Device for stirring and supplying fibrous filler, method for supplying fibrous filler, method for producing fibrous filler, and method for producing thermoplastic resin composition

Abstract

The present invention relates to a fibrous filler stirring / supplying device capable of uniformly and stably transporting a fibrous filler using a screw, even for a fibrous filler that is easy to open, has a low bulk density, and is easy to accumulate into a cotton-like structure. The fibrous filler stirring / supplying device supplies a fibrous filler from a hopper accommodating the fibrous filler to a discharge part, and is characterized by comprising: a connection tank between the hopper and the discharge part; a shaft rotating around a rotating shaft and a stirring blade for stirring the fibrous filler are arranged in the connecting tank, and the blade is attached to the tail end of the shaft in a manner of rotating along the inner circumference of the connecting tank; and the stirring blades are inclined inwards at an angle theta of 10-70 degrees relative to the rotation direction of the stirring blades.

Description

Technical Field

[0001] The present invention relates to a stirring and supplying device, a supplying method, and a production method of a fibrous filler, and a production method of a thermoplastic resin composition. Background Art

[0002] In order to produce a resin composition, a method of supplying a raw material resin and various additives to an extruder and melt-kneading to produce pellets of the resin composition is widely performed. A fiber-reinforced thermoplastic resin composition (in which a fibrous filler such as carbon fiber or glass fiber has been compounded as an additive) makes the strength of the molded product to be obtained greater and is widely used in various fields.

[0003] In order to produce a fiber-reinforced thermoplastic resin composition, resin particles of a thermoplastic resin as a raw material are supplied to an extruder, and the resin particles are melted in the cylinder of the extruder and conveyed forward (downstream) by a screw. A fibrous filler is supplied to the cylinder at a predetermined position in the cylinder of the extruder using a side feeder. In the extruder, the molten thermoplastic resin and the fibrous filler are mixed together by the rotation of the screw, and the fibrous filler is dispersed into fragments, appropriately cut, extruded from a terminal nozzle, and then cooled and cut, thereby producing particles of a fiber-reinforced thermoplastic resin composition.

[0004] In the case of supplying various additives from a side feeder, a stirring and supplying device is provided, which is composed of a hopper (metering tank) for storing raw material additives, a connecting tank below the hopper, an agitator for stirring the raw materials in the connecting tank, and a screw cylinder at the bottom of the connecting tank with a screw for transporting the additives to a discharge portion.

[0005] Generally, the fibrous filler is provided as chopped fibers. When such a fibrous filler is actually supplied from a side feeder to an extruder cylinder, the stress applied to the fibrous filler during kneading with a thermoplastic resin becomes uneven, and the fibrous filler is likely to be broken or cut, and the fiber length distribution in the thermoplastic resin composition also becomes uneven.

[0006] However, the agitator in the conventional stirring and feeding device is constructed to stir the raw materials in the connecting tank, and is intended to suppress the phenomenon of bridging (part or all of the fibrous filler no longer falls into the connecting tank) or only the central part of the fiber falling. However, when the fibrous filler has a small bulk density and is easy to open, the fiber cannot be stably supplied to the cylinder using a screw. The fibrous filler that is easy to open is easily opened and condensed into a cotton-like shape by being loaded into a hopper (metering tank), moving downward, and further rotating with the agitator, thereby forming a bridge at the cylinder opening without falling into the cylinder. Therefore, the fibrous filler cannot be fully loaded into the cylinder, and it is difficult to transport it evenly using a screw. Summary of the invention

[0007] Problem that the invention aims to solve

[0008] An object of the present invention is to provide a stirring and supplying device for a fibrous filler and a supplying method for a fibrous filler, which, in consideration of the above-mentioned problems of the prior art, enables even a fibrous filler that is easy to open, has a low bulk density, and is easy to agglomerate into a cotton-like state to be uniformly and stably conveyed by a screw. In addition, another object of the present invention is to provide a production method for a fibrous filler in which the opening of the fiber has been promoted and the bulk density has been reduced by the stirring and supplying device or the supplying method, and a method for stably producing a thermoplastic resin composition in which the fibrous filler obtained by the above-mentioned production method has been compounded.

[0009] Solutions for solving problems

[0010] In order to achieve the above-mentioned purpose, the stirring and supplying device of the fibrous filler of the present invention is a device for supplying the fibrous filler from a hopper storing the fibrous filler to a discharge part, and the stirring and supplying device includes: a connecting tank between the hopper and the discharge part, wherein a shaft rotating around a rotating axis is provided in the connecting tank, and a stirring blade for stirring the fibrous filler is arranged at the end of the shaft so that the stirring blade rotates along the inner circumferential surface of the connecting tank, and the stirring blade is inclined inwardly at an angle θ of 10° to 70° relative to the rotation direction of the stirring blade.

[0011] Preferably, the stirring and supplying device for the fibrous filler includes a connecting tank having a substantially hemispherical inner peripheral surface between the hopper and the discharge portion, a shaft vertically rotating around a rotation shaft horizontally protruding inward from the inner peripheral surface of the connecting tank is provided in the connecting tank, and a stirring blade for stirring the fibrous filler is provided at the end of the shaft so that the stirring blade rotates vertically along the inner peripheral surface of the connecting tank, and the stirring blade is inclined inwardly at an angle θ of 10° to 70° relative to the rotation direction of the stirring blade. In the stirring and supplying device, the shortest distance of the gap between the stirring blade and the inner peripheral surface of the connecting tank is preferably in the range of 0.2 cm to 5 cm.

[0012] Preferably, the stirring and supplying device of the fibrous filler includes a connecting tank between the hopper and the discharge portion, a circular inclined surface is provided at the lower portion of the connecting tank obliquely upward from the lower portion of the connecting tank, a shaft is provided that rotates around a rotating shaft protruding inward from the center of the circular inclined surface, and a stirring blade for stirring the fibrous filler is provided at the end of the shaft so that the stirring blade rotates on the circular inclined surface, and the stirring blade is inclined inward at an angle θ of 10° to 70° relative to the rotation direction of the stirring blade. The shortest distance of the gap between the end of the stirring blade and the inner wall surface of the connecting tank is preferably in the range of 0.2 cm to 5 cm.

[0013] The number of stirring blades is preferably two to six.

[0014] A screw for supplying the fibrous filler to the discharge portion is preferably provided at the bottom of the connection tank.

[0015] The area obtained by multiplying the area of ​​each stirring blade by cosθ of the inclination angle is preferably 0.1 to 1.0 times the opening area of ​​the opening portion at the bottom of the connection tank toward the screw when viewed from directly above.

[0016] The supply method of the fibrous filler of the present invention is a method for supplying the fibrous filler stored in a hopper to a discharge portion, wherein a connecting tank is provided between the hopper and the discharge portion, an agitator is provided in the connecting tank, in the agitator, an axis rotating around a rotating axis is provided, and a stirring blade for stirring the fibrous filler is provided at the end of the axis so that the stirring blade rotates along the inner circumferential surface of the connecting tank, and the stirring blade is inclined inwardly at an angle θ of 10° to 70° relative to the rotation direction of the stirring blade, and the fibrous filler is opened by the agitator and supplied to the discharge portion by a screw provided at the bottom of the connecting tank.

[0017] In the supply method, the rotation speed of the agitator is preferably 1% to 20% of the rotation speed of the screw.

[0018] Preferably, the bulk density V0 of the fibrous filler stored in the hopper is 0.3 to 0.7 g / cm 3 , and the bulk density V1 of the discharged fibrous filler is less than 0.1 to 0.5 g / cm 3 within the range.

