Method for producing polyalkylene terephthalate resin compositions

Abstract

The present invention provides a method for producing a resin composition with low gas generation. [Solution] A method for producing a resin composition comprising: component (A): polyalkylene terephthalate resin; component (B): styrene resin; component (D): one or more selected from the group consisting of (d1) stabilizer, (d2) release agent, (d3) colorant, and (d4) polymers other than polyalkylene terephthalate resin and styrene resin, and optionally component (C): inorganic filler, wherein the vacuum level during vacuum defoliation at the first and second vacuum vents is set to 10 to 150 mmHg in absolute pressure, and vacuum defoliation at the first vacuum vent is performed either after adding and dispersing 4 parts by mass or less of water per 100 parts by mass of the molten resin composition, or without adding and dispersing water, and the resin temperature of the strands extruded from the die hole is 300°C or less.

Description

[Technical Field]

[0001] This invention relates to a method for producing a polyalkylene terephthalate resin composition. [Background technology]

[0002] Polyalkylene terephthalate resins, such as polybutylene terephthalate resin, have excellent mechanical and electrical properties, as well as superior chemical and heat resistance. Therefore, injection-molded products made from these resins are widely used as materials for various electrical and electronic equipment components, interior parts for vehicles such as automobiles, and other general industrial products.

[0003] For example, Patent Document 1 describes a molded polybutylene terephthalate resin composition containing a specific amount of a specific styrene copolymer (B) in a polybutylene terephthalate resin, wherein the domains containing the styrene copolymer (B) are dispersed in an island-like manner in a specific shape within the continuous phase of the polybutylene terephthalate resin, and the volatile organic compound (TVOC) content is 30 μgC / g or less. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2019 / 167292 [Overview of the project] [Problems that the invention aims to solve]

[0005] As described in Patent Document 1, when polybutylene terephthalate resin materials are used in the interior of automobiles, there are regulations on TVOC (total volatile organic compounds) emissions, which are guidelines for released organic matter, and it is becoming increasingly important for vehicle interior parts to meet these requirements. According to Patent Document 1, reducing the amount of styrene monomer gas and ethylbenzene generated from the pellets of the raw material polybutylene terephthalate resin composition is expected to reduce the amount of TVOC generated from the molded product. However, a method for reducing the gas in the pellets of the composition by extrusion conditions is not clearly described.

[0006] The object of the present invention is to provide a method for producing a polyalkylene terephthalate resin composition with low gas generation. [Means for solving the problem]

[0007] The inventors of this invention have conducted extensive research to solve the above problems and have found that the following invention is suitable for the above purpose, leading to the present invention.

[0008] In other words, the present invention relates to the following invention. <1> A method for producing a polyalkylene terephthalate resin composition, comprising: melt-kneading in a twin-screw extruder; extruding strands from a die attached to the tip of the twin-screw extruder; wherein the twin-screw extruder has, at least, a first kneading section, a first vacuum vent, and a second vacuum vent from the upstream side; and the polyalkylene terephthalate resin composition comprises: (A) 5 to 94% by mass of polyalkylene terephthalate resin; (B) 5 to 60% by mass of styrene resin; and (D) 0.01 to 18.5% by mass of one or more polymers selected from the group consisting of (d1) stabilizer, (d2) release agent, (d3) colorant, and (d4) polymers other than polyalkylene terephthalate resin and styrene resin. A manufacturing method comprising: a first kneading step in which components (A), (B), and (D) are included in % and supplied to the twin-screw extruder and melt-kneaded in the first kneading section; a first defoliation step in which the vacuum of the first vacuum vent is reduced to 10 to 150 mmHg in absolute pressure and defoliated; a second defoliation step in which the vacuum of the second vacuum vent is reduced to 10 to 150 mmHg in absolute pressure and defoliated; and a step in which the strand is extruded from the die hole of the die, wherein the first defoliation step is performed after the first kneading step by adding and dispersing 4 parts by mass or less of water per 100 parts by mass of the molten resin composition, or by performing the step without adding and dispersing water, and the resin temperature of the strand extruded from the die hole is 300°C or less. <2> The above component (D) contains a polycarbonate resin, and the amount of the polycarbonate resin in the polyalkylene terephthalate resin composition is 1 to 10% by mass. <1> The manufacturing method described above. <3> The twin-screw extruder has a second kneading section between the first vacuum vent and the second vacuum vent, <1> or <2> The manufacturing method described above. <4> The polyalkylene terephthalate resin composition further contains an inorganic filler as component (C) in an amount of 0.99 mass% or more and 65 mass% or less, and between the first devolatilization step and the second devolatilization step, has a side feed step of supplying the component (C) to the twin-screw extruder by side feed, and a second kneading step of kneading in the second kneading section, the production method according to the aforementioned <3>. <5> The method has, between the first kneading step and the first devolatilization step, a water injection and dispersion step of adding and dispersing 4 parts by mass or less of water relative to 100 parts by mass of the molten resin composition, and the twin-screw extruder has a water injection and dispersion section between the first kneading section and the first vacuum vent, the production method according to any one of the aforementioned <1> to <4>. <6> The production method according to any one of the aforementioned <1> to <5>, wherein the polyalkylene terephthalate resin of the component (A) is a polybutylene terephthalate resin. <7> The polyalkylene terephthalate resin composition has a styrene monomer content of 3 mass ppm or less and a total VOC gas content of 10 mass ppm or less as detected by gas chromatography analysis after heating at 150°C for 120 minutes, the production method according to any one of the aforementioned <1> to <6>. Effects of the Invention

[0009] According to the present invention, a method for producing a polyalkylene terephthalate resin composition with low gas generation amount is provided. Brief Description of the Drawings

[0010] [Figure 1] It is a flowchart showing an example of the production method of the present invention. [Figure 2] It is a schematic diagram of an extruder that can be used in the production method shown in Figure 1. [Figure 3] It is a flowchart showing another example of the production method of the present invention. [Figure 4] It is a schematic diagram of an extruder that can be used in the production method shown in Figure 3. [Figure 5] It is a flowchart showing still another example of the production method of the present invention. [Figure 6] Figure 5 is a schematic diagram of an extruder that can be used in the manufacturing method shown. [Figure 7] This is a schematic diagram of the screw configuration of the extruder used in the example. [Figure 8] This is a schematic diagram of the screw configuration of the extruder used in the example. [Modes for carrying out the invention]

[0011] The embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is just one example (representative example) of an embodiment of the present invention, and the present invention is not limited to the following unless its gist is changed. In this specification, when the expression "~" is used, it is used to mean an expression that includes the numerical value or physical property value before and after it.

[0012] <Method for producing the polyalkylene terephthalate-based resin composition of the present invention> The present invention relates to a method for producing a polyalkylene terephthalate resin composition, wherein the composition is produced by melt-kneading in a twin-screw extruder and extruding strands from a die attached to the tip of the twin-screw extruder, the twin-screw extruder having at least a first kneading section, a first vacuum vent and a second vacuum vent from the upstream side, and the polyalkylene terephthalate resin composition comprises, as component (A), 5 to 94% by mass of polyalkylene terephthalate resin, as component (B), 5 to 60% by mass of styrene resin, and as component (D), 0.01 to 18.5% by mass of one or more selected from the group consisting of (d1) stabilizers, (d2) release agents, (d3) colorants and (d4) polymers other than polyalkylene terephthalate resin and styrene resin, and the above The present invention relates to a manufacturing method (hereinafter sometimes referred to as "the manufacturing method of the present invention") comprising: a first kneading step of supplying component (B) and component (D) to the twin-screw extruder and melting and kneading them in the first kneading section; a first defloration step of vacuum defloration by reducing the pressure so that the vacuum of the first vacuum vent is set to an absolute pressure of 10 to 150 mmHg; a second defloration step of vacuum defloration by reducing the pressure so that the vacuum of the second vacuum vent is set to an absolute pressure of 10 to 150 mmHg; and a step of extruding strands from the die hole of the die, wherein the first defloration step is performed after the first kneading step by adding and dispersing 4 parts by mass or less of water per 100 parts by mass of the molten resin composition, or by performing the step without adding or dispersing water, and the resin temperature of the strands extruded from the die hole is 300°C or less.

[0013] The inventors of this invention have discovered that a polyalkylene terephthalate resin composition with low gas generation can be efficiently produced by melt-kneading and extruding a polyalkylene terephthalate resin (component A), a styrene-based resin (component B), and a stabilizer (component D) under specific conditions for water injection and defoliation, and by controlling the temperature so that the resin temperature of the strands extruded from the die hole is 300°C or lower. This invention is based on this finding.

[0014] Furthermore, the manufacturing method of the present invention can also be used to produce polyalkylene terephthalate resin compositions with low warp properties and low specific gravity.

[0015] First, the raw material components used in the manufacturing method of the present invention will be described.

[0016] In the manufacturing method of the present invention, a polyalkylene terephthalate resin composition (hereinafter sometimes simply referred to as "resin composition") is manufactured using, as raw material components, at least, component (A) which is a polyalkylene terephthalate resin, component (B) which is a styrene resin, and component (D) which is one or more components selected from the group consisting of (d1) a stabilizer, (d2) a release agent, (d3) a colorant, and (d4) a polymer other than polyalkylene terephthalate resin and styrene resin. Furthermore, from the viewpoint of imparting the rigidity and strength required for molded products, it is preferable to manufacture the polyalkylene terephthalate resin composition using, in addition to components (A), (B), and (D), an inorganic filler component (C) as raw material components.

[0017] [Component (A): Polyalkylene terephthalate resin] In the manufacturing method of the present invention, polyalkylene terephthalate resin is used as a raw material component. Polyalkylene terephthalate resin is a polyester resin having a structure in which a dicarboxylic acid compound such as terephthalic acid and a diol such as an aliphatic diol are ester-bonded. The polyalkylene terephthalate resin may be a homopolymer, copolymer, or a mixture thereof, but usually, a structure mainly derived from the polycondensation of terephthalic acid and an aliphatic diol is used, that is, a structure that accounts for more than 50% by mass of the total resin is this structure. In the polyalkylene terephthalate resin, the structure derived from the polycondensation of terephthalic acid and an aliphatic diol is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 99% by mass or more.

