Molding material and resin molded article

Abstract

Provided is a molding material obtained by adding a fatty acid metal salt to the outside of methacrylic resin pellets containing a methacrylic resin and a benzotriazole ultraviolet absorber, the content of the benzotriazole ultraviolet absorber is 0.001 parts by mass or more and less than 0.3 parts by mass per 100 parts by mass of the methacrylic resin pellets, and the metal of the fatty acid metal salt is a divalent or trivalent main group metal.

Description

Technical Field

[0001] The present invention relates to a molding material, a resin molded body formed by molding the molding material, a vehicle component, an optical component, a container, a medical component, and a housing equipment component. Background Art

[0002] Methacrylic resins are widely used as vehicle parts such as interior and exterior materials of vehicles such as tail lamp covers, head lamp covers, instrument panels, pillar garnishes, front grills, and emblems; building parts; parts for residential equipment such as washstands, bathtubs, and flush toilets; optical parts such as lenses and light guides, containers for cosmetics, and medical parts such as cuvettes.

[0003] When used for these purposes, the methacrylic resin is formed by a forming method such as press molding, injection molding, gas-assisted injection molding, welding molding, extrusion molding, blow molding, film molding, hollow molding, multilayer molding, melt spinning, etc. For example, in injection molding, methacrylic resin pellets are fed into a high-temperature cylinder of an injection molding machine, and then the molten resin is injected into a mold processed into various shapes. Then, the molded body obtained by cooling is demolded from the mold, and the supporting product is taken out.

[0004] Conventionally, in order to improve the plasticity, mold release properties, low-temperature moldability, etc. of methacrylic resin during injection molding and to improve the appearance of the resulting product, fatty acid metal salts have been added to methacrylic resin pellets. For example, Patent Document 1 discloses that a thick film product having good optical properties and a highly aesthetic appearance can be obtained by injection molding acrylic polymer particles using a monovalent fatty acid metal salt such as lithium stearate at low temperature.

[0005] However, in methacrylic resin products, in order to ensure weather resistance during storage and use, ultraviolet absorbers are mixed into the molding materials. In this case, as ultraviolet absorbers, benzotriazole ultraviolet absorbers are generally used from the viewpoint of imparting weather resistance. Prior art literature Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 8-294935 Summary of the invention Problems to be solved by the invention

[0007] Patent Document 1 does not include any example of using an ultraviolet absorber such as a benzotriazole-based ultraviolet absorber, and therefore the resulting resin molded article has a problem of poor weather resistance. It is believed that the problem of weather resistance can be solved by including a benzotriazole ultraviolet absorber in Patent Document 1. However, according to the research of the present inventors, it was found that when a fatty acid metal salt and a benzotriazole ultraviolet absorber coexist, the obtained resin molded body turns yellow.

[0008] Methacrylic resins are often used in design parts due to their transparency, but yellowing is a major problem because good appearance and color tone are required. Conventionally, there is no known technology for solving the yellowing caused by the coexistence of such a benzotriazole-based ultraviolet absorber and a fatty acid metal salt.

[0009] The object of the present invention is to provide a molding material and a resin molding thereof which can solve the yellowing problem in a molding material obtained by adding a fatty acid metal salt to methacrylic resin pellets containing a benzotriazole-based ultraviolet absorber, and can form a resin molding having excellent weather resistance and good appearance and color tone. Means of solving problems

[0010] The present inventors have found that yellowing can be suppressed by using a fatty acid metal salt of a divalent or trivalent main group metal as the fatty acid metal salt to be added to methacrylic resin pellets containing a benzotriazole-based ultraviolet absorber. The present invention has been achieved based on such findings, and the following contents are the main points.

[0011] [1] A molding material characterized in that a fatty acid metal salt is added to a methacrylic resin pellet containing a methacrylic resin and a benzotriazole ultraviolet absorber, wherein the content of the benzotriazole ultraviolet absorber in 100 parts by mass of the methacrylic resin pellet is 0.001 parts by mass or more and less than 0.3 parts by mass, and the metal of the fatty acid metal salt is a divalent or trivalent main group metal.

[0012] [2] The forming material according to [1], wherein the main group metal is one or more selected from Mg, Ca and Al.

[0013] [3] The formed material according to [2], wherein the main group metal is Al.

[0014] [4] The molding material according to any one of [1] to [3], wherein the benzotriazole-based ultraviolet absorber is one or more selected from 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2H-benzotriazol-2-yl)-4-methylphenol, 6-di-tert-amylphenol and 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole.

[0015] [5] The molding material according to [4], wherein the benzotriazole-based ultraviolet absorber is 2-(2H-benzotriazole-2-yl)-4-methylphenol.

[0016] [6] The molding material according to any one of [1] to [5], wherein the fatty acid of the fatty acid metal salt is one or more selected from saturated fatty acids having 8 to 22 carbon atoms and unsaturated fatty acids having 8 to 22 carbon atoms.

[0017] [7] The molding material according to [6], wherein the fatty acid of the fatty acid metal salt is one or more selected from palmitic acid, stearic acid, myristic acid, lauric acid and montanic acid.

[0018] [8] The molding material according to [7], wherein the fatty acid of the fatty acid metal salt is stearic acid.

[0019] [9] The molding material according to any one of [1] to [8], wherein the amount of the fatty acid metal salt added is 0.0001 to 0.5 parts by mass based on 100 parts by mass of the methacrylic resin pellets.

[0020]

[10] The molding material according to any one of [1] to [9], wherein the surface area of ​​the methacrylic resin pellets is 10 mm 2 ~450mm 2 .

[0021]

[11] The molding material according to any one of [1] to

[10] , wherein the content of the repeating unit derived from methyl methacrylate in the methacrylic resin is 50% by mass or more.

[0022]

[12] The molding material according to any one of [1] to

[11] , wherein the molding material is a molding material for press molding, extrusion molding, injection molding or film molding.

[0023]

[13] A molding material for injection molding, characterized in that it is composed of the molding material according to any one of [1] to

[11] .

[0024]

[14] Use of the molding material according to any one of [1] to

[11] in stamping molding, extrusion molding, injection molding or film molding.

[0025]

[15] Use of the molding material according to any one of [1] to

[11] in injection molding.

[0026]

[16] A resin molded body, characterized in that it is molded from the molding material described in any one of [1] to

[13] .

[0027]

[17] A vehicle component, characterized in that it is formed from the molding material described in any one of [1] to

[13] .

[0028]

[18] An optical component, characterized in that it is formed from the molding material described in any one of [1] to

[13] .

[0029]

[19] A container, characterized in that it is formed from the molding material described in any one of [1] to

[13] .

