Resin composition, pellets, molded article, and discoloration suppression method

Abstract

A resin composition containing, per 100 parts by mass of a thermoplastic resin: 0.001-10.0 parts by mass of a stabilizer; 0.1 to 10.0 parts by mass of an antibacterial agent containing silver; and 0.1-30 parts by mass of a halogen compound. A pellet, a molded article, and a discoloration suppression method.

Description

Technical Field

[0001] This invention relates to resin compositions, granulated articles, and methods for inhibiting discoloration. In particular, it relates to resin compositions with thermoplastic polyester resin as the main component. Background Technology

[0002] Thermoplastic polyester resins possess excellent mechanical strength, electrical properties, and physical / chemical properties, making them widely used as engineering plastics in hygiene fields such as automobiles, electrical / electronic equipment, and toilets / bathrooms. In recent years, the generation of bacteria or adverse effects on human health has become a concern in products using thermoplastic polyester resins. Furthermore, there is an increasing trend of imparting antibacterial properties to products to add value. One method for imparting antibacterial properties to thermoplastic polyester resins is by compounding commercially available antibacterial agents; however, depending on the type of antibacterial agent, sufficient antibacterial activity may not always be achieved. Therefore, thermoplastic polyester resin compositions with superior antibacterial properties are under investigation.

[0003] Specifically, Patent Document 1 discloses a flame-retardant polyester resin composition, which, relative to (A) a thermoplastic polyester resin, is formulated with the following components: (B) 0.1 to 5% by weight of an antibacterial agent of general formula (I) (in the entire composition), wherein the antibacterial agent is prepared by loading silver ions and hydrogen ions onto an alkali metal salt, alkaline earth metal salt, or ammonium salt of zirconium phosphate in a ratio of phosphate ions to zirconium ions of 3 / 2, and firing at 500 to 1300°C.

[0004] Ag a A b H c Zr2(PO4)3·nH2O(I)

[0005] (In the formula, A is at least one ion selected from alkali metal ions, alkaline earth metal ions, and ammonium ions; q is the valence of A; a and c are positive numbers; b is 0 or a positive number; and q, a, b, and c are numbers that satisfy a + qb + c = 1. In addition, n is a number that satisfies 0 ≤ n ≤ 6.)

[0006] (C) 1 to 30% by weight of the halogenated aromatic diimide compound represented by general formula (II) (in all compositions).

[0007] [Chemical Formula 1]

[0008]

[0009] (In the formula, R1 represents a divalent organic acid group, and R2 and R3 represent at least one of them as a divalent organic group having one or more halogen atoms X. n=1~4, n'=0~4).

[0010] Existing technical documents

[0011] Patent documents

[0012] Patent Document 1: Japanese Patent Application Publication No. 2002-348444 Summary of the Invention

[0013] The problem that the invention aims to solve

[0014] As mentioned above, antibacterial properties can be imparted to thermoplastic polyester resins by incorporating antibacterial agents containing silver.

[0015] On the other hand, in order to impart thermal stability to thermoplastic polyester resins, it is usually necessary to add stabilizers.

[0016] Here, the inventors conducted research and found that if a stabilizer is added to the thermoplastic polyester resin containing the antibacterial agent, the degree of discoloration of the resulting resin composition will increase.

[0017] The purpose of this invention is to solve the above-mentioned technical problems and to provide a resin composition, granules, molded articles, and a method for inhibiting discoloration that have excellent balance in antibacterial properties, thermal stability, and color stability.

[0018] Solution for solving the problem

[0019] Based on the above-mentioned technical problems, the inventors conducted research and found that by combining halogen compounds with thermoplastic resins, stabilizers, and silver-containing antibacterial agents, the above-mentioned technical problems can be solved.

[0020] Specifically, the above-mentioned technical problems were solved by the following means.

[0021] [1] A resin composition comprising, relative to 100 parts by weight of a thermoplastic resin:

[0022] Stabilizer 0.001 to 10.0 parts by weight; silver-containing antibacterial agent 0.1 to 10.0 parts by weight; and halogen compound 0.1 to 30 parts by weight.

[0023] [2] According to the resin composition of [1], wherein the mass ratio of halogen atoms contained in the resin composition to the stabilizer, i.e., halogen atoms / stabilizer, is 1.0 or more.

[0024] [3] The resin composition according to any one of [1] or [2], wherein the thermoplastic resin comprises a thermoplastic polyester resin.

[0025] [4] The resin composition according to [3], wherein the thermoplastic polyester resin comprises polybutylene terephthalate resin.

[0026] [5] The resin composition according to any one of [1] to [4], wherein the stabilizer comprises one or more compounds selected from the group consisting of thioether compounds, hindered phenolic compounds and phosphite compounds.

[0027] [6] The resin composition according to any one of [1] to [5], wherein the stabilizer comprises a thioether compound.

[0028] [7] The resin composition according to any one of [1] to [6], wherein the silver-containing antibacterial agent comprises an inorganic silver-based antibacterial agent.

[0029] [8] The resin composition according to any one of [1] to [7], wherein the silver-containing antibacterial agent comprises a glass-based antibacterial agent.

[0030] [9] The resin composition according to any one of [1] to [8], wherein the halogen compound comprises bromine atoms and / or fluorine atoms.

[0031]

[10] The resin composition according to any one of [1] to [9], wherein the halogen compound contains fluorine atoms.

[0032]

[11] The resin composition according to any one of [1] to

[10] , wherein the halogen compound contains bromine atoms.

[0033]

[12] The resin composition according to

[11] wherein the free bromine content of the halogen compound is 0.5% by mass or more.

[0034]

[13] A resin composition for use in sanitary applications, the resin composition comprising: a thermoplastic polyester resin having an intrinsic viscosity of 1.0 dL / g or higher; an antibacterial agent containing silver; and titanium dioxide.

[0035]

[14] According to the resin composition of [1], wherein the mass ratio of halogen atoms in the resin composition to the stabilizer, i.e., halogen atoms / stabilizer, is 1.0 or more, the thermoplastic resin comprises polybutylene terephthalate resin, the stabilizer comprises one or more compounds selected from the group consisting of hindered phenolic compounds and phosphite compounds, the silver-containing antibacterial agent comprises a glass-based antibacterial agent, and the halogen compound comprises bromine atoms and / or fluorine atoms.

[0036]

[15] A particle, which is a particle of the resin composition according to any one of [1] to

[14] .

[0037]

[16] A molded article formed from a resin composition according to any one of [1] to

[14] .

[0038]

[17] A molded article formed from particles according to

[15] .

[0039]

[18] The molded article according to

[16] or

[17] is a sanitary component.

[0040]

[19] A method for inhibiting discoloration, comprising a resin composition containing 0.001 to 10.0 parts by weight of a stabilizer and 0.1 to 10.0 parts by weight of an antibacterial agent containing silver relative to 100 parts by weight of a thermoplastic resin, the method comprising: adding 0.1 to 30 parts by weight of a halogen compound relative to 100 parts by weight of the thermoplastic resin.

[0041]

[20] A method for suppressing discoloration, comprising a resin composition containing 0.01 to 1.0 parts by weight of a stabilizer and 0.1 to 3.0 parts by weight of an antibacterial agent containing silver relative to 100 parts by weight of a thermoplastic polyester resin, the method comprising: adding 0.1 to 30 parts by weight of a halogen compound relative to 100 parts by weight of the thermoplastic polyester resin.

[0042] Invention Effects

[0043] According to the present invention, it is possible to provide resin compositions, particles, molded articles, and methods for inhibiting discoloration that exhibit excellent balance in antibacterial properties, thermal stability, and color stability. Detailed Implementation

[0044] The following describes in detail the methods for implementing the present invention (hereinafter referred to only as "this embodiment"). It should be noted that the following embodiment is an example for illustrating the present invention, and the present invention is not limited to this embodiment.

[0045] It should be noted that in this specification, "~" is used to include the values ​​recorded before and after it as the lower limit and upper limit values.

[0046] Unless otherwise specified, all physical property values ​​and characteristic values ​​in this specification refer to those at 23°C.

[0047] In this specification, unless otherwise specified, the weight-average molecular weight and number-average molecular weight are as follows: determined by GPC (gel permeation chromatography) using a Tosoh HLC-8320GPC EcoSEC, tetrahydrofuran as solvent, Shodex KF-G, KF-805L×3, and KF-800D columns at a column temperature of 40°C and a flow rate of 1.2 mL / min, with the polystyrene conversion value detected at a wavelength of 254 nm.

[0048] Unless otherwise specified, the measurement methods described in the standards shown in this instruction manual may vary depending on the year, and are based on the standards at the time of January 1, 2023.

[0049] The resin composition of this embodiment is characterized in that, relative to 100 parts by weight of the thermoplastic resin, it comprises 0.001 to 10.0 parts by weight of a stabilizer, 0.1 to 10.0 parts by weight of a silver-containing antibacterial agent, and 0.1 to 30 parts by weight of a halogen compound. With this configuration, a resin composition exhibiting excellent balance of antibacterial properties, thermal stability, and color stability can be obtained.

[0050] It is speculated that silver, due to its high reactivity, would react with sulfur, phosphorus, and other substances contained in the stabilizer, causing discoloration of the resin composition. In this embodiment, it is speculated that by coordinating with a halogen compound, the halogen would be coordinated around the silver, inhibiting the interaction between silver and the stabilizer.

[0051] Moreover, by using a specified amount of halogenated flame retardant as a halogen compound, the antibacterial properties, thermal stability, and color stability of the resin composition can be maintained at a high level, and the flame retardancy can also be improved.

