Carbon fiber tape material, reinforced fiber laminate, and molded article using the same

Abstract

In order to achieve a carbon fiber tape material that has favorable mold conformability and favorable matrix resin impregnability, that improves productivity when producing a reinforced fiber laminate via a fiber placement method, and that, upon being impregnated in resin and molded, is capable of providing a molded article having high mechanical strength, the present invention provides a carbon fiber tape material wherein a carbon fiber group, in which a plurality of carbon fiber bundles are aligned parallel to the fiber orientation direction, is integrated with a fabric, characterized in that the carbon fiber tape material satisfies the following (a) to (c): (a) the fabric is formed from one or more types of thermoplastic resin; (b) the carbon fiber tape material, excluding the fabric, has a mass per unit area of between 120 g / m2 and 400 g / m2; and (c) in at least one direction of the fabric, the fabric elongation percentage Ep(%) when a 80mN / 50mm load is applied to the fabric is 5-100%. Ep=[(L1-L0) / L0]×100. Ep: Fabric elongation percentage (%). L0: Original fabric length (mm) between marks. L1: Fabric length (mm) when load has been applied.

Description

Technical Field

[0001] The present invention relates to a reinforced fiber tape material, a reinforced fiber laminate formed by arranging and laminating the same, and a molded body.

Background Art

[0002] Fiber Reinforced Plastic (FRP) composed of reinforcing fibers and a resin is used in applications such as aviation, space, and automobiles due to its characteristics of being lightweight and having high strength. As a molding method that combines the productivity and high strength of FRP, for example, molding methods such as Resin Transfer Molding (RTM) and Vacuum-assisted Resin Transfer Molding (VaRTM) are available, in which a resin is impregnated and cured in a reinforced fiber laminate after the fact. The RTM molding method is a molding method in which a reinforced fiber laminate composed of a dry reinforced fiber bundle group not preliminarily impregnated with a matrix resin is placed in a mold, and a liquid and low-viscosity matrix resin is injected to impregnate and solidify the matrix resin later to form FRP. When particularly high productivity is required, techniques such as making the cavity in the mold thicker than the final molded product thickness during resin injection and shortening the molding time of the fiber-reinforced plastic by high-speed impregnation by closing the mold are used. In recent years, a wet press molding method in which a liquid resin is applied to a reinforced fiber laminate and then the mold is clamped to impregnate the resin is also used.

[0003] A reinforced fiber laminate impregnated and cured with resin is conventionally formed by shaping and fixing a three-dimensional shape by cutting out a desired shape from a reinforcing fiber base material in the form of a fabric having a certain width (i.e., a substantially rectangular shape) composed of dry reinforcing fiber bundles in which the resin is not impregnated, such as a woven fabric or a non-crimp fabric (NCF). However, when cutting out a desired shape from a fabric of a certain width in this way, a large amount of end materials are generated afterwards. That is, there is a problem that the amount of waste of reinforcing fibers increases and the manufacturing cost becomes high in the conventional method of manufacturing a reinforcing fiber base material in the form of a fabric of a certain width in advance.

[0004] In response to such problems, the fiber placement method in which the reinforcing fiber bundles are arranged only at necessary locations so as to have a desired shape according to the product shape has attracted attention. According to the fiber placement method, in order to arrange the necessary amount of reinforcing fibers at necessary locations, the reinforcing fibers are formed in the form of a tape, and by arranging such a tape material only at necessary locations, the amount of reinforcing fibers to be discarded can be significantly reduced. Furthermore, the reinforcing fiber base material manufactured by the fiber placement method has less crimp of the reinforcing fiber bundles and is superior in straightness compared to conventional woven fabrics and NCFs, so the FRP obtained by injecting and curing resin into it has high mechanical strength.

[0005] As a prior art regarding the carbon fiber tape material used in the fiber placement method, for example, in Patent Document 1, a carbon fiber tape material having a polymer adhesive bonded to both sides and a manufacturing method thereof have been proposed. According to such a method, it is possible to manufacture a carbon fiber tape of a desired width with high accuracy by melting the polymer adhesive and attaching it to the reinforcing fiber bundle group.

[0006] In Patent Document 2, a carbon fiber tape material, a preform, and a method for producing the same, in which a non-woven veil is adhered to at least one side, are proposed. According to such a method, by using a carbon fiber tape material to which a non-woven veil is adhered, an effect of increasing the ease of in-plane resin diffusion during resin injection in RTM molding or VaRTM molding can be obtained. Further, when a thermoplastic fiber material is used for the non-woven veil, as a result, the obtained composite material can be toughened.

[0007] Furthermore, in Patent Document 3, a reinforcing sheet material made of a woven fabric of a reinforcing fiber material having a basis weight of 80 g / m 2 or less and a thermoplastic resin material is proposed. According to such a configuration, by using a flexible woven fabric, a sheet material that maintains straightness in a thin and wide state and has no deformation such as curling can be obtained. Further, since a thin woven fabric with many voids is used, the air inside can be degassed, and a molded product with few voids can be obtained.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0009] However, in the fiber placement method, when directly attaching a carbon fiber tape to a mold, it is necessary to make the carbon fiber tape follow and conform to the mold shape. Therefore, the wider the width of the carbon fiber tape and the more complex the mold shape, the higher the deformability of the carbon fiber tape is required. Further, high productivity is required in the lamination of carbon fiber tapes and resin injection in RTM molding or VaRTM molding.

[0010] Here, in the invention of Patent Document 1, the deformability of the polymer adhesive is not mentioned. And when using, for example, a non-woven veil for the polymer adhesive, since the non-woven veil is formed by randomly orienting short fibers, it generally does not have sufficient deformability in the plane direction. Furthermore, when the polymer adhesive melts, the form of the non-woven veil is lost, so that the deformability originally possessed by the fabric material is reduced.

[0011] In the invention of Patent Document 2, a carbon fiber tape material with a non-woven veil adhered to at least one side is used. Therefore, similar to Cited Document 1, since the non-woven veil is formed by randomly orienting short fibers, it does not have sufficient deformability.

[0012] In the invention of Patent Document 3, a fabric having deformability is used, but the basis weight of the reinforcing fiber material is low, and in order to obtain a desired product thickness, it is necessary to laminate many sheet materials, which makes the operation complicated and reduces productivity. Also, the invention described in Patent Document 3 relates to a reinforcing sheet material and does not suggest the application to the fiber placement method of such a reinforcing sheet material.

[0013] The present invention solves such problems of the prior art. Specifically, it provides a carbon fiber tape material that has good followability to a mold and impregnability of a matrix resin, can enhance productivity when manufacturing a reinforced fiber laminate by a fiber placement method, and can provide a molded body having high mechanical strength when impregnated with resin and molded. Also, it provides a reinforced fiber laminate and a molded body obtained from such a carbon fiber tape material.

