JP2020165286A - Structural material - Google Patents

Abstract

To provide a structural material having both rigidity and lightness.SOLUTION: The structural material 1 in resin has at least an upper surface configuration part 11 and a lower surface configuration part 12. The structural material 1 comprises unidirectional carbon fiber reinforcement resin sheets 11b and 12b in which the upper surface configuration part 11 and the lower surface configuration part 12 are at 0° ± 20° of orientation direction of a reinforced fiber relative to a longitudinal direction of the structural material. In addition, the structural material 1 may comprise support parts 13 and 14 for connecting the upper surface configuration part 11 and the lower surface configuration part 12 and this support part 13 and 14 may comprise a unidirectional carbon fiber reinforcement resin sheet 13b, 13c, 14b and 14c.SELECTED DRAWING: Figure 1

Description

The present invention relates to a structural material useful for, for example, applications of buildings or civil engineering structures, applications of transportation equipment, and various other applications, and has both rigidity and lightness.

As a building material for constructing a building, a steel building material having excellent rigidity is generally used. However, steel building materials are heavy and require excessive labor to transport and install them. Therefore, it has been proposed to use an aluminum material, which is lighter than steel, as a building material. For example, Patent Document 1 describes a carbon fiber reinforced aluminum beam structural material in which carbon fibers are adhered and laminated on one surface of an extruded aluminum profile. Then, it is explained that the bending resistance of the aluminum beam structural material is improved by adhering and laminating such carbon fibers.

On the other hand, when a building is damaged or deteriorated, a method of reinforcing the part with a fiber sheet has also been proposed. For example, Patent Document 2 proposes to use a fiber sheet made of a specific woven or knitted material for reinforcing a building. Then, it is explained that the workability and work efficiency at the time of reinforcement construction are improved by using the fiber sheet made of this specific woven or knitted material for reinforcing the building.

JP-A-10-54107 JP-A-2018-172823

According to the study by the present inventors, a building material in which an aluminum material and carbon fiber are combined as described in Patent Document 1 may generate electricity when water droplets adhere to it, causing electrolytic corrosion and reducing its rigidity. It turned out that there was. In addition, a building material that is simply a combination of aluminum material and carbon fiber may not be able to sufficiently balance the rigidity and lightness of the building material even if electrolytic corrosion does not occur so much. I also found that there was.

On the other hand, the reinforcing method as described in Patent Document 2 is a method of reinforcing the portion when the building is damaged or deteriorated, and concrete is mentioned as a target for reinforcement. Therefore, in Patent Document 2, the point of achieving both rigidity and lightness of the building material itself is not examined at all.

As mentioned earlier, building materials are required to have sufficient rigidity, but steel building materials are heavy and require excessive labor for transportation and installation. For example, prefabricated buildings are often assembled by a small number of workers. In this case, if a heavy building material is transported and installed by one person, there is a risk that the building being assembled may be damaged at that time. Therefore, when transporting and installing heavy building materials, two or more workers may be required for safe transport and installation.

Therefore, the present inventors considered that if the rigidity of structural materials such as building materials is reduced without significantly reducing the rigidity, even one person can safely transport and install the material, and the work efficiency will be significantly improved.

Furthermore, the present inventors have considered that it is also important to achieve both rigidity and lightness in various structural materials other than building materials. For example, with the recent demand for weight reduction of vehicle members, various resin vehicle members have been proposed in place of the conventional steel vehicle members. Such a resin-made vehicle member is excellent in terms of weight reduction, but it is also required that the member itself has sufficient rigidity.

That is, an object of the present invention is to provide a structural material having both rigidity and lightness.

As a result of diligent studies to achieve the above object, the present inventors have conducted a unidirectional carbon fiber reinforced resin in which the orientation direction of the reinforcing fibers is within 0 ° ± 20 ° with respect to the longitudinal direction of the structural material at least on both the upper and lower surfaces. We have found that a resin-made structural material using a sheet is very useful, and have completed the present invention. That is, the present invention is specified by the following matters.

[1] A structural material made of resin having at least a top surface component and a bottom surface component.
The upper surface component and the lower surface component include a unidirectional carbon fiber reinforced resin sheet in which the orientation direction of the reinforcing fibers is within 0 ° ± 20 ° with respect to the longitudinal direction of the structural material.
The thickness of the unidirectional carbon fiber reinforced resin sheet with respect to the thickness of the entire upper surface component and / or the thickness of the unidirectional carbon fiber reinforced resin sheet with respect to the thickness of the entire lower surface component is 35%. A structural material characterized by the above.

[2] The thickness of the unidirectional carbon fiber reinforced resin sheet with respect to the thickness of the entire upper surface component and / or the thickness of the unidirectional carbon fiber reinforced resin sheet with respect to the thickness of the entire lower surface component. , 50% or more of the structural material according to [1].

[3] The structural material according to [1] or [2], which has a support portion for connecting the upper surface constituent portion and the lower surface constituent portion.

[4] The structural material according to [3], wherein the support portion includes a unidirectional fiber reinforced resin sheet.

