Ultraviolet absorber-containing solution and ultraviolet absorber-containing resin composition

Abstract

To provide an excellent method for using an ultraviolet absorber obtained by converting the powder form of the ultraviolet absorber into a convenient form.SOLUTION: The ultraviolet absorber-containing solution is composed of a mixed solution containing at least one ultraviolet absorber and at least one organic solvent. The ultraviolet absorber is a triazine-based ultraviolet absorber. The mixed solution containing the ultraviolet absorber and the organic solvent can be subjected to dissolution treatment at a heating temperature of 30 °C to 90 °C. In addition, it is possible to provide a molded product made of a resin composition kneaded or impregnated with an ultraviolet absorber-containing solution.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a solution containing an ultraviolet absorber and a resin composition containing an ultraviolet absorber. [Background technology]

[0002] Various ultraviolet absorbers are used in resin materials to prevent damage to the material from sunlight. Patent Document 1 discloses the use of a triazine compound obtained by crystallization as the ultraviolet absorber. Patent Documents 2 to 4 also disclose that, as a preferred form of ultraviolet absorber, the powder properties of a granular ultraviolet absorber can be improved by adjusting the powder's umbrella density and sieving characteristics to fall within predetermined numerical ranges. However, when the ultraviolet absorber is in powder form, it is not possible to avoid the risk of dust absorption into the body of the worker during operation and the risk of dust explosion due to static electricity.Furthermore, more space than necessary is required for transportation, and improvements in these areas are desired. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-6517 A [Patent Document 2] Re-tabled publication No. 2019-188987 [Patent Document 3] Patent Publication No. 2021-50345 [Patent Document 4] JP 2024-45320 A DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0004] The first object of the present invention is to convert the powder form of an ultraviolet absorber into a convenient form, and the second object of the present invention is to propose an excellent method for using an ultraviolet absorber. [Means for solving the problem]

[0005] The present inventors have conducted extensive research in light of the above problems, and as a result have been able to propose an excellent method of using an ultraviolet absorber, which can convert a powder-type ultraviolet absorber into a suitable form, avoid the risk of dust absorption into the body of a worker during work and dust explosions due to static electricity, and further does not require more space than necessary during transportation. Specifically, the problem can be solved by the following (Aspect 1) to (Aspect 6).

[0006] (Embodiment 1) The ultraviolet absorber-containing solution is composed of a mixed solution containing at least one type of ultraviolet absorber and at least one type of organic solvent.

[0007] (Aspect 2) The ultraviolet absorber-containing solution according to aspect 1, wherein the ultraviolet absorber is a triazine-based ultraviolet absorber.

[0008] (Aspect 3) The ultraviolet absorber-containing mixed solution according to Aspect 1, wherein the organic solvent is selected from the group consisting of aromatic organic solvents, ester organic solvents, ketone organic solvents, and amide organic solvents.

[0009] (Embodiment 4) A method for producing an ultraviolet absorber-containing solution, characterized by dissolving a mixed solution containing at least one ultraviolet absorber and at least one organic solvent at a heating temperature of 30°C to 90°C.

[0010] (Embodiment 5) A resin composition obtained by kneading or impregnating the ultraviolet absorbent-containing solution described in any one of embodiments 1 to 3 or the ultraviolet absorbent-containing solution produced by the production method described in embodiment 4.

[0011] (Embodiment 6) A molded article made of a resin composition kneaded with or impregnated with the ultraviolet absorber-containing solution described in any one of Embodiments 1 to 3 or the ultraviolet absorber-containing solution produced by the production method described in Embodiment 4. [Effects of the Invention]

[0012] The present invention is achieved by an ultraviolet absorber-containing solution comprising a mixed solution containing at least one ultraviolet absorber and at least one organic solvent. According to the present invention, by incorporating ultraviolet light into various materials using the ultraviolet absorber-containing solution, molded articles with excellent light weather resistance can be provided. Furthermore, when adding the ultraviolet absorbing suppository during the production of molded articles, since it is in a solution state, it can be added using a simple addition device. This avoids problems that are a concern with solid ultraviolet absorbers such as powders, such as dust explosions, obstacles to umbrella height during transportation and storage, and measures to prevent dust from irritating the human body, and is also cost-effective. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention is not limited to the described embodiments, but may be practiced in various ways.

