阅读说明：本技术 金属-碳纤维增强树脂材料复合体及其制造方法 (Metal-carbon fiber reinforced resin material composite and method for producing same ) 是由 植田浩平 河村保明 郡真纯 茨木雅晴 于 2019-04-02 设计创作，主要内容包括：提供金属部件的异种材料接触腐蚀得到抑制、并且电沉积涂装性优异的新型且改良的金属-碳纤维增强树脂材料复合体和金属-碳纤维增强树脂材料复合体的制造方法。本发明涉及的金属-碳纤维增强树脂材料复合体,具有金属部件、配置在金属部件的表面的至少一部分的树脂皮膜层、以及包含基体树脂和碳纤维材料的碳纤维增强树脂材料,树脂皮膜层包含选自金属粒子、金属间化合物粒子、导电性氧化物粒子和导电性非氧化物陶瓷粒子中的一种以上作为导电性粒子,并且还包含粘合剂树脂,导电性粒子的23～27℃的粉体电阻率为7.0×10～(7)Ωcm以下,并且包含选自Zn、Si、Zr、V、Cr、Mo、Mn和W中的任一种或多种。(Provided are a novel and improved metal-carbon fiber reinforced resin material composite and a method for producing a metal-carbon fiber reinforced resin material composite, wherein dissimilar material contact corrosion of a metal member is suppressed and electrodeposition coating properties are excellent. The metal-carbon fiber reinforced resin material composite according to the present invention comprises a metal member, a resin coating layer disposed on at least a part of the surface of the metal member, and a carbon fiber reinforced resin material comprising a matrix resin and a carbon fiber material, wherein the resin coating layer comprises at least one selected from the group consisting of metal particles, intermetallic compound particles, conductive oxide particles and conductive non-oxide ceramic particles as conductive particles, and further comprises a binder resin, and the conductive particles have a powder resistivity of 7.0 x 10 at 23 to 27 ℃ 7 Omega cm or less, and contains any one or more selected from Zn, Si, Zr, V, Cr, Mo, Mn, and W.)

1. A metal-carbon fiber reinforced resin material composite,

comprises a metal component, a resin coating layer and a carbon fiber reinforced resin material,

the resin coating layer is disposed on at least a part of the surface of the metal member,

the carbon fiber reinforced resin material is disposed on at least a part of the surface of the resin coating layer and includes a matrix resin and a carbon fiber material present in the matrix resin,

the resin coating layer contains, as conductive particles, any one or more selected from the group consisting of metal particles, intermetallic compound particles, conductive oxide particles and conductive non-oxide ceramic particles, and further contains a binder resin,

the conductive particles have a powder resistivity of 7.0 x 10 at 23-27 DEG C⁷Ω cm or less, and contains any one or more selected from Zn, Si, Zr, V, Cr, Mo, Mn, and W as a constituent element.

2. The metal-carbon fiber reinforced resin material composite according to claim 1,

the conductive oxide particles are doped conductive oxide particles.

3. The metal-carbon fiber reinforced resin material composite body according to claim 1 or 2,

the conductive particles are made of Al-doped zinc oxide or ZrB₂、MoSi₂、CrB₂、WSi₂、VB₂And ferrosilicon and ferromanganese.

4. The metal-carbon fiber reinforced resin material composite according to any one of claims 1 to 3,

the volume ratio of the conductive particles in the resin coating layer is 1.0% or more and 30.0% or less.

5. The metal-carbon fiber reinforced resin material composite body according to any one of claims 1 to 4,

the average thickness of the resin coating layer is 1.0 [ mu ] m or more and 200.0 [ mu ] m or less.

6. The metal-carbon fiber reinforced resin material composite according to any one of claims 1 to 5,

the conductive particles have an average particle diameter of 50.0 [ mu ] m or less.

7. The metal-carbon fiber reinforced resin material composite according to any one of claims 1 to 6,

when the average thickness of the resin coating layer is T and the average particle diameter of the conductive particles is r, the relationship of T/r is more than or equal to 0.5 and less than or equal to 300.0 is satisfied, and the unit of T and r is mum.

8. The metal-carbon fiber reinforced resin material composite according to any one of claims 1 to 7,

the glass transition temperature of the resin coating layer is below 100 ℃.

9. The metal-carbon fiber reinforced resin material composite according to any one of claims 1 to 8,

the binder resin is an epoxy resin, or a resin containing one or more selected from a polyurethane resin, a polyester resin, and a melamine resin, and an epoxy resin.

10. The metal-carbon fiber reinforced resin material composite according to any one of claims 1 to 9,

the matrix resin comprises a thermoplastic resin.

11. The metal-carbon fiber reinforced resin material composite according to any one of claims 1 to 10,

the base resin comprises a phenoxy resin.

12. The metal-carbon fiber reinforced resin material composite according to any one of claims 1 to 11,

the carbon fiber reinforced resin material has an electrodeposition coating film formed on the resin film layer and/or the carbon fiber reinforced resin material.

13. The metal-carbon fiber reinforced resin material composite according to any one of claims 1 to 12,

the metal part is steel or plated steel.

14. A method for manufacturing a metal-carbon fiber reinforced resin material composite,

comprising a step of thermocompression bonding a metal member provided on at least a part of the surface of a resin coating layer containing conductive particles and a binder resin to a carbon fiber-reinforced resin material via the resin coating layer,

the conductive particles comprise any one or more selected from the group consisting of metal particles, intermetallic compound particles, conductive oxide particles, and conductive non-oxide ceramic particles,

the conductive particles have a powder resistivity of 7.0 x 10 at 23-27 DEG C⁷Ω cm or less, and contains any one or more selected from Zn, Si, Zr, V, Cr, Mo, Mn, and W as a constituent element.

15. The method of producing a metal-carbon fiber-reinforced resin material composite according to claim 14,

the method further includes a step of molding the metal member before the step of thermocompression bonding.

16. The method of producing a metal-carbon fiber-reinforced resin material composite according to claim 14,

the method further includes a step of molding a laminate in which the metal member and the carbon fiber reinforced resin material are laminated after the step of thermocompression bonding.

17. The method for producing a metal-carbon fiber-reinforced resin material composite according to any one of claims 14 to 16,

the method further comprises a step of forming an electrodeposition coating film on the resin coating layer and/or the carbon fiber-reinforced resin material by electrodeposition coating.

Technical Field

The present invention relates to a metal-carbon fiber reinforced resin material composite and a method for producing a metal-carbon fiber reinforced resin material composite.

Background

Fiber Reinforced Plastics (FRP) in which a matrix resin is compounded by containing reinforcing fibers (e.g., glass fibers, carbon fibers, etc.) are lightweight and have excellent tensile strength, processability, and the like. Therefore, it is widely used from the civil field to industrial use. In the automobile industry, in order to satisfy the demand for weight reduction of a vehicle body in relation to improvement of fuel consumption and other performances, application of FRP to automobile parts has been studied with attention paid to lightweight property, tensile strength, workability, and the like of FRP.

Among them, Carbon Fiber Reinforced Plastics (CFRP) using Carbon fibers as reinforcing fibers are materials that are expected for various uses including automobile parts because of their strength, particularly light weight, and particularly excellent tensile strength.

On the other hand, since the matrix resin of CFRP is usually a thermosetting resin such as an epoxy resin, it is brittle, and therefore, brittle fracture may occur when it is deformed. In addition, CFRP using a thermosetting resin as a matrix resin does not undergo plastic deformation, and therefore once cured, cannot be subjected to bending. CFRP is generally expensive, and causes an increase in the cost of various parts such as automobile parts.

In order to solve these problems while maintaining the above-described advantages of CFRP, a metal-CFRP composite material in which a metal member and CFRP are laminated and integrated (composite) has been recently studied. Since the metal member has ductility, the brittleness is reduced by combining the metal member with such a metal member, and the composite material can be deformed and processed. Further, by combining a low-cost metal member with CFRP, the amount of CFRP used can be reduced, and therefore the cost of automobile parts can be reduced.

The carbon fibers in CFRP are good electrical conductors. Therefore, electrical conduction to the metal member in contact with the CFRP may cause a phenomenon of corrosion due to galvanic corrosion (dissimilar material contact corrosion). In order to prevent such dissimilar materials from corrosion by contact, several proposals have been made.

Patent document 1 proposes a carbon fiber-reinforced resin molded article used in a state of being in contact with a metal member, in which a particulate or oily organic silicon compound is dispersed in a matrix resin of the carbon fiber-reinforced resin molded article.

Patent document 2 proposes a fiber-reinforced resin member in which a nonconductive sleeve and a nonconductive sheet such as a glass fiber-reinforced resin are disposed between a metal fastening member and a CFRP laminate. Patent document 3 proposes a fastening structure of a carbon fiber reinforced resin material in which a contact portion between the carbon fiber reinforced resin material and a metal collar is bonded via an insulating adhesive.

Patent document 4 discloses an electrically conductive and corrosion resistant coated metal sheet, which is characterized in that a coating film (α) is formed on at least one surface of the metal sheet, the coating film (α) comprising an organic resin (a) and non-oxide ceramic particles (B) selected from the group consisting of those having a resistivity of 0.1 × 10 at 25 ℃^-6～185×10^-6The volume ratio of an organic resin (A) and non-oxide ceramic particles (B) in the coating film (alpha) at 25 ℃ is 90: 10-99.9: 0.1, the organic resin (A) comprises a resin (A1) or further comprises a derivative (A2) of the resin (A1), and the resin (A1) comprises at least 1 functional group selected from carboxyl and sulfonic acid groups in the structure.

Prior art documents

Patent document 1: japanese patent laid-open No. 2014-162848

Patent document 2: international publication No. 2016/021259

Patent document 3: international publication No. 2016/117062

Patent document 4: international publication No. 2012/029988

Disclosure of Invention

Problems to be solved by the invention

The metal-CFRP composite is subjected to electrodeposition coating according to the use. Therefore, when a metal-CFRP composite material is used for such applications, excellent electrodeposition coatability is also required for the metal part-CFRP composite material. When electrodeposition coating is also performed on CFRP, it is necessary to appropriately conduct CFRP and metal parts. However, when the CFRP is conducted to the metal member, the dissimilar material contact corrosion cannot be suppressed.

On the other hand, in the techniques described in patent documents 2 and 3, since the CFRP is isolated from the metal member by the insulator, it is difficult to apply electrodeposition coating. The molded article described in patent document 1 is a molded article in which the surface of a carbon fiber-reinforced resin molded article is provided with water repellency by silicone, and is not a molded article in which conduction between carbon fibers and a metal member is prevented. Therefore, it is difficult to suppress the dissimilar material contact corrosion.

As a result of the studies by the present inventors, it was found that if electrodeposition coating is applied to a composite material in which CFRP is directly attached to a metal part, the electrodeposition coating covers not only the surface of the metal part but also the CFRP surface. However, it has also been found that a composite obtained by electrodeposition coating only a composite material in which CFRP is directly adhered to a metal member cannot suppress corrosion from a contact portion between the metal member and the CFRP. On the other hand, even if a resin film as an insulator is provided in order to suppress contact corrosion between the dissimilar materials of the metal member and the carbon fibers in the CFRP, since thermocompression bonding is generally performed when the CFRP is attached to the metal plate, the carbon fibers in the CFRP penetrate through the resin insulation film and come into contact with the metal in this step, and it is difficult to completely suppress contact corrosion between the dissimilar materials. Further, since the composite material having the insulating coating layer has an insulating coating film, even if a part of the carbon fibers is in contact with the metal member, the conductivity is impaired, and therefore, even if the composite material having the insulating coating layer is subjected to electrodeposition coating, the electrodeposition coating film is hardly coated, and there is no effect of suppressing contact corrosion of dissimilar materials.

As described above, conventionally, no studies have been made on the suppression of corrosion of dissimilar metals and the improvement of electrodeposition coatability, and no metal-CFRP composite material that combines these has been known.

Patent document 4 discloses an invention relating to a conductive coating film in which an organic resin and non-oxide ceramic particles are contained in a metal plate. However, if CFRP is directly applied to the steel sheet according to the present invention, the steel sheet is coated with an electrodeposition coating film, but corrosion cannot be suppressed. Even if electrodeposition coating properties are imparted by coating only a conductive film on a metal like the metal sheet described in patent document 4, water or the like as a corrosion factor enters an interface between the film coated on the metal sheet and the CFRP from a defective portion or the like of the electrodeposition coating, and contact corrosion of a dissimilar material occurs.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a novel and improved metal-carbon fiber reinforced resin material composite and a method for producing a metal-carbon fiber reinforced resin material composite, in which dissimilar material contact corrosion of a metal member is suppressed and electrodeposition coatability is excellent.

Means for solving the problems

The present inventors have conducted extensive studies to solve the above problems, and as a result, have found that a powder resistivity at 23 to 27 ℃ is set to 7.0 × 10 by providing a resin coating layer containing, as conductive particles, one or more kinds selected from the group consisting of metal particles, intermetallic compound particles, conductive oxide particles and conductive non-oxide ceramic particles between a metal member and a carbon fiber-reinforced resin material, and making the powder resistivity to be 7.0 × 10⁷Omega cm or less, and contains any one or more selected from Zn, Si, Zr, V, Cr, Mo, Mn and W as a constituent element, and can suppress dissimilar material contact corrosion of a metal part and improve electrodeposition paintability. This is presumably because the metal member and the carbon fiber reinforced resin material are electrically conducted by adding a conductive substance to the resin coating layer between the metal member and the carbon fiber reinforced resin material, and the electrodeposition coating film covers the surfaces of the metal material and the CFRP at the time of electrodeposition coating, and further exhibits a barrier effect against corrosion factors that enter the composite material, and further, by making the conductive fine particles of each metal of Zn, Si, Zr, V, Cr, Mo, Mn, and W, or an intermetallic compound containing, Zn, Si, Zr, V, Cr, Mo, Mn, and W, or a conductive oxide or non-oxide ceramic containing each of these metals, these transition elements are eluted and deposited on the surface of the carbon fiber in the metal plate or the CFRP, and an insulating coating is formed between the two, so that contact of dissimilar materials is avoided, and corrosion resistance is improved.

The present invention has been completed based on such findings, and the gist thereof is as follows.