[0030]

[22] A medical component, characterized in that it is formed from the molding material described in any one of [1] to

[13] .

[0031]

[21] A housing equipment component, characterized in that it is formed from the molding material described in any one of [1] to

[13] .

[0032]

[22] A method for manufacturing a resin molded body, characterized in that it comprises: molding a molding material formed by adding a fatty acid metal salt to methacrylic resin pellets to obtain a resin molded body, wherein the metal is a divalent or trivalent main group metal, and the methacrylic resin pellets are methacrylic resin pellets containing methacrylic resin and a benzotriazole-based ultraviolet absorber, and the content of the benzotriazole-based ultraviolet absorber in 100 parts by mass of the methacrylic resin pellets is not less than 0.001 parts by mass and less than 0.3 parts by mass.

[0033]

[23] The method for producing a resin molded body according to

[22] , wherein the molding material is injection molded to obtain the resin molded body. Effects of the Invention

[0034] According to the present invention, a methacrylic resin molded article can be provided, wherein the problem of yellowing can be solved, the article has excellent weather resistance, and has good appearance and color tone, by using a divalent or trivalent main group metal salt of a fatty acid as the fatty acid metal salt in a molding material formed by externally adding a fatty acid metal salt to methacrylic resin pellets containing a benzotriazole ultraviolet absorber, and setting the content of the benzotriazole ultraviolet absorber in 100 parts by mass of the methacrylic resin pellets to 0.001 parts by mass or more and less than 0.3 parts by mass. DETAILED DESCRIPTION

[0035] The following will describe the embodiments of the present invention in detail. The present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the invention.

[0036] [Molding materials] The molding material of the present invention is characterized in that it is a molding material formed by adding a fatty acid metal salt to a methacrylic resin pellet containing a methacrylic resin and a benzotriazole-based ultraviolet absorber, the metal of the fatty acid metal salt is a divalent or trivalent main group metal, and the content of the benzotriazole-based ultraviolet absorber in 100 parts by mass of the methacrylic resin pellet is 0.001 parts by mass or more and less than 0.3 parts by mass.

[0037] Hereinafter, the methacrylic resin pellets containing the methacrylic resin and the benzotriazole ultraviolet absorber before the addition of the fatty acid metal salt may be referred to as "the methacrylic resin pellets of the present invention". Hereinafter, the act of making the methacrylic resin pellets contain the benzotriazole-based ultraviolet absorber may be referred to as "internal addition", and the act of making the fatty acid metal salt adhere to or apply to the methacrylic resin pellets may be referred to as "external addition". In addition, the main group metal refers to the elements of Group 1, Group 2, and Groups 12 to 18 in the periodic table.

[0038] <Principle> The principle of the invention that the addition of a divalent or trivalent main group metal fatty acid metal salt to methacrylic resin pellets can suppress yellowing even in the presence of a benzotriazole ultraviolet absorber can be inferred as follows.

[0039] The mechanism of improving weather resistance by using benzotriazole-based ultraviolet absorbers is as follows. The ultraviolet rays cause the benzotriazole compounds (e.g. Tinuvin (registered trademark)-P) to transition to an excited state, and then deactivate to an electronic ground state without luminescence through the intramolecular hydrogen bond between the phenolic hydroxyl group and the benzotriazole group. Through this process, the ultraviolet energy is converted into heat energy. That is, by providing the benzotriazole compound with a phenolic hydroxyl group that participates in a hydrogen bond within the molecule, ultraviolet degradation can be prevented, thereby exhibiting an effect of improving weather resistance.

[0040] As described above, since the benzotriazole-based ultraviolet absorber has a phenolic hydroxyl group, a coordination formation reaction may occur in the presence of a metal species such as a fatty acid metal salt, and the metal complex generated by the reaction is considered to be the cause of yellowing.

[0041] However, it is believed that when the metal of the fatty acid metal salt is a divalent or trivalent main group metal, it does not have a highly reactive d orbital or f orbital and is divalent or trivalent, so it is not easy to react with the phenolic hydroxyl group. Therefore, it is believed that no phenol salt ions are produced, and yellowing is suppressed.

[0042] <Molding Materials> The molding material of the present invention is a material obtained by adding a fatty acid metal salt to the methacrylic resin pellets of the present invention. The methacrylic resin pellets of the present invention contain a methacrylic resin (which has the same meaning as a methacrylic polymer) and a benzotriazole ultraviolet absorber.

[0043] <Methacrylic acid polymer> The methacrylic acid polymer is a polymer having a repeating unit derived from methyl methacrylate (hereinafter, sometimes referred to as "methyl methacrylate unit") as a main component. By making the molding material of the present invention contain a methacrylic acid polymer, the transparency of the obtained resin molding can be improved, and the thermal decomposition of the resin molding can be suppressed, and the weather resistance and moldability are good. In the present invention, "having methyl methacrylate units as the main component" means that, as one embodiment, the content ratio of methyl methacrylate units in the methacrylic acid polymer (100% by mass) is 50% by mass or more.

[0044] For the above reasons, the content ratio of methyl methacrylate units in the methacrylic acid polymer (100% by mass) contained in the molding material of the present invention is preferably 50% by mass or more. Examples of such methacrylic acid polymers include homopolymers of methyl methacrylate and copolymers containing 50% by mass or more and less than 100% by mass of methyl methacrylate units and more than 0% by mass and less than 50% by mass of repeating units derived from monomers other than methyl methacrylate (hereinafter also referred to as "other monomer units").

[0045] The monomers other than methyl methacrylate forming other monomer units are not particularly limited as long as they are monomers copolymerizable with methyl methacrylate. The other monomers may be monofunctional monomers having one double bond capable of free radical polymerization in one molecule, or may be polyfunctional monomers having two or more double bonds capable of free radical polymerization in one molecule. From the viewpoint of excellent balance among fluidity, moldability and thermal decomposition of methacrylic acid-based polymers, acrylic acid esters are preferred as monomers other than methyl methacrylate.

[0046] When the methacrylic acid polymer contains repeating units derived from acrylic acid ester (hereinafter also referred to as "acrylic acid ester units") as other monomer units, the methacrylic acid polymer (100% by mass) preferably contains 50% by mass or more and less than 100% by mass of methyl methacrylate units and more than 0% by mass and less than 50% by mass of acrylic acid ester units, more preferably contains 70% by mass or more and less than 100% by mass of methyl methacrylate units and more than 0% by mass and less than 30% by mass of acrylic acid ester units, further preferably contains 80% by mass or more and less than 99.9% by mass of methyl methacrylate units and more than 0.1% by mass and less than 20% by mass of acrylic acid ester units, and particularly preferably contains 90% by mass or more and less than 99.5% by mass of methyl methacrylate units and more than 0.5% by mass and less than 10% by mass of acrylic acid ester units.