[0019] A method for producing a fibrous filler of the present invention is a method for producing a fibrous filler having a reduced bulk density by opening the fibrous filler stored in a hopper, wherein a connecting tank is provided between the hopper and a discharge portion, an agitator is provided in the connecting tank, in the agitator, a shaft rotating around a rotating axis is provided, a stirring blade for stirring the fibrous filler is provided at the end of the shaft so that the stirring blade rotates along the inner circumferential surface of the connecting tank, and the stirring blade is inclined inwardly at an angle θ of 10° to 70° relative to the rotation direction of the stirring blade, and the fibrous filler is opened by the agitator and supplied to the discharge portion by a screw provided at the bottom of the connecting tank.

[0020] It is preferred that the bulk density V0 of the fibrous filler stored in the hopper is 0.3 to 0.7 g / cm 3 , and the bulk density V1 of the discharged fibrous filler is less than 0.1 to 0.5 g / cm 3 within the range.

[0021] A method for producing a thermoplastic resin composition is a method for producing a thermoplastic resin composition containing a fibrous filler compounded into a thermoplastic resin using an extruder, wherein the fibrous filler having a reduced bulk density obtained by the method for producing a fibrous filler is side-fed from a side feeder disposed downstream of a main feed port of a raw material containing a thermoplastic resin and is melt-kneaded.

[0022] Effects of the Invention

[0023] According to the stirring and feeding device for a fibrous filler of the present invention, even a fibrous filler that is easy to open, has a low bulk density, and is easy to agglomerate into a cotton-like state can be uniformly and stably transported by the screw.

[0024] Furthermore, according to the method for supplying a fibrous filler of the present invention, even a fibrous filler that is easily opened and has a low bulk density can be stably supplied to the discharge portion.

[0025] Furthermore, according to the method for producing a fibrous filler of the present invention, a fibrous filler which has been opened and has a reduced bulk density can be stably produced.

[0026] Furthermore, according to the method for producing a thermoplastic resin composition of the present invention, a thermoplastic resin composition in which a fibrous filler has been uniformly dispersed can be stably produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] [ Figure 1 ]

[0028] Figure 1 This is an exploded perspective view showing one embodiment of the stirring and supplying device of the present invention.

[0029] [ Figure 2 ]

[0030] Figure 2 This is a partial cross-sectional view of one embodiment of the stirring and supplying device of the present invention.

[0031] [ Figure 3 ]

[0032] Figure 3 1 and 2 are a plan view and a side view showing one embodiment of a stirring blade used in the stirring and supplying device of the present invention.

[0033] [ Figure 4 ]

[0034] Figure 4 is an exploded perspective view showing an embodiment having a circular inclined surface at a lower portion of a connection tank.

[0035] [ Figure 5 ]

[0036] Figure 5 Is has Figure 4 A partial cross-sectional view of an embodiment of a circular inclined surface.

[0037] [ Figure 6 ]

[0038] Figure 6 It is shown that Figure 4 Plan and side views of one embodiment of a mixing blade for use with a circular inclined surface. DETAILED DESCRIPTION

[0039] Hereinafter, the stirring and supplying device, supplying method, and production method of the fibrous filler of the present invention, and the production method of the thermoplastic resin composition will be described with reference to the accompanying drawings. The embodiments to be described below are merely examples, and the present invention is not necessarily limited thereto.

[0040] Figure 1 This is an exploded perspective view showing one embodiment of the stirring and supplying device of the present invention. Figure 2 FIG. 1 is a partial cross-sectional view of an embodiment of the stirring and feeding device of the present invention. Figure 1 and Figure 2 In the method, a connecting tank having a roughly hemispherical inner circumferential surface is provided between a hopper and a discharge portion, and a shaft that vertically rotates around a rotating shaft that horizontally protrudes inward from the inner circumferential surface of the connecting tank is provided in the connecting tank, and a stirring blade for stirring the fibrous filler is provided at the end of the shaft so that the stirring blade rotates vertically along the inner circumferential surface of the connecting tank.

[0041] like Figure 1 and Figure 2 As shown in FIG. 1 , the stirring and supplying device of the present invention includes a hopper 1 for storing a fibrous filler, a connecting tank 2 having a substantially hemispherical inner peripheral surface below the hopper 1, and a screw 5 for supplying the fibrous filler from an opening 6 at the bottom of the connecting tank 2 to a discharge portion 3. The hopper 1 may be as follows: Figure 1 The connection tank 2 needs to be substantially hemispherical and may partially have a curved surface such as an ellipsoidal shape as long as the rotating stirring blade 10 does not come into contact with the connection tank 2 .

[0042] An agitator 4 is provided in the connecting tank 2, and the agitator 4 is provided with a shaft 9 that rotates vertically around a rotating shaft 8 that protrudes horizontally inward from the inner circumference of the connecting tank 2, and a stirring blade 10 for stirring the fibrous filler is provided at the end of the shaft 9 so that the stirring blade 10 rotates vertically along the inner circumference of the connecting tank 2.

[0043] The fibrous filler stored in the hopper 1 falls into the connection tank 2 due to gravity, and is stirred and opened by the vertical rotation (rotation) of the stirring blade 10 provided at the front of the shaft 9 in the stirrer 4 .

[0044] Figure 3 An embodiment of the stirring blade in the stirrer 4 is shown. Figure 3 (a) is a plane graph, and Figure 3 (b) is the right side view. Figure 3 In (b), the Figure 3 (a) includes a horizontally extending shaft 9 and a stirring blade 10 at the end thereof.

[0045] In axis 9, as Figure 3 As shown in (a), two shafts can be combined with each other at the rotating shaft 8 to form a cross, and a total of four stirring blades 10 can be provided. In addition, three shafts can cross and combine with each other at the rotating shaft 8, and a total of six stirring blades 10 can be arranged at its end in a point-symmetrical manner relative to the rotating shaft 8 as a center point. Three shafts 9 can extend radially at intervals of 120 ° from the center of the rotating shaft 8, and a total of three stirring blades 10 can be arranged at its end (one stirring blade for each shaft). A stirring blade can be provided at each of the two ends of a shaft 9. The number of stirring blades 10 is preferably two to six.

[0046] The stirring blade 10 may be Figure 3 As shown, it extends on the same surface side of the shaft 9, or it can be as shown Figure 2 In the case of a plurality of shafts 9, it is preferred that, for example, the stirring blades 10 are alternately arranged on the front side, the back side and the front side of the rotating surface of the shaft 9 so that Figure 3 As shown in (a).

[0047] like Figure 3As shown in (a), the stirring blade 10 is tilted inwardly relative to the rotation direction D (tangential direction of the rotation circle) of the stirring blade 10 so that its angle becomes the angle θ in the direction of the rotation axis 8, and the angle θ is set to 10° to 70°. When the angle is set in the manner described above, the uneven supply from the bottom of the connecting tank 2 to the discharge portion 3 is suppressed, and uniform supply becomes possible. When the angle θ is less than 10°, the force for conveying the fibrous filler to the cylinder 7 becomes weak, and a sufficient amount of the fibrous filler cannot be loaded into the screw 5 for supplying the fibrous filler from the bottom of the connecting tank 2 to the discharge portion 3, and uniform supply using the screw becomes difficult. When the angle θ is greater than 70°, the force applied to the rotating shaft of the agitator becomes too strong, and the rotating shaft is likely to be damaged. More preferably, the angle θ is in the range of 20° to 60°. The angle θ is preferably 20° or more and preferably 60° or less, and more preferably 50° or less.

