Molding material and resin molded article

Abstract

A molding material which is obtained by adding a fatty acid metal salt to the outside of methacrylic resin pellets containing a methacrylic resin and a benzotriazole ultraviolet absorber, and which is characterized in that the molding material contains a fatty acid. A method for producing a resin molded article, characterized by comprising molding a molding material obtained by adding a fatty acid metal salt to the outside of methacrylic resin pellets containing a methacrylic resin, a benzotriazole ultraviolet absorber and a fatty acid, to obtain a resin molded article.

Description

Technical Field

[0001] The present invention relates to a molding material, a resin molded body formed from 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 components such as interior and exterior materials for vehicles such as tail lamp covers, head lamp covers, meter panels, pillar garnishes, front grills, emblems; building components; housing equipment such as washbasins, bathtubs, and flush toilets; optical components such as lenses and light guides, containers for cosmetics, etc.; and molding materials for medical components such as cuvettes.

[0003] When applied to these uses, methacrylic resins are formed by molding methods such as stamping, injection molding, gas-assisted injection molding, welding molding, extrusion molding, blow molding, film molding, hollow molding, multilayer molding, and melt spinning. For example, in injection molding, methacrylic resin pellets are fed into the high-temperature cylinder of an injection molding machine, and then the molten resin is injected into a mold processed into various shapes. Then, the cooled molded body is demolded from the mold and the product is taken out.

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

[0005] However, in methacrylic resin products, in order to ensure weather resistance during storage and use, an ultraviolet absorber is incorporated into the molding material. In this case, as the ultraviolet absorber, a benzotriazole-based ultraviolet absorber is usually used from the viewpoint of the effect of imparting weather resistance. Prior Art Documents Patent Documents

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

[0007] In Patent Document 1, since there are no examples of using ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers, the resulting resin molded article has a problem of poor weather resistance. It is considered that in Patent Document 1, the problem of weather resistance can be solved by containing a benzotriazole-based ultraviolet absorber. However, according to the research of the present inventors, it has been found that when a fatty acid metal salt coexists with a benzotriazole-based ultraviolet absorber, the resulting resin molded article will turn yellow.

[0008] Methacrylic resins are often used for design parts because of their transparency. Since good appearance and color tone are required, yellowing is a major problem. In the past, techniques for solving the yellowing caused by the coexistence of such a benzotriazole-based ultraviolet absorber and a fatty acid metal salt were unknown.

[0009] An object of the present invention is to provide a molding material and a resin molded article thereof that can solve the yellowing problem in a molding material obtained by externally adding a fatty acid metal salt to a methacrylic resin pellet containing a benzotriazole-based ultraviolet absorber, and can form a resin molded article having excellent weather resistance and good appearance and color tone. Means for Solving the Problem

[0010] The present inventors have found that by making a molding material obtained by externally adding a fatty acid metal salt to a methacrylic resin pellet contain a fatty acid, the yellowing caused by the coexistence of a benzotriazole-based ultraviolet absorber and a fatty acid metal salt can be suppressed. The present invention is based on the following.

[0011] [1] A molding material, characterized in that it is a molding material obtained by externally adding a fatty acid metal salt to a methacrylic resin pellet containing a methacrylic resin and a benzotriazole-based ultraviolet absorber, and the molding material contains a fatty acid.

[0012] [2] The molding material according to [1], wherein the metal of the fatty acid metal salt is a metal having a valence of 1 to 3.

[0013] [3] The molding material according to [2], wherein the metal of the fatty acid metal salt is a monovalent metal.

[0014] [4] The molding material according to [2], wherein the metal of the fatty acid metal salt is one or more selected from Li, Na, Mg, Ca, Ba, K, and Al.

[0015] [5] The molding material according to [4], wherein the metal of the fatty acid metal salt is Li.

[0016] [6] The molding material according to any one of [1] to [5], 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-ditert-amylphenol, and 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole.

[0017] [7] The molding material according to [6], wherein the benzotriazole-based ultraviolet absorber is 2-(2H-benzotriazol-2-yl)-4-methylphenol.

[0018] [8] The molding material according to any one of [1] to [7], wherein the fatty acid 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.

[0019] [9] The molding material according to [8], wherein the fatty acid is one or more selected from palmitic acid, stearic acid, myristic acid, lauric acid, and montanic acid.

[0020]

[10] The molding material according to [9], wherein the fatty acid is palmitic acid.

[0021]

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

[10] , wherein the addition amount of the fatty acid metal salt is 0.0001 part by mass to 0.5 part by mass with respect to 100 parts by mass of the methacrylic resin pellets.

[0022]

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

[11] , wherein the content of the benzotriazole-based ultraviolet absorber is 0.001 part by mass to 0.3 part by mass with respect to 100 parts by mass of the methacrylic resin pellets.

[0023]

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

[12] , wherein when the methacrylic resin pellets contain the fatty acid, the content of the fatty acid is 0.0001 part by mass to 0.5 part by mass with respect to 100 parts by mass of the methacrylic resin pellets, and when the fatty acid is externally added to the methacrylic resin pellets, the content of the fatty acid is 0.0001 part by mass to 0.5 part by mass with respect to 100 parts by mass of the total mass of the methacrylic resin pellets and the fatty acid.

[0024]

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

[13] , wherein the surface area of the methacrylic resin pellets is 10 mm 2 ~450 mm 2 .

[0025]

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

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

[0026]

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

[15] , wherein the molding material is a molding material for stamping, extrusion molding, injection molding, or film molding.

[0027]

[17] An injection molding material, characterized in that it is composed of the molding material according to any one of [1] to

[15] .

[0028]

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

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

[0029]

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

[15] in injection molding.

[0030]

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

[17] .

[0031]

[21] A vehicle component, characterized in that it is molded from the molding material according to any one of [1] to

[17] .

[0032]

[22] An optical component, characterized in that it is molded from the molding material according to any one of [1] to

[17] .

[0033]

[23] A container, characterized in that it is molded from the molding material according to any one of [1] to

[17] .

[0034]

[24] A medical component, characterized in that it is molded from the molding material according to any one of [1] to

[17] .

[0035]

[25] A housing equipment component, characterized in that it is molded from the molding material according to any one of [1] to

[17] .

[0036]

[26] A method for manufacturing a resin molded body, characterized by comprising: molding a molding material obtained by externally adding a fatty acid metal salt to a methacrylic resin pellet, to obtain a resin molded body, wherein the methacrylic resin pellet contains a methacrylic resin, a benzotriazole-based ultraviolet absorber, and a fatty acid.

[0037]

[27] A method for manufacturing a resin molded body, characterized by comprising: molding a molding material obtained by externally adding a fatty acid metal salt and a fatty acid to a methacrylic resin pellet, to obtain a resin molded body, wherein the methacrylic resin pellet contains a methacrylic resin and a benzotriazole-based ultraviolet absorber.

[0038]

[28] The method for manufacturing a resin molded body according to

[26] or

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

[0039] According to the present invention, a methacrylic resin molded body can be provided, which, in a molding material obtained by externally adding a fatty acid metal salt to a methacrylic resin pellet containing a benzotriazole-based ultraviolet absorber, contains a fatty acid in the molding material, can solve the problem of yellowing, has excellent weather resistance, and has a good appearance and hue. Detailed Embodiments

[0040] 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 its gist.

