Methods for producing resin compositions, molded articles, and pellets, and light transmittance enhancers.

Abstract

To provide a resin composition that can provide a molding having high light transmittance, a molding formed from the resin composition, and a method for producing a pellet, and to provide a light transmittance improver for improving the light transmittance of thermoplastic resin.SOLUTION: A resin composition comprises a thermoplastic resin 100 pts.mass and a non-aromatic organic iron complex 0.08-3.50 mass ppm.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a resin composition, a molded article, a method for producing pellets, and a light transmittance improver.

Background Art

[0002] Conventionally, thermoplastic resins such as polycarbonate resins have been widely used in various applications because of their excellent various properties. Among them, as one of the utilization forms of thermoplastic resins, especially polycarbonate resins, their use in members that require transparency such as power covers, lighting lenses, lighting covers, and light guide members is active. For example, Patent Document 1 discloses an aromatic polycarbonate resin composition containing an aromatic polycarbonate resin (A), a phosphorus-based antioxidant (B), a fatty acid ester (C), and a specific aromatic compound (D), wherein the phosphorus-based antioxidant (B) is contained in an amount of 0.01 to 0.1 parts by weight, the fatty acid ester (C) is contained in an amount of 0.01 to 0.5 parts by weight, and the specific aromatic compound (D) is contained in an amount of 0.0001 parts by weight or more and less than 0.05 parts by weight, based on 100 parts by weight of the aromatic polycarbonate resin (A). Further, it is described that the molded article obtained from such a resin composition has a high light transmittance.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As described above, resin compositions having a high light transmittance are known, but with the increasing use of thermoplastic resins, a new resin composition having a high light transmittance is required. The present invention aims to solve the above problems and relates to a resin composition capable of providing a molded article with high light transmittance, a molded article formed from the resin composition, and a method for producing pellets. It also relates to a light transmittance improving agent for improving the light transmittance of thermoplastic resins. [Means for solving the problem]

[0005] Based on the above-mentioned problems, the inventors conducted research and found that it is possible to improve light transmittance by incorporating a small amount of non-aromatic organic iron complex into a thermoplastic resin. Specifically, the above-mentioned problems were solved by the following means. <1> A resin composition comprising 100 parts by mass of a thermoplastic resin and 0.08 to 3.50 ppm by mass of a non-aromatic organic iron complex. <2> The aforementioned non-aromatic organic iron complex includes an acetylacetone iron complex. <1> The resin composition described above. <3> The thermoplastic resin includes an amorphous resin, <1> or <2> The resin composition described above. <4> The thermoplastic resin includes an aromatic polycarbonate resin. <1> or <2> The resin composition described above. <5> <1> ~ <4> A molded article formed from any one of the resin compositions described above. <6> A method for producing pellets, comprising melt-kneading a composition containing 100 parts by mass of thermoplastic resin and 0.08 to 3.50 ppm by mass of a non-aromatic organic iron complex. <7> An additive for improving the light transmittance of a resin, comprising a non-aromatic organoiron complex, which is a light transmittance enhancer. <8> The aforementioned non-aromatic organoiron complex is an acetylacetone iron complex. <7> The light transmittance enhancer described in [reference]. <9> The resin is an amorphous thermoplastic resin. <7> or <8> The light transmittance enhancer described in [reference]. <10> The aforementioned resin is an aromatic polycarbonate resin. <7> ~ <9> A light transmittance enhancer as described in any one of the following. [Effects of the Invention]

[0006] The present invention provides a resin composition capable of providing a molded article with high light transmittance, a molded article formed from the resin composition, and a method for producing pellets. Furthermore, it provides a light transmittance improving agent for improving the light transmittance of thermoplastic resins. [Modes for carrying out the invention]

[0007] The following describes in detail embodiments for carrying out the present invention (hereinafter simply referred to as "this embodiment"). Note that the following embodiment is illustrative for explaining the present invention, and the present invention is not limited to this embodiment. In this specification, "~" is used to mean that the numbers before and after it are included as the lower and upper limits, respectively. In this specification, all physical properties and characteristic values ​​shall be those at 23°C unless otherwise specified. In this specification, the number-average molecular weight is a polystyrene-equivalent value measured by GPC (gel permeation chromatography). If the standards described herein differ in measurement methods, etc., from year to year, unless otherwise specified, the standards as of January 1, 2021 shall apply.