[0048] The stirring blade 10 extends along the substantially hemispherical inner circumference of the connection tank 2, and the shortest distance of the gap between the stirring blade 10 and the inner circumference of the connection tank is preferably set in the range of 0.2 cm to 5 cm and more preferably 0.3 cm to 3 cm. When the shortest distance is greater than 5 cm, the force for pressing the fibrous filler into the cylinder 7 becomes weak, it is difficult to load a sufficient amount of the fibrous filler into the cylinder 7, and it is likely to be difficult to uniformly supply the screw 5. When the shortest distance is less than 0.2 cm, the stirring blade 10 contacts the inner surface of the hopper, and thus the agitator 4 may be damaged.

[0049] The connection tank 2 is generally hemispherical, but the diameter of the inner surface at the upper portion thereof is generally 15 cm to 50 cm and preferably 20 cm to 40 cm.

[0050] In the present invention, the fibrous filler includes inorganic fibers such as carbon fiber, glass fiber, alumina fiber, boron fiber and ceramic fiber, organic fibers such as plant fiber (including kenaf and bamboo fiber), polyester fiber, aramid fiber, polyoxymethylene fiber, aromatic polyamide fiber, poly(p-phenylene benzobisoxazole) fiber and ultra-high molecular weight polyethylene fiber, etc. Among them, carbon fiber and glass fiber are preferred, and carbon fiber is particularly preferred.

[0051] The number average fiber length of the fibrous filler used is preferably 20 mm or shorter, and further, 10 mm or shorter and 1 mm or longer. Specifically, chopped fibers and milled fibers are preferred.

[0052] The bulk density V0 of the raw material fibrous filler stored in the hopper is preferably 0.3 g / cm 3 Up to 0.7g / cm 3 , more preferably 0.35 g / cm3 Up to 0.65g / cm 3 , and further more preferably at 0.4 g / cm 3 Up to 0.6g / cm 3 When the bulk density V0 is 0.3 / cm 3 When the bulk density V0 exceeds 0.7 g / cm2, it is impossible for the stirring blade to press a sufficient amount of the raw material having a bulk density increased by stirring into the cylinder, and uneven supply is likely to occur. 3 When the agitator is stirred, a strong force is applied to the rotating shaft in the agitator, and the rotating shaft is likely to be damaged.

[0053] In particular, in the present invention, since the effect of the present invention is large, a substance that is easily opened and easily becomes looser by stirring (having a reduced bulk density) is suitable as a fibrous filler as a raw material. Examples of the fibrous filler that is easily loosened by stirring include a fibrous filler that does not use an astringent or the like or a fibrous filler that has been treated only to a low degree.

[0054] In the present invention, bulk density refers to the weight of a fibrous filler per a certain volume, which is the same as the relaxed bulk specific gravity, the relaxed bulk density or the relaxed apparent density, and refers to the bulk density when the fibrous filler is lightly and calmly loaded into a receiver. The bulk density (V0 and V1) is a value measured based on a measurement method according to ISO 60. Specifically, a metal cylinder having a volume of 100cc, an inner diameter of 50mm and a smoothed inner surface is used as a receiver into which the fibrous filler is to be loaded, the fibrous filler is calmly and slowly loaded into the receiver, and once the receiver is filled, the raw material protruding from the receiver is scraped off with a straight plate, the weight of the contents in the receiver is measured to one decimal place, and the bulk density is obtained.

[0055] The fibrous filler opened and stirred by the stirrer 4 comes out from the opening 6 provided at the bottom of the connection tank 2, and is supplied to the discharge portion 3 by the screw 5 intended to supply the fibrous filler to the discharge portion 3. The screw 5 may be a single screw, or may be composed of a twin screw. The screw 5 is arranged in a cylinder 7, the fibrous filler from the opening 6 is loaded into the cylinder 7, and the screw 5 is driven to rotate to supply the fibrous filler to the discharge portion 3.

[0056] The opening 6 has a rectangular shape corresponding to the screw 5 located just below the opening 6, and the center line of the opening 6 in the longitudinal direction preferably matches the rotating shaft 8 in the agitator 4 located just above the opening 6. The agitating blade 10 rotates above the inner circumferential surface of the connecting tank 2 at an inclination angle of 10° to 70°, and the fibrous filler is sufficiently pressed from the opening 6 into the cylinder 7 where the screw 5 is located, which makes it possible to uniformly supply the fibrous filler with a reduced bulk density.

[0057] The area obtained by multiplying the area of ​​one stirring blade 10 by cosθ of the inclination angle is preferably in the range of 0.1 to 1.0 times the opening area of ​​the opening portion 6 viewed from directly above, and more preferably in the range of 0.2 to 0.8 times. When the area is less than 0.1 times, the force for pressing the fibrous filler into the cylinder 7 becomes weak, which cannot load a sufficient amount of the fibrous filler into the cylinder 7, and it is likely to be difficult to perform uniform supply using the screw 5. When the area is greater than 1.0 times, the force applied to the stirrer 4 becomes strong, and the rotating shaft 8 is likely to be damaged.

[0058] Regarding the size of the opening 6, it is preferred that the long side is approximately 10 cm to 25 cm and the short side is approximately 5 cm to 15 cm, and the opening area is preferably approximately 50 cm 2 Up to 350cm 2 .

[0059] The area obtained by multiplying the area of ​​one stirring blade 10 by cosθ of the inclination angle is preferably approximately 10 cm 2 Up to 350cm 2 .

[0060] The rotation speed of the agitator 4 is preferably 1% to 20%, more preferably 2% to 15%, and further more preferably 3% to 10% of the rotation speed of the screw 5. When the rotation speed is less than 1%, the amount of fibrous filler pressed in by the agitator 4 becomes small, and it is likely to be difficult to perform uniform supply. When the rotation speed exceeds 20%, the fibrous filler is excessively opened to generate fabric balls, the fibrous filler becomes difficult to press into the cylinder 7, a sufficient amount of the fibrous filler cannot be loaded into the cylinder 7, and it is likely to be difficult to perform uniform supply using the screw 5.

[0061] The rotation speed of the screw 5 is preferably approximately 10 rpm to 600 rpm, and the rotation speed of the agitator 4 is preferably approximately 2 rpm to 90 rpm.

[0062] The distance that the screw advances in the axial direction when the screw has rotated one circle is called the "lead", and in a single-thread screw, the lead and the pitch become equal to each other. In a double-thread screw, the lead becomes twice the pitch. When the screw diameter (outer diameter) is represented by D, the lead of the screw 5 is preferably 0.5D to 1.5D. When the lead is greater than 1.5D, the force used to transport the fibrous filler becomes weak, and it is likely to be difficult to supply evenly. Even when the lead is less than 0.5D, the force used to transport the fibrous filler will become weak, and it is likely to be difficult to supply evenly. The lead of the screw 5 is more preferably 0.6D to 1.4D, and further more preferably 0.7D to 1.3D.

[0063] The bulk density V1 of the fibrous filler supplied to the discharge portion 3 becomes smaller than the bulk density V0 (preferably 0.3 g / cm 3 Up to 0.7g / cm 3 ), and preferably at 0.1 g / cm 3 Up to 0.5g / cm 3 In the range of 0.15 g / cm 3 Up to 0.45g / cm 3 and further more preferably in the range of 0.2 g / cm 3 Up to 0.4g / cm 3 within the range.

[0064] According to the present invention, in particular, even when a fibrous filler without an astringent or the like or a fibrous filler that has only been processed to a low degree is used as a raw material, the fibrous filler can be opened and stirred using an agitator having the above-mentioned structure, conveyed to the screw 5, and supplied to the discharge section 3, which makes it possible to obtain a fibrous filler that has been opened and has a low bulk density.

