Method for producing glass fiber-reinforced polyamide resin composition

Abstract

A method for producing a glass fiber-reinforced polyamide resin composition containing (A) 20-70 mass% of a polyamide resin and (B) 10-75 mass% of a glass fiber by a twin-screw extruder, the method being characterized in that: the glass fiber-reinforced polyamide resin composition has a shear viscosity of 400-2,000 Pa * s at 280 DEG C and 91 / sec; when a wire material is extruded from a transverse flat die mounted on a die holder at the front end of the twin-screw extruder, the temperature of the wire material from a die hole in the center of the flat die is 310-360 DEG C; (i) the temperature of the wire material from the die hole at the end of the flat die is 4-14 DEG C lower than the temperature of the wire material from the die hole at the center of the flat die or (ii) the wire material is extruded such that the resin pressure in the die when leaving the flat die is 2.0-8.5 MPa.

Description

Technical Field

[0001] The present invention relates to a method for producing a glass fiber reinforced polyamide resin composition, and more particularly, to a method in which a glass fiber reinforced polyamide resin composition in which glass fiber or other reinforcing materials are compounded at a high concentration is produced as pellets maintaining a good pellet shape by using a twin-screw extruder with high productivity while suppressing strand breakage and enabling continuous and stable production. Background Art

[0002] Polyamide resins represented by poly(m-xylylene adipamide) (hereinafter, also referred to as nylon MXD6), polyamide 6 (also referred to as nylon 6), or polyamide 66 (also referred to as nylon 66) are widely used in various mechanical parts and automobile parts, etc., and are mainly used for injection molding. In particular, a glass fiber reinforced polyamide resin composition in which a high content of glass fiber is blended is excellent in mechanical strength, heat resistance, chemical resistance, etc., and is used as a component in the automotive industry and the field of mechanical equipment, etc.

[0003] Patent Document 1 describes (1) a glass fiber reinforced polyamide resin composition comprising a polyamide resin (A) composed of an aliphatic polyamide (a1) and a polyamide (a2) containing an aromatic component and a glass fiber reinforced polyamide having a cross-sectional area of ​​1.5 to 5.0×10 - 6 cm 2 The glass fiber (B) is prepared from polyamide resin (A) and glass fiber (B), wherein the weight ratio between the polyamide resin (A) and the glass fiber (B) is (A):(B) from 20:80 to 35:65.

[0004] However, when producing a polyamide resin composition in which glass fiber or other reinforcing materials are compounded at high concentrations with a twin-screw extruder, strand breakage occurs easily when the composition is extruded from a die. When strand breakage occurs, the strand breakage contacts adjacent strands, and adjacent strands may also break. In addition, it is necessary to feed the strand breakage to the operation in the pelletizer again or to rectify the strand breakage, so productivity is significantly reduced. In addition, when the strand breakage is fed to the pelletizer, the strands overlap each other, and the flow of the strands is disturbed, so long pellets may be produced. In addition, due to high concentration, strand breakage also deteriorates, and the cross section of the pellets is not sharp, and a large amount of chips are also produced. This trend becomes more significant as the concentration of glass fiber or other reinforcing materials becomes higher. Long pellets or chips may cause poor plasticization when formed with an injection molding machine, and make the measurement time long, stop the injection molding machine or deteriorate productivity. In particular, this phenomenon becomes remarkable when the content of glass fiber and other reinforcing materials exceeds 30% by mass, becomes more remarkable when the content exceeds 40% by mass, and becomes particularly remarkable when the content exceeds 50% by mass.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: WO 2014 / 171363 Summary of the invention

[0008] Problem that the invention aims to solve

[0009] The subject (object) of the present invention is to suppress the breakage of strands extruded from a die when producing a glass fiber reinforced polyamide resin composition in which glass fiber and other reinforcing materials are blended at high concentrations using a twin-screw extruder, to enable continuous and stable production, and to suppress the generation of long pellets.

[0010] Solutions for solving problems

[0011] As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that, in the case of producing a polyamide resin composition containing glass fiber and other reinforcing materials in high contents of 10 to 75% by mass and 0 to 40% by mass, respectively, by a twin-screw extruder, the viscosity of the resin composition becomes high; however, when the viscosity is set to a shear viscosity of 400 to 2000 Pa·s (280° C., a shear rate of 91 / sec), the strand temperature is set to a specific temperature, and (i) the strand temperature at the die end is set to be 4° C. to 14° C. lower than the strand temperature at the center of the die or (ii) the die pressure is set to a specific range, strand breakage is suppressed, continuous and stable production is possible, and the generation of long pellets can be significantly suppressed, thereby achieving the present invention.

[0012] Furthermore, the present inventors have found that, at this time, the temperature of a die holder is preferably set to a high temperature of 250° C. to 350° C., and the resin pressure in the die is preferably set to 2.0 to 8.5 MPa.

[0013] The present invention relates to the following method for producing a glass fiber reinforced polyamide resin composition.

[0014] 1. A method for producing a glass fiber reinforced polyamide resin composition, comprising producing the glass fiber reinforced polyamide resin composition by using a twin-screw extruder, wherein the glass fiber reinforced polyamide resin composition comprises 20 to 70% by mass of a polyamide resin (A), 10 to 75% by mass of a glass fiber (B), 0 to 40% by mass of other reinforcing materials (C) and 0 to 30% by mass of other polymers or additives (D) (the total of the components is 100% by mass), wherein

[0015] The shear viscosity of the glass fiber reinforced polyamide resin composition at a temperature of 280° C. and a shear rate of 91 / sec is 400 to 2000 Pa·s.

[0016] When a strand is extruded from a transverse flat die in a die holder at the front end of the twin-screw extruder, the temperature of the strand from the die hole in the center of the flat die is 310°C to 360°C, and

[0017] (i) The temperature of the strands from the die holes at the ends of the flat die is 4°C to 14°C lower than the temperature of the strands from the die holes in the center of the flat die, or

[0018] (ii) The strands are extruded from the flat die so that the resin pressure in the die becomes 2.0 to 8.5 MPa.

[0019] 2. A manufacturing method as described in 1, wherein (i) the temperature of the strand from the die hole at the end of the flat die is 4°C to 14°C lower than the temperature of the strand from the die hole in the center of the flat die, and (ii) the strand is extruded in such a way that the resin pressure in the die when extruding from the flat die is 2.0 to 8.5 MPa.

[0020] 3. The manufacturing method according to 1 or 2, wherein the temperature of the mold base is 250°C to 350°C.

[0021] 4. The production method according to any one of 1 to 3, wherein the polyamide resin (A) comprises one to three of polymeta-xylylene adipamide, polyamide 6, and polyamide 66.

[0022] 5. The production method according to any one of 1 to 4, wherein the total content of the glass fiber (B) and the other reinforcing material (C) is 30% by mass or more.

[0023] 6. The production method according to any one of 1 to 5, wherein the glass fiber (B) comprises a glass fiber having an aspect ratio of a longitudinal cross section in the range of 2.0 to 6.0.

[0024] Effects of the Invention

[0025] According to the production method of the present invention, a glass fiber-reinforced polyamide resin composition (pellets) containing glass fiber or other reinforcing materials at a high concentration can be produced in a good pellet shape while suppressing strand breakage and in continuous stable production. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] [ Figure 1 ] is a conceptual diagram showing an example of the process from a twin-screw extruder to a granulator used in the present invention.

[0027] [ Figure 2 ] is a diagram showing an example of a die portion of a twin-screw extruder used in the present invention.

[0028] [ Figure 3 ] is a cross-sectional view showing an example of a transverse flat die, etc. used in the present invention.

[0029] [ Figure 4 ] is a cross-sectional view showing another example of the transverse flat die used in the present invention.

[0030] [ Figure 5 ] is a cross-sectional view showing yet another example of the transverse flat die used in the present invention.

[0031] [ Figure 6 ] is a conceptual diagram of the screw structure of the extruder used in the embodiments or comparative examples. DETAILED DESCRIPTION

[0032] Hereinafter, the present invention will be described in detail by showing embodiments and examples, but the present invention is not limited to the embodiments and examples described later, and can be arbitrarily changed and implemented within the scope of the gist of the present invention. In this specification, "~(to)" is used to mean the numerical value before and after "~(to)" as the lower limit and upper limit.

[0033] In the manufacturing method of the present invention, a glass fiber reinforced polyamide resin composition composed of 20 to 70 mass % of a polyamide resin (A), 10 to 75 mass % of a glass fiber (B), 0 to 40 mass % of other reinforcing materials (C) and 0 to 30 mass % of other polymers or additives (D) (the total of all components is 100 mass %) is manufactured using a twin-screw extruder.

[0034] The extruder used in the present invention is a ventilated twin-screw extruder, and preferably an intermeshing co-rotating twin-screw extruder, in which two screws rotating in the same direction are arranged in a barrel and a kneading section each consisting of a plurality of kneading disks is arranged in the middle of the screw in a mutually intermeshing manner.

[0035] like Figure 1 As shown, the vented twin-screw extruder has a barrel, which includes a main raw material hopper 1, an open vent 2, a side feed hopper 3, a decompression vent 4, and a die base 8 passing through a flange 6 at the front end. The screw in the barrel is driven and rotated by a motor 16 passing through a screw connection 14 and a gear box 15.

[0036] The polyamide resin (A) and other polymers or additives (D) are fed from the main raw material hopper 1 and kneaded in the first kneading section (first process). The glass fiber (B) is usually side-fed from the side feed hopper 3 present in the downstream portion of the first kneading section and kneaded in the second kneading section (second process). Other reinforcing materials (C) may be fed from the hopper 1, or may be fed from the side feed hopper 3 like the glass fiber (B). Other reinforcing materials may also be fed from a separate location.

