Apparatus and method for producing composite resin composition

Abstract

To provide an apparatus for producing a composite resin composition having high mechanical strength.SOLUTION: An apparatus for producing a composite resin composition by kneading raw materials including a fibrous filler and a thermoplastic resin includes: a first rotor that rotates about a central axis; a second rotor that is disposed in parallel with the first rotor and rotates about a central axis to form a kneading part that kneads the raw materials in combination with the first rotor; a first temperature control part for controlling a temperature of the first rotor; a second temperature control part for controlling the temperature of the second rotor; a first cooling part for cooling a position facing the kneading part across the central axis of the first rotor; and a second cooling part for cooling a position facing the kneading part across the central axis of the second rotor.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] The present invention relates to an apparatus and method for producing a composite resin composition, and more particularly to an apparatus and method for producing a composite resin composition containing a fibrous filler having excellent mechanical properties. [Background technology]

[0002] So-called "general-purpose plastics" such as polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC) are relatively inexpensive, lightweight (a fraction of the weight of metals or ceramics), and easy to process, such as molding. For this reason, general-purpose plastics are used as materials for a variety of everyday items such as bags, various types of packaging, various containers, and sheets, as well as industrial parts such as automobile parts and electrical parts, and daily necessities and miscellaneous goods.

[0003] However, general-purpose plastics have drawbacks such as insufficient mechanical strength, etc. Therefore, general-purpose plastics do not have sufficient properties required for materials used in various industrial products such as mechanical products such as automobiles, and electrical, electronic, and information products, and the current situation is that the range of applications of general-purpose plastics is limited.

[0004] On the other hand, so-called "engineering plastics" such as polyacetal (POM), polyamide (PA), polycarbonate (PC), and fluororesin have excellent mechanical properties and are used in various industrial products such as automobiles, machinery products, and electrical, electronic, and information products. However, engineering plastics have problems such as being expensive, difficulty in monomer recycling, and a large environmental load.

[0005] Therefore, there is a demand for a significant improvement in the material properties (mechanical strength, etc.) of general-purpose plastics. A known method for improving the material properties of general-purpose plastics is to manufacture composite resins by blending two or more types of resins or additives such as fillers. In particular, fibrous fillers such as natural fibers, glass fibers, and carbon fibers are used to improve mechanical strength. Among these, organic fibrous fillers such as cellulose are attracting attention in recent years as reinforcing fibers because they are inexpensive and have excellent environmental friendliness when disposed of.

[0006] However, in order to fully utilize the mechanical strength improving effect of the addition of fibrous filler, uniform dispersion of the fibrous filler is required. Fibrous filler is prone to agglomeration, making it difficult to uniformly disperse. In particular, when large-sized agglomerates are present, cracks are generated from the agglomerates, making the material more likely to break, resulting in a decrease in impact strength. In addition, the effect of improving the elastic modulus of the fibrous filler is not fully exhibited due to agglomeration. Therefore, it is important to uniformly disperse the fibrous filler in the production of composite resins. Patent Document 1 is an example of a production method in which raw materials are dispersed by kneading. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2011-184520 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the manufacturing method described in Patent Document 1, the resin material is continuously heated at a constant temperature during kneading, which causes problems such as a high temperature being maintained, a decrease in the viscosity of the composite resin, a lack of strong shear, and low dispersibility of the raw materials, resulting in a decrease in strength of the composite resin. In addition, there is also a problem that the raw materials are maintained at a high temperature during kneading, which causes deterioration of the raw materials (e.g., a decrease in molecular weight, coloration, etc.).

[0009] The present invention has been made to solve the above-mentioned problems in the prior art, and has an object to provide an apparatus for producing a composite resin composition having high mechanical strength. [Means for solving the problem]

[0010] The manufacturing apparatus for a composite resin composition according to the present invention is a manufacturing apparatus for kneading raw materials including a fibrous filler and a thermoplastic resin to manufacture a composite resin composition, A first rotor that rotates about a central axis; A second rotor is arranged in parallel with the first rotor and rotates about a central axis to form a kneading section that kneads the raw materials in a pair with the first rotor; A first temperature control unit that controls a temperature of the first rotating body; A second temperature control unit that controls a temperature of the second rotating body; A first cooling section that cools a position facing the kneading section across the central axis of the first rotating body; A second cooling section that cools a position facing the kneading section across the central axis of the second rotating body; Equipped with.

[0011] The method for producing a composite resin composition according to the present invention is a method for producing a composite resin composition by kneading raw materials including a fibrous filler and a thermoplastic resin, comprising the steps of: Controlling the temperature of a first rotor and the temperature of a second rotor that is arranged in parallel to the first rotor and forms a pair with the first rotor to constitute a kneading section that kneads the raw materials; Cooling a position facing the kneading section across the central axis of the first rotor and a position facing the kneading section across the central axis of the second rotor, Rotating the first rotor and the second rotor; The raw materials are kneaded in the kneading section. Effect of the Invention

[0012] According to the apparatus and method for producing a composite resin composition according to the present invention, it is possible to apply a stronger shear force to the raw materials than in the conventional method of constantly heating and kneading, and it is possible to uniformly disperse additives such as fillers in the resin. As a result, it is possible to produce a composite resin composition having high mechanical strength and in which the effects of additives such as fillers are fully exerted. [Brief description of the drawings]

[0013] [Figure 1A] 1 is a schematic plan view showing a configuration of a production apparatus for a composite resin composition according to a first embodiment. [Figure 1B] FIG. 1B is a schematic cross-sectional view taken along the aa direction in FIG. 1A. [Figure 2A] FIG. 4 is a schematic side view of another example of a production apparatus (twin-screw kneader) according to the first embodiment. [Figure 2B] FIG. 2B is a top view (plan view) of a kneading section of the production apparatus in FIG. 2A, with the barrel omitted. [Figure 2C] FIG. 2B is a cross-sectional view taken along the bb direction in FIG. 2A. [Figure 3A] FIG. 2 is a diagram showing the change in temperature over time when kneading is performed using a kneading device having a structure in which heating and cooling occur cyclically in the kneading method according to the first embodiment. [Figure 3B] FIG. 4 is a diagram showing the change in viscosity over time when kneading is performed using a kneading device having a structure in which heating and cooling occur cyclically in the kneading method according to the first embodiment. [Figure 3C] FIG. 1 is a diagram showing temperature changes over time when kneading is performed by a conventional method using a kneading device that is constantly heated. [Figure 3D]FIG. 1 is a graph showing the change in viscosity over time when kneading is performed by a conventional method using a kneading device that is constantly heated. [Figure 4A] 3 is a schematic enlarged view showing a locally enlarged portion of two rotating bodies facing each other in a cross-sectional view of a kneading section in the first embodiment. FIG. [Figure 4B] FIG. 2 is an enlarged schematic view showing the movement of fibrous filler due to convection of resin. [Figure 4C] FIG. 2 is an enlarged schematic view showing the state of a fibrous filler before kneading. [Figure 4D] FIG. 2 is an enlarged schematic view showing the state of a fibrous filler during kneading. [Figure 4E] FIG. 2 is an enlarged schematic view showing the state of a fibrous filler after kneading. [Diagram 5] FIG. 1 is a table summarizing the measurement results in each of Examples 1 to 4 and Comparative Examples 1 to 12. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The manufacturing apparatus for a composite resin composition according to a first aspect is a manufacturing apparatus for manufacturing a composite resin composition by kneading raw materials including a fibrous filler and a thermoplastic resin, and comprising: A first rotor that rotates about a central axis; A second rotor is arranged in parallel with the first rotor and rotates about a central axis to form a kneading section that kneads the raw materials in a pair with the first rotor; A first temperature control unit that controls a temperature of the first rotating body; A second temperature control unit that controls a temperature of the second rotating body; A first cooling section that cools a position facing the kneading section across the central axis of the first rotating body; A second cooling section that cools a position facing the kneading section across the central axis of the second rotating body; Equipped with.

