JP5902903B2 - Polyamide resin composition and molded body formed by molding the same - Google Patents

Description

  The present invention relates to a polyamide resin composition having improved moldability such as surface gloss and molding cycle in addition to mechanical properties.

Semi-aromatic polyamides typified by polyamide 6T and polyamide 9T are excellent in heat absorption and mechanical properties, as well as low water absorption, and are used as many electrical / electronic parts and parts around automobile engines.
On the other hand, high heat-resistant materials represented by polyimide and liquid crystal polyester are used as substrate materials for electric and electronic parts. However, although such a material is very excellent in terms of performance, it is very expensive and inferior in processability. Therefore, the use of the semi-aromatic polyamide for such applications has been studied.
Since the melting point of the homopolymer of the polyamide 6T is too high at 370 ° C., the thermal decomposition of the polyamide 6T at the time of melt processing cannot be suppressed. Therefore, the polyamide 6T is used in a state where the melting point is sufficiently lowered by introducing a large amount of copolymer components. However, such copolymerized polyamide 6T has a loss of crystallinity and cannot accelerate crystallization.

Patent Document 1 discloses a polyamide molded body containing glass fibers with respect to polyamide 10T. However, such a molded product cannot obtain the required mechanical properties unless a large amount of glass fiber is used, and the surface gloss of the molded product obtained from the glass fiber contained is impaired.
Patent Document 2 discloses a resin composition containing a crystalline polyamide resin and an amorphous polyamide resin and having improved surface design. However, such a resin composition has poor crystallinity due to the amorphous polyamide resin used and has insufficient moldability.

JP-A-6-239990 JP 2008-133465 A

  An object of the present invention is to provide a polyamide resin composition having improved surface gloss and moldability in addition to mechanical properties.

  The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the above problems.

  That is, the gist of the present invention is as follows.

(1) A polyamide resin composition containing 5 to 200 parts by mass of a fibrous reinforcing material with respect to a total of 100 parts by mass of the crystalline polyamide resin (A) and the amorphous polyamide resin (B), wherein the crystalline property The dicarboxylic acid component constituting the polyamide resin (A) is mainly composed of terephthalic acid, and the diamine component is composed of only a linear aliphatic diamine having 8, 10, or 12 carbon atoms, and the crystalline polyamide resin (A) The triamine unit is 0.2 mol% or less with respect to the diamine unit therein, and is (B) / {(A) + (B)} = 0.1 to 0.5 (mass ratio). Polyamide resin composition.
(2) The degree of supercooling ΔT measured using DSC of the crystalline polyamide resin (A) is 40 ° C. or less, and the polyamide resin composition according to claim 1.
(3) The polyamide resin composition as described in (1) or (2), wherein the diamine component of the crystalline polyamide resin (A) is 1,10-decanediamine.
( 4 ) Amorphous polyamide resin (B) is a polycondensate of isophthalic acid / terephthalic acid / 1,6-hexanediamine, isophthalic acid / terephthalic acid / 1,6-hexanediamine / bis (3-methyl-4 The polyamide resin composition according to any one of (1) to ( 3 ), which is a polycondensate of -aminocyclohexyl) methane or a mixture thereof.
( 5 ) The polyamide resin composition according to any one of (1) to ( 4 ), wherein the fibrous reinforcing material is at least one selected from glass fiber, carbon fiber, and metal fiber.
( 6 ) A molded article formed by molding the polyamide resin composition according to any one of (1) to ( 5 ).

  According to the present invention, a polyamide resin composition having improved moldability in addition to mechanical properties can be obtained. A molded body obtained from such a polyamide resin composition has excellent surface gloss.

  Hereinafter, the present invention will be described in detail. The polyamide resin composition of the present invention contains a crystalline polyamide resin and an amorphous polyamide resin.

Crystallinity means that the value of the heat of fusion measured with a differential scanning calorimeter (DSC) at a heating rate of 16 ° C./min in a nitrogen atmosphere is greater than 1 cal / g.
Amorphous means that the value of heat of fusion measured with a differential scanning calorimeter (DSC) at a heating rate of 16 ° C./min in a nitrogen atmosphere is 1 cal / g or less.

In general, when a crystalline polyamide resin and an amorphous polyamide resin are mixed and molded, the crystallization during cooling of the crystalline polyamide resin is hindered by the amorphous polyamide resin, and the crystallization is delayed. To do. As a result, the crystallization of the mixed resin as described above proceeds gradually. On the other hand, the crystalline polyamide resin shrinks in volume at the time of crystallization, and undulation may occur particularly on the surface of the molded body as the molten resin is crystallized and cooled. In particular, in the polyamide resin composition containing glass fiber, the swell is significant, and on the surface of the molded body, the matrix resin portion shrinks, and the vicinity of the glass fiber is suppressed from shrinking, from the polyamide resin composition, A so-called “glass floating” phenomenon occurs in which glass fibers are exposed. Such waviness on the surface of the molded body tends to reduce mold transfer during injection molding and lower the surface gloss.
By mixing and processing a crystalline polyamide resin and an amorphous polyamide resin, it is possible to suppress the crystallization of the crystalline polyamide resin, reduce the undulation during molding, and obtain a molded body with improved surface gloss It has become possible. However, since such a polyamide resin composition suppresses the crystallinity of the crystalline polyamide resin, there is a problem in moldability such as a long molding cycle. This invention provides the polyamide resin composition which solves such a problem.

The crystalline polyamide resin (A) used in the present invention needs to use a terephthalic acid component and an aliphatic diamine component from the viewpoint of high crystallinity.
This is because terephthalic acid is most preferable in obtaining a crystalline polyamide resin (A) having high crystallinity and high crystallinity among aromatic dicarboxylic acids.
The diamine component constituting the crystalline polyamide resin (A) must be a linear aliphatic diamine having 8 to 12 carbon atoms from the viewpoint of the melt processability of the resulting polyamide, and any diamine should be used alone. Is preferred. Further, 1,8-octanediamine, 1,10-decanediamine, and 1,12-dodecanediamine are preferable for obtaining a crystalline polyamide resin (A) having high crystallinity because of its high chemical structure symmetry. .