Means for Solving the Problems

[0014] The present invention has been made to solve at least a part of the above-described problems and is characterized by any of the following configurations. (1) A carbon fiber tape material in which a group of carbon fiber bundles arranged in parallel with the fiber orientation direction and a fabric are integrated, characterized in that the following (a) to (c) are satisfied. (a) The fabric is composed of one or more types of thermoplastic resins. (b) Among the carbon fiber tape materials, the basis weight excluding the fabric is between 120 g / m 2 and 400 g / m 2 . (c) In at least one direction of the fabric, when a load of 80 mN / 50 mm is applied to the fabric, the fabric elongation rate E p (%) is 5% to 100%. E p =[(L 1 -L 0 ) / L 0 ×100 E p : Fabric elongation rate (%). L 0 : Fabric length between the original marks (mm). L 1 : Fabric length when the load is applied (mm). (2) The carbon fiber tape material according to (1), characterized in that the fabric has regularity. (3) The carbon fiber tape material according to (1) or (2), characterized in that a gap of 0.1 mm to 1 mm is provided between the carbon fiber bundles. (4) The carbon fiber tape material according to any one of (1) to (3), characterized in that the tape width of the carbon fiber tape material is 2 mm to 2000 mm. (5) The carbon fiber tape material according to any one of (1) to (4), characterized in that the carbon fiber bundle group and the fabric are integrated by adhesion via a resin binder attached to at least one side of the carbon fiber bundle group. (6) The carbon fiber tape material according to (5), characterized in that the adhesion region where the fabric and the carbon fiber bundle group are adhered via the resin binder is discretely formed in the fiber orientation direction of the carbon fiber bundles in at least a part of the carbon fiber tape material. (7) The adhesive region where the fabric and the carbon fiber bundle group are adhered via the resin binder is discretely formed in the fiber orientation direction of the carbon fiber bundles throughout the entire area of the carbon fiber tape material, characterized in that the carbon fiber tape material according to (6) above. (8) Among the carbon fiber bundle group, two carbon fiber bundles located at both ends in the direction orthogonal to the fiber orientation direction of the carbon fiber bundles are continuously adhered to the fabric in the fiber orientation direction of the carbon fiber bundles, and the other carbon fiber bundles located between the two carbon fiber bundles are intermittently adhered to the fabric in the fiber orientation direction of the carbon fiber bundles, characterized in that the carbon fiber tape material according to (6) above. (9) Among the adhesive regions where the fabric and the carbon fiber bundle group are adhered via the resin binder, in adjacent carbon fiber bundles, the adhesive regions are shifted in the fiber orientation direction of the carbon fibers, characterized in that the carbon fiber tape material according to any one of (6) to (8) above. (10) The adhesive region where the fabric and the carbon fiber bundle group are adhered via the resin binder is discretely formed in the direction orthogonal to the fiber orientation of the carbon fiber bundles in at least a part of the carbon fiber tape material, characterized in that the carbon fiber tape material according to (5) above. (11) The tensile load F [N] measured in the range of shear angle θ [°] from 0° to 45° using the picture frame method by the two-side gripping method does not have the maximum value of the tensile load F [N] between shear angles θ [°] from 0° to 1.0°, and the maximum value of the tensile load F [N] measured in the range of shear angle θ [°] from 0° to 45° is greater than 0.5 [N], and in the range of θ [°] from 0.1° to 1.0°, ΔF / Δθ is greater than 0.1 and less than 1.0, characterized in that the carbon fiber tape material according to any one of (1) to (10) above. (12) The form of the fabric is a cylindrical body or a bag-like body, characterized in that the carbon fiber tape material according to (1) to (11) above. (13) A reinforced fiber laminate using the carbon fiber tape material according to any one of (1) to (12) above. (14) A molded body using the reinforced fiber laminate according to (13) above.

Advantages of the Invention

[0015] The carbon fiber tape material of the present invention has good mold followability and resin impregnation properties, can improve productivity when manufacturing a reinforced fiber laminate by the fiber placement method, and can provide a molded body having high mechanical strength when impregnated with resin and molded.

Brief Description of the Drawings

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Embodiments for Carrying Out the Invention

[0017] A schematic view of the carbon fiber tape material according to the present invention is shown in FIG. 1.

[0018] The carbon fiber tape material 100 shown in Fig. 1 is composed of a plurality of carbon fiber bundles 101 integrated with each other by a fabric 103, and each carbon fiber bundle is arranged parallel (in parallel) to each other in the width direction to form a carbon fiber bundle group 102.

[0019] As the carbon fiber bundle used in the present invention, for example, a carbon fiber bundle that has been previously sized can also be used. By performing the sizing treatment, the bundling property of the carbon fiber bundle can be improved, and the generation of fluff can be suppressed. Further, the carbon fiber bundle used in the present invention may be a mixture of carbon fibers and organic fibers.

[0020] The number of filaments N (unit: K = 1,000) of the carbon fiber bundle is preferably 1K (1,000) or more and 60K (60,000) or less. When the number of single fibers of the carbon fiber bundle 101 is less than 1K, the yarn width of the carbon fiber bundle 101 is thin, and defects such as twisting are likely to occur. When the number of single fibers of the carbon fiber bundle 101 is more than 60K, the carbon fiber areal density of the carbon fiber bundle 101 becomes high, and when the carbon fiber bundle 101 is aligned and made into a base material by the fiber placement method, the carbon fiber areal density per layer becomes too high, so there is a risk of narrowing the allowable range of the orientation design.

[0021] The carbon fiber tape material 100 includes a plurality of carbon fiber bundles 101 and is integrated with the fabric 103, so that the number of carbon fiber filaments and the weight per unit length of the carbon fiber tape material can be increased. Further, when manufacturing a fiber-reinforced plastic by arranging and laminating the carbon fiber tape material by the fiber placement method, the arrangement and lamination time of the carbon fiber tape material required to obtain a desired fiber volume content can be shortened, and the productivity can be improved.

[0022] The fabric 103 is composed of one or more types of thermoplastic resins. Here, the thermoplastic resin refers to, in addition to thermoplastic resins such as polyamide resin, polyester resin, polyethylene terephthalate resin, polyvinyl formal resin, polyethersulfone resin, phenoxy resin, and polycarbonate resin, further, thermoplastic elastomers (polystyrene-based resin, polyolefin-based resin, polyurethane-based resin, polyester-based resin, polyamide-based resin, polybutadiene-based resin, polyisoprene-based resin, fluorine-based resin, and acrylonitrile-based, etc.), as well as copolymers, modified products, and resins obtained by blending two or more of these resins. These resins can be made into a fibrous form such as a woven fabric (woven fabric, knitted fabric) or a non-woven fabric, or into a film form to obtain the fabric 103. By partially melting such a fabric 103, it is integrated with the carbon fiber bundle group 102.

[0023] In the present invention, it is important that the fabric 103 has deformability. That is, in at least one direction of the fabric, it is important that the fabric elongation rate when a load of 80 mN / 50 mm is applied to the fabric is 5% to 100%, and more preferably 15% to 100%. By using a fabric with deformability, the deformability of the tape can be improved, and when directly attaching it to a mold by the fiber placement method, the carbon fiber tape can follow and conform to the mold shape. When the fabric elongation rate is less than 5%, the fabric does not have sufficient deformability, and the carbon fiber tape cannot follow and conform to the mold shape. When the fabric elongation rate is greater than 100%, the fabric is deformed by a slight external force, and it becomes difficult to accurately attach the fabric to the carbon fiber and integrate them. Here, the elongation rate of the fabric is obtained by the following formula in accordance with JIS L 1096 8.16.1.

