JP7118149B2 - CFRP sheet, laminate using CFRP sheet, and method for manufacturing CFRP sheet - Google Patents

Description

TECHNICAL FIELD The present invention relates to improvements in CFRP sheets, and more particularly to a CFRP sheet with excellent design, a laminate using the same, and an efficient method for producing the CFRP sheet.

In recent years, carbon fiber reinforced plastic (CFRP), which is composed of carbon fiber as a reinforcing fiber material and matrix resin, has been used in various applications due to its excellent functionality. As a CFRP sheet, a sheet in which continuous fiber-like carbon fiber bundles are vertically and horizontally oriented or a sheet formed by impregnating a matrix resin into a sheet in which carbon fiber bundles are plain-woven is widely known.

However, with regard to the above conventional CFRP sheet, when the CFRP sheet is formed into an arbitrary shape by hot pressing, the continuous fiber-like carbon fiber bundles extending over the entire sheet become a factor that hinders the conformability to the press die. There is a drawback that the formability is deteriorated due to the increase in the shape, and as a result, the shape that can be formed is limited.

Therefore, conventionally, a UD sheet in which carbon fiber bundles aligned in the length direction are bonded and integrated with a matrix resin is finely cut into strips, and the cut strip-shaped UD sheet pieces are arranged in a two-dimensional direction. A sheet-like CFRP sheet has also been developed that is integrated by hot pressing (see, for example, Patent Document 1).

However, the above-mentioned conventional CFRP sheet has an appearance of only strip-shaped (rectangular) UD sheet pieces lined up on the surface, and there is no big difference in the shape of each UD sheet piece. It was easy to become a monotonous design. Therefore, CFRP sheets have rarely been used in applications such as decorative sheets that require good design.

JP 2016-27956 A

The present invention has been made in view of the above problems, and its object is to provide a CFRP sheet that not only has excellent mechanical strength such as tensile strength but also has excellent design on the visible surface, and a An object of the present invention is to provide a laminate using the CFRP sheet and an efficient method for producing the CFRP sheet.

The means employed by the inventors to solve the above problems will be described below with reference to the accompanying drawings.

That is, in the present invention, a CFRP sheet is formed by forming a transparent resin layer C made of a thermoplastic resin on one side of a CFRP layer S, which is one layer, and the CFRP layer S is formed of a plurality of continuous fibrous layers. A plurality of UD sheet pieces obtained by bonding and integrating the carbon fibers of the carbon fibers in the longitudinal direction with a matrix resin M of a thermoplastic resin, with the fiber direction of each sheet piece randomly oriented, and , the sheet pieces are arranged two-dimensionally so as to overlap each other and are adhered with a matrix resin M, while in the CFRP layer S , among the plurality of UD sheet pieces arranged in the two-dimensional direction so as to overlap , while the UD sheet piece appearing on the back surface side, which is the opposite surface to the transparent resin layer side, is rectangular, the UD sheet piece appearing on the back surface side is on the surface side of the transparent resin layer side. and the difference between the maximum and minimum values in the length direction of the carbon fiber is 10% or more of the maximum value in the length direction, or in the direction perpendicular to the length direction of the carbon fiber A non-rectangularly distorted UD sheet piece whose difference between the maximum value and the minimum value of the dimension is 10% or more of the maximum value of the vertical dimension, and the entire UD sheet piece that appears on the surface side It is characterized by the fact that it has a composition that appears at a rate of 30% or more .

In this specification, the term “non-rectangular” means that the difference between the maximum and minimum width dimensions of the UD sheet piece (the dimension perpendicular to the length direction of the carbon fiber) is the maximum width dimension. Those with a size of 10% or more, or the difference between the maximum and minimum length dimensions (parallel to the length direction of the carbon fiber) of the UD sheet piece is the maximum length dimension It refers to those with a size of 10% or more.

In addition, the present invention provides a CFRP sheet in which a transparent resin layer C made of a thermoplastic resin is formed on one side of a CFRP layer S, which is one layer , wherein the CFRP layer S is composed of a plurality of continuous fibrous carbon fibers. A plurality of UD sheet pieces formed by bonding and integrating with a matrix resin M of a thermoplastic resin in a state of being aligned in the longitudinal direction, with the fiber direction of each sheet piece randomly oriented, and each sheet While the pieces are arranged two-dimensionally so as to overlap each other and formed by bonding with a matrix resin M , among the plurality of UD sheet pieces arranged in the two-dimensional direction so as to overlap in the CFRP layer (S), The UD sheet pieces appearing on the front side, which is the transparent resin layer side, and the UD sheet pieces appearing on the back side, which is the opposite side to the transparent resin layer side, include non-rectangularly distorted UD sheet pieces. The non-rectangularly distorted UD sheet pieces included in the UD sheet pieces appearing on the front side are configured so as to account for 30% or more of the entire UD sheet pieces appearing on the front side. can also

In addition, in the present invention, the ratio of the non-rectangularly distorted UD sheet pieces P appearing on the surface side of the CFRP layer S is set to 30% or more (preferably 50% or more), thereby providing a unique appearance design. It is possible to form a CFRP sheet excellent in

On the other hand, in the present invention, the average area per UD sheet piece P appearing on the front side of the CFRP layer S is made larger than the average area of the UD sheet piece Q appearing on the back side . The design effect can be enhanced by increasing the distortion of the shape of the UD sheet piece P appearing on the surface side .