[0015] In a second aspect of the present invention, in the first aspect, the first rotor and the second rotor have a screw shape that moves the raw materials from the raw material supply section to the composite resin discharge section along a direction parallel to central axes of the first rotor and the second rotor, the first temperature control unit includes a third temperature control unit that controls a temperature of the raw material supply unit of the first rotating body, and a fourth temperature control unit that controls a temperature of the composite resin discharge unit of the first rotating body; The second temperature control unit may have a fifth temperature control unit that controls the temperature of the raw material supply unit of the second rotating body, and a sixth temperature control unit that controls the temperature of the composite resin discharge unit of the second rotating body.

[0016] In the apparatus for producing a composite resin composition according to a third aspect, in the first aspect, the first rotating body and the second rotating body may each have a convex portion and a concave portion on a surface of the rotating body.

[0017] In a fourth aspect of the apparatus for manufacturing a composite resin composition, in the third aspect described above, a difference between a distance from a central axis of an apex of the convex portion and a distance from a central axis of a bottom surface of the concave portion may be 0.05% or more and 14% or less of a diameter of each of the first rotating body and the second rotating body.

[0018] A method for producing a composite resin composition according to a fifth aspect is a method for producing a composite resin composition by kneading raw materials including a fibrous filler and a thermoplastic resin, comprising the steps of: Controlling the temperature of a first rotor and the temperature of a second rotor that is arranged in parallel to the first rotor and forms a pair with the first rotor to constitute a kneading section that kneads the raw materials; Cooling a position facing the kneading section across the central axis of the first rotor and a position facing the kneading section across the central axis of the second rotor, Rotating the first rotor and the second rotor; The raw materials are kneaded in the kneading section.

[0019] A sixth aspect of the method for producing a composite resin composition is the same as the fifth aspect, and further comprises cooling a position facing the kneading section across the central axis of the first rotor and a position facing the kneading section across the central axis of the second rotor so that the temperature difference with the kneading section is 5°C to 80°C.

[0020] In a seventh aspect of the method for producing a composite resin composition according to the fifth aspect, the temperatures of the first rotor and the second rotor may be controlled so that the temperature difference between the first rotor and the second rotor is 5°C or more and 100°C or less at a position corresponding to the kneading section.

[0021] In an eighth aspect of the present invention, in the method for producing a composite resin composition according to the fifth aspect, the first rotor and the second rotor have a screw shape that moves the raw materials from a raw material input portion to a composite resin discharge portion along a direction parallel to central axes of the first rotor and the second rotor, The temperatures of the first rotating body and the second rotating body may be controlled so that the temperature of the raw material input section is higher than the temperature of the composite resin discharge section by a range of 5°C or more and 100°C or less at a position corresponding to the kneading section.

[0022] A ninth aspect of the method for producing a composite resin composition may be such that, in any one of the fifth to eighth aspects, the first rotating body and the second rotating body are rotated so that a rotational speed difference is 5% or more and 80% or less.

[0023] Hereinafter, a manufacturing apparatus and a manufacturing method for a composite resin composition according to an embodiment will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals and the description will be omitted as appropriate.

[0024] (Embodiment 1) FIG. 1A is a schematic plan view showing the configuration of a manufacturing apparatus (roll mixer) 10 for a composite resin composition according to the first embodiment. FIG. 1B is a schematic cross-sectional view seen from the aa direction in FIG. 1A. FIG. 2A is a side view of a manufacturing apparatus (two-screw mixer) 10a for a composite resin composition according to another embodiment. FIG. 2B is a top view (plan view) of a kneading section 20 of the manufacturing apparatus of FIG. 2A, omitting the barrel. FIG. 2C is a cross-sectional view seen from the bb direction in FIG. 2A. Here, the kneading section 20 refers to a portion where the raw materials are dispersed and mixed. For convenience, in the drawings, the central axis direction of the rotors 12, 12a, and 12b constituting the manufacturing apparatus 10 and 10a is the x direction, the vertical upward direction is the z direction, and the arrangement direction of the two rotors 12a and 12b is the -y direction.

[0025] As the manufacturing apparatus 10, 10a in the first embodiment, a twin-screw kneader, a kneader, a Banbury mixer, an extruder, a roll kneader, etc. shown in Figs. 1A and 1B, and a roll kneader shown in Figs. 2A to 2C can be used. Among them, it is more preferable to use a twin-screw kneader or a roll kneader. In the following context, the rotating body of the twin-screw kneader is treated as a screw, and the rotating body of the roll kneader is treated as a roll. Note that the manufacturing apparatus 10, 10a is not limited to the above apparatuses as long as it has a rotating body as a kneading means.

[0026] The manufacturing apparatus 10 shown in Figures 1A and 1B is a roll kneader. As shown in Figure 1A, the manufacturing apparatus 10 is provided with two roll-shaped rotors 12a and 12b facing each other. Specifically, the manufacturing apparatus 10 includes a rotor 12a that rotates about a central axis 2a, and a rotor 12b that is arranged parallel to the rotor 12a and rotates about a central axis 2b. The two rotors 12a and 12b form a pair to constitute a kneading section 20 that kneads raw materials.

[0027] The composite resin composition manufacturing apparatus 10 also includes a first cooling section 18a for cooling a position of the rotor 12a facing the kneading section 20 across the central axis 2a, and a second cooling section 18b for cooling a position of the rotor 12b facing the kneading section 20 across the central axis 2b. The apparatus also includes a first temperature control section 19a for controlling the temperature of the rotor 12a, and a second temperature control section 19b for controlling the temperature of the rotor 12b. The first temperature control section 19a may further include a third temperature control section 29a for controlling the temperature on the upstream side of the rotor 12a, and a fourth temperature control section 29b for controlling the temperature on the downstream side. The second temperature control section 19b may further include a fifth temperature control section 29c for controlling the temperature on the upstream side of the rotor 12b, and a sixth temperature control section 29d for controlling the temperature on the downstream side.

