JP2014015532A - Semi-aromatic polyamide resin composition and molded article obtained by molding the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide resin composition having excellent creep deformation resistance under high temperature environment.SOLUTION: A resin composition comprises a semi-aromatic polyamide resin (A), a polyarylate resin comprising an isophthalic acid as a main dicarboxylic acid component (B), and fibrous reinforcements (C), the compounding ratio (mass ratio) of (A)-(C) satisfying the following formulas (1) and (2): (A)/(B)=95/5-50/50 (1); and {(A)+(B)}/(C)=100/10-100/160 (2).

Description

  The present invention relates to a semi-aromatic polyamide resin composition having excellent creep deformation resistance under a high temperature environment.

  A resin composition in which a fibrous reinforcing material is blended with a semi-aromatic polyamide resin represented by polyamide 6T and polyamide 9T is excellent in heat resistance and mechanical properties. It is used.

  For example, Patent Documents 1 and 2 disclose resin compositions comprising polyamide 9T, nylon 10T, and fibrous reinforcing materials such as glass fibers, respectively, and Patent Document 3 discloses aromatic dicarboxylic acid and carbon. A resin composition comprising a semi-aromatic polyamide resin composed of a linear aliphatic alkylene diamine of several 6 to 18 and a filler such as a fibrous reinforcing material is disclosed.

JP 7-228769 A JP-A-6-239990 JP 59-53536 A

  However, although the polyamide resin compositions of Patent Documents 1 to 3 have high heat resistance and good mechanical properties such as tensile strength and impact strength, they are inferior in so-called creep deformation resistance when used in a high temperature environment. In the case of being used around a heating element or around an automobile engine, there is a problem that the shape of the molded product is deformed.

  An object of this invention is to provide the polyamide resin composition excellent in the creep deformation resistance in a high temperature environment.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by blending a polyarylate resin with a semi-aromatic polyamide resin containing a fibrous reinforcing material. The invention has been reached. That is, the gist of the present invention is as follows.

(1) A resin composition comprising a semi-aromatic polyamide resin (A), a polyarylate resin (B) containing isophthalic acid as a main dicarboxylic acid component, and a fibrous reinforcing material (C), wherein (A) to (C ) Satisfying the following formulas (1) and (2):
(2) The polyamide resin composition according to (1), wherein the polyarylate resin (B) has a carboxyl value of 30 equivalents / ton or more.
(3) The semi-aromatic polyamide resin (A) comprises a dicarboxylic acid component containing terephthalic acid as a main component and an aliphatic diamine component, and the aliphatic diamine component is 1,8-octanediamine, 1,10-decane. The polyamide resin composition according to (1) or (2), wherein the polyamide resin composition is one or more selected from the group consisting of diamine and 1,12-dodecanediamine.
(4) The polyamide resin composition as described in (3), wherein the aliphatic diamine component of the semi-aromatic polyamide resin (A) is 1,10-decanediamine.
(5) The polyamide resin composition according to any one of (1) to (4), wherein the triamine unit relative to the diamine unit in the semi-aromatic polyamide resin (A) is 0.3 mol% or less.
(6) The polyamide according to any one of (1) to (5), wherein the degree of supercooling measured using a differential scanning calorimeter of the semi-aromatic polyamide resin (A) is 40 ° C. or less. Resin composition.
(7) The polyamide resin composition according to any one of (1) to (6), wherein the fibrous reinforcing material is at least one selected from glass fiber, carbon fiber, and metal fiber.
(8) The polyamide resin composition according to any one of (1) to (7), which has a creep deformation rate of 20% or less.
(9) A molded article obtained by molding the polyamide resin composition according to any one of (1) to (8).

  ADVANTAGE OF THE INVENTION According to this invention, the polyamide resin composition excellent in the creep deformation resistance in high temperature environment can be obtained, and it can use suitably as components around a heat generating body or an engine.

It is the schematic which showed the test method of creep deformation resistance.

  Hereinafter, the present invention will be described in detail.

  The polyamide resin composition of the present invention is composed of a semi-aromatic polyamide resin (A), a polyarylate resin (B), and a fibrous reinforcing material (C).

  The semi-aromatic polyamide resin (A) used in the present invention is composed of an aromatic dicarboxylic acid component and an aliphatic diamine component.

  Examples of the aromatic dicarboxylic acid component include 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, terephthalic acid, isophthalic acid, and phthalic acid. Among them, terephthalic acid is preferable. Terephthalic acid has high chemical structure symmetry, and can improve the crystallinity of the resulting semi-aromatic polyamide resin.

  As the aliphatic diamine component, a linear diamine having 8 to 12 carbon atoms is preferable. By using a linear diamine having a carbon number within the above range, the melting point and crystallinity of the obtained semi-aromatic polyamide resin can be increased. Among linear diamines having 8 to 12 carbon atoms, it is more preferable to use linear diamines having 8, 10, or 12 carbon atoms. In general, a so-called even-odd effect appears in polyamide. That is, when the number of carbon atoms of the monomer unit of the linear diamine component used is an even number, the crystallinity can be further enhanced because a more stable crystal structure is obtained as compared with the case of an odd number. Among linear diamines having 8, 10, and 12 carbon atoms, linear diamines having 10 carbon atoms are preferably used from the viewpoint of versatility. Examples of the linear diamine having 8 to 12 carbon atoms include 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, and 1,12-dodecanediamine.

  As long as the characteristics of the present invention are not impaired, the semiaromatic polyamide resin (A) is copolymerized with a dicarboxylic acid component other than the aromatic dicarboxylic acid component, a diamine component other than the aliphatic diamine component, or a lactam. Also good. Examples of dicarboxylic acid components other than aromatic dicarboxylic acid components include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, etc. And alicyclic dicarboxylic acids such as cycloaliphatic dicarboxylic acid. Examples of the diamine component other than the aliphatic diamine component include alicyclic diamines such as cyclohexanediamine and aromatic diamines such as xylylenediamine. Examples of lactams include ε-caprolactam.

