Resin Composition and Resin Molded Body

Abstract

To provide a resin composition excellent in weather resistance, and a resin molding comprising the resin composition.SOLUTION: A resin composition comprises a transparent resin (A), an ultraviolet absorber (B), and a hindered amine-based photostabilizer (C). In the ultraviolet absorber (B), the wavelength where the absorbance is maximized is in the range of 200 nm to 330 nm inclusive, and the molecular weight is 200 to 550 inclusive. The hindered amine-based photostabilizer (C) has a molecular weight of 400 to 1000 inclusive. A resin molding comprises the resin composition.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a resin composition and a resin molded article.

Background Art

[0002] Conventionally, methacrylic resins have been used as cover materials for outdoor signs and outdoor lighting. However, since outdoor signs and outdoor lighting discolor when exposed to ultraviolet rays such as sunlight for a long time, excellent weather resistance has been required for methacrylic resins.

[0003] As a method for improving the weather resistance of methacrylic resins, Patent Document 1 proposes a technique of blending a hindered amine-based light stabilizer with a methacrylic resin. Further, Patent Document 2 proposes a technique of blending a benzotriazole-based ultraviolet absorber with a methacrylic resin.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the techniques disclosed in Patent Document 1 and Patent Document 2, the weather resistance was insufficient. In particular, in methacrylic resin products with a thin thickness, it is necessary to add a large amount of ultraviolet absorber and light stabilizer, and since the methacrylic resin and the ultraviolet absorber and light stabilizer are hardly compatible, plate out, bleed out during molding, bleed out during storage, etc. occur, and a product with stable weather resistance over a long period cannot be obtained.

[0006] The object of the present invention is to solve these problems. That is, an object of the present invention is to provide a resin molded article having excellent weather resistance and a resin composition for obtaining the resin molded article.

Means for Solving the Problems

[0007] As a result of repeated studies to solve the above problems, the present inventors have arrived at the present invention. That is, the first gist of the present invention is a resin composition containing a transparent resin (A), an ultraviolet absorber (B), and a hindered amine light stabilizer (C), wherein the ultraviolet absorber (B) has a maximum absorbance wavelength in the range of 200 nm or more and 330 nm or less, and a molecular weight of 200 or more and 550 or less. The second gist of the present invention is a resin molded article containing the resin composition.

Effects of the Invention

[0008] According to the present invention, a resin molded article having excellent weather resistance and a resin composition for obtaining the resin molded article can be provided. Since the resin composition and the resin molded article of the present invention are excellent in weather resistance, they can be suitably used for applications such as outdoor signs and cover materials for outdoor lighting.

Modes for Carrying Out the Invention

[0009] Hereinafter, the present invention will be described in detail. In this specification, “(meth)acrylic acid” means at least one selected from “acrylic acid” and “methacrylic acid”. In this specification, “monomer” means an unpolymerized compound, and “repeating unit” and “structural unit” mean units derived from the monomer formed by polymerization of the monomer. The repeating unit and the structural unit may be units directly formed by a polymerization reaction, or may be those in which a part of the unit is converted into another structure by treating the polymer. In this specification, “mass%” indicates the content ratio of a predetermined component contained in 100 mass% of the total amount. Unless otherwise specified, in this specification, a numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value, and "A~B" means A or more and B or less.

[0010] <Resin composition> The resin composition in the present invention is a resin composition containing a transparent resin (A) described later, an ultraviolet absorber (B) described later, and a hindered amine light stabilizer (C) described later.

[0011] Since the resin composition contains the transparent resin (A), the obtained resin molded article has excellent transparency. Since the resin composition of the present invention contains the ultraviolet absorber (B) and the hindered amine light stabilizer (C), the obtained resin molded article has excellent weather resistance.

[0012] <Transparent resin (A)> The transparent resin (A) is one of the constituent components constituting the resin molded article of the present invention. The transparent resin (A) is not particularly limited as long as it is a transparent resin having a high light transmittance at least in the visible light region, and known transparent resins can be used. At least one selected from methacrylic resins, polycarbonate resins, and polystyrene resins is preferable from the viewpoint of excellent transparency. Since the methacrylic resin is particularly excellent in transparency, it is suitable for applications such as face-to-face counters such as reception counters and service counters.

