JP2018108740A - Laminate structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-weight laminate structure of which the folded part is almost free of protruding wrinkles and recesses caused by buckling.SOLUTION: A laminate structure 4 is formed by laminating a fiber sheet 2 and a thermoplastic resin film 3 in this order on both principal surfaces of a polypropylene honeycomb core material 1 where a hollow tabular body made of a thermoplastic resin is arranged in the thickness direction, wherein the core material 1 is formed by molding a polypropylene sheet. The fiber sheet 2 is a polypropylene textile, while the thermoplastic resin film 3 is a polypropylene film. The core material 1 and the polypropylene textile 2 are bonded by heat lamination with a film of a low melting point in between. The laminate structure 4 is free of protruding wrinkles 6 caused by buckling or bending in the inside of a folded part and has sufficient both bending rigidity and bending strength while keeping a light weight as a whole.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laminated structure in which a fiber sheet and a thermoplastic resin film are bonded to at least one main surface of a hollow plate-like body.

  The hollow plate-like body is also referred to as a honeycomb core, a corrugated core, a hollow columnar core, etc., and is light in weight and high in strength. Patent Document 1 proposes a structure in which a hollow portion of a honeycomb core material is filled with a synthetic resin foam and an outer cover plate is bonded on both sides of the honeycomb core material on a sandwich. Patent Document 2 proposes a structure in which fiber reinforced plastic (FRP) is bonded to both surfaces of a honeycomb core material. Patent Document 3 proposes a structure in which a honeycomb composite material layer is bonded with a cloth-like composite material layer made of woven or non-woven fabric and a unidirectional fiber reinforced resin made of a prepreg thereon. Patent Document 4 proposes a structure in which an intermediate material in which unidirectional fiber bodies are separately arranged in different directions on both sides of a honeycomb core material and a decorative film thereon are integrated. Patent Document 5 proposes making a honeycomb core material from a single sheet by vacuum forming and folding.

  However, the conventional proposal has a problem in that when it is bent, protruding wrinkles or recesses due to buckling occur in the bent portion, and bending resistance is reduced.

Japanese Utility Model Publication No. 61-30844 JP-A-8-258189 Japanese Patent No. 2627851 Japanese Patent No. 4278678 Japanese Patent No. 4408331

  In order to solve the above problems, the present invention provides a laminated structure that can be reduced in weight and is less likely to generate protrusion wrinkles or recesses due to buckling in the bent portion even when bent.

  The laminated structure of the present invention is characterized in that a fiber sheet (excluding a multiaxial fiber sheet alone) and a thermoplastic resin film are bonded to at least one main surface of a thermoplastic resin hollow plate-like body. And

  The present invention can reduce the weight by forming a laminated structure in which a fiber sheet and a thermoplastic resin film are bonded to at least one main surface of a thermoplastic resin hollow plate-like body. It can be set as the laminated structure in which the protrusion wrinkles and recessed part by bending are hard to generate | occur | produce. The hollow plate-like body has a thickness, and when bent, there are protruding wrinkles and recesses due to buckling on the bent side. By laminating and sticking a fiber sheet and a thermoplastic resin film, the protruding wrinkles and recesses due to buckling are formed. It can be set as the laminated structure which does not generate | occur | produce easily.

FIG. 1A is a cross-sectional view when measuring the bending strength of the laminated structure in one embodiment of the present invention, and FIG. 1B is a cross-sectional view when measuring the bending strength of the laminated structure in the comparative example. 2A to 2E are cross-sectional views of the laminated structure in one embodiment of the present invention.

  In laminated structures such as containers, shelves, pallets, panels, bags, etc., resistance to bending becomes important. The present inventors initially thought that bending resistance would be improved by bonding a fiber sheet to the surface layer of the hollow plate-like body, and bonded the fiber sheet to the surface layer of the hollow plate-like body. However, it is difficult to improve the bending resistance, as expected, only by bonding the fiber sheets. When the cause is investigated, the hollow plate-like body has a thickness of about 3 to 30 mm, and when bent, it is easy to bend or bend on the bent side, and the protruding wrinkles do not disturb the constituent fibers of the fiber sheet. It has been found that there is a problem that the bending resistance becomes low due to destruction.

