JP2024062758A - Fiber-reinforced resin sheet and fiber-reinforced laminate using same - Google Patents

Abstract

[Problem] To provide a fiber-reinforced resin sheet capable of increasing the strength of a fiber-reinforced laminate including a substrate and a fiber-reinforced resin sheet when attached to a substrate. [Solution] In one aspect, the present invention relates to a fiber-reinforced resin sheet including a spread sheet in which continuous fibers are aligned in one direction and a matrix resin, the matrix resin being a thermoplastic resin, and the volume ratio (Vf) of the continuous fibers being 10 volume % or more and 60 volume % or less when the volume of the fiber-reinforced resin sheet is taken as 100 volume %. The matrix resin is preferably a dried thermoplastic resin emulsion. The substrate is preferably a strength reinforcement material that is fixed to the substrate by thermal adhesion or adhesive, the strength reinforcement being preferably at least one selected from resin, wood, and metal. [Selected Figure] Figure 1

Description

The present invention relates to a fiber-reinforced resin sheet and a fiber-reinforced laminate using the same.

Wood-based materials, plastic materials, metal materials, concrete, ceramics, and other inorganic materials are used as substrates in various applications, including industrial applications and building materials. Wood-based building materials such as MDF (Medium Density Fiberboard) change in moisture content and dimensions with changes in atmospheric conditions, just like wood. For this reason, strength reinforcement materials that contribute to improving dimensional stability as well as strength have been proposed. In addition, polyvinyl chloride resin is flame retardant, has excellent thermal insulation, chemical resistance, electrical insulation, and impact resistance, is lightweight, and is easy to process, so it is widely used, for example, as a material for building interiors. Since it is also used in applications that require impact resistance, such as sashes, further improvements in strength are required.

The following Patent Document 1 discloses a strength reinforcing material for wood-based plywood. When this strength reinforcing material is attached to wood-based plywood, it increases the dimensional stability of the plywood and contributes to improving its strength. The strength reinforcing material has a two-layer structure consisting of paper and a net-like sheet in which glass fiber bundles of a specific diameter are arranged vertically and horizontally at a specific density. The net-like sheet is formed by immersing it in an adhesive solution such as polyacrylic acid ethyl ester emulsion, squeezing it, and then drying it.

Patent Document 2 discloses a reinforced fiber fabric as a reinforcing material for plastics and the like. The reinforced fiber fabric is woven with warp and weft threads, and the warp and weft threads are made of reinforcing multifilament yarns that are flattened and spread to have a yarn width of 3 mm or more. Thermoplastic resin is partially present between each filament of the multifilament yarns that form the warp and weft threads, and the filaments are bonded to each other by fusion of this thermoplastic resin. A thermoplastic resin emulsion in which thermoplastic resin particles are dispersed in a liquid phase is used as the thermoplastic resin raw material. The amount of thermoplastic resin emulsion applied is preferably as small as possible to suppress the opening of the finally obtained reinforced fiber fabric, and is an amount that results in a thermoplastic resin content of 10% by weight or less, preferably 5% by weight or less in the fabric.

Japanese Patent Application Laid-Open No. 9-52316 JP 2001-226850 A

However, although the above-mentioned glass fiber net is effective in suppressing shrinkage of the attached substrate, such as MDF or resin board, its effect in improving bending strength is insufficient, and further improvement is required.

The present invention provides a fiber-reinforced resin sheet that, when attached to a substrate, can increase the strength of a fiber-reinforced laminate that includes the substrate and a fiber-reinforced resin sheet. The present invention also provides a fiber-reinforced laminate that includes the fiber-reinforced resin sheet and the substrate.

The present invention, in one aspect, comprises:
A fiber-reinforced resin sheet including a spread sheet in which continuous fibers are aligned in one direction and a matrix resin,
the matrix resin is a thermoplastic resin,
The fiber reinforced resin sheet has a volume ratio (Vf) of the continuous fibers of 10 volume% or more and 60 volume% or less when the volume of the fiber reinforced resin sheet is 100 volume%.