In addition, in the present invention, the ratio of the unraveled portion L where the parallel carbon fibers are partially separated in the UD sheet piece P appearing on the front side of the CFRP layer S is determined from the UD sheet piece Q appearing on the back side. By increasing , it is possible to increase the distortion of the shape of the UD sheet piece P appearing on the surface side and enhance the design effect.

In the present invention, by using a thermoplastic resin having adhesion to the thermoplastic resin of the transparent resin layer C as the matrix resin of the CFRP layer S, the UD appearing on the surface side when the transparent resin layer C is formed The sheet piece P can be easily unraveled.

In addition, in the present invention, by laminating and integrating the CFRP sheet on the surface of the same or different material, a laminate having a unique appearance and superior design can be constructed.

In the present invention, as the method for producing the CFRP sheet, a UD sheet in which a plurality of continuous fiber-like carbon fibers are aligned in the longitudinal direction and integrated by bonding with a thermoplastic resin matrix resin is cut into a rectangular shape. Then, a plurality of UD sheet pieces arranged in a two-dimensional direction and a resin film made of a thermoplastic resin that is the material of the transparent resin layer are roll-molded and temporarily bonded, or the plurality of pieces arranged in a two-dimensional direction A UD sheet piece is coated with a molten thermoplastic resin, which is the material of the transparent resin layer, and hot-pressed to produce an intermediate sheet material in which the CFRP layer and the transparent resin layer are integrated. By hot pressing, 30% or more of the entire UD sheet piece appearing on the surface side, which is the transparent resin layer side, is removed so that the difference between the maximum value and the minimum value of the carbon fiber lengthwise dimension is 10% or more of the maximum value of the carbon fiber, or the difference between the maximum and minimum values in the longitudinal and vertical dimensions of the carbon fiber is 10% or more of the maximum value in the vertical direction. A method is adopted in which the UD sheet piece appearing on the back side, which is the opposite surface of the transparent resin layer, is made into a rectangular UD sheet piece or a UD sheet piece including the UD sheet piece distorted into a non-rectangular shape. can do.

Further, in the above manufacturing method, the pressure applied by the heat press to the intermediate sheet material is the pressure applied by the roll forming when the UD sheet piece and the resin film are temporarily adhered, or the pressure applied by the hot press to the UD sheet piece coated with the molten resin. It is preferable to make it larger than the applied pressure.

On the other hand, in the present invention, instead of the above-described manufacturing method, in the CFRP sheet manufacturing method, a plurality of continuous fiber-like carbon fibers aligned in the length direction and a thermoplastic resin are roll-molded to form the carbon fibers. are bonded and integrated with the matrix resin made of the thermoplastic resin to prepare a UD sheet, and a UD sheet piece prepared by cutting the UD sheet into a rectangular shape is cut from the thermoplastic resin that is the material of the transparent resin layer. By coating a plurality of UD sheet pieces arranged in a two-dimensional direction on a resin film or arranged in a two-dimensional direction with a molten thermoplastic resin that is a material of a transparent resin layer and performing heat compression molding, 30% or more of the entire UD sheet piece appearing on the surface side which is the transparent resin layer side, the difference between the maximum value and the minimum value of the lengthwise dimension of the carbon fiber is 10% of the maximum value of the lengthwise dimension or more, or the transparent resin distorted into a non-rectangular shape in which the difference between the maximum and minimum values of the longitudinal and vertical dimensions of the carbon fiber is 10% or more of the maximum value of said vertical dimension It is also possible to employ a method in which the UD sheet pieces appearing on the back side, which is the surface opposite to the layer side, are rectangular UD sheet pieces or UD sheet pieces including the aforementioned non-rectangularly distorted UD sheet pieces.

Further, in the above manufacturing method, the pressure of heat compression molding for the resin film and the UD sheet piece, or the pressure of heat compression molding for the UD sheet piece coated with the molten resin is the pressure of the roll molding during the production of the UD sheet. preferably larger than

Further, in the present invention, in the above manufacturing method, it is preferable that the basis weight of the resin film is 5% or more of the total basis weight of the UD sheet piece in order to enhance the design of the surface.

In the present invention, a large number of UD sheet pieces are adhered in a state in which the fiber direction of each sheet piece is randomly oriented and are arranged in a two-dimensional direction so that the sheet pieces overlap each other to form a CFRP sheet. A unique appearance can be imparted to the surface of the sheet by fabricating the UD sheet piece and including the UD sheet piece appearing on the surface side and including the UD sheet piece distorted in a non-rectangular shape.

In the present invention, the UD sheet piece appearing on the back side of the CFRP sheet is formed of a rectangular UD sheet piece that is thicker than the UD sheet piece appearing on the front side and has a uniform shape. Therefore, there is no concern that the tensile strength and the like of the CFRP sheet will be greatly impaired, and both designability and mechanical strength can be achieved.

