Resin compositions, pellets, and molded articles

Abstract

To provide resin compositions, pellets, and molded articles that exhibit excellent flame retardancy and effectively suppress gas generation. [Solution] The resin composition according to this disclosure contains 1 to 40 parts by mass of a flame retardant per 100 parts by mass of polybutylene terephthalate resin, and the polybutylene terephthalate resin (T) contains 30 to 500 ppm by mass of titanium element and has an active titanium parameter X of 25 or less as shown below.

Description

[Technical Field]

[0001] This invention relates to resin compositions, pellets, and molded articles. In particular, it relates to resin compositions having polybutylene terephthalate resin as a main component. [Background technology]

[0002] Polybutylene terephthalate resin, a representative engineered plastic among thermoplastic polyester resins, is widely used in injection-molded products such as automotive parts, electrical and electronic components, and precision instrument parts due to its ease of molding, excellent mechanical properties, heat resistance, chemical resistance, fragrance retention, and other physical and chemical properties.

[0003] In this case, a flame retardant may be added to the polybutylene terephthalate to impart flame retardancy. For example, Patent Document 1 describes a flame-retardant thermoplastic polyester resin composition comprising (A) a thermoplastic polyester resin such as polybutylene terephthalate resin, (B) a halogen-based flame retardant, and (C) an antimony compound. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-203963 [Overview of the project] [Problems that the invention aims to solve]

[0005] It is common practice to use flame retardants or flame retardant additives to impart flame retardancy to polybutylene terephthalate resin. However, the inventors' research has revealed that, depending on the type, flame retardants and flame retardant additives can accelerate the decomposition of polybutylene terephthalate resin during melt mixing, leading to increased gas generation. The object of the present invention is to solve such problems, and it is an object to provide a resin composition, pellets, and a molded article that are excellent in flame retardancy and can effectively suppress the generation of gas.

Means for Solving the Problems

[0006] As a result of the study by the present inventors under the above problems, it has been found that the above problems can be solved by using a polybutylene terephthalate resin that satisfies predetermined conditions. Specifically, the above problems have been solved by the following means. [1] Based on 100 parts by mass of the polybutylene terephthalate resin, containing 1 to 40 parts by mass of a flame retardant, a resin composition containing a polybutylene terephthalate resin (T) in which the polybutylene terephthalate resin contains 30 to 500 ppm by mass of titanium element and the active titanium parameter X shown below is 25 or less.

Number

Number

[10] [8]. [Effects of the Invention]

[0007] The present invention makes it possible to provide resin compositions, pellets, and molded articles that have excellent flame retardancy and can effectively suppress gas generation. [Modes for carrying out the invention]

[0008] 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. "A~B" means that it is greater than or equal to A and less than or equal to B. Furthermore, the upper and lower limits of the numerical values ​​in this specification are given as examples of this embodiment, regardless of the combination of upper and lower limits.

[0009] In this specification, all physical properties and characteristic values ​​shall be those at 23°C unless otherwise specified. In this specification, ppm means mass ppm. If the measurement methods, etc., described in the standards shown in this specification differ from year to year, unless otherwise specified, the standards as of January 1, 2024 shall apply. If the measurement methods, etc., described in the standards shown in this specification have been discontinued as of January 1, 2024, the standards in effect at the time of discontinuation shall apply.

[0010] The resin composition of this embodiment is composed of 100 parts by mass of polybutylene terephthalate resin, The present invention is characterized by containing 1 to 40 parts by mass of a flame retardant, and the polybutylene terephthalate resin (T) containing 30 to 500 ppm by mass of titanium element, and having an active titanium parameter X of 25 or less as shown below.

number

number

[0011] The embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is merely one example of an embodiment of the present invention and is not limited to these.

[0012] <Polybutylene terephthalate resin> The resin composition of this embodiment includes a polybutylene terephthalate resin (hereinafter sometimes referred to as "polybutylene terephthalate resin (T)") which contains 30 to 500 ppm by mass of titanium element and has an active titanium parameter X of 25 or less as shown below.

number

number

[0013] Titanium catalysts are often added during the synthesis of polybutylene terephthalate resin. However, it has been found that if the titanium catalyst activity is high even in the polymerized polybutylene terephthalate resin, tetrahydrofuran derived from butanediol tends to be generated more easily. In particular, when mass-producing the resin industrially, extrusion is carried out continuously for long periods using large extruders, and in such cases, tetrahydrofuran tends to be generated more easily. In this embodiment, it is presumed that the generation of tetrahydrofuran gas in the molded product was effectively suppressed by using a polybutylene terephthalate resin (T) with low titanium activity. Furthermore, the resin composition of this embodiment may also contain a polybutylene terephthalate resin (N) other than polybutylene terephthalate resin (T). In this specification, unless otherwise specified, polybutylene terephthalate resin refers to a material containing both polybutylene terephthalate resin (T) and polybutylene terephthalate resin (N).

[0014] The active titanium parameter X of the polybutylene terephthalate resin (T) used in this embodiment is 25 or less, preferably 20 or less, more preferably 15 or less, and even more preferably 10 or less. The lower limit of the active titanium parameter X of the polybutylene terephthalate resin (T) is preferably 0, but even if it is 1 or more, it will sufficiently satisfy the required performance.

[0015] A polybutylene terephthalate resin (T) synthesized using a titanium catalyst, wherein the active titanium parameter X is low, can be obtained, for example, by the following method. (1) Increase the concentration of metal elements such as sodium and calcium in the polybutylene terephthalate resin (T). These metal elements tend to reduce the activity of the titanium catalyst. (2) Increase the alkali component in the polybutylene terephthalate resin (T). Since titanium catalysts are acid catalysts, their activity tends to decrease in the presence of alkali components. (3) Increase the concentration of terminal carboxylic acid in the polybutylene terephthalate resin (T). (4) Recycled polybutylene terephthalate resin (T) is used. In particular, material-recycled polybutylene terephthalate resin tends to have a low titanium activation catalyst content. α=X / M...Equation (3) (In equation (3), X is the active titanium parameter, and [M] is the concentration of titanium element (mass ppm) in the polybutylene terephthalate resin (T).)

[0016] The time-dependent evaluation of terminal carboxyl group concentration is performed under a nitrogen atmosphere to prevent the influence of oxygen. Furthermore, if the water content in the polybutylene terephthalate resin (T) being evaluated is high, hydrolysis reactions occur frequently, making it difficult to accurately grasp the decomposition behavior involving catalytic activity other than hydrolysis. Therefore, a low water content is preferable, and the evaluation is performed at 300 ppm by mass or less. The temperature is 245°C. Under these heat treatment conditions, the decrease in number-average molecular weight due to reactions other than hydrolysis caused by the water content in the polybutylene terephthalate resin (T) can be ignored. The increase in terminal carboxyl group concentration due to hydrolysis can be considered equal to the increase in terminal hydroxyl group concentration before and after heat treatment. Therefore, the change in terminal carboxyl group concentration due to thermal decomposition reactions other than hydrolysis is calculated using the following equation (4).

[0017] Formula (4)

number

[0018] The titanium element concentration in the polybutylene terephthalate resin (T) used in this embodiment is 30 ppm by mass or more, may be 35 ppm by mass or more, 40 ppm by mass or more, 45 ppm by mass or more, 50 ppm by mass or more, 55 ppm by mass or more, 60 ppm by mass or more, 65 ppm by mass or more, 70 ppm by mass or more, 75 ppm by mass or more, and preferably 500 ppm by mass or less, may be 400 ppm by mass or less, 300 ppm by mass or less, 150 ppm by mass or less, 120 ppm by mass or less, 110 ppm by mass or less, 100 ppm by mass or less, 90 ppm by mass or less, or 80 ppm by mass or less.

[0019] The sodium element concentration in the polybutylene terephthalate resin (T) used in this embodiment is preferably 0.5 ppm by mass or more, more preferably 0.7 ppm by mass or more, even more preferably 0.9 ppm by mass or more, even more preferably 1 ppm by mass or more, and also preferably 100 ppm by mass or less, more preferably 50 ppm by mass or less, even more preferably 30 ppm by mass or less, even more preferably 20 ppm by mass or less, and even more preferably 10 ppm by mass or less. Setting it above the lower limit tends to more effectively suppress the generation of tetrahydrofuran gas. Furthermore, setting it below the upper limit tends to further improve alkali degradation resistance. The sodium element in the polybutylene terephthalate resin (T) originates, for example, from the detergent used in the resin cleaning process.

[0020] The calcium element concentration of the polybutylene terephthalate resin (T) used in this embodiment is preferably 1 ppm by mass or more, more preferably 3 ppm by mass or more, even more preferably 5 ppm by mass or more, even more preferably 7 ppm by mass or more, and also preferably 3000 ppm by mass or less, preferably 2500 ppm by mass or less, preferably 1500 ppm by mass or less, preferably 1000 ppm by mass or less, more preferably 500 ppm by mass or less, even more preferably 300 ppm by mass or less, even more preferably 200 ppm by mass or less, and may also be 100 ppm by mass or less, 50 ppm by mass or less, 30 ppm by mass or less, or 10 ppm by mass or less. Setting it above the lower limit tends to more effectively suppress the generation of tetrahydrofuran gas. Also, setting it below the upper limit tends to further improve alkali degradation resistance. The calcium element in polybutylene terephthalate resin (T) originates from, for example, inorganic fillers.

[0021] The concentrations of titanium, sodium, and calcium are measured according to the examples described below.

[0022] In this embodiment, the polybutylene terephthalate resin (T) preferably has an active titanium content α represented by formula (3) of 0.50 or less. By setting the active titanium content α to 0.50 or less, the generation of tetrahydrofuran gas tends to be suppressed more effectively. α=X / M...Equation (3) (In equation (3), X is the active titanium parameter, and [M] is the concentration of titanium element (mass ppm) in the polybutylene terephthalate resin (T).) The proportion α of the activated titanium is preferably 0.45 or less, more preferably 0.40 or less, even more preferably 0.35 or less, even more preferably 0.30 or less, even more preferably 0.25 or less, even more preferably 0.20 or less, and even more preferably 0.15 or less. The lower limit of the proportion α of the activated titanium is preferably 0, but even if it is 0.01 or more, it will still sufficiently satisfy the required performance.

[0023] The intrinsic viscosity of the polybutylene terephthalate resin is preferably 0.60 dL / g or higher, more preferably 0.75 dL / g or higher, even more preferably 0.80 dL / g or higher, and even more preferably 0.85 dL / g or higher. Setting it above the lower limit tends to effectively suppress a decrease in physical properties such as strength. Furthermore, the intrinsic viscosity of the polybutylene terephthalate resin is preferably 1.30 dL / g or lower, more preferably 1.10 dL / g or lower, even more preferably 1.00 dL / g or lower, and even more preferably 0.90 dL / g or lower. Setting it below the upper limit tends to effectively suppress a decrease in fluidity. The intrinsic viscosity is measured according to the example described below.

