JP5400456B2 - Polyamide resin composition and molded body comprising the same - Google Patents

Description

  The present invention relates to a polyamide resin composition and a molded body comprising the same.

  Portable electronic devices typified by mobile phones and digital cameras often drop because they are carried around, and in particular, exterior parts such as housings and internal reinforcements are required to have sufficient strength. It is done. The materials that have been used for these parts have been magnesium alloys and aluminum die casts, but they have been replaced by resin materials because they are required to reduce the weight of equipment, have insulation properties for parts, and are difficult to process. ing.

Among them, a polyamide resin composition in which an inorganic filler is blended at a high concentration has been devised and used for parts that have become thinner with the recent miniaturization of portable electronic devices. For example, Patent Document 1 discloses a polyamide resin composition composed of a terpolymer polyamide resin and an inorganic filler.
Patent Document 2 discloses a polyamide resin composition comprising a terpolymer polyamide resin, polyamide 6 or polyamide 610, and an inorganic filler.
Patent Document 3 discloses a polyamide resin composition comprising a specific semi-aromatic polyamide resin, a fibrous filler and a plate-like filler.

JP 2000-219808 A JP 2006-193727 A JP 2008-007753 A

  However, the techniques described in Patent Documents 1 and 2 have a problem that burrs are likely to occur when molding a thin molded product. The technique described in Patent Document 3 has a problem that it is inferior in impact resistance and cannot obtain sufficient strength, although the generation of burrs during molding can be suppressed.

  Moreover, when a polyamide resin is formed into a molded body, there is a problem that rigidity and dimensional stability at the time of water absorption are lowered. Development of technology that can solve this problem is desired.

  The present invention has been made in view of the above circumstances, and provides a polyamide resin composition having excellent impact resistance, excellent rigidity and dimensional stability at the time of water absorption, and excellent moldability, and a molded body thereof. For the purpose.

  As a result of intensive studies to solve the above problems, the present inventor includes a polyamide resin having a specific composition ratio, a specific long-chain polyamide resin, and a high-concentration fiber length inorganic filler. The present inventors have found that a polyamide resin composition having excellent impact resistance, excellent rigidity and dimensional stability during water absorption, and excellent moldability can be obtained, and the present invention has been completed.

That is, the present invention
(1) (A) 70 to 85% by mass of hexamethylene adipamide units (N66) obtained from hexamethylenediamine and adipic acid, and 15 to 6 units of hexamethyleneisophthalamide (N6I) obtained from hexamethylenediamine and isophthalic acid A copolymerized polyamide resin consisting of 30% by mass;
(B) the ratio of the number of carbon atoms to the number of nitrogen atoms contained (C / N) is 7 or more and 12 or less, and an aliphatic polyamide resin obtained from a combination of aminocarboxylic acid and / or diamine and dicarboxylic acid;
(C) glass fiber,
The mass ratio (A / B) of the component (A) and the component (B) is 40/60 to 60/40,
A polyamide resin composition comprising 20 to 250 parts by mass of the component (C) with respect to a total of 100 parts by mass of the component (A) and the component (B),
(2) The relative viscosity (ηr) of the component (B) measured at 25 ° C. in a 98% sulfuric acid concentration of 1% according to JIS K 6810 is 2.0 to 2.5, (1) A polyamide resin composition,
(3) The polyamide resin composition according to (1) or (2), wherein the component (B) is polyamide 612.
(4) (D) The polyamide resin composition according to any one of (1) to (3), further comprising a ternary copolymer comprising the component (A) and the component (B),
(5) The component (B) is polyamide 612,
The (D) terpolymer is a terpolymer comprising N66 units, N6I units and polyamide 612 units.
(4) polyamide resin composition,
(6) The polyamide resin composition according to any one of (1) to (5), further comprising zinc sulfide,
(7) A molded body comprising the polyamide resin composition according to any one of (1) to (6),
It is.

