JPWO2020009125A1 - CFRP sheet, laminate using CFRP sheet, and method for manufacturing CFRP sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a CFRP sheet which is excellent not only in mechanical strength such as tensile strength but also in designability of a visible surface. SOLUTION: A transparent resin layer C is formed on the outside of a surface layer of a CFRP layer S to form a CFRP sheet, and the CFRP layer S is aligned with continuous fibrous carbon fibers FF ... in the length direction. A large number of UD sheet pieces, which are bonded and integrated by the matrix resin M in the state of being arranged in a row, are arranged in a two-dimensional direction so that the fiber directions of the sheet pieces are randomly oriented and the sheet pieces overlap each other. While they are formed by adhering them together with a matrix resin M in an arranged state, the UD sheet pieces P · Q ... Of the back surface layer or the intermediate layer of the CFRP layer S are rectangular, whereas the UD sheet pieces P · Q of the front surface layer P ... was composed of a sheet piece having an average thickness smaller than that of the UD sheet piece Q of the back surface layer or the intermediate layer and at least partially distorted in a non-rectangular shape. [Selection diagram] Fig. 1

Description

The present invention relates to an improvement of a CFRP sheet, specifically, a CFRP sheet having excellent design, a laminate using the same, and an efficient method for producing the CFRP sheet.

In recent years, carbon fiber reinforced plastic (CFRP) composed of carbon fiber and matrix resin, which are reinforcing fiber materials, has been used in various applications due to its excellent functionality. Further, as a CFRP sheet, a sheet in which continuous fibrous carbon fiber bundles are oriented vertically and horizontally, or a sheet in which carbon fiber bundles are plain-woven and impregnated with a matrix resin is widely known.

However, with respect to the above-mentioned conventional CFRP sheet, when the CFRP sheet is formed into an arbitrary shape by hot pressing, the continuous fibrous carbon fiber bundle extending over the entire sheet becomes a factor that hinders the followability to the press die. As a result, there is a drawback that the shape that can be molded is limited.

Therefore, conventionally, a UD sheet in which carbon fiber bundles arranged 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 CFRP sheet that is integrated by hot pressing to form a sheet has also been developed (see, for example, Patent Document 1).

However, the conventional CFRP sheet has an appearance in which strip-shaped (rectangular) UD sheet pieces are lined up on the surface, and there is no big difference in the shape of each UD sheet piece, so that the appearance of the surface is different. It was easy to get a monotonous design. Therefore, CFRP sheets are rarely used for applications such as decorative sheets that require design.

Japanese Unexamined Patent Publication No. 2016-27956

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

The means adopted by the present inventor to solve the above problems will be described below with reference to the accompanying drawings.

That is, in the present invention, a transparent resin layer C is formed on the outside of the surface layer of the CFRP layer S to form a CFRP sheet, and the CFRP layer S is formed of continuous fibrous carbon fibers FF in the length direction. A large number of UD sheet pieces, which are bonded and integrated by the matrix resin M in a state of being aligned and integrated with each other, are two-dimensionally arranged so that the fiber directions of the sheet pieces are randomly oriented and the sheet pieces overlap each other. While they are formed by adhering with matrix resin M in a state of being arranged in the direction, the UD sheet pieces PQ ... Of the back surface layer or the intermediate layer of the CFRP layer S are rectangular, whereas the UD sheet pieces of the front surface layer are formed. The P / P ... Is characterized in that the average thickness is smaller than that of the UD sheet piece Q of the back surface layer or the intermediate layer, and at least a part of the sheet piece is distorted in a non-rectangular shape.

In the present specification, "non-rectangular shape" means that the difference between the maximum value and the minimum value of the width dimension (dimension in the direction perpendicular to the length direction of the carbon fiber) of the UD sheet piece is the maximum value of the width dimension. The maximum value of the length dimension is the difference between the maximum and minimum values of the length dimension of the UD sheet piece (dimension in the direction parallel to the length direction of the carbon fiber) that is 10% or more in size. Refers to those that are 10% or more in size.

