LAMINATE AND METHOD FOR MANUFACTURING LAMINATE

Abstract

To provide a technique that can suppress the electrolytic corrosion of aluminum at low cost in a composite material of an aluminum shaped material and a carbon fiber-reinforced resin.SOLUTION: A laminate 10 includes a substrate 12 containing aluminum, a coat 14 that is formed on the surface of the substrate 12 and contains a thermosetting resin, and a carbon fiber-reinforced resin layer 16 disposed on the coat 14. There is also provided a method for producing a laminate that includes forming, on the surface of a substrate containing aluminum, a coat containing a thermosetting resin; burning the coat; and disposing a carbon fiber-reinforced resin layer on the cured coat.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a laminate and a method for making the laminate. [Background technology]

[0002] Aluminum profiles are widely used as building materials due to their ease of processing and light weight. However, when building materials are large and long, the aluminum profiles may bend significantly due to wind or snow. Therefore, when long aluminum profiles are used as building materials, it is necessary to improve their rigidity in some way to suppress bending.

[0003] One method for improving the rigidity of aluminum extrusions is to reinforce them with materials that have a higher Young's modulus than aluminum, and one example is joining carbon fiber reinforced plastic (CFRP) to the aluminum extrusions. CFRP is characterized by high rigidity and light weight, and by joining it to aluminum extrusions, it is possible to improve the rigidity of the component while suppressing the increase in weight.

[0004] For example, Patent Document 1 discloses a laminated structure including an aluminum layer, a glass composite layer including a glass fiber reinforced thermoplastic prepreg layer adjacent to the aluminum layer, and a carbon composite layer including a carbon fiber reinforced thermoplastic prepreg layer adjacent to the glass composite layer and located on the opposite side of the aluminum layer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2018-103617 Summary of the Invention [Problem to be solved by the invention]

[0006] Aluminum profiles have a high ionization tendency, and when they are joined to a different material with a high standard single-electrode potential, such as carbon fiber, the aluminum may be oxidized and corrosion (galvanic corrosion) may occur. As described in Patent Document 1, galvanic corrosion can be prevented by sandwiching an insulating layer, such as a glass composite layer, at the interface between the aluminum profile and the carbon fiber composite. However, using such an insulating layer is disadvantageous in terms of cost.

[0007] One aspect of the present invention has been made in consideration of these problems, and one of its objectives is to provide a technology that can suppress electrolytic corrosion of aluminum at low cost in a composite material of aluminum profile and carbon fiber reinforced resin. [Means for solving the problem]

[0008] In order to solve the above problems, a first aspect of the present invention is a laminate. A substrate containing aluminum; A coating including a thermosetting resin formed on a surface of a substrate; a carbon fiber reinforced resin layer disposed on the coating; Includes. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view illustrating a laminate according to a first embodiment of the present invention. [Diagram 2] 1 is a graph showing the results of an electrolytic corrosion test of samples of an example and a comparative example. [Diagram 3] 1 shows images of a comparative example sample before an electrolytic corrosion test, and comparative example and example samples after an electrolytic corrosion test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (First embodiment) As shown in FIG. 1, the laminate 10 of the first embodiment includes a substrate 12, a coating 14, and a carbon fiber reinforced resin layer 16.

[0011] The substrate 12 is made of a material containing aluminum, such as pure aluminum or an aluminum alloy. For example, the substrate 12 can be manufactured by extruding an aluminum alloy. In order to increase the corrosion resistance and wear resistance of the substrate, the surface of the substrate may be chemically treated. For example, the substrate may be anodized to form an oxide film (anodized film) on the surface layer of the substrate.

[0012] The coating 14 is formed on the substrate 12 and contains a thermosetting resin. The dense coating of the thermosetting resin can prevent short circuits between the substrate 12 and the carbon fiber reinforced resin layer 16, and can prevent electrolytic corrosion of the substrate 12. Furthermore, by forming the coating 14 from a thermosetting resin, electrolytic corrosion can be prevented even if the coating is thin, and in this respect, the cost is lower than that of a method using an insulating layer such as a glass composite layer. Furthermore, the thermosetting resin is resistant to heat, and by using the thermosetting resin, a dense coating that can withstand outdoor environments can be formed. For this reason, the laminate 10 can withstand long-term use in outdoor environments.

[0013] The type of thermosetting resin constituting the coating 14 is not particularly limited, but examples include phenol resin, epoxy resin, melamine urea resin, unsaturated polyester resin, alkyd resin, polyurethane resin, silicone resin, vinyl ester resin, acrylic-melamine resin, polyester resin, etc. From the viewpoint of being able to form a dense coating that can better prevent electrolytic corrosion, acrylic-melamine resin and polyester resin are preferred as thermosetting resins.