[0037] Next, in the downstream part of the second kneading section, the pressure reduction vent 4 is reduced to cause devolatilization, and the pressure rises, and a strand is extruded from a die set at a die holder 8 (third process). Then, the strand 10 extruded from the die is cooled with water, cut by a pelletizer 11 (fourth process), and pellets 12 of the resin composition are obtained.

[0038] In the first process, polyamide resin (A) and other polymers or additives (D) are fed into the extruder from the main raw material hopper 1, and melted by heating and kneading with a screw. A first kneading section composed of a plurality of kneading disks is arranged in the middle of the screw. The first kneading section is a kneading section where the polyamide resin (A) and other polymers or additives (D) are fed and then kneaded, and means a kneading section before feeding the glass fiber (B). The screw structure is preferably composed of the following: a combination of two or more of an R kneading disk, an N kneading disk, an L kneading disk, an L screw, a sealing ring, a mixing screw or a rotor screw, and the length is preferably set to 4.0 to 9.0D (D is the barrel diameter). The first kneading section is a kneading section where the polyamide resin (A) and other polymers or additives (D) are fed and then kneaded, and is a kneading section before feeding the glass fiber (B).

[0039] The first kneading section may be a single combined section, or may be divided into a plurality of sections. That is, the first kneading section may be divided, and a conveying screw may be inserted therebetween. Even in the case where the first kneading section is divided, the total length of the kneading section is preferably set within a range of 4.0 to 9.0D.

[0040] The R kneading disk (hereinafter, sometimes referred to as R) is a forward conveying kneading disk element and generally has two or more blades, and the blade twist angle θ is preferably 10 degrees to 75 degrees. When the blades are arranged at a predetermined angle as described above, a region is formed in which a pseudo-helical structure is formed, a strong shearing force is applied to the resin while the resin is conveyed in the conveying direction, and the resin is kneaded.

[0041] The L kneading disk (hereinafter, sometimes referred to as L) is a reverse conveying kneading disk element, which generally has two or more blades, and the blade twist angle θ is preferably -10 degrees to -75 degrees. The reverse conveying kneading disk element is an element having a compression capability to block the resin from entering or to send the resin back, and is an element provided downstream of the element promoting kneading to block the resin and exert a strong kneading effect.

[0042] The N kneading disk (hereinafter, sometimes referred to as N) is an orthogonal kneading disk element and generally has two or more blades, and the blade twist angle θ is 75 to 105 degrees. Since the blades are arranged at approximately 90 degrees, the resin conveying force is weak, but the kneading force is strong.

[0043] The L screw is a reverse conveying screw, the seal ring is a ring that restricts the flow of the upstream portion with gaps in the seal ring portion, the mixing screw is a screw element in which the screw flight (flight portion) has been cut off, and the rotor screw is a screw element in which one or more threads are provided on the outer peripheral surface.

[0044] Among them, an R kneading disk, an N kneading disk, and an L kneading disk are preferable, and a combined configuration of a plurality thereof is preferable.

[0045] Regarding the screw configuration in the first kneading section in the first process, it is preferred that an element that promotes kneading is arranged upstream, and an element having compression capability is arranged downstream. Therefore, in the first kneading section, it is preferred that two or more selected from R, N, and L are arranged in the order of R, N, and L from the upstream side, and the number of each of the arranged R, N, and L is also preferably plural. In particular, a configuration in which R is arranged upstream and a plurality of N are arranged, and then L is arranged is preferred.

[0046] When the barrel diameter is expressed as D, it is preferred to set the screw length of the first kneading section within the range of 4.0 to 9.0D. When the screw length is set as described above, the polyamide resin (A) is fully melted and plasticized, and the decomposition of the resin composition can also be suppressed. When the screw length in the first kneading section is less than 4.0D, the resin is easily insufficiently melted and plasticized due to insufficient shearing. When the screw length exceeds 9.0D, there is a tendency for the resin composition to be partially decomposed due to excessive kneading, and the mechanical properties of the resin composition are easily deteriorated.

[0047] After the polyamide resin (A) is kneaded and melted in the first step, it is preferably ventilated through the open vent 2. A seal ring is preferably provided downstream of the open vent 2.

[0048] In the second process, after the above-mentioned first process, glass fiber (B) is side-fed from the side feed hopper 3 present in the downstream portion of the first kneading section, and the glass fiber (B) and the molten polyamide resin (A) are kneaded together in the second kneading section.

[0049] The second kneading section means a kneading section in which the glass fiber (B) is fed, opened, and kneaded. The screw configuration in the second kneading section is preferably a configuration in which one or more of an R kneading disk, an N kneading disk, an L kneading disk, an L screw, a seal ring, and a mixing screw are combined together, and when kneading with such a screw configuration, the glass fiber (B) is easily opened and dispersed sufficiently. In particular, it is preferred to provide a mixing screw in this configuration, particularly at least one forward delivery notch type mixing screw and a reverse delivery notch type mixing screw.

[0050] The screw length in the second kneading section is preferably set within the range of 2.5 to 5.0D. The second kneading section may be a single combined section, or divided into a plurality of sections. That is, the second kneading section may be divided, and a conveying screw may be inserted therebetween. In any configuration, the total length of the kneading sections is preferably set within the range of 2.5 to 5.0D. When the screw length in the second kneading section is set as described above, the fiber opening and dispersion of the glass fiber (B) become good, and the strength of the resin composition is easily improved.

[0051] As mentioned above, the reinforcing material (C) except glass fibre can be fed from hopper 1 like polyamide resin (A), and can also be fed in the forcing machine from other position like glass fibre (B).In addition, the first kneading section is divided, and other reinforcing materials can be fed between the parts divided, or the second kneading section is divided, and other reinforcing materials can be fed between the parts divided.Yet, in order to improve the interface adhesion with polyamide resin (A), preferably feed other reinforcing materials from the position identical with polyamide resin (A).

[0052] Regarding the barrel setting temperature in the second step, the barrel is usually operated at about 270°C, but in the method of the present invention, the barrel setting temperature is set to a lower temperature than the general temperature, such as 150°C to 250°C. The second kneading section is a step in which the glass fiber (B) is fed and kneaded with the polyamide resin (A) and other polymers or additives (D), and the resin temperature is likely to rise. When the barrel temperature of this section is set to a temperature range lower than the general temperature, such as 150°C to 250°C, the breakage of the strand 10 when extruded from the die base 8 is effectively suppressed. When the barrel temperature is lower than 150°C, the viscosity of the resin is likely to become high, the impregnation of the glass fiber (B) cannot be properly performed, the kneading of the resin and the glass fiber is uneven, and the strand is likely to break. On the other hand, when the barrel temperature is higher than 250°C, the temperature of the resin is likely to become high, pyrolysis gas is likely to be generated, and the strand is likely to break. The resin temperature (barrel temperature) in the second step is more preferably 160°C or higher and 240°C or lower.

[0053] The screw speed of the twin-screw extruder is preferably 250 to 800 rpm, more preferably 300 to 700 rpm. In addition, in the case of "TEX44αIII" manufactured by The Japan Steel Works in which the barrel diameter of the extruder is 47 mm, the discharge is preferably 200 to 650 kg / h, more preferably 250 to 630 kg / h. In extruders of different sizes, the discharge proportional to the 2.5th power of the barrel diameter ratio becomes a preferred range.

[0054] After the second step, in the third step, at the downstream portion of the second kneading section, the pressure-reducing vent 4 is depressurized to cause devolatilization and compression, and a strand is extruded from a die provided at a die holder 8. The vacuum degree during the decompression and devolatilization in the pressure-reducing vent 4 is preferably set to -0.097 MPa to -0.07 MPa. Here, the vacuum degree refers to the gauge pressure.

[0055] In the third step, compression is performed at the front end of the screw, and the composition is extruded from the die as a strand. When a transverse flat die is provided in the die holder 8 at the front end of the twin-screw extruder and a strand is extruded therefrom, the temperature of the strand extruded from the die hole in the center of the transverse flat die is set to 310°C to 360°C.

[0056] In the present invention, (i) the temperature of the strands from the die holes at the ends of the flat die is 4°C to 14°C lower than the temperature of the strands from the die holes at the center of the flat die, or (ii) the strands are extruded in such a manner that the resin pressure in the die during extrusion from the flat die reaches 2.0 to 8.5 MPa.

[0057] In the present invention, it is also preferred that (i) the temperature of the strands from the die holes at the ends of the flat die is set to be 4°C to 14°C lower than the temperature of the strands from the die holes in the center of the flat die, or (ii) the strands are extruded in such a manner that the resin pressure in the die during extrusion from the flat die reaches 2.0 to 8.5 MPa.

[0058] The resin pressure in the mold (also referred to as mold pressure) refers to the resin pressure at the position of the front end of the screw. The pressure at this position is the highest. Usually, a resin pressure gauge 7 is provided at this position, and the pressure can be measured over time. The glass fiber (B) is usually in a bundle state during feeding, and when the resin pressure in the mold is set to 2.0MPa or more and 8.5MPa or less, the glass fiber is kneaded with the resin, and an appropriate pressure is applied to make it easy to impregnate the bundle of the glass fiber (B) with the resin, and it can be kneaded evenly, and it becomes easy to suppress the occurrence of strand breakage. When the resin pressure is lower than 2.0MPa, the kneading state of the resin and the glass fiber (B) becomes uneven, and when the strand is extruded from the mold, the strand is easily broken. The glass fiber (B) is usually in a bundle state during feeding, and is kneaded with the resin, and an appropriate pressure is applied to make it easy to impregnate the bundle of the glass fiber (B) with the resin, and it can be kneaded evenly. The resin pressure in the mold is more preferably more than 2.5MPa, and more preferably more than 3.0MPa. When the resin pressure is too high, the retention area at the front end of the screw becomes longer, gas is easily generated by pyrolysis, and when the strand is extruded from the die, the strand is easily broken by the gas. The resin pressure is more preferably 8.0 MPa or less, and more preferably 7.0 MPa or less.