  The weight average molecular weight of the semi-aromatic polyamide resin (A) is preferably 15000 to 50000, more preferably 20000 to 50000, and further preferably 26000 to 50000.

  The semi-aromatic polyamide resin (A) preferably has a sufficiently reduced amount of triamine. The semi-aromatic polyamide resin (A) tends to have a triamine structure as a by-product due to a condensation reaction between diamines during polymerization. When the amount of triamine is large, a crosslinked structure is formed in the molecular chain, and the crosslinked structure restricts the movement and arrangement of the molecular chain, so that the crystallinity is lowered. Further, when the amount of triamine is large, a large amount of gel is generated, so that when the polyamide resin composition of the present invention is formed into a molded body, it may become a cause of damage to the surface appearance as fish eyes or lumps. Therefore, the triamine unit contained in the semi-aromatic polyamide resin (A) is preferably 0.3 mol% or less of the diamine unit, and more preferably 0.2 mol% or less. When the triamine structure in the semi-aromatic polyamide resin (A) exceeds 0.3 mol% of the diamine unit, the crystallinity is deteriorated or the surface smoothness of the molded product obtained by gel generation is impaired. There is.

  The semi-aromatic polyamide resin (A) preferably has a crystallization rate controlled within a specific range. The crystallization speed in the present invention can be determined by using the degree of supercooling measured using a differential scanning calorimeter (DSC) as an index. In the present invention, the degree of supercooling is preferably 40 ° C. or less, and more preferably 35 ° C. or less. When the degree of supercooling exceeds 40 ° C., the crystallinity cannot be sufficiently increased, and the creep deformation resistance may not be improved. In the present invention, the degree of supercooling is the difference between the melting point of the semi-aromatic polyamide resin (A) and the cooling crystallization temperature. The smaller the degree of supercooling, the faster the crystallization from the polymer molten state. In order to set the degree of supercooling to 40 ° C. or less, in the semi-aromatic polyamide resin (A), the copolymer component other than the aromatic dicarboxylic acid component and the aliphatic diamine component is 0 to 5 mol%, Thus, it is preferable that the triamine unit with respect to the diamine unit in a semi-aromatic polyamide resin (A) shall be 0.3 mol% or less.

  The semi-aromatic polyamide resin (A) can be produced by a conventionally known method such as a heat polymerization method or a solution polymerization method as a method for producing a polyamide. Of these, the heat polymerization method is preferably used because it is industrially advantageous. Examples of the heat polymerization method include a melt polymerization method, a melt extrusion method, and a solid phase polymerization method. The semi-aromatic polyamide resin (A) has a high melting point of 280 to 340 ° C. and is close to the decomposition temperature. Therefore, the melt polymerization method and the melt extrusion method in which the reaction is performed at a temperature equal to or higher than the melting point of the produced polymer may deteriorate the product quality. Therefore, a solid phase polymerization method in which the reaction is performed at a temperature below the melting point of the produced polymer is preferable.

  In general, the production of the semi-aromatic polyamide resin (A) often includes a step (i) of obtaining a reactant such as a nylon salt from a monomer and a step (ii) of polymerizing the reactant. In the present invention, in order to obtain a semi-aromatic polyamide resin in which the triamine unit is 0.3 mol% or less of the diamine unit, the step of step (i) is performed under the condition that there are few moisture and solvent in the polymerization system, It is preferable that the amount of water is 5 parts by mass or less with respect to 100 parts by mass of the total of dicarboxylic acid and diamine.

  As the step (i), for example, dicarboxylic acid powder and monocarboxylic acid are heated in advance to a temperature not lower than the melting point of diamine and not higher than the melting point of dicarboxylic acid, and at a temperature not lower than the melting point of diamine and not higher than the melting point of dicarboxylic acid. In order to maintain the state of the powder, a method of adding diamine to the dicarboxylic acid powder and the monocarboxylic acid without substantially containing water can be mentioned. Alternatively, as another method, a suspension of a molten diamine and solid terephthalic acid is stirred and mixed to obtain a mixed solution, and then at a temperature lower than the melting point of the semi-aromatic polyamide resin to be finally produced. And a method of producing a salt by reacting terephthalic acid, diamine and monocarboxylic acid and producing a low polymer by polymerization of the salt to obtain a mixture of the salt and the low polymer. In this case, crushing may be performed while the reaction is performed, or crushing may be performed after the reaction is once taken out. As the step (i), the former is preferable because the shape of the reactant can be easily controlled.

  As 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 finally produced polyamide resin to increase the molecular weight to a predetermined molecular weight, and the polyamide resin is obtained. It is the process of obtaining. The solid phase polymerization is preferably performed in a stream of inert gas such as nitrogen at a polymerization temperature of 180 to 270 ° C. and a reaction time of 0.5 to 10 hours.

  In the production of the semi-aromatic polyamide resin (A), a polymerization catalyst for increasing the efficiency of polymerization, an adjustment of the degree of polymerization, a terminal blocking agent for suppressing thermal decomposition and coloring can be used. Examples of the polymerization catalyst include phosphoric acid, phosphorous acid, hypophosphorous acid, and salts thereof. The addition amount of a polymerization catalyst is 0-2 mol% normally with respect to the total mole of dicarboxylic acid and diamine. Examples of the terminal blocking agent include monocarboxylic acids such as acetic acid, lauric acid and benzoic acid, and monoamines such as octylamine, cyclohexylamine and aniline. These may be used alone or in combination. The amount of the end-capping agent added is usually 0 to 5 mol% with respect to the total moles of terephthalic acid and diamine.

  The polyarylate resin (B) used in the present invention is composed of an aromatic dicarboxylic acid component and a dihydric phenol component. However, the polyarylate resin (B) used in the present invention does not include a so-called liquid crystalline polymer having a mesogenic group.

