WO2019163633A1

WO2019163633A1 - Cfrp sheet, frp-metal composite, and method for manufacturing same

Info

Publication number: WO2019163633A1
Application number: PCT/JP2019/005317
Authority: WO
Inventors: 金森尚哲; 山崎達也
Original assignee: フクビ化学工業株式会社
Priority date: 2018-02-23
Filing date: 2019-02-14
Publication date: 2019-08-29
Also published as: JP7043290B2; JP2019143087A

Abstract

The present invention addresses the problem of providing: a CFRP sheet having excellent fire resistance and metal adherence; an FRP-metal composite having excellent fire resistance and bonding integrity that uses the same; and a method for efficiently manufacturing the FRP-metal composite. A CFRP sheet is composed by using a fluorine resin having metal adherence and fire resistance and a melting point of 170 to 260°C as a matrix resin for impregnating carbon fiber bundles, these being a fiber-reinforced material, and the FRP-metal composite is composed by directly laminating together, without an intervening adhesive layer, an FRP layer comprising the CFRP sheet and a metal layer comprising a metal material.

Description

CFRP sheet, FRP-metal composite and production method thereof

The present invention relates to an improvement of a CFRP sheet, more specifically, a CFRP sheet excellent in flame retardancy and metal adhesion, an FRP-metal composite using the same and excellent in flame retardancy and adhesion integrity, and the FRP- The present invention relates to an efficient method for producing a metal composite.

In recent years, fiber reinforced plastics (hereinafter referred to as “CFRP”) obtained by impregnating a carbon fiber, which is a reinforced fiber material, with a matrix resin, have been used in industrial fields due to their superior functionality (bending strength, tensile strength, light weight, etc.). The use is progressing in many fields such as the construction field. In particular, the CFRP sheet can be used by being bonded to other materials, and thus can be used for various purposes.

As for the composite material in which the above CFRP and other materials are integrated, conventionally, a material in which CFRP and a metal material are integrated with a thermosetting resin (epoxy resin, etc.) adhesive is known (patents). If a thermosetting resin-based adhesive is used, it takes a long time to apply and cure, and thus there is a drawback that it is difficult to manufacture in a short time.

In addition, it is conceivable to use a thermoplastic resin-based adhesive for laminating and integrating the CFRP and the metal material, but the curing time of the adhesive may be short, but in any case the CFRP or the metal material Since a process of applying an adhesive to the surface and a process of pasting both are required, there is a problem that the number of processes increases and manufacturing cannot be performed efficiently.

In the past, although techniques using various thermosetting resins (epoxy resins, phenol resins, etc.) and thermoplastic resins (polyamide resins, polypropylene, etc.) for the matrix resin of CFRP have been known, metal adhesion From the viewpoint of flame retardancy, a technique for selecting a matrix resin material has not been generally known.

JP 2009-191186 A

The present invention has been made in view of the above problems, and its object is a CFRP sheet excellent in flame retardancy and metal adhesion, and excellent in flame retardancy and adhesion integrity using the same. Another object of the present invention is to provide an FRP-metal composite and an efficient method for producing the FRP-metal composite.

<Means adopted by the present inventor for solving the above-mentioned problems will be described with reference to the accompanying drawings.

That is, according to the present invention, the CFRP sheet 1 is formed by using a fluororesin having a melting point of 170 to 260 ° C. having metal adhesion and flame retardancy as the matrix resin 12 impregnated between the carbon fiber bundles 11 which are reinforcing fiber materials. There is a feature in the point that it constituted.

As the fluororesin used for the matrix resin 12, it is preferable to use a resin having flame retardancy satisfying at least the determination standard of V-0 in the UL94V combustion test and having a critical oxygen index of 30 or more.

As the fluororesin used for the matrix resin 12, ETFE or EFEP is preferably used. Particularly, when ETFE is used for the matrix resin 12, the ratio of polymerized units based on TFE in ETFE is 50 to 80 mol%. In addition, it is preferable to use those having a polymer unit ratio of 50 to 80 mol% based on ethylene.

The fiber volume content of the carbon fiber is preferably 20 to 70% in order to secure the bond strength, flame retardancy, and metal adhesion of the carbon fiber bundle 11.

Further, as the carbon fiber bundle 11, it is preferable to use a sizing agent coated with a polyamide resin in order to increase the bonding strength between the matrix resin and the carbon fiber bundle to improve the bending strength and the tensile strength.

In addition, regarding the flame retardancy of the above-mentioned seat body, meet the criteria for V-0 or V-1 in the UL94V combustion test, and meet the criteria for 5V-A or 5V-B in the UL94-5V combustion test. It is preferable to do this.