[0008] The resin composition of this embodiment is characterized by containing 100 parts by mass of a thermoplastic resin and 0.08 to 3.50 ppm by mass of a non-aromatic organic iron complex. This configuration improves the light transmittance (particularly total light transmittance) of the thermoplastic resin. Furthermore, this effect can be maintained at a high level even when various resin additives are incorporated. Additionally, the inclusion of a non-aromatic organic iron complex effectively suppresses the increase in the YI value.

[0009] <Thermoplastic resin> The resin composition of this embodiment includes a thermoplastic resin. Examples of thermoplastic resins include polycarbonate resin (PC resin), polystyrene resin (PS resin), acrylic resin, polyethylene resin (PE resin), polypropylene resin (PP resin), cyclic cycloolefin resin (COP resin), cyclic cycloolefin copolymer (COC) resin, and other polyolefin resins; polyamide resin (PA resin); polyimide resin (PI resin); polyetherimide resin (PEI resin); polyurethane resin (PU resin); polyphenylene ether resin (PPE resin); polyphenylene sulfide resin (PPS resin); polysulfone resin (PSU resin); and polymethacrylate resin (PMMA resin). Polycarbonate resin (PC resin), polystyrene resin (PS resin), and acrylic resin are preferred, polycarbonate resin is more preferred, and aromatic polycarbonate resin is even more preferred.

[0010] The thermoplastic resin used in this embodiment may be a crystalline thermoplastic resin or an amorphous thermoplastic resin, but it is preferable to include an amorphous thermoplastic resin. Amorphous thermoplastic resins are transparent and therefore suitable for applications where improved light transmittance is required. However, even crystalline thermoplastic resins may be used as transparent materials, such as when molded without crystallization. In such cases, crystalline thermoplastic resins are also preferably used as the resin included in the resin composition of this embodiment. Furthermore, in this embodiment, a blend of amorphous and crystalline thermoplastic resins is also acceptable.

[0011] In this embodiment, it is preferable that the thermoplastic resin is preferably amorphous thermoplastic resin (preferably aromatic polycarbonate resin) at a concentration of 85% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and particularly preferably 97% by mass or more.

[0012] The polycarbonate resin is not particularly limited as long as it contains a carbonate ester bond-containing -[OR-OC(=O)]- unit in the molecular main chain (where R is an organic group, preferably a hydrocarbon group, more preferably an aliphatic group, an aromatic group, or a group containing both an aliphatic and an aromatic group, and furthermore, a linear or branched structure). In this embodiment, the polycarbonate resin is preferably an aromatic polycarbonate resin, and more preferably a polycarbonate resin having a bisphenol skeleton. By using such a polycarbonate resin, better heat resistance and toughness can be achieved. In this embodiment, in the polycarbonate resin having a bisphenol skeleton, it is preferable that 90 mol% or more of the total constituent units are bisphenol skeleton-containing units, and more preferably that 90 mol% or more of the total constituent units are bisphenol A-derived units.

[0013] Furthermore, the viscosity-average molecular weight (Mv) of the polycarbonate resin is preferably 10,000 or more, more preferably 12,000 or more, and even more preferably 15,000 or more. Setting it above the lower limit tends to further improve the durability of the resulting molded article. The upper limit of the viscosity-average molecular weight (Mv) of the polycarbonate resin is preferably 50,000 or less, more preferably 40,000 or less, even more preferably 30,000 or less, and even more preferably 25,000 or less. Setting it below the upper limit tends to further improve the moldability of the molded article. The viscosity-average molecular weight (Mv) is calculated using methylene chloride as the solvent, determining the intrinsic viscosity [η] (unit: dL / g) at 25°C using an Ubbelohde viscometer, and then using Schnell's viscosity formula, i.e., η = 1.23 × 10⁻⁶ -4 ×Mv 0.83 It means a value calculated from ,. When using two or more types of polycarbonate resin, the viscosity-average molecular weight of the mixture shall be used.