  1B, the laminated structure 5 in which the fiber sheet 2 is bonded to the surface of the hollow plate-like body 1 is easy to form a protruding wrinkle 6 due to buckling or bending inside when bent. The wrinkles 6 do not disturb or destroy the constituent fibers of the fiber sheet 2 and lower the bending resistance.

  Therefore, in order to prevent the occurrence of protruding wrinkles due to buckling, the fiber sheet and the thermoplastic resin film were combined and laminated on the surface of the hollow plate-like body. Thereby, even if it bends, the protrusion wrinkle by buckling or a bending became difficult to generate | occur | produce. The order of lamination of the fiber sheet and the thermoplastic resin film may be any from the viewpoint of bending rigidity and bending strength, but it is preferable to dispose the thermoplastic resin film outside in consideration of the smoothness of the surface.

  The fiber sheet and the thermoplastic resin film of the present invention are bonded to at least one main surface of the hollow plate. In the case of bonding to one main surface, if the laminated structure is bent as described above, protruding wrinkles are likely to be generated on the inner side. In this case, a fiber sheet or a thermoplastic resin film may be bonded to the other main surface, or both may be bonded. When stress is applied in various directions in use, the fiber sheet and the thermoplastic resin film are preferably bonded to both main surfaces of the hollow plate. Since the fiber sheet and the thermoplastic resin film are bonded to the hollow plate using heat or an adhesive, both main surfaces become symmetrical by bonding to both main surfaces, and it is difficult for product defects such as warpage to occur. Become a flat product. In the above, a main surface is a flat front and back.

Any method may be used for bonding the hollow plate-like body, the fiber sheet, and the thermoplastic resin film. For example, there are the following methods.
(1) A method in which a fiber sheet is bonded to a hollow plate-like body, and a thermoplastic resin film is further bonded to be integrated.
(2) A method in which a thermoplastic resin film is bonded to a hollow plate-like body, and a fiber sheet is further bonded to be integrated.
(3) A method in which a hollow plate and a composite sheet obtained by previously integrating a fiber sheet and a thermoplastic resin film are bonded together to be integrated.

  The fiber sheet and the thermoplastic resin film, the thermoplastic resin film and the hollow plate-like body, or the fiber sheet and the hollow plate-like body may be bonded together using an adhesive. The adhesive may be used between all the layers or between arbitrary layers. For example, hollow plate / adhesive / fiber sheet / adhesive / thermoplastic resin film, hollow plate / adhesive / fiber sheet / thermoplastic resin film and hollow plate / adhesive / thermoplastic resin film / Adhesive / fiber sheet / adhesive / thermoplastic resin film.

  As the laminating means, there are a method of direct heating or indirect heating by heat and pressure, a method of laminating an adhesive film such as a low melting point film as an adhesive, a method of laminating by applying a liquid adhesive, etc. It can be used as appropriate. Furthermore, the method of bonding a fiber sheet and a thermoplastic resin film simultaneously with manufacture of a hollow plate-shaped body may be used. In view of handling during production, it is preferable to use a composite sheet in which a fiber sheet and a thermoplastic resin film are integrated in advance. The bonding method for making the composite sheet may be direct heating or indirect heating. Further, a sheet such as a thermoplastic prepreg similar to the composite sheet may be used.

  FIG. 1A is a cross-sectional view when a laminated structure in one embodiment of the present invention is bent, and a laminated structure 4 in which a fiber sheet 2 and a thermoplastic resin film 3 are bonded to the surface of a hollow plate-like body 1, Even if bent, protrusion wrinkles due to buckling or bending do not occur or hardly occur. The reason for this is that the fiber sheet is strong against tension but weak against compression, so it tends to buckle when bent. However, since the thermoplastic resin film has the same strength in tension and compression, the strength reduction of the fiber sheet is suppressed and the buckling strength is improved. As a result, the strength does not decrease, and both the bending rigidity and the bending strength can be satisfied while maintaining the light weight as a whole. In addition to the fiber sheet and the thermoplastic resin film, an adhesive sheet or a protective sheet (such as a decorative sheet) may be optionally laminated.

  The adhesive may be, for example, a PE (polyethylene) or PP (polypropylene) film, or a material in which both materials are mixed. As a form, an adhesive film, an adhesive nonwoven fabric, a liquid adhesive, or the like may be used. The adhesive film, the adhesive nonwoven fabric, or the like may be a multi-layer adhesive film. Other materials may be ethylene vinyl acetate copolymer (EVA) or olefinic film.