[5] The structural material according to [4], wherein the thickness of the unidirectional fiber reinforced resin sheet with respect to the thickness of the entire support portion is 50% or more.

[6] The structural material according to any one of [1] to [5], wherein the cross section of the structural material is any one of a hollow box shape, a solid box shape, and an H shape.

[7] The structural material according to any one of [1] to [6], which is a building material.

[8] The structural material according to [7], which is a building material for a bathroom.

[9] The structural material according to any one of [1] to [6], which is a vehicle member.

Since the structural material of the present invention is made of resin, it is much lighter than the conventional structural material made of steel, and is less likely to cause rust or corrosion, and is suitable for use in a place with high humidity. Further, at least the upper surface component and the lower surface component are 35% or more of the unidirectional carbon fiber reinforced resin sheet in which the orientation direction of the reinforcing fibers is within 0 ° ± 20 ° with respect to the longitudinal direction of the structural material. Since it is included in the thickness of, it has excellent rigidity. As a result, according to the present invention, it is possible to provide a structural material having both rigidity and lightness.

In the present invention, the "resin-made structural material" means that the structural material composed of the fiber-reinforced resin material is also included. That is, the structural material of the present invention may contain a resin, reinforcing fibers, and, if necessary, other optional components or arbitrary structural materials.

(A) is a schematic perspective view showing one embodiment of the structural material of the present invention, and (B) is a schematic enlarged sectional view thereof. (A) is a schematic perspective view showing another embodiment of the structural material of the present invention, and (B) is a schematic enlarged sectional view thereof. (A) is a schematic perspective view showing another embodiment of the structural material of the present invention, and (B) is a schematic enlarged sectional view thereof.

<Structural material>
FIG. 1A is a schematic perspective view showing an embodiment of the structural material of the present invention, and FIG. 1B is a schematic enlarged sectional view thereof. As shown in FIG. 1, the structural material of the present invention is a resin structural material 1 having at least an upper surface constituent portion 11 and a lower surface constituent portion 12. The upper surface constituent portion 11 includes a unidirectional carbon fiber reinforced resin sheet 11b on the outside thereof, and the lower surface constituent portion 12 includes a unidirectional carbon fiber reinforced resin sheet 12b on the outer side thereof. In these unidirectional carbon fiber reinforced resin sheets 11b and 12b, the orientation direction of the reinforcing fibers is within 0 ° ± 20 ° with respect to the longitudinal direction of the structural material 1. The rigidity of the structural material 1 is improved by the unidirectional carbon fiber reinforced resin sheets 11b and 12b. The upper surface constituent portion 11 of the structural material 1 is a portion forming a flat surface which is the upper surface of the structural material 1, and the lower surface constituent portion 12 is a portion which constitutes a flat surface which is the lower surface of the structural material 1. ..

The structural material 1 shown in FIG. 1 is a long structural material (hereinafter referred to as “hollow box type structural material”) having a hollow box-shaped cross section (hollow square pillar shape). Then, in the hollow box type structural material 1, the upper surface constituent portion 11 constitutes the upper side portion of the hollow box shape, and the lower surface constituent portion 12 constitutes the lower side portion of the hollow box shape. The hollow box-shaped structural member 1 shown in FIG. 1 has a substantially square hollow box-shaped cross section (hollow square shape), but may be, for example, a horizontally long or vertically long rectangle.

In FIG. 1, the upper surface constituent portion 11 has a structure in which a unidirectional carbon fiber reinforced resin sheet 11b is laminated on the upper side of the upper surface constituent base material portion 11a, and the lower surface constituent portion 12 is a lower surface constituent base material portion 12a. It has a structure in which a unidirectional carbon fiber reinforced resin sheet 12b is laminated on the lower side. As shown in FIG. 1, in the hollow box type structural material 1, an example in which the unidirectional carbon fiber reinforced resin sheet is arranged outside the upper surface constituent portion 11 and the lower surface constituent portion 12 is shown. Is not limited to this. In the structural material of the present invention, the unidirectional carbon fiber reinforced resin sheet may be arranged inside the upper surface constituent portion 11 and the lower surface constituent portion 12. From the viewpoint of further improving the rigidity, the unidirectional carbon fiber reinforced resin sheet is preferably arranged on the outside of at least one of the upper surface constituent portion 11 and the lower surface constituent portion 12, and as shown in FIG. 1, the upper surface constituent portion It is more preferable that the components 11 and the lower surface component 12 are arranged outside, and it is particularly preferable that the surface component 11 and the lower surface component 12 are arranged outside and inside both of the lower surface component 12.

The hollow box type structural member 1 shown in FIG. 1 further has support portions 13 and 14 for connecting the upper surface constituent portion 11 and the lower surface constituent portion 12. The right support portion 13 constitutes a hollow box-shaped right side portion, and the left support portion 14 constitutes a hollow box-shaped left side portion. The right side support portion 13 includes a unidirectional carbon fiber reinforced resin sheet 13b on the outside of the support base material portion 13a and a unidirectional carbon fiber reinforced resin sheet 13c on the inside. The left side support portion 14 includes a unidirectional carbon fiber reinforced resin sheet 14b on the outside of the support base material portion 14a and a unidirectional carbon fiber reinforced resin sheet 14c on the inside. The hollow box type structural material 1 tends to be able to prevent buckling deformation by the unidirectional carbon fiber reinforced resin sheets 13b, 13c, 14b and 14c.