[0059] The temperature of the die base 8 is preferably set higher than the general temperature, and is preferably 250°C or more and 350°C or less. When the temperature of the die base is set to such a temperature, it becomes easy to suppress the strand from breaking. When the temperature is lower than 250°C, the temperature of the mold is lower than the resin temperature of the resin composition, and the temperature of the strands at both ends of the mold becomes lower than the temperature of the strands in the center. Therefore, a difference in viscosity is caused in the strands, and the strands are easily broken. The temperature of the die base 8 is more preferably 260°C or more, particularly 270°C or more and 280°C or more, and even more preferably 290°C or more. When the temperature of the die base exceeds 350°C, gas is easily generated due to heat retention in the mold, and indeed the strands are easily broken. The temperature of the die base 8 is more preferably 340°C or less, and even more preferably 330°C or less.

[0060] Thermocouple 5 or die base thermocouple 9 have been inserted into the barrel and die base 8 of the extruder, which makes it possible to measure the temperature of the barrel and die base. In addition, a heater has been incorporated into the barrel or die base, which makes it possible to control the temperature. The temperature of the barrel or the temperature of the die base refers to the temperature measured with the inserted thermocouple.

[0061] In the method of the present invention, as described above, the resin pressure in the mold is set to 2.0 to 8.5 MPa, or the temperature of the strands extruded from the die holes at the ends of the lateral flat die is set to be 4 to 14°C lower than the temperature of the strands from the die holes in the center of the flat die.

[0062] Figure 2 : is a diagram showing one example of a die portion of a twin-screw extruder used in the present invention, and is a cross-sectional view obtained by cutting the die portion on a surface parallel to the bottom surface of the die portion.

[0063] The molten polyamide resin composition is conveyed from the screw 21 of the twin-screw extruder to the die section. The die section is composed of a breaker plate 23 (or annular plate), a die base 8, a flange 6, a manifold section 24, and a transverse flat die 25. Depending on the situation, the die base will be referred to as a die plate, and the flange will be referred to as a hinge plate. The combination of the flange 6 (or hinge plate) and the die base 8 (or die plate) is generally referred to as a die head.

[0064] The screen may be installed in the perforated plate 23 .

[0065] The porous plate 23 is provided with a desired number of holes having a desired diameter d and a land length L. In particular, when a screen is not used, an annular plate 23 as an annular plate is generally provided. In the embodiments and comparative examples of the present application, an annular plate is provided. The porous plate or annular plate makes it possible to prevent resin leakage.

[0066] A transverse flat die is a die having die holes arranged in the transverse direction. Figure 3 The mold shown in (a) has a plurality of mold holes 31, 32 and 33 arranged in a horizontal row, as shown in Figure 3 (b) has a plurality of die holes 31, 32 and 33 arranged in a zigzag shape in the transverse direction, or as shown in Figure 4 (d) shows a die having a plurality of die holes 31, 32 and 33 arranged in two (upper and lower) rows in the transverse direction. Figure 5 (a) and Figure 5 As shown in (b), the transverse flat die also includes a die having a circular overall shape and having die holes 31, 32 and 33 arranged in the transverse direction from the manifold portion 24, and in the present invention, all of the above-mentioned dies can be exemplified as preferred embodiments.

[0067] In such Figure 4In the case of the die holes arranged in two rows, i.e., upper and lower rows, in the transverse direction as shown in (d), the die holes 32 and 33 at the end are usually arranged on the lower side of the upper die hole and the upper side of the lower die hole. Such an arrangement is performed when a separation plate 34 is provided between the two (upper and lower) rows in the transverse flat die 25 and the resin flow path is divided up and down.

[0068] In addition, there are Figure 4 (e) shows a case where the die holes are randomly arranged in the transverse direction. In this case, the die holes 32 and 33 at the left and right ends of the mold become the die holes at the ends, and the die hole 31 closest to the geometric center when viewed from the front of the mold becomes the die hole in the center of the mold. The transverse flat mold 25 is usually located at the front end of the manifold portion 24 where the flow path of the resin in the mold base expands in the transverse direction, and refers to a mold having die holes arranged in the transverse direction. The diameter d of each die hole does not need to be the same diameter, and the molding section length L of the die hole does not need to be the same length, and the diameter d or the molding section length L may be different for each die hole.

[0069] The shape of the extrusion die is not particularly limited, and a known shape is used. The diameter d of the die hole is generally 2 to 5 mm, preferably about 3 to 4 mm, although depending on the desired size of the pellets.

[0070] The diameters d of the various die holes do not need to all be the same diameter, nor do the forming section lengths L of the die holes need to be the same length, and the diameter d or the forming section length L may be different for each die hole.

[0071] In the case of producing glass fiber reinforced polyamide resin composition pellets, it is advantageous to use the transverse flat die in terms of improving productivity. Figure 3 The so-called circular die shown in (c), that is, a die in which die holes are arranged on the circumference, but in the case of high discharge, the number of die holes becomes large. In this case, the diameter of the circumference becomes larger, the distance from the strands extruded from the die holes on the circumference to the water tank becomes longer, and the strands become unstable and easily break. As described above, for improving productivity, a horizontal flat die is conducive to stable production. A die in which the die holes are not arranged in the horizontal direction but arranged on the circumference is not within the scope of the present invention.

[0072] However, in the case of a horizontal flat die, the strands from the die holes 32 and 33 at the end are more likely to break than the strands from the die hole 31 on the inside. The strands extruded from the die holes 32 and 33 at the end are easily bent outward when viewed from the center of the die. This is a phenomenon called curling, and the strands extruded from the die holes 32 and 33 at the end tend to pull out a spiral (curl) while rotating outward. This curling makes the strands extruded from the die holes at the end break easily. As the concentration of glass fiber or other reinforcing materials becomes higher, this phenomenon becomes more significant.

[0073] The cause of this curling is not clear, but the die holes 32 and 33 at the end are easily affected by the wall surface of the die base. It is believed that the friction between the resin and the wall surface of the die base remains as residual stress and causes the phenomenon that the strands bend outward (curl). In the present invention, the temperature of the strands from the central die hole is set to 310°C to 360°C, and a temperature difference of 4°C to 14°C is intentionally formed between the strands from the center of the mold and the strands from the ends of the mold, thereby completely or largely preventing the strands from breaking at the ends and suppressing the strand breakage of all strands.

[0074] The strand temperature at the center of the die refers to the strand temperature immediately after the strand is extruded from the die hole 31 closest to the geometric center when viewed from the front of the die. The temperature immediately after the strand is extruded from the die is the temperature immediately after the strand is extruded from the die hole in the center of the die when the number of die holes in the die in which the die holes are arranged at equal intervals in the transverse direction is an odd number, and is the average value of the temperatures immediately after two strands are extruded from the center of the die when the number of die holes is an even number.

[0075] By bringing a thermocouple into contact with the strand, the strand temperature at the center of the mold can be directly measured. Alternatively, the strand temperature can be measured using an infrared temperature measuring instrument. The strand temperature at the center of the mold can be considered to be close to the resin temperature inside the mold.

[0076] The temperature of the strand at the die end refers to the strand temperature at one of the two ends (left and right) 32 and 33 of the die when viewed from the front of the die. In the case where the left and right temperatures of the strand are different from each other, the temperature is defined as its average value. Similarly, the temperature is the strand temperature immediately after the strand is extruded from the die. The temperature of the strand at the end is easily affected by the die base, flange and die temperature. However, for each extruder, the die base, flange and die are different, so the relationship between its temperature and the strand temperature at the end is not uniformly determined.

[0077] The temperature (ΔT) obtained by subtracting the temperature of the strands at both ends of the mold from the temperature of the strands in the center of the mold is set to be above 4°C and below 14°C. When ΔT is set as described above, strand breakage at the ends is completely prevented, and strand breakage of all strands can be suppressed. When ΔT is less than 4°C, the elastic restoring force of the strands at the ends is reduced due to the high temperature of the strands, and the strands are easily broken due to curling (the elastic restoring force against curling is weak). On the other hand, when ΔT is greater than 14°C, the force causing curling becomes stronger, and the strands break due to curling. For example, by setting the temperature of the mold base to be slightly lower than the resin temperature in the mold, ΔT can be adjusted to be above 4°C and below 14°C.

[0078] ΔT is preferably 5° C. or more, more preferably 6° C. or more, and is preferably 13° C. or less, more preferably 12° C. or less.

[0079] The temperature of the strands from the center of the die must be 310°C or higher and 360°C or lower. When the temperature is set as above, the impregnation of the glass fiber bundles by the resin component of the resin composition becomes good, and by setting ΔT as above, the strand breakage can be prevented. When the temperature is lower than 310°C, the viscosity of the resin component of the resin composition is high, the impregnation of the glass fiber bundles is poor, the fibers remain in a bundle state, and when the strands are extruded from the die, stress concentration points are generated in the strands, and the strands are easily broken.

[0080] The temperature of the strand from the center of the die is preferably 315°C or higher, more preferably 320°C or higher. On the other hand, when the temperature exceeds 360°C, the polyamide resin (A) is pyrolyzed to generate gas, and when the strand is extruded from the die, the strand is easily broken due to the gas. In addition, when multiple polyamide resins are used, the amide exchange reaction proceeds and the physical properties are easily deteriorated. The temperature of the strand from the center of the die is preferably 355°C or lower, more preferably 350°C or lower.