In one aspect, the present invention provides a method for producing a fiber-reinforced resin sheet of the present invention,
a resin adhering step of adhering a thermoplastic resin emulsion to the continuous fibers;
a sheet forming step of spreading and widening a continuous fiber bundle made of a large number of continuous fibers to form a thin-film spread sheet in which the continuous fibers are arranged in one direction;
A drying step of drying the thermoplastic resin emulsion,
The present invention relates to a method for producing a fiber-reinforced resin sheet, wherein a volume ratio (Vf) of the continuous fibers is 10 volume% or more and 60 volume% or less when the volume of the fiber-reinforced resin sheet is 100 volume%.

The present invention, in one aspect, comprises:
The present invention relates to a fiber-reinforced laminate comprising a substrate and the fiber-reinforced resin sheet of the present invention attached to one or both main surfaces of the substrate.

When the fiber-reinforced resin sheet of the present invention is attached to a substrate, it can increase the strength of a fiber-reinforced laminate including the substrate and the fiber-reinforced resin sheet.
The fiber-reinforced laminate of the present invention has high strength because it contains the fiber-reinforced resin sheet of the present invention.

FIG. 1 is a schematic perspective view of a fiber-reinforced resin sheet according to one embodiment of the present invention. FIG. 2 is a schematic perspective view of a fiber-reinforced resin sheet according to one embodiment of the present invention. FIG. 3 is a schematic process diagram showing a method for producing a fiber-reinforced resin sheet according to one embodiment of the present invention. FIG. 4 is a schematic perspective view of a fiber-reinforced laminate according to one embodiment of the present invention. FIG. 5 is a schematic perspective view of a fiber-reinforced laminate according to one embodiment of the present invention. FIG. 6 is a schematic perspective view of a fiber-reinforced laminate according to one embodiment of the present invention. FIG. 7 is a schematic diagram illustrating the three-point bending test. FIG. 8 is a photograph of the fiber reinforced resin sheet of Example 1.

[Fiber-reinforced resin sheet]
In one aspect, the present invention provides a fiber-reinforced resin sheet including a matrix resin and an open fiber sheet in which continuous fiber bundles are opened and widened to align a plurality of continuous fibers in one direction. The fiber-reinforced resin sheet is a strength reinforcing material that is fixed by thermal bonding or adhesive to a substrate containing at least one material selected from resin, wood, metal, and inorganic materials other than metal. Examples of substrates include building materials, and specific examples thereof include wood-based boards such as particle boards, plywood, and MDF, resin boards such as polyvinyl chloride resin and olefin resin, metal boards laminated with polyvinyl chloride resin sheets, metal boards laminated with polyolefin resin sheets, and boards made of inorganic materials such as concrete and ceramics.

The continuous fibers are long fibers and are reinforcing fibers that constitute the fiber-reinforced resin sheet. The continuous fibers preferably contain at least one continuous fiber selected from glass fibers, carbon fibers, basalt fibers, and high-modulus fibers with an elastic modulus of 380 cN/dtex or more. Examples of the high-modulus fibers include aramid fibers, particularly para-aramid fibers (elastic modulus: 380 to 980 cN/dtex), polyarylate fibers (elastic modulus: 600 to 741 cN/dtex), heterocyclic polymer fibers (PBO, elastic modulus: 1060 to 2200 cN/dtex), high molecular weight polyethylene fibers (elastic modulus: 883 to 1413 cN/dtex), and polyvinyl alcohol fibers (PVA, strength: 14 to 18 cN/dtex). These fibers are useful as resin-reinforced fibers and can be selected according to the application of the fiber-reinforced resin sheet. In particular, glass fibers are useful from the standpoints of cost, light weight, and flame retardancy.