In the present invention, the FRP-metal composite 2 can be configured by directly laminating and integrating the FRP layer 21 made of the CFRP sheet and the metal layer 22 made of a metal material directly without using an adhesive layer.

In the present invention, as a method for producing the FRP-metal composite, the CFRP sheet and the metal material are hot-pressed under the conditions of a heating temperature of 180 to 280 ° C. and a pressure of 1 to 5 MPa, so that the CFRP sheet is converted into a metal material. A method of laminating and integrating the two by heat welding can be employed.

In the present invention, as the matrix resin impregnated between the carbon fiber bundles of the CFRP sheet, a fluororesin having a melting point of 170 to 260 ° C. having metal adhesion is used, and these are laminated and integrated only by heat welding by hot press. Thus, the FRP-metal composite can be produced. Also, the adhesive strength between the CFRP sheet and the metal material can be improved.

In the CFRP sheet of the present invention, since a fluorine-based resin having excellent flame retardancy is used as the matrix resin impregnated between the carbon fiber bundles, a building material that requires a very high level of flame retardancy is used. It becomes possible to produce an FRP-metal composite that can be suitably used for applications such as industrial materials and industrial parts.

Therefore, according to the present invention, it is possible to produce an FRP-metal composite that is more excellent in flame retardancy and adhesion integrity than in the past, and moreover, a CFRP sheet that can efficiently produce an FRP-metal composite with a small number of steps. Therefore, the practical utility value of the present invention is very high.

It is explanatory sectional drawing showing the CFRP sheet of 1st embodiment of this invention. It is explanatory sectional drawing showing the example of a change of the CFRP sheet of this invention. It is explanatory sectional drawing showing the metal-FRP composite_body | complex of 2nd embodiment of this invention. It is explanatory drawing showing the test method of adhesiveness.

"First embodiment"
A first embodiment of the present invention will be described with reference to FIG. In the figure, a CFRP sheet is designated by reference numeral 1.

“Configuration of CFRP sheet”
[1] Basic Configuration of CFRP Sheet First, the basic configuration of the CFRP sheet 1 will be described. In this embodiment, a carbon fiber bundle 11 is used as a reinforcing fiber material, and a matrix resin 12 impregnated between the carbon fiber bundles 11 is used. The sheet body of the CFRP sheet 1 shown in FIG. 1 is formed using a fluorine-based resin having a melting point of 170 to 260 ° C. having metal adhesion and flame retardancy.

[2] Carbon fiber bundle Next, each component of the CFRP sheet 1 will be described. First, with respect to the carbon fiber bundle 11, in the present embodiment, when carbon fibers having a filament diameter of 3 to 12 μm (preferably 5 to 7 μm) are bundled into 5000 to 50000 (preferably 12000 to 15000) carbon fibers to form a thread shape Although the carbon fiber bundle 11 having a thickness of about 0.1 to 2.0 mm (preferably 0.3 to 0.4 mm) is used, the number of carbon fibers can be appropriately changed according to the thickness of the carbon fiber bundle 11. In the present embodiment, PAN-based carbon fibers are used, but pitch-based carbon fibers can also be used.

In this embodiment, the UD sheet in which the orientations of the carbon fiber bundles 11 are aligned in the same direction is used, but the carbon fiber bundles 11 can be arranged in two or more different directions. Specifically, a method of laminating a plurality of UD sheets by changing the orientation of the carbon fiber bundles, or a method of forming a sheet by weaving the carbon fiber bundles by plain weaving or multiaxial weaving can be adopted. In this embodiment, a continuous fiber-like carbon fiber bundle is used. However, a carbon fiber bundle finely chopped into short fibers can also be used. Specifically, many UD sheets are cut into strips. These UD sheet pieces can be arranged in a random orientation so as to form a sheet (pseudo isotropic sheet).

In the present embodiment, the carbon fiber bundle 11 applied with a sizing agent is used. In addition, as a sizing agent, an epoxy resin type, a vinyl ester resin type, a polyamide resin type, or the like can be used. The sizing agent has a role of adjusting the bond strength between the carbon fiber bundle 11 and the matrix resin 12 and a role of suppressing damage to the carbon fiber bundle 11 during processing. Preferably, a CFRP sheet 1 is used by using a polyamide-based resin. The bending strength and tensile strength of can be improved.

[3] Regarding the fiber volume content of carbon fiber As for the fiber volume content (Vf) of carbon fiber in the CFRP sheet, if the carbon fiber content is too low, sufficient flame retardancy cannot be obtained. If the fiber content is too high, the proportion of the resin decreases and the bond strength and metal adhesion between the carbon fiber bundles 11 decrease, so it is preferable to adjust within the range of Vf 20% to 70%.