Further, according to the present invention, in a CFRP sheet in which a transparent resin layer C is formed on the outside of the surface layer of the CFRP layer S, the CFRP layer S aligns continuous fibrous carbon fibers FF ... in the length direction. A large number of UD sheet pieces that are adhered and integrated with the matrix resin M in an arranged state are arranged in a two-dimensional direction so that the fiber directions of the sheet pieces are randomly oriented and the sheet pieces overlap each other. The UD sheet pieces P and Q of the front surface layer and the back surface layer of the CFRP layer S may be configured to include the sheet pieces distorted in a non-rectangular shape while being formed by bonding with the matrix resin M in the state of being in the state. ..

Further, in the present invention, the ratio of the UD sheet piece P distorted in a non-rectangular shape in the surface layer of the CFRP layer S is 30% or more (preferably 50% or more), so that the design of a unique appearance is excellent. A CFRP sheet can be formed.

On the other hand, in the present invention, the average area of each UD sheet piece P in the surface layer of the CFRP layer S is made larger than the average area of the UD sheet pieces Q in the back surface layer or the intermediate layer to make the surface layer. The distortion of the shape of the UD sheet piece P can be increased to enhance the design effect.

Further, in the present invention, the ratio of the melted portion L in which the parallel carbon fibers are partially separated from each other in the UD sheet piece P of the front surface layer of the CFRP layer S is made larger than that of the UD sheet piece Q of the back surface layer or the intermediate layer. As a result, the distortion of the shape of the UD sheet piece P in the surface layer can be increased to enhance the design effect.

Further, in the present invention, by using a thermoplastic resin having adhesion with the thermoplastic resin of the transparent resin layer C as the matrix resin of the CFRP layer S, the UD sheet piece P of the surface layer is formed when the transparent resin layer C is formed. Can be easily solved.

Further, in the present invention, by laminating and integrating the CFRP sheet on the surface of the same or different materials, it is possible to construct a laminated body having a unique appearance and excellent design.

Further, in the present invention, as a method for producing the CFRP sheet, a large number of UD sheet pieces arranged in the two-dimensional direction and a resin film which is a material of the transparent resin layer are roll-molded and temporarily bonded, or in the two-dimensional direction. A large number of UD sheet pieces arranged in the above are coated with molten resin, which is a material of a transparent resin layer, and heat-pressed to prepare an intermediate sheet material in which a CFRP layer and a transparent resin layer are integrated. A method of distorting the UD sheet piece of the surface layer by further hot-pressing the surface layer can be adopted.

Further, in the above manufacturing method, the pressure of the heat press on the intermediate sheet material is the pressure of roll molding when the UD sheet piece and the resin film are temporarily bonded, or the pressure of the heat press on the UD sheet piece coated with the molten resin. It is preferable to make it larger than the pressing force.

On the other hand, in the present invention, instead of the above manufacturing method, in the CFRP sheet manufacturing method, the continuous fibrous carbon fibers and the thermoplastic resin are roll-molded to bond the carbon fibers to each other to prepare a UD sheet. , The UD sheet pieces produced by cutting the UD sheet into a rectangular shape are arranged in the two-dimensional direction on the resin film which is the material of the transparent resin layer, or are arranged in a large number of UD sheet pieces in the two-dimensional direction. It is also possible to adopt a method of distorting the UD sheet piece of the surface layer by coating the molten resin which is the material of the transparent resin layer and heat-compress molding.

Further, in the above manufacturing method, the pressure of heat compression molding on the resin film and the UD sheet piece, or the pressure of heat compression molding on the UD sheet piece coated with the molten resin is applied to the pressure of roll molding at the time of producing the UD sheet. It is preferable to make it larger than.

Further, in the present invention, in the above-mentioned manufacturing method, it is preferable that the basis weight of the resin film is 5% or more of the total 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 where 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 to form a CFRP sheet. It is possible to give a unique appearance to the sheet surface by forming the surface layer and including the UD sheet piece distorted in a non-rectangular shape.