[0047] As the acrylate, for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, isobornyl acrylate, glycidyl acrylate, tetrahydrofurfuryl acrylate, norbornyl acrylate, adamantyl acrylate, dicyclopentenyl acrylate, dicyclopentyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, etc. are listed. Methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate are preferred, and methyl acrylate and ethyl acrylate are more preferred. One type of acrylate can be used alone, or two or more types can be used in combination.

[0048] As another embodiment of the methacrylic acid-based polymer, a polymer (A) containing a repeating unit derived from a (meth)acrylate monomer (hereinafter, also referred to as a "(meth)acrylate unit". Here, "(meth)acrylate" means "methacrylate" or "methacrylate and acrylate") and a structural unit derived from a ring structure (hereinafter, abbreviated as a "ring structural unit") in the main chain can be cited. As the ring structural unit, for example, a glutaric anhydride structural unit, a maleic anhydride structural unit, a glutarimide structural unit, a lactone ring structural unit, and an N-substituted maleimide structural unit can be cited. The ring structural unit can be used alone or in combination of two or more.

[0049] The lower limit of the content of the (meth)acrylate unit in the polymer (A) is not particularly limited. From the viewpoint of not damaging the original performance of the methacrylic resin, such as excellent transparency, processability, and mechanical properties of the obtained resin molding, the content of the (meth)acrylate unit is preferably 80 mol% or more, more preferably 90 mol% or more, and further preferably 94 mol% or more relative to the total molar number (100 mol%) of the repeating units (including structural units. The same below). The upper limit of the content of the (meth)acrylate unit in the polymer (A) is not particularly limited. From the viewpoint of excellent heat resistance of the obtained resin molding, the content of the (meth)acrylate unit is preferably 99.999 mol% or less, more preferably 99.9 mol% or less, and further preferably 99.5 mol% or less relative to the total molar number (100 mol%) of the repeating units contained in the polymer (A). The above upper and lower limits may be combined arbitrarily. For example, the content ratio of the (meth)acrylate unit in the polymer (A) is preferably 80 to 99.999 mol%, more preferably 90 to 99.9 mol%, and further preferably 94 to 99.5 mol%, relative to the total molar number (100 mol%) of the repeating units contained in the polymer (A).

[0050] The lower limit of the content ratio of the ring structural unit in the polymer (A) is not particularly limited. From the viewpoint of excellent heat resistance of the obtained resin molding, the content ratio of the ring structural unit relative to the total molar number (100 mol%) of the repeating units contained in the polymer (A) is preferably 0.001 mol% or more, more preferably 0.01 mol% or more, and further preferably 0.05 mol% or more. The upper limit of the content ratio of the ring structural unit in the polymer (A) is not particularly limited. From the viewpoint of excellent heat resistance of the obtained resin molding, suppression of molding coloring, excellent molding appearance and weather resistance, the content ratio of the ring structural unit relative to the total molar number (100 mol%) of the repeating units in the polymer (A) is preferably 10 mol% or less, more preferably 3 mol% or less, and further preferably 0.3 mol% or less. The above upper and lower limits may be combined arbitrarily. For example, the content ratio of the ring structure unit in the polymer (A) is preferably 0.001 to 10 mol%, more preferably 0.01 to 3 mol%, and further preferably 0.05 to 0.3 mol%, relative to the total molar number (100 mol%) of the repeating units contained in the polymer (A).

[0051] Among the (meth)acrylates other than methyl methacrylate forming the (meth)acrylate units, examples of the acrylates include those exemplified in the description of the methacrylic acid-based polymers described above. In addition, examples of methacrylates other than methyl methacrylate include ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, isobornyl methacrylate, glycidyl methacrylate, tetrahydrofurfuryl methacrylate, norbornyl methacrylate, adamantyl methacrylate, dicyclopentenyl methacrylate, dicyclopentyl methacrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate. These (meth)acrylates may be used alone or in combination of two or more.

[0052] The polymer (A) may contain a structural unit derived from a monomer having a carboxyl group (hereinafter, also referred to as a "monomer unit having a carboxyl group"). For example, a part of the monomer units having a carboxyl group may form a ring structural unit through a cyclization reaction with an ester group, and the ring structural unit may be introduced into the main chain of the methacrylic acid polymer. Therefore, the methacrylic acid polymer may also contain a monomer unit having a carboxyl group. As monomers having a carboxyl group, for example, acrylic acid, methacrylic acid (hereinafter, acrylic acid and / or methacrylic acid are referred to as "(meth) acrylic acid"), 2-(hydroxymethyl) acrylic acid, 2-(hydroxyethyl) acrylic acid, and crotonic acid may be cited. One monomer having a carboxyl group may be used alone, or two or more monomers may be used in combination.

[0053] As one embodiment of the polymer (A), there can be mentioned a polymer containing a repeating unit (A1) derived from methyl methacrylate (hereinafter also referred to as “unit (A1)”), a repeating unit (A2) derived from (meth)acrylic acid (hereinafter also referred to as “unit (A2)”) as a (meth)acrylate unit, and a glutaric anhydride structural unit (A3) (hereinafter also referred to as “unit (A3)”) as a ring structural unit.

[0054] When the polymer (A) contains the unit (A3), the heat resistance of the obtained resin molded article can be easily improved. The unit (A3) is represented by the following chemical structural formula.

[0055] [Chemistry 1]

[0056] (Where R A and R B Each independently represents a hydrogen atom or a methyl group. )

[0057] The lower limit of the content of the unit (A1) in the polymer (A) is not particularly limited. From the viewpoint of not damaging the original performance of the methacrylic resin, such as excellent transparency, processability, and mechanical properties of the obtained resin molding, the content of the unit (A1) in the polymer (A) is preferably 80 mol% or more, more preferably 90 mol% or more, and further preferably 94 mol% or more relative to the total molar number (100 mol%) of the repeating units contained in the polymer (A). The upper limit of the content of the unit (A1) in the polymer (A) is not particularly limited. From the viewpoint of excellent heat resistance of the obtained resin molding, the content of the unit (A1) in the polymer (A) is preferably 99.4 mol% or less, more preferably 99 mol% or less, and further preferably 98 mol% or less relative to the total molar number (100 mol%) of the repeating units contained in the polymer (A). The above upper and lower limits may be combined arbitrarily. For example, the content of the unit (A1) in the polymer (A) is preferably 80 to 99.4 mol%, more preferably 90 to 99 mol%, and further preferably 94 to 98 mol%, relative to the total molar number (100 mol%) of the repeating units contained in the polymer (A).