[0024] In the resin composition of this embodiment, the concentration of terminal carboxyl groups (acid value) of the polybutylene terephthalate resin (T) is preferably 100 μmol / g (μeq / g) or less, more preferably 80 μmol / g or less, even more preferably 60 μmol / g or less, even more preferably 40 μmol / g or less, even more preferably 30 μmol / g or less, and also preferably 10 μmol / g or more, more preferably 20 μmol / g or more, and may be 25 μmol / g or more. Setting it below the upper limit tends to result in excellent hydrolysis resistance. Setting it above the lower limit tends to result in improved adhesive strength to adhesives. When the resin composition of this embodiment contains two or more polybutylene terephthalate resins (T), it is preferable that the concentration of terminal carboxyl groups in the mixture falls within the above range. The concentration of terminal carboxyl groups in the polybutylene terephthalate resin (T) is measured according to the example described below. Polybutylene terephthalate resin (T) having such a concentration of terminal carboxyl groups can be obtained, for example, by subjecting it to a thermal history above its melting point, such as by melt kneading.

[0025] In the resin composition of this embodiment, the concentration of terminal hydroxyl groups of polybutylene terephthalate resin (T) is preferably 110 μmol / g or less, more preferably 100 μmol / g or less, even more preferably 95 μmol / g or less, preferably 30 μmol / g or more, more preferably 35 μmol / g or more, even more preferably 40 μmol / g or more, even more preferably 50 μmol / g or more, and even more preferably 60 μmol / g or more. Setting it below the upper limit suppresses transesterification reactions during melt-kneading with other resins such as polycarbonate, thereby accelerating the molding cycle. Furthermore, setting it above the lower limit tends to further improve the adhesive strength to adhesives.

[0026] When the resin composition of this embodiment contains two or more polybutylene terephthalate resins (T), it is preferable that the concentration of terminal hydroxyl groups in the mixture falls within the above range. The concentration of terminal hydroxyl groups in the polybutylene terephthalate resin (T) is measured according to the example described below. Polybutylene terephthalate resin (T) having such a concentration of terminal hydroxyl groups can be obtained, for example, by subjecting it to a thermal history above its melting point, such as by melt kneading.

[0027] The concentration of terminal vinyl groups in polybutylene terephthalate resin (T) is preferably 50 μmol / g or less, more preferably 15 μmol / g or less, even more preferably 12 μmol / g or less, even more preferably 10 μmol / g or less, even more preferably 8 μmol / g or less, and also preferably 1 μmol / g or more, more preferably 2 μmol / g or more, and even more preferably 3 μmol / g or more. Setting it below the upper limit tends to relatively increase the concentration of terminal hydroxyl groups and terminal carboxyl groups, thereby improving adhesion with epoxy adhesives. Conversely, setting it above the lower limit tends to relatively decrease the concentration of terminal hydroxyl groups and terminal carboxyl groups, suppressing reactivity with other resins such as polycarbonate and epoxy resins, resulting in a smaller thickening effect and improved fluidity. When the resin composition of this embodiment contains two or more polybutylene terephthalate resins (T), it is preferable that the concentration of terminal vinyl groups in the mixture falls within the above range. The concentration of terminal vinyl groups in the polybutylene terephthalate resin (T) is measured according to the example described below. Polybutylene terephthalate resin (T) having such a concentration of terminal vinyl groups can be obtained by increasing the number of thermal histories of the polybutylene terephthalate resin (T), for example, by increasing the number of melt-kneading cycles.

[0028] The resin composition of this embodiment may contain, in addition to polybutylene terephthalate resin (T), a polybutylene terephthalate resin (N) other than polybutylene terephthalate resin (T). Virgin polybutylene terephthalate resin is preferred for the polybutylene terephthalate resin (N) other than polybutylene terephthalate resin (T). An example of polybutylene terephthalate resin (N) is one in which the titanium activity parameter is greater than 25, preferably 26 or higher, more preferably 27 or higher, preferably 40 or lower, and more preferably 35 or lower. The proportion of polybutylene terephthalate resin (N) other than the aforementioned polybutylene terephthalate resin (T) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and depending on the application, it may be 20 parts by mass or more, 30 parts by mass or more, 40 parts by mass or more, or 100 parts by mass or less, and depending on the application, it may be 90 parts by mass or less, 80 parts by mass or less, 70 parts by mass or less, or 60 parts by mass or less. The higher the proportion of polybutylene terephthalate resin (T), the more gas generation tends to be suppressed relatively.

[0029] The polybutylene terephthalate resin used in the resin composition of this embodiment is a polyester resin having a structure in which terephthalic acid units and 1,4-butanediol units are ester-bonded, and includes, in addition to the polybutylene terephthalate resin (homopolymer), a polybutylene terephthalate copolymer containing other copolymer components other than terephthalic acid units and 1,4-butanediol units, or a mixture of the homopolymer and the polybutylene terephthalate copolymer.

[0030] Polybutylene terephthalate resin may contain one or more dicarboxylic acid units other than terephthalic acid. Other specific examples of dicarboxylic acids include aromatic dicarboxylic acids such as isophthalic acid, orthophthalic 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, bis(4,4'-carboxyphenyl)methane, anthracenedicarboxylic acid, and 4,4'-diphenyletherdicarboxylic acid; alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid and 4,4'-dicyclohexyldicarboxylic acid; and aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, and dimer acid. In this embodiment, the polybutylene terephthalate resin preferably contains terephthalic acid units accounting for 80 mol% or more of the total dicarboxylic acid units, more preferably 90 mol% or more, even more preferably 95 mol% or more, and may also contain 99 mol% or more.

[0031] The diol unit may include one or more other diol units in addition to 1,4-butanediol. Other specific examples of diol units include aliphatic or alicyclic diols with 2 to 20 carbon atoms, and bisphenol derivatives. Specific examples include ethylene glycol, propylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, decamethylene glycol, cyclohexanedimethanol, 4,4'-dicyclohexylhydroxymethane, 4,4'-dicyclohexylhydroxypropane, and ethylene oxide addition diols of bisphenol A. In addition to the bifunctional monomers mentioned above, small amounts of trifunctional monomers such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, and trimethylolpropane can be used to introduce branched structures, and monofunctional compounds such as fatty acids can be used to adjust molecular weight. In this embodiment, the polybutylene terephthalate resin preferably contains 1,4-butanediol units accounting for 80 mol% or more of the total diol units, more preferably 90 mol% or more, even more preferably 95 mol% or more, and may also contain 99 mol% or more.

[0032] As described above, the polybutylene terephthalate resin is preferably a polybutylene terephthalate homopolymer obtained by polycondensation of terephthalic acid and 1,4-butanediol. Alternatively, it may be a polybutylene terephthalate copolymer containing one or more dicarboxylic acids other than terephthalic acid as the carboxylic acid unit and / or one or more diols other than 1,4-butanediol as the diol unit. When the polybutylene terephthalate resin is a polybutylene terephthalate resin modified by copolymerization, specific preferred copolymers include polyester ether resins copolymerized with polyalkylene glycols, particularly polytetramethylene glycol, dimer acid copolymerized polybutylene terephthalate resins, and isophthalic acid copolymerized polybutylene terephthalate resins. Among these, it is preferable to use a polyester ether resin copolymerized with polytetramethylene glycol. Furthermore, when the polybutylene terephthalate resin is a copolymer, the copolymerization amount is 1 mol% or more and less than 50 mol% of the total polybutylene terephthalate resin units. In particular, the copolymerization amount is preferably 2 mol% or more and less than 50 mol%, more preferably 3 to 40 mol%, and even more preferably 5 to 20 mol%. Such copolymerization ratios are preferable because they result in molded products with low molding shrinkage and high impact resistance.

[0033] In this embodiment, it is preferable that the polybutylene terephthalate resin used has a high degree of dispersion. A high degree of dispersion increases the amount of terminal groups (particularly terminal hydroxyl groups and / or terminal carboxyl groups) in the polybutylene terephthalate resin, which can further improve adhesion with epoxy adhesives.

[0034] The polybutylene terephthalate resin preferably has an Mw / Mn ratio of 2.1 or higher, more preferably 2.2 or higher, even more preferably 2.3 or higher, preferably 3.5 or lower, more preferably 3.0 or lower, even more preferably 2.7 or lower, even more preferably 2.6 or lower, and even more preferably 2.5 or lower. Setting the ratio above the lower limit tends to further improve the adhesive strength to epoxy adhesives. Conversely, setting the ratio below the upper limit tends to further improve the mechanical strength. Polybutylene terephthalate resins with such high dispersion can be obtained by increasing the number of thermal histories of the polybutylene terephthalate resin, for example, by increasing the number of melt-kneading cycles, or by blending two or more polybutylene terephthalate resins with different average molecular weights.

[0035] The number-average molecular weight (Mn) of the polybutylene terephthalate resin used in this embodiment is preferably 2500 or more, more preferably 3000 or more, even more preferably 3500 or more, even more preferably 3700 or more, even more preferably 4000 or more, and also preferably 20000 or less, more preferably 18000 or less, even more preferably 14000 or less, even more preferably 10000 or less, and even more preferably 6000 or less. Setting it above the lower limit tends to result in superior mechanical strength. Setting it below the upper limit tends to improve the fluidity of the resin.

[0036] The weight-average molecular weight (Mw) of the polybutylene terephthalate resin used in this embodiment is preferably 5000 or more, more preferably 6000 or more, even more preferably 7000 or more, even more preferably 8000 or more, even more preferably 9500 or more, and also preferably 40000 or less, more preferably 35000 or less, even more preferably 30000 or less, even more preferably 25000 or less, and even more preferably 20000 or less. Setting it above the lower limit tends to further improve the mechanical strength. Also, setting it below the upper limit tends to improve the fluidity of the resin.

[0037] The number-average molecular weight and weight-average molecular weight of polybutylene terephthalate resin are measured by the following method.

[0038] <<Weight-average molecular weight (Mw) and number-average molecular weight (Mn)>> Using a Tosoh HLC-8320, polybutylene terephthalate resin is weighed, and a predetermined amount of HFIP (hexafluoro-2-propanol) and 10 mM-CF3COONa eluent are added. The mixture is then allowed to dissolve overnight at room temperature. Subsequently, the mixture is filtered through a 0.45 μm PTFE cartridge filter. The molecular weight (Mw, Mn) of the dissolved sample (filtrate) is measured by GPC. A cubic approximation curve using standard PMMA is used as the calibration curve, and the molecular weight is calculated using PMMA equivalent. For GPC measurements, the Tosoh TSKgel GMHhr-M column (manufactured by Tosoh) can be used.