  The polyamide resin composition of the present invention has excellent impact resistance when formed into a molded body, and has an effect of excellent balance between moldability, rigidity at the time of water absorption and dimensional stability.

It is a simplification figure of the molded product used for the burr | flash measurement in an Example.

  Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be implemented with appropriate modifications within the scope of the gist thereof.

  The polyamide resin composition of the present embodiment comprises 70 to 85% by mass of hexamethylene adipamide units (N66) obtained from hexamethylene diamine and adipic acid, and hexamethylene isophthalamide units obtained from hexamethylene diamine and isophthalic acid ( N6I) a copolymerized polyamide consisting of 15 to 30% by mass, (B) the ratio of carbon atoms to the number of nitrogen atoms contained (C / N) is 7 or more and 12 or less, and aminocarboxylic acid and / or diamine An aliphatic polyamide resin obtained from a combination of dicarboxylic acids and (C) glass fiber, and the mass ratio (A / B) of the component (A) to the component (B) is 40/60 to 60 / 40 and includes 20 to 250 parts by mass of the component (C) with respect to 100 parts by mass in total of the component (A) and the component (B). A. By containing the component (A), the component (B), and the component (C) in the above proportions, a molded body having excellent impact resistance and excellent balance between moldability, rigidity at the time of water absorption and dimensional stability is obtained. be able to.

  The (A) copolymerized polyamide resin of this embodiment is a hexamethylene adipamide unit (hereinafter referred to as “N66”) obtained from adipic acid and hexamethylene diamine, and a hexamethylene obtained from isophthalic acid and hexamethylene diamine. Methyleneisophthalamide unit (hereinafter referred to as “N6I”). The composition ratio of each component is 70 to 85% by mass for N66 and 15 to 30% by mass for N6I. From the viewpoint of the crystallinity of the copolymerized polyamide resin and the rigidity at the time of water absorption, preferred constitution ratios are 72 to 83% by mass for N66 and 17 to 28% by mass for N6I.

  (A) The degree of polymerization of the copolymerized polyamide resin is a relative viscosity ηr measured at a concentration of 1% in 98% sulfuric acid according to JIS K 6810 at 25 ° C., preferably 1.5 to 2.8, more preferably It is 1.6 to 2.7, more preferably 1.7 to 2.6. By using a copolymerized polyamide in such a range, the gloss of the surface of the resin molded product can be further improved.

  In the (B) aliphatic polyamide resin of the present embodiment, the ratio of carbon atoms to the number of nitrogen atoms contained (C / N) is 7 or more and 12 or less, and a combination of aminocarboxylic acid and / or diamine and dicarboxylic acid. The resulting aliphatic polyamide resin.

  The component (B) has a ratio (C / N) of the number of carbon atoms to the number of nitrogen atoms of 7 to 12 in the polymer having an amide bond (—NHCO—) in the main chain. Further, it is composed of an aliphatic monomer. For example, polyhexamethylene sebacamide (polyamide 610), polyhexamethylene dodecamide (polyamide 612), polyundecalactam (polyamide 11), polydodecalactam (polyamide). 12) and a polyamide copolymer containing at least two different polyamide-forming components, or a mixture thereof. Among these, preferred (B) aliphatic polyamide resins include polyamide 612 and polyamide 12 from the viewpoint of rigidity during water absorption. More preferred is polyamide 612.

  The degree of polymerization of the aliphatic polyamide which is the component (B) of this embodiment is a relative viscosity ηr measured at 25 ° C. in a 98% sulfuric acid concentration of 1% according to JIS K 6810, preferably 2.0-2. .5, more preferably 2.1 to 2.4. By using an aliphatic polyamide in such a range, the gloss of the surface of the resin molded product can be improved.

  (C) The glass fiber of this embodiment can use what is normally used for a thermoplastic resin, There is no restriction | limiting in particular in a fiber diameter and length, For example, an average fiber diameter is 5-30 micrometers chopped strand. , Roving or milled fiber. What is necessary is just to select suitably in the range whose length is 0.1-6 mm when using a chopped strand.