[0018] Polyalkylene terephthalate resins have structural parts derived from dicarboxylic acid compounds, specifically structural parts derived from terphthalic acid compounds or their ester-forming derivatives. Furthermore, the structural parts derived from dicarboxylic acid compounds may also include structural parts derived from dicarboxylic acids other than terephthalic acid and its ester-forming derivatives. Other dicarboxylic acids include, for example, 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. These can be used in polycondensation reactions not only as free acids but also as ester-forming derivatives such as dimethyl esters.

[0019] Polyalkylene terephthalate resins have structural parts derived from aliphatic diols. Examples of aliphatic diols include linear or branched aliphatic diols such as ethylene glycol, propylene glycol, butanediol, hexylene glycol, neopentyl glycol, 2-methylpropane-1,3-diol, diethylene glycol, and triethylene glycol; cyclic aliphatic diols such as cyclohexane-1,4-dimethanol; and mixtures thereof. Among these, butanediol and ethylene glycol are particularly preferred.

[0020] Furthermore, it may also be a copolymer of one or more long-chain diols with a molecular weight of 400 to 6,000, such as polyethylene glycol, poly-1,3-propylene glycol, or polytetramethylene glycol. It may also contain structural parts derived from aromatic diols such as hydroquinone, resorcinol, naphthalenediol, dihydroxydiphenyl ether, or 2,2-bis(4-hydroxyphenyl)propane.

[0021] In addition to the difunctional monomers mentioned above, trifunctional monomers such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, and trimethylolpropane may be used in combination to introduce a branched structure, or small amounts of monofunctional compounds such as fatty acids may be used to adjust the molecular weight.

[0022] The polyalkylene terephthalate resin is preferably close to a homopolymer, and preferably 95 mol% or more of the dicarboxylic acid-derived structural portion is derived from terephthalic acid, and 95 mol% or more of the diol-derived structural portion is derived from aliphatic diols. For example, in the case of polybutylene terephthalate resin, it is preferable that 95 mol% or more of the total resin consists of structural portions derived from terephthalic acid and structural portions derived from 1,4-butanediol.

[0023] The polyalkylene terephthalate resin is preferably a polybutylene terephthalate resin and / or a polyethylene terephthalate resin, and more preferably a polybutylene terephthalate resin. The polybutylene terephthalate resin may be a homopolymer obtained by polycondensation of terephthalic acid and 1,4-butanediol, or a copolymer of monomers copolymerizable thereto (i.e., one or more dicarboxylic acids other than terephthalic acid, and / or one or more diols other than 1,4-butanediol).

[0024] Specific preferred copolymers of copolymerized polybutylene terephthalate resin (hereinafter sometimes referred to as "modified polybutylene terephthalate resin") include polyester ether resin copolymerized with polyalkylene glycols (particularly polytetramethylene glycol), dimer acid copolymerized polybutylene terephthalate resin, and isophthalic acid copolymerized polybutylene terephthalate resin.

[0025] When using a polyester ether resin copolymerized with polytetramethylene glycol as the modified polybutylene terephthalate resin, the proportion of the tetramethylene glycol component in the copolymer is preferably 3 to 40% by mass, more preferably 5 to 30% by mass, and even more preferably 10 to 25% by mass.

[0026] When using a dimer acid copolymerized polybutylene terephthalate resin as the modified polybutylene terephthalate resin, the proportion of the dimer acid component to the total carboxylic acid component is preferably 0.5 to 30 mol%, more preferably 1 to 20 mol%, and even more preferably 3 to 15 mol% as carboxylic acid groups.

[0027] When using an isophthalic acid copolymerized polybutylene terephthalate resin as the modified polybutylene terephthalate resin, the proportion of isophthalic acid components to the total carboxylic acid components is preferably 1 to 30 mol%, more preferably 1 to 20 mol%, and even more preferably 3 to 15 mol% as carboxylic acid groups.

[0028] Among modified polybutylene terephthalate resins, polyester ether resin copolymerized with polytetramethylene glycol and isophthalic acid copolymerized polybutylene terephthalate resin are preferred.

[0029] The amount of terminal carboxyl groups in the polyalkylene terephthalate resin (preferably polybutylene terephthalate resin) can be appropriately selected and determined, but is usually 60 eq / ton or less, preferably 50 eq / ton or less, and more preferably 30 eq / ton or less. Setting it to 60 eq / ton or less tends to more effectively suppress gas generation during melt molding of the resin composition. There is no particular lower limit for the amount of terminal carboxyl groups, but is usually 3 eq / ton or more, preferably 5 eq / ton or more, and more preferably 10 eq / ton or more.

[0030] The amount of terminal carboxyl groups in polyalkylene terephthalate resin is measured by dissolving 0.5 g of resin in 25 mL of benzyl alcohol and titrating with a 0.01 mol / L benzyl alcohol solution of sodium hydroxide. The amount of terminal carboxyl groups can be adjusted by any conventionally known method, such as adjusting polymerization conditions like the raw material ratio, polymerization temperature, and reduced pressure method during polymerization, or by reacting with a chelating agent.

[0031] The intrinsic viscosity of the polyalkylene terephthalate resin (preferably polybutylene terephthalate resin) is preferably 0.40 dL / g or higher, more preferably 0.50 dL / g or higher, even more preferably 0.55 dL / g or higher, even more preferably 0.60 dL / g or higher, and even more preferably 0.65 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 polyalkylene terephthalate resin (preferably polybutylene terephthalate resin) is preferably 1.2 dL / g or lower, more preferably 0.85 dL / g or lower, even more preferably 0.80 dL / g or lower, even more preferably 0.75 dL / g or lower, and even more preferably 0.72 dL / g or lower. Setting it below the upper limit effectively suppresses a decrease in fluidity, and by adjusting the blend ratio with styrene-based resin, it tends to more effectively suppress a decrease in load deflection temperature.

[0032] Intrinsic viscosity is measured by the following method. Dissolve the polyalkylene terephthalate resin pellets in a phenol / 1,1,2,2-tetrachloroethane (mass ratio 1 / 1) mixed solvent by stirring at 110°C for 1 hour to a concentration of 1.00 g / dL. Then, cool to 30°C. Using a fully automated solution viscometer, measure the drop time of the sample solution and the drop time of the solvent alone at 30°C, and calculate the intrinsic viscosity using the following formula. Intrinsic viscosity=((1+4KHη sp )0.5-1) / (2KHC) Here, ηsp The formula is =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 KH is Huggins' constant. A KH of 0.33 was used. The fully automatic solution viscometer used is manufactured by Shibayama Kagaku Co., Ltd. Furthermore, if the mixture contains two or more types of polyalkylene terephthalate resins, the intrinsic viscosity of the polyalkylene terephthalate resins shall be the intrinsic viscosity of the mixture.

[0033] Polyalkylene terephthalate resin may include recycled materials. Examples of recycled polyalkylene terephthalate resin include those obtained through material recycling, where molded product scraps, rejected products, and collected used polyalkylene terephthalate resin molded products are crushed, washed, and reused, as well as those obtained through chemical recycling (chemical decomposition method).

[0034] The polyalkylene terephthalate resin is used such that its content in 100% by mass of the manufactured resin composition is between 5% by mass and 94% by mass. Furthermore, if the manufactured resin composition contains component (C) described later, the content of polyalkylene terephthalate resin in 100% by mass of the resin composition may be 84% by mass or less, 74% by mass or less, or 64% by mass or less. The resin composition may also contain only one type of polyalkylene terephthalate resin or two or more types. When two or more types of polyalkylene terephthalate resin are used as component (A), the total amount is used so as to be between 5% and 94% by mass, and may fall within the aforementioned numerical range.

[0035] [Component (B): Styrene resin] In the manufacturing method of the present invention, a styrene-based resin is used as a raw material component. The styrene-based resin may be a homopolymer, copolymer, or a mixture thereof, but usually, a resin mainly consisting of structures derived from styrene monomers is used, that is, a resin in which more than 50% by mass of the total resin is this structure. In the styrene-based resin, the structure derived from ethylene monomers is preferably 60% by mass or more, and preferably 100% by mass or less.

[0036] 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.

[0037] Furthermore, monomers copolymerizable with styrene 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 dienes such as butadiene.

[0038] Styrene-based resins may include rubber-reinforced polystyrene resins. 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.

[0039] It is also preferable that the styrene-based resin is partly 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.

[0040] The styrene-based resin preferably contains 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 contains high-impact polystyrene resin (HIPS). Furthermore, from the viewpoint of heat resistance, polystyrene resin (GPPS) and acrylonitrile-styrene copolymer (AS resin) are more preferred.

[0041] Polystyrene resin may include recycled materials. Examples of recycled polystyrene resin include those obtained through material recycling, where leftover or rejected molded products, or collected used polystyrene resin molded products are crushed, washed, and reused, and those obtained through chemical recycling (chemical decomposition).

[0042] The styrene-based resin is used such that its content in 100% by mass of the manufactured resin composition is between 5% by mass and 60% by mass. The resin composition may contain only one type of styrene-based resin, or it may contain two or more types. When two or more types of styrene-based resin are used, it is preferable that the total amount is between 5% and 60% by mass, within the aforementioned numerical range.

[0043] Furthermore, the styrene-based resin is preferably 45% by mass or more, more preferably 50% by mass or more, even more preferably 55% by mass or more, even more preferably 60% by mass or more, preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, based on 100% by mass of the total of the polyalkylene terephthalate resin and the styrene-based resin. If it is below the above upper limit, the heat resistance of the molded product can be improved and the amount of generated gas can be reduced. If it is above the above lower limit, the warpage of the molded product can be improved.

[0044] [Component (C): Inorganic filler] In the manufacturing method of the present invention, an inorganic filler can be used as any raw material component. The inorganic filler has the effect of improving the mechanical properties of the resin composition obtained by blending it with the resin, and commonly used inorganic fillers for plastics can be widely used. The shape of the inorganic filler that can be used in the manufacturing method of the present invention is not particularly specified and may be any of the following: fibers, fillers, beads, etc., but fibers are preferred. If the inorganic filler is fibers, it may be short fibers or long fibers.