[0041] [Molding Material] The molding material of the present invention is characterized in that it is a molding material obtained by externally adding a fatty acid metal salt to a methacrylic resin pellet containing a methacrylic resin and a benzotriazole-based ultraviolet absorber, and the molding material contains a fatty acid.

[0042] Hereinafter, a molding material obtained by externally adding a fatty acid metal salt to a methacrylic resin pellet containing a methacrylic resin and a benzotriazole-based ultraviolet absorber, and further containing a fatty acid may sometimes be referred to as "the molding material of the present invention". Hereinafter, the methacrylic resin pellet before externally adding a fatty acid metal salt and containing a benzotriazole-based ultraviolet absorber may sometimes be referred to as "the methacrylic resin pellet of the present invention". In addition, hereinafter, the act of making a benzotriazole-based ultraviolet absorber contained in a methacrylic resin pellet may sometimes be referred to as "internal addition", and the act of attaching or coating a fatty acid metal salt to a methacrylic resin pellet may sometimes be referred to as "external addition". Regarding fatty acids, they can be "internally added" to the methacrylic resin pellets, or "externally added" by attaching or coating them onto the methacrylic resin pellets, as long as they are contained in the molding material of the present invention.

[0043] <Principle> Regarding the principle of suppressing yellowing caused by the coexistence of a benzotriazole-based ultraviolet absorber and a fatty acid metal salt by making the molding material contain a fatty acid according to the present invention, the following speculation can be made.

[0044] The principle of improving weather resistance based on the benzotriazole-based ultraviolet absorber is as follows. Through ultraviolet light, a benzotriazole-based compound (e.g., Tinuvin (registered trademark)-P) jumps to an excited state and deactivates to the electronic ground state without accompanying luminescence through an intramolecular hydrogen bond between a phenolic hydroxyl group and a benzotriazolyl group. Through this process, ultraviolet energy is converted into heat energy. That is, by making the benzotriazole-based compound have a phenolic hydroxyl group participating in the intramolecular hydrogen bond within the molecule, ultraviolet degradation can be prevented, and the effect of improving weather resistance can be exerted.

[0045] Thus, since the benzotriazole-based ultraviolet absorber has a phenolic hydroxyl group, when there is a metal species such as a fatty acid metal salt, a coordination formation reaction sometimes occurs, and the metal complex generated by this reaction is considered to be the cause of yellowing.

[0046] It can be considered that the coordination reaction is a reversible reaction. When there is a fatty acid (e.g., palmitic acid) that acts as the conjugate acid of the fatty acid metal salt in such a reaction system, the reaction between the fatty acid metal salt and the benzotriazole-based ultraviolet absorber is inhibited, and as a result, yellowing is inhibited.

[0047] <Molding material> The molding material of the present invention is a material obtained by externally adding a fatty acid metal salt to the methacrylic resin pellets of the present invention. The methacrylic resin pellets of the present invention contain at least a methacrylic resin (having the same meaning as a methacrylic polymer. Hereinafter, the methacrylic resin related to the present invention may sometimes be referred to as "methacrylic polymer") and a benzotriazole-based ultraviolet absorber.

[0048] <Methacrylic polymer> The methacrylic polymer is a polymer having a repeating unit derived from methyl methacrylate (hereinafter, sometimes also referred to as "methyl methacrylate unit") as a main component. By including the methacrylic polymer in the molding material of the present invention, while the transparency of the obtained resin molded body is improved, the thermal decomposition of the resin molded body is suppressed, and good weather resistance and moldability can be achieved. In the present invention, "having a methyl methacrylate unit as a main component" means that, as one mode, the content ratio of the methyl methacrylate unit in the methacrylic polymer (100% by mass) is 50% by mass or more.

[0049] For the above reasons, the content ratio of the methyl methacrylate unit in the methacrylic polymer (100% by mass) contained in the molding material of the present invention is preferably 50% by mass or more. As such a methacrylic polymer, for example, a homopolymer of methyl methacrylate, a copolymer containing 50% by mass or more and less than 100% by mass of methyl methacrylate units and more than 0% by mass and 50% by mass or less of repeating units derived from monomers other than methyl methacrylate (hereinafter, also referred to as "other monomer units") can be cited.

[0050] The monomer other than methyl methacrylate that forms the other monomer units is not particularly limited as long as it can copolymerize with methyl methacrylate. The other monomer may be a monofunctional monomer having 1 polymerizable double bond in one molecule, or a polyfunctional monomer having 2 or more polymerizable double bonds in one molecule. From the viewpoint of excellent balance of fluidity, moldability, and thermal decomposability of the methacrylic polymer, an acrylate is preferably used as the monomer other than methyl methacrylate.

[0051] When the methacrylic polymer contains a repeating unit derived from an acrylate (hereinafter, also referred to as "acrylate unit") as the other monomer unit, in the methacrylic polymer (100% by mass), it is preferably contains 50% by mass or more and less than 100% by mass of methyl methacrylate units and more than 0% by mass and 50% by mass or less of acrylate 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 30% by mass or less of acrylate units, still more preferably contains 80% by mass or more and 99.9% by mass or less of methyl methacrylate units and 0.1% by mass or more and 20% by mass or less of acrylate units, and particularly preferably contains 90% by mass or more and 99.5% by mass or less of methyl methacrylate units and 0.5% by mass or more and 10% by mass or less of acrylate units.

[0052] 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, norbornenyl acrylate, adamantyl acrylate, dicyclopentenyl acrylate, dicyclopentyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, etc. may be mentioned. 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. The acrylate may be used alone or in combination of two or more.

[0053] As another mode of the methacrylic 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 structure unit”) on the main chain may be mentioned. As the ring structure unit, for example, a glutaric anhydride structure unit, a maleic anhydride structure unit, a glutaric imide structure unit, a lactone ring structure unit, and an N-substituted maleimide structure unit may be mentioned. The ring structure unit may be used alone or in combination of two or more.

[0054] The lower limit of the content ratio of the (meth)acrylate unit in the polymer (A) is not particularly limited. From the viewpoint of not impairing the excellent transparency, processability, and mechanical properties of the obtained resin molded body, which are the original properties of the methacrylic resin, the content ratio of the (meth)acrylate unit is preferably 80 mol% or more, more preferably 90 mol% or more, and further preferably 94 mol% or more with respect to the total number of moles (100 mol%) of the repeating units (including structural units, the same applies hereinafter) contained in the polymer (A). The upper limit of the content ratio of the (meth)acrylate unit in the polymer (A) is not particularly limited. From the viewpoint of the excellent heat resistance of the obtained resin molded body, the content ratio 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 with respect to the total number of moles of the repeating units contained in the polymer (A). The above upper limit value and lower limit value can be arbitrarily combined. 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 still more preferably 94 to 99.5 mol% based on the total molar number (100 mol%) of the repeating units contained in the polymer (A).