  For these glass fibers, it is also possible to preferably use a glass fiber with a generally known sizing agent or silane coupling agent attached to its surface. For example, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, vinyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, etc. Available.

  In this embodiment, it is preferable that the (D) component further includes a ternary copolymer component of the (A) component and the (B) component. The ternary copolymer component of the component (D) has the same components as the components used as the component (A) and has the same components as the components used as the component (B). For example, when a polyamide resin composed of N66 and N6I is used as the component (A) and a polyamide 612 is used as the component (B), a terpolymer containing polyamide 612 units is included as the component (D) in addition to N66 and N6I. . By further adding the component (D), it is possible to further increase the mixed state of the component (A) and the component (B), thereby contributing to improvement in impact strength and fluidity. In particular, by making the aliphatic polyamide used in the ternary copolymer of the component (D) the same as the component (B), it is possible to further enhance the mixed state of the component (A) and the component (B). (However, the action is not limited to this.) In this embodiment, it is particularly preferred that the component (B) is polyamide 612 and the component (D) is a terpolymer comprising N66 units, N6I units and polyamide 612 units. By setting it as such a polyamide resin composition, the mixed state of (A) component and (B) component can be improved further.

  The content of the ternary copolymer component of the component (A) and the component (B) in the component (D) is not particularly limited, but from the viewpoint of rigidity and crystallinity during water absorption, the mass ratio (A / B) Is preferably 30/70 to 70/30.

  When obtaining the polyamide resin composition of this embodiment, the mass ratio (A / B) of (A) copolymer polyamide resin and (B) aliphatic polyamide resin is 40 / 60-60 / 40, and the rigidity at the time of water absorption From this point of view, the mass ratio (A / B) is preferably 45/55 to 60/40.

  The blending amount of the (C) glass fiber in the polyamide resin composition of the present embodiment is (C) a glass fiber 20 to a total of 100 parts by mass of the (A) copolymer polyamide resin and the (B) aliphatic polyamide resin. From the viewpoint of the balance between rigidity and fluidity, it is preferably 60 to 180 parts by mass of component (C) with respect to 100 parts by mass of component (A) and component (B), more preferably ( C) 80 to 150 parts by mass.

  The blending amount of (D) ternary copolymer in the polyamide resin composition of the present embodiment is 100 parts by mass in total of (A) copolymer polyamide resin and (B) aliphatic polyamide resin from the viewpoint of heat resistance and rigidity. On the other hand, (D) the terpolymer is preferably 2 to 20 parts by mass, more preferably 3 to 10 parts by mass.

  The polyamide resin composition of the present embodiment includes other polyamide resins and other polymers, fillers, crystal nucleating agents, heat stabilizers, ultraviolet absorbers and the like as long as the purpose of the present embodiment is not impaired as necessary. Stabilizers, flame retardants, antistatic agents, plasticizers, lubricants, colorants, coupling agents and the like can be added.

  Examples of other polyamide resins include polyamide 6, polyamide 46, polyamide 66, polyamide 6T, polyamide 9T, polyamide 12T, polyamide MXD6, and polyamide copolymers containing at least two different polyamide-forming components. .

  Other polymers include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-octene copolymer, styrene-ethylene copolymer, styrene-isoprene copolymer, styrene-ethylenebutylene-styrene block copolymer. Styrene-ethylenepropylene-styrene block copolymer, liquid crystal resin, unsaturated aliphatic carboxylic acid anhydride-modified polyphenylene ether resin, polyphenylene sulfide and the like.

  As fillers, inorganic fibers such as glass fiber and carbon fiber, mica, talc, clay mineral, alumina, silica, apatite, aluminum hydroxide, magnesium hydroxide, zinc borate, zinc stannate, zinc hydroxystannate, cellulose Etc.

  Examples of the crystal nucleating agent include kaolin, boron nitride, and phosphoric acid-2,2'-methylenebis (4,6-di-t-butylphenyl) sodium.