[0039] The melting point (Tm) of the polybutylene terephthalate resin used in this embodiment, as measured according to DSC, is preferably 200°C or higher, more preferably 205°C or higher, even more preferably 210°C or higher, even more preferably 215°C or higher, even more preferably 220°C or higher, and also preferably 280°C or lower, more preferably 270°C or lower, even more preferably 260°C or lower, even more preferably 255°C or lower, and even more preferably 240°C or lower. Setting it above the lower limit tends to further improve heat resistance. Also, setting it below the upper limit tends to further improve the molding cycle. If the resin composition of this embodiment contains two or more polyalkylene terephthalate resins, the melting point shall be the melting point of the mixture. If multiple melting point peaks are detected, it is sufficient that at least one of the multiple melting points falls within the range of the lower limit and the upper limit. However, it is preferable that the component with the highest content among the multiple melting points falls within the range of the lower limit and the upper limit, and it is more preferable that all of the multiple melting points fall within the range of the lower limit and the upper limit.

[0040] The crystallization temperature (Tc) of the polybutylene terephthalate resin used in this embodiment, as measured according to DSC, is preferably 130°C or higher, more preferably 145°C or higher, even more preferably 160°C or higher, even more preferably 175°C or higher, even more preferably 190°C or higher, and also preferably 240°C or lower, more preferably 230°C or lower, even more preferably 220°C or lower, even more preferably 210°C or lower, and even more preferably 200°C or lower. Setting it above the lower limit tends to improve the solidification rate and further improve the molding cycle. Also, setting it below the upper limit tends to improve the appearance of the molded product. If the resin composition of this embodiment contains two or more polyalkylene terephthalate resins, the crystallization temperature is the crystallization temperature of the mixture. If multiple crystallization temperature peaks are detected, it is sufficient that at least one of the multiple crystallization temperatures falls within the range of the lower limit and the upper limit. However, it is preferable that the component with the highest content among the multiple crystallization temperatures falls within the range of the lower limit and the upper limit, and it is more preferable that all of the multiple crystallization temperatures fall within the range of the lower limit and the upper limit. The Tm and Tc of the polyalkylene terephthalate resin are measured by the following method.

[0041] <<Melting point (Tm) and crystallization temperature (Tc)>> The melting point (Tm) and crystallization temperature (Tc) of polybutylene terephthalate resin are measured using a differential scanning calorimetry (DSC) in accordance with JIS K7121. The resin is heated from 40°C to 300°C at a rate of 20°C / min under a nitrogen atmosphere, held at 300°C for 3 minutes, and then cooled down to 40°C at a rate of -20°C / min. This constitutes one cycle. The crystallization temperature Tc is defined as the temperature of the maximum peak due to crystallization during cooling. The melting point Tm is determined from the peak during melting. The unit is °C. For differential scanning calorimetry, the "DSC7020" manufactured by Hitachi High-Tech Science Corporation can be used.

[0042] In particular, the polybutylene terephthalate resin used in this embodiment (especially the polybutylene terephthalate resin (T)) has dicarboxylic acid units and diol units, and it is preferable that 80 mol% or more (preferably 90 mol% or more, more preferably 95 mol% or more, and even more preferably 99 mol% or more) of the total dicarboxylic acid units are terephthalic acid units derived from fossil resources, and 80 mol% or more (preferably 90 mol% or more, more preferably 95 mol% or more, and even more preferably 99 mol% or more) of the total diol units are 1,4-butanediol units derived from fossil resources. Furthermore, it is preferable that the polybutylene terephthalate resin (especially the polybutylene terephthalate resin (T)) used in this embodiment is not a biopolybutylene terephthalate resin. An example of a biopolybutylene terephthalate resin is one in which 10% by mass or more, more specifically 30% by mass or more, 90% by mass or less, and more specifically 60% by mass or less of the total amount of dicarboxylic acids and diols that are raw materials for the polybutylene terephthalate resin is a bio-derived polybutylene terephthalate resin.

[0043] The polybutylene terephthalate resin (in particular, polybutylene terephthalate resin (T)) used in this embodiment may be a recycled product, and is preferably a recycled product. Examples of recycled polybutylene terephthalate resin include those derived from material recycling, where molded products of recovered used polybutylene terephthalate resin are crushed, washed, and reused, and those derived from chemical recycling (chemical decomposition). In this embodiment, it is preferable to include polybutylene terephthalate resin derived from material recycling. Compared to virgin products, recycled products can effectively reduce the amount of gas generated by undergoing the repelletization extrusion process. In this embodiment, recycled polybutylene terephthalate resin with a high number of thermal history cycles can be used. Examples of thermal history include melt kneading, as well as thermoforming such as injection molding and extrusion molding. In this embodiment, polybutylene terephthalate resin having 3 to 10 thermal history cycles is an example. Examples of such recycled products include connectors, home appliances, toothbrushes, textiles, general merchandise, automotive parts, films, and recycled products derived from extruded parts such as tubes.

[0044] The polybutylene terephthalate resin content in the resin composition of this embodiment is preferably 30% by mass or more, more preferably 35% by mass or more, and depending on the application, more preferably 40% by mass or more, even more preferably 45% by mass or more, and preferably 60% by mass or less, and more preferably 55% by mass or less. Setting the content above the lower limit tends to further improve the heat resistance of the resulting molded product. Conversely, setting the content below the upper limit tends to reduce the shrinkage rate of the resulting molded product. The resin composition of this embodiment may contain only one type of polybutylene terephthalate resin, 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.

[0045] <Amorphous resin> The resin composition of this embodiment may also contain an amorphous resin. While there are no specific requirements regarding the type of amorphous resin, it is usually an amorphous thermoplastic resin, with examples including styrene resins, polycarbonate resins, acrylic resins, and modified polyphenylene ether resins. Styrene resins and / or polycarbonate resins are preferred, and styrene resins are more preferred.

[0046] The amorphous resin used in this embodiment may be a virgin amorphous resin or a recycled amorphous resin, and it is preferable that it contains a recycled amorphous resin. Examples of recycled amorphous resins include those obtained through material recycling, which involves crushing and washing recovered used amorphous resin molded products for reuse, and those obtained through chemical recycling (chemical decomposition). In this embodiment, material recycled products are preferred. In one example of this embodiment, the recycled amorphous resin is preferably in proportion to 0 to 100% by mass of the amorphous resin content in the resin composition of this embodiment, more preferably in proportion to 0 to 30% by mass, and even more preferably in proportion to 0 to 10% by mass. In another example of this embodiment, the virgin amorphous resin is preferably in proportion to 0 to 100% by mass of the amorphous resin content in the resin composition of this embodiment, more preferably in proportion to 0 to 30% by mass, and even more preferably in proportion to 0 to 10% by mass.

[0047] <<Styrene resin>> The styrene resin used in this embodiment may be a virgin styrene resin or a recycled amorphous styrene resin, but a recycled styrene resin is preferred. Examples of polystyrene resins include homopolymers of styrene monomers and copolymers of styrene monomers and monomers copolymerizable with styrene monomers. In copolymers of styrene monomers and copolymerizable monomers, it is preferable that 50% by mass or more of the total monomer is styrene monomer, more preferably 60% by mass or more is styrene monomer, and preferably 100% by mass or less is styrene monomer.

[0048] Styrene monomers refer to styrene and styrene having substituents, and include styrene, α-methylstyrene, p-methylstyrene, vinylxylene, ethylstyrene, dimethylstyrene, p-tert-butylstyrene, vinylnaphthalene, methoxystyrene, monobromstyrene, dibromstyrene, fluorostyrene, and tribromstyrene, with styrene and α-methylstyrene being more preferred, and styrene being particularly preferred. Furthermore, among the monomers that make up styrene-based resins, monomers other than styrene-based monomers include (meth)acrylic acid ester monomers, maleimide monomers such as maleimide, N-methylmaleimide, and N-phenylmaleimide, α,β-unsaturated carboxylic acids and their anhydrides such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, phthalic acid, and itaconic acid, and rubbers such as butadiene.

[0049] 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), styrene-IPN type rubber copolymer, and other resins.

[0050] In this embodiment, it is also preferable that a portion of the polystyrene resin used is a styrene-maleic acid polymer (preferably a styrene-maleic anhydride polymer). The styrene-maleic acid polymer acts as a compatibilizer between the polybutylene terephthalate resin and the polystyrene resin and / or rubber-reinforced polystyrene resin. As a result, the strength of the resulting molded article can be increased.

[0051] In this embodiment, the polystyrene 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 high-impact polystyrene resin (HIPS). Furthermore, from the viewpoint of heat resistance, polystyrene resin (GPPS) and acrylonitrile-styrene copolymer (AS resin) are more preferred, and AS resin is even more preferred.

[0052] <<Polycarbonate resin>> The polycarbonate resin used in this embodiment may be virgin polycarbonate resin or recycled polycarbonate resin, but recycled polycarbonate resin is preferred.

[0053] Polycarbonate resin is a branched thermoplastic polymer or copolymer obtained by reacting a dihydroxy compound, or a small amount thereof, with a polyhydroxy compound with phosgene or a diester carbonate.

[0054] The dihydroxy compounds used as raw materials are substantially free of bromine atoms, and aromatic dihydroxy compounds are preferred. Specifically, examples include 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A), tetramethylbisphenol A, bis(4-hydroxyphenyl)-p-diisopropylbenzene, hydroquinone, resorcinol, 4,4-dihydroxydiphenyl, etc., with bisphenol A being preferred. In addition, compounds in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compounds can also be used.

[0055] Among the polycarbonate resins mentioned above, aromatic polycarbonate resins derived from 2,2-bis(4-hydroxyphenyl)propane, or aromatic polycarbonate copolymers derived from 2,2-bis(4-hydroxyphenyl)propane and other aromatic dihydroxy compounds are preferred. Alternatively, copolymers mainly composed of aromatic polycarbonate resins, such as copolymers with polymers or oligomers having a siloxane structure, may also be used. Furthermore, two or more of the above-mentioned polycarbonate resins may be mixed and used.

[0056] To adjust the molecular weight of polycarbonate resin, monovalent aromatic hydroxy compounds can be used, such as m- and p-methylphenol, m- and p-propylphenol, p-tert-butylphenol, and p-long-chain alkyl-substituted phenols.

[0057] The viscosity-average molecular weight (Mv) of the polycarbonate resin is preferably 10,000 or higher, more preferably 12,000 or higher, even more preferably 13,000 or higher, and particularly preferably exceeding 14,000. If a viscosity-average molecular weight lower than 10,000 is used, the resulting resin composition tends to have low mechanical strength, such as impact resistance. Furthermore, the Mv is preferably 60,000 or lower, more preferably 40,000 or lower, even more preferably 35,000 or lower, even more preferably 30,000 or lower, and may also be 25,000 or lower or 20,000 or lower. If it is higher than 60,000, the fluidity of the resin composition may deteriorate, resulting in poor moldability.