Therefore, the present invention can provide a CFRP sheet that can be used without problems as a reinforcing sheet or the like, and can also be suitably used as a surface sheet or the like that requires designability, so the practical utility value of the present invention is high. Extremely expensive.

1 is a schematic cross-sectional view showing a laminated structure of a CFRP sheet according to a first embodiment of the invention; FIG. 1A and 1B are a schematic cross-sectional view and a schematic plan view showing the structure of a CFRP layer according to a first embodiment of the present invention; FIG. FIG. 2 is a schematic diagram showing a UD sheet piece of the surface layer and a UD sheet piece of the back layer or intermediate layer of the first embodiment of the present invention; FIG. 4A is a schematic cross-sectional view and a schematic plan view showing the structure of a CFRP layer according to a second embodiment of the present invention; 1 is a photograph showing the appearance of an example in a demonstration test of the effects of the present invention. It is a photograph showing the external appearance of a comparative example in a demonstration test of the effects of the present invention.

"First Embodiment"
In the following description, the "surface" is described as "surface layer", and the "back surface" is described as "back surface layer".
A first embodiment of the present invention will be described below with reference to FIGS. 1, 2 and 4. FIG . In the drawing, the material indicated by symbol S is the sheet body, and the material indicated by symbol M is the matrix resin. Further, the UD sheet piece of the surface layer is indicated by P, and the UD sheet piece of the inner layer is indicated by Q. Also, those designated by symbol F are carbon fibers.

"Construction of CFRP sheet"
[1] Basic Structure of CFRP Sheet First, in the present embodiment, as shown in FIG. 1, a sheet body is constructed by forming a transparent resin layer C on the outside of a CFRP layer S and a surface layer serving as the visible side of the CFRP layer S. ing. As shown in FIGS. 2(a), 2(b) and 2(c), the CFRP layer S consists of a large number of UD sheet pieces P and Q arranged two-dimensionally so that the sheet pieces overlap each other, and furthermore, the UD sheet pieces P and Carbon fiber materials in which the fiber direction of Q is randomly oriented (arranged so that the fiber direction of the UD sheet pieces is random) are bonded and integrated with a matrix resin M. As shown in FIG.

In addition, as shown in FIGS. 4(a) and 4 (b), the UD sheet pieces P and Q of the CFRP layer S are provided with continuous fiber-like carbon fibers F and F, which are aligned in the length direction, and the matrix resin The one that is bonded and integrated by M is used. As for the back layer or intermediate layer, which is the invisible surface of the CFRP layer S, the rectangular UD sheet pieces Q Q shown in FIG. UD sheet pieces P · P … having a smaller average thickness than the UD sheet piece Q of the back layer or intermediate layer shown in FIG. so that it can be

By constructing the sheet body as described above, the relatively thick UD sheet pieces Q Q of the back layer and the intermediate layer ensure the mechanical strength of the CFRP layer S, while the thickness is relatively small and the shape is small. The UD sheet pieces P·P . Further, the transparent resin layer C formed on the outside of the surface layer of the CFRP layer S can improve the smoothness of the surface of the sheet body, and can also provide the CFRP layer S with a protective effect and an optical visual effect. .

[2] Carbon Fiber Material of CFRP Layer Next, each component of the sheet body will be described. First, with regard to the continuous fiber-like carbon fibers F constituting the UD sheet pieces PQ of the CFRP layer S, in this embodiment, carbon fiber bundles (tows) in which filaments are bundled into strands are used. Also, in the present embodiment, PAN-based carbon fibers are used as the carbon fibers F, but pitch-based carbon fibers can also be used. The number of filaments constituting the carbon fiber bundle can be arbitrarily changed according to the strength and the like.

[3] Regarding the matrix resin of the CFRP layer As for the matrix resin M of the CFRP layer S, polyamide resin (nylon resin) is used in the present embodiment, but the carbon fiber material is not limited to this. Other thermoplastic resins (acrylic resin, polyester, polyolefin, polystyrene, polycarbonate, ABS resin, polyetherimide, fluororesin, polyphenylene sulfide, etc.) and thermosetting resins can also be used.

When the CFRP layer S and the transparent resin layer C are integrated by hot pressing (which will be described later in detail), a thermoplastic resin having adhesiveness to the thermoplastic resin of the transparent resin layer C is added to the matrix resin of the CFRP layer S. By using, the UD sheet piece P of the surface layer can be easily melted during hot pressing.

[4] Shape of UD sheet piece
[4-1] Shape of UD sheet piece of surface layer In addition, regarding the UD sheet piece P of the surface layer of the CFRP layer S, in the present embodiment, the UD sheet piece P is distorted in a non-rectangular shape in order to enhance the design effect. ratio of 30% or more. As for the non-rectangular UD sheet piece P, as shown in FIG. 4 (a), the difference between the maximum value X1 and the minimum value X2 of the length dimension of the UD sheet piece is 10% or more of the maximum value X1. or the difference between the maximum value Y1 and the minimum value Y2 of the width dimension is 10% or more of the maximum value Y1.