[0014] The coating 14 can be formed, for example, by painting the surface of the substrate 12 with paint containing a thermosetting resin to form a coating, and then baking the coating. The coating method is not particularly limited as long as it can form a dense coating of the thermosetting resin, and any known method can be used. Examples of such coating methods include spray coating, electrodeposition coating, and the like.

[0015] From the viewpoint of reliably preventing electrolytic corrosion, the thickness of the coating 14 is preferably 1 μm or more and 1000 μm or less, more preferably 3 μm or more and 200 μm or less, and even more preferably 7 μm or more and 100 μm or less.

[0016] The carbon fiber reinforced resin layer 16 is disposed on the coating 14 and reinforces the substrate 12 via the coating 14. The thickness of the carbon fiber reinforced resin layer 16 can be adjusted appropriately depending on the application of the laminate 10. Although the carbon fiber reinforced resin layer 16 is one layer in FIG. 1, it may be two or more layers. When the carbon fiber reinforced resin layer 16 is two or more layers, each layer may be formed from the same type of carbon fiber reinforced resin, or may be formed from a combination of different types of carbon fiber reinforced resin.

[0017] Second embodiment The method for producing a laminate according to the second embodiment includes forming a coating containing a thermosetting resin on the surface of a substrate containing aluminum, baking the coating, and disposing a carbon fiber reinforced resin layer on the cured coating. This method makes it possible to form a dense coating of a thermosetting resin on the surface of the substrate, and such a coating can prevent electrolytic corrosion of the substrate.

[0018] The means for forming the coating on the surface of the substrate is not particularly limited as long as it can form a uniform coating. For example, the coating can be formed by painting the surface of the substrate with a paint containing a thermosetting resin that constitutes the coating. From the viewpoint of forming a denser coating and enhancing the effect of suppressing electrolytic corrosion of the substrate, the coating 14 can be formed by electrocoating and spray It is preferable to form the protective layer by any one of the methods described above.

[0019] When disposing the carbon fiber reinforced resin layer on the coating, the coating and the carbon fiber resin layer may be joined using either a mechanical joint such as double-sided tape or caulking, or an adhesive.

[0020] Third embodiment The building material of the third embodiment includes the laminate of the first embodiment. By using the laminate in which the electrolytic corrosion of the aluminum-containing base material is suppressed, a building material that can withstand long-term use in an outdoor environment can be provided at low cost. In addition, since the base material is reinforced by the carbon fiber reinforced resin layer in the laminate, the building material of this embodiment is suitable as a large building material in which deflection due to wind and snow is suppressed.

[0021] The present disclosure will be described in more detail below with reference to examples, but these examples are not intended to limit the present disclosure in any way. EXAMPLES

[0022] (Sample Preparation) An aluminum 6063 alloy was used to prepare a flat aluminum profile with dimensions of W30 x H80 x t2 mm. This profile was electrocoated with an acrylic-melamine electrocoating paint. The resulting coating was then heated at 200°C for 30 minutes to obtain a sample of the example. The coating thickness of the sample of the example was 10 μm.

[0023] In addition, an aluminum oxide film was formed on the surface of the same aluminum profile used in the examples by anodizing to obtain a sample for comparison.

[0024] A flat CFRP sample of the same size as the above aluminum profile was produced using Toray's Torica Laminate.

[0025] (Electrical corrosion test) The electrolytic corrosion test was performed with reference to the reference literature: Masahiro Sakai, Chinami Sakamoto, "Galvanic corrosion behavior of pure aluminum 1050 and CFRP in NaCl solution", Materials and Environment, June 2015, Vol. 64, No. 6, pp. 224-227. In order to make the area of ​​the corroded part uniform between the aluminum shaped material samples, the samples of the embodiment and comparative example were covered with vinyl tape with holes. The diameter of the holes was 19 mm. In order to conduct a test assuming use in cement (weakly alkaline atmosphere), a saturated calcium hydroxide aqueous solution (pH: 12) was prepared in a disposable cup. The test sample and the CFRP sample were clamped with clips and immersed in the saturated calcium hydroxide aqueous solution. The liquid temperature was room temperature (23°C), and the distance between the two was about 5 cm.

[0026] The test sample and CFRP were short-circuited via a zero-resistance ammeter. The saturated calcium hydroxide aqueous solution was stirred at 250 rpm using a stirrer. The current flowing between the aluminum profile and the CFRP was measured using a data logger. After the test, the samples of the Example and Comparative Example were visually observed to confirm the state of electrolytic corrosion. The results of the current measurement are shown in Figure 2. Also, images of the Comparative Example sample before and after the test, and the Example sample after the test are shown in Figure 3.