[0058] As the unit (A2), a methacrylic acid unit is preferred because the obtained resin molded article has excellent heat resistance.

[0059] The lower limit of the content of the unit (A2) in the polymer (A) is not particularly limited. From the viewpoint of excellent heat resistance and mechanical properties of the obtained resin molding, the content of the unit (A2) in the polymer (A) is preferably 0.5 mol% or more, more preferably 1 mol% or more, and further preferably 2 mol% or more relative to the total molar number (100 mol%) of the repeating units contained in the polymer (A). The upper limit of the content of the unit (A2) in the polymer (A) is not particularly limited. From the viewpoint of not damaging the original properties of the methacrylic resin such as the molding appearance, low water absorption and excellent moldability of the obtained resin molding, the content of the unit (A2) in the polymer (A) is preferably 20 mol% or less, more preferably 7 mol% or less, and further preferably 3.5 mol% or less relative to the total molar number (100 mol%) of the repeating units contained in the polymer (A). The above upper and lower limits may be combined arbitrarily. For example, the content of the unit (A2) in the polymer (A) is preferably 0.5 to 20 mol%, more preferably 1 to 7 mol%, and further preferably 2 to 3.5 mol%, relative to the total molar number (100 mol%) of the repeating units contained in the polymer (A).

[0060] The lower limit of the content of the unit (A3) in the polymer (A) is not particularly limited. From the viewpoint of excellent heat resistance of the obtained resin molded body, the content of the unit (A3) is preferably 0.001 mol% or more, more preferably 0.01 mol% or more, and further preferably 0.05 mol% or more relative to the total molar number (100 mol%) of the repeating units contained in the polymer (A). From the viewpoint of suppression of molding coloration, excellent molding appearance and weather resistance of the obtained resin molded body, as the upper limit of the content of the unit (A3) in the polymer (A), the content of the unit (A3) is preferably 10 mol% or less, more preferably 3 mol% or less, and further preferably 0.3 mol% or less relative to the total molar number (100 mol%) of the repeating units contained in the polymer (A). The above upper limit and lower limit may be combined arbitrarily. For example, the content ratio of the unit (A3) in the polymer (A) is preferably 0.001 to 10 mol%, more preferably 0.01 to 3 mol%, and further preferably 0.05 to 0.3 mol%, relative to the total molar number (100 mol%) of the repeating units contained in the polymer (A).

[0061] The unit (A3) may be a unit constructed by a cyclization reaction between a methoxycarbonyl group derived from the unit (A1) and a carboxyl group derived from an adjacent unit (A2) in a copolymer obtained by copolymerizing methyl methacrylate and (meth)acrylic acid.

[0062] In the present invention, the content of each unit in the methacrylic resin such as polymer (A) is set to 1 H-NMR measurement calculated value. Specifically, the method disclosed in International Publication No. 2019 / 013186 can be used.

[0063] The method for producing the methacrylic resin is not particularly limited. For example, block polymerization, suspension polymerization, emulsion polymerization, and solution polymerization can be cited. From the viewpoint of excellent productivity, block polymerization and suspension polymerization are preferred.

[0064] In the methacrylic resin, the method for producing a polymer (A) containing units (A1), units (A2) and units (A3) is not particularly limited. For example, the production methods disclosed in International Publication No. 2017 / 022393 and International Publication No. 2019 / 013186 can be used.

[0065] <Benzotriazole UV absorber> The methacrylic resin pellets of the present invention contain a benzotriazole ultraviolet absorber in a ratio of 0.001 parts by mass or more and less than 0.3 parts by mass based on 100 parts by mass of the methacrylic resin pellets of the present invention. The benzotriazole ultraviolet absorber contained in the methacrylic resin pellets of the present invention is not particularly limited, and a conventionally known benzotriazole ultraviolet absorber can be used.

[0066] Examples of the benzotriazole ultraviolet absorber include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2H-benzotriazol-2-yl)-4-methylphenol, 6-di-tert-amylphenol, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2-(2-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, -3,5-dicumylphenyl)benzotriazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], 2-(2-hydroxy-3,5-di-tert-butylphenyl)benzotriazole, 2-(2-hydroxy-3,5-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3,5-di-tert-amylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-butylphenyl)benzotriazole, 2-(2-hydroxy-4- 2-[2-hydroxy-3-(4,5,6,7-tetrahydro-1,3-dioxo-1H-isoindol-2-ylmethyl)-5-methylphenyl]-2H-benzotriazole, etc. Among them, 2-[2-hydroxy-3-(4,5,6,7-tetrahydro-1,3-dioxo-1H-isoindol-2-ylmethyl)-5-methylphenyl]-2H-benzotriazole is preferred from the viewpoint of compatibility with methacrylic resins. (2'-Hydroxy-5'-methylphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2H-benzotriazol-2-yl)-4-methylphenol, 6-di-tert-amylphenol, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, and 2-(2H-benzotriazol-2-yl)-4-methylphenol is particularly preferred.

[0067] These benzotriazole-based ultraviolet absorbers may be used alone or in combination of two or more.

[0068] Commercially available products can be used for these benzotriazole-based ultraviolet absorbers, for example, Tinuvin (registered trademark) series manufactured by BASF Japan can be used.

[0069] The content (internal addition amount) of the benzotriazole ultraviolet absorber in the methacrylic resin pellets of the present invention is 0.001 parts by mass or more and less than 0.3 parts by mass based on 100 parts by mass of the methacrylic resin pellets. When the content of the benzotriazole ultraviolet absorber is greater than the above lower limit, the effect of improving weather resistance due to the inclusion of the benzotriazole ultraviolet absorber can be fully obtained. The content of the benzotriazole ultraviolet absorber is preferably greater than 0.002 parts by mass, more preferably greater than 0.003 parts by mass, further preferably greater than 0.005 parts by mass, and particularly preferably greater than 0.009 parts by mass. When the content of the benzotriazole ultraviolet absorber is less than the above upper limit, yellowing of the resin molded body caused by the benzotriazole ultraviolet absorber can be reduced. The content of the benzotriazole ultraviolet absorber is preferably 0.1 parts by mass or less, more preferably 0.07 parts by mass or less, further preferably 0.06 parts by mass or less, and particularly preferably 0.05 parts by mass or less. The above upper limit and lower limit may be combined arbitrarily. That is, the content of the benzotriazole ultraviolet absorber in the methacrylic resin pellets of the present invention is preferably 0.002 to 0.1 parts by mass, more preferably 0.003 to 0.07 parts by mass, further preferably 0.005 to 0.06 parts by mass, and particularly preferably 0.009 to 0.05 parts by mass.