[0024] E p =[(L 1 -L 0 ) / L 0 ×100 E p : Fabric elongation rate (%) L 0 : Fabric length between the original marks (mm) L1 : Fabric length at load application (mm) The method for measuring the fabric elongation rate is shown in Fig. 8. Fig. 8(a) shows the state of the fabric 803 before applying a constant load. Cut the fabric to the specified size, mark the specified mark 808 on the fabric, and measure the distance L 0 between the marks. After that, chuck the fabric with the clamp 807 as shown in Fig. 8(a). Then, apply a load. Fig. 8(b) shows the state of the fabric 803 after applying a constant load. As shown in Fig. 8(b), by measuring the distance L 1 between the marks after applying a constant load, the elongation rate can be calculated from the specified formula. When measuring the elongation rate of the fabric from the tape material in which the carbon fiber bundle and the fabric are integrated, after peeling the fabric from the tape material, measure it according to the above procedure.

[0025] The carbon fiber tape material of the present invention has an areal weight excluding the fabric of 120 g / m 2 to 400 g / m 2 is important. Among the carbon fiber tape materials, when the areal weight excluding the fabric is less than 120 g / m 2 , when arranging the carbon fiber tape material by the fiber placement method, the number of carbon fiber tape materials to be laminated to obtain a laminate with the desired areal weight increases, the time required for lamination increases, and it becomes a constraint in further improving productivity. On the other hand, among the carbon fiber tape materials, when the areal weight excluding the fabric is greater than 400 g / m 2 , the number of carbon fiber tape materials to be laminated to obtain a laminate with the desired areal weight becomes too small, and there is a risk that the degree of freedom in designing the fiber orientation will be narrowed. Such an areal weight is preferably 160 g / m 2 to 300 g / m 2 .

[0026] Also, it is desirable that the fabric 103 has regularity. In the present invention, "having regularity" means that a certain tissue form is continuously repeated in the longitudinal direction of the fabric (i.e., the longitudinal direction of the carbon fiber tape material). Examples of fabrics having regularity include knitted fabrics and woven fabrics. Knitted fabrics and woven fabrics have their tissue forms continuously repeated in the longitudinal direction, and the positions where the fibers are present are determined by the tissue. Therefore, it can be said that they are materials with little variation or deviation in the areal density as fabrics. On the other hand, an example of a fabric without regularity is a non-woven fabric (non-woven veil). Since a non-woven fabric is configured by randomly scattering short fibers and then adhering the fibers to each other, it is difficult to exhibit the above-described fabric elongation rate. Also, since its tissue form is not continuously repeated in the longitudinal direction, it is characterized by being prone to fiber orientation and variation or deviation in areal density.

[0027] As the tissue form of the fabric having regularity, woven tissues such as plain weave, twill weave, and crepe weave, warp knitting tissues such as denim, cord, atlas, lock knitting, inlay, satin, half, and tulle, weft knitting tissues, or combinations thereof can be used.

[0028] These fabrics having regularity maintain their form by knitting or weaving the fibers together. That is, compared to a non-woven fabric in which the fibers are adhered to each other and the relative positions are fixed, the positions of the knitted or woven fibers are not completely fixed and have a high degree of freedom. As a result, they have excellent deformability when a force is applied in the plane (plane direction) of the fabric.

[0029] The fabric 103 has an areal density greater than 2 g / m 2 and preferably less than or equal to 40 g / m 2 More preferably, it is greater than 4 g / m 2 and less than or equal to 20 g / m 2 The areal density of the fabric 103 is greater than 2 g / m 2In the following cases, the fabric of the cloth is likely to tear and it becomes difficult to obtain the desired deformability. Also, since the thickness of the cloth becomes thin, it becomes difficult to sufficiently secure the matrix resin flow path during impregnation. Furthermore, since the cloth is thin, the thickness of the interlayer reinforcing material in the molded body becomes thin, making it difficult to strengthen the interlayer of the laminated fiber bundles. On the other hand, when the basis weight of the cloth 103 is greater than 40 g / m 2 than, since the thickness of the cloth becomes thick, the thickness of the carbon fiber tape material increases, and the thickness of the reinforced fiber laminate using the carbon fiber tape material is likely to be greater than the desired product thickness, that is, it becomes difficult to make the reinforced fiber laminate using the carbon fiber tape material into a near-net shape of the desired molded body. Also, the molded body molded using this reinforced fiber laminate is likely to have a large thickness of the interlayer reinforcing material, making it difficult to increase the fiber content rate (Vf: %) in the molded body.

[0030] Also, the cloth 103 can be used not only for the purpose of improving the deformability of the tape, but also for the purpose of securing a matrix resin flow path during resin impregnation and for the purpose of strengthening the interlayer by using a resin of a material that exhibits high toughness.

[0031] It is preferable that a gap 106 is provided between the plurality of carbon fiber bundles 101 constituting the carbon fiber tape material 100. By having a gap 106 between the plurality of carbon fiber bundles 101 constituting the carbon fiber tape material 100, when arranged in one direction as a base material by the fiber placement method, it is easy to secure a flow path for the matrix resin. Also, even when a plurality of carbon fiber tape materials 100 are arranged in one direction without gaps as a base material by the fiber placement method, if a gap is provided between the plurality of carbon fiber bundles 101 fixed within one carbon fiber tape material 100, it becomes easy to secure the fluidity of the matrix resin during molding.

[0032] The gap 106 between carbon fiber bundles is preferably from 0.1 mm to 1 mm. When the gap 106 is less than 0.1 mm, the flow path of the matrix resin becomes small, so the time required for molding increases, which may lead to a decrease in productivity. When the gap 106 is greater than 1 mm, when the carbon fiber tape material is laminated by the fiber placement method to form a reinforced fiber laminate and molded, a part of the upper layer tape may fall into the gap between the lower layer carbon fiber bundles, and the straightness of the carbon fiber bundles may decrease. As a result, the compression characteristics of the obtained molded body may decrease.

[0033] The tape width of the carbon fiber tape material 100 is preferably from 2 mm to 2000 mm, and more preferably from 5 mm to 100 mm. When the tape width of the carbon fiber tape material 100 is less than 2 mm, it is necessary to arrange more carbon fiber tape materials in the fiber placement process, and the productivity is likely to decrease. When the tape width of the carbon fiber tape material 100 is greater than 2000 mm, the apparatus for manufacturing the tape becomes large, which easily leads to an increase in tape cost, which is not preferable.

[0034] The carbon fiber tape material 200 shown in FIG. 2 is a schematic perspective view of another carbon fiber tape material according to the present invention. In this carbon fiber tape material 200, a fabric 203 having regularity is located on at least one side of the carbon fiber bundle group 202, similar to the carbon fiber tape material shown in FIG. 1. However, the fabric 203 is integrated with the carbon fiber bundle group 202 via a resin binder 204 attached to at least one side of the carbon fiber bundle group 202 for the purpose of maintaining the form of each carbon fiber bundle 201. Other points have the same configuration as the carbon fiber tape material 100 shown in FIG. 1. The resin binder 204 may be in the form of particles or a non-woven fabric. Moreover, it is not limited to these shapes, and it may also be a film, a mesh, an emulsion, a coating, or an auxiliary thread wound around the carbon fiber bundle.