[0055] The lower limit value of the content ratio of the ring structure unit in the polymer (A) is not particularly limited. From the viewpoint of excellent heat resistance of the obtained resin molded body, the content ratio of the ring structure unit is preferably 0.001 mol% or more, more preferably 0.01 mol% or more, and still more preferably 0.05 mol% or more based on the total molar number (100 mol%) of the repeating units contained in the polymer (A). The upper limit value of the content ratio of the ring structure unit in the polymer (A) is not particularly limited. From the viewpoints of excellent heat resistance of the obtained resin molded body, suppression of molding coloring, excellent molding appearance, and excellent weather resistance, the content ratio of the ring structure unit is preferably 10 mol% or less, more preferably 3 mol% or less, and still more preferably 0.3 mol% or less based on the total molar number (100 mol%) of the repeating units contained in the polymer (A). The above upper limit value and lower limit value can be arbitrarily combined. 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 still more preferably 0.05 to 0.3 mol% based on the total molar number (100 mol%) of the repeating units contained in the polymer (A).

[0056] Among the (meth)acrylates other than methyl methacrylate that form the (meth)acrylate unit, as the acrylate, the acrylates exemplified in the description of the aforementioned methacrylic acid-based polymer can be mentioned. In addition, as the methacrylate other than methyl methacrylate, for example, 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, norbornene methacrylate, adamantyl methacrylate, dicyclopentene methacrylate, dicyclopentyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, etc. can be mentioned. These (meth)acrylates can be used alone or in combination of two or more.

[0057] The polymer (A) may contain structural units derived from monomers having a carboxyl group (hereinafter, also referred to as "monomer units having a carboxyl group"). Some of the monomer units having a carboxyl group can form a ring structure unit, for example, through a cyclization reaction with an ester group, and introduce the ring structure unit into the main chain of the methacrylic polymer. Therefore, the methacrylic polymer may also contain monomer units having a carboxyl group. Examples of the monomer having a carboxyl group include 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. The monomer having a carboxyl group can be used alone or in combination of two or more.

[0058] As one mode of the polymer (A), the following polymers can be mentioned, which contain repeating units (A1) derived from methyl methacrylate (hereinafter, also referred to as "unit (A1)"), repeating units (A2) derived from (meth)acrylic acid (hereinafter, also referred to as "unit (A2)") as (meth)acrylate units, and contain a glutaric anhydride structure unit (A3) (hereinafter, also referred to as "unit (A3)") as a ring structure unit.

[0059] By making the polymer (A) contain the unit (A3), it is easy to improve the heat resistance of the obtained resin molded body. The unit (A3) is shown by the following chemical structural formula.

[0060] [Chemical Formula 1]

[0061] (In the formula, R A and R B each independently represent a hydrogen atom or a methyl group.)

[0062] The lower limit of the content ratio of the unit (A1) in the polymer (A) is not particularly limited. From the viewpoint of not impairing the original properties of the methacrylic resin such as excellent transparency, processability, and mechanical properties of the obtained resin molded body, the content ratio 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 ratio of the unit (A1) in the polymer (A) is not particularly limited. From the viewpoint of excellent heat resistance of the obtained resin molded body, the content ratio 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 limit value and lower limit value can be combined arbitrarily. For example, the content ratio of the unit (A1) in the polymer (A) is preferably 80 to 99.4 mol%, more preferably 90 to 99 mol%, and still more preferably 94 to 98 mol% with respect to the total molar number (100 mol%) of the repeating units contained in the polymer (A).

[0063] As the unit (A2), a methacrylic acid unit is preferred in order to obtain a resin molded body having excellent heat resistance.

[0064] The lower limit value of the content ratio 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 molded body, the content ratio of the unit (A2) in the polymer (A) is preferably 0.5 mol% or more, more preferably 1 mol% or more, and still more preferably 2 mol% or more with respect to the total molar number (100 mol%) of the repeating units contained in the polymer (A). The upper limit value of the content ratio of the unit (A2) in the polymer (A) is not particularly limited. From the viewpoint of not impairing the original properties of the methacrylic resin such as excellent molding appearance, low water absorption, and excellent moldability of the obtained resin molded body, the content ratio of the unit (A2) in the polymer (A) is preferably 20 mol% or less, more preferably 7 mol% or less, and still more preferably 3.5 mol% or less with respect to the total molar number (100 mol%) of the repeating units contained in the polymer (A). The above upper limit value and lower limit value can be combined arbitrarily. For example, the content ratio of the unit (A2) in the polymer (A) is preferably 0.5 to 20 mol%, more preferably 1 to 7 mol%, and still more preferably 2 to 3.5 mol% with respect to the total molar number (100 mol%) of the repeating units contained in the polymer (A).

[0065] The lower limit value of the content ratio 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 ratio of the unit (A3) is preferably 0.001 mol% or more, more preferably 0.01 mol% or more, and still more preferably 0.05 mol% or more with respect to the total molar number (100 mol%) of the repeating units contained in the polymer (A). From the viewpoints of suppressing molding coloring, excellent molding appearance, and excellent weather resistance of the obtained resin molded body, as the upper limit value of the content ratio of the unit (A3) in the polymer (A), the content ratio of the unit (A3) is preferably 10 mol% or less, more preferably 3 mol% or less, and still more preferably 0.3 mol% or less with respect to the total molar number (100 mol%) of the repeating units contained in the polymer (A). The above upper limit value and lower limit value can be combined arbitrarily. For example, the content ratio of the unit (A3) in the polymer (A) relative to the total molar amount (100 mol%) of the repeating units contained in the polymer (A) is, for example, preferably 0.001 to 10 mol%, more preferably 0.01 to 3 mol%, and still more preferably 0.05 to 0.3 mol%.

[0066] The unit (A3) can also be a unit constructed by a cyclization reaction of 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.

[0067] In the present invention, the content of each unit in the methacrylic resin such as the polymer (A) is set to be a value calculated by 1 1H-NMR measurement. Specifically, the method disclosed in International Publication No. 2019 / 013186 can be used.

[0068] The method for producing the methacrylic resin is not particularly limited. For example, bulk polymerization method, suspension polymerization method, emulsion polymerization method, solution polymerization method can be mentioned. From the viewpoint of excellent productivity, bulk polymerization method and suspension polymerization method are preferred.

[0069] In the methacrylic resin, the method for producing the polymer (A) containing the unit (A1), the unit (A2) and the unit (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.

[0070] <Benzotriazole-based ultraviolet absorber> As the benzotriazole-based ultraviolet absorber, there is no particular limitation, and a conventionally known benzotriazole-based ultraviolet absorber can be used.

[0071] Examples of benzotriazole-based ultraviolet absorbers 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-ditertiary amylphenol, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2-(2-hydroxy-3,5-dicumylphenyl)benzotriazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], 2-(2-hydroxy-3,5-ditert-butylphenyl)benzotriazole, 2-(2-hydroxy-3,5-ditert-butylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3,5-ditertiary amylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-butylphenyl)benzotriazole, 2-(2-hydroxy-4-octoxyphenyl)benzotriazole, 2,2'-methylenebis(4-cumyl-6-(2H-benzotriazol-2-yl)phenol), 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-(2-hydroxyethyl)phenol], 2-[2-hydroxy-3-(4,5,6,7-tetrahydro-1,3-dioxo-1H-isoindol-2-ylmethyl)-5-methylphenyl]-2H-benzotriazole, etc. Among them, from the viewpoint of compatibility with methacrylic resins, 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-ditertiary amylphenol, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole are preferred, and 2-(2H-benzotriazol-2-yl)-4-methylphenol is particularly preferred.

