and the wavelength shifts to a shorter wavelength. Therefore, it is preferably not to contain a dispersion medium other than water as much as possible. It is desirable to suppress it to 1% by weight or less in the dispersion liquid. Preferably, the dispersion medium is 100% water.

[0028] 〔Content of each component〕 The content of the ultraviolet absorber is preferably 5 to 20% by mass in the dispersion liquid. If it is 5% or less, it is difficult to achieve a share and the dispersion hardly progresses. If it exceeds 20% by mass, the viscosity becomes high and the dispersion hardly progresses. Preferably it is 8 to 12% by mass, and most preferably 10% by mass. The content of the surfactant is preferably 1 to 100 parts by mass with respect to 100 parts by mass of the ultraviolet absorber. If the content of this surfactant is less than 1 part by mass, the crushing of 50 nm or less hardly progresses, and there are problems such as a long dispersion time. If it exceeds 100 parts by mass, the viscosity becomes high and the dispersion hardly progresses. Preferably it is 50 to 90 parts by mass, and most preferably 70 parts by mass.

[0029] When a polymer dispersant is used in combination with the surfactant, it is preferably used in an amount of 1 to 100 parts by mass with respect to 100 parts by mass of the ultraviolet absorber within the range of the content of the above surfactant. If it is less than 1 part by mass, the effect of the combination is small. If it exceeds 100 parts by mass, the viscosity becomes high and the dispersion hardly progresses. Preferably it is 5 to 20 parts by mass, and most preferably 10 parts by mass.

[0030] 〔Production of ultraviolet absorber dispersion〕 The ultraviolet absorber dispersion of the present invention can be produced using devices such as a media type disperser or a collision type disperser. A media type disperser is a disperser that disperses by moving media such as glass, alumina, zirconia, steel, tungsten, etc. with a small diameter at high speed in a vessel and grinding the slurry passing through it with the shearing force between the media. Specific examples of media type dispersers include, for example, ball mills, sand mills, pearl mills, spike mills, agitator mills, cob mills, and ultra viscomills.

[0031] A collision type disperser is a disperser that disperses by colliding a fluid at high speed against one wall surface or by colliding fluids against each other and grinding pigments and the like in the fluid. Examples of collision type dispersers include, for example, jet mills that accelerate and grind raw material particles by a high-speed jet air current, and "Starburst" (registered trademark, manufactured by Sugino Machine Limited), which is a wet atomization device. It may also be produced using other known dispersing devices, such as roll mills and ultrasonic dispersers. Among the devices of various dispersers as described above, any device and media that can obtain sufficient shearing force to obtain the desired particle size may be used. Generally, various media type dispersers are suitable. These devices and media are appropriately selected, the above-described respective components are charged, and the treatment is performed until the ultraviolet absorbing compound becomes fine particles having the above-described desired particle size.

[0032] 〔Physical properties of ultraviolet absorber dispersion〕 1. Transparency The ultraviolet absorber dispersion of the present invention can be made into a composition that is excellent in transparency while maintaining sufficient ultraviolet absorption performance. This can be confirmed by the following two indicators. First, it is diluted with water so that the ultraviolet absorber concentration of the ultraviolet absorber dispersion becomes 0.0982%, and the transmission spectrum is measured at room temperature using an ultraviolet-visible spectrophotometer (UV-1850, manufactured by Shimadzu Corporation), and the transmittance at 600 nm is confirmed.

[0033] The composition of the present invention can have a transmittance at 600 nm of 75% or more in this case. Furthermore, it can be 85% or more, and can also be 93% or more. In this case, in a dispersion with a concentration lower than 75%, turbidity increases and transparency decreases. However, as shown in the comparative examples described later, it is difficult to achieve 75% or more in the prior art.

[0034] Next, the ultraviolet absorber dispersion of the present invention is diluted with water so that the concentration of the ultraviolet absorber becomes 0.002%, and the absorption spectrum is measured at room temperature using an ultraviolet-visible spectrophotometer (UV-1850, manufactured by Shimadzu Corporation). In this case, the absorbance at 380 nm (A380) can be 0.50 to 0.70. In addition, A380 / A600, which is the result of calculating the ratio of the absorbance at 380 nm (A380) to the absorbance at 600 nm (A600) of the absorption spectrum, can be 200 or more, can further be 250 or more, and can also be 600 or more, 650. A large value of A380 / A600 means that the ultraviolet region can be sufficiently absorbed while sufficiently transmitting the visible light region. When A380 / A600 is lower than 200, it is difficult to maintain high transparency while sufficiently cutting off the ultraviolet region. The relationship between the wavelength and transmittance of the ultraviolet absorber dispersion of the present invention is shown in FIG. 1, and the relationship between the wavelength and absorbance is shown in FIG. 2. As can be seen from these figures, in the ultraviolet absorber dispersion of the present invention, the transmittance is high in the defect region, the transparency is excellent, and high transparency is maintained while sufficiently shielding the ultraviolet region.