[0035] As the material of the resin binder, thermoplastic resins such as polyamide resin, polyester resin, polyethylene terephthalate resin, polyvinyl formal resin, polyethersulfone resin, phenoxy resin, and polycarbonate resin can be used. Additionally, phenolic resins, phenoxy resins, epoxy resins, and furthermore, thermoplastic elastomers such as polystyrene-based resins, polyolefin-based resins, polyurethane-based resins, polyester-based resins, polyamide-based resins, polybutadiene-based resins, polyisoprene-based resins, fluorine-based resins, and acrylonitrile-based resins, etc., as well as copolymers, modified products, and resins obtained by blending two or more of these resins can be used.

[0036] These resin binders can be used not only for the adhesion function of fixing the interface when forming a reinforced fiber laminate, but also for the purpose of ensuring the flow path of the matrix resin during resin impregnation and for strengthening the interface by using a resin material with high toughness.

[0037] As the fixing form of the carbon fiber bundle 201 by the resin binder 204, the resin binder 204 can be adhered and partially impregnated in a visible state on the surface of the carbon fiber bundle 201 to restrain a plurality of filaments contained in the carbon fiber bundle. Also, the resin binder 204 can be impregnated into the interior of the carbon fiber bundle 201 so as not to be visible from the surface, and a plurality of filaments contained in the carbon fiber bundle can be mutually restrained. In addition to this, the resin binder can be wound around the carbon fiber bundle 201, or the carbon fiber bundle 201 can be coated with the resin binder.

[0038] The amount of the resin binder required to fix the carbon fiber bundle 201 is preferably 25 wt% or less, more preferably 20 wt% or less, and even more preferably 15 wt% or less based on the weight of the carbon fiber bundle 201. When the amount of the resin binder exceeds 25 wt%, when the tape material is arranged and laminated by the fiber placement method to form a reinforced fiber laminate and molded, the viscosity of the matrix resin increases and the fluidity tends to decrease, so the productivity tends to decrease. In addition, since it takes a long time for the matrix resin to flow, the viscosity of the matrix resin further increases, and resin non-impregnated portions are likely to occur in the molded body, leading to deterioration of the mechanical properties of the molded body.

[0039] The softening point Ts (°C) of the fabric 203 is preferably higher than the softening point of the resin binder 204. Here, when the fabric 203 is composed of a plurality of types of thermoplastic resins, among the plurality of types of thermoplastic resins, the softening point of the thermoplastic resin with the lowest softening point is regarded as the softening point Ts (°C) of the fabric 203. At this time, by heating and pressing at a temperature higher than the softening point of the resin binder 204 and lower than the softening point of the fabric 203, the melted resin binder 204 can be used as an adhesive to integrate the fabric 203 and the carbon fiber bundle group 202. In this case, since the fabric 203 retains its tissue form without melting, a carbon fiber tape material 200 with excellent deformability can be obtained without impairing the deformability of the fabric 203.

[0040] Further, it is preferable that the resin binder 204 has a softening point (°C) higher than 40°C and lower than the softening point Ts (°C) of the fabric 203. By using such a resin binder, after the viscosity is reduced by heating and then cooled to return to room temperature, a plurality of filaments constituting the carbon fiber bundle are fixed to each other, and a certain form of the carbon fiber bundle can be more reliably maintained. When the form of the carbon fiber bundle is kept constant, when the carbon fiber tape material 200 is placed on the mold by the fiber placement method and pressure or tension is applied to the carbon fiber tape material 200, it is possible to suppress the collapse of the form of the carbon fiber bundle. As a result, the gap 206 provided between the carbon fiber bundles 201 can be held without being crushed, and the flow path of the matrix resin during molding can be more reliably ensured.

[0041] In this specification, the "softening point" refers to the temperature at which a resin material such as a fabric or a resin binder softens / melts when the temperature of the resin material becomes higher than that temperature. Specifically, when the resin material is a crystalline polymer, it refers to the melting point, and when the resin material is an amorphous polymer, it refers to the glass transition point.

[0042] FIG. 3 shows a schematic perspective view of yet another carbon fiber tape material 300 according to the present invention. In this carbon fiber tape material 300, similar to the embodiment of FIG. 2, a fabric 303 having regularity is disposed on at least one side (both sides in FIG. 3) of a carbon fiber bundle group 302 in which a plurality of carbon fiber bundles 301 are arranged in parallel. The fabric 303 is integrated with the carbon fiber bundle group 302 via a resin binder 304 attached to the surface of the carbon fiber bundle group 302 for the purpose of maintaining the form of each carbon fiber bundle 301. And in the embodiment shown in FIG. 3, among the resin binders 304 provided on the surface of the carbon fiber bundle group 302, only the resin binder 304 in the region surrounded by the adhesion region 305 is melted to contribute to the adhesion between the fabric 303 and the carbon fiber bundle group 302. The adhesion region 305 is formed discretely (intermittently) rather than continuously in the fiber orientation direction of the carbon fiber bundles 301 in at least a part of the carbon fiber tape material 300. Here, the "adhesion region" refers to a region where the fabric 303 and the carbon fiber bundle group 302 are adhered to each other via the resin binder 304. The fabric 303 and the carbon fiber bundle group 302 are integrated with each other by being adhered at at least a part of the adhesion region, and the form of the carbon fiber tape material can be maintained. The carbon fiber tape material 300 shown in FIG. 3 has the same configuration as the carbon fiber tape material 200 shown in FIG. 2 except for the above points.

[0043] In the present invention, it is preferable that the adhesion region 305 is formed discretely in the fiber orientation direction of the carbon fiber bundles 301 as described above. When the adhesion region 305 extends over the entire tape and the carbon fiber bundle group 302 and the fabric 303 are adhered over the entire surface of the tape, the position of the thermoplastic fibers constituting the fabric is completely fixed by the adhesion to the carbon fiber bundles, and the deformability originally possessed by the fabric decreases. In FIG. 3, since the adhesion regions 305 are discretely dispersed in the fiber orientation direction, leaving room for the fabric to move locally freely, it is possible to suppress the decrease in the deformability of the fabric due to adhesion.