  The reason why the diamine used preferably has an even number of carbon atoms will be described below. In general, a so-called even-odd effect appears in polyamide. That is, when the number of carbon atoms in the monomer unit of the diamine component used is an even number, a more stable crystal structure is formed as compared with the case where the number is an odd number, so that the effect of improving crystallinity is exhibited. Therefore, from the viewpoint of high crystallinity, the linear aliphatic diamine preferably has an even number of carbon atoms.

  When the number of carbon atoms of the diamine is less than 8, the melting point of the obtained crystalline polyamide resin (A) exceeds 340 ° C. and exceeds the decomposition temperature, which is not preferable. On the other hand, when the diamine has more than 12 carbon atoms, the crystalline polyamide resin (A) to be obtained has a melting point of less than 280 ° C., which is not preferable because the heat resistance is insufficient in practical use. The diamine having 9 or 11 carbon atoms lacks crystallinity due to the even-odd effect of polyamide.

  The crystalline polyamide resin (A) used in the present invention includes a dicarboxylic acid component other than a terephthalic acid component as a main component and / or a diamine component other than a linear aliphatic diamine component having 8 to 12 carbon atoms. (Hereinafter sometimes referred to as “copolymerization component”) may be copolymerized. The copolymer component is preferably 5 mol% or less with respect to the total number of moles of raw material monomers (100 mol%), and more preferably substantially free of the copolymer component. This is because, from the viewpoint of high crystallinity, it is preferable to have a structure close to a homopolymer having high regularity rather than a copolymer having an irregular chemical structure. That is, when the copolymerization component exceeds 5 mol%, the crystallinity is lowered and it may be impossible to obtain a crystalline polyamide resin (A) having high crystallinity.

  Examples of dicarboxylic acid components other than terephthalic acid that can be used as a copolymerization component of the crystalline polyamide resin (A) include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, and azelaic acid. And aliphatic dicarboxylic acids such as sebacic acid, undecanedioic acid and dodecanedioic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, and aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and naphthalenedicarboxylic acid.

  Other diamine components that can be used as the copolymerization component of the crystalline polyamide resin (A) include 1,2-ethanediamine, 1,3-propanediamine, 1,4-butanediamine, and 1,5-pentane. Diamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, etc. And aliphatic diamines, cycloaliphatic diamines and other alicyclic diamines, and xylylenediamine and other aromatic diamines. In addition, any of the 1,8-octanediamine, 1,10-decanediamine, and 1,12-octanediamine listed above is an essential diamine component in the crystalline polyamide resin (A) of the present invention. When any one of 1,8-octanediamine, 1,10-decanediamine, and 1,12-dodecanediamine is used as an essential diamine component, the other diamine components are used as copolymerization components. For example, when 1,8-octanediamine is used as an essential diamine component, 1,10-decanediamine and 1,12-dodecanediamine are used as copolymerization components.

  The crystalline polyamide resin (A) may be copolymerized with lactams such as caprolactam as necessary.

  The weight average molecular weight of the crystalline polyamide resin (A) is preferably 15,000 to 50,000, more preferably 20,000 to 50,000, and 26,000 to 50,000. Is more preferable. When the weight average molecular weight of the crystalline polyamide resin (A) is less than 15,000, crystallization of the obtained crystalline polyamide resin (A) is accelerated, but the rigidity is lowered. When the weight average molecular weight of the crystalline polyamide resin (A) exceeds 50,000, crystallization is slowed down, and fluidity during injection molding is reduced.

  The relative viscosity of the crystalline polyamide resin (A) is not particularly limited, and may be appropriately set depending on the purpose. For example, in order to obtain a crystalline polyamide resin (A) that can be easily molded, the relative viscosity is preferably 2.0 or more.

  The crystalline polyamide resin (A) used in the present invention preferably has a sufficiently reduced triamine amount. The crystalline 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 it may be present as fish eyes or irregularities on the surface of the obtained molded body, which may cause a deterioration of the surface appearance.

  Therefore, the triamine unit contained in the crystalline polyamide resin (A) needs to be 0.3 mol% or less of the diamine unit, and preferably 0.2 mol% or less. When the triamine structure in the crystalline polyamide resin (A) exceeds 0.3 mol% of the diamine unit, the crystallinity is lowered, or the surface smoothness of the molded product obtained by generating a gel is impaired, There may be a problem that the color tone is lowered.

  In order to make the above-mentioned triamine unit 0.3 mol% or less of the diamine unit, when the salt is formed from the terephthalic acid component and the diamine component, the blending amount of water and organic solvent is 100 parts by mass in total of the raw material monomers. It is necessary that the amount be 5 parts by mass or less.

  In general, in order to proceed the heating polymerization reaction of the crystalline polyamide resin (A) uniformly, a method is used in which the raw materials are mixed in the presence of water and heated to advance the dehydration reaction. However, in such a method, when the total amount of water and the organic solvent during polymerization is more than 5 parts by mass with respect to 100 parts by mass of the raw material monomers, an increase in the degree of polymerization is suppressed. There is. In that case, the residence time in the polymerization apparatus in a state where there are many amine ends becomes longer, and the amount of triamine by-produced by the condensation reaction between diamines increases. As a result, part of the crystalline polyamide resin (A) has a cross-linked structure, and gelation is promoted or the color tone is lowered. Gelation causes a decrease in crystallinity of the crystalline polyamide resin (A) and delays the crystallization speed. And in the semi-aromatic polyamide like this invention, the production | generation of a triamine is more remarkable than an aliphatic polyamide. Therefore, as in the present invention, in order to obtain a crystalline polyamide resin (A) in which the triamine unit is 0.3 mol% or less of the diamine unit, the blending amount of water and the organic solvent is set to 100 mass in total of the raw material monomers. 5 parts by mass or less with respect to parts, and it is more preferable that water is not substantially mixed.