[0045] Examples of raw materials for inorganic fillers include inorganic substances such as glass, carbon (carbon fiber, etc.), alumina, boron, ceramics, and metals (steel, etc.), as well as plants (including kenaf, bamboo, etc.), with glass being preferred.

[0046] The inorganic filler used in the manufacturing method of the present invention preferably contains glass fibers. The type of glass fiber is not particularly limited, and examples include glass fibers such as E glass, C glass, A glass, and S glass. Among these, E glass fibers are preferred because they do not adversely affect the thermal stability of the polyalkylene terephthalate resin.

[0047] The average fiber diameter of the glass fibers is not particularly limited, but it is preferably selected within the range of 1 to 100 μm, more preferably 2 to 50 μm, even more preferably 3 to 30 μm, and particularly preferably 5 to 20 μm. Glass fibers with an average fiber diameter of less than 1 μm are difficult to manufacture and may be costly, while those exceeding 100 μm may have reduced tensile strength. The fiber cross-section may be circular or flattened.

[0048] The glass fibers may have a perfectly circular or flattened cross-section, but it is preferable that the glass fibers have a nearly circular cross-section with an oblateness ratio (major axis / minor axis) of 1 to 1.5. This oblateness ratio is preferably 1 to 1.4, more preferably 1 to 1.2, and particularly preferably 1 to 1.1. The value of the oblateness ratio is the average value calculated by an image analysis device from images of 2000 glass fibers of filler residue collected during processing such as high-temperature ashing, dissolution with solvents, and decomposition with chemicals of the molded product, observed with an optical microscope.

[0049] The average fiber length of the glass fibers is not particularly limited, but is preferably 1 to 10 mm, more preferably 1.5 to 6 mm, and even more preferably 2 to 5 mm. If the average fiber length of the glass fibers is less than 1 mm, the reinforcing effect may not be sufficiently exhibited, and if it exceeds 10 mm, it may become difficult to mold the resulting resin composition. The average fiber length is the number-average fiber length value calculated by an image analysis device from images obtained by observing 2000 glass fibers of the filler residue collected by processing the molded product at high temperature ashing, dissolution with solvents, and decomposition with chemicals using an optical microscope. Furthermore, in calculating this value, the fiber diameter is used as a guideline, and fibers with a length less than that are not counted.

[0050] Glass fibers can be surface-treated with coupling agents such as aminosilanes and epoxysilanes to improve adhesion with polyalkylene terephthalates (particularly polybutylene terephthalate resins). Examples of coupling agents include chlorosilane compounds such as vinyltrichlorosilane and methylvinyldichlorosilane, alkoxysilane compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, and γ-methacryloxypropyltrimethoxysilane, epoxysilane compounds such as β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and γ-glycidoxypropyltrimethoxysilane, as well as acrylic compounds, isocyanate compounds, titanate compounds, and epoxy compounds.

[0051] Furthermore, glass fibers are usually preferably used as chopped strands (chopped glass fibers) obtained by bundling many of these fibers together and cutting them to a predetermined length, and it is preferable to blend a sizing agent with the glass fibers in this case. Blending a sizing agent has the advantage of increasing the production stability of the resin composition and molded article, as well as obtaining good mechanical properties. There are no particular restrictions on the sizing agent for glass fibers, and examples include resin emulsions such as vinyl acetate resin, ethylene-vinyl acetate copolymer, acrylic resin, epoxy resin, polyurethane resin, and polyester resin, with acrylic resin, epoxy resin, and polyurethane resin being preferred.

[0052] When using inorganic fillers, it is preferable that the inorganic filler content in 100% by mass of the manufactured resin composition is between 0.99% by mass and 65% by mass. This content is expected to improve the rigidity and strength of the molded product. More preferably, the inorganic filler content in 100% by mass of the manufactured resin composition is 10% by mass or more, even more preferably 20% by mass or more, even more preferably 30% by mass or more, more preferably 55% by mass or less, and even more preferably 45% by mass or less. Furthermore, the resin composition may contain only one type of inorganic filler, or two or more types. When using two or more types of inorganic fillers, it is preferable that the total amount falls within the aforementioned numerical range.

[0053] [Component (D)] In the manufacturing method of the present invention, component (D) is used as a raw material component, which is one or more selected from the group consisting of (d1) stabilizers, (d2) release agents, (d3) colorants, and (d4) polymers other than polyalkylene terephthalate resins and styrene-based resins. The content of component (D) in 100% by mass of the manufactured resin composition is 0.01 to 18.5% by mass, and preferably 0.01 to 13% by mass.

[0054] ((d1) Stabilizer) Resin compositions are preferable to contain stabilizers, as these have the effect of improving thermal stability and preventing deterioration of mechanical strength and color. Preferred stabilizers include phosphorus-based stabilizers, sulfur-based stabilizers, and phenol-based stabilizers.

[0055] 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 phosphites, phosphonites, and phosphate compounds being preferred among them. Preferably, the organic phosphate compound is one of the following general formulas: (R 1 O) 3-n P(=O)OH n (In the formula, R 1is an alkyl group or an aryl group, which may be the same or different from each other. n represents an integer of 0 to 2.) The compound is represented by: More preferably, R 1 includes long-chain alkyl acid phosphate compounds having 8 to 30 carbon atoms. Specific examples of the alkyl group 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, triacontyl group and the like. Examples of the long-chain alkyl acid phosphate 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, alkoxy polyethylene glycol 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, bisnonylphenyl acid phosphate and the like. Among these, octadecyl acid phosphate is preferred, which is commercially available as "ADEKA STAB (registered trademark) AX-71" manufactured by ADEKA Corporation.

[0056] As the organic phosphite compound, the following general formula is preferred: R 2 O-P(OR 3 )(OR 4 ) (wherein, R 2 , R 3 and R4 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 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.

[0057] 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.

[0058] Preferably, the organic phosphonite compound is one of the following general formulas: R 5 -P(OR 6 )(OR 7 ) (In the formula, R 5 , R 6 and R7 Each of these is a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or an aryl group having 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.

[0059] 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.

[0060] As sulfur-based stabilizers, any conventionally known sulfur atom-containing compound can be used, with thioethers being particularly preferred. Specifically, examples include didodecylthiodipropionate, ditetradecylthiodipropionate, dioctadecylthiodipropionate, pentaerythritol tetrakis(3-dodecylthiopropionate), thiobis(N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickel dibutyldithiocarbamate, nickel isopropylxanthate, and trilauryl trithiophosphite. Among these, pentaerythritol tetrakis(3-dodecylthiopropionate) is preferred.

[0061] Examples of phenolic stabilizers 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), and pentaerythritol tetrakis(3-(3,5-di-neopentyl-4-hydroxyphenyl)propionate). Among these, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate are preferred. Commercially available products include BASF's "Irganox® 1010" and "Irganox® 1076," and ADEKA's "ADEKA Stab® AO-50" and "ADEKA Stab® AO-60."

[0062] The stabilizer content in the resin composition is preferably 0.001 to 1.5% by mass, more preferably 0.005 to 1.2% by mass, and even more preferably 0.01 to 1.0% by mass. When molded, if the content is above the lower limit, deterioration of hue and decrease in molecular weight can be suppressed, and if it is below the upper limit, the appearance and color of the molded article can be good. The stabilizer may contain one type, or two or more types in any combination and ratio, and if two or more types are included, it is preferable that the total content is within the above numerical range.

[0063] ((d2) Release agent) The resin composition preferably contains a release agent from the viewpoint of improving release properties. Examples of release agents include aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds, and polysiloxane-based silicone oils.

[0064] Examples of aliphatic carboxylic acids include saturated or unsaturated aliphatic monovalent, divalent, or trivalent carboxylic acids. Here, aliphatic carboxylic acids also include alicyclic carboxylic acids. Among these, preferred aliphatic carboxylic acids are monovalent or divalent carboxylic acids having 6 to 36 carbon atoms, and more preferably aliphatic saturated monovalent carboxylic acids having 6 to 36 carbon atoms. Specific examples of such aliphatic carboxylic 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.

[0065] As the aliphatic carboxylic acid in the ester of an aliphatic carboxylic acid and an alcohol, for example, the same aliphatic carboxylic acid as described above can be used. On the other hand, as the alcohol, for example, saturated or unsaturated monohydric or polyhydric alcohols can be used. These alcohols may have substituents such as fluorine atoms or aryl groups. Among these, monohydric or polyhydric saturated alcohols having 30 or fewer carbon atoms are preferred, and aliphatic saturated monohydric alcohols or aliphatic saturated polyhydric alcohols having 30 or fewer carbon atoms are more preferred. Here, "aliphatic" also includes alicyclic compounds.

[0066] 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.

[0067] Furthermore, the above esters may contain aliphatic carboxylic acids and / or alcohols as impurities. Also, the above esters may be pure substances or mixtures of multiple compounds. Moreover, the aliphatic carboxylic acids and alcohols that combine to form a single ester may be used individually, or two or more may be used in any combination and ratio.

[0068] Specific examples of esters of aliphatic carboxylic acids and alcohols include montanic acid wax, beeswax (a mixture mainly composed of myricyl palmitate), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, glycerin monostearate, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, and pentaerythritol tetrastearate.

[0069] Examples of aliphatic hydrocarbon compounds include liquid paraffin, paraffin wax, microcrystalline wax, polyolefin waxes such as polyethylene wax, Fischer-Tropsch wax, and α-olefin oligomers having 3 to 12 carbon atoms. Alicyclic hydrocarbons are also included as aliphatic hydrocarbons. These hydrocarbons may be partially oxidized. The number-average molecular weight is preferably 200 to 30,000, more preferably 1,000 to 15,000, even more preferably 1,500 to 10,000, and particularly preferably 2,000 to 5,000. The aliphatic hydrocarbon compound may be a single substance, but a mixture of substances with various components and molecular weights can be used as long as the main component falls within the above range.

[0070] As a mold release agent, polyolefin wax is preferred from the viewpoint of heat resistance. Any conventionally known polyolefin wax can be used, for example, a (co)polymer (meaning polymer or copolymer) containing one type of olefin, or two or more types in any proportion, preferably having 2 to 30 carbon atoms, more preferably 2 to 12, and even more preferably 2 to 10 carbon atoms.