[0058] In this invention, the viscosity-average molecular weight (Mv) of the polycarbonate resin is determined by measuring the viscosity of a methylene chloride solution of the polycarbonate resin at 25°C using an Ubbelohde viscometer, finding the intrinsic viscosity ([η]), and then calculating the value from Schnell's viscosity formula. [η] = 1.23 × 10 -4 Mv 0.83

[0059] The melt flow rate (MFR) of polycarbonate resin, measured according to JIS K7210 (temperature 300°C, load 1.20 kgf), is preferably 3 to 100 g / 10 min, and more preferably 6 to 70 g / 10 min. When the MFR is within the above range, the effects of the present invention tend to be exhibited more effectively. The melt volume rate (MVR) of polycarbonate resin, measured according to JIS K7210 (temperature 300°C, load 1.20 kgf), is 0.5 to 20 cm³. 3 It is preferable that the value is g / 10 mins, and the distance is 1-10 cm. 3 A value of 10 minutes is more preferable. When the MVR is within the above range, the effects of the present invention tend to be exhibited more effectively.

[0060] The method for producing the polycarbonate resin is not particularly limited, and polycarbonate resin produced by either the phosgene method (interfacial polymerization method) or the melting method (transesterification method) can be used. Furthermore, polycarbonate resin produced by the melting method and then subjected to post-treatment to adjust the amount of terminal OH groups is also preferred.

[0061] The amorphous resin content in the resin composition of this embodiment is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, even more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, and also preferably 100 parts by mass or less, more preferably 80 parts by mass or less, even more preferably 60 parts by mass or less, even more preferably 50 parts by mass or less, and even more preferably 45 parts by mass or less. Setting the content above the lower limit tends to reduce the molding shrinkage rate of the resulting molded product and further reduce warping. Setting the content below the upper limit tends to improve the mechanical properties and heat resistance of the resulting molded product.

[0062] The total content of polybutylene terephthalate resin and amorphous resin in the resin composition of this embodiment is more preferably 30% by mass or more, even more preferably 40% by mass or more, even more preferably 45% by mass or more, and also preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 55% by mass or less, based on 100% by mass of the resin composition. The resin composition of this embodiment may contain only one type of amorphous resin, 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.

[0063] The thermoplastic resin (total of polybutylene terephthalate resin, other crystalline thermoplastic resins, and amorphous thermoplastic resins) contained in the resin composition of this embodiment preferably has a recycled content of 10 to 100% by mass, more preferably 15 to 100% by mass, even more preferably 20 to 100% by mass, and 25 to 100% by mass.

[0064] <Flame retardant> The resin composition of this embodiment preferably contains a flame retardant. There are no specific requirements regarding the type of flame retardant; known flame retardants can be used, and examples include halogenated flame retardants, phosphorus-based flame retardants (such as phosphinate metal salts and polyphosphate melamine), nitrogen-based flame retardants (such as cyanurate melamine), and metal hydroxides (such as magnesium hydroxide). One example of a flame retardant in this embodiment is a phosphorus-based flame retardant, another example is a nitrogen-based flame retardant, and yet another example is a halogen-based flame retardant.

[0065] <<Halogenated flame retardant>> As for halogen-based flame retardants, bromine-based flame retardants are more preferred. While there are no specific requirements for the type of brominated flame retardant, brominated phthalimide, brominated poly(meth)acrylate, brominated polycarbonate, brominated epoxy, and brominated polystyrene are preferred, with brominated epoxy being more preferred.

[0066] As the brominated phthalimide, one represented by formula (1) is preferred. [ka] (In equation (1), D represents a group consisting of two or more combinations of alkylene groups, arylene groups, -S(=O)2-, -C(=O)-, and -O-. i is an integer from 1 to 4.)

[0067] In formula (1), D represents a group consisting of two or more combinations of an alkylene group, an arylene group, -S(=O)2-, -C(=O)-, and -O-, with a preferred group consisting of an alkylene group or an arylene group and at least one of -S(=O)2-, -C(=O)-, and -O-, more preferred a group consisting of an alkylene group or an arylene group and one of -S(=O)2-, -C(=O)-, and -O-, and an even more preferred alkylene group. The group consisting of an alkylene group and an -O- group includes, for example, a combination of two alkylene groups and one -O- group (the same applies to other combinations). The alkylene group D is preferably an alkylene group having 1 to 6 carbon atoms, and more preferably a methylene group, ethylene group, propylene group, or butylene group. The arylene group is preferably a phenylene group. i is an integer between 1 and 4, and is preferably 4.

[0068] 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)diphenylsulfone, N,N'-(bistetrabromophthalimide)diphenyl ketone, and N,N'-(bistetrabromophthalimide)diphenyl ether.

[0069] As for the brominated phthalimide, formula (1) is preferably the brominated phthalimide represented by formula (2). [ka] (In equation (2), i is an integer between 1 and 4.) i is an integer between 1 and 4, and is preferably 4.

[0070] The brominated poly(meth)acrylate is preferably a polymer obtained by polymerizing benzyl(meth)acrylate containing bromine atoms alone, copolymerizing two or more types, or copolymerizing with other vinyl monomers. The bromine atoms are attached to the benzene ring, and the number of attached atoms is preferably 1 to 5 per benzene ring, with 4 to 5 being particularly preferred.

[0071] Examples of benzyl acrylates containing a bromine atom include pentabrom benzyl acrylate, tetrabrom benzyl acrylate, tribrom benzyl acrylate, and mixtures thereof. Examples of benzyl methacrylates containing a bromine atom include methacrylates corresponding to the acrylates mentioned above.

[0072] Other vinyl monomers used for copolymerization with benzyl (meth)acrylate containing bromine atoms include, specifically, acrylic acid esters such as acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and benzyl acrylate; methacrylic acid esters 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, and the like.

[0073] These are usually used in amounts equal to or less than equimolar to the benzyl (meth)acrylate containing bromine atoms, and preferably in amounts of 0.5 times the molar amount or less.

[0074] In addition, vinyl monomers such as xylene acrylate, xylene methacrylate, tetrabrom xylene acrylate, tetrabrom xylene methacrylate, butadiene, isoprene, and divinylbenzene can also be used, and these can usually be used in amounts of 0.5 times or less molar relative to benzyl acrylate or benzyl methacrylate which contains bromine atoms.

[0075] The brominated poly(meth)acrylate is preferably a polymer obtained by polymerizing a (meth)acrylate monomer containing bromine atoms, particularly benzyl (meth)acrylate alone, copolymerizing two or more of them, or copolymerizing them with other vinyl monomers. Furthermore, the bromine atoms are attached to the benzene ring, and the number of attached atoms is preferably 1 to 5 per benzene ring, with 4 to 5 being particularly preferable.

[0076] As the brominated poly(meth)acrylate, pentabromobenzyl poly(meth)acrylate is preferred due to its high bromine content.

[0077] The molecular weight of the brominated poly(meth)acrylate is arbitrary and can be selected and determined as appropriate, but it is preferably 3,000 or more in weight-average molecular weight (Mw), more preferably 10,000 or more, and even more preferably 15,000 or more. Setting it above the lower limit tends to yield molded articles with higher mechanical strength. Furthermore, the upper limit of the weight-average molecular weight (Mw) is preferably 100,000 or less, more preferably 80,000 or less, even more preferably 60,000 or less, even more preferably 50,000 or less, and even more preferably 35,000 or less. Setting it below the upper limit tends to further improve the fluidity of the resin composition.

[0078] The brominated polycarbonate preferably has a free bromine content of 0.05% by mass or more, and more preferably 0.20% by mass or less. This range tends to further improve the heat resistance stability of the resin composition. The brominated polycarbonate also preferably has a chlorine atom content of 0.001% by mass or more, and more preferably 0.20% by mass or less. This range tends to further improve mold corrosion resistance during molding. The brominated polycarbonate is preferably, for example, a brominated polycarbonate obtained from brominated bisphenol A, particularly tetrabromobisphenol A. Its terminal structure may include a phenyl group, a 4-t-butylphenyl group, or a 2,4,6-tribromophenyl group, with a 2,4,6-tribromophenyl group being particularly preferred.

[0079] The average number of carbonate constituent units in brominated polycarbonate can be appropriately selected and determined, but it is preferably 2 to 30, more preferably 3 to 15, and even more preferably 3 to 10.

[0080] The molecular weight of the brominated polycarbonate is arbitrary and can be selected and determined as appropriate, but preferably, the viscosity-average molecular weight is 1,000 to 20,000, and more preferably, 2,000 to 10,000.

[0081] The brominated polycarbonate obtained from the above-mentioned brominated bisphenol A can be obtained, for example, by a conventional method of reacting brominated bisphenol with phosgene. Examples of end-capping agents include aromatic monohydroxy compounds, which may be substituted with halogens or organic groups.

[0082] As brominated epoxy compounds, preferred examples include bisphenol A type brominated epoxy compounds, such as tetrabromobisphenol A epoxy compounds and glycidyl brominated bisphenol A epoxy compounds.

[0083] The molecular weight of the brominated epoxy compound is arbitrary and can be appropriately selected and determined, but it is preferably 3,000 or more in weight-average molecular weight (Mw), more preferably 10,000 or more, even more preferably 13,000 or more, even more preferably 15,000 or more, and even more preferably 18,000 or more. Setting it above the lower limit tends to yield molded articles with higher mechanical strength. Furthermore, the upper limit of the weight-average molecular weight (Mw) is preferably 100,000 or less, more preferably 80,000 or less, even more preferably 78,000 or less, even more preferably 75,000 or less, and even more preferably 70,000 or less. Setting it below the upper limit tends to further improve the fluidity of the resin composition. The brominated epoxy compound preferably has an epoxy equivalent of 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.

[0084] Furthermore, brominated epoxy oligomers can also be used in combination as brominated epoxy. In this case, for example, by using oligomers with an Mw of 5,000 or less in a proportion of about 50% by mass or less, flame retardancy, mold release properties, and fluidity can be appropriately adjusted. The bromine atom content in the brominated epoxy compound is arbitrary, but in order to impart sufficient flame retardancy, it is usually 10% by mass or more, more preferably 20% by mass or more, and especially preferably 30% by mass or more, with an upper limit of 60% by mass, and more preferably 55% by mass or less.

[0085] Preferably, the brominated polystyrene is a brominated polystyrene containing the constituent unit shown in formula (3). [ka] (In equation (3), t is an integer between 1 and 5, and n is the number of constituent units.)

[0086] Brominated polystyrene may be produced by brominating polystyrene or by polymerizing brominated styrene monomer, but polymerized brominated styrene is preferred because it contains a small amount of free bromine (atoms). In formula (3), the CH group to which brominated benzene is bonded may be substituted with a methyl group. Brominated polystyrene may also be a copolymer obtained by copolymerizing other vinyl monomers. Examples of vinyl monomers in this case include styrene, α-methylstyrene, (meth)acrylonitrile, methyl (meth)acrylate, butadiene, and vinyl acetate. Brominated polystyrene may also be used as a single substance or a mixture of two or more substances with different structures, and may contain units derived from styrene monomers with different numbers of bromine atoms in a single molecular chain.