[0035] 2. Dispersion particle size It is preferable to adjust the particle diameter of the ultraviolet absorbing compound in a certain range in the dispersion of the present invention. Specifically, the ultraviolet absorber concentration of the ultraviolet absorber dispersion of the present invention is diluted with water so that the loading index ranges from 0.1 to 100, and when the particle size is measured at room temperature using a particle size distribution measuring instrument (Microtrac UPA EX-150 manufactured by Nikkiso Co., Ltd.), the particle size is 10 to 35 nm, preferably 10 to 30 nm, and most preferably 13 to 20 nm. Within this range, the balance between the ultraviolet absorption performance and transparency described above is the best. When it becomes larger than 35 nm, the transparency tends to decrease. On the contrary, when the particle size is smaller than 10 nm, the stability of the liquid over time decreases, and the ultraviolet absorption performance tends to decrease.

[0036] 3. Viscosity The viscosity of the ultraviolet absorber dispersion of the present invention is preferably such that the viscosity measured at 25 °C using a viscometer (VISCOMETER TV-22, manufactured by Toki Sangyo Co., Ltd.) is 2.0 to 4.5 mPa·s, particularly preferably 2.0 to 3.0 mPa·s. Within this range, it is easy to mix with other materials such as resin components and is easy to handle, which is particularly preferable. By blending the above-described components in the above-described proportions, it can be easily adjusted to a preferable viscosity range.

[0037] 4. pH The pH of the ultraviolet absorber dispersion of the present invention can be appropriately selected according to the purpose and the relationship with the pH of other components such as the resin to be blended. The pH can be appropriately adjusted by selecting the functional group of the surfactant.

[0038] The coating composition can be obtained by further mixing the above-described ultraviolet absorber aqueous composition with a resin component and liquefying the coating. Here, the coating composition of the present invention is a composition capable of forming a film on a substrate. For example, it can also be used for various applications as described in WO2015 / 152057.

[0039] According to the coating composition of the present invention, since the performance of the ultraviolet absorber contained in the formed film is high, in the formed film itself, in the substrate coated with the film, and in the substance exposed to sunlight or ultraviolet rays passing through the coated substrate (coated article), the damage received from sunlight or ultraviolet rays can be reduced.

[0040] The substrate to be coated with the coating composition of the present invention is not particularly limited, and examples thereof include glass, resin glass, metal, plastic, fiber, cloth, paper, wood, concrete, etc. These substrates may be, for example, members for window glass, interior and exterior finishing materials, building materials such as building structures, containers for containing foods, pharmaceuticals, cosmetics, chemical products, etc., signboards, signs, members constituting solar cell modules, etc. Further, by using the coating composition of the present invention with a printed matter as a substrate, the fading of the ink can be prevented. The coating composition of the present invention may be an ink, and in this case, for example, the fading of the ink can be prevented. The coating composition of the present invention may be an adhesive, and in this case, for example, the deterioration of the adhesive due to sunlight or ultraviolet rays can be prevented. Furthermore, by coating a substrate such as a fiber with the coating composition of the present invention, it is also possible to manufacture clothing, hats, umbrellas, etc. having an ultraviolet shielding effect.

[0041] Hereinafter, the present invention will be described more specifically with reference to examples. Example 1 In the general formula (I), both R1 and R 1' are chlorine atoms, and both R2 and R 2' are 1,1,3,3-tetramethylbutyl groups. 10.0 parts by weight of Compound 1 (2,2'-methylenebis[6-(5-chloro-2H-benzotriazol-2-yl)-4-tert-octylphenol]), 7.0 parts by weight of polyoxyethylene tribenzylphenyl ether (manufactured by Kao Corporation, "Emulgen B-66", HLB 13.2) as a surfactant, and 83.0 parts by weight of water were mixed and pulverized using zirconia beads with a diameter of φ0.1 mm for 10 hours with a paint conditioner to obtain an ultraviolet absorber dispersion 1. The average particle diameter of the fine particles of the ultraviolet absorber in the obtained dispersion was 28 nm (median diameter, D 50 ) as measured at room temperature using a particle size distribution analyzer (Microtrac, manufactured by Nikkiso Co., Ltd.). The ultraviolet absorber concentration of the obtained ultraviolet absorber dispersion 1 was diluted with water to 0.0982%, and the transmittance spectrum was measured at room temperature using an ultraviolet-visible spectrophotometer (UV-1850, manufactured by Shimadzu Corporation). As a result, the transmittance at 600 nm was 86.9%.