[0044] Furthermore, a mode in which the adhesion regions are discretely formed in the fiber orientation direction of the carbon fiber bundles will be described in detail below. The carbon fiber tape material 400 shown in FIGS. 4(a) and 4(b) is a plan view of another carbon fiber tape material according to the present invention. In the embodiment of FIG. 4(a), the adhesion regions 405 where the fabric and the carbon fiber bundle group are adhered via a resin binder are discretely formed in the fiber orientation direction of the carbon fiber bundles 401 throughout the entire area of the carbon fiber tape material 400. In this embodiment, since the adhesion regions 405 are discretely formed throughout the entire area of the carbon fiber tape material 400, the fabric has a large margin for local free movement, and excellent tape deformability can be exhibited. In the embodiment of FIG. 4(b), among the carbon fiber bundle group 402, two carbon fiber bundles 401(a) and 401(b) located at both ends in the direction orthogonal to the fiber orientation direction of the carbon fiber bundle 401 are continuously adhered to the fabric 403 in the fiber orientation direction of the carbon fiber bundles, and the carbon fiber bundles 401(c), 401(d), and 401(e) located between the two carbon fiber bundles 401(a) and 401(b) are intermittently adhered to the fabric 403 in the fiber orientation direction of the carbon fiber bundles. In this embodiment, since the two carbon fiber bundles 401(a) and 401(b) located at both ends in the direction orthogonal to the fiber orientation direction of the carbon fiber bundles are continuously adhered to the fabric 403, it is possible to prevent the fabric 403 from being peeled off from the tape end, and both tape stability and tape deformability can be achieved. In the carbon fiber tape materials 400 shown in FIGS. 4(a) and 4(b), it is preferable that each adhesion region 405 is provided so as not to span a plurality of carbon fiber bundles.

[0045] The carbon fiber tape material 500 shown in Fig. 5(a) is a plan view of another carbon fiber tape material according to the present invention. The b-b cross section and c-c cross section of such a carbon fiber tape material 500 are shown in Fig. 5(b) and Fig. 5(c), respectively. Also in the present embodiment, the adhesion regions 505 where the fabric and the carbon fiber bundle group are adhered via a resin binder are discretely formed in the entire area of the carbon fiber tape material 500 in the fiber orientation direction of the carbon fiber bundles 501. Each adhesion region 505 is provided so as not to straddle a plurality of carbon fiber bundles. And in adjacent carbon fiber bundles (for example, 501(a) and 501(b)), the adhesion regions (for example, 505(a) and 505(b)) are displaced in the fiber orientation direction of the carbon fibers. In the present embodiment, since the adhesion regions provided in adjacent carbon fiber bundles are displaced in the fiber orientation direction of the carbon fibers, the relative positions of adjacent carbon fiber bundles are not fixed and can move independently. Therefore, when the fabric is deformed, the carbon fiber bundles can move independently following the movement of the portions of the fabric to which they are adhered.

[0046] In the present invention, the adhesion region may be provided as shown in Fig. 6(a). However, in the carbon fiber tape material 600 shown in Fig. 6(a), in adjacent carbon fiber bundles (for example, carbon fiber bundles 601(a) and 601(b)), the adhesion regions (for example, adhesion regions 605(a) and 605(b)) are not displaced in the fiber orientation direction of the carbon fibers. Therefore, the positions of adjacent carbon fiber bundles are fixed, making it difficult for each carbon fiber bundle to follow the movement of the portion of the fabric to which it is adhered and making it difficult to move independently. Thus, compared with the case where the adhesion regions in adjacent carbon fiber bundles are not displaced in the fiber orientation direction of the carbon fibers, the case where they are displaced is preferable because a tape with higher deformability can be obtained. Note that Fig. 6(a) is a plan view of the carbon fiber tape material 600, and Fig. 6(b) is a b-b cross-sectional view of the carbon fiber tape material 600.

[0047] And, as shown in FIG. 5, even when the bonding region 505 is provided with a substantial shift in the fiber orientation direction of the carbon fibers, it is more preferable to do as follows. That is, in any cross-section in the direction orthogonal to the fiber orientation direction of the carbon fibers, it is ensured that the bonding regions (e.g., 505(a) and 505(b)) do not simultaneously exist on adjacent carbon fiber bundles (e.g., 501(a) and 501(b)). In other words, in adjacent carbon fiber bundles (e.g., 501(a) and 501(b)), the bonding regions (e.g., 505(a) and 505(b)) are preferably provided so as to be shifted (as shown in FIG. 5(c)) rather than being partially overlapped in the fiber orientation direction of the carbon fibers (as shown in FIG. 5(b)). With such a configuration, the carbon fiber tape material can exhibit better deformability. Therefore, in the carbon fiber tape material 500, it is preferable that the portion having a cross-section as shown in FIG. 5(b) is within a range of 30% or less of all the cross-sections taken at regular intervals in the fiber orientation direction of the carbon fibers.

[0048] Furthermore, FIGS. 7(a) and (b) show a plan view of another carbon fiber tape material 700 according to the present invention. In FIGS. 3 to 6 above, a mode in which the bonding regions are discretely formed in the fiber orientation direction of the carbon fiber bundles is shown. However, in the carbon fiber tape material 700 shown in FIG. 7, the bonding regions 705 in which the fabric and the carbon fiber bundle group are bonded via a resin binder are discretely formed in the direction orthogonal to the fiber orientation direction of the carbon fiber bundles. Also with such a configuration, the relative positions of adjacent carbon fiber bundles are not fixed and can move independently, so that the carbon fiber tape material can exhibit good deformation.

[0049] The carbon fiber tape material according to the present invention having the above-described configuration can exhibit the following shear deformation performance. That is, the tensile load F [N] measured in the range of the shear angle θ [°] from 0° to 45° using the picture frame method by the two-side gripping method does not have the maximum value of the tensile load F [N] between the shear angle θ [°] from 0° to 1.0°, the maximum value of the tensile load F [N] measured in the range of the shear angle θ [°] from 0° to 45° is greater than 0.5 [N], and between θ [°] from 0.1° to 1.0°, ΔF / Δθ is greater than 0.1 and less than 1.0.

[0050] The picture frame method by the two-side gripping method, which is a method for evaluating the shear deformation performance, will be described. FIG. 9 shows a schematic diagram of the picture frame method by the two-side gripping method. One or more carbon fiber tape materials 900 having a length of 220 mm are arranged in parallel without gaps so that the sum of the total widths is 150 mm. After marking the gripping portions 902 so that the gripping interval is 200 mm, the carbon fiber tape material 900 is attached to the picture frame jig 904 so that the gripping portions 902 are 200 mm, the measurement angle α [°] is 90°, and the longitudinal direction of the carbon fiber tape is parallel to the two sides 903 of the picture frame that do not grip the carbon fiber tape material, and the two sides at both ends of the carbon fiber tape are gripped. After attaching the picture frame jig to a universal testing machine (not shown) so that the measurement angle α [°] is 90°, the picture frame jig is pulled in the vertical direction at a speed of 50 mm / min, and the tensile force F [N] and the measurement angle α at that time are measured. Then, the shear angle θ [°] calculated from the following formula and ΔF / Δθ between θ [°] from 0.1° to 1.0° are calculated.

[0051] θ [°]=90°−α [°] An example of the shear angle-tensile load graph when the picture frame method by the two-side gripping method is performed on the carbon fiber tape material according to the present invention is shown in FIG. 10. FIG. 10(a) is a shear angle-tensile load graph when the shear angle θ [°] is tested from 0 to 45, and FIG. 10(b) is an enlarged graph of the vicinity of the shear angle θ [°] from 0 to 1 of the same graph.

