JPWO2019155982A1 - Thermoplastic resin composition and molded article formed by molding the thermoplastic resin composition - Google Patents

Abstract

A thermoplastic resin composition containing a semi-aromatic polyamide (A) and a polyphenylene ether (B), wherein the semi-aromatic polyamide (A) contains an aromatic dicarboxylic acid component and a diamine component, and is an aromatic dicarboxylic acid. The main component is terephthalic acid, and the main component is 1,10-decanediamine, 1,11-undecanediamine or 1,12-dodecanediamine, and the semi-aromatic polyamide (A) and polyphenylene ether (B). The mass ratio (A / B) with and to is 15/85 to 85/15, the melting point of the thermoplastic resin composition is 290 ° C. or higher, and the difference between the melting point of the thermoplastic resin composition and the crystallization temperature is A thermoplastic resin composition having a temperature of 30 ° C. or lower.

Description

The present invention relates to a thermoplastic resin composition containing a semi-aromatic polyamide and a polyphenylene ether, and a molded product obtained by molding the thermoplastic resin composition.

Thermoplastic resin compositions containing semi-aromatic polyamides and polyphenylene ethers have excellent heat resistance and low water absorption, and are therefore widely used as exterior materials for automobiles and materials in engine rooms.

Japanese Patent Application Laid-Open No. 63-305650 discloses a thermoplastic resin composition composed of a semi-aromatic polyamide containing 1,6-hexadiamine as a main component of a diamine component and polyphenylene ether. In 2004-083792, International Publication No. 2005/017041, Japanese Patent Application Laid-Open No. 2013-23672, and Japanese Patent Application Laid-Open No. 2011-46781, 1,9-nonanediamine is the main component of the diamine component. A thermoplastic resin composition comprising an aromatic polyamide and a polyphenylene ether is disclosed.

According to Japanese Patent Application Laid-Open No. 2013-23672, since crystallization proceeds in a short time, it is preferable that the difference between the melting point and the crystallization temperature of the thermoplastic polyamide resin constituting the resin composition is 40 ° C. or less. It is described as. However, specifically, only a thermoplastic polyamide resin having a difference of 38 ° C. is used, and the thermoplastic polyamide resin constituting the resin composition has insufficient crystallinity.
Japanese Patent Application Laid-Open No. 2011-46781 discloses that a polyamide resin composition having a difference between a melting point and a crystallization temperature of 33 ° C. or higher is used to improve molding fluidity.

In recent years, with the demand for weight reduction of automobiles, a thermoplastic resin composition containing a semi-aromatic polyamide and polyphenylene ether has been studied as a material for replacing a metal part in an engine room. In this case, the thermoplastic resin composition has a decrease in strength and elastic modulus even in a high temperature environment, specifically, in an environment of 150 ° C. or 200 ° C., while maintaining heat resistance and low water absorption. It is required to be small. However, the thermoplastic resin composition has a problem that the strength and elastic modulus are lowered in a high temperature environment because the crystallinity of the semi-aromatic polyamide resin is low.

In view of the prior art, it is an object of the present invention to provide a thermoplastic resin composition which has high heat resistance and low water absorption, and whose strength and elastic modulus are suppressed to decrease even in a high temperature environment.

As a result of intensive studies to solve the above problems, the present inventors have found that a thermoplastic resin composition containing a specific semi-aromatic polyamide and polyphenylene ether can solve the above problems, and reached the present invention. did.

That is, the gist of the present invention is as follows.
[1] A thermoplastic resin composition containing a semi-aromatic polyamide (A) and a polyphenylene ether (B).
The semi-aromatic polyamide (A) contains an aromatic dicarboxylic acid component and a diamine component,
Aromatic dicarboxylic acid component contains terephthalic acid as the main component
The main component of the diamine is 1,10-decanediamine, 1,11-undecanediamine or 1,12-dodecanediamine.
The mass ratio (A / B) of the semi-aromatic polyamide (A) and the polyphenylene ether (B) is 15/85 to 85/15.
The melting point of the thermoplastic resin composition is 290 ° C. or higher.
A thermoplastic resin composition characterized in that the difference between the melting point and the crystallization temperature of the thermoplastic resin composition is 30 ° C. or less.
[2] The thermoplastic resin composition according to [1], which further contains a crystal nucleating agent (C).
[3] The thermoplastic resin composition according to [1] or [2], which further contains a reinforcing material (D).
[4] The thermoplastic resin composition according to any one of [1] to [3], which further contains a compatibilizer (E).
[5] The thermoplastic resin composition according to any one of [1] to [4], which further contains an impact resistance improving agent (F).
[6] A molded product obtained by molding the thermoplastic resin composition according to any one of the above [1] to [5].

According to the present invention, it is possible to provide a thermoplastic resin composition having high heat resistance and low water absorption, in which a decrease in strength and elastic modulus is suppressed even in a high temperature environment.