  The polyamide resin composition of the present invention is intended to accelerate crystallization, improve moldability, and improve surface gloss by containing an amorphous polyamide resin. Must be suppressed. In order to obtain such a polyamide resin composition, the crystallization rate of the crystalline polyamide resin (A) used is preferably controlled within a specific range. The crystallization rate in the present invention can be determined by using the degree of supercooling ΔT measured using a differential scanning calorimeter (DSC) as an index. In the crystalline polyamide resin (A) used in the present invention, ΔT is preferably 40 ° C. or less, and more preferably 35 ° C. or less. If ΔT exceeds 40 ° C, the crystallinity cannot be sufficiently increased, the molding cycle cannot be shortened, and it is difficult to release from the mold, resulting in a decrease in continuous productivity during molding. There are things to do.

In the present invention, as shown in the following formula, the degree of supercooling ΔT is the melting point of the crystalline polyamide resin (A) (hereinafter sometimes abbreviated as Tm) and the cooling crystallization temperature (hereinafter referred to as Tcc). It may be abbreviated).
ΔT = Tm-Tcc
In the above formula, a differential scanning calorimeter (DSC) is used to lower the crystalline polyamide resin (A) from the molten state to 25 ° C. at a temperature lowering rate of 20 ° C./min under an inert gas atmosphere. The temperature of the endothermic peak that appears when the temperature is raised at a rate of temperature increase of ° C./min is defined as the melting point (Tm). Similarly, the temperature of the exothermic peak that appears when the temperature is lowered from the molten state to 25 ° C. at a temperature lowering rate of 20 ° C./min is defined as the temperature-falling crystallization temperature (Tcc). It shows that crystallization from a polymer molten state is quick, so that this (DELTA) T is small.

  By satisfying the range of ΔT of 40 ° C. or less, the crystallinity of the molded body is improved, and the rigidity of the molded body at the time of taking out from the mold at the time of injection molding is increased. Therefore, the polyamide resin having ΔT of less than 40 ° C. Compared to the molded body, the molded body can be taken out from the mold even if the cooling time is shortened. Therefore, it is possible to shorten the time required to form one molded body by injection molding (hereinafter referred to as a molding cycle). This not only improves the production efficiency of the molded body, but also shortens the residence time of the resin that stays in the cylinder of the injection molding machine, especially when performing continuous injection molding. It is possible to suppress the generation of gas, suppress the deterioration product, decomposition gas, and mold contamination of the molded body, thereby improving the quality of the molded body. Suppression of mold contamination improves mold release at the time of taking out from the mold, and it can maintain good mold release performance continuously. Therefore, mold release failure when performing automatic molding on production lines etc. Continuous productivity capable of continuous molding for a long time can be improved without causing the operation to stop.

  Further, like the crystalline polyamide resin (A) used in the present invention, when the melting point is high, the resin melting temperature for obtaining a molded body is high, and the resin stays in the molding machine cylinder for a long time, Since the deterioration of the resin and generation of decomposition gas become remarkable, shortening the molding cycle and suppressing the residence of the molten resin in the molding machine cylinder as much as possible can be achieved by molding the polyamide resin composition of the present invention and making it heat resistant. This is preferable in terms of the quality of the molded body and the molding handling surface for obtaining an excellent molded body.

  In addition, the crystalline polyamide resin (A) in which the diamine component having an even number of carbon atoms is used has high crystallinity in the first place. In order to achieve further high crystallinity, as described above, the copolymerization component in the crystalline polyamide resin (A) of the present invention can be 0 to 5 mol%. In order to achieve further high crystallinity, as described above, the triamine unit in the crystalline polyamide resin (A) may be 0.3 mol% or less with respect to the diamine unit.

  The crystalline polyamide resin (A) used in the present invention 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 crystalline polyamide resin (A) has a high melting point of 280 ° C. to 340 ° C. and is close to the decomposition temperature. Therefore, the melt polymerization method or 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 be inappropriate because the quality of the product may be deteriorated. Therefore, a solid phase polymerization method at a temperature below the melting point of the produced polymer is preferable.

  In general, the production of the crystalline polyamide resin (A) often comprises a step (i) of obtaining a reactant from a monomer and a step (ii) of polymerizing such a reactant. In order to obtain a crystalline polyamide resin (A) whose unit is 0.3 mol% or less of the diamine unit, the step of step (i) is carried out under the condition that there are few moisture and solvent in the polymerization system, that is, dicarboxylic acid and diamine. It is preferable to carry out in the presence of water and / or an organic solvent in which the total amount of water and the organic solvent is 5 parts by mass or less with respect to 100 parts by mass in total.

  As a specific example of the step (i), for example, a suspension composed of a molten diamine and a solid dicarboxylic acid is stirred and mixed to obtain a mixed solution, and finally a crystalline polyamide resin (A) to be produced And a method of obtaining a mixture of a salt and a low polymer by performing a salt formation by a reaction between a dicarboxylic acid and a diamine and a low polymer formation reaction by polymerization of the salt. Since such a reaction product is usually in the form of a lump, a powdery reaction product can be obtained by crushing while reacting, or by taking out after the reaction and then crushing.

  As a specific example of 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 a step of obtaining a polyamide resin. 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 crystalline polyamide resin (A), a polymerization catalyst can be used in order to increase the efficiency of polymerization, and an end-capping agent can be used to adjust the degree of polymerization, suppress thermal decomposition, and coloring.

  Examples of the polymerization catalyst include phosphoric acid, phosphorous acid, hypophosphorous acid or salts thereof. The addition amount of the polymerization catalyst is usually 0 to 2 mol relative to the total mol of dicarboxylic acid and diamine. % Is preferably used.

