Method for manufacturing resin composition pellets

Abstract

To produce pellets of polycarbonate resin composition or polyester resin composition that contain epoxy compounds but do not have burning problems. [Solution] A method for producing pellets of a polycarbonate resin composition or polyester resin composition using an extruder, wherein a twin-screw extruder is used as the extruder, having a raw material feed section, a conveying section, a kneading section, a conveying section, a vacuum vent section, a conveying section, and a die section in order from upstream to downstream of the extruder; raw materials containing polycarbonate resin or polyester resin supplied from the raw material feed section are melt-kneaded in the kneading section; volatile components are removed by reducing the pressure in the vacuum vent section; an epoxy compound is added in the conveying section located downstream thereafter, and the distance from the position where the epoxy compound is added to the tip of the screw is in the range of 1D to 10D (where D is the inner diameter of the extruder cylinder).

Description

Technical Field

[0001] The present invention relates to a method for producing resin composition pellets, and more specifically, to a method for producing pellets of a polycarbonate resin composition or a polyester resin composition containing an epoxy compound using an extruder, which can produce pellets of a polycarbonate resin composition or a polyester resin composition in which the epoxy compound is uniformly dispersed without the generation of burned foreign substances.

Background Art

[0002] Polycarbonate resin or polyester resin such as polybutylene terephthalate resin is excellent in mechanical strength and the like, and also has excellent heat resistance, moldability, and recyclability. Therefore, molded products formed therefrom are widely used as parts of various products. In order to produce raw material pellets used for molding molded products, various additives are blended with polycarbonate resin or polyester resin for desired performance improvement, and then melt-kneaded with an extruder and extruded in a strand shape, which is cut into pellets of polycarbonate resin or polyester resin composition.

[0003] Polycarbonate resin and polyester resin have ester bonds, which are hydrolyzed to generate terminal OH groups. This terminal OH group has acidic properties and releases H + to serve as a catalyst, which chain-reactionly promotes the hydrolysis of polycarbonate resin and polyester resin. Since an epoxy compound can bind to the terminal OH group and eliminate its activity, thereby improving the moisture and heat resistance of the molded product, the epoxy compound is blended as an additive to increase the moisture and heat resistance of the molded product obtained by molding from polycarbonate resin or polyester resin, and made into resin composition pellets (for example, see Patent Document 1).

[0004] Thus, epoxy compounds are extremely effective in suppressing the hydrolysis of polycarbonate and polyester resins. However, on the other hand, due to their strong reactivity, epoxy compounds tend to cause burning of polycarbonate and polyester resins when resin composition pellets are manufactured in an extruder. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2014-121837 [Overview of the project] [Problems that the invention aims to solve]

[0006] Furthermore, it is known that epoxy compounds are also adsorbed onto the metal surface of the extruder. The surface of the steel material that makes up the extruder is thought to have OH groups due to oxygen and water in the air, and these OH groups react with the epoxy compound, causing it to be adsorbed onto the metal surface. In particular, with polyfunctional epoxy compounds, one of the unreacted epoxy groups reacts with the polycarbonate resin, forming a bond between the extruder surface, the epoxy compound, and the polycarbonate resin. It is thought that this bond then burns on the metal surface due to the high temperature during extrusion. This burning of polycarbonate resin can cause carbonization, resulting in a brown or black discoloration, and may delaminate due to shear forces in the extruder. When this happens, the burnt material enters the pellets of the polycarbonate or polyester resin composition, causing various adverse effects on the molded products. For example, polycarbonate resin is often used to form optical components, and burning can degrade the optical properties of these components and severely impair their aesthetic appeal. Polyester resins such as polybutylene terephthalate are also frequently used in electrical and electronic components, but burning, or charring, can lead to electrical conductivity, which is undesirable.

[0007] To suppress this burning, the set temperature at various points in the extruder or the resin temperature may be lowered during extrusion, but it is difficult to completely suppress this burning. The object (problem) of the present invention is to produce polycarbonate resin composition or polyester resin composition pellets containing epoxy compounds in an extruder without burning problems and with uniformly blended epoxy compounds. [Means for solving the problem]

[0008] In order to achieve the above objectives, the inventors diligently investigated methods to suppress burning and, as a result, discovered that by melt-kneading polycarbonate resin or polyester resin, defoliating the low molecular weight components, and then adding an epoxy compound, this burning can be significantly suppressed, leading to the present invention. The present invention relates to a method for producing the following polycarbonate resin composition or polyester resin composition pellets.

[0009] 1. A method for producing pellets of a polycarbonate resin composition or polyester resin composition using an extruder, wherein the extruder is a twin-screw extruder having, in order from upstream to downstream, a raw material feed section, a conveying section, a kneading section, a conveying section, a vacuum vent section, a conveying section, and a die section; the raw material containing polycarbonate resin or polyester resin supplied from the raw material feed section is melt-kneaded in the kneading section, the pressure is reduced in the vacuum vent section to remove volatile components, an epoxy compound is added in the conveying section located downstream thereafter, and the distance from the position where the epoxy compound is added to the tip of the screw is in the range of 1D to 10D (where D is the inner diameter of the extruder cylinder). 2. The manufacturing method according to item 1 above, wherein the epoxy compound is added by pumping an epoxy compound that is in liquid state at room temperature. 3. The manufacturing method according to 1 or 2 above, wherein the amount of epoxy compound added is in the range of 0.01 to 1% by mass. 4. The manufacturing method according to any one of items 1 to 3 above, wherein the polyester resin is polyethylene terephthalate resin or polybutylene terephthalate resin. [Effects of the Invention]

[0010] According to the manufacturing method of the present invention, pellets of a polycarbonate resin composition or polyester resin composition can be produced that contain an epoxy compound but are free from burning problems. Molded articles formed from the resulting pellets of the resin composition exhibit suppressed hydrolysis and moisture-heat resistance of the polycarbonate resin or polyester resin, and do not suffer from a decrease in optical properties, electrical properties, or mechanical strength. In this invention, an epoxy compound is added in the conveying section downstream of the reduced-pressure vent section. It has been confirmed that the epoxy compound added in this way is uniformly dispersed in the strand, demonstrating the effectiveness of the method of this invention. The reason for this is that resin pressure is generated when the resin passes through the die nozzle, and if there is a screen mesh, resin pressure is also generated when the resin passes through it. As a result, the resin accumulates at the tip of the screw, and the rotation of the screw in this accumulation area acts like a mixing section, causing the epoxy compound to be uniformly dispersed in the extruded resin strand. [Brief explanation of the drawing]

[0011] [Figure 1] This is a cross-sectional view showing the screw configuration of the extruder used in an embodiment of the present invention. [Figure 2] This is a cross-sectional view showing the screw configuration of the extruder used in Comparative Examples 3 and 6 of the present invention. [Modes for carrying out the invention]

[0012] The present invention will be described in detail below with reference to embodiments and examples, but the present invention is not limited to these embodiments and examples.