[0014] The method for producing the polycarbonate resin is not particularly limited, and those produced by conventionally known phosgene methods (interfacial polymerization methods) or melting methods (transesterification methods) can be used. Further, when the melting method is used, a polycarbonate resin with the amount of OH groups at the terminal groups adjusted can be used.

[0015] In addition to the above, details of the polycarbonate resin can be referred to the descriptions in paragraphs 0013 to 0041 of JP-A-2021-084942 and paragraphs 0030 to 0035 of JP-A-2021-119211, and this content is incorporated herein.

[0016] The content of the thermoplastic resin (preferably polycarbonate resin) in the resin composition of this embodiment is preferably 85% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, even more preferably 97% by mass or more, and even more preferably 98% by mass or more of the resin composition. The upper limit of the content of the thermoplastic resin in the resin composition is the amount at which the total of the thermoplastic resin (preferably polycarbonate resin) and the non-aromatic organic iron complex is 100% by mass. The resin composition of this embodiment may contain only one type of thermoplastic resin (preferably polycarbonate resin), or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0017] <Non-aromatic organic iron complex> The resin composition of this embodiment contains a non-aromatic organic iron complex at a predetermined ratio. By containing the non-aromatic organic iron complex at a predetermined ratio, the light transmittance can be improved. Non-aromatic organoiron complexes refer to organoiron complexes that do not contain aromatic rings (aromatic hydrocarbon rings and aromatic heterocycles). Aromatic organoiron complexes containing aromatic rings are used as colorants for thermoplastic resins, but when such colorants are added, the total light transmittance is usually lower. In addition, the YI value may also be higher. In this embodiment, we succeeded in increasing the light transmittance by adding a non-aromatic organoiron complex to the thermoplastic resin in a very small proportion. In particular, this is effective because it can maintain this function even when other resin additives are added.

[0018] The ligands constituting the aforementioned non-aromatic organic iron complex are not particularly limited as long as they are non-aromatic and act as iron ligands, but ligands whose coordination site is an oxygen atom are preferred, and ligands represented by the following formula (1) are more preferred. Formula (1) [ka] (In formula (1), R 1 ~R 3 Each of these is independently either a hydrogen atom or an organic group. * indicates a coordination site with iron. R 1 and R 3 Each of these groups is preferably an organic group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an alkoxy group having 2 to 11 carbon atoms, even more preferably an alkyl group having 1 to 10 carbon atoms, even more preferably a methyl group or an ethyl group, and even more preferably a methyl group. R 2 It is preferably a hydrogen atom or an organic group having 1 to 12 carbon atoms, more preferably a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an alkoxy group having 2 to 11 carbon atoms, even more preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, even more preferably a hydrogen atom, a methyl group, or an ethyl group, even more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom.

[0019] The non-aromatic organoiron complex of this embodiment preferably contains an acetylacetone iron complex. The acetylacetone iron complex is preferably a trivalent complex. [ka]

[0020] Furthermore, the acetylacetone iron complex in this embodiment includes not only a single acetylacetone iron complex but also a complex of a mixed ligand consisting of acetylacetone and other ligands. However, the acetylacetone iron complex in this embodiment is preferably a single acetylacetone iron complex.

[0021] The content of the non-aromatic organic iron complex (preferably acetylacetone iron complex) in the resin composition of this embodiment is 0.08 ppm by mass or more, preferably 0.09 ppm by mass or more, more preferably 0.10 ppm by mass or more, even more preferably 0.50 ppm by mass or more, even more preferably 0.70 ppm by mass or more, even more preferably 0.80 ppm by mass or more, and even more preferably 0.90 ppm by mass or more, per 100 parts by mass of thermoplastic resin. Setting the content above the lower limit tends to further improve the light transmittance of the resulting molded article. Furthermore, the upper limit of the content of the non-aromatic organic iron complex (preferably acetylacetone iron complex) is 3.50 ppm by mass or less, preferably 3.00 ppm by mass or less, more preferably 2.50 ppm by mass or less, even more preferably 2.00 ppm by mass or less, even more preferably 1.50 ppm by mass or less, and even more preferably 1.20 ppm by mass or less, per 100 parts by mass of thermoplastic resin. By setting it below the aforementioned upper limit, the YI value of the resulting molded body tends to be lower. The resin composition of this embodiment may contain only one non-aromatic organic iron complex (preferably an acetylacetone iron complex), or it may contain two or more. When two or more are included, it is preferable that the total amount is within the above range.