Further, in the present invention, the back surface layer and the intermediate layer of the CFRP sheet are composed of a rectangular UD sheet piece having a thickness larger than that of the UD sheet piece of the front surface layer and having a uniform shape. There is no concern that the tensile strength and the like will be significantly impaired, and both designability and mechanical strength can be achieved.

Therefore, according to the present invention, it is possible to provide a CFRP sheet that can be used as a reinforcing sheet or the like without any problem and that can be suitably used as a surface sheet or the like that requires designability. Therefore, the practical utility value of the present invention is high. Very expensive.

It is schematic cross-sectional view which shows the laminated structure of the CFRP sheet of the 1st Embodiment of this invention. It is a schematic cross-sectional view and the schematic plan view which shows the structure of the CFRP layer of the 1st Embodiment of this invention. It is the schematic which shows the UD sheet piece of the front surface layer of the 1st Embodiment of this invention, and the UD sheet piece of a back surface layer or an intermediate layer. It is a schematic cross-sectional view and the schematic plan view which shows the structure of the CFRP layer of the 2nd Embodiment of this invention. It is a photograph which showed the appearance of the Example in the demonstration test of the effect of this invention. It is a photograph which showed the appearance of the comparative example in the demonstration test of the effect of this invention.

"First embodiment"
The first embodiment of the present invention will be described below with reference to FIGS. 1 to 3. In the figure, the one indicated by the reference numeral S is the sheet body, and the one indicated by the reference numeral M is the matrix resin. Further, what is indicated by the reference numeral P is a UD sheet piece of the surface layer, and what is indicated by the reference numeral Q is a UD sheet piece of the inner layer. Further, what is indicated by the reference numeral F is a carbon fiber.

"Construction of CFRP sheet"
[1] Basic configuration of CFRP sheet First, in the present embodiment, as shown in FIG. 1, a transparent resin layer C is formed on the outside of the CFRP layer S and the surface layer on the visible surface side thereof to form a sheet body. ing. Further, in the CFRP layer S, as shown in FIGS. 2A, 2B, and 2C, a large number of UD sheet pieces P and Q are arranged in a two-dimensional direction so that the sheet pieces overlap each other, and further, the UD sheet pieces P and Q are arranged in a two-dimensional direction. A carbon fiber material in which the fiber directions of Q are randomly oriented (arranged so that the directions of the fiber directions of the UD sheet pieces are different) is formed by adhesive integration with the matrix resin M.

Further, on the UD sheet pieces P and Q of the CFRP layer S, as shown in FIGS. 3 (a) and 3 (b), continuous fibrous carbon fibers F and F ... The one that is bonded and integrated by M is used. Further, the back surface layer or the intermediate layer which is the invisible surface of the CFRP layer S is formed by arranging the rectangular UD sheet pieces QQ ... As shown in FIG. 3 (b), while the front surface layer of the CFRP layer S is formed. UD sheet pieces P · P ... With an average thickness smaller than that of the back surface layer or intermediate layer UD sheet piece Q shown in FIG. I am trying to do it.

By constructing the sheet body as described above, the CFRP layer S has a relatively small thickness and a shape while ensuring the mechanical strength of the CFRP layer S by the relatively thick UD sheet pieces QQ of the back surface layer and the intermediate layer. As shown in FIG. 2B, the UD sheet pieces P and P ... Of the non-uniform surface layer can give the sheet body a unique appearance. 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 impart a protective effect and an optical visual effect of the CFRP layer S. ..

