plaster

Abstract

To provide a novel floor mat that is lightweight while possessing the same compressive strength as wooden or plastic mats, and also has excellent repeated load-bearing capacity and is resistant to slipping. [Solution] A base plate comprising a pair of honeycomb boards, The honeycomb plate has a substrate portion and ribs that form a honeycomb structure on one main surface of the substrate portion. The pair of honeycomb plates are arranged such that the honeycomb surfaces of each honeycomb plate having the ribs face each other. The honeycomb board is made of fiber-reinforced plastic, A base plate in which the aforementioned fiber-reinforced plastic is formed by integrating a random laminate of prepregs containing glass fibers and thermoplastic resin.

Description

Technical Field

[0001] This disclosure relates to floor boards.

Background Art

[0002] Floor boards are laid on the bottom of various articles, vehicles, etc., and are used for the purpose of stabilizing the articles, vehicles, etc. placed on the floor boards and preventing damage to the floor or ground.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Outriggers are used to prevent the overturning of work vehicles such as mobile cranes, aerial work platforms, and column construction vehicles at construction sites. When using an outrigger, a floor board is laid between the outrigger and the ground. In Patent Document 1, a floor board adopting a predetermined honeycomb structure is disclosed, but further improvement is required in terms of product durability (repeated load-bearing capacity). In addition, when using carbon fiber as a reinforcing fiber, since the elastic modulus is too high, problems such as slippage (including slippage not only on the surface of the floor board but also between the floor board and the grounding surface) will occur. This disclosure aims to provide a novel floor board that has the same compressive strength as a wooden or plastic floor board, is lightweight, has excellent repeated load-bearing capacity, and is less likely to cause slippage.

Means for Solving the Problems

[0005] This disclosure includes the following aspects: [Item 1] A floor board including a pair of honeycomb plates, wherein the honeycomb plate has a substrate portion and ribs forming a honeycomb structure on one main surface of the substrate portion. The pair of honeycomb plates are arranged such that the honeycomb surfaces of each honeycomb plate having the ribs face each other. The honeycomb board is made of fiber-reinforced plastic, A base plate in which the aforementioned fiber-reinforced plastic is formed by integrating a random laminate of prepregs containing glass fibers and thermoplastic resin. [Section 2] The base plate according to item 1, comprising a middle plate, wherein the middle plate is positioned between the pair of honeycomb plates. [Section 3] The base plate according to item 1 or 2, wherein the prepreg is a unidirectional prepreg. [Section 4] The base plate according to any one of items 1 to 3, wherein the flexural modulus of the fiber-reinforced plastic is 10 GPa or more and 20 GPa or less. [Section 5] A base plate according to any one of items 1 to 4, wherein the fiber volume content Vf in the fiber-reinforced plastic is 40% or more and 60% or less. [Section 6] The base plate according to any one of claims 1 to 5, wherein the thermoplastic resin is a polyolefin. [Section 7] The fiber volume content Vf of the aforementioned fiber-reinforced plastic is 45-50%. The thermoplastic resin is polypropylene, The base plate according to any one of claims 1 to 6, wherein the flexural modulus of the fiber-reinforced plastic is 12 GPa or more and 18 GPa or less. [Section 8] The thickness of the prepreg is 50 μm or more and 100 μm or less. The base plate according to any one of items 1 to 7, wherein the average fiber length of the glass fibers is 10 mm or more and 30 mm or less. [Section 9] The base plate according to any one of items 1 to 8, wherein the honeycomb plate includes, as part thereof, a housing portion and / or a handle portion. [Section 10] A base plate according to any one of items 1 to 9, wherein the honeycomb structure is a hexagonal honeycomb structure. [Section 11] The base plate according to any one of items 1 to 10, wherein the ratio of the ribs is 20% or more and 60% or less of the vertical projection area of ​​the honeycomb surface. [Section 12] The base plate according to any one of items 1 to 11, wherein the thickness of the ribs is 3% or more and 30% or less of the maximum inner diameter of each cell in the honeycomb structure. [Section 13] The base plate according to any one of claims 1 to 12, wherein the volume occupied by the ribs is 10% or more and 60% or less of the hollow volume of each cell in the honeycomb structure. [Section 14] The proportion of the ribs is 20% or more and 60% or less of the vertical projection area of ​​the honeycomb surface; The thickness of the rib is 3% to 40% of the maximum inner diameter of each cell in the honeycomb structure; The base plate according to any one of claims 1 to 13, wherein the volume occupied by the ribs is 10% or more and 60% or less of the hollow volume of each cell in the honeycomb structure. [Section 15] A base plate according to any one of items 1 to 14, wherein the rib has a tapered shape with a draft angle of 0.5° or more and 30° or less. [Section 16] The base plate according to any one of items 1 to 15, wherein the tip of the rib is chamfered with an R-shape. [Section 17] A base plate according to any one of items 1 to 16, wherein the base of the rib is chamfered with an R-shape. [Section 18] A base plate according to any one of items 1 to 17, wherein the thickness of the honeycomb plate is 50 mm or less, and the height of the ribs is 30% to 90% of the thickness of the honeycomb plate. [Section 19] The base plate according to any one of claims 1 to 18, wherein the outermost surface of the base plate has a plurality of grooves. [Section 20] A base plate for outriggers, as described in any one of items 1 to 19.

Advantages of the Invention

[0006] The floor board in the present disclosure is lightweight while having a compression strength equivalent to that of a wooden or plastic floor board. Furthermore, it has excellent repeated load resistance and is less likely to slip.

Embodiments for Carrying Out the Invention

[0007] Hereinafter, the floor board according to an embodiment of the present disclosure will be described in more detail with reference to the drawings as necessary. However, a more detailed description may be omitted as needed. For example, detailed descriptions of well-known matters or duplicate descriptions of substantially the same configurations may be omitted. This is to avoid making the description unnecessarily redundant and to facilitate the understanding of those skilled in the art.

[0008] The applicant provides the accompanying drawings and the following description for those skilled in the art to fully understand the present disclosure, and does not intend to limit the subject matter described in the claims thereby. Note that various elements in the drawings are merely shown schematically and exemplarily for the understanding of the present disclosure, and the appearance, dimensional ratios, etc. may be different from the actual ones.

