JP2019104170A - Metal-resin laminate - Google Patents

Abstract

To provide a metal-resin laminate having a base material mainly made of metal and a resin layer mainly made of fluorine-containing resin, wherein, the metal-resin laminate satisfactorily maintains advantageous properties of the fluorine-containing resin layer, while maintaining sufficient adhesiveness between the base material and the resin layer.SOLUTION: A metal-resin laminate 10 has a metal base material 20 having a first surface 20A, and a fluorine-containing resin layer 30 disposed in contact with the first surface 20A, and containing a fluorine-containing resin having a polar group.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a metal-resin laminate.

Metal-resin laminates comprising a metal-based substrate and a resin layer are widely used in various fields. The fluorine-containing resin is a material which is excellent in durability and insulation and small in relative dielectric constant (ε _r ) and dielectric loss tangent (tan δ), and is also applied to the metal-resin laminate as described above. On the other hand, fluorine-containing resins inherently have low adhesion to metals. Therefore, in a metal-resin laminate in which the resin layer is mainly composed of a fluorine-containing resin layer, it is necessary to enhance the adhesion between the substrate and the resin layer to prevent peeling of the resin layer from the substrate .

  In order to enhance the adhesion between the metal-based substrate and the fluorine-containing resin layer, for example, an adhesive layer such as an adhesive layer or a primer layer is interposed between the substrate and the resin layer. It is done. Patent Document 1 discloses a laminate in which a primer layer is disposed between a metal base and a resin layer containing a fluorine-containing resin.

JP, 2000-326441, A

  As described above, in a metal-resin laminate containing a fluorine-containing resin having an essentially low adhesion to metals, it is required to increase the adhesion between metal and resin. At this time, it is desirable to improve the adhesion between metal and resin and not to impair the characteristics such as high durability which the fluorine-containing resin layer originally has.

  Therefore, in a metal-resin laminate comprising a base mainly composed of metal and a resin layer mainly composed of a fluorine-containing resin, the base material and the resin layer are sufficiently maintained while the advantageous characteristics possessed by the fluorine-containing resin layer are sufficiently maintained. It is an object of the present invention to provide a metal-resin laminate in which sufficient adhesion is maintained.

  The metal-resin laminate of the present application comprises a metal base having a first surface, and a fluorine-containing resin layer containing a fluorine-containing resin having a polar group, disposed in contact with the first surface. .

  According to the metal-resin laminate, a metal-resin laminate is provided in which sufficient adhesiveness is maintained between the base and the resin layer while sufficiently maintaining the advantageous properties of the fluorine-containing resin layer. can do.

It is a schematic sectional drawing which shows an example of a metal-resin laminated body. It is the schematic for demonstrating the relationship of an uncrosslinked fluoropolymer molecule and a metal base material. It is the schematic for demonstrating the relationship between the fluorine-containing polymer molecule | numerator of the electron beam crosslinked state, and a metal base material.

Description of an embodiment of the present invention
First, embodiments of the present invention will be listed and described. The metal-resin laminate of the present application comprises a metal base having a first surface, and a fluorine-containing resin layer containing a fluorine-containing resin having a polar group, disposed in contact with the first surface. .

  As mentioned above, the fluorine-containing resin inherently has low adhesion to metals. Therefore, peeling is likely to occur between the fluorine-containing resin layer and the metal base simply by laminating the resin layer mainly containing the fluorine-containing resin on the metal-based base. In a metal-resin laminate including a resin layer mainly composed of a fluorine-containing resin, in order to prevent peeling between the fluorine-containing resin layer and the metal base, the space between the base and the resin layer It is necessary to improve the adhesion of

  On the other hand, for example, when an adhesive layer or a primer layer is disposed between the fluorine-containing resin layer and the metal base in order to enhance the adhesiveness, the advantageous characteristics inherent in the metal-resin laminate may not be sufficiently exhibited. . For example, in an application where high insulation is required, when the adhesive layer made of a substance having a lower insulation than the fluorine-containing resin layer is provided, the insulation as the whole laminate may be impaired. It is also disadvantageous from the viewpoint of thinning. Furthermore, in order to form an adhesive bond layer and a primer layer, the number of processes increases by the part of a process. Therefore, a laminate having a laminated structure in which the base material and the resin layer are in direct contact with each other is desired.