[0028] The manufacturing apparatus 10a shown in Figures 2A to 2C is a twin-screw kneader. As shown in Figure 2A, the manufacturing apparatus 10a includes a hopper 14 for feeding raw materials, a raw material supply section 16 for directing the raw materials fed from the hopper 14 to the kneading section of the manufacturing apparatus 10a, two rotors 12 constituting the kneading section, and a barrel 11 covering the rotors 12.

[0029] As shown in FIG. 1A, FIG. 1B, and FIG. 2B, the kneading section 20 of the manufacturing apparatus 10, 10a is configured between two rotating bodies 12a, 12b arranged in parallel to each other. Each of the rotating bodies 12a, 12b has a central axis 2a, 2b extending in the x direction and kneading disks 3a, 3b provided around the central axis 2a, 2b. Furthermore, the rotating bodies 12a, 12b have fine convex portions 13A and concave portions 13B on the surfaces of the rotating bodies 12a, 12b themselves, not on the kneading disks. The central axes 2a, 2b are rotated by a motor (not shown). The two rotating bodies 12a, 12b may rotate in the same direction or in different directions. The kneading disks 3a, 3b may be helical screws aligned along the central axis direction. As a result, the raw materials are kneaded and transported in the rotation axis direction (x direction) as the rotating bodies 12a, 12b rotate. In this manufacturing apparatus 10a, convex portions 13A and concave portions 13B on the surfaces of two rotors 12a and 12b arranged parallel to each other in the y direction face each other via a kneading section 20. As shown in Fig. 2B, in the direction of the rotation axes of the two rotors 12a and 12b (x direction), a portion where raw materials are supplied to the rotors 12a and 12b is defined as a raw material supply section 16. A portion of the rotors 12a and 12b where the composite resin composition is discharged is defined as a composite resin discharge section 17.

[0030] The composite resin composition manufacturing apparatus 10a includes a first cooling section 18a for cooling a position of the rotor 12a facing the kneading section 20 across the central axis 2a, and a second cooling section 18b for cooling a position of the rotor 12b facing the kneading section 20 across the central axis 2b. Although not shown in Fig. 2B, the apparatus also includes a first temperature control section for controlling the temperature of the rotor 12a and a second temperature control section for controlling the temperature of the rotor 12b, similar to Fig. 1A.

[0031] In the present embodiment 1, the temperature of the two rotors 12a, 12b may be decreased as the raw material proceeds from the supply direction to the discharge direction. The two rotors 12a, 12b may have a heating section. In addition, in order to uniformly disperse additives such as fibrous fillers, it is preferable that the resin is in a molten state during kneading. Therefore, in the raw material supply section 16 in the first half of the kneading, in order to quickly change the state of the resin from a solid state to a molten state, it is necessary that the temperature be higher than the softening temperature (melting point) of the resin. By making the resin in a molten state, the resin has fluidity and functions as a solvent, and the additives are uniformly dispersed. If the resin does not become molten and remains in a solid state, the solvent has no fluidity, so the dispersion of the raw materials does not proceed. Therefore, among the kneading section 20, the raw material supply section 16 is required to have the highest temperature. On the other hand, in the composite resin discharge section 17 in the second half of the kneading, the viscosity of the resin is high, and it is preferable that a strong shear stress is applied, so that the temperature is preferably lower than that of the raw material supply section 16. In addition, the temperature of the composite resin discharge section 17 is preferably lower than that of the raw material supply section 16 in order to discharge the composite resin composition smoothly. If the temperature is too high, the composite resin composition sticks to the rotors 12a and 12b, making it difficult to discharge the composite resin composition smoothly. If the temperature is too low, the composite resin composition adheres to the surfaces of the rotors 12a and 12b, making it difficult to discharge the composite resin composition. Therefore, it is preferable that the temperature of the composite resin discharge section 17, which is the lowest, has a temperature difference of 5°C or more and 100°C or less compared to the temperature of the raw material supply section 16, which is the highest temperature of the rotors 12a and 12b. Furthermore, depending on the raw material, it is more preferable that the temperature difference between the raw material supply section 16 and the composite resin discharge section 17 is 20°C or more and 100°C or less.

[0032] In the present embodiment 1, there may be a temperature difference between the two rotors 12a and 12b. For example, when the temperature of the rotor 12a is higher than that of the rotor 12b, the rotor 12b functions as a cooling unit during kneading, and the temperature rise of the resin due to shear heat can be prevented. For example, as shown in FIG. 1A, the temperature of the rotor 12a may be made higher than that of the rotor 12b by the first temperature control unit 19a and the second temperature control unit 19b. In the following context, the rotor 12a is treated as having a higher temperature than the rotor 12b. In addition, the temperature difference between the rotors 12a and 12b causes convection in the resin, which promotes the dispersion of the raw materials and the defibration of the fibrous filler. To increase the temperature difference between the rotors, it is necessary to extremely increase the temperature of the rotor 12a, extremely decrease the temperature of the rotor 12b, or both. On the other hand, if the temperature difference between the rotors 12a and 12b is extremely large, problems may occur. If the temperature is set too high, the raw materials will be maintained at a high temperature, causing deterioration of the raw materials (reduction in molecular weight, coloration, etc.). Conversely, if the temperature is set too low, the resin will adhere to the surface of the rotor 12b, making it difficult to knead the materials properly. Therefore, specifically, the temperature difference between the two rotors 12a and 12b is preferably 5°C or more and 100°C or less, and more preferably 5°C or more and 90°C or less depending on the raw materials.

[0033] Therefore, the manufacturing apparatus 10, 10a may have a third temperature control section 29a, a fourth temperature control section 29b, a fifth temperature control section 29c, and a sixth temperature control section 29d in the central axis direction of the two rotating bodies 12a, 12b.

[0034] 3A to 3D are diagrams showing the change over time in temperature and viscosity during kneading of a composite resin composition. FIG. 3A is a diagram showing the change over time in temperature when kneading is performed using a kneading device having a structure in which heating and cooling occur periodically in the kneading method according to the first embodiment. FIG. 3B is a diagram showing the change over time in viscosity when kneading is performed using a kneading device having a structure in which heating and cooling occur periodically in the kneading method according to the first embodiment. FIG. 3C is a diagram showing the change over time in temperature when kneading is performed using a conventional method using a kneading device that is constantly heated. FIG. 3D is a diagram showing the change over time in viscosity when kneading is performed using a conventional method using a kneading device that is constantly heated.