[0013] The above-mentioned transparent resin (A) may contain known additives such as an impact strength modifier, a release agent, an ultraviolet absorber, a polymerization inhibitor, an antioxidant, and a flame retardant within a range that does not impair the effects of the present invention.

[0014] (Methacrylic resin) The methacrylic resin that can be used as the transparent resin (A) in the present invention is not particularly limited, but is a homopolymer of methyl methacrylate (hereinafter abbreviated as "MMA"), or a copolymer of MMA and a monomer other than MMA (hereinafter abbreviated as "other monomer") (hereinafter abbreviated as "MMA copolymer"), and the content of the repeating unit derived from MMA (hereinafter abbreviated as "MMA unit") is preferably 70% by mass or more and less than 100% by mass of the total mass of the MMA copolymer. It is also possible to crosslink with a known crosslinkable monomer copolymerizable with the methacrylic resin.

[0015] The above-mentioned other monomer is not particularly limited as long as it is copolymerizable with MMA. Examples of the above-mentioned other monomer include (meth)acrylic acid esters having an alkyl group with 1 to 8 carbon atoms such as methyl acrylate, ethyl (meth)acrylate, and n-butyl (meth)acrylate, aromatic vinyl monomers such as styrene and α-methylstyrene, and vinyl cyanide monomers such as acrylonitrile and methacrylonitrile. The methacrylic resin can be produced using the production method described later. Specifically, examples include methacrylic resins produced using known casting polymerization methods such as the cell casting method and the continuous casting method.

[0016] <Ultraviolet absorber (B)> The ultraviolet absorber (B) is one of the constituent components constituting the resin composition of the present invention. When the resin composition of the present invention contains the ultraviolet absorber (B), the weather resistance of the obtained resin molded body can be made excellent.

[0017] The wavelength showing the maximum value of the absorbance of the ultraviolet absorber (B) is in the range of 200 nm or more and 330 nm or less from the viewpoint that the obtained resin molded body has excellent weather resistance when exposed to ultraviolet rays for a long time when used in combination with the hindered amine light stabilizer (C) described later. More preferably, it is 240 nm or more and 300 nm or less, and even more preferably, it is 260 nm or more and 280 nm or less.

[0018] The upper limit of the molecular weight of the ultraviolet absorber (B) is 550 or less from the viewpoint that the ultraviolet absorber (B) is localized in the vicinity of the surface without bleeding out to the surface of the resin molded body, and the weather resistance of the resin molded body is more excellent. More preferably, it is 500 or less, and even more preferably, it is 450 or less. On the other hand, the lower limit of the molecular weight is not particularly limited, but from the viewpoint that bleeding out of the ultraviolet absorber (B) to the surface of the resin molded body can be suppressed and the antiblocking property of the resin molded body can be maintained, 200 or more is preferable. More preferably, it is 300 or more, and even more preferably, it is 400 or more. The above-mentioned preferable upper limit and preferable lower limit can be arbitrarily combined. That is, the molecular weight of the ultraviolet absorber (B) is 200 or more and 550 or less, preferably 300 or more and 500 or less, and more preferably 400 or more and 450 or less.

[0019] The structure of the ultraviolet absorber (B) is not particularly limited, but when the transparent resin (A) is a methacrylic resin, it is preferably a heterocyclic compound from the viewpoint that the solubility in the resin composition is good and the weather resistance of the obtained resin molded body is more excellent.

[0020] The type of the ultraviolet absorber (B) is not particularly limited, but when the transparent resin (A) is a methacrylic resin, it is preferably a triazine-based compound from the viewpoint that the solubility in the resin composition is good and the weather resistance of the obtained resin molded body is more excellent. Examples of the triazine-based compound include compounds having a 1,3,5-triazine skeleton, and specifically, commercially available products such as Tinuvin1577ED (product name, manufactured by BASF Japan Ltd.) can be obtained.

[0021] The structure of the ultraviolet absorber (B) is not particularly limited, but when the transparent resin (A) is a methacrylic resin, it preferably has three or more aromatic rings in the molecule from the viewpoint that the solubility in the resin composition is good and the weather resistance of the obtained resin molded body is more excellent.