[4] Matrix Resin On the other hand, with respect to the matrix resin 12, in this embodiment, the proportion of polymerized units based on TFE as the fluororesin is 50 to 80 mol%, and the proportion of polymerized units based on ethylene is 50 to 80 mol. % ETFE (tetrafluoroethylene / ethylene copolymer) is used, but fluorine resins other than ETFE can also be used. In addition, it is preferable to select a fluororesin that has a flame retardancy that satisfies at least the determination criteria of V-0 in the UL94V combustion test and has a critical oxygen index of 30 or more. Is preferably ETFE or EFEP.

<Description of UL94V Combustion Test (ASTM D3801)>
Briefly explaining the above UL94V combustion test, a strip-shaped test piece (dimension: 125 ± 5mm × 13 ± 0.5 × t mm) is mounted vertically on the clamp and flame contact is performed twice for 10 seconds with a 20mm flame. “V-0”, “V-1”, “V-2” and “Not” are judged by the combustion behavior. Specific determination criteria are shown in Table 1 below.

<Explanation of limiting oxygen index (ASTM D2863)>
The “Limited Oxygen Index” is the minimum oxygen concentration required for a material to continue to burn. Calculated from the oxygen concentration. The higher the critical oxygen index, the higher the flame retardancy.

[5] About the impregnation method of the matrix resin As for the impregnation method of the matrix resin 12 with respect to the carbon fiber bundle 11, in this embodiment, the planar spread yarn groups in which the carbon fiber bundles are arranged in one direction are arranged vertically, Further, a matrix resin in the form of a film is inserted between them, and the resin film and the upper and lower spread yarn groups are thermocompression bonded by a roll, so that the matrix resin 12 is semi-impregnated between the carbon fiber bundles 11 as shown in FIG. I am letting. In addition, as an impregnation method, a granular or short fiber matrix resin can be laminated and impregnated. Further, the impregnation ratio of the matrix resin 12 may be impregnated to such an extent that the carbon fiber bundles 11 are bonded and integrated, and as shown in FIG. 2, all the carbon fiber bundles 11 are completely buried in the matrix resin. It may be impregnated.

[6] Flame Retardancy of CFRP Sheet Further, regarding the flame retardancy of the CFRP sheet 1, in this embodiment, it satisfies the criteria of V-0 or V-1 in the UL94V combustion test and UL94-5V combustion. Meet the 5V-A or 5V-B criteria for testing.

<Description of UL94-5V Combustion Test (ASTM D5048)>
Briefly explaining the above UL94-5V combustion test, a strip-shaped test piece (dimension: 125 ± 5mm × 13 ± 0.5 × t mm) is mounted vertically on the clamp, and 5 seconds of flame contact with 125mm flame is performed 5 times. Based on the combustion behavior, “5V-A”, “5V-B” and “Not” are determined. Specific determination criteria are shown in Table 2 below.

“Second Embodiment”
"Structure of FRP-metal composite"
[1] Basic configuration of FRP-metal composite Next, a second embodiment of the present invention will be described with reference to FIG. In the present embodiment, the FRP-metal composite 2 is configured by laminating and integrating the FRP layer 21 made of the CFRP sheet of the first embodiment and the metal layer 22 made of a metal material. Further, the FRP layer 21 and the metal layer 22 of the FRP-metal composite 2 are directly integrated by thermal welding without using an adhesive layer. Thereby, the FRP-metal composite 2 excellent in adhesion integrity and flame retardancy is obtained.

[2] Metal layer Also, in this embodiment, an aluminum plate is used as the metal material used for the metal layer 22, but the metal material is not limited to this, and other metal materials (for example, iron-based materials). Materials, etc.) can also be used. Further, the thickness and shape of the metal layer 22 can be appropriately changed according to the use of the FRP-metal composite 2.

"Production method of FRP-metal composite"
Next, a method for producing the FRP-metal composite 2 will be described. In this embodiment, a CFRP sheet and a metal material are hot-pressed under the conditions of a heating temperature of 180 to 280 ° C. and a pressing force of 1 to 5 MPa. The two are laminated and integrated by thermally welding the sheet to a metal material. As a result, the FRP-metal composite can be easily produced only by hot pressing. The heating temperature and pressure of the hot press can be appropriately adjusted according to the fiber volume content of the carbon fibers and the matrix resin material used for the CFRP sheet.

[Effectiveness test]
Next, a verification test of the effect of the present invention will be described. In this test, a plurality of samples made of an FRP-metal composite using an aluminum plate as a metal layer were prepared by changing the material of the matrix resin of the CFRP sheet, and each of these samples (the following Example 1 and Comparative Examples 1 to The adhesion between the FRP layer and the metal layer in 3) was evaluated by the magnitude of the shear stress at which peeling of the FRP layer and the metal layer occurred.