[2] Carbon fiber material for CFRP layer Next, each component of the sheet body will be described. First, with respect to the continuous fibrous carbon fibers F constituting the UD sheet pieces P and Q of the CFRP layer S, in the present embodiment, a carbon fiber bundle (toe) in which filaments are bundled in a strand shape is used. Further, in the present embodiment, the PAN-based carbon fiber is used for the carbon fiber F, but a pitch-based carbon fiber 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] Matrix resin of CFRP layer Regarding the matrix resin M of the CFRP layer S, a polyamide resin (nylon resin) is used in this embodiment, but the present invention is not limited to this, and the carbon fiber material is impregnated. Other thermoplastic resins having properties (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 (details will be described later), the matrix resin of the CFRP layer S is a thermoplastic resin having adhesion to the thermoplastic resin of the transparent resin layer C. By using, the UD sheet piece P of the surface layer can be easily unraveled at the time of hot pressing.

[4] About the shape of the UD sheet piece
[4-1] Shape of UD sheet piece P of surface layer Further, regarding the UD sheet piece P of the surface layer of the CFRP layer S, in the present embodiment, the UD sheet piece P distorted into a non-rectangular shape in order to enhance the design effect. The ratio is set to 30% or more. For the non-rectangular UD sheet piece P, as shown in FIG. 3A, the difference between _{the maximum value X 1} and the minimum value X ₂ of the length dimension of the UD sheet piece is 10% or more of the _{maximum value X 1.} It refers to the size, or the difference between _{the maximum value Y 1} and the minimum value Y ₂ of the width dimension is 10% or more of the _{maximum value Y 1.}

Regarding the thickness of the UD sheet piece P of the surface layer, in the present embodiment, the average thickness is the average thickness of the UD sheet piece Q of the back surface layer or the intermediate layer so that the distortion of the shape of the UD sheet piece P of the surface layer becomes large. I try to make it about half of. _{Further, in the present embodiment, the average value of the maximum value Y 1} of the width dimension of the UD sheet piece P is set as the average width, and this average width is 1.5 times or more the average width of the UD sheet piece Q of the back surface layer or the intermediate layer. I have to. Further, in the present 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 piece P of the surface layer is larger than the average width of the UD sheet piece Q of the back surface layer or the intermediate layer so that the shape distortion of the UD sheet piece P of the surface layer becomes large. Is also trying to grow. Further, for the same purpose, the ratio of the unraveled portion L in which the parallel carbon fibers F of the UD sheet pieces P of the front surface layer are partially separated from each other is made larger than that of the UD sheet piece Q of the back surface layer or the intermediate layer. ..

[4-2] Shape of UD sheet piece of back surface layer or intermediate layer As for the UD sheet piece Q of the back surface layer or intermediate layer of the CFRP layer S, the one having a width W5 mm × a length L20 mm is used in this embodiment. However, in consideration of strength and shapeability, 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 to 1. It is preferable to use a 1: 6 rectangular shape. In the present specification, the direction along the length direction of the carbon fiber F is the length direction of the UD sheet piece P, and the direction perpendicular to it is the width direction. The thickness of the UD sheet piece Q of the back surface layer or the intermediate layer is preferably in the range of 40 μm to 100 μm.

[4-3] Number of Stacked UD Sheet Pieces In the present 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 sheets. However, any number of sheets can be designed according to the strength of the sheet body. Further, the thickness of the CFRP layer S is preferably designed in the range of 0.3 mm to 1.0 mm, but it can also be formed in a plate shape thicker than this.

[5] Surface layer, back surface layer, and intermediate layer of CFRP layer Further, the surface layer to be the visible surface of the CFRP layer S is formed on only one side of the sheet body in the present embodiment, but both sides of the sheet body. It can also be formed into. In that case, the back surface layer of the CFRP layer S does not exist, and is composed only of the front 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 does not exist and only the front surface layer and the back surface layer are formed.

[6] About the transparent resin layer
[6-1] Material of transparent resin layer As for the material of the transparent resin layer C, a polyamide resin is used in this embodiment, but the material is not limited to this and has impregnation property with respect to carbon fiber materials. 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 Regarding the thickness of the transparent resin layer C, when the thickness of the CFRP layer S is small, the basis weight of the resin film used as the material is the basis weight of the entire UD sheet piece. The size is preferably 5% or more (more preferably 5 to 100%, still more preferably 10 to 50%). When the CFRP layer S is thick (when it is formed in a thick plate shape), the basis weight of the resin film can be made smaller than 5% with respect to the basis weight of the entire UD sheet piece.