In the fiber-reinforced resin sheet, the main reinforcing fiber is a spread sheet in which continuous fiber bundles are spread and widened to align the continuous fibers in one direction. In the fiber-reinforced resin sheet, fibers other than the main reinforcing fiber may be arranged as auxiliary fibers at an angle different from the longitudinal direction (also called the orientation direction or MD direction) of the continuous fibers. Examples of auxiliary fibers include carbon fiber, glass fiber, aramid (including para-type and meta-type) fiber, polyarylate fiber, poly(p-phenylene benzobisoxal) (PBO) fiber, poly(p-phenylene benzobisthiazole) (PBZT) fiber, high molecular weight polyethylene fiber, polyether ether ketone fiber, and polyvinyl alcohol fiber. In addition, the spread sheet may further contain bridge fibers oriented in a direction transverse to the continuous fibers. The bridge fibers can be generated from the continuous fibers during or after the spread of the continuous fiber bundles (filament group). The auxiliary fibers and bridge fibers are bonded and fixed to the continuous fibers by a thermoplastic resin.

The continuous fibers constituting the continuous fiber bundle may be twisted, but it is preferable that the fibers be untwisted roving yarns, since this makes it easier for the thermoplastic resin emulsion to soak into the spread fiber sheet during the manufacturing process of the fiber-reinforced resin sheet.

The thickness (single fiber diameter) of the continuous fibers constituting the continuous fiber bundle is preferably large because the thermoplastic resin emulsion can easily penetrate into the spread fiber sheet during the manufacturing process of the fiber reinforced resin sheet. Specifically, the thickness is preferably 5 to 50 μm, and more preferably 7 to 30 μm.

The volume ratio (Vf) of the continuous fibers when the volume of the fiber-reinforced resin sheet is taken as 100% by volume is preferably 10% by volume or more, more preferably 15% by volume or more, from the viewpoint of improving the strength of the fiber-reinforced laminate including the substrate and the fiber-reinforced resin sheet, and is preferably 60% by volume or less, more preferably 50% by volume or less, from the viewpoint of improving adhesion to the substrate.

The type of thermoplastic resin constituting the fiber-reinforced resin sheet may be appropriately selected according to the material of the substrate to be adhered, but one or more types selected from vinyl chloride resins, ethylene vinyl alcohol resins, urethane resins, acrylic resins, polyolefin resins such as polypropylene resins and polyethylene resins are preferred, one or more types selected from vinyl chloride resins, acrylic resins, and polyolefin resins are more preferred, and one or more types selected from vinyl chloride resins and acrylic resins are even more preferred. Examples of vinyl chloride resins include vinyl chloride homopolymers and resins whose main constituent unit is vinyl chloride, such as copolymers of vinyl chloride with other monomers copolymerizable with vinyl chloride. Examples of other monomers copolymerizable with vinyl chloride include one or more types of ethylene, propylene, vinyl acetate, etc. Examples of polyacrylic resins are resins whose main constituent unit is a monomer having a (meth)acrylic group, and examples of such resins include acrylic resins, polymethyl methacrylate resins, polymethyl acrylate resins, etc.

The content of the thermoplastic resin in the fiber-reinforced resin sheet is preferably 3% by mass or more, more preferably 5% by mass or more, from the viewpoint of improving adhesion to the substrate, and is preferably 70% by mass or less, more preferably 50% by mass or less, from the viewpoint of improving the strength of the fiber-reinforced laminate including the substrate and the fiber-reinforced resin sheet.

The mass per unit area of the spread sheet in which the continuous fiber bundles are spread and expanded and the continuous fibers are aligned in one direction is preferably 30 g/ ^m2 or more and more preferably 50 g/ ^m2 or more from the viewpoint of improving the strength of the fiber reinforced laminate including the adherend substrate and the fiber reinforced resin sheet, and is preferably 400 g/ ^m2 or less and more preferably 300 g/ ^m2 or less from the viewpoint of adhesion of the thermoplastic resin.

The mass per unit area of the fiber-reinforced resin sheet is preferably 40 g/ ^m2 or more, more preferably 50 g/ ^m2 or more, from the viewpoint of the handleability of the fiber-reinforced resin sheet and the strength retention of the fiber-reinforced resin sheet itself, and is preferably 500 g/ ^m2 or less, more preferably 400 g/ ^m2 or less, from the viewpoint of the drapeability of the fiber-reinforced resin sheet.