<Test method>
As shown in FIG. 4, metal layers (dimensions: width 25 mm × length 250 mm × thickness 2 mm) are formed on both upper and lower sides of the FRP layer (dimensions: width 25 mm × length 100 mm × thickness 0.5 mm). A part that protrudes to the left and right is formed on the metal layer, and the protruding part of the metal layer is 1 mm / min in an environment of temperature 25 ° C. and humidity 50% using a test device (manufactured by Shimadzu Corporation: universal testing machine I-0108). It was measured how much the FRP layer and the metal layer were peeled off by pulling outward at a speed.

"Example 1"
In this example, ETFE is used for the matrix resin of the CFRP sheet constituting the FRP layer, and the CFRP sheet and the aluminum plate are hot pressed for 3 minutes under conditions of a heating temperature of 250 ° C. and a pressure of 5 MPa. The FRP layer and the metal layer were laminated and integrated by thermally welding the sheet to the metal material.

"Comparative Example 1"
In this example, PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer) is used as a matrix resin of the CFRP sheet constituting the FRP layer, and the CFRP sheet and the aluminum plate are heated at a heating temperature of 340 ° C. and an applied pressure. The CFRP sheet was thermally welded to the metal plate by hot pressing for 3 minutes under the condition of 5 MPa to integrate the FRP layer and the metal layer.

"Comparative Example 2"
In this example, PA6 (polyamide resin) is used as a matrix resin of the CFRP sheet constituting the FRP layer, and this CFRP sheet and an aluminum plate are hot pressed for 3 minutes under the conditions of a heating temperature of 270 ° C. and a pressure of 5 MPa. As a result, the CFRP sheet was thermally welded to the metal plate to integrate the FRP layer and the metal layer.

“Comparative Example 3”
In this example, PP (polypropylene resin) is used as the matrix resin of the CFRP sheet constituting the FRP layer, and the CFRP sheet and the aluminum plate are hot pressed for 3 minutes under the conditions of a heating temperature of 180 ° C. and a pressure of 5 MPa. As a result, the CFRP sheet was thermally welded to the metal plate to integrate the FRP layer and the metal layer.

<Test results>
When the tensile test in the shear direction was performed on the samples of Example 1 and Comparative Examples 1 to 3, the samples of Comparative Examples 1 to 3 had a low adhesive force with a shear load (maximum load) of less than 5 kN during peeling. On the other hand, the sample of Example 1 exhibited high adhesion with a shear load of 5 kN or more during peeling. A table summarizing the materials and dimensions of the metal layer and FRP layer of each sample and the test results of each sample is shown below.

1 CFRP sheet 11 Carbon fiber
12 Matrix resin 2 Metal-FRP composite 21 FRP layer 22 Metal layer

Claims

The matrix resin (12) to be impregnated between the carbon fiber bundles (11), which is a reinforcing fiber material, is characterized by using a fluororesin having a melting point of 170 to 260 ° C. having metal adhesion and flame retardancy. CFRP sheet.
The flame retardancy of the fluororesin used for the matrix resin (12) satisfies at least the determination criteria of V-0 in the UL94V combustion test, and the limiting oxygen index is 30 or more. CFRP sheet.
The CFRP sheet according to claim 1 or 2, wherein the fluororesin used for the matrix resin (12) is ETFE or EFEP.
ETFE is used for the matrix resin (12), the proportion of polymerized units based on TFE in ETFE is 50 to 80 mol%, and the proportion of polymerized units based on ethylene is 50 to 80 mol%. Item 4. A CFRP sheet according to Item 3.
The CFRP sheet according to any one of claims 1 to 4, wherein the fiber volume content of the carbon fibers is 20 to 70%.
The CFRP sheet according to any one of claims 1 to 5, wherein a carbon fiber bundle (11) coated with a sizing agent comprising a polyamide-based resin is used.
The flame retardancy of the seat body meets the criteria for V-0 or V-1 in the UL94V combustion test and the criteria for 5V-A or 5V-B in the UL94-5V combustion test. The CFRP sheet according to any one of claims 1 to 6.
The FRP-metal composite comprising the FRP layer (21) made of the CFRP sheet according to claim 1 and the metal layer (22) made of a metal material, which are directly laminated and integrated without an adhesive layer. .
The CFRP sheet according to claim 1 and the metal material are heat-pressed under the conditions of a heating temperature of 180 to 280 ° C. and a pressing force of 1 to 5 MPa, and the CFRP sheet is thermally welded to the metal material to laminate and integrate them. A method for producing a metal-FRP composite characterized by the above.