[0070] <Other additives> The methacrylic resin pellets of the present invention may contain, in addition to the above-mentioned benzotriazole ultraviolet absorber, one or more kinds of various additives usually added to molding materials within a range not impairing the effects of the present invention. Examples of the additive include light diffusers, antioxidants, colorants, pigments, dyes, heat stabilizers, reinforcing agents, fillers, flame retardants, foaming agents, lubricants other than fatty acids, plasticizers, antistatic agents, light stabilizers, impact resistance improvers, flowability enhancers, mold release agents, processing elasticity imparting agents, and ultraviolet absorbers other than benzotriazole ultraviolet absorbers.

[0071] <Shape / Size / Surface Area> The methacrylic resin pellets of the present invention are supplied to a molding machine such as press molding, extrusion molding, injection molding or film molding, and their shapes are not particularly limited, and may be cylindrical, spherical, dice-shaped or the like.

[0072] The size of the methacrylic resin pellets is not particularly limited. For example, in the case of a cylindrical shape, the length of the cylinder in the axial direction (axial length) is 1.5 to 6 mm, the length of the major diameter of the surface perpendicular to the axial direction is preferably about 1.5 to 5 mm, and the length of the minor diameter of the surface perpendicular to the axial direction is preferably about 1.5 to 4.5 mm. In the case of other shapes, the size is preferably about the same volume as the cylindrical methacrylic resin pellets of the above size.

[0073] There is no particular limitation on the surface area of ​​the methacrylic resin pellets. For example, when the pellets are cylindrical, the surface area is preferably 10 mm 2 ~450mm 2 , preferably 30 mm 2 ~300mm 2 , particularly preferably 40 mm 2 ~200mm 2 When it is another shape, it is preferably the same surface area as the cylindrical methacrylic resin pellets of the above size. When the surface area of ​​the methacrylic resin pellets is within the above range, fatty acid metal salts can be added within the specified range to provide a resin molded body with excellent appearance, color tone, and weather resistance.

[0074] <Method for producing methacrylic resin pellets> In order to produce the methacrylic resin pellets of the present invention containing the aforementioned benzotriazole ultraviolet absorber and other additives used as needed, when producing methacrylic resin by a conventional method, the benzotriazole ultraviolet absorber and other additives used as needed are added to a polymerization reaction tank or a raw material feeding path of the polymerization reaction tank at a predetermined ratio, and polymerization reaction is carried out, and the reaction product is granulated. Alternatively, the methacrylic resin, benzotriazole ultraviolet absorber and other additives used as needed are fed into a single screw extruder or a twin screw extruder at a predetermined ratio, and the methacrylic resin pellets of the present invention containing these can be obtained by heating, melting and kneading them and then granulating the materials.

[0075] A portion of the benzotriazole ultraviolet absorber and other additives used as needed may be added to the polymerization reaction tank or in the path for feeding raw materials into the polymerization reaction tank, and the remainder may be melt-kneaded with the produced methacrylic resin using a single-screw extruder or a twin-screw extruder.

[0076] <Divalent or trivalent main group metal fatty acid metal salt> From the viewpoint of excellent yellowing suppression effect of the obtained resin molded body, the metal species of the fatty acid metal salt added to the methacrylic resin pellets of the present invention is a divalent or trivalent main group metal. Hereinafter, the "fatty acid metal salt of a divalent or trivalent main group metal" is also referred to as the "fatty acid metal salt of the present invention".

[0077] As the divalent or trivalent main group metal of the fatty acid metal salt of the present invention, divalent or trivalent metal elements of Group 1, Group 2, and Groups 13 to 18 in the periodic table can be preferably listed, and Mg, Ca, Al, Ba and the like are more preferred. Mg, Ca and Al are particularly preferred because they have high compatibility with methacrylic resins and the resulting resin molded body is less likely to be hazy. In particular, Al is most preferred from the viewpoint of the effect of improving the appearance of the resulting resin molded body.

[0078] As the fatty acid constituting the fatty acid metal salt of the present invention, a saturated fatty acid having 8 to 22 carbon atoms and / or an unsaturated fatty acid having 8 to 22 carbon atoms is preferred from the viewpoint of compatibility with the methacrylic resin.

[0079] Examples of the saturated fatty acids having 8 to 22 carbon atoms include caprylic acid (carbon number 8), nonanoic acid (carbon number 9), capric acid (carbon number 10), lauric acid (carbon number 12), myristic acid (carbon number 14), pentadecanoic acid (carbon number 15), palmitic acid (carbon number 16), heptadecanoic acid (carbon number 17), stearic acid (carbon number 18), arachidic acid (carbon number 20), heneicosanoic acid (carbon number 21), and docosanoic acid (carbon number 22).

[0080] Examples of the unsaturated fatty acid having 8 to 22 carbon atoms include myristic acid (14 carbon atoms), palmitoleic acid (16 carbon atoms), sapienic acid (16 carbon atoms), oleic acid (18 carbon atoms), elaidic acid (18 carbon atoms), vaccenic acid (18 carbon atoms), gadoleic acid (20 carbon atoms), eicosenoic acid (20 carbon atoms), erucic acid (22 carbon atoms), linoleic acid (18 carbon atoms), eicosadienoic acid (20 carbon atoms), docosadienoic acid (22 carbon atoms), α-linolenic acid (18 carbon atoms), γ-linolenic acid (18 carbon atoms), pinolenic acid (18 carbon atoms), α-eleostearic acid (18 carbon atoms), β-eleostearic acid (18 carbon atoms), mead trienoic acid (20 carbon atoms), acid) (carbon number 20), dihomo-γ-linolenic acid (carbon number 20), eicosatrienoic acid (carbon number 20), stearidonic acid (carbon number 18), arachidonic acid (carbon number 20), eicosatetraenoic acid (carbon number 20), adrenic acid (carbon number 22), bosseopentaenoic acid (carbon number 18), eicosapentaenoic acid (carbon number 20), osbond acid (carbon number 22), clupanodonic acid (carbon number 22), docosahexaenoic acid (carbon number 22), etc.

[0081] As the fatty acid of the fatty acid metal salt of the present invention, palmitic acid, stearic acid, myristic acid, lauric acid or montanic acid is preferred from the viewpoint of availability, and stearic acid is particularly preferred.

[0082] As the fatty acid metal salt of the present invention, aluminum stearate is most preferred from the viewpoint of the effect of improving the appearance of the obtained resin molded article.

[0083] The fatty acid metal salt of the present invention may be used alone or in combination of two or more.