[0009] <Overall Structure of the Floor Board> The floor board of the present disclosure has a laminated structure and includes at least a pair of honeycomb plates, and the pair of honeycomb plates are arranged such that the honeycomb surfaces face each other. The floor board of the present disclosure may further include at least one selected from a rubber plate, an intermediate plate, a housing, a handle, etc. The floor board of the present disclosure may include other members. Some or all of these members may be fixed by chemical fixtures such as adhesives or mechanical fixtures such as screws and rivets. In FIGS. 2-1 and 2-2, schematic diagrams using mechanical fixtures are shown.

[0010] The shape of the base plate is a stacked structure of flat surfaces such as rectangles, squares, rhombuses, or circles, but it is typically a stacked rectangular structure. The thickness of the base plate may be 1 cm or more, 2 cm or more, 3 cm or more, 4 cm or more, or 5 cm or more. The thickness of the base plate may be 10 cm or less, 8 cm or less, 6 cm or less, 4 cm or less, or 2 cm or less. A smaller thickness of the base plate is preferable from the standpoint of weight reduction. The length and width dimensions are not particularly limited and will vary depending on the application of the base plate, but for example, they may be around 20-80 cm x 20-80 cm.

[0011] <Honeycomb board> The base plate of this disclosure includes a pair of honeycomb plates. Each honeycomb plate has a base portion and ribs forming a honeycomb structure on one main surface of the base portion, and the pair of honeycomb plates are arranged so that the honeycomb surfaces of each honeycomb plate having the ribs face each other. By including a pair of honeycomb plates, the strength of the base plate against static compression can be ensured, and at the same time, the weight of the base plate can be reduced. In addition, by including a pair of honeycomb plates, unevenness in compression resistance can be reduced throughout the base plate. In conventional base plates, the effect of localized load concentration depending on the position of the load on the base plate (e.g., the load of the outrigger) is significant, and unevenness in compression resistance is likely to occur, which is a problem. However, in the case of the base plate of this disclosure, it is easy to ensure similar strength against static compression at any position (for example, even if the load position is shifted up, down, left, or right relative to the center of the base plate).

[0012] The base plate of this disclosure includes a pair of honeycomb plates. Compared to a case where only one honeycomb plate is included, the height of the ribs can be reduced, buckling of the ribs can be suppressed, impact resistance can be increased, and compressive strength can be strengthened. Furthermore, by arranging the pair of honeycomb structures so that their honeycomb surfaces face each other, the base plate has a vertically symmetrical structure, eliminating the need to worry about the orientation of the surfaces, which is advantageous from the viewpoint of workability. The base plate may include one or more additional pairs of honeycomb plates. In that case, the compressive strength will increase, but from the viewpoint of weight reduction, it is preferable to include only a pair of honeycomb plates without including additional honeycomb plates.

[0013] [Shape of honeycomb board] The honeycomb plate in this disclosure has a substrate portion and ribs that form a honeycomb structure on one main surface of the substrate portion. The surface having the ribs is referred to as the honeycomb surface.

[0014] A honeycomb structure is a structure formed by an aggregate of multiple hollow cells (small chambers) on a surface. While hexagonal honeycomb structures, where the cell shape is hexagonal, are common, the structure is not limited to this. Examples of cell shapes include polygons (e.g., 3 to 12 sides, specifically triangles, squares, pentagons, heptagons, octagons), circles, ellipses, diamonds, herringbone patterns, and irregular shapes. The cell shape may be a single type, or a combination of multiple shapes and sizes. From the viewpoint of compressive strength of the base plate, a polygonal honeycomb structure, where the cell shape is polygonal, is preferred, and a hexagonal honeycomb structure, where the cell shape is hexagonal, is particularly preferred. Schematic diagrams of honeycomb plates having a honeycomb surface of a hexagonal honeycomb structure are shown in Figures 3-1 and 3-2. Note that the ribs of one honeycomb plate and the other honeycomb plate may be arranged so that they coincide vertically, or they may be offset.

[0015] The sides of the honeycomb board may be in a form where the cross-section of the honeycomb structure is exposed, as shown in Figure 3-1, or the honeycomb board may have a wall-like housing portion and / or a handle portion as part of it, as shown in Figure 3-2.

[0016] The maximum inner diameter of each cell may be 0.5 cm or more, 1 cm or more, 1.5 cm or more, 2 cm or more, or 2.5 cm or more, and may also be 10 cm or less, 8 cm or less, 6 cm or less, 4 cm or less, or 2 cm or less. Having the maximum inner diameter of each cell within the above range is preferable from the viewpoint of the base plate having a good balance of compressive strength and lightness.

[0017] The proportion of ribs may be 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, or 45% or more relative to the vertical projected area of ​​the honeycomb surface, preferably 30% or more, and also 60% or less, 55% or less, 50% or less, 45% or less, 40% or less, or 35% or less, preferably 50% or less. Having the proportion of ribs within the above range is preferable from the viewpoint of the base plate having a good combination of compressive strength and lightness.

[0018] The thickness of the ribs may be 3% or more, 6% or more, 9% or more, 12% or more, 15% or more, 18% or more, 21% or more, or 24% or more relative to the maximum inner diameter of each cell in the honeycomb structure, preferably 6% or more, and may also be 40% or less, 35% or less, 30% or less, 27% or less, 24% or less, 21% or less, 18% or less, 15% or less, 12% or less, or 9% or less, preferably 24% or less. Here, the thickness of the ribs may be the maximum thickness of the cross section obtained by cutting the rib perpendicular to the direction of extension of the rib, and is typically the length of the bottom of the cross section. Having the thickness of the ribs within the above range is preferable from the viewpoint of the base plate having a good combination of compressive strength and lightness. The thickness of the ribs may also be set to be thicker (for example, 9% or more, 12% or more, 15% or more, etc. relative to the maximum inner diameter of the cell). By setting the thickness to a higher level, the conformability of the fibers to the matrix resin during molding is improved, the homogeneity of the material inside the rib is enhanced, and the compressive strength and durability of the base plate can be improved. For example, when glass fibers (e.g., glass mat) are used as the fiber component, the thickness of the rib may be set to a higher level. The thickness of the rib may also be changed according to the strength of the material used (bending strength, tensile strength, and modulus of elasticity, etc.). For example, when using a high-strength material, the thickness of the rib may be set to a lower level, and when using a low-strength material, the thickness of the rib may be set to a higher level.