  In the aromatic dicarboxylic acid component, isophthalic acid (hereinafter sometimes abbreviated as “IPA”) is preferably contained in an amount of 80 mol% or more, more preferably 90 mol%, more preferably 100%. More preferably. By making IPA 80 mol% or more, creep deformation resistance can be improved. Examples of dicarboxylic acid components other than IPA include terephthalic acid, isophthalic acid, phthalic acid, chlorophthalic acid, nitrophthalic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, methyl terephthalic acid, 4,4′-biphenyl dicarboxylic acid, 2,2′-biphenyl dicarboxylic acid, 4,4′-diphenyl ether dicarboxylic acid, 4,4′-diphenylmethane dicarboxylic acid, 4, Examples include 4′-diphenylsulfone dicarboxylic acid, 4,4′-diphenylisopropylidenedicarboxylic acid, 1,2-bis (4-carboxyphenoxy) ethane, and 5-sodium sulfoisophthalic acid.

  Examples of the dihydric phenol component include resorcinol, 1,1-bis (4-hydroxyphenyl) ethane, 2,2- (4-hydroxyphenyl) butane, 2,2,-(4-hydroxyphenyl) -4- Methylpentane, 2,2-bis (4-hydroxyphenyl) propane (hereinafter sometimes abbreviated as “BPA”), 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2 , 2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) ) Propane, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenylsulfur 4,4′-dihydroxydiphenyl ketone, 4,4′-dihydroxydiphenylmethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 3,3,5-trimethyl-1,1-bis (4-hydroxyphenyl) cyclohexane is mentioned, and BPA is preferable because of its high versatility. These compounds may be used alone or in combination.

  In the dihydric phenol component, when BPA is used, BPA is preferably contained in an amount of 80 mol% or more, more preferably 90 mol%, and even more preferably 100%. By making BPA 80 mol% or more, creep deformation resistance can be improved.

  Inherent viscosity measured under conditions of a concentration of 1 g / dL and a temperature of 25 ° C. using a mixed liquid of polyarylate resin (B) in phenol / 1,1,2,2-tetrachloroethane = 60/40 (mass ratio) Is preferably 0.42 or more, more preferably 0.42 to 0.75, and still more preferably 0.42 to 0.65. By setting the inherent viscosity to 0.42 or more, a resin composition having good mechanical properties can be obtained.

  The carboxyl value of the polyarylate resin (B) is preferably 30 equivalent / ton or more, more preferably 40 equivalent / ton or more, and further preferably 70 equivalent / ton or more. The carboxyl value of the polyarylate resin (B) is derived from the terminal carboxylic acid and the carboxylic anhydride bond formed by the side reaction. By setting the carboxyl value to 30 equivalents / ton or more, it is possible to suppress a decrease in mechanical properties when the polyarylate resin (B) is added to the semi-aromatic polyamide resin (A).

  The production method of the polyarylate resin (B) is not particularly limited, and examples thereof include melt polymerization, solution polymerization, and interfacial polymerization. Among these, melt polymerization is preferable. When the polyarylate resin is polymerized by solution polymerization or interfacial polymerization, depending on the mixing ratio of terephthalic acid and isophthalic acid, the polyarylate resin is precipitated from the solvent, so the mixing ratio is limited. In contrast, when the polyarylate resin is polymerized by the melt polymerization method, it can be polymerized regardless of the mixing ratio of terephthalic acid and isophthalic acid.

  As a melt polymerization method of the polyarylate resin (B), the aromatic dicarboxylic acid and the dihydric phenol component can be combined and produced by a known method. Specific examples include a method comprising an acetylation reaction, an esterification reaction and a polycondensation reaction.

  In the acetylation reaction, a dihydric phenol component and acetic anhydride are charged into a reaction vessel, and then purged with nitrogen and reacted in an inert atmosphere to obtain an acetylated product. The molar ratio of acetic anhydride to the dihydric phenol component is preferably 1.00 to 2.00. The reaction temperature is preferably 100 to 160 ° C, more preferably 130 to 150 ° C. The reaction time is preferably 1 to 5 hours.

  In the esterification reaction, an acetylated product and an aromatic dicarboxylic acid component are reacted to obtain a low polymer. The reaction temperature is preferably 180 to 240 ° C, more preferably 200 to 220 ° C. The reaction temperature is preferably raised gradually as the reaction proceeds. The reaction time is preferably 0.5 to 5 hours, more preferably 1 to 2 hours.

  In the polycondensation reaction, the acetic acid component is distilled off from the low polymer obtained by the esterification reaction under reduced pressure until the desired molecular weight is reached. The reaction temperature is preferably 290 to 350 ° C, more preferably 320 to 340 ° C. The reaction temperature is preferably raised gradually as the reaction proceeds. The degree of vacuum is preferably 130 Pa or less, and more preferably 100 Pa or less. It is preferable that the pressure is gradually reduced over 1 to 3 hours until reaching a predetermined degree of pressure reduction from atmospheric pressure.

  In the acetylation reaction, esterification reaction and polycondensation reaction, a catalyst can be used as necessary. Catalysts include organic titanate compounds such as tetrabutyl titanate, alkali metals such as zinc acetate and magnesium acetate, acetates of alkaline earth metals, organotin compounds such as antimony trioxide, hydroxybutyltin oxide, and tin octylate. Can be mentioned. The amount of the catalyst used is preferably 1.0% by mass or less with respect to the mass of the resin produced.

  The blending ratio {(A) / (B)} (mass ratio) of the semi-aromatic polyamide resin (A) and the polyarylate resin (B) needs to be in the range of 95/5 to 50/50. 90/10 to 55/45, and more preferably 85/15 to 60/40. When the blending ratio of (A) exceeds 95% with respect to the total of (A) and (B), the effect of improving the creep deformation resistance becomes poor, which is not preferable. On the other hand, when the blending ratio of (A) is less than 50% with respect to the total of (A) and (B), the original mechanical properties of the semi-aromatic polyamide resin (A) are greatly deteriorated, which is not preferable.