[0081] In the fourth step, the strand 10 extruded from the die is cooled with water and cut with a pelletizer 11. The strand temperature when the strand is cut is preferably above 100°C and below 160°C. When the temperature is made as described above, it becomes easy to suppress the generation of chips or the generation of pellets with poor shapes. When the temperature is lower than 100°C, the strand is hard, and chips are easily generated when the strand is cut with a pelletizer. Therefore, plasticization during molding such as injection molding is prone to instability. When the temperature exceeds 160°C, the aspect ratio of the elliptical cylindrical shape of the cut pellets becomes larger. In some cases, this also leads to poor plasticization. The strand temperature when the strand is cut is more preferably above 110°C and below 150°C.

[0082] The glass fiber reinforced polyamide resin composition in which glass fiber (B) or other reinforcing materials (C) are compounded at a high concentration is easy to break before the strands extruded from the die are cooled and cut. The amount of the resin component is small, the viscoelasticity becomes weak, the strands lose toughness, become brittle, and are easy to break. Due to the large amount of glass fiber, it is easy to produce a fiber bundle with poor fiber opening ability. When the strand is pulled (stretched), the fiber bundle with poor fiber opening ability easily becomes the starting point of the break. In addition, when the fiber bundle is impregnated with a small amount of resin (the impregnation of the glass fiber bundle by the resin is insufficient), there is also a situation where this part becomes the starting point of the break. In addition, due to the high concentration of glass fiber or other reinforcing materials, the viscosity of the resin becomes high, and the resin temperature rises easily. This produces pyrolysis gas, which causes the strands to break when the strands have been extruded from the die. As mentioned above, the toughness of the strands deteriorates, the fiber opening of the glass fiber bundles is insufficient, the impregnation of the glass fiber bundles by the resin is insufficient, and the generation of gas, etc., make it difficult to stably cut the strands. When the strands break, it is necessary to manually feed the strands into the granulator again. At this time, the flow of all strands is disturbed, and the strands are fed in an inclined direction relative to the cutter, which easily produces long pellets. In addition, due to the high concentration of glass fiber and the hard strands, the surface cut by the granulator does not become sharp, but becomes blunt, producing chips. In order to suppress the generation of chips, it is necessary to increase the strand cutting temperature. This allows the strands to be cut sharply and reduce chips. However, when the strand cutting temperature is excessively increased, the strands become soft and are crushed by the traction roller of the granulator, and the eccentricity of the elliptical pellets becomes larger. As the number of these long pellets or chips increases and the aspect ratio becomes larger, when the pellets are used for injection molding, it is more likely to cause poor plasticization, resulting in deterioration of productivity. The number of long pellets (usually more than twice the length of the pellets) is preferably less than 3 per kilogram. The amount of chips in the total mass (pellets and chips) is preferably less than 300 mass ppm. Furthermore, the aspect ratio (major axis / minor axis) is preferably 1.30 or less.

[0083] The strand 10 is pulled with a pulling roller so that it contacts water and is cooled. With regard to contact with water, the strand can be cooled by being conveyed into water accumulated in a cooling water tank 13, the strand 10 can be contacted with water and cooled by sprinkling water, or the strand can be put into water by a method in which the strand is pulled with a mesh belt conveyor and water is sprinkled thereon with a water sprayer. The time taken for the strand to be extruded from the die and then cooled with water or inserted into water is preferably short. Generally, it is preferred that the strand is fed into water within 1 second after being extruded from the die.

[0084] The cooled strands are sent to a pelletizer by means of traction rollers, cut and made into pellets.

[0085] In the method of the present invention, the shear viscosity of the glass fiber reinforced polyamide resin composition at 280°C and 91 / sec is set to 400Pa·s or more and 2000Pa·s or less. When the shear viscosity is within the range of 400Pa·s or more and 2000Pa·s or less and the above-mentioned processes are combined, it is possible to suppress the breakage of the strands and to produce continuously and stably. When the shear viscosity is lower than 400Pa·s, the elasticity of the strands is weak and the strands are easily broken. In addition, when the shear viscosity exceeds 2000Pa·s, the shear heat generation becomes larger, the resin temperature rises, pyrolysis occurs, and the strands are easily broken. A more preferred range is 500Pa·s or more and 1700Pa·s or less, and an even more preferred range is 600Pa·s or more and preferably 1400Pa·s or less.

[0086] The shear viscosity is a value measured according to JIS K 7199 using a capillary rheometer (Capilograph, 1D2 manufactured by Toyo Seiki Seisaku-sho, Ltd.) and an aperture having a capillary diameter of 1 mm and a capillary length of 3 mm at 280° C. and a shear rate of 9 1 / sec.

[0087] The shear viscosity can be adjusted to the above range by changing the viscosity of the polyamide resin (A), or can be adjusted by a method in which the amount or molecular weight of other polymers or additives (D) to be compounded is adjusted. The shear viscosity can also be adjusted by changing the amount of glass fiber (B) or other reinforcing materials (C). In addition, there are also cases where the resin component undergoes pyrolysis, hydrolysis or amidation reaction due to the thermal history in the extruder and the shear viscosity decreases.

[0088] Next, the raw material components used in the present invention will be described.

[0089] (A) Polyamide resin

[0090] The polyamide resin (A) is not particularly limited, and examples thereof include polycaproamide (polyamide 6), polytetramethylene adipamide (polyamide 46), polyhexamethylene adipamide (polyamide 66), polyundemethylene adipamide (polyamide 116), polym-xylylene adipamide (polyamide MXD6), polyp-xylylene adipamide (polyamide PXD6), polyxylylene sebacamide (polyamide XD10), polytetramethylene sebacamide (polyamide 410), polyhexamethylene sebacamide (polyamide 610), polydecamethylene adipamide (polyamide 106), polydecamethylene sebacamide (polyamide 1010), polyhexamethylene dodecamamide (polyamide 612), polydecamethylene dodecamamide (polyamide 101 2), polyhexamethylene isophthalamide (polyamide 6I), polytetramethylene terephthalamide (polyamide 4T), polypentamethylene terephthalamide (polyamide 5T), poly-2-methylpentamethylene terephthalamide (polyamide M-5T), polyhexamethylene terephthalamide (polyamide 6T), polyhexamethylene hexahydroterephthalamide (polyamide 6T(H)), polynonamethylene terephthalamide (polyamide 9T), polydecamethylene terephthalamide (polyamide 10T), polyundemethylene terephthalamide (polyamide 11T), polydodecamethylene terephthalamide (polyamide 12T), polylauryl lactam (polyamide 12), poly-11-aminoundecanoic acid (polyamide 11), and copolymers containing their constituent units, etc.

[0091] Only one polyamide resin (A) may be used alone or a plurality of them may be used in combination. Among them, the polyamide resin (A) is preferably polycaproamide (polyamide 6), polyhexamethylene adipamide (polyamide 66), polym-xylylene adipamide (polyamide MXD6) or polyhexamethylene terephthalamide (polyamide 6T) in terms of heat resistance and general applicability.

[0092] (B) Glass fiber

[0093] As the glass fiber (B), any known glass fiber can be used as long as the glass fiber is generally used for polyamide resins, regardless of the form of the glass fiber during compounding, such as an alkali-resistant glass composition containing A glass, E glass and zirconium oxide components, chopped strands, roving glass, or a masterbatch of a thermoplastic resin and glass fiber. Among them, for the purpose of improving the thermal stability of the resin composition, the glass fiber (B) used in the present invention is preferably alkali-free glass (E glass).

[0094] The glass fiber (B) may be a glass fiber having a circular cross section in the longitudinal direction, and it is also preferable to use a glass fiber having an aspect ratio of the longitudinal cross section in the range of 2.0 to 6.0.

[0095] The aspect ratio of the longitudinal cross section refers to the ratio of the major axis to the minor axis when a rectangle with the minimum area circumscribing the cross section perpendicular to the longitudinal direction of the glass fiber is assumed, the length of the long side of the rectangle is defined as the major axis, and the length of the short side is defined as the minor axis.

[0096] The cross-sectional area of ​​the glass fiber (B) in the longitudinal direction is preferably more than 90 μm 2 and 300μm 2 When the cross-sectional area is as described above, the polyamide resin (A) easily becomes a matrix and the heat resistance is easily and effectively improved. The cross-sectional area is more preferably more than 90 μm 2 and 250μm 2 Below, more preferably more than 90 μm 2 and 200μm 2 the following.

[0097] The thickness of the glass fiber (B) is not particularly limited, but it is preferred that the minor axis is 2 to 20 μm and the major axis is approximately 5 to 50 μm.

[0098] The glass fiber (B) may be treated with a sizing agent or a surface treatment agent. Furthermore, during the production of the resin composition of the present invention, in addition to the untreated glass fiber, a sizing agent or a surface treatment agent may be added to treat the surface.

[0099] Examples of the sizing agent include resin emulsions such as vinyl acetate resins, ethylene / vinyl acetate copolymers, acrylic resins, epoxy resins, polyurethane resins, and polyamide resins.

[0100] Examples of the surface treatment agent include aminosilane compounds such as γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane and γ-(2-aminoethyl)aminopropyltrimethoxysilane; chlorosilane compounds such as vinyltrichlorosilane and methylvinyldichlorosilane; alkoxysilane compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane and γ-methacryloxypropyltrimethoxysilane; epoxysilane compounds such as β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and γ-glycidoxypropyltrimethoxysilane; acrylic compounds; isocyanate compounds; titanate compounds; and epoxy compounds.

[0101] Two or more of these sizing agents or surface treatment agents may be used together, and the amount used (adherence) is usually 10% by mass or less, preferably 0.05 to 5% by mass, relative to the mass of the glass fiber (B). When the adhesion amount is 10% by mass or less, a desired and sufficient effect can be obtained, which is preferred.

[0102] Two or more kinds of the glass fibers (B) may be used in combination depending on the desired properties.

