Aqueous ultraviolet absorber composition

Abstract

To provide: an aqueous ultraviolet absorber composition that exhibits excellent transparency and sufficiently blocks ultraviolet rays; and a method for producing a coating composition using the same.SOLUTION: An aqueous composition comprises at least an ultraviolet absorber and a dispersing agent that are present in an aqueous medium. The ultraviolet absorber is a compound represented by the general formula in the figure. In the formula, R1 and R1' each independently represent a halogen atom, a nitro group, a cyano group, a perfluoroalkyl group, or the like, and R2 and R2' each independently represent an alkyl group having 1 to 12 carbon atoms, or the like.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. However, since it is an organic compound, it is generally dissolved in a volatile organic solvent or the like and used in a molecular state. However, due to concerns about the environmental and human impacts of volatile organic solvents, the use of aqueous solvents is desired. However, 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. In addition, since the absorption increases up to longer wavelengths in the dispersed state than in the dissolved state, the amount of the ultraviolet absorber used can be reduced. Therefore, it is expected that the range of product applications will expand to aqueous paints, sol-gel coating solutions, in-line coating solutions, etc. Furthermore, by making it into an aqueous dispersion, it can be processed into a paint form or a film form. In particular, by making it into a transparent dispersion, wide applications 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, as a result of 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 to uses that require higher transparency than the above report, such as glass coating.

[0005] In addition, in Patent Documents 4 and 5, a high transmittance is maintained by undergoing 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 has a high transmittance and 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 the transmittance can be improved in a shorter time than before by dispersing using a specific ultraviolet absorber. That is, it is a dispersion liquid in which a specific bis-octrizole-related compound is dispersed in water.

[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 compound represented by the following general formula (I), and is characterized as an ultraviolet absorber aqueous composition. General formula (I) [Chemical formula] In the formula, R1 and R 1' may be the same as or different from each other, and are 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. 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 group portion, or a cycloalkyl group having 5 to 8 carbon atoms. 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 portion of this group consists of 6 to 16 carbon atoms). (2) The aqueous composition of the ultraviolet absorber according to (1) above, characterized in that the ultraviolet absorber is dispersed with an average dispersed particle diameter of 10 to 35 nm.

[0008] (3) The aqueous composition of the ultraviolet absorber according to (1) or (2) above, characterized in that the dispersant is one or more compounds selected from acrylic copolymers of controlled polymerization. (4) The aqueous composition of the ultraviolet absorber according to any one of (1) to (3) above, further characterized by containing a surfactant. (5) In the compound of general formula (I), The aqueous composition of the ultraviolet absorber according to any one of (1) to (4) above, wherein R1 is chlorine and R2 is tert-octyl, (6) A method for producing a coating composition, characterized in that the aqueous composition of the ultraviolet absorber according to any one of (1) to (5) above is further mixed with a resin component and liquefied by coating, is in.

Effect of the Invention

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

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Mode 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, an ultraviolet absorbing compound represented by the following general formula (1) is used.

[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 is a halogen atom, nitro group, cyano group, perfluoroalkyl group having 1 to 12 carbon atoms, R3SO- group or R3O2- group.

[0014] R2 and R 2' may be the same as or different from each other and is 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' is preferably an alkyl group having 1 to 4 carbon atoms or a halogen group. More preferably, it is a halogen group. Most preferably, it is a chlorine atom.

[0016] R2 and R 2' is preferably an alkyl group 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 in the art. Generally, after producing the benzotriazole compound of phenolic raw materials, 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 absorber compound The ultraviolet absorber 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, and the crystallinity cannot be maintained, making it difficult for dispersion to proceed. As a result, the particle size becomes large and the transparency decreases.

[0020] 3. Melting point of the ultraviolet absorber compound The ultraviolet absorber 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 glass transition point are the values measured by DSC. More specifically, it is based on 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 absorber compound used in the present invention preferably has a molecular weight of 400 to 2500, more preferably 650 to 750, and most preferably 727.76. If the molecular weight is lower than 400, the melting point and glass transition point tend to be low, and if it is larger than 2500, it tends to be difficult to crystallize, resulting in the problem that it cannot be dispersed.

