Molded body

Abstract

To provide a technique for producing a molded body with improved color tone comprising a resin composition containing a transparent resin and an antioxidant having no hydroxyl groups.SOLUTION: A molded body comprising a resin composition containing a transparent resin and an antioxidant having no hydroxyl groups is provided, where the molded body contains 0.01 pts.mass or more of the antioxidant having no hydroxyl groups and contains no or less than 0.01 pts.mass of an antioxidant having a hydroxyl group per 100 pts.mass of the transparent resin. When irradiated with light from a light-emitting diode light source having a peak emission wavelength in a range of 390 to 460 nm at an integrated light intensity of 1.9 W hr / cm2, the molded body exhibits a decrease in average gram absorption coefficient of 30% or less for light of 400-500 nm wavelength after irradiation.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a molded article. [Background technology]

[0002] Traditionally, glass has been used for optical components such as lenses and prisms, but in recent years, plastics have come to be used in response to the need for greater design freedom, such as lighter and smaller sizes and aspherical lenses. Generally, transparent optical resins such as methacrylic resins, polycarbonates, cyclic olefin resins, and styrene resins are known to be used in optical components.

[0003] Furthermore, in recent years, higher optical performance has been required in various fields, including optical and automotive applications, and the level of requirements for the properties of substrate materials has also been increasing. On the other hand, high-definition optical components such as lenses and prisms require large amounts of thermal energy to be applied during molding, but because they tend to accumulate heat, heat-induced oxygen radicals cause resin degradation and coloration.

[0004] Visible light transparency is a particularly important performance of resins for transparent optical materials, and various methods have been used to improve the coloration. Generally, methods for inhibiting coloration and preventing yellowing include blending various antioxidants in the process of hot melting and molding or the process of melting the resin and stretching it into fibers. Known antioxidants for preventing coloration due to deterioration of synthetic resins include phenol-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants.

[0005] However, it is known that phenolic antioxidants having a phenol skeleton are oxidized and converted into carbonyl compounds with conjugated double bonds such as quinone structures or stilbene quinone structures during storage or when used in a melted state, causing the antioxidants themselves to turn yellow or brown (yellowing phenomenon).Furthermore, with regard to phosphorus-based antioxidants, components produced by thermal decomposition also cause similar coloring due to yellowing.

[0006] As means for suppressing the yellowing phenomenon of the antioxidant, for example, a method of using a phenolic antioxidant in combination with an organic phosphite compound (Patent Document 1 and Patent Document 2), a method of using a phenolic antioxidant in combination with a dihydrooxaphosphaphenanthrene phosphorus compound (Patent Document 3), a method of using a phenolic antioxidant in combination with a polyol or a fatty acid ester of a polyol (Patent Document 4 and Patent Document 5), and a method of using a phenolic antioxidant in combination with an amide compound (Patent Document 6) have been proposed. However, none of these methods can be said to be sufficient in preventing the yellowing of the antioxidant after high-temperature molding. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 50-52152 [Patent Document 2] Japanese Patent Application Publication No. 50-139836 [Patent Document 3] Patent No. 3669032 [Patent Document 4] Japanese Patent Application Publication No. 58-213036 [Patent Document 5] Japanese Patent Application Publication No. 62-252443 [Patent Document 6] Patent No. 3296051 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a molded article having an improved color tone, which contains a resin composition comprising a transparent resin and an antioxidant having no hydroxyl group. [Means for solving the problem]

[0009] The present inventors conducted extensive research to solve the problems of the prior art described above and found that yellowing components derived from antioxidants generated during thermal processing are one of the main causes of color deterioration in resin molded articles containing a transparent resin and an antioxidant. Furthermore, the use of an antioxidant without a hydroxyl group can also suppress color changes at room temperature in resin compositions after color improvement. The present invention is effective regardless of the type of transparent resin and can be equally applied to resin molded articles containing a transparent resin and an antioxidant without a hydroxyl group. Therefore, it can be suitably used in resin molded articles for transparent optical materials, where transparency is particularly important.

[0010] That is, the present invention is as follows. (1) A molded article containing a resin composition including a transparent resin and an antioxidant not having a hydroxyl group, wherein the resin composition contains 0.01 part by mass or more of the antioxidant not having a hydroxyl group per 100 parts by mass of the transparent resin, and the resin composition contains no antioxidant having a hydroxyl group or the content of the antioxidant having a hydroxyl group is less than 0.01 part by mass, and the molded article is provided with a light emitting diode light source having an emission peak wavelength of 390 nm to 460 nm with an integrated light intensity of 1.9 W hr / cm. 2 When irradiated so as to satisfy the above condition, the rate of decrease in the average gram absorption coefficient before and after irradiation with light having a wavelength of 400 nm to 500 nm is 30% or less. (2) The molded article according to (1), further comprising 0.01 parts by mass or more and 5 parts by mass or less of the antioxidant not having a hydroxyl group, based on 100 parts by mass of the transparent resin. (3) The molded article according to (1) or (2), wherein the antioxidant having no hydroxyl group is a phosphorus-based antioxidant. (4) The molded article according to any one of (1) to (3), characterized in that the transparent resin is one or more selected from the group consisting of acrylic resin, methacrylic resin, polycarbonate resin, polycycloolefin resin, polyolefin resin, polyether resin, ene-thiol resin, epoxy resin, polyamide resin, polyimide resin, polyurethane resin and polyester resin. (5) A molded body according to any one of (1) to (4), characterized in that when the molded body is heated at 90°C for 24 hours, the increase rate of the average gram absorption coefficient for light with a wavelength of 400 nm to 500 nm before and after heating is 90% or less. (6) The molded body according to any one of (1) to (5), wherein the average gram absorption coefficient of a 15 w / v% chloroform solution of the molded body measured using a 10 cm optical path length cell for light with a wavelength of 400 nm to 500 nm is 0.40 or less. [Effects of the Invention]

[0011] According to the present invention, a molded article having an improved color tone can be obtained, which contains a resin composition comprising a transparent resin and an antioxidant having no hydroxyl group. [Brief explanation of the drawings]

[0012] [Figure 1] Figure 1 shows the UV-vis spectra of a commercially available antioxidant (Irgafos 168) for the following antioxidants: an antioxidant that was not heated or irradiated ("untreated"), an antioxidant that was heated at 250°C for 10 minutes ("before light irradiation"), and an antioxidant that was heated at 250°C for 10 minutes and then irradiated with 445 nm light at an integrated light intensity of 7.5 W·hr / cm2 ("after light irradiation"). DETAILED DESCRIPTION OF THE INVENTION

[0013] Below, we will explain in detail the form for implementing the present invention (hereinafter referred to as the ``present embodiment''), but the present invention is not limited to the following description and can be implemented in various modifications within the scope of its gist.

[0014] (Resin composition) The resin composition of this embodiment is a resin composition containing a transparent resin and an antioxidant. Furthermore, the resin composition is preferably composed of a transparent resin, an antioxidant, and various additives, and the proportion of the transparent resin in 100 parts by mass of the resin composition is, for example, 90 to 99.9 parts by mass, and preferably 95 to 99.9 parts by mass.

[0015] The resin composition of this embodiment can be suitably processed by various methods, such as melt extrusion, injection molding, film molding, etc. The thermal history experienced during processing varies depending on the processing method, ranging from several tens of seconds, as in an extruder, to several tens of minutes to several hours, as in the molding of thick-walled products or sheet molding. When the resin composition is subjected to a long thermal history, it is necessary to increase the amount of antioxidant added to obtain the desired thermal stability.

[0016] -Transparent resin- The transparent resin of this embodiment is not limited and may be any of various conventionally known resins that transmit light in the visible light range. The weight average molecular weight (Mw) of the resin may be, for example, 3,000 or more and 500,000 or less.

[0017] Specific examples of transparent resins include acrylic resins, methacrylic resins, polyolefin resins, polycycloolefin resins, polycarbonate resins, polyester resins, polyether resins, enethiol resins, epoxy resins, polyamide resins, polyimide resins, polyurethane resins, polysulfone resins, polyphenylene sulfide resins, polystyrene resins, cellulose resins, and silicone resins. These resins can be used alone or in combination of two or more. Commercially available transparent resins may also be used. The present invention is particularly suitable for transparent resins that have high visible light transparency and are processed at high temperatures, and therefore is suitable for applications that involve a process of heating and kneading additives at high temperatures or a process of molding at high temperatures. From the above-mentioned viewpoint, the following resins are preferred as transparent resins.

[0018] --Acrylic resin, methacrylic resin-- The acrylic or methacrylic resin may be any conventionally known acrylic or methacrylic resin as long as it has a (meth)acrylic acid (ester) unit as a constituent unit. Examples include polymethacrylic acid esters such as polymethyl methacrylate, methyl methacrylate-(meth)acrylic acid copolymers, methyl methacrylate-(meth)acrylic acid ester copolymers, methyl methacrylate-acrylic acid ester-(meth)acrylic acid copolymers, methyl (meth)acrylate-styrene copolymers (such as MS resins), polymers having alicyclic hydrocarbon groups (such as methyl methacrylate-cyclohexyl methacrylate copolymers and methyl (meth)acrylate-norbornyl (meth)acrylate copolymers), and copolymers of methyl methacrylate with maleimide-based monomers. Examples of such resins include (see JP 2013-033237 A and WO 2013 / 005634 A), (meth)acrylic resins having a ring structure in the molecule (see WO 2005 / 108438 A and JP 2009-197151 A), (meth)acrylic resins with a high glass transition temperature obtained by intramolecular crosslinking or intramolecular cyclization reaction, and (meth)acrylic resins having a lactone ring structure (see JP 2000-230016 A, JP 2001-151814 A, JP 2002-120326 A, JP 2002-254544 A, and JP 2005-146084 A).

[0019] Various acrylic resins or methacrylic resins are commercially available, and specific examples include those manufactured by Asahi Kasei Corporation under the trade name "Delpet," those manufactured by Mitsubishi Chemical Corporation under the trade names "Dianal" and "Acrypet," and those manufactured by Sumitomo Chemical Co., Ltd. under the trade name "Sumipex."