[0052] <Thermoplastic Resins>

[0053] The resin composition of this embodiment comprises a thermoplastic resin.

[0054] Examples of thermoplastic resins used in this embodiment include: polyester resin (thermoplastic polyester resin), polyamide resin, polycarbonate resin, polystyrene resin, polyethylene resin, polypropylene resin, cyclic olefin resin, polyacetal resin, polyimide resin, polyetherimide resin, polyurethane resin, polyphenylene ether resin, polyphenylene sulfide resin, polysulfone resin, polymethyl methacrylate resin, etc., with thermoplastic polyester resin being preferred.

[0055] The resin composition of this embodiment may contain only one thermoplastic resin or may contain two or more.

[0056] The resin composition of this embodiment may be an alloy formed by mixing two or more thermoplastic resins.

[0057] For example, examples can be given of combining polybutylene terephthalate resin with polycarbonate resin, polybutylene terephthalate resin with polyethylene terephthalate resin, and polybutylene terephthalate resin with polystyrene resin.

[0058] <<Thermoplastic Polyester Resin>>

[0059] There are no particular limitations on the type of thermoplastic polyester resin, but it is preferred to include alkylene terephthalate resin, more preferably ethylene terephthalate resin and / or butylene terephthalate resin, and even more preferably butylene terephthalate resin.

[0060] Polyalkylene terephthalate resin is a polyester obtained by polycondensation of terephthalic acid (a dicarboxylic acid compound) and diol, and can be either homopolymer or copolyester.

[0061] As the dicarboxylic acid compound constituting the polyalkylene terephthalate resin, a terephthalic acid compound or its ester-forming derivative is preferably used.

[0062] Aromatic dicarboxylic acids other than terephthalic acid can also be used in combination, such as isophthalic acid, phthalic acid, 1,5-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyl-2,2'-dicarboxylic acid, biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenyl sulfone-4,4'-dicarboxylic acid, diphenyl isopropylidene-4,4'-dicarboxylic acid, 1,2-bis(phenoxy)ethane-4,4'-dicarboxylic acid, anthracene-2,5-dicarboxylic acid, anthracene-2,6-dicarboxylic acid, p-tert-butylphenylene-4,4'-dicarboxylic acid, pyridine-2,5-dicarboxylic acid, etc. In addition to being free acids, they can also be used as ester-forming derivatives such as dimethyl esters in polycondensation reactions. Of the above, isophthalic acid or its ester-forming derivatives are particularly preferred.

[0063] It should be noted that, if the quantity is small, it can be used in combination with terephthalic acid, the above-mentioned aromatic dicarboxylic acids, adipic acid, azelaic acid, dodecanoic acid, sebacic acid and other aliphatic dicarboxylic acids, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid and other alicyclic dicarboxylic acids.

[0064] Examples of dihydroxy compounds constituting polyalkylene terephthalate resins include: ethylene glycol, propylene glycol, 1,4-butanediol, hexanediol, neopentyl glycol, 2-methylpropane-1,3-diol, diethylene glycol, triethylene glycol, and other aliphatic diols, cyclohexane-1,4-diethanol, and mixtures thereof. Among these, 1,4-butanediol and ethylene glycol are particularly preferred.

[0065] It should be noted that one or more long-chain diols with a molecular weight of 400 to 6000, such as polyethylene glycol, poly1,3-propanediol, and polytetramethylene glycol, can also be copolymerized. In addition, aromatic diols such as hydroquinone, resorcinol, naphthalene glycol, dihydroxydiphenyl ether, and 2,2-bis(4-hydroxyphenyl)propane can also be used.

[0066] In addition to the difunctional monomers mentioned above, trifunctional monomers such as trimellitic acid, pyromellitic acid, pyromellitic acid, pentaerythritol, and trimethylolpropane can be used in small amounts to introduce branched structures. In order to adjust the molecular weight, monofunctional compounds such as fatty acids can also be used in small amounts.

[0067] As the polyalkylene terephthalate resin, a resin mainly formed by the condensation polymerization of terephthalic acid and a glycol is preferred. Specifically, the resin is preferably composed of more than 50% by mass of the total resin, more preferably 70% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more, even more preferably 95% by mass or more, and still more preferably 99% by mass or more of the resin formed from this condensation polymer. As the glycol, an aliphatic glycol is preferred, preferably 1,4-butanediol or ethylene glycol, more preferably 1,4-butanediol.

[0068] The amount of terminal carboxyl groups in the thermoplastic polyester resin (preferably polybutylene terephthalate resin) can be appropriately selected and determined, typically 60 eq / ton or less, preferably 50 eq / ton or less, and more preferably 30 eq / ton or less. By setting it to 60 eq / ton or less, there is a tendency to more effectively suppress gas generation during melt molding of the resin composition. The lower limit of the amount of terminal carboxyl groups is not particularly limited, typically 3 eq / ton or more, preferably 5 eq / ton or more, and more preferably typically 10 eq / ton or more.

[0069] It should be noted that the amount of terminal carboxyl groups in the thermoplastic polyester resin is determined by titration using a 0.01 mol / L benzyl alcohol solution containing sodium hydroxide, with 0.5 g of the resin dissolved in 25 mL of benzyl alcohol. Adjusting the amount of terminal carboxyl groups can be achieved through any conventionally known method, such as adjusting the polymerization conditions (e.g., feed ratio, polymerization temperature, reduced pressure method) or reacting the end-capping agent.

[0070] The intrinsic viscosity of the thermoplastic polyester resin (preferably polybutylene terephthalate resin) is preferably 0.60 dL / g or higher, more preferably 0.70 dL / g or higher, even more preferably 0.80 dL / g or higher, further preferably 0.90 dL / g or higher, and even more preferably 1.00 dL / g or higher. Setting this value above the lower limit effectively suppresses the reduction in physical properties such as strength. Furthermore, the intrinsic viscosity of the thermoplastic polyester resin (preferably polybutylene terephthalate resin) is preferably 2.0 dL / g or lower, more preferably 1.8 dL / g or lower, even more preferably 1.5 dL / g or lower, even more preferably 1.3 dL / g or lower, and even more preferably 1.2 dL / g or lower. Setting this value below the upper limit effectively suppresses the reduction in flowability.

[0071] Intrinsic viscosity was determined by the following method.

[0072] Particles of thermoplastic polyester resin were dissolved in a mixed solvent of phenol and 1,1,2,2-tetrachloroethane (mass ratio 1 / 1) at 110°C for 1 hour with stirring. The solution was then cooled to 30°C. Using an automated solution viscometer, the drop times of the sample solution and the drop times of the solvent alone were measured at 30°C, and the intrinsic viscosity was calculated using a formula.

[0073] Intrinsic viscosity = ((1+4K)) H η sp ) 0.5 -1) / (2K) H C)

[0074] Here, η sp =η / η0-1, where η is the number of seconds the sample solution falls, η0 is the number of seconds the solvent alone falls, C is the concentration of the sample solution (g / dL), and K H K is the Hutchins constant. H Use 0.33.

[0075] The fully automated solution viscometer uses a viscometer manufactured by Shibayama Scientific Corporation.

[0076] In the case where the resin composition of this embodiment contains two or more thermoplastic polyester resins, the intrinsic viscosity of the mixture is set.

[0077] The catalyst used in the esterification reaction can be any known catalyst, such as titanium compounds, tin compounds, magnesium compounds, calcium compounds, etc. Among these, titanium compounds are particularly preferred. Specific examples of titanium compounds as esterification catalysts include titanium alkoxides such as tetramethyl titanate, tetraisopropyl titanate, and tetrabutyl titanate, and titanium phenolates such as tetraphenyl titanate.

[0078] Polybutylene terephthalate resin can be a polybutylene terephthalate resin modified by copolymerization (hereinafter, sometimes also referred to as "modified polybutylene terephthalate resin"). As specific preferred copolymers, examples include polyester ether resins copolymerized from polyalkylene glycols (especially polytetramethylene glycol), dimer acid copolymerized polybutylene terephthalate resins, and isophthalic acid copolymerized polybutylene terephthalate resins.

[0079] When using a polyester ether resin copolymerized from polytetramethylene glycol as a modified polybutylene terephthalate resin, the proportion of tetramethylene glycol in the copolymer is preferably 3 to 40% by mass, more preferably 5 to 30% by mass, and even more preferably 10 to 25% by mass.

[0080] When using dimer acid copolymerized polybutylene terephthalate resin as modified polybutylene terephthalate resin, the proportion of dimer acid component in the total carboxylic acid component, calculated by carboxylic acid groups, is preferably 0.5 to 30 mol%, more preferably 1 to 20 mol%, and even more preferably 3 to 15 mol%.

[0081] When using isophthalic acid copolymer polybutylene terephthalate resin as the modified polybutylene terephthalate resin, the proportion of isophthalic acid in the total carboxylic acid components, calculated by carboxylic acid groups, is preferably 1 to 30 mol%, more preferably 1 to 20 mol%, and even more preferably 3 to 15 mol%.

[0082] Among the modified polybutylene terephthalate resins, polyester ether resins copolymerized from polytetramethylene glycol and polybutylene terephthalate resins copolymerized from isophthalic acid are preferred.