[0019] The volume occupied by the ribs may be 10% or more, 20% or more, 30% or more, 40% or more, or 50% or more relative to the hollow volume of each cell in the honeycomb structure, and preferably 20% or more. The volume occupied by the ribs may be 60% or less, 50% or less, 40% or less, 30% or less, or 20% or less relative to the hollow volume of each cell in the honeycomb structure, and preferably 50% or less. Having the volume occupied by the ribs within the above range is preferable from the viewpoint of the base plate having a good combination of compressive strength and lightness.

[0020] The ribs may have a tapered shape such that the wall thickness decreases from the base to the tip. The draft angle in the tapered shape may be 0.5° or more, 1.5° or more, 2.5° or more, 4.5° or more, 7.5° or more, 10° or more, 12.5° or more, or 15° or more, preferably 10° or more, more preferably 12.5° or more, and may also be 35° or less, 30° or less, 25° or less, 20° or less, 17.5° or less, 15° or less, 10° or less, 7.5° or less, 5° or less, or 2.5° or less, preferably 25° or less, or 20° or less. By making the ribs tapered, especially tapered with draft angles within the above ranges, buckling of the ribs can be suppressed, compressive strength can be improved, and it is also advantageous from the viewpoint of weight reduction. Furthermore, by making the ribs tapered, a gap can be easily created between the molded product and the mold during demolding, allowing the molded product to be removed smoothly, which is also advantageous from the viewpoint of productivity. Figure 4-1 shows a cross-sectional view of a honeycomb plate with tapered ribs.

[0021] The ends of the ribs may be chamfered. The chamfering may be R-chamfering or C-chamfering, and R-chamfering is preferred. By chamfering, damage to the ribs can be prevented and the compressive strength and durability of the base plate can be improved. As an example, Figure 4-1 shows a cross-sectional view of a honeycomb plate with R-chamfered rib ends.

[0022] The base of the ribs may be chamfered. The chamfering may be R-chamfering or C-chamfering, and R-chamfering is preferred. By chamfering, damage to the ribs can be prevented and the compressive strength and durability of the base plate can be improved. Furthermore, by chamfering, the conformability of the fibers to the matrix resin during molding can be improved, the homogeneity of the material inside the ribs can be improved and the compressive strength and durability of the base plate can be improved. For example, when glass fibers (e.g., glass mat) are used as the fiber component, the base of the ribs may be chamfered. Both the tip and the base of the ribs may be chamfered. As an example, Figure 4-2 shows a cross-sectional view (enlarged view of the rib portion) of a honeycomb plate in which the tip and base of the ribs are R-chamfered.

[0023] The chamfer dimension at the tip of the rib (radius of curvature for R-faces, length of cut edge for C-faces) may be 0.3 mm or more, 0.5 mm or more, 0.7 mm or more, 1.0 mm or more, 1.2 mm or more, or 1.5 mm or more, preferably 0.7 mm or more, or 1.0 mm or more. It may also be 9.0 mm or less, 7.5 mm or less, 6.0 mm or less, 4.5 mm or less, 4.0 mm or less, 3.0 mm or less, 2.5 mm or less, 2.0 mm or less, or 1.5 mm or less, preferably 3.0 mm or less, more preferably 2.0 mm or less. Being within the above range is preferable from the viewpoint of compressive strength and durability of the base plate.

[0024] The chamfer dimension at the base of the rib (radius of curvature for R-shaped surfaces, length of the cut edge for C-shaped surfaces) may be 0.5 mm or more, 1.0 mm or more, 1.5 mm or more, 2.0 mm or more, 2.5 mm or more, or 3.0 mm or more, preferably 1.5 mm or more or 2.5 mm or more, and may also be 9.0 mm or less, 7.5 mm or less, 6.0 mm or less, 4.5 mm or less, 4.0 mm or less, 3.5 mm or less, or 3.0 mm or less, preferably 4.5 mm or less, more preferably 3.5 mm or less. Being within the above range is preferable from the viewpoint of compressive strength and durability of the base plate.

[0025] The thickness of the honeycomb board may be 1 mm or more, 3 mm or more, 5 mm or more, 8 mm or more, or 10 mm or more, and may also be 50 mm or less, 40 mm or less, 30 mm or less, 25 mm or less, 20 mm or less, or 15 mm or less. Here, the thickness of the honeycomb board is the sum of the thickness of the substrate portion of the honeycomb board and the height of the ribs. A smaller honeycomb board thickness is preferable from the viewpoint of weight reduction.

[0026] The height of the ribs may be 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, or 80% or more of the thickness of the honeycomb plate, and may also be 90% or less, 80% or less, 70% or less, 60% or less, 50% or less, or 40% or less. From the viewpoint of weight reduction, it is preferable that the height of the ribs be above the lower limit, and from the viewpoint of preventing buckling of the ribs and improving compressive strength, it is preferable that the height of the ribs be below the upper limit.

[0027] The non-honeycomb surface (the main surface without ribs) may be flat, but the non-honeycomb surface (especially the non-honeycomb surface constituting the outermost surface of the base plate) may have multiple grooves. The shape of the multiple grooves is not limited, but is typically striped or mesh-like. Schematic diagrams of a base plate with multiple mesh-like grooves are shown in Figures 2-1 and 2-2. The spacing between grooves may be 3 mm or more, 5 mm or more, 8 mm or more, or 10 mm or more, and may also be 50 mm or less, 40 mm or less, 30 mm or less, 20 mm or less, or 10 mm or less. The groove width is not limited, but may be, for example, 0.1 mm or more, 0.3 mm or more, 0.5 mm or more, or 0.7 mm or more, and may be 5 mm or less, 3 mm or less, or 1 mm or less. Having multiple grooves on the non-honeycomb surface enhances grip and prevents the base plate from slipping or shifting when in use.