[0103] The content of the glass fiber (B) is set to a content as high as 10 to 75% by mass relative to a total of 100% by mass of the polyamide resin (A), the glass fiber (B), the reinforcing material (C) other than the glass fiber, and other polymers or additives (D). When the content of the glass fiber (B) is less than 10% by mass, the rigidity is easily insufficient, and conversely, when the content exceeds 75% by mass, the fluidity is easily insufficient and the production is easily difficult. The content of the glass fiber (B) is more preferably 15% by mass or more, more preferably 20% by mass or more, more preferably 70% by mass or less, and more preferably 65% ​​by mass or less.

[0104] (C) Other reinforcement materials

[0105] The other reinforcing material (C) other than glass fiber refers to a reinforcing material other than glass fiber that is a material capable of improving mechanical properties, specifically improving the mechanical properties of a molded product obtained by pellet molding. The shape of the reinforcing material (C) is not particularly limited, and may be, for example, fibrous or granular.

[0106] The reinforcing material (C) other than glass fiber is not particularly limited, and examples thereof include glass flakes, glass beads, powdered glass (grinding fiber), needle-shaped wollastonite, mica, talc, uncalcined clay, whiskers (e.g., potassium titanate whiskers), titanium dioxide, carbon fiber, ceramic fiber, silicon dioxide, aluminum oxide, kaolin, quartz, graphite, calcium carbonate, barium sulfate, carbon black, and metal powder, etc. Among them, inorganic reinforcing materials such as mica and talc are preferred. Other reinforcing materials (C) can be used alone, or a variety of them can be used in combination.

[0107] The amount of other reinforcing material (C) is 0 to 40 mass %, preferably 35 mass % or less, more preferably 30 mass % or less, and still more preferably 28 mass % or less, based on 100 mass % in total of (A) to (D).

[0108] (D) Other polymers or additives

[0109] The other polymer or additive (D) is a polymer other than the polyamide resin (A) and / or various additives.

[0110] The polymer other than the polyamide resin (A) is not particularly limited, and examples thereof include polyphenylene sulfide (PPS), liquid crystal polymer (LCP), aromatic polyamide resin, polyetheretherketone (PEEK), polyetherketone (PEK), polyetherimide (PEI), thermoplastic polyimide, polyamideimide (PAI), polyetherketoneketone (PEKK), polyphenylene ether (PPE), polyethersulfone (PES), polysulfone (PSU), polyarylate (PAR), polyester (PEs), polycarbonate (PC), polyoxymethylene (POM), polypropylene (PP), polyethylene (PE), polymethylpentene (TPX), polystyrene (PS), polymethyl methacrylate, acrylonitrile-styrene copolymer (AS), acrylonitrile-butadiene-styrene copolymer (ABS), fluororesin, polyacrylate, etc. Among them, polyphenylene ether (PPE) and polypropylene (PP) are preferred.

[0111] The other polymer (D) may be contained alone, or two or more other polymers may be contained in any combination and ratio.

[0112] Examples of other additives include flame retardants, flame retardant aids, impact modifiers for elastomers, stabilizers, mold release agents, colorants such as dyes or pigments, catalyst deactivators, antistatic agents, foaming agents, plasticizers, crystal nucleating agents and crystallization accelerators, and the like.

[0113] Examples of stabilizers include organic antioxidants such as hindered phenol antioxidants, sulfur antioxidants, and phosphorus antioxidants; heat stabilizers; light stabilizers such as hindered amines, benzophenones, and imidazoles; ultraviolet absorbers; metal deactivators; copper compounds; and alkali metal halide compounds; etc. Among them, copper compounds are preferred. The stabilizer may be used alone, or a plurality of them may be used in combination. The content of the stabilizer may be appropriately adjusted, and in 100% by mass of the resin composition, it is preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less.

[0114] Here, the content of the stabilizer refers to the total content of the stabilizer in the case where the composition contains a plurality of stabilizers.

[0115] As the copper compound that can be used as a stabilizer, copper salts of organic carboxylic acids such as cuprous chloride, cuprous bromide, cuprous iodide, cupric chloride, cupric bromide, cupric iodide, copper phosphate, copper pyrophosphate, copper sulfide, copper nitrate, and copper acetate can be used. The copper compound can be used alone, or a plurality of them can be used in combination.

[0116] Examples of the release agent include long-chain fatty acids or esters and metal salts thereof, amide compounds, polyethylene wax, silicone, polyethylene oxide, and the like.

[0117] Long-chain fatty acids particularly preferably have 12 or more carbon atoms, and examples thereof include stearic acid, 12-hydroxystearic acid, behenic acid, montanic acid, and the like. A portion or all of the carboxylic acid may have been esterified with monoethylene glycol or polyethylene glycol, or may have been formed into a metal salt. Examples of amide compounds include ethylene bis terephthalamide and methylene bis stearamide, and the like. These release agents may be used alone or as a mixture.

[0118] The content of the release agent in 100 mass % of the resin composition is preferably 0.01 mass % or more, more preferably 0.05 mass % or more, and is preferably 5.0 mass % or less, more preferably 3.0 mass % or less, still more preferably 1.0 mass % or less.

[0119] The amount of other polymers or additives (D) is 0 to 30% by mass, preferably 25% by mass or less, more preferably 20% by mass or less, and still more preferably 17% by mass or less, based on 100% by mass of (A) to (D) in total.

[0120] The glass fiber reinforced polyamide resin composition manufactured by the method of the present invention can make the molded product have high strength, so it can fully meet the required properties such as weight reduction, thickness reduction and strength, and can be widely used in molded products or parts in, for example, the fields of precision equipment, automobiles, electrical and electronic equipment, computers and other office automation equipment, optical equipment and various other industrial fields.

[0121] Example

[0122] Hereinafter, the present invention will be described in more detail by showing embodiments. However, the present invention is not limited to the following embodiments, and the present invention can be arbitrarily modified and implemented within the scope of the gist of the present invention.

[0123] [(i) Examples and Comparative Examples in which the temperature of the strands from the die holes at the end of the transverse flat die is 4 to 14° C. lower than the temperature of the strands from the die holes at the center of the transverse flat die]

[0124] The raw material components used and their blending ratios (formulations) are shown in Table 1 below.

[0125] [Table 1]

[0126]

[0127] In the following Examples and Comparative Examples, as an extruder, a ventilated intermeshing co-rotating twin-screw extruder ("TEX44αIII", manufactured by The Japan Steel Works, Ltd., barrel diameter D=47 mm) was used.

[0128] Screw structure Figure 6 shown.

[0129] Cylinder position C1 is a feed cylinder (also called a barrel), C7 and C12 are vent cylinders, C7 is an open vent, C12 is a pressure reduction vent, and C9 is a side feed cylinder. The first kneading section in which the polyamide resin (A) and other polymers (D) are melt-kneaded is configured at C5 to C6, and as its screw structure, RRNNL is provided, each of which has 5 blades and is 1Ds long (1Ds=44mm). Glass fiber (B) is fed from the C9 side. In the second kneading section in which the glass fiber (B) is kneaded, as shown in Figure 6 As shown, there is an R having 5 blades and a length of 1Ds and 3 reverse mixing screws each of which is also 1Ds long (lead 0.25Ds).

[0130] The kneading section where the polyamide resin (A) and other polymers or additives (D) are added and the glass fiber (B) is fed is the first kneading section, and C1 to C9 are the first process. Other reinforcing materials (C) other than the glass fiber are also fed to the feeding cylinder C1 like the polyamide resin (A) and other polymers (D).

[0131] Next, the kneading section in which the glass fiber (B) is fed into the extruder and provided with a decompression vent is the second kneading section, and C10 to C11 are the second process. C12 to C14 in which a die holder is included and the kneaded resin composition is extruded from the die are the third process. In addition, the process of cooling the strands extruded from the die with water and cutting the strands with a pelletizer to obtain pellets is the fourth process.

[0132] In Examples 1 to 7 and Comparative Examples 1 to 4 described below, resin compositions were produced using the raw material ratios shown in Formulation 1 in Table 1.

[0133] Example 1

[0134] 87.5 kg / h of nylon MXD6 (PA1), 10 kg / h of nylon 66 (PA2) and 2.5 kg / h of titanium oxide (C2) as other reinforcing materials were fed from the main raw material hopper to the feed cylinder C1 of the twin-screw extruder ("TEX44αIII" manufactured by The Japan Steel Works, Ltd.), and 150 kg / h of glass fiber (GF) was further fed from the side feed hopper to the side feed cylinder C9. The feed amount of the raw materials was set to a total of 250 kg / h, and the screw speed was set to 300 rpm.

[0135] The set temperature of barrels C2 to C9 and barrels C12 to C14 is set to 270°C. The set temperature of the barrels of C10 and C11 in the second kneading section is set to 220°C. The set temperature of the die base present in the third process is set to 310°C. The temperature of the flange is also set to 310°C. In addition, as a transverse flat die, a die in which the hole diameter of the die hole is 3.8 mm, the forming section length is 20 mm, and the number of die holes is 10 is used. At this time, the resin pressure of the die base is 4.9 MPa. The average temperature of the two strands in the center of the die is 345°C. The average temperature of the strands at both ends of the die is 339°C. In all embodiments and comparative examples, the temperature of the flange is set to be the same as the temperature of the die base.

[0136] The pulling speed of the pelletizer was set to 40 m / min. Extrusion was continued for 1 hour under this condition. All 10 strands were stable and did not break even once. Some strands at both ends of the die looked as if the strands were curling outward slightly, but there were no breaks.

[0137] The strands extruded from the die were cooled in a water tank and cut with a pelletizer to obtain pellets having an average length of 3 mm.