[0065] When the obtained fibrous filler is side-fed to an extruder, it is possible to obtain a fibrous filler that enables stable production of a thermoplastic resin composition containing the fibrous filler uniformly dispersed therein.

[0066] The type of raw material thermoplastic resin used is not particularly limited, and any resin can be used as long as the resin is a thermoplastic resin. Examples of thermoplastic resins suitable for use in the present invention include crystalline thermoplastic resins or amorphous thermoplastic resins, and specific examples thereof include polycarbonate resins; polyester resins such as polybutylene terephthalate resins and polyethylene terephthalate resins; styrene resins such as polystyrene resins, high impact polystyrene resins (HIPS), ABS resins, AES resins, and AS resins; polyolefin resins such as polyethylene resins and polypropylene resins; polyamide resins such as polyamide 6, polyamide 66, and polyamide MXD6; polyoxymethylene resins; polyphenylene sulfide resins; methacrylic resins such as PMMA resins; polyphenylene oxide resins; polysulfone resins; polyethersulfone resins; polyarylate resins; polyetherimide resins; polyamideimide resins; polyimide resins; polyetherketone resins; polyetheretherketone resins; polyestercarbonate resins; liquid crystal polymers; and the like.

[0067] As the extruder, a single-screw extruder or a twin-screw extruder, particularly a twin-screw extruder is preferred, and either a vented screw or a non-vented screw may be used, but a vented screw is preferred.

[0068] A raw material containing a thermoplastic resin and a resin additive compounded as needed is supplied to the cylinder in the form of particles or powder from a main supply port of a hopper at the base of an extruder (not shown) and transported to a first mixing section. The raw material is heated in the first mixing section, and the heating temperature is set based on the melting point, glass transition temperature, etc. of the thermoplastic resin as the main component. The raw material melt-mixed in the first mixing section is further pressed against the resin supplied later. In addition, the fibrous filler obtained in the stirring and feeding device is supplied to the cylinder of the extruder from a side feeder arranged downstream of the main supply port, and is melt-mixed in the second mixing section.

[0069] The screw configuration in the kneading section is preferably a combination of two or more elements selected from a forward conveying kneading disc, a reverse conveying kneading disc, and an orthogonal kneading disc.

[0070] The forward conveying kneading disc element is also referred to as R-kneading (hereinafter, also referred to as R in some cases), and generally has two or more blades, and the blade twist angle is preferably 10° to 75°. When the blades are installed to be twisted at a predetermined angle as described above, a region is formed in which a pseudo-screw structure is formed, a strong shear force is applied to the resin while the resin is conveyed in the conveying direction, and kneading is performed.

[0071] The reverse conveying kneading disc element is also referred to as L-mixing (hereinafter, also referred to as L in some cases), and generally has two or more blades, and the blade twist angle is preferably -10° to -75°. The reverse conveying kneading disc element is an element having a compression capability that blocks the incoming resin or causes the incoming resin to act in a conveying return direction, and is an element that is provided downstream of the element that promotes kneading to block the resin and allow a strong kneading effect to be exhibited.

[0072] The orthogonal kneading disc element is also called N-kneading (hereinafter, also referred to as N in some cases), and generally has two or more blades, and the blade twist angle is 75° to 105°. Since the blades are installed to be twisted at substantially 90°, the force for conveying the resin is weak, but the kneading force is strong.

[0073] The screw configuration in the first kneading section is preferably composed of a combination of two or more elements, and preferably, an element that promotes kneading is arranged upstream, and an element having compression capability is arranged downstream. Therefore, in the kneading area of ​​the first step, 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 it is also preferred that the number of each of R, N, and L arranged is plural.

[0074] The screw in the second mixing section is preferably composed of an element selected from a forward conveying mixing disk (R), a reverse conveying mixing disk (L), an orthogonal mixing disk (N), a forward conveying notched mixing screw, and a reverse conveying notched mixing screw.

[0075] The resin composition which has been melt-kneaded in the second kneading section and contains the fibrous filler dispersed therein is extruded from the nozzle at the end of the extruder in a strand shape, cooled and then cut with a cutter, thereby producing pellets of the thermoplastic resin composition. This makes it possible to stably produce a thermoplastic resin composition in which the fibrous filler has been uniformly dispersed.

[0076] Figures 4 to 6 This is a view for describing another embodiment of the present invention, in which a circular inclined surface is provided at the lower portion of the connecting tank obliquely upward from the lower portion of the connecting tank, a shaft rotating around a rotating shaft protruding inward from the center of the circular inclined surface is provided, and a stirring blade for stirring the fibrous filler is provided at the end of the shaft so that the stirring blade rotates on the circular inclined surface.

[0077] like Figure 4 and Figure 5 As shown, the stirring and supplying device includes a hopper 1 storing a fibrous filler, a connecting tank 2 below the hopper 1, a screw 5 for supplying the fibrous filler from an opening 6 at the bottom of the connecting tank 2 to a discharge portion 3, etc. The hopper 1 is preferably as shown in FIG. Figure 4 Conical or cylindrical shapes are shown, but prismatic shapes are also possible.

[0078] The connecting tank 2 is connected to the hopper 1 at the upper part, and the side wall of the connecting tank 2 may be formed into a circular conical shape in a plan view, or may be formed into an elliptical shape in a plan view and vertically the same or different cross-sectional shapes. It is also preferred that the side wall of the connecting tank 2 has a cross-sectional shape in which the lower side is larger than the upper side.

[0079] In the connecting tank 2, a circular inclined surface 11 is provided obliquely upward from the lower part, preferably the bottom of the connecting tank, and an agitator 4 is provided, in which a shaft 9 rotating around a rotating shaft 8 protruding inwardly in an inclined direction from the center of the circular inclined surface 11 is provided, and a stirring blade 10 for stirring the fibrous filler is provided at the end of the shaft 9 so that the stirring blade rotates on the circular inclined surface 11.

[0080] The fibrous filler stored in the hopper 1 falls into the connection tank 2 due to gravity, and is stirred and opened by the rotation (turning) of the stirring blade 10 at the front of the shaft 9 in the stirrer 4 along the inclined surface 11 .

[0081] Figure 6 An embodiment of the stirring blade in the stirrer 4 is shown. Figure 6 (a) is a plane diagram, Figure 6 (b) is the right side view, and Figure 6 (c) is the front view. Figure 6 In (b), the Figure 6 (a) of the horizontally extending shaft 9 and the stirring blade 10 at the end thereof. Figure 6 In (c), the horizontal and rearward extending shaft 9 and the stirring blade 10 at the end thereof are omitted.

[0082] In axis 9, as Figure 6 As shown in (a), two shafts can be combined with each other at the rotating shaft 8 to form a cross, and a total of four stirring blades 10 can be provided. In addition, three shafts can cross and combine with each other at the rotating shaft 8, and a total of six stirring blades 10 can be arranged at its end in a point-symmetrical manner relative to the rotating shaft 8 as a center point. Three shafts 9 can extend radially at intervals of 120 ° from the center of the rotating shaft 8, and a total of three stirring blades 10 can be arranged at its end (one stirring blade for each shaft). A stirring blade can be provided at each of the two ends of a shaft 9. The number of stirring blades 10 is preferably two to six.

[0083] Preferably, if Figure 6As shown in (b) , the stirring blade 10 extends from the shaft 9 along the side wall of the connecting tank 2 toward the upper side of the inclined surface 11 .