[0087] Specific examples of brominated polystyrene include, for example, 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), and poly(4-bromo-α-methylstyrene). Examples include 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), with poly(2,4,6-tribromostyrene), poly(2,4,5-tribromostyrene), and polydibromostyrene and polytribromostyrene containing an average of 2 to 3 bromine groups in the benzene ring being particularly preferred.

[0088] The brominated polystyrene preferably has an average degree of polymerization (n) of 30 to 1,500, more preferably 150 to 1,000, and particularly preferably 300 to 800. If the average degree of polymerization is less than 30, blooming is likely to occur, while if it exceeds 1,500, dispersion problems are likely to occur, and mechanical properties tend to deteriorate. Furthermore, the weight-average molecular weight (Mw) of the brominated polystyrene is preferably 5,000 to 500,000, more preferably 10,000 to 500,000, even more preferably 10,000 to 300,000, even more preferably 10,000 to 100,000, and even more preferably 10,000 to 70,000. In particular, for the brominated polystyrene mentioned above, the weight-average molecular weight (Mw) is preferably 50,000 to 70,000, and for brominated polystyrene produced by polymerization, the weight-average molecular weight (Mw) is preferably around 10,000 to 30,000. The weight-average molecular weight (Mw) can be determined as a value converted to standard polystyrene by GPC measurement.

[0089] The content of the halogenated flame retardant in the resin composition of this embodiment is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, even more preferably 7 parts by mass or more, even more preferably 9 parts by mass or more, and also preferably 40 parts by mass or less, preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less, above the lower limit. Setting the content above the lower limit tends to further improve the flame retardancy of the resulting molded article. Setting the content below the upper limit tends to further improve the mechanical strength of the resulting molded article. The resin composition of this embodiment may contain only one halogen-based flame retardant or two or more. When two or more are included, it is preferable that the total amount is within the above range.

[0090] <<Phosphorus-based flame retardant>> Examples of phosphorus-based flame retardants include metal phosphinates, melamine polyphosphate, condensed phosphate esters, phosphazene compounds, etc., with metal phosphinates being preferred.

[0091] When using a metal phosphinate as the flame retardant, its type is not particularly defined. However, a metal phosphinate preferably has an anion part represented by formula (4) or formula (5) and a metal ion in the cation part being any one of calcium, magnesium, aluminum, or zinc.

[0092]

Chemical formula

[0093] Specific examples of phosphinate metal salts include calcium dimethylphosphinate, magnesium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, magnesium ethylmethylphosphinate, aluminum ethylmethylphosphinate, zinc ethylmethylphosphinate, calcium diethylphosphinate, magnesium diethylphosphinate, aluminum diethylphosphinate, zinc diethylphosphinate, calcium methyl-n-propylphosphinate, magnesium methyl-n-propylphosphinate, aluminum methyl-n-propylphosphinate, zinc methyl-n-propylphosphinate, calcium methanedi(methylphosphinate), Examples include magnesium methanedi(methylphosphinate), aluminum methanebis(methylphosphinate), zinc methanebis(methylphosphinate), calcium benzene-1,4-bis(methylphosphinate), magnesium benzene-1,4-bis(methylphosphinate), aluminum benzene-1,4-bis(methylphosphinate), zinc benzene-1,4-bis(methylphosphinate), calcium methylphenylphosphinate, magnesium methylphenylphosphinate, aluminum methylphenylphosphinate, zinc methylphenylphosphinate, calcium diphenylphosphinate, magnesium diphenylphosphinate, aluminum diphenylphosphinate, and zinc diphenylphosphinate. Details of phosphinate metal salts can be found in paragraphs 0052-0058 of International Publication No. 2010 / 010669, which are incorporated herein by reference. Further details regarding phosphorus-based flame retardants can be found in paragraphs 0064-0084 of International Publication No. 2021 / 241471, which are incorporated herein by reference.

[0094] The phosphorus-based flame retardant content in the resin composition of this embodiment is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, even more preferably 15 parts by mass or more, even more preferably 20 parts by mass or more, even more preferably 25 parts by mass or more, and also preferably 40 parts by mass or less, more preferably 35 parts by mass or less, and even more preferably 30 parts by mass or less. Setting the content above the lower limit tends to further improve the flame retardancy of the resulting molded article. Setting the content below the upper limit tends to further improve the mechanical strength of the resulting molded article. The resin composition of this embodiment may contain only one phosphorus-based flame retardant, or it may contain two or more. When it contains two or more, it is preferable that the total amount is within the above range.

[0095] <<Nitrogen-based flame retardant>> Examples of nitrogen-based flame retardants include aliphatic amine compounds, aromatic amine compounds, nitrogen-containing heterocyclic compounds, cyanide compounds, aliphatic amides, aromatic amides, urea, and thiourea. Examples of aliphatic amines include ethylamine, butylamine, diethylamine, ethylenediamine, butylenediamine, triethylenetetramine, 1,2-diaminocyclohexane, and 1,2-diaminocyclooctane. Examples of aromatic amines include aniline and phenylenediamine, while examples of nitrogen-containing heterocyclic compounds include uric acid, adenine, guanine, 2,6-diaminopurine, 2,4,6-triaminopyridine, and triazine compounds. Examples of cyanide compounds include dicyandiamide, examples of aliphatic amides include N,N-dimethylacetamide, and examples of aromatic amides include N,N-diphenylacetamide.

[0096] The triazine compounds exemplified above are nitrogen-containing heterocyclic compounds having a triazine skeleton, and examples include triazine, melamine, benzoguanamine, methylguanamine, cyanuric acid, melamine cyanurate, melamine isocyanurate, trimethyltriazine, triphenyltriazine, amelin, amelido, thiocyanuric acid, diaminomercaptotriazine, diaminomethyltriazine, diaminophenyltriazine, and diaminoisopropoxytriazine. As melamine cyanurate or melamine isocyanurate, adducts of cyanuric acid or isocyanuric acid with a triazine compound are preferred, and adducts having a composition of 1:1 (molar ratio) or sometimes 1:2 (molar ratio) are examples.

[0097] Among nitrogen-based flame retardants, nitrogen-containing heterocyclic compounds are preferred, triazine compounds are preferred, and melamine cyanurate is even more preferred.

[0098] The resin composition of this embodiment may or may not contain a nitrogen-based flame retardant. If the resin composition of this embodiment contains a nitrogen-based flame retardant, the content is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, and also 19 parts by mass or less, preferably 18 parts by mass or less, more preferably 16 parts by mass or less, even more preferably 14 parts by mass or less, even more preferably 13 parts by mass or less, and even more preferably 10 parts by mass or less. Depending on the application, it may also be 8 parts by mass or less, 5 parts by mass or less, 3 parts by mass or less, 1 part by mass or less, or 0.1 parts by mass or less. Setting the content above the lower limit tends to further improve the flame retardancy and tracking resistance of the resulting molded product. Setting the content below the upper limit tends to further improve the mechanical strength, suppress gelation during resin composition manufacturing, and suppress the decrease in fluidity due to thickening of the resin composition. The resin composition of this embodiment may contain only one nitrogen-based flame retardant or two or more. When two or more are included, it is preferable that the total amount is within the above range.

[0099] The total amount of flame retardant in the resin composition of this embodiment is 1 part by mass or more, preferably 5 parts by mass or more, more preferably 10 parts by mass or more, even more preferably 15 parts by mass or more, even more preferably 20 parts by mass or more, even more preferably 25 parts by mass or more, and even more preferably 40 parts by mass or less, preferably 35 parts by mass or less, even more preferably 30 parts by mass or less, even more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less. Setting the amount above the lower limit tends to further improve flame retardancy. Setting the amount below the upper limit tends to further improve mechanical strength. 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.

[0100] <Flame retardant additive> The resin composition of this embodiment may contain a flame retardant additive. If a flame retardant additive is included, it is preferable that it contains an antimony compound. The flame retardant additive (preferably an antimony compound) improves the flame retardancy of the resulting molded article. Preferred antimony compounds include antimony trioxide (Sb2O3), antimony pentoxide (Sb2O5), and sodium antimonate, with antimony trioxide being particularly preferred among these.

[0101] In the resin composition of this embodiment, the antimony compound may be blended as a masterbatch with the thermoplastic resin. This makes it easier for the antimony compound to be present in the thermoplastic resin phase, resulting in good thermal stability during melt mixing and molding, suppressing the decrease in impact resistance, and further reducing the variability in flame retardancy and impact resistance. The antimony compound content in the masterbatch is preferably 20 to 90% by mass. More preferably, the antimony compound content in the masterbatch is 30% by mass or more, even more preferably 40% by mass or more, even more preferably 50% by mass or more, even more preferably 60% by mass or more, and especially most preferably 70% by mass or more.

[0102] The antimony compound content in the resin composition of this embodiment is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 2 parts by mass or more, per 100 parts by mass of polybutylene terephthalate resin contained in the resin composition of this embodiment. Setting it above the lower limit further improves the flame retardancy of the resulting molded article. Furthermore, the upper limit of the antimony compound content is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, even more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of polybutylene terephthalate resin. Setting it below the upper limit tends to improve the release properties and impact resistance of the resulting molded article.

[0103] <Coloring agent> The resin composition of this embodiment may contain a coloring agent (dye and / or pigment). The coloring agent may be a dye or a pigment, but a pigment is preferred. The coloring agent may be either an organic or inorganic coloring agent. Furthermore, it may be either a chromatic or achromatic coloring agent. Examples of colorants include those described in paragraphs 0121 to 0123 of Japanese Patent Publication No. 2021-101020 and paragraphs 0088 to 0090 of Japanese Patent Publication No. 2019-188393, the contents of which are incorporated herein by reference. The resin composition of this embodiment preferably contains carbon black. There are no restrictions on the type, raw material, or manufacturing method of the carbon black; furnace black, channel black, acetylene black, Ketjen black, etc., can be used. Among these, furnace black is preferred. There are no particular restrictions on the number-average particle size, but it is preferably about 5 to 60 nm.