[0035] In the present embodiment 1, there may be a temperature difference between the resin in the kneading section of the manufacturing apparatus 10a and other sections. As shown in FIG. 3A and FIG. 3B, in the manufacturing method of the composite resin composition in the embodiment 1, cooling and heating occur periodically during kneading, so that the temperature of the composite resin composition in the cooling section decreases and the viscosity increases. Since the composite resin composition has a high viscosity due to cooling, a large shear stress is applied to the composite resin composition when kneaded in the kneading section 20, and the dispersion of the raw materials and the defibration of the fibrous filler progress. Therefore, in the manufacturing method of the composite resin composition in the present embodiment, a composite resin composition with high mechanical strength in which the raw materials are uniformly dispersed can be manufactured. To increase the temperature difference, it is necessary to extremely increase the temperature of one of the rotating bodies 12a, or to extremely decrease the temperature of the other rotating body 12b, or to perform both. On the other hand, if the temperature difference is extremely large, problems may occur. If the temperature of the rotor 12a is extremely high, the raw materials may deteriorate (reduction in molecular weight, coloration, etc.) due to the high temperature, and only a weak shear stress may be applied due to the decrease in viscosity, and the raw materials may not be uniformly dispersed. If the temperature of the rotor 12b is extremely low, the resin that has been solidified by the rotor 12b cannot be changed to a molten state in the heating section because the temperature is too low, and as a result, pulverization is performed in the solid state instead of kneading, and a composite resin composition cannot be produced. Therefore, specifically, the temperature difference between the resins of the rotors 12a and 12b in the kneading section is preferably 5°C or more and 80°C or less, and more preferably 10°C or more and 80°C or less depending on the raw materials.

[0036] In contrast, as shown in Figure 3B, in the conventional manufacturing method, heating is performed constantly, so that the temperature of the composite resin composition is maintained at a high temperature and the viscosity decreases, and as a result, the shear stress is not sufficiently applied, the raw materials are not uniformly dispersed, and exist as aggregates, resulting in the production of a composite resin composition with poor properties such as mechanical strength.

[0037] In addition, deterioration of raw materials (reduction in molecular weight, coloration, etc.) progresses more when a high temperature is maintained for a long time than when it is instantaneously heated. Therefore, by using the manufacturing method according to the first embodiment, in which cooling and heating occur periodically with respect to the rotation around the rotating shaft, it is possible to suppress deterioration of raw materials.

[0038] Specific examples of the structure of the kneading device include a twin-screw kneader having a pipe for passing cooling water attached to the outer periphery of the barrel of the twin-screw kneader and a roll kneader having a blower attached to locally blow air to the rolls. The pipe for passing cooling water provided on the outer periphery of the barrel and the blower for locally blowing air correspond to the above-mentioned cooling unit.

[0039] 4A to 4E are locally enlarged views of the opposing portions 22 of the two rotors 12a and 12b in the cross-sectional views of the kneading section 20 in FIG. 1B and FIG. 2C. FIG. 4A is an enlarged schematic view showing the configuration of the surfaces of the rotors 12a and 12b having fine irregularities 13A and 13B facing each other across the kneading section 20. FIG. 4B is an enlarged schematic view showing the movement of the fibrous filler 26 due to the convection of the resin 24. FIG. 4C to 4E show the change over time in the state of the fibrous filler 26 during kneading, and FIG. 4C is an enlarged schematic view showing the state of the fibrous filler 26 before kneading. FIG. 4D is an enlarged schematic view showing the state of the fibrous filler 26 during kneading. FIG. 4E is an enlarged schematic view showing the state of the fibrous filler 26 after kneading.

[0040] As shown in FIG. 4A to FIG. 4E, the rotors 12a and 12b preferably have fine irregularities 13A and 13B on their surfaces. Due to the presence of the irregularities 13A and 13B, the clearance between the rotors 12a and 12b changes continuously when the rotors 12a and 12b rotate. As a result, the fibrous filler 26 is not constantly subjected to a shear stress of approximately constant strength, and when the clearance is wide, the shear stress is small, and when the clearance is narrow, the shear stress is large. When the clearance becomes narrow, the tip of the fibrous filler 26 is defibrated by the shear stress, but the fibrous filler is pressed down by the shear stress, making it difficult for defibration to proceed further. However, when the clearance changes from a narrow state to a wide state, the shear stress is relaxed, causing the defibrated tip to expand, and when the clearance changes from a wide state to a narrow state, a strong shear stress is applied, causing the cracks at the tip to expand. The repeated change in the clearance widens and narrows effectively advances defibration. In addition, by having fine irregularities, convection is effectively generated, and the dispersion of the raw material also progresses. On the other hand, when a rotor having irregularities is used, if the clearance is too wide, sufficient shear stress is not applied, and defibration and dispersion do not progress. Therefore, specifically, the appropriate range of irregularities on the rotor surface is calculated by simulation. For example, when the distance between the apex of the convex portion 13A and the bottom surface of the concave portion 13B, that is, the distance between the apex of the convex portion 13A and the point of the concave portion 13B that is the farthest from the apex of the convex portion 13A, is defined as the depth of the concave portion, it is preferable that the rotor surface has a concave portion having a depth of 0.05% to 14% of the diameter of the rotor. Furthermore, depending on the raw material, it is preferable to have a concave portion having a depth of 0.1% to 14%.

[0041] In contrast, when a rotating body without unevenness on the surface is used, a pressure of almost constant strength is applied microscopically, so that the fibrous filler tends to maintain a constant shape due to the pressure, and defibration does not progress easily.

[0042] In the present embodiment 1, it is preferable that the two rotors 12a and 12b have a speed difference. In this case, it is preferable that the rotor 12a, which is hotter than the rotor 12b, has a speed higher than the rotor 12b. Since the rotor 12a has a higher temperature than the rotor 12b, the composite resin composition continues to adhere to the rotor 12b side, making it easier to discharge and collect the composite resin composition. In addition, since the two rotors 12a and 12b have a speed difference, the opposing surfaces between the rotors 12a and 12b change constantly, and the clearance at the narrowest part changes, so that the dispersion of the raw materials and the defibration of the fiber-based filler progress efficiently. Specifically, it is preferable that the speed difference between the two rotors 12a and 12b is 5% or more and 80% or less, and it is more preferable that the speed difference between the two rotors 12a and 12b is 30% or more and 80% or less.

[0043] The raw material in the first embodiment is composed of at least a thermoplastic resin and a fibrous filler. If the affinity between the thermoplastic resin and the fibrous filler is low, a dispersant may be added.

[0044] The weight ratio of the thermoplastic resin to the fibrous filler in the first embodiment is preferably within the range of 95%:5% to 10%:90%. If the weight ratio of the fibrous filler is less than 5%, the amount of filler is small, and therefore improvement in the mechanical properties of the composite resin composition due to the fiber reinforcement effect cannot be expected. If the weight ratio of the fibrous filler is more than 90%, the amount of resin is small, and therefore a composite resin composition cannot be formed. Therefore, the weight ratio of the thermoplastic resin to the fibrous filler is preferably within the above range.

[0045] The resin in the first embodiment is preferably a thermoplastic resin in order to ensure good performance even when heating and cooling are repeated. Examples of the thermoplastic resin include olefin resins (including cyclic olefin resins), styrene resins, (meth)acrylic resins, organic acid vinyl ester resins or derivatives thereof, vinyl ether resins, halogen-containing resins, polycarbonate resins, polyester resins, polyamide resins, thermoplastic polyurethane resins, polysulfone resins (polyethersulfone, polysulfone, etc.), polyphenylene ether resins (polymers of 2,6-xylenol, etc.), cellulose derivatives (cellulose esters, cellulose carbamates, cellulose ethers, etc.), silicone resins (polydimethylsiloxane, polymethylphenylsiloxane, etc.), rubber or elastomers (diene rubbers such as polybutadiene and polyisoprene, styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, acrylic rubbers, urethane rubbers, silicone rubbers, etc.). The above resins may be used alone or in combination of two or more kinds. The resins are not limited to the above materials as long as they have thermoplasticity.