The thermoplastic resin composition of the present invention contains a semi-aromatic polyamide (A) and a polyphenylene ether (B).

The semi-aromatic polyamide (A) constituting the thermoplastic resin composition of the present invention contains an aromatic dicarboxylic acid component and a diamine component. In the present invention, the aromatic dicarboxylic acid component of the semi-aromatic polyamide (A) needs to contain terephthalic acid as a main component, and the diamine component is 1,10-decanediamine, 1,11-undecanediamine or It is necessary to have 1,12-dodecanediamine as a main component.

The content of terephthalic acid in the aromatic dicarboxylic acid component is preferably 50 mol% or more, more preferably 60 mol% or more, further preferably 75 mol% or more, and 95 mol% or more. It is particularly preferable to have, and most preferably 100%.

Examples of the dicarboxylic acid component other than terephthalic acid in the semi-aromatic polyamide (A) include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and naphthalenedicarboxylic acid, oxalic acid, malonic acid, succinic acid, glutaric acid and adipic acid. Examples thereof include aliphatic dicarboxylic acids such as acid, pimelic acid, suberic acid, adipic acid, sebacic acid, undecanedioic acid and dodecanedioic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid.

The content of 1,10-decanediamine, 1,11-undecanediamine or 1,12-dodecanediamine in the diamine component of the semi-aromatic polyamide (A) is preferably 50 mol% or more, preferably 60 mol%. The above is more preferable, 75 mol% or more is further preferable, 95 mol% or more is particularly preferable, and 100% is most preferable.

Examples of the diamine component other than 1,10-decanediamine, 1,11-undecanediamine, or 1,12-dodecanediamine in the semi-aromatic polyamide (A) include 1,2-ethanediamine and 1,3-. Propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 2-methyl-1,5-pentanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1 , 9-Nonandiamine, 2-methyl-1,8-octanediamine, 1,13-tridecanediamine, 1,14-tetradecanediamine, 1,15-pentadecanediamine and other aliphatic diamine components, cyclohexanediamine and other alicyclics Examples thereof include formula diamines and aromatic diamines such as xylylene diamine and benzene diamine. The diamine may be linear or branched.

The semi-aromatic polyamide (A) may contain lactams such as caprolactam and laurolactam, and ω-aminocarboxylic acids such as aminocaproic acid and 11-aminoundecanoic acid, if necessary.

Specific examples of the semi-aromatic polyamide (A) include polyamide 10T, polyamide 11T, and polyamide 12T.

The semi-aromatic polyamide (A) preferably contains a monocarboxylic acid component as a constituent component. By containing the monocarboxylic acid, the semi-aromatic polyamide can keep the amount of free amino groups at the ends low, and the decomposition and discoloration of the polyamide due to thermal deterioration and oxidative deterioration when receiving heat can be suppressed. In addition, since the end is hydrophobic, it has low water absorption. As a result, the obtained thermoplastic resin composition has improved heat resistance and low water absorption.

The content of the monocarboxylic acid component is preferably 0.3 to 4.0 mol%, preferably 0.3 to 3.0 mol%, based on all the monomer components constituting the semi-aromatic polyamide (A). It is more preferably present, more preferably 0.3 to 2.5 mol%, and particularly preferably 0.8 to 2.5 mol%. When the content of the monocarboxylic acid component is 0.3 to 4.0 mol%, the semi-aromatic polyamide (A) has a small molecular weight distribution during polymerization, improves releasability during molding, and is molded. The amount of gas generated during processing is suppressed. On the other hand, if the content of the monocarboxylic acid component exceeds 4.0 mol%, the mechanical properties of the semi-aromatic polyamide (A) may deteriorate. In the present invention, the content of the monocarboxylic acid refers to the ratio of the residue of the monocarboxylic acid in the semi-aromatic polyamide (A), that is, the monocarboxylic acid desorbed from the terminal hydroxyl group.

The monocarboxylic acid component is preferably a monocarboxylic acid having a molecular weight of 140 or more, and more preferably a monocarboxylic acid having a molecular weight of 170 or more. By containing a monocarboxylic acid having a molecular weight of 140 or more, the semi-aromatic polyamide (A) has improved mold releasability, can suppress the amount of gas generated at the temperature during molding, and has a molding flow. Improves sex.