  The metal-resin laminate of the present application includes, as a resin layer, a fluorine-containing resin layer containing a fluorine-containing resin having a polar group. By containing the fluorine-containing resin having a polar group, the affinity with the metal substrate is enhanced, and sufficient adhesiveness is maintained to such an extent that peeling does not occur between the metal substrate and the resin layer. In addition, this makes it possible to fully exhibit the advantageous properties inherent to the fluorine-containing resin layer.

  In the metal-resin laminate, the polar group may contain at least one of oxygen and nitrogen. By the fluorine-containing resin having such a polar group, the adhesion between the substrate and the resin layer can be further enhanced.

  In the metal-resin laminate, a group containing at least one of oxygen and nitrogen is a group consisting of a carboxy group, a carboxylic acid anhydride group, an alkoxycarbonyl group, a hydroxy group, an epoxy group, and an isocyanate group. Or at least one selected from By the fluorine-containing resin having such a polar group, the adhesion between the substrate and the resin layer can be further enhanced.

  In the metal-resin laminate, the metal base may be a metal base made of aluminum, nickel, copper, or stainless steel. By providing these metal substrates, the characteristics of the metal-resin laminate including the fluorine-containing resin layer can be more suitably exhibited.

  In the metal-resin laminate, the fluororesin layer may contain a crosslinked fluoropolymer. By adopting such a fluorine-containing resin layer, it is possible to obtain a metal-resin laminate which is more excellent in various characteristics such as durability.

[Details of the Embodiment of the Present Invention]
Next, an embodiment of the metal-resin laminate of the present application will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated.

[Composition of a metal-resin laminate]
The configuration of the metal-resin laminate will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic cross-sectional view showing an example of a metal-resin laminate.

  Referring to FIG. 1, metal-resin laminate 10 includes metal substrate 20 and fluorine-containing resin layer 30. The fluorine-containing resin layer 30 is disposed in contact with the first surface 20 A of the metal base 20. More specifically, the fluorine-containing resin layer 30 is adhered to the first surface 20A of the metal substrate 20.

[Base material]
In the present embodiment, examples of the metal constituting the metal base 20 include aluminum, nickel, copper, stainless steel and the like. The shape of the metal base 20 is not particularly limited as long as it is a shape capable of laminating the fluorine-containing resin layer, and is, for example, plate-like or foil-like.

[Fluorinated resin layer]
The fluorine-containing resin layer 30 is a layer containing a fluorine-containing resin as a main component. Specifically, 50% by mass or more, more preferably 90% by mass or more, and still more preferably 99% by mass or more of the components constituting the resin layer is a fluorine-containing resin. The fluorine-containing resin is a resin having a bond of carbon atom (C) and fluorine atom (F) in a molecular chain.

  The fluorine-containing resin is not particularly limited, but, for example, tetrafluoroethylene / hexaoropropylene copolymer (FEP: Fluorinated ethylene propylene), tetrafluoroethylene / perfluoroalkylvinylether copolymer (PFA: Perfluoroalkane), polytetrafluoroethylene (PTFE: Polytetrafluoroethylene) or tetrafluoroethylene-perfluorodioxole copolymer (TFE / PDD: Tetrafluoroethylene-Perfluorodioxol copolymer), polyvinylidene fluoride, polychlorotrifluoroethylene, chlorotrifluoroethylene-ethylene copolymer, Polyvinyl fluoride, Tet Fluoroethylene - can vinylidene fluoride terpolymer, a fluoroelastomer or the like - hexafluoropropylene. Furthermore, a mixture containing these compounds, a copolymer formed by the combination of each monomer constituting these fluorine-containing resin, etc. are also included.

  Among these, FEP, PFA, PTFE and TFE / PDD are particularly preferred. As these fluorine-containing resins, radicals are relatively easily generated as fluorine-containing resins by heating, electron beam irradiation or the like. It is also possible to modify the fluorine-containing resin by the reaction of the generated radical.