[0083] <<Styrene-based Resins>>

[0084] Examples of polystyrene-based resins include homopolymers of styrene monomers and copolymers of styrene monomers with monomers that can copolymerize with styrene monomers. In copolymers of styrene monomers and copolymerizable monomers, preferably 50% or more by mass of all monomers are styrene monomers, more preferably 60% or more by mass of styrene monomers, and further preferably 100% or less by mass of styrene monomers.

[0085] Styrene monomers refer to styrene and styrene with substituents, including: styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, ethylstyrene, dimethylstyrene, p-tert-butylstyrene, vinylnaphthalene, methoxystyrene, monobromostyrene, dibromostyrene, fluorostyrene, tribromostyrene, etc., with styrene and α-methylstyrene being more preferred, and styrene being particularly preferred.

[0086] In addition, monomers that are not styrene monomers and constitute styrene-based resins include: (meth)acrylate monomers, maleimide monomers such as maleimide, N-methylmaleimide, and N-phenylmaleimide, acrylic acid, methacrylic acid, maleic acid anhydride, phthalic acid, itaconic acid and other α,β-unsaturated carboxylic acids and their anhydrides, and rubber such as butadiene.

[0087] The polystyrene resin used in this embodiment may include rubber-reinforced polystyrene resin. Specific examples of rubber-reinforced polystyrene resins include acrylonitrile-styrene copolymer (AS resin), high-impact polystyrene resin (HIPS), acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-acrylic rubber-styrene copolymer (AAS resin), acrylonitrile-styrene-acrylic rubber copolymer (ASA resin), acrylonitrile-ethylene-propylene rubber-styrene copolymer (AES resin), and styrene-IPN type rubber copolymer, etc.

[0088] In this embodiment, a portion of the polystyrene-based resin is preferably a styrene-maleic acid polymer (preferably a styrene-maleic anhydride polymer). The styrene-maleic acid polymer acts as a compatibilizer between the polyester resin and the polystyrene resin and / or the rubber-reinforced polystyrene resin. As a result, the strength of the obtained molded article can be improved.

[0089] In this embodiment, the polystyrene-based resin preferably includes at least one selected from polystyrene resin (GPPS), acrylonitrile-styrene copolymer (AS resin), high-impact polystyrene resin (HIPS), acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-acrylic rubber-styrene copolymer (AAS resin), acrylonitrile-styrene-acrylic rubber copolymer (ASA resin), and acrylonitrile-ethylene-propylene rubber-styrene copolymer (AES resin), and more preferably includes high-impact polystyrene resin (HIPS). Furthermore, from the viewpoint of heat resistance, polystyrene resin (GPPS) and acrylonitrile-styrene copolymer (AS resin) are more preferred.

[0090] The styrene-based resin used in this embodiment can be either virgin styrene-based resin or recycled amorphous styrene-based resin.

[0091] <<Polycarbonate resin>>

[0092] Polycarbonate resins are thermoplastic polymers or copolymers that are optionally branched and obtained by reacting a dihydroxy compound or a compound with a small amount of a polyhydroxy compound with phosgene or diester.

[0093] The dihydroxy compound of the raw material substantially does not contain bromine atoms, and is preferably an aromatic dihydroxy compound. Specifically, examples include 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A), tetramethylbisphenol A, bis(4-hydroxyphenyl)-p-diisopropylbenzene, hydroquinone, resorcinol, 4,4-dihydroxybiphenyl, etc., with bisphenol A being a preferred example. Furthermore, compounds in which one or more tetraalkylphosphonium sulfonate atoms are bonded to the aforementioned aromatic dihydroxy compound may also be used.

[0094] Of the polycarbonate resins described above, aromatic polycarbonate resins derived from 2,2-bis(4-hydroxyphenyl)propane are preferred, as are aromatic polycarbonate copolymers derived from 2,2-bis(4-hydroxyphenyl)propane and other aromatic dihydroxy compounds. Alternatively, copolymers based on aromatic polycarbonate resins, such as copolymers with polymers or oligomers having a siloxane structure, may also be used. Furthermore, two or more of the aforementioned polycarbonate resins may be used in combination.

[0095] To adjust the molecular weight of polycarbonate resin, monoary aromatic hydroxyl compounds can be used, such as m-methylphenol and p-methylphenol, m-propylphenol and p-propylphenol, p-tert-butylphenol, p-long-chain alkyl-substituted phenols, etc.

[0096] The viscosity-average molecular weight (Mv) of the polycarbonate resin is preferably 10,000 or more, more preferably 12,000 or more, even more preferably 13,000 or more, and particularly preferably greater than 14,000. If a substance with a viscosity-average molecular weight lower than 10,000 is used, the resulting resin composition is prone to having low mechanical strength, such as impact resistance. Furthermore, Mv is preferably 60,000 or less, more preferably 40,000 or less, even more preferably 35,000 or less, and even more preferably 30,000 or less, but it can also be 25,000 or less, or 20,000 or less. If it is higher than 60,000, the flowability of the resin composition may deteriorate, and the moldability may be worsened.

[0097] It should be noted that, in this invention, the viscosity-average molecular weight (Mv) of polycarbonate resin represents the intrinsic viscosity ([η]) obtained by measuring the viscosity of a dichloromethane solution of polycarbonate resin at 25°C using an Ubbelohde viscometer, and then calculating the value according to the following Schnell viscosity formula.

[0098] [η] = 1.23 × 10 -4 Mv 0.83

[0099] The melt flow rate (MFR) of the polycarbonate resin, as determined according to JIS K7210 (temperature 300°C, load 1.20 kgf), is preferably 3 to 100 g / 10 min, more preferably 6 to 70 g / 10 min. If the MFR is within the above range, there is a tendency to more effectively exert the effects of the present invention.

[0100] The melt volumetric flow rate (MVR) of the polycarbonate resin, as determined according to JIS K7210 (temperature 300°C, load 1.20 kgf), is preferably 0.5–20 cm⁻¹. 3 g / 10 minutes, more preferably 1-10 cm 3 / 10 minutes. If the MVR is within the above range, there is a tendency to achieve the effects of the invention more effectively.

[0101] There is no particular limitation on the manufacturing method of polycarbonate resin; polycarbonate resin manufactured by either the phosgene method (interfacial polymerization) or the melt method (transesterification) can be used. Furthermore, polycarbonate resin obtained by performing post-treatment to adjust the amount of terminal OH groups on polycarbonate resin manufactured by the melt method is preferred.

[0102] The polycarbonate resin used in this embodiment can be either virgin polycarbonate resin or recycled polycarbonate resin.

[0103] An example of the mixed form of thermoplastic resin in this embodiment is that 70% or more, preferably 80% or more, 85% or more, 90% or more, or 95% or more of the thermoplastic resin contained in the resin composition is thermoplastic polyester resin (preferably polyalkylene terephthalate resin, more preferably polybutylene terephthalate resin).

[0104] An example of the mixed form of thermoplastic resin in this embodiment is that the thermoplastic resin contained in the resin composition comprises 70% or more, preferably 80% or more, 85% or more, 90% or more, or 95% or more of thermoplastic resin, which is thermoplastic polyester resin (preferably polybutylene terephthalate resin), as well as polystyrene resin and / or polycarbonate resin. In this embodiment, the thermoplastic polyester resin contained in the resin composition is preferably 50% or more, more preferably 55% or more, and further preferably 80% or less, more preferably 75% or less.

[0105] The content of thermoplastic resin in the resin composition of this embodiment is preferably 70% by mass or more, more preferably 75% by mass or more, and even more preferably 80% by mass or more. Depending on the application, it may also be 85% by mass or more, 90% by mass or more, or 95% by mass or more. In addition, it is preferably 99% by mass or less. Depending on the application, it may also be 95% by mass or less or 90% by mass or less.

[0106] The resin composition of this embodiment may contain only one thermoplastic resin, or it may contain two or more. When it contains two or more, the total amount is preferably within the range described above.

[0107] Stabilizer

[0108] The resin composition of this embodiment preferably includes a stabilizer. By including the stabilizer, a resin composition or molded article with excellent thermal stability can be obtained.

[0109] The stabilizer preferably comprises one or more compounds selected from the group consisting of thioether compounds, hindered phenolic compounds, and phosphite compounds, more preferably comprises one or more compounds selected from the group consisting of hindered phenolic compounds and phosphite compounds, and even more preferably comprises thioether compounds.

[0110] In this embodiment, it is also preferable to use two or more of the following compounds: thioether compounds, hindered phenolic compounds, and phosphite compounds, as needed. By using two or more stabilizers in this way, there is a tendency to further improve thermal stability and thus maintain thermal stability over a long period of time.

[0111] As a thioether compound, any sulfur-containing compound known in the art can be used, with thioethers being preferred. The resin composition of this embodiment, by including a thioether compound, tends to have a better appearance of the molded article and improved thermal stability. Specifically, examples include: didodecyl thiodipropionate, ditetradecyl thiodipropionate, dioctadecyl thiodipropionate, pentaerythritol tetra(3-dodecyl thiopropionate), 2,2-bis{[3-(dodecylthio)-1-oxopropoxy]methyl}propane-1,3-diylbis[3-(dodecylthio)propionate], thiobis(N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickel dibutyldithiocarbamate, nickel isopropyl xanthate, and trilauryl trithiophosphite. Among them, 2,2-bis{[3-(dodecylthio)-1-oxopropoxy]methyl}propane-1,3-dimethylbis[3-(dodecylthio)propionate] is preferred. Commercially available examples include Shipro Kasei Co., Ltd., under the trade name "Cinox412S", and ADEKA Co., Ltd., under the trade name "ADK STAB AO-412S".