(1) A metal-carbon fiber reinforced resin material composite body comprises a metal member, a resin coating layer and a carbon fiber reinforced resin material,

the resin coating layer is disposed on at least a part of the surface of the metal member,

the carbon fiber reinforced resin material is disposed on at least a part of the surface of the resin coating layer and includes a matrix resin and a carbon fiber material present in the matrix resin,

the resin coating layer contains, as conductive particles, any one or more selected from the group consisting of metal particles, intermetallic compound particles, conductive oxide particles and conductive non-oxide ceramic particles, and further contains a binder resin,

the conductive particles have a powder resistivity of 7.0 x 10 at 23-27 DEG C⁷Ω cm or less, and contains any one or more selected from Zn, Si, Zr, V, Cr, Mo, Mn, and W as a constituent element.

(2) The metal-carbon fiber-reinforced resin material composite according to item (1), wherein the conductive oxide particles are doped conductive oxide particles.

(3) The metal-carbon fiber reinforced resin material composite according to item (1) or (2), wherein the conductive particles are made of a material selected from Al-doped zinc oxide and ZrB₂、MoSi₂、CrB₂、WSi₂、VB₂And ferrosilicon and ferromanganese.

(4) The metal-carbon fiber-reinforced resin material composite according to any one of (1) to (3), wherein a volume fraction of the conductive particles in the resin coating layer is 1.0% or more and 30.0% or less.

(5) The metal-carbon fiber-reinforced resin material composite according to any one of (1) to (4), wherein the resin coating layer has an average thickness of 1.0 μm or more and 200.0 μm or less.

(6) The metal-carbon fiber-reinforced resin material composite according to any one of (1) to (5), wherein the conductive particles have an average particle diameter of 50.0 μm or less.

(7) The metal-carbon fiber-reinforced resin material composite according to any one of (1) to (6), wherein T (μm) is an average thickness of the resin coating layer and r (μm) is an average particle diameter of the conductive particles, wherein T/r is 0.5. ltoreq. T/300.0.

(8) The metal-carbon fiber-reinforced resin material composite according to any one of (1) to (7), wherein the glass transition temperature of the resin coating layer is 100 ℃ or lower.

(9) The metal-carbon fiber-reinforced resin material composite according to any one of (1) to (8), wherein the binder resin is an epoxy resin or a resin containing an epoxy resin and one or more selected from the group consisting of a polyurethane resin, an epoxy resin, a polyester resin and a melamine resin.

(10) The metal-carbon fiber-reinforced resin material composite according to any one of (1) to (9), wherein the matrix resin comprises a thermoplastic resin.

(11) The metal-carbon fiber-reinforced resin material composite according to any one of (1) to (10), wherein the matrix resin contains a phenoxy resin.

(12) The metal-carbon fiber-reinforced resin material composite according to any one of (1) to (11), which comprises an electrodeposition coating film formed on the resin film layer and/or the carbon fiber-reinforced resin material.

(13) The metal-carbon fiber-reinforced resin material composite according to any one of (1) to (12), wherein the metal member is a steel material or a plated steel material.

(14) A method for producing a metal-carbon fiber-reinforced resin material composite, comprising the step of thermocompression bonding a metal member provided on at least a part of the surface of a resin coating layer containing conductive particles and a binder resin to a carbon fiber-reinforced resin material via the resin coating layer,

the carbon fiber reinforced resin material comprises a matrix resin and a carbon fiber material present in the matrix resin,

the conductive particles comprise any one or more selected from the group consisting of metal particles, intermetallic compound particles, conductive oxide particles, and conductive non-oxide ceramic particles,

the conductive particles have a powder resistivity of 7.0 x 10 at 23-27 DEG C⁷Omega cm or less, and contains Zn, Si, Zr, V, or,Any one or more of Cr, Mo, Mn and W as a constituent element.

(15) The method of manufacturing a metal-carbon fiber reinforced resin material composite according to item (14), further comprising a step of molding the metal member before the step of thermocompression bonding.

(16) The method of manufacturing a metal-carbon fiber reinforced resin material composite according to (14), further comprising a step of molding a laminate in which the metal member and the carbon fiber reinforced resin material are laminated after the step of thermocompression bonding.

(17) The method for producing a metal-carbon fiber-reinforced resin material composite according to any one of (14) to (16), further comprising a step of forming an electrodeposition coating film on the resin coating layer and/or the carbon fiber-reinforced resin material by electrodeposition coating.

ADVANTAGEOUS EFFECTS OF INVENTION

As described above, according to the present invention, it is possible to provide a metal-carbon fiber reinforced resin material composite and a method for producing a metal-carbon fiber reinforced resin material composite, in which dissimilar material contact corrosion of a metal member is suppressed and electrodeposition coatability is excellent.

Drawings

Fig. 1 is a schematic cross-sectional view of a metal-carbon fiber reinforced resin material composite according to an embodiment of the present invention in a stacking direction.

Fig. 2 is a schematic cross-sectional view of a metal-carbon fiber reinforced resin material composite according to a modification of the present invention in the stacking direction.

Fig. 3 is a schematic cross-sectional view of a metal-carbon fiber reinforced resin material composite according to another modification of the present invention in the stacking direction.

Fig. 4 is a schematic cross-sectional view of a metal-carbon fiber reinforced resin material composite according to another modification of the present invention in the stacking direction.

Fig. 5 is a schematic cross-sectional view of a metal-carbon fiber reinforced resin material composite according to another modification of the present invention in the stacking direction.

Fig. 6 is a schematic cross-sectional view of a metal-carbon fiber reinforced resin material composite according to another modification of the present invention in the stacking direction.

Fig. 7 is a schematic cross-sectional view of a metal-carbon fiber reinforced resin material composite according to another modification of the present invention in the stacking direction.

Fig. 8 is a schematic diagram for explaining a method of manufacturing a metal-CFRP composite according to embodiment 1 of the present invention.

Fig. 9 is a schematic diagram for explaining a method of manufacturing a metal-CFRP composite according to embodiment 1 of the present invention.

Fig. 10 is a schematic view for explaining a method of manufacturing a metal-CFRP composite according to embodiment 2 of the present invention.

Fig. 11 is a schematic diagram for explaining a method of manufacturing a metal-CFRP composite according to embodiment 2 of the present invention.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and the drawings, the same reference numerals are given to the constituent elements having substantially the same functional configurations, and redundant description is omitted.

Note that similar components in different embodiments are distinguished by the same reference numerals and different letters. However, the same reference numerals are given only when there is no need to particularly distinguish between a plurality of components having substantially the same functional configuration. For convenience of explanation, the drawings are enlarged and reduced as appropriate, and the actual sizes and proportions of the respective portions are not shown in the drawings.

< 1. Metal-carbon fiber reinforced resin Material composite

[1.1. Structure of Metal-carbon fiber-reinforced resin Material composite ]

First, the structure of the metal-carbon fiber reinforced resin material composite according to one embodiment of the present invention will be described with reference to fig. 1. Fig. 1 is a schematic view showing a cross-sectional structure in the stacking direction of a metal-carbon fiber reinforced resin material composite 1 as an example of the metal-carbon fiber reinforced resin material composite according to the present embodiment.

As shown in fig. 1, a metal-carbon fiber reinforced resin material (CFRP) composite 1 includes a metal member 11, a carbon fiber reinforced resin material (CFRP layer) 12, and a resin coating layer 13. The metal member 11 and the CFRP layer 12 are combined with each other through a resin coating layer 13. Here, "composite" means that the metal member 11 and the CFRP layer 12 are bonded (bonded) to each other via the resin coating layer 13 and integrated. Further, "integrated" means that the metal member 11, the CFRP layer 12, and the resin coating layer 13 move as one body when being processed or deformed.

In the present embodiment, the resin coating layer 13 contains conductive particles 131 composed of one or more selected from the group consisting of metal particles, intermetallic compound particles, conductive oxide particles, and conductive non-oxide ceramic particles, and the powder resistivity of the conductive particles 131 at 23 to 27 ℃ is 7.0 × 10⁷Omega cm or less, and contains any one or more selected from Zn, Si, Zr, V, Cr, Mo, Mn and W as a constituent element. Thus, the metal-CFRP composite 1 can suppress contact corrosion of dissimilar materials and is excellent in electrodeposition coatability. Specifically, the conductive particles 131 comprise one or more selected from metal particles, intermetallic compound particles, conductive oxide particles and conductive non-oxide ceramic particles, and have a powder resistivity of 7.0 × 10 at 23-27 ℃⁷Ω cm or less, and contains any one or more selected from Zn, Si, Zr, V, Cr, Mo, Mn, and W as a constituent element, thereby exhibiting sacrificial corrosion prevention effect, and further, an oxide film is generated at a site where the element is oxidized to prevent corrosion of the metal member 11. On the other hand, the powder resistivity of the conductive particles 131 at 23 to 27 ℃ is set to 7.0X 10⁷Hereinafter, the resin coating layer 13 has appropriate conductivity to improve the electrodeposition coatability.

The respective structures of the metal-CFRP composite 1 will be described in detail below.

(Metal component 11)

The material, shape, thickness, and the like of the metal member 11 are not particularly limited as long as they can be formed by pressing or the like, but the shape is preferably a thin plate. Examples of the material of the metal member 11 include iron, titanium, aluminum, magnesium, and alloys thereof. Examples of the alloy include iron-based alloys (including stainless steel), Ti-based alloys, Al-based alloys, and Mg alloys. The material of the metal member 11 is preferably a ferrous material, an iron-based alloy, titanium, or aluminum, and more preferably a ferrous material having higher tensile strength than other metal species. Examples of such steel materials include steel materials represented by general cold-rolled steel sheets for drawing or ultra deep drawing, cold-rolled steel sheets for automotive workability cold rolling, high tensile steel sheets for general or working, hot-rolled steel sheets for automotive construction, and hot-rolled high tensile steel sheets for automotive workability, which are standardized in Japanese Industrial Standards (JIS) and the like as sheet-shaped steel sheets for automobiles, and carbon steels, alloy steels, high tensile steels, and the like used for general structural or mechanical construction may be cited as not limited to the sheet-shaped steel materials.

In addition, when the metal member 11 is an aluminum alloy, it is preferable because the weight of the member can be reduced. The aluminum alloy is an alloy obtained by adding 1 or 2 or more of Si, Fe, Cu, Mn, Mg, Cr, Zn, Ti, V, Zr, Pb, and Bi to aluminum, and commonly known alloys such as 1000 series, 2000 series, 3000 series, 4000 series, 5000 series, 6000 series, and 7000 series described in JIS H4000:2006 can be used. 5000 series, 6000 series, etc. having strength and moldability are preferable. The magnesium alloy is an alloy obtained by adding 1 or 2 or more of Al, Zn, Mn, Fe, Si, Cu, Ni, Ca, Zr, Li, Pb, Ag, Cr, Sn, Y, Sb, and other rare earth elements to magnesium, and generally known alloys such as AM system described in ASTM standard with Al added, AZ system with Al and Zn added, ZK system with Zn added, and the like can be used. In addition, in the case where the metal member 11 is plate-shaped, these may be molded.

The ferrous material may be subjected to any surface treatment. Examples of the surface treatment include various plating treatments such as zinc plating and aluminum plating, chemical conversion treatments such as chromate treatment and non-chromate treatment, and chemical surface roughening treatments such as physical surface roughening treatment such as sandblasting and chemical etching, but the surface treatment is not limited thereto. Further, alloying of the plating layer or various surface treatments may be performed. As the surface treatment, at least a treatment for the purpose of imparting rust prevention is preferably performed.

Among steel materials, in particular, a plated steel material subjected to plating treatment is preferable because it is excellent in corrosion resistance. Particularly preferred coated steel materials for the metal member 11 include hot-dip galvanized steel sheets, zinc alloy-plated steel sheets, alloyed hot-dip galvanized steel sheets alloyed by heat-treating them to diffuse Fe in the zinc coating layer, electrogalvanized steel sheets, Zn-Ni electroplated steel sheets, Zn-5% Al alloy-plated steel sheets, 55% Al-Zn alloy-plated steel sheets, Zn-Al-Mg alloy-plated steel sheets typified by Zn-1 to 12% Al-1 to 4% Mg alloy-plated steel sheets, 55% Al-Zn-0.1 to 3% Mg alloy-plated steel sheets, Ni-plated steel sheets, or alloyed Ni-plated steel sheets alloyed by heat-treating them to diffuse Fe in the Ni coating layer to alloy, Al-plated steel sheets, tin-plated steel sheets, and the like, Chrome plated steel sheet, and the like. The zinc-based plated steel sheet is preferable because it has excellent corrosion resistance. Further, the Zn — Al — Mg alloy-plated steel sheet is more preferable because it is more excellent in corrosion resistance.