The hollow box type structural material 1 shown in FIG. 1 contains unidirectional carbon fiber reinforced resin sheets 13b, 13c, 14b, 14c on the outside and inside of the supporting base material portions 13a and 14a. Is not limited to this. In the structural material of the present invention, for example, a unidirectional carbon fiber reinforced resin sheet may be contained only on one of the outer side and the inner side of the support base material portions 13a and 14a, and on both sides of the support base material portions 13a and 14a. It does not have to contain a unidirectional carbon fiber reinforced resin sheet.

The hollow box-type structural material 1 shown in FIG. 1 has a hollow box-shaped cross section (hollow square pillar shape), but the present invention is not limited thereto. The structural material of the present invention may have, for example, a solid box shape (a square pillar shape having no space inside). In that case as well, the upper surface constituent portion and the upper surface constituent portion may contain the unidirectional carbon fiber reinforced resin sheet, and the right side surface constituent portion and the left side surface constituent portion may include the unidirectional carbon fiber reinforced resin sheet as desired. It may be included.

FIG. 2A is a schematic perspective view showing another embodiment of the structural material of the present invention, and FIG. 2B is a schematic enlarged sectional view thereof. The structural material 2 of this embodiment is also a resin structural material having at least an upper surface constituent portion 21 and a lower surface constituent portion 22. The upper surface component 21 includes a unidirectional carbon fiber reinforced resin sheet 21b, and the lower surface component 22 includes a unidirectional carbon fiber reinforced resin sheet 22b. In these unidirectional carbon fiber reinforced resin sheets 21b and 22b, the orientation direction of the reinforcing fibers is within 0 ° ± 20 ° with respect to the longitudinal direction of the structural material 2. The rigidity of the structural material 2 is improved by the unidirectional carbon fiber reinforced resin sheets 21a and 21b.

The structural material 2 shown in FIG. 2 is a long structural material (hereinafter referred to as “H-type structural material”) having an H-shaped cross section (corresponding to the shape of H-shaped steel). In the H-shaped structural material 2, the upper surface constituent portion 21 constitutes the upper side portion of the H-shaped shape, and the lower surface constituent portion 22 constitutes the lower side portion of the H-shaped shape.

In FIG. 2, the upper surface constituent portion 21 has a configuration in which a unidirectional carbon fiber reinforced resin sheet 21b is laminated on the upper side of the upper surface constituent base material portion 21a, and the lower surface constituent portion 22 is a lower surface constituent base material portion 22a. It has a structure in which a unidirectional carbon fiber reinforced resin sheet 22b is laminated on the lower side.

The H-type structural member 2 shown in FIG. 2 further has a support portion 23 for connecting the upper surface constituent portion 21 and the lower surface constituent portion 22. The support portion 23 is a portion connected to the center of the upper surface constituent portion 21 and the lower surface constituent portion 22. The support portion 23 includes a unidirectional carbon fiber reinforced resin sheet 23b on the right side of the support base material portion 23a, and also includes a unidirectional carbon fiber reinforced resin sheet 23c on the left side thereof. The H-type structural material 2 tends to be able to prevent buckling deformation by the unidirectional carbon fiber reinforced resin sheets 23b and 23c.

The H-type structural material 2 shown in FIG. 2 includes unidirectional carbon fiber reinforced resin sheets 23b and 23c on both sides of the supporting base material portion 22a, but the present invention is not limited thereto. For example, the structural material of the present invention may contain a unidirectional carbon fiber reinforced resin sheet only on one side of the supporting base material portion 22a, and both sides of the supporting base material portion 22a may contain a unidirectional carbon fiber reinforced resin sheet. Does not have to be included.

FIG. 3A is a schematic perspective view showing another embodiment of the structural material of the present invention, and FIG. 3B is a schematic enlarged sectional view thereof. The structural material 3 of this embodiment is also a resin structural material having at least an upper surface constituent portion 31 and a lower surface constituent portion 32. The upper surface constituent portion 31 includes a unidirectional carbon fiber reinforced resin sheet 31a, and the lower surface constituent portion 32 includes a unidirectional carbon fiber reinforced resin sheet 32a. In these unidirectional carbon fiber reinforced resin sheets 31a and 32a, the orientation direction of the reinforcing fibers is within 0 ° ± 20 ° with respect to the longitudinal direction of the structural material 3. The rigidity of the structural material 3 is improved by the unidirectional carbon fiber reinforced resin sheets 31a and 32a.

The structural material 3 shown in FIG. 3 is an H-type structural material similar to the structural material 2 shown in FIG. 2, the upper surface constituent portion 31 constitutes an H-shaped upper side portion, and the lower surface constituent portion 32 is H. It constitutes the lower side of the mold shape. Further, similarly to the structural member 2 shown in FIG. 2, it has a support portion 33 for connecting the upper surface constituent portion 31 and the lower surface constituent portion 32. The support portion 33 is a portion connected to the center of the upper surface constituent portion 31 and the lower surface constituent portion 32.