[0014] The present invention relates to an ultraviolet absorber-containing solution comprising a mixed solution containing at least one ultraviolet absorber and at least one organic solvent, a resin composition impregnated with the ultraviolet absorber-containing solution, and a molded article made of the resin composition. The ultraviolet absorber, organic solvent, resin composition, resin composition and molded article of the present invention will be described below.

[0015] 1. UV absorbers The ultraviolet absorber of the present invention exhibits its function as an ultraviolet absorber by exhibiting a molar absorption coefficient of 10,000 (L mol) in solution at the maximum absorption wavelength for light in the wavelength range of 300 nm to 400 nm. -1 ·cm -1 ) or more is preferable. The ultraviolet absorber according to the present invention may be solid or liquid at room temperature. The molecular weight of the ultraviolet absorber is not particularly limited, but is preferably 200 to 10,000, more preferably 400 to 2,000 for low molecular weights, and 1,000 to 5,000 for high molecular weights.

[0016] The structure of the ultraviolet absorber is not particularly limited. Examples include triazine-based compounds, benzophenone-based compounds, triazole-based compounds, benzoate-based compounds, and salicylate-based compounds. Triazine-based compounds are preferred, and hydroxyphenyltriazine-based compounds are more preferred. The hydroxyphenyltriazine skeleton is a skeleton ((2-hydroxyphenyl)-1,3,5-triazine skeleton) consisting of triazine and three hydroxyphenyl groups bonded to the triazine, and can provide high UV absorption ability with a small amount. The hydroxyphenyl group in the hydroxyphenyltriazine skeleton may be bonded to a substituent such as an alkyl group or an alkyl ester group, but it is preferable that the substituent does not have a structure that can serve as a crosslinking point with the resin. Examples of structures that can serve as crosslinking points include functional groups such as a hydroxyl group, a thiol group, and an amine group, or a double bond.

[0017] Although the hydroxyphenyl group has a hydroxyl group as a substituent, the hydroxyl group directly bonded to the benzene ring does not form a crosslinked structure with the resin, and therefore is not treated as a structure that can serve as a crosslinking point with the resin. The alkyl ester group is preferably a group represented by the formula "-CH(-R)C(=O)OR'". In the formula, R is a hydrogen atom or a methyl group, and R' is a linear or branched alkyl group. If a structure that can serve as a crosslinking point with the acrylic resin is present in the substituent of the hydroxyphenyl group in the hydroxyphenyltriazine skeleton, the possibility of gel formation increases when the resin composition is molded.

[0018] Examples of usable ultraviolet absorbers are listed below, but the ultraviolet absorber is not limited to these. Triazine compounds include 2,4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-ethoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine, and 2,4-diphenyl-6-(2-hydroxy-4-octyl oxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-butoxyethoxy)-1,3,5-triazine, 2,4-bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3,5-triazine, 2,4-bis(2,4-dimethylphenyl)-6-[2-hydroxy-4-(3-alkyloxy-2-hydroxypropyloxy)-5-α-cumylphenyl]-s-triazine backbone (alkyloxy;UV absorbers having long-chain alkyloxy groups such as octyloxy, nonyloxy, and decyloxy), 2,4,6-tris(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2- Hydroxy-4-(1-(2-ethoxyhexyloxy)-1-oxopropan-2-yloxy)phenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-hexyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-octyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl -4-benzyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-butoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-propoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-methoxycarbonylpropyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-ethoxycarbonylethyloxyphenyl)-1,3,5-triazine )-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-(1-(2-ethoxyhexyloxy)-1-oxopropan-2-yloxy)phenyl)-1,3,5-triazine, and ultraviolet absorbers having a 2,4-bis(2,4-dimethylphenyl)-6-[2-hydroxy-4-(3-alkyloxy-2-hydroxypropyloxy)-5-α-cumylphenyl]-s-triazine skeleton (alkyloxy; long-chain alkyloxy groups such as octyloxy, nonyloxy, and decyloxy);

[0019] Examples of commercially available products include triazine-based UV absorbers such as "Tinuvin 1577," "Tinuvin 460," and "Tinuvin 477" (manufactured by BASF Japan), and triazole-based UV absorbers such as "Adekastab LA-31" (manufactured by ADEKA).