Examples of the monocarboxylic acid component include aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, and aromatic monocarboxylic acids. Of these, an aliphatic monocarboxylic acid is preferable because it can reduce the amount of gas generated from the semi-aromatic polyamide-derived component, reduce mold stains, and improve mold releasability. Examples of aliphatic monocarboxylic acids having a molecular weight of 140 or more include caprylic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, and behenic acid, and alicyclic acids having a molecular weight of 140 or more. Examples of the monocarboxylic acid include 4-ethylcyclohexanecarboxylic acid, 4-hexylcyclohexanecarboxylic acid, and 4-laurylcyclohexanecarboxylic acid, and examples of the aromatic monocarboxylic acid having a molecular weight of 140 or more include 4-. Included are ethylbenzoic acid, 4-hexylbenzoic acid, 4-laurylbenzoic acid, 1-naphthoic acid, 2-naphthoic acid and derivatives thereof. The monocarboxylic acid component may be used alone or in combination. Further, a monocarboxylic acid having a molecular weight of 140 or more and a monocarboxylic acid having a molecular weight of less than 140 may be used in combination. In the present invention, the molecular weight of the monocarboxylic acid refers to the molecular weight of the raw material monocarboxylic acid.

The semi-aromatic polyamide (A) in the present invention can be produced by using a conventionally known method of heat polymerization method or solution polymerization method. The heat polymerization method is preferably used because it is industrially advantageous. Examples of the heat polymerization method include a step (i) of obtaining a reaction product from an aromatic dicarboxylic acid component and a diamine component, and a step (ii) of polymerizing the obtained reaction product.

In the step (i), for example, the dicarboxylic acid powder is preheated to a temperature equal to or higher than the melting point of the diamine and lower than the melting point of the dicarboxylic acid, and the dicarboxylic acid powder at this temperature is kept in the state of the dicarboxylic acid powder. , A method of adding a diamine without substantially containing water can be mentioned. Alternatively, a suspension of a molten diamine and a solid dicarboxylic acid is stirred and mixed to obtain a mixture, which is then dicarboxylic at a temperature below the melting point of the semi-aromatic polyamide that is finally produced. Examples thereof include a method of obtaining a mixture of a salt and a low polymer by carrying out a reaction of producing a salt by a reaction of an acid and a diamine and a reaction of producing a low polymer by polymerizing the produced salt. In this case, crushing may be carried out while allowing the reaction, or crushing may be carried out after taking out the reaction once. As the step (i), the former is preferable because the shape of the reaction product can be easily controlled.

In the step (ii), for example, the reaction product obtained in the step (i) is solid-phase polymerized at a temperature lower than the melting point of the semi-aromatic polyamide finally produced to increase the molecular weight to a predetermined molecular weight. , A method of obtaining a semi-aromatic polyamide. Solid-state polymerization is preferably carried out at a polymerization temperature of 180 to 270 ° C. and a reaction time of 0.5 to 10 hours in an inert gas stream such as nitrogen.

The reaction apparatus for the step (i) and the step (ii) is not particularly limited, and a known apparatus may be used. Step (i) and step (ii) may be carried out on the same device or on different devices.

In the production of the semi-aromatic polyamide (A), a polymerization catalyst may be used to increase the efficiency of polymerization. Examples of the polymerization catalyst include phosphoric acid, phosphorous acid, hypophosphorous acid or salts thereof. The amount of the polymerization catalyst added is usually preferably 2.0 mol% or less with respect to all the monomers constituting the semi-aromatic polyamide (A).

The polyphenylene ether (B) used in the present invention is a homopolymer or copolymer containing a repeating structural unit represented by the following formula (1).

In the formula, O represents an oxygen atom, and R ¹ , R ² , R ³ and R ⁴ are independently hydrogen, halogen, primary or secondary C1-C7 alkyl groups, phenyl groups, C1- Represents a C7 haloalkyl group, a C1-C7 aminoalkyl group, a C1-C7 alkoxy group, or a haloalkoxy group (where at least two carbon atoms separate a halogen atom from an oxygen atom).

Examples of the polyphenylene ether include poly (2,6-dimethyl-1,4-phenylene ether), poly (2-methyl-6-ethyl-1,4-phenylene ether), and poly (2-methyl-6-phenyl). -1,4-Phenylene ether), poly (2,6-dichloro-1,4-phenylene ether), and polyphenylene ethers such as copolymers of 2,6-dimethylphenol and other phenols. Polymers can also be mentioned. Of these, a copolymer of poly (2,6-dimethyl-1,4-phenylene ether), 2,6-dimethyl-1,4-phenol and 2,3,6-trimethyl-1,4-phenol is preferable. .. In the copolymer of 2,6-dimethyl-1,4-phenol and 2,3,6-trimethyl-1,4-phenol, 2,3, when the total amount of the polyphenylene ether copolymer is 100% by mass. The content of the structural unit derived from 6-trimethyl-1,4-phenol is preferably 10 to 30% by mass, more preferably 15 to 25% by mass, and 20 to 25% by mass. Is even more preferable.

The polyphenylene ether (B) may be modified with an unsaturated carboxylic acid or a derivative thereof. Specific examples of the unsaturated carboxylic acid include maleic anhydride and the like.