In order to improve the adhesion with the CFRP layer 12, the surface of the metal member 11 is preferably treated with a primer. As the primer used in this treatment, for example, a silane coupling agent or a triazine thiol derivative is preferable. The silane coupling agent includes generally known silane coupling agents, such as gamma- (2-aminoethyl) aminopropyltrimethoxysilane, gamma- (2-aminoethyl) aminopropylmethyldimethoxysilane, gamma- (2-aminoethyl) aminopropyltriethoxysilane, gamma- (2-aminoethyl) aminopropylmethyldiethoxysilane, gamma- (2-aminoethyl) aminopropylmethyldimethoxysilane, gamma-methacryloxypropyltrimethoxysilane, gamma-methacryloxypropylmethyldimethoxysilane, gamma-methacryloxypropyltriethoxysilane, gamma-methacryloxypropylmethyldiethoxysilane, N-beta- (N-vinylbenzylaminoethyl) -gamma-aminopropyltrimethoxysilane, gamma-N-vinylbenzylaminoethyl) and gamma-N-aminopropyltrimethoxysilane, N-beta- (N-vinylbenzylaminoethyl) -gamma-aminopropylmethyldimethoxysilane, N-beta- (N-vinylbenzylaminoethyl) -gamma-aminopropyltriethoxysilane, N-beta- (N-vinylbenzylaminoethyl) -gamma-aminopropylmethyldiethoxysilane, gamma-glycidoxypropyltrimethoxysilane, gamma-glycidoxypropylmethyldimethoxysilane, gamma-glycidoxypropyltriethoxysilane, gamma-glycidoxypropylmethyldiethoxysilane, gamma-mercaptopropyltrimethoxysilane, gamma-mercaptopropylmethyldimethoxysilane, gamma-mercaptopropyltriethoxysilane, gamma-mercaptopropylmethyldiethoxysilane, gamma-N-butylaminopropyltriethoxysilane, gamma-N-butylaminopropylmethyldiethoxysilane, gamma-butylaminopropyltriethoxysilane, gamma-propyltriethoxysilane, gamma-hydroxyethyltrimethoxysilane, gamma-butylmethyldiethoxysilane, gamma-propyltriethoxysilane, gamma-butyltrimethoxysilane, gamma-vinyltriethoxysilane, gamma-vinylmethyldiethoxysilane, gamma-vinyltrimethoxysilane, gamma-vinyltriethoxysilane, gamma-vinylbenzyltriethoxysilane, gamma-vinylmethyldiethoxysilane, gamma-vinyltrimethoxysilane, gamma-vinylmethyldiethoxysilane, gamma-vinyltrimethoxysilane, gamma-vinylmethyldiethoxysilane, gamma-vinylmethyldimethacrylate, gamma-vinyltrimethoxysilane, gamma-vinylbenzyltriethoxysilane, gamma-vinyltrimethoxysilane, gamma-vinylbenzyltriethoxysilane, gamma-vinyltrimethoxysilane, gamma-vinylbenzyltriethoxysilane, gamma-vinyltrimethoxysilane, gamma-vinylmethyldimethacrylate, gamma-vinyltrimethoxysilane, gamma, Methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, vinyltriacetoxysilane, gamma-chloropropyltrimethoxysilane, gamma-chloropropylmethyldimethoxysilane, gamma-chloropropyltriethoxysilane, gamma-chloropropylmethyldiethoxysilane, hexamethyldisilazane, gamma-anilinopropyltrimethoxysilane, gamma-anilinopropylmethyldimethoxysilane, gamma-anilinopropyltriethoxysilane, gamma-anilinopropylmethyldiethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, octadecyldimethyl [3- (trimethoxysilyl) propyl ] ammonium chloride, methyl-p-methoxysilane, methyl-triethoxysilane, methyl-n-butyl-methyl-p-methoxysilane, methyl-n-butyl-ethyl-methyl-p-ethoxysilane, methyl-n-butyl-ethyl-methyl-3- (trimethoxysilyl) propyl ] ammonium chloride, methyl-ethyl-methyl-methoxysilane, methyl-diethoxy-ethyl-methyl-disilazane, methyl-ethyl-methyl-ethyl-methyl-trimethoxysilane, ethyl-trimethoxysilane, ethyl-methyl-trimethoxysilane, ethyl-methyl-ethyl-methyl-propyl-ethyl-propyl-ethyl-propyl-methyl-ethyl-methyl-propyl-ethyl-propyl-methyl-propyl-methyl-propyl-ammonium chloride, ethyl-propyl-ethyl-propyl-methyl-ethyl-propyl-ethyl-propyl-ethyl-methyl-ethyl-methyl-propyl-ethyl-methyl-ethyl-methyl-propyl-ethyl-methyl-ethyl-propyl-ethyl-methyl-ethyl-methyl-ethyl, Octadecyldimethyl [3- (methyldimethoxysilyl) propyl ] ammonium chloride, octadecyldimethyl [3- (triethoxysilyl) propyl ] ammonium chloride, octadecyldimethyl [3- (methyldiethoxysilyl) propyl ] ammonium chloride, gamma-chloropropylmethyldimethoxysilane, gamma-mercaptopropylmethyldimethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane and the like, and if a silane coupling agent having a glycidyl ether group, for example, gamma-glycidoxypropyltrimethoxysilane and gamma-glycidoxypropyltriethoxysilane having a glycidyl ether group is used, the processing adhesion of the coating film is particularly improved. Further, if a triethoxy type silane coupling agent is used, the storage stability of the base treatment agent (primer) can be improved. This is considered to be because triethoxysilane is relatively stable in an aqueous solution and the polymerization rate is slow. The silane coupling agent may be used in 1 kind, or 2 or more kinds may be used in combination. Examples of the triazine thiol derivative include diallylamino-2, 4-dithiol-1, 3, 5-triazine, 6-methoxy-2, 4-dithiol-1, 3, 5-triazine monosodium salt, 6-propyl-2, 4-dithiol-amino-1, 3, 5-triazine monosodium salt, and 2,4, 6-trithiol-1, 3, 5-triazine.

(CFRP layer 12)

The CFRP layer 12 is joined to the metal member 11 via a resin coating layer 13 described later. That is, the CFRP layer 12 is disposed on the surface of the resin coating layer 13. In the present embodiment, for the purpose of explaining the effects of the present invention, the form in which the CFRP layer 12 is disposed only on a part of the surface of the resin coating layer 13 is shown, but the present invention is not limited to the form shown in the drawings, and a CFRP layer of an arbitrary shape may be disposed on all or a part of the surface of the resin coating layer 13. Further, for reasons described below, the CFRP layer 12 can form a relatively uniform electrodeposition coating film on the surface 125 thereof.

The CFRP layer 12 includes a matrix resin 123 and a carbon fiber material 121 that is contained in the matrix resin 123 and is compounded.

The carbon fiber material 121 is not particularly limited, and may be selected according to the purpose or use, for example, using any of PAN-based materials and pitch-based materials. As the carbon fiber material 121, 1 kind of the above fibers may be used alone, or a plurality of kinds may be used in combination.

In the CFRP used for the CFRP layer 12, as the reinforcing fiber base material as the base material of the carbon fiber material 121, for example, a nonwoven fabric base material using short fibers, a cloth using continuous fibers, a unidirectional reinforcing fiber base material (UD material), or the like can be used. From the viewpoint of the reinforcing effect, a cloth or UD material is preferably used as the reinforcing fiber base material.

The matrix resin 123 may be a cured product or a cured product of the resin composition. The term "cured product" as used herein refers to a product obtained by curing a resin component by itself, and the term "cured product" refers to a product obtained by curing (solidifying) a resin component by containing various kinds of hardeners (solidifying agents). The curing agent that may be contained in the cured product may include a crosslinking agent as described later, and the "cured product" includes a crosslinked cured product formed by crosslinking.

The resin composition constituting the matrix resin 123 may be either a thermosetting resin or a thermoplastic resin, and preferably contains a thermoplastic resin as a main component. The type of thermoplastic resin that can be used for the base resin 123 is not particularly limited, and for example, 1 or more selected from phenoxy resins, polyolefins and acid-modified products thereof, polystyrene, polymethyl methacrylate, AS resins, ABS resins, thermoplastic aromatic polyesters such AS polyethylene terephthalate and polybutylene terephthalate, polycarbonates, polyimides, polyamides, polyamideimides, polyetherimides, polyethersulfones, polyphenylene ethers and modified products thereof, polyphenylene sulfides, polyoxymethylenes, polyarylates, polyetherketones, polyetheretherketones, polyetherketoneketones, and nylons can be used. The "thermoplastic resin" also includes a resin which can be a crosslinked cured product in the 2 nd cured state described later. As the thermosetting resin that can be used for the matrix resin 123, for example, 1 or more selected from epoxy resin, vinyl ester resin, phenol resin, and urethane resin can be used.

Here, when the matrix resin 123 contains a thermoplastic resin, the above-described problems in the case of using a thermosetting resin as the matrix resin of the CFRP, that is, the problems of brittleness, long takt time (takt time), inability to bend, and the like of the CFRP layer 12 can be solved. However, the thermoplastic resin generally has a high viscosity when melted, and cannot be impregnated into the carbon fiber material 121 in a low-viscosity state as in the case of a thermosetting resin such as an epoxy resin before thermosetting, and therefore, the impregnation property with respect to the carbon fiber material 121 is poor. Therefore, it is not possible to increase the reinforcing fiber density (VF) in the CFRP layer 12 as in the case of using a thermosetting resin as the matrix resin 123. For example, when an epoxy resin is used as the matrix resin 123, VF can be about 60%, but when a thermoplastic resin such as polypropylene or nylon is used as the matrix resin 123, VF is about 50%. In addition, if a thermoplastic resin such as polypropylene or nylon is used, the CFRP layer 12 cannot have high heat resistance as in the case of using a thermosetting resin such as an epoxy resin.

In order to solve such a problem when a thermoplastic resin is used, a phenoxy resin is preferably used as the matrix resin 123. The phenoxy resin has a molecular structure very similar to that of an epoxy resin, and therefore has heat resistance of the same degree as that of an epoxy resin, and has good adhesion to the metal member 11 or the carbon fiber material 121. Further, a so-called partially curable resin can be formed by adding a curing component such as an epoxy resin to the phenoxy resin and copolymerizing the curing component. By using such a partially curable resin as the matrix resin 123, a matrix resin having excellent impregnation properties with respect to the carbon fiber material 121 can be formed. Further, by thermally curing the curing component in the partially curable resin, it is possible to suppress melting or softening when the matrix resin 123 in the CFRP layer 12 is exposed to high temperature like a normal thermoplastic resin. The amount of the curing component added to the phenoxy resin can be appropriately determined in consideration of the impregnation property with respect to the carbon fiber material 121, the brittleness of the CFRP layer 12, the tact time, the workability, and the like. By using a phenoxy resin as the matrix resin 123 in this manner, addition and control of a curing component with a high degree of freedom can be performed.

For example, a sizing agent having good fusion with an epoxy resin is often applied to the surface of the carbon fiber material 121. Since the phenoxy resin has a very similar structure to the epoxy resin, a sizing agent for the epoxy resin can be directly used by using the phenoxy resin as the matrix resin 123. Therefore, the cost competitiveness can be improved.

Among thermoplastic resins, phenoxy resins have good moldability and excellent adhesion to the carbon fiber material 121 and the metal member 11, and can also have properties similar to those of thermosetting resins having high heat resistance after molding by using acid anhydrides, isocyanate compounds, caprolactam, and the like as a crosslinking agent. Thus, in the present embodiment, it is preferable to use a cured product or a cured product of a resin composition containing 50 parts by mass or more of a phenoxy resin per 100 parts by mass of the resin component as the resin component of the matrix resin 123. By using such a resin composition, the metal member 11 and the CFRP layer 12 can be firmly joined. The resin composition more preferably contains not less than 55 parts by mass of the phenoxy resin per 100 parts by mass of the resin component. The form of the adhesive resin composition may be, for example, a liquid such as powder or varnish, or a solid such as a film.

The content of the phenoxy resin can be measured by InfraRed spectroscopy (IR) as described below, and when the content of the phenoxy resin is analyzed from the target resin composition by IR, the content can be measured by a general method of IR analysis such as transmission method or ATR reflection method.

The CFRP layer 12 is cut with a sharp cutter or the like, and the fibers are removed as much as possible with tweezers or the like, and the resin composition to be analyzed is collected from the CFRP layer 12. In the case of the permeation method, a KBr powder and a powder of a resin composition to be analyzed are uniformly mixed in a mortar and crushed to prepare a thin film, which is used as a sample. In the case of the ATR reflection method, as in the transmission method, a tablet may be prepared by crushing the powder in a mortar while uniformly mixing the powder, or a sample may be prepared by scratching the surface of a single crystal KBr tablet (for example, 2mm in diameter × 1.8mm in thickness) with a file or the like, and scattering the powder of the resin composition to be analyzed to adhere thereto. In either method, the key point is to measure the background (background) of the KBr monomer before mixing with the resin to be analyzed. The IR measuring apparatus may be a commercially available general apparatus, and preferably has a precision such that the absorption (Absorbance) is 1% unit and the wave number (Wavenumber) is 1cm^-1Examples of the device for analyzing the accuracy of the unit discrimination include FT/IR-6300 manufactured by Nippon spectral Co., Ltd.

When the content of the phenoxy resin is investigated, the absorption peak of the phenoxy resin is, for example, 1450 to 1480cm^-1、1500cm^-1About 1600cm^-1And the like, and therefore the content can be calculated based on the intensity of the absorption peak.

The term "phenoxy resin" refers to a linear polymer obtained by a condensation reaction between a dihydric phenol compound and an epihalohydrin or an addition polymerization reaction between a dihydric phenol compound and a bifunctional epoxy resin, and is an amorphous thermoplastic resin. The phenoxy resin can be obtained in a solution or in a solvent-free state by a conventionally known method, and can be used in any form of powder, varnish, or film. The average molecular weight (Mw) of the phenoxy resin is, for example, in the range of 10,000 to 200,000, preferably 20,000 to 100,000, and more preferably 30,000 to 80,000. When the Mw of the phenoxy resin (a) is in the range of 10,000 or more, the strength of the molded article can be improved, and when the Mw is 20,000 or more, further 30,000 or more, the effect is further improved. On the other hand, when the Mw of the phenoxy resin is 200,000 or less, the workability and the processability can be improved, and when the Mw is 100,000 or less, further 80,000 or less, the effect can be further improved. The Mw in the present specification is a value measured by Gel Permeation Chromatography (GPC) and converted by using a standard polystyrene calibration curve.

The phenoxy resin used in the present embodiment has a hydroxyl group equivalent (g/eq) of, for example, 50 or more and 1000 or less, preferably 50 or more and 750 or less, and more preferably 50 or more and 500 or less. When the hydroxyl group equivalent of the phenoxy resin is 50 or more, the hydroxyl group is reduced, and the water absorption rate is lowered, so that the mechanical properties of the cured product can be improved. On the other hand, when the hydroxyl equivalent of the phenoxy resin is 1,000 or less, the decrease of hydroxyl groups can be suppressed, and therefore, the affinity with the adherend can be improved, and the mechanical properties of the metal-CFRP composite 1 can be improved. This effect is further improved by setting the hydroxyl equivalent weight to 750 or less, and further 500 or less.

The glass transition temperature (Tg) of the phenoxy resin is, for example, in the range of 65 ℃ to 150 ℃, preferably 70 ℃ to 150 ℃. If Tg is 65 ℃ or more, moldability can be ensured and excessive fluidity of the resin can be suppressed, so that the thickness of the resin film layer 13 can be sufficiently ensured. On the other hand, if Tg is 150 ℃ or less, the melt viscosity becomes low, so that the reinforcing fiber base material is easily impregnated without defects such as voids, and a bonding process at a lower temperature can be performed. The Tg of the resin in the present specification is a value obtained by measuring the Tg at a temperature in the range of 20 to 280 ℃ under a temperature rise condition of 10 ℃/min using a differential scanning calorimeter and calculating from the peak value of the second scan.