The structural material 3 shown in FIG. 3 is different from the structural material 2 shown in FIG. 2 in that the upper surface constituent portion 31, the lower surface constituent portion 32, and the support portion 33 are all made of a fiber reinforced resin sheet. Specifically, the upper surface constituent portion 31 is composed of a unidirectional carbon fiber reinforced resin sheet 31a and fiber reinforced resin sheets 31b and 31c, and the lower surface constituent portion 32 is composed of a unidirectional carbon fiber reinforced resin sheet 32a and a fiber reinforced resin. It is composed of sheets 32b and 32c, and the support portion 33 is composed of fiber reinforced resin sheets 33b and 33c. The unidirectional carbon fiber reinforced resin sheets 31a and 32a are sheets laminated in a plane on the upper and lower surfaces thereof, and are sheets that form a part of the upper surface constituent portion 31 and the lower surface constituent portion 32 and face the upper and lower surfaces. is there. On the other hand, the fiber reinforced resin sheets 31b, 32b and 33b, and the fiber reinforced resin sheets 31c, 32c and 33c are one sheet bent in a U shape, respectively, and both ends (31b and 31c) of the respective sheets. , 32b and 32c) form a part of the upper surface constituent portion 31 and the lower surface constituent portion 32, and the central portion (33b and 33c) of each sheet constitutes the support portion 33. Such an H-type structural material 3 is preferable because it has excellent rigidity and tends to prevent buckling deformation. The fiber-reinforced resin sheets 31b, 32b and 33b in FIG. 3 and the fiber-reinforced resin sheets 31c, 32c and 33c may be unidirectional fiber-reinforced resin sheets, or short fibers are blended in a random direction. It may be a fiber-reinforced resin sheet or a fiber-reinforced resin sheet in which a woven fiber is impregnated with a resin.

Although the embodiment of the structural material in which the cross section of the structural material is any one of a hollow box shape, a solid box shape, and an H shape has been described above, the present invention is not limited thereto. The shape of the structural material of the present invention can be appropriately changed as desired. Other shapes include, for example, a hat-shaped shape. The hat-shaped shape is a shape in which the cross section of the structural material is a hat-shaped shape and corresponds to the shape of the hat-shaped steel.

The unidirectional carbon fiber reinforced resin sheets 11b, 21b and 31a of the upper surface components 11, 21 and 31 shown in FIGS. 1 to 3 and the unidirectional carbon fiber reinforced resin sheets 12b of the lower surface components 12, 22 and 32. , 22b and 32a (that is, unidirectional carbon fiber reinforced resin sheets located on the upper and lower surfaces), the orientation direction of the reinforcing fibers is within 0 ° ± 20 °, preferably 0, with respect to the longitudinal direction of the structural members 1 to 3. It is within ° ± 15 °. The thickness of the unidirectional carbon fiber reinforced resin sheet having such an orientation is 35% or more with respect to the thickness of the entire upper surface component and / or the thickness of the entire lower surface component. Yes, preferably 50% or more. In the present invention, the rigidity is remarkably improved by having the upper surface constituent portion and the lower surface constituent portion having such a configuration.

The structural materials 1 to 3 shown in FIGS. 1 to 3 have support portions 13, 14, 23, and 33 for connecting the upper surface constituent portion and the lower surface constituent portion, and such an embodiment is preferable. is there. Then, the unidirectional carbon fiber reinforced resin sheets 13b, 13c, 14b, 14c, 23b and 23c of the support portions 13, 14, 23 and 33 (and the fiber reinforced resin sheets 31b 33b and 33c are unidirectional carbon fiber reinforced resin sheets. In the case of), the orientation direction of the reinforcing fibers is not particularly limited and can be appropriately changed as desired. However, the orientation direction of the reinforcing fibers of the support portion is preferably within 90 ° ± 55 °, more preferably within 90 ° ± 45 ° with respect to the longitudinal direction of the structural members 1 to 3. Such a configuration is preferable from the viewpoint of preventing buckling deformation of the support portion, for example.

In the structural materials 1 to 3 shown in FIGS. 1 to 3, one fiber reinforced resin sheet such as a unidirectional carbon fiber reinforced resin sheet is laminated at each location, but the present invention is not limited thereto. For example, two or more fiber-reinforced resin sheets may be laminated in one place. In that case, it is preferable that the fiber orientation directions of the two or more fiber-reinforced resin sheets are aligned with each other. Further, not only when the fiber orientation directions of all the fiber reinforced resin sheets are aligned with each other, but also when the fiber orientation directions of some (two or more) fiber reinforced resin sheets of all the fiber reinforced resin sheets are aligned with each other. It is also preferable.

In the present invention, the total thickness of the upper surface constituent portion and the lower surface constituent portion is not particularly limited, and may be appropriately determined as desired. However, as described above, the thickness of the unidirectional carbon fiber reinforced resin sheet having an orientation within 0 ° ± 20 ° with respect to the thickness of the entire upper surface component and / or the thickness of the entire lower surface component is It is 35% or more, preferably 50%. Further, in the present invention, the overall thickness of the support portion is not particularly limited, and may be appropriately determined as desired. When the support portion includes the unidirectional fiber reinforced resin sheet, the thickness of the unidirectional fiber reinforced resin sheet is preferably 50% or more with respect to the thickness of the entire support portion.