[0028] [Molding] Honeycomb boards can be obtained by molding fiber-reinforced plastic, as detailed below. Various methods for molding fiber-reinforced plastic can be employed, such as press molding. Press molding is a method of producing a molded body by applying deformation such as bending, shearing, or compression to a sheet of fiber-reinforced plastic, which has been cut to a predetermined size as needed, using processing equipment and molds. Examples of molded forms include deep drawing, flanges, col gates, edge curling, and stamping. Suitable press molding methods include the heat and cool method, in which the mold is heated and then cooled, and the cold press (stamping) method, in which the sheet is heated and softened before molding in a low-temperature mold.

[0029] The molding conditions can be adjusted as appropriate from the standpoint of the fluidity of the resin used as the raw material. The press temperature may be, for example, 100-300°C, 150-250°C, or 180-220°C. The press pressure may be, for example, 0.1-10 MPa, 1-8 MPa, or 2-7 MPa. The press time may be, for example, 10 seconds to 10 minutes, 20 seconds to 5 minutes, or 30 seconds to 3 minutes. These conditions can be appropriately changed depending on the desired thickness, shape, etc. of the molded product.

[0030] <Fiber-reinforced plastic> The honeycomb board in this disclosure is made of fiber-reinforced plastic, which is an integrated random laminate of prepregs containing glass fibers and thermoplastic resin. By using such a material, the fiber filling into the rib portions of the honeycomb structure is improved, and the homogeneity of the material (especially the homogeneity of fiber density) in those portions is enhanced. As a result, the base plate of this disclosure combines strength and lightness and also has good durability. Furthermore, by using glass fibers instead of carbon fibers as reinforcing fibers, the base plate has an appropriate flexural modulus, giving it appropriate flexibility, making it less slippery as a base plate and improving usability. Another important advantage is that it can be manufactured inexpensively by using glass instead of carbon as reinforcing fibers.

[0031] [Prepreg] The prepreg in this disclosure is a tape-like material in which glass fibers are pre-impregnated with a thermoplastic resin. The prepreg may be obtained by impregnating a fiber bundle of glass filaments with a thermoplastic resin, and then cutting the resulting unidirectional prepreg to a predetermined length (fiber length) and width.

[0032] The prepreg may be cut to the desired size by cutting or other means as needed and then laminated. The width of the prepreg may be 5 mm or more, 10 mm or more, 15 mm or more, 60 mm or less, 40 mm or less, 20 mm or more, 25 mm or more, or 30 mm or more, and may also be 40 mm or less, 30 mm or less, 20 mm or less, or 15 mm or less, preferably 10 mm or more and 20 mm or less. The height of the prepreg may be 10 mm or more, 15 mm or more, 20 mm or more, 25 mm or more, or 30 mm or more, and may also be 100 mm or less, 80 mm or less, 60 mm or less, 50 mm or less, or 30 mm or less, preferably 40 mm or less, and in one embodiment 15 mm or more and 40 mm or less. The shape of the prepreg is not limited, but may be quadrilateral (rectangle, square, rhombus), circular, polygon, etc., but is typically used in the form of quadrilateral cut tape. For shapes other than rectangles, the aforementioned width and height correspond to their respective maximum widths. Being within the above range is preferable from the standpoint of improving the workability of the lamination process, as well as enhancing the strength and durability of the product.

[0033] [Glass fiber] Examples of glass fibers used in this disclosure include, for example, E glass, AR glass, C glass, D glass, H glass, S glass, T glass, M glass, NE glass, and the like.

[0034] The glass fiber length (average fiber length) may be 0.5 mm or more, 1 mm or more, 3 mm or more, 5 mm or more, 10 mm or more, or 20 mm or more, preferably 10 mm or more, more preferably 12.5 mm or more, and may also be 50 mm or less, 40 mm or less, 30 mm or less, 25 mm or less, or 20 mm or less, preferably 30 mm or less, more preferably 25 mm or less, and in one embodiment, 10 mm or more and 30 mm or less, preferably 12.5 mm or more and 25 mm or less. Being below the above upper limit results in good fiber filling properties and good moldability of the rib structure. Furthermore, being within the above range is preferable from the viewpoint of suppressing variations in product performance and from the viewpoint of improving product strength and product durability. From the viewpoint of environmental considerations and / or cost reduction, some or all of the glass fibers used may be recycled materials (for example, glass fibers mixed with short and long fibers).

[0035] From the viewpoint of improving adhesion with resin and increasing product strength, it is preferable that the surface of the glass fiber is acid-treated.

[0036] The diameter (average diameter) of the glass fibers may be 0.5 μm or more, 1 μm or more, 5 μm or more, 10 μm or more, or 25 μm or more, and may also be 100 μm or less, 75 μm or less, 25 μm or less, or 10 μm or less. It is preferable that the diameter is within the above range from the viewpoint of fiber dispersion and the strength and durability of the base plate.

[0037] [Thermoplastic resin] Examples of thermoplastic resins include polyolefins (polyethylene, polypropylene, etc.), thermoplastic epoxy resins, polyhalogenated olefins, polystyrene, polyvinyl acetate, polyurethane, Teflon®, ABS resin, AS resin, polyamide, polyacetal, polycarbonate, polyether, polyester, thermoplastic polyimide, polyamide resin, polyamide-imide resin, polyester resin, and thermoplastic acrylic resin, with polyolefin being preferred. Examples of polyolefins include homopolymers and copolymers having repeating units derived from one or more α-olefins, such as ethylene, propylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-hexene, 1-octene, 1-decene, and 1-dodecene, with polyethylene or polypropylene being preferred, and polypropylene being more preferred.

[0038] [Characteristics of prepreg, etc.] The thickness of the prepreg may be 10 μm or more, 30 μm or more, 50 μm or more, 70 μm or more, or 90 μm or more, preferably 50 μm or more, and may also be 500 μm or less, 300 μm or less, 200 μm or less, 100 μm or less, 75 μm or less, or 50 μm or less, preferably 100 μm or less, and in one embodiment, 50 μm or more and 100 μm or less. A thickness above the lower limit can suppress cracking of the prepreg and reduce variations in product performance. A thickness below the upper limit improves the moldability of the rib structure. Being within the above range is also preferable from the viewpoint of improving the strength and durability of the product.