  The semi-aromatic polyamide resin (A) and the polyarylate resin (B) used in the present invention can both be obtained in powder form. Powdered (A) and (B) are easy to mix as compared with the case of mixing pellets.

  In the present invention, by adding a fibrous reinforcing material (C) to the semi-aromatic polyamide resin (A) and the polyarylate resin (B), the heat resistance and mechanical properties are improved, and the creep deformation resistance is improved. The property can be further improved.

  Examples of the fibrous reinforcing material (C) used in the present invention include carbon fiber, glass fiber, boron fiber, asbestos fiber, polyvinyl alcohol fiber, polyester fiber, acrylic fiber, wholly aromatic polyamide fiber, polybenzoxazole fiber, poly Tetrafluoroethylene fiber, kenaf fiber, bamboo fiber, hemp fiber, bagasse fiber, high strength polyethylene fiber, alumina fiber, silicon carbide fiber, potassium titanate fiber, brass fiber, stainless steel fiber, steel fiber, ceramic fiber, basalt fiber In view of heat resistance and versatility, glass fiber, carbon fiber and metal fiber are preferable. In addition, when using glass fiber and carbon fiber, it is preferable that it is surface-treated with a silane coupling agent. Examples of the silane coupling agent include a vinyl silane coupling agent, an acrylic silane coupling agent, an epoxy silane coupling agent, and an amino silane coupling agent, and have an adhesion effect with a polyamide resin or a polyarylate resin. Therefore, an aminosilane coupling agent is more preferable. These fibrous reinforcing materials may be used alone or in combination.

  The fiber length of the fibrous reinforcing material (C) is preferably 0.1 to 7 mm, and more preferably 0.5 to 6 mm. By setting the fiber length of the fibrous reinforcing material (C) to 0.1 to 7 mm, the mechanical properties can be further improved. Moreover, it is preferable that the fiber diameter of a fibrous reinforcement (C) shall be 3-20 micrometers, and it is more preferable to set it as 5-13 micrometers. By setting the fiber diameter of the fibrous reinforcing material (C) to 3 to 20 μm, mechanical properties can be improved without breaking during melt-kneading. Moreover, as a cross-sectional shape of a fibrous reinforcement (C), a circular cross section, a rectangle, an ellipse, and other irregular cross sections can be mentioned, for example, Among these, a circular cross section is preferable.

  In the resin composition of the present invention, the content of the fibrous reinforcing material (C) is 10 to 160 parts by mass with respect to a total of 100 parts by mass of the semi-aromatic polyamide resin (A) and the polyarylate resin (B). It is necessary, and it is preferable to set it as 15-130 mass parts, and it is more preferable to set it as 20-100 mass parts. When the content of the fibrous reinforcing material (C) is less than 10 parts by mass, the effect of improving the creep deformation resistance is poor, which is not preferable. On the other hand, when the content of the fibrous reinforcing material (C) exceeds 160 parts by mass, workability during melt-kneading is lowered, and it is difficult to obtain pellets of the resin composition, which is not preferable.

  The method for blending the fibrous reinforcing material (C) is not particularly limited as long as the reinforcing effect is obtained, but melt kneading using a biaxial kneader is preferably used. The kneading temperature is preferably not less than the melting point (Tm) of the semi-aromatic polyamide resin (A) and preferably less than (Tm + 100 ° C.). If the kneading temperature is less than Tm, the kneader is overloaded, and problems such as vent-up may occur. If the kneading temperature is too high, the semi-aromatic polyamide resin (A) may be colored by heat. The method for collecting the obtained polyamide resin composition is not particularly limited, but it is preferable to produce a strand and pelletize it in consideration of subsequent molding.

  The resin composition of the present invention is particularly preferably used in molding applications, and a molded product can be obtained by a usual molding method. Examples of the molding method include injection molding, extrusion molding, blow molding, and sintering molding. Among these, the injection molding method is preferable because mechanical characteristics and molding processability can be sufficiently improved. Although it does not specifically limit as an injection molding machine, For example, a screw in-line type injection molding machine or a plunger type injection molding machine is mentioned. The resin composition heated and melted in the cylinder of the injection molding machine is weighed for each shot, injected into the mold in a molten state, cooled and solidified in a predetermined shape, and then taken out from the mold as a molded body. It is. The resin temperature at the time of injection molding is preferably Tm or more and less than (Tm + 100 ° C.). In the molding process of the resin composition of the present invention, it is preferable to use sufficiently dried resin composition pellets. If the amount of water contained is large, the resin foams in the cylinder of the injection molding machine, making it difficult to obtain an optimal molded product, and the polyarylate resin (B) has a low molecular weight due to hydrolysis, resulting in mechanical properties. May decrease. The moisture content of the resin composition pellets of the present invention used for injection molding is preferably less than 0.05% by mass and more preferably less than 0.03% by mass in 100% by mass of the resin composition. The mold temperature at the time of injection molding needs to be kept below the glass transition temperature (Tg) of the polyarylate resin (B), and is preferably less than (Tg-30 ° C), and less than (Tg-50 ° C). It is more preferable that If the mold temperature exceeds the Tg of the polyarylate resin (B), the resin composition may not be sufficiently solidified when the molded product is released from the mold, and may be deformed. The mold temperature is the actual temperature of the mold dividing surface, and is adjusted using a mold temperature controller so that this portion is within the above temperature range. You may circulate a refrigerant | coolant in a metal mold | die as needed.

  You may add additives, such as another filler and a stabilizer, to the resin composition of this invention as needed. These additives may be added during the polymerization of the semi-aromatic polyamide resin (A), or the semi-aromatic polyamide resin (A) and the polyarylate resin (B) may be added during melt kneading. Examples of additives include fillers such as talc, swellable clay minerals, silica, alumina, glass beads and graphite, pigments such as titanium oxide and carbon black, antioxidants, antistatic agents, flame retardants, and flame retardant aids. Agents.