  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, and any one of these or a combination thereof can be used. As the addition amount of the end capping agent, it is usually preferable to use 0 to 5% by mole based on the total moles of terephthalic acid and diamine.

The amorphous polyamide resin (B) used in the present invention is a polyamide having an aromatic ring or alicyclic structural unit in the main chain, and is a substantially amorphous transparent polyamide or copolyamide.
Specific examples of the amorphous polyamide resin (B) include a polycondensate of isophthalic acid / terephthalic acid / 1,6-hexanediamine / bis (3-methyl-4-aminocyclohexyl) methane, terephthalic acid / 2, Polycondensate of 2,4-trimethyl-1,6-hexanediamine / 2,4,4-trimethyl-1,6-hexanediamine, isophthalic acid / bis (3-methyl-4-aminocyclohexyl) methane / ω- Laurolactam polycondensate, isophthalic acid / terephthalic acid / 1,6-hexanediamine polycondensate, isophthalic acid / 2,2,4-trimethyl-1,6-hexanediamine / 2,4,4-trimethyl- 1,6-hexanediamine polycondensate, isophthalic acid / terephthalic acid / 2,2,4-trimethyl-1,6-hexanediamine / 2,4,4-tri Polycondensate of til-1,6-hexanediamine, polycondensate of isophthalic acid / bis (3-methyl-4-aminocyclohexyl) methane / ω-laurolactam, heavy phthalic acid / terephthalic acid / other diamine components Examples include condensates. Also included are those in which the benzene ring of the terephthalic acid component and / or isophthalic acid component constituting these polycondensates is substituted with an alkyl group or a halogen atom. Among them, isophthalic acid / terephthalic acid / 1,6-hexanediamine polycondensate, isophthalic acid / terephthalic acid / 1,6-hexanediamine / bis (3-methyl-4-aminocyclohexyl) methane polycondensate, or Polycondensate of terephthalic acid / 2,2,4-trimethyl-1,6-hexanediamine / 2,4,4-trimethyl-1,6-hexanediamine, or isophthalic acid / terephthalic acid / 1,6-hexanediamine / Bis (3-methyl-4-aminocyclohexyl) methane polycondensate and terephthalic acid / 2,2,4-trimethyl-1,6-hexanediamine / 2,4,4-trimethyl-1,6-hexanediamine A mixture with the polycondensate can be preferably used. Among these, a polycondensate of isophthalic acid / terephthalic acid / 1,6-hexanediamine, isophthalic acid, has a high effect of improving the surface appearance of the molded article obtained without inhibiting the crystallinity of the polyamide resin composition. A polycondensate of acid / terephthalic acid / 1,6-hexanediamine / bis (3-methyl-4-aminocyclohexyl) methane or a mixture thereof can be more preferably used. Two or more of these amorphous polyamide resins (B) can be used in combination.
Here, the crystalline polyamide resin (A) and the amorphous polyamide resin (B) used in the present invention partially overlap with the aromatic dicarboxylic acid component and the aliphatic diamine component constituting the polyamide resin. In contrast, the crystalline polyamide resin (A) having high crystallinity has substantially no crystallinity, that is, the temperature is increased by 16 ° C./min under a nitrogen atmosphere using a differential scanning calorimeter (DSC). A polyamide resin having a calorific value measured by a temperature rate of 1 cal / g or less is defined as an amorphous polyamide resin, and is distinguished from a crystalline polyamide resin.

  The glass transition temperature of the amorphous polyamide resin (B) is preferably 80 to 200 ° C. from the viewpoint of improving the heat resistance of the resulting polyamide resin composition and improving processability. It is more preferable that it is 110-170 degreeC. When the glass transition temperature is less than 80 ° C., solidification occurs during molding using the polyamide resin composition, which may cause defective release or a longer molding cycle. When the glass transition temperature exceeds 200 ° C., when the polyamide resin composition is used for molding, solidification is too early, and appearance defects such as sink marks and glass floating tend to occur, and the melt viscosity during kneading is also low. Since it becomes high, uniform kneading becomes difficult, which is not preferable.

  The compounding ratio of the crystalline polyamide resin (A) and the amorphous polyamide resin (B) is the amorphous polyamide resin (B) with respect to a total of 100 parts by mass of the crystalline polyamide resin (A) and the amorphous polyamide resin (B). ) Ratio (mass ratio), (B) / {(A) + (B)} = need to be 0.1 to 0.5, 0.15 to 0.45 Is preferable, and it is more preferable that it is 0.2-0.4. When (B) / {(A) + (B)} is less than 0.1, especially when reinforcing materials are added, the surface gloss tends to decrease, and a particularly sophisticated surface appearance is required for notebook PC housings. It becomes difficult to use in the intended use. When (B) / {(A) + (B)} exceeds 0.5, the crystallinity of the polyamide resin composition is improved even when used in a mixture with the crystalline polyamide resin (A) of the present invention. Lowering, the molding cycle in injection molding or the like becomes longer, and the moldability deteriorates.

The relative viscosity of the crystalline polyamide resin (A) and the amorphous polyamide resin (B) of the present invention is not particularly limited, but 96 wt% concentrated sulfuric acid is used as a solvent, the temperature is 25 ° C., and the concentration is 1 g / dl. The measured relative viscosity is preferably in the range of 1.5 to 4.0, more preferably in the range of 1.7 to 3.8, and even more preferably in the range of 1.9 to 3.6. . When the relative viscosity is less than 1.5, it becomes difficult to take up the strands during melt-kneading, or the mechanical properties of the obtained molded article are deteriorated. If the relative viscosity exceeds 4.0, the fluidity at the time of molding processing is poor, and the time until the molten resin is filled in the mold becomes longer, the mold transferability is lowered, and the surface gloss of the obtained molded body is reduced. May be inferior.
In order to improve the mixing property, the relative viscosity ηa of the crystalline polyamide resin (A) and the relative viscosity ηb of the amorphous polyamide resin (B) are preferably close to each other, but the surface gloss is increased. Therefore, | ηa−ηb | ≦ 0.5 is preferable, and | ηa−ηb | ≦ 0.3 is more preferable. By setting | ηa−ηb | ≦ 0.5, the crystallinity of the crystalline polyamide resin (A) and the surface glossiness of the amorphous polyamide resin (B) can be preferably expressed.