When an adhesive film is used as the adhesive, the thickness is preferably about 5 to 200 μm, and the weight (weight per unit area) of the adhesive film is preferably 10 to ²⁰⁰ g / m ² . The adhesive film and the adhesive nonwoven fabric are 5 to 40 ° C. lower than the thermoplastic resin film.

  In the present invention, the hollow plate-like body refers to an uneven core layer. For example, it refers to a rigid body such as a honeycomb core, a corrugated core, or a hollow columnar core, and may be any type. For example, all the hollow plate-like bodies disclosed in Patent Documents 1 to 5 can be used. When shown in the drawing, the hollow plate-like body of FIGS. 2A-E can be mentioned as an example. 2A is an example of a honeycomb core, FIG. 2B is an example of a hollow cylindrical core, FIG. 2C is an example of a corrugated core by embossing, FIG. 2D is an example of an extruded harmonica core, and FIG. 2E is a honeycomb formed from a film It is an example of a core. As another example of the honeycomb core, there is a hollow plate-like body in which conical shapes are faced and bonded. 2A to 2E are examples in which the composite sheet 9 in which the fiber sheet 7 and the thermoplastic resin film 8 are integrated in advance is bonded to both surfaces of the hollow plate 1. In addition, the hollow plate-like body includes those in which a resin film is pasted or integrally formed on an uneven core layer to form a flat surface.

  The material of the hollow plate may be any thermoplastic resin, such as polypropylene (PP), polyethylene (PE), polystyrene (PS), acrylonitrile-styrene resin (AS), acrylonitrile-butadiene-styrene. Resin (ABS), vinyl chloride resin (PVC), methacrylic resin (PMMA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyvinylidene chloride (PVDC), ethylene vinyl alcohol copolymer (E / VAL), ionomer ( A resin obtained by allowing a polyvalent metal ion to act on a copolymer of ethylene and acrylic acid or methacrylic acid), polyamide (PA), polyacetal (POM), polycarbonate (PC), or the like can be used. Among these, polypropylene is preferable from the viewpoint of cost and lightness. For example, the thickness of the hollow plate is 3 to 30 mm.

  The fiber sheet used in the present invention is preferably at least one fiber sheet selected from woven fabric, knitted fabric and non-woven fabric. Examples of the woven fabric include plain weave, twill weave, satin weave and iris weave using continuous fibers, triaxial woven fabric, and the like. Examples of the knitted fabric include flat knitting using continuous fibers, rib knitting, tricot, russell, and moquette. Examples of the nonwoven fabric include spunbond nonwoven fabric, thermal bond nonwoven fabric, and needle punched nonwoven fabric. As the fiber sheet, a lace, a braid, a net and the like can be used. When these fiber sheets are laminated with a film, even if bent, protrusion wrinkles and recesses due to buckling are hardly formed, and bending strength (buckling strength) can be increased. Among these, a woven fabric using continuous fibers is preferable because it is thin, can have high strength, and has high surface smoothness. In the above, continuous fibers are long fibers (filament fibers). In the above, the filament fiber may be a monofilament or a multifilament.

  The fiber material composing the fiber sheet may be any fiber such as polypropylene (PP) fiber, polyethylene terephthalate (PET) fiber, thermoplastic resin fiber such as nylon fiber, natural fiber such as cotton or hemp, glass fiber, carbon fiber, etc. You can choose. Among these, considering the balance of cost, strength, durability, easy waste, etc., fabrics made of organic fibers such as thermoplastic resin fibers and natural fibers are preferable, and fabrics made of thermoplastic resin fibers are particularly preferable.

The basis weight of the fiber sheet is usually 100 to 800 g / m ² , and preferably 200 to 700 g / m ² from the viewpoint of the balance between lightness and reinforcement.