[0052] In the carbon fiber tape material according to the present invention, when tested with the shear angle θ [°] ranging from 0° to 45°, it is preferable that the tensile load F does not have a maximum value between the shear angle θ [°] of 0° and 1.0°. When the maximum value of the tensile load F [N] is between the shear angle θ [°] of 0° and 1.0°, it means that the carbon fiber tape material cannot maintain its form and collapses before the shear angle θ [°] reaches 1.0°. In this case, the value of ΔF / Δθ cannot be evaluated as the shear deformation performance of the carbon fiber tape material.

[0053] In the carbon fiber tape material according to the present invention, when the tensile load F does not have a maximum value between the shear angle θ [°] of 0° and 1.0°, it is preferable that ΔF / Δθ between the shear angle θ [°] of 0.1° and 1.0° is less than 1.0, more preferably less than 0.4, and even more preferably less than 0.2. When ΔF / Δθ is 1.0 or more, a large force is required when shearing and deforming the carbon fiber tape material, and good followability to the mold cannot be obtained when aligning and arranging it in the mold by the fiber placement method. On the other hand, ΔF / Δθ is preferably greater than 0.1. When ΔF / Δθ is 0.1 or less, the carbon fiber tape material undergoes large shear deformation with the application of a slight force, and the stability of the carbon fiber tape material is impaired.

[0054] In the carbon fiber tape material according to the present invention, when tested with the shear angle θ [°] ranging from 0° to 45°, it is preferable that the maximum value of the tensile load F is greater than 0.5 N, and more preferably greater than 1.0 N. When the maximum value of the tensile load F is 0.5 N or less when tested with the shear angle θ [°] ranging from 0° to 45°, the carbon fiber tape material cannot maintain its tape form, such as the carbon fiber bundle and the cloth material peeling off.

[0055] In the carbon fiber tape material according to the present invention, for example, as shown in FIGS. 11(a) and (b), it is preferable to arrange the fabric 1103 on both sides of the carbon fiber bundle group 1102 so that it becomes a cylindrical body (FIG. 11(a)) or a bag-shaped body (FIG. 11(b)) when viewed as a whole. That is, as shown in FIG. 11(a), two carbon fiber bundles 1101(a) and 1101(b) located at both ends in the direction orthogonal to the fiber orientation direction of the carbon fiber bundle 1101 are adhered to the fabric 1103 on both sides thereof, and it is preferable that a cylindrical closed system is formed by the carbon fiber bundles 1101(a) and 1101(b) at both ends and the fabric 1103 on both sides. By doing so, the inner three carbon fiber bundles 1101(c), 1101(d), and 1101(e) can be prevented from falling off. Also, for the same reason, as shown in FIG. 11(b), it is also preferable to arrange the fabric 1103 so as to enclose all the carbon fiber bundles 1101. By arranging the fabric on both sides of the carbon fiber bundle group in this way, it is possible to suppress the detachment of the carbon fiber bundles during the handling of the carbon fiber tape material, and the production stability of the carbon fiber tape material can be improved.

[0056] The carbon fiber tape material of the present invention is used for a reinforced fiber laminate. The reinforced fiber laminate is formed by arranging and laminating the carbon fiber tape material of the present invention and fixing at least a part of the layers therebetween to maintain the shape. By adopting such a configuration, the gaps between the carbon fiber bundles constituting the reinforced fiber laminate can be set and arranged at an arbitrary distance. As a result, the fluidity of the matrix resin during molding can be ensured, and the productivity can be improved, such as widening the types of resins to be injected and the width of the process window.

[0057] Also, it is preferable that the reinforced fiber laminate using the carbon fiber tape material is impregnated with a matrix resin to form a fiber-reinforced resin molded body. By adopting the above configuration, the obtained fiber-reinforced resin molded body can be completely impregnated with the resin up to the inside and can have high mechanical properties.

Example

[0058] The carbon fiber tape material according to the present invention will be described based on examples. Table 1 shows the conditions and results of the examples and comparative examples.

[0059] (Example 1) <Reinforcing fiber bundle> As the reinforcing fiber bundle, carbon fiber "Torayca" (registered trademark) T800SC manufactured by Toray Industries, Inc., which had been previously sized, and having 24,000 carbon fiber filaments (N = 24K) was used.

[0060] <Fabric> As the fabric, a regular knitted fabric (material: polyamide, basis weight: 8 g / m 2 ) knitted in a tulle-like pattern using a tricot machine was used.

[0061] <Measurement of elongation rate of fabric> The elongation rate of the fabric was measured as follows with reference to JIS L 1096 8.16.1. That is, it was cut into a width of 50 mm and a length of 300 mm so that the wale direction of the fabric was the longitudinal direction, and marks were made on the gripping portions so that the gripping interval was 200 mm. After fixing one end of the test piece with a clamp, a load of 80 mN / 50 mm was gently applied and the length between the marks after holding for 1 minute was measured. As a result of calculating the fabric elongation rate from the following formula, the elongation rate was 52%.

[0062] E p =[(L 1 -L 0 ) / L 0 ×100 E p : Fabric elongation rate (%) L 0 : Original fabric length between marks (mm) L 1 : Fabric length when load is applied (mm) <Carbon fiber tape material> Using a carbon fiber bundle manufacturing apparatus (not shown), one carbon fiber bundle was drawn out from a bobbin, the width was narrowed without slitting while adjusting the thickness, and then, heat-meltable binder particles (average particle size: 0.2 mm) with a softening point temperature of 80 °C were sprayed onto the surface of the carbon fiber bundle. After spraying so that the weight ratio of the binder particles was 5% (assuming the weight of the obtained carbon fiber bundle as 100%), melting and cooling were performed to obtain a carbon fiber bundle with a yarn width of 4.8 mm in which its form was fixed.

[0063] After aligning 10 carbon fiber bundles in parallel in the longitudinal direction, a knitted fabric (cloth) with a softening point temperature of 200 °C was placed on one side thereof, heated at 120 °C to melt the binder particles, and the knitted fabric and the carbon fiber bundles were partially adhered (for the carbon fiber bundles other than both ends, the binder particles were arranged in a staggered pattern as spherical bodies with a diameter of 4.5 mm, and for the two carbon fiber bundles at both ends, the binder particles were arranged over the entire surface) as shown in Fig. 4(b) through the binder particles to be integrated. By doing so, a carbon fiber tape material with a width of 50 mm, a basis weight excluding the cloth of 206 g / m 2 and each gap between the carbon fiber bundles of 0.2 mm was obtained.

[0064] <Deformability of carbon fiber tape material> As an evaluation of the deformability of the carbon fiber tape material, the picture frame method by the two-side gripping method was carried out. Three carbon fiber tape materials with a length of 220 mm and a width of 50 mm were arranged in parallel, and marks were made on the gripping parts so that the gripping interval was 200 mm. Then, the three carbon fiber tape materials arranged in parallel were attached to the picture frame jig shown in Fig. 9 so as to grip two sides such that the gripping part was 200 mm and the measurement angle α [°] was 90 °, and the measurement was carried out. As a result, for the tensile load F [N] in the range where the shear angle θ [°] was from 0 ° to 45 °, the maximum value was greater than 0.5 [N], and the maximum value did not exist between the shear angle θ [°] of 0 ° and 1.0 °. And ΔF / Δθ = 0.3, and it was confirmed that the carbon fiber tape material showed good deformability with respect to the in-plane shear force.