[0084] The lower limit and upper limit of the amount of the fatty acid metal salt of the present invention added to the methacrylic resin pellets of the present invention are not particularly limited, but are preferably 0.0001 parts by mass or more and 0.5 parts by mass or less per 100 parts by mass of the methacrylic resin pellets (methacrylic resin pellets not containing the fatty acid metal salt). When the amount of the fatty acid metal salt added is greater than the above lower limit, the appearance improvement effect of the obtained resin molded body can be further effectively obtained by the improvement effect of the plasticization behavior during molding brought about by the fatty acid metal salt of the present invention. The lower limit is more preferably 0.001 parts by mass or more, further preferably 0.003 parts by mass or more, particularly preferably 0.005 parts by mass or more, and most preferably 0.01 parts by mass or more. When the amount of the fatty acid metal salt added is below the upper limit, it is less likely that the mold or the resin molded body will be contaminated by the excess fatty acid metal salt remaining on the mold surface during demolding. The upper limit is more preferably 0.3 parts by mass or less, further preferably 0.2 parts by mass or less, particularly preferably 0.1 parts by mass or less, and most preferably 0.05 parts by mass or less. The above upper and lower limits may be combined arbitrarily. That is, the amount of the fatty acid metal salt added in the present invention is preferably 0.0001 to 0.5 parts by mass, more preferably 0.001 to 0.3 parts by mass, further preferably 0.003 to 0.2 parts by mass, particularly preferably 0.005 to 0.1 parts by mass, and most preferably 0.01 to 0.05 parts by mass, relative to 100 parts by mass of the methacrylic resin pellets of the present invention.

[0085] <Method for producing molding material> There are no particular restrictions on the method of manufacturing the molding material of the present invention by adding the fatty acid metal salt of the present invention to the methacrylic resin pellets of the present invention, as long as the fatty acid metal salt is added in a state where it is not chemically bonded. For example, there can be mentioned a dry blending method, a method of spraying or adding a powder of the fatty acid metal salt of the present invention to the methacrylic resin pellets of the present invention using a stirring device and stirring, and a method of removing the solvent on the surface of the methacrylic resin pellets after dispersing the methacrylic resin pellets in a liquid containing the fatty acid metal salt of the present invention.

[0086] Examples of the dry mixing method include a method of mixing the methacrylic resin pellets of the present invention and the fatty acid metal salt using a conventional mixer such as a ribbon blender, a tumbler, a Nauta mixer, or a Henschel mixer.

[0087] An example of a stirring device used in the above-mentioned spraying and stirring is a device comprising a bottomed cylindrical container, a screw that rotates and revolves along the inner wall surface of the container, and a spraying means for spraying the fatty acid metal salt of the present invention onto the methacrylic resin pellets of the present invention placed in the container. Examples of the spraying means include a nozzle for spraying the fatty acid metal salt, etc. The spraying means may include a heating means such as a heater for heating the fatty acid metal salt.

[0088] The methacrylic resin pellets of the present invention are placed in a container of such a stirring device, and the fatty acid metal salt of the present invention is made into a powder, liquid or molten state by spraying means to adhere to the methacrylic resin pellets of the present invention in the container under stirring. Then, the methacrylic resin pellets sprayed with the fatty acid metal salt are further stirred uniformly by a screw rotating and revolving along the inner wall of the container. Thus, the fatty acid metal salt of the present invention can be uniformly added to the methacrylic resin pellets of the present invention.

[0089] In order to more uniformly add the fatty acid metal salt of the present invention to the methacrylic resin pellets of the present invention, it is preferred to change the temperature in the container according to the type of the fatty acid metal salt. For example, by setting the temperature in the container to about 60 to 80° C., the uniform addition of the fatty acid metal salt of the present invention can be improved. Examples of methods for changing the temperature in a container include a method of introducing a heated inert gas into the container, a method of heating the inside of the container with a heater, and a method of controlling the temperature by introducing a heat medium into the outer jacket of the container.

[0090] As a method for dispersing the methacrylic resin pellets of the present invention in a liquid containing the fatty acid metal salt of the present invention and then removing the solvent on the surface of the methacrylic resin pellets, for example, there can be mentioned a method in which a solution or dispersion in which the total amount of the fatty acid metal salt of the present invention added to the solvent is 0.05 to 1% by mass is prepared and the dispersion is sprayed onto the methacrylic resin pellets of the present invention, or the methacrylic resin pellets of the present invention are added into the liquid for treatment.

[0091] Examples of a method for applying the fatty acid metal salt of the present invention to the methacrylic resin pellets of the present invention by spraying a liquid containing the fatty acid metal salt of the present invention include a method in which the methacrylic resin pellets are arranged on a conveying device such as a conveyor belt, and the liquid containing the fatty acid metal salt is continuously sprayed while the pellets pass through a sprayer.

[0092] The method of adding the fatty acid metal salt of the present invention to the methacrylic resin pellets of the present invention by adding the fatty acid metal salt to the methacrylic resin pellets of the present invention can be carried out by a generally known method. For example, the liquid containing the fatty acid metal salt and the methacrylic resin pellets are added to a mixing tank equipped with a stirrer, mixed for a predetermined time at a temperature of 0° C. to a boiling point of the solvent or lower, and the methacrylic resin pellets and the liquid are separated by filtration or the like.

[0093] Then, the solvent is dried by blowing air or supplying hot air as needed. At this time, since the fatty acid metal salt does not volatilize, it remains directly on the surface of the methacrylic resin pellets. Therefore, the fatty acid metal salt of the present invention can be added to the methacrylic resin pellets after drying.

[0094] As the solvent, a commonly used solvent can be used, and preferably a solvent in which the methacrylic resin is not dissolved or hardly dissolved according to the composition of the methacrylic resin of the methacrylic resin pellet of the present invention. As such a solvent, water can be cited, for example. As a preferred solvent, a solvent having a boiling point of 30°C to 150°C at normal pressure is preferred in terms of efficiency and workability of the drying process, and water is particularly preferred in view of cost and safety.

[0095] [Resin molded body] The resin molded article of the present invention is a molded article obtained by molding the molding material of the present invention. The resin molded body of the present invention is not particularly limited as long as it is a molded body formed by a known molding method, for example, stamping molding, injection molding, gas-assisted injection molding, welding molding, extrusion molding, blow molding, film molding, hollow molding, multilayer molding, melt spinning, etc. Stamping molding, extrusion molding, injection molding or film molding is more preferred, and injection molding is further preferred from the viewpoint of obtaining excellent plasticizing properties. Therefore, the molding material of the present invention is preferably used as a molding material for stamping molding, extrusion molding, injection molding or film molding (also referred to as a molding material for stamping molding, extrusion molding, injection molding or film molding), and is particularly preferably used as a molding material for injection molding (also referred to as a molding material for injection molding).