Regarding the thickness of the UD sheet piece P of the surface layer, in the present embodiment, the average thickness of the UD sheet piece Q of the back layer or the intermediate layer is set so that the distortion of the shape of the UD sheet piece P of the surface layer becomes large. is set to be about half of Further, in the present embodiment, the _average value of the maximum value Y1 of the width dimension of the UD sheet piece P is defined as the average width, and this average width is set to be 1.5 times or more of the average width of the UD sheet piece Q of the back layer or the intermediate layer. I have to. Further, in this embodiment, the average area per UD sheet piece P of the surface layer is set to be larger than the average area of the UD sheet piece Q of the inner layer.

Further, in the present embodiment, the average width of the UD sheet pieces P of the surface layer is larger than the average width of the UD sheet pieces Q of the back layer or the intermediate layer so that the distortion of the shape of the UD sheet pieces P of the surface layer becomes large. is also getting bigger. For the same purpose, the ratio of the raveling portion L where the parallel carbon fibers F of the UD sheet piece P of the surface layer are partially separated from each other is made larger than that of the UD sheet piece Q of the back layer or intermediate layer. .

[4-2] Shape of back layer or intermediate layer UD sheet piece Q As for the back layer or intermediate layer UD sheet piece Q of the above-mentioned CFRP layer S, in this embodiment, a width W of 5 mm and a length L of 20 mm is used. However, in consideration of strength and formability, the width W is 2 mm to 20 mm (preferably 5 mm to 10 mm), the length L is 5 mm to 70 mm (preferably 10 mm to 30 mm), and the ratio of width W to length L is 1: 1 ~ It is preferred to use 1:6 squares. In this specification, the direction along the length direction of the carbon fibers F is defined as the length direction of the UD sheet piece P, and the direction perpendicular thereto is defined as the width direction. Further, the thickness of the UD sheet piece Q of the back layer or intermediate layer is preferably in the range of 40 μm to 100 μm.

[4-3] Number of stacked UD sheet pieces In this embodiment, the average number of UD sheet pieces P and Q laminated in the CFRP layer S in the thickness direction is designed to be in the range of 5.0 to 8.0. However, it is possible to design with any number of sheets according to the strength of the sheet body. As for the thickness of the CFRP layer S, it is preferable to design it in the range of 0.3 mm to 1.0 mm, but it can be formed in a plate shape with a thickness greater than this.

[5] Regarding the surface layer, back layer, and intermediate layer of the CFRP layer In this embodiment, the surface layer, which is the visible surface of the CFRP layer S, is formed only on one side of the sheet body. can also be formed into In that case, the back layer of the CFRP layer S does not exist and is composed only of the surface layer and the intermediate layer. Further, when the thickness of the CFRP layer S is very small, there may be a case where the intermediate layer is not present and the CFRP layer is composed only of the surface layer and the back layer.

[6] Transparent resin layer
[6-1] Material of the transparent resin layer In this embodiment, the material of the transparent resin layer C is a polyamide-based resin. Thermoplastic resins (acrylic resin, PET, polyethylene, polystyrene, polycarbonate, ABS resin, polyetherimide, fluororesin, polyphenylene sulfide, etc.) and thermosetting resins can also be used. Further, the transparent resin layer C includes not only a colorless and transparent one but also a slightly colored translucent one.

[6-2] Thickness of transparent resin layer In addition, regarding the thickness of transparent resin layer C, when the thickness of CFRP layer S is small, the basis weight of the resin film used as the material is set to the basis weight of the entire UD sheet piece. A size of 5% or more (more preferably 5 to 100%, still more preferably 10 to 50%) is preferred. When the thickness of the CFRP layer S is large (when formed into a thick plate), the basis weight of the resin film can be made smaller than 5% of the total basis weight of the UD sheet piece.

"CFRP sheet manufacturing method (i)"
Next, the manufacturing method (i) of the CFRP sheet will be described. In this manufacturing method, a UD sheet is first cut to produce a uniform rectangular UD sheet piece, and then a large number of UD sheet pieces arranged in a two-dimensional direction and a thermoplastic resin film, which is the material of the transparent resin layer, are combined. By roll forming, the two are temporarily bonded to produce an intermediate sheet material in which the CFRP layer and the transparent resin layer are integrated. Then, the intermediate sheet material produced by roll forming is further hot-pressed to distort the UD sheet piece of the surface layer, and then cooled-pressed.

Regarding the principle of distortion of the UD sheet piece of the surface layer, the carbon fiber of the UD sheet piece whose bonding strength is weakened by heating when the molten transparent resin flows (deforms) and enters into the fine unevenness of the CFRP layer surface. It is presumed that it is caused by being dragged and moving. In addition, the UD sheet pieces in which the bonding force between the carbon fibers is weakened during the heat pressing are crushed and the carbon fibers move in the width direction, so that the thickness of the UD sheet piece of the surface layer is reduced to the thickness of the UD sheet piece of the back layer or intermediate layer. and the width dimension of the UD sheet piece of the surface layer is greater than the width dimension of the UD sheet piece of the back layer or the intermediate layer.