[0020] --Polycycloolefin resin-- Polycycloolefin resin is a general term for resins obtained by polymerizing cyclic olefins. Examples include ring-opening (co)polymers of cyclic olefins (see JP-A-1-240517 and JP-A-3-122137), addition polymers of cyclic olefins, copolymers of cyclic olefins with α-olefins such as ethylene and propylene (see JP-A-3-14882), graft polymers of these modified with unsaturated carboxylic acids or their derivatives, and hydrogenated products thereof.

[0021] Various polycycloolefin resin products are commercially available, and specific examples include those manufactured by Zeon Corporation under the trade names "Zeonex" and "Zeonor," those manufactured by JSR Corporation under the trade name "Arton," those manufactured by Polyplastics Co., Ltd. under the trade name "Topas," and those manufactured by Mitsui Chemicals, Inc. under the trade name "APEL."

[0022] --Polycarbonate resin-- The polycarbonate resin may be any conventionally known polycarbonate resin, such as a (co)polymer obtained by reacting various dihydroxydiaryl compounds with phosgene, or a (co)polymer obtained by reacting a dihydroxydiaryl compound with a carbonate ester such as diphenyl carbonate.

[0023] Various polycarbonate resin products are commercially available, including those manufactured by Teijin Chemical Co., Ltd. under the trade names "Panlite" and "Multilon," those manufactured by Mitsubishi Engineering Plastics Corporation under the trade names "Iupilon" and "Novarex," those manufactured by Idemitsu Kosan Co., Ltd. under the trade name "Toughlon," and those manufactured by Sabic Corporation under the trade name "Lexan."

[0024] -Antioxidants- The resin composition according to the present embodiment contains an antioxidant from the viewpoint of suppressing discoloration due to oxidative deterioration of the resin. One type of antioxidant may be used alone, or two or more types may be used in combination.

[0025] --Antioxidants without hydroxyl groups-- The antioxidant having no hydroxyl group used in the present invention will be described in detail below. The antioxidant having no hydroxyl group is not particularly limited, but examples thereof include phosphorus-based antioxidants and sulfur-based antioxidants.

[0026] As the phosphorus-based antioxidant in the present invention, a phosphite-based antioxidant or a phosphine-based antioxidant is preferred from the viewpoint of obtaining a resin composition that can suppress discoloration and other occurrences even when retained at high temperatures. Phosphorus-based compounds are known to have a strong reducing effect, and have the function of quickly reducing peroxides generated from the resin or phenol-based antioxidants during molding and converting them into hydroxyl groups. This reducing effect can suppress oxidative degradation of the resin.

[0027] Examples of the phosphorus-based antioxidant include, but are not limited to, triphenyl phosphite, tris(2,4-di-tert-butylphenyl) phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite, tris[2-[[2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]dioxaphosphen-6-yl]oxy]ethyl]amine, tetramethyl methyl phosphate, tetra ... Tetrakis(2,4-di-tert-butylphenyl)(1,1-biphenyl)-4,4'-diyl bisphosphonite, tetrakis(2,4-di-tert-butyl-5-methylphenyl)-4,4'-biphenylene diphosphonite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, bis[2,4-di(1-phenylisopropyl)phenyl]pentaerythritol diphosphite, bis(nonylphenyl)pentaerythritol diphosphite Phosphite, tris(nonylphenyl)phosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)-2-ethylhexyl phosphite, tetra(C12-C15 mixed alkyl)-4,4'-isopropylidene diphenyl diphosphite, diphenyl monodecyl phosphite, phenyl didecyl phosphite, tridecyl phosphite, trioctadecyl phosphite, diphenyl monooctyl phosphite, tricresyl phosphite, triethyl phosphite, tri-n-butyl phosphite, tris(2-ethyl (hexyl) phosphite, trilauryl trithiophosphite, tristearyl phosphite, trioleyl phosphite, tris(tridecyl) phosphite, tetraphenyldipropylene glycol diphosphite, 4,4'-butylidenebis(3-methyl-6-tert-butylphenylditridecyl) phosphite, 4-[3-[(2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]dioxaphosphepin)-6-yloxy]propyl]-2-methyl-6-tert-butylphenol, bis(2,4-Dicumylphenyl)pentaerythritol diphosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, hydrogenated bisphenol A pentaerythritol phosphite polymer, etc.

[0028] Furthermore, commercially available phosphorus-based antioxidants may be used as the phosphorus-based antioxidant. Examples of such commercially available phosphorus-based antioxidants include, but are not limited to, Irgafos 168 (Irgafos 168: tris(2,4-di-tert-butylphenyl)phosphite, manufactured by BASF), Irgafos 126 (Irgafos 126: bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, manufactured by BASF), Irgafos 38 (Irgafos 38: bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite, manufactured by BASF), Irgafos 12 (Irgafos 12: tris[2-[[2,4,8,10-tetra-t-butyldibenzo[d,f][1,3,2]dioxaphosphen-6-yl]oxy]ethyl]amine, manufactured by BASF), Sandstab P-EPQ (Sandstab P-EPQ: tetrakis(2,4-di-tert-butylphenyl)(1,1-biphenyl)-4,4'-diyl bisphosphonite, manufactured by Clariant), ADK STAB PEP-36 (ADK STAB PEP-36: bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, manufactured by ADEKA), ADK STAB PEP-36A (ADK STAB PEP-36A, manufactured by ADEKA), ADK STAB PEP-8 (ADK STAB PEP-8: distearyl pentaerythritol diphosphite, manufactured by ADEKA), pentaerythritol diphosphite, manufactured by ADEKA), ADK STAB PEP-45 (ADK STAB PEP-45: bis[2,4-di(1-phenylisopropyl)phenyl]pentaerythritol diphosphite, manufactured by ADEKA), ADK STAB PEP-4C (ADK STAB PEP-4C: bis(nonylphenyl)pentaerythritol diphosphite, manufactured by ADEKA), ADK STAB PEP-24G (ADK STAB PEP-24G: bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, manufactured by ADEKA), ADK STAB 1178 (ADK STAB 1178: tris(nonylphenyl)phosphite, manufactured by ADEKA), ADK STAB 329K (ADK STAB 329K: tris(mono,dinonylphenyl) phosphite, manufactured by ADEKA), ADK STAB HP-10 (ADK STAB HP-10: 2,2-methylenebis(4,6-di-tert-butylphenyl)-2-ethylhexyl phosphite, manufactured by ADEKA), ADK STAB 2112 (ADK STAB 2112, manufactured by ADEKA), ADK STAB 1500 (ADK STAB 1500: tetra(C12-C15 mixed alkyl)-4,4'-isopropylidene diphenyl diphosphite, manufactured by ADEKA), ADK STAB C (ADK STAB C: diphenyl monooctyl phosphite, manufactured by ADEKA), ADK STAB 517 (ADK STAB 517: phenyl didecyl phosphite, manufactured by ADEKA), ADK STAB 3010 (ADK STAB 3010: Tridecyl phosphite, manufactured by ADEKA), JPM-311 (Diphenyl monodecyl phosphite, manufactured by Johoku Chemical), JP-3CP (Tricresyl phosphite, manufactured by Johoku Chemical), JP-302 (Triethyl phosphite, manufactured by Johoku Chemical), JP-304 (Tri-n-butyl phosphite, manufactured by Johoku Chemical), JP-308 (Tris(2-ethylhexyl) phosphite, manufactured by Johoku Chemical), JPS-312 (Trilauryl trithiophosphite, manufactured by Johoku Chemical), JP-318E (Tristearyl phosphite, manufactured by Johoku Chemical), JP-318O (Tri Oleyl phosphite, manufactured by Johoku Chemical), JP-333E (tris(tridecyl) phosphite, manufactured by Johoku Chemical), JPP-100 (tetraphenyldipropylene glycol diphosphite, manufactured by Johoku Chemical), JPH-1200 (4,4'-butylidenebis(3-methyl-6-tert-butylphenylditridecyl) phosphite, manufactured by Johoku Chemical), JPH-3800 (hydrogenated bisphenol A·pentaerythritol phosphite polymer, manufactured by Johoku Chemical), JC263 (triphenylphosphine, manufactured by Johoku Chemical), Sumilizer GP GP: 4-[3-[(2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]dioxaphosphepin)-6-yloxy]propyl]-2-methyl-6-tert-butylphenol, manufactured by Sumitomo Chemical Co., Ltd.), Doverphos S-9228PC (bis(2,Examples of suitable phosphite include (4-dicumylphenyl)pentaerythritol diphosphite, manufactured by Dover Chemical Corporation), SANKOHCA (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, manufactured by Sanko Co., Ltd.), Ultranox 626 (Ultranox 626: 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, manufactured by GE), and Ultranox 618 (Ultranox 618: 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, manufactured by GE).

[0029] Among these commercially available phosphorus-based antioxidants, from the viewpoint of the effect of imparting thermal stability to the resin and the effect of using them in combination with various other antioxidants, Irgafos 168, Adekastab PEP-36, Ultranox 626, JPH-1200, and Sumilizer GP are preferred, and Irgafos 168, Adekastab PEP-36, and Ultranox 626 are particularly preferred. These phosphorus-based antioxidants may be used alone or in combination of two or more.

[0030] Examples of sulfur-based antioxidants include, but are not limited to, 2,4-bis(dodecylthiomethyl)-6-methylphenol (Irganox 1726, manufactured by BASF), 2,4-bis(octylthiomethyl)-6-methylphenol (Irganox 1520L, manufactured by BASF), 2,2-bis{[3-(dodecylthio)-1-oxoporopoxy]methyl}propane-1,3- diylbis[3-dodecylthio]propionate] (ADEKA STAB AO-412S, manufactured by ADEKA Corporation), 2,2-bis{[3-(dodecylthio)-1-oxoporopoxy]methyl}propane-1,3-diylbis[3-dodecylthio]propionate] (CHEMINOX PLS, manufactured by Chemipro Chemical Co., Ltd.), and di(tridecyl) 3,3′-thiodipropionate (AO-503, manufactured by ADEKA Corporation).

[0031] Among these commercially available sulfur antioxidants, Adekastab AO-412S and Cheminox PLS are preferred from the viewpoints of their effect of imparting thermal stability to the resin, their effect in combination with various antioxidants, and ease of handling. These sulfur-based antioxidants may be used alone or in combination of two or more.