[0020] Benzophenone compounds include 2,4-dihydroxybenzophenone, 4-n-octyloxy-2-hydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, bis(5-benzoyl-4-hydroxy-2-methoxyphenyl)methane, 1,4-bis(4-benzoyl-3-hydroxyphenone)-butane, etc. Salicylate compounds include pt-butylphenyl salicylate, etc. Benzoate compounds include 2,4-di-t-butylphenyl-3',5'-di-t-butyl-4'-hydroxybenzoate, etc.

[0021] Triazole compounds include 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], 2-(3,5-di-tert-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(2H-benzotriazol-2-yl)-p-cresol, and 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)benzotriazole. )phenol, 2-benzotriazol-2-yl-4,6-di-tert-butylphenol, 2-[5-chloro(2H)-benzotriazol-2-yl]-4-methyl-6-(tert-butyl)phenol, 2-(2H-benzotriazol-2-yl)-4,6-di-tert-butylphenol, 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol, 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol 2-(2H-benzotriazol-2-yl)-4-methyl-6-(3,4,5,6-tetrahydrophthalimidylmethyl)phenol, methyl 3-(3-(2H-benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl)propionate / polyethylene glycol 300 reaction products, 2-(2H-benzotriazol-2-yl)-6-(linear and branched chain dodecyl)-4-methylphenol, 2-(5-methyl-2-hydroxyphenyl)-3-(2H-benzotriazol-2-yl)-4-methylphenol phenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy-C7-9 side and straight chain alkyl esters, 2,2-methylenebis[6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol].

[0022] The ultraviolet absorber to be mixed with the solvent described below can be used alone or in combination of two or more types. When the ultraviolet absorber is a mixture of two or more compounds, it is preferable that at least one of them has a triazine skeleton, but this is not limited thereto. A method for synthesizing triazine-based compounds is described in, for example, Patent Document 1 (Publication No. 2019-188987). The ultraviolet absorber can be subjected to processing such as pulverization, granulation, classification, melting, and solidification after purification as needed. These may be used alone or in combination of two or more types, and different types of ultraviolet absorbers may also be mixed and used. From the viewpoint of preventing deterioration of liquid crystals, etc., it is preferable for the absorber to have excellent absorption ability for ultraviolet rays with wavelengths of 380 nm or less, and from the viewpoint of liquid crystal display properties, to have little absorption of visible light with wavelengths of 400 nm or more.

[0023] The ultraviolet absorber-containing solution of the present invention may be obtained by obtaining a desired ultraviolet absorber in a solid state and then dissolving it in an organic solvent to be used. Alternatively, a solvent may be added to the molten form of the ultraviolet absorber in the final production process of the ultraviolet absorber to directly prepare the ultraviolet absorber-containing solution. Here, the solid ultraviolet absorber used before being dissolved may be in the form of powder, granules, flakes, pellets, briquettes, tablets, etc., and is not particularly limited.

[0024] 2. Organic solvents In the present invention, at least one organic solvent is used to dissolve the ultraviolet absorber. The organic solvent is not particularly limited, and may be one type or a mixed solution of two or more types.