[0071] Examples of olefins having 2 to 30 carbon atoms include ethylene, propylene, α-olefins having 4 to 30 carbon atoms (preferably 4 to 12, more preferably 4 to 10), and dienes having 4 to 30 carbon atoms (preferably 4 to 18, more preferably 4 to 8). Examples of α-olefins include 1-butene, 4-methyl-1-pentene, 1-pentene, 1-octene, 1-decene, and 1-dodecene. Examples of dienes include butadiene, isoprene, cyclopentadiene, and 11-dodecadiene.

[0072] As a polyolefin wax, polyethylene wax is preferred in terms of release properties and heat resistance. The method for producing polyethylene wax is arbitrary and can be, for example, by polymerization of ethylene or thermal decomposition of polyethylene.

[0073] As a mold release agent, one with an acid value of 10 to 40 mgKOH / g is preferred because it has low mold release resistance, significantly improves mold release properties, and contains little volatile matter. More preferably, the acid value is 11 to 35 mgKOH / g, and even more preferably 12 to 32 mgKOH / g. As long as the acid value is in the range of 10 to 40 mgKOH / g, an acid value of less than 10 mgKOH / g and one exceeding 40 mgKOH / g may be used in combination, as long as the overall acid value of the multiple types of mold release agents is 10 to 40 mgKOH / g.

[0074] As a mold release agent with an acid value of 10 to 40 mg KOH / g, it is preferable to use an ester of an aliphatic carboxylic acid and an alcohol with an acid value of 10 to 40 mg KOH / g, or a modified polyolefin wax which is obtained by imparting a functional group that has affinity with polyester resin, such as a carboxyl group (carboxylic acid (anhydride) group, i.e., a carboxylic acid group and / or a carboxylic acid anhydride group; the same applies hereinafter), a haloformyl group, an ester group, a carboxylic acid metal base, a hydroxyl group, an alkosyl group, an epoxy group, an amino group, or an amide group, to the aliphatic hydrocarbon compound, preferably a polyolefin wax.

[0075] Examples of carboxyl groups used to modify polyolefin waxes include low molecular weight compounds containing carboxylic acid groups such as maleic acid, maleic anhydride, acrylic acid, and methacrylic acid; low molecular weight compounds containing sulfonic acid and other sulfo groups; and low molecular weight compounds containing phosphonic acid and other phospho groups. Among these, low molecular weight compounds containing carboxylic acid groups are preferred, with maleic acid, maleic anhydride, acrylic acid, and methacrylic acid being particularly preferred. These carboxylic acids may be used individually or in combination of two or more in any proportion.

[0076] The amount of acid added to the modified polyolefin wax is typically 0.01 to 10% by mass, preferably 0.05 to 5% by mass, relative to the modified polyolefin wax.

[0077] Examples of haloformyl groups include chloroformyl groups and bromoformyl groups. The means by which these functional groups are imparted to the polyolefin wax can be any conventionally known method, specifically, copolymerization with a compound having a functional group, or post-processing such as oxidation. As for the type of functional group, a carboxyl group is preferred because it has a suitable affinity for polyalkylene terephthalate resin.

[0078] The concentration of carboxyl groups in modified polyolefin wax can be appropriately selected and determined, but if it is too low, the affinity with polyalkylene terephthalate resin will be small, reducing the volatile content suppression effect and potentially decreasing the mold release effect. Conversely, if the concentration is too high, for example, the polymer main chain constituting the polyolefin wax may be excessively cleaved during modification, causing the molecular weight of the modified polyolefin wax to decrease too much, resulting in increased volatile content generation and potentially causing clouding on the surface of the polyester resin molded product.

[0079] As the modified polyolefin wax, polyethylene oxide wax is preferred.

[0080] The content of the mold release agent in the resin composition is preferably 0.001 to 2.0% by mass, more preferably 0.005 to 1.5% by mass, and even more preferably 0.01 to 1.0% by mass. If the content is above the lower limit, sufficient mold release properties can be obtained during molding, and if it is below the upper limit, mold contamination can be suppressed during molding. The mold release agent may contain one type, or two or more types in any combination and ratio, and if two or more types are included, it is preferable that the total content is within the above numerical range.

[0081] ((d3) coloring agent) The resin composition may contain a colorant. The colorant may be a dye or a pigment, but a pigment is preferred. The colorant may be either an organic colorant or an inorganic colorant. Furthermore, it may be either a chromatic colorant or an achromatic colorant. Examples of colorants are given in paragraphs 0121 to 0123 of Japanese Patent Application Publication No. 2021-101020 and paragraphs 0088 to 0090 of Japanese Patent Application Publication No. 2019-188393, the contents of which are incorporated herein by reference.

[0082] The resin composition may also preferably contain carbon black. The inclusion of carbon black improves the weather resistance and appearance of the molded article. 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.

[0083] There are no particular restrictions on the number-average particle size of carbon black, but it is preferably around 5 to 60 nm. By using carbon black with a number-average particle size within this predetermined range, a composition that is less prone to blistering at high temperatures can be obtained. 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.

[0084] Nitrogen adsorption specific surface area of ​​carbon black (unit: m²) 2 ( / g) is typically 1,000m 2 Less than / g is preferable, and among them 50-400m 2 It is preferable that the nitrogen adsorption specific surface area is 1,000 m². 2 Reducing the nitrogen adsorption specific surface area to less than / g tends to improve the fluidity of the resin composition and the appearance of the molded product, which is preferable. The nitrogen adsorption specific surface area can be measured in accordance with JIS K6217.

[0085] Furthermore, the amount of DBP (dibutyl phthalate) absorbed by carbon black is 300 cm³. 3 It is preferable that the amount be less than 100g, and especially 30-200cm. 3 It is preferable that the DBP absorption amount is 300 cm³. 3 Reducing the amount to less than 100g tends to improve the fluidity of the resin composition and the appearance of the molded product, which is preferable. 3 The amount (per 100g) can be measured in accordance with JIS K6217.

[0086] Furthermore, there are no particular restrictions on the pH of the carbon black used, but it is usually between 2 and 10, preferably between 3 and 9, and more preferably between 4 and 8.

[0087] Carbon black can be used alone or in combination of two or more types. Furthermore, carbon black can be granulated using a binder, and can also be used in a masterbatch in which it is melt-kneaded at a high concentration in the resin. By using a melt-kneaded masterbatch, improvements in handling properties during extrusion and improved dispersibility in the resin composition can be achieved. Examples of the above-mentioned resins include polyester resins, polystyrene resins, polycarbonate resins, and acrylic resins. The carbon black content in the masterbatch is preferably 10 to 80% by mass, more preferably 20 to 70% by mass, and even more preferably 30 to 60% by mass.

[0088] The content of the colorant in the resin composition is preferably 0.01 to 5% by mass, more preferably 0.05 to 2.0% by mass, and even more preferably 0.1 to 1.0% by mass. If it is above the lower limit, sufficient weather resistance can be obtained, and if it is below the upper limit, a decrease in the impact resistance of the molded product can be suppressed. The colorant may contain one type, or two or more types in any combination and ratio, and if two or more types are included, it is preferable that the total content is within the above numerical range.

[0089] ((d4) Polymers other than polyalkylene terephthalate resins and styrene-based resins) The resin composition may also contain polymers other than polyalkylene terephthalate resin and styrene-based resins (hereinafter sometimes referred to as "other polymers"). Examples of other polymers include polycarbonate resin; polyolefin resins such as polyethylene resin and polypropylene resin; polyamide resin; polyimide resin; polyetherimide resin; polyphenylene ether resin; polyphenylene sulfide resin; polysulfone resin; thermoplastic resins such as polymethacrylate resin, and various elastomers. Among the above, polycarbonate resin is particularly preferred for maintaining high heat resistance.

[0090] The content of other polymers in the resin composition is preferably 1 to 10% by mass, more preferably 2 to 9% by mass, and even more preferably 3 to 8% by mass. The other polymers may consist of one type, or two or more types in any combination and ratio, and if two or more types are included, it is preferable that the total content is within the above numerical range.

[0091] (Polycarbonate resin) Since polycarbonate resin functions as a compatibilizer between component (A) polyalkylene terephthalate resin and component (B) styrene-based resin, it is preferable that the resin composition contains polycarbonate resin as component (D). Including polycarbonate resin allows the resin composition to have heat resistance and low warping when molded. However, this is not necessarily required when other components, such as the styrene-maleic acid polymer mentioned above, act as compatibilizers.

[0092] Polycarbonate resin is a branched homopolymer, copolymer, or mixture thereof obtained by reacting a dihydroxy compound or a small amount thereof with a polyhydroxy compound with phosgene or a diester carbonate. The method for producing polycarbonate resin is not particularly limited, and conventionally known methods such as the phosgene method (interfacial polymerization) or the melting method (transesterification) can be used.

[0093] As the raw material dihydroxy compound, aromatic dihydroxy compounds are preferred, bisphenol is more preferred, 2,2-bis(4-hydroxyphenyl)propane (=bisphenol A), tetramethylbisphenol A, bis(4-hydroxyphenyl)-p-diisopropylbenzene, hydroquinone, resorcinol, 4,4-dihydroxydiphenyl, etc. are even more preferred, and bisphenol A is even more preferred. In addition, compounds in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compounds can also be used.

[0094] Among the polycarbonate resins mentioned above, aromatic polycarbonate resins derived from 2,2-bis(4-hydroxyphenyl)propane (bisphenol A type polycarbonate resins), 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.

[0095] 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.

[0096] The viscosity-average molecular weight (Mv) of the polycarbonate resin is preferably 5,000 or more, more preferably 10,000 or more, and even more preferably 13,000 or more. Using a polycarbonate resin with a viscosity-average molecular weight (Mv) of 5,000 or more tends to improve the mechanical strength of the resulting resin composition. Furthermore, the viscosity-average molecular weight (Mv) of the polycarbonate resin is preferably 60,000 or less, more preferably 40,000 or less, even more preferably 30,000 or less, even more preferably 25,000 or less, and may also be 20,000 or less. Using a polycarbonate resin with a viscosity-average molecular weight (Mv) of 60,000 or less tends to improve the fluidity of the resin composition and improve its moldability. When two or more types of polycarbonate resin are included, it is preferable that the mixture satisfies the above numerical ranges.