[0096] Specific examples of the resin molded body of the present invention include vehicle parts such as taillight covers or headlight covers, instrument panels, pillar decorations, front grilles, and vehicle logos; building parts; parts for residential equipment such as washstands, bathtubs, and flush toilets; optical parts such as lenses and light guides; containers for cosmetics; and medical parts such as cuvettes. Among them, the resin molded article of the present invention is particularly preferably used for vehicle parts, optical parts, containers, medical parts, housing equipment, cosmetic containers, etc. due to its excellent appearance, weather resistance, transparency, and chemical resistance. Example

[0097] The present invention is specifically described below with reference to the following examples.

[0098] [Raw materials used] The raw materials used in the following Examples and Comparative Examples are as follows.

[0099] Methacrylic resin: Methacrylic resin "ACRYPET (registered trademark) VH" manufactured by Mitsubishi Chemical Corporation Fatty acid metal salts: Lithium stearate: "Lithium stearate" manufactured by Kawamura Chemical Industries, Ltd. (described as "Li stearate" in Table 1.) Sodium stearate: "Sodium stearate" manufactured by Kawamura Chemicals Co., Ltd. (described as "Na stearate" in Table 1.) Calcium stearate: "Calcium stearate" manufactured by Kawamura Chemical Industries, Ltd. (described as "Ca stearate" in Table 1.) Aluminum stearate: "ARUSUTE #30" manufactured by Kawamura Chemical Industries, Ltd. (described as "Al stearate" in Table 1.) Magnesium stearate: "Mg-St" manufactured by Nitto Kasei Kogyo Co., Ltd. (described as "Mg stearate" in Table 1.) "Tinuvin (registered trademark)-P" (2-(2H-benzotriazol-2-yl)-4-methylphenol) manufactured by BASF Japan

[0100] [Evaluation method] The evaluation methods of the resin molded bodies produced in the following Examples and Comparative Examples are as follows.

[0101] (1) Appearance The resin molded product test piece was visually observed, and the number of occurrences of silver streaks (defective appearance) was evaluated according to the following criteria. ○: Among 10 test pieces, the number of test pieces with silver streaks is 1 or less △: Among 10 test pieces, the number of test pieces with silver streaks is 2 or more and 4 or less ×: Among 10 test pieces, the number of test pieces with silver streaks is 5 or more

[0102] (2) Hue For the resin molded body test piece, the yellow index (YI) value of the optical path length of 140 mm was measured using a spectrophotometer "U-4100" manufactured by Hitachi High-Tech Corporation in the light transmission mode according to JIS K7105 and the light transmission method with a C light source. The measurement was performed on three test pieces, the average value was calculated, and the evaluation was performed using the following criteria. ○: YI value is less than 10.0 ×: YI value is 10.0 or more

[0103] (3) Weather resistance The following accelerated exposure test was performed on the resin molded body test piece, and L*, a*, and b* after the test were measured to determine the color difference ΔE*ab. <Accelerated Exposure Test> The accelerated exposure test was conducted using the "EYE SUPER UV TESTER" manufactured by Iwasaki Electric Co., Ltd. Specifically, the injection molded test piece produced in the appearance evaluation was cut, and a resin molded body test piece (50 mm × 50 mm × 4 mm) was set in the evaluation room and irradiated from the EYE SUPER UV TESTER for 200 hours at a wavelength of 300 to 400 nm and an irradiation intensity of 150 mW / m 2 By adjusting the irradiation position every 25 hours, the test piece is evenly irradiated with UV. The test pieces before and after the test were measured for L*, a*, and b* at an optical path length of 4.0 mm using a spectrophotometer (model name "U-4100", manufactured by Hitachi High-Technologies Corporation) to obtain the color difference ΔE*ab and make judgments based on the following criteria. ○: ΔE*ab value is less than 3.0 ×: ΔE*ab value is 3.0 or more

[0104] [Example 1] A methacrylic resin and a benzotriazole ultraviolet absorber (Tinuvin-P) were used so that the content of Tinuvin-P in 100 parts by mass of the obtained methacrylic resin pellets was 0.03 parts by mass, and these were supplied to a twin-screw extruder (model name "TEM35", manufactured by Shibaura Machine Co., Ltd.), melt-kneaded at a cylinder temperature of 250° C. of the extruder, and methacrylic resin pellets containing a benzotriazole ultraviolet absorber were obtained at a die temperature of 60° C. The methacrylic resin pellets containing a benzotriazole-based ultraviolet absorber are cylindrical (surface area 46 mm2) with a major diameter of 3.2 mm in a direction perpendicular to the axial direction and an axial length of 3.0 mm. 2 ). Calcium stearate was externally added to the obtained methacrylic resin pellets containing a benzotriazole-based ultraviolet absorber in the following manner. Methacrylic resin pellets dried at 80°C for more than 16 hours and powdered calcium stearate were placed in a polyethylene bag and mixed manually for 1 minute to obtain pellets in which calcium stearate was added to methacrylic resin pellets containing a benzotriazole ultraviolet absorber in an amount shown in Table 1.

[0105] The obtained pellets were dried with hot air at 80°C for about 16 hours and then injection molded under the following conditions to produce 20 test pieces of resin molded bodies, which were then evaluated in the above-mentioned (1) to (3). Injection molding machine: Model: EC75-SXII, manufactured by Shibaura Machine Co., Ltd. ·Mold: 120mm×140mm×4mm sheet metal forming mold Cylinder temperature: 230℃ Temperature under hopper: 50℃ Mold temperature: 60℃ Cycle time: 60 seconds Screw speed: 90rpm Back pressure: 10MPa The evaluation results are shown in Table 1.

[0106] [Example 2] A test piece of a resin molded article was produced in the same manner as in Example 1, except that magnesium stearate was added as the fatty acid metal salt instead of calcium stearate, and the test piece was evaluated in the same manner.

[0107] [Example 3] A test piece of a resin molded article was produced in the same manner as in Example 1, except that aluminum stearate was added as the fatty acid metal salt instead of calcium stearate, and the test piece was evaluated in the same manner.

[0108] [Comparative Example 1] A test piece of a resin molded body was produced in the same manner as in Example 1, except that calcium stearate was not added to the methacrylic resin pellets containing the benzotriazole ultraviolet absorber and the pellets were injection molded, and the test piece was evaluated in the same manner.

[0109] [Comparative Example 2] A test piece of a resin molded body was produced in the same manner as in Example 1, except that lithium stearate was added as the fatty acid metal salt instead of calcium stearate, and the test piece was evaluated in the same manner.