  As the fibrous reinforcing material used in the present invention, carbon fiber, glass fiber, boron fiber, asbestos fiber, polyvinyl alcohol fiber, polyester fiber, acrylic fiber, wholly aromatic polyamide fiber, polybenzoxazole fiber, polytetrafluoroethylene fiber, Examples include 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, and basalt fiber. These fibrous reinforcing materials may be used in combination of two or more. In particular, glass fibers, carbon fibers, and metal fibers are preferably used because of their heat resistance that can withstand the heating temperature during melt kneading with the polyamide resin of the present invention and availability.

When glass fiber or carbon fiber is used, it is preferably surface-treated with a silane coupling agent. Further, the silane coupling agent may be dispersed in the sizing agent and surface-treated as a sizing agent for bundling glass fibers. Examples of the silane coupling agent include vinyl silane, acrylic silane, epoxy silane, amino silane, etc.
An aminosilane-based coupling agent is particularly preferable in that an adhesion effect between the polyamide resin and the glass fiber or carbon fiber is easily obtained.

  The fiber length of the fibrous reinforcing material is preferably 0.1 to 7 mm, and more preferably 0.5 to 6 mm. If the fiber length of the fibrous reinforcing material is less than 0.1 mm, the reinforcing effect may be inferior, while if it exceeds 7 mm, the moldability may be adversely affected. The fiber diameter is preferably 3 to 20 μm, more preferably 5 to 13 μm. If the fiber diameter is less than 3 μm, it is easy to break during melt kneading, whereas if it exceeds 20 μm, the reinforcing effect may be inferior. As the cross-sectional shape, a fibrous reinforcing material having a circular cross section can be preferably used, but a fibrous reinforcing material having a rectangular, elliptical, or other irregular cross section can be used as necessary.

  In the polyamide resin composition of this invention, it is preferable that it is 5-200 mass parts of fibrous reinforcements with respect to a total of 100 mass parts of a crystalline polyamide resin (A) and an amorphous polyamide resin (B). More preferably, it is -180 mass parts, More preferably, it is 20-150 mass parts, Most preferably, it is 30-130 mass parts. When the blending amount of the fibrous reinforcing material is less than 5 parts by mass, the improvement of the mechanical strength is poor, and when it exceeds 200 parts by mass, not only the reinforcement efficiency of the mechanical strength is lowered, but also the molded article obtained Surface glossiness decreases.

  The method for blending the fibrous reinforcing material is not particularly limited as long as the reinforcing effect is not impaired, but melt kneading using a biaxial kneader is preferably used. The kneading temperature needs to be not less than the melting point (Tm) of the crystalline polyamide resin (A), and is 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 crystalline polyamide resin (A) or the amorphous polyamide resin (B) may be decomposed or yellowed. 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.

  As a viscosity characteristic at the time of melting of the polyamide resin composition, a melt flow rate (hereinafter referred to as MFR) at 340 ° C. and 1.20 kg is preferably 0.1 to 50 g / 10 minutes, and preferably 1 to 40 g / 10. More preferably, it is 10 to 30 g / 10 minutes. By making MFR into the range of 0.1-50 g / 10min, the balance of the fluidity | liquidity at the time of injection molding of a polyamide resin composition, the mechanical strength of the molded object, and surface glossiness can be aimed at. Furthermore, it is preferable because crystallization of the polyamide resin composition can be accelerated. If the MFR is less than 0.1 g / 10 min, not only the fluidity tends to be insufficient and melt kneading or injection molding tends to be difficult, but the surface gloss of the resulting molded product may be lowered. If the MFR exceeds 50 g / 10 min, it becomes difficult to improve the mechanical strength of the obtained molded body.

  Examples of the method of molding using the polyamide resin composition include an injection molding method, an extrusion molding method, a blow molding method, and the like. The crystalline polyamide resin (A) and the amorphous polyamide resin ( The injection molding method can be preferably used in that the mechanical properties and moldability of B) 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 etc. are mentioned. The polyamide 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 to a predetermined shape and solidified, and then as a molded body from the mold. It is taken out. The resin temperature at the time of injection molding needs to be heated and melted at a melting point (Tm) or higher of the crystalline polyamide resin (A), and is preferably less than (Tm + 100 ° C.). In addition, when the polyamide resin composition is heated and melted, it is preferable to use a sufficiently dried polyamide resin composition pellet. If the water content is large, the resin foams in the cylinder of the injection molding machine, and it may be difficult to obtain an optimal molded body. The moisture content of the polyamide resin composition pellets used for injection molding is preferably less than 0.3% by mass and more preferably less than 0.1% by mass in 100% by mass of the polyamide resin composition.

  When the polyamide resin composition used in the present invention is injection-molded, the mold temperature must be kept below the glass transition temperature (Tg) of the crystalline polyamide resin (A), and is less than (Tg-30 ° C). Is preferable, and it is more preferable that it is less than (Tg-50 degreeC). When the mold temperature exceeds the Tg of the crystalline polyamide resin (A), the effect of improving the mechanical properties due to the blending of the fibrous reinforcing material of the crystalline polyamide resin (A) and the amorphous polyamide resin (B) can be sufficiently obtained. I can't. 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 polyamide resin composition of this invention as needed. Examples of the method of addition include adding at the time of polymerization of polyamide, or melt-kneading to the obtained polyamide resin. Additives include talc, swellable clay minerals, silica, alumina, glass beads, fillers such as graphite, pigments such as titanium oxide, carbon black, other antioxidants, antistatic agents, flame retardants, Well-known additives such as flame retardant aids can be mentioned.