[0025] The organic solvent preferably used in the present invention is one selected from the group consisting of hydrocarbons, alcohols, ketones, esters, glycol ethers, and other solvents, which may be mixed appropriately, but are not limited to these. Examples of hydrocarbons include benzene, toluene, xylene, hexane, and cyclohexane. Examples of alcohols include methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, 2-butanol, tert-butanol, pentanol, 2-methyl-2-butanol, and cyclohexanol. Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of esters include methyl formate, ethyl formate, methyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, ethyl lactate, and methyl lactate. Examples of glycol ethers (C1-C4) include methyl cellosolve, ethyl cellosolve, propylene glycol monomethyl ether (PGME), propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol monoisopropyl ether, and propylene glycol monobutyl ether; examples of propylene glycol mono(C1-C4) alkyl ether esters include propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; and examples of other solvents include N-methylpyrrolidone. Although not particularly limited to these, suitable mixtures of these solvents are also preferably used.

[0026] Regarding the mixing of the UV absorber with the organic solvent, the mixing ratio is not particularly limited as long as the UV absorber dissolves. A preferred mixing ratio is 1 to 70% by mass of the UV absorber, with 5 to 60% by mass being more preferred. It is also preferable to prepare a highly concentrated UV absorber-containing solution in advance. The dissolution temperature is not particularly limited, but a room temperature range of 10 to 35°C is generally preferred. When the solution has been exposed to low temperatures for a long period of time or for a long period of time, it is recommended to re-stir or heat the solution to the dissolution temperature. In some cases, the solution may be heated to a high temperature to accelerate the dissolution rate. The heating temperature is not particularly limited, but a preferred temperature is set depending on the solvent used. A preferred heating temperature is 30 to 90°C, more preferably 40 to 80°C, and even more preferably 50 to 70°C. If precipitation is observed in the obtained UV absorber-containing solution at low temperatures, it is also preferable to heat the solution and then stir and disperse it with ultrasound. Furthermore, if precipitation is observed in the solution after exposure to low temperatures, it is also recommended to add additional solvent to obtain a stable UV absorber-containing solution. The ultraviolet absorber-containing solution of the present invention is preferably filtered to remove foreign matter present in the solution. The filtration process to be used is not particularly limited, and filter paper, filter cloth, cartridge, mesh, etc. can be used, and it is also preferable to apply normal pressure, increased pressure, reduced pressure, centrifugation, etc.

[0027] 3.Resin composition The resin composition of the present invention is a resin composition obtained by kneading or impregnating a resin or the like with the ultraviolet absorber-containing solution of the present invention (hereinafter simply referred to as "resin composition"). When kneading or impregnating a resin with the ultraviolet absorber-containing solution, if the resin is solid, it is preferable to remove the solvent after addition and melt-knead the resulting mixture. Also, if the resin is dissolved in a solvent, the ultraviolet absorber-containing solution can be added to obtain the desired resin composition, for example, by a solution casting method.

[0028] The resin composition of the present invention may contain a synthetic resin. This allows for the production of desired resin molded products for various applications. Examples of synthetic resins include thermoplastic resins, thermosetting resins, and elastomers. These may be used alone or in combination of two or more. Specific examples of the synthetic resin include the following. Examples of the thermoplastic resin include α-olefin polymers (polypropylene, polyethylene, polybutene-1, poly-3-methylpentene, etc.), polyolefins and their copolymers, halogen-containing resins (polyvinyl chlorides, polyvinylidene chlorides, polyvinylidene fluoride, vinyl chloride copolymers, etc.), polyacrylic acid, polyacrylic acid esters, polyacrylonitrile, polymethacrylic acid, polymethacrylic acid esters, polyvinylidene chloride, polyamide, polyimide, polyurethane, polypeptide, polycarbonate, polyoxymethylene, polyether, epoxy resin, and polyvinyl butyral. Further examples include degradable aliphatic polyesters (such as polylactic acid resin, polymalic acid, polyglycolic acid, and poly(2-oxetanone)), polyamides, polycarbonates, polyphenylene sulfide, polyurethanes, and cellulose-based resins.