[0039] The prepreg may be a unidirectional prepreg in which the glass fibers contained are unidirectional. The unidirectionality of the glass fibers can be evaluated as follows. First, the midpoint of the width length is determined at each of the two cut ends of the prepreg, which has been cut to have a predetermined length in the fiber direction (for example, 150 mm in the fiber direction). A line is drawn connecting the midpoint of one end and the midpoint of the other end, and this line is used as the reference line. For one side of the prepreg from the reference line, the length in the width direction (a length that is approximately half of the width length, hereinafter also referred to as "half width") is measured at least 10 times along the fiber direction. The coefficient of variation calculated from the average value of the half width obtained at least 10 times and the standard deviation is preferably 10% or less, more preferably 9% or less, even more preferably 7% or less, and particularly preferably 5% or less.

[0040] In the prepreg, the average number of glass fibers in the thickness direction is preferably 20 or less, more preferably 15 or less, even more preferably 10 or less, even more preferably 8 or less, even more preferably 7 or less, and particularly preferably 6 or less. The lower limit of the average number of glass fibers in the thickness direction is not particularly limited, but is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more, from the viewpoint of easily enhancing resin penetration. Being within the above range makes it easier for the resin to impregnate between the fibers, suppresses the occurrence of voids that cause product defects, and is preferable from the viewpoint of improving the strength and durability of the product.

[0041] The number of glass fibers in the thickness direction of the prepreg is measured by embedding a cross-section of the prepreg cut in the thickness direction with resin or the like, observing it using an electron microscope or the like, and counting the number of fibers present in the thickness direction in the resulting image. In this way, the number of fibers present in the thickness direction is counted in at least five cross-sectional images, and the average value is taken as the average number of glass fibers in the thickness direction. In the above cross-sectional observation, in order to minimize the effect of external force on the prepreg during cutting, for example, the prepreg may be cut while both sides are sandwiched and fixed with a rigid plate such as metal, and the cross-sectional observation may be performed. Note that if the prepreg has a certain length (for example, in the form of a tape wound on a bobbin), the measurement of at least five locations may be performed at intervals of about 50 cm in the fiber axis direction, or if the prepreg is in the form of a cut tape, at least five prepregs may be arbitrarily selected from multiple cut prepregs and measured. When multiple locations are to be measured, the measurement may be performed in the same manner as above.

[0042] The coefficient of variation (CV value) of the number of glass fibers in the thickness direction contained in the prepreg is preferably 20% or less, more preferably 10% or less, and even more preferably 5% or less. In this disclosure, the coefficient of variation is calculated by measuring the number of glass fibers in the thickness direction contained in each prepreg at at least 10 locations, and using the mean value and standard deviation obtained from these results, the coefficient of variation (CV value) = standard deviation / mean value × 100 (%). When the coefficient of variation of the number of glass fibers in the thickness direction is below the above upper limit, uneven lamination is less likely to occur when manufacturing a random laminate from the prepreg, and it becomes easier to ensure the isotropy of the glass fibers.

[0043] In prepregs, the following formula: Average fiber density in the width direction [fibers / mm] = (Average number of glass fibers in the thickness direction [fibers]) × (1 / diameter of glass fiber filament [mm]) The average fiber density in the width direction calculated by the formula (hereinafter also referred to as "average fiber density A") is preferably 150 to 2,000 fibers / mm, more preferably 500 to 1,500 fibers / mm, and even more preferably 700 to 1,000 fibers / mm. When the average fiber density in the width direction is below the above upper limit, the resin is more easily impregnated between the fibers, which can suppress the generation of voids that cause product defects, and is preferable from the viewpoint of improving the strength and durability of the product. The method for measuring the average number of glass fibers in the thickness direction in the formula is as described above. In addition, (1 / single fiber diameter of glass fiber [mm]) in the formula represents the number of glass fibers that can be contained in a unit laminate per 1 mm in the width direction.

[0044] When manufacturing the prepreg, it is preferable that the glass fibers are opened to enhance resin impregnation. A restraining agent may be attached to the opened glass fibers. By attaching a restraining agent, it is easier to increase the width restraint of the opened glass fibers and to suppress cracking that may occur during the manufacturing of the prepreg. The amount of restraining agent attached is preferably 0 to 0.8% by mass, and more preferably 0.3 to 0.5% by mass, based on the mass of the glass fibers, taking into consideration its effect on the deterioration of the physical properties of the final prepreg. It is preferable to set the amount of restraining agent attached to be above the lower limit above, as this can increase the width restraint of the opened glass fibers. By setting the amount of restraining agent attached to be within the above range, there are no particular limitations on the type of restraining agent used, but emulsified epoxy resins and emulsified modified polyolefin resins are preferably used.

[0045] The number, density, and average length of glass fibers in a prepreg do not fundamentally change after lamination. Therefore, the descriptions regarding preferred ranges for prepregs also apply to the random laminates (fiber-reinforced plastics) of this disclosure.

[0046] [Prepreg preparation] Prepregs can be obtained by impregnating glass fibers with thermoplastic resin.

[0047] Methods of impregnation include, but are not limited to, methods of directly impregnating with molten thermoplastic resin, methods of impregnating with molten film-like thermoplastic resin, and methods of impregnating with molten powder-like thermoplastic resin. It is preferable to fully open the glass fibers before impregnation. This suppresses the generation of voids and can improve the strength and durability of the product.

[0048] [Method for manufacturing fiber-reinforced plastics] The fiber-reinforced plastic in this disclosure is a sheet-like material that can be obtained by integrating a random laminate, which is obtained by randomly stacking the above-mentioned prepregs.

[0049] Methods for randomly stacking prepregs include, for continuous manufacturing, dropping the prepregs from a high position and stacking them on a conveyor such as a steel belt, blowing air into the drop path, or installing baffles. For batch manufacturing, it is preferable to store the prepregs in a container, attach a conveying device to the bottom of the container, and distribute them to molds or the like.