The thermoplastic resin composition of the present invention needs to have a mass ratio (A / B) of semi-aromatic polyamide (A) and polyphenylene ether (B) of 15 / 85-85 / 15, which is 20 /. It is preferably 80 to 80/20, and more preferably 40/60 to 60/40. When the mass ratio is within the above range, the thermoplastic resin composition has an excellent balance between physical properties such as heat resistance, low water absorption, and mechanical properties at high temperature, and processability such as moldability. ..

The thermoplastic resin composition of the present invention needs to have a melting point of 290 ° C. or higher, preferably 300 ° C. or higher, more preferably 305 ° C. or higher, and particularly preferably 310 ° C. or higher. preferable.
Further, the thermoplastic resin composition of the present invention needs to have a difference between the melting point and the crystallization temperature of 30 ° C. or lower, preferably 28 ° C. or lower, and more preferably 25 ° C. or lower. ..
The melting point and crystallization temperature can be measured by a differential scanning calorimeter. The melting point itself or the difference between the melting point and the crystallization temperature is an index indicating the crystallinity of the resin composition, and the higher the melting point or the smaller the difference between the melting point and the crystallization temperature, the higher the resin composition. It can be said that it is crystalline. When the resin composition has high crystallinity, it crystallizes quickly in the temperature lowering process during molding, and the obtained molded product also has a high crystallinity. That is, it becomes easy to obtain a molded product having low water absorption and high heat resistance, high strength and high elastic modulus at high temperature.

The thermoplastic resin composition of the present invention improves the crystallinity of the resin composition, lowers the water absorption rate of the resin composition, and improves heat resistance and mechanical properties at high temperatures. It is preferable to contain C).
Examples of the crystal nucleating agent (C) include inorganic fine particles such as talc, silica, graphite and boron nitride, and metal oxides such as magnesium oxide, aluminum oxide and zinc oxide. Among them, inorganic fine particles such as talc, silica, and boron nitride are preferable, and talc is particularly preferable.
The average particle size of the crystal nucleating agent is preferably 0.1 to 10 μm, more preferably 0.1 to 5 μm, and even more preferably 0.5 to 3 μm.

The content of the crystal nucleating agent (C) in the thermoplastic resin composition is preferably 0 to 5.0% by mass, more preferably 0.2 to 2.0% by mass. When the content of the crystal nucleating agent (C) exceeds 5.0% by mass, the effect of improving the crystallinity is saturated, and the mechanical properties of the thermoplastic resin composition may be deteriorated.

The thermoplastic resin composition of the present invention preferably contains a reinforcing material (D) because it improves mechanical properties.
Examples of the reinforcing material (D) include a fibrous reinforcing material. Examples of the fibrous reinforcing material include glass fiber, carbon fiber, boron fiber, asbestos fiber, polyvinyl alcohol fiber, polyester fiber, acrylic fiber, aramid fiber, polybenzoxazole fiber, kenaf fiber, bamboo fiber, hemp fiber, and bagus fiber. , High-strength polyethylene fiber, alumina fiber, silicon carbide fiber, potassium titanate fiber, brass fiber, stainless steel fiber, steel fiber, ceramics fiber, genbuiwa fiber.
Among them, glass fiber, carbon fiber, and aramid fiber have a high effect of improving mechanical properties, have heat resistance that can withstand the heating temperature during melt-kneading with the semi-aromatic polyamide (A), and are easily available. preferable. Specific examples of glass fibers include "CS3G225S" manufactured by Nitto Boseki Co., Ltd. and "T-781H" manufactured by Nippon Electric Glass Co., Ltd. Specific examples of carbon fibers include "HTA-C6" manufactured by Toho Tenax Co., Ltd. -NR "is mentioned.
The fibrous reinforcing material may be used alone or in combination.

The fiber length and fiber diameter of the fibrous reinforcing material are not particularly limited, but the fiber length is preferably 0.1 to 7 mm, more preferably 0.5 to 6 mm. Since the fiber length of the fibrous reinforcing material is 0.1 to 7 mm, the resin composition can be reinforced without adversely affecting the moldability.
The fiber diameter is preferably 3 to 20 μm, more preferably 5 to 13 μm. Since the fiber diameter is 3 to 20 μm, the resin composition can be efficiently reinforced without breaking during melt kneading.
Examples of the cross-sectional shape of the fibrous reinforcing material include a circular shape, a rectangular shape, an ellipse shape, and other irregular cross-sectional shapes. Among them, a circular shape is preferable.

In the present invention, as the reinforcing material (D), a needle-shaped reinforcing material or a plate-shaped reinforcing material may be used in addition to the fibrous reinforcing material. In particular, by using the fibrous reinforcing material in combination with the needle-shaped reinforcing material or the plate-shaped reinforcing material, it is possible to reduce the warp of the molded product and improve the drip resistance during the flame retardant test. Examples of the needle-shaped reinforcing material include wollastonite, potassium titanate whiskers, zinc oxide whiskers, and magnesium sulfate whiskers. Examples of the plate-shaped reinforcing material include mica and glass flakes.