[0032] The content of the antioxidant that does not have a hydroxyl group may be any amount that is effective in suppressing oxidative degradation. If the content is excessive, problems such as bleeding out during processing may occur. Therefore, the content is preferably 0.01 parts by mass or more and 5 parts by mass or less, more preferably 0.01 parts by mass or more and 1 part by mass or less, and even more preferably 0.01 to 0.5 parts by mass, relative to 100 parts by mass of the resin composition.

[0033] --Other antioxidants-- The resin composition according to this embodiment may not contain an antioxidant having a hydroxyl group, or may contain a small amount of an antioxidant having a hydroxyl group, such as a phenol-based antioxidant. As the phenolic antioxidant, a hindered phenol compound is preferred from the viewpoint of suppressing coloration of the resin. The hindered phenolic antioxidant referred to here refers to a compound having a phenol skeleton in the molecule, in which at least one ortho-position of the phenolic hydroxyl group is substituted with a substituent, particularly a bulky substituent such as t-butyl, t-pentyl, t-amyl, etc., and in which at least one bond other than hydrogen is present among the other ortho-position of the phenolic hydroxyl group, the para-position and meta-position of the phenolic hydroxyl group, and the para-position of the t-alkyl.

[0034] Examples of the hindered phenol antioxidant include, but are not limited to, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], thiodiethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 3,9-bis[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, octadecyl- 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, bis-[3,3-bis-(4'-hydroxy-3'-tert-butylphenyl)-butanoic acid]-glycol ester, 3,3',3'',5,5',5''-hexa-tert-butyl-a,a',a''-(mesitylene-2,4,6-triyl)tri-p-cresol, 4,4'-thiobis(3-methyl-6-tert-butylphenol), 4,6-bis(octylthiomethyl)-o-cresol, 4,6-bis(dodecylthiomethyl)-o-cresol, 4, 4'-Butylidenebis(6-tert-butyl-m-cresol), ethylene bis(oxyethylene) bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris[(4-tert-butyl-3-hydroxy-2,6-xylin)methyl] ]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamine)phenol, 2,6-di-tert-butyl-4-methylphenol, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-ethylidenebis(4,6-di-tert-butylphenol), 2-[1-(2-hydroxy-3,Examples of such acrylates include 2,4-di-tert-amyl-6-[1-(3,5-di-tert-amyl-2-hydroxyphenyl)ethyl]phenyl acrylate, 2,4-di-tert-butyl-6-[1-(3,5-di-tert-butyl-2-hydroxyphenyl)ethyl]phenyl acrylate, and 2,4-di-tert-butyl-6-[1-(3,5-di-tert-butyl-2-hydroxyphenyl)ethyl]phenyl acrylate.

[0035] Furthermore, as the hindered phenol-based antioxidant, a commercially available phenol-based antioxidant may be used. Examples of such commercially available phenol-based antioxidants include, but are not limited to, Irganox 1010 (Irganox 1010: pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], manufactured by BASF), Irganox 1076 (Irganox 1076: octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, manufactured by BASF), Irganox 1330 (Irganox 1330: octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, manufactured by BASF), and the like. 1330: 3,3',3'',5,5',5''-hexa-t-butyl-a,a',a''-(mesitylene-2,4,6-triyl)tri-p-cresol, manufactured by BASF), Irganox 1098 (Irganox 1098: N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), manufactured by BASF), Irganox 259 (Irganox 259: hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], manufactured by BASF), Irganox 1135 (Irganox 1135: isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, BASF), Irganox 3114 (Irganox 3114: 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, BASF), Irganox 3125 (Irganox 3125, manufactured by BASF), Adekastab AO-60 (pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], manufactured by ADEKA), Adekastab AO-80 (3,9-bis{2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]Undecane, manufactured by ADEKA Corporation), Sumilizer BHT (Sumilizer BHT, manufactured by Sumitomo Chemical), Cyanox 1790 (Cyanox 1790, manufactured by Cytec), Sumilizer GA-80 (Sumilizer GA-80, manufactured by Sumitomo Chemical), Sumilizer GS (Sumilizer GS: 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, manufactured by Sumitomo Chemical), Sumilizer GM (Sumilizer GM: 2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5-methylbenzyl)phenyl acrylate, manufactured by Sumitomo Chemical), Sumilizer GP (Sumilizer Examples of such anti-inflammatory agents include GP (6-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra-t-butyldibenz[d,f][1,3,2]dioxaphosphepine, manufactured by Sumitomo Chemical), Sumilizer WX-R (4,4'-thiobis(6-tert-butyl-3-methylphenol), manufactured by Sumitomo Chemical), and Vitamin E (manufactured by Eisai). Among these commercially available phenolic antioxidants, Irganox 1010, Irganox 245, Irganox 3114, Adekastab AO-60, Adekastab AO-80, Irganox 1076, Sumilizer GS, and the like are preferred from the viewpoint of the effect of imparting thermal stability to the resin. These may be used alone or in combination of two or more.

[0036] The content of the antioxidant having a hydroxyl group may be any amount that does not inhibit the suppression of color change at room temperature. If the content is excessive, there is a risk of re-coloring due to a color change at room temperature after light irradiation. Therefore, it is preferable that the antioxidant having a hydroxyl group is not contained or that the content is less than 0.01 part by mass per 100 parts by mass of the resin composition.

[0037] The timing of adding the antioxidant is not particularly limited, and examples include adding it to a monomer solution before polymerization and then initiating polymerization, adding it to and mixing it with a polymer solution after polymerization and then subjecting it to a devolatilization step, adding it to a molten polymer after devolatilization and mixing it and then pelletizing it, and adding it to and mixing it when the pellets after devolatilization and pelletization are re-melt-extruded. Among these, from the viewpoint of preventing thermal degradation and coloration in the devolatilization step, it is preferable to add the antioxidant to and mix it with a polymer solution after polymerization and then before the devolatilization step, and then subject it to the devolatilization step.

[0038] -Additives- The resin composition according to this embodiment may contain various additives within the range that does not significantly impair the effects of the present invention. The additives are not particularly limited, and examples thereof include light stabilizers such as hindered amine light stabilizers, ultraviolet absorbers, mold release agents, other resins, softeners / plasticizers such as paraffinic process oil, naphthenic process oil, aromatic process oil, paraffin, organic polysiloxane, and mineral oil, flame retardants, antistatic agents, inorganic fillers such as organic fibers and pigments such as iron oxide, reinforcing agents such as glass fibers, carbon fibers, and metal whiskers, colorants, organic phosphorus compounds such as phosphites, phosphonites, and phosphate esters, other additives, and mixtures thereof.

[0039] --Hindered amine light stabilizers-- The resin composition of the present embodiment may contain a hindered amine-based light stabilizer. The hindered amine light stabilizer is not particularly limited, but is preferably a compound containing three or more ring structures. Here, the ring structure is preferably at least one selected from the group consisting of an aromatic ring, an aliphatic ring, an aromatic heterocycle, and a non-aromatic heterocycle, and when one compound has two or more ring structures, they may be the same or different.

[0040] Examples of the hindered amine light stabilizer include, but are not limited to, bis(1,2,2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butyl malonate, a mixture of bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidylsebacate, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, N ,N'-Bis(2,2,6,6-tetramethyl-4-piperidyl)-N,N'-diformylhexamethylenediamine, polycondensate of dibutylamine·1,3,5-triazine·N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine and N-(2,2,6,6-tetramethyl-4-piperidyl)butylamine, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{2,2,6,6-tetramethyl- 4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino}], tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate, 1,2,2,6,6-pentamethyl-4-piperidiol and β,β,β',β'-tetramethyl-2,4,8,10-tetraoxaspiro[5. 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, 2,2,6,6-tetramethyl-4-piperidiol, and 2,2,6,6-tetramethyl-4-piperidyl methacrylate. Among these, bis(1,2,2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, a polycondensate of dibutylamine·1,3,5-triazine·N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine) and N-(2,2,6,6-tetramethyl-4-piperidyl)butylamine, and poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl} {2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino}], a reaction product of 1,2,2,6,6-pentamethyl-4-piperidiol and β,β,β',β'-tetramethyl-2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diethanol, and a reaction product of 2,2,6,6-tetramethyl-4-piperidiol and β,β,β',β'-tetramethyl-2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diethanol are preferred.

[0041] The content of the hindered amine light stabilizer may be any amount that is effective in improving light stability, and if the content is excessive, problems such as bleed-out may occur during processing. Therefore, the content is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, even more preferably 1 part by mass or less, still more preferably 0.8 parts by mass or less, still more preferably 0.01 to 0.8 parts by mass, and particularly preferably 0.01 to 0.5 parts by mass, relative to 100 parts by mass of the resin.

[0042] --UV absorber-- The resin composition of the present embodiment may contain an ultraviolet absorber. The ultraviolet absorber is not particularly limited, but is preferably an ultraviolet absorber having a maximum absorption wavelength of 280 to 380 nm, and examples thereof include benzotriazole-based compounds, benzotriazine-based compounds, benzophenone-based compounds, oxybenzophenone-based compounds, benzoate-based compounds, phenol-based compounds, oxazole-based compounds, cyanoacrylate-based compounds, and benzoxazinone-based compounds.

[0043] Benzotriazole compounds include 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], 2-(3,5-di-tert-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(2H-benzotriazol-2-yl)-p-cresol, 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-benzotriazol-2-yl-4,6-di-tert-butylphenol, 2-[5-chloro(2H)-benzotriazol-2-yl]-4-methyl-6-t-butylphenol, 2-(2H-benzotriazol-2-yl)-4,6-di-t-butylphenol, 2-(2H-benzotriazol-2-yl)-4-(1,1 ,3,3-tetramethylbutyl)phenol, 2-(2H-benzotriazol-2-yl)-4-methyl-6-(3,4,5,6-tetrahydrophthalimidylmethyl)phenol, methyl 3-(3-(2H-benzotriazol-2-yl)-5-t-butyl-4-hydroxyphenyl)propionate / polyethylene glycol 300 reaction products, 2-(2H-benzotriazol-2-yl)-6-(linear and branched chain dodecyl)-4-methylphenol, 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy-C7-9 branched and linear alkyl esters. Among these, benzotriazole compounds having a molecular weight of 400 or more are preferred, and examples of commercially available products include Kemisorb (registered trademark) 2792 (manufactured by Chemipro Chemicals), Adekastab (registered trademark) LA31 (manufactured by ADEKA Corporation), and Tinuvin (registered trademark) 234 (manufactured by BASF).