In addition, in this manufacturing method, the fluidity (deformability) of the transparent resin is improved by making the pressure of the heat press on the intermediate sheet material larger than the pressure of the roll forming when temporarily bonding the UD sheet piece and the resin film. is increased to greatly distort the shape of the UD sheet piece of the surface layer. Further, by increasing the pressure applied by the heat press to the intermediate sheet material, it is possible to form more unraveled portions in the UD sheet pieces of the surface layer.

In this manufacturing method, a thermoplastic resin film is used as the material of the transparent resin layer as described above, but instead of the resin film, granular or short fiber thermoplastic resin is laminated to temporarily form a UD sheet piece. A transparent resin layer can also be formed by bonding and hot-pressing them, and in that case, the UD sheet piece of the surface layer can be distorted in the same manner as described above. The weight per unit area of the resin film is preferably 5% or more (more preferably 5% to 100%, still more preferably 10% to 50%) relative to the total weight per unit area of the UD sheet piece.

Regarding the method of manufacturing the intermediate sheet material, it is not always necessary to use a resin film, and a large number of UD sheet pieces arranged in a two-dimensional direction are coated with a molten resin, which is the material of the transparent resin layer, and hot-pressed. By doing so, an intermediate sheet material in which the CFRP layer and the transparent resin layer are integrated can be produced. In this case, it is preferable that the pressure applied by the hot press to the intermediate sheet material is greater than the pressure applied by the hot press to the UD sheet piece coated with the molten resin.

"CFRP sheet manufacturing method (ii)"
Next, the manufacturing method (ii) of the CFRP sheet will be described. In this manufacturing method, a continuous carbon fiber and a thermoplastic resin are roll-molded to bond the carbon fibers together to produce a UD sheet, and the UD sheet is cut to form a uniform rectangular UD sheet. Make a piece. After that, the UD sheet pieces are arranged two-dimensionally on the thermoplastic resin film which is the material of the transparent resin layer, and the UD sheet pieces of the surface layer are distorted by heat compression molding (stampable molding, etc.). Manufacture the seat body.

In addition, in this manufacturing method, the fluidity (deformability) of the transparent resin is increased by making the pressure applied to the resin film and the UD sheet pieces in the heat compression molding higher than the pressure applied in the roll molding during the production of the UD sheet. The shape of the UD sheet piece of the surface layer is greatly distorted. Further, by increasing the pressure applied to the resin film and the UD sheet pieces in the heat compression molding, more loose portions can be formed in the UD sheet pieces of the surface layer.

Further, in this manufacturing method, a transparent resin layer can be formed by laminating a granular or short-fiber thermoplastic resin instead of the thermoplastic resin film. A piece can be distorted. The weight per unit area of the resin film is preferably 5% or more (more preferably 5% to 100%, still more preferably 10% to 50%) relative to the total weight per unit area of the UD sheet piece.

The heat compression molding does not always have to use a resin film, and can be performed on a large number of UD sheet pieces arranged in layers and coated with a molten resin, which is the material of the transparent resin layer.

"Second Embodiment"
[1] Basic structure of CFRP sheet First, in this embodiment, as shown in FIGS. At the same time, both the UD sheet pieces P, Q, . Further, in this embodiment, the average area per UD sheet piece P in the surface layer of the CFRP layer S is made larger than the average area of the UD sheet piece Q in the back layer.

The CFRP layer S preferably has a thickness within the range of 0.1 mm to 0.2 mm (average number of UD sheet pieces P and Q overlapped is 2 to 4) so that the transparent resin penetrates to the back layer. Moreover, it is preferable that the proportion of the UD sheet pieces P of the surface layer of the CFRP layer S is 30% or more (preferably 50% or more) that is distorted in a non-rectangular shape.

By configuring the seat body as described above, it is possible to give the seat body a unique appearance. Further, the transparent resin layer C formed outside the surface layer of the CFRP layer S can improve the smoothness of the surface of the sheet body, and can provide the CFRP layer S with a protective effect and an optical visual effect. Other configurations and manufacturing methods are the same as in the first embodiment.

"Third Embodiment"
"Structure of laminate using CFRP sheet"
Next, a third embodiment of the invention will be described. In this embodiment, the CFRP sheet of the first embodiment is laminated and integrated on the surface of a plastic material by hot pressing to form a laminate having excellent surface design (not shown). In addition to plastic materials, CFRP sheets of the same type or materials of different types such as metals can also be used for lamination of CFRP sheets.

[Demonstration test of effect (i)]
Next, the demonstration test (i) of the effects of the present invention will be described. In this test, a plurality of CFRP sheet samples were prepared with or without a transparent resin layer and with different non-rectangular proportions and width dimensions of the UD sheet pieces in the surface layer. 2) was evaluated for appearance.