The reinforcing material (D) is preferably surface-treated with a silane coupling agent or surface-treated with a sizing agent in which the silane coupling agent is dispersed. Examples of the silane coupling agent include vinylsilane-based, acrylicsilane-based, epoxysilane-based, and aminosilane-based silane coupling agents, which obtain an adhesion effect between the semi-aromatic polyamide (A) and the reinforcing material (D). Aminosilane-based silane coupling agents are preferable because they are easy to use.

The content of the reinforcing material (D) in the thermoplastic resin composition is preferably 0 to 60% by mass, and more preferably 1 to 50% by mass because the mechanical strength is improved. Above all, it is more preferably 15 to 50% by mass because the effect of improving the bending strength and the bending elastic modulus becomes larger than the case where the conventional semi-aromatic polyamide is used. When the content of the reinforcing material (D) exceeds 60% by mass, the effect of improving the tree mechanical properties is saturated and no further improvement effect can be expected, and the thermoplastic resin composition has a fluidity. It may be difficult to obtain a molded product due to the extreme decrease.

The thermoplastic resin composition of the present invention may contain a compatibilizer (E) because the compatibility between the semi-aromatic polyamide (A) and the polyphenylene ether (B) is improved. As the compatibilizer, known ones can be used. Examples of the compatibilizer (E) include a polyfunctional compound that chemically or physically interacts with a semi-aromatic polyamide and / or a polyphenylene ether. Examples of the polyfunctional compound include citric acid, maleic acid, itaconic acid and their anhydrides. Of these, maleic anhydride and citric acid are more preferable.

The content of the compatibilizer (E) in the thermoplastic resin composition is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, and 0.1 to 2% by mass. It is more preferably%.

Since the thermoplastic resin composition of the present invention can compensate for the decrease in impact resistance, the impact resistance improving agent (F) may be contained. As the impact resistance improving agent (F), known ones can be used. Examples of the impact resistance improving agent (F) include a block copolymer containing at least one block mainly composed of an aromatic vinyl compound and / or a conjugated diene compound, and a hydrogenated additive of the block copolymer. Examples of the aromatic vinyl compound include styrene, α-methylstyrene and vinyltoluene, and examples of the conjugated diene compound include butadiene, isoprene, piperylene and 1,3-pentadiene. Two or more of these aromatic vinyl compounds and / or conjugated diene compounds may be used in combination.

The content of the impact resistance improving agent (F) in the thermoplastic resin composition is preferably 2 to 25% by mass, more preferably 5 to 20% by mass, and preferably 5 to 15% by mass. More preferred.

The thermoplastic resin composition of the present invention may further contain additives such as stabilizers, colorants, antistatic agents, flame retardants, flame retardants, and carbonization inhibitors, if necessary.
Examples of the colorant include pigments such as titanium oxide, zinc oxide and carbon black, and dyes such as niglosin. Examples of the stabilizer include a hindered phenol-based antioxidant, a phosphorus-based antioxidant, a sulfur-based antioxidant, a light stabilizer, a heat stabilizer made of a copper compound, and a heat stabilizer made of alcohols. Examples of the flame retardant include a brominated flame retardant, a phosphorus flame retardant composed of a metal phosphinic acid salt, and a flame retardant composed of a phosphazene compound. Examples of the flame retardant aid include metal salts such as zinc nitrate, zinc borate, antimony trioxide, antimony pentoxide and sodium antimonate. The carbonization inhibitor is an additive that improves tracking resistance, and examples thereof include inorganic substances such as metal hydroxides and metal borate salts.

Examples of the method for producing the thermoplastic resin composition of the present invention include a semi-aromatic polyamide (A), a polyphenylene ether (B), a crystal nucleating agent (C) added as needed, a reinforcing material (D), and the like. A method of blending an additive or the like and melt-kneading is preferable.

Examples of the melt-kneading method include a method using a batch kneader such as lavender, a Banbury mixer, a Henschel mixer, a helical rotor, a roll, a single-screw extruder, a twin-screw extruder and the like.

Examples of the method of processing the thermoplastic resin composition into various shapes include a method of extruding the molten mixture into a strand shape into a pellet shape, a method of hot-cutting and underwater-cutting the molten mixture into a pellet shape, and a method of forming a pellet shape. Examples thereof include a method of extruding into a sheet and cutting, and a method of extruding into a block and pulverizing to form a powder.

The molded product of the present invention is formed by molding the thermoplastic resin composition of the present invention.
Examples of the method for producing a molded product by molding a thermoplastic resin composition include an injection molding method, an extrusion molding method, a blow molding method, and a sintering molding method. Of these, the injection molding method is preferable because it has a large effect of improving mechanical properties and moldability.