[0023] 〔Surfactant〕 In the present invention, a surfactant is preferably contained. Examples of surfactants include ionic surfactants, nonionic surfactants, and cationic surfactants. Examples of ionic surfactants include fatty acid salts, alkyl sulfate esters, alkylbenzene sulfonate salts, alkylnaphthalene sulfonate salts, alkyl sulfosuccinate salts, alkyl diphenyl ether disulfonate salts, polyoxyethylene alkyl sulfate esters, polyoxyethylene alkyl aryl sulfate esters, alkane sulfonate salts, naphthalene sulfonic acid formalin condensates, polyoxyethylene alkyl phosphate esters, N-methyl-oleoyl taurate salts, and α-olefin sulfonate salts. Examples of nonionic surfactants 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 alkyl amines, acetylene glycols, and ethylene glycol adducts of acetylene glycols. Examples of cationic surfactants and amphoteric surfactants include alkylamine salts, quaternary ammonium salts, alkyl betaines, and amine oxides. These ionic surfactants may be used as dispersants, wetting agents, detergents, and surface tension regulators, which will be described later.

[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 Yushi'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 Yushi's Trim CB#32, Daiichi Kogyo Seiyaku's Hitenol NF-13, Prisurf AL, Neugen EA-87, EA-137, EA-157, EA-167, EA-177 can be used. Most preferably, it is Emulgen B66.

[0026] 〔Polymer dispersant〕 Furthermore, in addition to the above surfactants, a polymer dispersant may be used in combination. Preferred polymer dispersants include acrylic copolymers of controlled polymerization. As commercial products, BYK'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 not 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, and 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, and 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 causing media such as glass, alumina, zirconia, steel, tungsten, etc. with a small diameter to move at high speed in a vessel and grinding the slurry passing between them 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 ultraviscomills.

[0031] A collision type disperser is a disperser that disperses by colliding a fluid against one wall surface at high speed or by colliding fluids against each other at high speed 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 flow, 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, dilute with water so that the ultraviolet absorber concentration of the ultraviolet absorber dispersion becomes 0.0982%, measure the transmission spectrum at room temperature using an ultraviolet-visible spectrophotometer (UV-1850, manufactured by Shimadzu Corporation), and confirm the transmittance at 600 nm.

[0033] The composition of the present invention can achieve a transmittance of 75% or more at 600 nm 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. Also, 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. The fact that the value of A380 / A600 is large means that it can sufficiently absorb the ultraviolet region 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 is in the range of 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 other hand, 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 ratios, 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 in relation to the purpose and 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 coating it to be liquefied. 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 through the coated substrate (coated article), the damage received from sunlight or ultraviolet rays can be reduced.

[0040] The substrates to be coated with the coating composition of the present invention are not limited at all, and examples 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 drugs, etc., signboards, signs, members constituting solar cell panels, 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 Both R1 and R in the general formula (I) 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 parts by weight of polyoxyethylene tribenzylphenyl ether (manufactured by Kao Corporation, "Emulgen B-66", HLB 13.2) as a surfactant, and 83 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 a result of measurement 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 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] Comparative Example 1 An ultraviolet absorber was dispersed in the same manner as in Example 1, except that compound 2 (2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-tert-octylphenol] (TINUVIN 360, manufactured by BASF)) in which both R1 and R 1' in the general formula (I) are hydrogen atoms and both R2 and R 2' are 1,1,3,3-tetramethylbutyl groups 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 32 nm and the transmittance was 78.0%.

[0044] Comparative Example 2 As the surfactant, 1.0 part by weight of polyoxyethylene tribenzyl phenyl ether ("Emulgen B-66" manufactured by Kao Corporation, HLB 13.2), as the dispersant, 17.5 parts by weight of a high molecular weight dispersant having an acid value ("disperbyk-2015" manufactured by BYK Chemie, acid value 10 mg KOH / g, active ingredient 40.0% by weight), and 71.5 parts by weight of water were changed. An ultraviolet absorber was dispersed in the same manner as in Comparative Example 1 except for this change. 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%.

[0045] Comparative Example 3 As the dispersant, 17.5 parts by weight of a high molecular weight dispersant having an acid value ("disperbyk-2015" manufactured by BYK Chemie, acid value 10 mg KOH / g, active ingredient 40.0% by weight) and 72.5 parts by weight of water were changed. An ultraviolet absorber was dispersed in the same manner as in Comparative Example 1 except for this change. 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 43 nm and the transmittance was 68.5%.

[0046] Comparative Example 4 The ultraviolet absorber was dispersed in the same manner as in Example 1 except that the ultraviolet absorber was changed to Compound 3 represented by the following chemical formula (II) (2-(5-chloro-2H-benzotriazol-2-yl)-6-tert-butyl-4-methylphenol ("TINUVIN 326" manufactured by BASF)).