"Method of manufacturing CFRP sheet (i)"
Next, the method (i) for manufacturing the CFRP sheet will be described. In this manufacturing method, first, a UD sheet is cut to prepare 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 a material of a transparent resin layer are formed. The two are temporarily bonded by roll molding to prepare an intermediate sheet material in which the CFRP layer and the transparent resin layer are integrated. Then, the intermediate sheet material produced by roll molding is further heat-pressed to distort the UD sheet piece of the surface layer, and then a cooling press is performed.

Regarding the principle that the UD sheet piece of the surface layer is distorted, the carbon fiber of the UD sheet piece whose bonding force is weakened by heating when the melted transparent resin flows (deforms) into the fine irregularities on the CFRP layer surface. It is presumed that it is caused by the movement of the sword. Further, the UD sheet piece whose bonding force between the carbon fibers is weakened during the hot pressing is crushed and the carbon fiber moves in the width direction, so that the thickness of the UD sheet piece in the front layer becomes the UD sheet piece in the back layer or the intermediate layer. The width dimension of the UD sheet piece of the front surface layer is larger than the width dimension of the UD sheet piece of the back surface layer or the intermediate layer.

Further, in this manufacturing method, the pressing force of the heat press on the intermediate sheet material is made larger than the pressing force of the roll molding when temporarily adhering the UD sheet piece and the resin film, so that the fluidity (deformability) of the transparent resin is increased. The shape of the UD sheet piece of the surface layer is greatly distorted. Further, by increasing the pressing force of the heat press on the intermediate sheet material, more unraveled portions can be formed in the UD sheet piece of the surface layer.

Further, in this manufacturing method, the thermoplastic resin film is used as the material of the transparent resin layer as described above, but instead of the resin film, a granular or short fibrous thermoplastic resin is laminated and temporarily formed on the UD sheet piece. It is also possible to bond them and heat press them to form a transparent resin layer, and in that case as well, the UD sheet piece of the surface layer can be distorted as described above. The basis weight of the resin film is preferably 5% or more (more preferably 5 to 100%, still more preferably 10 to 50%) with respect to the total basis weight of the UD sheet piece.

Further, regarding the method for producing 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 molten resin, which is a material of a transparent resin layer, and heat-pressed. By doing so, it is possible to produce an intermediate sheet material in which the CFRP layer and the transparent resin layer are integrated. In that case, it is preferable that the pressing force of the hot press on the intermediate sheet material is larger than the pressing force of the hot press on the UD sheet piece coated with the molten resin.

"Method of manufacturing CFRP sheet (ii)"
Next, the method (ii) for manufacturing the CFRP sheet will be described. In this manufacturing method, a continuous fibrous carbon fiber and a thermoplastic resin are roll-molded to bond the carbon fibers to each other 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 side by side in the two-dimensional direction 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 or the like). Manufacture the seat body.

Further, in this manufacturing method, the fluidity (deformability) of the transparent resin is increased by making the pressing force of the heat compression molding on the resin film and the UD sheet piece larger than the pressing force of the roll molding at the time of producing the UD sheet. The shape of the UD sheet piece of the surface layer is greatly distorted. Further, by increasing the pressing force of the heat compression molding on the resin film and the UD sheet piece, more unraveled portions can be formed in the UD sheet piece of the surface layer.

Further, in this production method, instead of the above-mentioned thermoplastic resin film, a granular or short-fiber thermoplastic resin can be laminated to form a transparent resin layer. In that case, the UD sheet of the surface layer is also formed. You can distort the piece. The basis weight of the resin film is preferably 5% or more (more preferably 5 to 100%, still more preferably 10 to 50%) with respect to the total basis weight of the UD sheet piece.

