A method for producing a composite composition of discontinuous reinforcing fibers and resin.

Abstract

To provide a method for producing a composite composition of discontinuous reinforcing fibers and resin by spraying the discontinuous reinforcing fibers and resin, in which the discontinuous reinforcing fibers and resin are uniformly mixed. [Solution] A method for producing a composite composition of discontinuous reinforcing fibers and a resin, comprising: a first roll having a plurality of cutter blades and a second roll opposed to the first roll; Continuous reinforcing fibers are supplied between the first roll and the second roll and cut with the cutter blade to form the discontinuous reinforcing fibers; The discontinuous reinforcing fibers and the resin are dispersed, A method for producing a composite composition of discontinuous reinforcing fibers and resin.

Description

[Technical Field]

[0001] The present invention relates to a method for producing a composite composition in which discontinuous reinforcing fibers and a resin are uniformly mixed. [Background technology]

[0002] Fiber-reinforced composite materials have excellent mechanical properties and have recently been attracting attention as structural members for automobiles and the like.

[0003] Patent Document 1 relates to a sheet molding compound manufacturing device for uniformly dispersing glass fibers of 1 inch or less (25.4 mm or less), and in particular discloses a technology that uses a glass roving cutting roll with an angle of 15 degrees or more between the cutter blades, so that the glass fiber substrate is supplied to a film coated with an unsaturated polyester composition without being caught in the chopper.

[0004] The invention described in Patent Document 2 relates to an apparatus for cutting glass fibers between, for example, a cutter roll and a rubber roll, and describes an invention in which glass fibers are supplied to the cutter roll using a feed roll, and the cutter roll is driven at a speed slower than the speed of the cutter roll, thereby preventing the cut glass fibers from clogging between the cutter blades.

[0005] The invention described in Patent Document 3 relates to a manufacturing method in which continuous carbon fiber bundles are divided into sub-bundles, chopped with a rotary cutter, and then deposited on a carrier film to form a carbon fiber mat. In particular, the method is characterized in that the fiber bundles are pulled out from a package, and the chopped carbon fiber bundles are fragmented and then deposited on a carrier film, and this method can improve the uniformity of the carbon fiber mat. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-138300 [Patent Document 2] Japanese Patent Application Publication No. 07-033475 [Patent Document 3] International Publication No. 2021 / 149578 Summary of the Invention [Problem to be solved by the invention]

[0007] However, none of the inventions in Patent Documents 1 to 3 considers spraying the resin in the same manner as the discontinuous reinforcing fibers. Therefore, there is no mention of the issue of uniformity in mixing the discontinuous reinforcing fibers and the resin. The resins described in Patent Documents 1 to 3 are supplied by coating or the like separately from the discontinuous reinforcing fibers.

[0008] Therefore, the present invention aims to provide a method for producing a composite composition of discontinuous reinforcing fibers and resin by spraying the discontinuous reinforcing fibers and resin, in which the discontinuous reinforcing fibers and resin are uniformly mixed. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention provides the following means. 1. A method for producing a composite composition of discontinuous reinforcing fibers and a resin, comprising: a first roll having a plurality of cutter blades and a second roll opposed to the first roll; Continuous reinforcing fibers are supplied between the first roll and the second roll and cut with the cutter blade to form the discontinuous reinforcing fibers; The discontinuous reinforcing fibers and the resin are dispersed, A method for producing a composite composition of discontinuous reinforcing fibers and resin. 2. A method for producing a composite composition of discontinuous reinforcing fibers and resin according to 1 above, At least one of the first roll and the second roll has a groove; The resin is introduced into the groove and rotated, and is supplied between the first roll and the second roll together with the continuous reinforcing fibers. The discontinuous reinforcing fibers and the resin are sprayed from between the first roll and the second roll. Method for producing a composite composition. 3. The grooves are arranged between the plurality of cutter blades provided on the first roll. 3. A method for producing the composite composition described in 2 above. 4. A groove is placed on the second roll, and 3. A method for producing the composite composition described in 2 above. 5. The second roll is a rubber roll, Grasp and transport continuous reinforcing fibers; 5. A method for producing the composite composition according to any one of 1 to 4 above. 6. Spreading the discontinuous reinforcing fibers and the resin onto a rocker disposed below the first roll and the second roll; The oscillator is oscillated in the MD direction to mix the discontinuous reinforcing fibers and the resin, The discontinuous reinforcing fibers and the resin mixed on the oscillator are transported onto a support to form a composite composition. 6. A method for producing the composite composition described in any one of 1 to 5 above. 7. A rotating body is disposed below the first roll and the second roll; The resin is introduced into the rotor and then supplied from the rotor to the discontinuous reinforcing fibers and mixed therewith. 1. A method for producing the composite composition described in 1. 8. A rotating body is disposed below the first roll and the second roll; The resin is held by a gripping tool provided on the rotating body, and the rotating body rotates, and the resin is supplied from the rotating body to the discontinuous reinforcing fibers and mixed. 1. A method for producing the composite composition described in 1. 9. A rotating body is disposed below the first roll and the second roll; At least a portion of the discontinuous reinforcing fibers is dropped toward the rotating body, The resin is supplied from the rotating body and mixed with the discontinuous reinforcing fibers. 1. A method for producing the composite composition described in 1. 10. The resin is held by a holding tool provided on the rotating body, and the rotating body rotates, and the resin is supplied from the rotating body to the discontinuous reinforcing fibers and mixed therewith. 10. A method for producing the composite composition described in 9 above. 11. The rotating body comprises a hollow pipe; The resin is supplied from the hollow pipe, Mixing resin with discontinuous reinforcing fibers, 10. A method for producing the composite composition described in 9 above. 12. Two opposing feed rolls are provided on the supply side of the continuous reinforcing fiber of the second roll, and the reinforcing fiber is fed at the peripheral speed of the feed rolls by passing the reinforcing fiber between these two feed rolls. 12. A method for producing the composite composition according to any one of 1 to 11 above. 13. A method for producing a composite composition according to any one of 1 to 12 above, wherein the resin is a thermoplastic resin. 14. Using the composite composition described in 1 to 13 above, A method for producing a composite material by impregnating the discontinuous reinforcing fibers with the resin contained in a composite composition. [Effects of the Invention]