[0046] Among these thermoplastic resins, the resin is preferably an olefin-based resin having a relatively low melting point. The olefin-based resin includes homopolymers of olefin-based monomers, copolymers of olefin-based monomers, and copolymers of olefin-based monomers and other copolymerizable monomers. Examples of the olefin-based monomer include linear olefins (α-C2-20 olefins such as ethylene, propylene, 1-butene, isobutene, 1-pentene, 4-methyl-1-pentene, and 1-octene), and cyclic olefins. These olefin-based monomers may be used alone or in combination of two or more kinds. Among the above olefin-based monomers, linear olefins such as ethylene and propylene are preferred. Examples of other copolymerizable monomers include fatty acid vinyl esters such as vinyl acetate and vinyl propionate; (meth)acrylic monomers such as (meth)acrylic acid, alkyl (meth)acrylates, and glycidyl (meth)acrylates; unsaturated dicarboxylic acids or anhydrides such as maleic acid, fumaric acid, and maleic anhydride; vinyl esters of carboxylic acids (e.g., vinyl acetate and vinyl propionate); cyclic olefins such as norbornene and cyclopentadiene; and dienes such as butadiene and isoprene. These copolymerizable monomers may be used alone or in combination of two or more. Specific examples of olefin resins include copolymers of chain olefins (particularly α-C2-4 olefins) such as polyethylene (low density, medium density, high density, or linear low density polyethylene), polypropylene, ethylene-propylene copolymers, and terpolymers such as ethylene-propylene-butene-1.

[0047] The fibrous filler in the first embodiment is preferably used to improve mechanical properties, and therefore has a higher elastic modulus than resin. Specifically, carbon fiber, carbon nanotube, pulp, cellulose, cellulose nanofiber, lignocellulose, lignocellulose nanofiber, basic magnesium sulfate fiber (magnesium oxysulfate fiber), potassium titanate fiber, aluminum borate fiber, calcium silicate fiber, calcium carbonate fiber, silicon carbide fiber, wollastonite, xonotlite, various metal fibers, natural fibers such as cotton, silk, wool, or hemp, regenerated fibers such as jute fiber, rayon, or cupra, semi-synthetic fibers such as acetate and promix, synthetic fibers such as polyester, polyacrylonitrile, polyamide, aramid, and polyolefin, and further modified fibers chemically modified on the surface and end thereof. Furthermore, among these, carbons and celluloses are particularly preferred from the viewpoints of availability, high elastic modulus, and low linear expansion coefficient. Furthermore, natural cellulose fibers are preferred from the viewpoint of environmental friendliness.

[0048] Examples of the dispersant in the first embodiment include various titanate-based coupling agents, silane coupling agents, unsaturated carboxylic acids, maleic acid, maleic anhydride, or modified polyolefins grafted with the anhydrides thereof, fatty acids, fatty acid metal salts, and fatty acid esters. The silane coupling agents are preferably unsaturated hydrocarbon-based or epoxy-based. The surface of the dispersant may be modified by treating it with a thermosetting or thermoplastic polymer component. The content of the dispersant in the composite resin molded body in the embodiment of the present invention is preferably 0.01% by mass or more and 20% by mass or less, more preferably 0.1% by mass or more and 10% by mass or less, and even more preferably 0.5% by mass or more and 5% by mass or less. If the content of the dispersant is less than 0.01% by mass, poor dispersion may occur. On the other hand, if the content of the dispersant exceeds 20% by mass, the strength of the composite resin molded body may decrease. The dispersant is appropriately selected depending on the combination of the resin and the fibrous filler, and it is not necessary to add a dispersant in the case of a combination in which a dispersant is not required.

[0049] In the first embodiment, an example was described in which a roll kneader (FIGS. 1A and 1B) and a twin-screw kneader (FIGS. 2A to 2C) were used as the manufacturing apparatus. However, other kneaders may be used in addition to the twin-screw kneader and roll kneader. EXAMPLES

[0050] Example 1 The cellulose fiber-containing composite resin molding was produced by the following production method. As described above, a kneader, a Banbury mixer, an extruder, a roll mixer, or the like can be used as the production device, but a twin-screw mixer was used in the examples.

[0051] A block polymer polypropylene (manufactured by Japan Polypropylene Corporation, product name: BC03B) as the thermoplastic resin, softwood pulp (manufactured by Mitsubishi Paper Mills, product name: NBKP Celgar) as the fibrous filler, and maleic anhydride-modified polypropylene (manufactured by Sanyo Chemical Industries, Ltd., product name: Umex) as the dispersant were weighed out in a weight ratio of 80:15:5 and dry-blended.

[0052] The dry-blended raw materials were fed to the kneader at 2 kg / h by a weight feeder. As described above, a twin-screw kneader (JSW TEX30a, Inc.) was used, which was modified to have a structure in which heating and cooling occur periodically by attaching a pipe for passing cooling water to the outside of the barrel. The screw was of medium shear type. The composite resin composition discharged from the twin-screw kneader was hot-cut to produce cellulose fiber-containing composite resin pellets.

[0053] Using the prepared cellulose fiber-containing composite resin pellets, a composite resin molded body test piece was prepared by an injection molding machine (180AD manufactured by Japan Steel Works, Ltd.). The preparation conditions for the test piece were resin temperature 190°C, mold temperature 60°C, injection speed 60mm / s, and holding pressure 80Pa. The pellets were bitten into the screw of the molding machine through a hopper, and the penetration at that time was measured by the pellet loss amount per time, and it was confirmed that it was constant. The shape of the test piece was changed according to the evaluation items described below, and a dumbbell of size 1 was prepared for measuring the elastic modulus. In addition, a flat plate of 60 mm square and 1.2 mm thick was prepared for the drop impact test. The obtained cellulose fiber-containing composite resin molded body test piece was evaluated by the following method.

[0054] [Evaluation items for composite resin molded products] (Aspect ratio of undefibrated area, length ratio of defibrated area) The obtained cellulose fiber-containing composite resin pellets were immersed in a xylene solvent to dissolve the polypropylene, and the fiber shape of the remaining pulp fibers was observed by SEM. Measurements of about 10 representative fibers showed that the fiber diameter was in the range of 2 to 10 μm and the fiber length was in the range of 200 to 1000 μm. The aspect ratio of the non-defibrated portion (hereinafter sometimes simply referred to as the aspect ratio) was about 100 to 200. Defibrated portions were observed at the ends in the fiber length direction, and the defibrated portions accounted for about 30 to 40% of the total fiber length.