[0013] The manufacturing method of the present invention is a method for manufacturing pellets of a polycarbonate resin composition or a polyester resin composition using an extruder. As the extruder, a twin-screw extruder having, in order from the upstream to the downstream of the extruder, a raw material feed section, a conveying section, a kneading section, a conveying section, a vacuum vent section, a conveying section, and a die section is used. In the kneading section, the raw material containing the polycarbonate resin or polyester resin supplied from the raw material feed section is melt-kneaded, volatile components are removed in the vacuum vent section, and an epoxy compound is added in the conveying section downstream thereof, and the distance from the position where the epoxy compound is added to the tip of the screw is in the range of 1D to 10D (D is the inner diameter of the extruder cylinder).

[0014] A twin-screw extruder is used in the manufacturing method of the present invention. Various types of twin-screw extruders can be used, and the rotation mode of the screw may be a co-rotating type or a counter-rotating type, but a co-rotating meshing type twin-screw extruder is preferred. In addition, the twin-screw extruder is provided with a vent port that is depressurized.

[0015] FIG. 1 is a cross-sectional view showing an example of the screw configuration of the extruder used in the method of the present invention. Hereinafter, the manufacturing method of the present invention will be described while also referring to FIG. 1.

[0016] Raw materials such as polycarbonate resin or polyester resin other than the epoxy compound are supplied to the extruder from the raw material feed section of the twin-screw extruder. The polycarbonate resin or polyester resin is transported while being melt-kneaded toward the die section on the right side in FIG. 1 by the heating of the extruder barrel and the rotation of the screw, and the strand discharged from the discharge die is pelletized by a granulator (not shown).

[0017] The raw material feed section is a section for feeding raw materials such as polycarbonate resin or polybutylene terephthalate resin other than the epoxy compound, and consists of the base of the extruder for raw material feeding or the screw at the upper opening upstream. In the case of an extruder with a side feed screw, it is the feed section for feeding the raw material to the side feed screw.

[0018] The conveying section is the part that conveys raw materials from upstream to downstream by means of a screw, and consists of a flight screw or the like. As the screw for conveying, a full flight screw in the forward direction is preferred. The polycarbonate resin, polyester resin, etc. supplied from the supply port are conveyed and preheated in the first conveying section.

[0019] Next, the polycarbonate resin or polyester resin is melted in the kneading section. The kneading section is the part that kneads the resin, plasticizes it, or disperses it, and consists of a mixing screw, kneading disks, etc. Preferred kneading disks, etc. used in the kneading section include R kneading disks, N kneading disks, L kneading disks, L screws, seal rings, etc. In the kneading section, a full flight screw for normal feeding may be placed between a plurality of kneading disks.

[0020] The R kneading disk is also called a forward feeding kneading disk (hereinafter sometimes referred to as R), and usually has two or more blades, and the twist angle Θ of the blades is from 10 degrees to 75 degrees. By installing the blades with such a predetermined angle shift, the resin can be sent and a strong shearing force can be applied.

[0021] The N kneading disk is also called an orthogonal kneading disk (hereinafter sometimes referred to as N), and usually has two or more blades, and the twist angle Θ of the blades is from 75 degrees to 105 degrees. Since the blades are installed with a shift of approximately 90 degrees, there is almost no force to send the resin, but the kneading force is strong.

[0022] An L-kneading disc, also called a reverse-feed kneading disc (hereinafter sometimes referred to as L), typically has two or more blades with a twist angle Θ of -10 to -75 degrees. The L-kneading disc is an element with the ability to increase pressure, either by blocking the incoming resin or by pushing the incoming resin back. By placing it downstream of the element that promotes kneading, it blocks the resin and exerts a powerful kneading effect.

[0023] An L-screw, also called a reverse-feed screw, is a screw that spirals in the opposite direction to a normal feed screw. It is an element that can block the resin flow or increase pressure in the direction that the fed resin is returned. Similar to an L-kneading disc, it is installed downstream of the element that promotes kneading to block the resin flow and exert a powerful kneading effect.

[0024] The blades described above are usually elliptical, with flat sections at the two vertices of the ellipse. These blades are also called discs, and each kneading disc is usually composed of 3 to 7 discs. These discs are sometimes roughly triangular and have three vertices, and are also called three-pronged kneading discs. Similarly, there are R, N, and L types. These can also be used in the same way. Among kneading discs, there are also twisted kneading discs, in which the vertices are twisted in the direction of the screw axis, and similar kneading effects can be obtained.

[0025] A seal ring is a ring-shaped component fitted onto a screw, which blocks approximately 70-90% of the flow path, causing the resin flow to stagnate and thereby increasing the resin pressure. Similar to an L-kneading disc, by placing it downstream of the element that promotes kneading, it can dam the resin flow and exert a powerful kneading effect.

[0026] The mixing section is preferably composed of the kneading disc and seal ring described above, but a mixing screw, rotor screw, or reverse-feed full-flight screw may also be used.

[0027] A mixing screw is made by machining the peaks of a screw flight. It is a single- or double-flute feed or reverse-flute screw and is an element with strong shear dispersion force. There are forward-flute notched mixing screws and reverse-flute notched mixing screws.

[0028] A rotor screw has elliptical (two-blade structure) or triangular rotor blades, and can generate strong shear force through the gap (tip clearance) between the rotor and the inner wall of the barrel. A reverse-feed full-flight screw is a screw that operates in the opposite direction to a feed screw and has a strong resin boost pressure.

[0029] Thus, the mixing section refers to the part where the resin is retained, subjected to strong shearing, and melted and mixed. The mixing section can be located in one place or divided into multiple sections. If divided into two sections, the mixing section and conveying section should be arranged in that order. In this invention, the kneading section refers to the beginning and end of the kneading area.

[0030] In the mixing section, the polycarbonate resin or polyester resin is sufficiently melted, and then it is conveyed downstream towards the die section by the conveying section, with a vacuum vent located along the conveying section. Vacuum vents are installed to remove volatile components generated from plasticized resins and additives. Volatile components include volatile components (low molecular weight components) contained in the raw materials and low molecular weight components generated during plasticization. The degree of pressure reduction of the depressurization vent is preferably in the range of -0.03 MPa to -0.099 MPa, with atmospheric pressure being 0 MPa.

[0031] The conveying section is located after the depressurization vent, and then the tip of the screw is located after that. In this invention, an epoxy compound is added to the conveying section after vacuum venting. The addition position is shown as position P in Figure 1. The distance L from the epoxy compound addition position P to the screw tip is in the range of 1D to 10D (where D is the inner diameter of the extruder cylinder). If the distance L is shorter than 1D, the epoxy compound will not be completely mixed with the polycarbonate or polyester resin, resulting in a concentration distribution of the epoxy compound in each strand. The distance L is preferably 1.25D or more, more preferably 1.5D or more. If the distance L is longer than 10D, the thermal history of the epoxy compound increases, making it more susceptible to burning. The distance L is preferably 8D or less, more preferably 6D or less. To further improve the dispersibility of epoxy compounds, a short mixing section may be provided near the tip of the screw.

[0032] There are no particular restrictions on the method of adding the epoxy compound to the extruder, but if the epoxy compound is liquid at room temperature, it is preferable to add it to the extruder cylinder using a liquid addition nozzle with a pump. If the epoxy compound is solid or highly viscous at room temperature, it is preferable to heat it to a liquid state or reduce its viscosity, and then add it to the extruder cylinder from a liquid addition nozzle using a pump. Here, "liquid at room temperature" means that it is liquid at 23°C. The pump used is preferably a positive displacement pump, and among these, plunger pumps, diaphragm pumps, gear pumps, and tube pumps are preferred. Among plunger pumps, multi-phase plunger pumps are more preferable in suppressing flow pulsation.