  Examples of the stabilizer include metal phosphites such as sodium hypophosphite, hindered phenols, organic phosphorus compounds and hindered amines.

  Examples of the antistatic agent include sorbitan fatty acid ester, glycerin fatty acid ester, polyglycerin fatty acid ester and higher alcohol fatty acid ester.

  Examples of the flame retardant include ammonium polyphosphate, melamine cyanurate, succinoguanamine, melamine polyphosphate, melamine sulfate, melamine phthalate, and aluminum phosphate.

  Examples of lubricants and plasticizers include higher fatty acid metal salts, higher fatty acid amides, and higher fatty acid esters.

  Examples of the colorant include zinc sulfide, titanium white, carbon black, azine dyes, and phthalocyanine derivatives. Among these, zinc sulfide is preferable from the viewpoint of rigidity and impact resistance. The blending amount of zinc sulfide in the polyamide resin composition of the present embodiment is preferably 0.1 to 5 parts by mass in 100 parts by mass of the polyamide resin composition of the present embodiment from the viewpoint of heat resistance and rigidity. More preferably, it is 0.5-3 mass parts.

  As a method for obtaining the polyamide resin composition of the present embodiment, it can be produced by melt kneading. As a device for performing melt kneading, a kneading machine generally used can be applied. For example, a single-screw or multi-screw kneading extruder, a Banbury mixer, a roll, or the like may be used. There is no particular restriction on the order of melt-kneading, and a method of kneading all the components simultaneously, or a method of kneading any two components in advance and kneading the obtained one with the remaining one component, further in the middle of the extruder Alternatively, a method may be used in which each component is sequentially fed and kneaded. The kneading temperature is preferably 1 to 100 degrees higher than the highest melting point or softening point of the copolymerized polyamide resin and aliphatic polyamide resin, more preferably 10 to 60 ° C, and still more preferably 20 to 50 ° C. That is, it is preferable that the resin used as a raw material in the present embodiment is melted and mixed during the production method. The melting point or softening point can be determined by differential scanning calorimetry (DSC) measurement according to JIS K7121. When the temperature is out of the temperature range, the effect of the present embodiment tends to be hardly exhibited, and at the same time, the productivity tends to be lowered.

  The molded body obtained from the polyamide resin composition of the present embodiment is excellent in impact resistance, and has excellent balance of rigidity and dimensional stability upon water absorption and moldability. Can be suitably used.

  Hereinafter, the present embodiment will be described in more detail with reference to examples. However, the present embodiment is not limited to the following examples unless it exceeds the gist. In addition, the physical property evaluation described in the following examples and comparative examples was performed as follows.

(1) Flexural modulus (dry state)
Using an injection molding machine (manufactured by Nissei Resin Co., Ltd., PS-40E), the cylinder temperature was set to 280 ° C., the mold temperature was set to 100 ° C., and a test piece for evaluation having a thickness of 4 mm was obtained. The flexural modulus was measured.

(2) Flexural modulus (wet condition)
The test piece obtained by injection molding in the same manner as in (1) was left in an environment of 23 ° C. × 50% relative humidity, and left to stand until the mass became constant, and a water absorption treatment was performed. The test piece after the water absorption treatment was subjected to a bending test in the same manner as (1).

(3) Change in water absorption dimension, water absorption rate Using an injection molding machine (manufactured by Nissei Resin Co., Ltd., FN3000), the cylinder temperature is set to 280 ° C, the mold temperature is set to 100 ° C, and the thickness is 3 mm × width 60 mm × length 90 mm. After getting the flat plate
The length dimension (L1) was measured. The measurement position at this time was the center of the width and the center of the end. Using this test piece, it was left in an environment of 23 ° C. × 50% relative humidity, left to stand until the mass became constant, and subjected to water absorption treatment, and then the dimension (L2) was measured in the same manner. The water absorption dimensional change (ΔL) was calculated as follows.
ΔL = (L2−L1) / L1 × 100
The water absorption (W3) was calculated as follows by measuring the test piece weight (W1) immediately after molding of the same flat plate test piece and the test piece weight (W2) after water absorption treatment.
W3 = (W2-W1) / W1 × 100

(4) Impact resistance The test piece obtained in (1) was cut, and a Charpy impact test was carried out by a method based on ISO 179 with a notched test piece to determine the impact resistance.