[0010] According to the present invention, a composite composition can be produced in which discontinuous reinforcing fibers and resin are uniformly mixed, and by using this composite composition, the discontinuous reinforcing fibers can be easily impregnated with resin. [Brief explanation of the drawings]

[0011] [Figure 1] (a) A schematic diagram showing a first roll having grooves, which rotates with resin placed in the grooves, and which is supplied between the first roll and the second roll together with the continuous reinforcing fibers, and the discontinuous reinforcing fibers and the resin being dispersed from between the first roll and the second roll. (b) A schematic diagram showing a resin being supplied from the opposite side of the second roll, and the discontinuous reinforcing fibers and the resin being dispersed from between the first roll and the second roll. [Figure 2]The second roll has a groove, and resin is poured into the groove and rotated, and is supplied between the first roll and the second roll together with the continuous reinforcing fibers, and the discontinuous reinforcing fibers and the resin are sprayed from between the first roll and the second roll. [Figure 3] FIG. 1 is a schematic diagram showing a process in which the discontinuous reinforcing fibers and the resin are sprayed onto a rocker disposed below a first roll and a second roll, the rocker is rocked in the MD direction to mix the discontinuous reinforcing fibers and the resin, and the mixed discontinuous reinforcing fibers and the resin on the rocker are transported onto a support to form a composite composition. [Figure 4] A schematic diagram showing a rotating body placed below the first roll and the second roll, in which resin is poured into the rotating body and then supplied from the rotating body to the discontinuous reinforcing fibers and mixed therein. [Figure 5] A schematic diagram showing a rotating body disposed below a first roll and the second roll, at least some of the discontinuous reinforcing fibers falling toward the rotating body, and the resin being supplied from the rotating body and mixed with the discontinuous reinforcing fibers. [Figure 6] 1 is a schematic diagram showing how the rotating body is provided with a hollow pipe, resin is supplied from the hollow pipe, and the resin and discontinuous reinforcing fibers are mixed. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Material: Reinforced fiber] In this specification, the reinforcing fiber is preferably at least one selected from the group consisting of carbon fiber, aramid fiber, glass fiber, polyester fiber, nylon fiber, polypropylene fiber, and polyethylene fiber, and more preferably carbon fiber or glass fiber.

[0013] 1. Reinforced fiber: Carbon fiber 1.1. Carbon fiber in general When carbon fibers are used, polyacrylonitrile (PAN)-based carbon fibers, petroleum / coal pitch-based carbon fibers, rayon-based carbon fibers, cellulose-based carbon fibers, lignin-based carbon fibers, phenol-based carbon fibers, etc. are generally known, and any of these carbon fibers can be suitably used in the present invention. Among these, polyacrylonitrile (PAN)-based carbon fibers are preferred in the present invention because of their excellent tensile strength. As a PAN-based carbon fiber, for example, TENAX® STS4014KS (average fiber diameter 7 μm) carbon fiber manufactured by Teijin Limited can be used. 1.2.Carbon fiber sizing agent The carbon fiber used in the present invention may have a sizing agent attached to its surface. When using carbon fiber with a sizing agent attached, the type of sizing agent can be appropriately selected depending on the type of carbon fiber and the type of resin used in the X material or Y material, and is not particularly limited. 1.3. Carbon fiber diameter The fiber diameter of a carbon fiber single yarn (generally, a single yarn is sometimes called a filament) is not particularly limited and may be determined appropriately depending on the type of carbon fiber. The average fiber diameter is usually preferably in the range of 3 μm to 50 μm, more preferably in the range of 4 μm to 12 μm, and even more preferably in the range of 5 μm to 8 μm. When the carbon fiber is in the form of a fiber bundle, the fiber diameter of the carbon fiber does not refer to the diameter of the fiber bundle, but refers to the diameter of the carbon fiber (single yarn) constituting the fiber bundle. The average fiber diameter of the carbon fiber can be measured, for example, by the method described in JIS R-7607:2000.