[0033] The amount of epoxy compound added is preferably 0.01% by mass or more in the resin composition; if it is less than 0.01% by mass, the effect of improving moisture and heat resistance will be reduced. The amount added is more preferably 0.02% by mass or more, and even more preferably 0.03% by mass or more. Furthermore, the preferred upper limit is 1% by mass; if it is higher than this, burning will become severe, and the quality of molded products molded using the resulting polycarbonate resin composition or polyester resin composition pellets will deteriorate. Specifically, the color tone YI of the pellets will increase (turning yellow), and when the pellets are injection molded, discoloration will progress in the molding machine, turning them brown. In some cases, carbonization will occur. If this enters the molded product, it will become black spots and impair the design. In the case of polyester, since it is used in electrical components such as connectors, the carbonized black spots will conduct electricity and significantly impair the performance of the electrical components. The amount of epoxy compound added is more preferably 0.7% by mass or less, even more preferably 0.6% by mass or less, and even more preferably 0.5% by mass or less.

[0034] Epoxy compounds used are those having one or more epoxy groups in one molecule. Specifically, these include phenyl glycidyl ether, allyl glycidyl ether, t-butylphenyl glycidyl ether, 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexyl carboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-3',4'-epoxy-6'-methylcyclohexyl carboxylate, 2,3-epoxycyclohexylmethyl-3',4'-epoxycyclohexyl carboxylate, and 4-(3,4-epoxy-5-methylcyclohexyl)butyl-3',4'-epoxy Xycyclohexyl carboxylate, 3,4-epoxycyclohexylethylene oxide, cyclohexylmethyl 3,4-epoxycyclohexyl carboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-6'-methylsilohexyl carboxylate, bisphenol-A diglycidyl ether, tetrabromobisphenol-A glycidyl ether, diglycidyl ester of phthalate, diglycidyl ester of hexahydrophthalate, bis-epoxydicyclopentadienyl ether, bis-epoxyethylene Lenglycol, bis-epoxycyclohexyl adipate, butadiene diepoxide, tetraphenylethylene epoxide, octyl epoxytalate, epoxidized polybutadiene, 3,4-dimethyl-1,2-epoxycyclohexane, 3,5-dimethyl-1,2-epoxycyclohexane, 3-methyl-5-t-butyl-1,2-epoxycyclohexane, octadecyl-2,2-dimethyl-3,4-epoxycyclohexyl carboxylate, N-butyl-2,2-dimethyl-3,4-epoxycyclohexyl carboxylate Silate, cyclohexyl-2-methyl-3,4-epoxycyclohexyl carboxylate, N-butyl-2-isopropyl-3,4-epoxy-5-methylcyclohexyl carboxylate, octadecyl-3,4-epoxycyclohexyl carboxylate, 2-ethylhexyl-3',4'-epoxycyclohexyl carboxylate, 4,6-dimethyl-2,3-epoxycyclohexyl-3',4'-epoxycyclohexyl carboxylate, 4,5-epoxy tetrahydrophthalic anhydride, 3-t-butyl-4,Preferred examples include 5-epoxy tetrahydrophthalic anhydride, diethyl 4,5-epoxy-cis-1,2-cyclohexyl dicarboxylate, di-n-butyl-3-t-butyl-4,5-epoxy-cis-1,2-cyclohexyl dicarboxylate, epoxidized soybean oil, and epoxidized linseed oil.

[0035] Of these, in the case of polycarbonate resins, alicyclic epoxy compounds are preferably used, with 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexylcarboxylate being particularly preferred. In the case of polyester resins, bisphenol-A diglycidyl ether is preferred.

[0036] At the end of the conveying section is the die section. The die section consists of a flange, a die holder, and a die. Between the flange and the die holder is a ring plate or a breaker plate, and if a breaker plate is used, multiple screen meshes are arranged there. In some cases, the flange is called a hinge plate and the die holder is called a die plate. The die has multiple nozzles from which the resin is extruded in a strand-like form. Typically, the resin composition is spread out in the die holder, and the strands are extruded from the multiple nozzles of the die.

[0037] The rotational speed of the twin-screw extruder's screw is preferably around 200 to 700 rpm.

[0038] The strand-like molten material of the polycarbonate resin composition or polyester resin composition extruded from the die is cooled in water and cut into pellets. There are no particular restrictions on the die shape, and known shapes are used. The inner diameter of the die bore (inner diameter of the die nozzle) is usually around 2 to 5 mm, although this depends on the extrusion pressure and the desired pellet dimensions.

[0039] The raw materials, resins, and additives used in the method of the present invention will be described below.

[0040] [Polycarbonate resin] Examples of polycarbonate resins include aromatic polycarbonate resins, aliphatic polycarbonate resins, and aromatic-aliphatic polycarbonate resins. Preferably, an aromatic polycarbonate resin is used, and specifically, an aromatic polycarbonate polymer or copolymer obtained by reacting an aromatic dihydroxy compound with a phosgene or carbonic acid diester is used.

[0041] Preferred aromatic dihydroxy compounds include 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A), 2,2-bis(3-methyl-4-hydroxyphenyl)propane (i.e., bisphenol C), tetramethylbisphenol A, α,α'-bis(4-hydroxyphenyl)-p-diisopropylbenzene, hydroquinone, resorcinol, and 4,4'-dihydroxydiphenyl.

[0042] Preferred examples of polycarbonate resins include polycarbonate resins in which bisphenol A or bisphenol A is used in combination with other aromatic dihydroxy compounds as the dihydroxy compound, and polycarbonate resins in which bisphenol C or bisphenol C is used in combination with other aromatic dihydroxy compounds (particularly bisphenol A).

[0043] The polycarbonate resin may be a homopolymer consisting of one type of repeating unit, or a copolymer having two or more types of repeating units. In this case, various copolymerization forms such as random copolymers and block copolymers can be selected. The method for producing aromatic polycarbonate resin is not particularly limited and can be conventionally used, such as the phosgene method (interfacial polymerization method) or the melting method (transesterification method).

[0044] While there are no restrictions on the molecular weight of polycarbonate resin, the viscosity-average molecular weight (Mv) is typically around 10,000 to 100,000, preferably around 12,000 to 35,000. By setting the viscosity-average molecular weight above the lower limit of the above range, the mechanical strength of the polycarbonate resin composition can be further improved, making it more preferable for applications requiring high mechanical strength. On the other hand, by setting the viscosity-average molecular weight below the upper limit of the above range, the decrease in fluidity of the polycarbonate resin composition can be suppressed and improved, increasing moldability and facilitating thin-wall molding. Furthermore, two or more polycarbonate resins with different viscosity-average molecular weights may be mixed and used. In this case, polycarbonate resins whose viscosity-average molecular weight is outside the preferred range described above may also be mixed.