[0104] DBP oil absorption capacity of carbon black (unit: cm) 3 (100g) is 40-300cm 3 It is preferable that it be / 100g. The upper limit is 300cm 3 It is preferable that the amount be 100g or less, and 200cm 3 It is more preferable that the weight be 100g or less, and 150cm 3 It is even more preferable that the amount be 100g or less, and 100cm 3 It may be less than 100g. Also, the lower limit is 40cm. 3 / 100g or more is preferable, 50cm 3 / 100g or more is more preferable, 60cm 3 A value of 100g or more is even more preferable. Keeping the value within the above upper and lower limits tends to improve the appearance of the molded product. Note that DBP oil absorption (unit: cm) 3 The amount (per 100g) can be measured in accordance with JIS K6217. The number-average particle size of carbon black is preferably 5 to 60 nm. The upper limit is preferably 60 nm or less, more preferably 40 nm or less, even more preferably 30 nm or less, and even more preferably 25 nm or less. The lower limit is preferably 10 nm or more, more preferably 13 nm or more, even more preferably 16 nm or more, and even more preferably 19 nm or more. Keeping the number-average particle size within these upper and lower limits tends to improve the appearance of the molded product. The number-average particle size can be determined by obtaining an aggregate magnified image according to the procedure described in ASTM D3849 standard (Standard Test Methods for Carbon Black - Morphological Characterization by Electron Microscopy), measuring the particle size of 3,000 unit constituent particles from this aggregate image, and taking the arithmetic mean.

[0105] When carbon black is incorporated as a masterbatch, which is a pre-mixed mixture of carbon black with a thermoplastic resin, preferably a polyester resin such as polyalkylene terephthalate resin or a polystyrene-based resin, the dispersion of the carbon black is increased, and the appearance of the molded product tends to improve. The concentration of carbon black in the masterbatch is preferably 10 to 40% by mass.

[0106] If the resin composition of this embodiment contains a coloring agent (preferably carbon black), the amount is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more, and even more preferably 0.2 parts by mass or more, per 100 parts by mass of polybutylene terephthalate resin contained in the resin composition. By setting the amount above the lower limit, the coloring effect is more effectively exhibited. Furthermore, the upper limit of the coloring agent content is preferably 4 parts by mass or less, more preferably 2 parts by mass or less, and may be 1 part by mass or less, per 100 parts by mass of polybutylene terephthalate resin contained in the resin composition. By setting the amount below the upper limit, the mechanical strength of the resulting molded product tends to be further improved. The resin composition of this embodiment may contain only one coloring agent or two or more. When two or more coloring agents are included, it is preferable that the total amount is within the above range.

[0107] <Stabilizer> The resin composition of this embodiment may contain stabilizers (light stabilizers and / or heat stabilizers). The stabilizer preferably contains one or more compounds selected from the group consisting of thioether compounds, phosphorus compounds, hindered phenol compounds, and phosphite compounds, with phosphorus compounds and / or hindered phenol compounds being more preferred. Furthermore, in this embodiment, it is also preferable to use two or more thioether compounds, hindered phenol compounds, and phosphite compounds in combination as needed.

[0108] As the thioether compound, any conventionally known sulfur atom-containing compound can be used, with thioethers being particularly preferred. The resin composition of this embodiment tends to have a good appearance and improved thermal stability when it contains a thioether compound. Specifically, examples include didodecylthiodipropionate, ditetradecylthiodipropionate, dioctadecylthiodipropionate, pentaerythritol tetrakis(3-dodecylthiopropionate), 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 isopropylxanthate, and trilauryl trithiophosphite. Among these, 2,2-bis{[3-(dodecylthio)-1-oxopropoxy]methyl}propane-1,3-diylbis[3-(dodecylthio)propionate] is preferred. Commercially available products include "C-NOX 412S" manufactured by Cipro Chemical Co., Ltd. and "ADEKA AO-412S" manufactured by ADEKA Corporation.

[0109] Examples of phosphorus-based stabilizers include phosphorous acid, phosphoric acid, phosphorous acid esters (phosphites), trivalent phosphate esters (phosphonites), and pentavalent phosphate esters (phosphates), with organic phosphite compounds, organic phosphonite compounds, and organic phosphate compounds being preferred.

[0110] Preferably, the following organic phosphate compounds are used. Formula (R 1 O) 3-n P(=O)OH n (In the formula, R 1 (where n is an alkyl group or an aryl group, which may be the same or different; n is an integer between 0 and 2.) It is a compound represented by . More preferably, R1 Examples include long-chain alkyl acid phosphate compounds having 8 to 30 carbon atoms. Specific examples of alkyl groups having 8 to 30 carbon atoms include octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, hexadecyl group, octadecyl group, eicosyl group, and triacontyl group.

[0111] Examples of long-chain alkyl acid phosphates include octyl acid phosphate, 2-ethylhexyl acid phosphate, decyl acid phosphate, lauryl acid phosphate, octadecyl acid phosphate, oleyl acid phosphate, behenyl acid phosphate, phenyl acid phosphate, nonylphenyl acid phosphate, cyclohexyl acid phosphate, phenoxyethyl acid phosphate, and alkoxypolyethylene glycol acid phosphate. Examples include octadecyl acid phosphate, bisphenol A acid phosphate, dimethyl acid phosphate, diethyl acid phosphate, dipropyl acid phosphate, diisopropyl acid phosphate, dibutyl acid phosphate, dioctyl acid phosphate, di-2-ethylhexyl acid phosphate, dioctyl acid phosphate, dilauryl acid phosphate, distearyl acid phosphate, diphenyl acid phosphate, and bisnonylphenyl acid phosphate. Among these, octadecyl acid phosphate is preferred, and this is commercially available under the trade name "ADEKA Stab AX-71" from ADEKA Corporation.

[0112] Preferably, the organophosphite compound is of the following formula: R 2 OP(OR 3 )(OR 4 ) (In the formula, R 2 , R 3 and R 4These are a hydrogen atom, an alkyl group with 1 to 30 carbon atoms, or an aryl group with 6 to 30 carbon atoms, and R 2 , R 3 and R 4 At least one of them is an aryl group with 6 to 30 carbon atoms. Examples of compounds represented by [the formula shown] are given.

[0113] Examples of organic phosphite compounds include triphenyl phosphite, tris(nonylphenyl) phosphite, dilauryl hydrogen phosphite, triethyl phosphite, tridecyl phosphite, tris(2-ethylhexyl) phosphite, tris(tridecyl) phosphite, tristearyl phosphite, diphenyl monodecyl phosphite, monophenyl didecyl phosphite, diphenyl mono(tridecyl) phosphite, tetraphenyldipropylene glycol diphosphite, tetraphenyltetra(tridecyl)pentaerythritol tetraphosphite, hydrogenated bisphenol A phenol phosphite polymer, diphenyl hydrogen phosphite, 4,4'-butylidene-bis(3-methyl-6-tert-butylphenyl di(tridecyl) phosphite), and tetra(tridecyl)4,4'-iso Examples include propyridene diphenyl diphosphite, bis(tridecyl)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'-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, and bis(2,4-dicumylphenyl)pentaerythritol diphosphite. Among these, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is preferred.

[0114] The organic phosphonite compound is preferably one of the following formulas: R 5 -P(OR 6 )(OR 7 ) (In the formula, R 5 , R 6 and R7 These are a hydrogen atom, an alkyl group with 1 to 30 carbon atoms, or an aryl group with 6 to 30 carbon atoms, and R 5 , R 6 and R 7 At least one of them is an aryl group with 6 to 30 carbon atoms. Examples of compounds represented by [the formula shown] are given.

[0115] Examples of organic phosphonite compounds include tetrakis(2,4-di-iso-propylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-n-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,3'-biphenylenediphosphonite, and tetrakis(2,4-di-tert-butylphenyl)-3,3'-biphenylenediphosphona Examples include tetrakis(2,6-di-iso-propylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,6-di-n-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,3'-biphenylenediphosphonite, and tetrakis(2,6-di-tert-butylphenyl)-3,3'-biphenylenediphosphonite.

[0116] Examples of hindered phenol compounds include pentaerythritol tetrakis(3-(3,5-di-t-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 tetrakis(3-(3,5-di-neopentyl-4-hydroxyphenyl)propionate), and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene. 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. Commercially available options include ADEKA products such as "ADEKA Stub AO-60" and "ADEKA Stub AO-330," and BASF products such as "Irganox Knox 1010."

[0117] Preferably, the phosphite compound is of the formula: R 2 OP(OR 3 )(OR 4 ) (In the formula, R 2 , R 3 and R 4 These are a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or an aryl group having 6 to 30 carbon atoms, respectively. 2 , R 3 and R 4 At least one of them is an aryl group with 6 to 30 carbon atoms. Examples of compounds represented by [the formula shown] are given.

[0118] Phosphite compounds include, for example, triphenyl phosphite, tris(nonylphenyl) phosphite, dilauryl hydrogen phosphite, triethyl phosphite, tridecyl phosphite, tris(2-ethylhexyl) phosphite, tris(tridecyl) phosphite, tristearyl phosphite, diphenyl monodecyl phosphite, monophenyl didecyl phosphite, diphenyl mono(tridecyl) phosphite, tetraphenyldipropylene glycol diphosphite, tetraphenyltetra(tridecyl)pentaerythritol tetraphosphite, hydrogenated bisphenol A phenol phosphite polymer, diphenyl hydrogen phosphite, 4,4'-butylidene-bis(3-methyl-6-tert-butylphenyl di(tridecyl) phosphite, tetra(tridecyl)4,4'-isopropyl Examples include lopyridene diphenyl diphosphite, bis(tridecyl)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'-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, and bis(2,4-dicumylphenyl)pentaerythritol diphosphite. Among these, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite is preferred. A commercially available example is "ADEKA Stab PEP-36" manufactured by ADEKA Corporation.

[0119] In addition, as stabilizers, specific examples can be found in paragraphs 0067-0075 of Japanese Patent Publication No. 2021-063196, paragraphs 0046-0057 of Japanese Patent Publication No. 2018-070722, paragraphs 0030-0037 of Japanese Patent Publication No. 2019-056035, and paragraphs 0066-0078 of International Publication No. 2017 / 038949, the contents of which are incorporated herein by reference.

[0120] The stabilizer content in the resin composition of this embodiment is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more, per 100 parts by mass of polybutylene terephthalate resin contained in the resin composition. Setting the content above the lower limit tends to further improve the effect of suppressing thermal degradation and oxidative degradation of the resin during melt mixing, molding, and use as a molded article, and tends to improve heat resistance. Furthermore, the upper limit of the stabilizer content is preferably 1.0 part by mass or less, more preferably 0.8 parts by mass or less, more preferably 0.6 parts 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 polybutylene terephthalate resin contained in the resin composition. Setting the content below the upper limit tends to effectively suppress adverse effects on appearance and physical properties due to aggregation of additives such as stabilizers, and tends to suppress discoloration of the resin composition. 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.

[0121] <Release agent> The resin composition of this embodiment may contain a mold release agent. As a release agent, known release agents commonly used for polyester resins can be used, but among them, polyolefin compounds and fatty acid ester compounds are preferred due to their good alkali resistance, and polyolefin compounds are particularly preferred.

[0122] Examples of polyolefin compounds include those selected from paraffin wax and polyethylene wax, with a preferred weight-average molecular weight of 700 to 10,000, and more preferably 900 to 8,000.