(5) Fluidity (Burr)
Using an injection molding machine (FE120 manufactured by Nissei Resin Co., Ltd.), the cylinder temperature was set to 280 ° C. and the mold temperature was set to 100 ° C., and the molded product shown in FIG. 1 was injection molded. When molding was performed at a pressure filled with the injection molded product, the length of the burr that appeared at the gas vent portion (thickness: 100 μm) provided for burr evaluation was measured.
Next, the raw materials used in the examples of this embodiment will be described. The polyamide copolymer as component (A), the polyamide polymer as component (B), and the ternary copolymer as component (D) were prepared based on the production examples described below. Moreover, the raw material used for the manufacture example, (C) component, and (E) other raw materials used the commercially available thing.

[raw materials]
Hexamethylenediamine (made by Wako Pure Chemical Industries, trade name: hexamethylenediamine)
Adipic acid (made by Wako Pure Chemical Industries, trade name: adipic acid)
Isophthalic acid (made by Wako Pure Chemical Industries, trade name: isophthalic acid)
Dodecanedioic acid (made by Wako Pure Chemical Industries, trade name: dodecanedioic acid)
(C) Glass fiber manufactured by Nippon Electric Glass Co., Ltd .; trade name ECS03T-275 / H
(E) Other raw materials Zinc sulfide: manufactured by Sachtleben Chemie GmbH, trade name: SachtolithHD

(Production Example 1)
12 kg of an aqueous solution containing 50% by mass of an equimolar salt of hexamethylenediamine and adipic acid as a polymer component, and 3 kg of an aqueous solution containing 50% by mass of an equimolar salt of hexamethylenediamine and isophthalic acid as a polyamide resin. Was prepared. Next, the aqueous solution was charged into a 40 liter autoclave having a stirring device and having a discharge nozzle at the bottom, and the aqueous solution was sufficiently stirred at a temperature of 50 ° C. Next, after the inside of the autoclave was sufficiently substituted with nitrogen, the temperature inside the autoclave was increased from 50 ° C. to about 270 ° C. while stirring the aqueous solution. At this time, the pressure in the autoclave was about 1.8 MPa in terms of gauge pressure, but water was discharged from the system as needed so that the pressure did not exceed 1.8 MPa. Further, the polymerization time was adjusted so that the relative viscosity of the polyamide resin became the target relative viscosity. After the polymerization in the autoclave is completed, the polyamide resin is sent in a strand form from the lower nozzle, and after water cooling and cutting, a pellet-like polyhexamethylene adipamide and polyhexamethylene isophthalamide copolymer (polyamide 66 / 6I). ) This polyamide copolymer was vacuum dried at 80 ° C. for 24 hours. When the relative viscosity (ηr) of the polyamide copolymer was measured as described above, it was 2.30.

(Production Example 2)
15 kg of an aqueous solution containing an equimolar salt of hexamethylenediamine and dodecanedioic acid as a polymerization component in an amount corresponding to 50% by mass as a polyamide resin was prepared. Next, the aqueous solution was charged into a 40 liter autoclave having a stirring device and having a discharge nozzle at the bottom, and the aqueous solution was sufficiently stirred at a temperature of 50 ° C. Next, after the inside of the autoclave was sufficiently substituted with nitrogen, the temperature inside the autoclave was increased from 50 ° C. to about 270 ° C. while stirring the aqueous solution. At this time, the pressure in the autoclave was about 1.8 MPa in terms of gauge pressure, but water was discharged from the system as needed so that the pressure did not exceed 1.8 MPa. The polymerization time was adjusted so that the relative viscosity of the polyamide polymer was the target relative viscosity. After the polymerization in the autoclave was completed, the polyamide polymer was sent out in a strand form from the lower nozzle, and after water cooling and cutting, pelletized polyhexamethylene dodecamide (polyamide 612) was obtained. This polyamide 612 was vacuum dried at 80 ° C. for 24 hours. It was 2.10 when the relative viscosity ((eta) r) of the polyamide 612 was measured as mentioned above.