[0044] Examples of benzotriazine compounds include 2-mono(hydroxyphenyl)-1,3,5-triazine compounds, 2,4-bis(hydroxyphenyl)-1,3,5-triazine compounds, and 2,4,6-tris(hydroxyphenyl)-1,3,5-triazine compounds. Specific examples include 2,4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-ethoxyphenyl)-1,3,5-triazine, and 2,4-diphenyl-(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine. )-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4 -diphenyl-6-(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-butoxyethoxy)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-butoxyphenyl)-6-(2,4-dibutoxyphenyl)-1,3-5-triazine, 2,4,6-tris(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-ethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy -4-propoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4,6-Tris(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-ethoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-butoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-propoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-methoxycarbonylpropyloxyphenyl)-1,3,5-triazine, 2,4,6-tri Tris(2-hydroxy-4-ethoxycarbonylethyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-(1-(2-ethoxyhexyloxy)-1-oxopropan-2-yloxy)phenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-methoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-ethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-ethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4- propoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-butoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-butoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-hexyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-octyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-octyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-benzyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-ethoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-butoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-propoxyethoxyphenyl)-1,3,5-triazine, 2,4,Examples include 6-tris(2-hydroxy-3-methyl-4-methoxycarbonylpropyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-ethoxycarbonylethyloxyphenyl)-1,3,5-triazine, and 2,4,6-tris(2-hydroxy-3-methyl-4-(1-(2-ethoxyhexyloxy)-1-oxopropan-2-yloxy)phenyl)-1,3,5-triazine. As the benzotriazine-based compound, commercially available products may be used, such as Kemisorb 102 (manufactured by Chemipro Chemicals), LA-F70 (manufactured by ADEKA Corporation), LA-46 (manufactured by ADEKA Corporation), Tinuvin 405 (manufactured by BASF), Tinuvin 460 (manufactured by BASF), Tinuvin 479 (manufactured by BASF), and Tinuvin 1577FF (manufactured by BASF). Among these, ultraviolet absorbers having a 2,4-bis(2,4-dimethylphenyl)-6-[2-hydroxy-4-(3-alkyloxy-2-hydroxypropyloxy)-5-α-cumylphenyl]-s-triazine skeleton (where "alkyloxy" refers to a long-chain alkyloxy group such as octyloxy, nonyloxy, or decyloxy) are more preferably used because of their excellent ultraviolet absorption properties.

[0045] As the ultraviolet absorber, benzotriazole-based compounds and benzotriazine-based compounds having a molecular weight of 400 or more are preferred, particularly from the viewpoints of compatibility with the resin and volatility upon heating, and benzotriazine-based compounds are particularly preferred from the viewpoint of suppressing decomposition of the ultraviolet absorber itself due to heating during extrusion processing.

[0046] The melting point (Tm) of the ultraviolet absorber is preferably 80°C or higher, more preferably 100°C or higher, even more preferably 130°C or higher, and even more preferably 160°C or higher. The ultraviolet absorber preferably exhibits a weight loss rate of 50% or less, more preferably 30% or less, even more preferably 15% or less, even more preferably 10% or less, and even more preferably 5% or less when heated from 23°C to 260°C at a rate of 20°C / min.

[0047] These ultraviolet absorbents may be used alone or in combination of two or more. By using two types of UV absorbers with different structures in combination, it is possible to absorb UV rays over a wide wavelength range.

[0048] The content of the ultraviolet absorber is not particularly limited as long as it does not impair heat resistance, moist heat resistance, thermal stability, and moldability and exhibits the effects of the present invention, but is preferably 0.1 to 5 parts by mass, more preferably 0.2 to 4 parts by mass or less, more preferably 0.25 to 3 parts by mass, and even more preferably 0.3 to 3 parts by mass, relative to 100 parts by mass of the resin composition. Within this range, an excellent balance of ultraviolet absorption performance, moldability, etc. is achieved.

[0049] --Mold release agent-- The resin composition of the present embodiment may contain a release agent, including, but not limited to, fatty acid esters, fatty acid amides, fatty acid metal salts, hydrocarbon-based lubricants, alcohol-based lubricants, polyalkylene glycols, carboxylic acid esters, and hydrocarbon paraffin-based mineral oils.

[0050] The fatty acid ester that can be used as the release agent is not particularly limited, and any of the conventionally known fatty acid esters can be used. Examples of fatty acid esters that can be used include ester compounds of fatty acids having 12 to 32 carbon atoms, such as lauric acid, palmitic acid, heptadecanoic acid, stearic acid, oleic acid, arachic acid, and behenic acid, with monohydric aliphatic alcohols, such as palmityl alcohol, stearyl alcohol, and behenyl alcohol, and polyhydric aliphatic alcohols, such as glycerin, pentaerythritol, dipentaerythritol, and sorbitan; and complex ester compounds of fatty acids, polybasic organic acids, and monohydric aliphatic alcohols or polyhydric aliphatic alcohols. Examples of such fatty acid ester lubricants include cetyl palmitate, butyl stearate, stearyl stearate, stearyl citrate, glycerin monocaprylate, glycerin monocaprate, glycerin monolaurate, glycerin monopalmitate, glycerin dipalmitate, glycerin monostearate, glycerin distearate, glycerin tristearate, glycerin monooleate, glycerin dioleate, glycerin trioleate, glycerin monolinoleate, and the like. glycerin monobehenate, glycerin mono-12-hydroxystearate, glycerin di-12-hydroxystearate, glycerin tri-12-hydroxystearate, glycerin diacetomonostearate, glycerin citrate fatty acid ester, pentaerythritol adipate stearate, partially saponified montanic acid ester, pentaerythritol tetrastearate, dipentaerythritol hexastearate, sorbitan tristearate, and the like. These fatty acid ester lubricants can be used alone or in combination of two or more. Examples of commercially available products include the Rikemal series, Poem series, Rikestar series, and Rikemaster series manufactured by Riken Vitamin Co., Ltd., and the Excel series, Leodor series, Excelpearl series, and Coconard series manufactured by Kao Corporation, and more specific examples include Rikemal S-100, Rikemal H-100, Poem V-100, Rikemal B-100, Rikemal HC-100, Rikemal S-200, Poem B-200, Rikestar EW-200, Rikestar EW-400, Excel S-95, and Leodor MS-50.

[0051] There are no particular limitations on the fatty acid amide lubricant, and any of the conventionally known lubricants can be used. Examples of fatty acid amide lubricants include saturated fatty acid amides such as lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide; unsaturated fatty acid amides such as oleic acid amide, erucic acid amide, and ricinoleic acid amide; substituted amides such as N-stearyl stearic acid amide, N-oleyl oleic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide, and N-oleyl palmitic acid amide; methylol amides such as methylol stearic acid amide and methylol behenic acid amide; methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, and ethylene bisstearic acid amide (ethylene bisstearic acid amide). Examples of the bisamide include saturated fatty acid bisamides such as ethylene bisstearylamide, ethylene bisisostearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene bishydroxystearic acid amide, N,N'-distearyl adipamide, and N,N'-distearyl sebacic acid amide; unsaturated fatty acid bisamides such as ethylene bisoleic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipamide, and N,N'-dioleyl sebacic acid amide; and aromatic bisamides such as m-xylylene bisstearic acid amide and N,N'-distearyl isophthalic acid amide. These fatty acid amide-based release agents can be used alone or in combination of two or more. Examples of commercially available products include the Diamid series (manufactured by Nippon Kasei Co., Ltd.), the Amide series (manufactured by Nippon Kasei Co., Ltd.), the Nikka Amide series (manufactured by Nippon Kasei Co., Ltd.), the Methylol Amide series, the Bis Amide series, the Suripax series (manufactured by Nippon Kasei Co., Ltd.), the Kaowax series (manufactured by Kao Corporation), the Fatty Acid Amide series (manufactured by Kao Corporation), and ethylene bisstearic acid amides (manufactured by Dainichi Chemical Industry Co., Ltd.).

[0052] The term "metal salt of fatty acid" refers to a metal salt of a higher fatty acid, and examples thereof include lithium stearate, magnesium stearate, calcium stearate, calcium laurate, calcium ricinoleate, strontium stearate, barium stearate, barium laurate, barium ricinoleate, zinc stearate, zinc laurate, zinc ricinoleate, zinc 2-ethylhexoate, lead stearate, dibasic lead stearate, lead naphthenate, calcium 12-hydroxystearate, and lithium 12-hydroxystearate. Of these, calcium stearate, magnesium stearate, and zinc stearate are particularly preferred because they result in the resulting transparent resin composition having excellent processability and extremely excellent transparency. Examples of commercially available products include the SZ series, SC series, SM series, and SA series manufactured by Sakai Chemical Industry Co., Ltd. When the fatty acid metal salt is used, the content thereof is preferably 0.2 parts by mass or less per 100 parts by mass of the resin composition, from the viewpoint of maintaining transparency. The above-mentioned release agents may be used alone or in combination of two or more.

[0053] The release agent to be used preferably has a decomposition starting temperature of 200° C. or higher. The decomposition starting temperature can be measured by the 1% mass loss temperature using TGA. The content of the release agent may be any amount that is effective as a release agent, and since an excessive content can cause problems such as bleed-out during processing or poor extrusion due to screw slippage, the content is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, even more preferably 1 part by mass or less, still more preferably 0.8 parts by mass or less, even more preferably 0.01 to 0.8 parts by mass, and particularly preferably 0.01 to 0.5 parts by mass, per 100 parts by mass of resin. Addition in an amount within the above range is preferred because it suppresses the decrease in transparency due to the addition of the release agent and also tends to suppress poor mold release during injection molding and sticking to metal rolls during sheet molding.