In the present invention, for example, like the structural materials 1 and 2 shown in FIGS. 1 and 2, parts other than the unidirectional carbon fiber reinforced resin sheet (for example, the base material portions 11a, 12a, 13a, 14a in FIG. 1, FIG. As a method of attaching the unidirectional carbon fiber reinforced resin sheet to the base material portions 21a, 22a and 23a, hereinafter simply referred to as “base material portion”), for example, a method of attaching with an adhesive, There is a method of adhering with an adhesive after treating the surface of the adhesive with sandblasting or the like, and a method of adhering with a thermoplastic resin by heat fusion.

In the present invention, the type of material constituting the above-mentioned base material portion is not particularly limited. For example, it may be a portion composed of only a resin, a portion composed of a fiber-reinforced resin composition containing a resin and reinforcing fibers, and further, if necessary, other optional components or arbitrary structural materials. It may be a member including. Above all, from the viewpoint of further improving the strength, the portion made of the fiber reinforced resin composition is preferable. The fiber-reinforced resin composition used for the base material portion may be a resin composition in which short fibers are blended in a random direction, or may be a resin composition in which a woven fiber is impregnated with a resin. , The resin composition in which the long fibers are oriented in one direction may be used as in the case of the unidirectional fiber reinforced resin sheet, but from the viewpoint of further improving the strength, the resin composition in which the long fibers are oriented in one direction and the short It is preferable to use it in combination with a resin composition in which fibers are blended in a random direction. Further, a laminate of a plurality of fiber-reinforced resin sheets in which woven fibers (for example, carbon fibers or glass fibers) are impregnated with a resin, or a plurality of long fibers (for example, carbon fibers or glass fibers) oriented in one direction. It is also preferable to form a base material portion and / or a support portion by using a laminate in which unidirectional fiber-reinforced resin sheets are laminated in a desired direction (fiber orientation direction).

In the present invention, the type of resin in the unidirectional carbon fiber reinforced resin sheet and the type of resin in the fiber reinforced resin composition of the base material portion are not particularly limited. The resin may be a thermoplastic resin or a thermosetting resin. In particular, a thermosetting resin is preferable from the viewpoint of creep characteristics, but a thermoplastic resin is preferable from the viewpoint of recyclability.

<Fiber reinforced resin composition>
The types of the carbon fiber reinforced resin composition constituting the unidirectional carbon fiber reinforced resin sheet used in the present invention and the types of the fiber reinforced resin composition when the base material portion is a portion made of the fiber reinforced resin composition Although not particularly limited, specific examples thereof will be described below.

The fiber-reinforced resin composition is usually a composition containing reinforcing fibers (preferably a reinforcing fiber bundle) and a matrix resin. Reinforcing fiber bundles are obtained, for example, by treating the reinforcing fibers with a sizing agent. By aligning the reinforcing fiber bundles and bringing them into contact with, for example, a molten matrix resin, a unidirectional fiber reinforced resin sheet made of the fiber reinforced resin composition can be obtained.

As the reinforcing fibers contained in the fiber-reinforced resin composition, for example, high-strength, high-elasticity fibers such as carbon fibers, glass fibers, aramid fibers, alumina fibers, silicon carbide fibers, boron fibers, and metal fibers can be used. Two or more of these may be used in combination. Above all, it is preferable to contain at least one kind of fiber selected from the group consisting of carbon fiber and glass fiber. In particular, carbon fiber is preferable from the viewpoint of elastic modulus. On the other hand, from the viewpoint of cost, glass fiber is preferable.

The average diameter of the single yarn is not particularly limited, but is preferably 1 to 20 μm, more preferably 4 to 10 μm from the viewpoint of mechanical properties and surface appearance. The number of single yarns of the carbon fiber bundle is also not particularly limited, but is preferably 100 to 100,000, more preferably 1,000 to 50,000, from the viewpoint of productivity and characteristics.

Examples of the sizing agent used for the reinforcing fiber bundle include modified polyolefin. The modified polyolefin is preferably a modified polyolefin containing at least a carboxylic acid metal salt bonded to the polymer chain. Examples of the raw material (unmodified polyolefin) of the modified polyolefin include ethylene-based polymers having an ethylene-derived skeleton content of more than 50 mol% and propylene-based polymers having a propylene-derived skeleton content of more than 50 mol%. Specific examples of the ethylene-based polymer include an ethylene homopolymer and a copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms. Specific examples of the propylene-based polymer include a propylene homopolymer and a copolymer of propylene and ethylene and / or an α-olefin having 4 to 10 carbon atoms. More specifically, homopolypropylene, homopolyethylene, ethylene / propylene copolymer, propylene / 1-butene copolymer, ethylene / propylene / 1-butene copolymer can be mentioned.