[0045] In this invention, the viscosity-average molecular weight (Mv) of the polycarbonate resin is calculated using an Ubbelohde viscometer to determine the viscosity of a methylene chloride solution of the polycarbonate resin at 25°C, thereby obtaining the intrinsic viscosity ([η]), and then using Schnell's viscosity formula. [η] = 1.23 × 10 -4 Mv 0.83

[0046] 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.

[0047] The polycarbonate resin may be made from virgin raw materials or from polycarbonate resin recycled from used products (so-called material-recycled polycarbonate resin). It is also preferable to contain both virgin raw materials and recycled resin, or to consist solely of recycled polycarbonate resin. When using recycled polycarbonate resin, the proportion of recycled polycarbonate resin in the polycarbonate resin is preferably 40% by mass or more, 50% by mass or more, 60% by mass or more, or 80% by mass or more, and may be 100% by mass.

[0048] [Polyester resin] The polyester resin is a thermoplastic polyester resin, and among thermoplastic polyester resins, polybutylene terephthalate resin and polyethylene terephthalate resin are preferred, with polybutylene terephthalate resin being preferred.

[0049] <Polybutylene terephthalate resin> Polybutylene terephthalate resin is a resin obtained by polycondensation of terephthalic acid as the main component of the acid component and 1,4-butanediol as the main component of the diol component. When the main component of the acid component is terephthalic acid, it means that 50% or more by mass of the acid component is terephthalic acid, preferably 60% or more by mass, more preferably 70% or more by mass, and may be 80% or more by mass, 90% or more by mass, or 95% or more by mass. When the main component of the diol component is 1,4-butanediol, it means that 50% or more by mass of the diol component is 1,4-butanediol, preferably 60% or more by mass, more preferably 70% or more by mass, and may be 80% or more by mass, 90% or more by mass, or 95% or more by mass. When polybutylene terephthalate resin contains other acidic components, examples include isophthalic acid and dimer acid. Furthermore, when polybutylene terephthalate resin contains other diol components, examples include polyalkylene glycols such as polytetramethylene glycol (PTMG).

[0050] When using a copolymer of polytetramethylene glycol as the 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. Such copolymerization ratios tend to result in a better balance between laser weldability and heat resistance, which is preferable.

[0051] When using dimer acid copolymerized polybutylene terephthalate as the 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%. Such copolymerization ratios tend to result in an excellent balance of laser weldability, long-term heat resistance, and toughness, which is preferable.

[0052] When using isophthalic acid copolymerized polybutylene terephthalate as the 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%. Such copolymerization ratios tend to result in an excellent balance of laser weldability, heat resistance, injection moldability, and toughness, which is preferable.

[0053] The polybutylene terephthalate resin is preferably a resin (polybutylene terephthalate homopolymer) in which 90% or more by mass of the acid component is terephthalic acid and 90% or more by mass of the diol component is 1,4-butanediol, or a copolymerized polybutylene terephthalate resin obtained by copolymerizing with polytetramethylene glycol, or an isophthalic acid copolymerized polybutylene terephthalate resin.

[0054] The intrinsic viscosity of the polybutylene terephthalate resin is preferably 0.5 dL / g or higher, more preferably 0.6 dL / g or higher, preferably 2.0 dL / g or lower, more preferably 1.5 dL / g or lower, and even more preferably 1.2 dL / g or lower. Using a resin with an intrinsic viscosity of 0.5 dL / g or higher tends to improve the mechanical strength of the resulting molded article. Conversely, using a resin with an intrinsic viscosity of 2 dL / g or lower causes the viscosity of the polybutylene terephthalate resin to increase drastically, making molding difficult. The intrinsic viscosity of polybutylene terephthalate resin is measured at 30°C in a 1:1 (mass ratio) mixed solvent of tetrachloroethane and phenol. If the mixture contains two or more types of polybutylene terephthalate resin, the intrinsic viscosity shall be the intrinsic viscosity of the mixture.

[0055] The amount of terminal carboxyl groups in 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. By limiting the amount of terminal carboxyl groups to 50 eq / ton or less, gas generation during melt molding of polybutylene terephthalate resin can be more effectively suppressed. There is no specific lower limit for the amount of terminal carboxyl groups, but it is usually 5 eq / ton. When two or more types of polybutylene terephthalate resins are included, the amount of terminal carboxyl groups shall be the amount of terminal carboxyl groups in the mixture.

[0056] The amount of terminal carboxyl groups in polybutylene terephthalate resin can be determined by dissolving 0.5 g of polybutylene terephthalate resin in 25 mL of benzyl alcohol and titrating with a 0.01 mol / L benzyl alcohol solution of sodium hydroxide. Methods for adjusting the amount of terminal carboxyl groups include adjusting polymerization conditions such as the raw material ratio, polymerization temperature, and reduced pressure method during polymerization, as well as reacting with end-sealing agents, and any other conventionally known methods.

[0057] <Polyethylene terephthalate resin> Polyethylene terephthalate resin is a resin obtained by polycondensing terephthalic acid as the main component of the acid component and ethylene glycol as the main component of the diol component. When the main component of the acid component is terephthalic acid, it means that 50% by mass or more of the acid component is terephthalic acid, preferably 60% by mass or more, more preferably 70% by mass or more, and may be 80% by mass or more, 90% by mass or more, or 95% by mass or more. When the main component of the diol component is ethylene glycol, it means that 50% by mass or more of the diol component is ethylene glycol, preferably 60% by mass or more, more preferably 70% by mass or more, and may be 80% by mass or more, 90% by mass or more, or 95% by mass or more.

[0058] When polyethylene terephthalate resin contains other acidic components, examples include phthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 4,4'-diphenylsulfondicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-phenylenedioxydiacetic acid and their structural isomers, dicarboxylic acids such as malonic acid, succinic acid, and adipic acid and their derivatives, and oxyacids such as p-hydroxybenzoic acid and glycolic acid or their derivatives. Furthermore, if the polyethylene terephthalate resin contains other acidic components, other diol components may include aliphatic glycols such as 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, pentamethylene glycol, hexamethylene glycol, and neopentyl glycol, alicyclic glycols such as cyclohexanedimethanol, and aromatic dihydroxy compound derivatives such as bisphenol A and bisphenol S.

[0059] Furthermore, the polyethylene terephthalate resin may be copolymerized with a branched component, such as a trifunctional or tetrafunctional acid like tricarbaryl acid, trimellicinic acid, or trimellitic acid, or a trifunctional or tetrafunctional alcohol like pyromellitic acid, at a concentration of 1.0 mol% or less, preferably 0.5 mol% or less, and more preferably 0.3 mol% or less.

[0060] The intrinsic viscosity of the polyethylene terephthalate resin is preferably 0.3 to 1.5 dL / g, more preferably 0.3 to 1.2 dL / g, and even more preferably 0.4 to 0.8 dL / g. The intrinsic viscosity of polyethylene terephthalate resin is measured at 30°C in a 1:1 (mass ratio) mixed solvent of tetrachloroethane and phenol.