[0022] <Stabilizer> Examples of stabilizers include heat stabilizers and antioxidants. Other examples of stabilizers include phenolic, amine, phosphorus, and thioether-based stabilizers. In this embodiment, in particular, phosphorus-based heat stabilizers and / or phenolic antioxidants are preferred.

[0023] Any known phosphorus-based heat stabilizer can be used. Specific examples include phosphorus oxoacids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphate; acidic pyrophosphate metal salts such as sodium acidic pyrophosphate, potassium acidic pyrophosphate, and calcium acidic pyrophosphate; phosphates of Group 1 or Group 2B metals such as potassium phosphate, sodium phosphate, cesium phosphate, and zinc phosphate; and organic phosphate compounds, organic phosphite compounds, and organic phosphonite compounds, with organic phosphite compounds being particularly preferred.

[0024] Examples of organic phosphite compounds include triphenyl phosphite, tris(mononylphenyl) phosphite, tris(mononyl / dinonylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, monooctyldiphenyl phosphite, dioctylmonophenyl phosphite, monodecyldiphenyl phosphite, didecylmonophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, and 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite. Examples of such organic phosphite compounds include, for example, "ADEKA Stab (registered trademark; hereinafter the same) 1178," "ADEKA Stab 2112," and "ADEKA Stab HP-10" manufactured by ADEKA Corporation, "JP-351," "JP-360," and "JP-3CP" manufactured by Johoku Chemical Industry Co., Ltd., and "Irgaphos (registered trademark; hereinafter the same) 168" manufactured by BASF.

[0025] As a phenolic antioxidant, a hindered phenolic antioxidant is preferably used. Specific examples of hindered phenol antioxidants include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphate, 4,6-bis(octyl) Examples include ruthiomethyl)-o-cresol, ethylenebis(oxyethylene)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylenebis[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, 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazine-2-ylamino)phenol, and 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate.

[0026] Among these, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are preferred. Specific examples of such hindered phenol antioxidants include, for example, BASF's "Irganox (registered trademark; hereinafter the same) 1010" and "Irganox 1076," and ADEKA's "ADEKA Stab AO-50" and "ADEKA Stab AO-60."

[0027] The stabilizer content in the resin composition of this embodiment is typically 0.001 parts by mass or more, preferably 0.005 parts by mass or more, more preferably 0.01 parts by mass or more, and typically 1 part by mass or less, preferably 0.5 parts by mass or less, more preferably 0.3 parts by mass or less, per 100 parts by mass of thermoplastic resin. By setting the stabilizer content within the above range, the effect of adding the stabilizer is more effectively exerted. The resin composition of this embodiment may contain only one stabilizer or two or more stabilizers. When two or more stabilizers are included, it is preferable that the total amount is within the above range.

[0028] <Flame retardant> The resin composition of this embodiment may contain a flame retardant. By including a flame retardant, the flame retardancy of the resulting molded article can be further improved. Examples of flame retardants include metal salt-based flame retardants, organosilicon-based flame retardants, phosphorus-based flame retardants, inorganic filler-based flame retardants, and halogen-based flame retardants. In this embodiment, when polycarbonate resin is used as the thermoplastic resin, a metal salt-based flame retardant is preferred.

[0029] The metals contained in metal salt-based flame retardants are preferably alkali metals or alkaline earth metals, more preferably alkali metals, and even more preferably sodium, potassium, and cesium.