  The fiber sheet may be a laminate of at least one fiber sheet selected from woven fabric, knitted fabric and non-woven fabric and a multiaxial fiber sheet. A multiaxial fiber sheet is a laminate of thermoplastic resin fibers arranged in one direction, laminated in multiple layers so that the fiber directions are different, and integrated, using a stitch yarn, fusion of constituent fibers, low melting point The whole is integrated by a method such as fiber bonding or adhesive bonding. In view of handleability, a method of knitting with a thermoplastic stitch yarn is preferable. A fiber layer arranged in one direction has fibers arranged in multiple directions such as vertical, horizontal, and diagonal, and there is no crossing point of fibers like woven or knitted fabrics. high. However, since the layers of the multiaxial fiber sheet are arranged in one direction, gaps may be formed between the fibers when attempting to reduce the weight, and the appearance may be uneven. Therefore, by applying a fabric having a basis weight equivalent to that of a multiaxial fiber sheet that is reduced in weight instead of the multiaxial fiber sheet, the appearance becomes uniform and the design can be improved. For example, in a method of attaching a woven fabric on a 90 ° / 30 ° / −30 ° triaxial fiber sheet or a 90 ° / 30 ° / −30 ° triaxial fiber sheet, the basis weight is the same as that of a 90 ° fiber sheet. The appearance becomes uniform and the design is improved by a method of sticking an amount of woven fabric on a biaxial fiber sheet of 30 ° / −30 °. Furthermore, by using a multiaxial fiber sheet having a fiber direction in a direction different from the warp and weft of the woven fabric, it is possible to use such that the directionality of the strength is reduced. Furthermore, when two or more of the triaxial fiber sheets are laminated and used, one of them (particularly, the uppermost layer) can be made into a woven fabric.

  The thermoplastic resin film may be any film such as an unstretched film, a uniaxially stretched film, or a biaxially stretched film (biaxially oriented film). Examples of the material include polypropylene (PP), polyethylene (PE), and polystyrene. (PS), acrylonitrile-styrene resin (AS), acrylonitrile-butadiene-styrene resin (ABS), vinyl chloride resin (PVC), methacrylic resin (PMMA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polychlorinated Vinylidene (PVDC), ethylene vinyl alcohol copolymer (E / VAL), ionomer (resin obtained by allowing polyvalent metal ions to act on a copolymer of ethylene and acrylic acid or methacrylic acid), polyamide (PA), polyaceter (POM), polycarbonate (PC), such as ethylene vinyl acetate copolymer (EVA) can be used. Among these, PP and PE are preferable from the viewpoint of cost and lightness. The preferable thickness of the thermoplastic resin film is preferably 0.1 to 0.5 mm because it is lightweight and has high impact strength. A thickness of 0.5 to 3.0 mm is also possible. Note that the thermoplastic resin film may be a single layer or a multilayer, and even if the single layer is a film thinner than the above thickness, if it is within the above range as a multilayer film, it is possible to cause protrusion wrinkles due to buckling. This is effective to prevent the occurrence of Further, it is preferable to increase the impact strength by adding a softening agent (elastomer). Weathering agents, antistatic agents, and other effective materials may be added to the thermoplastic resin film.

  Regarding the fiber sheet and the hollow plate-like body, when the hollow plate-like body has a honeycomb shape, the angle of the honeycomb-shaped pieces and the warp or weft direction of the woven fabric of the fiber sheet may be the same. Alternatively, the pair of honeycomb pieces and the warp or weft direction of the fabric may be the same, or the pair of honeycomb pieces and the warp or weft direction of the fabric may be the same. Further, when the warp or weft direction of the fabric of the fiber sheet is orthogonal to the parallel honeycomb-shaped pieces, the bending rigidity or bending strength is improved. Furthermore, when there are a strong direction and a weak direction in the bending rigidity and bending strength of the hollow plate-like body, the fiber sheet may be provided with directionality so as to particularly compensate for the weak direction of the hollow plate-like body.

For the laminated structure, it is preferable to use the same material from the viewpoint of bonding such as welding and recyclability. In particular, the hollow plate-like body, the fiber sheet, and the thermoplastic resin film are made of the same material, for example, polypropylene (PP), polyethylene (PE), polystyrene (PS), acrylonitrile-styrene resin (AS), acrylonitrile-butadiene-styrene resin (ABS). ), Vinyl chloride resin (PVC), methacrylic resin (PMMA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyvinylidene chloride (PVDC), ethylene vinyl alcohol copolymer (E / VAL), ionomer (ethylene and acrylic) Resin obtained by allowing polyvalent metal ions to act on a copolymer with acid or methacrylic acid), polyamide (PA), polyacetal (POM), polycarbonate (PC), ethylene vinyl acetate copolymer (EVA), etc. It can be. Among these, PP and PE are preferable from the viewpoint of cost and lightness. Since this laminated structure has a fiber sheet even if the thermoplastic resin film or the hollow plate-like body is damaged by an impact, it prevents scattering. The apparent density of the laminated structure is 0.05 to 1.0 g / cm ^3, preferably 0.1 to 0.5 g / cm ³ . It is also possible to reduce the weight (weight per unit area) of the fiber sheet from the thermoplastic resin film, and it is possible to reduce the weight (per unit area) of the thermoplastic resin film from the fiber sheet.