The phenoxy resin is not particularly limited as long as the above physical properties are satisfied, and preferable phenoxy resins include bisphenol A type phenoxy resins (for example, those available as フェノトート YP-50, フェノトート YP-50S and フェノトート YP-55U manufactured by Nippon Tekken chemical Co., Ltd.), bisphenol F type phenoxy resins (for example, those available as フェノトート FX-316 manufactured by Nippon Tekken chemical Co., Ltd.), copolymer type phenoxy resins of bisphenol A and bisphenol F (for example, those available as YP-70 manufactured by Nippon Tekken chemical Co., Ltd.), brominated phenoxy resins other than the above-mentioned phenoxy resins, phospho-containing phenoxy resins, sulfonic acid group-containing phenoxy resins, and other special phenoxy resins (for example, those available as フェノトート B-43C manufactured by Nippon Tekken chemical Co., Ltd.), フェノトート FX293, YPS-007, etc.). These resins may be used alone in 1 kind, or in combination of 2 or more kinds.

The thermoplastic resin used as the resin component of the matrix resin 123 preferably has a melt viscosity of 3,000Pa · s or less at any temperature in a temperature range of 160 to 250 ℃, more preferably has a melt viscosity of 90Pa · s or more and 2,900Pa · s or less, and still more preferably has a melt viscosity of 100Pa · s or more and 2,800Pa · s or less. When the melt viscosity in the temperature range of 160 to 250 ℃ is 3,000 pas or less, the fluidity at the time of melting is improved, and defects such as voids are less likely to occur in the CFRP layer 12. On the other hand, by setting the melt viscosity to 90Pa · s or more, the molecular weight of the resin composition can be made appropriate, and embrittlement and the consequent decrease in mechanical strength of the metal-CFRP composite 1 can be suppressed.

The resin composition constituting the matrix resin 123 may be a crosslinkable resin composition in which a crosslinking agent is blended with the resin composition. For example, a crosslinkable resin composition (that is, a cured product of the resin composition) can also be prepared by blending a phenoxy resin (hereinafter also referred to as "phenoxy resin (a)") with a crosslinking agent such as an acid anhydride, isocyanate, or caprolactam. The crosslinkable resin composition is advantageous for use in parts used under higher temperature environments because the heat resistance of the resin composition is improved by the crosslinking reaction using the secondary hydroxyl group contained in the phenoxy resin (a). In order to form a crosslink by the secondary hydroxyl group of the phenoxy resin (a), a crosslinkable resin composition containing a crosslinking curable resin (B) and a crosslinking agent (C) is preferably used. The crosslinking curable resin (B) may be, for example, an epoxy resin, but is not particularly limited thereto. By using such a crosslinkable resin composition, a cured product (crosslinked cured product) in the 2 nd cured state, in which the Tg of the resin composition is greatly increased, can be obtained as compared with the case of using the phenoxy resin (a) alone. The Tg of the crosslinked cured product of the crosslinkable resin composition is, for example, 160 ℃ or higher, and preferably in the range of 170 ℃ or higher and 220 ℃ or lower.

In the crosslinkable resin composition, the crosslinking curable resin (B) to be blended with the phenoxy resin (a) is preferably a bifunctional or higher epoxy resin. Examples of the bifunctional or higher epoxy resin include bisphenol A type epoxy resins (for example, those obtained as エポトート YD-011, エポトート YD-7011, エポトート YD-900 manufactured by Nippon Tekken chemical Co., Ltd.), bisphenol F type epoxy resins (for example, those obtained as エポトート YDF-2001 manufactured by Nippon Tekken chemical Co., Ltd.), diphenyl ether type epoxy resins (for example, those obtained as YSLV-80DE manufactured by Nippon Tekken chemical Co., Ltd.), tetramethyl bisphenol F type epoxy resins (for example, those obtained as YSLV-80XY manufactured by Nippon Tekken chemical Co., Ltd.), bisphenol sulfur type epoxy resins (for example, those obtained as YSLV-120TE manufactured by Nippon Tekken chemical Co., Ltd.), and hydroquinone type epoxy resins (for example, those obtained as エポトート YDC-1312 manufactured by Nippon Tekken chemical Co., Ltd.), Examples of the epoxy resin include phenol novolak type epoxy resins (for example, those available as エポトート YDPN-638 available from Nippon Tekken chemical Co., Ltd.), o-cresol novolak type epoxy resins (for example, those available as エポトート YDCN-701, エポトート YDCN-702, エポトート YDCN-703 and エポトート YDCN-704 available from Nippon Tekken chemical Co., Ltd.), aralkyl naphthalenediol novolak type epoxy resins (for example, those available as ESN-355 available from Nippon Tekken chemical Co., Ltd.), and triphenylmethane type epoxy resins (for example, those available as EPPN-502H available from Nippon Tekken chemical Co., Ltd.), but the present invention is not limited thereto. These epoxy resins may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

The crosslinking curable resin (B) is not particularly limited, but is preferably a crystalline epoxy resin, and more preferably a crystalline epoxy resin having a melting point in the range of 70 ℃ to 145 ℃ and a melt viscosity at 150 ℃ of 2.0Pa · s or less. By using a crystalline epoxy resin exhibiting such melt characteristics, the melt viscosity of a crosslinkable resin composition as a resin composition can be reduced, and the adhesiveness of the CFRP layer 12 can be improved. Further, by setting the melt viscosity to 2.0Pa · s or less, the moldability of the crosslinkable resin composition can be sufficiently excellent, and the homogeneity of the metal-CFRP composite 1 can be improved.

Examples of the crystalline epoxy resin suitable for use as the crosslinkable curable resin (B) include エポトート YSLV-80XY, YSLV-70XY, YSLV-120TE, YDC-1312, YX-4000H, YX-8800 and YL-6121H, YL-6640 manufactured by Mitsubishi chemical Co., Ltd., HP-4032D, HP-4700 manufactured by DIC Co., Ltd., NC-3000 manufactured by Nippon chemical Co., Ltd., and the like.

The crosslinking agent (C) forms an ester bond with a secondary hydroxyl group of the phenoxy resin (a) to three-dimensionally crosslink the phenoxy resin (a). Therefore, unlike strong crosslinking such as curing of a thermosetting resin, since the crosslinking can be released by a hydrolysis reaction, the metal member 11 and the CFRP layer 12 can be easily peeled off. Therefore, the metal member 11 can be recycled.

As the crosslinking agent (C), acid anhydride is preferable. The acid anhydride is not particularly limited as long as it is a solid at room temperature and hardly sublimes, and an aromatic acid anhydride having 2 or more acid anhydrides that react with the hydroxyl group of the phenoxy resin (a) is preferable from the viewpoint of imparting heat resistance and reactivity to the metal-CFRP composite 1. In particular, an aromatic compound having two acid anhydride groups such as pyromellitic anhydride is preferably used because it has a higher crosslinking density and improved heat resistance as compared with a combination of trimellitic anhydride and hydroxyl groups. Even aromatic acid dianhydrides such as 4,4 ' -oxydiphthalic acid, ethylene glycol dianhydro trimellitate, and 4,4 ' - (4,4 ' -isopropyldiphenoxy) diphthalic anhydride, which are compatible with phenoxy resins and epoxy resins, are more preferable because they have a large effect of increasing Tg. In particular, an aromatic acid dianhydride having two acid anhydride groups such as pyromellitic anhydride is preferably used because it has higher crosslinking density and higher heat resistance than phthalic anhydride having only one acid anhydride group, for example. That is, since the aromatic acid dianhydride has 2 acid anhydride groups, it has good reactivity, can obtain a crosslinked cured product having a strength sufficient for mold release in a short molding time, and can increase the final crosslinking density because 4 carboxyl groups are generated by the esterification reaction with the secondary hydroxyl group in the phenoxy resin (a).

The reaction of the phenoxy resin (a), the epoxy resin as the crosslinking curable resin (B), and the crosslinking agent (C) crosslinks and cures by an esterification reaction of a secondary hydroxyl group in the phenoxy resin (a) with an acid anhydride group of the crosslinking agent (C), and a reaction of a carboxyl group generated by the esterification reaction with an epoxy group of the epoxy resin. The crosslinked phenoxy resin can be obtained by the reaction between the phenoxy resin (a) and the crosslinking agent (C), but since the melt viscosity of the resin composition is reduced by the coexistence with the epoxy resin, excellent characteristics such as improvement in impregnation with an adherend (resin coating layer 13), acceleration of a crosslinking reaction, improvement in crosslinking density, and improvement in mechanical strength are exhibited.

In the crosslinkable resin composition, although the epoxy resin as the crosslinking curable resin (B) coexists, the phenoxy resin (a) as the thermoplastic resin is considered to be the main component, and the esterification reaction of the secondary hydroxyl group thereof with the acid anhydride group of the crosslinking agent (C) is considered to be preferred. That is, since it takes time (reaction speed is slow) for the acid anhydride used as the crosslinking agent (C) to react with the epoxy resin used as the crosslinking curable resin (B), the reaction of the crosslinking agent (C) with the secondary hydroxyl group of the phenoxy resin (a) occurs first, and then the crosslinking agent (C) remaining in the previous reaction or the residual carboxyl group derived from the crosslinking agent (C) reacts with the epoxy resin, thereby further increasing the crosslinking density. Therefore, unlike a resin composition containing an epoxy resin as a main component, which is a thermosetting resin, a crosslinked cured product obtained from a crosslinkable resin composition is a thermoplastic resin and is excellent in storage stability.

In the crosslinkable resin composition crosslinked by the phenoxy resin (a), the crosslinking curable resin (B) is preferably contained in an amount of 5 parts by mass or more and 85 parts by mass or less with respect to 100 parts by mass of the phenoxy resin (a). The content of the crosslinking curable resin (B) is more preferably in the range of 9 parts by mass or more and 83 parts by mass or less, and still more preferably in the range of 10 parts by mass or more and 80 parts by mass or less, with respect to 100 parts by mass of the phenoxy resin (a). By setting the content of the crosslinking curable resin (B) to 85 parts by mass or less, the curing time of the crosslinking curable resin (B) can be shortened, and thus the strength required for mold release can be easily obtained in a short time, and the recyclability of the FRP layer 12 is improved. This effect is further improved by setting the content of the crosslinking curable resin (B) to 83 parts by mass or less, and further 80 parts by mass or less. On the other hand, when the content of the crosslinking curable resin (B) is 5 parts by mass or more, the effect of improving the crosslinking density by the addition of the crosslinking curable resin (B) is easily obtained, and the crosslinked cured product of the crosslinkable resin composition easily exhibits Tg of 160 ℃ or more and has good fluidity. The content of the crosslinking curable resin (B) can be measured by measuring the peak derived from the epoxy resin in the same manner as described above by the method using IR.

The amount of the crosslinking agent (C) is usually in the range of 0.6 to 1.3 moles, preferably 0.7 to 1.3 moles, and more preferably 1.1 to 1.3 moles, of an acid anhydride group, based on 1 mole of the secondary hydroxyl group of the phenoxy resin (a). When the amount of the acid anhydride group is 0.6 mol or more, the crosslinking density becomes high, and therefore, the mechanical properties and heat resistance are excellent. This effect is further improved by setting the amount of the acid anhydride group to 0.7 mol or more, and further to 1.1 mol or more. If the amount of the acid anhydride group is 1.3 mol or less, the curing property or crosslinking density can be inhibited from being adversely affected by unreacted acid anhydride or carboxyl group. Therefore, the amount of the crosslinking curable resin (B) is preferably adjusted according to the amount of the crosslinking agent (C). Specifically, for example, in order to react a carboxyl group generated by the reaction of a secondary hydroxyl group of the phenoxy resin (a) with an acid anhydride group of the crosslinking agent (C) with an epoxy resin used as the crosslinking curable resin (B), the equivalent ratio of the amount of the epoxy resin to the crosslinking agent (C) may be in the range of 0.5 mol or more and 1.2 mol or less. The equivalent ratio of the crosslinking agent (C) to the epoxy resin is preferably in the range of 0.7 mol or more and 1.0 mol or less.

The crosslinkable resin composition can be obtained by blending the crosslinking agent (C) with the phenoxy resin (a) and the crosslinking curable resin (B), but an accelerator (D) may be further added as a catalyst in order to ensure the crosslinking reaction. The accelerator (D) is not particularly limited as long as it is solid at ordinary temperature and does not sublime, and examples thereof include tertiary amines such as triethylenediamine, imidazoles such as 2-methylimidazole, 2-phenylimidazole and 2-phenyl-4-methylimidazole, organophosphines such as triphenylphosphine, tetraphenylboronic acids such as tetraphenylboronic acid and tetraphenylphosphonium, and the like. These accelerators (D) may be used alone in 1 kind, or may be used in combination in 2 or more kinds. When the crosslinkable resin composition is made into fine powder and adhered to the reinforcing fiber base material by electrostatic field powder coating to form the matrix resin 123, it is preferable to use, as the accelerator (D), an imidazole-based latent catalyst which is solid at ordinary temperature and has a catalyst activation temperature of 130 ℃. When the accelerator (D) is used, the amount of the accelerator (D) is preferably in the range of 0.1 to 5 parts by mass based on 100 parts by mass of the total amount of the phenoxy resin (a), the crosslinking curable resin (B), and the crosslinking agent (C).

The crosslinkable resin composition is a solid at ordinary temperature, and the melt viscosity thereof is preferably 3,000 pas or less, more preferably 2,900 pas or less, and still more preferably 2,800 pas or less, as the lowest value of the melt viscosity in a temperature range of 160 to 250 ℃. When the minimum melt viscosity in the temperature range of 160 to 250 ℃ is 3,000Pa · s or less, the crosslinkable resin composition can be sufficiently impregnated into the adherend when pressure-bonded by heating such as hot pressing, and defects such as voids can be suppressed from occurring in the CFRP layer 12, so that the mechanical properties of the metal-CFRP composite 1 are improved. The effect is further improved by setting the minimum melt viscosity to 2,900 pas or less, and further to 2,800 pas or less in a temperature range of 160 to 250 ℃.