[0072] These benzotriazole-based ultraviolet absorbers can be used alone or in combination of two or more.

[0073] These benzotriazole-based ultraviolet absorbers can be commercially available products. For example, Tinuvin (registered trademark) series manufactured by BASF Japan can be used.

[0074] The lower limit and upper limit of the content (internal addition amount) of the benzotriazole-based ultraviolet absorber in the methacrylic resin pellets of the present invention are not particularly limited, but are preferably 0.001 parts by mass or more and 0.3 parts by mass or less with respect to 100 parts by mass of the methacrylic resin pellets. When the content of the benzotriazole-based ultraviolet absorber is above the above lower limit, the effect of improving weather resistance brought by containing the benzotriazole-based ultraviolet absorber can be fully obtained. The content of the benzotriazole-based ultraviolet absorber is more preferably 0.002 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 0.009 parts by mass or more. When the content of the benzotriazole-based ultraviolet absorber is below the above upper limit, the yellowing of the resin molded body caused by containing the benzotriazole-based ultraviolet absorber can be reduced. The content of the benzotriazole-based ultraviolet absorber is more preferably 0.1 part by mass or less, further preferably 0.07 part by mass or less, particularly preferably 0.06 part by mass or less, and most preferably 0.05 part by mass or less. The above upper limit value and lower limit value can be arbitrarily combined. That is, the content of the benzotriazole-based ultraviolet absorber in the methacrylic resin pellets of the present invention is preferably 0.001 part by mass to 0.3 part by mass, more preferably 0.002 part by mass to 0.1 part by mass, further preferably 0.003 part by mass to 0.07 part by mass, particularly preferably 0.005 part by mass to 0.06 part by mass, and most preferably 0.009 part by mass to 0.05 part by mass.

[0075] <Other additives> In the methacrylic resin pellets of the present invention, in addition to the above-mentioned benzotriazole-based ultraviolet absorber, within the range not impairing the effects of the present invention, the following fatty acids can also be contained. Further, one or two or more kinds of various additives usually added to the molding material can also be contained. Examples of such additives include light diffusing agents, 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, fluidity improvers, mold release agents, processing elasticity imparting agents, ultraviolet absorbers other than benzotriazole-based ultraviolet absorbers, etc.

[0076] <Shape / size / surface area> The methacrylic resin pellets of the present invention are, for example, substances supplied to molding machines such as stamping molding, extrusion molding, injection molding, or film molding, and their shape is not particularly limited and can be cylindrical, spherical, dice-shaped, etc.

[0077] There is no particular limitation on the size of the methacrylic resin pellets. For example, when they are cylindrical, the length of the cylinder in the axial direction (axial length) is 1.5 to 6 mm, the major axis length of the face perpendicular to the axial direction is preferably about 1.5 to 5 mm, and the minor axis length of the face perpendicular to the axial direction is preferably about 1.5 to 4.5 mm. When they are of other shapes, it is preferably a size equivalent to the volume of the cylindrical methacrylic resin pellets of the above dimensions.

[0078] There is no particular limitation on the surface area of the methacrylic resin pellets. For example, when they are cylindrical, it is preferably 10 mm 2 ~450 mm 2 , more preferably 30 mm 2 ~300 mm 2 , particularly preferably 40 mm 2 ~200 mm 2 . When they are of other shapes, it is preferably a surface area equivalent to that of the cylindrical methacrylic resin pellets of the above dimensions. When the surface area of the methacrylic resin pellets is within the above range, a fatty acid metal salt can be externally added within a specified range, and a resin molded body with excellent appearance, hue, and weather resistance can be provided.

[0079] <Method for manufacturing methacrylic resin pellets> In order to manufacture the methacrylic resin pellets of the present invention internally added with the aforementioned benzotriazole-based ultraviolet absorber, and also internally added with the following fatty acids when internally adding fatty acids and other additives used as required, when manufacturing the methacrylic resin by a conventional method, the benzotriazole-based ultraviolet absorber is added in a specified proportion into the polymerization reaction tank or the raw material input path of the polymerization reaction tank, and when internally adding fatty acids, the following fatty acids and other additives used as required are also added, and a polymerization reaction is carried out to granulate the reaction product. Alternatively, by adding the prepared methacrylic resin, the benzotriazole-based ultraviolet absorber, and when internally adding fatty acids, the following fatty acids and other additives used as required into a single-screw extruder or a twin-screw extruder in a specified proportion, heating, melting, and kneading, and then granulating, the methacrylic resin pellets of the present invention internally added with these can also be obtained.

[0080] It is also possible to add a part of the benzotriazole-based ultraviolet absorber, and when internally adding fatty acids, the following fatty acids and other additives used as required into the polymerization reaction tank or the path for inputting raw materials into the polymerization reaction tank, and melt-knead the remainder with a single-screw extruder or a twin-screw extruder with respect to the manufactured methacrylic resin.

[0081] <Fatty acid> As the fatty acids contained in the methacrylic resin pellets of the present invention when adding fatty acids internally and the fatty acids contained in the molding material of the present invention when adding fatty acids externally, from the viewpoint of compatibility with the methacrylic resin, saturated fatty acids having 8 to 22 carbon atoms and / or unsaturated fatty acids having 8 to 22 carbon atoms are preferred.

[0082] Examples of the saturated fatty acids having 8 to 22 carbon atoms include caprylic acid (8 carbon atoms), pelargonic acid (9 carbon atoms), capric acid (10 carbon atoms), lauric acid (12 carbon atoms), myristic acid (14 carbon atoms), pentadecanoic acid (15 carbon atoms), palmitic acid (16 carbon atoms), margaric acid (17 carbon atoms), stearic acid (18 carbon atoms), arachidic acid (20 carbon atoms), heneicosanoic acid (21 carbon atoms), behenic acid (22 carbon atoms), etc.

[0083] As unsaturated fatty acids having 8 to 22 carbon atoms, for example, myristoleic 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 acid (20 carbon atoms), dihomo-γ-linolenic acid (20 carbon atoms), eicosatrienoic acid (20 carbon atoms), stearidonic acid (18 carbon atoms), arachidonic acid (20 carbon atoms), eicosatetraenoic acid (20 carbon atoms), adrenic acid (22 carbon atoms), bosseopentaenoic acid (18 carbon atoms), eicosapentaenoic acid (20 carbon atoms), osbond acid (22 carbon atoms), clupanodonic acid (22 carbon atoms), docosahexaenoic acid (22 carbon atoms), etc. can be cited.

[0084] These fatty acids can be used alone or in combination of two or more.

[0085] Among the above fatty acids, from the viewpoint of weather resistance, saturated fatty acids having 8 to 22 carbon atoms are preferred, and from the viewpoint of being less likely to contaminate the mold during molding, palmitic acid, stearic acid, myristic acid, lauric acid or montanic acid is particularly preferred, and palmitic acid is most preferred.