  In the laminated structure of the present invention, when a composite sheet in which a fiber sheet and a thermoplastic resin film are integrated is used, the fiber sheet may be sandwiched between thermoplastic resin films to form a sandwich structure. If it does in this way, generation | occurrence | production of the wrinkle of a fiber sheet can be prevented.

  Further, when the fiber sheet is composed of a laminate of a plurality of layers and the surface layer is a PE fiber layer, the adhesive film is also preferably made of PE. This is because the adhesiveness can be improved.

  In the laminated structure of the present invention, wrinkles are unlikely to occur even if an adhesive film is not used, as long as each sheet is laminated in order on a core made of a hollow plate. Further, when the thermoplastic resin film is formed by mixing the resin material on the outside of the fiber sheet and other materials, and the thermoplastic resin film and the fiber sheet are bonded together, the peel strength is improved.

  A thermoplastic resin film is good also as a resin layer extruded directly with respect to a fiber sheet. Each sheet or film may be a single layer or a multilayer. In the case of a multilayer, it can be made into two layers, three layers or more. As an example, the melting point of each layer can be thermoplastic resin film> adhesive film ≧ fiber sheet or thermoplastic resin sheet> fiber sheet. The melting point of the hollow plate-like body is preferably equal to that of the thermoplastic resin film, and preferably equal to or higher than that of the fiber sheet. The thermoplastic resin film is preferably thinner than the resin film on the uneven core layer, and may be equal or thicker than the resin film on the core layer.

  Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to the following examples.

Example 1
<Hollow plate>
A core material (the shape shown in FIG. 2E) having a thickness of 8 mm manufactured by Gifu Plastic Industry Co., Ltd. was used (hereinafter referred to as “T8”). The weight (weight) per square meter was 1100 g / m ² . This hollow plate-like body is obtained by forming a honeycomb core material by vacuum forming a polypropylene (PP) sheet having a thickness of 0.3 mm and folding it. Since the surface of the honeycomb core material has recesses and holes, the bonding area of the fiber sheet is increased and an anchor effect is obtained, so that the welding strength is increased.
<Fiber sheet>
The yarn of the total denier 1100dtex stocked pull the polypropylene monofilament yarns, were used warp density and weft density 12 yarns / inch and the plain weave fabric (the weight per unit area 105 g / m ²⁾ with 3 stacked.
<Thermoplastic resin film>
An unstretched sheet made of polypropylene resin having a thickness of 0.8 mm and a tensile elastic modulus of 1600 (MPa) was used (abbreviated as “PP 0.8 mm”). An unstretched sheet made of polypropylene resin with a thickness of 0.2 mm is abbreviated as “PP 0.2 mm”, and an unstretched sheet made of polypropylene resin with a thickness of 0.4 mm is abbreviated as “PP 0.4 mm”.
<Adhesive film>
A polyethylene film having a thickness of 0.03 mm was interposed as an adhesive film between the hollow plate-like body, the fiber sheet, and the thermoplastic resin film.
<Creation of laminated structure>
A fiber sheet was laminated on both surfaces of the hollow plate-like body, a thermoplastic resin film was further laminated with an adhesive film interposed therebetween, and the whole was integrated by welding the adhesive film by a thermal laminating method.

  The bending test of the obtained laminated structure was measured by a four-point bending method based on ASTM C393. The test piece size was 75 mm in width, 550 mm in length, and the test speed was 20 mm / min. The fulcrum span was 500 mm and the load span was 50 mm. The results were as shown in Table 1 below. The weight ratio is the weight ratio when the weight of the reference experiment number 1-1 is 100.

  As is apparent from Table 1, the products of the present invention (Experiment Nos. 1-3 and 1-4) could be reduced in weight, and no protruding wrinkles due to buckling occurred in the bending test.