[0084] like Figure 6 As shown in (c), the stirring blade 10 is tilted inwardly relative to the rotation direction D (tangential direction of the rotation circle) of the stirring blade 10 so that its angle becomes the angle θ in the direction of the rotation axis 8, and the angle θ is set to 10° to 70°. When the angle is set in the manner described above, uneven supply from the bottom of the connecting tank 2 to the discharge portion 3 is suppressed, and uniform supply is made possible. When the angle θ is less than 10°, the force for conveying the fibrous filler to the cylinder 7 becomes weak, a sufficient amount of the fibrous filler cannot be loaded into the screw 5 for supplying the fibrous filler from the bottom of the connecting tank 2 to the discharge portion 3, and uniform supply using the screw becomes difficult. When the angle θ is greater than 70°, the force applied to the rotating shaft of the agitator becomes too strong, and the rotating shaft is likely to be damaged. More preferably, the angle θ is in the range of 20° to 60°. The angle θ is preferably 20° or more and preferably 60° or less, and more preferably 50° or less.

[0085] like Figure 5 As shown, the stirring blade 10 rotates on the inclined surface 11 along the side wall of the connection tank 2, and the shortest distance of the gap between the stirring blade 10 and the inner wall surface of the connection tank is preferably set in the range of 0.2 cm to 5 cm, and more preferably 0.3 cm to 3 cm. When the shortest distance is greater than 5 cm, the force for pressing the fibrous filler into the cylinder 7 becomes weak, it is difficult to load a sufficient amount of the fibrous filler into the cylinder 7, and it is likely to be difficult to uniformly supply using the screw 5. When the shortest distance is less than 0.2 cm, the stirring blade 10 contacts the inner surface of the hopper, and thus the agitator 4 may be damaged.

[0086] The connection tank 2 is preferably in a conical shape, which is circular in plan view or elliptical in plan view, but the diameter of the inner wall surface is generally 15 cm to 60 cm, and preferably 20 cm to 50 cm.

[0087] The diameter of the inclined surface 11 is preferably 15 cm to 60 cm and more preferably 20 cm to 50 cm.

[0088] The length of the connection portion from the rotation shaft 8 of the shaft 9 to the stirring blade 10 is preferably 8 cm to 30 cm and more preferably 10 cm to 25 cm.

[0089] The fibrous filler opened and stirred by the stirrer 4 comes out from the opening 6 provided at the bottom of the connection tank 2, and is supplied to the discharge portion 3 by the screw 5 for supplying the fibrous filler to the discharge portion 3. The opening 6 is provided at a position where the stirring blade 10 presses the fibrous filler from just above between the bottom of the connection tank 2 and the inclined surface 11.

[0090] The screw 5 may be a single screw, or may be composed of a twin screw. The screw 5 is arranged in a cylinder 7 , a fibrous filler is loaded into the cylinder 7 from an opening 6 , and the screw 5 is driven to rotate to supply the fibrous filler to the discharge portion 3 .

[0091] The opening portion 6 has a rectangular shape corresponding to the screw 5 located directly below the opening portion 6, and the stirring blade 10 fully presses the fibrous filler from the opening portion 6 into the cylinder 7 at an inclined angle of 10° to 70°, which makes it possible to uniformly supply the fibrous filler with a reduced bulk density.

[0092] The area obtained by multiplying the area of ​​one stirring blade 10 by cosθ of the inclination angle is preferably in the range of 0.1 to 1.0 times the opening area of ​​the opening portion 6 viewed from directly above, and more preferably in the range of 0.2 to 0.8 times. When the area is less than 0.1 times, the force for pressing the fibrous filler into the cylinder 7 becomes weak, which cannot load a sufficient amount of the fibrous filler into the cylinder 7, and it is likely to be difficult to perform uniform supply using the screw 5. When the area is greater than 1.0 times, the force applied to the stirrer 4 becomes strong, and the rotating shaft 8 is likely to be damaged.

[0093] Regarding the size of the opening 6, it is preferred that the long side is approximately 8 cm to 25 cm and the short side is approximately 4 cm to 15 cm, and the opening area is preferably approximately 35 cm 2 Up to 350cm 2 .

[0094] The area obtained by multiplying the area of ​​one stirring blade 10 by cosθ of the inclination angle is preferably approximately 5 cm 2 Up to 350cm 2 .

[0095] The rotation speed of the agitator 4 is preferably 1% to 20%, more preferably 2% to 15%, and further more preferably 3% to 10% of the rotation speed of the screw 5. When the rotation speed is less than 1% thereof, the amount of the fibrous filler pressed in with the agitator 4 becomes small, and it is likely to be difficult to perform uniform supply. When the rotation speed exceeds 20%, the fibrous filler is excessively opened to generate fabric balls, the fibrous filler becomes difficult to be pressed into the cylinder 7, a sufficient amount of the fibrous filler cannot be loaded into the cylinder 7, and it is likely to be difficult to perform uniform supply using the screw 5.

[0096] The rotation speed of the screw 5 is preferably approximately 10 rpm to 600 rpm, and the rotation speed of the agitator 4 is preferably approximately 2 rpm to 90 rpm.

[0097] The distance that the screw advances in the axial direction when the screw has rotated one circle is called the "lead", and in a single-thread screw, the lead and the pitch become equal to each other. In a double-thread screw, the lead becomes twice the pitch. When the screw diameter (outer diameter) is represented by D, the lead of the screw 5 is preferably 0.5D to 1.5D. When the lead is greater than 1.5D, the force for transporting the fibrous filler becomes weak, and it is likely to be difficult to perform uniform supply. Even when the lead is less than 0.5D, the force for transporting the fibrous filler becomes weak, and it is likely to be difficult to perform uniform supply using the screw 5. The lead of the screw 5 is more preferably 0.6D to 1.4D, and further more preferably 0.7D to 1.3D.

[0098] The bulk density V1 of the fibrous filler supplied to the discharge portion 3 becomes smaller than the bulk density V0 (preferably 0.3 g / cm 3 Up to 0.7g / cm 3 ), and preferably at 0.1 g / cm 3 Up to 0.5g / cm 3 In the range of 0.15 g / cm 3 Up to 0.45g / cm 3 and further more preferably in the range of 0.2 g / cm 3 Up to 0.4g / cm 3 within the range.

[0099] Even in the case where the circular inclined surface is arranged at the lower part of the connecting tank obliquely upward from the lower part of the connecting tank, according to the present invention, in particular, even when a fibrous filler such as an astringent is not used or a fibrous filler that has only been processed to a low degree is used as a raw material, the fibrous filler is opened and stirred using an agitator having the above-mentioned structure, transported to the screw 5, and supplied to the discharge section 3, which makes it possible to obtain a fibrous filler that has been opened and has a low bulk density.

[0100] Example

[0101] First, the following experiment was performed to determine to what extent stirring of a fibrous filler as a raw material increases the bulk density (or decreases the bulk density).

[0102] A stirring and feeding device "Twin Screw Weight Feeder CE-W-1" manufactured by Kubota Corporation (the connection tank has a hemispherical shape and an inner diameter of 25 cm) was used, the stirrer was connected to "Stirrer 2 for CE-W-1" manufactured by Kubota Corporation (two stirring blades having a length of 11.8 cm and a terminal width of 1.0 cm were attached to a shaft having a length of 22.2 cm and a width of 3.2 cm, the shaft being centered on a 12.2 cm long rotation axis extending from the hemispherical side surface of the connection tank and rotating vertically at an inclination angle θ of 0° relative to the rotation direction), no screw was connected, the opening was sealed, and the stirred fibrous filler was forced to stay. One kilogram of the fibrous filler (the bulk density V0 before it was fed into the hopper had been measured) was loaded into the hopper 1, the stirrer 4 was rotated at a speed of one revolution per second for 15 minutes, and the bulk density V1 (bulk density after stirring) was obtained.