[0050] The fiber-reinforced plastic of the present disclosure is obtained by heating and / or pressurizing randomly stacked prepregs to integrate them. Pressurization may be performed along with heating. The heating temperature when manufacturing the laminate of the present disclosure may be, for example, 50 to 300°C, 100 to 200°C, or 150 to 180°C. When pressurization is performed, the pressure during pressurization is preferably 0.1 to 10 MPa, more preferably 1 to 5 MPa. Specifically, examples include a method in which prepregs stacked on a conveyor such as a steel belt are passed between hot rolls together with the steel belt and heated, pressurized, or intermittently pressed; a method in which heating and cooling are performed continuously by belt pressing; a method in which cold pressing is performed after preheating with a far-infrared heater; or a batch method using heating and cooling pressing. The heating temperature is preferably higher than the glass transition temperature of the thermoplastic resin, preferably in the temperature range of 100 to 200°C, more preferably 150 to 180°C. This allows the resin to maintain its fluidity while promoting polymerization, and further pressurization makes it possible to fill the gaps present between the stacked prepregs. As a result, it becomes easier to reduce voids in the product.

[0051] The number of prepreg layers per unit thickness of fiber-reinforced plastic is preferably 6 layers / mm or more, more preferably 8 layers / mm or more, even more preferably 10 layers / mm or more, and particularly preferably 11 layers / mm or more. The number of prepreg layers per unit thickness is preferably 40 layers / mm or less, more preferably 25 layers / mm or less, and particularly preferably 20 layers / mm or less. The number of prepreg layers per unit thickness can be measured by observing an image of the cross-section of the fiber-reinforced plastic using an electron or optical microscope.

[0052] [Characteristics of fiber-reinforced plastics, etc.] The thickness of the fiber-reinforced plastic may be 0.5 mm or more, 1 mm or more, 3 mm or more, 5 mm or more, 7 mm or more, or 9 mm or more, and may be 30 mm or less, 25 mm or less, 20 mm or less, 15 mm or less, 10 mm or less, 5 mm or less, or 3 mm or less, and in one embodiment it is 3 mm or more and 10 mm or less. The thickness of the fiber-reinforced plastic may be changed as appropriate depending on the form of the product, etc.

[0053] The fiber volume content Vf in fiber-reinforced plastics may be 30% or more, 35% or more, 40% or more, 45% or more, or 47% or more, preferably 40% or more, more preferably 45% or more, and may also be 80% or less, 75% or less, 70% or less, 65% or less, 60% or less, 55% or more, or 50% or less, preferably 60% or less, more preferably 50% or less, and in one embodiment, 40% or more and 60% or less, preferably 45% or more and 50% or less. Setting it within the above range is preferable from the viewpoint of suitable mechanical properties of the fiber-reinforced plastic, particularly suitable flexural modulus, and further from the viewpoint of product durability.

[0054] The thermoplastic resin volume content Vt in fiber-reinforced plastics may be 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, 45% or more, or 50% or more, and may also be 70% or less, 65% or less, 60% or less, 55% or less, or 53% or less, preferably 60% or less, more preferably 55% or less, preferably 40% or more, more preferably 50% or more, and in one embodiment, 40% or more and 60% or less, preferably 50% or more and 55% or less. The above range is preferable from the viewpoint of moldability of the laminate and strength of the product.

[0055] The flexural modulus of the fiber-reinforced plastics of this disclosure, as measured according to ASTM D790, may be 5 GPa or more, 8 GPa or more, 10 GPa or more, 12 GPa or more, or 15 GPa or more, preferably 10 GPa or more, more preferably 12 GPa or more, and may also be 25 GPa or less, 23 GPa or less, 20 GPa or less, 18 GPa or less, or 16 GPa or less, preferably 20 GPa or less, more preferably 18 GPa or less, and in one embodiment 10 GPa or more and 20 GPa or less, preferably 12 GPa or more and 18 GPa or less. The flexural strength of the fiber-reinforced plastics of this disclosure, as measured according to ASTM D790, may be 150 MPa or more, 200 MPa or more, 250 MPa or more, or 280 MPa or more, preferably 250 MPa or more, more preferably 280 MPa or more, and may also be 500 MPa or less, 450 MPa or less, 400 MPa or less, 350 MPa or less, or 320 MPa or less, preferably 350 MPa or less, more preferably 320 MPa or less, and in one embodiment, 250 MPa or more and 350 MPa or less, preferably 280 MPa or more and 320 MPa or less. Within the above range, good product durability can be achieved while suppressing the slippage of the base plate.

[0056] The tensile modulus of the fiber-reinforced plastic of this disclosure, as measured according to JIS K 7164 (ISO 527-4), may be 5 GPa or more, 8 GPa or more, 10 GPa or more, 12 GPa or more, or 15 GPa or more, preferably 10 GPa or more, more preferably 12 GPa or more, and may also be 25 GPa or less, 23 GPa or less, 20 GPa or less, 18 GPa or less, or 16 GPa or less, preferably 20 GPa or less, more preferably 18 GPa or less, and in one embodiment, 10 GPa or more and 20 GPa or less, preferably 12 GPa or more and 18 GPa or less. The tensile strength of the fiber-reinforced plastics of this disclosure, as measured according to JIS K 7164 (ISO 527-4), may be 80 MPa or more, 100 MPa or more, 120 MPa or more, or 150 MPa or more, preferably 120 MPa or more, more preferably 150 MPa or more, and may also be 400 MPa or less, 350 MPa or less, 300 MPa or less, 250 MPa or less, or 200 MPa or less, preferably 250 MPa or less, more preferably 200 MPa or less, and in one embodiment, 120 MPa or more and 250 MPa or less, preferably 150 MPa or more and 200 MPa or less. Within the above range, good product durability can be achieved while suppressing the slippage of the base plate.

[0057] The mechanical properties described above can be modified by selecting the fiber volume content (Vf), etc., according to the desired strength.

[0058] Examples of fiber-reinforced plastics in this disclosure include the Quickform® series manufactured by Toyobo MC Corporation.