The thickness of the fiber-reinforced resin sheet is preferably 0.01 mm or more, more preferably 0.5 mm or more, from the viewpoint of the handleability of the fiber-reinforced resin sheet and the strength retention of the fiber-reinforced resin sheet itself, and is preferably 2 mm or less, more preferably 1 mm or less, from the viewpoint of the drapeability of the fiber-reinforced resin sheet.

Next, an example of a fiber-reinforced resin sheet will be described in more detail with reference to Figures 1 and 2, taking as an example a case in which the continuous fibers are glass fibers. Figure 1 is a schematic perspective view of an example of the fiber-reinforced resin sheet 1, and Figure 2 is a schematic cross-sectional view of the fiber-reinforced resin sheet 1 shown in Figure 1.

In FIG. 1, the fiber reinforced resin sheet 1 includes a spread sheet 3 in which glass fibers 2 are arranged in one direction. The spread sheet 3 is in the form of a thin film. The glass fibers 2 are monofilament threads. Adjacent glass fibers 2 are bonded to each other by the thermoplastic resin 4 that has entered between them, and the thermoplastic resin 4 and the thin spread sheet 3 are integrated. The thermoplastic resin 4 is the matrix resin in the fiber reinforced resin sheet 1. In addition, the thermoplastic resin 4 may be attached not only between adjacent glass fibers 2 but also above and below the glass fibers, so that the entire circumference of the glass fibers 2 is coated with the thermoplastic resin 4.

Figure 3 is a schematic process diagram showing a method for manufacturing a fiber-reinforced resin sheet. A large number of supply bobbins 7 are installed on a creel (frame), and glass fiber rovings 8 are drawn from each bobbin 7 and supplied to a supply section 9 of thermoplastic resin emulsion (resin attachment process). The supply section 9 is not particularly limited as long as it is an apparatus that can attach the thermoplastic resin emulsion 92 to the roving 8 by a roll coating method, a dipping method, a spray method, or the like. However, as shown in Figure 3, a supply section 9 equipped with a coating roller 91 and capable of applying the thermoplastic resin emulsion by a roll coating method or a roll touch method is preferred because it is easy to apply uniformly. The amount of the thermoplastic resin emulsion 92 attached to the roving 8 can be adjusted by adjusting the contact length of the roving 8 with the coating roller 91, the rotation speed of the coating roller 91, the solids concentration of the thermoplastic resin emulsion, etc. The amount of thermoplastic resin emulsion applied is such that the volume ratio (Vf) of the thermoplastic resin emulsion (i.e., thermoplastic resin) after drying is 40% by volume or more and 90% by volume or less, preferably 50% by volume or more and 85% by volume or less, when the volume of the fiber-reinforced resin sheet is 100% by volume.

Next, the roving 8 coated with the thermoplastic resin emulsion is opened and widened in the opening and widening section 11 to form a thin film (sheet formation process). As the opening and widening method by the opening and widening section 11, at least one method selected from the roll opening method, the airflow suction opening method, the airflow blowing opening method, the method using a vibration bar, and the ultrasonic opening method is preferable, and among them, the roll opening method in which the roving 8 is opened and widened by passing it between multiple opening rolls is preferable. In this way, it is preferable that the attachment of the thermoplastic resin emulsion to the continuous fibers and the opening and widening process of the continuous fibers are performed continuously. Next, the roving 8 to which the thermoplastic resin emulsion is attached and which has been opened and widened (i.e., the opened sheet to which the thermoplastic resin emulsion is attached) is supplied into the dryer 12, and the liquid component of the thermoplastic resin emulsion is vaporized in the dryer 12. The appropriate ambient temperature in the dryer is 100 to 200°C. The thermoplastic resin emulsion becomes the matrix resin of the fiber-reinforced resin sheet by drying (drying process). It is then wound up by a winding machine 13.

While the resin attachment process and the sheet formation process can be carried out in either order, it is preferable to carry out the resin attachment process and the sheet formation process in this order, as this makes it easier to obtain a soft fiber-reinforced resin sheet.