"Example 1"
In this example, in the CFRP sheet having the structure of the first embodiment, a polyamide resin (nylon 6) was used for each of the matrix resin of the CFRP layer and the thermoplastic resin of the transparent resin layer, and the manufacturing method (i) was used. Samples were prepared by Further, in this embodiment, the pressurizing force of the roll forming at the time of temporary bonding (the pressurizing force when manufacturing the intermediate sheet material) is set to 0.2 to 0.4 MPa, and the pressurizing force of the hot press to the intermediate sheet material (from the intermediate sheet material to the sheet main body). The pressurizing force in manufacturing the was set to 3 MPa.

Then, when a part of the surface layer of the CFRP layer (10 cm × 10 cm = 100 cm ² ) was visually confirmed, the proportion of non-rectangular UD sheet pieces in the surface layer was 100%, and the width dimension of the UD sheet pieces was The percentage of those that expanded to 1.5 times or more from the state before molding was also 100%. As a result, it was possible to produce a highly designed sample having an appearance shown in FIG. 5 and having a unique appearance.

"Comparative Example 1"
In this comparative example , when a part of the back layer of the CFRP layer (10 cm x 10 cm = 100 cm ² ) was visually checked in the above example, the proportion of non-rectangular UD sheet pieces in the back layer remained at 24%. However, the ratio of UD sheet pieces whose width dimension was expanded to 1.5 times or more was only 18%. As a result, the appearance shown in FIG. 6(a) was obtained, and the design effect of the sample could not be sufficiently enhanced in the back layer .

"Comparative Example 2"
In this comparative example , in a CFRP sheet consisting of only a CFRP layer without a transparent resin layer, a polyamide resin (nylon 6) is used as the matrix resin of the CFRP layer, and a UD sheet piece is heat-pressed to prepare a sample. gone. Then, when a part of the surface layer of the CFRP layer (10 cm × 10 cm = 100 cm) was visually confirmed, the ratio of non-rectangular UD sheet pieces in the surface layer was 0%, and the width dimension of the UD sheet pieces was the same as before molding. The percentage of those that expanded from the state to 1.5 times or more was also 0%. As a result, the appearance shown in FIG. 6(b) was obtained, and the design effect of the sample could not be sufficiently enhanced.

<Test results>
Summarizing the test results of Example 1 and Comparative Examples 1 and 2, the sample of Example 1 was able to sufficiently improve the design of the surface layer, while the samples of Comparative Examples 1 and 2 were It was not possible to sufficiently enhance the design of the layer . A table summarizing the conditions and test results of each sample is shown below.

[Effect verification test (ii)]
Next, the demonstration test (ii) of the effects of the present invention will be described. In this test , a plurality of CFRP sheet samples having different width dimensions and Vf values of UD sheet pieces used as materials were prepared, and the appearance of each of these samples ( Examples 1 to 3 below) was evaluated.

"Example 1"
In this example, in the CFRP sheet having the configuration of the second embodiment, a polyamide resin (nylon 6) was used for each of the matrix resin of the CFRP layer and the thermoplastic resin of the transparent resin layer, and the sample was prepared by the manufacturing method (i). was made. In this example, a UD sheet piece having dimensions of width 5 mm×length 20 mm×thickness 0.043 mm and Vf 53% was used as the material.

In this example, the UD sheet pieces arranged in two dimensions and the thermoplastic resin film which is the material of the transparent resin layer were roll-molded under the conditions of a roll temperature of 270°C and a roll pressure of 0.5 MPa, and the basis weight was 150 g/ An intermediate sheet material of m2, thickness 0.15 mm and Vf 43.3% was produced. Then, the intermediate sheet material was hot-pressed under the conditions of a mold temperature of 270°C, a pressure of 3 MPa, and a pressure time of 0.5 min. A sheet body having dimensions of 381 mm in width, 277 mm in length, 0.12 mm in thickness, and Vf of 43.3% was produced by cold pressing under the conditions. As a result, a highly designed sample with a unique appearance was produced.

"Example 2"
In this example, in the CFRP sheet having the configuration of the second embodiment, a polyphenylene sulfide (PPS) resin is used as the matrix resin of the CFRP layer, and a polyamide resin is used as the thermoplastic resin of the transparent resin layer. Samples were prepared by In this example, a UD sheet piece having dimensions of width 5 mm, length 20 mm, thickness 0.048 mm, and Vf 47% was used as the material.

In this example, the UD sheet pieces arranged in two dimensions and the thermoplastic resin film which is the material of the transparent resin layer were roll-molded under the conditions of a roll temperature of 270°C and a roll pressure of 0.5 MPa, and the basis weight was 150 g/ An intermediate sheet material of m2, thickness 0.15 mm and Vf 35% was produced. Then, the intermediate sheet material was hot-pressed under the conditions of a mold temperature of 320°C, a pressure of 3 MPa, and a pressure time of 0.5 min. A sheet body having dimensions of 381 mm in width, 277 mm in length, 0.12 mm in thickness, and Vf of 35% was produced by cold pressing under these conditions. As a result, a highly designed sample with a unique appearance was produced.