[0014] 2 Reinforced fiber: Glass fiber The case where the reinforcing fiber used in the present invention is glass fiber will be described. 2.1.Glass fiber in general The glass fiber used in the present invention may be any glass fiber generally referred to as glass fiber. The glass composition is not particularly limited, and may include A-glass, C-glass, E-glass, etc., and may contain components such as TiO2, SO3, and P2O5 in some cases. For example, Nitto Boseki's E-glass RS240QR-483 (count: 2400 g / 1000 m) glass fiber can be used as the glass fiber. 2.2.Glass fiber sizing agent The glass fiber used in the present invention may have a sizing agent attached to its surface. When using glass fiber with a sizing agent attached, the type of sizing agent can be appropriately selected depending on the type of glass fiber and the type of resin, and is not particularly limited. Glass fiber that has been pre-treated with a conventionally known coupling agent such as an organosilane compound, an organotitanium compound, an organoborane compound, or an epoxy compound can be preferably used.

[0015] [Discontinuous reinforcing fiber (continuous reinforcing fiber material is cut)] 1. In the present invention, continuous reinforcing fibers are cut with a cutter blade to form discontinuous reinforcing fibers. The weight-average fiber length of the discontinuous reinforcing fibers contained in the composite composition is preferably 1 mm or more and 100 mm or less, more preferably 3 mm or more and 80 mm or less, and even more preferably 5 mm or more and 60 mm or less.

[0016] When a composite material is produced by impregnating discontinuous reinforcing fibers with the resin contained in the composite composition, if the weight-average fiber length Lw of the discontinuous reinforcing fibers is 100 mm or less, the fluidity of the composite material is not reduced during press molding, and it is easy to produce the composite material in the desired shape. Furthermore, if the weight-average fiber length Lw is 1 mm or more, the mechanical strength of the resulting molded product is not reduced, which is preferable.

[0017] When discontinuous reinforcing fibers are used as the reinforcing fibers in a composite material, the formability is improved compared to when only continuous reinforcing fibers are used, making it easier to create complex molded bodies. Furthermore, by using discontinuous reinforcing fibers, no matter what direction stress is applied to the molded body, it is unlikely that a direction will result in an extreme weakening of mechanical properties.

[0018] In a molded article produced by injection molding, the weight-average fiber length of the reinforcing fibers is about 0.1 to 0.3 mm. Therefore, when the weight-average fiber length of the discontinuous reinforcing fibers is set to 1 mm or more and 100 mm or less, it is preferable to produce the molded article by press molding.

[0019] In the present invention, discontinuous reinforcing fibers having different fiber lengths may be used in combination. In other words, the discontinuous reinforcing fibers used in the present invention may have a single peak in the weight-average fiber length distribution, or may have multiple peaks.

[0020] 2. Number-average fiber length Ln and weight-average fiber length Lw of reinforcing fibers Generally, if the fiber length of each reinforcing fiber is Li, the number average fiber length Ln and weight average fiber length Lw can be calculated by the following formulas (1) and (2). The units of the number average fiber length Ln and weight average fiber length Lw are mm. Ln=ΣLi / I equation (1) Lw=(ΣLi 2 ) / (ΣLi)...Equation (2) Here, "I" indicates the number of reinforcing fibers measured.

[0021] When the fiber length is constant, the number average fiber length and the weight average fiber length are the same value. To measure the reinforcing fibers contained in a composite material, it is advisable to take a sample from the composite composition of discontinuous reinforcing fibers and resin before impregnation with resin.

[0022] The average fiber length can be calculated, for example, by measuring the fiber lengths of 100 fibers randomly extracted from the composite composition to the nearest 1 mm using a caliper or the like, and then calculating the average fiber length based on formula (1).

[0023] If the dispersion contains short fibers that cannot be measured with a caliper, remove the resin, then place the resulting reinforcing fibers in water containing a surfactant and thoroughly stir using ultrasonic vibrations. Samples for evaluation can be obtained by randomly sampling the stirred dispersion with a measuring spoon, and measuring the lengths of 3,000 fibers using a Nireco Luzex AP image analyzer. The measured fiber lengths can be used to calculate the number-average fiber length Ln and weight-average fiber length Lw using the same formulas (1) and (2) described above.

[0024] 3. Random distribution in two dimensions The discontinuous reinforcing fibers are preferably dispersed two-dimensionally at random in the in-plane direction of the composite composition and the composite material obtained by impregnating the discontinuous reinforcing fibers with the resin in the composite composition. When the composite material is press-molded without flowing, the shape of the reinforcing fibers is largely maintained before and after molding, so it is preferable that the reinforcing fibers contained in the reinforcing portion after molding the composite material are also dispersed two-dimensionally at random in the in-plane direction.

[0025] Here, "two-dimensionally randomly dispersed" refers to a state in which the discontinuous reinforcing fibers are randomly oriented in the in-plane direction of the composite material, rather than in a specific direction such as one direction, and are arranged in the sheet plane without any specific directionality overall. A composite material obtained using such two-dimensionally randomly dispersed discontinuous reinforcing fibers does not have anisotropy in the plane, and is substantially isotropic.