[0097] The viscosity-average molecular weight (Mv) of polycarbonate resin is calculated using an Ubbelohde viscometer at 20°C to determine the intrinsic viscosity ([η]) of the methylene chloride solution of the polycarbonate resin, and the value shown is derived from Schnell's viscosity formula. [η] = 1.23 × 10 -4 Mv 0.83

[0098] The melt volume rate (MVR) of polycarbonate resin, measured according to JIS K7210 (temperature 300°C, load 1.2 kgf), is typically 1 cm 3 / 10 minutes or more, 3cm 3 It is preferable that the MVR is 10 minutes or more. Setting it above the lower limit tends to further improve the fluidity of the resulting resin composition or molded product. The upper limit of the MVR is, for example, 100 cm. 3 / 10 minutes or less, and furthermore, 50cm 3 It is preferable that it be 10 minutes or less, and moreover, 30 cm 3 / 10 minutes or less, 20cm 3 / 10 minutes or less, 10cm 3 It can be less than 10 minutes.

[0099] Furthermore, the melt flow rate (MFR) measured in accordance with JIS K7210 (temperature 300°C, load 1.2 kgf) for polycarbonate resin is usually 1 g / 10 min or more, preferably 3 g / 10 min or more, and more preferably 5 g / 10 min or more. Setting it above the lower limit tends to further improve the fluidity of the resulting resin composition or molded product. The upper limit of the MFR is, for example, 100 g / 10 min or less, more preferably 50 g / 10 min or less, and may also be 30 g / 10 min or less, 20 g / 10 min or less, or 10 g / 10 min or less.

[0100] 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.

[0101] Recycled polycarbonate resin may be used. Examples of recycled polycarbonate resin include that obtained through material recycling, which involves crushing and washing off-the-shelf or rejected molded products, or collected used polycarbonate resin molded products, as well as that obtained through chemical recycling (chemical decomposition).

[0102] The polycarbonate resin content in the resin composition is preferably 1 to 10% by mass, more preferably 2 to 9% by mass, and even more preferably 3 to 8% by mass. If it is above the lower limit, sufficient compatibility can be obtained, and strength can be improved while maintaining heat resistance. If it is below the upper limit, a decrease in heat resistance can be suppressed. The polycarbonate resin may contain one type, or two or more types in any combination and ratio, and if two or more types are included, it is preferable that the total content is within the above numerical range.

[0103] [Other ingredients] The resin composition may contain components other than components (A) to (D) as long as it does not impair the effects of the present invention. However, the total content of components (A) to (D) in the manufactured resin composition is usually 80% by mass or more, 85% by mass or more, 90% by mass or more, or 95% by mass or more, based on 100% by mass of the resin composition.

[0104] In addition to components (A) to (D), the product may also contain additives such as flame retardants, flame retardant enhancers, anti-dripping agents, ultraviolet absorbers, antistatic agents, anti-fogging agents, anti-blocking agents, plasticizers, dispersants, and antibacterial agents. These are typically supplied to the twin-screw extruder together with components (A), (B), and (D).

[0105] Next, the apparatus and manufacturing process used in the manufacturing method of the present invention will be described with reference to Figures 1 to 6. Note that common parts in each figure may be denoted by the same reference numerals, and their descriptions may be omitted.

[0106] <Embodiment 1> As Embodiment 1, the manufacturing method shown in the flow chart of Figure 1 will be described. The manufacturing method shown in Figure 1 includes a first kneading step in which components (A), (B), and (D) are supplied to a twin-screw extruder and melt-kneaded in the first kneading section; a water-adding dispersion step in which 4 parts by mass or less of water is added and dispersed per 100 parts by mass of the molten resin composition; a first defloration step in which the vacuum of the first vacuum vent is reduced to 10 to 150 mmHg in absolute pressure and defloration is performed; a side-feed step in which component (C) is supplied to the twin-screw extruder by side feed; a second kneading step in which the components are kneaded in the second kneading section; a second defloration step in which the vacuum of the second vacuum vent is reduced to 10 to 150 mmHg in absolute pressure and defloration is performed; and an extrusion step in which the strand is extruded, with the resin temperature of the strand extruded from the die hole being 300°C or less. The composition of the raw material components is as described above.

[0107] The manufacturing method shown in Figure 1 is an example of producing a polyalkylene terephthalate resin composition by using components (A), (B), (C), and (D) as raw materials, melting and kneading them in a twin-screw extruder, and extruding the strands from a die attached to the tip of the twin-screw extruder. In the manufacturing method shown in Figure 1, the first defoliation step is performed after the first kneading step, following a water dispersion step in which water is added to and dispersed in the molten resin composition. This method has the advantage that the defoliation of low-boiling point components contained in the molten resin composition is promoted by dispersing water in the molten resin composition under high pressure, and then vaporizing and foaming after the pressure is reduced.

[0108] The manufacturing method shown in Figure 1 can be carried out using, for example, a manufacturing apparatus 100 equipped with an extruder 10 having a water injection and dispersion section as shown in Figure 2. The extruder 10 comprises a cylinder 12 having, from the upstream side, a first supply port 1 connected to a hopper 30, a water injection port 2 (a nozzle for liquid injection), a first vacuum vent 3, a side supply port 4 connected to a side feeder (not shown), and a second vacuum vent 5, and a screw 6 inside the cylinder 12. A first kneading section 14, a water injection and dispersion section 16, and a second kneading section 18 are provided along the screw 6. The extruder 10 performs kneading and extrusion by rotating the screw 6 with a motor M. A die 20 is attached to the tip of the extruder 10.

[0109] In the first kneading step, components (A), (B), and (D) (components other than component (C)) are supplied from the first supply port 1 into the cylinder 12, transported to the first kneading section 14, and kneaded in the first kneading section 14. The first kneading section 14 is the kneading section between the first supply port 1 and the water injection / dispersion section 2 (specifically, the kneading section upstream of the sealing on the upstream side of the water injection / dispersion section 2), and is composed of multiple kneading discs. As will be described later, if the extruder does not have a water injection / dispersion section, the first kneading section is the kneading section between the first supply port and the first vacuum vent 3.

[0110] The screw configuration of the first kneading section 14 can be a combination of two or more of the following: R kneading disc, N kneading disc, L kneading disc, L screw, seal ring, mixing screw, or rotor screw. The R kneading disc (hereinafter sometimes referred to as "R") is a progressive kneading disc element, and usually has two or more blades, preferably with a blade twist angle θ of 10 to 75 degrees. By setting the blades offset by a predetermined angle in this way, a pseudo-screw structure is formed, which is the zone where the resin is fed in the feeding direction while a strong shear force is applied and kneading takes place. The L-kneading disc (hereinafter sometimes referred to as "L") is a reverse-feed kneading disc element, and it is preferable that it usually has two or more blades and that the twist angle θ of the blades is between -10 and -75 degrees. The reverse-feed kneading disc element is an element that has the ability to increase pressure by damming the incoming resin or by working in the direction of sending the incoming resin back. By installing it downstream of the element that promotes kneading, it dams the resin and exerts a strong kneading effect. An N-kneading disc (hereinafter sometimes referred to as "N") is an orthogonal kneading disc element, typically having two or more blades, with a blade twist angle θ between 75 and 105 degrees. Because the blades are positioned offset by approximately 90 degrees, the force for dispensing resin is weak, but the kneading force is strong. An L-screw is a reverse-feed screw; a seal ring restricts the flow upstream through the gaps in the seal ring section; a mixing screw is a screw element with notches cut out from the screw peaks (flight section); and a rotor screw is a screw element with one or more grooves provided on its outer surface.

[0111] Since it is preferable to thoroughly melt the resin in the first kneading section 14 in order to disperse the water, one appropriate configuration for the first kneading section 14 is, for example, a combination of an R kneading disc, an N kneading disc, an L kneading disc, and an L screw.

[0112] In the screw configuration of the first kneading section 14, it is preferable to arrange the elements that promote kneading on the upstream side and the elements that have a pressure-boosting capacity on the downstream side. Therefore, in the first kneading section 14, it is preferable to arrange two or more elements selected from R, N, and L from the upstream side in the order R → N → L, and it is also preferable to arrange one or more of R, N, or L in multiples. In particular, a configuration in which R is arranged upstream, followed by multiple Ns, and then Ls is preferred.

[0113] The screw length of the first kneading section 14 is preferably in the range of 2.8D to 4.8D, where D is the inner diameter of the cylinder. By setting the screw length in this range, sufficient melt-plasticization of the resin can be achieved, and the occurrence of resin decomposition can be suppressed. If the screw length of the first kneading section 14 is 2.8D or more, sufficient shear force is applied to the resin, allowing for sufficient melt-plasticization of the resin. If it is 4.8D or less, decomposition of the resin composition can be suppressed, and mechanical properties can be maintained or improved. The first kneading section 14 may be a single unit or divided into multiple sections. That is, the first kneading section may be divided, and a conveying screw may be placed between the sections. The conveying screw is composed of a normal flight-shaped screw. Since the conveying screw does not perform a kneading action, the conveying screw is not included in the length of the kneading section, and if the first kneading section is divided, it is preferable that the total length of the first kneading section be within the aforementioned numerical range.

[0114] In the water injection and dispersion step, water is injected (added) from the water inlet 2 in the injection and dispersion section 16 and dispersed in the molten resin composition. The molten resin composition is a composition consisting of raw material components supplied from the first supply port 1, which includes component (A), component (B), and component (D), and is a composition in which the resin has melted and been kneaded with other raw materials. The amount of water injected is 4 parts by mass or less, preferably 2 parts by mass or less, per 100 parts by mass of the molten resin composition. By using such an amount of water injected, it is possible to reduce VOC gas without production problems such as vent up. It is preferable that the water injected is pure water in order to prevent resin degradation due to impurity components such as calcium and sodium. Pure water refers to water with an electrical resistivity of about 0.1 to 15 MΩ·cm at 25℃, and distilled water, ion-exchanged water, RO water, etc. can be used.