  The polyamide resin composition of the present invention is particularly preferably used in molding applications and can be formed into a molded body. In order to produce a molded body from the polyamide resin composition of the present invention, a normal molding method is used. Examples of the molding method include hot melt molding methods such as injection molding, extrusion molding, blow molding, and sintering molding. By such a method, various molded articles can be obtained.

In the polyamide resin composition of the present invention, ΔT measured using a differential scanning calorimeter (DSC) satisfies the range of 40 ° C. or less, and the crystallization speed is high. Can be shortened, which can contribute to a reduction in 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.

Since the polyamide resin composition of the present invention is excellent in surface gloss in addition to the conventional mechanical strength, it can be used in a wide range of applications such as automobile parts, electrical and electronic parts, sundries, and civil engineering and building supplies. Especially, it can use suitably for a motor vehicle part and an electrical / electronic component using the reinforcement effect by a fibrous reinforcement.
In automotive parts applications, 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, fan shrouds Engine peripheral parts such as 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 -Fuel filler and piping system parts such as L filler neck, fuel sender module, fuel pipe joint, wire harness, relay block, sensor housing, encapsulation, ignition coil, distributor, thermostat housing, quick connector, lamp reflector, Electrical parts such as lamp housing, lamp extension, 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, It can be suitably used for various interior and exterior parts such as door locks, door handles, and outside door mirror stays.
In electrical / electronic component applications, connectors, LED reflectors, switches, sensors, sockets, capacitors, jacks, fuse holders, relays, coil bobbins, resistors, ICs, LED housings, and the like can be given.
Since these automobile parts and electrical / electronic parts are mainly molded by injection molding and blow molding, when the polyamide resin composition of the present invention is used, the molding cycle is shortened, and resin degradation products and decomposition gas are mixed. Can be obtained, and a molded article excellent in appearance can be obtained. In addition, since the molding cycle is shortened, it is excellent in mass productivity, and has a remarkably excellent moldability in the molding of parts that are produced in large quantities with uniform quality.

1. Measurement Method According to the following method, measurement of resin characteristics and performance evaluation of the molded body were performed.

(1) Relative Viscosity of Crystalline Polyamide Resin (A) and Amorphous Polyamide Resin (B) Measured at a concentration of 1 g / dL and 25 ° C. using 96% by mass sulfuric acid as a solvent.

(2) Weight average molecular weight of crystalline polyamide resin (A) 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 used. The weight average molecular weight was determined using a calibration curve prepared as a standard sample.
<Sample preparation>
2 ml of hexafluoroisopropanol containing 10 mM sodium trifluoroacetate 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: 10 mM sodium trifluoroacetate-containing hexafluoroisopropanol Flow rate: 0.4 ml / min
・ Temperature: 40 ℃

(3) Heat of fusion of crystalline polyamide resin (A) and amorphous polyamide resin (B) Using a differential scanning calorimeter DSC-7 manufactured by PerkinElmer, Inc., a temperature rising rate of 16 ° C./min in a nitrogen atmosphere The heat of fusion was calculated from the area of the endothermic peak.

(4) Decreasing crystallization temperature, melting point, and degree of supercooling of crystalline polyamide resin (A) Using a differential scanning calorimeter DSC-7 manufactured by PerkinElmer, Inc., the temperature was increased to 350 ° C. at a rate of temperature increase of 20 ° C./min. After that, the temperature is maintained at 350 ° C. for 5 minutes, and the temperature that gives the top of the exothermic peak when the temperature is decreased to 25 ° C. at a temperature decrease rate of 20 ° C./min is set to the temperature lowering crystallization temperature (Tcc), The top of the endothermic peak when the temperature rise was measured again at a rate of temperature rise of 20 ° C./min was defined as the melting point (Tm). The difference between the melting point and the cooling crystallization temperature (Tm−Tcc) was defined as the degree of supercooling (ΔT).

(5) Determination of triamine in crystalline polyamide resin (A) Add 3 mL of 47% hydrobromic acid to 10 mg of polyamide resin, heat at 130 ° C. for 20 hours, evaporate to dryness, and further dry 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.

(6) Melt flow rate (MFR) of polyamide resin composition
According to JIS K7210, the measurement was performed using a polyamide resin composition pellet at 340 ° C. and a load of 1.2 kgf. The unit is g / 10 minutes.

(7) Flexural strength and flexural modulus of polyamide resin composition Measured according to ASTM D790.

(8) Formability After setting the cylinder temperature (melting point + 25 ° C.) and the mold temperature (melting point−185 ° C.) using an injection molding machine EC-100 manufactured by Toshiba Machine Co., Ltd., injection pressure 100 MPa, injection time The molded body (127 mm × 12.7 mm × 10 mm) was molded in 10 seconds and with a takeout time of 5 seconds.
(8-1) Molding cycle The molded body was molded. The shortest cooling time that can be easily taken out without deforming the compact with the protruding pin was measured. Here, 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). This molding cycle is preferably 35 seconds or shorter, and more preferably 30 seconds or shorter.
(8-2) Continuous Productivity The molded body was continuously molded according to the molding cycle obtained in (7-1) (up to 100). At the time of taking out the molded body from the mold, the number of the molded bodies that could be taken out up to the number of times that smooth removal without the deformation of the molded body by the protruding pin was possible was counted. 90 or more are preferable, and 95 or more are more preferable.

(9) Surface gloss (surface roughness)
Using a flat plate of 50 mm × 90 mm × 2 mm, the average roughness (μm) of the surface of any 10 parts was measured with a surface roughness measuring instrument (Surfcoder SE-3400 type) manufactured by Kosaka Laboratory. . 15 μm or less was accepted.