[0026] The degree of orientation, which indicates the degree to which discontinuous reinforcing fibers are randomly dispersed in two dimensions in the in-plane direction of the composite material, is evaluated by calculating the ratio of the tensile moduli of the composite material in two mutually intersecting directions. The discontinuous reinforcing fibers can be evaluated as being randomly dispersed in two dimensions if the (Eδ) ratio, calculated by dividing the larger of the tensile moduli measured in any direction of the composite material by the smaller of the two measured values, is 5 or less, more preferably 2 or less, and even more preferably 1.5 or less. When a molded article formed from a composite material has a curved surface, the degree of two-dimensional random dispersion (orientation) of discontinuous reinforcing fibers in the in-plane direction of this portion can be evaluated by heating the curved portion to above its softening temperature to return it to a flat plate shape, removing only the curved portion, and solidifying it. Then, a test piece is cut from the curved portion that has been returned to a flat plate shape, and the tensile moduli of the test piece in two mutually intersecting directions can be measured to evaluate the two-dimensional random dispersion in the curved portion.

[0027] By using a composite material containing discontinuous reinforcing fibers dispersed in the in-plane direction, even if the composite material flows slightly during molding or is misaligned, the basic mechanical properties will not change significantly. In addition, shape conformability is improved compared to materials using continuous fibers such as plain weave cloth.

[0028] [Material: Resin] The resin contained in the composite composition may be thermosetting or thermoplastic. 1.Thermoplastic resin When the resin used is a thermoplastic resin, the type is not particularly limited, and a resin having a desired softening point or melting point can be appropriately selected and used. As the thermoplastic resin, one having a softening point in the range of 180°C to 350°C is usually used, but is not limited thereto.

[0029] Examples of thermoplastic resins include polyolefin resins, polystyrene resins, polyamide resins, polyester resins, polyacetal resins (polyoxymethylene resins), polycarbonate resins, (meth)acrylic resins, polyarylate resins, polyphenylene ether resins, polyimide resins, polyethernitrile resins, phenoxy resins, polyphenylene sulfide resins, polysulfone resins, polyketone resins, polyether ketone resins, thermoplastic urethane resins, fluorine-based resins, and thermoplastic polybenzimidazole resins.

[0030] The composite composition of the present invention may contain one or more types of thermoplastic resins. Examples of the use of two or more types of thermoplastic resins in combination include, but are not limited to, the use of thermoplastic resins having different softening points or melting points or the use of thermoplastic resins having different average molecular weights. When a thermoplastic resin is used, it is more preferable to use a polyolefin resin, and even more preferable to use a polypropylene resin.

[0031] 2.Thermosetting resin The resin may be a thermosetting resin. When a thermosetting resin is used, it is preferably an unsaturated polyester resin, a vinyl ester resin, an epoxy resin, or a phenol resin. One type of resin may be used alone, or two or more types may be used in combination.

[0032] Furthermore, when a thermosetting resin is used as the resin of the present invention, it is preferable to use a sheet molding compound (sometimes called SMC) containing reinforcing fibers. Because of its high moldability, sheet molding compounds can be easily molded into even complex shapes. Sheet molding compounds have higher fluidity and formability than continuous reinforcing fibers, making it easy to create ribs and bosses.

[0033] 3. Resin form When the resin is supplied, it is preferably in a granular form such as powder or particles so that it can easily enter the grooves provided in the roll. It is also preferable to use a resin that is solid at room temperature.

[0034] [Material: Other] The resin may contain additives such as various fibrous or non-fibrous fillers such as organic or inorganic fibers, flame retardants, UV-resistant agents, stabilizers, release agents, pigments, softeners, plasticizers, surfactants, etc. When a thermosetting resin is used, it may also contain thickeners, curing agents, polymerization initiators, polymerization inhibitors, etc. One type of additive may be used alone, or two or more types may be used in combination.

[0035] [Method of manufacturing composite composition: Overview] In the method for producing a composite composition of discontinuous reinforcing fibers and resin according to the present invention, a first roll having a plurality of cutter blades and a second roll opposed to the first roll are provided, continuous reinforcing fibers are supplied between the first roll and the second roll and cut with the cutter blades to form the discontinuous reinforcing fibers, and the discontinuous reinforcing fibers and the resin are then sprayed. In this case, the continuous reinforcing fibers are contained in the composite composition through the following steps (i) to (iii). (i) A process of drawing out continuous reinforcing fibers from a package (a fiber bundle wound on a bobbin). (ii) A step of cutting the continuous reinforcing fibers drawn out from the package with a rotary cutter to form discontinuous reinforcing fibers. The cut discontinuous reinforcing fibers will be described in detail separately. (iii) Discontinuous reinforcing fibers are scattered below the rotary cutter.

[0036] On the other hand, the method of spraying the resin is not particularly limited, and it is sufficient to spray the discontinuous reinforcing fibers and the resin to form a composite composition. The manufacturing process up to the point where the resin is included in the composite composition will be described in the following embodiments. In all embodiments, the purpose is to make it easier to uniformly mix the discontinuous reinforcing fibers and the resin in the composite composition.

[0037] [Method of manufacturing a composite composition: embodiment 1] The first embodiment of the present invention will be described with reference to Fig. 1(a). In other words, Fig. 1(a) illustrates the first embodiment. 1.Cutting and feeding continuous reinforcing fibers As shown in Figure 1(a), the continuous reinforcing fiber cutting device has a second roll 106 disposed opposite a first roll 105 to which a large number of cutter blades 107 are fixed. The second roll 106 is rotated in the direction of arrow A by a second roll drive motor (not shown). In the first embodiment, the second roll 106 is driven by the second roll drive motor in this way, but this is not necessarily limited to this, and the second roll 106 may also be a driven roll without a second roll drive motor.