For the modified polyolefin, for example, a carboxylic acid group, a carboxylic acid anhydride group or a carboxylic acid ester group is graft-introduced into the polymer chain of the unmodified polyolefin as described above, and the group is converted into a salt state with a cation. Obtained by doing.

By immersing the reinforcing fibers in an emulsion containing, for example, the sizing agent described above (and, if necessary, an additive such as an amine compound) and then drying, a reinforcing fiber bundle treated with the sizing agent can be obtained. The content of the sizing agent in the emulsion is preferably 0.001% by mass or more and 10% by mass or less. The amount of the sizing agent attached to the reinforcing fiber bundle is preferably 0.1% by mass or more and 5.0% by mass or less.

A fiber-reinforced resin composition can be obtained by aligning the reinforcing fiber bundles described above and bringing them into contact with, for example, a molten matrix resin. The type of matrix resin is not limited, but a thermoplastic resin is preferable. Specific examples of the thermoplastic resin include polyolefin resins (polypropylene resins, polyethylene resins, etc.), polyamide resins, polyester resins, polycarbonate resins, polyacetal resins, polyetherketone resins, polyetheretherketone resins, polysulfone resins, and the like. Thermoplastic resin can be mentioned. Above all, it is more preferable to contain at least one thermoplastic resin selected from the group consisting of polypropylene-based resins and polyamide-based resins. Further, the matrix resin may contain a modified polyolefin.

<Use of structural materials>
The application of the structural material of the present invention described above is not particularly limited, and it can be used in various applications in which both rigidity and lightness are required. In the present invention, the "structural material" means a member for constituting the structure of a certain product, and therefore, the structural material of the present invention is a structural material (that is, a building material) used for the use of a building or a civil engineering structure. ), For example, structural materials used for transportation equipment for carrying people or goods such as vehicles, ships, and aircraft, and also includes structural materials for other purposes.

Structural materials (that is, building materials) used for the use of buildings or civil engineering structures include, for example, members for forming various structures of indoor or outdoor structures such as columns, beams, yagura, and suspended floors, and windmills. Members for forming various structures of outdoor buildings such as pillars and wings of the building can be mentioned. In particular, since the structural material of the present invention can achieve both rigidity and lightness, it is useful as a building material for constructing an assembly-type building assembled by a small number of workers. For example, a building material for a bathroom (such as a base of a unit bath). ) Is very useful. In addition, taking advantage of its corrosion resistance, it is also very useful as a structural material for draft chambers used in chemical experiments.

Structural materials used for transport equipment include, for example, vehicle members (automobile members, train members, etc.), ship members, and aircraft members.

Specific examples of vehicle members include impact beams and braces used for doors such as side doors and back doors. However, the types of vehicle members are not limited to these. In general, there is a strong demand for weight reduction of vehicle members, and the structural material of the present invention can achieve both rigidity and lightness. Therefore, the structural material of the present invention is also useful as various vehicle members other than the above. The impact beam is generally a member arranged inside the hollow of the door in order to ensure the safety of passengers against an external impact, and can be used for both metal doors and resin doors, and is made of metal. It is a particularly important member for resin doors, which have lower strength than doors made of resin. In addition, the brace is generally used to prevent deformation of a thin-walled door member (for example, a door member whose outer shell is made of iron and whose main body is made of resin) during door assembly work (for example, dent deformation when lifted horizontally). It is a member of the above, and is a member contained in the door even after the assembly is completed.

Specific examples of marine members include keel members (spine members). As the aircraft member, it can be used for any member of a large aircraft, a small aircraft, and a drone.

Among the above, building materials and vehicle members are preferable as the use of the structural material from the viewpoint of utilizing the rigidity and lightness of the structural material of the present invention.

Hereinafter, the present invention will be described in more detail with reference to Examples. The evaluation method used in the examples is as follows.

<Elastic modulus of 3-point bending, amount of deflection>
A load was applied at a speed of 6 mm / min under the condition of a distance between fulcrums of 1600 mm using a hydraulic fatigue tester (device name INSTRON 8804 type, maximum test force 500 kN). The curvature of the tip of the indenter is φ100 mm, and the curvature of the tip of the fulcrum is φ50 mm. A GFRP tab was attached to the contact area to avoid one-sided contact with the indenter and the fulcrum. In addition, a laser displacement meter (manufactured by KEYENCE CORPORATION, trade name LK-H027) was installed on the lower surface of the sample in the indenter portion in the center of the device, and the amount of deflection when stresses of 2940N, 5194N, and 6860N were applied was measured. .. From the amount of deflection at each stress, the elastic modulus of 3-point bending was calculated according to the following formula 1, and the average value was taken as the elastic modulus.
E = WL ³ / 48δI (Equation 1)
Here, E is the elastic modulus, W is the load, L is the distance between the fulcrums of the three-point bending test, δ is the amount of deflection, and I is the moment of inertia of area.
In the case of a square pipe (hollow box type), I = (H ^4- h ⁴ ) / 12,
In the case of the H type, I = (BH ^3- bh ³ ) / 12.