  In the present invention, by setting the degree of supercooling of the semi-aromatic polyamide resin (A) to 40 ° C. or less, the crystallization speed of the resin composition is increased, and the molding cycle, particularly in the injection molding, is shortened. Can contribute to the reduction of the molding cost.

  The molding cycle refers to the time from the start of the injection of the first shot of the molded body to the start of the injection of the second shot of the molded body when continuously molded under the same injection conditions. That is, it refers to the time required to mold one molded body (total of injection time + cooling time + removal time). The shortening of the molding cycle means a shortening of the cooling time during the time required for molding the one molded body.

  The resin composition of the present invention can be used in a wide range of applications such as automobile parts, electrical and electronic parts, sundries, and civil engineering and building supplies.

  Examples of automotive parts include engine covers, air intake manifolds, throttle bodies, air intake pipes, radiator tanks, radiator supports, radiator hoses, radiator grills, timing belt covers, water pump renlets, water pump outlets, cooling fans, fans Engine peripheral parts such as shroud, engine mount, propeller shaft, stabilizer bar linkage rod, accelerator pedal, pedal module, seal ring, bearing retainer, gear and other mechanical parts, oil pan, oil filter housing, oil filter cap, oil level gauge , Fuel tank, fuel tube, fuel cutoff valve, canister, fuel delivery pipe, Fuel filler neck, fuel sender module, fuel and piping system parts such as fuel piping joints, wire harnesses, relay blocks, sensor housings, encapsulation, ignition coils, distributors, thermostat housings, quick connectors, lamp reflectors , Lamp housing, lamp extension, electric parts such as lamp socket, rear spoiler, wheel cover, wheel cap, cowl vent grill, air outlet louver, air scoop, hood bulge, fender, back door, shift lever housing, window regulator Various interior and exterior parts such as door locks, door handles, and outside door mirror stays can be mentioned.

  Examples of the electrical and electronic parts include connectors, LED reflectors, switches, sensors, sockets, capacitors, jacks, fuse holders, relays, coil bobbins, resistors, ICs, LEDs, and housings.

  Examples of miscellaneous goods include a watch housing, a fastener, and a screw.

  Among them, since the resin composition of the present invention is excellent in creep deformation resistance under high temperature environment, the engine cover, the air intake manifold, the throttle body, the air intake pipe, the radiator tank, the radiator support, the radiator hose, and the radiator grille. It can be suitably used as a component around a heating element such as an engine periphery such as a timing belt cover, a water pump renlet, a water pump outlet, a cooling fan, a fan shroud, and an engine mount, and an LED reflector.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited by these. The physical properties were measured by the following method.

1. Measurement Method (1) Relative Viscosity of Polyamide Resin A polyamide resin was dissolved in 96% by mass sulfuric acid to prepare a sample solution having a concentration of 1 g / dL. Subsequently, the drop time of the sample solution and the solvent was measured at a temperature of 25 ° C. using an Ubbelohde viscometer, and the relative viscosity was determined using the following equation.
Relative viscosity = (Drop time of sample solution / Drop time of solvent only) / Resin concentration (g / dL)
(2) Weight average molecular weight of polyamide resin Using a gel permeation chromatography apparatus manufactured by Tosoh Corporation, GPC analysis was performed on a sample solution prepared under the following conditions, and then polymethyl methacrylate (manufactured by Polymer Laboratories) was prepared as a standard sample. The weight average molecular weight was determined using a calibration curve.
<Sample preparation>
2 mL of 10 mM sodium trifluoroacetate-containing hexafluoroisopropanol was added to 5 mg of polyamide resin and dissolved, followed by filtration with a disk filter.
<Conditions>
・ Detector: Differential refractive index detector RI-8010 (manufactured by Tosoh Corporation)
・ Eluent: Hexafluoroisopropanol containing 10 mM sodium trifluoroacetate ・ Flow rate: 0.4 mL / min ・ Temperature: 40 ° C.

(3) Decreasing crystallization temperature, melting point, and degree of supercooling of polyamide resin After heating up to 350 ° C. at a heating rate of 20 ° C./min using a differential scanning calorimeter DSC-7 manufactured by PerkinElmer, 350 ° C. The temperature giving the top of the exothermic peak when the temperature is lowered to 25 ° C. at a temperature decrease rate of 20 ° C./min is maintained at 5 ° C., and the temperature is increased again at a temperature increase rate of 20 ° C./min. The top of the endothermic peak when the temperature rise measurement was performed with the melting point. The difference between the melting point and the cooling crystallization temperature was defined as the degree of supercooling.
(4) Determination of triamine in polyamide resin 3 mL of 47% hydrobromic acid is added to 10 mg of polyamide resin, heated at 130 ° C. for 20 hours, evaporated to dryness, and further dried under reduced pressure at 80 ° C. for 2 hours. To this, 2 mL of pyridine and 1 mL of N, O-bis (trimethylsilyl) trifluoroacetamide are added and heated at 90 ° C. for 30 minutes. After cooling, the solution filtered with a membrane filter was analyzed with a gas chromatography apparatus equipped with a mass spectrometer. Using a calibration curve obtained from diamine and triamine as standard substances separately measured, diamine and triamine in the polyamide resin were quantified, and the molar ratio of triamine to diamine was calculated. As a triamine standard substance, a triamine compound obtained by reacting diamine with heating and stirring at 240 ° C. for 3 hours in an autoclave using palladium oxide as a catalyst was used.

(5) Inherent viscosity of polyarylate resin Polyarylate resin was dissolved in phenol / 1,1,2,2-tetrachloroethane (6/4 (mass ratio)) to prepare a sample solution having a concentration of 1 g / dL. Subsequently, the drop time of the sample solution and the solvent was measured at a temperature of 25 ° C. using an Ubbelohde viscometer, and the inherent viscosity was determined using the following equation.
Inherent viscosity = ln [(dropping time of sample solution / falling time of solvent only) / resin concentration (g / dL)]
(6) Carboxyl value of polyarylate resin 0.15 g of polyarylate resin was precisely weighed and dissolved in 5 mL of benzyl alcohol by heating. Furthermore, after mixing 10 mL of chloroform, phenol red was added as an indicator, and neutralization titration was performed with a 0.1 NKOH benzyl alcohol solution while stirring to obtain a carboxyl value.