[0110] [Comparative Example 3] A test piece of a resin molded article was produced in the same manner as in Example 1, except that sodium stearate was added as the fatty acid metal salt instead of calcium stearate, and the test piece was evaluated in the same manner.

[0111] [Comparative Example 4] The test pieces of the resin molded body were prepared in the same manner as in Example 1, except that the benzotriazole-based ultraviolet absorber was not used to prepare a methacrylic resin pellet containing no benzotriazole-based ultraviolet absorber, and lithium stearate was added to the methacrylic resin pellet instead of calcium stearate as the fatty acid metal salt, and the test pieces were evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0112] [Comparative Example 5] Methacrylic resin pellets containing a benzotriazole ultraviolet absorber were prepared in the same manner as in Example 1 except that the content of the benzotriazole ultraviolet absorber was changed to 0.3 parts by mass, and test pieces of resin molded bodies were prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0113] [Table 1]

[0114] As can be seen from Examples 1 to 3 in Table 1, the methacrylic resin pellets of the present invention, which are obtained by adding 0.001 parts by mass or more and less than 0.3 parts by mass of a benzotriazole-based ultraviolet absorber to methacrylic resin pellets and externally adding calcium stearate, magnesium stearate, and aluminum stearate, can provide a methacrylic resin molded article having excellent appearance, color tone, and weather resistance.

[0115] In contrast, in Comparative Example 1 in which a benzotriazole-based ultraviolet absorber is added to methacrylic resin pellets without adding a fatty acid metal salt, although there is no yellowing problem, the plasticizing properties during injection molding are poor, resulting in poor appearance (silver streaks) and a poor appearance. In the pellets of Comparative Example 2 in which a benzotriazole-based ultraviolet absorber was added internally and lithium stearate was added externally, the benzotriazole-based ultraviolet absorber and the monovalent metal salt coexisted, so there was a problem of yellowing and the color tone was poor. In the pellets of Comparative Example 3 in which a benzotriazole-based ultraviolet absorber was added internally and sodium stearate was added externally, the benzotriazole-based ultraviolet absorber and the monovalent metal salt coexisted, so there was a problem of yellowing and the color tone was poor. In the pellets of Comparative Example 4 in which lithium stearate was added externally and no benzotriazole-based ultraviolet absorber was contained in the pellets, there was no yellowing problem, but the weather resistance was poor. In the pellets of Comparative Example 5, in which calcium stearate was externally added and a large amount of benzotriazole-based ultraviolet absorber was contained in the pellets, although there was no problem with weather resistance, yellowing occurred.

[0116] In summary, when a fatty acid metal salt is added to methacrylic resin pellets to improve the appearance and a benzotriazole ultraviolet absorber is added to improve the weather resistance, according to the present invention, a divalent or trivalent main group metal salt is used as the fatty acid metal salt, so that a resin molded body with excellent appearance, color tone and weather resistance can be provided.

[0117] Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications can be made within the scope of the invention. This application is based on Japanese patent application No. 2022-166336 filed on October 17, 2022, and the entirety of the patent application is incorporated herein by reference.

Claims

1. A forming material, It is characterized in that The present invention is a molding material obtained by adding a fatty acid metal salt to a methacrylic resin pellet containing a methacrylic resin and a benzotriazole ultraviolet absorber, wherein the content of the benzotriazole ultraviolet absorber in 100 parts by mass of the methacrylic resin pellet is 0.001 parts by mass or more and less than 0.3 parts by mass, and the metal of the fatty acid metal salt is a divalent or trivalent main group metal.

2. The molding material according to claim 1, in, The main group metal is one or more selected from Mg, Ca and Al.

3. The molding material according to claim 2, in, The main group metal is Al.

4. The molding material according to claim 1, in, The benzotriazole-based ultraviolet absorber is one or more selected from 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2H-benzotriazol-2-yl)-4-methylphenol, 6-di-tert-amylphenol and 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole.

5. The molding material according to claim 4, in, The benzotriazole-based ultraviolet absorber is 2-(2H-benzotriazole-2-yl)-4-methylphenol.

6. The molding material according to claim 1, in, The fatty acid of the fatty acid metal salt is one or more selected from saturated fatty acids having 8 to 22 carbon atoms and unsaturated fatty acids having 8 to 22 carbon atoms.

7. The molding material according to claim 6, in, The fatty acid of the fatty acid metal salt is one or more selected from palmitic acid, stearic acid, myristic acid, lauric acid and montanic acid.

8. The molding material according to claim 7, in, The fatty acid of the fatty acid metal salt is stearic acid.

9. The molding material according to claim 1, in, The amount of the fatty acid metal salt added is 0.0001 to 0.5 parts by mass relative to 100 parts by mass of the methacrylic resin pellets.

10. The forming material according to claim 1, in, The surface area of ​​the methacrylic resin pellets is 10 mm 2 ~450mm 2 .

11. The molding material according to claim 1, in, The content ratio of the repeating unit derived from methyl methacrylate in the methacrylic resin is 50% by mass or more.

12. The molding material according to any one of claims 1 to 11, in, The molding material is a molding material for press molding, extrusion molding, injection molding or film molding.

13. A molding material for injection molding, It is characterized in that The molding material is composed of any one of claims 1 to 11.

14. Use of the molding material according to any one of claims 1 to 11 in stamping molding, extrusion molding, injection molding or film molding.

15. Use of the molding material according to any one of claims 1 to 11 in injection molding.

16. A resin molded body, It is characterized in that The molding material is molded from any one of claims 1 to 11.

17. A vehicle component, It is characterized in that The molding material is molded from any one of claims 1 to 11.

18. An optical component, It is characterized in that The molding material is molded from any one of claims 1 to 11.

19. A container, It is characterized in that The molding material is molded from any one of claims 1 to 11.

20. A medical component, It is characterized in that The molding material is molded from any one of claims 1 to 11.

21. A residential device, It is characterized in that The molding material is molded from any one of claims 1 to 11.

22. A method for producing a resin molded body, It is characterized in that include: A molding material obtained by adding a fatty acid metal salt to methacrylic resin pellets is molded to obtain a resin molded body, wherein the metal is a divalent or trivalent main group metal. The methacrylic resin pellets are methacrylic resin pellets containing methacrylic resin and a benzotriazole ultraviolet absorber. The content of the benzotriazole ultraviolet absorber in 100 parts by mass of the methacrylic resin pellets is 0.001 parts by mass or more and less than 0.3 parts by mass.

23. The method for producing a resin molded body according to claim 22, in, The molding material is injection molded to obtain the resin molded body.

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