[0022] Further, the structure of the ultraviolet absorber (B) is not particularly limited. However, when the transparent resin (A) is a methacrylic resin, it preferably contains at least one hydroxyl group in the molecule from the viewpoint of good solubility in the resin composition and more excellent weather resistance of the obtained resin molded body.

[0023] Also, the type of the ultraviolet absorber (B) is not particularly limited. However, when the transparent resin (A) is a methacrylic resin, a hydroxytriphenyltriazine-based compound is preferable from the viewpoint of good solubility in the resin composition and more excellent weather resistance and product appearance of the obtained resin molded body.

[0024] The structure of the ultraviolet absorber (B) is not particularly limited. However, when the transparent resin (A) is a methacrylic resin, a compound represented by the following general formula (I) is preferable from the viewpoint of good solubility in the resin composition and more excellent weather resistance and product appearance of the obtained resin molded body.

[0025] JPEG0007690748000001.jpg57168(In formula (I), R 1 is a linear or branched alkoxy group or alkyl group having 1 to 8 carbon atoms, and R 2 and R 3 are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 8 carbon atoms, and R 4 , R 5 and R 6 are each independently a hydrogen atom, a halogen atom, or a linear or branched alkyl group having 1 to 4 carbon atoms, and R 7 and R 8 are each independently a hydrogen atom or a hydroxyl group.)

[0026] Examples of the compound represented by the general formula (I) include 2-[4,6-diphenyl-1,3,5-triazin-2-yl]-5-[(hexyl)oxy]-phenol. Specifically, commercially available products such as Tinuvin1577ED (product name, manufactured by BASF Japan Ltd.) can be used.

[0027] The lower limit of the content ratio of the ultraviolet absorber (B) contained in the resin composition of the present invention is not particularly limited, but from the viewpoint of excellent weather resistance of the obtained resin molded body, it is preferably 0.01% by mass or more with respect to 100% by mass of the total mass of the resin composition. More preferably 0.1% by mass or more, and even more preferably 0.3% by mass or more. On the other hand, the upper limit of the content ratio of the ultraviolet absorber (B) is not particularly limited, but from the viewpoint of good solubility in the resin composition and good maintenance of the weather resistance and product appearance of the obtained resin molded body, it is preferably 2.0% by mass or less with respect to 100% by mass of the total mass of the resin composition. More preferably 1.0% by mass or less, and even more preferably 0.7% by mass or less. The above-mentioned preferable upper limit and preferable lower limit can be arbitrarily combined. That is, the content ratio of the ultraviolet absorber (B) contained in the resin composition is preferably 0.01% by mass or more and 2.0% by mass or less, more preferably 0.1% by mass or more and 1.0% by mass or less, and even more preferably 0.3% by mass or more and 0.7% by mass or less with respect to 100% by mass of the total mass of the resin composition.

[0028] <Hindered amine light stabilizer (C)> The hindered amine light stabilizer (C) is one of the components of the methacrylic resin composition of the present invention. When the resin composition of the present invention contains the hindered amine light stabilizer (C), the obtained resin molded body can have excellent weather resistance when exposed to ultraviolet rays for a long time. In the resin composition of the present invention, by using the hindered amine light stabilizer (C) in combination with the ultraviolet absorber (B), the weather resistance of the obtained resin molded body becomes more excellent.

[0029] The upper limit of the molecular weight of the hindered amine light stabilizer (C) is not particularly limited. However, from the viewpoint that the hindered amine light stabilizer (C) localizes in the vicinity of the surface without bleeding out to the surface of the obtained resin molded article and the weather resistance of the resin molded article is more excellent, the molecular weight is preferably 1000 or less. More preferably, the molecular weight is 800 or less, and even more preferably, the molecular weight is 600 or less. On the other hand, the lower limit of the molecular weight is not particularly limited. However, from the viewpoint that bleeding out of the hindered amine light stabilizer (C) to the surface of the resin molded article can be suppressed and the antiblocking property of the resin molded article can be maintained, the molecular weight is preferably 400 or more. More preferably, the molecular weight is 450 or more, and even more preferably, the molecular weight is 500 or more. The above-mentioned preferable upper limit and preferable lower limit can be arbitrarily combined. That is, the molecular weight of the hindered amine light stabilizer (C) is preferably 400 or more and 1000 or less, more preferably 450 or more and 800 or less, and even more preferably 500 or more and 600 or less.