(7) Tensile Strength and Tensile Breaking Elongation of Resin Composition The polyamide resin composition was injection molded using an injection molding machine EC100 manufactured by Toshiba Machine Co., Ltd. to produce a dumbbell test piece having a width of 10 mm and a thickness of 4 mm. In Examples 1 to 19 and Comparative Examples 1 to 3 and 7 to 11, the cylinder temperature was 340 ° C. and the mold temperature was 130 ° C. In Comparative Examples 5 and 6, the cylinder temperature was 280 ° C and the mold temperature was 100 ° C.
Using the obtained test piece, the tensile strength and the tensile elongation at break were measured according to ISO 527.

(8) Creep Deformation Rate of Resin Composition The polyamide resin composition was injection molded using an injection molding machine EC100 manufactured by Toshiba Machine Co., Ltd. to produce a dumbbell test piece having a width of 10 mm and a thickness of 4 mm. In Examples 1 to 19 and Comparative Examples 1 to 3 and 7 to 11, the cylinder temperature was 340 ° C. and the mold temperature was 130 ° C. In Comparative Examples 5 and 6, the cylinder temperature was 280 ° C and the mold temperature was 100 ° C.
Using the obtained test piece, the thickness h was measured by placing the test piece on four columnar restraining jigs arranged horizontally (FIG. 1A). Next, the test piece was fixed to the restraining jig in a bent state, and the height y of the central part of the test piece was measured from the restraining jig (FIG. 1B). Thereafter, the test piece was placed in a constant temperature hot air oven at 80 ° C., subjected to heat treatment for 24 hours, and then taken out, and the two outer restraining jigs were removed (FIG. 1C). After standing for 1 week at room temperature, the height k at the center of the test piece was measured from the restraining jig, and the creep deformation rate was calculated by the following equation.
Creep deformation rate (%) = displacement amount after restraint release / displacement amount when restraint × 100 = (k−h) / (y−h) × 100
Generally, if a plastic material continues to be elastically deformed, it will creep and will not return to its original shape. Good creep deformation resistance means that the creep deformation rate calculated by the above equation is small. Practically, it is preferably 20% or less.

2. Raw materials The raw materials used in Examples and Comparative Examples are shown below.
<Semi-aromatic polyamide resin (A)>
A semi-aromatic polyamide resin synthesized by the following method was used.
Semi-aromatic polyamide resin (A-1)
[Step (i)]
1,10-decanediamine (5050 parts by mass) as a diamine component, powdered terephthalic acid (4870 parts by mass), benzoic acid (72 parts by mass) as a terminal blocking agent, and sodium hypophosphite monohydrate ( (6 parts by mass) was put in an autoclave, heated to 100 ° C., stirred using a double helical stirring blade at a rotation speed of 28 rpm, and heated for 1 hour. The molar ratio of the raw material monomers was 1,10-decanediamine: terephthalic acid = 50: 50. The mixture was heated to 230 ° C. while maintaining the rotation speed at 28 rpm, and then heated at 230 ° C. for 3 hours. The formation reaction and crushing of salt and low polymer were carried out simultaneously. After releasing the water vapor generated by the reaction, the resulting reaction product was taken out.
[Step (ii)]
The reaction product obtained in step (i) was polymerized by heating at 230 ° C. for 5 hours in a drier in a normal pressure nitrogen stream to prepare a semi-aromatic polyamide resin.

Semi-aromatic polyamide resin (A-2)
[Step (i)]
A mixture of powdered terephthalic acid powder (4870 parts by mass), sodium hypophosphite (6 parts by mass) as a polymerization catalyst, and benzoic acid (72 parts by mass) as an end-capping agent is added to a ribbon blender reactor. The mixture was supplied and heated to 170 ° C. with stirring at a rotation speed of 30 rpm using a double helical stirring blade under nitrogen sealing. Thereafter, decanediamine (5050 parts by mass, 100% by mass) heated to 100 ° C. using a liquid injection device while maintaining the temperature at 170 ° C. and the rotation speed at 30 rpm was 28 parts by mass / min. Was added to the terephthalic acid powder continuously (continuous liquid injection method) over 3 hours to obtain a reaction product.
[Step (ii)]
The reaction product obtained in step (i) was subsequently polymerized by heating to 230 ° C. under a nitrogen stream and heating at 230 ° C. for 5 hours in the ribbon blender reactor used in step (i). A semi-aromatic polyamide resin was prepared.

Semi-aromatic polyamide resins (A-3) to (A-6)
A semi-aromatic polyamide resin was produced in the same manner as in the production of the semi-aromatic polyamide resin (A-2) except that the type of monomer used and the production conditions were changed as shown in Table 1.

Semi-aromatic polyamide resin (A-7)
[Step (i)]
1,10-decanediamine (5050 parts by mass) as a diamine component, powdered terephthalic acid (4870 parts by mass), benzoic acid (72 parts by mass) as a terminal blocking agent, and sodium hypophosphite monohydrate ( 6 parts by weight), 600 parts by weight of distilled water (6 parts by weight with respect to 100 parts by weight of the total amount of raw material monomers) are placed in an autoclave, heated to 100 ° C., and then stirred at a rotation speed of 28 rpm and heated for 1 hour did. The mixture was heated to 230 ° C. while maintaining the rotation speed at 28 rpm, and then heated at 230 ° C. for 3 hours. The resulting solid was crushed while the salt and low polymer were formed. After releasing the water vapor, the obtained reaction product was taken out.
[Step (ii)]
The reaction product obtained in step (i) was polymerized by heating at 230 ° C. for 5 hours in a drier in a normal pressure nitrogen stream to prepare a semi-aromatic polyamide resin. In the polymerization, 6 parts by mass of distilled water was used with respect to 100 parts by mass of the total amount of raw material monomers. Therefore, compared with the semi-aromatic polyamide resin (A-1) produced under the same conditions except for the addition of distilled water, the weight average molecular weight was slightly lower and the amount of triamine was larger.