[0061] Furthermore, the concentration of terminal carboxyl groups in the polyethylene terephthalate resin is preferably 3 to 60 eq / ton, more preferably 5 to 50 eq / ton, and even more preferably 8 to 40 eq / ton. By setting the terminal carboxyl group concentration to 60 eq / ton or less, gas generation during melt molding of the resin material is reduced, and the mechanical properties of the resulting molded article tend to improve. There is no specific lower limit for the amount of terminal carboxyl groups, but it is usually 3 eq / ton. The concentration of terminal carboxyl groups in polyethylene terephthalate resin can be determined by dissolving 0.5 g of polyethylene terephthalate resin in 25 mL of benzyl alcohol and titrating it with a 0.01 mol / L benzyl alcohol solution of sodium hydroxide.

[0062] [Benzyl alcohol] Benzyl alcohol may be added as an aromatic alcohol to improve the hue of polycarbonate resin molded products. If added, the amount is preferably 0 to 1 part by mass per 100 parts by mass of polycarbonate resin. If the benzyl alcohol content in the polycarbonate resin composition is excessively high, the molded product may become cloudy or its durability against heat and light may deteriorate.

[0063] [Phosphorus stabilizers] It is also preferable to include a phosphorus-based stabilizer. Including a phosphorus-based stabilizer improves the hue of the resin composition and further enhances its resistance to humid and heat discoloration. Any known phosphorus-based stabilizer can be used. Specific examples include phosphorus oxoacids such as phosphoric acid, phosphonic acid, phosphinic acid, phosphinic acid, and polyphosphate; acidic pyrophosphate metal salts such as sodium acidic pyrophosphate, potassium acidic pyrophosphate, and calcium acidic pyrophosphate; phosphates of Group 1 or Group 2 metals such as potassium phosphate, sodium phosphate, cesium phosphate, and zinc phosphate; phosphate compounds, phosphite compounds, and phosphonite compounds, but compounds having a phosphite structure are particularly preferred. By selecting a phosphite compound, a resin composition with higher discoloration resistance and continuous productivity can be obtained.

[0064] Here, a phosphite compound is a trivalent phosphorus compound having a structure represented by the general formula: P(OR)3, where R represents a monovalent or divalent organic group. Examples of such phosphite compounds include triphenyl phosphite, tris(mononylphenyl) phosphite, tris(mononyl / dinonylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, monooctyldiphenyl phosphite, dioctylmonophenyl phosphite, monodecyldiphenyl phosphite, didecylmonophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, distearylpentaerythritol diphosphite, bis(2,4- Examples include di-tert-butyl-4-methylphenyl)pentaerythritol phosphite, bis(2,6-di-tert-butylphenyl)octyl phosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene-diphosphite, and 6-[3-(3-tert-butyl-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]-dioxaphosfepine.

[0065] Among such phosphite compounds, aromatic phosphite compounds represented by the following formulas (1) or (2) are more preferred because they effectively enhance the moisture- and heat-induced discoloration resistance of the resin composition.

[0066] [ka] [In formula (1), R 1 , R 2 and R 3 These may be the same or different, and each represents an aryl group with 6 to 30 carbon atoms.

[0067] [ka] [In formula (2), R 4 and R5 These may be the same or different, and each represents an aryl group with 6 to 30 carbon atoms.

[0068] Among the phosphite compounds represented by the above formula (1), triphenyl phosphite, tris(mononylphenyl) phosphite, and tris(2,4-di-tert-butylphenyl) phosphite are particularly preferred, with tris(2,4-di-tert-butylphenyl) phosphite being more preferred. Specific examples of such organic phosphite compounds include "ADEKA Stab 1178" manufactured by ADEKA, "Sumilyzer TNP" manufactured by Sumitomo Chemical Co., Ltd., "JP-351" manufactured by Johoku Chemical Industry Co., Ltd., "ADEKA Stab 2112" manufactured by ADEKA, "Irgaphos 168" manufactured by BASF, and "JP-650" manufactured by Johoku Chemical Industry Co., Ltd.

[0069] Among the phosphite compounds represented by formula (2) above, those having a pentaerythritol diphosphite structure, such as bis(2,4-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, and bis(2,4-dicumylphenyl)pentaerythritol diphosphite, are particularly preferred. Specific examples of such organic phosphite compounds include, for example, "ADEKA Stab PEP-36" and "ADEKA Stab PEP-24G" manufactured by ADEKA Corporation, and "DoverphosS-9228" manufactured by Doverchemical Corporation.

[0070] Furthermore, the phosphorus-based stabilizer may be present in any combination and ratio, or in any combination of two or more types.

[0071] The amount of phosphorus-based stabilizer added is preferably 0.005 to 0.5 parts by mass, more preferably 0.007 parts by mass or more, even more preferably 0.008 parts by mass or more, particularly preferably 0.01 parts by mass or more, even more preferably 0.4 parts by mass or less, even more preferably 0.3 parts by mass or less, most preferably 0.2 parts by mass or less, and particularly preferably 0.1 parts by mass or less, per 100 parts by mass of polycarbonate resin or polyester resin. If the phosphorus-based stabilizer content is less than 0.005 parts by mass, the effect of further improving hue and resistance to humid and heat discoloration is likely to be insufficient, and if the phosphorus-based stabilizer content exceeds 0.5 parts by mass, resistance to humid and heat discoloration may actually worsen, and humid and heat stability may also decrease.

[0072] <Other stabilizers> The resin composition according to the present invention may contain stabilizers other than phosphorus-based stabilizers (light stabilizers and / or heat stabilizers). Examples of these stabilizers include one or more compounds selected from the group consisting of thioether compounds and hindered phenol compounds. Any conventionally known sulfur atom-containing compound can be used as the thioether compound. Specifically, examples include didodecylthiodipropionate, ditetradecylthiodipropionate, dioctadecylthiodipropionate, pentaerythritol tetrakis(3-dodecylthiopropionate), 2,2-bis{[3-(dodecylthio)-1-oxopropoxy]methyl}propane-1,3-diylbis[3-(dodecylthio)propionate], thiobis(N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickel dibutyldithiocarbamate, nickel isopropylxanthate, and trilauryl trithiophosphite. Among these, 2,2-bis{[3-(dodecylthio)-1-oxopropoxy]methyl}propane-1,3-diylbis[3-(dodecylthio)propionate] is preferred. Commercially available products include "C-NOX 412S" manufactured by Cipro Chemical Co., Ltd. and "ADEKA AO-412S" manufactured by ADEKA Corporation.

[0073] Examples of hindered phenol compounds include pentaerythritol tetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, thiodiethylenebis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), pentaerythritol tetrakis(3-(3,5-di-neopentyl-4-hydroxyphenyl)propionate), and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene. Commercially available options include ADEKA products such as "ADEKA Stub AO-60" and "ADEKA Stub AO-330," and BASF products such as "Irganox Knox 1010." The amount of stabilizers such as thioether compounds and hindered phenol compounds can preferably be 0.01 parts by mass or more per 100 parts by mass of polycarbonate resin or polyester resin. By setting the amount above the lower limit, the effect of suppressing thermal and oxidative degradation of the resin during melt mixing, molding, and use as a molded article tends to be further improved, resulting in improved heat resistance. Furthermore, the upper limit of the amount of stabilizers can preferably be 1 part by mass or less per 100 parts by mass of polycarbonate resin or polyester resin. By setting the amount below the upper limit, adverse effects on appearance and physical properties due to aggregation of additives such as stabilizers tend to be effectively suppressed.