[0030] The hindered amine light stabilizer (C) in the present invention is not particularly limited. As bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, for example, Tinuvin770DF (trade name, manufactured by BASF), LA-77 (trade name, manufactured by ADEKA), SanolLS-770 (trade name, manufactured by BASF); as bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, for example, Tinuvin765 (trade name, manufactured by BASF), SanolLS-765 (trade name, manufactured by BASF); as the dimethyl succinate and 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethyl-4-piperidine polycondensate, for example, Tinuvin622SF (trade name, manufactured by BASF); as tetrakis(1,2,2,6,6-pentamethyl-4-piperidinyl) butane-1,2,3,4-tetracarboxylate, for example, LA-52 (trade name, manufactured by ADEKA); as 1-hexadecyl-2,3,4-tris(1,2,2,6,6-pentamethyl-4-piperidinyl) butane-1,2,3,4-tetracarboxylate, for example, LA-57 (trade name, manufactured by ADEKA); as the mixed esterified product of 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4-piperidinol and 3,9-bis(2-hydroxy-1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, for example, LA-63P (trade name, manufactured by ADEKA), etc. These may be used alone or in combination of two or more. Among these, from the viewpoint that the obtained resin molded body has excellent weather resistance, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, the polycondensate of dimethyl succinate and 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethyl-4-piperidine, tetrakis(1,2,2,6,6-pentamethyl-4-piperidinyl) butane-1,2,3,4-tetracarboxylate, and 1-hexadecyl-2,3,4-tris(1,2,2,6,6-pentamethyl-4-piperidinyl) butane-1,2,3,4-tetracarboxylate are preferable.

[0031] Among the hindered amine light stabilizers (C) described above, from the viewpoint that the weather resistance of the obtained resin molded article becomes more excellent when used in combination with the ultraviolet absorber (B), the hindered amine light stabilizer (C) preferably has a wavelength at which the maximum value of absorbance is in the range of 200 nm or more and 300 nm or less, and more preferably in the range of 220 nm or more and 270 nm or less.

[0032] The lower limit of the content ratio of the hindered amine light stabilizer (C) contained in the resin composition of the present invention is not particularly limited, but from the viewpoint of excellent weather resistance of the obtained resin molded article, it is preferably 0.01% by mass or more with respect to 100% by mass of the total mass of the resin composition. More preferably 0.1% by mass or more, and even more preferably 0.2% by mass or more. On the other hand, the upper limit of the content ratio of the hindered amine light stabilizer (C) is not particularly limited, but from the viewpoint of good solubility in the resin composition and good maintenance of the weather resistance and product appearance of the obtained resin molded article, it is preferably 1.0% by mass or less with respect to 100% by mass of the total mass of the resin composition. More preferably 0.7% by mass or less, and even more preferably 0.5% by mass or less. The above-mentioned preferable upper limit and preferable lower limit can be arbitrarily combined. That is, the content ratio of the hindered amine light stabilizer (C) contained in the resin composition is preferably 0.01% by mass or more and 1.0% by mass or less, more preferably 0.1% by mass or more and 0.7% by mass or less, and even more preferably 0.2% by mass or more and 0.5% by mass or less with respect to 100% by mass of the total mass of the resin composition.

[0033] <Resin molded article> The resin molded article of the present invention is a resin molded article containing the resin composition of the present invention.

[0034] The overall thickness of the resin molded article of the present invention is not particularly limited, but from the viewpoints of mechanical strength and moldability, it can be 100 to 5000 μm.

[0035] <Method for producing resin composition and resin molded article> The resin molded body of the present invention can be obtained by polymerizing a polymerizable raw material described later to obtain a resin composition, and then molding the obtained resin composition into a resin molded body having a desired shape using a known melt molding method such as an injection molding method or an extrusion molding method. Alternatively, when the transparent resin is the methacrylic resin, the resin molded body of the present invention can be obtained as a resin molded body having a desired shape by polymerizing a polymerizable raw material described later using a known casting polymerization method such as a cell casting method or a continuous casting method.