[0030] Examples of metal salt-based flame retardants include metal salts of organic sulfonic acids, metal salts of organic sulfonamides, metal salts of organic carboxylic acids, metal salts of organic borates, and metal salts of organic phosphates. Among these, metal salts of organic sulfonic acids, metal salts of organic sulfonamides, and metal salts of organic phosphates are preferred, with metal salts of organic sulfonic acids being particularly preferred.

[0031] As examples of metal organic sulfonic acid salts, the metal organic sulfonic acid salts described in paragraphs 0099 to 0107 of Japanese Patent Publication No. 2014-058660 can be considered, and the contents of these are incorporated herein by reference. Examples of metal salt-based flame retardants include Megafac F114P (manufactured by DIC Corporation), Biowet C4 (manufactured by Lanxess Corporation), IHT-FR2 (manufactured by Insight High Technology Corporation), and KSS-FR (manufactured by Arichem Corporation).

[0032] As halogen-based flame retardants, reference can be given to the halogen-based flame retardants described in paragraphs 0095 to 0112 of Japanese Patent Publication No. 2020-114674, and the contents of these are incorporated herein.

[0033] As phosphorus-based flame retardants, reference can be given to the phosphorus-based flame retardants described in paragraphs 0051 to 0072 of Japanese Patent Publication No. 2019-059813, and the contents of these are incorporated herein.

[0034] If the resin composition of this embodiment contains a flame retardant, the amount of the flame retardant is preferably 0.01 parts by mass or more per 100 parts by mass of thermoplastic resin, although this depends on the type of flame retardant. Furthermore, it may be 0.1 parts by mass or more, 1 part by mass or more, or 10 parts by mass or more. In addition, the upper limit of the amount of the flame retardant is preferably 20 parts by mass or less per 100 parts by mass of thermoplastic resin, and may be 10 parts by mass or less, 5 parts by mass or less, or 3 parts by mass or less, depending on the type of flame retardant. The resin composition of this embodiment may contain only one type of flame retardant, or it may contain two or more types. When it contains two or more types, it is preferable that the total amount is within the above range.

[0035] <Release agent> The resin composition of this embodiment may contain a mold release agent. Examples of release agents include aliphatic carboxylic acids, salts of aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds with a number average molecular weight of 200 to 15,000, polysiloxane-based silicone oils, ketone waxes, and light amides. Aliphatic carboxylic acids, salts of aliphatic carboxylic acids, and esters of aliphatic carboxylic acids and alcohols are preferred, and salts of aliphatic carboxylic acids are more preferred. Details of the release agent can be found in paragraphs 0055 to 0061 of Japanese Patent Publication No. 2018-095706, and these contents are incorporated herein by reference. If the resin composition of this embodiment contains a release agent, its content is preferably 0.05 to 3% by mass, more preferably 0.1 to 0.8% by mass, and even more preferably 0.1 to 0.6% by mass. The resin composition of this embodiment may contain only one type of release agent, or it may contain two or more types. When it contains two or more types, it is preferable that the total amount is within the above range.

[0036] <UV absorber> The resin composition of this embodiment may contain an ultraviolet absorber. By including an ultraviolet absorber, the weather resistance of the resin composition can be improved, and the improvement in weather resistance can prevent a decrease in transparency.

[0037] Examples of UV absorbers include inorganic UV absorbers such as cerium oxide and zinc oxide; and organic UV absorbers such as benzotriazole compounds, benzophenone compounds, salicylate compounds, cyanoacrylate compounds, triazine compounds, oxanilide compounds, malonic acid ester compounds, and hindered amine compounds. Among these, organic UV absorbers are preferred, and benzotriazole compounds are more preferred. By selecting an organic UV absorber, the transparency and mechanical properties of the thermoplastic resin composition of the present invention are improved.