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

"Second embodiment"
[1] Basic configuration of CFRP sheet First, in the present embodiment, as shown in FIGS. 4A, 4B, and 4C, the number of UD sheet pieces P and Q stacked is reduced to form the CFRP layer S thinly. At the same time, both the UD sheet pieces PQ ... Of the front surface layer and the back surface layer of the CFRP layer S are configured to include the sheet pieces distorted in a non-rectangular shape. Further, in the present embodiment, the average area of each UD sheet piece P in the front surface layer of the CFRP layer S is made larger than the average area of the UD sheet piece Q in the back surface layer.

Further, the CFRP layer S is preferably set to a thickness of 0.1 mm to 0.2 mm (an average number of UD sheet pieces P and Q to be stacked 2 to 4) so that the transparent resin penetrates to the back surface layer. Further, in the UD sheet piece P of the surface layer of the CFRP layer S, the ratio of the UD sheet piece P distorted in a non-rectangular shape is preferably 30% or more (preferably 50% or more).

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 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 impart the protective effect and the optical visual effect of the CFRP layer S. The other configurations and manufacturing methods are the same as those in the first embodiment.

"Third embodiment"
"Structure of laminate using CFRP sheet"
Next, a third embodiment of the present invention will be described. In the present embodiment, the CFRP sheet of the first embodiment is laminated and integrated on the surface of the plastic material by a hot press to form a laminated body having excellent surface design (not shown). Further, as the target for laminating the CFRP sheet, not only a plastic material but also a different material such as the same type of CFRP material or metal can be adopted.

[Effect verification test (i)]
Next, a demonstration test (i) of the effect of the present invention will be described. In this test, a plurality of CFRP sheet samples having different presence / absence of the transparent resin layer and different non-rectangular proportions and width dimensions of the UD sheet pieces of the surface layer were prepared, and each of these samples (Example 1 and Comparative Examples 1 to the following) was prepared. The appearance of 2) was evaluated.

"Example 1"
In this embodiment, in the CFRP sheet having the configuration of the first embodiment, a polyamide resin (nylon 6) is used as the matrix resin of the CFRP layer and the thermoplastic resin of the transparent resin layer, respectively, and the method of the production method (i) is used. A sample was prepared by. Further, in this embodiment, the pressurization of roll forming during temporary bonding (pressurization when manufacturing the intermediate sheet material) is set to 0.2 to 0.4 MPa, and the pressurization of the heat press on the intermediate sheet material (from the intermediate sheet material to the sheet body). The pressing force when manufacturing the product) was set to 3 MPa.

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

"Comparative Example 1"
In this embodiment, in the CFRP sheet having the configuration of the first embodiment, a polyamide resin (nylon 6) is used as the matrix resin of the CFRP layer and the thermoplastic resin of the transparent resin layer, respectively, and the same as in Example 1 is produced. Samples were prepared by the method of method (i). Then, when a part of the back surface layer (10 cm × 10 cm = 100 cm ² ) of the CFRP layer was visually confirmed, the ratio of the non-rectangular UD sheet piece in the back surface layer was only 24%, and the width dimension of the UD sheet piece was large. The percentage of those that expanded to more than 1.5 times the size remained at 18%. As a result, the appearance shown in FIG. 6A was obtained, and the design effect of the sample could not be sufficiently enhanced.

"Comparative Example 2"
In this embodiment, in a CFRP sheet composed of only a CFRP layer having no transparent resin layer, a polyamide resin (nylon 6) is used as the matrix resin of the CFRP layer, and a UD sheet piece is hot-pressed to prepare a sample. went. Then, when a part of the surface layer of the CFRP layer (10 cm × 10 cm = 100 cm ² ) was visually confirmed, the ratio of the non-rectangular UD sheet piece in the surface layer was 0%, and the width dimension of the UD sheet piece was molded. The percentage of those that expanded from the previous 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 Examples 1 and Comparative Examples 1 and 2, the sample of Example 1 was able to sufficiently enhance the design, whereas the samples of Comparative Examples 1 and 2 were sufficiently designed. Could not be raised to. A table summarizing the conditions and test results of each sample is shown below.