[0038] As shown in Fig. 1(a), cutter blades 107 are attached at equal intervals to a first roll 105 to which the cutter blades are fixed. The intervals at which the cutter blades 107 are fixed are set to the desired cutting length of the continuous reinforcing fibers. If the length of the discontinuous reinforcing fibers is 30 mm, the intervals at which the cutter blades are fixed should be 30 mm.

[0039] The diameter of the first roll 105 is preferably, for example, 150 mm or more and 350 mm, and is approximately the same diameter as the second roll 106. A drive motor (not shown) for the second roll 106 rotates the first roll 105 in the direction of arrow B at the same peripheral speed as the second roll 106. The diameters of the first roll and the second roll do not necessarily have to be the same.

[0040] It is also preferable to arrange the first roll 105 and the second roll 106 so that they come into contact with each other. That is, by arranging the first roll 105 and the second roll 106 in a state where they come into contact with each other, the continuous reinforcing fibers 101 are pulled between the first roll 105 and the second roll 106, and therefore the continuous reinforcing fibers 101 can be supplied.

[0041] The second roll 106 is preferably a rubber roll. The rubber roll is made of a relatively hard elastic rubber such as natural rubber, synthetic rubber, silicone rubber, or urethane rubber. A rubber roll is preferred as an example of a roll that plays a role in gripping and transporting the continuous reinforcing fibers.

[0042] As shown in FIG. 1(a), two opposing feed rolls are provided on the supply side of the continuous reinforcing fiber of the second roll. The continuous reinforcing fiber 101 is passed between these two feed rolls, and is fed to the first roll 105 at the peripheral speed of the feed rolls. The continuous reinforcing fiber 101 is supplied from above the feed roll 108, passed between the feed roll 108 and the first roll 105, and fed downward. Next, when the lower end of the continuous reinforcing fiber 101 moves downward while contacting the peripheral surface of the second roll 106, the cutter blade 107 of the first roll 105 presses the continuous reinforcing fiber 101 when the second roll 106 and the first roll 105 are closest to each other, thereby cutting the continuous reinforcing fiber 101. During cutting, the cutter blade 107 is engaged with the second roll 106.

[0043] It is preferable that the second roll 106 and the feed roll 108 are in contact with each other, and that the second roll 106 and the continuous reinforcing fiber 101 immediately before cutting are in contact with each other by the cutter blade 107. The continuous reinforcing fiber 101 is fed by being sandwiched between the second roll 106, the feed roll 108, and the cutter blade 107. The continuous reinforcing fiber 101 can also be fed by being sandwiched (held) between the second roll 106 and the cutter blade 107.

[0044] In order to make it easier to drop the discontinuous reinforcing fibers 103, the feed speed of the feed roll 108 should be slower than that of the first roll 105. The discontinuous reinforcing fibers 103 are fed by the first roll 105 and the second roll 106.

[0045] 2. Resin supply In embodiment 1, the first roll has a groove, and the resin is introduced into the groove and rotated, and is supplied between the first roll and the second roll together with the continuous fiber, and the resin is sprayed from between the first roll and the second roll.

[0046] For example, as shown in Fig. 1(a), a first roll 105 to which cutter blades are fixed has grooves 104 formed at equal intervals radially on the outer periphery of the first roll 105. The grooves 104 are formed between cutter blades 107 arranged at equal intervals.

[0047] There are no particular limitations on the size and spacing of the grooves, but it is preferable to have at least one groove between each pair of cutter blades. The grooves may be formed concentrically on the first roll 105, for example, with a depth of 0.5 mm to 5 mm and a width of 0.5 mm to 5 mm, depending on the type and amount of resin to be supplied. If particulate resin is used, the grooves are designed so that the particulate resin can enter the grooves.

[0048] The grooves may be provided between the blades in the circumferential direction of the first roll, instead of in the direction shown in FIG. 1(a). With this design, the resin is sprayed downward from the grooves each time the discontinuous reinforcing fibers are cut and sprayed downward, so that the discontinuous reinforcing fibers and the resin are uniformly mixed together. This uniform mixing of the discontinuous reinforcing fibers and the reinforcing fibers allows the resin contained in the composite composition to easily impregnate the discontinuous reinforcing fibers.

[0049] In Figure 1(a), resin 102 is supplied from above the first roll 105 toward the grooves, and the resin is preferably in a granular form such as powder or particles to facilitate entry into the grooves. As the first roll rotates, the resin supplied to the grooves moves between the first roll and the second roll together with the continuous reinforcing fibers.

[0050] Each time the continuous reinforcing fibers 101 are cut, the resin 102 is sprayed from between the first roll and the second roll. To prevent the discontinuous reinforcing fibers and resin from clogging between the first roll 105 and the second roll 106, gas may be injected to blow the discontinuous reinforcing fibers and resin downward and spray them.

[0051] 3. Composite composition The dispersed discontinuous reinforcing fibers and resin form a composite composition 110 on the support 109. In this composite composition, the resin and discontinuous reinforcing fibers are dispersed and mixed together, and the discontinuous reinforcing fibers are in an unimpregnated state.