  The fluorine-containing resin contains a polar group. Examples of polar groups include groups containing at least one of oxygen and nitrogen. By the fluorine-containing resin having such a polar group, the adhesion between the substrate and the resin layer can be further improved. Among them, as a polar group, a carboxy (-COOH) group, a carboxylic acid anhydride (-CO-O-CO-) group, an alkoxycarbonyl (RCOO- (R is a monovalent hydrocarbon group)) group, a hydroxy (- It is preferably at least one selected from the group consisting of an OH) group, an epoxy group, and an isocyanate (-N (C = O) group. When these groups are included, interaction between the metal substrate surface and the fluorine-containing resin layer is likely to occur, and such interaction stabilizes the adhesion between the substrate and the resin layer at a high level.

In a preferred embodiment, the fluorine-containing resin layer 30 is a layer containing a cross-linked fluoropolymer. By including the cross-linked fluoropolymer, durability such as abrasion resistance is improved. In some cases, chemical bonding may occur between the substrate and the resin layer. Thereby, the durability of the fluorine-containing resin layer 30 is further improved.

  The uncrosslinked state and the state after crosslinking of the fluoropolymer are schematically described with reference to FIGS. 2 and 3. FIG. 2 is a schematic view for explaining the relationship between an uncrosslinked fluoropolymer molecule and a metal substrate. FIG. 3 is a schematic view for explaining the relationship between the fluorine-containing polymer molecule in the electron beam crosslinked state and the metal substrate.

  In the uncrosslinked state of FIG. 2, the intermolecular cohesion between the linear fluoropolymer molecule 31 and the linear fluoropolymer molecule 32 is weak. On the other hand, in the state after crosslinking shown in FIG. 3, the molecular chains of the fluorine-containing polymer molecule 33 extend in the form of a network. Therefore, compared with the uncrosslinked state of FIG. 2 in which the intermolecular force is weak, the crosslinked body shown in FIG. 3 has higher durability and heat resistance because it has a network structure by crosslinking. As a result, the durability and the heat resistance of the fluorine-containing resin layer 30 are improved by the crosslinking. In addition, at the bonding points 111, 112, 113, part of the molecular chains can interact with the surface of the metal substrate.

  Whether or not the fluorine-containing resin layer 30 contains a fluorine-containing polymer cross-linked substance is detected, for example, by the presence of tertiary carbons 101, 102, 103, 104, 105 by an analysis means such as solid NMR (Nuclear Magnetic Resonance). It is possible to confirm by.

  The cross-linked fluoropolymer is preferably an electron beam cross-linked structure, that is, one cross-linked by irradiating the fluorine-containing resin with an electron beam. Crosslinking can modify the properties of the fluorine-containing resin layer 30, such as durability and heat resistance. The form of crosslinking is not particularly limited. For example, the crosslinking may be performed by heating the metal-resin laminate 10 in a vacuum to generate thermal radicals.

  The fluorine-containing resin layer 30 may have a porous structure having pores inside. By doing this, the heat resistance, insulation properties, etc. of the fluorine-containing resin layer 30 may be improved.

  Further, referring to FIG. 1, in order to improve the bending strength of fluorine-containing resin layer 30 and adjust the linear expansion coefficient, fluorine-containing resin layer 30 may have an intermediate layer. As an example of such an intermediate | middle layer, the glass cloth etc. which the fluorine-containing resin which comprises the fluorine-containing resin layer 30 was impregnated, etc. are mentioned. Other examples include metal cloth, ceramic cloth, alumina cloth, or heat resistant fiber cloth such as polytetrafluoroethylene, polyetheretherketone, polyimide and aramid, or polytetrafluoroethylene, liquid crystal polymer, polyimide, polyamide imide, poly The heat-resistant film etc. which consist of a benzimidazole, a polyether ether ketone, a tetrafluoroethylene perfluoro alkyl vinyl ether copolymer etc. are mentioned.

  When the intermediate layer is a cloth-like material, the method of weaving the cloth is not particularly limited, and known folding methods can be applied. For example, plain weave is preferred to thin the middle. In addition, twill weave, satin weave, etc. are preferable for use in bending.