[0036] Hereinafter, when the transparent resin is the methacrylic resin, a method for manufacturing a resin molded body using a casting polymerization method will be described. The casting polymerization method seals the outer peripheral portions of two inorganic glass plates or metal plates (for example, SUS plates) arranged opposite to each other with a gasket made of a soft resin, uses this as a mold, and then injects a polymerizable raw material described later, which is a raw material of the resin composition, into the mold and polymerizes it to form a sheet-like resin composition. Next, the obtained resin composition is peeled off from the mold to obtain a plate-like resin molded body.

[0037] The form of the mold for casting polymerization is not particularly limited, and a known mold can be used. For example, a mold for cell casting and a mold for continuous casting can be mentioned. Examples of the mold for cell casting include two plate-like bodies such as an inorganic glass plate, a chromium-plated metal plate, and a stainless steel plate (SUS plate) arranged opposite to each other at a predetermined interval, and a gasket made of a soft resin is arranged at the edge thereof to form a sealed space by the plate-like bodies and the gasket. Examples of the mold for continuous casting include those in which a sealed space is formed by the opposing surfaces of a pair of endless belts running in the same direction at the same speed and gaskets running at the same speed as the endless belts on both side portions of the endless belts.

[0038] The polymerization method when using the casting polymerization method is not particularly limited, and for example, a known polymerization method used in the production of methacrylic resins can be adopted. Specifically, a so-called bulk polymerization method (mass polymerization method) using a monomer as a polymerization solvent can be carried out under the conditions of known radical polymerization.

[0039] When using the casting polymerization method, the following steps (1) to (3) can be sequentially carried out. Step (1): Prepare a mold in which the outer peripheral portions of two opposed metal plates (SUS plates) are sealed with a soft resin gasket, and use this mold as a reaction vessel. Next, a polymerizable raw material described later is injected into the reaction vessel, and the reaction vessel is introduced into a polymerization apparatus. Step (2): Heat the polymerizable raw material in the reaction vessel in a temperature range of 50°C or higher and 100°C or lower in a first heating region and in a temperature range of 100°C or higher and 150°C or lower in a second heating region in the polymerization apparatus to effect polymerization and obtain a polymer. Step (3): Take out the obtained polymer from the reaction vessel to obtain a plate-shaped resin molded body made of a resin composition containing a methacrylic resin as the transparent resin.

[0040] The weight average molecular weight of the methacrylic resin can be controlled by adjusting the polymerization method, the type and addition amount of the polymerization initiator during polymerization, the type and addition amount of the chain transfer agent, the polymerization temperature, the charged composition of the monomer, etc., so that the weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) by those skilled in the art according to common general knowledge is 20,000 or more and 3,000,000 or less.

[0041] <Polymerizable raw material> The polymerizable raw material is a raw material for the resin composition or resin molded body in the present invention. Specifically, as the polymerizable raw material, a mixture of methyl methacrylate alone, the light diffusing agent, and a known polymerization initiator, or a monomer composition containing 80% by mass or more and less than 100% by mass of MMA and more than 0% by mass and 20% by mass or less of the above-mentioned (meth)acrylic acid alkyl ester, the light diffusing agent, and a known polymerization initiator can be used. As known polymerization initiators, the above-described known azo initiators and peroxide initiators used in the production of methacrylic resins can be used.

[0042] Furthermore, by incorporating the above-described known mercaptan compounds such as n-octyl mercaptan and n-butyl mercaptan into the polymerizable raw material as a chain transfer agent, the weight average molecular weight of the methacrylic resin can be controlled.

[0043] Furthermore, known additives such as impact strength modifiers, mold release agents, ultraviolet absorbers, polymerization inhibitors, antioxidants, flame retardants, lubricants, plasticizers, antistatic agents, light stabilizers, fillers, pigments, dyes, fluorescent agents, silane coupling agents, leveling agents, and defoaming agents can be incorporated into the polymerizable raw material within a range that does not impair the effects of the present invention.

Examples

[0044] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples.