[0065] <Reinforced fiber laminate> Using a fiber placement device (not shown), on a gantry, the carbon fiber tape materials obtained as described above were arranged side by side in one direction with a gap of 0.7 mm provided between each carbon fiber tape material, and the arrangement was repeated while cutting the carbon fiber tape materials to form a square shape of 300 mm × 300 mm to produce a sheet base material. Adjacent carbon fiber tape materials were overlapped by 1 mm of adjacent knitted fabrics, and the overlapped portions were heated at 200 °C to be adhesively integrated to produce a sheet base material.

[0066] The obtained sheet base material was placed in a pyramid (tetrahedron) - shaped mold (bottom surface: an equilateral triangle with a side length of 14 cm, height: 7 cm). After applying tension to the sheet base material and lowering the upper mold for press - shaping, the lower mold was heated at 120 °C for 10 minutes. As a result, the sheet base material showed good formability without large wrinkles. After sequentially shaping the sheet base material layer by layer in the pyramid - shaped mold in the same procedure, the upper mold was closed and then the lower mold was heated at 120 °C for 10 minutes. As a result, a good reinforced fiber laminate without large wrinkles was obtained.

[0067] <Formed body> The obtained reinforced fiber laminate was placed in the aforementioned pyramid - shaped lower mold, vacuum - bagged using a bag film, and then the mold was placed in an oven at an ambient temperature of 100 °C. Then, a matrix resin (epoxy resin) was injected and cured in an atmosphere of 180 °C. As a result, a good formed body without resin - non - impregnated parts was obtained.

[0068] (Example 2) Carbon fiber tapes were obtained in the same manner as in Example 1 except for the following points. · As the fabric, a regular knitted fabric (material: polyamide, basis weight: 10 g / m 2 ) knitted in a chain + half - stitch pattern using a tricot machine was used.

[0069] <Measurement of fabric elongation rate> As a result of measuring the elongation rate in the same method as in Example 1, the elongation rate in the wale direction was 35%.

[0070] <Deformability of Carbon Fiber Tape Material> As a result of performing the picture frame method by the two-side gripping method in the same manner as in Example 1, the tensile load F [N] in the range where the shear angle θ [°] is from 0° to 45° has a maximum value greater than 0.5 [N], and the maximum value does not exist between the shear angle θ [°] of 0° and 1.0°. And ΔF / Δθ = 0.37, and it was confirmed that the carbon fiber tape material exhibits good deformability with respect to the in-plane shear force.

[0071] <Reinforced Fiber Laminate> As a result of performing in the same manner as in Example 1, a good reinforced fiber laminate was obtained without the sheet base material being wrinkled or creased. <Molded Body> As a result of performing in the same manner as in Example 1, a good molded body without resin-impregnated portions was obtained.

[0072] (Example 3) A carbon fiber tape was obtained in the same manner as in Example 1 except for the following points. · In the same manner as in Example 1, after obtaining a carbon fiber bundle with a fixed form and a yarn width of 3.5 mm, 10 carbon fiber bundles were aligned parallel in the longitudinal direction, and each gap between the carbon fiber bundles was adjusted to approximately 0.3 mm, and the width in the finally obtained carbon fiber tape material was 38 mm, and the tape basis weight excluding the fabric was 271 g / m 2 was made to be. · The woven fabric and the carbon fiber bundle were integrally bonded by partial adhesion (the binder particles were arranged in a staggered pattern as spherical bodies with a diameter of 4.5 mm) as shown in Fig. 4(a) via the binder particles.

[0073] <Deformability of Carbon Fiber Tape Material> As a result of performing the picture frame method by the two-side gripping method in the same manner as in Example 1, the tensile load F [N] in the range where the shear angle θ [°] is from 0° to 45° has a maximum value greater than 0.5 [N], and the maximum value does not exist between the shear angle θ [°] of 0° and 1.0°. And ΔF / Δθ = 0.17, and it was confirmed that the carbon fiber tape material exhibits good deformability with respect to the in-plane shear force.

[0074] <Reinforced fiber laminate> As a result of carrying out in the same manner as in Example 1, a good reinforced fiber laminate was obtained without the occurrence of wrinkles or creases in the sheet base material. <Formed body> As a result of carrying out in the same manner as in Example 1, a good formed body without resin non-impregnated portions was obtained.

[0075] (Example 4) A carbon fiber tape was obtained in the same manner as in Example 1, except for the following points. · After obtaining a carbon fiber bundle having a yarn width of 7.0 mm with a fixed form in the same manner as in Example 1, five carbon fiber bundles were aligned in parallel in the longitudinal direction, and each gap between the carbon fiber bundles was adjusted to approximately 0.7 mm, and the width in the finally obtained carbon fiber tape material was 38 mm, and the tape basis weight excluding the fabric was 135 g / m 2 was made to be. · The woven fabric and the carbon fiber bundles were discretely partially adhered (in a 5 mm width portion from the center in the longitudinal direction continuously adhered in each carbon fiber bundle (width 7 mm)) in a direction orthogonal to the fiber orientation of the carbon fiber bundles through binder particles as shown in Fig. 7(a) and integrated.

[0076] <Deformability of carbon fiber tape material> As a result of carrying out the picture frame method by the two-side gripping method in the same manner as in Example 1, the tensile load F [N] in the range where the shear angle θ [°] is from 0° to 45° has a maximum value larger than 0.5 [N], and the maximum value does not exist between the shear angle θ [°] of 0° and 1.0°. And ΔF / Δθ = 0.33, and it was confirmed that the carbon fiber tape material exhibits good deformability with respect to the in-plane shear force.

[0077] <Reinforced fiber laminate> As a result of carrying out in the same manner as in Example 1, a good reinforced fiber laminate was obtained without the occurrence of wrinkles or creases in the sheet base material.

[0078] <Formed body> As a result of carrying out in the same manner as in Example 1, a good formed body without resin non-impregnated portions was obtained.

[0079] (Example 5) A carbon fiber tape was obtained in the same manner as in Example 1, except for the following points. · As the fabric, a non-woven fabric manufactured by Spunfab (material: polyamide, basis weight: 6 g / m 2 ) was used. · After obtaining carbon fiber bundles with a yarn width of 3.5 mm with a fixed form in the same manner as in Example 1, 10 carbon fiber bundles were aligned parallel in the longitudinal direction, and each gap between the carbon fiber bundles was adjusted to 0.3 mm, and the width in the finally obtained carbon fiber tape material was 38 mm, and the tape basis weight excluding the fabric was 271 g / m 2 was achieved. · The non-woven fabric and the carbon fiber bundles were integrally bonded by partial adhesion (the binder particles were arranged in a zigzag pattern as spherical bodies with a diameter of 4.5 mm) as shown in Fig. 4(a) through the binder particles.

[0080] <Measurement of the elongation rate of the fabric> As a result of measuring the elongation rate in the same manner as in Example 1, the elongation rate in the warp direction was 10%, and good deformability was obtained.