The resin composition (including the crosslinkable resin composition) for forming the matrix resin 123 may contain, for example, natural rubber, synthetic rubber, elastomer, various inorganic fillers, solvents, extender pigments, colorants, antioxidants, ultraviolet inhibitors, flame retardants, flame retardant aids, and other additives, as long as the adhesiveness and physical properties thereof are not impaired.

In the metal-CFRP composite 1, the base resin 123 of the CFRP layer 12 and the resin constituting the resin coating layer 13 may be the same resin or different resins. However, from the viewpoint of sufficiently ensuring the adhesiveness between the CFRP layer 12 and the resin coating layer 13, it is preferable to select a resin type similar to or the same as the resin forming the resin coating layer 13, the ratio of polar groups contained in the polymer, or the like as the matrix resin 123. Here, "the same resin" means that the resin is composed of the same components and has the same composition ratio, and "the same resin" means that the composition ratio may be different as long as the main components are the same. The "same kind of resin" includes "the same resin". The term "main component" means a component that is contained in an amount of 50 parts by mass or more per 100 parts by mass of the total resin components. The "resin component" includes a thermoplastic resin and a thermosetting resin, but does not include a non-resin component such as a crosslinking agent.

In the metal-CFRP composite 1, the CFRP layer 12 is formed using at least one or more sheets of prepreg for CFRP molding. The number of prepregs for CFRP molding to be stacked may be selected according to the desired thickness of the CFRP layer 12.

(resin coating layer 13)

The resin coating layer 13 is disposed between the metal member 11 and the CFRP layer 12 of the metal-CFRP composite 1, and bonds them. The resin coating layer 13 is insulating in a corrosive environment, and insulates the metal member 11 and the CFRP layer 12 from each other. Specific examples of the corrosive environment include an environment in which moisture adheres to and/or exists around the metal-CFRP composite 1, such as when or after the metal-CFRP composite 1 is wetted with water.

The resin coating layer 13 contains at least one or more of metal particles, intermetallic compound particles, conductive oxide particles, and conductive non-oxide ceramic particles as the conductive particles 131, and further contains a binder resin 133. The powder resistivity of the conductive particles 131 at 23-27 ℃ is 7.0 x 10⁷Omega cm or less, and contains any one or more selected from Zn, Si, Zr, V, Cr, Mo, Mn and W as a constituent element. Thus, the metal-CFRP composite 1 can suppress contact corrosion of dissimilar materials and is excellent in electrodeposition coatability.

First, the dissimilar material contact corrosion will be described in detail, and usually, the CFRP layer and the metal member are bonded by thermocompression bonding via a resin coating layer. At this time, a part of the carbon fiber material in the CFRP layer is pressed by the pressure at the time of thermocompression bonding to protrude from the surface of the CFRP layer. In addition, since the carbon fiber material that protrudes penetrates the resin coating layer, the carbon fiber material comes into contact with the metal member, and corrosion occurs due to the electrolytic corrosion.

In contrast, in the present embodiment, the conductive particles 131 function as a rust preventive pigment by containing any one or more of Zn, Si, Zr, V, Cr, Mo, Mn, and W. Therefore, when carbon fiber material 121 protrudes from the surface of CFRP layer 12, carbon fiber material 121 first enters resin coating layer 13 and comes into contact with conductive particles 131. Next, in the conductive particles 131, the metal component in the conductive particles 131 having a lower potential than the metal member 11 or the carbon fiber material 121 is eluted as metal ions by sacrificial corrosion protection in the corrosive environment, and an oxide or hydroxide of the metal component of the conductive particles is deposited also on the surfaces of the conductive particles 131. Further, the same deposits are formed on the surfaces of the metal member 11 and the carbon fiber material 121, thereby preventing oxidation of the metal member 11. The conductive particles 131 also form an oxide having reduced conductivity at the oxidized portion, and function as a protective film around the oxidized portion. As a result, contact corrosion of dissimilar materials can be suppressed.

On the other hand, the powder resistivity of the conductive particles 131 at 23 to 27 ℃ is 7.0X 10⁷Omega cm or less. As a result, during the electrodeposition coating process, electrical conduction between the carbon fiber material 121 and the metal member 11 can be achieved via the conductive particles 131, and a relatively uniform electrodeposition coating film can be formed on the surface 125 of the CFRP layer 12. Even on the surface 135 of the resin coating layer 13 not covered with the CFRP layer 12, the conductive particles 131 can conduct to the metal member 11, and a relatively uniform electrodeposition coating film can be formed.

As described above, in the present embodiment, by using the specific conductive particles 131 in the resin coating layer 13, it is possible to achieve both suppression of contact corrosion of dissimilar materials and improvement of electrodeposition coatability.

Further, the main component of the metal member 11 may be the largest component in the metal member 11. For example, in the case of a steel material or a plated steel material, the main component of the metal member 11 is Fe, which is the largest component constituting the base material thereof.

Further, as described above, the powder resistivity of the conductive particles 131 at 23 to 27 ℃ is 7.0 × 10⁷Omega cm or less. Since the conductivity of the conductive particles 131 is relatively high, the conductive particles 131 can achieve electrical conduction between the carbon fiber material 121 and the metal member 11. On the other hand, the powder resistivity at 23 to 27 ℃ of the conductive particles 131 exceeds 7.0X 10⁷In the case of Ω cm, the electrical conduction between the carbon fiber material 121 and the metal member 11 is insufficient, and the electrodeposition paintability is not sufficiently improved. The powder resistance of the conductive particles 131 at 23 to 27 ℃ can be determined by measuring the resistance of powder particles compressed at 10MPa using a commercially available powder resistance measuring machine, such as "powder resistance measuring system MCP-PD 51" manufactured by mitsubishi ケミカルアナリテック. In addition, in generalThe powder resistivity can be considered to be the same as the measured volume resistivity of the material itself of the conductive particles 131.

Specifically, the conductive particles 131 are preferably metal particles containing one or more kinds selected from Zn, Si, Zr, V, Cr, Mo, Mn, and W as a constituent element, and are also preferably intermetallic compound particles containing one or more kinds selected from Zn, Si, Zr, V, Cr, Mo, Mn, and W, such as a ferrosilicon alloy and a ferromanganese alloy. In addition, it is also preferable to use a conductive oxide or non-oxide ceramic containing any one or more selected from Zn, Si, Zr, V, Cr, Mo, Mn, and W.

Here, as the conductive oxide, a substance having conductivity by doping an impurity in a crystal lattice of the oxide (a doped conductive oxide) or a substance of a type in which a surface of the oxide is modified with a conductive substance can be used. As the former, a generally known metal oxide (for example, Al-doped zinc oxide, Nb-doped zinc oxide, Ga-doped zinc oxide, Sn-doped zinc oxide, or the like) doped with 1 or more metal elements selected from Al, Nb, Ga, Sn, and the like can be used. As the latter, SnO modified with an oxide having conductivity can be used₂And generally known substances such as zinc oxide and silicon dioxide. The conductive oxide is preferably a doped conductive oxide, and the doped conductive oxide is preferably Al-doped zinc oxide.

The non-oxide ceramic means a ceramic composed of an element or a compound not containing oxygen, and examples thereof include boride ceramics, carbide ceramics, nitride ceramics, and silicide ceramics. The boride ceramic, carbide ceramic, nitride ceramic, and silicide ceramic are non-oxide ceramics containing boron B, carbon C, nitrogen N, and silicon Si as main non-metal constituent elements, and ceramics containing one or more selected from Zn, Si, Zr, V, Cr, Mo, Mn, and W can be used as these generally known non-oxide ceramics. The non-oxide ceramic particles are more preferably non-oxide ceramics exemplified below from the viewpoints of the presence or absence of industrial products, stable flow properties in domestic and foreign markets, price, resistivity, and the like. For example Mo₂B、MoB、MoB₂、Mo₂B₅、NbB₂、VB、VB₂、W₂B₅、ZrB₂、Mo₂C、V₂C、VC、WC、W₂C、ZrC、Mo₂N、VN、ZrN、Mo₃Si、Mo₅Si₃、MoSi₂、NbSi₂、Ni₂Si、Ta₂Si、TaSi₂、TiSi、TiSi₂、V₅Si₃、VSi₂、W₃Si、WSi₂、ZrSi、ZrSi₂、CrB、CrB₂、Cr₃C₂、Cr₂N, CrSi, and a mixture of 2 or more selected from these.

Among the above, from the viewpoint of more reliably suppressing corrosion including dissimilar material contact corrosion, the conductive particles 131 are preferably 1 or 2 or more selected from conductive oxide particles, non-oxide ceramics, and intermetallic compound particles, and more preferably selected from Al-doped zinc oxide and ZrB₂、MoSi₂、CrB₂、WSi₂、VB₂1 or more selected from the group consisting of silicon-iron alloy, ferrosilicon alloy and ferromanganese alloy, and more preferably from the group consisting of Al-doped zinc oxide and VB₂And ferromanganese alloy 1 or more.

The average particle diameter of the conductive particles 131 is not particularly limited, and is, for example, 50.0 μm or less, preferably 10.0 μm or less. By setting the average particle diameter of the conductive particles 131 to 50.0 μm or less, the particles 131 of an oxide or an inorganic salt can be further suppressed from protruding onto the surface of the resin coating layer 13, and by setting the average particle diameter of the conductive particles 131 to 10.0 μm or less, the surface area of all the particles in the coating becomes larger, and the particles are easily eluted in a corrosive environment, and therefore, the corrosion resistance is also effective. It is preferable that the thickness is 10.0 μm or less because the above-mentioned effects can be more effectively exhibited. Further, by making the average particle diameter of conductive particles 131 to be 1.0 μm or more, the contact of carbon fiber material 121 with metal member 11 can be made more reliable, and the conduction therebetween can be made more reliable. However, in the case of nano-sized fine particles having a particle size of 1.0 μm or less, even if the 1 st order particle size is of the nano order, the effect is exhibited when the particles are aggregated by intermolecular force so that the particle size of 2 nd order particles becomes 1.0 μm or more. Therefore, it is difficult to define the particle size of the 2-order particles, and therefore the lower limit of the conductive particles is not defined in the present invention.

The average particle diameter of the conductive particles 131 in the resin coating layer 13 can be measured by a commonly known particle distribution measuring apparatus, for example, a laser diffraction scattering particle diameter distribution measuring apparatus (マイクロトラック MT3300EX, manufactured by japan electronics corporation) to obtain a particle diameter (D50) at a cumulative volume of 50% on a volume basis. In order to confirm the average particle diameter of the particles added in a mixed state to the resin coating layer 13, an arbitrary cross section of the resin coating layer 13 may be analyzed by a Field Emission Electron Probe microanalyzer (FE-EPMA) to obtain an average value of the particle radius measured by a surface distribution photograph of the metal component contained in the conductive particles 131.

The volume fraction of the conductive particles 131 in the resin coating layer 13 may be 1.0% or more and 40.0% or less. Preferably 10.0% or more and 30.0% or less. By setting the volume fraction of the conductive particles 131 to 1.0% or more, the conductive particles 131 can ensure electrical conduction between the metal member 11 and the carbon fiber material 121. Further, by setting the volume fraction of the conductive particles 131 to 40.0% or less, the aggregation breakdown of the resin coating layer 13 can be prevented, and the adhesion between the resin coating layer 13 and the CFRP layer 12 is extremely excellent.

The volume fraction of the conductive particles 131 in the resin coating layer 13 can be calculated by obtaining the mass ratio of the solid content of the conductive particles 131 in the resin coating layer 13 added at the time of producing the resin coating layer 13, and calculating the volume fraction from the specific gravity of the coating resin (binder resin 133) and the specific gravity of the conductive particles 131.

In addition, as for the volume fraction of the conductive particles 131 in the resin coating layer 13, an arbitrary cross section of the resin coating layer 13 may be analyzed by a Field Emission Electron Probe microanalyzer (FE-EPMA) and an image analysis may be performed by a surface distribution photograph of the metal component contained in the conductive particles 131, and the area fraction thus obtained may be used as the volume fraction of the conductive particles 131 in the resin coating layer 13. The present inventors have conducted extensive studies and found that the volume fraction in the resin coating layer 13 and the area fraction of the metal component contained in the conductive particles 131 measured in cross section using FE-EPMA are strictly different but have close values, and therefore, the present invention can be obtained as described above.

As described above, in the present embodiment, the resin coating layer 13 contains the binder resin 133. The binder resin 133 functions as a binder of the conductive particles. The binder resin 133 is not particularly limited, and both a thermosetting resin and a thermoplastic resin can be used. Examples of the thermosetting resin include a polyurethane resin, an epoxy resin, a melamine resin, and a vinyl ester resin. Examples of the thermoplastic resin include phenoxy resins, polyolefins (such as polypropylene) and acid-modified products thereof, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polycarbonates, polyimides, polyamides, polyamideimides, polyetherimides, polyethersulfones, polyphenylene ethers and modified products thereof, polyarylates, polyetherketones, polyetheretherketones, polyetherketoneketones, and nylons. The phenoxy resin may be the same as the phenoxy resin used for the matrix resin 123 in the CFRP layer 12.

Among the above, the binder resin 133 preferably contains 1 or 2 or more selected from a polyurethane resin, an epoxy resin, a polyester resin, and a melamine resin. These resins are also preferred because they flow easily at room temperature or are easily dissolved in a solvent or the like for coating, depending on the molecular weight and glass transition temperature.

In the case of a CFRP layer in which the base resin is a phenoxy resin, the binder resin 133 is preferably an epoxy resin or a resin containing an epoxy resin and 1 or 2 or more selected from among a polyurethane resin, a polyester resin, and a melamine resin, from the viewpoint of adhesion to the CFRP layer. If the binder resin 133 is an epoxy resin or a resin containing the epoxy resin, it is difficult for water or the like, which is a corrosive factor, to enter the interface between the phenoxy resin and the resin coating layer 13, and corrosion resistance is improved, which is preferable.

The glass transition temperature of the binder resin 133 is, for example, 100 ℃ or lower, preferably 10 ℃ or higher and 60 ℃ or lower, and more preferably 10 ℃ or higher and 35 ℃ or lower. Thus, the carbon fiber reinforced resin is not easily peeled off even if the CFRP is attached and then subjected to molding.

The resin coating layer 13 may contain, for example, natural rubber, synthetic rubber, elastomer, various inorganic fillers, solvents, extender pigments, colorants, antioxidants, ultraviolet-resistant agents, flame retardants, flame retardant aids, and other additives, as long as the adhesiveness and physical properties thereof are not impaired.