"Example 3"
In this example, in the CFRP sheet having the configuration of the second embodiment, polycarbonate (PC) resin was used as the matrix resin of the CFRP layer, and polyamide resin was used as the thermoplastic resin of the transparent resin layer. A sample was produced. In this example, a UD sheet piece having dimensions of width 5 mm, length 20 mm, thickness 0.048 mm, and Vf 47% was used as the material.

In this example, the UD sheet pieces arranged in two dimensions and the thermoplastic resin film which is the material of the transparent resin layer were roll-molded under the conditions of a roll temperature of 270°C and a roll pressure of 0.5 MPa, and the basis weight was 150 g/ An intermediate sheet material of m2, thickness 0.15 mm and Vf 35% was produced. Then, the intermediate sheet material was hot-pressed under the conditions of a mold temperature of 300°C, a pressure of 3 MPa, and a pressure time of 0.5 min. A sheet body having dimensions of 381 mm in width, 277 mm in length, 0.12 mm in thickness, and Vf of 35% was produced by cold pressing under these conditions. As a result, a highly designed sample with a unique appearance was produced.

<Test results>
Summarizing the test results of Examples 1 to 3 above, it was found that all samples of Examples 1 to 3 could be sufficiently improved in designability. A table summarizing the conditions of each sample is shown below.

S CFRP layer M Transparent resin layer P Surface layer UD sheet piece Q Back layer or intermediate layer UD sheet piece

Claims (10)