[0112] Examples of hindered phenolic compounds include pentaerythritol tetra(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), pentaerythritol tetra(3-(3,5-dineopentyl-4-hydroxyphenyl)propionate), and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene. Among these, pentaerythritol tetra(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are preferred. Commercially available examples include those manufactured by ADEKA under the trade names "ADK STAB AO-60" and "ADK STAB AO-330".

[0113] As phosphite compounds, compounds represented by the following formula are preferred:

[0114] R 2 OP (OR) 3 (OR) 4 )

[0115] (where R) 2 R 3 and R 4 They are, respectively, an alkyl group with 1 to 30 carbon atoms or an aryl group with 6 to 30 carbon atoms, R 2 R 3 and R 4 At least one of them is an aryl group having 6 to 30 carbon atoms.

[0116] Examples of phosphite compounds include: triphenyl phosphite, tris(nonylphenyl) phosphite, dilauryl hydrogen phosphite, triethyl phosphite, tridecyl phosphite, tri(2-ethylhexyl) phosphite, tri(tridecyl) phosphite, tristearate phosphite, diphenylmonodecane phosphite, monophenyldidecyl phosphite, diphenylmonodecane phosphite, tetraphenyldipropylene glycol diphosphite, tetraphenyltetra(tridecyl)pentaerythritol tetraphosphite, hydrogenated bisphenol A phenyl phosphite polymer, diphenyl hydrogen phosphite, 4,4'-butylene-bis(3-methyl-6-tert-butylphenyl di(tridecyl)phosphite, tetra(tridecyl)4, 4'-Isopropylidene diphenyl diphosphite, bis(tetranyl)pentaerythritol diphosphite, bis(nonylphenyl)pentaerythritol diphosphite, dilauryl pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tris(4-tert-butylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, hydrogenated bisphenol A pentaerythritol phosphite polymer, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, 2,2'-methylene bis(4,6-di-tert-butylphenyl)octyl phosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, etc. Among these, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is preferred. As a commercially available product, one example is the product manufactured by ADEKA under the brand name "ADK STABPEP-36".

[0117] Furthermore, as a stabilizer, specifically, reference can be made to paragraphs 0067 to 0075 of Japanese Patent Application Publication No. 2021-063196, paragraphs 0046 to 0057 of Japanese Patent Application Publication No. 2018-070722, paragraphs 0030 to 0037 of Japanese Patent Application Publication No. 2019-056035, and paragraphs 0066 to 0078 of International Publication No. 2017 / 038949, all of which are incorporated herein by reference.

[0118] Relative to 100 parts by weight of thermoplastic polyester resin, the stabilizer content in the resin composition of this embodiment is 0.001 parts by weight or more, preferably 0.01 parts by weight or more, more preferably 0.03 parts by weight or more, further preferably 0.05 parts by weight or more, and even more preferably 0.1 parts by weight or more. By setting it to the lower limit or above, there is a tendency to further improve the inhibition effect of resin thermal degradation and oxidative degradation during melt mixing, molding, and use in the form of molded articles, and there is a tendency to improve heat resistance. In addition, relative to the total 100 parts by weight of thermoplastic polyester resin, the upper limit of the stabilizer content is 10.0 parts by weight or less, preferably 1.0 parts by weight or less, more preferably 0.8 parts by weight or less, more preferably 0.6 parts by weight or less, further preferably 0.5 parts by weight or less, even more preferably 0.4 parts by weight or less, even more preferably 0.3 parts by weight or less, and even more preferably 0.24 parts by weight or less. By setting the value below the aforementioned upper limit, there is a tendency to effectively suppress adverse effects on appearance and physical properties caused by the aggregation of additives such as stabilizers, and there is a tendency to suppress discoloration of the resin composition.

[0119] The resin composition of this embodiment may contain only one stabilizer or two or more stabilizers. When two or more stabilizers are contained, the total amount is preferably within the range described above.

[0120] Furthermore, the resin composition of this embodiment may be substantially free of stabilizers. "Substantially free of stabilizers" means, for example, that the stabilizer content is less than 0.001 parts by weight relative to 100 parts by weight of the thermoplastic resin; it may be less than 0.0001 parts by weight or even 0 parts by weight.

[0121] Without stabilizers, resin compositions can discolor upon retention, but this can be mitigated by adding colorants. For example, to achieve whiteness, the addition of titanium dioxide can create a composition that is essentially free of stabilizers.

[0122] <Antibacterial agents containing silver>

[0123] The resin composition of this embodiment contains an antibacterial agent comprising silver. By including the antibacterial agent, a resin composition or molded article with excellent antibacterial properties can be obtained.

[0124] In this embodiment, the silver-containing antibacterial agent is generally preferred to be an inorganic antibacterial agent that dissolves silver ions (an inorganic silver-based antibacterial agent). More specifically, the silver-containing antibacterial agent in this embodiment is an antibacterial agent in which silver (preferably silver ions) is supported, such as zeolite, glass, or phosphate compound, and preferably exhibits an antibacterial effect by releasing silver (preferably silver ions).

[0125] In addition to silver (preferably silver ions), antibacterial agents containing silver can also carry other metals. Examples of metals other than silver include copper (preferably copper ions) and zinc (preferably zinc ions).

[0126] The silver-containing antibacterial agent in this embodiment preferably contains a glass-based antibacterial agent.

[0127] The silver-containing antibacterial agent used in this embodiment preferably does not substantially contain zeolite. "Substantially does not contain" means that, when the total amount of the silver-containing antibacterial agent is set to 100 parts by weight, the zeolite content is less than 10 parts by weight, preferably less than 1 part by weight, more preferably less than 0.1 parts by weight, and even more preferably less than 0.01 parts by weight.

[0128] As a glass-based antibacterial agent, examples include soluble glasses in which silver (preferably silver ions) is leached out. Examples of soluble glasses include P2O5-RO-R2O type glasses or B2O3-SiO2-R2O type glasses (RO is an oxide of alkaline earth metals such as CaO and MgO, and R2O is an oxide of alkali metals such as Li2O, Na2O, and K2O).

[0129] In this embodiment, the average particle size of the silver-containing antibacterial agent is preferably 20 μm or less, more preferably 15 μm or less, and may also be 1.5 μm or less, or even 0.01 μm or more. The average particle size refers to the diameter converted to a sphere of the same volume as the silver-containing antibacterial agent, and its value is the number-average particle size.

[0130] The silver-containing antibacterial agent can be incorporated into the resin composition in the form of a masterbatch. When mastering the silver-containing antibacterial agent, the resin used in the masterbatch is preferably a thermoplastic polyester resin, more preferably polyethylene terephthalate resin and / or polybutylene terephthalate resin. The concentration of the silver-containing antibacterial agent during mastering is preferably 1 to 50% by mass, more preferably 5 to 30% by mass.

[0131] In particular, when the resin composition of this embodiment contains a flame retardant, it is preferable to also masterbatch the silver-containing antibacterial agent. With such a configuration, there is a tendency to further improve the productivity of the resin composition (e.g., granules).

[0132] Commercially available products include "Bactekiller" (BM-102NS(SB), BM-103CL, BM-103CK, BM-103NA, FK-68, etc.) manufactured by Fuji Chemical Co., Ltd., "Million Guard" manufactured by Hsing-A Glass Co., Ltd., and "Novaron" manufactured by Toa Synthetic Co., Ltd.

[0133] Relative to 100 parts by weight of the thermoplastic polyester resin, the content of the silver-containing antibacterial agent in the resin composition of this embodiment is 0.1 parts by weight or more, preferably 0.2 parts by weight or more, more preferably 0.3 parts by weight or more, and even more preferably 0.4 parts by weight or more. By setting this lower limit value or above, there is a tendency to further improve the antibacterial properties of the obtained molded article. Furthermore, relative to 100 parts by weight of the thermoplastic polyester resin, the upper limit value of the content of the silver-containing antibacterial agent is 10.0 parts by weight or less, preferably 3.0 parts by weight or less, more preferably 2.5 parts by weight or less, more preferably 2.0 parts by weight or less, even more preferably 1.5 parts by weight or less, further preferably 1.0 parts by weight or less, even more preferably 0.9 parts by weight or less, and even more preferably 0.6 parts by weight or less. By setting this upper limit value or below, there is a tendency to more effectively suppress color changes in the obtained molded article.

[0134] It should be noted that when mastering silver-containing antibacterial agents, the amount of resin used in the masterbatch is not included in the above-mentioned content.

[0135] The resin composition of this embodiment may contain only one silver-containing antibacterial agent, or it may contain two or more. When two or more are contained, the total amount is preferably within the range described above.

[0136] <Halogen compounds>

[0137] The resin composition of this embodiment contains a halogen compound. By including a halogen compound, a resin composition or molded article with excellent color stability can be obtained.

[0138] The halogen compound used in this embodiment preferably contains at least one selected from the group consisting of fluorine atoms, chlorine atoms, bromine atoms and iodine atoms, more preferably contains at least one selected from the group consisting of fluorine atoms, chlorine atoms and bromine atoms, and even more preferably contains bromine atoms and / or fluorine atoms.

[0139] An example of a halogen compound in this embodiment is a compound containing fluorine atoms, more preferably containing polytetrafluoroethylene.