  Table 1 shows the resin composition of the obtained semiaromatic polyamide resin, its production conditions, and the characteristic values of the obtained resin.

Semi-aromatic polyamide resin (A-8)
Semi-aromatic polyamide resin consisting of 1,6-hexanediamine, isophthalic acid, terephthalic acid (Mitsui Chemicals, Aalen A335), melting point 320 ° C.

<Aliphatic polyamide resin>
E2000: Polyamide 66 (E2000 manufactured by Unitika), relative viscosity 2.7
A1030: Polyamide 6 (A1030BRF-BA manufactured by Unitika Ltd.), relative viscosity 3.1

<Polyarylate resin (B)>
Polyarylate resin (B-1)
An acetylation reaction was performed by heating and stirring a mixture of 29.7 parts by mass of BPA, 21.6 parts by mass of IPA, and 26.6 parts by mass of acetic anhydride (Ac ₂ O) in a reaction vessel at 140 ° C. for 3 hours in a nitrogen atmosphere. (BPA: IPA: Ac ₂ O = 100: 100: 200 (molar ratio)). Thereafter, while stirring, the temperature of the system was raised to 280 ° C. over 4 hours, held for 1 hour, and further raised to 310 ° C. over 1.5 hours to carry out an esterification reaction. Subsequently, the system pressure was gradually reduced to 1 hPa after 2 hours, and a polycondensation reaction was performed for 2 hours under these conditions. Then, after making the inside of a system into a normal pressure using nitrogen, polyester was discharged from a reaction container with nitrogen pressure, and a pellet-like polyarylate resin was obtained using a strand cutter. The obtained resin was dried at 120 ° C. under reduced pressure for 24 hours using a vacuum dryer.

Polyarylate resin (B-2)
A mixture consisting of 29.7 parts by mass of BPA, 17.3 parts by mass of IPA, 4.3 parts by mass of terephthalic acid (TPA), and 26.6 parts by mass of Ac ₂ O in a reaction vessel at 140 ° C. for 3 hours in a nitrogen atmosphere. Acetylation reaction was performed by heating and stirring (BPA: IPA: TPA: Ac ₂ O = 100: 80: 20: 200 (molar ratio)). Thereafter, while stirring, the temperature of the system was raised to 280 ° C. over 4 hours, held for 1 hour, and further raised to 310 ° C. over 1.5 hours to carry out an esterification reaction. Subsequently, the system pressure was gradually reduced to 1 hPa after 2 hours, and a polycondensation reaction was performed for 2 hours under these conditions. Then, after making the inside of a system into a normal pressure using nitrogen, polyester was discharged from a reaction container with nitrogen pressure, and a pellet-like polyarylate resin was obtained using a strand cutter. The obtained resin was dried at 120 ° C. under reduced pressure for 24 hours using a vacuum dryer.

Polyarylate resin (B-3)
A mixture of 23.8 parts by mass of BPA, 6.9 parts by mass of 1,1-bis (4-hydroxyphenyl) cyclohexane (BPZ), 21.6 parts by mass of IPA, and 26.6 parts by mass of Ac ₂ O was added in a reaction vessel. In a nitrogen atmosphere, the mixture was heated and stirred at 140 ° C. for 3 hours to carry out acetylation reaction (BPA: BPZ: IPA: Ac ₂ O = 80: 20: 100: 200 (molar ratio)). Thereafter, while stirring, the temperature of the system was raised to 280 ° C. over 4 hours, held for 1 hour, and further raised to 310 ° C. over 1.5 hours to carry out an esterification reaction. Subsequently, the system pressure was gradually reduced to 1 hPa after 2 hours, and a polycondensation reaction was performed for 2 hours under these conditions. Then, after making the inside of a system into a normal pressure using nitrogen, polyester was discharged from a reaction container with nitrogen pressure, and a pellet-like polyarylate resin was obtained using a strand cutter. The obtained resin was dried at 120 ° C. under reduced pressure for 24 hours using a vacuum dryer.

Polyarylate resin (B-4)
A mixture consisting of 23.8 parts by weight of BPA, 6.9 parts by weight of BPZ, 17.3 parts by weight of IPA, 4.3 parts by weight of TPA, and 26.6 parts by weight of Ac ₂ O was placed in a reaction vessel at 140 ° C. under a nitrogen atmosphere. Acetylation reaction was performed by heating and stirring for a period of time (BPA: BPZ: IPA: TPA: Ac ₂ O = 80: 20: 80: 20: 200 (molar ratio)). Thereafter, while stirring, the temperature of the system was raised to 280 ° C. over 4 hours, held for 1 hour, and further raised to 310 ° C. over 1.5 hours to carry out an esterification reaction. Subsequently, the system pressure was gradually reduced to 1 hPa after 2 hours, and a polycondensation reaction was performed for 2 hours under these conditions. Then, after making the inside of a system into a normal pressure using nitrogen, polyester was discharged from a reaction container with nitrogen pressure, and a pellet-like polyarylate resin was obtained using a strand cutter. The obtained resin was dried at 120 ° C. under reduced pressure for 24 hours using a vacuum dryer.