A CFRP sheet in which a transparent resin layer (C) made of a thermoplastic resin is formed on one side of a CFRP layer (S), which is one layer,
In the CFRP layer (S), a plurality of UD sheet pieces formed by bonding and integrating a plurality of continuous fiber-like carbon fibers arranged in the longitudinal direction with a matrix resin (M) of a thermoplastic resin are each While the fiber directions of the sheet pieces are randomly oriented and the sheet pieces are arranged in a two-dimensional direction so as to overlap each other, the sheet pieces are adhered with the matrix resin (M),
Among the plurality of UD sheet pieces arranged two-dimensionally so as to overlap each other in the CFRP layer (S), the UD sheet piece appearing on the back surface side opposite to the transparent resin layer side has a rectangular shape. for
On the surface side of the transparent resin layer side, the average thickness is smaller than the UD sheet piece appearing on the back side, and the difference between the maximum and minimum values of the dimensions in the length direction of the carbon fibers is the length 10% or more of the maximum dimension in the direction, or the difference between the maximum and minimum values of the carbon fiber length direction and the vertical dimension is 10% or more of the maximum dimension in the vertical direction A CFRP sheet characterized in that rectangular distorted UD sheet pieces appear at a rate of 30% or more of the entire UD sheet pieces appearing on the surface side. A CFRP sheet in which a transparent resin layer (C) made of a thermoplastic resin is formed on one side of a CFRP layer (S), which is one layer,
In the CFRP layer (S), a plurality of UD sheet pieces formed by bonding and integrating a plurality of continuous fiber-like carbon fibers arranged in the longitudinal direction with a matrix resin (M) of a thermoplastic resin are each While the fiber directions of the sheet pieces are randomly oriented and the sheet pieces are arranged in a two-dimensional direction so as to overlap each other, the sheet pieces are adhered with the matrix resin (M),
Among the plurality of UD sheet pieces arranged in the two-dimensional direction so as to overlap in the CFRP layer (S), the UD sheet piece appearing on the surface side, which is the transparent resin layer side, and the opposite side of the transparent resin layer side In the UD sheet piece appearing on the back side, which is the surface, the difference between the maximum value and the minimum value of the lengthwise dimension of the carbon fiber is 10% or more of the maximum value of the lengthwise dimension, or the length of the carbon fiber comprising a piece of non-rectangularly distorted UD sheet in which the difference between the maximum and minimum directional and vertical dimensions is greater than or equal to 10% of said maximum vertical dimension;
The non-rectangularly distorted UD sheet pieces contained in the UD sheet pieces appearing on the surface side are characterized by accounting for 30% or more of the entire UD sheet pieces appearing on the surface side. CFRP sheet. The average area per UD sheet piece (P) appearing on the front side of the CFRP layer (S) is larger than the average area of the UD sheet piece (Q) appearing on the back side. The CFRP sheet according to claim 1 or 2. The ratio of the unraveled portion (L) where the parallel carbon fibers are partially separated in the UD sheet piece (P) appearing on the front side of the CFRP layer (S) is the UD sheet piece (Q ), the CFRP sheet according to any one of claims 1 to 3. In the method of manufacturing a CFRP sheet, a UD sheet in which a plurality of continuous fiber-like carbon fibers are aligned in the length direction and integrated by bonding with a matrix resin of a thermoplastic resin is cut into a rectangular shape and two-dimensionally A plurality of UD sheet pieces arranged side by side and a resin film made of a thermoplastic resin which is the material of the transparent resin layer are roll-molded and temporarily adhered, or a transparent resin is applied to the plurality of UD sheet pieces arranged in a two-dimensional direction. After manufacturing an intermediate sheet material in which the CFRP layer and the transparent resin layer are integrated by coating the melted thermoplastic resin, which is the material of the layer, and hot-pressing,
By further heat-pressing this intermediate sheet material, 30% or more of the entire UD sheet piece appearing on the surface side, which is the transparent resin layer side, is reduced to the difference between the maximum value and the minimum value of the dimension in the length direction of the carbon fiber. 10% or more of the maximum dimension in the longitudinal direction, or the difference between the maximum and minimum dimensions of the carbon fiber in the longitudinal direction and the vertical direction is 10% or more of the maximum dimension in the vertical direction. is distorted into a non-rectangular shape,
A method for producing a CFRP sheet, wherein the UD sheet piece appearing on the back surface side opposite to the transparent resin layer side is a rectangular UD sheet piece. In the method of manufacturing a CFRP sheet, a UD sheet in which a plurality of continuous fiber-like carbon fibers are aligned in the length direction and integrated by bonding with a matrix resin of a thermoplastic resin is cut into a rectangular shape and two-dimensionally A plurality of UD sheet pieces arranged side by side and a resin film made of a thermoplastic resin which is the material of the transparent resin layer are roll-molded and temporarily adhered, or a transparent resin is applied to the plurality of UD sheet pieces arranged in a two-dimensional direction. After manufacturing an intermediate sheet material in which the CFRP layer and the transparent resin layer are integrated by coating the melted thermoplastic resin, which is the material of the layer, and hot-pressing,
By further heat-pressing this intermediate sheet material, 30% or more of the entire UD sheet piece appearing on the surface side, which is the transparent resin layer side, is reduced to the difference between the maximum value and the minimum value of the dimension in the length direction of the carbon fiber. 10% or more of the maximum dimension in the longitudinal direction, or the difference between the maximum and minimum dimensions of the carbon fiber in the longitudinal direction and the vertical direction is 10% or more of the maximum dimension in the vertical direction. is distorted into a non-rectangular shape,
A method for producing a CFRP sheet, wherein the UD sheet pieces appearing on the back surface side opposite to the transparent resin layer side are UD sheet pieces including the UD sheet pieces distorted in a non-rectangular shape. The pressurizing force of the hot press to the intermediate sheet material is made larger than the pressurizing force of the roll forming when temporarily bonding the UD sheet piece and the resin film, or the pressurizing force of the hot press to the UD sheet piece coated with the molten resin. The method for producing a CFRP sheet according to claim 5 or 6 , characterized by: In the CFRP sheet manufacturing method, a plurality of continuous fiber-like carbon fibers aligned in the length direction and a thermoplastic resin are roll-molded to bond and integrate the carbon fibers with a matrix resin made of the thermoplastic resin. A UD sheet is produced by cutting the UD sheet into a rectangular shape, and a UD sheet piece produced by cutting the UD sheet is arranged in a two-dimensional direction on a resin film made of a thermoplastic resin that is the material of the transparent resin layer, Alternatively, the plurality of UD sheet pieces arranged in a two-dimensional direction are coated with a molten thermoplastic resin that is the material of the transparent resin layer, and the UD sheet appears on the surface side, which is the transparent resin layer side, by heat compression molding. 30% or more of the whole piece, the difference between the maximum and minimum values of the lengthwise dimension of the carbon fiber is 10% or more of the said maximum lengthwise dimension, or the lengthwise and perpendicular dimension of the carbon fiber distorted into a non-rectangular shape in which the difference between the maximum and minimum values of the
A method for producing a CFRP sheet, wherein the UD sheet piece appearing on the back surface side opposite to the transparent resin layer side is a rectangular UD sheet piece. In the method for producing a CFRP sheet, a plurality of continuous fiber-like carbon fibers aligned in the longitudinal direction and a thermoplastic resin are roll-molded to bond and integrate the carbon fibers with a matrix resin made of the thermoplastic resin. A UD sheet is produced by cutting the UD sheet into a rectangular shape, and a UD sheet piece produced by cutting the UD sheet is arranged in a two-dimensional direction on a resin film made of a thermoplastic resin that is the material of the transparent resin layer, or The plurality of UD sheet pieces arranged in a two-dimensional direction are coated with a molten thermoplastic resin, which is the material of the transparent resin layer, and the UD sheet pieces appear on the surface side, which is the transparent resin layer side, by heat compression molding. 30% or more of the whole, the difference between the maximum value and the minimum value of the length direction of the carbon fiber is 10% or more of the maximum value of the length direction of the carbon fiber, or the length direction and the vertical dimension of the carbon fiber distorted into a non-rectangular shape in which the difference between the maximum value and the minimum value is 10% or more of the maximum value of said vertical dimension;
A method for producing a CFRP sheet, wherein the UD sheet pieces appearing on the back surface side opposite to the transparent resin layer side are UD sheet pieces including the UD sheet pieces distorted in a non-rectangular shape. The method for producing a CFRP sheet according to any one of claims 5 to 9 , wherein the basis weight of the resin film is 5% or more of the basis weight of the entire UD sheet piece.

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