[0054] (Molded body) The molded article of this embodiment is a molded article made from the resin composition of this embodiment. That is, the resin composition of this embodiment is a molded article containing a resin composition including a transparent resin and an antioxidant that does not have a hydroxyl group. The content of the antioxidant in the molded article of this embodiment is 0.01 parts by mass or more and 5 parts by mass or less of the antioxidant that does not have a hydroxyl group per 100 parts by mass of the transparent resin. As for the physical properties of the molded article of this embodiment, the molded article is molded from a light-emitting diode light source having an emission peak wavelength of 390 nm to 460 nm, and has an integrated light intensity of 1.9 W·hr / cm. 2 When irradiated so as to achieve this, the rate of decrease in the average gram absorption coefficient for light with a wavelength of 400 nm to 500 nm before and after irradiation is 30% or less.

[0055] The preferred content of the antioxidant in the molded product of this embodiment is the same as that described as the preferred content of the antioxidant in the resin composition of this embodiment. The additives that may be contained in the molded product of this embodiment are also the same as those described as the additives that may be contained in the resin composition of this embodiment.

[0056] The reduction rate of the average gram absorption coefficient of the molded body of this embodiment under the above conditions is 30% or less, preferably 25% or less, and more preferably 20% or less. The average gram absorption coefficient can be measured, for example, by the method described in the Examples.

[0057] When the molded article of this embodiment is heated at 90°C for 24 hours, the increase in the average gram extinction coefficient for light with a wavelength of 400 to 500 nm before and after heating is preferably 90% or less, more preferably 70% or less, and even more preferably 50% or less. The increase in the average gram extinction coefficient is an index of the resistance to thermal discoloration of the molded article, and it can be evaluated that the lower the increase in the gram extinction coefficient, the less thermal discoloration after heating.

[0058] In order to achieve the object of the present invention, the molded article of the present embodiment is prepared by irradiating a precursor molded article containing a resin composition including a transparent resin and an antioxidant having no hydroxyl group with a light source having an emission peak wavelength of 390 nm to 460 nm at an integrated light intensity of preferably 0.1 to 10,000 W·hr / cm. 2 in the range of 0.1 to 100 W·hr / cm 2 , and more preferably 0.1 to 20 W·hr / cm 2 More detailed conditions for light irradiation are as described below.

[0059] (Method of manufacturing resin composition and molded article) Examples of methods for producing the resin composition of this embodiment include kneading using a kneading machine such as an extruder, a heated roll, a kneader, a roller mixer, or a Banbury mixer. Among these, kneading using an extruder is preferred in terms of productivity. The kneading temperature may be determined according to the preferred processing temperatures of the polymers constituting the resin and the other resins to be mixed, and is generally in the range of 140 to 300°C, preferably 230 to 300°C. In addition, it is preferable to provide a vent port in the extruder to reduce volatile content.

[0060] The molded article of this embodiment can be produced by molding a melt-kneaded product of the resin composition or pellets obtained by melt-kneading the resin composition as a raw material. Various molding methods, such as extrusion molding, injection molding, compression molding, calendar molding, inflation molding, blow molding, and film molding, can be used for the molding. Among these, injection molding and injection compression molding are preferred from the viewpoint of productivity. Typically, injection molding consists of (1) an injection process in which resin is melted and filled into the cavity of a temperature-controlled mold; (2) a pressure holding process in which pressure is applied to the cavity until the gate is sealed, and an amount of resin equivalent to the amount of molten resin filled in the injection process that contracts as it comes into contact with the mold and cools; (3) a cooling process in which the molded body is held until the resin cools after the pressure holding process is released; and (4) the mold is opened and the cooled molded body is removed.

[0061] In this case, the molding temperature is preferably in the range of Tg+100° C. to Tg+160° C., and more preferably in the range of Tg+110° C. to Tg+150° C., based on the glass transition temperature of the resin composition. Here, the molding temperature refers to the controlled temperature of a band heater wrapped around the injection nozzle. The mold temperature is preferably in the range of Tg-70°C to Tg, and more preferably in the range of Tg-50°C to Tg-20°C, based on the glass transition temperature (Tg) of the resin composition.

[0062] The injection speed can be appropriately selected depending on the thickness and dimensions of the injection molded article to be obtained, and can be appropriately selected, for example, from the range of 200 to 1000 mm / sec. The pressure for holding can be selected appropriately depending on the shape of the injection-molded article to be obtained, and can be selected appropriately within the range of, for example, 30 to 120 MPa. In the case of a thin-walled molded article whose solidification rate is fast, holding pressure may not be applied. Here, the pressure for holding pressure is the pressure maintained by a screw for further feeding the molten resin from the gate after the molten resin has been filled.

[0063] Injection compression molding is an injection molding method in which the mold is opened slightly before the start of injection molding, and molten resin is filled into the mold at high speed and low pressure. After that, the mold clamping pressure is increased at high speed, and a compression and pressure holding process is added to hold the pressure uniformly over the entire surface of the resin. This makes it possible to mold molded articles with excellent surface and optical properties. When attempting to obtain thinner injection molded articles, for example, those with a thickness of less than 1 mm and a diagonal dimension of more than 100 mm, injection compression molding is particularly preferred, as it allows for the production of molded articles with excellent optical properties and color tone.

[0064] Furthermore, when an injection-molded article obtained using pellets of the resin composition is used as a light guide plate, the surface may be provided with fine irregularities. Providing such fine irregularities is preferable because it eliminates the need for a separate reflective layer by printing or the like. Examples of fine irregularities include, but are not limited to, irregularities with clear structural units such as rectangular parallelepiped, cylindrical, elliptical cylinder, triangular prism, sphere, and aspherical surface; irregularities with a matte or hairline texture but no clear structural unit; or combinations thereof; and irregularities with clear structural units but varying shapes, particularly sizes. Examples of irregularity shapes include heights or depressions of 0.1 to 500 μm and pitches of 10 to 1,000 μm.

[0065] The molded article obtained from the resin composition of this embodiment may further be subjected to a surface functionalization treatment such as an anti-reflection treatment, a transparent conductive treatment, an electromagnetic wave shielding treatment, or a gas barrier treatment.

[0066] As described above, the molded article of the present embodiment is not particularly limited in its manufacturing method. However, as a result of research by the inventors, it has been found that while additives having antioxidant properties suppress thermal degradation of resins, the additives themselves are denatured and significantly discolored when subjected to heating (thermal processing) during the manufacturing or molding process, for example, heating (thermal processing) at 250°C or higher (Fig. 1). The thermally denatured additives cause discoloration of the resin composition and molded articles made from the resin composition, resulting in yellowing. On the other hand, even when the molded article of the present invention is obtained through thermal processing, the yellowing caused by the thermally denatured additives, which is one cause of discoloration of the molded article, can be suppressed, thereby allowing the molded article to have an improved color tone.

[0067] For example, in the case of Irgafos 168 (tris(2,4-di-tert-butylphenyl)phosphite, manufactured by BASF), a compound (Mw=206) modified into a conjugated structure by thermal decomposition was confirmed by MS spectroscopy, and it is presumed that a compound having a structure represented by the following formula (1) was produced.

[0068] [ka]

[0069] -Method for improving the color tone of molded products- An effective way to improve the color tone of a molded article containing the resin composition of this embodiment is to reduce the yellowing components resulting from the antioxidant that does not have a hydroxyl group, which are generated during thermal processing. Methods for suppressing the yellowing phenomenon of the antioxidant include, for example, (1) using a phosphorus compound, a fatty acid ester, or an amide compound in combination, and (2) irradiating the molded article with light to convert the yellowing components resulting from the antioxidant contained in the resin composition into other compounds. For molded articles containing the resin composition of this embodiment, light irradiation is preferably performed as a post-process, since it can efficiently improve the color tone deterioration caused by thermal processing.

[0070] --Light irradiation process-- The method for producing a molded article containing the resin composition of the present embodiment preferably includes a post-step of irradiating the resin composition with light having a wavelength of 390 to 460 nm as a step for reducing yellowing components derived from the antioxidant having no hydroxyl group contained in the resin composition. The present inventors have found light irradiation conditions that can uniformly improve the color tone of the entire molded product and at the same time prevent the antioxidant from deteriorating.

[0071] Although the reason why light irradiation has the effect of improving the yellowing caused by antioxidants is not entirely clear, it is thought that this is because the yellowing components derived from the antioxidant in the molded product absorb the irradiated light and decompose or modify, converting the colored components into non-colored components. In other words, it is speculated that a molded product with improved color tone can be easily obtained by irradiating the molded product with light of a wavelength in the absorption range of the yellowing components derived from the antioxidant to cause decomposition or modification. Note that, in this case, not only the yellowing components derived from the antioxidant but also some of the yellowing components derived from other resin compositions and additives can be similarly decolorized.

[0072] Because the absorbance of yellowing compounds is particularly high in the wavelength range of 390 to 460 nm, it is believed that irradiating them with light including wavelengths of 390 to 460 nm is highly effective in improving color tone. As shown in Figure 1, when a simple antioxidant without a hydroxyl group was heated at 250°C for 10 minutes and colored, it was irradiated with light at 445 nm, and it was confirmed that the average gram absorption coefficient in the 400 to 500 nm range was significantly reduced.

[0073] On the other hand, it has been found that when a resin composition containing a large amount of antioxidants having hydroxyl groups is left at room temperature after its color tone has been improved by light irradiation, the average gram absorption coefficient at 400 to 500 nm increases again. The cause of this phenomenon is not entirely clear, but it is presumed that colored compounds derived from antioxidants having hydroxyl groups that have been decolorized by light irradiation are regenerated over time.

[0074] The output of the light to be irradiated is 0.001 to 10 W / cm2 It is preferable that the range is 0.001 W / cm 2 If the light output is lower than 10 W / cm, the photoreaction does not proceed sufficiently and long irradiation times are required, which may result in insufficient improvement in color tone. 2 If the light output is higher than 0.005 to 5 W / cm, part of the absorbed light is converted into thermal energy and deactivated, but the photoreaction and thermal reaction may cause deterioration of the resin itself or the generation of new coloring components, which may result in a decrease in transmittance competing with the improvement in color tone, resulting in a decrease in color tone. 2 is more preferable, and even more preferable is 0.01 to 3 W / cm 2 The light output of the irradiated light preferably satisfies the above range for the entire molded article, and it is more preferable that the light be irradiated so that the light output is uniform over the entire surface. The optical output can be measured using a photodiode-based actinometer or power meter. If the radiant flux (W) can be measured, the irradiated area (cm 2 ) to determine the light output. Specifically, the light output can be estimated by measuring it on the surface of the molded body. In the above-mentioned light irradiation, the light output is preferably constant during irradiation, but may be varied. When the light output is varied, there is no problem as long as the light output of the irradiated light is adjusted so as to satisfy the above-mentioned range. The light may be irradiated from multiple directions or from a single direction, but it is preferable to arrange the light sources uniformly from the viewpoint of uniform irradiation.