[0042] Example 2 An ultraviolet absorber was dispersed in the same manner as in Example 1, except that 7.0 parts by weight of polyoxyethylene tribenzylphenyl ether (Emulgen B-6, manufactured by Kao Corporation, HLB 13.2) was used as the surfactant, 2.5 parts by weight of a polymer dispersant having an acid value (disperbyk-2015, manufactured by BYK Chemie, acid value 10 mgKOH / g, active ingredient 40.0% by weight) was used as the dispersant, and 80.5 parts by weight of water was used. The average particle diameter and transmittance of the ultraviolet absorber in the obtained dispersion were measured in the same manner as in Example 1, and the average particle diameter was 15 nm and the transmittance was 93.2%.

[0043] Example 3 An ultraviolet absorber was dispersed in the same manner as in Example 1, except that 1.0 part by weight of polyoxyethylene tribenzylphenyl ether (Emulgen B-66, manufactured by Kao Corporation, HLB 13.2) was used as the surfactant, 17.5 parts by weight of a polymer dispersant having an acid value (disperbyk-2015, manufactured by BYK Chemie, acid value 10 mgKOH / g, active ingredient 40.0% by weight) was used as the dispersant, and 71.5 parts by weight of water was used. The average particle diameter and transmittance of the ultraviolet absorber in the obtained dispersion were measured in the same manner as in Example 1, and the average particle diameter was 31 nm and the transmittance was 80.4%.

[0044] Example 4 As the ultraviolet absorber, when both R1 and R 1' in the general formula (I) are hydrogen atoms, and R2 and R 2'The ultraviolet absorber was dispersed in the same manner as in Example 1, except that all of them were changed to Compound 2 (2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-tert-octylphenol] (manufactured by BASF, "TINUVIN 360")) in which all are 1,1,3,3-tetramethylbutyl groups. The average particle diameter and transmittance of the ultraviolet absorber in the obtained dispersion were measured in the same manner as in Example 1, and the average particle diameter was 32 nm and the transmittance was 78.0%.

[0045] Example 5 As the ultraviolet absorber, except that all of R1 and R in the general formula (I) are hydrogen atoms, and all of R2 and R 1' are hydrogen atoms, and all of R2 and R 2' are changed to 1,1,3,3-tetramethylbutyl groups, that is, Compound 2 (2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-tert-octylphenol] (manufactured by BASF, "TINUVIN 360")), the ultraviolet absorber was dispersed in the same manner as in Example 2. The average particle diameter and transmittance of the ultraviolet absorber in the obtained dispersion were measured in the same manner as in Example 1, and the average particle diameter was 24 nm and the transmittance was 87.9%.

[0046] Example 6 As the ultraviolet absorber, except that all of R1 and R in the general formula (I) are hydrogen atoms, and all of R2 and R 1' are hydrogen atoms, and all of R2 and R 2' are changed to 1,1,3,3-tetramethylbutyl groups, that is, Compound 2 (2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-tert-octylphenol] (manufactured by BASF, "TINUVIN 360")), the ultraviolet absorber was dispersed in the same manner as in Example 3. The average particle diameter and transmittance of the ultraviolet absorber in the obtained dispersion were measured in the same manner as in Example 1, and the average particle diameter was 30 nm and the transmittance was 81.9%.

[0047] Comparative Example 1 The ultraviolet absorber was dispersed in the same manner as in Example 1, except that the compound 4 (2,2'-(1,4-phenylene)bis-4H-3,1-benzoxazin-4-one (manufactured by Chemipro Kasei Co., Ltd., "KEMISORB 500")) represented by the following chemical formula (III) was used as the ultraviolet absorber.

[0048]

Chemical formula

[0049] The average particle diameter and transmittance of the ultraviolet absorber in the obtained dispersion were measured in the same manner as in Example 1, and the average particle diameter was 90 nm and the transmittance was 1.0%.