Here, H is the outer diameter and h is the inner diameter. Note that (Hh) corresponds to the wall thickness. B is the length of the upper surface or lower surface constituent portion, and b is the length of the inner surface of the constituent portion other than the support portion. Note that (Bb) corresponds to the thickness of the support portion.

<Example 1>
An H-type structural material as shown in FIG. 3 was produced by the following procedure.

(Manufacturing of each component)
28 layers of carbon fiber unidirectional prepreg (manufactured by Mitsubishi Chemical Corporation, trade name TR380G125S) impregnated with epoxy resin with the longitudinal direction as 0 ° (unidirectional fiber orientation direction: 0 ° / 0 ° / 0 ° / 0 ° / 0 ° / 15 ° / 0 ° / 0 ° / 0 ° / -15 ° / 0 ° / 0 ° / 0 ° / 15 ° / 0 ° / 0 ° / 0 ° / -15 ° / By laminating 0 ° / 0 ° / 0 ° / 15 ° / 0 ° / 0 ° / 0 ° / -15 ° / 0 ° / 0 °) to form a laminated body of unidirectional carbon fiber reinforced resin sheets. An upper component A1 for forming the upper portion (the portion of 31a) of the upper surface component 31 was produced. Further, by the same method, a lower component A2 for forming the lower portion (the portion of 32a) of the lower surface component 32 was also manufactured.

Separately, 7 layers of carbon fiber 3K twill prepreg (manufactured by Mitsubishi Chemical Corporation, trade name TR3523-318GMX) impregnated with epoxy resin are used with the longitudinal direction as 0 ° (twill warp direction: 45 ° /). 0 ° / 45 ° / 0 ° / 45 ° / 0 ° / 45 °) Laminated, wrapped around a mold with a cross section of 88 mm square and a length of 1820 mm in a C shape, and integrally molded to form the lower left side of the upper surface component 31. A left-side component B1 for forming a portion (31b portion), an upper left side portion (32b portion) of the lower surface constituent portion 32, and a left side portion (33b portion) of the support portion 33 was produced. Further, by the same method, the lower right side portion (31c portion) of the upper surface constituent portion 31, the upper right side portion (32c portion) of the lower surface constituent portion 32, and the right side portion (33c portion) of the support portion 33 are configured. A right-side component B2 for this purpose was produced.

(Manufacturing of H-type structural material)
An H-shaped shape is formed by contacting the 33b part of the left side component B1 and the 33c part of the right side component B2, and this is placed on the lower component A2, and further, the left side component B1 And, after placing the upper component A1 on the right component B2 and putting it in the bag, the air is evacuated under negative pressure and cured by an autoclave, and the thickness 6 of the upper surface component 31 and the lower surface component 32. An H-type structural material having a thickness of .16 mm and a thickness of the support portion 33 of 3.15 mm was obtained. The mass per 1 m of the length of this H-type structural material was 2304 g / m, and the density was 1.4 g / cm ³ .

The elastic modulus and the amount of deflection of this H-type structural material at three-point bending were measured by the method described above. The results are shown in Table 1.

<Example 2>
A hollow box type structural material as shown in FIG. 1 was produced by the following procedure.
(Making a unidirectional carbon fiber reinforced resin sheet)
A unidirectional carbon fiber reinforced resin sheet (thickness 0.166 mm, matrix resin = polypropylene resin, fiber volume fraction Vf = 0.5) was prepared by the method described in Example A1 of International Publication No. 2018/135562. Made. Further, 15 layers with the longitudinal direction as 0 ° (unidirectional fiber orientation direction: 0 ° / 0 ° / 0 ° / 0 ° / 0 ° / 0 ° / 0 ° / 0 ° / 0 ° / 0 ° / 0 ° Laminated (/ 0 ° / 0 ° / 0 ° / 0 °) and pressed at a temperature of 180 ° C. to obtain a laminate of unidirectional carbon fiber reinforced resin sheets having a thickness of 2.5 mm.

(Manufacturing of hollow box type carbon fiber reinforced resin member)
A unidirectional prepreg of carbon fiber impregnated with epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name TR380G125S) is molded into a mold having a cross section of 95 mm square and a length of 1820 mm (unidirectional fiber orientation direction: 45). ° / 0 ° / -45 ° / 90 ° / 90 ° / -45 ° / 0 ° / 45 ° / 45 ° / 0 ° / -45 ° / 90 ° / 90 ° / -45 ° / 0 ° / 45 ° ), 16 layers were laminated. After putting this in a bag, air was evacuated under a negative pressure and cured by an autoclave to obtain a hollow box-shaped carbon fiber reinforced resin member having a length of 100 mm, a width of 100 mm and a wall thickness of 2.46 mm. The mass per 1 m of the length of this hollow box-shaped carbon fiber reinforced resin member was 1391 g / m, and the density was 1.4 g / cm ³ .

(Manufacturing of hollow box type structural material)
A laminated body of the unidirectional carbon fiber reinforced resin sheet prepared above is attached to the upper surface and the lower surface of the hollow box type carbon fiber reinforced resin member with an epoxy adhesive after primer treatment to form a hollow box type. Obtained structural material. The orientation direction of the reinforcing fibers of the unidirectional carbon fiber reinforced resin sheet was set to 0 ° with respect to the longitudinal direction of the hollow box-shaped carbon fiber reinforced resin member. The mass of this hollow box type member per 1 m in length was 2246 g / m, and the overall density was 1.38 g / cm ³ .