[0074] [Release agent] It is also preferable to include a release agent. Examples of release agents include aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds with a number average molecular weight of 200 to 15,000, and polysiloxane-based silicone oils.

[0075] 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.

[0076] 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" is used as a term that also includes alicyclic compounds.

[0077] 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.

[0078] Furthermore, the above-mentioned esters may contain aliphatic carboxylic acids and / or alcohols as impurities. Also, the above-mentioned 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.

[0079] Specific examples of esters of aliphatic carboxylic acids and alcohols include 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.

[0080] Aliphatic hydrocarbons with a number-average molecular weight of 200 to 15000 include, for example, liquid paraffin, paraffin wax, microwax, 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 also be partially oxidized. Among these, paraffin wax, polyethylene wax, or partially oxidized polyethylene wax are preferred, with paraffin wax and polyethylene wax being more preferred. Furthermore, the number-average molecular weight of the aliphatic hydrocarbons is preferably 5000 or less. Furthermore, while aliphatic hydrocarbons may be single substances, mixtures of substances with varying constituent components and molecular weights can also be used as long as the main component falls within the above-mentioned range.

[0081] Examples of polysiloxane-based silicone oils include dimethyl silicone oil, methylphenyl silicone oil, diphenyl silicone oil, and fluorinated alkyl silicone.

[0082] Furthermore, the above-mentioned release agent may contain one type, or two or more types in any combination and ratio.

[0083] The release agent content is typically 0.001 parts by mass or more, preferably 0.01 parts by mass or more, and typically 2 parts by mass or less, preferably 1 part by mass or less, and more preferably 0.5 parts by mass or less, per 100 parts by mass of polycarbonate resin or polyester resin. If the release agent content is below the lower limit of the above range, the release effect may not be sufficient, and if the release agent content exceeds the upper limit of the above range, a decrease in hydrolysis resistance and mold contamination during injection molding may occur.

[0084] [UV absorber] It is also preferable to include an ultraviolet absorber. Examples of ultraviolet absorbers include inorganic ultraviolet absorbers such as cerium oxide and zinc oxide; and organic ultraviolet absorbers such as benzotriazole compounds, benzophenone compounds, salicylate compounds, cyanoacrylate compounds, triazine compounds, oxanilide compounds, malonic acid ester compounds, and hindered amine compounds. Among these, organic ultraviolet absorbers are preferred, and benzotriazole compounds are more preferred. By selecting an organic ultraviolet absorber, the transparency and mechanical properties of the resin composition of the present invention are improved.

[0085] Specific examples of benzotriazole compounds include, for example, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-[2'-hydroxy-3',5'-bis(α,α-dimethylbenzyl)phenyl]-benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butyl-phenyl)-benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butyl-phenyl)-5-chlorobenzotriazole), and 2-(2'-hydroxy-3',5'-di-ter Examples include t-amyl)-benzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, and 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazole-2-yl)phenol], among which 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole and 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazole-2-yl)phenol] are preferred, and 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole is particularly preferred.

[0086] Specific examples of benzophenone compounds include, for example, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-n-dodecyloxybenzophenone, bis(5-benzoyl-4-hydroxy-2-methoxyphenyl)methane, 2,2'-dihydroxy-4-methoxybenzophenone, and 2,2'-dihydroxy-4,4'-dimethoxybenzophenone.

[0087] Specific examples of salicylate compounds include, for example, phenyl salicylate and 4-tert-butylphenyl salicylate. Specific examples of cyanoacrylate compounds include, for example, ethyl-2-cyano-3,3-diphenyl acrylate and 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate. Specific examples of oxalilide compounds include, for example, 2-ethoxy-2'-ethyl oxalinic acid bisalilide. As for malonic acid ester compounds, 2-(alkylidene) malonic acid esters are preferred, and 2-(1-arylalkylidene) malonic acid esters are more preferred.

[0088] When an ultraviolet absorber is included, its content is usually 0.05 parts by mass or more, preferably 0.1 parts by mass or more, and usually 1 part by mass or less, preferably 0.5 parts by mass or less, per 100 parts by mass of polycarbonate resin or polyester resin. If the content of the ultraviolet absorber is below the lower limit of the above range, the improvement effect on weather resistance and light resistance may be insufficient, and if the content of the ultraviolet absorber exceeds the upper limit of the above range, mold deposits may occur and cause mold contamination. The ultraviolet absorber may be one type, or two or more types may be included in any combination and ratio.

[0089] [Flame retardants, flame retardant enhancers] The resin composition according to the present invention may contain flame retardants or flame retardant additives. Examples of flame retardants include halogen-based flame retardants, phosphorus-based flame retardants (e.g., phosphinate metal salts, polyphosphate melamine), nitrogen-based flame retardants (e.g., cyanurate melamine), metal hydroxides (e.g., magnesium hydroxide), and alkali metal sulfonates. However, phosphorus-based flame retardants and halogen-based flame retardants are preferred. Among phosphorus-based flame retardants, phosphinate metal salts are more preferred. Brominated flame retardants are more preferred as halogenated flame retardants. When using brominated flame retardants, there are no specific requirements regarding the type, but brominated phthalimide, brominated poly(meth)acrylate, brominated polycarbonate, brominated epoxy, and brominated polystyrene, brominated phthalimide, etc., can be used. Further details regarding phosphinate metal salts can be found in paragraphs 0052-0058 of International Publication No. 2010 / 010669, which are incorporated herein by reference. Examples of flame retardant additives include various metal oxide salts, metal sulfate salts, metal silicate salts, metal borate salts, antimony oxide compounds, and silicone compounds. Additionally, fluorine-based compounds are used as drip inhibitors.

[0090] [Additives, etc.] Polycarbonate resin compositions and polyester resin compositions may contain other additives besides those mentioned above, such as antioxidants, fluorescent whitening agents, pigments, dyes, impact modifiers, reinforcing fillers, plasticizers, and compatibilizers. These additives may be present in one or more types. Furthermore, other resins besides polycarbonate resin and polyester resin may be included. Examples of other resins include styrene-based resins such as polystyrene resin, high-impact polystyrene resin (HIPS), and acrylonitrile-styrene copolymer (AS resin); polyolefin resins such as polyethylene resin and polypropylene resin; polyamide resin; polyimide resin; polyetherimide resin; polyurethane resin; polyphenylene ether resin; polyphenylene sulfide resin; polysulfone resin; and polymethacrylate resin. Among the other resins, ABS resin is particularly preferred.

[0091] Various types of reinforcing fillers, such as fibrous, powdered, or plate-shaped fillers, may be included as reinforcing fillers. Examples of fibrous reinforcing fillers include glass fibers, carbon fibers, silica fibers, silica-alumina fibers, zirconia fibers, boron nitride fibers, silicon nitride fibers, boron fibers, potassium titanate fibers, and fibrous materials of metals such as stainless steel, aluminum, titanium, copper, and brass. Glass fibers and carbon fibers are particularly representative fibrous reinforcing fillers.