[0045] In addition, the abbreviations of the compounds used in the examples and comparative examples are as follows. MMA: Methyl methacrylate BA: Butyl acrylate HPP: t-Hexyl peroxypivalate (trade name: Perhexyl PV, manufactured by NOF Corporation) AVN: 2,2'-Azobis(2,4-dimethylvaleronitrile) (trade name: V-65, manufactured by FUJIFILM Wako Pure Chemical Corporation) Ultraviolet absorber (B-1): Triazine-based ultraviolet absorber, 2-[4,6-diphenyl-1,3,5-triazin-2-yl]-5-(hexyloxy)phenol (trade name: Tinuvin1577ED, manufactured by BASF Japan Ltd., molecular weight 426, wavelength showing the maximum value of absorbance is 274 nm) Hindered amine light stabilizer (C-1): Bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (trade name: Tinuvin765, manufactured by BASF Japan Ltd., molecular weight 509) Benzotriazole-based ultraviolet absorber (D-1): 2-(2'-hydroxy-5'-methylphenyl)benzotriazole (trade name: Tinuvin P, manufactured by ADEKA, molecular weight 225, wavelength at which the maximum absorbance is shown is 341 nm) Dye (1): Dye with Color Index Pigment Green 7 Dye (2): Dye with Color Index Pigment Yellow 183 Dye (3): Dye with Color Index Pigment Yellow 138 Dye (4): Dye with Color Index Pigment White 21 Styrene resin particles (1): Fine particles of a styrene-acrylic copolymer (trade name: Dianal BR-50, manufactured by Mitsubishi Chemical Corporation)

[0046] <Evaluation method> The evaluations in the examples and comparative examples were carried out by the following methods.

[0047] (1) Weather resistance test For the resin molded articles obtained in the examples and comparative examples, using a carbon arc type sunshine weather meter (SWOM), in accordance with JIS K7350-4, an accelerated weather resistance test was carried out with the following process (1) as one cycle. For the resin molded articles before the accelerated weather resistance test and 3000 hours after the start of the test, the color difference (ΔE*ab) in the L*a*b* color system was evaluated. Process (1) UV irradiation process (ultraviolet irradiation intensity in the wavelength range of 300 - 700 nm: 255 W / m 2 , temperature of the black panel: 63 °C, temperature in the weather meter tank: 40 °C, humidity in the weather meter tank: 50% RH, one cycle: 120 minutes (with a shower in the middle: 18 minutes))

[0048] (2) Bleed test: The resin molded articles obtained in the examples and comparative examples were left in an oven at 40 °C for 7 days, and the presence or absence of bleed was visually confirmed.

[0049] Hereinafter, an example of the resin composition and resin molded article of the present invention will be disclosed in the examples.

[0050] [Example 1] (1) Production of syrup 98.5 parts by mass of MMA and 1.5 parts by mass of BA were supplied to a reactor (polymerization kettle) equipped with a cooling pipe, a thermometer, and a stirrer. After bubbling with nitrogen gas while stirring, heating was started. When the internal temperature reached 60 °C, 0.05 part by mass of AVN, which is a radical polymerization initiator, was added. After further heating to an internal temperature of 100 °C, it was held for 10 minutes. Then, the reactor was cooled to room temperature to obtain a syrup (S) composed of 20% by mass of a polymer and 80% by mass of a monomer.

[0051] (2) Cast polymerization To 100 parts by mass of the above syrup (S), 0.2 part by mass of HPP as a polymerization initiator, 1.5 parts by mass of styrene-based resin particles (1) as a dispersant, 1000 ppm by mass of an ultraviolet absorber (B), 1000 ppm by mass of a hindered amine-based light stabilizer (C), and furthermore, dyes (1) to (4) were blended so that the three stimulus values (X, Y, Z) of the finally obtained resin molded body would be the values described in Table 1 to obtain a polymerizable composition. A soft resin gasket was installed at the peripheral portion between two SUS plates arranged opposite to each other so that the gap interval between the two SUS plates was 2.2 mm to prepare a mold. The polymerizable composition was poured into the mold and completely sealed with a soft resin gasket. After holding in a hot water bath at 82 °C for 30 minutes, it was heated at 130 °C for 30 minutes in a hot air circulation furnace to cause polymerization and curing. Then, it was cooled to room temperature, and the soft resin gasket and SUS plates were removed to obtain a plate-shaped resin molded body (500 mm in length × 500 mm in width × 2 mm in thickness) made of a resin composition. The resin composition was 1 When analyzed using the H-NMR method, it was a methacrylic resin (1) composed of 98.5% by mass of MMA units and 1.5% by mass of BA units. The evaluation results of the obtained resin molded body are shown in Table 1.