[0123] Examples of fatty acid ester compounds include saturated or unsaturated monovalent or divalent aliphatic carboxylic acid esters, glycerol fatty acid esters, sorbitan fatty acid esters, and other fatty acid esters and their partially saponified products. Among these, mono or di fatty acid esters composed of a fatty acid having 11 to 28 carbon atoms, preferably 17 to 21 carbon atoms, and an alcohol are preferred.

[0124] Examples of fatty acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, melissic acid, tetrariacontanoic acid, montanic acid, adipic acid, and azelaic acid. Furthermore, fatty acids may also be alicyclic. Examples of alcohols 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. Here, "aliphatic" includes alicyclic compounds. Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, and dipentaerythritol. The above-mentioned ester compounds may contain aliphatic carboxylic acids and / or alcohols as impurities, and may also be mixtures of multiple compounds.

[0125] Specific examples of fatty acid ester compounds include glycerin monostearate, glycerin monobehenate, glycerin dibehenate, glycerin-12-hydroxymonostearate, sorbitan monobehenate, pentaerythritol monostearate, pentaerythritol distearate, stearyl stearate, and ethylene glycol montanate.

[0126] If the resin composition of this embodiment contains a release agent, its content is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, preferably 2.0 parts by mass or less, more preferably 1.5 parts by mass or less, and even more preferably 1.0 part by mass or less, based on 100 parts by mass of the polybutylene terephthalate resin contained in the resin composition. Setting the content above the lower limit tends to improve the release properties and mechanical strength of the molded product.

[0127] <Fibrous filler> The resin composition of this embodiment preferably further contains a fibrous filler. Including a fibrous filler tends to improve the mechanical strength.

[0128] The fibrous filler that can be included in the resin composition of this embodiment is one that has the effect of improving the mechanical properties of the resin composition obtained by being blended with the resin, and commonly used fibrous fillers for plastics can be used. Preferably, fibrous fillers such as glass fibers, carbon fibers, basalt fibers, wollastonite, and potassium titanate fibers can be used, with glass fibers and / or carbon fibers being preferred, and glass fibers being more preferred. It is more preferable to use fibrous fillers that have been surface-treated with a surface treatment agent such as a coupling agent. Glass fibers to which a surface treatment agent has been applied are preferable because they have excellent durability, resistance to humid heat, resistance to hydrolysis, and resistance to thermal shock.

[0129] Any conventionally known surface treatment agent can be used, and specifically, silane coupling agents such as aminosilane, epoxysilane, allylsilane, and vinylsilane are preferred. Among these, aminosilane surface treatment agents are preferred, and specifically, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and γ-(2-aminoethyl)aminopropyltrimethoxysilane are preferred examples.

[0130] In addition, other preferred surface treatment agents include epoxy resin-based surface treatment agents such as novolac-type and bisphenol A-type epoxy resin-based surface treatment agents, with treatment using a novolac-type epoxy resin-based surface treatment agent being particularly preferred. Silane-based surface treatment agents and epoxy resin-based surface treatment agents may be used individually or in combination, and it is also preferable to use both in combination. In this embodiment, glass fibers refer to fibrous glass material, and more specifically, chopped glass fibers, which are bundled together in a manner of 1,000 to 10,000 strands and cut to a predetermined length, are preferred.

[0131] In this embodiment, the glass fibers have a number-average fiber length of 0.5 to 10 mm, and more preferably 1 to 5 mm. By using glass fibers with such a number-average fiber length, the mechanical strength can be further improved. The number-average fiber length is calculated by randomly selecting glass fibers to be measured from an image obtained by observation with an optical microscope, measuring their longest side, and then calculating the number-average fiber length from the obtained measurement values. The observation magnification is 20x, and the number of measurements is 1,000 or more. This roughly corresponds to the cut length. Furthermore, the cross-section of the glass fiber may be circular, elliptical, oblong, rectangular, a rectangle with semicircles attached to both short sides, or cocoon-shaped, but a circular shape is preferred. Here, "circular" includes not only a circular shape in the geometric sense, but also what is commonly referred to as circular in the technical field of this embodiment. The number-average fiber diameter of glass fibers is preferably 4.0 μm or more at the lower limit, more preferably 4.5 μm or more, and even more preferably 5.0 μm or more. The upper limit of the number-average fiber diameter of glass fibers is preferably 15.0 μm or less, and more preferably 14.0 μm or less. Using glass fibers having a number-average fiber diameter within this range tends to yield molded products with superior mechanical strength. The number-average fiber diameter of glass fibers is calculated by randomly selecting glass fibers to be measured from an image obtained by observing with an electron microscope, measuring the fiber diameter near the center, and obtaining the measured values. The observation magnification is 1,000x, and the number of measurements is 1,000 or more. For glass fibers with a cross-section other than circular, the number-average fiber diameter is calculated as the number-average fiber diameter when converted to a circle with the same area as the cross-sectional area.

[0132] Glass fibers are generally obtained by melt-spinning supplied glass such as E glass (Electrical glass), C glass (Chemical glass), A glass (Alkali glass), S glass (High strength glass), D glass, R glass, and alkali-resistant glass, but any material that can be made into glass fibers can be used and is not particularly limited. In this embodiment, it is preferable to include E glass.

[0133] The glass fibers used in this embodiment are preferably surface-treated with a surface treatment agent such as a silane coupling agent, such as γ-methacrylateoxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, or γ-aminopropyltriethoxysilane. The amount of surface treatment agent applied is preferably 0.01 to 1% by mass of the glass fibers. Furthermore, if necessary, glass fibers may be surface-treated with a lubricant such as a fatty acid amide compound or silicone oil, an antistatic agent such as a quaternary ammonium salt, a resin with film-forming ability such as epoxy resin or urethane resin, or a mixture of a resin with film-forming ability and a heat stabilizer.

[0134] Glass fibers are available commercially. Examples of commercially available products include T-286H, T-756H, T-127, T-289H from Nippon Electric Glass Co., Ltd., DEFT2A from Owens Corning, HP3540 from PPG, and CSG3PA820 from Nitto Boseki Co., Ltd.

[0135] The content of fibrous filler (preferably glass fiber) in the resin composition of this embodiment is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, even more preferably 40 parts by mass or more, even more preferably 50 parts by mass or more, and may be 55 parts by mass or more, based on 100 parts by mass of the total polybutylene terephthalate resin contained in the resin composition of this embodiment. Setting the content above the lower limit tends to increase the mechanical strength of the resulting molded product. Furthermore, the upper limit of the content of fibrous filler is preferably 70 parts by mass or less, more preferably 65 parts by mass or less, and even more preferably 60 parts by mass or less, based on 100 parts by mass of polybutylene terephthalate resin. Setting the content below the upper limit tends to increase the welding strength of the interface.

[0136] Furthermore, the content of fibrous filler (preferably glass fiber) in the resin composition of this embodiment is preferably 20% by mass or more, and more preferably 25% by mass or more. Moreover, the content of the fibrous filler (preferably glass fiber) is preferably 45% by mass or less, more preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 32% by mass or less. The resin composition of this embodiment may contain only one type of fibrous filler (preferably glass fiber), or it may contain two or more types. When two or more types are included, it is preferable that the total amount is within the above range.

[0137] <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. The other components may be present as a single component, or as two or more components in any combination and ratio. Other examples of components include resin additives and fillers other than the fibrous fillers mentioned above. Examples of resin additives include transesterification inhibitors, UV absorbers, antistatic agents, antifogging agents, antiblocking agents, flow improvers, plasticizers, and dispersants. The total amount of these other components is preferably 0% by mass or more and less than 10% by mass, more preferably 0% by mass or more and less than 5% by mass, and even more preferably 0% by mass or more and less than 3% by mass, based on 100% by mass of the resin composition.

[0138] Other fillers besides fibrous fillers include granular or amorphous fillers such as calcium carbonate, titanium oxide, feldspar minerals, clay, organic clay, and glass beads; plate-like fillers such as talc; and flake-like fillers such as glass flakes, mica, and graphite. The total amount of fillers other than fibrous fillers is preferably 0% by mass or more and less than 10% by mass, more preferably 0% by mass or more and less than 5% by mass, and even more preferably 0% by mass or more and less than 3% by mass, based on 100% by mass of the resin composition.

[0139] In this embodiment, the resin composition preferably contains a total of 90% or more by mass of polybutylene terephthalate resin, a halogenated flame retardant, and an antimony compound, as well as amorphous resin, colorants, stabilizers, release agents, and fibrous fillers, which may be added as needed. More preferably, it may contain 95% or more by mass, and may even be 100% by mass. The proportion of recycled material in the resin composition of this embodiment is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and preferably 100% by mass or less. The recycled material here includes thermoplastic resin components such as polybutylene terephthalate resin and amorphous resin, and glass fibers.

[0140] <Method for producing resin compositions> The resin composition of this embodiment can be manufactured by conventional methods for preparing resin compositions (e.g., pellets). Typically, each component and various additives added as desired are thoroughly mixed together and then melt-kneaded in a single-screw or twin-screw extruder. Alternatively, the resin composition of this embodiment can be prepared by supplying the components to the extruder using a feeder and melt-kneading them without pre-mixing them, or by pre-mixing only a portion of them. For example, it is preferable to supply glass fibers to the extruder using a side feeder and melt-knead them. Alternatively, a masterbatch may be prepared by melt-kneading some of the components with a thermoplastic resin, and then the remaining components may be added to this and melt-kneaded. The thermoplastic resin used to make the masterbatch is preferably a polyalkylene terephthalate resin, more preferably a polyalkylene terephthalate resin and / or polyethylene terephthalate resin, and even more preferably a polyalkylene terephthalate resin.

[0141] <Method for manufacturing molded products> The resin composition or pellets of this embodiment are molded according to known methods. The method for manufacturing the molded product is not particularly limited, and any molding method commonly used for resin compositions can be arbitrarily employed. Examples include injection molding, ultra-high-speed injection molding, injection compression molding, two-color molding, hollow molding methods such as gas-assisted molding, molding using a heat-insulating mold, molding using a rapidly heated mold, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating) molding, extrusion molding, sheet molding, thermoforming, rotational molding, lamination molding, press molding, blow molding, etc., with injection molding being preferred among them. Details of the injection molding method can be found in paragraphs 0113 to 0116 of Japanese Patent No. 6183822, and these contents are incorporated herein by reference. Furthermore, the mold temperature during mold molding, such as injection molding, is preferably between 40 and 150°C.