[Effect verification test (ii)]
Next, a demonstration test (ii) of the effect of the present invention will be described. In this test, a plurality of CFRP sheet samples having different width dimensions and Vf values of the transparent resin layer material and the UD sheet piece used as the material were prepared, and each of these samples (Example 1 and Comparative Examples 1 and 2 below). The appearance of was evaluated.

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

Further, in this embodiment, the above-mentioned UD sheet pieces arranged in the two-dimensional direction and the thermoplastic resin film which is the material of the transparent resin layer are roll-molded under the conditions of a roll temperature of 270 ° C. and a roll pressing force of 0.5 MPa, and have a grain size of 150 g /. An intermediate sheet material of m2, thickness 0.15 mm, and Vf 43.3% was prepared. Then, after hot pressing the intermediate sheet material under the conditions of a mold temperature of 270 ° C., a pressing force of 3 MPa, and a pressurizing time of 0.5 min, the mold temperature is 30 ° C., a pressing force of 5 MPa, and a pressurizing time of 3 min. A cooling press was performed under the conditions to prepare a sheet body having dimensions of 381 mm in width × 277 mm in length × 0.12 mm in thickness and Vf 43.3%. As a result, a highly designed sample having a unique appearance could be produced.

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

Further, in this embodiment, the above-mentioned UD sheet pieces arranged in the two-dimensional direction and the thermoplastic resin film which is the material of the transparent resin layer are roll-molded under the conditions of a roll temperature of 270 ° C. and a roll pressing force of 0.5 MPa, and have a grain size of 150 g /. An intermediate sheet material of m2, thickness 0.15 mm, and Vf 35% was prepared. Then, after hot pressing the intermediate sheet material under the conditions of a mold temperature of 320 ° C., a pressing force of 3 MPa, and a pressurizing time of 0.5 min, the mold temperature is 30 ° C., a pressing force of 5 MPa, and a pressurizing time of 3 min. A cooling press was performed under the conditions to prepare a sheet body having dimensions of 381 mm in width × 277 mm in length × 0.12 mm in thickness and Vf 35%. As a result, a highly designed sample having a unique appearance could be produced.

"Example 3"
In this embodiment, in the CFRP sheet having the configuration of the second embodiment, a polycarbonate (PC) 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, and the manufacturing method (i) is used. A sample was prepared. Further, in this embodiment, a UD sheet piece having dimensions of 5 mm in width × 20 mm in length × 0.048 mm in thickness and Vf 47% was used as the material.

Further, in this embodiment, the above-mentioned UD sheet pieces arranged in the two-dimensional direction and the thermoplastic resin film which is the material of the transparent resin layer are roll-molded under the conditions of a roll temperature of 270 ° C. and a roll pressing force of 0.5 MPa, and have a grain size of 150 g /. An intermediate sheet material of m2, thickness 0.15 mm, and Vf 35% was prepared. Then, after hot pressing the intermediate sheet material under the conditions of a mold temperature of 300 ° C., a pressing force of 3 MPa, and a pressurizing time of 0.5 min, the mold temperature is 30 ° C., a pressing force of 5 MPa, and a pressurizing time of 3 min. A cooling press was performed under the conditions to prepare a sheet body having dimensions of 381 mm in width × 277 mm in length × 0.12 mm in thickness and Vf 35%. As a result, a highly designed sample having a unique appearance could be produced.