The density of the intermediate layer is preferably 1 g / m ³ or more and 5 g / m ³ or more, and more preferably 2 g / m ³ or more and 3 g / m ³ or more. Moreover, as tensile strength of the said intermediate | middle layer independent, 1 GPa or more and 10 GPa or less are preferable, and 2 GPa or more and 5 GPa or less are more preferable. Moreover, as a tensile elasticity modulus of the said intermediate | middle layer independent, 10 GPa or more and 200 GPa or less are preferable, and 50 GPa or more and 100 GPa or less are more preferable. Furthermore, as a maximum elongation rate of the above-mentioned middle class alone, 1% or more and 20% or less are preferable, and 3% or more and 10% or less are more preferable. Moreover, as a softening point of the material which comprises the said intermediate | middle layer, 700 degreeC or more and 1200 degrees C or less are preferable, and 800 degreeC or more and 1000 degrees C or less are more preferable. With the above-described properties of the intermediate layer, a desired function can be suitably exhibited.

  The fluorine-containing resin layer 30 may further contain other additives. As such an additive, for example, a filler for improving bending strength, heat resistance and heat dissipation may be included. It may also contain an adhesion promoter such as a silane coupling agent. The fluorine-containing resin layer 30 may contain, as other additive components, a flame retardant auxiliary, a pigment, an antioxidant, a reflection imparting agent, a hiding agent, a lubricant, a processing stabilizer, a plasticizer, a foaming agent, and the like.

[Method of Forming Metal-Resin Laminate 10]
The method for forming the metal-resin laminate 10 is not particularly limited. As an example, it is possible to form the metal-resin laminate 10 according to the following procedure.

  First, the metal base 20 is prepared. For example, a plate-like or foil-like member in which the region including the first surface 20A is made of aluminum, nickel, copper, or stainless steel is prepared.

  Next, a sheet of fluorine-containing resin for forming the fluorine-containing resin layer 30 is prepared. The sheet may include an intermediate layer (for example, a glass cloth impregnated with a fluorine-containing resin) which functions as a reinforcing material or the like. The prepared fluorine-containing resin sheet is adhered onto the first surface 20A so as to cover the first surface 20A of the metal substrate 20 under pressure and heat. Pressurization and heating can be performed by, for example, a heat press.

  The heating temperature at the time of adhesion is preferably not lower than the crystal melting point of the fluorine-containing resin which is the main component of the fluorine-containing resin layer 30, more preferably 30 ° C. higher than the crystal melting point, and 50 ° C. higher than the crystal melting point More preferable. For example, when the main component of the fluorine-containing resin layer 30 is FEP, the crystal melting point of this FEP is about 270 ° C. Therefore, the heating temperature is preferably 270 ° C. or more, more preferably 300 ° C. or more, still more preferably 320 ° C. or more . By heating the fluorine-containing resin layer 30 at such a heating temperature, radicals of the fluorine-containing resin can be effectively generated. However, since there is a possibility that fluorine-containing resin itself may deteriorate if heating temperature becomes too high, as a maximum of heating temperature, 600 ° C or less is preferred, and 500 ° C or less is more preferred.

  Further, in addition to the above steps, electron beam irradiation may be further performed to promote the crosslinking of the fluorine-containing resin.

  The metal-resin laminate 10 can be produced by such a procedure. In addition, the shape of the metal-resin laminate 10 is not limited to a plate-like or sheet-like shape, and various shapes capable of bonding the metal base 20 and the fluorine-containing resin layer 30 can be adopted.

[Use]
The metal-resin laminate according to the present embodiment can be applied to various fields. In particular, the present invention can be suitably applied to electric and electronic members such as wiring members, dip members, batteries, and flexible printed circuit boards.

  In order to confirm the effect of the invention, the following experiment was performed to evaluate the characteristics. The results are shown below.

[Preparation of evaluation sample]
The sample of the metal-resin laminate was produced by the method described in the above embodiment. The peel strength between the metal base and the resin layer was measured and evaluated for each of the produced samples. The measurement results of peel strength are shown in the column of “Peel evaluation” in Tables 1 and 2.

  Peel strength was measured according to JIS K 6854-2.

The materials used to form the fluorine-containing resin layer 30 are as follows.
・ Adhesive fluorocarbon resin (1)
Maleic anhydride modified ETFE (Asahi Glass Co., Ltd., “LM-ETFE AH-2000”), thickness 50 μm
・ Adhesive fluorocarbon resin (2)
Itaconic anhydride modified PFA (Asahi Glass Co., Ltd., "Fluon (R) EA-2000"), thickness 25 μm

  The adhesive fluorocarbon resin was adhered by hot pressing the sheet on both sides so as to sandwich the metal base 20. "Pressing condition" indicates the condition of heat pressing at the time of sheet bonding.