[0052] [Method of manufacturing a composite composition: embodiment 2] The second embodiment of the present invention will be described with reference to Fig. 1(b). In other words, Fig. 1(b) illustrates the second embodiment. 1.Cutting and feeding continuous reinforcing fibers This is the same as in the first embodiment. 2. Resin supply In the second embodiment, as shown in Fig. 1(b), the resin 102 is supplied to the groove of the first roll on the opposite side to where the continuous reinforcing fibers are cut. By scooping up and supplying the resin as shown in Fig. 1(b), there is no need to use a high-precision quantitative feeder, which reduces capital investment.

[0053] [Method of manufacturing a composite composition: embodiment 3] A third embodiment of the present invention will be described with reference to Fig. 2. In other words, Fig. 2 illustrates the third embodiment. 1.Cutting and feeding continuous reinforcing fibers This is the same as in the first embodiment. 2. Resin supply As shown in FIG. 2, the second roll 106 has grooves 104 formed at equal intervals radially around the outer periphery of the first roll 106 . The groove spacing is not particularly limited, but it is preferable to design the groove 104 so that it can pass between the second roll 106 and the first roll 105 each time the cutter blade 107 cuts the continuous reinforcing fibers. The spacing is also preferably the same as that of the cutter blade 107. The grooves may be provided in the first roll 105 in a concentric pattern with a depth of 0.5 mm to 5 mm and a width of 0.5 mm to 5 mm, depending on the form and supply amount of resin. If particulate resin is used, the grooves are designed so that the particulate resin can enter the grooves. The grooves may be provided between the blades in the circumferential direction of the first roll, instead of in the direction shown in FIG. 1(b).

[0054] With this design, every time the discontinuous reinforcing fibers are cut and sprayed downward, the resin is sprayed downward from the grooves, so that the discontinuous reinforcing fibers and the resin are mixed well together. By successfully mixing the discontinuous reinforcing fibers with the reinforcing fibers, the resin contained in the composite composition can be easily impregnated into the discontinuous reinforcing fibers when heated and melted.

[0055] In the third embodiment, resin 102 is supplied from the supply path for the continuous reinforcing fibers to a groove 104 located below. The supplied resin moves between the first roll and the second roll as the second roll rotates. Each time the continuous reinforcing fibers 101 are cut, resin 102 is sprayed from between the first roll and the second roll. To prevent the discontinuous reinforcing fibers and resin from clogging between the first roll 105 and the second roll 106, gas may be injected to blow the discontinuous reinforcing fibers and resin downward and spray them.

[0056] [Method of manufacturing a composite composition: embodiment 4 (swing)] A fourth embodiment of the present invention will be described with reference to Fig. 3. In other words, Fig. 3 illustrates the fourth embodiment. 1.Cutting and feeding continuous reinforcing fibers This is the same as in the first embodiment. 2. Resin supply 3, the resin 102 is sprayed separately from the discontinuous reinforcing fibers. The resin spraying method in the fourth embodiment does not necessarily require separate spraying, and the resin spraying methods in the first to third embodiments may be used, for example. 3. Rocking The discontinuous reinforcing fibers and the resin are spread on a rocker disposed below the first roll and the second roll, and the rocker is rocked in the MD direction to mix the discontinuous reinforcing fibers and the resin. The mixed discontinuous reinforcing fibers and the resin on the rocker are transported onto a support to form a composite composition. There are no particular limitations on the type of rocker, and a commercially available plate, sheet, or conveyor may be used.

[0057] The MD direction is the "machine direction," which is the Y-axis direction in Figure 3. The application range 301 in Figure 3 is approximately 300 mm, and by swinging, the resin and discontinuous reinforcing fibers on the swinging body can be mixed. Furthermore, by further spraying discontinuous reinforcing fibers 103 and resin 102 onto the swinging body, the discontinuous reinforcing fibers 103 can be layered from above after the resin 102 has fallen. The swinging motion is performed left and right along the Y-axis in Figure 3, with more movement along the left side of the Y-axis than along the right side of the Y-axis. For example, it is preferable to swing the swinging motion 200 mm left along the Y-axis and 160 mm right along the Y-axis. 4. Composite composition The mixed discontinuous reinforcing fibers and resin are transported to a support to form a composite composition. In embodiment 4, the discontinuous reinforcing fibers and resin can be stably supplied without interfering with the gripping of the continuous reinforcing fibers when they are supplied.

[0058] [Method of manufacturing a composite composition: Embodiment 5 (use of a rotating body)] A fifth embodiment of the present invention will be described with reference to Fig. 4. In other words, Fig. 4 illustrates the fifth embodiment. 1.Cutting and feeding continuous reinforcing fibers This is the same as in the first embodiment. 2. Resin supply A rotating body 401 is placed below the first roll 105 and the second roll 106, and the resin is poured into the rotating body 401, and then supplied from the rotating body to the discontinuous reinforcing fibers and mixed therewith. In Figure 4, resin is supplied to the gripping tool 402 of the rotor 401, which is on the opposite side to the side where the cut discontinuous reinforcing fibers are scattered. Then, the rotor 401 rotates while the resin 102 is held by the gripping tool 402 provided on the rotor 401, and the resin 102 is supplied from the rotor 401 to the discontinuous reinforcing fibers 103 and mixed therein. A plurality of gripping tools 402 are provided radially at equal intervals around the outer periphery of the rotor 401. The gripping tools 402 may be plates, or may have the shape of a small semi-cylinder cut out from a semi-cylinder, as shown in 403 in FIG. 4. In FIG. 4, the resin 102 is poured onto the discontinuous reinforcing fiber side using centrifugal force. If the centrifugal force is insufficient, gas may be blown to assist. In the fifth embodiment, the gripping of the continuous reinforcing fibers is not disturbed when the continuous reinforcing fibers are fed, and the discontinuous reinforcing fibers can be stably fed.