The solids concentration of the thermoplastic resin emulsion is preferably within the range of 5 to 70% by mass, and more preferably 20 to 65% by mass, because this makes it easier to obtain the desired Vf value. The particle size of the thermoplastic resin particles dispersed in the liquid phase is preferably smaller than the diameter of the filament.

Thermoplastic resin emulsions may be emulsified during synthesis or after synthesis. The polymer composition may be selected appropriately depending on the material of the substrate to be adhered. The solvent for thermoplastic resin emulsions is water, but small amounts of organic solvents such as alcohol may also be included. Thermoplastic resin emulsions may also contain antiblocking agents such as melamine resins, crosslinking agents, flame retardants, etc.

[Fiber-reinforced laminate]
In one aspect, the present invention relates to a fiber-reinforced laminate in which the fiber-reinforced resin sheet of the present invention is attached to one or both main surfaces of a substrate such as a wood-based board such as MDF or a polyvinyl chloride (PVC) board. The number of fiber-reinforced resin sheets attached may be multiple sheets on each main surface, but is preferably one sheet from the viewpoint of strength improvement effect vs. cost and productivity. When multiple fiber-reinforced resin sheets are laminated on one or both of the substrates, they may be laminated at any angle such as 0°, 45°, or 90°.

The fiber-reinforced resin sheet is bonded to the substrate by heat or adhesive depending on the type of substrate. When the bonding surface of the substrate with the fiber-reinforced resin sheet is made of a resin material, for example, a laminate in which the substrate is arranged between two fiber-reinforced resin sheets is hot-pressed to melt the resin constituting the substrate, which then solidifies and bonds them together. When the bonding surface of the substrate with the fiber-reinforced resin sheet is made of a material that is difficult to bond with heat alone, such as wood, the fiber-reinforced resin sheet and the substrate are bonded to each other by adhesive. Examples of adhesives include epoxy adhesives that harden at room temperature and heat-curing adhesives. The amount of adhesive applied is appropriately about 50 to 300 g/m ^2. After the fiber-reinforced resin sheet is bonded to the substrate by heat or adhesive, the substrate is cured for a predetermined time, preferably one day or more, preferably under pressure, to increase the bonding strength between the substrate and the fiber-reinforced resin sheet. The fiber-reinforced laminate of the present invention may further include a surface decorative layer, which is disposed above the fiber-reinforced resin sheet and serves as one of the outermost layers of the fiber-reinforced laminate, depending on the intended use. There are no particular limitations on the material of the surface decorative layer, and it may be a known material such as polyethylene.

Figure 4 is a schematic perspective view of a fiber-reinforced laminate 10 according to one embodiment of the present invention. In Figure 4, 1 is a fiber-reinforced resin sheet, and 15 is a resin plate (adhering substrate). A pair of fiber-reinforced resin sheets 1 are each thermally bonded to the main surface of the adhering substrate. The resin plate is, for example, a polyvinyl chloride resin plate, the thermoplastic resin contained in the fiber-reinforced resin sheet 1 is, for example, a mixture of acrylic resin and polyvinyl chloride resin, and the continuous fibers are glass fibers.

Figure 5 is a schematic perspective view of a fiber-reinforced laminate 10 according to another embodiment of the present invention. In Figure 5, 1 is a fiber-reinforced resin sheet, and 15 is a wood-based board (adhering substrate) such as MDF. The fiber-reinforced resin sheet 1 and the wood-based board are bonded together with an adhesive 16. The adhesive 16 is an epoxy resin-based adhesive, the thermoplastic resin contained in the fiber-reinforced resin sheet 1 is, for example, 100% acrylic resin, and the continuous fibers are glass fibers.

Figure 6 is a schematic perspective view of a fiber-reinforced laminate 10 according to another embodiment of the present invention. The fiber-reinforced laminate 10 shown in Figure 6 has the same structure as the fiber-reinforced laminate 10 shown in Figure 4, except that a surface decorative layer 17 is disposed on one of the fiber-reinforced resin sheets 1. The surface decorative layer 17 is, for example, a polyethylene sheet.