[0092] Examples of granular reinforcing fillers include carbon black, silica, quartz powder, glass beads, glass powder, calcium silicate, aluminum silicate, kaolin, talc, clay, diatomaceous earth, silicates such as wollastonite, metal oxides such as iron oxide, titanium oxide, zinc oxide, and alumina, metal carbonates such as calcium carbonate and magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, and other materials such as silicon carbide, silicon nitride, boron nitride, and various metal powders. Examples of plate-type reinforcing fillers include mica, glass flakes, and various metal foils. These reinforcing fillers may be used individually or in combination of two or more in any proportion.

[0093] Regarding the location of adding the reinforcing filler to the extruder, it can be added to the raw material feed section at the base of the extruder along with the polycarbonate resin or polyester resin. Alternatively, it can be added using a side feed screw or the like after the polycarbonate resin or polyester resin has melted in the kneading section. In particular, in the case of fibrous reinforcing fillers, adding them after the polycarbonate resin or polyester resin has melted in the kneading section, and then allowing the fibers to be opened in the next kneading section, suppresses fiber breakage and allows for the achievement of high strength.

[0094] The method for producing molded articles from the obtained polycarbonate resin composition or polyester resin composition pellets is not particularly limited, and any molding method commonly used for these resins can be employed, namely, general injection molding, ultra-high-speed injection molding, injection compression molding, multi-color injection molding, gas-assisted injection molding, molding using a heat-insulating mold, molding using a rapidly heating and cooling mold, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating) molding, extrusion molding, sheet molding, thermoforming, rotational molding, lamination molding, press molding, etc.

[0095] The resulting molded products can be applied to electrical and electronic components, home appliance parts, automobile parts, office automation equipment parts, mechanical mechanism parts, building material parts, other precision equipment parts, various containers, etc. [Examples]

[0096] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following examples. The twin-screw extruder used in the following examples and comparative examples was the "TEX44αIII" manufactured by Japan Steel Works, Ltd. (L / D = 38.5, cylinder bore diameter = 47 mm). The die section consisted of a flat die with 19 die holes, each with a hole diameter (inner diameter) of 5 mm and a land length of 16 mm, arranged in a single row horizontally. A ring plate was used, and no screen mesh was employed. For the addition of the epoxy compound, a plunger pump (Fuji Techno Kogyo Co., Ltd. "HYM-03" 3-stage continuous pulsation-free metering pump) was used in Examples 1-2 and Comparative Examples 1-3. For Examples 3-4 and Comparative Examples 4-6, a plunger pump (Fuji Techno Kogyo Co., Ltd. "HYM-06" 3-stage continuous pulsation-free metering pump) was used.

[0097] <Examples 1-2, Comparative Examples 1-3> As the polycarbonate resin, we used polycarbonate resin powder (S-3000F, manufactured by Mitsubishi Engineering Plastics Co., Ltd., viscosity-average molecular weight Mv = 21,500). The epoxy compound used was an alicyclic epoxy compound [3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexylcarboxylate, Daicel Corporation's "CELLOXIDE 2021P", liquid at room temperature, viscosity: 240 mPa·s (25℃), epoxy equivalent: 130 g / eq].

[0098] Example 1 The screw configuration is as shown in Figure 1. The kneading section consists of two R-kneading discs, one N-kneading disc, and one L-kneading disc, positioned between cylinder positions C7 and C8. Each kneading disc has a length of 0.936D (D: inner diameter of the cylinder, 47mm) and five blades (also called discs or paddles). A vacuum vent is located at position C9, and a liquid addition nozzle from a plunger pump for adding epoxy compounds is located at position C10. The distance L from the epoxy compound addition position at C10 to the screw tip was 5.25D. The aforementioned polycarbonate resin at a rate of 299.7 kg / h (99.9%) was fed into the C1 hopper, and 0.3 kg / h (0.1%) of epoxy compound was added at a pressure of 2 MPa through the liquid addition nozzle of the C10 cylinder using a plunger pump. The cylinder temperature was set to 260°C for all cylinders from C2 to C11, as well as for the flange and die holder. The screw rotation speed was set to 300 rpm, and the resin temperature was 316°C. The extrusion process was carried out for 5 hours. After that, a 2 kg pellet sample was taken, and the extrusion process was terminated.

[0099] Using a pellet inspection device (OCS Corporation, "PS-25C"), pellets containing burnt foreign matter were detected in 2 kg of pellets. The pellet inspection device described above can detect burnt foreign matter (brown to black) larger than 50 μm in size within the pellets. Pellets that were discharged after foreign matter was detected were measured for the size of the burnt foreign matter using a "Digital Microscope KH-1300" manufactured by Hirox Corporation. The burnt foreign matter was then categorized into three size groups: 50 μm or more but less than 200 μm (indicated as "500~200" in Tables 1 and 2), 200 μm or more but less than 500 μm (indicated as "200~500" in Tables 1 and 2), and 500 μm or more (indicated as "≧500" in Tables 1 and 2). The number of burnt foreign matter particles is recorded in Table 1. Typically, foreign objects that a person can easily detect with the naked eye are 200 μm or larger. Foreign objects that are easily noticeable at a glance are 500 μm or larger. A circle (○) indicates only foreign objects smaller than 200 μm, a cross (×) indicates foreign objects larger than 500 μm, and a triangle (△) indicates that the largest foreign object is between 200 μm and 500 μm.

[0100] After the extrusion process was complete, the screw was removed and visually inspected. A slight brown discoloration was observed on the tip of the screw downstream of the epoxy compound addition point in C10. However, no burning was observed upstream of C10, specifically in the raw material feed section, conveying section, mixing section, conveying section, and vacuum vent section. Here, "burning" refers to discoloration of brown or black areas.

[0101] Example 2 Extrusion was performed in the same manner as in Example 1, except that the epoxy compound was added from a liquid-addition nozzle positioned at C11. The distance L from the epoxy compound addition position at C11 to the screw tip was 1.75D. The number of burnt foreign objects measured by sampling 2 kg of pellets in the same manner as in Example 1 is shown in Table 1. After sampling 2 kg, pellets A from the rightmost strand, pellet B from the center strand, and pellet C from the leftmost strand were sampled. After the extrusion process was complete, the screw was removed and examined. A slight brown discoloration was observed on the tip of the screw (the flat part at the top of the screw) downstream of the epoxy compound addition point of C11. No burning was observed upstream of C11, i.e., in the raw material feed section, conveying section, mixing section, conveying section, and vacuum vent section.

[0102] The epoxy compound content in pellets A, B, and C was investigated using gas chromatography (GC). The quantitative determination of epoxy compounds by GC was performed using the following method. Each sampled pellet (2.0 g) was dissolved in 20 ml of dichloromethane, and 250 cc of n-hexane was added to the solution to precipitate and remove the polycarbonate resin portion. The soluble components were then subjected to GC analysis using an Agilent "8890 GC System" to quantify the epoxy compounds. Pellet A contained 0.11% by mass of the epoxy compound, Pellet B contained 0.09% by mass, and Pellet C contained 0.10% by mass, and it was confirmed that these compounds were dispersed almost uniformly throughout the strand.