The average thickness of the resin coating layer 13 is not particularly limited, and is, for example, 1.0 μm or more and 200.0 μm or less, preferably 5.0 μm or more and 50.0 μm or less, and more preferably 10.0 μm or more and 20.0 μm or less. By setting the average thickness of the resin coating layer 13 to 1.0 μm or more, the bonding strength between the metal member 11 and the CFRP layer 12 through the resin coating layer 13 becomes sufficient. On the other hand, by setting the average thickness T of the resin coating layer 13 to 200.0 μm or less, the conduction between the metal member 11 and the CFRP layer 12 via the conductive particles 131 can be more reliably ensured. In addition, the cohesive failure of the resin coating layer 13 can be prevented, and the adhesion between the resin coating layer 13 and the CFRP layer 12 is extremely excellent.

When the average thickness of the resin coating layer 13 is T (μm) and the average particle diameter of the conductive particles 131 is r (μm), T and r preferably satisfy the relationship of T/r of 0.5. ltoreq.T/300.0. When the average particle diameter r of the conductive particles 131 and the average thickness T of the resin coating layer 13 satisfy the relationship of T/r ≦ 300.0, the conductivity of the resin coating layer 13 is improved, and the electrodeposition coatability is further improved. Further, satisfying the relationship of 0.5. ltoreq. T/r increases the surface area of the conductive particles in the coating film, and the metal component in the conductive particles is eluted more in a corrosive environment, thereby effectively contributing to corrosion resistance.

In the resin coating layer 13, in addition to the conductive particles, commonly known rust preventive pigments such as chromium (II) oxide, silicon dioxide, vanadium (II) oxide, vanadium (V) oxide, manganese (II) oxide, manganese (III) oxide, magnesium oxide, zinc oxide, and the like can be used. The inorganic salt may be added with 1 or more selected from chromate such as potassium chromate, calcium chromate, strontium chromate, etc., phosphate such as zinc phosphate, aluminum tripolyphosphate, sodium phosphate, magnesium phosphate, trimagnesium phosphate, etc., molybdate such as potassium molybdate, calcium molybdate, etc., vanadate such as sodium metavanadate, calcium vanadate, etc., tungstate such as calcium tungstate, sodium tungstate, tungstic acid, etc. By adding these, metal ions are eluted from these rust preventive pigments in a corrosive environment, and are easily deposited on the surface of the metal member 11 serving as an anode or the carbon fiber serving as a cathode, which is more effective in corrosion resistance. The amount of the rust preventive pigment added may be appropriately selected as needed.

The glass transition temperature of the resin coating layer 13 is, for example, 100 ℃ or lower, preferably 10 ℃ or higher and 60 ℃ or lower, and more preferably 10 ℃ or higher and 35 ℃ or lower. Thus, the carbon fiber reinforced resin is not easily peeled off even if the CFRP is attached and then subjected to molding.

The glass transition temperature of the resin coating layer 13 can be measured by Thermomechanical Analysis (TMA). The thermomechanical analysis device can be performed by a commercially available device, for example, "TMA 7000 series" manufactured by hitachi ハイテックサイエンス.

The respective structures of the metal-CFRP composite 1 are explained above.

The thicknesses of the metal component 11, the CFRP layer 12 and the resin coating layer 13 can be measured by the following cross-sectional method according to the optical method in JIS K5600-1-7, 5.4. That is, a room temperature curing resin which does not adversely affect a sample and can be embedded without a gap was used, and a sample was embedded using low viscosity エポマウント 27-777 manufactured by リファインテック K.K. as a main agent and 27-772 as a curing agent. A sample is cut parallel to the thickness direction by a cutter at a site to be observed to form a cross section, and the cross section is polished using a polishing paper (for example, No. 280, No. 400, or No. 600) of a number prescribed in JIS R6252 or 6253 to prepare an observation surface. In the case of using an abrasive, the observation surface is prepared by polishing with an appropriate grade of diamond or a similar paste. Further, polishing may be performed as necessary to smooth the surface of the sample to a state suitable for observation.

In order to provide an optimal image contrast, a microscope with a suitable illumination system is used, which is capable of measuring an accuracy of 1 μm (e.g. BX51 manufactured by olympus) and selecting a field size of 300 μm. The size of the field of view may be changed to a size that allows confirmation of the thickness of each layer (for example, if the thickness of the CFRP layer 12 is 1mm, the size of the field of view may be changed to a size that allows confirmation of the thickness). For example, when the thickness of the resin film layer 13 is measured, the thickness of the resin film layer 13 is measured by dividing the observation field into four equal parts, and the average thickness is determined as the thickness in the observation field at the widthwise central portion of each division point. The observation field was performed by selecting 5 different sites, and the thickness was measured in each divided region by dividing the observation field into four equal parts, and the average value was calculated. Adjacent fields of view may be selected separated from each other by more than 3 cm. The average value of 5 points is further averaged to obtain a value as the thickness of the resin coating layer 13. The thickness of the metal member 11 or the CFRP layer 12 may be measured in the same manner as the thickness of the resin coating layer 13.

[1.2. modified example ]

Next, a modification of the metal-carbon fiber reinforced resin material composite 1 according to the above embodiment will be described. The modifications described below may be applied to the above-described embodiments of the present invention alone or in combination. Note that the respective modifications may be applied instead of or in addition to the configurations described in the above embodiments of the present invention. Fig. 2 to 7 are schematic cross-sectional views illustrating metal-carbon fiber reinforced resin material composites according to modifications of the present invention.

(modification 1)

In the above embodiment, the case where the metal-CFRP composite 1 is composed of the metal member 11, the CFRP layer 12, and the resin coating layer 13 has been described, but the present invention is not limited thereto. The metal-CFRP composite material 1 according to the present invention may have another layer disposed between or on the surface of each of these structures. For example, as shown in fig. 2, in a metal-CFRP composite material 1A according to a modification, a chemical conversion treatment layer 14 is disposed between a resin coating layer 13 and a metal member 11. By disposing such a chemical conversion treatment layer 14 between the metal member 11 and the resin coating layer 13, the corrosion resistance of the metal member 11 is improved, and the adhesion between the metal member 11 and the resin coating layer 13 of the metal-CFRP composite 1A is improved.

The chemical conversion layer 14 is not particularly limited, but is preferably a chemical conversion layer containing Cr, P, Si, and/or Zr. This can more significantly improve the corrosion resistance and adhesion.

Such a chemical conversion treatment layer 14 may be an inorganic type or an inorganic-organic hybrid type in which Cr, P, Si, and/or Zr form a network by polymerization via C or CO, or may be a type in which a coating film obtained by adding a compound composed of Cr, P, Si, and/or Zr to a binder such as a resin is applied and dried. In the chemical conversion treatment, other generally known anticorrosive components such as V-acids, Ti-acids, P-acids, and the like may be added as necessary. These chemical conversion treatments may be of a reaction type in which a film is deposited by reacting with a metal on the surface of a metal material during the treatment, or of a type in which a treatment liquid in a wet state is applied and dried and cured. Can be appropriately selected as necessary.

In this case, the chemical conversion treatment layer 14 may contain 10mg/m in total²Above and 500mg/m²The following Cr, P, Si and/or Zr is preferably 30g/m²Above and 300g/m²The following. This makes it possible to further improve the corrosion resistance and sufficiently improve the adhesion between the metal member 11 and the resin coating layer 13.

(modification 2)

In the above embodiment, the case where the CFRP layer 12 and the resin coating layer 13 are disposed on one surface of the metal member 11 has been described, but the present invention is not limited thereto. For example, like the metal-CFRP composite 1B shown in fig. 3, the CFRP layer 12 and the resin coating layer 13 may be disposed on both surfaces of the metal member 11. In this case, the CFRP layers 12 and the resin skin layer 13 may have different or the same structure.

(modification 3)

The CFRP layer is not limited to the above embodiment, and may be a multilayer. For example, like the metal-CFRP composite material 1C shown in fig. 4, the CFRP layer 12A is not limited to 1 layer, and may be 2 or more layers. When the CFRP layer 12A is a multilayer, the number n of the CFRP layer 12A can be appropriately set according to the purpose of use. In the case where the CFRP layer 12A is a multilayer, the structures of the layers may be the same or different. That is, the resin type of the matrix resin 123 constituting the CFRP layer 12A, the type and content ratio of the carbon fiber material 121, and the like may be different for each layer.

(modification 4)

In the above embodiment, the metal-CFRP composite 1 not subjected to electrodeposition coating has been described, but the present invention is not limited to this, and for example, the electrodeposition coating film 15 may be formed on the CFRP layer 12 and the resin coating layer 13 as in the metal-CFRP composites 1D, 1E, and 1F shown in fig. 5 to 7.

(modification 5)

In the above embodiment, the case where the metal-CFRP composite 1 is a plate-like one has been schematically described, but the present invention is not limited to this, and it is needless to say that the metal-CFRP composite according to the present invention may be molded.

< 2. method for producing metal-carbon fiber-reinforced resin material composite

Next, a method for producing a metal-carbon fiber reinforced resin material composite according to an embodiment of the present invention will be described. A method for producing a metal-carbon fiber reinforced resin material composite according to an embodiment of the present invention includes a step of thermocompression bonding a metal member provided on at least a part of a surface of a resin coating layer including conductive particles and a binder resin to a carbon fiber reinforced resin material via the resin coating layer. The method may further include a step of molding the metal member or a laminate in which the metal member and the carbon fiber reinforced resin material are laminated before and after the thermocompression bonding step. Hereinafter, the method for producing the metal-carbon fiber reinforced resin material composite according to the embodiment of the present invention will be described in detail on the premise of molding, but it is needless to say that molding may be omitted.

[2.1 ] embodiment 1 ]

Fig. 8 and 9 are schematic views for explaining a method of manufacturing a metal-CFRP composite according to embodiment 1 of the present invention. The method for producing the metal-CFRP composite 1G according to embodiment 1 includes at least a thermocompression bonding step a in which the metal member 11A having the resin coating layer 13A provided on at least a part of the surface thereof and a carbon fiber reinforced resin material (CFRP or a prepreg for forming CFRP) are thermocompression bonded via the resin coating layer 13A to obtain a laminate 100. The method for producing the metal-CFRP composite 1G according to the present embodiment includes a molding step a of molding the laminate 100.

In addition, the present embodiment may include, as necessary: a resin coating layer forming step of forming a resin coating layer 13A on at least a part of the surface of the metal member 11A, an electrodeposition coating step, a pretreatment step, and/or a post-treatment step. Hereinafter, each step will be explained.

(pretreatment step)

First, the metal member 11A is prepared (fig. 8 (a)). The metal member 11 is preferably degreased as generally known as needed. The degreasing method may be a method of wiping with a solvent, a method of washing with water, a method of washing with an aqueous solution or a detergent containing a surfactant, a method of volatilizing an oil component by heating, an alkali degreasing method, or the like. Alkaline degreasing is a method generally used industrially, and is preferable because of its high degreasing effect. Further, it is more preferable to perform a mold release treatment for the mold used, or to remove deposits on the surface of the metal member 11A (garbage removal). By these pretreatments, the adhesion between the metal member 11A and the resin coating layer 13A is improved.

(film formation step)

Next, a resin coating layer 13A is formed on the surface of the metal member 11A (fig. 8 b). The resin coating layer 13A is formed by applying a resin coating layer material composition containing a material of the resin coating layer 13A to the surface of the metal member 11A, drying, and sintering. The resin coating layer material composition may be in a liquid state, a slurry state, or a powder state. A sheet of the resin coating layer material composition formed in advance in a plate shape may be attached by thermocompression bonding or the like.

The coating method is not limited to this, and in the case of a sheet type, the application method may be performed by a generally known method such as a human hand or a robot. In the case of a viscous liquid, the coating can be performed by a generally known method such as coating by ejecting from a slit nozzle or a circular nozzle, brush coating, blade coating, or spatula coating. The coating material dissolved in the solvent can be applied by a generally known coating method such as brush coating, spray coating, bar coating, coating by spraying from a nozzle having various shapes, die coating, curtain coating, roll coating, screen printing, and inkjet coating. When the resin coating layer material composition is in the form of powder, a known method such as powder coating can be used. In particular, in the resin coating layer 13A formed by powder coating, since the coating layer material composition is fine particles, the resin component is easily melted, and since appropriate voids are present in the resin coating layer 13A, voids are easily generated. In addition, when the CFRP or the prepreg for CFRP molding is thermocompression bonded, the resin component constituting the resin coating layer 13A can favorably wet the surface of the metal member 11A, and therefore a degassing step such as varnish coating is not required. The resin coating layer 13A may be applied to the entire surface of the metal member 11A, or may be applied only partially to a portion to which a carbon fiber reinforced resin material (CFRP) is to be applied.

Before the resin coating layer 13A is applied, a chemical conversion treatment layer 14 may be provided on the metal member 11A. As a method for providing the chemical conversion treatment layer 14, a generally known treatment method, for example, a dip drying method, a dip/water washing/drying method, a spray/water washing/drying method, a coating/drying curing method, or the like can be used. As the coating method, a generally known method such as dipping, brush coating, spray coating, roll coating, bar coating, and knife coating can be used.

The drying and sintering may be performed by, for example, heat treatment. The heating conditions are not particularly limited, and may be, for example, 10 seconds to 30 minutes under conditions of 100 ℃ to 250 ℃. The resin coating layer material composition can also be made into a normal temperature curing type. In this case, the resin coating layer material composition may be a one-pack type in which the main resin and the curing agent are mixed. The curing agent may be a two-liquid curing type in which the main resin and the curing agent are separated and mixed before application, or may be a three-liquid or more type in which the main resin, the curing agent, other additives, and the like are separated and mixed before application.

The resin coating layer 13A may be coated or attached when a CFRP forming prepreg or CFRP to be the CFRP layer 12B is placed on the metal member 11A, and cured when thermocompression bonding described later is performed on these laminates, or may be formed by coating or attaching the resin coating layer 13A in advance on the metal member 11A, stacking and curing the resin coating layer, and then placing a CFRP forming prepreg or CFRP thereon, and thermocompression bonding described later.