1. Methods for Measuring Various Parameters The present invention will be specifically described below using examples. Note that the present invention is not limited to the following examples. Methods for measuring various parameters are as follows.

<Three-point bending test>
The flexural modulus of the following samples was measured in accordance with JIS K 7017-1999 using the following measuring device under the following conditions. Specifically, a three-point bending test shown in FIG. 7 was performed to measure the load and the displacement of the pressure support, and the flexural modulus and flexural strength were calculated using these values. The number of tests (n) was 3, and the average values are shown in Tables 3 and 4.
Conditioning: Performed after leaving the sample to stand for 48 hours or more in an atmosphere having a temperature of 23° C. and a relative humidity of 50% RH.
Test: Three-point bending test (JIS K7017 compliant)
・Equipment: Precision universal testing machine AG-50kNXDplus (manufactured by Shimadzu Corporation)
Jig: indenter = R5 (corner roundness 5 mm), fulcrum = R2 (corner roundness 2 mm)
・Lower support interval: 37.5 mm
Test speed: 2 mm/min

[sample]
(1) fiber-reinforced laminate;
Samples of the following sizes were prepared, with the sample length (L) being in the same direction as the longitudinal direction (fiber direction) of the reinforcing fibers.
Sample length (L): 250 mm
Sample width (B): 50 mm
The sample thickness (H) differs for each sample and is shown in Table 3 or Table 4.
(2) PVC board, MDF or these substrates coated with adhesive Sample length (L): 250 mm
Sample width (B): 50 mm
The sample thickness (H) differs for each sample and is shown in Table 2 or Table 3.

<Tensile test of fiber reinforced resin sheet>
The tensile properties of the following fiber reinforced resin sheet A were evaluated under the following conditions in accordance with JIS K 7161-1:2014. The length of the sample in the same direction as the longitudinal direction (fiber direction) of the reinforcing fiber was 250 mm, and the width was 50 mm. The test length was 100 mm, and the test speed was 1 mm/min. The number of n (number of tests) was 5, and the average value is shown in Table 2.

<Glass transition temperature (Tg)>
The glass transition temperature of the thermoplastic resin is a value measured by differential scanning calorimetry (DSC) at 10° C./min according to ISO 11357.

2. Preparation of fiber reinforced resin sheet [Example 1: Fiber reinforced resin sheet A]
As the continuous fiber bundle, a glass fiber bundle (manufactured by Nitto Boseki Co., Ltd., product name "RS240PE-535FC", 2400 tex, single fiber diameter 14 μm, untwisted) was used. In addition, as the aqueous emulsion, an acrylic resin emulsion (Tg = -18 ° C.) with a resin solid concentration of 50 mass %) was prepared. Next, after impregnating the glass fiber bundle with the aqueous emulsion, the glass fiber bundle was opened and widened to form a spread sheet with a spread width of 100 mm, and then pressed against a hot plate set at 130 ° C. to vaporize the liquid component of the aqueous emulsion from the spread sheet, and a fiber reinforced resin sheet A was obtained. FIG. 8 shows a photograph of the fiber reinforced resin sheet A.
The fiber volume ratio (Vf) in the fiber reinforced resin sheet A was 32 volume%, the thickness of the fiber reinforced resin sheet was 0.3 mm, and the mass per unit area of the fiber reinforced resin sheet A was 290 g/m ^2. Of these, the mass per unit area of the glass fiber was 240 g/m ² .

[Example 2: Fiber reinforced resin sheet B]
A fiber reinforced resin sheet B was produced in the same manner as in [Example 1: Fiber Reinforced Resin Sheet A], except that a mixture of an acrylic resin emulsion (Tg = -18 ° C.) and a vinyl chloride resin emulsion (manufactured by Sumika Chemtex Co., Ltd., product name "S-830") was used instead of the acrylic resin emulsion. The mixing ratio of the acrylic resin emulsion and the vinyl chloride resin emulsion was 70 mass% acrylic resin and 30 mass% vinyl chloride resin, and the concentration of the resin solids of the aqueous emulsion diluted with water was 50 mass%.
The fiber volume ratio (Vf) in the fiber reinforced resin sheet B was 30 volume%, the thickness of the fiber reinforced resin sheet was 0.1 mm, and the mass per unit area of the fiber reinforced resin sheet B was 300 g/m ^2. Of these, the mass per unit area of the glass fiber was 240 g/m ² .