[0138] The obtained pellets were dried at 120° C. for 5 hours, and the shear viscosity at a temperature of 280° C. and a shear rate of 91 / sec was obtained using “Capilograph 1D2” manufactured by Toyo Seiki Seisaku-sho, Ltd. and an aperture having a capillary diameter of 1 mm and a capillary length of 3 mm. The shear viscosity was 1080 Pa·s.

[0139] 1 kg of the produced pellets was visually confirmed, and the number of long pellets (pellets having a length of 6 mm or more) was counted.

[0140] The strand break evaluation was determined by the following criteria.

[0141] A: The number of wire breakages is 0 times / hour

[0142] B: The number of wire breakages is 1 to 2 times per hour

[0143] C: The number of wire breakages is 3 to 5 times per hour

[0144] D: The number of wire breakages is 6 to 9 times per hour

[0145] E: The number of wire breakages is more than 10 times / hour

[0146] The above results are shown in Table 2 below.

[0147] Example 2

[0148] The same manner as in Example 1 was carried out except that the hole diameter in the transverse flat die was set to 3.8 mm, the number of holes was similarly set to 10, and the forming section length was set to 10 mm.

[0149] Example 3

[0150] The same manner as in Example 1 was carried out except that the hole diameter in the transverse flat die was set to 3.8 mm, the number of holes was similarly set to 10, and the forming section length was set to 30 mm.

[0151] Example 4

[0152] The same procedure as in Example 1 was carried out except that the temperature of the mold base was set to 285°C.

[0153] Example 5

[0154] The same procedure as in Example 1 was carried out except that the temperature of the mold base was set to 335°C.

[0155] Example 6

[0156] The same procedure as in Example 1 was carried out except that the temperature of the mold base was set to 260°C.

[0157] Example 7

[0158] The same procedure as in Example 1 was carried out except that the temperature of the mold base was set to 345°C.

[0159] Comparative Example 1

[0160] The same method as in Example 1 was performed except that the temperature of the die base was set to 240° C. The temperature difference ΔT between the temperature of the strands in the center of the die and the temperature of the strands at both ends of the die was 16° C. All strand breaks occurred at both ends of the die. The curl was strong and showed an appearance that the strands were bent toward the outside of the die, which was considered to be curl breakage.

[0161] Comparative Example 2

[0162] The same method as in Example 1 was used except that the temperature of the die base was set to 360°C. The temperature difference ΔT between the temperature of the strands in the center of the die and the temperature of the strands at both ends of the die was as small as 3°C. The temperature of the strands in the center of the die was also as high as 357°C, and the strands broke 7 times at both ends of the die and 11 times on the inside. It is considered that ΔT is small, curling resistance is not achieved, the strands are broken, the resin temperature is also high, gas is generated, and the strands are even broken on the inside.

[0163] Comparative Example 3

[0164] The same method as in Example 1 was performed except that the screw rotation was set to 200 rpm, the hole diameter in the horizontal flat die was set to 3.8 mm, the number of holes was similarly set to 10, and the molding section length was set to 10 mm. The temperature of the strand in the center of the die was 308° C. It is believed that the temperature of the resin was low, the impregnation of the fiber was insufficient, the fiber opening was poor, and the strand breakage occurred frequently.

[0165] Comparative Example 4

[0166] The same method as in Example 1 was used except that the screw rotation was set to 500 rpm. The temperature of the strand in the center of the die was 367°C. The strand was broken not only inside the die but also at both ends of the die. The strand surface was beautiful and did not show poor glass fiber opening. The strand breakage occurred at the exit of the die, so it was considered to be caused by gas.

[0167] The above results are shown in Table 2 below.

[0168] [Table 2]

[0169]

[0170] In Examples 8 to 14 and Comparative Examples 5 to 8, resin compositions were produced using the raw material ratios shown in Formula 2 in Table 1.

[0171] Example 8

[0172] The experiment was carried out in the same manner as in Example 1, except that 72.5 kg / h of nylon MXD6 (PA1), 12.5 kg / h of nylon 66 (PA2), 25 kg / h of nylon 6 (PA3), 37.5 kg / h of mica (C1) as other reinforcing materials, and 2.5 kg / h of release agent (D2) were fed from the main raw material hopper to the feed barrel C1 of the twin-screw extruder ("TEX44αIII" manufactured by The Japan Steel Works, Ltd.), and 100 kg / h of glass fiber (GF) was further fed from the side feed hopper to the side feed barrel C9.

[0173] Some of the strands at the ends looked as if the strands were curling outward slightly, but were not broken.

[0174] The strands extruded from the die were cooled in a water tank, and the strands were cut with a pelletizer to obtain pellets. The shear viscosity of the pellets measured in the same manner as in Example 1 was 1030 Pa·s.

[0175] Example 9

[0176] The same procedure as in Example 8 was carried out except that the hole diameter in the transverse flat die was set to 3.8 mm, the number of holes was similarly set to 10, and the forming section length was set to 10 mm.

[0177] Example 10

[0178] The same procedure as in Example 8 was carried out except that the hole diameter in the transverse flat die was set to 3.8 mm, the number of holes was similarly set to 10, and the forming section length was set to 30 mm.

[0179] Embodiment 11

[0180] The same procedure as in Example 8 was carried out except that the temperature of the mold base was set to 285°C.

[0181] Example 12

[0182] The same procedure as in Example 8 was carried out except that the temperature of the mold base was set to 335°C.

[0183] Example 13

[0184] The same procedure as in Example 8 was carried out except that the temperature of the mold base was set to 260°C.

[0185] Embodiment 14

[0186] The same procedure as in Example 8 was carried out except that the temperature of the mold base was set to 345°C.

[0187] Comparative Example 5

[0188] The same method as in Example 8 was used except that the temperature of the die base was set to 240° C. The temperature difference ΔT between the temperature of the strands in the center of the die and the temperature of the strands at both ends of the die was 16° C. All strand breaks occurred at both ends of the die. The curl was strong and showed an appearance that the strands were bent toward the outside of the die, which was considered to be curl breakage.

[0189] Comparative Example 6

[0190] The same method as in Example 8 was used except that the temperature of the die base was set to 360°C. The temperature difference ΔT between the temperature of the strand in the center of the die and the temperature of the strand at both ends of the die was as small as 2°C. The temperature of the strand in the center of the die was also as high as 354°C, and the strand broke 7 times at both ends of the die and 10 times on the inside. It is considered that ΔT is small, curling resistance is not achieved, the strand breaks, the resin temperature is also high, gas is generated, and the strand breaks even on the inside.

[0191] Comparative Example 7

[0192] The same method as in Example 8 was used except that the screw rotation was set to 200 rpm, the hole diameter in the horizontal flat die was set to 3.8 mm, the number of holes was similarly set to 10, and the molding section length was set to 10 mm. The temperature of the strand in the center of the die was 305° C. It is believed that the temperature of the resin was low, the impregnation of the fiber was insufficient, the fiber opening was poor, and the strand breakage occurred frequently.

[0193] Comparative Example 8

[0194] The same method as in Example 8 was used except that the screw rotation was set to 500 rpm. The temperature of the strand in the center of the die was 364°C. The strand was broken not only inside the die but also at both ends of the die. The strand surface was beautiful and did not show poor glass fiber opening. The strand breakage occurred at the exit of the die, so it was considered to be caused by gas.

[0195] The above results are shown in Table 3 below.

[0196] [Table 3]

[0197]

[0198] In Examples 15 to 21 and Comparative Examples 9 to 12, resin compositions were produced using the raw material ratios shown in Formula 3 in Table 1.

[0199] Embodiment 15

[0200] The experiment was carried out in the same manner as in Example 1, except that 12.5 kg / h of nylon MXD6 (PA1), 7.5 kg / h of nylon 66 (PA2), 57.5 kg / h of nylon 6 (PA3), 62.5 kg / h of mica (C1) as other reinforcing materials, and 2.5 kg / h of a release agent (D2) were fed from the main raw material hopper to the feed barrel C1 of a twin-screw extruder ("TEX44αIII" manufactured by The Japan Steel Works, Ltd.), and 70 kg / h of glass fiber (GF) was further fed from the side feed hopper to the side feed barrel C9.

[0201] Some of the strands at the ends looked as if the strands were curling outward slightly, but were not broken.

[0202] The strands extruded from the die were cooled in a water tank, and the strands were cut with a pelletizer to obtain pellets. The shear viscosity of the pellets measured in the same manner as in Example 1 was 1110 Pa·s.

[0203] Example 16

[0204] The same procedure as in Example 15 was carried out except that the hole diameter in the transverse flat die was set to 3.8 mm, the number of holes was similarly set to 10, and the forming section length was set to 10 mm.

[0205] Embodiment 17

[0206] The same procedure as in Example 15 was carried out except that the hole diameter in the transverse flat die was set to 3.8 mm, the number of holes was similarly set to 10, and the forming section length was set to 30 mm.

[0207] Embodiment 18

[0208] The same procedure as in Example 15 was carried out except that the temperature of the mold base was set to 285°C.

[0209] Embodiment 19

[0210] The same procedure as in Example 15 was carried out except that the temperature of the mold base was set to 335°C.

[0211] Embodiment 20

[0212] The same procedure as in Example 15 was carried out except that the temperature of the mold base was set to 260°C.

[0213] Embodiment 21

[0214] The same procedure as in Example 15 was carried out except that the temperature of the mold base was set to 345°C.

[0215] Comparative Example 9

[0216] The same method as in Example 15 was performed except that the temperature of the die base was set to 240° C. The temperature difference ΔT between the temperature of the strands in the center of the die and the temperature of the strands at both ends of the die was 17° C. All strand breaks occurred at both ends of the die. The curl was strong and showed an appearance that the strands were bent toward the outside of the die, which was considered to be curl breakage.