(Production Example 3)
15 kg of an aqueous solution containing an equimolar salt of hexamethylenediamine and adipic acid as a polymerization component in an amount corresponding to 50% by mass as a polyamide resin was prepared. Next, the aqueous solution was charged into a 40 liter autoclave having a stirring device and having a discharge nozzle at the bottom, and the aqueous solution was sufficiently stirred at a temperature of 50 ° C. Next, after the inside of the autoclave was sufficiently substituted with nitrogen, the temperature inside the autoclave was increased from 50 ° C. to about 270 ° C. while stirring the aqueous solution. At this time, the pressure in the autoclave was about 1.8 MPa in terms of gauge pressure, but water was discharged from the system as needed so that the pressure did not exceed 1.8 MPa. The polymerization time was adjusted so that the relative viscosity of the polyamide polymer was the target relative viscosity. After the polymerization in the autoclave was completed, the polyamide polymer was sent out in a strand form from the lower nozzle, and water-cooling and cutting were performed to obtain pellet-shaped polyhexamethylene adipamide (polyamide 66). This polyamide 66 was vacuum dried at 80 ° C. for 24 hours. When the relative viscosity (ηr) of the polyamide 66 was measured as described above, it was 2.60.

(Production Example 4)
An aqueous solution containing 6 kg of an equimolar salt of hexamethylenediamine and adipic acid as a polymerization component in an amount equivalent to 50% by mass as a polyamide resin and an aqueous solution containing 50% by mass in an equimolar salt of hexamethylenediamine and isophthalic acid as a polyamide resin. 7.5 kg of an aqueous solution containing 1.5 kg, equimolar salt of hexamethylenediamine and dodecanedioic acid as a polyamide resin, corresponding to 50% by mass, was prepared. Next, the aqueous solution was charged into a 40 liter autoclave having a stirring device and having a discharge nozzle at the bottom, and the aqueous solution was sufficiently stirred at a temperature of 50 ° C. Next, after the inside of the autoclave was sufficiently substituted with nitrogen, the temperature inside the autoclave was increased from 50 ° C. to about 270 ° C. while stirring the aqueous solution. At this time, the pressure in the autoclave was about 1.8 MPa in terms of gauge pressure, but water was discharged from the system as needed so that the pressure did not exceed 1.8 MPa. Further, the polymerization time was adjusted so that the relative viscosity of the polyamide resin became the target relative viscosity. After the polymerization in the autoclave is completed, the polyamide resin is sent in a strand form from the lower nozzle, and after cooling with water and cutting, the pellets of polyhexamethylene adipamide, polyhexamethylene isophthalamide and polyhexamethylene sebacamide are co-polymerized. A polymer (polyamide 66 / 6I / 612) was obtained. This polyamide copolymer was vacuum dried at 80 ° C. for 24 hours. When the relative viscosity (ηr) of the polyamide copolymer was measured as described above, it was 2.10.

[Example 1]
A mixture of 50 parts by mass of polyamide 66 / 6I copolymer of Production Example 1 and 50 parts by mass of polyamide 612 polymer of Production Example 2 was mixed with a twin-screw extruder (TEM 35 manufactured by Toshiba Machine Co., Ltd. Using a rotary type, L / D = 47.6 (D = 37 mmφ), when the polyamide mixture is sufficiently melted, side feed is performed so that the glass fiber becomes 100 parts by mass with respect to 100 parts by mass of the polyamide mixture, and then melted. Kneaded. Extrusion was performed while reducing the pressure at a screw speed of 300 rpm, a cylinder temperature of 280 ° C. (the polymer temperature in the vicinity of the tip nozzle was 290 ° C.), and a rate of 50 kg / hr. The polymer was discharged in a strand form from the tip nozzle, water-cooled and cut to form pellets. Table 1 shows the evaluation results of the moldings obtained.