[Example 3: Fiber reinforced resin sheet C]
A fiber reinforced resin sheet C was produced in the same manner as in [Example 1: Fiber Reinforced Resin Sheet A] except that a vinyl chloride resin emulsion (manufactured by Sumika Chemtex Co., Ltd., product name “S-830”) was used instead of the acrylic resin emulsion. The concentration of the resin solid content of the aqueous emulsion was 50% by mass.
The fiber volume ratio (Vf) in the fiber reinforced resin sheet C was 30 volume%, the thickness of the fiber reinforced resin sheet was 0.1 mm, and the mass per unit area of the fiber reinforced resin sheet was 300 g/m ^2. Of these, the mass per unit area of the glass fiber was 240 g/m ² .

The compositions of fiber reinforced resin sheets A to C are summarized in Table 1 below.

The various tensile properties of the fiber-reinforced resin sheet A were measured using the method described above in "Tensile test of fiber-reinforced resin sheet" and are shown in Table 2 below.

3. Preparation of fiber-reinforced laminate 3-1. When the substrate is a PVC plate [Example 4]
Two fiber-reinforced resin sheets B were prepared by the method described in (1) above, and a PVC plate (manufactured by Sekisui Seiki Kogyo Co., Ltd., product name "Evislon", thickness 3.0 mm) was placed between the two fiber-reinforced resin sheets B to obtain a laminate, which was then heat-pressed at 160° C. for 3 minutes to be integrated. The pressure during the heat press was set to 0 MPa and was not substantially applied, so that the fiber-reinforced resin sheet B and the PVC plate were in sufficient contact with each other.

[Example 5]
A fiber-reinforced laminate of Example 5 was produced in the same manner as in [Example 4] except that the fiber-reinforced resin sheet C was used.

[Comparative Example 1]
An unreinforced PVC plate (manufactured by Sekisui Seisakusho Co., Ltd., product name "Esbilon", thickness 3.0 mm) was used as Comparative Example 1.

3-2. When the substrate is MDF [Example 6]
An epoxy resin adhesive (manufactured by Konishi, product name "Bond E Set") was applied to both main surfaces of MDF (thickness 2.5 mm), and the above fiber reinforced resin sheet A was attached to each main surface, and the sheets were cured for one day while being sandwiched in a press with a pressure sufficient to bring them into contact. The amount of epoxy resin adhesive applied was 200 g/ ^m2 .

[Comparative Example 2]
The same MDF board (thickness 2.5 mm) as that used in Example 6 was used as Comparative Example 2.

[Comparative Example 3]
An epoxy resin adhesive (manufactured by Konishi Co., Ltd., product name "Bond E Set") was applied to both main surfaces of the MDF (thickness 2.5 mm) used in Example 6, and the material was left to cure at room temperature for one day. The amount of epoxy resin adhesive applied was 200 g/ ^m2 .

[Example 7]
A polyvinyl acetate adhesive (manufactured by Konishi Co., Ltd., product name "Bond") was applied to both main surfaces of the same MDF (thickness 2.5 mm) used in Example 6, and the above-mentioned fiber reinforced resin sheet A was attached to each main surface, and the sheets were cured for one day while being sandwiched with a pressure sufficient to bring them into contact with each other using a press. The amount of polyvinyl acetate adhesive applied was 200 g/ ^m2 .

[Comparative Example 4]
A polyvinyl acetate adhesive (manufactured by Konishi Co., Ltd., product name "Bond") was applied to both main surfaces of the same MDF (thickness 2.5 mm) used in Example 6, and the material was left to cure at room temperature for one day. The amount of polyvinyl acetate adhesive applied was 200 g/ ^m2 .