[0075] The cumulative light intensity of the light to be irradiated is 0.1 to 10,000 W·hr / cm 2 It is preferable that the range is 0.1W·hr / cm 2 At an integrated light intensity lower than 10,000 W·hr / cm, the photoreaction does not proceed sufficiently and the improvement in fluorescence intensity and color tone tends to be insufficient. 2If the integrated light intensity is higher than this, some of the absorbed light will be deactivated as heat energy, but the photoreaction and thermal reaction may cause deterioration of the resin itself and the generation of new coloring components, and the decrease in transmittance may compete with the improvement in color tone, resulting in a decrease in color tone. The integrated light intensity above is 0.5 to 5000 W·hr / cm 2 is more preferable, and even more preferable is 0.1 to 1000 W·hr / cm 2 and more preferably 0.1 to 20 W·hr / cm 2 and most preferably 0.3 to 20 W·hr / cm 2 is. The integrated light amount can be measured using an integrated light meter or a power meter that uses a photodiode. The integrated light amount can also be calculated using the radiation density (energy density, W / cm 2 ) is the time (hr) integral value, so if you can measure the radiant flux (W), you can calculate the irradiated area (cm 2 ) per unit of energy, the energy density can be calculated, and the cumulative amount of light can be calculated based on the irradiation time.

[0076] Regarding the time for light irradiation, a short irradiation time is desirable from the viewpoint of productivity, but a long irradiation time is also acceptable if the molded body is irradiated with light during storage. Furthermore, light irradiation may be performed continuously or discontinuously, but continuous irradiation is preferred from the viewpoint of efficiency. Even in the case of discontinuous light irradiation, it is preferable that the light output satisfies the above range.

[0077] The light irradiated onto the molded article contains light with a wavelength of 390 to 460 nm, and preferably contains mainly light with a wavelength of 390 to 460 nm. The light may be light of a single wavelength, or may contain light of multiple wavelengths. Examples include light of a single wavelength or multiple wavelengths within the range of 390 to 460 nm, and light containing light of a single wavelength or multiple wavelengths outside the range of 390 to 460 nm. Although it is not a problem if the irradiated light contains a small amount of light with a wavelength shorter than 390 nm, prolonged irradiation of high-power short-wavelength light less than 390 nm can cause decomposition and discoloration of the irradiated object, so it is preferable to use a light source that emits only light with a wavelength of 390 to 460 nm. In order to minimize decomposition and discoloration, for example, a light source that does not contain light with a wavelength shorter than 390 nm can be selected, or a filter that cuts out wavelengths other than the target wavelength can be used. The light to be irradiated may contain light with wavelengths greater than 460 nm, and the longer the wavelength, the less effect there is on the color tone. However, irradiation with light in the infrared region in particular raises the temperature of the irradiated object itself, and if the temperature rise is too great, there is a possibility of deterioration in color tone due to heat. Therefore, it is preferable to use only light in the visible light region. The phrase "mainly containing light with a wavelength of 390 to 460 nm" means that the spectral output of light with a wavelength of 390 to 460 nm in the light irradiated onto the molded article is 50% or more of the total irradiated light.

[0078] The temperature of the irradiated object during light irradiation is preferably in the range of 20°C or higher and 20°C lower than the glass transition temperature of the resin composition constituting the irradiated object, in order to promote the photoreaction. By irradiating with light within the above temperature range, the photoreaction is promoted, and a sufficient color tone improvement effect can be obtained in a shorter time. Although a certain degree of color improvement can be achieved even at temperatures lower than 20°C during light irradiation, sufficient color improvement may not be expected unless light is irradiated for a longer period of time. On the other hand, if light irradiation is performed at a temperature higher than 20°C below the glass transition temperature, the irradiated object may be heated above the glass transition region, causing problems such as the object being unable to maintain its shape or fusing. For example, when irradiating with light containing light in the infrared region, the irradiated object can be used without any problems if the temperature is adjusted to be 20°C lower than the glass transition temperature, taking into account the effects of heating. Although the color improvement effect can be obtained using light alone without heating, irradiating with light while heating to a certain extent is preferable from the viewpoint of productivity, as this allows the color improvement effect to be obtained in a shorter period of time. The temperature can be appropriately selected from the range of 20°C to 20°C or more lower than the glass transition temperature of the resin composition depending on the conditions of use. The temperature is more preferably 30° C. or higher and not higher than a temperature 25° C. lower than the glass transition temperature of the resin composition, and even more preferably 40° C. or higher and not higher than a temperature 30° C. lower than the glass transition temperature.

[0079] The light source used for light irradiation can be appropriately selected from natural light such as sunlight and artificial light sources. Examples of artificial light sources include incandescent lamps, fluorescent lamps, halogen lamps, mercury lamps, metal halide lamps, xenon lamps, LEDs, lasers, etc. Among these, LEDs are preferred from the viewpoint of irradiating only light with a wavelength of 360 to 460 nm, which is particularly effective in improving color tone, and light sources can also be used in appropriate combinations taking into account reaction promotion by heating, etc. If the temperature rise of the molded body due to light irradiation becomes a problem, the shape of the molded body can be maintained and deterioration of color tone due to temperatures above the glass transition region can be suppressed by attaching an infrared cut filter or providing a cooling mechanism using air or water cooling.

[0080] The molded article containing the resin composition of this embodiment has excellent transmittance, and its color tone improving effect can be quantitatively evaluated by dissolving it in a solvent and measuring the transmittance. The average gram absorption coefficient of a 15 w / v % chloroform solution of the molded article at wavelengths of 400 nm to 500 nm, measured using a 10 cm optical path length cell, is preferably 0.40 or less, more preferably 0.30 or less, and even more preferably 0.20 or less. The average gram absorption coefficient of the molded product can be calculated by the method described in the Examples below.

[0081] (Use of molded body) The molded article of the present embodiment is a molded article made of a resin composition that has improved transmittance while maintaining visible light transparency, and therefore can be suitably used for applications such as optical components in household products, office automation equipment, audio-visual equipment, battery electrical components, lighting equipment, automobiles, etc. Examples of optical components used in household goods, office automation equipment, audiovisual equipment, battery-powered electrical components, lighting equipment, and the like include light guide plates, display front panels, and touch panels used in displays of smartphones, PDAs, tablet PCs, LCD televisions, and the like; lenses for smartphone and tablet PC cameras; and optical lens components for head-mounted displays and LCD projectors, such as prism elements, waveguides, lenses, and particularly small, thin, non-uniformly shaped optical lenses, optical fibers, coating materials for optical fibers, lenses, Fresnel lenses, phase plates equipped with microlens arrays, and optical cover components. Optical components for automobiles and the like include light guide plates for in-vehicle displays; in-vehicle meter panels; optical components for head-up displays such as front panels, combiners, and optical cover parts for car navigation systems; in-vehicle camera lenses, light guide rods, and the like. In addition to the above, the present invention can also be preferably used as a camera focusing screen, or as a component for a digital signage display device that displays information on a thin display connected to a network for the purpose of publicity, advertising, etc., in places such as outdoors, in stores, public institutions, and transportation facilities. [Example]

[0082] Hereinafter, the present embodiment will be described in detail with reference to specific synthesis examples, examples, and comparative examples, but the present invention is not limited in any way to the following synthesis examples, examples, and comparative examples. The methods for measuring and evaluating physical properties in the Synthesis Examples, Examples, and Comparative Examples are as follows.

[0083] <1. Measurement of polymerization conversion rate> A portion of the polymerization solution in Synthesis Example 1 was collected, and the amount of monomer remaining in this polymerization solution sample was measured by dissolving the sample in chloroform to prepare a 5-parts-by-mass solution, adding n-decane as an internal standard, and measuring the concentration of the monomer remaining in the sample using gas chromatography (Shimadzu Corporation, GC-2010) to determine the total mass (a) of the monomer remaining in the polymerization solution. The polymerization conversion rate (%) was then calculated using the formula (ba) / c×100 from this total mass (a), the total mass (b) assuming that all of the monomers added up to the time the sample was collected remained in the polymerization solution, and the total mass (c) of the monomers to be added up to the end of the polymerization process.

[0084] <2. Analysis of structural units> 1 H-NMR measurement and 13 The structural units of the produced methacrylic resin were identified by C-NMR measurement, and their abundance was calculated. 1 H-NMR measurement and 13 The measurement conditions for C-NMR measurement are as follows: Measuring equipment: Bruker DPX-400 Measurement solvent: CDCl3 or DMSO-d6 ·Measurement temperature: 40℃

[0085] <3. Measurement of molecular weight and molecular weight distribution> The weight average molecular weight (Mw) and number average molecular weight (Mn) of the methacrylic resin produced in Synthesis Example 1 described below were measured using the following apparatus and under the following conditions. Measurement equipment: Tosoh Corporation, gel permeation chromatography (HLC-8320GPC) Measurement conditions: Columns: One TSKguardcolumn SuperH-H, two TSKgel SuperHM-M, and one TSKgel SuperH2500 connected in series. Column temperature: 40°C The developing solvent was tetrahydrofuran, the flow rate was 0.6 mL / min, and 0.1 g / L of 2,6-di-t-butyl-4-methylphenol (BHT) was added as an internal standard. Detector: RI (differential refractive index) detector, detection sensitivity: 3.0 mV / min Sample: 0.02 g of methacrylic resin or 20 mL of tetrahydrofuran solution of methacrylic resin. Injection volume: 10 μL Standard sample for calibration curve: The following ten types of polymethyl methacrylate (PMMACalibration Kit MM-10, manufactured by Polymer Laboratories) with known monodisperse weight peak molecular weights and different molecular weights were used. Weight peak molecular weight (Mp) Standard sample 1 1,916,000 Standard sample 2 625,500 Standard sample 3 298,900 Standard sample 4 138,600 Standard sample 5 60,150 Standard sample 6 27,600 Standard sample 7 10,290 Standard sample 8 5,000 Standard sample 9 2,810 Standard sample 10,850 Under the above conditions, the RI detection intensity was measured against the elution time of the methacrylic resin. Based on the calibration curve obtained by measuring the standard sample for the calibration curve, the weight average molecular weight (Mw) and number average molecular weight (Mn) of the methacrylic resin were determined.