  Further, in Tables 1 and 2, in the experiment No. 1 to No. 3 and No. 6 shows a comparative example. Experiment No. 4, 5, 7, 8 are examples.

[Discussion]
As shown in Tables 1 and 2, the metal-resin laminate according to the example (experiments No. 4, 5, 7, 8) was easily peeled off between the metal base 20 and the fluorine-containing resin layer 30. Have a sufficient peel strength that does not occur.

  The tendency is particularly remarkable when an aluminum (Al) substrate is used as the metal substrate. Referring to Table 1, first, in Experiment No. 1 comprising a fluorine-containing resin layer containing a fluorine-containing resin having no polar group. 1 to No. In the sample No. 3, the peel strength of the fluorine-containing resin layer 30 is as low as 3.0 N / cm or less. Thus, the fluorine-containing resin is essentially difficult to adhere to metal. Moreover, experiment No. 1 to No. There is almost no difference in peel strength even if the heat press conditions are changed as in No. 3.

  On the other hand, Experiment No. 1 including a fluorine-containing resin layer 30 (a layer of an adhesive fluorine resin) containing a fluorine-containing resin having a polar group. 4 and Experiment No. The sample of No. 5 is experiment No. 1 to No. It showed high peel strength compared with 3.

  The following can be seen from Table 2 showing the results when using a nickel (Ni) substrate as the metal substrate. Experiment No. 2 which is a comparative example. In No. 6, there is substantially no adhesion between the metal base 20 and the fluorine-containing resin layer 30 (the peel strength was almost zero). Such components are unsuitable for application to actual industrial products. On the other hand, in the sample (Experiment No. 7 and Experiment No. 8) including the fluorine-containing resin layer 30 containing the fluorine-containing resin having a polar group, it had stably high peel strength. Since such high peel strength is stably obtained, it is suitable for use as an industrial product or the like.

  As described above, by preparing the metal base 20 and bonding the fluorine-containing resin layer 30 containing the fluorine-containing resin having a polar group on the first surface 20A, the metal base 20 and the fluorine-containing resin layer It is possible to obtain a metal-resin laminate in which peeling is unlikely to occur between 30 and 30. In addition, by adhering the metal base 20 and the fluorine-containing resin layer 30 so as to be in direct contact with each other, metal-resin lamination which sufficiently exerts the advantageous characteristics inherent in the fluorine-containing resin layer 30 and contributes to thinning The body 10 can be obtained.

  It should be understood that the embodiments and examples disclosed herein are illustrative in all respects and not restrictive in any respect. The scope of the present invention is not the meaning described above, but is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

  The metal-resin laminate of the present application includes a substrate mainly composed of metal and a resin layer mainly composed of a fluorine-containing resin, and a metal-resin laminate in which peeling between the substrate and the resin layer hardly occurs is required. It can be applied particularly advantageously in the field of

DESCRIPTION OF SYMBOLS 10 metal-resin laminated body 20 metal base 20A 1st surface 30 fluorine-containing resin layer 31, 32, 33 fluorine-containing polymer molecule 101, 102, 103, 104, 105 tertiary carbon 111, 112, 113 bonding point

Claims (5)

A metal substrate having a first surface;
A metal-resin laminate comprising: a fluorine-containing resin layer containing a polar group-containing fluorine-containing resin disposed in contact with the first surface.   The metal-resin laminate according to claim 1, wherein the polar group is a group containing at least one of oxygen and nitrogen.   The group containing at least one of oxygen and nitrogen is at least one selected from the group consisting of a carboxy group, a carboxylic acid anhydride group, an alkoxycarbonyl group, a hydroxy group, an epoxy group, and an isocyanate group. The metal-resin laminate according to claim 2.   The metal-resin laminated body of any one of Claims 1-3 in which the said fluorine-containing resin layer contains a fluorine-containing polymer crosslinked body.   The metal-resin laminate according to any one of claims 1 to 4, wherein the metal base is a metal base made of aluminum, nickel, copper, or stainless steel.

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