The injection molding machine is not particularly limited, and examples thereof include a screw in-line type injection molding machine and a plunger type injection molding machine. The thermoplastic resin composition heated and melted in the cylinder of an injection molding machine is weighed for each shot, injected into a mold in a molten state, cooled and solidified in a predetermined shape, and then molded as a mold. Taken from. The temperature at which the resin composition is heated and melted during injection molding is preferably equal to or higher than the melting point (Tm) of the semi-aromatic polyamide (A), and more preferably lower than (Tm + 50 ° C.).

The mold temperature during molding is not particularly limited, but if it is set between 150 and 230 ° C., crystallization during molding is particularly likely to proceed, and a molded product containing a thermoplastic resin composition having a high degree of crystallinity is produced. It can be obtained, and by extension, a molded product having excellent heat resistance and low water absorption can be obtained. When the thermoplastic resin composition is heated and melted, it is preferable to use sufficiently dried thermoplastic resin composition pellets. If the amount of water contained is large, the thermoplastic resin composition may foam in the cylinder of the injection molding machine, making it difficult to obtain an optimum molded product. The water content of the resin composition pellets used for injection molding is preferably less than 0.3% by mass, more preferably less than 0.1% by mass.

The thermoplastic resin composition of the present invention has high heat resistance and low water absorption, and since a decrease in strength and elastic modulus in a high temperature environment is suppressed, automobile parts, electrical and electronic parts, miscellaneous goods, industrial equipment parts It can be used as a resin for molding a molded product for a wide range of purposes.
Examples of automobile parts include thermostat members, IGBT module members for inverters, insulators, motor insulators, exhaust finishers, power device housings, ECU housings, PCU housings, motor members, coil members, cable covering materials, and automobile parts. Camera housing, in-vehicle camera lens holder, in-vehicle connector, engine mount, intercooler, bearing retainer, oil seal ring, chain cover, ball joint, chain tensioner, starter gear, reducer gear, transmission gear, electric power steering gear, Examples include an in-vehicle lithium-ion battery tray, an in-vehicle high-voltage fuse housing, and an in-vehicle turbocharger intercooler.
Electrical and electronic components include, for example, connectors, ECU connectors, main ten lock connectors, modular jacks, reflectors, LED reflectors, switches, sensors, sockets, pin sockets, condensers, jacks, fuse holders, relays, coil bobbins, breakers, circuits. Parts, electromagnetic switches, holders, covers, plugs, housing parts for electrical and electronic devices such as portable personal computers and word processors, impellers, vacuum cleaner impellers, resistors, variable resistors, ICs, LED housings, camera housings Body, camera barrel, camera lens holder, tact switch, tact switch for lighting, hair iron housing, hair iron comb, small switch for all mold DC, organic EL display switch, material for 3D printer, bond magnet for motor Materials can be mentioned.
Examples of miscellaneous goods include trays, sheets, and cable ties.
Examples of industrial equipment parts include insulators, connectors, gears, switches, motors, sensors, impellers, and Plarail chains.
Among these applications, it can be particularly preferably used for parts and the like used in the engine room of an automobile.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.

1. 1. Measuring method The characteristics of the thermoplastic resin composition and the molded product were measured and evaluated by the following methods.

(1) Melting point and crystallization temperature Using a differential scanning calorimeter (DSC-7 type manufactured by PerkinElmer), the temperature is raised to 360 ° C at a heating rate of 20 ° C./min, and then held at 360 ° C. for 5 minutes to lower the temperature. The temperature was lowered to 25 ° C. at a rate of 20 ° C./min, held at 25 ° C. for 5 minutes, and then raised again at a rate of temperature rise of 20 ° C./min. The top of the endothermic peak observed at the time of the second temperature rise was defined as the melting point, and the top of the exothermic peak observed at the time of temperature decrease was defined as the crystallization temperature.

(2) Density After the pellets of the obtained thermoplastic resin composition are sufficiently dried, a cylinder temperature (melting point + 15 ° C.) and a mold temperature of 130 ° C. are used using an injection molding machine (S2000i-100B type manufactured by FANUC). , Injection molding was performed under the condition of a molding cycle of 35 seconds to prepare a dumbbell test piece.
Using the obtained dumbbell test piece, the density was measured according to ISO1183.

(3) Deflection temperature under load Using the dumbbell test piece obtained in (3) above, the deflection temperature under load at a load of 1.8 MPa was measured in accordance with ISO75-1 and ISO75-1.