[0140] As halogen compounds, when using compounds containing fluorine atoms, the types are not particularly limited, and examples include homopolymers or copolymers of fluorine-containing monomers such as tetrafluoroethylene, trifluorochloroethylene, vinylidene fluoride, hexafluoropropylene, and perfluoroalkyl vinyl ethers. Specifically, examples include homopolymers such as polytetrafluoroethylene, polychlorotrifluoroethylene, and polyvinylidene fluoride; copolymers such as tetrafluoroethylene-hexafluoropropylene copolymers; tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers; ethylene-tetrafluoroethylene copolymers; and ethylene-chlorotrifluoroethylene copolymers.

[0141] Another example of a halogen compound in this embodiment is a compound containing bromine atoms, more preferably a bromine-based flame retardant.

[0142] When using brominated flame retardants as halogen compounds, there is no particular limitation on the type. Brominated phthalimide, brominated poly(meth)acrylate, brominated polycarbonate, brominated epoxy, and brominated polystyrene are preferred. Brominated phthalimide, brominated poly(meth)acrylate, brominated polycarbonate, and brominated epoxy resin are more preferred. Brominated poly(meth)acrylate, brominated polycarbonate, and brominated epoxy resin are even more preferred. Brominated poly(meth)acrylate is the next most preferred.

[0143] In particular, brominated poly(meth)acrylates are easier to mix with antimony compounds, resulting in superior flame retardancy.

[0144] The free bromine content of the brominated flame retardant is preferably 0.5% by mass or more. Setting it within this range tends to further suppress discoloration of the resin composition. Furthermore, the free bromine content is preferably 2.0% by mass or less. Setting it within this range tends to further improve resistance to mold corrosion during molding.

[0145] As a brominated phthalimide, the substance represented by formula (1) is preferred.

[0146] [Chemical Formula 2]

[0147]

[0148] (In formula (1), D represents a group consisting of two or more combinations of alkylene, arylene, -S(=O)2-, -C(=O)-, and -O-. i is an integer from 1 to 4.)

[0149] In formula (1), D represents a group consisting of two or more combinations of alkylene, arylene, -S(=O)2-, -C(=O)- and -O-, preferably a group consisting of a combination of alkylene or arylene with at least one of -S(=O)2-, -C(=O)- and -O-, more preferably a group consisting of a combination of alkylene or arylene with one of -S(=O)2-, -C(=O)- and -O-, and even more preferably alkylene.

[0150] As a group consisting of a combination of alkylene and -O-, for example, it is intended to also include combinations of two alkylene and one -O- (the same applies to other combinations).

[0151] The alkylene group of D is preferably an alkylene group having 1 to 6 carbon atoms, and more preferably methylene, ethylene, propylene, or butylene. The aryl group is preferably phenylene.

[0152] i is an integer from 1 to 4, preferably 4.

[0153] Examples of brominated phthalimides represented by formula (1) include N,N'-(bistetrabromophthalimide) ethane, N,N'-(bistetrabromophthalimide) propane, N,N'-(bistetrabromophthalimide) butane, N,N'-(bistetrabromophthalimide) diethyl ether, N,N'-(bistetrabromophthalimide) dipropyl ether, N,N'-(bistetrabromophthalimide) dibutyl ether, N,N'-(bistetrabromophthalimide) diphenyl sulfone, N,N'-(bistetrabromophthalimide) diphenyl ketone, and N,N'-(bistetrabromophthalimide) diphenyl ether.

[0154] As a bromophthalimide, formula (1) is preferably a bromophthalimide represented by formula (2).

[0155] [Chemical Formula 3]

[0156]

[0157] (In equation (2), i is an integer from 1 to 4.)

[0158] i is an integer from 1 to 4, preferably 4.

[0159] As a brominated poly(meth)acrylate, the preferred polymer is obtained by homopolymerization of benzyl (meth)acrylate containing bromine atoms, copolymerization of two or more monomers, or copolymerization with other vinyl monomers, wherein the bromine atoms are added to the benzene rings and the number of additions is preferably 1 to 5 per benzene ring, and more preferably 4 to 5.

[0160] Examples of benzyl acrylates containing bromine atoms include pentabromobenzyl acrylate, tetrabromobenzyl acrylate, tribromobenzyl acrylate, or mixtures thereof. Furthermore, examples of benzyl methacrylates containing bromine atoms include methacrylates corresponding to the aforementioned acrylates.

[0161] Other vinyl monomers used for copolymerization with benzyl methacrylate containing bromine atoms include, specifically: acrylates such as acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and benzyl acrylate; methacrylates such as methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and benzyl methacrylate; unsaturated carboxylic acids or their anhydrides such as styrene, acrylonitrile, fumaric acid, and maleic acid; vinyl acetate, vinyl chloride, etc.

[0162] They are generally preferred to be used in amounts of equimolar or less, and especially preferred to be used in amounts of 0.5 times or less, relative to benzyl methacrylate containing bromine atoms.

[0163] In addition, as vinyl monomers, xylene diacrylate, xylene dimethacrylate, tetrabromoxylene diacrylate, tetrabromoxylene dimethacrylate, butadiene, isoprene, divinylbenzene, etc. can also be used, and they can usually be used in amounts of less than 0.5 times the molar amount of benzyl acrylate or benzyl methacrylate containing bromine atoms.

[0164] As a brominated poly(meth)acrylate, the preferred polymer is one obtained by homopolymerization of bromine-containing (meth)acrylate monomers, particularly benzyl (meth)acrylate, or copolymerization of two or more monomers, or copolymerization with other vinyl monomers. Furthermore, the bromine atom is added to the benzene ring, preferably 1 to 5 bromine atoms per benzene ring, and particularly preferably 4 to 5 bromine atoms per benzene ring.

[0165] As a brominated poly(meth)acrylate, pentabromobenzyl poly(meth)acrylate is preferred from the perspective of high bromine content.

[0166] The molecular weight of the brominated poly(meth)acrylate is arbitrary and can be appropriately selected. Preferred by weight-average molecular weight (Mw), it is 3000 or more, more preferably 10000 or more, further preferably 15000 or more, even more preferably 20000 or more, and still more preferably 25000 or more. By setting it to the lower limit or above, there is a tendency to obtain molded articles with higher mechanical strength. Furthermore, the upper limit of the weight-average molecular weight (Mw) is preferably 100000 or less, more preferably 80000 or less, even more preferably 60000 or less, still more preferably 50000 or less, and still more preferably 35000 or less. By setting it to the upper limit or below, there is a tendency to further improve the flowability of the resin composition.

[0167] As a brominated polycarbonate, brominated polycarbonates obtained from bromobisphenol A, particularly tetrabromobisphenol A, are preferred. Examples of its terminal structures include phenyl, 4-tert-butylphenyl, and 2,4,6-tribromophenyl, with a 2,4,6-tribromophenyl terminal structure being particularly preferred.

[0168] The average number of carbonate structural units in the brominated polycarbonate can be appropriately selected and determined, preferably 2 to 30, more preferably 3 to 15, and even more preferably 3 to 10.

[0169] The molecular weight of brominated polycarbonate is arbitrary and can be determined by appropriate selection. Preferably, the viscosity-average molecular weight is 1,000 to 20,000, and more preferably 2,000 to 10,000.

[0170] The brominated polycarbonate obtained from the above-mentioned bromobisphenol A can be obtained, for example, by a conventional method of reacting bromobisphenol with phosgene. Aromatic monohydroxy compounds, which can be substituted with halogen or organic groups, can be listed as end-capping agents.

[0171] Specifically, bisphenol A-type brominated epoxy compounds, such as tetrabromobisphenol A epoxy compounds and glycidyl brominated bisphenol A epoxy compounds, are preferred examples of brominated epoxy compounds.

[0172] The molecular weight of the brominated epoxy compound is arbitrary and can be appropriately selected. Preferred by weight-average molecular weight (Mw), it is 3000 or more, more preferably 10000 or more, further preferably 13000 or more, even more preferably 15000 or more, and still more preferably 18000 or more. By setting it to the lower limit or above, there is a tendency to obtain molded articles with higher mechanical strength. Furthermore, the upper limit of the weight-average molecular weight (Mw) is preferably 100000 or less, more preferably 80000 or less, even more preferably 78000 or less, still more preferably 75000 or less, even more preferably 70000 or less, and further preferably 50000 or less, 30000 or less, or 25000 or less. By setting it to the upper limit or below, there is a tendency to further improve the flowability of the resin composition.

[0173] The epoxy equivalent of the brominated epoxy compound is preferably 3,000 to 40,000 g / eq, more preferably 4,000 to 35,000 g / eq, and particularly preferably 10,000 to 30,000 g / eq.

[0174] Furthermore, brominated epoxy oligomers can also be used in conjunction with the brominated epoxy compound. In this case, for example, by using an oligomer with a Mw of 5000 or less at a proportion of about 50% by mass or less, the flame retardancy, mold release properties, and flowability can be appropriately adjusted. The bromine atom content in the brominated epoxy compound is arbitrary, but from the perspective of imparting sufficient flame retardancy, it is typically 10% by mass or more, preferably 20% by mass or more, particularly preferably 30% by mass or more, and preferably up to 60% by mass, with a preferred maximum of 55% by mass or less.

[0175] As brominated polystyrene, brominated polystyrene containing the structural unit represented by formula (3) is preferably listed.

[0176] [Chemical Formula 4]

[0177]

[0178] (In equation (3), t is an integer from 1 to 5, and n is the number of structural units.)