[0142] <Application> The resin composition of this embodiment is used as a molded article formed from the resin composition or pellets. The resin composition and pellets can be widely used in known applications. For example, they can be widely used both indoors and outdoors in electrical and electronic equipment materials, automotive materials, housing materials, and materials for manufacturing parts in other industrial fields. More specifically, examples include circuit breakers, electromagnetic switches, various relay components, transformer components, sensor components, switch components, connector components, terminal components, actuator components, outlet components, socket components, plug components, capacitor components, resistor components, charging components, battery components, housing components, structural components, and insulating components. In particular, it can be suitably used as a material for relay components. Automotive materials include housings, reflectors, bezels, and extensions for lamps, as well as connectors, ECU cases, enclosures for in-vehicle cameras and millimeter-wave radar, battery cases, and sensor enclosures. Examples of electrical and electronic components include various housings, personal computers, game consoles, display devices such as televisions, printers, copiers, scanners, fax machines, electronic organizers and PDAs, electronic desktop calculators, electronic dictionaries, cameras, video cameras, mobile phones, battery packs, drives and readers for recording media, mice, numeric keypads, housings, covers, keyboards, buttons, and switch components for CD players, MD players, portable radios and audio players, power meter housings, battery cases, battery transport trays, relays, sensors, actuators, terminal switches, and components for grill cooking equipment. [Examples]

[0143] The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, treatment details, treatment procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. When the measuring instruments etc. used in the examples are difficult to obtain due to being obsolete etc., measurements can be made using other devices having equivalent performance.

[0144] 1. Raw materials The raw materials shown in Table 1 below were used.

[0145] [Table 1]

[0146] [[ID=ID=20]]<Measurement of Ti concentration, Na concentration, Ca concentration> Qualitative / semi - quantitative analysis (μg / g) of Ti, Na, and Ca in the polybutylene terephthalate resin was performed by ICP emission spectrometry. In this case, as a pretreatment, 200 mg of the sample was weighed, and Kjeldahl wet digestion (sulfuric acid / nitric acid, sulfuric acid / hydrogen peroxide) was carried out, and the volume was fixed to 50 mL. Subsequently, ICP emission analysis was performed by the acid concentration matching single - point calibration method. The unit was shown in mass ppm. ICP emission analysis was performed using "iCAP7600duoiCAP76000uo" manufactured by Thermo Fisher Scientific, with axial / radial photometry.

[0147] <Active titanium parameter X and ratio α of active titanium> Five capillaries with an inner diameter of 5 mm were filled with powder of polybutylene terephthalate resin (pellets). Next, after thoroughly purging the contents with nitrogen, the capillaries were immersed in an oil bath accurately controlled at 245 °C (temperature T), taken out over time, and quenched with liquid nitrogen. Then, the contents were taken out, and the terminal carboxyl group concentration and terminal hydroxyl group concentration were determined. Using these values, the ratio α of active titanium was determined from formulas (1), (2), and formula (3). [Equation]

number

[0148] The time-dependent evaluation of the terminal carboxyl group concentration is performed under a nitrogen atmosphere to prevent the influence of oxygen. Furthermore, if the water content in the polybutylene terephthalate resin being evaluated is high, hydrolysis reactions occur frequently, making it difficult to accurately grasp the decomposition behavior involving catalytic activity other than hydrolysis. Therefore, a low water content is preferable, and the evaluation is performed at 300 ppm by mass or less. The temperature is 245°C. Under these heat treatment conditions, the decrease in number-average molecular weight due to reactions other than hydrolysis caused by the water contained in the polybutylene terephthalate resin can be ignored. The increase in terminal carboxyl group concentration due to hydrolysis can be considered equal to the increase in terminal hydroxyl group concentration before and after heat treatment. Therefore, the change in terminal carboxyl group concentration due to thermal decomposition reactions other than hydrolysis is calculated using the following equation (4).

[0149] Formula (4)

number

[0150] <Intrinsic viscosity (IV)> The intrinsic viscosity was measured using the following method. Polybutylene terephthalate resin pellets were dissolved in a phenol / 1,1,2,2-tetrachloroethane (mass ratio 1 / 1) mixture by stirring at 110°C for 1 hour to a concentration of 1.00 g / dL. The mixture was then cooled to 30°C. Using a fully automated solution viscometer, the drop time of the sample solution and the drop time of the solvent alone were measured at 30°C, and the intrinsic viscosity was calculated using a specific formula. Intrinsic viscosity=((1+4K H η sp ) 0.5-1) / (2K H C) Here, η sp =η / η0-1, where η is the number of seconds for the sample solution to fall, η0 is the number of seconds for the solvent only to fall, C is the concentration of the sample solution (g / dL), and K is the concentration of the sample solution (g / dL). H K is Huggins' constant. H The value used was 0.33. The unit is expressed in dL / g. A fully automatic solution viscometer manufactured by Shibayama Kagaku Co., Ltd. was used.

[0151] <Concentration of terminal carboxyl groups (acid value)> The concentration of terminal carboxyl groups in polybutylene terephthalate resin was determined by dissolving 0.5 g of polybutylene terephthalate resin in 25 mL of benzyl alcohol and titrating with a 0.01 mol / L benzyl alcohol solution of sodium hydroxide. The unit is expressed in μmol / g (μeq / g).

[0152] <Concentration of terminal hydroxyl groups> The terminal hydroxyl group concentration of polyalkylene terephthalate resin was determined by dissolving 25 mg of the sample in 0.75 mL of a mixed solvent of deuterated chloroform / hexafluoroisopropanol (volume ratio: 7 / 3) containing a small amount of TMS (tetramethylsilane) in a vial, then adding 25 μL of deuterated pyridine, and transferring the mixture to a 5 mm outer diameter NMR sample tube. The 1H NMR spectrum was measured using a Bruke AVANCE NEO 600 spectrometer. The resonance frequencies were 600 Hz and 1 MHz, the flip angle was 45°, data acquisition was 3 s, the pulse repetition time was 10 s, the number of integrations was 16, and the temperature was 25°C. The unit is given in μmol / g.

[0153] <Terminal vinyl group concentration> The concentration of terminal vinyl groups in polyalkylene terephthalate resin was measured under the same conditions as the concentration of terminal hydroxyl groups in polyalkylene terephthalate resin. The unit is expressed in μmol / g. [Table 2]

[0154] Examples 1-3, Comparative Example 1, Comparative Example 2 <Compound> Each component shown in Table 1 was uniformly mixed in a tumbler mixer in the proportions shown in Table 3 (each component in Table 3 is expressed in parts by mass), excluding the glass fibers. The resulting mixture was supplied to a twin-screw extruder (TEX30α, manufactured by Japan Steel Works, Ltd.) through the main feed port. The cylinder temperature of the first kneading section was set to 260°C, and the glass fibers were supplied from the side feeder. The resin composition, which was melt-kneaded under the conditions of a cylinder temperature of 220°C and a screw rotation speed of 200 rpm after the addition of the glass fibers, was rapidly cooled in a water bath and pelletized using a pelletizer to obtain pellets of the resin composition.

[0155] <Tensile strength> The resin pellets obtained above were dried at 120°C for 5 hours, and then ISO multipurpose test specimens (4 mm thick) were injection molded using an injection molding machine (Japan Steel Works, Ltd. "J85AD") under the conditions of a cylinder temperature of 250°C and a mold temperature of 80°C. Using molded multi-purpose ISO test specimens, tensile strength (in MPa) was measured in accordance with ISO 527-1 and ISO 527-2.

[0156] <Amount of gas generated by heating (ppm)> The obtained pellets were heated at 280°C for 10 minutes, the gas generated by He was flowed through, and the gas generated at -10°C was trapped. The trapped substances were analyzed by GC-MS. The gas amounts of tetrahydrofuran (THF) and 1,4BG (1,4-butanediol) were measured. The gas amounts are expressed in mass ppm, converted to decane.

[0157] GC-MS conditions The gas was held at 50°C for 2 minutes, then heated to 380°C at a rate of 10°C / min, and the detected substances were calculated in decane equivalent concentrations. Equipment: Shimadzu TD-20 (TD) / GC-2010 Plus (GC) / GC-MS-QP-2010 Ultra (MS) Column: UA5 0.25mm ID x 30m

[0158] <Flame-retardant> The pellets obtained as described above were dried at 110°C for 5 hours, and then combustion test specimens (12.7 mm wide x 127 mm long x 1.5 mm thick) were injection molded using an injection molding machine (Japan Steel Works, Ltd. "J-50AD") under conditions of cylinder temperature of 250°C and mold temperature of 80°C. The obtained combustion test specimens were left to stand for one week in a 70°C atmosphere, and then their flame retardancy was evaluated according to the Subject 94 (UL94) method of Underwriters Laboratories.

[0159] [Table 3]

[0160] As is clear from the above results, the resin composition of the present invention was able to effectively suppress gas generation by including a polybutylene terephthalate resin with a low titanium activity parameter. Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications are possible without departing from the intent and scope of the invention.

Claims

1. Per 100 parts by mass of polybutylene terephthalate resin, It contains 1 to 40 parts by mass of a flame retardant. A resin composition comprising a polybutylene terephthalate resin (T) which contains 30 to 500 ppm by mass of titanium element and has an active titanium parameter X of 25 or less as shown below. 【Number 1】 [Math 2]

2. The aforementioned flame retardant comprises a halogen-based flame retardant and an antimony compound. The content of the halogen-based flame retardant is 10 to 40 parts by mass per 100 parts by mass of polybutylene terephthalate resin. The resin composition according to claim 1, wherein the antimony compound content is 0.1 to 15 parts by mass per 100 parts by mass of polybutylene terephthalate resin.

3. The resin composition according to claim 1 or 2, wherein 15 to 100 parts by mass of the 100 parts by mass of the polybutylene terephthalate resin is polybutylene terephthalate resin derived from material recycling.

4. The resin composition according to claim 1, wherein the proportion α of activated titanium represented by the following formula (3) in the polybutylene terephthalate resin (T) is 0.50 or less. α=X / M...Formula (3) (In equation (3), X is the active titanium parameter, and [M] is the concentration of titanium element in the polybutylene terephthalate resin (mass ppm).)

5. The resin composition according to claim 1 or 2, further comprising an amorphous resin.

6. The resin composition according to claim 1 or 2, further comprising 10 to 150 parts by mass of a fibrous reinforcing material per 100 parts by mass of the polybutylene terephthalate resin.

7. The aforementioned flame retardant comprises a halogen-based flame retardant and an antimony compound. The content of the halogen-based flame retardant is 10 to 40 parts by mass per 100 parts by mass of polybutylene terephthalate resin. The antimony compound content is 0.1 to 15 parts by mass per 100 parts by mass of polybutylene terephthalate resin. Of the 100 parts by mass of the polybutylene terephthalate resin, 15 to 100 parts by mass is polybutylene terephthalate resin derived from material recycling. The proportion α of activated titanium represented by the following formula (3) in the polybutylene terephthalate resin (T) is 0.50 or less. The resin composition according to claim 1, further comprising an amorphous resin. α=X / M...Formula (3) (In equation (3), X is the active titanium parameter, and [M] is the concentration of titanium element in the polybutylene terephthalate resin (mass ppm).)

8. Pellets of the resin composition according to any one of claims 1, 2, and 7.

9. A molded article formed from the resin composition according to any one of claims 1, 2, and 7.

10. A molded article formed from the pellets described in claim 8.

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