[0038] Specific examples of benzotriazole compounds include, for example, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-[2'-hydroxy-3',5'-bis(α,α-dimethylbenzyl)phenyl]-benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butyl-phenyl)-benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butyl-phenyl)-5-chlorobenzotriazole), and 2-(2'-hydroxy-3',5'-di-tert Examples include (-amyl)-benzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, and 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2N-benzotriazole-2-yl)phenol], among which 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole and 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2N-benzotriazole-2-yl)phenol] are preferred, with 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole being particularly preferred. Examples of such benzotriazole compounds include, specifically, Cipro Chemical's "Seesorb 701 (S-701)", "Seesorb 705 (S-705)", "Seesorb 703 (S-703)", "Seesorb 702 (S-702)", "Seesorb 704 (S-704)", and "Seesorb 709 (S-709)", and Kyodo Pharmaceutical's "Biosorb 520", "Biosorb 582", and "Biosorb Examples include "580", "Biosorb 583", "Chemisorb 71" and "Chemisorb 72" from Chemipro Chemical Co., Ltd., "Siasorb UV5411" from Cytec Industries, "LA-32", "LA-38", "LA-36", "LA-34", and "LA-31" from ADEKA, and "Chinubin P", "Chinubin 234", "Chinubin 326", "Chinubin 327", and "Chinubin 328" from BASF.

[0039] Details of benzophenone compounds, salicylate compounds, cyanoacrylate compounds, oxanilide compounds, and malonic acid ester compounds can be found in paragraphs 0089 to 0093 of Japanese Patent Application Publication No. 2021-001309, the contents of which are incorporated herein by reference.

[0040] When the resin composition of this embodiment contains an ultraviolet absorber, its content is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and even more preferably 0.1 parts by mass or more, per 100 parts by mass of the thermoplastic resin. Setting the content above the lower limit tends to effectively exert the effect of adding the ultraviolet absorber. Furthermore, the upper limit of the ultraviolet absorber content is preferably 3 parts by mass or less, more preferably 1 part by mass or less, even more preferably 0.5 parts by mass or less, and even more preferably 0.4 parts by mass or less, per 100 parts by mass of the thermoplastic resin. Setting the content below the upper limit can effectively prevent mold contamination by mold deposits and the like. The resin composition of this embodiment may contain only one type of ultraviolet absorber, or it may contain two or more types. When it contains two or more types, it is preferable that the total amount is within the above range.

[0041] <Other ingredients> The resin composition of this embodiment may contain other components as needed, as long as they do not significantly impair the desired physical properties. Examples of other components include various resin additives. Examples of resin additives include colorants (dyes, pigments), antistatic agents, flame retardant additives, anti-dripping agents, anti-fogging agents, anti-blocking agents, flow improvers, plasticizers, dispersants, and antibacterial agents. The resin may contain only one type of additive, or two or more types in any combination and ratio. The resin composition of this embodiment may be substantially colorant-free. "Substantially colorant-free" means that the colorant content in the resin composition is less than 0.1% by mass, preferably less than 0.01% by mass, and more preferably less than 0.001% by mass. Furthermore, it is even more preferable that the colorant content per 100 parts by mass of thermoplastic resin in the resin composition be less than 1 ppm by mass, even more preferable less than 0.1 ppm by mass, even more preferable less than 0.08 ppm by mass, particularly preferable less than 0.01 ppm by mass, and most particularly preferable less than 0.001 ppm by mass. The lower limit may be 0, but will be substantially below the detection limit.

[0042] <Physical properties of resin compositions> The resin composition of this embodiment has a high rate of improvement in total light transmittance (light transmittance improvement ratio). Specifically, the total light transmittance of the resin composition of this embodiment is higher when molded to a thickness of 12 mm than when molded to a thickness of 12 mm The resin composition of this embodiment can achieve a low YI value. For example, when the resin composition of this embodiment is molded to a thickness of 12 mm, the YI value can be 6.0 or less, 5.0 or less, 3.5 or less, or 3.0 or less. While a lower limit of 0 is ideal for the YI value, a value of 0.1 or higher is sufficient to meet the required performance. The aforementioned light transmittance improvement ratio and YI value are measured according to the description in the examples below.