[0059] [Method of manufacturing a composite composition: Embodiment 6 (use of a rotating body)] A sixth embodiment of the present invention will be described with reference to Fig. 5. In other words, Fig. 5 illustrates the sixth embodiment. 1.Cutting and feeding continuous reinforcing fibers This is the same as in the first embodiment. 2. Resin supply As shown in FIG. 5, a gripper 402 attached to a rotor 401 is placed below the first and second rolls. At least some of the discontinuous reinforcing fibers 103 are dropped toward the gripper 402, and resin 102 is supplied from the rotor 401 and mixed with the discontinuous reinforcing fibers 103. It is sufficient for at least some of the discontinuous reinforcing fibers 103 to drop toward the gripper 402; the remaining discontinuous reinforcing fibers 103 may simply fall onto the support. By hitting the discontinuous reinforcing fibers 103 against the gripper 402, the discontinuous reinforcing fibers contained in the composite composition tend to be randomly dispersed. Specifically, in the XY plane of FIG. 5, the discontinuous reinforcing fibers are randomly dispersed in two directions to form a composite composition. Here, the XY plane direction is the two-dimensional direction. 5, the resin 102 is held by a holder 402 provided on a rotor 401, and as the rotor rotates, the resin is supplied from the rotor to the discontinuous reinforcing fibers and mixed. The resin is not sprayed separately, but the discontinuous reinforcing fibers are mixed on the holder. In the sixth embodiment, the discontinuous reinforcing fibers can be stably supplied without interfering with the gripping of the fibers when the continuous reinforcing fibers are supplied.

[0060] [Method for producing a composite composition: Embodiment 7 (use of hollow pipe)] A seventh embodiment of the present invention will be described with reference to Fig. 6. In other words, Fig. 6 illustrates the seventh embodiment. 1.Cutting and feeding continuous reinforcing fibers This is the same as in the first embodiment. 2. Resin supply 6, the rotor is equipped with a hollow pipe 502, and the resin 102 is supplied from the hollow pipe 502 to mix with the discontinuous reinforcing fibers. Since the resin 102 passes through the hollow pipe 502 and is supplied to the discontinuous reinforcing fibers, the supply amount can be stabilized.

[0061] As shown in FIG. 6 , a gripping tool 401 attached to a rotating body 401 is placed below the first roll 105 and the second roll 106. At least some of the discontinuous reinforcing fibers 103 are dropped toward the gripping tool 401, and resin 102 is supplied from a hollow pipe 502 of the rotating body 401 and mixed with the discontinuous reinforcing fibers 103. It is sufficient for at least some of the discontinuous reinforcing fibers 103 to drop toward the gripping tool 402; the remaining discontinuous reinforcing fibers 103 may simply drop onto a support. By hitting the discontinuous reinforcing fibers 103 against the gripping tool 401, the discontinuous reinforcing fibers contained in the composite composition tend to be randomly dispersed in two dimensions. Specifically, in the XY plane of FIG. 6 , the discontinuous reinforcing fibers are randomly dispersed in two dimensions to form a composite composition. Here, the XY plane direction is the two-dimensional direction.

[0062] In the seventh embodiment, the continuous reinforcing fibers are not disturbed when being supplied, and a fixed amount of resin can be supplied. The inside of the rotor is hollow, and the resin 102 can be supplied by extruding it from the TD direction or by conveying it with a gas.

[0063] [Method of manufacturing composite materials] The composite material is an impregnated plate obtained by impregnating the discontinuous reinforcing fibers with a resin in a composite composition of discontinuous reinforcing fibers and a resin. The composite composition is preferably heated and pressurized to impregnate the discontinuous reinforcing fibers with the resin. The composite composition may also include other materials as previously mentioned.

[0064] The composite material of the present invention is preferably made into a sheet shape from a composite composition containing a resin and discontinuous reinforcing fibers. The term "sheet shape" refers to a planar shape in which, when the smallest dimension of the three dimensions (e.g., length, width, and thickness) that indicate the size of the fiber-reinforced plastic is the thickness and the largest dimension is the length, the length is 10 times or more the thickness.

[0065] In the present invention, the composite composition refers to the state before the reinforcing fibers are impregnated with the resin. The discontinuous reinforcing fibers in the composite composition may be provided with a sizing agent, or a binder may be provided after the discontinuous reinforcing fibers are dispersed. These are not matrix resins, but are provided in advance to the reinforcing fibers in the composite composition.

[0066] [Reinforced fiber: fiber volume fraction Vf] The fiber volume fraction (Vf) of the reinforcing fibers of the composite material is 40% or more, preferably 45% or more, and more preferably 50% or more. The upper limit of the fiber volume fraction (Vf) of the composite material is preferably 65% ​​or less, more preferably 60% or less, and even more preferably 55% or less. If the fiber volume fraction (Vf) of the composite material is 65 vol% or less, the flowability when used in press molding or the like is good, and the desired molded shape can be easily obtained.