[0179] As brominated polystyrene, it can be any product manufactured by brominating polystyrene or by polymerizing brominated polystyrene monomers. Substances obtained by polymerizing brominated polystyrene are preferred because they contain less free bromine (atoms). It should be noted that in formula (3), the CH group bonded to bromobenzene can be replaced by a methyl group. Furthermore, brominated polystyrene can be a copolymer formed by copolymerizing other vinyl monomers. Examples of vinyl monomers in this case include styrene, α-methylstyrene, (meth)acrylonitrile, (meth)acrylate, butadiene, and vinyl acetate. In addition, brominated polystyrene can be used as a single substance or as a mixture of two or more substances with different structures, and it can also contain units derived from styrene monomers with different numbers of bromine atoms in a single molecular chain.

[0180] Specific examples of brominated polystyrene include: poly(4-bromostyrene), poly(2-bromostyrene), poly(3-bromostyrene), poly(2,4-dibromostyrene), poly(2,6-dibromostyrene), poly(2,5-dibromostyrene), poly(3,5-dibromostyrene), poly(2,4,6-tribromostyrene), poly(2,4,5-tribromostyrene), poly(2,3,5-tribromostyrene), poly(4-bromo-α-methylstyrene), poly(2,4-dibromo-α-methylstyrene), poly(2,5-dibromo-α-methylstyrene), poly(2,4,6-tribromo-α-methylstyrene), and poly(2,4,5-tribromo-α-methylstyrene), etc. Poly(2,4,6-tribromostyrene), poly(2,4,5-tribromostyrene), and poly(2,4,6-tribromo-α-methylstyrene) containing an average of 2 to 3 bromine groups in the benzene ring are particularly preferred.

[0181] In brominated polystyrene, the number of structural units n (average degree of polymerization) in formula (3) is preferably 30 to 1500, more preferably 150 to 1000, and particularly preferably 300 to 800. When the average degree of polymerization is less than 30, blooming is likely to occur. On the other hand, when the average degree of polymerization exceeds 1500, poor dispersion is likely to occur, and mechanical properties are likely to decrease. Furthermore, the weight-average molecular weight (Mw) of brominated polystyrene is preferably 5000 to 500000, more preferably 10000 to 500000, further preferably 10000 to 300000, even more preferably 10000 to 100000, and even more preferably 10000 to 70000. In particular, in the case of the brominated polystyrene described above, the weight-average molecular weight (Mw) is preferably 50000 to 70000, and in the case of brominated polystyrene based on polymerization, the weight-average molecular weight (Mw) is preferably around 10000 to 30000.

[0182] The bromine concentration in the brominated flame retardant is preferably 45% by mass or more, more preferably 48% by mass or more, even more preferably 50% by mass or more, and can be 55% by mass or more, or 60% by mass or more. By setting it to the lower limit or above, there is a tendency to effectively improve the flame retardancy of the molded article. The upper limit of the bromine concentration is preferably 85% by mass or less, more preferably 80% by mass or less, even more preferably 75% by mass or less, and can also be 73% by mass or less.

[0183] Regarding the content of halogen compounds in the resin composition of this embodiment, it is 0.1 parts by mass or more, preferably 0.5 parts by mass or more, more preferably 0.7 parts by mass or more, and even more preferably 1 part by mass or more, relative to a total of 100 parts by mass of thermoplastic polyester resin. When imparting flame retardancy to the resin composition, it is even more preferably 5 parts by mass or more, further preferably 8 parts by mass or more, and even more preferably 10 parts by mass or more. By setting it to the lower limit or above, there is a tendency to further improve the flame retardancy of the obtained molded article and to more effectively suppress color changes. Furthermore, relative to a total of 100 parts by mass of thermoplastic polyester resin, the upper limit of the content of the halogen compounds is 30 parts by mass or less, preferably 25 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less. When the resin composition is used for applications where high flame retardancy is not required, it is even more preferably 10 parts by mass or less, even more preferably 7 parts by mass or less, even more preferably 5 parts by mass or less, particularly more preferably 4 parts by mass or less, and even more particularly more preferably 3 parts by mass or less. By setting it below the aforementioned upper limit value, there is a tendency to more effectively suppress changes in the hue of the resulting molded article, and there is a tendency to effectively suppress the reduction of physical properties such as strength.

[0184] The resin composition of this embodiment may contain only one halogen compound, or it may contain two or more. When two or more halogen compounds are contained, the total amount is preferably within the range described above.

[0185] In the resin composition of this embodiment, the mass ratio of halogen atoms in the halogen compound to the stabilizer, i.e., halogen atom / stabilizer, is preferably 1.0 or more, more preferably 2.0 or more, and even more preferably 3.3 or more. By setting it to the lower limit or above, color changes can be suppressed more effectively. Moreover, when high flame retardancy is required for the resin composition, the halogen atom / stabilizer ratio is preferably 10 or more, more preferably 15 or more, even more preferably 20 or more, further preferably 25 or more, even more preferably 30 or more, and particularly more preferably 35 or more. The upper limit of the halogen atom / stabilizer ratio is not particularly limited, and is generally 100 or less, 70 or less, 50 or less, 40 or less, or 20 or less. Furthermore, depending on the application, even a ratio of 10 or less or 5 or less is sufficient to meet the required performance.

[0186] <Other Ingredients>

[0187] The resin composition of this embodiment may, as needed, contain other components besides those described above, provided that the desired physical properties are not significantly impaired. It should be noted that the other components may be one, or two or more may be contained in any combination and ratio.

[0188] Other components include reinforcing fillers and resin additives.

[0189] As resin additives, specifically, the following can be listed: flame retardants, release agents, colorants (pigments, dyes), nucleating agents, reactive compounds, antistatic agents, antifogging agents, antiblocking agents, flow improvers, plasticizers, dispersants, etc.

[0190] The total amount of these other components is preferably 0 to 10% by mass in 100% by mass of the resin composition, more preferably 0 to 5% by mass, and even more preferably 0 to 3% by mass.

[0191] In the resin composition of this embodiment, the total amount of thermoplastic polyester resin, stabilizer, silver-containing antibacterial agent, halogen compound, and other components to be added as needed is 100 by mass.

[0192] In the resin composition of this embodiment, the total amount of thermoplastic polyester resin, stabilizer, silver-containing antibacterial agent, halogen compound, flame retardant additive, and release agent preferably accounts for 90% or more by mass, more preferably 95% or more by mass, even more preferably 97% or more by mass, and even more preferably 99% or more by mass, and in addition, 100% or less by mass.

[0193] <<Flame Retardant Additives>>

[0194] The resin composition of this embodiment may contain a flame retardant additive. By including a flame retardant additive, the flame retardancy of the molded article can be further improved. Flame retardant additives are particularly preferred when halogen-based flame retardants are included. Examples of flame retardant additives used in this embodiment include antimony compounds, such as antimony trioxide (Sb₂O₃), antimony pentoxide (Sb₂O₅), and sodium antimonate. Especially from the perspectives of flame retardancy and impact resistance, antimony oxide is preferred, and antimony trioxide is particularly preferred.

[0195] When combined with flame retardant additives, it can be formulated in the form of masterbatch. The content of antimony compound in the masterbatch is preferably 30-90% by mass, more preferably 40-85% by mass, even more preferably 50-85% by mass, further preferably 60-85% by mass, and even more preferably 70-85% by mass. The resin used in the masterbatch is preferably polyester resin, more preferably polybutylene terephthalate resin.

[0196] When the resin composition of this embodiment contains a flame retardant additive (e.g., an antimony compound), its content relative to 100 parts by weight of thermoplastic polyester resin is preferably 0.1 parts by weight or more, more preferably 1.0 parts by weight or more, further preferably 3.0 parts by weight or more, even more preferably 4.0 parts by weight or more, and still more preferably 5.0 parts by weight or more. By setting it to the lower limit or above, there is a tendency to more effectively exert flame retardancy. Furthermore, relative to 100 parts by weight of thermoplastic polyester resin, the upper limit of the antimony compound content is preferably 20.0 parts by weight or less, more preferably 15.0 parts by weight or less, even more preferably 10.0 parts by weight or less, and still more preferably 8.0 parts by weight or less. By setting it to the upper limit or below, there is a tendency to improve the impact resistance of the resulting molded article.

[0197] The resin composition of this embodiment may contain only one flame retardant additive, or it may contain two or more. When two or more are contained, the total amount is preferably within the range described above.

[0198] <<Mold Release Agent>>

[0199] The resin composition of this embodiment may contain a release agent.

[0200] 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, with aliphatic hydrocarbon compounds with a number average molecular weight of 200 to 15,000 being preferred.

[0201] Examples of aliphatic carboxylic acids include, for example, saturated or unsaturated aliphatic mono-, di-, or tri-carboxylic acids. Aliphatic carboxylic acids also include alicyclic carboxylic acids. Among these, preferred aliphatic carboxylic acids are mono- or di-carboxylic acids with 6 to 36 carbon atoms, and more preferably, saturated aliphatic mono-carboxylic acids with 6 to 36 carbon atoms. Specific examples of such aliphatic carboxylic acids include: palmitic acid, stearic acid, hexanoic acid, decanoic acid, lauric acid, arachidic acid, benzanoic acid, tetracosanoic acid, ceric acid, beeswax acid, tritetracosanoic acid, linaloic acid, adipic acid, azelaic acid, etc.

[0202] The aliphatic carboxylic acid in the ester of an aliphatic carboxylic acid and an alcohol can be, for example, the same aliphatic carboxylic acid as the aliphatic carboxylic acid. On the other hand, as an alcohol, examples include saturated or unsaturated monohydric or polyhydric alcohols. These alcohols may have substituents such as fluorine atoms or aryl groups. Among these, monohydric or polyhydric saturated alcohols with 30 or fewer carbon atoms are preferred, and aliphatic saturated monohydric or polyhydric alcohols with 30 or fewer carbon atoms are more preferred. It should be noted that, here, "aliphatic" is also used as a term encompassing alicyclic compounds.