[0043] <Manufacturing of resin compositions> There are no limitations on the manufacturing method of the resin composition of this embodiment, and a wide range of known methods for manufacturing resin compositions can be employed. For example, a method may be used in which a thermoplastic resin, a non-aromatic organoiron complex, and other components to be added as needed are pre-mixed using various mixers such as a tumbler or a Henschel mixer, and then melt-kneaded using a mixer such as a Banbury mixer, roll, braver, single-screw extruder, twin-screw extruder, or kneader. The melt-kneading temperature is not particularly limited, but is usually in the range of 240 to 320°C. In this embodiment, a method for producing pellets is preferably disclosed, which includes melt-kneading a composition containing 0.08 to 3.50 ppm by mass of a non-aromatic organic iron complex with 100 parts by mass of thermoplastic resin. Here, the preferred ranges for the thermoplastic resin and non-aromatic metal-organic complex contained in the composition, as well as their content, are the same as those for the thermoplastic resin and non-aromatic metal-organic complex and their content in the resin composition of this embodiment. In addition, the composition may also contain other components described in the description of the resin composition of this embodiment.

[0044] <Molded body> The molded article of this embodiment is formed from the resin composition of this embodiment. The resin composition (for example, pellets) is molded into a molded article by various molding methods. There are no particular restrictions on the shape of the molded article, and it can be appropriately selected according to the application and purpose of the molded article. Examples include film-shaped, rod-shaped, cylindrical, annular, circular, elliptical, polygonal, irregularly shaped, hollow, frame-shaped, box-shaped, panel-shaped, button-shaped, etc.

[0045] The method for forming the molded article is not particularly limited, and conventionally known molding methods can be employed. Examples include injection molding, injection compression molding, extrusion molding, shape extrusion, transfer molding, hollow molding, gas-assisted hollow molding, blow molding, extrusion blow molding, IMC (in-mold coating) molding, rotational molding, multilayer molding, two-color molding, insert molding, sandwich molding, foam molding, and pressure molding. In particular, the resin composition of this embodiment is suitable for molded articles obtained by injection molding, injection compression molding, and extrusion molding. However, it goes without saying that the resin composition of this embodiment is not limited to molded articles obtained by these methods.

[0046] The molded article of this embodiment can be widely used in applications where transparency is required, particularly for molded articles containing thermoplastic resin. Specifically, it is preferably used in electrical and electronic equipment / components, office automation equipment / components, information terminal equipment / components, machine parts, home appliances, vehicle parts, building materials, various containers, leisure goods and miscellaneous items, lighting equipment, etc. More specifically, it is preferably used in power covers, lighting lenses, lighting covers, light guide members, etc.

[0047] <Light transmittance enhancer> This embodiment discloses a resin additive for improving the light transmittance of a thermoplastic resin, which includes a non-aromatic organoiron complex. Such a resin additive is particularly used as an improver of total light transmittance. The non-aromatic organic iron complex is preferably an acetylacetone iron complex. The details of the non-aromatic organic iron complex are the same as those described in the description of the resin composition of this embodiment above.

[0048] The light transmittance enhancer of this embodiment improves the light transmittance of thermoplastic resins, and is particularly preferred as a resin additive for improving the light transmittance of amorphous thermoplastic resins, and more preferably polycarbonate resins. The details of the thermoplastic resin are the same as those described in the description of the resin composition of this embodiment above. The light transmittance enhancer of this embodiment is preferably used in a ratio of 0.08 to 3.50 ppm by mass per 100 parts by mass of thermoplastic resin. The more preferable range is the same as the preferred range for the content of the non-aromatic organoiron complex in the resin composition of this embodiment described above. The light transmittance enhancer of this embodiment is usually preferably used by being blended with a thermoplastic resin and melt-kneaded together. [Examples]

[0049] The present invention will be described in more detail below with reference to examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate, as long as they do not depart from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. If the measuring instruments used in the examples are difficult to obtain due to discontinuation or other reasons, measurements can be taken using other instruments with equivalent performance.