[0103] A fibrous filler having a bulk density V1 after stirring reaching 0.8 times or less of the bulk density V0 of the raw material is particularly preferred as a raw material to which the present invention is applied.

[0104] For the following raw materials, bulk density V0 and bulk density V1 after stirring were obtained, and bulk density ratio (V1 / V0) was obtained. The results are as follows.

[0105] 1. Carbon fiber chopped fiber "DIALEAD K6371T" manufactured by Mitsubishi Chemical Corporation

[0106] V0:0.48g / cm 3 、V1:0.31g / cm 3 、V1 / V0:0.65

[0107] 2. Carbon fiber chopped fiber "PYROFIL TR06U" manufactured by Mitsubishi Chemical Corporation

[0108] V0:0.47g / cm 3 、V1:0.39g / cm 3 、V1 / V0:0.83

[0109] 3. Chopped strand T-187 glass fiber manufactured by Nippon Electric Glass Co., Ltd.

[0110] V0:0.62g / cm 3 、V1:0.54g / cm 3 、V1 / V0:0.87

[0111] From the above results, it can be seen that "K6371T" is a raw material whose bulk density increases by stirring.

[0112] [Example 1]

[0113] As a stirring and supplying device, a device including a conical hopper 1 and a hemispherical connection tank 2 was used, the conical hopper 1 having a lower inner diameter of 35 cm, a height of 65 cm and an upper inner diameter of 60 cm, the hemispherical connection tank 2 having an inner diameter of 35 cm, and as an agitator 4, the following agitator (A1) was used: wherein a shaft 9 having a length (from the rotation axis to the outermost periphery) of 16.0 cm and a width of 4.0 cm, a stirring blade 10 having a length of 17.0 cm and a terminal width of 1.0 cm, and a total of four stirring blades 10 inclined at 30° in the rotation direction were alternately arranged on the front side and the back side of the shaft surface at the terminal of the shaft 9, the shaft 9 being as Figure 3 The stirring blade 10 has an arc shape rotated along the inner surface of the hemispherical connection tank 2, and is installed so that the gap with the inner surface of the connection tank 2 at each position reaches 1.5 cm.

[0114] In the opening 6, the long side is 17.0 cm, the short side is 8.5 cm, and the opening area is 144.5 cm 2 The area of ​​a stirring blade 10 is 47.8 cm 2 , and the area obtained by multiplying the area of ​​one stirring blade 10 by the inclination angle cosθ (= 30°) is 41.4 cm 2 , which is 0.29 times the area of ​​the opening 6.

[0115] As the screw 5 in the cylinder 7, a single-thread screw having a screw diameter of 45 mm (D) and a lead of 42 mm (0.93D) was used.

[0116] 40 kg of carbon fiber chopped fibers "K6371T" were loaded into the hopper 1. The motor ratio of the rotation speed of the screw 5 (a value obtained by dividing the rotation speed rpm of the agitator by the rotation speed rpm of the screw) was set to 5%. The amount discharged to the discharge part 3 was set to 20 kg / h, and a constant weight operation was performed. The discharge amount after 60 minutes to 100 minutes was obtained in the manner described below.

[0117] After 60 minutes, the container was placed under the discharge section 3, and the weight W60 of the carbon fiber discharged for 36 seconds was obtained. Next, after 70 minutes, the weight was measured in the same manner and regarded as W70. W80, W90 and W100 were obtained in the same manner. The maximum and minimum values ​​of the five Ws from W60 to W100, the difference between the maximum and minimum values, the average value of the five Ws, and the fluctuation rate (%, the difference between the maximum and minimum values ​​of the five Ws / the average value of the five Ws) are shown in Table 1.

[0118] 40 kg of carbon fiber chopped fibers "K6371T" discharged to the discharge section 3 were collected, and further, 40 kg of new "K6371T" was fed into the hopper 1 and discharged under the same conditions, and a total of 80 kg of "K6371T" was obtained. The bulk density was measured, and the result was 0.19 g / cm 3 .

[0119] It was found that in the stirring and feeding device of the present invention, the rotation of the stirrer 4 or the rotation of the screw 5 promoted the opening of "K6371T", ​​and as described above, the bulk density was significantly reduced. The discharged "K6371T" is referred to as "opened K6371T".

[0120] [Example 2]

[0121] The operation was performed in the same manner as in Example 1 except that the agitator (A1) in Example 1 was changed to the agitator (A2) having a total of two agitating blades 10 inclined 30° in the rotation direction on the front side and the back side of the shaft surface at both ends of one shaft 9. The area of ​​one agitating blade 10 was 47.8 cm 2 , and the area obtained by multiplying the area of ​​one stirring blade 10 by the inclination angle cosθ (= 30°) is 41.4 cm 2 , which is 0.29 times the area of ​​the opening 6.

[0122] [Comparative Example 1]

[0123] The operation was performed in the same manner as in Example 1 except that the agitator 4 was changed to an agitator (AX) having a total of two agitating blades 10 that were not inclined on the front and back sides of the shaft surface at both ends of one shaft 9 .

[0124] [Example 3]

[0125] In addition to the carbon fiber chopped fiber "K6371T" (bulk density: 0.48g / cm 3 ) was changed to "open fiber K6371T" (bulk density: 0.19g / cm 3 ), perform the operation in the same manner as Example 1.

[0126] [Comparative Example 2]

[0127] In addition to the carbon fiber chopped fiber "K6371T" (bulk density: 0.48g / cm 3 ) was changed to "open fiber K6371T" (bulk density: 0.19g / cm 3 ), the operation was performed in the same manner as in Comparative Example 1.

[0128] The above results are shown in Table 1 below.

[0129] In Table 1, as an evaluation, the fluctuation rate (difference between the maximum value and the minimum value of five Ws / average value of five Ws) was determined according to the following criteria.

[0130] A: Volatility is 7% or less

[0131] B: Volatility is greater than 7% and 10% or less

[0132] C: greater than 10% and 15% or less

[0133] D: more than 15%

[0134] [Table 1]

[0135]

[0136]

[0137] [Production Example 1 of Thermoplastic Resin Composition]

[0138] As an extruder, a twin-screw extruder "TEX44αII" manufactured by Nippon Steel Works, Ltd. was used. The screw structure was RRNNL in the first kneading section and RNL in the second kneading section. R was a forward kneading disk, N was an orthogonal kneading disk, and L was a reverse kneading disk, and disks each having five blades and a length of 44 mm were used. The cylinder set temperature was set to 260°C.

[0139] As the main raw material, polybutylene terephthalate resin "NOVADURAN 5008" manufactured by Mitsubishi Engineering-Plastics Corporation was used, which was supplied to the screw root at 180 kg / h using a belt feeder and melted in the first mixing section. A side feed screw was installed between the first mixing section and the second mixing section, and the chopped carbon fiber "K6371T" obtained by the method of Example 1 was supplied at 20 kg / h and mixed in the second mixing section. The screw rotation speed was set to 250 rpm. The strand-like object was taken out of the mold, cooled in a water tank, and cut with a pelletizer to obtain pellets.