[0055] (Specific surface area of ​​fibrous filler) The obtained cellulose fiber-containing composite resin pellets were immersed in a xylene solvent to dissolve the polypropylene, and the specific surface area of ​​the remaining cellulose fibers was measured. Those with a specific surface area less than 150% of that of the raw material were marked with an X, those with a specific surface area between 150% and 200% were marked with an △, and those with a specific surface area of ​​200% or more were marked with an O. In the composite resin molding of Example 1, the specific surface area of ​​the cellulose fiber was 210%, and the evaluation was good.

[0056] (Elastic modulus of composite resin molding) A tensile test was carried out using the obtained No. 1 dumbbell-shaped test piece. Here, the elastic modulus was evaluated as follows: values ​​less than 1.8 GPa were marked x, values ​​between 1.8 GPa and 2.0 GPa were marked △, and values ​​2.0 GPa or more were marked ◯. In the composite resin molding of Example 1, the elastic modulus of the test piece was 2.3 GPa, and the evaluation was good.

[0057] (Drop impact strength of composite resin molded body) A drop impact test was carried out using the obtained flat plate-shaped test piece. Specifically, a weight of 250 g was dropped from a height of 80 cm onto the plate surface of the test piece, and it was confirmed whether cracks occurred. In this evaluation method, a mark of ◯ was given to a test piece in which no cracks were observed, a mark of △ was given to a test piece in which cracks were observed only on the surface and the length of the cracks was less than 10 mm, and a mark of × was given to a test piece in which a crack was observed that penetrated the plate or the length of the cracks was 10 mm or more. In the composite resin molding of Example 1, no cracks were found in the test piece, and the evaluation was ◯.

[0058] (Degree of aggregation of fibrous filler) The number and size of the fibrous filler aggregates were observed under an optical microscope using the obtained flat test piece. The degree of aggregation was evaluated as follows: x if there were 10 or more aggregates with a size of 1000 μm or more in a 10 mm square area, △ if there were 3 to 10 aggregates, and ◯ if there were less than 3 aggregates. In the composite resin molding of Example 1, the number of 1000 μm aggregates in the test piece was one, and the evaluation thereof was ◯.

[0059] (molecular weight) The molecular weight of the cellulose fiber-containing composite resin pellets was measured. If the molecular weight distribution of the composite resin pellets was more than 20% higher than that of the raw material, it was marked as x, and if it was 20% or less, it was marked as o. In the composite resin molding of Example 1, the pellets were evaluated as ◯.

[0060] (Colorability of Composite Resin Composition) A colorability test was conducted on the cellulose fiber-containing composite resin pellets. If the yellowness index (YI value) of the composite resin pellets was increased compared to the raw material, it was marked as ×, and if it was not increased, it was marked as ○. In the composite resin molding of Example 1, the pellets were evaluated as ◯.

[0061] Example 2 In Example 2, the temperature difference between the raw material supply section and the composite resin discharge section was changed to 80° C., and the other conditions were the same as in Example 1 to produce cellulose fiber-containing composite resin pellets and molded bodies. Evaluations were also performed in the same manner as in Example 1.

[0062] Example 3 In Example 3, the temperature difference between the screws was changed to 70° C., and the other material conditions and process conditions were the same as in Example 1 to produce cellulose fiber-containing composite resin pellets and molded bodies. Evaluations were also performed in the same manner as in Example 1.

[0063] Example 4 In Example 4, the speed of the cooling water flow was doubled, and the other material conditions and process conditions were the same as in Example 1 to produce cellulose fiber-containing composite resin pellets and molded bodies. Evaluations were also performed in the same manner as in Example 1.

[0064] Comparative Example 1 In Comparative Example 1, the temperature from the raw material supply section to the composite resin discharge section was changed to be constant, and the other material conditions and process conditions were the same as in Example 1 to produce cellulose fiber-containing composite resin pellets and molded bodies. Evaluations were also performed in the same manner as in Example 1.

[0065] Comparative Example 2 In Comparative Example 2, the temperature difference between the raw material supply section and the composite resin discharge section was changed to 120 degrees, and the other material conditions and process conditions were the same as in Example 1 to produce cellulose fiber-containing composite resin pellets and molded bodies. Evaluations were also performed in the same manner as in Example 1.

[0066] Comparative Example 3 In Comparative Example 3, the temperatures applied to the two screws were changed to be the same, and other material conditions and process conditions were the same as in Example 1 to produce cellulose fiber-containing composite resin pellets and molded bodies. Evaluations were also performed in the same manner as in Example 1.

[0067] Comparative Example 4 In Comparative Example 4, the temperature difference between the two screws was changed to 140° C., and the other material conditions and process conditions were the same as in Example 1 to produce cellulose fiber-containing composite resin pellets and molded bodies. Evaluations were also performed in the same manner as in Example 1.

[0068] Comparative Example 5 In Comparative Example 5, the kneading device was changed to a twin-screw kneader (JSW TEX30a, Inc.) that was not modified to cause cyclic heating and cooling, and other material conditions and process conditions were the same as in Example 1 to produce cellulose fiber-containing composite resin pellets and molded bodies. Evaluations were also performed in the same manner as in Example 1.

[0069] Comparative Example 6 In Comparative Example 6, the temperature difference between the heating section and the cooling section was changed to 135° C., and the other material conditions and process conditions were the same as in Example 1 to produce cellulose fiber-containing composite resin pellets and molded bodies. Evaluations were also performed in the same manner as in Example 1.

[0070] Comparative Example 7 In Comparative Example 7, the screw was changed to one without unevenness on the surface, and the other material conditions and process conditions were the same as those in Example 1 to produce cellulose fiber-containing composite resin pellets and molded bodies. Evaluations were also performed in the same manner as in Example 1.

[0071] Comparative Example 8 In Comparative Example 8, the screw was changed to one having a surface irregularity of 20% of the major axis of the screw, and other material conditions and process conditions were the same as in Example 1 to produce cellulose fiber-containing composite resin pellets and molded bodies. Evaluations were also performed in the same manner as in Example 1.

[0072] Comparative Example 9 In Comparative Example 9, the speeds of the two screws were changed to be the same, and other material conditions and process conditions were the same as in Example 1 to produce cellulose fiber-containing composite resin pellets and molded bodies. Evaluations were also performed in the same manner as in Example 1.

[0073] Comparative Example 10 In Comparative Example 10, the speed difference between the screws was changed to 100%, and other material conditions and process conditions were the same as in Example 1 to produce cellulose fiber-containing composite resin pellets and molded bodies. Evaluations were also performed in the same manner as in Example 1.

[0074] Comparative Example 11 In Comparative Example 11, the weight ratio of polypropylene, softwood pulp, and maleic anhydride-modified polypropylene was changed to 98.8:1:0.2, and the other material conditions and process conditions were the same as in Example 1 to produce cellulose fiber-containing composite resin pellets and molded bodies. Evaluations were also performed in the same manner as in Example 1.

[0075] Comparative Example 12 In Comparative Example 12, the weight ratio of polypropylene, softwood pulp, and maleic anhydride-modified polypropylene was changed to 4:95:1, and the other material conditions and process conditions were the same as in Example 1 to produce cellulose fiber-containing composite resin pellets.