(thermocompression bonding Process A)

Next, the metal member 11A and a carbon fiber reinforced resin material (CFRP or a prepreg for forming CFRP) are thermocompression bonded via a resin coating layer 13A to obtain a laminate 100 (fig. 8 c). Specifically, a laminate in which a prepreg for CFRP molding (or CFRP) to be the CFRP layer 12B is laminated on the resin skin layer 13A is set in a press machine and pressed while being heated. In this way, a laminate 100 in which the metal member 11A and the resin film layer 13A, CFRP and 12B are laminated in this order was produced.

Specifically, first, the metal member 11A and the CFRP molding prepreg or CFRP are placed in a superposed manner with the resin coating layer 13A interposed therebetween to obtain a laminate. When CFRP is used, the joint surface of CFRP is preferably roughened by sand blasting or the like, or activated by plasma treatment, corona treatment or the like. Next, the laminate is heated and pressed (thermocompression bonding), thereby obtaining a laminate 100.

Here, the thermocompression bonding conditions in this step are as follows.

The thermocompression bonding temperature is not particularly limited, and is, for example, in the range of 100 ℃ to 400 ℃, preferably 150 ℃ to 300 ℃, more preferably 160 ℃ to 270 ℃, and still more preferably 180 ℃ to 250 ℃. Within such a temperature range, a temperature of not less than the melting point is more preferable in the case of a crystalline resin, and a temperature of not less than Tg +150 ℃ is more preferable in the case of an amorphous resin. By setting the temperature to the upper limit temperature or lower, excessive heat application can be suppressed, and decomposition of the resin can be prevented. When the temperature is not lower than the lower limit temperature, the melt viscosity of the resin can be adjusted appropriately, and the adhesion to the CFRP and the impregnation into the CFRP base material can be improved.

The pressure at the time of thermocompression bonding is, for example, preferably 3MPa or more, and more preferably 3MPa or more and 5MPa or less. By setting the pressure to 5MPa or less, excessive pressure can be prevented from being applied, and the occurrence of deformation or damage can be more reliably prevented. Further, by setting the pressure to 3MPa or more, the impregnation property with respect to the CFRP base material can be improved.

The thermocompression bonding time is preferably in the range of 5 minutes to 20 minutes, as long as it is at least 3 minutes, and it can be sufficiently thermocompressed.

(additional heating step)

When a crosslinkable adhesive resin composition containing the crosslinkable cured resin (B) and the crosslinking agent (C) in the phenoxy resin (a) is used as the adhesive resin composition for forming the resin coating layer 13A or the raw material resin for forming the matrix resin 123, an additional heating step may be included.

In the case of using the crosslinkable adhesive resin composition, the resin coating layer 13A can be formed by a cured product (cured product) in the 1 st cured state which is cured but not crosslinked (cured) in the thermocompression bonding step. When the same or the same type of resin as the crosslinkable adhesive resin composition is used as the raw material resin of the matrix resin of the prepreg for CFRP molding which is to be the CFRP layer 12B, the CFRP layer 12B including the matrix resin 123 composed of the cured product (cured product) in the 1 st cured state can be formed.

Thus, through the thermocompression bonding step, an intermediate (preform) of the metal-CFRP composite 1 in which the metal member 11A, the uncured resin coating layer 13A, and the CFRP layer 12B are laminated and integrated can be produced. In this intermediate, a cured product (cured product) of the matrix resin 123 in the 1 st cured state may be used as the CFRP layer 12B as necessary. Then, after the thermocompression bonding step, by further performing an additional heating step on the intermediate, at least the resin coating layer 13A formed of the cured product (cured product) in the 1 st cured state can be post-cured, thereby crosslinking and curing the resin to change to a cured product (crosslinked cured product) in the 2 nd cured state. Preferably, the CFRP layer 12B is also post-cured, whereby the matrix resin 123 formed of the cured product (cured product) in the 1 st cured state can be cross-linked and cured to change to a cured product (cross-linked cured product) in the 2 nd cured state.

The additional heating step for post-curing is preferably performed at a temperature in the range of 200 ℃ to 250 ℃ for about 30 minutes to 60 minutes, for example. In place of the post-curing, heat history in a subsequent step such as coating may be used.

As described above, if the crosslinkable adhesive resin composition is used, Tg after crosslinking curing is greatly increased as compared with the phenoxy resin (A) alone. Therefore, before and after the additional heating step of the intermediate, i.e., in the process of changing the resin from the 1 st cured product (cured product) to the 2 nd cured product (crosslinked cured product), Tg changes. Specifically, the Tg of the resin before crosslinking of the intermediate is, for example, 150 ℃ or less, whereas the Tg of the resin formed by crosslinking after the additional heating step is, for example, increased to 160 ℃ or more, preferably 170 ℃ or more and 220 ℃ or less, and therefore the heat resistance can be greatly improved.

When the laminate 100 is not required to be molded, the following molding step a may be omitted, and the laminate 100 itself may be obtained as a metal-CFRP composite.

(Molding Process A)

Next, the laminate 100 is molded (fig. 9(d)), and a metal-CFRP composite 1G is obtained. The method of molding the laminate 100 is not particularly limited, and various press working such as shearing, bending, drawing, and forging may be used.

These press working may be performed at normal temperature, but is preferably performed by hot pressing because CFRP is less likely to peel off from the metal member 11A during the working. The temperature of the hot pressing is preferably the same temperature as in the hot pressing step.

In the present embodiment, the thermocompression bonding step a and the molding step a (molding of the metal-CFRP composite 1D) may be performed simultaneously. That is, the metal member 11A and the carbon fiber reinforced resin material (CFRP or a prepreg for forming CFRP) may be molded simultaneously by thermocompression bonding via the resin coating layer 13A in a press molding machine.

(electrodeposition coating Process)

If necessary, an electrodeposition coating film may be formed on the resin coating layer 13A and/or the CFRP layer 12B of the metal-CFRP composite 1G obtained by electrodeposition coating. If electrodeposition coating is performed on the CFRP layer 12B, the corrosion resistance is more excellent, and therefore, it is preferable. The metal-CFRP composite 1G was excellent in the electrodeposition coating properties and was able to form an electrodeposition coating film having a relatively uniform film thickness. The conditions for electrodeposition coating in this step are not particularly limited, and known coating materials and conditions can be used. As the electrodeposition coating paint, commercially available products can be used. Before the electrodeposition coating, generally known degreasing, surface conditioning, zinc phosphate treatment, or zirconia treatment may be performed as a pretreatment. Commercially available products of these degreasing agents, surface conditioners, zinc phosphate treatment agents and zirconia treatment agents can also be used.

(subsequent step)

In the subsequent step of the metal-CFRP composite 1D, in addition to painting, drilling, application of an adhesive for adhesive bonding, and the like are performed as necessary in order to mechanically bond other members by bolts, caulking, or the like.

[2.2 ] embodiment 2 ]

Fig. 10 and 11 are schematic views for explaining a method of manufacturing a metal-CFRP composite body according to embodiment 2 of the present invention. The method for producing the metal-CFRP composite 1H according to embodiment 2 includes: a molding step B of molding the metal member 11B provided on at least a part of the surface of the resin coating layer 13B; and a thermocompression bonding step (B) for thermocompression bonding the metal member (11B) and the carbon fiber reinforced resin material via the resin coating layer (13B) to obtain a metal-CFRP composite (1H).

That is, embodiment 2 differs from embodiment 1 in that a laminate of the metal member 11B and the resin film layer 13B is formed before the CFRP layer 12C is formed. In the case of embodiment 1, there is a possibility that cracks may be generated in the resin or peeling from the metal member 11A may occur depending on the matrix resin of the CFRP. In addition, warm pressing is required to prevent these problems. In embodiment 1, when the CFRP is thick, the press die after the attachment needs to be used to increase the effort. In this way, by molding the metal member 11B before forming the CFRP layer 12C, the disadvantages that may occur in the first embodiment can be eliminated, and a commonly used press die can be used.

The conditions used in embodiment 2 are basically the same as those in embodiment 1, and therefore, descriptions thereof are omitted.

Specifically, a metal member 11B is prepared (fig. 10 a), and a resin coating layer 13B is formed on the surface of the metal member 11B (fig. 10B). Then, the metal member 11B having the resin coating layer 13B formed thereon is molded (fig. 10 c). Finally, the carbon fiber reinforced resin material is thermocompression bonded to the molded metal member 11B via the resin coating layer 13B, thereby obtaining a metal-CFRP composite 1H (fig. 11(d), (e)). In addition, an electrodeposition coating process and/or a subsequent process is performed as necessary.

The method for producing the metal-CFRP composite according to the present embodiment is explained above. The method for manufacturing a metal-CFRP composite according to the present invention is not limited to the above embodiment.

Examples

The present invention will be described in more detail below with reference to examples. The embodiment described below is merely an example of the present invention, and does not limit the present invention.

< 1. production of Metal-CFRP composite body

(preparation of Metal plate)

The component C: 0.131 mass%, Si: 1.19 mass%, Mn: 1.92%, P: 0.009 mass%, S: 0.0025 mass%, Al: 0.027 mass%, N: the steel sheet was hot-rolled and acid-washed with 0.0032 mass% and the balance Fe, and then cold-rolled to obtain a cold-rolled steel sheet having a thickness of 1.0 mm. Subsequently, the cold-rolled steel sheet thus produced was annealed at a maximum plate temperature of 820 ℃ by a continuous annealing apparatus. The gas atmosphere in the annealing furnace in the annealing step was such that 1.0 vol% of H was contained₂N of (A)₂An atmosphere. The cold rolled steel sheet thus produced is referred to as "CR".

In addition, a steel sheet was prepared in which the cold-rolled steel sheet produced in the annealing step of the continuous hot dip coating apparatus having the annealing step was annealed at a maximum plate temperature of 820 ℃, and then hot-dip galvanized in the plating step. The gas atmosphere in the annealing furnace in the annealing step was such that 1.0 vol% of H was contained₂N of (A)₂An atmosphere. As the components of the plating bath in the plating step, 4 types of Zn-0.2% Al (referred to as "GI"), Zn-0.09% Al (referred to as "GA"), Zn-1.5% Al-1.5% Mg (referred to as "Zn-Al-Mg"), Zn-11% Al-3% Mg-0.2% Mg (referred to as "Zn-Al-Mg-Si") were used. Further, the hot-dip plating bath using Zn-0.09% Al plating (GA) was prepared by immersing the steel sheet in the hot-dip plating bath, and ejecting N from a slit nozzle while withdrawing the steel sheet from the plating bath₂After the gas wiping was performed to adjust the amount of adhesion, the steel sheet was alloyed by heating the steel sheet with an induction heater at a sheet temperature of 480 ℃, and Fe in the steel sheet was diffused into the plating layer.

The tensile strength of the produced metal sheet was measured and found to be 980 MPa.

In addition, regarding the plating adhesion amount of the plated steel sheet, GA was 45g/m²Plating other than GA was 60g/m²。

In addition to the above, as metal sheets other than steel sheets, aluminum alloy sheets (hereinafter referred to as "Al sheets") and magnesium alloy sheets (hereinafter referred to as "Mg alloy sheets") are prepared separately.

(pretreatment step)

The metal plate thus produced was degreased with an alkaline degreasing agent "ファインクリーナー E6404" manufactured by japan パーカライジング corporation.

(chemical conversion treatment Process)

AN aqueous solution containing 2.5g/L of γ -aminopropyltriethoxysilane and 1g/L of water-dispersible silica (スノーテック N manufactured by Nissan chemical Co., Ltd., 3g/L of a water-soluble acrylic resin (reagent polyacrylic acid)) was applied to a degreased metal plate by a bar coater, and dried in a hot air oven under a condition that the plate temperature reached 150 ℃ and, in addition, a 3g/L aqueous solution of zirconium ammonium carbonate and a chromate treatment solution "ZM-1300 AN" manufactured by パーカライジング Japan were similarly applied by a bar coater, and dried in a hot air oven under a condition that the plate temperature reached 150 ℃ in the same manner, and hereinafter, a treatment in which AN aqueous solution containing water-dispersible silica was applied was referred to as "Si-based treatment" (or simply referred to as "Si-based treatment"), a treatment in which AN aqueous solution containing zirconium ammonium carbonate was applied was referred to as "Zr-based treatment" (or simply referred to as "Zr-based treatment", the treatment with the chromate treatment liquid is referred to as "Cr-based treatment" (or simply "Cr-based").

In addition, the deposition amount of each treatment was 30mg/m². Is determined by the mass of the coated metal sheet]- [ quality of Metal sheet before coating]The wet coating amount before drying of each of the coatings applied to the entire surface of the metal plate was calculated, and the mass of each of Cr, Si, and Zr contained in the wet coating amount was calculated and calculated by dividing the mass by the area of the metal plate. Alternatively, the amount of adhesion may be calculated by the above-described method, a chemically converted metal plate having 5 different amounts of adhesion (after drying) may be prepared, the amount of adhesion may be measured by fluorescent X-ray, a calibration curve may be drawn from the relationship between the obtained detection intensity and the calculated amount of adhesion, and the amount of adhesion may be determined from the calibration curve.

(resin coating layer formation Process)

As the binder resin, epoxy resin "jER" manufactured by Mitsubishi chemical corporation was prepared^(R)828 ", urethane-modified epoxy resin manufactured by Mitsui chemical company エポキー^(R)802-30CX ", polyester resin manufactured by Toyo Boseki Inc." バイロン^(R)300". Further, as the curing agent, "MXDA (m-xylylenediamine)" made by Mitsubishi gas chemical company, "1, 12-dodecamethylenediamine" made by Yu Xin Co., Ltd., and "melamine ユーバン" made by Mitsui chemical company were prepared^(R)20SB ', aqueous polyurethane resin manufactured by first Industrial pharmaceutical Co Ltd.' スーパーフレックス^(R)150 ", サイテック Melamine resin サイメル^(R)325”。

Next, these resins were mixed with a curing agent to prepare the following film resin samples.

Epoxy resin-a: relative to "jER" manufactured by Mitsubishi chemical corporation^(R)828 "100 parts by mass, 30 parts by mass of" 1, 12-dodecamethylenediamine "manufactured by yokokkiso co.

Epoxy resin-B: relative to "jER" manufactured by Mitsubishi chemical corporation^(R)828 "100 parts by mass, 30 parts by mass of" MXDA (m-xylylenediamine) "manufactured by Mitsubishi gas chemical company, was added and mixed.