[0115] The injection dispersion section 16 is a kneading section with an inlet 2 on its upstream side, and is located between the first kneading section 14 and the first vacuum vent 3. Its screw configuration is preferably a combination of two or more types from among R kneading disc, N kneading disc, L kneading disc, L screw, seal ring, mixing screw, or rotor screw. The injection dispersion section 16 usually has a configuration with seal rings on the upstream and downstream sides. Among these, it is preferable to have seal rings on the upstream and downstream sides and to arrange multiple N kneading discs between them, with a length of 0.94 to 4.7D (where D is the inner diameter of the cylinder).

[0116] In the first defoliation step, the vacuum level of the first vacuum vent 3 is reduced to an absolute pressure of 10 to 150 mmHg for devastation. A vacuum pump (not shown) is connected to the first vacuum vent 3, and the vacuum pump is driven to draw air from the first vacuum vent 3 into the cylinder 12, thereby reducing the pressure and performing devastation. While a vacuum level of less than 10 mmHg in the first vacuum vent 3 is desirable in terms of reducing VOCs, such a low vacuum reduction is often difficult with standard pumps. A vacuum level of 150 mmHg or less is sufficient to promote the devastation of low-boiling point components and achieve low VOCs. The vacuum level of the first vacuum vent 3 is preferably 10 to 125 mmHg, more preferably 10 to 85 mmHg, and even more preferably 10 to 50 mmHg.

[0117] The degree of pressure reduction can be measured using known methods such as a manometer with a mercury column. Pressure can be expressed in two ways: absolute pressure, which is expressed relative to absolute vacuum, and gauge pressure, which is expressed relative to standard atmospheric pressure. Gauge pressure (MPa) = (absolute pressure (MPa)) - (standard atmospheric pressure (MPa)), and absolute pressure (mmHg) = (gauge pressure (MPa) + 0.101325) × (760 / 0.101325). Therefore, the degree of vacuum when evaporating under reduced pressure at the first vacuum vent 3 is -0.100 to -0.081 MPa in gauge pressure (MPa), preferably -0.100 to -0.085 MPa, more preferably -0.100 to -0.090 MPa, and even more preferably -0.100 to -0.095 MPa.

[0118] To prevent backflow of component (C) and to seal for devolatilization, it is preferable to provide a sealing ring between the first vacuum vent 3 and the side supply port 4.

[0119] In the side feed step, component (C) is supplied to the extruder 10 by a side feed. The side supply section 4 is located between the first vacuum vent 3 and the second kneading section 18. Component (C) is supplied from the side supply port 4 of the extruder 10 to the cylinder 12 via a side screw (not shown) in a side feeder (not shown), and together with the molten resin composition, is transported to the downstream second kneading section 18.

[0120] In the second kneading step, component (C) and the molten resin composition are kneaded together. The second kneading section 18, where the second kneading step takes place, is the kneading section between the side feeder 4 and the second vacuum vent port 5, and is composed of multiple kneading discs. As will be described later, if the manufacturing apparatus does not have a side feeder, the second kneading section of the extruder is the kneading section between the first vacuum vent 3 and the second vacuum vent 5.

[0121] The screw configuration of the second kneading section 18 is preferably composed of one or more types selected from R kneading disc, N kneading disc, L kneading disc, L screw, seal ring, or mixing screw.

[0122] The screw length of the second kneading section 18 is preferably in the range of 2.8 to 3.8D, where D is the inner diameter of the cylinder. By setting the screw length in this range, for example, when component (C) is glass fiber, it is possible to thoroughly knead the glass fiber and resin composition while leaving an appropriate fiber length. The second kneading section 18 may be a single unit or divided into multiple sections. That is, the second kneading section may be divided and a conveying screw may be placed between the sections. The conveying screw is composed of a normal flight-shaped screw. Since the conveying screw does not perform a kneading action, the conveying screw is not included in the length of the kneading section, and when the second kneading section is divided, it is preferable that the total length of the second kneading section be within the aforementioned numerical range.

[0123] In the second defoliation step, the vacuum level of the second vacuum vent 5 is reduced to 10-150 mmHg in absolute pressure for devastation. A vacuum pump (not shown) is connected to the second vacuum vent 5, and the vacuum pump is driven to draw suction from the second vacuum vent 5 into the cylinder 12, thereby performing devastation under reduced pressure. While a vacuum level of less than 10 mmHg in the second vacuum vent 5 is desirable in terms of reducing VOCs, such a vacuum reduction is often difficult with standard pumps. A vacuum level of 150 mmHg or less is sufficient to promote the devastation of low-boiling-point components and achieve low VOCs. The vacuum level of the second vacuum vent 5 is preferably 10-85 mmHg in absolute pressure, and more preferably 10-50 mmHg. Furthermore, the vacuum level during depressurization defloration at the second vacuum vent 5 is -0.100 to -0.081 MPa in gauge pressure (MPa), preferably -0.100 to -0.090 MPa, and more preferably -0.100 to -0.095 MPa.

[0124] The extrusion step is the step of extruding the strand. After the second defoliation step, the resin composition containing components (A) to (D) can be extruded as a strand from the die 20 attached to the tip of the extruder 10 by increasing the pressure. It is preferable that the resin pressure inside the die during extrusion be 0.5 to 8 MPa. There are no particular restrictions on the shape of the extrusion die, and known ones can be used. For example, a horizontal flat die with multiple die holes arranged laterally can be used. The diameter of the die holes depends on the desired pellet dimensions, but is usually 2 to 5 mm, preferably 3 to 4 mm.

[0125] Here, the resin temperature of the strand extruded from the die hole of die 20 is 300°C or lower. Preferably, the resin temperature of the strand extruded from the die hole is 295°C or lower, more preferably 290°C or lower, preferably 260°C or higher, and more preferably 270°C or higher. By setting the temperature to these levels, it is possible to reduce VOCs while suppressing the generation of volatile gases due to the decomposition of resins, including styrene. The resin temperature of the strand extruded from the die hole is measured using a contact thermometer.

[0126] In the manufacturing method shown in Figure 1, the screw rotation speed of the extruder 10, the cylinder temperature, the temperature of the die 20, etc., are controlled so that the resin temperature of the strand extruded from the die hole is 300°C or less, without impairing the objective of the present invention.

[0127] The temperature of cylinder 12 in the section from the first mixing step to the first defoliation step is preferably 240 to 260°C. By maintaining such a temperature, it is possible to promote plasticization of the resin and suppress venting.

[0128] The temperature of cylinder 12 from the side-feed step to the outlet (downstream end) is preferably 170-260°C, and more preferably 180-220°C. By maintaining such a temperature, shear heat generation after the side-feed is suppressed, and for example, if component (C) is glass fiber, it is possible to extrude while defibrating the glass fiber.

[0129] The temperature of the die 20 is preferably 250 to 290°C, and more preferably 250 to 280°C. By setting the temperature to this range, the strand can be stabilized while suppressing the rise in resin temperature, enabling extrusion production.

[0130] The strands exiting die 20 can be pelletized by conventional methods. For example, the strands exiting die 20 can be water-cooled and cut in a pelletizer to obtain pellets of the resin composition.

[0131] <Embodiment 2> As a second embodiment, the manufacturing method shown in the flow chart of Figure 3 will be described. The manufacturing method shown in Figure 3 includes a first kneading step in which components (A), (B), and (D) are supplied to a twin-screw extruder and melt-kneaded in a first kneading section; a first defloration step in which the vacuum of a first vacuum vent is reduced to 10 to 150 mmHg in absolute pressure and defloration is performed; a side-feed step in which component (C) is supplied to the twin-screw extruder by side feed; a second kneading step in which the components are kneaded in a second kneading section; a second defloration step in which the vacuum of a second vacuum vent is reduced to 10 to 150 mmHg in absolute pressure and defloration is performed; and an extrusion step in which the strand is extruded, wherein the resin temperature of the strand extruded from the die hole is 300°C or less.

[0132] The manufacturing method shown in Figure 3 is the same as the manufacturing method shown in Figure 1, except that the first defoliation step is performed without adding and dispersing water after the first kneading step, and the preferred conditions are also the same.

[0133] The manufacturing method shown in Figure 3 can be carried out, for example, using a manufacturing apparatus 100A equipped with an extruder 10A, as shown in Figure 4. The extruder 10A comprises a cylinder 12A having a first supply port 1 connected to a hopper 30, a first vacuum vent 3, a side supply port 4 connected to a side feeder (not shown), and a second vacuum vent 5, and a screw 6A inside the cylinder 12A. A first kneading section 14A and a second kneading section 18A are provided in the middle of the screw 6A. In the extruder 10A, the first kneading section 14A is the kneading section between the first supply port 1 and the first vacuum vent 3.

[0134] Extruder 10A is configured by removing the water injection and dispersion section 16 from extruder 10. The screw configuration of the first kneading section 14A of extruder 10A can be a combination of two or more types from among R kneading disc, N kneading disc, L kneading disc, L screw, seal ring, mixing screw, or rotor screw, similar to the first kneading section 14 of extruder 10. For example, a configuration combining R kneading disc, N kneading disc, and L kneading disc is given as an appropriate example for the screw configuration of the first kneading section 14A. Furthermore, the screw configuration of the second kneading section 18A of extruder 10A can be a combination of one or more types from among R kneading disc, N kneading disc, L kneading disc, L screw, seal ring, or mixing screw, similar to the second kneading section 18 of extruder 10.

[0135] In the manufacturing method shown in Figure 3, water is not added or dispersed between the first kneading step and the first defoliation step. However, the temperature of cylinder 12A in the section from the first kneading step to the first defoliation step is preferably set to the same temperature as cylinder 12 in the section from the first kneading step to the first defoliation step in the manufacturing method shown in Figure 1. Furthermore, the temperature of cylinder 12A and die 20 from the section where the side feed step is performed to the outlet (downstream end) is also preferably set to the same temperature as in the manufacturing method shown in Figure 1.

[0136] The manufacturing method shown in Figure 3 is not limited to the method using a manufacturing apparatus 100A equipped with an extruder 10A. For example, the manufacturing apparatus 100 described above may be used, but without water being injected from the water injection / dispersion section 16 of the extruder 10, and the manufacturing method shown in Figure 3 may be carried out.