[0086] The lower limit and the upper limit of the content (internal addition amount) of the fatty acid in 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 with respect to 100 parts by mass of the methacrylic resin pellets. When the content of the fatty acid is above the above lower limit, the yellowing inhibition effect brought by containing the fatty acid can be fully obtained. The lower limit value is more preferably 0.005 parts by mass or more, further preferably 0.01 parts by mass or more, particularly preferably 0.03 parts by mass or more, and most preferably 0.05 parts by mass or more. When the content of the fatty acid is below the above upper limit, the mold is not easily contaminated during molding. The upper limit value is more preferably 0.4 parts by mass or less, further preferably 0.3 parts by mass or less, particularly preferably 0.2 parts by mass or less, and most preferably 0.1 parts by mass or less. The above upper limit value and lower limit value can be arbitrarily combined. That is, the content of the fatty acid in the methacrylic resin pellets of the present invention is preferably 0.0001 parts by mass to 0.5 parts by mass, more preferably 0.005 parts by mass to 0.4 parts by mass, further preferably 0.01 parts by mass to 0.3 parts by mass, particularly preferably 0.03 parts by mass to 0.2 parts by mass, and most preferably 0.05 parts by mass to 0.1 parts by mass, based on 100 parts by mass of the methacrylic resin pellets. Even when adding a fatty acid externally to the methacrylic resin pellets, it is only necessary to make the content the same as the above internal addition amount. That is, the proportion of the fatty acid relative to 100 parts by mass of the total of the methacrylic resin pellets and the externally added fatty acid thereto is within the above range.

[0087] As a method for making the molding material of the present invention contain a fatty acid, it is not limited to the following methods. Examples include a method of internally adding a fatty acid to the methacrylic resin pellets, a method of externally adding a fatty acid to the methacrylic resin pellets, or a method of adding a fatty acid in the operation process. For example, the methacrylic resin pellets and the fatty acid are added to the same slurry and then injection molded.

[0088] As a method for internally adding a fatty acid, in the method for internally adding a benzotriazole-based ultraviolet absorber in <the method for manufacturing methacrylic resin pellets>, as described above, a method of using a fatty acid together with the benzotriazole-based ultraviolet absorber can be cited. As a method for externally adding a fatty acid, in the method for externally adding a fatty acid metal salt in <the method for manufacturing the molding material> described below, a method of using a fatty acid together with the fatty acid metal salt can be cited. Among them, the method for internally adding and / or externally adding a fatty acid is not limited to such a method. Regardless of any method, the yellowing inhibition effect can be fully obtained by making the molding material of the present invention contain a fatty acid.

[0089] <fatty acid metal salt> As the metal species of the fatty acid metal salt externally added to the methacrylic resin pellets of the present invention, from the viewpoint of easy availability, metals with a valence of 1 to 3 are preferred, metals with a valence of 1 to 2 are particularly preferred, and metals with a valence of 1 are especially preferred.

[0090] Specific examples of the metal of the fatty acid metal salt include Li, Na, Mg, Ca, Al, Ba, K, Zn, etc. Among them, since the compatibility with the methacrylic resin is high and the resulting resin molded body is not likely to become foggy, Li, Na, Mg, Ca, Al, Ba, and K are preferred. From the viewpoint of improving the appearance of the resulting resin molded body, Li is particularly preferred.

[0091] As the fatty acid constituting the fatty acid metal salt, the same fatty acids as those exemplified as the fatty acids contained in the molding material of the present invention can be cited, and the preferred fatty acids are also the same.

[0092] As the fatty acid of the fatty acid metal salt, from the viewpoint of easy availability, palmitic acid, stearic acid, myristic acid, lauric acid, or montanic acid is preferred, and stearic acid is particularly preferred.

[0093] As the fatty acid metal salt, from the viewpoint of improving the appearance of the resulting resin molded body, lithium stearate is most preferred.

[0094] These fatty acid metal salts can be used alone or in combination of two or more.

[0095] The lower limit and upper limit of the amount of the fatty acid metal salt externally added to the methacrylic resin pellets of the present invention are not particularly limited, and preferably 0.0001 part by mass or more and 0.5 part by mass or less with respect to 100 parts by mass of the methacrylic resin pellets. When the addition amount of the fatty acid metal salt is above the above lower limit, the effect of improving the appearance of the resulting resin molded body can be further effectively obtained through the effect of improving the plasticizing behavior during molding brought about by the fatty acid metal salt. This lower limit value is more preferably 0.001 part by mass or more, further preferably 0.003 part by mass or more, particularly preferably 0.005 part by mass or more, and most preferably 0.01 part by mass or more. When the addition amount of the fatty acid metal salt is below the above upper limit, it is not likely to cause contamination of the mold or the resin molded body due to the remaining fatty acid metal salt on the mold surface during demolding. This upper limit value is more preferably 0.3 part by mass or less, further preferably 0.2 part by mass or less, particularly preferably 0.1 part by mass or less, and most preferably 0.05 part by mass or less. The above upper limit value and lower limit value can be arbitrarily combined. That is, the addition amount of the fatty acid metal salt is preferably 0.0001 to 0.5 parts by mass, more preferably 0.001 to 0.3 parts by mass, still more 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 with respect to 100 parts by mass of the methacrylic resin pellets.

[0096] <Method for manufacturing a molding material> As a method for manufacturing the molding material of the present invention in which a fatty acid metal salt or a fatty acid metal salt and a fatty acid are externally added, there is no particular limitation as long as it is externally added to the methacrylic resin pellets of the present invention in a state where the fatty acid metal salt is not chemically bonded. For example, a dry blend method can be cited, a method of spraying or adding a powder of a fatty acid metal salt (or a fatty acid metal salt and a fatty acid) to the methacrylic resin pellets of the present invention using a stirring device and stirring, or a method of dispersing the methacrylic resin pellets of the present invention in a liquid containing a fatty acid metal salt (or a fatty acid metal salt and a fatty acid) and then removing the solvent on the surface of the pellets.

[0097] As a dry blend method, for example, a method of mixing the methacrylic resin pellets of the present invention and a fatty acid metal salt using a mixer such as a conventional ribbon blender, tumbler, Nauta mixer, or henschel mixer can be cited.

[0098] As an example of the stirring device used for spraying and stirring, a device can be cited which includes a bottom cylindrical container, a screw that rotates and revolves along the inner wall surface of the container, and a spraying means for spraying a fatty acid metal salt (or a fatty acid metal salt and a fatty acid) onto the methacrylic resin pellets introduced into the container. As the spraying means, for example, a nozzle for spraying a fatty acid metal salt (or a fatty acid metal salt and a fatty acid) can be cited. The spraying means may also have a heating means such as a heater for heating the fatty acid metal salt (or a fatty acid metal salt and a fatty acid).

[0099] The methacrylic resin pellets of the present invention are introduced into the container of such a stirring device, and under stirring, the fatty acid metal salt (or a fatty acid metal salt and a fatty acid) is made into a powder, liquid, or molten state by the spraying means and sprayed onto the methacrylic resin pellets in the container so as to adhere thereto. Then, the spray and the molding material attached with a fatty acid metal salt (or a fatty acid metal salt and a fatty acid) are further stirred evenly by a screw that rotates and revolves along the inner wall surface of the container. Thus, the fatty acid metal salt (or the fatty acid metal salt and the fatty acid) can be externally added to the methacrylic resin pellets evenly.