[Example 2]
A mixture of 50 parts by mass of polyamide 66 / 6I copolymer of Production Example 1 and 50 parts by mass of polyamide 612 polymer of Production Example 2 was mixed with a twin-screw extruder (TEM 35 manufactured by Toshiba Machine Co., Ltd. Using a rotary type, L / D = 47.6 (D = 37 mmφ), when the polyamide mixture is sufficiently melted, side feed is performed so that the glass fiber becomes 150 parts by mass with respect to 100 parts by mass of the polyamide mixture, and then melted. Kneaded. Extrusion was performed while reducing the pressure at a screw speed of 300 rpm, a cylinder temperature of 280 ° C. (the polymer temperature in the vicinity of the tip nozzle was 290 ° C.), and a rate of 50 kg / hr. The polymer was discharged in a strand form from the tip nozzle, water-cooled and cut to form pellets. Table 1 shows the evaluation results of the moldings obtained.

[Comparative Example 1]
100 parts by mass of polyamide 66 / 6I copolymer of Production Example 1 was added to a twin-screw extruder (TEM35 manufactured by Toshiba Machine Co., Ltd., twin-screw rotation type, L / D = 47.6 (D = 37 mmφ)) Was used, side feed was performed so that the amount of the glass fiber was 150 parts by mass with respect to 100 parts by mass of the polyamide copolymer, and melt kneading was performed. Extrusion was performed while reducing the pressure at a screw speed of 300 rpm, a cylinder temperature of 280 ° C. (the polymer temperature in the vicinity of the tip nozzle was 290 ° C.), and a rate of 50 kg / hr. The polymer was discharged in a strand form from the tip nozzle, water-cooled and cut to form pellets. Table 1 shows the evaluation results of the moldings obtained.

[Comparative Example 2]
A mixture consisting of 50 parts by mass of polyamide 66 / 6I copolymer of Production Example 1 and 50 parts by mass of polyamide 66 polymer of Production Example 3 was mixed with a twin screw extruder (TEM35, manufactured by Toshiba Machine Co., Ltd. Using a rotary type, L / D = 47.6 (D = 37 mmφ), when the polyamide mixture is sufficiently melted, side feed is performed so that the glass fiber becomes 150 parts by mass with respect to 100 parts by mass of the polyamide mixture, and then melted. Kneaded. Extrusion was performed while reducing the pressure at a screw speed of 300 rpm, a cylinder temperature of 280 ° C. (the polymer temperature in the vicinity of the tip nozzle was 290 ° C.), and a rate of 50 kg / hr. The polymer was discharged in a strand form from the tip nozzle, water-cooled and cut to form pellets. Table 1 shows the evaluation results of the moldings obtained.

[Example 3]
A mixture comprising 45 parts by mass of polyamide 66 / 6I copolymer of Production Example 1, 45 parts by mass of polyamide 612 polymer of Production Example 2, and 10 parts by mass of polyamide 66 / 6I / 612 copolymer of Production Example 4 Using a twin screw extruder (TEM35 manufactured by Toshiba Machine Co., Ltd., twin screw co-rotating type, L / D = 47.6 (D = 37 mmφ)), the polyamide mixture 100 was obtained when the polyamide mixture was sufficiently melted. Side feed was performed so that the glass fiber was 150 parts by mass with respect to the mass part, and melt kneading was performed. Extrusion was performed while reducing the pressure at a screw speed of 300 rpm, a cylinder temperature of 280 ° C. (the polymer temperature in the vicinity of the tip nozzle was 290 ° C.), and a rate of 50 kg / hr. The polymer was discharged in a strand form from the tip nozzle, water-cooled and cut to form pellets. Table 1 shows the evaluation results of the moldings obtained.