<Test results>
Summarizing the test results for Examples 2 to 4, the design of each of the samples of Examples 1 to 3 could be sufficiently enhanced. 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 surface layer or intermediate layer UD sheet piece

Claims (11)

In a CFRP sheet in which a transparent resin layer (C) is formed on the outside of the surface layer of the CFRP layer (S).
A large number of UD sheet pieces formed by adhering and integrating the CFRP layer (S) with a matrix resin (M) in a state where continuous fibrous carbon fibers (F) (F) ... Are arranged in the length direction. While the fiber directions of the sheet pieces are randomly oriented and the sheet pieces are arranged in the two-dimensional direction so as to overlap each other, they are bonded and formed by the matrix resin (M).
The UD sheet pieces (Q) (Q) ... Of the back surface layer or the intermediate layer of the CFRP layer (S) are rectangular, whereas the UD sheet pieces (P) (P) ... Of the front surface layer are the back surface layer or A CFRP sheet having an average thickness smaller than that of the UD sheet piece (Q) of the intermediate layer, and including at least a part of the sheet piece distorted in a non-rectangular shape. In a CFRP sheet in which a transparent resin layer (C) is formed on the outside of the surface layer of the CFRP layer (S).
A large number of UD sheet pieces formed by adhering and integrating the CFRP layer (S) with a matrix resin (M) in a state where continuous fibrous carbon fibers (F) (F) ... Are arranged in the length direction. While the fiber directions of the sheet pieces are randomly oriented and the sheet pieces are arranged in the two-dimensional direction so as to overlap each other, they are bonded and formed by the matrix resin (M).
A CFRP sheet characterized in that the UD sheet pieces (P) (Q) ... Of the front surface layer and the back surface layer of the CFRP layer (S) include sheet pieces distorted in a non-rectangular shape. The CFRP sheet according to claim 1 or 2, wherein the proportion of the UD sheet piece (P) distorted in a non-rectangular shape in the surface layer of the CFRP layer (S) is 30% or more. Claim 1 is characterized in that the average area per UD sheet piece (P) in the front surface layer of the CFRP layer (S) is larger than the average area of the UD sheet piece (Q) in the back surface layer or the intermediate layer. The CFRP sheet according to any one of ~ 3. The ratio of the unraveled portion (L) in which the parallel carbon fibers are partially separated from each other in the UD sheet piece (P) of the front surface layer of the CFRP layer (S) is higher than that of the UD sheet piece (Q) of the back surface layer or the intermediate layer. The CFRP sheet according to any one of claims 1 to 4, wherein the CFRP sheet is large. The invention according to any one of claims 1 to 5, wherein a thermoplastic resin having adhesion to the thermoplastic resin of the transparent resin layer (C) is used as the matrix resin of the CFRP layer (S). CFRP sheet. A laminate using a CFRP sheet according to claim 1 or 2, wherein the CFRP sheet is laminated and integrated on the surface of the same or different materials. In the CFRP sheet manufacturing method, a large number of UD sheet pieces arranged in a two-dimensional direction and a resin film which is a material of a transparent resin layer are roll-molded and temporarily bonded, or a large number of UDs arranged in a two-dimensional direction. A sheet piece is coated with a molten resin, which is a material for a transparent resin layer, and heat-pressed to prepare an intermediate sheet material in which a CFRP layer and a transparent resin layer are integrated, and then this intermediate sheet material is further heat-pressed. A method for producing a CFRP sheet, which comprises distorting a UD sheet piece in a surface layer by means of a method. The pressure of the heat press on the intermediate sheet material should be larger than the pressure of roll molding when temporarily bonding the UD sheet piece and the resin film, or the pressure of the heat press on the UD sheet piece coated with the molten resin. The method for producing a CFRP sheet according to claim 8, wherein the CFRP sheet is produced. In the CFRP sheet manufacturing method, continuous fibrous carbon fibers and thermoplastic resin are roll-formed to bond the carbon fibers to each other to produce a UD sheet, and the UD sheet is cut into a rectangular shape to produce a UD sheet. The UD sheet pieces are arranged in the two-dimensional direction on the resin film which is the material of the transparent resin layer, or a large number of UD sheet pieces arranged in the two-dimensional direction are coated with the molten resin which is the material of the transparent resin layer. A method for producing a CFRP sheet, which comprises distorting a UD sheet piece of a surface layer by heat compression molding. The method for producing a CFRP sheet according to any one of claims 8 to 10, 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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