[0100] In order to externally add the fatty acid metal salt (or the fatty acid metal salt and the fatty acid) to the methacrylic resin pellets more evenly, preferably, the temperature inside the container is changed according to the type of the fatty acid metal salt (or the fatty acid metal salt and the fatty acid). For example, by raising the temperature inside the container to about 60 to 80 °C, the uniform external addition property of the fatty acid metal salt (or the fatty acid metal salt and the fatty acid) can be improved. As a method for changing the temperature inside the container, for example, methods such as introducing a heated inert gas into the container, heating the inside of the container with a heater, and controlling the temperature by introducing a heat medium into the jacket layer of the container can be cited.

[0101] As a method for dispersing the methacrylic resin pellets of the present invention in a liquid containing a fatty acid metal salt (or a fatty acid metal salt and a fatty acid) and then removing the solvent on the surface of the methacrylic resin pellets, for example, methods such as preparing a solution or dispersion in which the total addition amount of the fatty acid metal salt (or the fatty acid metal salt and the fatty acid) to the solvent is 0.05 to 1% by mass, spraying it onto the methacrylic resin pellets, or putting the methacrylic resin pellets into the liquid for treatment can be cited.

[0102] As a method for coating the methacrylic resin pellets with the fatty acid metal salt (or the fatty acid metal salt and the fatty acid) by spraying a liquid containing the fatty acid metal salt (or the fatty acid metal salt and the fatty acid), for example, methods such as arranging the methacrylic resin pellets on a transfer device such as a conveyor belt and continuously spraying the liquid containing the fatty acid metal salt (or the fatty acid metal salt and the fatty acid) when they pass through a sprayer can be cited.

[0103] As a method for externally adding the fatty acid metal salt (or the fatty acid metal salt and the fatty acid) to the methacrylic resin pellets by putting the methacrylic resin pellets of the present invention into a liquid containing the fatty acid metal salt (or the fatty acid metal salt and the fatty acid), it can be implemented by a generally well-known method. For example, a liquid containing the fatty acid metal salt (or the fatty acid metal salt and the fatty acid) and the methacrylic resin pellets are put into a mixing tank equipped with a stirrer, and they are mixed at a temperature of 0 °C to below the boiling point of the solvent for a specified time, and the methacrylic resin pellets and the liquid are separated by methods such as filtration.

[0104] Then, hot air is blown or hot air is supplied as needed to dry the solvent. At this time, since the fatty acid metal salt (or the fatty acid metal salt and the fatty acid) does not volatilize, it directly remains on the surface of the methacrylic resin pellets. Therefore, after drying, the molded material of the present invention with the fatty acid metal salt (or the fatty acid metal salt and the fatty acid) added externally can be obtained.

[0105] As the solvent, commonly used solvents can be used. As the solvent, it is preferably a solvent in which the methacrylic resin is insoluble or in which almost no dissolution is observed, depending on the composition of the methacrylic resin in the methacrylic resin pellets. Examples of such a solvent include water. As a preferred solvent, from the viewpoints of good efficiency and workability of the drying process, a solvent having a boiling point of 30°C to 150°C under normal pressure is preferred, and water is particularly preferred in consideration of cost and safety.

[0106] [Resin molded body] The resin molded body of the present invention is a molded body formed by molding the molded 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, such as stamping molding, injection molding, gas-assisted injection molding, welding molding, extrusion molding, blow molding, film molding, hollow molding, multi-layer 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 characteristics.

[0107] Therefore, the molded material of the present invention is preferably used as a molded material for stamping molding, extrusion molding, injection molding or film molding (also refers to being used for stamping molding, extrusion molding, injection molding or film molding), and particularly preferably used as a molded material for injection molding (also refers to being used for injection molding).

[0108] Specific examples of the resin molded body of the present invention include interior and exterior trim materials for vehicles such as taillight covers, headlight covers, instrument panels, pillar trims, front grilles, and vehicle emblems; building components; residential equipment such as washbasins, bathtubs, and flush toilets; optical components such as lenses and light guides; containers for cosmetics; medical components such as cuvettes, etc. Among them, the resin molded body of the present invention is particularly preferably used for vehicle components, optical components, containers, medical components, residential equipment components, cosmetic containers, etc. due to its excellent appearance, weather resistance, transparency, and chemical resistance. Examples

[0109] The following examples are given to specifically illustrate the present invention.

[0110] [Raw materials used] The raw materials used in the following examples and comparative examples are as described below.

[0111] <Methacrylic resin> PMMA: Methacrylic resin "ACRYPET (registered trademark) VH" manufactured by Mitsubishi Chemical Corporation <Fatty acid> Palmitic acid: "LUNAC P-95" manufactured by Kao Corporation Stearic acid: "LUNAC S-98" manufactured by Kao Corporation <Metal salt of fatty acid> Lithium stearate: "Lithium stearate" manufactured by Kawamura Kasei Kogyo Co., Ltd. (recorded as "Stearic acid Li" in Table 1.) Sodium stearate: "Sodium stearate" manufactured by Kawamura Kasei Kogyo Co., Ltd. (recorded as "Stearic acid Na" in Table 1.) Calcium stearate: "Calcium stearate" manufactured by Kawamura Kasei Kogyo Co., Ltd. (recorded as "Stearic acid Ca" in Table 1.) Aluminum stearate: "ARUSUTE #30" manufactured by Kawamura Kasei Kogyo Co., Ltd. (recorded as "Stearic acid Al" in Table 1.) Magnesium stearate: "Mg-St" manufactured by Nitto Kasei Kogyo Co., Ltd. (recorded as "Stearic acid Mg" in Table 1.) <Other aliphatic compounds> Stearamide: "NEUTRON-2" manufactured by Nippon Seika Co., Ltd. Stearyl alcohol: "KALCOL 8098" manufactured by Kao Corporation Monoglyceryl stearate: "RIKEMAL S-100" manufactured by Riken Vitamin Co., Ltd. <Benzotriazole-based ultraviolet absorber> "Tinuvin (registered trademark)-P" 2-(2H-benzotriazol-2-yl)-4-methylphenol manufactured by BASF Japan Ltd.

[0112] [Evaluation method] The evaluation methods for the resin molded bodies manufactured in the following Examples and Comparative Examples are as described below.