[0137] <Embodiment 3> As Embodiment 3, the manufacturing method shown in the flow chart of Figure 5 will be described. The manufacturing method shown in Figure 5 includes a first kneading step in which components (A), (B), and (D) are supplied to a twin-screw extruder and melt-kneaded in the first kneading section, a water-adding dispersion step in which 4 parts by mass or less of water is added and dispersed per 100 parts by mass of the molten resin composition, a first defloration step in which the vacuum of the first vacuum vent is reduced to 10 to 150 mmHg in absolute pressure and defloration is performed, a second kneading step in which the components are kneaded in the second kneading section, a second defloration step in which the vacuum of the second vacuum vent is reduced to 10 to 150 mmHg in absolute pressure and defloration is performed, and an extrusion step in which the strands are pushed out, and the resin temperature of the strands pushed out from the die hole of the die is 300°C or less.

[0138] The manufacturing method shown in Figure 5 is an example of producing a polyalkylene terephthalate resin composition containing components (A), (B), and (D) using components (A), (B), and (D) as raw materials, without using component (C). It is the same as the manufacturing method shown in Figure 1, except that a side-feed step supplying component (C) is not performed between the first defoliation step and the second kneading step, and the preferred conditions are also the same.

[0139] In the manufacturing method shown in Figure 5, since component (C) is not supplied, a manufacturing apparatus 100B without a side feeder, such as the one shown in Figure 6, can be used as the extruder. The manufacturing apparatus 100B includes an extruder 10B. The extruder 10B includes, from the upstream side, a cylinder 12B having a first supply port 1 connected to the hopper 30, a water inlet 2, a first vacuum vent 3, and a second vacuum vent 5, and a screw 6B inside the cylinder 12B. In addition, a first kneading section 14B, a water dispersion section 16B, and a second kneading section 18B are provided in the middle of the screw 6B.

[0140] Extruder 10B is configured similarly to extruder 10, but without the side supply port 4. The screw configurations of the first kneading section 14B and injection dispersion section 16B of extruder 10B are the same as those of the first kneading section 14 and injection dispersion section 16 of extruder 10. In addition, if the side feed step is not performed as in the manufacturing method shown in Figure 5, a seal ring may be provided between the first vacuum vent 3 and the second kneading section 18B. However, since there is no need to consider backflow of component (C), a configuration without a seal ring is also acceptable. Furthermore, the screw of the second kneading section 18B of the extruder 10B can be a combination of one or more types from among the R kneading disc, N kneading disc, L kneading disc, L screw, seal ring, or mixing screw. However, since kneading of component (C) is unnecessary, a weak kneading configuration with a length of less than 2.8D of the second kneading section 18B is desirable because it suppresses resin degradation without raising the resin temperature.

[0141] In the manufacturing method shown in Figure 5, since the side-feed step is not performed, it is preferable to set the temperature of cylinder 12B from the end of the first devolatilization step to the outlet (downstream end) to 200-260°C, and more preferably to 220-260°C. By setting the temperature to this extent, it is possible to extrude while suppressing the generation of unmelted resin and thermal decomposition of the resin. The temperature of cylinder 12B in the section from the first kneading step to the first devolatilization step, the pressure of the first and second devolatilization, and the temperature of the die 20 are the same as in the manufacturing method shown in Figure 1.

[0142] <Other Embodiments> The manufacturing method of the present invention is not limited to those shown in Figures 1, 3, and 5. For example, in the manufacturing method shown in Figure 5, the second kneading step may be omitted. That is, the manufacturing method may include a first kneading step in which components (A), (B), and (D) are supplied to a twin-screw extruder and melt-kneaded in the first kneading section; a water dispersion step in which 4 parts by mass or less of water is added and dispersed per 100 parts by mass of the molten resin composition; a first defloration step in which the vacuum of the first vacuum vent is reduced to an absolute pressure of 10 to 150 mmHg and defloration is performed; a second defloration step in which the vacuum of the second vacuum vent is reduced to an absolute pressure of 10 to 150 mmHg and defloration is performed; and an extrusion step in which the strand is pushed out, wherein the resin temperature of the strand pushed out from the die hole of the die is 300°C or less. Such a manufacturing method can be carried out, for example, using an apparatus in which the second kneading section 18B is omitted from the apparatus configuration of the extruder 10B of the manufacturing apparatus 100B.

[0143] Furthermore, the manufacturing method shown in Figure 5 may be one in which the water injection and dispersion step is omitted. That is, the manufacturing method may include a first kneading step in which components (A), (B), and (D) are supplied to a twin-screw extruder and melt-kneaded in a first kneading section, a first defloration step in which the vacuum of the first vacuum vent is reduced to 10 to 150 absolute pressure and defloration is performed, a second kneading step in which the components are kneaded in a second kneading section, a second defloration step in which the vacuum of the second vacuum vent is reduced to 10 to 150 absolute pressure and defloration is performed, and an extrusion step in which the strands are pushed out, wherein the resin temperature of the strands pushed out from the die hole of the die is 300°C or less. Such a manufacturing method can be implemented, for example, by using the extruder 10B of the manufacturing apparatus 100B without performing the water injection and dispersion step, or by using an apparatus configured by omitting the side feeder and the side supply port 4 of the extruder 10A to which it is connected from the manufacturing apparatus 100A.

[0144] Furthermore, in the manufacturing method shown in Figure 5, the water injection dispersion step and the second kneading step may be omitted. That is, the manufacturing method may include a first kneading step in which components (A), (B), and (D) are supplied to a twin-screw extruder and melt-kneaded in the first kneading section, a first defloration step in which the vacuum of the first vacuum vent is reduced to 10 to 150 mmHg in absolute pressure and defloration is performed, a second defloration step in which the vacuum of the second vacuum vent is reduced to 10 to 150 mmHg in absolute pressure and defloration is performed, and an extrusion step in which the strand is pushed out, wherein the resin temperature of the strand pushed out from the die hole of the die is 300°C or less. Such a manufacturing method can be carried out, for example, using an apparatus in which the water injection dispersion section 16B and the second kneading section 18B are omitted from the apparatus configuration of the extruder 10B of the manufacturing apparatus 100B.

[0145] <Resin composition> The manufacturing method of the present invention yields a polyalkylene terephthalate resin composition comprising (A) 5 to 94% by mass of polyalkylene terephthalate resin, (B) 5 to 60% by mass of styrene resin, and (D) 0.01 to 18.5% by mass of an additive containing one or more selected from the group consisting of stabilizers, release agents, colorants, and compatibilizers. The manufacturing method of the present invention also yields a polyalkylene terephthalate resin composition comprising (A) 5 to 94% by mass of polyalkylene terephthalate resin, (B) 5 to 60% by mass of styrene resin, (C) 0.99% to 65% by mass of inorganic filler, and (D) 0.01 to 18.5% by mass of an additive containing one or more selected from the group consisting of stabilizers, release agents, colorants, and compatibilizers. These resin compositions are, for example, in the form of pellets. Furthermore, the pellets can be molded by conventional molding methods to produce various molded articles.

[0146] The resin composition obtained by the manufacturing method of the present invention has a styrene monomer content of 3 ppm by mass or less and a total VOC gas content of 10 ppm by mass or less, as detected by gas chromatography after heating at 150°C for 120 minutes. Furthermore, the manufacturing method of the present invention can also yield a resin composition in which the styrene monomer content is 2 ppm by mass or less and the total VOC gas content is 10 ppm by mass or less, as detected by gas chromatography after heating at 150°C for 120 minutes. [Examples]

[0147] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples unless its essence is changed.

[0148] <Device> In the following examples and comparative examples, a twin-screw extruder, "TEX25αIII" (L / D=52.5, cylinder inner diameter=26.5mm) manufactured by Japan Steel Works, was used. The screw configuration was either Configuration I or Configuration II as described below. The die consisted of two die holes with a bore diameter of 4mm and a land length of 10mm, arranged horizontally, using a ring plate, and no screen mesh was used.

[0149] [Screw configuration, etc.] (Configuration I) Configuration I is the configuration shown in Figure 7. The first kneading section is positioned from cylinder position C4 to C6, and the screws are arranged in the following order: one R-kneading, two N-kneading, one L-kneading, and a reverse-feeding flight (L-screw). Each kneading disc has a length of 0.943D (D: inner diameter of the cylinder, 26.5mm) and each has five blades (also called "discs" or "paddles"). The reverse-feeding flight has a length of 0.472D. A water injection and dispersion section was placed at C6, separated by the feed flight. The screw was configured with a seal ring, three N discs, and another seal ring. Each N disc had five blades, and both the seal ring and the N discs had a length of 0.472D. A seal ring was placed at the boundary between C10 and C11. The second mixing section is located between C12 and C13, and the screw configuration consists of one R-kneading disc and three forward mixing screws (referred to as "FMS") with a feed flight in between. The R-kneading disc has a length of 0.943D and five blades. The FMS is a forward-feeding mixing screw element with a notched screw peak (flight section), and the element length is 0.943D with a lead length of 0.472D. Furthermore, the upstream C1 was designated as a feed cylinder (C1 barrel), and C11 as a side feed cylinder (C11 barrel). A nozzle for liquid injection was installed in the C6 cylinder to allow water to be added to the cylinder. In addition, a first vacuum vent was installed at C9, and a second vacuum vent at C14.

[0150] (Configuration II) Configuration II is the configuration shown in Figure 8. The first kneading section is positioned from C5 to C7, and the screws are arranged in the order of two R-kneading discs, two N-kneading discs, and one L-kneading disc. Each kneading disc has a length of 0.943D (D: inner diameter of the cylinder, 26.5 mm) and each has five blades (also called discs or paddles). A water injection and distribution section was not included. A seal ring was placed at the boundary between C10 and C11. The second mixing section is positioned from C12 to C13, and the screw consists of one R-kneading disc and three forward mixing screws (referred to as "FMS") with a feed flight in between. The R-kneading disc has a length of 0.943D and five blades. The FMS is a forward-feeding mixing screw element with a notched screw peak (flight section), and the element length is 0.943D with a lead length of 0.472D. Furthermore, the upstream C1 was designated as a feed cylinder (C1 barrel), and C11 as a side feed cylinder (C11 barrel). In addition, a first vacuum vent was installed at C9, and a second vacuum vent at C14.