[0027] As shown in FIG. 2, in the comparative example, current started to flow 30 minutes after the start of the test. In the comparative example, the current value first rose to about 0.1 mA, then dropped to about 0.04 mA, and then rose again to about 0.1 mA. In the example, no current flowed even after 200 minutes. When the current measurement was further continued for the sample of the example, it was confirmed that no current flowed even after 3000 minutes. As shown in FIG. 3, the sample of the comparative example after the 160-minute test had unevenness on the surface, and a gray product was attached. From the above reference, this product is considered to be aluminum hydroxide (Al(OH)3). Also, as shown in FIG. 3, no change was observed on the surface of the sample of the example after the 3000-minute test.

[0028] As shown above, electrolytic corrosion progressed rapidly in the comparative example, but was suppressed in the examples. This is thought to be because, in the comparative example, the aluminum oxide layer was exposed, which caused electrolytic corrosion by CFRP to progress, whereas, in the examples, the aluminum profile was covered with a resin coating layer, which suppressed electrolytic corrosion. Also, the current value in the comparative example increased and then decreased due to the generated aluminum hydroxide adhering to the surface of the aluminum profile, which produced an insulating effect.

[0029] The above describes the embodiments of the present disclosure in detail. The above-mentioned embodiments merely show specific examples of implementing the present disclosure. The contents of the embodiments do not limit the technical scope of the present disclosure, and many design changes such as changes, additions, and deletions of components are possible within the scope of the disclosure. In the above-mentioned embodiments, the contents in which such design changes are possible are emphasized by adding the notation "embodiment", but design changes are also allowed even in contents without such notation. Any combination of the above-mentioned components is also effective as an aspect of the present disclosure. The hatching on the cross section of the drawing does not limit the material of the object to which the hatching is added.

[0030] The invention embodied in the above-mentioned embodiment can be generalized to derive the following technical idea, which will be described below using the aspects described in the problem to be solved by the invention.

[0031] In the laminate of the second aspect, the thickness of the coating is 7 μm or more and 100 μm or less in the first embodiment. According to this aspect, the effect of suppressing electrolytic corrosion of the substrate by the coating can be further improved.

[0032] The laminate of the third aspect is any one of the first and second embodiments, in which the thermosetting resin is selected from the group consisting of acrylic-melamine resins and polyester resins. According to this aspect, a denser coating can be formed, and as a result, electrolytic corrosion of the substrate can be better prevented.

[0033] The method for producing a laminate according to the fourth aspect includes forming a coating containing a thermosetting resin on the surface of a substrate containing aluminum, curing the coating by heating, and disposing a carbon fiber reinforced resin layer on the cured coating. According to this aspect, a dense coating of a thermosetting resin can be formed on the surface of the substrate, and such a coating can prevent galvanic corrosion of the substrate.

[0034] The method for producing a laminate according to the fifth aspect is the method for producing a laminate according to the fourth aspect, further comprising the steps of: forming a coating film by electrocoating; spray According to this embodiment, a denser coating can be formed, and the effect of suppressing electrolytic corrosion of the substrate can be enhanced.

[0035] A building material according to a sixth aspect includes the laminate according to any one of the first, second and third aspects. According to this aspect, a building material capable of withstanding long-term use in outdoor environments can be provided at low cost. [Explanation of symbols]

[0036] 10 laminate, 12 substrate, 14 coating, 16 carbon fiber reinforced resin layer.

Claims

1. A substrate comprising aluminum; a coating including a thermosetting resin formed on a surface of the substrate; a carbon fiber reinforced resin layer disposed on the coating; Including, The coating is formed by either spray coating or electrocoating, the coating does not contain conductive particles selected from the group consisting of metal particles, intermetallic compound particles, conductive oxide particles, and oxide ceramic particles; A laminate comprising: a substrate and a carbon fiber reinforced resin layer; and a layer containing an in-situ polymerized phenoxy resin not present between the substrate and the carbon fiber reinforced resin layer.

2. 2. The laminate according to claim 1, wherein the coating has a thickness of 1 μm or more and 1000 μm or less.

3. 3. The laminate according to claim 1, wherein the thermosetting resin is selected from the group consisting of acrylic-melamine resins and polyester resins.

4. A laminate described in any one of claims 1 to 3, characterized in that the laminate does not include an insulating layer between the coating and the carbon fiber reinforced resin layer.

5. A method for producing a laminate, comprising forming a coating containing a thermosetting resin on a surface of a substrate containing aluminum by either spray coating or electrocoating, baking the coating, and disposing a carbon fiber reinforced resin layer on the cured coating, wherein the coating does not contain conductive particles selected from the group consisting of metal particles, intermetallic compound particles, conductive oxide particles, and oxide ceramic particles.

6. The method for manufacturing a laminate described in Claim 5, characterized in that the laminate does not include an insulating layer between the coating and the carbon fiber reinforced resin layer.

7. A building material comprising the laminate according to any one of claims 1 to 4.

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