[0029] Examples of thermosetting resins include phenolic resins, urea resins, melamine resins, epoxy resins, and unsaturated polyester resins. Examples of elastomers include fluorine-based resins, silicone resins, polysulfones, polyphenylene ethers, and liquid crystal polymers. Further examples include isoprene rubber, butadiene rubber, acrylonitrile-butadiene copolymer rubber, styrene-butadiene copolymer rubber, fluorine-containing rubber, and silicone rubber. Among these, from the viewpoints of compatibility with the UV absorber and transparency, preferred synthetic resins include polycarbonate resins, polyester resins, acrylic resins, and ABS resins. These synthetic resins may be used alone or in combination of two or more, or may be alloyed. The amount of the granular UV absorber in the resin composition is preferably 0.001 to 20 parts by mass, more preferably 0.01 to 10 parts by mass, and even more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the synthetic resin. By making the content equal to or greater than the lower limit, the granular ultraviolet absorber can exhibit a sufficient effect.

[0030] The resin composition of the present invention may contain additional components other than those described above, as needed. Examples of such additional components include antioxidants, near-infrared absorbers, nucleating agents (clarifying agents), antistatic agents, lubricants, plasticizers, light-absorbing dyes, fillers, pigments, dyes, metal soaps, processing aids, flame retardants, flame retardant aids, zeolite compounds, foaming agents, (heavy) metal deactivators, crosslinking agents, epoxy stabilizers, matting agents, antifogging agents, antiplateout agents, surface treatment agents, fluorescent brighteners, antifungal agents, antibacterial agents, and mold release agents. Various additives (e.g., plasticizers, antidegradants, fine particles, optical property adjusters, etc.) can be added to the UV absorber-containing solution of the present invention or to a resin composition comprising the UV absorber-containing solution of the present invention and a resin, depending on the intended use, in each step. These additives may be added at any time during the production process, or may be added to the final preparation step of the preparation process.

[0031] The resin composition of the present invention may contain an anti-degradant (e.g., antioxidant, peroxide decomposer, radical inhibitor, metal deactivator, acid scavenger, amine). When the resin composition of the present invention is used for optical applications, an aromatic compound having at least two aromatic rings may be used as a retardation enhancer to adjust the retardation. The aromatic compound is used in an amount of 0.01 to 20 parts by mass relative to 100 parts by mass of the resin constituting the resin composition. The aromatic compound is preferably used in an amount of 0.05 to 15 parts by mass, more preferably 0.1 to 10 parts by mass, in the resin composition. Two or more aromatic compounds may be used in combination. The aromatic ring of the aromatic compound contains an aromatic heterocycle in addition to an aromatic hydrocarbon ring. Other additives that are preferably used in the resin composition of the present invention include inorganic fine particles such as silica, kaolin, talc, diatomaceous earth, quartz, calcium carbonate, barium sulfate, titanium oxide, and alumina; heat stabilizers such as salts of Group II metals such as calcium and magnesium; and flame retardants.

[0032] Examples of antioxidants include phenol-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, etc. Examples of near-infrared absorbers include polymethine dyes (cyanine dyes), indolinocyanine dyes, phthalocyanine dyes, naphthalocyanine dyes, naphthol metal complex dyes, squarylium dyes, triazo dyes, dithiol metal complex dyes, pyrylium dyes, thiapyrylium dyes, indoaniline dyes, azoanthraquinone dyes, naphthoquinone dyes, anthroquinone dyes, bis(dithiolene) dyes, triphenylmethane dyes, aminium (aluminum) dyes, and diimonium dyes. Inorganic near-infrared absorbers may also be used, such as carbon black, tin oxide doped with antimony oxide or indium oxide, and oxides, carbides, or borides of metals belonging to Group 4A, 5A, or 6A of the periodic table. Examples of nucleating agents include metal salts of benzoic acids, metal salts of aromatic phosphates, mixtures of metal salts of aromatic phosphates and alkali metal compounds, dibenzylidene sorbitols, metal salts of amino acids, metal salts of rosin acids, amide compounds, etc. Examples of lubricants include hydrocarbon-based lubricants, aliphatic-based lubricants, amide-based lubricants, metal soap-based lubricants, hardened fats and oils, and ester-based lubricants.