[0140] The extrusion lasted for one hour, and the extrusion and strands were stable, and no excessive torque or strand breakage occurred. One gram of the pellets was dissolved in a solvent mixture of phenol and tetrachloroethane (1 / 1), which is a good solvent, and the carbon fiber was filtered and dried, and then the weight was measured. The weight of the removed carbon fiber was 0.097g (the carbon component excluding the astringent in 0.1g of carbon fiber was 0.098g). Based on this fact, it was confirmed that the chopped carbon fiber "K6371T" was uniformly supplied.

[0141] [Comparative Example 1 for Production of Thermoplastic Resin Composition]

[0142] Production was performed in the same manner as in Production Example 1 except that the carbon fiber obtained in Comparative Example 2 was supplied instead of the chopped carbon fiber. Torque fluctuation was large, excessive torque occurred once per hour, and the extruder stopped. In addition, the strand-like object broke three times. It was well found that the weight of the carbon fiber taken out from one gram was 0.089 g, and the supply of the chopped carbon fiber had fluctuated.

[0143] [Comparative Example 2 of Production of Thermoplastic Resin Composition]

[0144] Production was performed in the same manner as in Production Example 1 of the thermoplastic resin composition, except that polycarbonate resin "IUPILON S3000F" manufactured by Mitsubishi Engineering-Plastics Corporation was used as the main raw material and ethylene chloride was used as the solvent for dissolving the polycarbonate resin. Extrusion and strands were stable, and no excessive torque or strand breakage occurred. The weight of the taken out carbon fiber was 0.096 g, and it was confirmed that the chopped carbon fiber K6371T was uniformly supplied.

[0145] [Production Example 3 of Thermoplastic Resin Composition]

[0146] Production was performed in the same manner as in Production Example 1 of the thermoplastic resin composition, except that polyamide resin "MXD NYLON 6000" manufactured by Mitsubishi Gas Chemical Co., Ltd. was used as the main raw material. Extrusion and strands were stable, and no excessive torque or strand breakage occurred. The weight of the taken out carbon fiber was 0.097 g, and it was confirmed that the chopped carbon fiber K6371T was uniformly supplied.

[0147] [Example 4]

[0148] As a stirring and supplying device, there are provided: a conical hopper 1 having a lower diameter of 29 cm, a height of 65 cm, and an upper diameter of 60 cm; a connecting tank 2 extending downward from an upper opening circle having a diameter of 29 cm in a generally conical shape having a bottom diameter of approximately 40 cm, and the connecting tank 2 includes a circular inclined surface 11 having a diameter of 26 cm, the circular inclined surface being arranged obliquely upward from the bottom at an angle of 45° at the bottom, and as an agitator 4, the following agitator is used: a shaft 9 rotating about a rotating shaft 8 located at the center of the inclined surface 11 is provided, and a stirring blade 10 rotating above the circular inclined surface is provided at the end of the shaft 9. The following agitator (A1) is used: the shaft 9 having a length of 13 cm from the rotating shaft and a width of 2.5 cm, the stirring blade 10 having a length of 10 cm, a root width of 2.9 cm, and a terminal width of 2.3 cm, and a total of four stirring blades 10 inclined by 30° in the rotating direction are provided at the end of the shaft 9, the shaft 9 being as Figure 3 The stirring blade 10 is installed so that the gap between its tip and the inner wall surface of the connection tank 2 reaches 0.7 cm at the closest position.

[0149] In the opening portion 6, the long side is 11.0 cm, the short side is 5.5 cm, and the opening area is 60.5 cm 2 The area of ​​a stirring blade 10 is 26.0 cm 2 , and the area obtained by multiplying the area of ​​one stirring blade 10 by the inclination angle cosθ (=30°) is 22.5 cm 2 , which is 0.37 times the area of ​​the opening 6 .

[0150] As the screw 5 in the cylinder 7, a single-thread screw having a screw diameter of 25.5 mm (D) and a lead of 26 mm (1.02D) was used.

[0151] 20 kg of chopped carbon fiber "K6371T" was loaded into the hopper 1. The motor ratio of the rotation speed of the screw 5 (a value obtained by dividing the rotation speed rpm of the agitator by the rotation speed rpm of the screw) was set to 5%. The amount discharged to the discharge part 3 was set to 10 kg / h, and a constant weight operation was performed. The discharge amount after 60 minutes to 100 minutes was obtained in the manner described below.

[0152] After 60 minutes, the container was placed under the discharge section 3, and the weight W60 of the carbon fiber discharged for 36 seconds was obtained. Next, after 70 minutes, the weight was measured in the same manner and regarded as W70. W80, W90 and W100 were obtained in the same manner. The maximum and minimum values ​​of the five Ws from W60 to W100, the difference between the maximum and minimum values, the five W average values ​​and the fluctuation rate (%, the difference between the maximum and minimum values ​​of the five Ws / the average value of the five Ws) are shown in Table 2.

[0153] 20 kg of chopped carbon fiber "K6371T" discharged to the discharge section 3 was collected, and further, 20 kg of new "K6371T" was fed into the hopper 1 and discharged under the same conditions, and a total of 40 kg of "K6371T" was obtained. The bulk density was measured, and the result was 0.19 g / cm 3 .

[0154] It was found that in the stirring and feeding device of the present invention, the rotation of the stirrer 4 or the rotation of the screw 5 promoted the opening of "K6371T", ​​and as described above, the bulk density was significantly reduced. The discharged "K6371T" is referred to as "opened K6371T".

[0155] [Example 5]

[0156] The operation was performed in the same manner as in Example 4 except that the agitator (A1) in Example 4 was changed to the agitator (A2) having a total of two agitating blades 10 inclined 30° in the rotation direction at both ends of one shaft 9. The area of ​​one agitating blade 10 was 26.0 cm 2 , and the area obtained by multiplying the area of ​​one stirring blade 10 by the inclination angle cosθ (=30°) is 22.5 cm 2 , which is 0.37 times the area of ​​the opening 6 .

[0157] [Comparative Example 3]

[0158] The operation was performed in the same manner as in Example 4 except that the agitator 4 was changed to an agitator (AX) having a total of two agitating blades 10 at both ends of one shaft 9 which were not inclined.

[0159] The above results are shown in Table 2 below.

[0160] In Table 2, as the evaluation, the fluctuation rate (difference between the maximum value and the minimum value of five Ws / average value of five Ws) is determined according to the same criteria (A to D) as described above.

[0161] [Table 2]

[0162]

[0163]

[0164] [Production Example 4 of Thermoplastic Resin Composition]

[0165] As an extruder, a twin-screw extruder "TEX44αII" manufactured by Nippon Steel Works, Ltd. was used. The screw configuration was RRNNL in the first kneading section, and RNL in the second kneading section. R was a forward kneading disk, N was an orthogonal kneading disk, and L was a reverse kneading disk, and disks each having five blades and a length of 44 mm were used. The cylinder set temperature was set to 260°C.

[0166] As the main raw material, polybutylene terephthalate resin "NOVADURAN 5008" manufactured by Mitsubishi Engineering-Plastics Corporation was used, which was supplied to the screw root at 180 kg / h using a belt feeder and melted in the first mixing section. A side feed screw was installed between the first mixing section and the second mixing section, and the chopped carbon fiber "K6371T" obtained by the method of Example 1 was supplied at 20 kg / h and mixed in the second mixing section. The screw rotation was set to 250 rpm. The strand-like object was taken out of the mold, cooled in a water tank, and cut with a pelletizer to obtain pellets.