[0059] The base plate of this disclosure may include a pair of rubber plates. The pair of honeycomb plates are arranged between the pair of rubber plates such that the pair of rubber plates sandwich the pair of honeycomb plates. The surface of mechanical fasteners such as rivets may be covered separately with rubber material.

[0060] The rubber sheet may be a component that constitutes the outermost surface of the mat. The rubber sheet may have multiple grooves on its surface (particularly the surface that constitutes the outermost surface of the mat). The shape of the multiple grooves is not limited, but is typically striped or mesh-like. A mat having multiple mesh-like grooves is illustrated in Figures 2-1 and 2-2. The spacing between grooves may be 3 mm or more, 5 mm or more, 8 mm or more, or 10 mm or more, and may also be 50 mm or less, 40 mm or less, 30 mm or less, 20 mm or less, or 10 mm or less. The groove width is not limited, but may be, for example, 0.1 mm or more, 0.3 mm or more, 0.5 mm or more, or 0.7 mm or more, and may also be 5 mm or less, 3 mm or less, or 1 mm or less. By having multiple grooves on the surface of the rubber sheet, grip strength can be increased and slippage and shifting on the surface of the mat can be prevented when using it. Furthermore, if the outermost surface of the base plate is a surface of a material other than a rubber sheet (for example, the non-honeycomb surface of a honeycomb sheet), that surface may have multiple grooves as described above.

[0061] The thickness of the rubber sheet may be 0.5 mm or more, 1 mm or more, 3 mm or more, or 5 mm or more, and may also be 30 mm or less, 25 mm or less, 20 mm or less, 15 mm or less, 10 mm or less, 5 mm or less, or 3 mm or less. From the viewpoint of strengthening the compressive strength, it is preferable that the thickness be above the lower limit, and from the viewpoint of reducing weight, it is preferable that the thickness be below the upper limit.

[0062] Examples of materials for rubber sheets include synthetic rubbers such as butadiene rubber, nitrile rubber, hydrogenated nitrile rubber, fluororubber, silicone rubber, urethane rubber, ethylene propylene rubber, and epichlorohydrin rubber, as well as natural rubber.

[0063] <Middle board> The base plate of this disclosure may include intermediate plates. The intermediate plates are positioned between a pair of honeycomb boards such that the intermediate plates sandwich the honeycomb boards. Including intermediate plates can distribute the load and suppress the transmission of localized loads due to contact between ribs, thereby improving the durability and compressive strength of the base plate. Cross-sectional views of the base plate with and without intermediate plates are shown in Figures 5 and 6, respectively. Figures 7-1 and 7-2 show a cross-section including the side of a base plate of one embodiment of this disclosure. Note that the base plate according to Figures 5 to 7-2 does not need to have a rubber plate.

[0064] The material for the middle plate is not particularly limited, and various materials with a certain degree of rigidity such as resin, metal, and ceramic may be used. However, from the viewpoint of weight reduction and compressive strength, aluminum, carbon, fiber-reinforced plastic (for example, a material similar to that of a honeycomb board) may be used.

[0065] The thickness of the middle plate may be 0.5 mm or more, 1 mm or more, 3 mm or more, or 5 mm or more, and may also be 30 mm or less, 25 mm or less, 20 mm or less, 15 mm or less, 10 mm or less, 5 mm or less, or 3 mm or less. From the viewpoint of strengthening compressive strength, it is preferable that the thickness be above the lower limit, and from the viewpoint of weight reduction, it is preferable that the thickness be below the upper limit.

[0066] <Enclosure (Enclosure part)> The base plate of this disclosure may include a housing. The housing is positioned to cover the sides of the honeycomb plate. If a rubber plate and / or intermediate plate are present, the housing may be positioned to cover the sides of the rubber plate and / or the sides of the intermediate plate.

[0067] The honeycomb panel may have a housing portion as part of it, in which case a separate housing is not required (Figures 2-2, 3-2, and 7-2). By not providing a separate housing, the concentration of load on the housing can be suppressed, resulting in good product strength, and preventing soil, water, etc. from entering the inside of the product through damaged parts of the housing.

[0068] The material of the enclosure is not particularly limited, and various materials with a certain degree of rigidity such as resin, metal, and ceramic may be used. However, from the viewpoint of weight reduction and compressive strength, aluminum, carbon, fiber-reinforced plastic (for example, a material similar to honeycomb board) may be used.

[0069] <Handle (Handle part)> The base plate of this disclosure may include a handle. Figure 2-1 illustrates a case where the handle is connected to the housing. The handle may be connected to the intermediate plate or the housing (housing portion). When the handle is connected to the intermediate plate, the extension of the intermediate plate may cause a portion of the intermediate plate to function as a handle (see Figure 7-1).

[0070] The honeycomb panel may have a handle portion as part of it, in which case a separate handle may not be necessary (Figures 2-2, 3-2, and 7-2). By not providing a separate handle, the concentration of load on the handle can be suppressed, which may result in better product strength.

[0071] The material for the handle is not particularly limited, and various materials with a certain degree of rigidity such as resin, metal, and ceramic may be used. However, from the viewpoint of weight reduction and compressive strength, aluminum, carbon, fiber-reinforced plastic (for example, a material similar to honeycomb board) may be used.

[0072] <Assistive devices> To improve grip with the contact surface (e.g., concrete or asphalt), auxiliary devices such as resin (especially rubber) belts or chains may be attached to the base plate itself. This prevents the base plate from slipping or shifting when the outriggers are extended.

[0073] <Uses of base plates> The base plate in this disclosure is lightweight and has excellent compressive strength, and can therefore be used as a substitute for conventional base plates in various fields. Preferably, the base plate in this disclosure can be used as a base plate for outriggers. Preferably, the base plate in this disclosure can be used as a base plate for outriggers. Exemplarily, it is preferably used as a base plate for aerial work platforms in construction related to social infrastructure facilities (e.g., road infrastructure construction, telecommunications cable construction, etc.).

[0074] Although embodiments have been described above, it should be understood that various modifications to the form and details are possible without departing from the spirit and scope of the claims. [Examples]

[0075] The present disclosure will be described in detail below with reference to examples, but the present disclosure is not limited to these examples.