[0033] The method for producing the resin composition of the present invention is not particularly limited, and any conventionally known method can be employed. One example of a method for producing a resin composition includes mixing the UV absorber-containing solution of the present invention, the synthetic resin described above, and other optional additives, optionally removing the organic solvent, and then premixing the mixture using various mixers such as a tumbler or Henschel mixer, followed by melt-kneading using a Banbury mixer, roll, Brabender mixer, single-screw extruder, twin-screw extruder, or kneader. Alternatively, the resin composition may be produced by premixing the components, or by premixing only some of the components, feeding the mixture into an extruder using a feeder, and melt-kneading the mixture. Furthermore, a resin composition obtained by premixing some of the components and feeding it into an extruder for melt-kneading can be used as a masterbatch, which can then be mixed with other components and melt-kneaded again to produce a resin composition. The synthetic resin used in the mixing and kneading process may be in a predetermined shape, such as powder or pellets, or in a fibrous form. The resin composition of the present embodiment may be solid at room temperature, and may have a fixed shape such as powder, granules, pellets, briquettes, or tablets, or may be in the form of a sheet.

[0034] 4. Molded products A molded article can be obtained by molding the resin composition of the present invention.

[0035] The molding method is not particularly limited, and examples thereof include injection molding, extrusion molding, blow molding, rotational molding, vacuum molding, inflation molding, calendar molding, slush molding, dip molding, and foam molding. The molded product can have various forms depending on the application, such as a resin plate, sheet, film, container (bottle, tray, bag), fiber, and various molded products. The resin composition can also be processed into a film or sheet using, for example, a cast film method. The resin varnish can also be used as a paint material for coating a predetermined substrate.

[0036] The resin composition of the present invention can be used in a wide range of industrial fields, including electrical / electronic / telecommunications, agriculture, forestry / fisheries, mining, construction, food, textiles, clothing, medicine, coal, petroleum, rubber, leather, automobiles, precision instruments, wood, building materials, civil engineering, furniture, printing, and musical instruments. It can also be used as an optical material, useful for image display devices such as liquid crystal displays (LCDs) and electroluminescent displays (ELDs). Applications for LCDs include polarizing plate protective films or sheets, retardation films, viewing angle expansion films, antiglare films, brightness enhancement films, light diffusion films and sheets, lens films and sheets, anti-fog films, antistatic films, optical compensation films, anti-reflection films, color tone adjustment films, and light guide plates. The resin composition is particularly suitable for optical films or sheets placed on the outer surface of a polarizing plate in contact with a liquid crystal display element, or polarizing plate protective films or sheets. [Example]

[0037] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the descriptions in these examples.

[0038] [Preparation of UV absorber-containing solution] Example 1 A solution containing 2,4,6-tris[2-hydroxy-3-methyl-4-hexyloxyphenyl]-1,3,5-triazine was prepared by the following procedure: 50% by mass of commercially available powdered 2,4,6-tris[2-hydroxy-3-methyl-4-hexyloxyphenyl]-1,3,5-triazine was added to 50% by mass of toluene, and the mixture was thoroughly stirred to dissolve, thereby obtaining a pale yellow UV absorber-containing solution 1 of the present invention containing the UV absorber of the present invention.

[0039] Example 2 A solution containing 2,4,6-tris[2-hydroxy-3-methyl-4-hexyloxyphenyl]-1,3,5-triazine was prepared according to the following procedure. Commercially available powdered 2,4,6-tris[2-hydroxy-3-methyl-4-hexyloxyphenyl]-1,3,5-triazine was melted on a metal plate and cooled to obtain flakes (melt-solidification process). The obtained flakes were roughly crushed to obtain a coarse, pale yellow powder. 50% by mass of the obtained coarse flakes were added to 50% by mass of toluene, heated to 60°C, and thoroughly stirred to dissolve, yielding UV absorber-containing solution 2 of the present invention.