[0103] Comparative Example 1 Extrusion was carried out in the same manner as in Example 1, except that the epoxy compound was added directly from the pump to the hopper section of C1. The results of the pellet inspection are shown in Table 1. After the extrusion was complete, the screw was removed and observed. Brown to black discoloration was observed from the area where the C1 epoxy compound was added to the conveying section and then to the mixing section, and the area from the mixing section to the tip of the screw was discolored brown.

[0104] Comparative Example 2 Extrusion was performed in the same manner as in Example 1, except that the epoxy compound was added from a liquid-addition nozzle positioned at C3. The results of the pellet inspection are shown in Table 1. After the extrusion was complete, the screw was removed and examined. Brown to black discoloration was observed from the area where the C3 epoxy compound was added to the conveying section and then to the mixing section, and the area from the mixing section to the tip of the screw was discolored brown.

[0105] Comparative Example 3 As shown in Figure 2, the extrusion was carried out in the same manner as in Example 1, except that the kneading section was positioned midway between C5 and C6, the vacuum vent was positioned at C7, and the epoxy compound was added from a liquid additive nozzle located midway between C8. The distance L from the epoxy compound addition position at C8 to the screw tip was 12.25D. The results of the pellet inspection are shown in Table 1. After the extrusion was complete, the screw was removed and examined. Brown discoloration was observed not only on the tip of the screw but also on the flank (belly) from the area where the C8 epoxy compound was added to the conveying section and to the screw tip, with the brown color becoming darker (burnt) towards the tip. Brown discoloration was also observed from the mixing section to the screw tip.

[0106] [Table 1]

[0107] <Examples 3-4, Comparative Examples 4-6> Polybutylene terephthalate resin pellets (Novaduran 5020, manufactured by Mitsubishi Chemical Corporation) were used as the polyester resin. The epoxy compound used was bisphenol-A diglycidyl ether [ADEKA "EP17", a highly viscous liquid at room temperature, epoxy equivalent: 185 g / eq].

[0108] Example 3 The screw configuration was the same as in Example 1, as shown in Figure 1. 298.8 kg / h (99.6%) of polybutylene terephthalate resin was fed into the C1 hopper, and 1.2 kg / h (0.4%) of epoxy compound was heated to 70°C to reduce its viscosity and added at a pressure of 2 MPa through the liquid addition nozzle of the C10 cylinder using a plunger pump. The distance from the epoxy compound addition position in C10 to the screw tip was 5.25D. The cylinder temperature was set to 260°C for all cylinders from C2 to C11, as well as the flange and die holder. The screw rotation speed was set to 300 rpm, and the resin temperature was 286°C. The extrusion process was carried out for 5 hours. After that, a 2 kg pellet sample was taken, and the extrusion process was terminated. The results of the pellet inspection, conducted in the same manner as in Example 1, are shown in Table 2. After the extrusion was completed, the screw was removed and visually inspected. A slight brown discoloration was observed on the tip of the screw downstream of the epoxy compound addition point in C10. However, no burning was observed upstream of C10, i.e., in the raw material feed section, conveying section, mixing section, conveying section, and vacuum vent section.

[0109] Example 4 Extrusion was carried out in the same manner as in Example 3, except that the epoxy compound was added from a liquid-addition nozzle positioned at C11. The results of the pellet inspection are shown in Table 2. After sampling 2 kg, we sampled pellet A from the rightmost strand, pellet B from the center strand, and pellet C from the leftmost strand. After the extrusion was complete, the screw was removed and observed. A slight brown discoloration was observed on the tip (top) of the screw downstream of the epoxy compound addition point of C11, but no burning was observed at all upstream of C11, i.e., in the raw material feed section, conveying section, mixing section, conveying section, and vacuum vent section. Each sampled pellet (50 mg) was dissolved in 700 μL of 1,1,2,2-tetrachloroethane at 120°C, and the amount of epoxy compound was quantified by NMR measurement at 120°C using a Bruker AVANCE600. Pellet A contained 0.38% by mass of the epoxy compound, Pellet B contained 0.41% by mass, and Pellet C contained 0.40% by mass, and it was confirmed that these compounds were dispersed almost uniformly throughout the strand.

[0110] Comparative Example 4 Extrusion was carried out in the same manner as in Example 3, except that the epoxy compound was added directly from the pump to the hopper section of C1. The results of the pellet inspection are shown in Table 2. After the extrusion was complete, the screw was removed and observed. Brown to black discoloration was observed from the area where the C1 epoxy compound was added to the conveying section and then to the mixing section, and the area from the mixing section to the tip of the screw was discolored brown.

[0111] Comparative Example 5 The experiment was conducted in the same manner as in Example 3, except that the epoxy compound was added from a liquid-addition nozzle positioned at C3. The results of the pellet inspection are shown in Table 2. After the extrusion was complete, the screw was removed and examined. Brown to black discoloration was observed from the area where the C3 epoxy compound was added to the conveying section and then to the mixing section, and the area from the mixing section to the tip of the screw was discolored brown.

[0112] Comparative Example 6 As shown in Figure 2, the kneading section was positioned midway between C5 and C6, the vacuum vent was placed at C7, and epoxy compound 2 was added from a liquid additive nozzle positioned midway between C8. The procedure was the same as in Example 3. The distance from the epoxy compound addition position at C8 to the screw tip was 12.25D. The results of the pellet inspection are shown in Table 2. After the extrusion was complete, the screw was removed and examined. Brown discoloration was observed not only on the screw tip but also on the flank, from the area where the C8 epoxy compound was added to the conveying section and up to the screw tip. It was confirmed that the brown color became darker (burnt) towards the tip. Brown discoloration was also observed from the mixing section to the screw tip.

[0113] [Table 2] [Industrial applicability]

[0114] According to the method of the present invention, pellets of polycarbonate resin composition or polyester resin composition can be produced that contain epoxy compounds but do not suffer from burning problems. Molded articles formed from the resulting pellets of resin composition have suppressed moisture and heat resistance, and do not suffer from a decrease in optical properties, electrical properties, or mechanical strength. Therefore, they can be widely used in electrical and electronic components, home appliance parts, automobile parts, office automation equipment parts, mechanical mechanism parts, building material parts, other precision equipment parts, various containers, etc., and have very high industrial applicability.

Claims

1. A method for producing pellets of a polycarbonate resin composition or polyester resin composition using an extruder, wherein the extruder is a twin-screw extruder having, in order from upstream to downstream, a raw material feed section, a conveying section, a kneading section, a conveying section, a vacuum vent section, a conveying section, and a die section; the raw material containing polycarbonate resin or polyester resin supplied from the raw material feed section is melt-kneaded in the kneading section, the pressure is reduced in the vacuum vent section to remove volatile components, an epoxy compound is added in the conveying section located downstream thereafter, and the distance from the position where the epoxy compound is added to the tip of the screw is in the range of 1D to 10D (where D is the inner diameter of the extruder cylinder).

2. The manufacturing method according to claim 1, wherein the epoxy compound is added by pump as a liquid epoxy compound at room temperature.

3. The manufacturing method according to claim 1 or 2, wherein the amount of epoxy compound added is in the range of 0.01 to 1% by mass.

4. The manufacturing method according to claim 1 or 2, wherein the polyester resin is polyethylene terephthalate resin or polybutylene terephthalate resin.

Images