[0052] [Example 2] The content ratio of the ultraviolet absorber (B) was changed as described in Table 1, and further, a resin molded body was obtained in the same manner as in Example 1, except that the blending amounts of the dyes (1) to (4) were changed so that the three stimulus values (X, Y, X) of the finally obtained resin molded body became the values described in Table 1. The evaluation results of the obtained resin molded body are shown in Table 1.

[0053] [Comparative Example 1] Instead of the ultraviolet absorber (B) and the hindered amine light stabilizer (C), a benzotriazole-based ultraviolet absorber (D-1) was used, and its content ratio was changed as described in Table 1. Further, a resin molded body was obtained in the same manner as in Example 1, except that the blending amounts of the dyes (1) to (4) were changed so that the three stimulus values (X, Y, X) of the finally obtained resin molded body became the values described in Table 1. The evaluation results of the obtained resin molded body are shown in Table 1.

[0054]

Table 1

[0055] The resin molded bodies obtained in Examples 1 to 2 had good weather resistance.

[0056] The resin molded body obtained in Comparative Example 1 was inferior in weather resistance because it did not contain the ultraviolet absorber (B) and the hindered amine light stabilizer (C).

Industrial Applicability

[0057] Since the resin composition of the present invention and the resin molded body containing the resin composition of the present invention are excellent in weather resistance, they can be suitably used for applications such as outdoor signboards and cover materials for outdoor lighting.

Claims

1. A resin composition comprising a transparent resin (A), an ultraviolet absorber (B), and a hindered amine light stabilizer (C), wherein the transparent resin (A) is a methacrylic resin, the ultraviolet absorber (B) has a wavelength at which the maximum value of absorbance is in the range of 200 nm or more and 330 nm or less, and a molecular weight of 200 or more and 550 or less, and the hindered amine light stabilizer (C) has a molecular weight of 500 or more and 600 or less.

2. The resin composition according to claim 1, wherein the ultraviolet absorber (B) has a molecular weight of 300 or more and 500 or less.

3. The resin composition according to claim 1 or 2, wherein the ultraviolet absorber (B) has a wavelength at which the maximum value of absorbance is in the range of 240 nm or more and 300 nm or less.

4. The resin composition according to any one of claims 1 to 3, wherein the ultraviolet absorber (B) is a heterocyclic compound.

5. The resin composition according to any one of claims 1 to 4, wherein the ultraviolet absorber (B) is a triazine compound.

6. The resin composition according to any one of claims 1 to 5, wherein the ultraviolet absorber (B) has three or more aromatic rings in the molecule.

7. The resin composition according to any one of claims 1 to 6, wherein the ultraviolet absorber (B) contains one or more hydroxyl groups in the molecule.

8. The resin composition according to any one of claims 1 to 7, wherein the ultraviolet absorber (B) is a hydroxytriphenyltriazine compound.

9. The resin composition according to any one of claims 1 to 8, wherein the ultraviolet absorber (B) is a compound represented by the following general formula (I). 【Chemical 1】 (In formula (I), R1 is a linear or branched alkoxy group or alkyl group having 1 to 8 carbon atoms, R2 and R3 are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 8 carbon atoms, R4, R5, and R6 are each independently a hydrogen atom, a halogen atom, or a linear or branched alkyl group having 1 to 4 carbon atoms, and R7 and R8 are each independently a hydrogen atom or a hydroxyl group.)

10. The resin composition according to any one of claims 1 to 9, wherein the resin composition contains 90% by mass or more of the transparent resin (A) and 0.01% by mass or more and 2.0% by mass or less of the ultraviolet absorber (B) based on 100% by mass of the total mass of the resin composition.

11. The resin composition according to any one of claims 1 to 10, wherein the resin composition contains 0.01% by mass or more and 1.0% by mass or less of the hindered amine light stabilizer (C) based on 100% by mass of the total mass of the resin composition.

12. A resin molded article comprising the resin composition according to any one of claims 1 to 11.

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