[0203] Specific examples of this alcohol include: octanol, decanol, dodecylol, stearyl alcohol, behenol, ethylene glycol, diethylene glycol, glycerol, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentyl glycol, bis(trimethylolpropane), dipentaerythritol, etc.

[0204] It should be noted that the above-mentioned esters may contain aliphatic carboxylic acids and / or alcohols as impurities. Furthermore, the above-mentioned esters may be pure substances or mixtures of multiple compounds. Moreover, the aliphatic carboxylic acids and alcohols that form an ester by bonding may each be one type, or two or more may be used in any combination and ratio.

[0205] Specific examples of esters of aliphatic carboxylic acids and alcohols include: beeswax (a mixture with myristyl palmitate as the main component), stearate, behenate, stearate, glyceryl monopalmitate, glyceryl monostearate, glyceryl distearate, glyceryl tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate, rice bran wax, etc.

[0206] Examples of aliphatic hydrocarbons with a number average molecular weight of 200–15,000 include liquid paraffin, paraffin wax, microcrystalline wax, polyethylene wax, Fischer-Tropsch wax, and α-olefin oligomers with 3–12 carbon atoms. It should be noted that aliphatic hydrocarbons here also include alicyclic hydrocarbons. Furthermore, these hydrocarbons can be partially oxidized.

[0207] Among these, microcrystalline wax, paraffin wax, polyethylene wax or partial oxides of polyethylene wax are preferred, with microcrystalline wax being even more preferred.

[0208] Furthermore, the number average molecular weight of the aliphatic hydrocarbon is preferably below 5000, and more preferably 400 to 1000.

[0209] Furthermore, aliphatic hydrocarbons can be a single substance, but even if they are mixtures of substances with a wide variety of constituent components and molecular weights, the main component is preferably within the above-mentioned range.

[0210] Examples of polysiloxane-based silicone oils include dimethyl silicone oil, methylphenyl silicone oil, diphenyl silicone oil, and fluorinated alkyl silicone oil.

[0211] For details on the release agent, please refer to paragraphs 0055 to 0061 of Japanese Patent Application Publication No. 2018-095706, which are incorporated in this specification.

[0212] When the resin composition of this embodiment contains a release agent, its content in the resin composition is preferably 0.05 to 3 parts by weight, more preferably 0.1 to 0.8 parts by weight, and even more preferably 0.1 to 0.6 parts by weight.

[0213] The resin composition of this embodiment may contain only one type of release agent, or it may contain two or more types. When two or more types are contained, the total amount is preferably within the range described above.

[0214] <<Coloring Agents>>

[0215] The resin composition of this method may contain a colorant (dye and / or pigment). Examples of colorants that can be used in this embodiment include inorganic pigments such as titanium dioxide and carbon black, organic dyes, and organic pigments, with inorganic pigments being preferred.

[0216] As inorganic pigments, examples include sulfide pigments such as carbon black, cadmium red, and cadmium yellow; silicate pigments such as ultramarine; oxide pigments such as zinc white, iron oxide red, chromium oxide, iron black, titanium yellow, zinc-iron brown, titanium-cobalt green, cobalt green, cobalt blue, copper-chromium black, and copper-iron black; chromic acid pigments such as chrome yellow and molybdenum orange; and ferrocyanide pigments such as Prussian blue, with titanium oxide being the preferred choice.

[0217] Examples of organic pigments and dyes include phthalocyanine dyes or pigments such as copper phthalocyanine blue and copper phthalocyanine green; azo dyes or pigments such as nickel azo yellow; condensed polycyclic dyes or pigments such as thioindole, perylene ketone, perylene, quinacridone, dioxazine, isoindolineone, and quinophthalone; and anthraquinone, heterocyclic, and methyl dyes or pigments.

[0218] Colorants can be masterbatch formulated. In this case, the concentration of colorant in the masterbatch is 30–80% by mass. Examples of thermoplastic resins that can be masterbatched include polyester resins.

[0219] The colorant content is preferably 0.01 parts by weight or more, more preferably 0.1 parts by weight or more, relative to 100 parts by weight of the thermoplastic resin. Furthermore, the colorant content is preferably 5.0 parts by weight or less, more preferably 3.0 parts by weight or less, and even more preferably 2.0 parts by weight or less, relative to 100 parts by weight of the thermoplastic resin.

[0220] The resin composition may contain only one colorant or two or more colorants. When two or more colorants are contained, the total amount is preferably within the range described above.

[0221] <Physical Properties of Resin Compositions>

[0222] The resin composition of this embodiment preferably exhibits minimal color variation caused by additives. Specifically, the difference (ΔE) between the color of the resin composition of this embodiment and the color of the resin composition after removing stabilizers, antibacterial agents, and halogen compounds is preferably 10 or less, more preferably 6 or less, even more preferably 5 or less, even further preferably 4 or less, and particularly even more preferably 3 or less. The lower limit value of ΔE is 0 or more, and even 0.1 or more is sufficient to meet the required performance.

[0223] The resin composition of this embodiment preferably exhibits excellent flame retardancy. For example, it is preferable to mold the resin composition into a 0.8 mm thick test piece, which meets V-0 requirements during UL-94 testing.

[0224] ΔE and flame retardancy were determined according to the description of the examples described later.

[0225] <Method for manufacturing resin composition>

[0226] The resin composition of this embodiment can be manufactured using conventional methods for preparing resin compositions (e.g., granules). Typically, the components and various additives added as needed are thoroughly mixed together, followed by melt blending using a single-screw or twin-screw extruder. Alternatively, the resin composition of this embodiment can be prepared by melt blending the components without premixing them, or by premixing only a portion thereof, using a feeder to supply the mixture to an extruder. A masterbatch can also be prepared by melt blending a portion of a silver-containing antibacterial agent and flame-retardant additive with a thermoplastic resin, followed by combining the remaining components and melt blending.

[0227] It should be noted that the reinforcing filler (especially glass fiber) is preferably supplied from the side feeder in the middle of the extruder barrel.

[0228] The heating temperature during melt mixing can typically be appropriately selected from the range of 220–300°C. If the temperature is too high, decomposition gases are easily generated, sometimes contributing to opacity. Therefore, a screw structure that takes into account shear heating and other factors is preferred.

[0229] <Manufacturing Methods for Molded Articles>

[0230] The resin composition or particles of this embodiment are molded according to a known method.

[0231] There are no particular limitations on the manufacturing method of the molded article; any molding method commonly used for resin compositions can be adopted. Examples include injection molding, high-speed injection molding, injection compression molding, two-color molding, gas-assisted hollow molding, molding using insulated molds, molding using rapidly heated molds, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating) molding, extrusion molding, sheet molding, thermoforming, rotational molding, lamination molding, compression molding, and blow molding, among which injection molding is preferred.

[0232] For details of the injection molding method, please refer to paragraphs 0113 to 0116 of Japanese Patent No. 6183822, which are incorporated herein by reference.

[0233] In addition, the mold temperature during injection molding and other mold forming processes is preferably 40 to 150°C.

[0234] <Application>

[0235] The resin composition of this embodiment is used in the form of a molded article formed from the resin composition or granules. There are no particular limitations on the applications of the resin composition and granules; they can be widely used in materials for home appliances, electrical and electronic equipment, automobiles, housing, and other industrial components.

[0236] More specifically, components for sanitary purposes, such as those used in kitchens, washrooms, toilets, and other water-using areas, are preferred.

[0237] The discoloration suppression method of this embodiment is a method for suppressing discoloration in a resin composition comprising 0.001 to 10.0 parts by weight of a stabilizer and 0.1 to 10.0 parts by weight of a silver-containing antibacterial agent relative to 100 parts by weight of the thermoplastic resin. The discoloration suppression method includes: adding 0.1 to 30 parts by weight of a halogen compound relative to 100 parts by weight of the thermoplastic resin. The details of the thermoplastic resin, stabilizer, silver-containing antibacterial agent, and halogen compound described above have the same meaning as those in the preceding description, and their proportions and preferred ranges are also the same.

[0238] Example

[0239] The present invention will be further described in detail below with examples. The materials, amounts, proportions, processing contents, and processing order shown in the following examples can be appropriately modified without departing from the spirit of the invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

[0240] If the measuring equipment used in the examples is difficult to obtain due to production stoppages or other reasons, other equipment with equivalent performance can be used for the measurement.

[0241] 1. Raw materials

[0242] Use the following raw materials.

[0243]

[0244]

[0245] <Free bromine content>

[0246] The free bromine content was quantified by combustion ion chromatography as described in paragraph 0083 of Japanese Patent Application Publication No. 2013-057009. Specifically, the amount of bromine produced was determined by heating the bromine-based flame retardant or resin composition at 270°C for 10 minutes under an argon atmosphere.

[0247] The resin composition was heated using an automatic sample combustion apparatus, model "AQF-100", manufactured by Mitsubishi Chemical ANALYTECH. The amount of bromine generated by the heating of the resin composition was determined using an apparatus, model "ICS-90", manufactured by DIONEX, Japan.