(4) Water absorption rate After the pellets of the obtained thermoplastic resin composition are sufficiently dried, a cylinder temperature (melting point + 15 ° C.) and a mold temperature are used using an injection molding machine (J35-AD manufactured by Japan Steel Works, Ltd.). A 20 mm × 20 mm × 0.5 mm test piece was molded under the conditions of 140 ° C. and a molding cycle of 25 seconds.
The obtained test piece was subjected to a moisture absorption treatment under the conditions of a temperature of 70 ° C. and a relative humidity of 62% in accordance with ISO1110, and was calculated from the mass before and after the moisture absorption treatment using the following formula.
Water absorption rate [%] = (mass after moisture absorption-mass before moisture absorption) / (mass before moisture absorption) x 100

(5) Bending strength and flexural modulus Using the dumbbell test piece obtained in (2) above, the bending strength and flexural modulus were measured in an atmosphere of 23 ° C. in accordance with ISO178. Similarly, bending strength and flexural modulus were measured even in an atmosphere of 150 ° C. and 200 ° C.
The bending strength retention rates at 150 ° C. and 200 ° C. were calculated by dividing the bending strength under the atmosphere of 150 ° C. and 200 ° C. by the bending strength under the atmosphere of 23 ° C., respectively.
Similarly, the flexural modulus retention rates at 150 ° C. and 200 ° C. were calculated by dividing the flexural modulus under the atmosphere of 150 ° C. and 200 ° C. by the flexural modulus under the atmosphere of 23 ° C., respectively.

(6) Charpy impact strength A strip-shaped test piece was cut out from the dumbbell test piece obtained in (2) above, and after notching, a notched Charpy impact in accordance with ISO179-1eA under an atmosphere of 23 ° C. The intensity was measured.

2. 2. Raw Materials The raw materials used in Examples and Comparative Examples are shown below.

(1) Polyamide / semi-aromatic polyamide (A-1)
4.81 kg of powdered terephthalic acid (TPA) as a dicarboxylic acid component, 0.15 kg of stearic acid (STA) as a monocarboxylic acid component, and 9.3 g of sodium hypophosphate monohydrate as a polymerization catalyst. The mixture was placed in a ribbon blender type reactor, sealed with nitrogen, and heated to 170 ° C. with stirring at a rotation speed of 30 rpm. After that, while keeping the temperature at 170 ° C. and the rotation speed at 30 rpm, 5.04 kg of 1,10-decanediamine (DDA) heated to 100 ° C. as a diamine component using a liquid injection device was added to 2 . Addition was carried out continuously (continuous liquid injection method) over 5 hours to obtain a reaction product. The molar ratio of the raw material monomer is TPA: DDA: STA = 49.3: 49.8: 0.9 (the equivalent ratio of the functional groups of the raw material monomer is TPA: DDA: STA = 49.5: 50.0). : 0.5).
Subsequently, the obtained reaction product was polymerized by heating it in the same reactor under a nitrogen stream at 250 ° C. and a rotation speed of 30 rpm for 8 hours to prepare a semi-aromatic polyamide powder.
Then, the obtained semi-aromatic polyamide powder was made into strands using a twin-screw kneader, the strands were passed through a water tank to be cooled and solidified, and the strands were cut with a pelletizer to form semi-aromatic polyamides (A-1). Pellets were obtained.

-Semi-aromatic polyamides (A-2) to (A-5), (A-7)
Semi-aromatic polyamide pellets were obtained in the same manner as the semi-aromatic polyamide (A-1) except that the resin composition was changed as shown in Table 1.

-Semi-aromatic polyamide (A-6)
Semi-aromatic polyamide (A) except that the resin composition is changed as shown in Table 1 and the obtained reaction product is polymerized by heating at 240 ° C. and a rotation speed of 30 rpm for 12 hours under a nitrogen stream. Semi-aromatic polyamide (A-6) pellets were obtained by performing the same operation as in the production method of -1).

Table 1 shows the resin composition and characteristic values of the semi-aromatic polyamides (A-1) to (A-7).

-Alphatic polyamide (A-8): Polyamide 66 (A125J manufactured by Unitika Ltd.), melting point 260 ° C.

(2) Polyphenylene ether B-1: Poly-2,6-dimethyl-1,4-phenylene ether (Noril PPO640 manufactured by SABIC)

(3) Crystal nucleating agent C-1: Talc (SG-2000 manufactured by Japan Talc), average particle size 1 μm
(4) Reinforcing material-D-1: Carbon fiber (HTA-C6-NR manufactured by Toho Tenax Co., Ltd.), average fiber length 6 mm
-D-2: Glass fiber (CS3G225S manufactured by Nitto Boseki Co., Ltd.), average fiber length 3 mm
(5) Compatibility agent (E)
-E-1: Maleic anhydride (reagent)
(6) Impact resistance improver F-1: Hydrogenated block copolymer (Tough Tech H1272 manufactured by Asahi Kasei Chemicals Co., Ltd.)