[Example 4]
A mixture of 48.8 parts by mass of polyamide 66 / 6I copolymer of Production Example 1, 48.8 parts by mass of polyamide 612 polymer of Production Example 2 and 2.4 parts by mass of zinc sulfide was added to a twin-screw extruder (TOSHIBA). Glass fiber for 100 parts by mass of the above mixture when the polyamide mixture is sufficiently melted by using TEM35, twin screw rotating type, L / D = 47.6 (D = 37 mmφ) manufactured by Kikai Co., Ltd. Side feed was performed so as to be 150 parts by mass, and melt kneading was performed. Extrusion was performed while reducing the pressure at a screw speed of 300 rpm, a cylinder temperature of 280 ° C. (the polymer temperature in the vicinity of the tip nozzle was 290 ° C.), and a rate of 50 kg / hr. The polymer was discharged in a strand form from the tip nozzle, water-cooled and cut to form pellets. Table 1 shows the evaluation results of the moldings obtained.

  The molded bodies of Examples 1 to 4 had a small change in flexural modulus in the dry state and the wet state, a small dimensional change rate due to water absorption, a small water absorption rate, and excellent impact resistance. Furthermore, the burr of the molded product was short. That is, the molded bodies of Examples 1 to 4 were excellent in all of rigidity and dimensional stability at the time of water absorption, impact resistance, and moldability. On the other hand, the molded bodies of Comparative Examples 1 and 2 were inferior in any of rigidity and dimensional stability at the time of water absorption, impact resistance, and moldability.

  From the above, it was shown that the polyamide resin composition of the present embodiment is excellent in impact resistance when formed into a molded body, is excellent in rigidity and dimensional stability at the time of water absorption, and is excellent in moldability. .

  The polyamide resin composition and molded body of the present invention are excellent in impact resistance, excellent in rigidity and dimensional stability at the time of water absorption, and excellent in moldability, so that various portable electronic devices, electronic parts, etc. It is useful as an industrial material.

Claims (8)

(A) 70 to 85% by mass of hexamethylene adipamide units (N66) obtained from hexamethylenediamine and adipic acid, and 15 to 30% by mass of hexamethyleneisophthalamide units (N6I) obtained from hexamethylenediamine and isophthalic acid A copolymerized polyamide resin comprising:
(B) the ratio of the number of carbon atoms to the number of nitrogen atoms contained (C / N) is 7 or more and 12 or less, and an aliphatic polyamide resin obtained from a combination of aminocarboxylic acid and / or diamine and dicarboxylic acid;
(C) glass fiber,
The relative viscosity (ηr) of the component (B) measured at 25 ° C. in a 98% sulfuric acid concentration of 1% according to JIS K 6810 is 2.0 to 2.5,
The mass ratio (A / B) of the component (A) and the component (B) is 40/60 to 60/40,
A polyamide resin composition comprising 20 to 250 parts by mass of the component (C) with respect to 100 parts by mass in total of the component (A) and the component (B). Wherein component (B), polyamide 610, polyamide 612, polyamide 11, polyamide 12, polyamide copolymers comprising at least two different polyamide forming components among these, or mixtures thereof, according to claim 1 Polyamide resin composition. The polyamide resin composition according to claim 1 , wherein the component (B) is polyamide 612 or polyamide 12. The polyamide resin composition according to claim 1 , wherein the component (B) is polyamide 612. (D) The polyamide resin composition according to any one of claims 1 to 4 , further comprising a ternary copolymer composed of the component (A) and the component (B). The component (B) is polyamide 612,
The polyamide resin composition according to claim 5 , wherein the component (D) is a terpolymer comprising N66 units, N6I units and polyamide 612 units. The polyamide resin composition according to any one of claims 1 to 6 , further comprising zinc sulfide. Molded body made of a polyamide resin composition according to any one of claims 1-7.

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