[0086] <4. Evaluation of Gram Extinction Coefficient> The gram absorption coefficients at wavelengths of 400 nm to 500 nm were calculated for the final film molded articles in the Examples and Comparative Examples described below. Specifically, the final film molded article was prepared as a measurement sample in an approximately 15 w / v% chloroform solution (i.e., a solution prepared by dissolving 0.45 g of the resin composition in chloroform to make a 3 mL solution). Using a UV-visible spectrophotometer (Shimadzu Corporation, UV-2600i spectrophotometer) with a measurement wavelength of 200 to 780 nm, a slit width of 2 nm, a 1 cm optical path length cell with a 10° viewing angle, auxiliary illuminant C, and chloroform as the reference object, transmittance was measured. The gram absorption coefficient and the rate of decrease in the gram absorption coefficient before and after light irradiation were calculated from the average absorbance (Abs.) of light at wavelengths of 400 nm to 500 nm using the following formula, and were evaluated. Gram absorption coefficient [(Abs.)·L / g] = Average gram absorption coefficient between 400 nm and 500 nm / Concentration of chloroform solution Gram absorption coefficient reduction rate [%] = (gram absorption coefficient before light irradiation - gram absorption coefficient after light irradiation) / gram absorption coefficient before light irradiation

[0087] 5. Evaluation of Solution YI The solution YI (yellowness index) was calculated for the final film molded body in the examples and comparative examples described below. Specifically, the final film molded body was dissolved in chloroform (a solution prepared to be 20 w / v% for methacrylic resin and 4 w / v% for polycycloolefin resin) and used as a measurement sample. The transmittance was measured using a UV-visible spectrophotometer (Shimadzu Corporation, UV-2600i spectrophotometer) at a viewing angle of 10° and auxiliary illuminant C. According to JIS K 7373, the XYZ color system is used, and the following formula is used: YI=100(1.28X-1.06Z) / Y The YI was calculated by the above, and a YI of less than 5.0 was evaluated as good, and a YI of 5.0 or more was evaluated as poor.

[0088] <6. Heat color resistance test> For the final film moldings in the Examples and Comparative Examples described below, a thermal discoloration resistance test was conducted at 90°C to accelerate and evaluate color tone changes at room temperature. Specifically, the final film moldings were left to stand at 90°C for 24 hours, and then their transmittance was measured. From the average absorbance (Abs.) of light at wavelengths of 400 nm to 500 nm, the increase in gram extinction coefficient before and after light irradiation was calculated using the following formula to evaluate thermal discoloration resistance. The lower the increase in gram extinction coefficient, the smaller the thermal discoloration after heating can be evaluated. Gram absorption coefficient increase rate [%] = (gram absorption coefficient after heat resistance test - gram absorption coefficient before heat resistance test) / gram absorption coefficient before heat resistance test

[0089] [Raw materials] The raw materials used in Synthesis Example 1 described later are shown below. [[monomer]] Methyl methacrylate: Asahi Kasei Corporation N-phenylmaleimide (phMI): Nippon Shokubai Co., Ltd. N-Cyclohexylmaleimide (chMI): Nippon Shokubai Co., Ltd. [[Polymerization initiator]] 1,1-Di(t-butylperoxy)cyclohexane: NOF Corporation "Perhexa C" [[Chain transfer agent]] n-Octyl mercaptan: Kao Corporation

[0090] [Synthesis Example 1] 358.6 kg of methyl methacrylate (hereinafter referred to as MMA), 29.4 kg of N-phenylmaleimide (hereinafter referred to as phMI), 67.7 kg of N-cyclohexylmaleimide (hereinafter referred to as chMI), 0.77 kg of n-octyl mercaptan as a chain transfer agent, and 224.3 kg of meta-xylene (hereinafter referred to as mXy) ​​were weighed and placed in a 1.25 m 3 The mixture was added to the reactor and stirred to obtain a mixed monomer solution. Next, 88.0 kg of MMA, 6.3 kg of phMI, and 142.4 kg of mXy were weighed and added to Tank 1 with stirring to obtain a mixed monomer solution for addition. The liquid in the reactor was bubbled with nitrogen at a rate of 30 L / min for 1 hour, and the liquid in Tank 1 was bubbled with nitrogen at a rate of 10 L / min for 30 minutes to remove dissolved oxygen. Thereafter, steam was blown into the jacket to raise the solution temperature in the reactor to 115°C, and polymerization was initiated by adding a polymerization initiator solution prepared by dissolving 0.487 kg of 1,1-di(t-butylperoxy)cyclohexane in 1.888 kg of mXy at a rate of 1.0 kg / hour while stirring at 50 rpm. During the polymerization, the solution temperature in the reactor was controlled at 115±2°C by adjusting the temperature with a jacket. 30 minutes after the start of polymerization, the addition rate of the initiator solution was reduced to 0.5 kg / hour. Starting one hour after the start of polymerization, the entire amount of the additional mixed monomer solution was added from Tank 1 at a constant rate over a period of four hours. Furthermore, the addition rate of the initiator solution was reduced to 0.25 kg / hour 3.5 hours after the start of polymerization, and the addition was stopped 5 hours after the start of polymerization. After 12 hours had passed since the start of polymerization, a polymer solution containing a methacrylic resin having structural units with a ring structure in the main chain was obtained. The polymer solution was sampled 2 and 12 hours after the start of polymerization, and the polymerization conversion was analyzed from the remaining monomer concentration. The polymerization conversion after 2 hours was 78.9% for MMA, 77.3% for pHMI, and 70.4% for chMI, and after 12 hours it was 97.9% for MMA, 99.4% for pHMI, and 99.3% for chMI. Taking into account the monomers added after 2 hours from the start of polymerization, the polymerization conversion after 2 hours was converted as the consumption rate of each monomer relative to the total amount added up to the end of polymerization, resulting in 67.2% for MMA, 67.1% for pHMI, and 70.4% for chMI. This polymer solution was fed to a concentration apparatus consisting of a tubular heat exchanger preheated to 250°C and a vaporization tank, and devolatilization was carried out. The degree of vacuum in the vaporization tank was set to 10 to 15 Torr. The resin flowing down the vaporization tank was discharged with a gear pump, extruded through a strand die, cooled with water, and pelletized to obtain methacrylic resin composition pellets. The composition of the resulting pellets was confirmed to be 81.0 parts by mass of structural units derived from MMA, 6.6 parts by mass of phMI, and 12.4 parts by mass of chMI monomers, respectively. The weight-average molecular weight was 108,000, Mw / Mn was 2.04, and the glass transition temperature was 134°C. In addition, the measurement results of the composition distribution of structural units are Mp: 253,000 (MMA: 81.4 parts by mass, phMI: 6.5 parts by mass, chMI: 12.1 parts by mass), Mp: 176,000 (MMA: 81.1 parts by mass, phMI: 6.6 parts by mass, chMI: 12.3 parts by mass), Mp: 111,000 (MMA: 8 parts by mass). Mp: 88,000 (MMA: 80.8 parts by mass, phMI: 6.7 parts by mass, chMI: 12.5 parts by mass), Mp: 48,000 (MMA: 80.4 parts by mass, phMI: 6.8 parts by mass, chMI: 12.8 parts by mass).

[0091] <Light irradiation device> Multiple blue LED chips, NCSC119BT-V1 (peak emission wavelength 445 nm) manufactured by Nichia Chemical, were mounted on a substrate and used as the light source for the light irradiation device. A water-cooled heat sink was attached to the device to suppress heat generation on the light source and irradiation surface side, and a chiller was connected to this to provide a cooling mechanism. In addition, a constant current power supply IT6533D manufactured by ITECH was used as the LED driving power source. The light output of the light irradiation device manufactured with the above configuration was approximately 1.25 W / cm at a distance of 10 mm from the light source when an applied current of 20 A was used. 2 A jack was attached inside the device so that the distance from the light source could be changed by adjusting the height. In addition, to prevent the irradiated light from directly or indirectly reaching the human eye, the device was enclosed in a housing to prevent light from leaking outside. In the examples and comparative examples described below, for the light irradiation process for producing the final film molded product or for the light irradiation treatment for evaluating the gram absorption coefficient, the film molded product was spread in a glass container and irradiated with light using a light irradiation device at an output condition of an applied current of 20 A. The distance from the light source to the irradiated product was 10 mm. The temperature of the irradiated product during light irradiation was approximately 30°C.

[0092] [Example 1-1] 3 g of the methacrylic resin prepared in Synthesis Example 1 was dissolved in 10 mL of chloroform, followed by 0.2 parts by weight of BASF's Irgafos 168 (tris(2,4-di-tert-butylphenyl)phosphite, hereafter referred to as Irgafos 168) antioxidant. The mixture was mixed for 1 hour using a shaker. The resulting solution was air-dried at room temperature for 3 hours and then vacuum-dried at 150°C for 3 hours to obtain a transparent film. The resulting film was then heated in an oven at 250°C for 10 minutes to produce a transparent film of the resin composition (hereafter referred to as methacrylic resin A1). The gram absorption coefficient of the transparent film was 0.040 [(Abs.)·L / g]. Using the above light irradiation device, the transparent film molded body of methacrylic resin A1 was irradiated for 90 minutes (accumulated light intensity 1.9 W·hr / cm 2 ), and a photo-irradiated molded product (hereinafter referred to as photo-irradiated methacrylic resin molded product A1-1) was obtained as the final film molded product. The gram absorption coefficient of the obtained photo-irradiated molded product was 0.010 [(Abs.)·L / g]. Furthermore, using the above-mentioned light irradiation device, the photo-irradiated methacrylic resin A1 molded product was irradiated for 90 minutes (accumulated light dose 1.9 W·hr / cm2). 2 The gram absorption coefficient of the photo-irradiated molded product was 0.010 [(Abs.)·L / g], and the reduction in the gram absorption coefficient was 0%. Furthermore, a heat resistance test was carried out on the photoirradiated methacrylic resin molded product A1-1 obtained as the final film molded product by leaving it at 90°C for 24 hours. After the heat resistance test, the gram absorption coefficient of the photoirradiated molded product was 0.014 [(Abs.) L / g], and the increase in the gram absorption coefficient was 40%.