[0067] The fiber volume fraction (Vf, unit: volume %) is the ratio of the volume of reinforcing fibers to the total volume, including not only the reinforcing fibers and resin, but also other additives, etc. The total fiber volume fraction (Vf) contained in a composite material is measured regardless of the type of reinforcing fiber. Vf = 100 x reinforcing fiber volume / (reinforcing fiber volume + resin volume + other additive volume)

[0068] There are no limitations on how to measure the fiber volume fraction, but it is best to calculate it from the volume fraction of the reinforcing fibers, resin, and other materials added. If the resin can be burned off, for example, heat treatment can be performed at 550°C for 3 hours, and the resin can be removed in the furnace, allowing the reinforcing fiber volume to be calculated from the weight of the reinforcing fibers.

[0069] [Relationship between composite materials and molded products] In the present invention, a composite material is a material for producing a molded body, and the composite material is press-molded (also called compression molding) to form the molded body. Therefore, the composite material in the present invention has a flat plate shape, but the molded body is shaped and has a three-dimensional shape.

[0070] [Molded body] The composite material of the present invention is preferably one to be press-molded to produce a molded article. When the resin is a thermoplastic resin, cold press molding is preferred as the press molding. [Industrial Applicability]

[0071] The composite material prepared using the composite composition of the present invention and the molded article obtained by molding the composite material can be used to produce various components, for example, structural members of automobiles, frames and housings of various electrical products and machines, and any other parts where impact absorption is desired, particularly preferably press-molded articles that can be used as automobile parts. [Explanation of symbols]

[0072] A: Rotation direction of the second roll B: Rotation direction of the first roll 101: Continuous reinforcing fiber 102: Resin 103: Discontinuous reinforcing fiber 104: Groove 105: First Roll 106: Second Roll 107: Cutter blade 108: Feed roll 109, 304: Support 110: Composite composition 301: Swing range (e.g., 300 mm) 302: MD direction 303: Oscillator 401: Rotating body 402:Gripper 403: Gripper (shape of a semi-cylinder cut out from a semi-cylinder) 502: Hollow pipe

Claims

1. A method for producing a composite composition of discontinuous reinforcing fibers and a resin, comprising: a first roll having a plurality of cutter blades and a second roll opposed to the first roll; Continuous reinforcing fibers are supplied between the first roll and the second roll and cut with the cutter blade to form the discontinuous reinforcing fibers; The discontinuous reinforcing fibers and the resin are dispersed, A method for producing a composite composition of discontinuous reinforcing fibers and resin.

2. A method for producing a composite composition of discontinuous reinforcing fibers and resin according to claim 1, At least one of the first roll and the second roll has a groove; The resin is introduced into the groove and rotated, and is supplied between the first roll and the second roll together with the continuous reinforcing fibers. The discontinuous reinforcing fibers and the resin are sprayed from between the first roll and the second roll. Method for producing a composite composition.

3. The grooves are arranged between the plurality of cutter blades provided on the first roll. A method for producing the composite composition of claim 2.

4. a groove is disposed in the second roll, and A method for producing the composite composition of claim 2.

5. the second roll is a rubber roll, Grasp and transport continuous reinforcing fibers; A method for producing the composite composition according to any one of claims 1 to 4.

6. The discontinuous reinforcing fibers and the resin are scattered on a rocker disposed below the first roll and the second roll, The oscillator is oscillated in the MD direction to mix the discontinuous reinforcing fibers and the resin, The discontinuous reinforcing fibers and the resin mixed on the oscillator are transported onto a support to form a composite composition. A method for producing the composite composition according to any one of claims 1 to 5.

7. a rotating body is disposed below the first roll and the second roll; The resin is introduced into the rotor and then supplied from the rotor to the discontinuous reinforcing fibers and mixed therewith. A method for producing the composite composition of claim 1.

8. a rotating body is disposed below the first roll and the second roll; The resin is held by a gripping tool provided on the rotating body, and the rotating body rotates, and the resin is supplied from the rotating body to the discontinuous reinforcing fibers and mixed. A method for producing the composite composition of claim 1.

9. a rotating body is disposed below the first roll and the second roll; At least a portion of the discontinuous reinforcing fibers is dropped toward the rotating body, The resin is supplied from the rotating body and mixed with the discontinuous reinforcing fibers. A method for producing the composite composition of claim 1.

10. The resin is held by a gripping tool provided on the rotating body, and the rotating body rotates, and the resin is supplied from the rotating body to the discontinuous reinforcing fibers and mixed. A method for producing the composite composition of claim 9.

11. The rotating body includes a hollow pipe, The resin is supplied from the hollow pipe, Mixing resin with discontinuous reinforcing fibers, A method for producing the composite composition of claim 9.

12. Two feed rolls facing each other are provided on the supply side of the continuous reinforcing fiber of the second roll, and the reinforcing fiber is supplied at the peripheral speed of the feed rolls by passing the reinforcing fiber between these two feed rolls. A method for producing the composite composition according to any one of claims 1 to 11.

13. The method for producing a composite composition according to claim 1 , wherein the resin is a thermoplastic resin.

14. Using the composite composition according to any one of claims 1 to 13, A method for producing a composite material by impregnating the discontinuous reinforcing fibers with the resin contained in a composite composition.

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