[0076] The measurement results for each of Examples 1 to 4 and Comparative Examples 1 to 12 are shown in the table of FIG.

[0077] As is clear from the table in FIG. 5, in Example 2, in which the temperature difference between the raw material supply section and the composite resin discharge section was changed to 80°C, a large shear stress was applied to the composite resin discharge section compared to Example 1, so the length ratio of the defibrated area was 40-50%, and the number of 1000 μm aggregates was 0. Therefore, even when an impact test was performed at 90 cm, no cracks were confirmed. Similar results were obtained in Example 3, in which the temperature difference between the two screws was changed to 70°C, and in Example 4, in which the temperature difference applied to the two screws was changed to 50°C. From the above, Examples 2, 3, and 4 achieved results equivalent to or better than Example 1 in all tests.

[0078] In Comparative Example 1, the temperature from the raw material supply section to the composite resin discharge section was changed to be constant. In this Comparative Example 1, the viscosity in the composite resin discharge section was lower than in Example 1, and the shear stress was weak, so the length ratio of the defibrated part was 10-20%. As a result, the impact resistance was reduced, and the product broke during the drop impact test.

[0079] In Comparative Example 2, the temperature difference between the raw material supply section and the composite resin discharge section was changed to 120°C. In this Comparative Example 2, the temperature of the composite resin discharge section was set too low, so the resin stuck to the screw and the composite resin composition could not be discharged. When the temperature of the composite resin discharge section was set to the minimum temperature at which the composite resin composition could be formed in order to conduct the experiment, it was necessary to raise the temperature of the raw material supply section so that the temperature difference was 120°C. In this case, on the contrary, the temperature was too high, so the viscosity of the resin significantly decreased and the composite resin composition could not be produced.

[0080] In Comparative Example 3, the temperature applied to the two screws was changed to be the same. In this Comparative Example 3, the length ratio of the defibrated portion was 10-20%. As a result, the impact resistance was reduced, and the product broke in the drop impact test.

[0081] In Comparative Example 4, the temperature difference between the two screws was changed to 140°C. In this Comparative Example 4, the temperature of the low-temperature screw was set too low, so that the resin adhered to the low-temperature screw, and the composite resin composition could not be discharged. On the other hand, when the temperature of the low-temperature screw was set to the minimum temperature at which the composite resin composition could be formed in order to carry out the experiment, it was necessary to raise the temperature of the high-temperature roll so that the temperature difference became 140°C. In this case, the temperature was too high, so the viscosity of the resin significantly decreased, and the composite resin composition could not be produced.

[0082] In Comparative Example 5, the kneading device was changed to a twin-screw kneader (JSW TEX30a, Ltd.) that had not been modified to heat and cool periodically. In this Comparative Example 5, the viscosity decreased due to the temperature increase caused by shear heating, so the dispersion of the raw materials and the defibration of the fibrous filler did not progress, and the length ratio of the defibrated part was 10-20%. As a result, the impact resistance decreased, and the product broke during the drop impact test.

[0083] In Comparative Example 6, the temperature difference between the heating section and the cooling section was changed to 135°C. In this Comparative Example 6, the temperature of the cooling section was set too low, so that the resin that had been solidified in the cooling section could not be changed to a molten state in the heating section, and as a result, pulverization in the solid state was performed instead of kneading, and a composite resin composition could not be produced. When the temperature of the cooling section was changed to a temperature at which the resin could be changed to a molten state in the heating section and the temperature of the heating section was raised to a temperature difference of 140°C in order to carry out an experiment, the temperature of the heating section became too high, the viscosity of the resin was significantly reduced, and a composite resin composition could not be produced.

[0084] In Comparative Example 7, the screw was changed to one without unevenness on the surface. In Comparative Example 7, the cellulose fibers could not be defibrated in localized areas on the screw surface, and the length ratio of the defibrated area was 10-20%. As a result, the impact resistance was reduced, and the screw broke during the drop impact test.

[0085] In Comparative Example 8, the screw was changed to one having a surface irregularity of 20% of the major axis of the screw. In this Comparative Example 8, the clearance between the screws became too large, so the raw material was not subjected to sufficient shear stress, and the number of aggregates with a size of 1000 μm or more was 20-30. As a result, the impact resistance was reduced, and the product was broken during the drop impact test.

[0086] In Comparative Example 9, the speeds of the two screws were changed to be the same. In this Comparative Example 9, the change in the clearance was small, so the dispersion of the raw materials and the defibration of the fibrous filler did not progress, and the length ratio of the defibrated part was 20-30%. As a result, the impact resistance was reduced, and the product broke during the drop impact test.

[0087] In Comparative Example 10, the speed difference between the screws was changed to 100%. In this Comparative Example 10, the dispersion of the raw materials and the defibration of the fibrous filler did not progress, and the length ratio of the defibrated part was 20-30%. As a result, the impact resistance was reduced and the product broke during the drop impact test.

[0088] In Comparative Example 11, the weight ratio of cellulose fiber was reduced. In this Comparative Example 11, the amount of cellulose fiber was small, so the viscosity was low, the dispersion of the raw materials and the defibration of the fibrous filler did not progress, and the length ratio of the defibrated part was 20-30%. In addition, because the amount of cellulose fiber was too small, the improvement in the mechanical properties of the composite resin composition due to the fiber reinforcement effect did not appear, and the elastic modulus was reduced to 1.4 GPa.

[0089] In Comparative Example 12, the weight ratio of the cellulose fibers was increased. In this Comparative Example 12, the amount of the resin was extremely small compared to the amount of the cellulose fibers, so that a composite resin composition could not be formed.

[0090] From the above evaluation, when the temperature difference between the raw material supply section and the composite resin discharge section, the temperature difference applied to the screw, or the temperature difference between the heating section and the cooling section was too large under the process conditions, it was not possible to form a composite resin composition. However, within the ranges specified in the above embodiments (ranges in which a composite resin composition can be formed), the larger the temperature difference, the larger the shear stress, so that the dispersion of the raw materials and the defibration of the cellulose fibers progressed effectively, and a sample having a high elastic modulus and high impact resistance could be produced. From the above, it was found that the composite resin composition exhibits a high elastic modulus and high impact resistance because the cellulose fibers added to the composite resin composition are defibrated, the ratio of the length of the defibrated part of the fibers is long, the aspect ratio of the cellulose fibers is large, the size of the aggregates is small, and they are uniformly dispersed.

[0091] The method for producing a composite resin composition according to the present disclosure is a method for producing a composite resin composition by kneading raw materials including at least a fibrous filler and a thermoplastic resin in a kneading device, The kneading device has two rotating bodies, each of which has a rotation shaft and a convex portion and a concave portion provided around the rotation shaft, and the two rotating bodies are arranged parallel to each other to form a kneading section; The kneading device is characterized in that the kneading section has a heating device for heating at least one of the rotating bodies, the surface temperatures of the two rotating bodies are set to different temperatures, and heating and cooling occur within one revolution around the rotation axis of at least one of the rotating bodies.