[0093] [Example 1-2] The exposure time for a transparent film molded product of methacrylic resin A1 was 15 minutes (cumulative light intensity 0.3 W·hr / cm 2The other conditions were the same as in Example 1-1, and a transparent film molded product of the resin composition and a photo-irradiated molded product as a final film molded product (hereinafter referred to as photo-irradiated methacrylic resin molded product A1-2) were obtained.

[0094] [Examples 1-3] The exposure time for a transparent film molded product of methacrylic resin A1 was 30 minutes (accumulated light intensity 0.6 W·hr / cm 2 The other conditions were the same as in Example 1-1, and a transparent film molded product of the resin composition and a photo-irradiated molded product as a final film molded product (hereinafter referred to as photo-irradiated methacrylic resin molded product A1-3) were obtained.

[0095] [Examples 1-4] The exposure time for a transparent film molded product of methacrylic resin A1 was 360 minutes (accumulated light intensity 7.5 W·hr / cm 2 The other conditions were the same as in Example 1-1, and a transparent film molded product of the resin composition and a photo-irradiated molded product as a final film molded product (hereinafter referred to as photo-irradiated methacrylic resin molded product A1-4) were obtained.

[0096] [Examples 1-5] The exposure time for a transparent film molded product of methacrylic resin A1 was 720 minutes (accumulated light intensity 15.0 W·hr / cm 2 The other conditions were the same as in Example 1-1, and a transparent film molded product of the resin composition and a photo-irradiated molded product as the final film molded product (hereinafter referred to as photo-irradiated methacrylic resin molded product A1-5) were obtained.

[0097] [Example 2] As an antioxidant, GE's trade name "Ultranox 626" (3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, hereinafter referred to as Ultranox 626) was used. Other conditions were the same as in Example 1-1, and a transparent film molded product of the resin composition and a light-irradiated molded product as the final film molded product (hereinafter referred to as the transparent film molded product of methacrylic resin A2 and the light-irradiated methacrylic resin molded product A2) were obtained.

[0098] [Example 3] As an antioxidant, Johoku Chemical Industry Co., Ltd.'s trade name "JPH-1200" (4,4'-butylidenebis(3-methyl-6-tert-butylphenylditridecyl)phosphite, hereinafter referred to as JPH-1200) was used. Other conditions were the same as in Example 1-1, and a transparent film molded product of the resin composition and a light-irradiated molded product as the final film molded product (hereinafter referred to as a transparent film molded product of methacrylic resin A3 and a light-irradiated methacrylic resin molded product A3) were obtained.

[0099] [Example 4] The transparent resin used was "Delpet 80N" manufactured by Asahi Kasei Corporation. Other conditions were the same as in Example 1-1, and a transparent film molded product of the resin composition and a light-irradiated molded product as the final film molded product (hereinafter referred to as a transparent film molded product of methacrylic resin B1 and a light-irradiated methacrylic resin molded product B1) were obtained.

[0100] [Example 5] The transparent resin used was Zeonex 330R, a product name manufactured by Zeon Corporation. Other conditions were the same as in Example 1-1, and a transparent film molded product of the resin composition and a photoirradiated molded product as the final film molded product (hereinafter referred to as a transparent film molded product of polycycloolefin resin C1 and a photoirradiated polycycloolefin resin molded product C1) were obtained.

[0101] [Comparative Example 1] The transparent film molded product of methacrylic resin A1 obtained in Example 1-1 was used as the final film molded product as it was. The transparent film of methacrylic resin A1 was irradiated for 90 minutes (accumulated light intensity 1.9 W hr / cm ). 2 ), the gram absorption coefficient of the photoirradiated substance was 0.010 [(Abs.)·L / g], a decrease of 75%.

[0102] Comparative Example 2 The transparent film molded product of methacrylic resin A2 obtained in Example 2 was used as it was as the final film molded product. Other conditions were the same as in Comparative Example 1, and a photoirradiated product was obtained.

[0103] Comparative Example 3 The transparent film molded product of methacrylic resin A3 obtained in Example 3 was used as it was as the final film molded product. Other conditions were the same as in Comparative Example 1, and a photoirradiated product was obtained.

[0104] Comparative Example 4 The transparent film molded product of methacrylic resin B1 obtained in Example 4 was used as it was as the final film molded product. Other conditions were the same as in Comparative Example 1, and a photoirradiated product was obtained.

[0105] Comparative Example 5 The transparent film molded product of polycycloolefin resin C1 obtained in Example 5 was used as it was as the final film molded product. Other conditions were the same as in Comparative Example 1, and a photoirradiated product was obtained.

[0106] Comparative Example 6 The antioxidant used was BASF's "Irganox 1010" (pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], hereinafter referred to as "Irganox 1010"). Other conditions were the same as in Comparative Example 1, and a transparent film molded product of the resin composition and a photoirradiated molded product as the final film molded product (hereinafter referred to as the transparent film molded product of methacrylic resin A4 and the photoirradiated methacrylic resin molded product A4) were obtained. The gram absorption coefficient of the photoirradiated methacrylic resin molded product A4 was 0.011 [(Abs.) L / g], and the reduction rate of the gram absorption coefficient was 21%. The gram absorption coefficient of the photo-irradiated molded product after the heat resistance test was 0.029 [(Abs.)·L / g], and the increase in the gram absorption coefficient was 107%.

[0107] Comparative Example 7 The methacrylic resin B prepared in Synthesis Example 1 was used as the transparent resin, and Irganox 1010 was used as the antioxidant. Other conditions were the same as in Example 1, and a transparent film molded product of the resin composition and a light-irradiated molded product as the final film molded product (hereinafter referred to as a transparent film molded product of methacrylic resin B2 and a light-irradiated methacrylic resin molded product B2) were obtained.

[0108] [Comparative Example 8] Zeonex 330R, a trade name of Zeon Corporation, was used as the transparent resin, and Irganox 1010 was used as the antioxidant. Other conditions were the same as in Example 1, and a transparent film molded product of the resin composition and a photoirradiated molded product as the final film molded product (hereinafter referred to as the transparent film molded product of polycycloolefin resin C2 and the photoirradiated polycycloolefin resin molded product C2) were obtained.

[0109] [Table 1-1] [Table 1-2] [Industrial Applicability]

[0110] The molded article of the present invention has excellent transparency to visible light and can therefore be suitably used for applications such as household products, office automation equipment, audiovisual equipment, battery electrical components, lighting equipment, and optical members in automobiles. Examples of optical components used in household goods, office automation equipment, audiovisual equipment, battery-powered electrical components, lighting equipment, and the like include light guide plates, display front panels, and touch panels used in displays of smartphones, PDAs, tablet PCs, LCD televisions, and the like; lenses for smartphone and tablet PC cameras; and optical lens components for head-mounted displays and LCD projectors, such as prism elements, waveguides, lenses, and particularly small, thin, non-uniformly shaped optical lenses, optical fibers, coating materials for optical fibers, lenses, Fresnel lenses, phase plates equipped with microlens arrays, and optical cover components. Optical components for automobiles and the like include light guide plates for in-vehicle displays; in-vehicle meter panels; optical components for head-up displays such as front panels, combiners, and optical cover parts for car navigation systems; in-vehicle camera lenses, light guide rods, and the like. In addition to the above, the present invention can also be preferably used as a camera focusing screen, or as a component for a digital signage display device that displays information on a thin display connected to a network for the purpose of publicity, advertising, etc., in places such as outdoors, in stores, public institutions, and transportation facilities.

[0111] Furthermore, according to the present invention, by improving the yellowing of the resin, it is possible to bring defective molded products that were previously out of spec in terms of color tone into the range of good molded products, thereby contributing to improved yield and an expanded operating range during manufacturing.

Claims

1. A molded article containing a resin composition including a transparent resin and an antioxidant not having a hydroxyl group, wherein the resin composition contains 0.01 part by mass or more of the antioxidant not having a hydroxyl group per 100 parts by mass of the transparent resin, and the resin composition contains either no antioxidant having a hydroxyl group or the content of the antioxidant having a hydroxyl group is less than 0.01 part by mass, and the molded article is a light-emitting diode light source having an emission peak wavelength of 390 nm to 460 nm with an integrated light intensity of 1.9 W hr / cm ２ When irradiated so as to satisfy the above condition, the rate of decrease in the average gram absorption coefficient before and after irradiation with light having a wavelength of 400 nm to 500 nm is 30% or less.

2. The molded article according to claim 1 , wherein the antioxidant not having a hydroxyl group is contained in an amount of 0.01 parts by mass or more and 5 parts by mass or less, based on 100 parts by mass of the transparent resin.

3. 3. The molded article according to claim 1, wherein the antioxidant having no hydroxyl group is a phosphorus-based antioxidant.

4. The molded article according to claim 1 or 2, characterized in that the transparent resin is one or more selected from the group consisting of acrylic resin, methacrylic resin, polycarbonate resin, polycycloolefin resin, polyolefin resin, polyether resin, ene-thiol resin, epoxy resin, polyamide resin, polyimide resin, polyurethane resin and polyester resin.

5. 3. The photoirradiated molded article according to claim 1, characterized in that when the molded article is heated at 90°C for 24 hours, the increase in the average gram absorption coefficient for light with a wavelength of 400 nm to 500 nm before and after heating is 90% or less.

6. 3. The molded article according to claim 1, wherein a 15 w / v% chloroform solution of the molded article has an average gram absorption coefficient of 0.40 or less for light having a wavelength of 400 nm to 500 nm, as measured using a 10 cm path length cell.

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