The elastic modulus and the amount of deflection of the three-point bending of this hollow box type structural material were measured by the method described above. The results are shown in Table 1.

<Comparative example 1>
The elastic modulus and the amount of deflection at the three-point bending were measured in the same manner as in Example 1 without laminating anything on the hollow box-shaped carbon fiber reinforced resin member produced in Example 2. The results are shown in Table 1.

<Comparative example 2>
As a conventional hollow box type building material, a commercially available square steel pipe STKR400 for general structure (length 100 mm, width 100 mm, wall thickness 2.2 mm) was prepared. The mass, density, elastic modulus and deflection amount of the three-point bending per 1 mm of length of this square steel pipe for general structure STKR400 were measured in the same manner as in Example 1. The results are shown in Table 1.

<Comparative example 3>
Commercially available H-shaped glass fiber reinforced resin members (Fukui Fibertech Co., Ltd., trade name: Pullcom H125 mm, length 125 mm, width 125 mm, wall thickness 10 mm, reinforced fiber = glass fiber, matrix resin = polyester resin) are available. did. The mass per 1 m of the length of this H-type building material was 6450 g / m, and the density was 1.9 g / cm ³ . The elastic modulus and the amount of deflection of the three-point bending were measured in the same manner as in Example 1. The results are shown in Table 1.

As is clear from the results shown in Table 1, the structural materials of Examples 1 and 2 are much lighter than the steel building materials of Comparative Example 2, and are made of glass fiber reinforced resin of Comparative Example 3. It was superior in rigidity to the structural material of Comparative Example 1 in which the building material and the unidirectional carbon fiber reinforced resin sheet were not laminated.

The structural material of the present invention is, for example, a structural material used for the use of a building or a civil engineering structure (that is, a building material), a structural material used for transportation equipment for carrying people or goods such as vehicles, ships, and aircraft, and other structural materials. It is very useful as a structural material for the purpose of. Specifically, for bases, pillars, beams, yagura, suspended floors, windmill pillars and wings, bathroom building materials (unit bath bases, etc.), draft chamber structural materials, impact beams and braces used for doors, and ships. Examples include the keel member used.

1 Hollow box type structural material 11 Upper surface constituent part 11a Upper surface constituent base material 11b Unidirectional carbon fiber reinforced resin sheet 12 Lower surface constituent 12a Lower surface constituent base material 12b Unidirectional carbon fiber reinforced resin sheet 13 Support 13a Support base material 13b, 13c Unidirectional carbon fiber reinforced resin sheet 14 Support base 14a Support base material 14b, 14c Unidirectional carbon fiber reinforced resin sheet 2 H-type structural material 21 Top surface component 21a Top surface component Part 21b Unidirectional carbon fiber reinforced resin sheet 22 Bottom surface constituent part 22a Bottom surface constituent base material part 22b Unidirectional carbon fiber reinforced resin sheet 23 Support part 23a Support base material part 23b, 23c Unidirectional carbon fiber reinforced resin sheet 3 H Mold type structural material 31 Top surface component 31a Unidirectional carbon fiber reinforced resin sheet 31b, 31c Fiber reinforced resin sheet 32 Bottom surface component 32a Unidirectional carbon fiber reinforced resin sheet 32b, 32c Fiber reinforced resin sheet 33 Support part 33b, 33c fiber reinforced resin sheet

Claims (9)

A structural material made of resin having at least a top surface component and a bottom surface component.
The upper surface component and the lower surface component include a unidirectional carbon fiber reinforced resin sheet in which the orientation direction of the reinforcing fibers is within 0 ° ± 20 ° with respect to the longitudinal direction of the structural material.
The thickness of the unidirectional carbon fiber reinforced resin sheet with respect to the thickness of the entire upper surface component and / or the thickness of the unidirectional carbon fiber reinforced resin sheet with respect to the thickness of the entire lower surface component is 35%. A structural material characterized by the above. The thickness of the unidirectional carbon fiber reinforced resin sheet with respect to the thickness of the entire upper surface component and / or the thickness of the unidirectional carbon fiber reinforced resin sheet with respect to the thickness of the entire lower surface component is 50%. The structural material according to claim 1 as described above. The structural material according to claim 1 or 2, which has a support portion for connecting the upper surface constituent portion and the lower surface constituent portion. The structural material according to claim 3, wherein the support portion includes a unidirectional fiber reinforced resin sheet. The structural material according to claim 4, wherein the thickness of the unidirectional fiber reinforced resin sheet with respect to the thickness of the entire support portion is 50% or more. The structural material according to any one of claims 1 to 5, wherein the cross section of the structural material is any one of a hollow box shape, a solid box shape, and an H shape. The structural material according to any one of claims 1 to 6, which is a building material. The structural material according to claim 7, which is a building material for a bathroom. The structural material according to any one of claims 1 to 6, which is a member for a vehicle.

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