[0113] (1) Appearance Visually confirm the resin molded body test piece, and evaluate based on the number of occurrences of silver streaks (appearance defect) using the following criteria. ○: Among 10 test pieces, the number of test pieces with silver streaks is 2 or less ×: Among 10 test pieces, the number of test pieces with silver streaks is 3 or more

[0114] (2) Hue For the resin molded test piece, using a spectrophotometer "U-4100" manufactured by Hitachi High-Technologies Corporation, in the light transmission mode, according to JIS K7105, the yellow index (YI) value with an optical path length of 140 mm was measured by the C light source light transmission method. Three test pieces were measured, and the calculated average value was evaluated according to the following criteria. ○: The YI value is less than 10.0 ×: The YI value is 10.0 or more

[0115] (3) Weather resistance The following accelerated exposure test was performed on the resin molded test piece, and the L*, a*, and b* after the test were measured to obtain the color difference ΔE*ab. <Accelerated exposure test> The accelerated exposure test was carried out using an "EYE SUPER UV TESTER" manufactured by Iwasaki Electric Co., Ltd. Specifically, the injection molded test piece produced in the appearance evaluation was cut, and the resin molded test piece (50 mm × 50 mm × 4 mm) was set in the evaluation chamber, and ultraviolet rays with a wavelength of 300 - 400 nm and an irradiation intensity of 150 mW / m 2 were irradiated from the EYE SUPER UV TESTER. By adjusting the irradiation position every 25 hours, the test piece was uniformly irradiated with UV. For the test pieces before and after the test, a spectrophotometer (model name "U-4100", manufactured by Hitachi High-Technologies) was used to measure L*, a*, and b* in an optical path length of 4.0 mm, and the color difference ΔE*ab was obtained and judged according to the following criteria. ○: The ΔE*ab value is less than 3.0 ×: The ΔE*ab value is 3.0 or more

[0116] [Example 1] In such a way that the contents of palmitic acid and Tinuvin-P in 100 parts by mass of the obtained methacrylic resin pellets are the contents shown in Table 1, PMMA, palmitic acid as a fatty acid, and a benzotriazole-based ultraviolet absorber (Tinuvin-P) were used, and these were supplied to a twin-screw extruder (model name "TEM35", manufactured by Shibaura Machine Co., Ltd.), and melt-kneaded at a cylinder temperature of 250 °C of the extruder to obtain methacrylic resin pellets containing a fatty acid and a benzotriazole-based ultraviolet absorber at a mold temperature of 60 °C. The methacrylic resin pellets are cylindrical with a major axis length of 3.2 mm and an axis length of 3.0 mm in the direction perpendicular to the axis direction (surface area 46 mm 2 ). Lithium stearate as a fatty acid metal salt was externally added to the obtained methacrylic resin pellets containing a fatty acid and a benzotriazole-based ultraviolet absorber by the following method. The methacrylic resin pellets dried at 80 °C for 16 hours or more and powdery lithium stearate were charged into a polyethylene bag in an amount of 0.005 parts by mass relative to 100 parts by mass of the methacrylic resin pellets, and mixed by hand for 1 minute to obtain a molding material obtained by externally adding lithium stearate to the methacrylic resin pellets containing a fatty acid and a benzotriazole-based ultraviolet absorber in the external addition amount shown in Table 1.

[0117] After the obtained molding material was hot air dried at 80 °C for about 16 hours, injection molding was carried out under the following conditions to manufacture 20 test pieces of resin molded bodies, and the evaluations of the above (1) to (3) were carried out. · Injection molding machine: Model name: EC75-SXII, manufactured by Shibaura Machine Co., Ltd. · Mold: Mold for plate-shaped molded body of 120 mm × 140 mm × 4 mm · Cylinder temperature: 230 °C · Temperature under the hopper: 50 °C · Mold temperature: 60 °C · Cycle time: 60 seconds · Screw rotation speed: 90 rpm · Back pressure: 10 MPa The evaluation results are shown in Table 1.

[0118] [Examples 2 and 3] Except that the external addition amount of lithium stearate was changed as described in Table 1, test pieces of resin molded bodies were manufactured in the same manner as in Example 1, and evaluations were carried out in the same manner. The results are shown in Table 1.

[0119] [Examples 4 and 6 to 8] Except that a fatty acid metal salt shown in Table 1 was used instead of lithium stearate and externally added in the external addition amount shown in Table 1, test pieces of resin molded bodies were manufactured in the same manner as in Example 1, and evaluations were carried out in the same manner. The results are shown in Table 1.

[0120] [Example 5] The content of Tinuvin-P in 100 parts by mass of the obtained methacrylic resin pellets was made to be the content shown in Table 1, and PMMA and a benzotriazole-based ultraviolet absorber (Tinuvin-P) were used to obtain methacrylic resin pellets containing a benzotriazole-based ultraviolet absorber in the same manner as in Example 1. Using the same method as in Example 1, palmitic acid as a fatty acid and lithium stearate as a metal salt of a fatty acid were externally added to the obtained methacrylic resin pellets containing a benzotriazole-based ultraviolet absorber in the amounts shown in Table 1 to obtain a molding material. A test piece of a resin molded body was produced in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 1.

[0121] [Example 9] A test piece of a resin molded body was produced in the same manner as in Example 5, except that stearic acid was used instead of palmitic acid, and evaluated in the same manner. The results are shown in Table 1.

[0122] [Comparative Example 1] Except that PMMA was not kneaded with a fatty acid and a benzotriazole-based ultraviolet absorber and directly pelletized, and lithium stearate was externally added to the obtained methacrylic resin pellets containing no fatty acid and benzotriazole-based ultraviolet absorber in the amounts shown in Table 1 in the same manner as in Example 1, a test piece of a resin molded body was produced in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 1.

[0123] [Comparative Example 2] Except that PMMA was not kneaded with a benzotriazole-based ultraviolet absorber and only kneaded with a fatty acid, and lithium stearate was externally added to the obtained methacrylic resin pellets containing a fatty acid in the amounts shown in Table 1 in the same manner as in Example 1, a test piece of a resin molded body was produced in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 1.

[0124] [Comparative Example 3] Except that PMMA was not kneaded with a fatty acid and only kneaded with a benzotriazole-based ultraviolet absorber, and lithium stearate was externally added to the obtained methacrylic resin pellets containing a benzotriazole-based ultraviolet absorber in the amounts shown in Table 1 in the same manner as in Example 1, a test piece of a resin molded body was produced in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 1.

[0125] [Comparative Example 4] Except that PMMA was not kneaded with a fatty acid and only kneaded with a benzotriazole-based ultraviolet absorber, and lithium stearate was not externally added to the obtained methacrylic resin pellets containing a benzotriazole-based ultraviolet absorber and was directly supplied for injection molding, a test piece of a resin molded body was produced in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 1.

[0126] [Comparative Example 5] Except for not adding lithium stearate externally to the methacrylic resin pellets containing fatty acids and benzotriazole-based ultraviolet absorbers and supplying them for injection molding, test pieces of resin molded bodies were manufactured in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 1.

[0127] [Comparative Example 6] Except for not kneading PMMA with fatty acids and only kneading benzotriazole-based ultraviolet absorbers, palmitic acid as a fatty acid was externally added to the obtained methacrylic resin pellets containing benzotriazole-based ultraviolet absorbers in the external addition amounts shown in Table 1 by the same method as in Example 1 to obtain a molding material, and test pieces of resin molded bodies were manufactured in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 1.

[0128] [Comparative Examples 7 - 9] Except for not kneading PMMA with fatty acids and only kneading benzotriazole-based ultraviolet absorbers, and externally adding the aliphatic compounds described in Table 1 to the obtained methacrylic resin pellets containing benzotriazole-based ultraviolet absorbers in the external addition amounts shown in Table 1 instead of lithium stearate, test pieces of resin molded bodies were manufactured in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 1.