[0047] Chemical formula (II)

Chemical formula

[0048] 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 130 nm and the transmittance was 1.3%.

[0049] Comparative Example 5 The ultraviolet absorber was dispersed in the same manner as in Example 2, except that Compound 3 (2-(5-chloro-2H-benzotriazol-2-yl)-6-tert-butyl-4-methylphenol, "TINUVIN 326" manufactured by BASF) was used instead of the one in Comparative Example 4. 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 119 nm and the transmittance was 1.9%.

[0050] Comparative Example 6 The ultraviolet absorber was dispersed in the same manner as in Comparative Example 2, except that Compound 3 (2-(5-chloro-2H-benzotriazol-2-yl)-6-tert-butyl-4-methylphenol, "TINUVIN 326" manufactured by BASF) was used instead of the one in Comparative Example 4. 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 155 nm and the transmittance was 2.1%.

[0051] Comparative Example 7 The ultraviolet absorber was dispersed in the same manner as in Comparative Example 3, except that Compound 3 (2-(5-chloro-2H-benzotriazol-2-yl)-6-tert-butyl-4-methylphenol, "TINUVIN 326" manufactured by BASF) was used instead of the one in Comparative Example 4. 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 158 nm and the transmittance was 4.1%.

[0052] Comparative Example 8 The ultraviolet absorber was dispersed in the same manner as in Example 1, except that Compound 4 (2,2'-(1,4-phenylene)bis-4H-3,1-benzoxazin-4-one, "KEMISORB 500" manufactured by Chemipro Kasei Co., Ltd.) represented by the following chemical formula (III) was used instead of the one in Example 1.

[0053] Chemical formula (III)

Chemical formula

[0054] 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%.

[0055] Comparative Example 9 The ultraviolet absorber was dispersed in the same manner as in Example 2, except that compound 4 (2,2'-(1,4-phenylene)bis-4H-3,1-benzoxazin-4-one (manufactured by Chemipro Kasei Co., Ltd., "KEMISORB500")) was used as the ultraviolet absorber as in Comparative Example 8. 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%.

[0056] Comparative Example 10 The ultraviolet absorber was dispersed in the same manner as in Comparative Example 2, except that compound 4 (2,2'-(1,4-phenylene)bis-4H-3,1-benzoxazin-4-one (manufactured by Chemipro Kasei Co., Ltd., "KEMISORB500")) was used as the ultraviolet absorber as in Comparative Example 8. 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 79 nm and the transmittance was 9.1%.

[0057] Comparative Example 11 The ultraviolet absorber was dispersed in the same manner as in Comparative Example 3, except that compound 4 (2,2'-(1,4-phenylene)bis-4H-3,1-benzoxazin-4-one (manufactured by Chemipro Kasei Co., Ltd., "KEMISORB500")) was used as the ultraviolet absorber as in Comparative Example 8. 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 58 nm and the transmittance was 25.4%.

[0058] Table 1 shows the ultraviolet absorbers, activators, dispersants, transmittance, absorbance, absorbance ratio, D10, D50, D90 and viscosity of each dispersion obtained in each of the above examples and comparative examples.

[0059]

Table 1

[0060] 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]

[0061] Comparing the transmittance of the examples and the comparative examples, it can be seen that the dispersion using Compound 1 as the ultraviolet absorber according to the present invention has a higher transmittance and better transparency compared to the dispersions using other ultraviolet absorbers. Comparing the absorbance ratios of the examples and the comparative examples, it can be seen that the absorbance ratio of the dispersion using Compound 1 as the ultraviolet absorber according to the present invention is larger than the absorbance ratios of the dispersions using other ultraviolet absorbers, and it maintains high transparency while sufficiently shielding the ultraviolet region.

Industrial Applicability

[0062] 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. An aqueous composition comprising at least an ultraviolet absorber and a dispersant present in an aqueous medium, the ultraviolet absorber being 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 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).

2. 2. 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.

3. 3. The aqueous ultraviolet absorbent composition according to claim 1, wherein the dispersant is one or more compounds selected from acrylic copolymers of control polymerization.

4. The aqueous ultraviolet absorbent composition according to any one of claims 1 to 3, further comprising a surfactant.

5. In the compound of formula (I), R １ is chlorine, R ２ 5. The aqueous ultraviolet absorbent composition according to claim 1, wherein is tert-octyl.

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

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