2. Raw materials The raw materials used in Examples and Comparative Examples are shown below.
(1) Dicarboxylic acid component, terephthalic acid, isophthalic acid (2) Diamine component, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,12-dodecanediamine (3) Amorphous Polyamide resin A-1: polycondensate of isophthalic acid / terephthalic acid / hexamethylenediamine / bis (3-methyl-4aminocyclohexyl) methane (CX-3000 manufactured by Unitika), glass transition temperature 125 ° C., relative viscosity: 1.9, heat of fusion 0.1 cal / g
A-2: isophthalic acid / terephthalic acid / hexamethylenediamine polycondensate (X21 manufactured by DSM), glass transition temperature 138 ° C., relative viscosity: 2.0, heat of fusion 0.1 cal / g
(4) Reinforcing material / GF: Glass fiber (03JAFT692 manufactured by Asahi Fiber Glass Co., Ltd.), average fiber diameter 10 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
MF: Stainless steel fiber (Naslon SUS304 manufactured by Nippon Seisen Co., Ltd.), average fiber diameter 8 μm, average fiber length 6 mm
GB: Glass beads (EGB731 manufactured by Potters Ballotini), average particle size 20 μm

Production Example 1
[Step (i)]
1,10-decanediamine (5050 parts by mass) as a diamine component, powdered terephthalic acid (4870 parts by mass) with an average particle size of 80 μm, benzoic acid (72 parts by mass) as a terminal blocking agent, and sodium hypophosphite as a polymerization catalyst The monohydrate (6 parts by mass) was placed in an autoclave, heated to 100 ° C., stirred using a double helical type 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 performed simultaneously. After releasing the water vapor generated by the reaction, the resulting reaction product was taken out.

[Step (ii)]
The reaction product obtained in the step (i) was polymerized by heating at 230 ° C. for 5 hours in a dryer under a normal pressure nitrogen stream to obtain a polyamide (P-1). With respect to the obtained polyamide (P-1), the relative viscosity, the weight average molecular weight, the melting point, the heat of fusion, the warm crystallization temperature, the degree of supercooling ΔT, and the amount of triamine were measured. The results are shown in Table 1.

Production Example 2
[Step (i)]
A mixture of terephthalic acid powder (4870 parts by mass) having a volume average particle size of 80 μm, sodium hypophosphite (6 parts by mass) as a polymerization catalyst, and benzoic acid (72 parts by mass) as a terminal blocker is a ribbon blender type. The reactor was 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). Polyamide (P-2) was obtained. About the obtained polyamide (P-2), the relative viscosity, the weight average molecular weight, the melting point, the heat of fusion, the cooling crystallization temperature, the degree of supercooling ΔT, and the amount of triamine were measured. The results are shown in Table 1.

Production Examples 3 to 5 and 7
Except changing the kind of monomer to be used and the production conditions as shown in Table 1, polyamides (P-3) to (P-5) and (P-7) were obtained in the same manner as in Example 2, and each characteristic was changed. Measurements were made. The results are shown in Table 1.

Production Example 6
[Step (i)]
1,10-decanediamine (5050 parts by mass) as a diamine component, powdered terephthalic acid (4870 parts by mass) with an average particle size of 80 μm, benzoic acid (72 parts by mass) as a terminal blocking agent, and sodium hypophosphite as a polymerization catalyst Monohydrate (6 parts by mass) and 400 parts by mass of distilled water (4 parts by mass with respect to 100 parts by mass of the raw material monomers) are put in an autoclave, heated to 100 ° C., and then stirred at a rotation speed of 28 rpm. And heated for 1 hour. 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 the step (i) was polymerized by heating at 230 ° C. for 5 hours under a normal pressure nitrogen stream in a dryer to obtain a polyamide (P-6). About the obtained polyamide (P-6), the relative viscosity, the weight average molecular weight, the melting point, the heat of fusion, the cooling crystallization temperature, the degree of supercooling ΔT, and the amount of triamine were measured. The results are shown in Table 1. In addition, in obtaining polyamide (P-6), since it superposed | polymerized using 4 mass parts of distilled water with respect to 100 mass parts of total amounts of a raw material monomer, manufacture other than the presence or absence of addition of distilled water is the same conditions Compared to Example 1, the weight average molecular weight was slightly lower and the amount of triamine was higher.

Production Example 8
[Step (i)]
1,10-decanediamine (5050 parts by mass) as a diamine component, powdered terephthalic acid (4870 parts by mass) with an average particle size of 80 μm, benzoic acid (72 parts by mass) as a terminal blocking agent, and sodium hypophosphite as a polymerization catalyst Monohydrate (6 parts by mass), 9200 parts by mass of distilled water (92 parts by mass with respect to 100 parts by mass of the raw material monomers) are put in an autoclave, heated to 100 ° C., and then stirred at a rotation speed of 28 rpm. And heated for 1 hour. 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 the step (i) was polymerized by heating at 230 ° C. for 5 hours in a dryer under a normal pressure nitrogen stream to obtain a polyamide (P-8). About the obtained polyamide (P-8), the relative viscosity, the weight average molecular weight, the melting point, the heat of fusion, the cooling crystallization temperature, the degree of supercooling ΔT, and the amount of triamine were measured. The results are shown in Table 1. In addition, in obtaining polyamide (P-8), since it superposed | polymerized using 92 mass parts of distilled water with respect to 100 mass parts of total amounts of a raw material monomer, manufacture other than the presence or absence of addition of distilled water is the same conditions Compared to Example 1, the weight average molecular weight was significantly lower and the amount of triamine was significantly higher.