[0217] Comparative Example 10

[0218] The same method as in Example 15 was performed except that the temperature of the die base was set to 360°C. The temperature difference ΔT between the temperature of the strand in the center of the die and the temperature of the strand at both ends of the die was as small as 1°C. The temperature of the strand in the center of the die was also as high as 360°C, and the strand broke 5 times at both ends of the die and 12 times on the inside. It is considered that ΔT is small, curling resistance is not achieved, the strand breaks, the resin temperature is also high, gas is generated, and the strand breaks even on the inside.

[0219] Comparative Example 11

[0220] The same method as in Example 15 was performed except that the screw rotation was set to 200 rpm, the hole diameter in the horizontal flat die was set to 3.8 mm, the number of holes was similarly set to 10, and the molding section length was set to 10 mm. The temperature of the strand in the center of the die was 309° C. It is believed that the temperature of the resin was low, the impregnation of the fiber was insufficient, the fiber opening was poor, and the strand breakage occurred frequently.

[0221] Comparative Example 12

[0222] The same method as in Example 15 was used except that the screw rotation was set to 500 rpm. The temperature of the strand in the center of the die was 369°C. The strand was broken not only inside the die but also at both ends of the die. The strand surface was beautiful and did not show poor glass fiber opening. The strand breakage occurred at the exit of the die, so it was considered to be due to gas.

[0223] The above results are shown in Table 4 below.

[0224] [Table 4]

[0225]

[0226] [(ii) Examples and Comparative Examples of the Present Invention in Which the Strands Were Extruded Such that the Resin Pressure in the Die During Extrusion from the Die Was 2.0 to 8.5 MPa]

[0227] The raw material components used and their blending ratios (formulations) are shown in Table 5 below.

[0228] [Table 5]

[0229]

[0230] In the following Examples and Comparative Examples, as an extruder, a ventilated intermeshing co-rotating twin-screw extruder ("TEX44αIII", manufactured by The Japan Steel Works, Ltd., barrel diameter D=47 mm) was used.

[0231] Screw structure Figure 6 Shown in.

[0232] Cylinder position C1 is a feed cylinder, C7 and C12 are vent cylinders, C7 is an open vent, C12 is a decompression vent, and C9 is a side feed cylinder. The first kneading section in which the polyamide resin (A) and the other polymer (D) are melt-kneaded is arranged at C5 to C6, and as its screw structure, R RN NL is provided, each of which has 5 blades and is 1Ds long (1Ds=44mm). Glass fiber (B) is fed from the C9 side. In the second kneading section in which the glass fiber (B) is kneaded, as shown in FIG. Figure 6 As shown, there is an R having 5 blades and a length of 1Ds and 3 reverse mixing screws each of which is also 1Ds long (lead 0.25Ds).

[0233] The kneading section where the polyamide resin (A) and other polymers or additives (D) are added and the glass fiber (B) is fed is the first kneading section, and C1 to C9 are the first process. Other reinforcing materials (C) other than the glass fiber are also fed to the feeding cylinder C1 like the polyamide resin (A) and other polymers (D).

[0234] Next, the kneading section in which the glass fiber (B) is fed into the extruder and provided with a decompression vent is the second kneading section, and C10 to C11 are the second process. C12 to C14 in which a die holder is included and the kneaded resin composition is extruded from the die are the third process. In addition, the process of cooling the strands extruded from the die with water and cutting the strands with a pelletizer to obtain pellets is the fourth process.

[0235] In Examples 22 to 28 and Comparative Examples 13 to 16 described below, resin compositions were produced using the raw material ratios shown in Formulation 1 in Table 5.

[0236] Embodiment 22

[0237] 87.5 kg / h of nylon MXD6 (PA1), 10 kg / h of nylon 66 (PA2) and 2.5 kg / h of titanium oxide (C2) as other reinforcing materials were fed from the main raw material hopper to the feed cylinder C1 of the twin-screw extruder ("TEX44αIII" manufactured by The Japan Steel Works, Ltd.), and 100 kg / h of round cross-section glass fiber (GF1) and 50 kg / h of irregular cross-section glass fiber (GF2) were further fed from the side feed hopper to the side feed cylinder C9. The feed amount of the raw materials was set to a total of 250 kg / h, and the screw speed was set to 300 rpm.

[0238] The set temperature of barrels C2 to C9 and barrels C12 to C14 is set to 270°C. The set temperature of the barrels of C10 and C11 in the second kneading section is set to 220°C. The set temperature of the die base present in the third process is set to 310°C. The temperature of the flange is also set to 310°C. In addition, as a transverse flat die, a mold in which the hole diameter of the die hole is 3.8 mm, the forming section length is 20 mm, and the number of die holes is 10 is used. At this time, the resin pressure of the die base is 4.5 MPa. The average temperature of the two strands in the center of the mold is 342°C. The average temperature of the strands at both ends of the mold is 335°C. In all embodiments and comparative examples, the temperature of the flange is set to be the same as the temperature of the die base.

[0239] The pulling speed of the pelletizer was set to 40 m / min. Extrusion was continued for 1 hour under this condition. All 10 strands were stable and did not break even once. Some strands at both ends of the die looked as if the strands were curling outward slightly, but there were no breaks.

[0240] The strands extruded from the die were cooled in a water tank and cut with a pelletizer to obtain pellets having an average length of 3 mm.

[0241] The obtained pellets were dried at 120° C. for 5 hours, and the shear viscosity at a temperature of 280° C. and a shear rate of 91 / sec was obtained using “Capilograph 1D2” manufactured by Toyo Seiki Seisaku-sho, Ltd. and an aperture having a capillary diameter of 1 mm and a capillary length of 3 mm. The shear viscosity was 1020 Pa·s.

[0242] 1 kg of the produced pellets was visually confirmed, and the number of long pellets (pellets having a length of 6 mm or more) was counted.

[0243] The strand break evaluation was determined by the following criteria.

[0244] A: The number of wire breakages is 0 times / hour

[0245] B: The number of wire breakages is 1 to 2 times per hour

[0246] C: The number of wire breakages is 3 to 5 times per hour

[0247] D: The number of wire breakages is 6 to 9 times per hour

[0248] E: The number of wire breakages is more than 10 times / hour

[0249] The above results are shown in Table 6.

[0250] Embodiment 23

[0251] The same procedure as in Example 22 was carried out except that the hole diameter in the transverse flat die was set to 3.8 mm, the number of holes was similarly set to 10, and the forming section length was set to 10 mm.

[0252] Embodiment 24

[0253] The same procedure as in Example 22 was carried out except that the hole diameter in the transverse flat die was set to 3.8 mm, the number of holes was similarly set to 10, and the forming section length was set to 30 mm.

[0254] Embodiment 25

[0255] The same procedure as in Example 22 was carried out except that the temperature of the mold base was set to 285°C.

[0256] Embodiment 26

[0257] The same procedure as in Example 22 was carried out except that the temperature of the mold base was set to 330°C.

[0258] Embodiment 27

[0259] The same procedure as in Example 22 was carried out except that the temperature of the mold base was set to 260°C.

[0260] Embodiment 28

[0261] The same procedure as in Example 22 was carried out except that the temperature of the mold base was set to 345°C.

[0262] Comparative Example 13

[0263] The same method as in Example 22 was used except that the hole diameter was set to 3.8 mm in the horizontal flat die, the number of holes was similarly set to 10, and the forming section length was set to 5 mm. The resin pressure in the die was 1.6 MPa. The strands inside the die and at both ends of the die were easily broken, and fibrous fluff was even shown in the strands. It was judged that the resin pressure was low, the impregnation of the resin into the fiber was insufficient, and the fiber opening property was insufficient.

[0264] Comparative Example 14

[0265] The same method as in Example 22 was carried out except that the hole diameter was set to 3.8 mm in the horizontal flat die, the number of holes was similarly set to 10, and the molding section length was set to 40 mm. The resin pressure in the mold was as high as 9.1 MPa, and the strands inside the mold and at both ends of the mold were easily broken. Since the position where the strands broke was the exit of the mold, it was considered that the strands were broken due to gas.

[0266] Comparative Example 15

[0267] The same method as in Example 22 was performed except that the screw rotation was set to 200 rpm, the hole diameter in the horizontal flat die was set to 3.8 mm, the number of holes was similarly set to 10, and the molding section length was set to 10 mm. The temperature of the strand in the center of the die was 306° C. It is believed that the temperature of the resin was low, the impregnation of the fiber was insufficient, the fiber opening was poor, and the strand breakage occurred frequently.

[0268] Comparative Example 16

[0269] The same method as in Example 22 was used except that the screw rotation was set to 500 rpm. The temperature of the strand in the center of the die was 363°C. The strand was broken not only inside the die but also at both ends of the die. The strand surface was beautiful and did not show poor glass fiber opening. The strand breakage occurred at the exit of the die, so it was considered to be due to gas.

[0270] The above results are shown in Table 6 below.

[0271] [Table 6]

[0272]

[0273] In Examples 29 to 35 and Comparative Examples 17 to 20, resin compositions were produced using the raw material ratios shown in Formulation 2 in Table 5.

[0274] Embodiment 29

[0275] The experiment was carried out in the same manner as in Example 22, except that 72.5 kg / h of nylon MXD6 (PA1), 12.5 kg / h of nylon 66 (PA2), 25 kg / h of nylon 6 (PA3), 37.5 kg / h of mica (C1) as other reinforcing materials, and 2.5 kg / h of release agent (D2) were fed from the main raw material hopper to the feed barrel C1 of the twin-screw extruder ("TEX44αIII" manufactured by The Japan Steel Works, Ltd.), and 50 kg / h of round cross-section glass fiber (GF1) and 50 kg / h of irregular cross-section glass fiber (GF2) were further fed from the side feed hopper to the side feed barrel C9.

[0276] Some of the strands at the ends looked as if the strands were curling outward slightly, but were not broken.