[0081] <Deformability of the carbon fiber tape material> As a result of performing the picture frame method by the two-side gripping method in the same manner as in Example 1, the tensile load F [N] in the range where the shear angle θ [°] is from 0° to 45° had a maximum value greater than 0.5 [N], and the maximum value did not exist between the shear angle θ [°] of 0° and 1.0°. And ΔF / Δθ = 0.23, and it was confirmed that the carbon fiber tape material exhibited good deformability against in-plane shear force.

[0082] <Reinforced fiber laminate> As a result of performing in the same manner as in Example 1, a good reinforced fiber laminate was obtained without wrinkles or creases in the sheet base material.

[0083] <Molded body> As a result of performing in the same manner as in Example 1, a good molded body without resin-impregnated parts was obtained.

[0084] (Comparative Example 1) A carbon fiber tape was obtained in the same manner as in Example 1 except for the following points. · As the fabric, a non-woven fabric manufactured by Spunfab (material: polyamide, softening point temperature: 130 °C, basis weight: 10 g / m 2 ) was used. · After aligning 10 carbon fiber bundles without adhered binder particles in parallel in the longitudinal direction, a non-woven fabric with a softening point temperature of 130 °C was placed on one side thereof, and the non-woven fabric was melted by heating at 130 °C to integrally bond the non-woven fabric and the carbon fiber bundles over the entire surface. By doing so, a carbon fiber tape material having a width of 50 mm, a tape basis weight excluding the fabric of 206 g / m 2 , and each gap between the carbon fiber bundles of 0.2 mm was obtained.

[0085] <Measurement of elongation rate of fabric> As a result of measuring the elongation rate in the same manner as in Example 1, the elongation rate in the weft direction was 3%, and good deformability was not obtained.

[0086] <Deformability of carbon fiber tape material> As a result of performing the picture frame method by the two-side gripping method in the same manner as in Example 1, the tensile load F [N] in the range where the shear angle θ [°] is from 0° to 45° had a maximum value larger than 0.5 [N], and the maximum value did not exist between the shear angle θ [°] of 0° and 1.0°. And ΔF / Δθ = 1.2, and it was confirmed that the carbon fiber tape material did not show good deformability with respect to the in-plane shear force.

[0087] <Reinforcing fiber laminate> As a result of performing in the same manner as in Example 1, wrinkles and creases were observed on the sheet base material, and a good reinforcing fiber laminate was not obtained.

[0088] <Molded body> As a result of performing in the same manner as in Example 1, a molded body having a resin non-impregnated portion at the location where wrinkles occurred was obtained.

[0089]

Table 1

Industrial Applicability

[0090] The carbon fiber tape material of the present invention and the reinforced fiber laminate using the same are excellent in the impregnation property of the matrix resin. Therefore, the molded body obtained using such a reinforced fiber laminate is particularly suitable for use in large members for aircraft, automobiles, ships, etc., and members for general industrial applications such as wind turbine blades.

Explanation of Symbols

[0091] 100, 200, 300, 400, 500, 900, 1100 Carbon fiber tape material 101, 201, 301, 401, 501, 601, 1101 Carbon fiber bundle 102, 202, 302, 402, 1102 Carbon fiber bundle group 103, 203, 303, 403, 503, 603, 703, 803, 1103 Fabric 106, 206, 306 Gap 204, 304, 1104 Resin binder 305, 405, 505, 605, 705, 1105 Adhesive area 807 Clamp 808 Mark 902 Gripping part 903 Two sides not gripping the carbon fiber tape material 904 Picture frame jig

Claims

1. A carbon fiber tape material in which a carbon fiber bundle group with a plurality of carbon fiber bundles arranged in parallel with the fiber orientation direction and a fabric are integrated, characterized in that the following (a) to (e) are satisfied. (a) The fabric has regularity and is composed of one or more types of thermoplastic resins (b) Among the carbon fiber tape materials, the basis weight excluding the fabric is between 120 g / m ２ and 400 g / m ２ inclusive (c) In at least one direction of the fabric, the fabric elongation rate E ｐ (%) when a load of 80 mN / 50 mm is applied to the fabric is 5% to 100% E ｐ = [(L １ - L ０ ) / L ０ × 100 E ｐ : Elongation rate of cloth (%) L ０ : Fabric length between original marks (mm) L １ : Fabric length at the time of load application (mm) (d) The carbon fiber bundle group and the fabric are integrally bonded by adhesion via a particulate resin binder attached to at least one side of the carbon fiber bundle group. (e) The softening point of the fabric is higher than the softening point of the resin binder.

2. The carbon fiber tape material according to claim 1, characterized in that a gap of 0.1 mm to 1 mm is provided between the carbon fiber bundles.

3. The carbon fiber tape material according to claim 1 or 2, characterized in that the tape width of the carbon fiber tape material is 2 mm to 2000 mm.

4. The carbon fiber tape material according to any one of claims 1 to 3, characterized in that the adhesion region where the fabric and the carbon fiber bundle group are adhered via the resin binder is discretely formed in the fiber orientation direction of the carbon fiber bundles in at least a part of the carbon fiber tape material.

5. The carbon fiber tape material according to claim 4, characterized in that the adhesion region where the fabric and the carbon fiber bundle group are adhered via the resin binder is discretely formed in the fiber orientation direction of the carbon fiber bundles over the entire area of the carbon fiber tape material.

6. Among the carbon fiber bundle group, two carbon fiber bundles located at both ends in the direction orthogonal to the fiber orientation direction of the carbon fiber bundles are continuously adhered to the fabric in the fiber orientation direction of the carbon fiber bundles, and other carbon fiber bundles located between the two carbon fiber bundles are intermittently adhered to the fabric in the fiber orientation direction of the carbon fiber bundles. The carbon fiber tape material according to claim 4.

7. The carbon fiber tape material according to any one of claims 4 to 6, characterized in that in the adjacent carbon fiber bundles among the adhesion regions where the fabric and the carbon fiber bundle group are adhered via the resin binder, the adhesion regions are shifted in the fiber orientation direction of the carbon fibers.

8. The adhesive region where the fabric and the carbon fiber bundle group are adhered via the resin binder is discretely formed in at least a part of the carbon fiber tape material in a direction orthogonal to the fiber orientation of the carbon fiber bundles. The carbon fiber tape material according to any one of claims 1 to 3, characterized in that.

9. The tensile load F [N] measured in the range of shear angle θ [°] from 0° to 45° using the picture frame method by the two-side gripping method does not have the maximum value of the tensile load F [N] between shear angle θ [°] from 0° to 1.0°, and the maximum value of the tensile load F [N] measured in the range of shear angle θ [°] from 0° to 45° is greater than 0.5 [N], and, when θ [°] is between 0.1° and 1.0°, ΔF / Δθ is greater than 0.1 and less than 1.

0. The carbon fiber tape material according to any one of claims 1 to 8, characterized in that.

10. The carbon fiber tape material according to any one of claims 1 to 9, characterized in that the form of the fabric is a cylindrical body or a bag-shaped body.

11. A reinforced fiber laminate using the carbon fiber tape material according to any one of claims 1 to 10.

12. A molded body using the reinforced fiber laminate according to claim 11.

Images