Production Example 9
[Step (i)]
1,10-decanediamine (5050 parts by mass) as a diamine component, powdered terephthalic acid (4870 parts by mass) with an average particle size of 80 μm, benzoic acid (72 parts by mass) as a terminal blocking agent, and sodium hypophosphite as a polymerization catalyst Monohydrate (6 parts by mass) and 600 parts by mass of distilled water (6 parts by mass with respect to 100 parts by mass of the raw material monomers) are put in an autoclave, heated to 100 ° C., and then stirred at a rotation speed of 28 rpm. And heated for 1 hour. 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 the step (i) was polymerized by heating at 230 ° C. for 5 hours in a dryer under a normal pressure nitrogen stream to obtain a polyamide (P-9). About the obtained polyamide (P-9), the relative viscosity, the weight average molecular weight, the melting point, the heat of fusion, the cooling crystallization temperature, the degree of supercooling ΔT, and the amount of triamine were measured. The results are shown in Table 1. In addition, in order to obtain polyamide (P-9), since it superposed | polymerized using 6 mass parts of distilled water with respect to 100 mass parts of total amounts of a raw material monomer, manufacture other than the presence or absence of addition of distilled water is the same conditions Compared to Example 1, the weight average molecular weight was slightly lower and the amount of triamine was higher.

Production Examples 10 and 11
Except changing the compounding quantity of the terminal blocker to be used, polyamide (P-10) and (P-11) were obtained in the same manner as in Example 1, and each characteristic was measured. The results are shown in Table 1.

Example 1
80 parts by mass of the crystalline polyamide resin (P-1) obtained in Production Example 1 and 20 parts by mass of the amorphous polyamide resin (A-1) are dry blended, and a loss-in-wait type continuous quantitative supply device CE- made by Kubota. It measured using W-1, and supplied to the main supply port of the same-direction twin-screw extruder (Toshiba machine company make TEM37BS type) of screw diameter 37mm and L / D40. In the middle, 30 parts by mass of glass fiber (GF) was supplied to the total 100 parts by mass of the crystalline polyamide resin (P-1) and the amorphous polyamide resin (A-1) from the side feeder, and further kneaded. Finally, the strand was taken out from the die into a strand shape, and then cooled and solidified by passing through a water tank, which was cut with a pelletizer to obtain polyamide resin composition pellets. The barrel temperature setting of the extruder was 320 ° C. to 340 ° C., the screw rotation speed was 250 rpm, and the discharge amount was 35 kg / h.

  Next, using an injection molding machine (EC100 type manufactured by Toshiba Machine Co., Ltd.), the obtained polyamide resin composition pellets were injection molded under conditions of a cylinder temperature of 350 ° C. and a mold temperature of 130 ° C. to obtain test pieces. Various evaluation tests were performed using the obtained test pieces. The results are shown in Table 2.

Examples 2-14 , Reference Examples 1-3
Using the crystalline polyamide resin, the amorphous polyamide resin and the reinforcing material shown in Table 2, dry blending was carried out with a predetermined composition, and a polyamide resin composition pellet was obtained in the same manner as in Example 1, followed by injection molding and testing. Pieces were obtained and subjected to various evaluation tests. The results are shown in Table 2.

Reference Examples 4-6 , Comparative Examples 1-10
Using the crystalline polyamide resin, the amorphous polyamide resin and the reinforcing material shown in Table 3, dry blending was carried out with a predetermined composition, and a polyamide resin composition pellet was obtained in the same manner as in Example 1, and then injection molding and testing. Pieces were obtained and subjected to various evaluation tests. The results are shown in Table 3.

In Example 1-14, since by the predetermined formulation, it was possible to obtain a flexural strength, flexural modulus, surface gloss on a molded article excellent. Moreover, since the degree of supercooling ΔT was 40 ° C. or less, the moldability during injection molding was good.

  Comparative Example 1 was inferior in surface gloss because the amount of amorphous polyamide was too small.

  In Comparative Example 2, since the amount of the amorphous polyamide was excessive, the molding cycle was long and the continuous productivity was inferior.

  Since the comparative example 3 did not mix | blend a fibrous reinforcement, it was inferior in bending strength and a bending elastic modulus. Furthermore, the molding cycle was long.

  In Comparative Example 4, the blended amount of the fibrous reinforcing material was excessive, so that the polyamide resin pellets could not be obtained with strand cutting.

Since Comparative Example 5 uses glass beads, bending strength and bending elastic modulus were inferior. Furthermore, the molding cycle was long.

Claims (6)

A polyamide resin composition containing 5 to 200 parts by mass of a fibrous reinforcing material with respect to 100 parts by mass in total of the crystalline polyamide resin (A) and the amorphous polyamide resin (B), the crystalline polyamide resin ( The dicarboxylic acid component constituting A) is mainly composed of terephthalic acid, and the diamine component is composed of only a linear aliphatic diamine having 8, 10, or 12 carbon atoms, and the diamine in the crystalline polyamide resin (A) The polyamide resin composition, wherein the triamine unit is 0.2 mol% or less with respect to the unit, and (B) / {(A) + (B)} = 0.1 to 0.5 (mass ratio) object.   The polyamide resin composition according to claim 1, wherein the degree of supercooling ΔT measured using DSC of the crystalline polyamide resin (A) is 40 ° C or lower.   The polyamide resin composition according to claim 1 or 2, wherein the diamine component of the crystalline polyamide resin (A) is 1,10-decanediamine. Amorphous polyamide resin (B) is a polycondensate of isophthalic acid / terephthalic acid / 1,6-hexanediamine, isophthalic acid / terephthalic acid / 1,6-hexanediamine / bis (3-methyl-4-aminocyclohexyl) The polyamide resin composition according to any one of claims 1 to 3 , which is a polycondensate of methane or a mixture thereof. The polyamide resin composition according to any one of claims 1 to 4 , wherein the fibrous reinforcing material is at least one selected from glass fiber, carbon fiber, and metal fiber. The molded object formed by shape | molding the polyamide resin composition in any one of Claims 1-5 .