[0277] The strands extruded from the die were cooled in a water tank, and the strands were cut with a pelletizer to obtain pellets. The shear viscosity of the pellets measured in the same manner as in Example 22 was 980 Pa·s.

[0278] Embodiment 30

[0279] The same procedure as in Example 29 was carried out except that the hole diameter in the transverse flat die was set to 3.8 mm, the number of holes was similarly set to 10, and the forming section length was set to 10 mm.

[0280] Embodiment 31

[0281] The same procedure as in Example 29 was carried out except that the hole diameter in the transverse flat die was set to 3.8 mm, the number of holes was similarly set to 10, and the forming section length was set to 30 mm.

[0282] Embodiment 32

[0283] The same procedure as in Example 29 was carried out except that the temperature of the mold base was set to 285°C.

[0284] Embodiment 33

[0285] The same procedure as in Example 29 was carried out except that the temperature of the mold base was set to 330°C.

[0286] Embodiment 34

[0287] The same procedure as in Example 29 was carried out except that the temperature of the mold base was set to 260°C.

[0288] Embodiment 35

[0289] The same procedure as in Example 29 was carried out except that the temperature of the mold base was set to 345°C.

[0290] Comparative Example 17

[0291] The same method as in Example 29 was used except that the hole diameter was set to 3.8 mm in the horizontal flat die, the number of holes was similarly set to 10, and the forming section length was set to 5 mm. The resin pressure in the die was 1.5 MPa. The strands inside the die and at both ends of the die were easily broken, and fibrous fluff was even shown in the strands. It was judged that the resin pressure was low, the impregnation of the resin into the fiber was insufficient, and the fiber opening property was insufficient.

[0292] Comparative Example 18

[0293] The same method as in Example 29 was used except that the hole diameter was set to 3.8 mm in the horizontal flat die, the number of holes was similarly set to 10, and the molding section length was set to 40 mm. The resin pressure in the mold was as high as 8.6 MPa, and the strands inside the mold and at both ends of the mold were easily broken. Since the position where the strands broke was the exit of the mold, it was considered that the breakage of the strands was caused by gas.

[0294] Comparative Example 19

[0295] The same method as in Example 29 was used except that the screw rotation was set to 200 rpm, the hole diameter in the horizontal flat die was set to 3.8 mm, the number of holes was similarly set to 10, and the molding section length was set to 10 mm. The temperature of the strand in the center of the die was 303° C. It is believed that the temperature of the resin was low, the impregnation of the fiber was insufficient, the fiber opening was poor, and the strand breakage occurred frequently.

[0296] Comparative Example 20

[0297] The same method as in Example 29 was used except that the screw rotation was set to 500 rpm. The temperature of the strand in the center of the die was 362°C. The strand was broken not only inside the die but also at both ends of the die. The strand surface was beautiful and did not show poor glass fiber opening. The strand breakage occurred at the exit of the die, so it was considered to be due to gas.

[0298] The above results are shown in Table 7 below.

[0299] [Table 7]

[0300]

[0301] In Examples 36 to 42 and Comparative Examples 21 to 24, resin compositions were produced using the raw material ratios shown in Formulation 3 in Table 5.

[0302] Embodiment 36

[0303] The experiment was carried out in the same manner as in Example 22, except that 12.5 kg / h of nylon MXD6 (PA1), 7.5 kg / h of nylon 66 (PA2), 57.5 kg / h of nylon 6 (PA3), 62.5 kg / h of mica (C1) as other reinforcing materials, and 2.5 kg / h of release agent (D2) were fed from the main raw material hopper to the feed barrel C1 of the twin-screw extruder ("TEX44αIII" manufactured by The Japan Steel Works, Ltd.), and 20 kg / h of round cross-section glass fiber (GF1) and 50 kg / h of irregular cross-section glass fiber (GF2) were further fed from the side feed hopper to the side feed barrel C9.

[0304] Some of the strands at the ends looked as if the strands were curling outwards slightly but were not broken. The strands on the inside only broke 2 times.

[0305] The strands extruded from the die were cooled in a water tank, and the strands were cut with a pelletizer to obtain pellets. The shear viscosity of the pellets measured in the same manner as in Example 22 was 1050 Pa·s.

[0306] Embodiment 37

[0307] The same procedure as in Example 36 was carried out except that the hole diameter in the transverse flat die was set to 3.8 mm, the number of holes was similarly set to 10, and the forming section length was set to 10 mm.

[0308] Embodiment 38

[0309] The same procedure as in Example 36 was carried out except that the hole diameter in the transverse flat die was set to 3.8 mm, the number of holes was similarly set to 10, and the forming section length was set to 30 mm.

[0310] Embodiment 39

[0311] The same procedure as in Example 36 was carried out except that the temperature of the mold base was set to 285°C.

[0312] Embodiment 40

[0313] The same procedure as in Example 36 was carried out except that the temperature of the mold base was set to 330°C.

[0314] Embodiment 41

[0315] The same procedure as in Example 36 was carried out except that the temperature of the mold base was set to 260°C.

[0316] Embodiment 42

[0317] The same procedure as in Example 36 was carried out except that the temperature of the mold base was set to 345°C.

[0318] Comparative Example 21

[0319] The same method as in Example 36 was used except that the hole diameter was set to 3.8 mm in the horizontal flat die, the number of holes was similarly set to 10, and the forming section length was set to 5 mm. The resin pressure in the die was 1.8 MPa. The strands inside the die and at both ends of the die were easily broken, and fibrous fluff was even shown in the strands. It was judged that the resin pressure was low, the impregnation of the resin into the fiber was insufficient, and the fiber opening property was insufficient.

[0320] Comparative Example 22

[0321] The same method as in Example 36 was used except that the hole diameter was set to 3.8 mm in the horizontal flat die, the number of holes was similarly set to 10, and the molding section length was set to 40 mm. The resin pressure in the mold was as high as 9.6 MPa, and the strands inside the mold and at both ends of the mold were easily broken. Since the position where the strands broke was the exit of the mold, it was considered that the strands were broken due to gas.

[0322] Comparative Example 23

[0323] The same method as in Example 36 was performed except that the screw rotation was set to 200 rpm, the hole diameter in the horizontal flat die was set to 3.8 mm, the number of holes was similarly set to 10, and the molding section length was set to 10 mm. The temperature of the strand in the center of the die was 308° C. It is believed that the temperature of the resin was low, the impregnation of the fiber was insufficient, the fiber opening was poor, and the strand breakage occurred frequently.

[0324] Comparative Example 24

[0325] The same method as in Example 36 was used except that the screw rotation was set to 500 rpm. The temperature of the strand in the center of the die was 367°C. The strand was broken not only inside the die but also at both ends of the die. The strand surface was beautiful and did not show poor glass fiber opening. The strand breakage occurred at the exit of the die, so it was considered to be due to gas.

[0326] The above results are shown in Table 8 below.

[0327] [Table 8]

[0328]

[0329] Industrial Applicability

[0330] According to the production method of the present invention, high-quality pellets of a glass fiber-reinforced polyamide resin composition containing a high concentration of glass fibers can be stably produced.

[0331] Reference numerals list

[0332] 1 Main raw material hopper

[0333] 3 Side feed hopper

[0334] 4 Pressure relief vent

[0335] 5 Thermocouple of the second kneading section

[0336] 6 Flange

[0337] 7 Resin pressure gauge

[0338] 8. Die Base

[0339] 9 Die base thermocouple

[0340] 10 Wire

[0341] 11 Granulator

[0342] 12 Pellets

[0343] 13 cooling water tank

[0344] 15 Gear Box

[0345] 16 Motor

[0346] 20 Front end of cylinder

[0347] 21 Screw

[0348] 23 Ring plate

[0349] 24 Manifold

[0350] 25 Horizontal flat die

[0351] 31,32,33 die holes

Claims

1. A method for producing a glass fiber reinforced polyamide resin composition, comprising producing the glass fiber reinforced polyamide resin composition by using a twin-screw extruder, wherein the glass fiber reinforced polyamide resin composition comprises 20 to 70% by mass of a polyamide resin (A), 10 to 75% by mass of a glass fiber (B), 0 to 40% by mass of other reinforcing materials (C) and 0 to 30% by mass of other polymers or additives (D) (the total of the components is 100% by mass), wherein The glass fiber reinforced polyamide resin composition has a shear viscosity of 400 to 2000 Pa·s at a temperature of 280° C. and a shear rate of 91 / sec, When a strand is extruded from a transverse flat die in a die holder at the front end of the twin-screw extruder, the temperature of the strand from the die hole in the center of the flat die is 310° C. to 360° C., and (i) the temperature of the strands from the die holes at the ends of the flat die is 4°C to 14°C lower than the temperature of the strands from the die holes in the center of the flat die, or (ii) Extruding the strands so that the resin pressure in the die during extrusion from the flat die is 2.0 to 8.5 MPa.

2. The manufacturing method according to claim 1, Wherein (i) the temperature of the strands from the die holes at the ends of the flat die is 4°C to 14°C lower than the temperature of the strands from the die holes in the center of the flat die, and (ii) the strands are extruded in such a way that the resin pressure in the die during extrusion from the flat die is 2.0 to 8.5 MPa.

3. The manufacturing method according to claim 1 or 2, The temperature of the mold base is 250°C to 350°C.

4. The manufacturing method according to any one of claims 1 to 3, The polyamide resin (A) comprises one to three of poly(meta-xylylene adipamide), polyamide 6 and polyamide 66.

5. The manufacturing method according to any one of claims 1 to 4, The total content of the glass fiber (B) and the other reinforcing material (C) is 30% by mass or more.

6. The manufacturing method according to any one of claims 1 to 5, The glass fiber (B) comprises a glass fiber having an aspect ratio of a longitudinal cross section in the range of 2.0 to 6.0.

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