[0151] <Examples and Comparative Examples> The raw material components listed in Table 1 were used in the following proportions: A-1: ​​20.34% by mass, B-1: 40.68% by mass, C-1: 30.00% by mass, d1-1: 0.30% by mass, d1-2: 0.10% by mass, d2-1: 0.50% by mass, d3-1: 1.30% by mass, and d4-1: 6.78% by mass. All components except (C) were supplied to the extruder from the upstream barrel (C1 barrel) after tumble mixing, while component (C) was supplied via side feed from the C11 barrel midway through the extruder. In Examples 2-4 and Comparative Examples 2-4 and 6, where pure water was injected, the apparatus of Configuration I was used, and the liquid was injected from the C6 barrel using a plunger pump (Fuji Techno Kogyo Co., Ltd. "HYM-06" Super Metering Pump). The strands that came out of the die were cooled in a water tank and cut in a pelletizer to obtain pellets.

[0152] [Table 1]

[0153] <Example 1> Using the apparatus of configuration I, pellets of the polybutylene terephthalate resin composition were obtained by the following method. No water was added. Vacuum reduction was performed at the pressure of the first vacuum vent (Vent 1 vacuum pressure (mmHg)) of 85 mmHg (gauge pressure -0.090 MPa) and the pressure of the second vacuum vent (Vent 2 vacuum pressure (mmHg)) of 85 mmHg (gauge pressure -0.090 MPa). A mixture containing all components except (C)(C-1) was tumble-mixed at a rate of 21.0 kg / h (70.0 mass%) from the C1 hopper to the C1 barrel, and component (C) was supplied at a rate of 9.0 kg / h (30.0 mass%) to the C11 barrel via side feed. Extrusion was performed with a discharge rate of 30 kg / h, a screw rotation speed of 400 rpm, barrel temperatures of 150°C for C2, 250°C for C3-C10, and 220°C for C11-C15. The strands coming out of the die at the extruder outlet were stable and unbroken, and there was no resin blockage (vent up) in the vent, resulting in good productivity. The resin temperature at the die outlet was measured with a contact thermometer and was found to be 273°C. The strands extruded from the die were cooled in water and cut using a pelletizer to obtain pellets. The size of 10 pellets was 2.8–2.9 mm in length, 1.8–1.9 mm in minor diameter, and 2.8–2.9 mm in major diameter. Here, length refers to the cut length (cutting interval) in the strand pull direction, and major and minor diameters refer to the long and short diameters of the cut cross-section. The implementation conditions, along with those of other examples and comparative examples, are shown in Table 2.

[0154] <Example 2> Pellets were obtained in the same manner as in Example 1, except that the vacuum pressures (mmHg) of vent 1 and vent 2 were changed to the conditions shown in Table 2, and 0.5 parts by mass of pure water were injected from a C6 barrel into 100 parts by mass of the molten resin composition (100 parts by mass of the sum of components (A), (B), and (D)). The productivity of the strands was good, similar to Example 1. The resin temperature at the die outlet was 275°C.

[0155] <Example 3> Pellets were obtained in the same manner as in Example 2, except that the amount of pure water injected per 100 parts by mass of the molten resin composition (amount of water injected) was changed to the conditions shown in Table 2. Strand productivity was good. The resin temperature at the die outlet was 275°C.

[0156] <Example 4> Pellets were obtained in the same manner as in Example 3, except that the barrel temperature, vent 1 vacuum pressure (mmHg), and vent 2 vacuum pressure (mmHg) were changed to the conditions shown in Table 2. Strand productivity was good. The resin temperature at the die outlet was 294°C.

[0157] <Example 5> Pellets were obtained in the same manner as in Example 1, except that the apparatus of Configuration II was used and each condition was changed to the conditions shown in Table 2. Strand productivity was good. The resin temperature at the die outlet was 275°C.

[0158] <Comparative Example 1> Pellets were obtained in the same manner as in Example 1, except that the first vacuum vent was left open to the atmosphere without depressurization, and the screw rotation speed, barrel temperature, and vent 2 vacuum pressure (mmHg) were changed to the conditions shown in Table 2. Strand productivity was good. The resin temperature at the die outlet was 307°C.

[0159] <Comparative Example 2> Pellets were obtained in the same manner as in Example 2, except that the screw rotation speed and barrel temperature were changed to the conditions shown in Table 2. Strand productivity was good. The resin temperature at the die exit was 307°C.

[0160] <Comparative Example 3> Pellets were obtained in the same manner as in Example 3, except that the screw rotation speed and barrel temperature were changed to the conditions shown in Table 2. Strand productivity was good. The resin temperature at the die exit was 307°C.

[0161] <Comparative Example 4> Pellets were obtained in the same manner as in Example 4, except that the vacuum pressures (mmHg) of vent 1 and vent 2 were changed to the conditions shown in Table 2. Strand productivity was good. The resin temperature at the die outlet was 294°C.

[0162] <Comparative Example 5> Pellets were obtained in the same manner as in Example 1, except that the first vacuum vent was opened to the atmosphere without depressurization. Strand productivity was good. The resin temperature at the die outlet was 275°C.

[0163] <Comparative Example 6> The procedure was the same as in Example 1, except that 5.0 parts by mass of pure water was added to 100 parts by mass of the molten resin composition (100 parts by mass of components (A), (B), and (D) in total) from a C6 barrel. However, due to the large amount of pure water added, vent-up occurred from the first vacuum vent due to poor water dispersion, preventing stable production.

[0164] <Measurement of styrene monomer content and total VOC gas content> The obtained pellets were placed in a 20 mL glass vial measuring 75.5 × 22.5 mm in size (5.0 g), and the resulting gas was measured by the following chromatograph after heat treatment at 150°C for 120 minutes. • Measuring equipment: Shimadzu NexisGC-2030, Headspace Sampler HS-20NX • Column: Rtx-Wax, inner diameter 0.25 mm, length 30 m, film thickness 0.25 μm, split ratio 20:1 Carrier gas: He ·Linear speed: 27cm / sec • Column oven temperature: Held at 50°C for 1 minute, then increased to 120°C at a rate of 5°C / min, and further increased to 230°C at a rate of 10°C / min, after which it was held for 1 minute. • Detector: FID Detector temperature: 240℃

[0165] The measured values ​​were converted to values ​​per unit mass of the resin composition to calculate the amount of styrene monomer and the total amount of VOC gas. The results are shown in Table 2.

[0166] [Table 2]

[0167] As shown in Table 2, stable extrusion is possible under the conditions of the examples, and both the amount of styrene monomer and total VOC gas generated can be reduced. Furthermore, even in Examples 1 and 5, where no water was added, the amount of styrene monomer and total VOC gas generated could be reduced. On the other hand, Comparative Examples 1 to 5 show that gas generation increases when vents 1 and vents 2 are not reduced to a vacuum, when the vacuum pressure is high, or when the resin temperature of the strand coming out of the die is high. Furthermore, Comparative Example 6 was unsuitable as a production condition because stable production was not possible. [Explanation of Symbols]

[0168] 1 First supply port 2 Water inlet 3. First Vacuum Vent 4 Side supply ports 5. Second vacuum vent 6, 6A, 6B Screws 10, 10A, 10B extruders 12, 12A, 12B cylinders 14, 14A, 14B First Mixing Section 16, 16B Water injection distribution section 18, 18A, 18B Second mixing section 20 Dies 30 hoppers 100, 100A, 100B manufacturing equipment M Motor

Claims

1. A method for producing a polyalkylene terephthalate resin composition, comprising melt-kneading in a twin-screw extruder, extruding strands from a die attached to the tip of the twin-screw extruder, and producing a polyalkylene terephthalate resin composition, The twin-screw extruder has, at least, a first kneading section, a first vacuum vent, and a second vacuum vent, starting from the upstream side. The aforementioned polyalkylene terephthalate resin composition is As component (A), 5 to 94% by mass of polyalkylene terephthalate resin, As component (B), 5 to 60% by mass of styrene resin, Component (D) contains, in an amount of 0.01 to 18.5% by mass, one or more selected from the group consisting of (d1) stabilizers, (d2) release agents, (d3) colorants, and (d4) polymers other than polyalkylene terephthalate resins and styrene-based resins. A first kneading step involves supplying the aforementioned components (A), (B), and (D) to the twin-screw extruder and melt-kneading them in the first kneading section, The first defoliation step involves reducing the vacuum level of the first vacuum vent to 10 to 150 mmHg in absolute pressure and performing devastation under reduced pressure. The second defoliation step involves reducing the vacuum level of the second vacuum vent to 10 to 150 mmHg in absolute pressure and performing devastation under reduced pressure. The step includes pushing the strand out of the die hole of the die, The first defoliation step is performed after the first kneading step, either by adding and dispersing 4 parts by mass or less of water per 100 parts by mass of the molten resin composition, or by performing the step without adding or dispersing water. A manufacturing method wherein the resin temperature of the strand extruded from the die hole is 300°C or less.

2. The aforementioned component (D) includes polycarbonate resin, The manufacturing method according to claim 1, wherein the polycarbonate resin in the polyalkylene terephthalate resin composition is 1 to 10% by mass.

3. The manufacturing method according to claim 1, wherein the twin-screw extruder has a second kneading section between the first vacuum vent and the second vacuum vent.

4. The polyalkylene terephthalate resin composition further contains an inorganic filler as component (C) in an amount of 0.99% by mass or more and 65% by mass or less. The manufacturing method according to claim 3, further comprising a side-feed step of supplying the component (C) to the twin-screw extruder by side-feed between the first devolatilization step and the second devolatilization step, and a second kneading step of kneading in the second kneading section.

5. Between the first kneading step and the first defoliation step, there is a water-adding and dispersion step in which 4 parts by mass or less of water is added and dispersed per 100 parts by mass of the molten resin composition. The manufacturing method according to claim 1, wherein the twin-screw extruder has a water injection and dispersion section between the first kneading section and the first vacuum vent.

6. The manufacturing method according to claim 1, wherein the polyalkylene terephthalate resin of component (A) is a polybutylene terephthalate resin.

7. The method for producing the polyalkylene terephthalate resin composition according to claim 1, wherein the styrene monomer detected when analyzed by gas chromatography after heating at 150°C for 120 minutes is 3 ppm by mass or less, and the total VOC gas is 10 ppm by mass or less.

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