[0040] Example 3 A solution containing 2,2-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)-3-hydroxyphenoxy)ethyl 2-ethylhexanoate was prepared by the following procedure: 40% by mass of commercially available 2-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)-3-hydroxyphenoxy)ethyl 2-ethylhexanoate was added to 60% by mass of toluene, and the mixture was thoroughly stirred to dissolve, yielding UV absorber-containing solution 3 of the present invention.

[0041] [Production of resin composition and molded product] Example 4 100 parts by mass of polycarbonate resin was dissolved in 225 parts by mass of toluene, and then 0.8 parts by mass of the filtered solutions of UV absorber-containing solutions 1 to 3 from Examples 1 to 3 was added and blended to prepare resin compositions 1 to 3. The resulting resin compositions were cast into films with a thickness of 40 μm. The resulting films were measured for their total light transmittance (%) retention (%) after 10 days using a sunshine weatherometer (83°C, carbon arc light source) to evaluate their light resistance. The initial film had excellent transparency, and the film transmittance after the weather resistance evaluation showed a decrease of less than 1% compared to the initial transmittance. This demonstrates that resin compositions using the UV absorber-containing solutions of the present invention exhibit excellent light resistance.

[0042] Example 5 A film was produced and evaluated in accordance with the same procedures as in Example 4, except that methacrylic resin was used instead of polycarbonate resin, and it was found that similarly excellent light resistance could be achieved.

[0043] Example 6 Comparative resin composition 6 was prepared in exactly the same manner as in Example 1, except that 100 parts by mass of polycarbonate resin was dissolved in 230 parts by mass of toluene, and then 0.4 parts by mass of 2,4,6-tris[2-hydroxy-3-methyl-4-hexyloxyphenyl]-1,3,5-triazine fine powder (umbrella specific gravity 0.65) used in Example 1 was added to the resin solution while stirring. The resulting film exhibited excellent light resistance. However, powder agglomerations occurred immediately after addition, requiring a long time for dissolution. Furthermore, powder adhered to the periphery of the container during addition, necessitating wall cleaning to remove the foreign matter. Furthermore, dust was raised during addition, requiring workers to wear dust masks, and work-related hazard prevention measures were necessary. Therefore, adding conventional ultraviolet absorber powder to a resin solution posed significant problems during the preparation process, and it became clear that the present invention is superior.

[0044] Example 7 One part by mass of the UV absorber-containing solution 1 obtained in Example 1 was added to 100 parts by mass of polyethylene terephthalate and mixed thoroughly, and the solvent was removed by heating under reduced pressure to obtain Resin Composition 7. The obtained resin composition was molded using an injection molding machine. Next, a plastic bottle was obtained by biaxial stretch blow molding at a mold temperature of 130°C. The obtained plastic bottle exhibited excellent UV shielding effect. [Industrial Applicability]

[0045] The ultraviolet absorber-containing solution of the present invention can provide resin compositions and resin molded articles that are excellent in weather resistance, durability and productivity, and can be applied to various lifestyle products.

Claims

1. The ultraviolet absorber-containing solution is composed of a mixed solution containing at least one type of ultraviolet absorber and at least one type of organic solvent.

2. 2. The ultraviolet absorber-containing solution according to claim 1, wherein the ultraviolet absorber is a triazine-based ultraviolet absorber.

3. 2. The ultraviolet absorber-containing mixed solution according to claim 1, wherein the organic solvent is selected from the group consisting of aromatic organic solvents, ester organic solvents, ketone organic solvents, and amide organic solvents.

4. A method for producing an ultraviolet absorber-containing solution, comprising dissolving a mixed solution containing at least one ultraviolet absorber and at least one organic solvent at a heating temperature of 30°C to 90°C.

5. A resin composition kneaded or impregnated with the ultraviolet absorbent-containing solution according to any one of claims 1 to 3 or the ultraviolet absorbent-containing solution produced by the production method according to claim 4.

6. A molded article made of a resin composition kneaded or impregnated with the ultraviolet absorbent-containing solution according to any one of claims 1 to 3 or the ultraviolet absorbent-containing solution produced by the production method according to claim 4.