Epoxy resin-C: manufactured by Mitsui chemical company "エポキー^(R)100 parts by mass of a solid content of 802 to 30CX ", ユーバン made by Mitsui chemical Co., Ltd., added in an amount of 20 parts by mass in terms of the solid content^(R)20SB "and mix.

Polyester/melamine resin: 30 mass% of "バイロン" manufactured by Toyo Boseki Co., Ltd.^(R)300 "was added to 100 parts by mass of the solid content of the solution, and 20 parts by mass of ユーバン made by Mitsui chemical Co., Ltd^(R)20SB "and mix.

Polyester/epoxy resin: 30 mass% of "バイ" manufactured by Toyo Boseki Co., Ltd.ロン^(R)300 "was added to 100 parts by mass of the solid content of the solution, and 20 parts by mass of ユーバン made by Mitsui chemical Co., Ltd^(R)20SB ", and 5 parts by mass of BPA type epoxy resin" YD-013 "manufactured by Nissan Cijin chemical company.

Polyurethane/melamine resin: water-making polyurethane resin "スーパーフレックス at first Industrial pharmaceutical Co^(R)150' of a melamine resin サイメル manufactured by サイテック was added in an amount of 20 parts by mass based on the solid content to 80 parts by mass based on the solid content^(R)325 "and mixed.

Further, the following particles were mixed with the prepared resin to prepare a resin coating liquid. The mass ratio of the solid content in the coating of the particles added to the resin coating liquid was determined with respect to the amount of the particles added, and the volume ratio was calculated from the specific gravity of the solid content of the resin coating and the specific gravity of the particles, and adjusted to the volume ratio shown in table 1. The specific gravity uses the index value or literature value of each substance.

Vanadium boride: using "VB" manufactured by Nippon New metals Co., Ltd₂The O' was classified by a sieve into a material having an average particle diameter of 3.1. mu.m. Hereinafter referred to as "VB 2".

Al-doped zinc oxide: conductive zinc oxide (Al-Doped ZnO) "23-K" manufactured by ハクステック was used, and the 1-order particle size was 120 to 250nm (index value). Hereinafter referred to as "Al-ZnO".

Metallic zinc: a material in which zinc particles as a reagent were classified by a sieve into particles having an average particle diameter of 10 μm was used. Hereinafter referred to as "Zn".

Ferrosilicon alloy: a silicon-iron alloy manufactured by shot テツゲン was pulverized into fine particles by a pulverizer and classified into particles having average particle diameters of 3 μm, 9 μm, 47 μm, and 98 μm by a sieve. Hereinafter referred to as "Fe-Si".

Ferromanganese alloy: a silicon-iron alloy manufactured by shot テツゲン was pulverized into fine particles by a pulverizer and classified into particles having an average particle size of 3.5 μm by a sieve. Hereinafter referred to as "Fe-Mn".

Zirconium boride: using "ZrB" manufactured by Nippon New metals Co., Ltd₂The O' was classified by a sieve into a material having an average particle diameter of 2 μm. Hereinafter referred to as "ZrB 2".

Molybdenum silicide: using "MoSi" manufactured by Nippon New metals Co., Ltd₂-F "was classified by sieve into a material having an average particle size of 3.5 μm. Hereinafter referred to as "MoSi 2".

Chromium boride: using "CrB" manufactured by Nippon New metals Co., Ltd₂The O' was classified by a sieve into a material having an average particle diameter of 5 μm. Hereinafter referred to as "CrB 2".

Tungsten silicide: using "B" manufactured by Nippon New metals Co₂The O' was classified by a sieve into a material having an average particle diameter of 2 μm. Hereinafter referred to as "WSi 2".

Nickel: a material obtained by classifying a nickel reagent powder into particles having an average particle diameter of 5 μm by a sieve was used. Hereinafter referred to as "Ni".

Alumina: fine-grained alumina "A-42-2" manufactured by Showa Denko K.K. was used, and the average particle diameter (particle size distribution center diameter) was 4.7 μm (table). Hereinafter referred to as "alumina".

Titanium oxide: タイペーク manufactured by Stone Productivity Co^(R)CR-95 "with an average particle size of 0.28. mu.m (table of contents). Hereinafter referred to as "TiO 2".

Aluminum nitride: an aluminum nitride powder for filler manufactured by トクヤマ was used, and the particle size was 1 μm (catalog value). Hereinafter referred to as "AlN".

Conductive titanium oxide: sn-doped titanium oxide "ET-500W" manufactured by Shigaku industries Co., Ltd is used, and the average particle diameter is 2 to 3 μm (index value). Hereinafter referred to as "conductive Ti".

The prepared coating solutions were distinguished by the marks "coating-1" to "coating-27", and are shown in table 1. The powder resistivity of the particles in table 1 is a resistance value obtained by compressing each powder at 25 ℃ under 10MPa using MCP-PD51, a powder resistivity measurement system of mitsubishi ケミカルアナリテック. The glass transition temperature of the resin coating layer was measured by an automatic differential scanning calorimeter "DSC-60A" manufactured by shimadzu corporation, for a product obtained by drying and curing the coating liquid in an oven at 200 ℃ for 20 minutes.

TABLE 1

The prepared coating liquid was applied by a knife coater only to one surface of a metal plate cut to a size necessary for evaluation, and only to a portion to which CFRP was applied, and dried and cured under conditions that the plate temperature reached 60 seconds and 230 ℃. The partial coating was carried out by applying a masking tape (manufactured by Nindon electric engineering Co., Ltd. "ニトフロン") to the part other than the part to which the CFRP was applied in advance^(R)Tape ") and then a resin coating layer is applied, dried and sintered, and then the masking tape is peeled off.

The film layer thickness was determined by measuring the film layer thickness by using a sample which was embedded in a resin and polished so as to be able to observe a vertical cross section in advance, and observing the vertical cross section with a microscope.

(thermal compression bonding Process)

A bisphenol a type phenoxy resin "フェノトート YP-50S" (Mw 40,000, hydroxyl group equivalent 284g/eq, melt viscosity at 250 ℃ 90Pa · S, Tg 83 ℃) manufactured by shiniewa chemical corporation was pulverized and classified, and the obtained powder having an average particle diameter D50 of 80 μm was powder-coated on a reinforcing fiber base material (fabric: IMS60 manufactured by tokho テナックス) made of carbon fiber in an electrostatic field under conditions of a charge of 70kV and a blown air pressure of 0.32 MPa. Then, the resin was melted by heating at 170 ℃ for 1 minute in an oven to melt the resin, thereby producing a phenoxy resin CFRP prepreg having a thickness of 0.65mm, an elastic modulus of 75 GPa, a tensile load of 13500N and a Vf (fiber volume content) of 60%. The prepreg has the same size as the metal plate.

Further, a reinforcing fiber base material (cloth: IMS60, manufactured by Toho テナックス Co.) made of carbon fiber was powder-coated with a powder having an average particle diameter D50 of 80 μm obtained by pulverizing and classifying nylon 6 reagent in an electrostatic field under conditions of a charge of 70kV and a blown air pressure of 0.32 MPa. Then, the resin was melted by heating at 170 ℃ for 1 minute in an oven to melt the resin, thereby producing a nylon CFRP prepreg having a thickness of 0.65mm and a Vf (fiber volume content) of 60%. The prepreg has the same size as the metal plate.

The average particle size of the crushed and classified phenoxy resin was measured by a laser diffraction scattering particle size distribution measuring apparatus (マイクロトラック MT3300EX, manufactured by japan electronics corporation) to determine the particle size at 50% cumulative volume on a volume basis.

Next, the prepared prepreg was stacked on a metal plate on which a resin skin layer was laminated, and pressed at 3MPa for 3 minutes by a press having a flat die heated to 250 ℃, thereby producing a metal-CFRP composite as a composite sample shown in tables 2 and 3.

< evaluation >

1. Electrodeposition coating property

The prepared composite sample having a width of 70mm × a length of 150mm was subjected to degreasing, surface conditioning, and zinc phosphate treatment, and then subjected to electrodeposition coating. Degreasing was performed by using a degreasing agent "ファインクリーナー E6408" manufactured by Japanese パーカライジング, and immersing the substrate at 60 ℃ for 5 minutes. The degreased sample was immersed at 40 ℃ for 5 minutes using "プレパレン X" manufactured by パーカライジング Japan to adjust the surface. Then, the steel sheet was immersed at 35 ℃ for 3 minutes using a zinc phosphate chemical treatment agent "パルボンド L3065" manufactured by Japan パーカライジング Co., Ltd, thereby performing a zinc phosphate treatment. After the zinc phosphate treatment, the mixture was washed with water and dried in an oven at 150 ℃. Then, the electrodeposition paint "パワーフロート 1200" manufactured by japan ペイント corporation was used as a sample by electrodeposition coating under the condition that the thickness of a metal plate used in each sample was 15 μm when the metal plate was coated in a non-treated state (a resin coating layer or a CFRP layer, a state without chemical conversion treatment), and was baked in an oven in an atmosphere of 170 ℃ for 20 minutes. Electrodeposition coating coats only the metal portion to which the CFRP is not attached.

The CFRP state of the prepared sample was visually observed to evaluate whether or not electrodeposition coating was performed.

2. Corrosion resistance

The prepared sample was subjected to a Cyclic Corrosion Test (CCT). The CCT mode is based on the automotive industry standard JASO-M609. The test specimen was set in a testing machine with the CFRP side as an evaluation surface and brine was sprayed on the evaluation surface to perform the test.

In the test, the appearance of the test piece was visually observed every 15 cycles (8 hours and 1 cycle) to determine the cycle of red rust generation. The greater the number of cycles until red rust is generated, the more excellent the corrosion resistance. Further, red rust is generated from the vicinity of the end of the CFRP adhered to the metal, and therefore, the observation is focused on this. When the metal sheets used were aluminum alloy sheets and magnesium alloy sheets, red rust, which is an oxide of iron, did not occur, and therefore the number of cycles in which white rust, which is an oxide of aluminum or magnesium, occurred was determined.

Further, the corrosion resistance varies depending on the metal plate used. Therefore, the corrosion resistance was evaluated based on the type of the metal plate. Specifically, the case where red rust occurred at 30 cycles or less when the cold-rolled steel sheet (CR) was used was evaluated as a defective product, the case where red rust occurred at 60 cycles or less when the plated steel sheet (GI) was used was evaluated as a defective product, the case other than this was evaluated as a non-defective product, the case where red rust occurred at 60 cycles or less when the plated steel sheet (GA) was used was evaluated as a defective product, the case other than this was evaluated as a non-defective product, the case where red rust occurred at 120 cycles or less when the plated steel sheet (Zn-Al-Mg) was used was evaluated as a defective product, the case where red rust occurred at 120 cycles or less when the plated steel sheet (Zn-Al-Mg-Si) was used was evaluated as a defective product, and the case other than this was evaluated as a non-defective product, the case where white rust occurred at 120 cycles or less when the aluminum alloy plate (Al plate) was used was evaluated as a defective product, and the cases other than the defective product were evaluated as non-defective products, and the cases other than the defective product were evaluated as a defective product, while the case where white rust occurred at 120 cycles or less when the magnesium alloy plate (Mg alloy plate) was used was evaluated as a defective product.

3.3 Point bend test

The test was carried out using a composite specimen 30mm wide by 100mm long. In this sample, a CFRP was applied to the entire surface of one side of a metal plate. The test piece was placed on a jig having a fulcrum pitch of 60mm, and a 3-point bending test was performed by applying a load to the center between the fulcrums. The test was performed by placing a specimen on the jig so that the side to which the load was applied was the CFRP side. In the 3-point bending test, the state of separation between the metal plate and the CFRP when the sample is bent under load was observed and evaluated. The peeling was evaluated as "D" when the bending was 1.0mm or less, as "C" when the bending was more than 1.0mm and 3.0mm or less, as "B" when the bending was more than 3.0mm and 5.0mm or less, and as "a" when the bending was more than 5.0 mm.

4. Punching workability

The punching workability was tested in hot working in which a V-shaped concave-convex mold was heated to 200 ℃ by using a composite sample having a width of 50mm X a length of 50 mm. In this sample, a sample in which CFRP was attached to the entire surface of one side of a metal plate was used, and the sample was set in a die so that the female die side was CFRP and the male die side was made of a metal material, and was pressed. Further, a die having an angle of the V portion of the V-shaped die of 90 ° was used, and press working was performed using dies having different R (radius of curvature) of the bent portion, respectively, to obtain a limit R at which the CFRP did not peel off. The material is free from peeling even in a smaller bend R and is excellent in press formability.

5. Coating uniformity of electrodeposition coating film

The electrodeposition-coated samples were observed with an optical microscope for vertical cross sections on the resin coating layer, on the CFRP layer, and on the CFRP end face, and the film thickness of the electrodeposition coating film was evaluated. The film thickness of the electrodeposition coating film was measured for 3 arbitrary fields, and the average value was taken. The electrodeposition coating film on the skin layer was evaluated as "A" when the film thickness was 10 μm or more, as "B" when the film thickness was 5 μm or more and less than 10 μm, as "C" when the film thickness was 2 μm or more and less than 5 μm, as "D" when the film thickness was 1 μm or more and less than 2 μm, and as "E" when the film thickness was less than 1 μm. The samples evaluated as "a" to "D" were regarded as non-defective products, and the samples evaluated as "E" were regarded as defective products.

The evaluation results are shown in tables 2 to 4 together with the composition of the composite sample.

According to the results, when the same kind of metal plate is used, the metal-CFRP composite body of the present invention is excellent in corrosion resistance against contact corrosion of dissimilar materials of carbon fiber and metal, and also excellent in electrodeposition paintability in the CFRP part.

The preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to these examples. A person skilled in the art having common knowledge in the technical field to which the present invention pertains can conceive various modifications and alterations within the scope of the technical idea described in the claims, and these are all within the technical scope of the present invention.

Description of the reference numerals

1. 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H metal-CFRP composite

11. 11A, 11B Metal Member

12. 12A, 12B, 12C CFRP layer

121 carbon fiber material

123 matrix resin

13. 13A, 13B resin coating layer

131 conductive particles

133 Binder resin

14 chemical conversion treated layer

15 electrodeposition coating film