Example 1
A loss-in weight formula is obtained by dry-blending 58.65 parts by mass of semi-aromatic polyamide (A-1), 10.35 parts by mass of polyphenylene ether (B-1), and 1.0 part by mass of crystal nucleating agent (C-1). Weigh using a continuous fixed quantity supply device (CE-W-1 type manufactured by Kubota) and supply to the main supply port of a biaxial extruder (TEM26SS type manufactured by Toshiba Machine Co., Ltd.) with a screw diameter of 26 mm and L / D50. Then, melt kneading was performed. On the way, 30.0 parts by mass of the reinforcing material (D-1) was supplied from the side feeder, and further melt-kneading was performed. After being taken into a strand shape from the die, it was cooled and solidified by passing it through a water tank, and it was cut with a pelletizer to obtain pellets of a thermoplastic resin composition. The barrel temperature of the extruder was set to (melting point of (A-1) −5 to + 15 ° C.), screw rotation speed of 250 rpm, and discharge rate of 30 kg / h.

Examples 2 to 17, Comparative Examples 1 to 20
Pellets of the resin composition were obtained in the same manner as in Example 1 except that the composition of the thermoplastic resin composition was changed as shown in Tables 2 and 4.

The resin composition of the thermoplastic resin composition and its characteristics are shown in Tables 2-5.

Since the resin compositions of Examples 1 to 17 contain polyamides 10T, 11T, and 12T as semi-aromatic polyamides, they have a lower water absorption rate and a higher deflection temperature under load than those containing polyamides 9T and 6T. It has excellent heat resistance, and the decrease in bending strength and bending elastic modulus is suppressed even in high temperature environments of 150 ° C. and 200 ° C.
In Examples 2 and 5 to 7, the resin composition containing the crystal nucleating agent has lower water absorption, higher deflection temperature under load, higher bending strength at high temperature, higher bending elastic modulus at high temperature, and higher heat resistance. It was excellent.
In Examples 2 and 8 to 10, when the resin composition contains a homopolymer having one dicarboxylic acid component and one diamine component as the semi-aromatic polyamide, the water absorption rate is lower and the deflection temperature under load is higher. It was high, and the bending strength at high temperature and the flexural modulus at high temperature were high.
In Examples 2 to 11-14, the higher the content of the reinforcing material, the higher the deflection temperature under load, the bending strength at high temperature, and the flexural modulus at high temperature, and the resin composition was excellent in heat resistance.
In Examples 13 and 14, when the resin composition contained carbon fibers rather than glass fibers, the deflection temperature under load, the bending strength at high temperature, and the flexural modulus at high temperature were higher, and the resin composition was excellent in heat resistance.
In Examples 2, 15 and 16, the resin composition contained a compatibilizer to have higher bending strength.
In Examples 2 and 17, the Charpy impact strength of the resin composition was higher when the resin composition contained the impact resistance improving agent.

In the resin compositions of Comparative Examples 1 and 2, the mass ratio (A / B) of the semi-aromatic polyamide (A) and the polyphenylene ether (B) deviated from 15 / 85-85 / 15, and the semi-aromatic polyamide was used. Since the content was high, the water absorption rate was high, and 150 ° C. and 200 ° C. were compared with Examples 1 to 3 in which the mass ratio (A / B) was in the range of 15/85 to 85/15. The bending strength retention rate and the bending elastic modulus retention rate were low.
In the resin compositions of Comparative Examples 3 and 4, the mass ratio (A / B) of the semi-aromatic polyamide (A) and the polyphenylene ether (B) was different from 15/85 to 85/15, and the content of the polyphenylene ether was different. The viscosity was too high for melt-kneading.
Since the resin compositions of Comparative Examples 5 to 20 do not meet the requirements specified in the present invention for the composition and content of the semi-aromatic polyamide (A), the bending strength and the bending strength in the high temperature environment of 150 ° C. and 200 ° C. The flexural modulus was lowered, and the water absorption rate was also high.

Claims (6)

A thermoplastic resin composition containing a semi-aromatic polyamide (A) and a polyphenylene ether (B).
The semi-aromatic polyamide (A) contains an aromatic dicarboxylic acid component and a diamine component,
Aromatic dicarboxylic acid component contains terephthalic acid as the main component
The main component of the diamine is 1,10-decanediamine, 1,11-undecanediamine or 1,12-dodecanediamine.
The mass ratio (A / B) of the semi-aromatic polyamide (A) and the polyphenylene ether (B) is 15/85 to 85/15.
The melting point of the thermoplastic resin composition is 290 ° C. or higher.
A thermoplastic resin composition characterized in that the difference between the melting point and the crystallization temperature of the thermoplastic resin composition is 30 ° C. or less. The thermoplastic resin composition according to claim 1, further comprising a crystal nucleating agent (C). The thermoplastic resin composition according to claim 1 or 2, further comprising a reinforcing material (D). The thermoplastic resin composition according to any one of claims 1 to 3, further comprising a compatibilizer (E). The thermoplastic resin composition according to any one of claims 1 to 4, further comprising an impact resistance improving agent (F). A molded product obtained by molding the thermoplastic resin composition according to any one of claims 1 to 5.