Polyarylate resin (B-5)
A mixture of 29.7 parts by mass of BPA, 21.4 parts by mass of IPA, and 26.6 parts by mass of Ac ₂ O was heated and stirred in a reaction vessel at 140 ° C. for 3 hours in a reaction vessel to carry out an acetylation reaction ( BPA: IPA: Ac ₂ O = 100: 99: 200 (molar ratio)). Thereafter, while stirring, the temperature of the system was raised to 280 ° C. over 4 hours, held for 1 hour, and further raised to 310 ° C. over 1.5 hours to carry out an esterification reaction. Subsequently, the system pressure was gradually reduced to 1 hPa after 2 hours, and a polycondensation reaction was performed for 4 hours under these conditions. Then, after making the inside of a system into a normal pressure using nitrogen, polyester was discharged from a reaction container with nitrogen pressure, and a pellet-like polyarylate resin was obtained using a strand cutter. The obtained resin was dried at 120 ° C. under reduced pressure for 24 hours using a vacuum dryer.

<Fibrous reinforcement (C)>
GF: Glass fiber (T-289 manufactured by Nippon Electric Glass Co., Ltd.), average fiber diameter 13 μm, average fiber length 3 mm
Flat GF: Flat glass fiber (CSG3PA820S manufactured by Nittobo Co., Ltd.), major axis 28 μm × minor axis 7 μm, average fiber length 3 mm
CF: carbon fiber (HTA-C6-NR manufactured by Toho Tenax Co., Ltd.), average fiber diameter 7 μm, average fiber length 6 mm

<Other reinforcements>
GB: Glass beads (EGB731 manufactured by Potters Ballotini), average particle size 20 μm

Example 1
A loss-in-weight continuous quantitative supply device CE-W-1 manufactured by Kubota Corporation was used with 80 parts by mass of the semi-aromatic polyamide resin (A-1) and 20 parts by mass of the polyarylate resin (B-1) obtained in Production Example 1. These were weighed and supplied to the main supply port of a twin screw extruder (TEM 37BS manufactured by Toshiba Machine Co., Ltd.) having a screw diameter of 37 mm and L / D40, and melt kneading was performed. In the middle, 42 parts by mass of GF was supplied to the total of 100 parts by mass of (A-1) and (B-1) from the side feeder and further kneaded. After taking the strand from the die, it was cooled and solidified by passing through a water tank, and cut with a pelletizer to obtain polyamide resin composition pellets. In addition, the barrel temperature setting of the extruder was 320 to 340 ° C., the screw rotation speed was 250 rpm, and the discharge amount was 35 kg / hour.

Examples 2-19, Comparative Examples 1-3, 5-9
Except having changed the kind and compounding ratio of resin, operation similar to Example 1 was performed and the polyamide resin composition was obtained.

Comparative Example 4
The same operation as in Example 1 was performed except that 200 parts by mass of GF was supplied to 100 parts by mass of (A-1) and (B-1) in total. However, since the resin was thermally decomposed and foamed by shearing heat generation in the extruder, the strand could not be drawn from the die.

  Tables 2 and 3 show the resin composition and resin characteristics of the obtained polyamide resin composition.

In the resin compositions of Examples 1 to 19, the semi-aromatic polyamide resin, polyarylate resin, and fibrous reinforcing material were used, and the respective blending ratios were set within a specific range, so the creep deformation rate was low.
In the resin compositions of Examples 1 to 18, since the carboxyl group of the polyarylate resin was 30 equivalents / ton or more, mechanical properties when the polyarylate resin (B) was added to the semi-aromatic polyamide resin (A) The decline of the was suppressed.

Since the resin compositions of Comparative Examples 1, 2, 7, and 8 did not contain a polyarylate resin, the creep deformation rate was high.
Since the resin composition of Comparative Example 3 did not contain a fibrous reinforcing material, the creep deformation rate was high, and the tensile strength and tensile elongation at break were low.
In the resin compositions of Comparative Examples 5 and 6, since the aliphatic polyamide resin was blended instead of the semi-aromatic polyamide resin, the creep deformation rate was high.
Since the resin composition of Comparative Example 9 was blended with glass beads instead of the fibrous reinforcement, the creep deformation rate was high, and the tensile strength and tensile elongation at break were low.

(A) State in which test piece is placed on restraining jig (B) State in which test piece is restrained and bent (C) State in which only outer restraining jig is removed after heat treatment 1 Test piece 2 Restraining jig ( Inside)
3 Restraint jig (outside)

Claims (9)

A resin composition comprising a semi-aromatic polyamide resin (A), a polyarylate resin (B) containing isophthalic acid as a main dicarboxylic acid component, and a fibrous reinforcing material (C), comprising (A) to (C) A polyamide resin composition characterized in that the ratio (mass ratio) satisfies the following formulas (1) and (2).
(A) / (B) = 95 / 5-50 / 50 (1)
{(A) + (B)} / (C) = 100/10 to 100/160 (2) The polyamide resin composition according to claim 1, wherein the carboxyl value of the polyarylate resin (B) is 30 equivalents / ton or more. The semi-aromatic polyamide resin (A) comprises a dicarboxylic acid component mainly composed of terephthalic acid and an aliphatic diamine component, and the aliphatic diamine component is 1,8-octanediamine, 1,10-decanediamine, The polyamide resin composition according to claim 1, wherein the polyamide resin composition is at least one selected from the group consisting of 1,12-dodecanediamine. The polyamide resin composition according to claim 3, wherein the aliphatic diamine component of the semi-aromatic polyamide resin (A) is 1,10-decanediamine. The triamine unit with respect to the diamine unit in a semi-aromatic polyamide resin (A) is 0.3 mol% or less, The polyamide resin composition in any one of Claims 1-4 characterized by the above-mentioned. The polyamide resin composition according to any one of claims 1 to 5, wherein the degree of supercooling measured using a differential scanning calorimeter of the semi-aromatic polyamide resin (A) is 40 ° C or less. The polyamide resin composition according to any one of claims 1 to 6, wherein the fibrous reinforcing material is at least one selected from glass fiber, carbon fiber, and metal fiber. The polyamide resin composition according to any one of claims 1 to 7, which has a creep deformation ratio of 20% or less. The molded object formed by shape | molding the polyamide resin composition in any one of Claims 1-8.