The flexural modulus and flexural strength of the fiber-reinforced laminates of Examples 4 and 5 and the PVC plate of Comparative Example 1 were calculated using the method described above in the <3-point bending test>. The results are shown in Table 3 below.

As shown in Table 3, the flexural modulus and flexural strength of the fiber-reinforced laminates of Examples 4 and 5 are significantly higher than those of the fiber-reinforced laminate of Comparative Example 1.

Next, the flexural modulus and flexural strength were calculated for the fiber-reinforced laminates of Examples 6 and 7 and the comparative examples 2 to 4 using the method described above in the <3-point bending test>. The results are shown in Table 4 below.

As shown in Table 4, it was confirmed that the flexural modulus and flexural strength of the fiber-reinforced laminate of Example 6 were higher than those of the fiber-reinforced laminates of Comparative Examples 2 and 3. It was also confirmed that the flexural modulus and flexural strength of the fiber-reinforced laminate of Example 7 were higher than those of the fiber-reinforced laminate of Comparative Example 4.

The fiber-reinforced resin sheet of the present invention is useful as a fiber-reinforced material in fields that require high mechanical properties and impact resistance, such as the construction field, the aviation and space field, sports applications, automobiles, and wind turbine blades.

1 Fiber reinforced resin sheet 2 Glass fiber (continuous fiber)
Reference Signs List 3: Spread sheet 4: Thermoplastic resin 7: Supply bobbin 8: Glass fiber roving 9: Supply section 91: Application roller 92: Thermoplastic resin emulsion 10: Fiber reinforced laminate 11: Spreading section 12: Dryer 13: Winder 15: Adhering substrate 16: Adhesive 17: Surface decorative layer

Claims (9)

A fiber-reinforced resin sheet including a spread sheet in which continuous fibers are aligned in one direction and a matrix resin,
the matrix resin is a thermoplastic resin,
A fiber reinforced resin sheet, wherein the volume ratio (Vf) of the continuous fibers is 10 vol% or more and 60 vol% or less when the volume of the fiber reinforced resin sheet is 100 vol%. The fiber-reinforced resin sheet according to claim 1, which is a strength reinforcing material that is thermally bonded or adhesively fixed to a substrate containing at least one material selected from resin, wood, and inorganic materials. The fiber-reinforced resin sheet according to claim 1 or 2, wherein the matrix resin is a dried thermoplastic resin emulsion. The fiber-reinforced resin sheet according to any one of claims 1 to 3, wherein the thermoplastic resin is one or more resins selected from acrylic resins, vinyl chloride resins, urethane resins, polypropylene resins, and polyethylene resins. The fiber-reinforced resin sheet according to any one of claims 1 to 4, wherein the continuous fibers are at least one continuous fiber selected from the group consisting of glass fibers, carbon fibers, basalt fibers, and high-modulus fibers having an elastic modulus of 380 cN/dtex or more. A method for producing a fiber-reinforced resin sheet according to any one of claims 1 to 5,
a resin adhering step of adhering a thermoplastic resin emulsion to the continuous fibers;
a sheet forming process in which a continuous fiber bundle made of a large number of continuous fibers is spread and widened to form a thin-film spread sheet in which the fibers are arranged in one direction;
A drying step of drying the thermoplastic resin emulsion,
The present invention relates to a method for producing a fiber-reinforced resin sheet, wherein a volume ratio (Vf) of the continuous fibers is 10 volume% or more and 60 volume% or less when the volume of the fiber-reinforced resin sheet is 100 volume%. A fiber-reinforced laminate comprising a substrate and a fiber-reinforced resin sheet according to any one of claims 1 to 5 attached to one or both main surfaces of the substrate. The fiber-reinforced laminate according to claim 7, in which a fiber-reinforced resin sheet is attached to one or both main surfaces of the substrate. The substrate is a resin plate,
The fiber-reinforced laminate according to claim 7 , wherein the fiber-reinforced resin sheet is thermally bonded to the resin plate.