[0129] [Comparative Example 10] Except for kneading PMMA with monoglyceryl stearate and benzotriazole-based ultraviolet absorbers instead of fatty acids, and externally adding lithium stearate to the obtained methacrylic resin pellets containing monoglyceryl stearate and benzotriazole-based ultraviolet absorbers in the external addition amounts shown in Table 1, test pieces of resin molded bodies were manufactured in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 1.

[0130] [Comparative Example 11] Except for not kneading PMMA with fatty acids, kneading lithium stearate and benzotriazole-based ultraviolet absorbers, and not externally adding lithium stearate to the obtained methacrylic resin pellets containing fatty acid metal salts and benzotriazole-based ultraviolet absorbers, test pieces of resin molded bodies were manufactured in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 1.

[0131] [Table 1]

[0132] As can be seen from Table 1, for the molding materials of the present invention in which benzotriazole-based ultraviolet absorbers are internally added and fatty acids or fatty acid metal salts are internally or externally added, resin molded bodies with excellent appearance, hue, and weather resistance can be obtained. In contrast, even when lithium stearate is added externally, the weather resistance is poor in the molding material of Comparative Example 1 that does not contain a benzotriazole-based ultraviolet absorber and fatty acid in the molding material. Even when only fatty acid is added internally as in Comparative Example 2, the weather resistance is not improved. In the molding material of Comparative Example 3 where only a benzotriazole-based ultraviolet absorber is added internally and lithium stearate is added externally, since the benzotriazole-based ultraviolet absorber coexists with the metal salt, there is a problem of yellowing and the hue is poor. In the molding material of Comparative Example 4 where only a benzotriazole-based ultraviolet absorber is contained in the methacrylic resin pellets and lithium stearate is not added externally, although there is no problem of yellowing, the plasticizing characteristics during injection molding are poor, and as a result, poor appearance (silver streaks) is caused. Even when fatty acid is added internally to the methacrylic resin pellets as in Comparative Example 5, or when fatty acid is added externally as in Comparative Example 6, the poor appearance is not improved. In addition, even when an aliphatic compound other than a fatty acid metal salt is added externally as in Comparative Examples 7 to 9, the poor appearance is not improved. Even when the methacrylic resin pellets contain an aliphatic compound that is not a fatty acid as in Comparative Example 10, the yellowing is not improved. As in Comparative Example 11, in the state where a fatty acid metal salt is not added internally to the methacrylic resin pellets, the poor appearance is not improved. In addition, in Comparative Example 11, by adding a fatty acid metal salt internally to the methacrylic resin pellets, foreign matter was mixed in during the formation of the test piece, and a molded body for which color tone and weather resistance could be evaluated was not obtained, making it difficult to measure.

[0133] As described above, according to the present invention, in a molding material in which a fatty acid metal salt is added externally to methacrylic resin pellets to improve appearance, and a benzotriazole-based ultraviolet absorber is added internally to the methacrylic resin pellets to improve weather resistance, by adding it internally or externally to contain a fatty acid, a resin molded body excellent in appearance, color tone, and weather resistance can be provided.

[0134] Although the present invention has been described in detail using a specific method, those skilled in the art know that various changes can be made within the range that can achieve the effects of the invention. This application is based on Japanese Patent Application 2022-166335 filed on October 17, 2022, and the whole of it is incorporated by reference.

Claims

1. A molding material, characterized in that it is a molding material obtained by externally adding a fatty acid metal salt to a methacrylic resin pellet containing a methacrylic resin and a benzotriazole-based ultraviolet absorber, and the molding material contains a fatty acid.

2. The molding material according to claim 1, wherein the metal of the fatty acid metal salt is a metal with a valence of 1 to 3.

3. The molding material according to claim 2, wherein the metal of the fatty acid metal salt is a monovalent metal.

4. The molding material according to claim 2, wherein the metal of the fatty acid metal salt is one or more selected from Li, Na, Mg, Ca, Ba, K, and Al.

5. The molding material according to claim 4, wherein the metal of the fatty acid metal salt is Li.

6. The molding material according to claim 1, 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-ditert-amylphenol, and 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole.

7. The molding material according to claim 6, wherein the benzotriazole-based ultraviolet absorber is 2-(2H-benzotriazol-2-yl)-4-methylphenol.

8. The molding material according to claim 1, wherein the fatty acid 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.

9. The molding material according to claim 8, wherein the fatty acid is one or more selected from palmitic acid, stearic acid, myristic acid, lauric acid, and montanic acid.

10. The molding material according to claim 9, wherein the fatty acid is palmitic acid.

11. The molding material according to claim 1, wherein the externally added amount of the fatty acid metal salt is 0.0001 to 0.5 parts by mass relative to 100 parts by mass of the methacrylic resin pellet.

12. The molding material according to claim 1, wherein the content of the benzotriazole-based ultraviolet absorber is 0.001 to 0.3 parts by mass relative to 100 parts by mass of the methacrylic resin pellet.

13. The molding material according to claim 1, wherein when the methacrylic resin pellet contains the fatty acid, the content of the fatty acid is 0.0001 to 0.5 parts by mass relative to 100 parts by mass of the methacrylic resin pellet, and when the fatty acid is externally added to the methacrylic resin pellet, the content of the fatty acid is 0.0001 to 0.5 parts by mass relative to 100 parts by mass of the total mass of the methacrylic resin pellet and the fatty acid.

14. The molding material according to claim 1, wherein The surface area of the methacrylic resin pellets is 10 mm 2 to 450 mm 2 .

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

16. The molding material according to any one of claims 1 to 15, wherein, the molding material is a molding material for stamping, extrusion molding, injection molding or film molding.

17. A molding material for injection molding, characterized in that, it is composed of the molding material according to any one of claims 1 to 15.

18. Use of the molding material according to any one of claims 1 to 15 in stamping, extrusion molding, injection molding or film molding.

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

20. A resin molded body, characterized in that, it is molded from the molding material according to any one of claims 1 to 15.

21. A vehicle component, characterized in that, it is molded from the molding material according to any one of claims 1 to 15.

22. An optical component, characterized in that, it is molded from the molding material according to any one of claims 1 to 15.

23. A container, characterized in that, it is molded from the molding material according to any one of claims 1 to 15.

24. A medical component, characterized in that, it is molded from the molding material according to any one of claims 1 to 15.

25. A housing equipment component, characterized in that, it is molded from the molding material according to any one of claims 1 to 15.

26. A method for manufacturing a resin molded body, characterized in that, comprising: molding a molding material obtained by externally adding a fatty acid metal salt to methacrylic resin pellets to obtain a resin molded body, wherein the methacrylic resin pellets contain a methacrylic resin, a benzotriazole-based ultraviolet absorber and a fatty acid.

27. A method for manufacturing a resin molded body, characterized in that, comprising: molding a molding material obtained by externally adding a fatty acid metal salt and a fatty acid to methacrylic resin pellets to obtain a resin molded body, wherein the methacrylic resin pellets contain a methacrylic resin and a benzotriazole-based ultraviolet absorber.

28. The method for manufacturing a resin molded body according to claim 26 or 27, wherein, injecting and molding the molding material to obtain the resin molded body.

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