[0050] Comparative Example 2 The ultraviolet absorber was dispersed in the same manner as in Example 2, except that the compound 4 (2,2'-(1,4-phenylene)bis-4H-3,1-benzoxazin-4-one (manufactured by Chemipro Kasei Co., Ltd., "KEMISORB 500")) was used as the ultraviolet absorber as in Comparative Example 1. The average particle diameter and transmittance of the ultraviolet absorber in the obtained dispersion were measured in the same manner as in Example 1, and the average particle diameter was 81 nm and the transmittance was 1.7%.

[0051] The ultraviolet absorbers, activators, dispersants, transmittance, absorbance, absorbance ratio, D10, D50, D90, and viscosity of the respective dispersions obtained in the above Examples and Comparative Examples are shown in Table 1.

[0052]

Table 1

[0053] Compound 1... 2,2'-methylenebis[6-(5-chloro-2H-benzotriazol-2-yl)-4-tert-octylphenol] Compound 2... 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-tert-octylphenol] Compound 3…2-(5-chloro-2H-benzotriazol-2-yl)-6-tert-butyl-4-methylphenol Compound 4…2,2'-(1,4-phenylene)-bis[4H-3,1-benzoxazin-4-one]

[0054] When comparing the transmittances of the examples and comparative examples, it can be seen that the dispersion using the compound of chemical formula (I) as an ultraviolet absorber and containing a polyoxyalkylene derivative according to the present invention has a higher transmittance compared to those of other dispersions and is excellent in transparency. When comparing the absorbance ratios of the examples and comparative examples, it can be seen that the absorbance ratio of the dispersion using the compound of chemical formula (I) as an ultraviolet absorber and containing a polyoxyalkylene derivative according to the present invention is larger than those of other dispersions, and it maintains high transparency while sufficiently shielding the ultraviolet region.

Industrial Applicability

[0055] According to the present invention, an ultraviolet absorber aqueous composition excellent in transparency and sufficiently shielding ultraviolet rays, and a coating composition using the same can be obtained.

Claims

1. The aqueous composition of ultraviolet absorber is characterized in that at least an ultraviolet absorber and a dispersant are present in an aqueous medium, the ultraviolet absorber is a benzotriazole-based ultraviolet absorber, the dispersant is one or more compounds selected from acrylic copolymers of control polymerization, and contains a polyoxyalkylene derivative.

2. 2. The aqueous ultraviolet absorbent composition according to claim 1, wherein the benzotriazole-based ultraviolet absorbent is a compound represented by the following general formula (I): General formula (I) 【Chemistry 1】 During the ceremony, R 1 and R 1' may be the same or different, and each represents a hydrogen atom, a halogen atom, a nitro group, a cyano group, a perfluoroalkyl group having 1 to 12 carbon atoms, R 3 SO- group or R 3 O 2 - group. R 2 and R 2' may be the same or different, and each represents an alkyl group having 1 to 12 carbon atoms; 2 It is an alkyl group having 1 to 12 carbon atoms substituted by an H group, a phenyl group, a phenylalkyl group containing 1 to 4 carbon atoms in the alkyl portion, or a cycloalkyl group having 5 to 8 carbon atoms. R 3 is an alkyl group having 1 to 20 carbon atoms, a hydroxyalkyl group having 2 to 20 carbon atoms, an alkyl group substituted by an alkoxycarbonyl group having 2 to 9 carbon atoms, an alkenyl group having 3 to 18 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, a phenylalkyl group having 7 to 15 carbon atoms, an aryl group having 6 to 10 carbon atoms, or the above aryl groups substituted by one or two alkyl groups having 1 to 4 carbon atoms, or a 1,1,2,2-tetrahydroperfluoroalkyl group (the perfluoroalkyl portion of this group consists of 6 to 16 carbon atoms).

3. 3. The aqueous ultraviolet absorbent composition according to claim 1, wherein the ultraviolet absorbent is dispersed with an average dispersed particle size of 10 to 35 nm.

4. In the compound of formula (I), R １ is chlorine or hydrogen, R ２ The aqueous ultraviolet absorbent composition according to claim 2, wherein is tert-octyl.

5. A method for producing a coating composition, comprising mixing the aqueous ultraviolet absorbent composition according to any one of claims 1 to 4 with a resin component to form a coating liquid.

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