[0050] 1.Raw materials The raw materials shown in Table 1 below were used. [Table 1]

[0051] 2. Examples 1-6, Comparative Examples 1-6 <Compound> Each component listed in Table 1 was blended in the proportions listed in Table 2 (all expressed in parts by mass, except for (B1) which is expressed in ppm by mass), and the mixture was uniformly mixed in a tumbler mixer to obtain a mixture. This mixture was supplied to a twin-screw extruder (Shibaura Machine Co., Ltd. "TEX26SX"), kneaded under the conditions of a screw rotation speed of 150 rpm, a discharge rate of 20 kg / hour, and a barrel temperature of 280°C, and extruded in a strand shape from the tip of the extrusion nozzle. The extruded material was rapidly cooled in a water bath and cut into pellets using a pelletizer to obtain pellets of the resin composition.

[0052] <Light transmittance improvement ratio> For each of the resin compositions obtained above, injection molding was carried out using an injection molding machine J85AD manufactured by Japan Steel Works, Ltd. under the conditions of a resin temperature of 280°C and a mold temperature of 80°C to obtain block pieces with a length of 50×50 mm and a thickness of 12 mm. Using these block pieces as test pieces, the total light transmittance of the 12-mm-thick test pieces was measured with a haze meter (NDH4000) manufactured by Nippon Denshoku Industries Co., Ltd. under a D65 light source in accordance with ASTM-D1003. Furthermore, the total light transmittance of a test piece without a non-aromatic organic iron complex (light transmittance improver) was measured, and the ratio of the total light transmittance of the test piece with the addition of the non-aromatic organic iron complex was calculated and defined as the light transmittance improvement ratio. That is, for Comparative Examples 1 to 4 and Examples 1 to 4, the light transmittance improvement ratio was calculated based on Comparative Example 1; for Comparative Example 5 and Example 5, and for Comparative Example 6 and Example 6, the light transmittance improvement ratio was calculated based on Comparative Example 5 and Comparative Example 6, respectively.

[0053] <YI value> Using the block pieces with a length of 50×50 mm and a thickness of 12 mm obtained above as test pieces, the YI (Yellow Index) value was measured by a spectrocolorimeter (SE6000) manufactured by Nippon Denshoku Industries Co., Ltd. using a C light source and a 2° field of view by the transmission method.

[0054] [Table 2]

[0055] As is clear from the above results, the resin composition of the present invention can improve the light transmittance and effectively suppress the increase in the YI value by blending a non-aromatic organic iron complex at a predetermined ratio (comparison between Examples 1 to 4 and Comparative Examples 1 to 4). Further, the improvement in the light transmittance showed a similar tendency without being affected by the blending of additives (comparison between Example 5 and Comparative Example 5, and between Example 6 and Comparative Example 6).

Claims

1. 100 parts by mass of thermoplastic resin, It contains 0.70 to 1.50 ppm by mass of a non-aromatic organoiron complex. The thermoplastic resin includes an amorphous resin, The aforementioned non-aromatic organic iron complex includes an acetylacetone iron complex. Resin composition.

2. The resin composition according to claim 1, wherein the thermoplastic resin includes an aromatic polycarbonate resin.

3. The resin composition according to claim 1 or 2, further comprising an organic phosphite compound in a proportion of 0.005 to 0.3 parts by mass per 100 parts by mass of the thermoplastic resin.

4. A molded article formed from the resin composition according to any one of claims 1 to 3.

5. The process involves melt-kneading a composition containing 100 parts by mass of thermoplastic resin and 0.70 to 1.50 ppm by mass of a non-aromatic organic iron complex. The thermoplastic resin includes an amorphous resin, The aforementioned non-aromatic organic iron complex includes an acetylacetone iron complex. A method for manufacturing pellets.

6. The method for producing pellets according to claim 5, wherein the composition further contains an organic phosphite compound in a proportion of 0.005 to 0.3 parts by mass per 100 parts by mass of the thermoplastic resin.

7. An additive for improving the light transmittance of amorphous thermoplastic resins containing metal salt-based flame retardants, comprising an acetylacetone iron complex as a light transmittance enhancer.

8. The light transmittance enhancer according to claim 7, wherein the amorphous thermoplastic resin is an aromatic polycarbonate resin.

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