(Example 2)
As the hollow plate-like body, a core material having a thickness of 30 mm (trade name “TECCELL” manufactured by Gifu Plastic Industry Co., Ltd.) was used (hereinafter referred to as T30). The weight per square meter (weight per unit area) was 2100 g / m ² . A laminated structure was produced in the same manner as in Example 1 except for the hollow plate-like body. The results of the bending test of the obtained laminated structure were as shown in Table 2 below. The weight ratio is a weight ratio when the weight of the reference experiment number 2-1 is 100.

  As is apparent from Table 2, the products of the present invention (Experiment Nos. 2-3 and 2-4) could be reduced in weight, and no protruding wrinkles due to buckling occurred in the bending test. Also, good results were obtained even when the lamination order of the woven fabric and the thermoplastic resin film was changed.

  The laminated structure of the present invention includes containers, shelves, pallets, panels, bags, sleeve boxes for automatic warehouses, doors, long boxes for roll collection, tatami cores, wall materials for exhibition booths, T-boards (truck pads) Plate) and a laminated structure such as a simple table set.

The preferred embodiments of the present invention are summarized as follows.
(1) A laminated structure characterized in that a fiber sheet (except a multiaxial fiber sheet alone) and a thermoplastic resin film are bonded to at least one main surface of a hollow plate made of thermoplastic resin.
(2) The laminated structure according to (1), wherein the fiber sheet and the thermoplastic resin film are bonded to both main surfaces of the hollow plate-like body.
(3) The laminated structure according to (1) or (2), wherein the laminating is at least one selected from direct lamination, adhesion with a low-melting film and thermal lamination and adhesive.
(4) The laminated structure according to any one of (1) to (3), in which a fiber sheet and a thermoplastic resin film are bonded in this order to a thermoplastic resin hollow plate-like body. Laminated structure.
(5) The laminated structure according to any one of (1) to (3), wherein a thermoplastic resin film and a fiber sheet are bonded in this order to a hollow plate-like body made of a thermoplastic resin. Laminated structure.
(6) The laminated structure according to any one of (1) to (5), wherein the sheet is composed of continuous fibers.

DESCRIPTION OF SYMBOLS 1 Hollow plate-like body 2,7 Fiber sheet 3,8 Thermoplastic resin film 4,5 Laminated structure 6 Protruding wrinkle 9 Composite sheet

In the laminated structure of the present invention, a fiber sheet and a thermoplastic resin film are arranged in this order on both main surfaces of a polypropylene hollow plate body core material in which hollow plate bodies are arranged in the thickness direction formed by a polypropylene sheet. The fiber sheet is a polypropylene woven fabric, the thermoplastic resin film is a polypropylene film, and a low melting point film is interposed between the core material and the polypropylene woven fabric. And bonded by heat lamination.
Another laminated structure of the present invention includes a fiber sheet and a thermoplastic resin film on both main surfaces of a polypropylene hollow plate body core material in which hollow plate bodies are arranged in the thickness direction formed by a polypropylene sheet. A laminated structure bonded in this order, wherein the fiber sheet is a polypropylene woven fabric, the thermoplastic resin film is a polypropylene film, and the polypropylene woven fabric is sandwiched between the polypropylene films to form a sandwich structure. The layers of the core material, the polypropylene fabric, and the polypropylene film are bonded by thermal lamination with a low melting point film interposed therebetween.
In another laminated structure of the present invention, a thermoplastic resin film and a nonwoven fabric sheet are attached to at least one main surface of a polypropylene honeycomb core material in which hollow plate-like bodies are arranged in the thickness direction formed by a polypropylene sheet. The honeycomb core material is obtained by forming a honeycomb core material by vacuum forming a polypropylene sheet into a three-dimensional shape, and folding the polypropylene sheet. In addition, a hole is formed, and a thermoplastic resin film is bonded to the surface of the honeycomb core material.

Claims (4)

  A laminated structure in which a fiber sheet (except a multiaxial fiber sheet alone) and a thermoplastic resin film are bonded to at least one main surface of a hollow plate made of thermoplastic resin.   The laminated structure according to claim 1, wherein the fiber sheet and the thermoplastic resin film are bonded to both main surfaces of the hollow plate-like body.   The laminated structure according to claim 1 or 2, wherein the fiber sheet is at least one fiber sheet selected from a woven fabric, a knitted fabric, a nonwoven fabric, a braid, a lace, and a net.   The laminated structure according to claim 1, wherein the sheet is composed of continuous fibers.

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