[0248] 2. Examples 1-1 to 1-13, 2-1 to 2-6; Comparative Examples 1-1 to 1-18, 2-1 to 2-6

[0249] <Mix>

[0250] The components shown in Table 1 were uniformly mixed using a drum mixer in the proportions shown in Tables 2-6 (each component in Tables 2-6 is expressed in parts by mass). The resulting mixture was fed from the main feed inlet to a twin-screw extruder (TEX30α, manufactured by Nippon Steel). The resin composition was melt-mixed at a barrel temperature of 260°C and a screw speed of 200 rpm in the first mixing section. The resulting resin composition was then rapidly cooled in a water bath and granulated using a granulator to obtain granules of the resin composition.

[0251] <hue>

[0252] The particles obtained above were left to stand in an indoor environment at 23°C and 50% humidity for at least 24 hours. The hue (L) was then measured using a SE6000 model (light source: C / 2, reflected light) manufactured by Nippon Denshoku Kogyo Co., Ltd. * a * b * The color difference ΔE of each resin composition particle was calculated based on the resin composition particles containing polybutylene terephthalate resin and release agent (Comparative Example 1-1).

[0253] Flame retardancy (Examples 2-1 to 2-6 only, Comparative Examples 2-1 to 2-6)

[0254] After drying the granules obtained above at 110°C for 5 hours, they were injection molded into combustion test pieces (12.7 mm wide × 127 mm long × 0.8 mm thick) using an injection molding machine (J-50AD manufactured by Japan Steel Works Co., Ltd.) at a barrel temperature of 250°C and a mold temperature of 80°C.

[0255] After the obtained combustion test specimens were left to stand at 70°C for one week, their flame retardancy was evaluated according to the Underwriters Laboratories Subject 94 (UL 94) method.

[0256] Antibacterial properties

[0257] Using an injection molding machine (Nissei Resin Kogyo Co., Ltd., NEX-80), the above-obtained granules were manufactured into molded sheets (100mm in length × 100mm in width × 2mm in thickness) at a resin temperature of 250°C and a mold temperature of 80°C. The molded sheets were then cut into pieces with a length of 50mm and a width of 50mm to obtain test pieces.

[0258] Antimicrobial tests were conducted in accordance with JIS Z 2801.

[0259] Place the test piece in a petri dish, add 0.4 mL of Escherichia coli or Staphylococcus epidermidis test bacterial suspension, cover with a membrane (40 mm × 40 mm), and then cover the petri dish with the lid. Incubate the petri dish at 35°C and above 90% RH for 24 hours. Then, add 10 mL of soybean-casein-digested agar (SCDLP) medium supplemented with lecithin-sorbate 80, wash the test bacteria from the membrane and test piece, determine the bacterial count in the liquid using the agar plate culture method, and calculate the antibacterial activity value according to formula (a).

[0260] Equation (a)

[0261] Antibacterial activity value = log (per 1cm) 2 Unprocessed sample - viable count after incubation - log (per 1 cm)2 (Processed sample, viable count after incubation)

[0262] Antibacterial activity value ≥2.0: + Antibacterial.

[0263] Antibacterial activity value <2.0: - No antibacterial activity.

[0264] Before conducting the above antibacterial test, the test pieces were pretreated as follows:

[0265] (Water resistant) Immerse in 50±10 mL of deionized water or distilled water at room temperature for 16–18 hours; or

[0266] (Lightfastness) Exposed to light for 10±0.5 hours using a xenon lamp weathering tester, or for 8±0.5 hours using a fluorescent lamp weathering tester.

[0267] Let A be the case where the antibacterial activity value is ≥2.0 under all of the following four conditions, and let B be the case where the antibacterial activity value is <2.0 under any of the following four conditions.

[0268] (1) Escherichia coli - water resistant;

[0269] (2) Escherichia coli·light-resistant;

[0270] (3) Staphylococcus aureus - water resistant;

[0271] (4) Staphylococcus aureus·light resistant.

[0272] Thermal stability

[0273] Using an injection molding machine (Jinhua Steel Works, J85-AD), the above-obtained granules were molded into dumbbell test pieces according to ISO 527 at a resin temperature of 250°C and a mold temperature of 80°C. Then, using a temperature testing machine (ESPEC), the dumbbell test pieces were left to stand at 120°C for 500 hours. Tensile tests were then performed according to ISO 527. Cases where the tensile strength retention rate of the heat-treated test piece relative to the untreated test piece is 80% or more are designated as A, and cases where it is less than 80% are designated as B.

[0274] <Retention thermal stability>

[0275] Using an injection molding machine (Nissei Resin Kogyo Co., Ltd., NEX-80), the above-obtained granules were manufactured into a "retention plate" (100mm in length × 100mm in width × 2mm in thickness) under the conditions of a barrel temperature of 270°C, a mold temperature of 80°C, and a cooling time of 300 seconds. Furthermore, using an injection molding machine (Nissei Resin Kogyo Co., Ltd., NEX-80), the above-obtained granules were manufactured into a "reference plate" (100mm in length × 100mm in width × 2mm in thickness) under the conditions of a barrel temperature of 270°C, a mold temperature of 80°C, and a cooling time of 15 seconds.

[0276] The hue of the obtained plates was determined using a Konica Minolta CM-36dg spectrophotometer (L). * a * b * Calculate the color difference ΔE between the "retained forming plate" and the "reference plate". Set the case where ΔE is less than 1 as A, the case where ΔE is greater than 1 but less than 3 as B, and the case where ΔE is greater than 3 as C.

[0277]

[0278]

[0279]

[0280]

[0281]

[0282]

[0283] In the table above, "antimicrobial agent" refers to the content of the antimicrobial agent itself in the resin composition, excluding the resin component formed by mastering the antimicrobial agent.

[0284] In the table above, "halogen atoms" in the content refers to the content of halogen atoms themselves contained in the halogen compound.

[0285] In the table above, "halogen atoms / stabilizer" in the content indicates the mass ratio of halogen atoms to stabilizers contained in the halogen compound.

[0286] As can be seen from the above results, the resin composition of this embodiment can achieve a good and excellent balance of antibacterial properties, thermal stability, and color stability. Moreover, by increasing the content of flame retardant, an excellent balance of antibacterial properties, thermal stability, and color stability can be maintained, and excellent flame retardancy is also achieved.

Claims

1. A resin composition comprising, with respect to 100 parts by mass of a thermoplastic resin: 0.001 to 10.0 parts by mass of a stabilizer; 0.1 to 10.0 parts by mass of an antibacterial agent containing silver; and 0.1 to 30 parts by mass of a halogen compound.

2. The resin composition according to claim 1, wherein the mass ratio of the halogen atom contained in the resin composition to the stabilizer, that is, halogen atom / stabilizer, is 1.0 or greater.

3. The resin composition according to claim 1, wherein the thermoplastic resin comprises a thermoplastic polyester resin.

4. The resin composition according to claim 3, wherein the thermoplastic polyester resin comprises a polybutylene terephthalate resin.

5. The resin composition according to claim 1, wherein the stabilizer comprises one or more compounds selected from the group consisting of a sulfide-based compound, a hindered phenol-based compound, and a phosphite-based compound.

6. The resin composition according to claim 1, wherein the stabilizer comprises a sulfide-based compound.

7. The resin composition according to claim 1, wherein the antibacterial agent containing silver comprises an inorganic silver-based antibacterial agent.

8. The resin composition according to claim 1, wherein the antibacterial agent containing silver comprises a glass-based antibacterial agent.

9. The resin composition according to claim 1, wherein the halogen compound comprises a bromine atom and / or a fluorine atom.

10. The resin composition according to claim 1, wherein the halogen compound comprises a fluorine atom.

11. The resin composition according to claim 1, wherein the halogen compound comprises a bromine atom.

12. The resin composition according to claim 11, wherein the free bromine amount of the halogen compound is 0.5% by mass or greater.

13. A resin composition for a sanitary-use member, the resin composition comprising: a thermoplastic polyester resin having an intrinsic viscosity of 1.0 dL / g or greater; an antibacterial agent containing silver; and titanium oxide.

14. The resin composition according to claim 1, wherein the mass ratio of the halogen atom contained in the resin composition to the stabilizer, that is, halogen atom / stabilizer, is 1.0 or greater, the thermoplastic resin comprises a polybutylene terephthalate resin, the stabilizer comprises one or more compounds selected from the group consisting of a hindered phenol-based compound and a phosphite-based compound, the antibacterial agent containing silver comprises a glass-based antibacterial agent, the halogen compound comprises a bromine atom and / or a fluorine atom.

15. A pellet of the resin composition according to any one of claims 1 to 14.

16. A molded article formed from the resin composition according to any one of claims 1 to 14.

17. A molded article formed from the pellet according to claim 15.

18. The molded article according to claim 16, which is a sanitary-use member.

19. A discoloration inhibition method, which is a discoloration inhibition method for a resin composition containing 0.001 to 10.0 parts by mass of a stabilizer and 0.1 to 10.0 parts by mass of an antibacterial agent containing silver with respect to 100 parts by mass of a thermoplastic resin, the discoloration inhibition method comprising: 0.1 to 30 parts by mass of a halogen compound are compounded with respect to 100 parts by mass of the thermoplastic resin.

20. A method for inhibiting discoloration, which is a method for inhibiting discoloration of a resin composition containing 0.01 to 1.0 parts by mass of a stabilizer and 0.1 to 3.0 parts by mass of an antibacterial agent containing silver, relative to 100 parts by mass of a thermoplastic polyester resin, the method comprising: 0.1 to 30 parts by mass of a halogen compound are compounded with respect to 100 parts by mass of the thermoplastic polyester resin.

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