[0092] According to the method for producing a composite resin composition according to the present disclosure, the specific surface area of ​​the fibrous filler after kneading may be increased compared to before kneading.

[0093] The method for producing a composite resin composition according to the present disclosure may include providing a cooling section on the downstream side along a direction of movement of raw materials parallel to a rotation axis of at least one of the rotors, and providing a heating section on the upstream side, and the temperature difference between the heating section and the cooling section may be 5°C or more and 100°C or less.

[0094] In the method for producing a composite resin composition according to the present disclosure, the temperature difference between the two rotating bodies may be 5° C. or more and 100° C. or less.

[0095] In the method for producing a composite resin composition according to the present disclosure, the resin temperature in the cooling section of the kneading device may have a temperature difference of 5° C. or more and 80° C. or less compared to the resin temperature in the heating section.

[0096] In the method for producing a composite resin composition according to the present disclosure, when the depth of the recess is defined as the distance between the apex of the convex portion and the point on the bottom surface of the recess that is farthest from the apex of the convex portion, a rotating body having a recess on its surface with a depth of 0.05% or more and 14% or less of a diameter of the rotating body may be used.

[0097] In the method for producing a composite resin composition according to the present disclosure, the difference in rotational speed between the two rotating bodies may be 5% or more and 80% or less.

[0098] In the method for producing a composite resin composition according to the present disclosure, the composite resin composition may be produced with a mixing ratio of thermoplastic resin:fibrous filler in the range of 95%:5% to 10%:90%.

[0099] The kneading apparatus for a composite resin composition according to the present disclosure is an apparatus for kneading a composite resin composition by kneading raw materials including at least a fibrous filler and a thermoplastic resin to produce a composite resin composition, Two rotating bodies arranged parallel to each other, each of the rotating bodies constituting a kneading section having a rotating shaft and a convex portion and a concave portion provided around the rotating shaft; A heating device for heating at least one of the rotors in the kneading section; A temperature control unit that controls the surface temperatures of the two rotating bodies to different temperatures from each other; The device may include:

[0100] In the kneading device for a composite resin composition according to the present disclosure, the rotating body may have a recess on a surface of the rotating body having a depth of 0.05% or more and 14% or less of a diameter of the rotating body, when the depth of the recess is defined as the distance between an apex of the convex portion and a point on the bottom surface of the recess that is farthest from the apex of the convex portion.

[0101] In the kneading device for a composite resin composition according to the present disclosure, the difference in rotation speed between the two rotors may be 5% or more and 80% or less.

[0102] In addition, the present disclosure includes appropriate combinations of any of the various embodiments and / or examples described above, and can achieve the effects of each embodiment and / or example. [Industrial Applicability]

[0103] The composite resin composition according to the present invention can provide a molded product having superior mechanical strength to conventional general-purpose resins. Since the properties of the resin can be improved by the present invention, the composite resin composition can be used as a substitute for engineering plastics or metal materials. Therefore, the manufacturing cost of various industrial products or daily necessities made of engineering plastics or metals can be significantly reduced. Furthermore, the composite resin composition can be used for housings of home appliances, building materials, and automobile parts. [Explanation of symbols]

[0104] 2a, 2b center axis 3a, 3b Kneading disc 10 Manufacturing equipment 11 Barrel 12 Rotating Body 12a Rotating body (first rotating body) 12b Rotating body (second rotating body) 13A Convex 13B Recess 14 Hopper 15 Raw material inlet 16 Raw Materials Supply Department 17 Composite resin discharge section 18a First cooling section 18b Second cooling section 19a First temperature control section 19b Second temperature control section 20 Kneading section 22 Opposing part 24 Resin 26 Fibrous fillers 29a Third temperature control section 29b Fourth temperature control section 29c Fifth temperature control section 29d Sixth temperature control section

Claims

1. A manufacturing apparatus for manufacturing a composite resin composition by kneading raw materials including a fibrous filler and a thermoplastic resin, comprising: A first rotor that rotates about a central axis; A second rotor is arranged in parallel with the first rotor and rotates about a central axis to form a kneading section that kneads the raw materials in a pair with the first rotor; A first temperature control unit that controls a temperature of the first rotating body; A second temperature control unit that controls a temperature of the second rotating body; A first cooling section that cools a position facing the kneading section across the central axis of the first rotating body; A second cooling section that cools a position facing the kneading section across the central axis of the second rotating body; An apparatus for producing a composite resin composition comprising:

2. the first rotating body and the second rotating body have a screw shape that moves the raw material from the raw material supply section to the composite resin discharge section along a direction parallel to the central axis of the first rotating body and the second rotating body; The first temperature control unit includes a third temperature control unit that controls a temperature of the raw material supply unit of the first rotating body, and a fourth temperature control unit that controls a temperature of the composite resin discharge unit of the first rotating body, The second temperature control unit has a fifth temperature control unit that controls a temperature of the raw material supply unit of the second rotating body, and a sixth temperature control unit that controls a temperature of the composite resin discharge unit of the second rotating body. An apparatus for producing the composite resin composition according to claim 1.

3. The first rotating body and the second rotating body each have a convex portion and a concave portion on a surface of the rotating body. An apparatus for producing the composite resin composition according to claim 1.

4. 4. The apparatus for producing a composite resin composition according to claim 3, wherein a difference between a distance from a central axis of an apex of the convex portion and a distance from a central axis of a bottom surface of the concave portion is 0.05% or more and 14% or less of a diameter of each of the first rotating body and the second rotating body.

5. A method for producing a composite resin composition by kneading raw materials including a fibrous filler and a thermoplastic resin, comprising the steps of: Controlling the temperature of a first rotor and the temperature of a second rotor that is arranged in parallel with the first rotor and forms a pair with the first rotor to constitute a kneading section that kneads the raw materials; Cooling a position facing the kneading section across a central axis of the first rotor and a position facing the kneading section across a central axis of the second rotor; Rotating the first rotor and the second rotor; The raw materials are kneaded in the kneading section.

6. The method for producing a composite resin composition according to claim 5, wherein a position facing the kneading section across the central axis of the first rotor and a position facing the kneading section across the central axis of the second rotor are cooled so that the temperature difference between the kneading section and the position is 5°C to 80°C.

7. 6. The method for producing a composite resin composition according to claim 5, wherein the temperatures of the first rotor and the second rotor are controlled so that the temperature difference between the first rotor and the second rotor is 5°C or more and 100°C or less at a position corresponding to the kneading section.

8. the first rotating body and the second rotating body have a screw shape that moves the raw material from the raw material input portion to the composite resin discharge portion along a direction parallel to the central axis of the first rotating body and the second rotating body; 6. The method for producing a composite resin composition according to claim 5, wherein the temperatures of the first rotor and the second rotor are controlled so that the temperature of the raw material input section is higher than the temperature of the composite resin discharge section by a range of 5°C to 100°C at a position corresponding to the kneading section.

9. 9. The method for producing a composite resin composition according to claim 5, wherein the first rotating body and the second rotating body are rotated so that a rotational speed difference between the first rotating body and the second rotating body is 5% or more and 80% or less.

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