[0076] (Examples) A repeated load-bearing test (10-ton load x 12,000 cycles) was conducted using a base plate including a pair of honeycomb boards and a middle plate. Details of the base plate used are as follows. Honeycomb board height: approximately 12mm (thickness of the circuit board portion: approximately 3mm) Honeycomb board material: Toyobo MC Co., Ltd. Quickform (flexural modulus: 15 GPa, flexural strength: 300 MPa, tensile modulus: 15 GPa, tensile strength: 180 MPa, Vf 48%) Honeycomb shape: Hexagonal honeycomb structure (maximum inner diameter of cells approximately 20mm) Rib shape (tapered shape (pull-out angle approximately 18°), rounded edge processing at the rib tip (R approximately 1.5mm), wall thickness at the rib tip approximately 6mm, wall thickness at the rib base approximately 16mm) Inner plate thickness: 2mm Middle plate material: Aluminum

[0077] (Comparative example) The test was conducted using the same base plate as in the example, except that glass mat-reinforced thermoplastic resin (manufactured by Mitsubishi Chemical Advanced Materials) was used as the material for the honeycomb board.

[0078] (result) In the comparative example, multiple cracks were observed in the rib portion of the base plate after the test. On the other hand, in the example, no cracks or other damage were observed in the base plate after the test, indicating good durability. [Brief explanation of the drawing]

[0079] [Figure 1] A schematic diagram of an outrigger base plate according to one embodiment of the present disclosure. [Figure 2-1] A perspective view of a base plate according to one embodiment of the present disclosure. [Figure 2-2] A perspective view of a base plate according to one embodiment of the present disclosure. [Figure 3-1] A perspective view of a honeycomb panel according to one embodiment of the present disclosure. [Figure 3-2] A perspective view of a honeycomb panel according to one embodiment of the present disclosure. [Figure 4-1] Perspective cross-sectional view of the honeycomb board in the zx or zy plane shown in Figure 3-1 or Figure 3-2. [Figure 4-2] A cross-sectional view (enlarged view of the rib portion) of a honeycomb plate in which the tips and bases of the ribs of one embodiment of the present disclosure are rounded off. [Figure 5] A cross-sectional view of a base plate according to one embodiment of the present disclosure. [Figure 6] A cross-sectional view of a base plate according to one embodiment of the present disclosure. [Figure 7-1] A plan view of a base plate according to one embodiment of the present disclosure, including the housing and handle. [Figure 7-2] A plan view of a base plate according to one embodiment of the present disclosure, including the housing portion and the handle portion. [Explanation of Symbols]

[0080] 1 bottom plate 10 Aerial work platform 11 Outriggers 2 honeycomb boards 3. Rubber sheet 4 Middle plate 5. Handle 6 cabinets 7 Mechanical fixings

Claims

1. A base plate including a pair of honeycomb boards, The honeycomb plate has a substrate portion and ribs that form a honeycomb structure on one main surface of the substrate portion. The pair of honeycomb plates are arranged such that the honeycomb surfaces of each honeycomb plate having the ribs face each other. The honeycomb board is made of fiber-reinforced plastic, A base plate in which the aforementioned fiber-reinforced plastic is formed by integrating a random laminate of prepregs containing glass fibers and thermoplastic resin.

2. The base plate according to claim 1, comprising a middle plate, wherein the middle plate is positioned between the pair of honeycomb plates.

3. The base plate according to claim 1 or 2, wherein the prepreg is a unidirectional prepreg.

4. The base plate according to claim 1, wherein the flexural modulus of the fiber-reinforced plastic is 10 GPa or more and 20 GPa or less.

5. The base plate according to claim 1 or 2, wherein the fiber volume content Vf in the fiber-reinforced plastic is 40% or more and 60% or less.

6. The base plate according to claim 1 or 2, wherein the thermoplastic resin is a polyolefin.

7. The fiber volume content Vf of the aforementioned fiber-reinforced plastic is 45-50%. The thermoplastic resin is polypropylene, The base plate according to claim 1 or 2, wherein the flexural modulus of the fiber-reinforced plastic is 12 GPa or more and 18 GPa or less.

8. The thickness of the prepreg is 50 μm or more and 100 μm or less. The base plate according to claim 1 or 2, wherein the average fiber length of the glass fibers is 10 mm or more and 30 mm or less.

9. The base plate according to claim 1 or 2, wherein the honeycomb plate includes, as part thereof, a housing portion and / or a handle portion.

10. The base plate according to claim 1 or 2, wherein the honeycomb structure is a hexagonal honeycomb structure.

11. The base plate according to claim 1 or 2, wherein the ratio of the ribs is 20% or more and 60% or less of the vertical projection area of ​​the honeycomb surface.

12. The base plate according to claim 1 or 2, wherein the thickness of the ribs is 3% or more and 30% or less of the maximum inner diameter of each cell in the honeycomb structure.

13. The base plate according to claim 1 or 2, wherein the volume occupied by the ribs is 10% or more and 60% or less of the hollow volume of each cell in the honeycomb structure.

14. The proportion of the ribs is 20% or more and 60% or less of the vertical projection area of ​​the honeycomb surface; The thickness of the rib is 3% to 40% of the maximum inner diameter of each cell in the honeycomb structure; The base plate according to claim 1 or 2, wherein the volume occupied by the ribs is 10% or more and 60% or less of the hollow volume of each cell in the honeycomb structure.

15. The base plate according to claim 1 or 2, wherein the rib has a tapered shape with a draft angle of 0.5° or more and 30° or less.

16. The base plate according to claim 1 or 2, wherein the tip of the rib is chamfered with an R-shape.

17. The base plate according to claim 1 or 2, wherein the base of the rib is chamfered with an R-shape.

18. The base plate according to claim 1 or 2, wherein the thickness of the honeycomb plate is 50 mm or less, and the height of the ribs is 30% to 90% of the thickness of the honeycomb plate.

19. The base plate according to claim 1 or 2, wherein the outermost surface of the base plate has a plurality of grooves.

20. A base plate for outriggers, as described in claim 1 or 2.

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