[0167] The extrusion was continued for one hour, and the extrusion and strand-like product were stable, and no excessive torque or strand-like product breakage occurred. One gram of the pellets was dissolved in a solvent mixture of phenol and tetrachloroethane (1 / 1) as a good solvent, and the carbon fiber was filtered and dried, and then the weight was measured. The weight of the carbon fiber taken out was 0.096g (the carbon component excluding the astringent in 0.1g of carbon fiber was 0.098g). Based on this fact, it was confirmed that the chopped carbon fiber "K6371T" was uniformly supplied.

[0168] [Comparative Example 2 of Production of Thermoplastic Resin Composition]

[0169] Production was performed in the same manner as in Production Example 4 except that the carbon fiber obtained in Comparative Example 3 was supplied instead of the chopped carbon fiber. Torque fluctuation was large, excessive torque occurred once per hour, and the extruder stopped. In addition, the strand-like object broke three times. It was well found that the weight of the carbon fiber taken out from one gram was 0.085 g, and the supply of the chopped carbon fiber had fluctuated.

[0170] [Production Example 5 of Thermoplastic Resin Composition]

[0171] Production was performed in the same manner as in Production Example 1 of the thermoplastic resin composition, except that polycarbonate resin "IUPILON S3000F" manufactured by Mitsubishi Engineering-Plastics Corporation was used as the main raw material and ethylene chloride was used as the solvent for dissolving the polycarbonate resin. Extrusion and strands were stable, and no excessive torque or strand breakage occurred. The weight of the taken out carbon fiber was 0.096 g, and it was confirmed that the chopped carbon fiber K6371T was uniformly supplied.

[0172] [Production Example 6 of Thermoplastic Resin Composition]

[0173] Production was performed in the same manner as Production Example 4 except that polyamide resin "MXD NYLON 6000" manufactured by Mitsubishi Gas Chemical Co., Ltd. was used as the main raw material and hexafluoroisopropanol was used as the solvent. Extrusion and strands were stable, and no excessive torque or strand breakage occurred. The weight of the taken out carbon fiber was 0.099 g, and it was confirmed that the chopped carbon fiber K6371T was uniformly supplied.

[0174] Industrial Applicability

[0175] The stirring and supplying device, supplying method and production method of the fibrous filler, and the production method of the thermoplastic resin composition of the present invention enable uniform and stable transportation of even a fibrous filler that is easy to open and has a low bulk density by means of a screw, and make it possible to stably produce a thermoplastic resin composition in which the fibrous filler has been uniformly dispersed.

[0176] Description of Reference Numerals

[0177] 1 Hopper

[0178] 2 connection tank

[0179] 3. Discharge section

[0180] 4. Agitator

[0181] 5 screw

[0182] 6 Opening

[0183] 7 cylinders

[0184] 8 Rotation Axes

[0185] 9-axis

[0186] 10 stirring blades

[0187] 11. Inclined Surface

Claims

1. A stirring and feeding device for feeding a fibrous filler from a hopper storing the fibrous filler to a discharge portion, comprising: A connecting tank between the hopper and the discharge portion, In which, a shaft rotating around a rotation axis is provided in the connecting tank, and a stirring blade for stirring the fibrous filler is provided at the end of the shaft so that the stirring blade rotates along the inner circumferential surface of the connecting tank, and the stirring blade is inclined inwardly at an angle θ of 10° to 70° relative to the rotation direction of the stirring blade.

2. The stirring and feeding device for fibrous fillers according to claim 1, The stirring and supplying device for the fibrous filler includes a connecting tank having a roughly hemispherical inner circumferential surface between the hopper and the discharge portion, in which a shaft is provided that rotates vertically around a rotating shaft that protrudes horizontally inward from the inner circumferential surface of the connecting tank, and a stirring blade for stirring the fibrous filler is arranged at the end of the shaft so that the stirring blade rotates vertically along the inner circumferential surface of the connecting tank, and the stirring blade is inclined inwardly at an angle θ of 10° to 70° relative to the rotation direction of the stirring blade.

3. The stirring and feeding device for fibrous filler according to claim 2, The shortest distance of the gap between the stirring blade and the inner peripheral surface of the connecting tank is in the range of 0.2 cm to 5 cm.

4. The stirring and feeding device for fibrous filler according to claim 1, A connecting tank is provided between the hopper and the discharge portion, and a circular inclined surface is provided at a lower portion of the connecting tank obliquely upward from the lower portion of the connecting tank, and a shaft rotating around a rotating shaft protruding inward from the center of the circular inclined surface is provided, and a stirring blade for stirring the fibrous filler is provided at the end of the shaft so that the stirring blade rotates on the circular inclined surface, and the stirring blade is inclined inwardly at an angle θ of 10° to 70° relative to the rotation direction of the stirring blade.

5. The stirring and feeding device according to claim 4, The shortest distance of the gap between the tip of the stirring blade and the inner wall surface of the connecting tank is in the range of 0.2 cm to 5 cm.

6. The stirring and feeding device according to claim 1, The number of the stirring blades is two to six.

7. The stirring and feeding device according to claim 1, in, A screw for supplying a fibrous filler to the discharge portion is provided at the bottom of the connection tank.

8. The stirring and feeding device according to claim 1, The area obtained by multiplying the area of ​​each stirring blade by cosθ of the inclination angle is 0.1 to 1.0 times the opening area of ​​the opening portion at the bottom of the connection tank toward the screw when viewed from directly above.

9. A method for supplying a fibrous filler stored in a hopper to a discharge portion, A connecting tank is provided between the hopper and the discharge portion, an agitator is provided in the connecting tank, a shaft rotating around a rotating shaft is provided in the agitator, and a stirring blade for stirring the fibrous filler is provided at the end of the shaft so that the stirring blade rotates along the inner circumferential surface of the connecting tank, and the stirring blade is inclined inwardly at an angle θ of 10° to 70° relative to the rotation direction of the stirring blade, and the fibrous filler is opened by the agitator and supplied to the discharge portion by a screw provided at the bottom of the connecting tank.

10. The method for supplying a fibrous filler according to claim 9, The rotation speed of the agitator is 1% to 20% of the rotation speed of the screw.

11. The method for supplying a fibrous filler according to claim 9 or 10, The bulk density V0 of the fibrous filler stored in the hopper is 0.3 g / cm 3 Up to 0.7g / cm 3 , and the bulk density V1 of the discharged fibrous filler is less than 0.1 g / cm2 of V0 3 Up to 0.5g / cm 3 within the range.

12. A method for producing a fibrous filler having a reduced bulk density by opening the fibrous filler stored in a hopper, A connecting tank is provided between the hopper and the discharge portion, an agitator is provided in the connecting tank, a shaft rotating around a rotating shaft is provided in the agitator, a stirring blade for stirring the fibrous filler is provided at the end of the shaft so that the stirring blade rotates along the inner circumferential surface of the connecting tank, and the stirring blade is inclined inwardly at an angle θ of 10° to 70° relative to the rotation direction of the stirring blade, and the fibrous filler is opened by the agitator and supplied to the discharge portion by a screw provided at the bottom of the connecting tank.

13. The method for producing a fibrous filler according to claim 12, The bulk density V0 of the fibrous filler stored in the hopper is 0.3 g / cm 3 Up to 0.7g / cm 3 , and the bulk density V1 of the discharged fibrous filler is less than 0.1 g / cm2 of V0 3 Up to 0.5g / cm 3 within the range.

14. A method for producing a thermoplastic resin composition containing a fibrous filler compounded into a thermoplastic resin using an extruder, wherein the fibrous filler having a reduced bulk density obtained by the production method of claim 12 or 13 is laterally supplied from a side feeder disposed downstream of a main supply port of a raw material containing a thermoplastic resin and is melt-kneaded.

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