JP6610375B2 - Adhesives and composite assemblies - Google Patents

Description

  The present invention provides a low dielectric constant adhesive capable of firmly bonding a metal layer and a heat resistant resin layer, and a composite in which the metal layer and the heat resistant resin layer are firmly bonded by the adhesive. It relates to the joined body.

In recent years, there has been a demand for downsizing, thinning, and weight reduction of electronic devices, and accordingly, there has been an increasing demand for higher density printed circuit boards. For high frequency applications, copper foil with low surface roughness is required to reduce transmission loss. Low profile copper foil with reduced unevenness on the matte surface of electrolytic copper foil and rolled copper foil with low surface roughness Has come to be used.
However, the copper foil having a small surface roughness has a weak adhesive force with the resin base material, and the fine circuit has an insufficient adhesive force, which is an obstacle to high density.

A number of methods for applying a silane coupling agent to the surface of a copper foil have been proposed as means for improving the adhesive force between a copper foil having a small surface roughness and a resin substrate (Patent Documents 1 to 4). ). Moreover, in order to improve the reactivity of copper foil and a silane coupling agent, the method of pre-processing the copper foil surface with a metal alcoholate etc. (patent document 5), The method of providing a polysiloxane film on the copper foil surface ( Patent Document 6) and the like have also been proposed.
However, although these methods improve the environmental stability of the adhesive properties such as moisture resistance and heat resistance, the initial adhesive strength itself is reduced by the anchor effect due to the roughening treatment of the electrolytic copper foil. It was not enough to make up.

  On the other hand, a flexible printed circuit board, which is a kind of printed circuit board, is an important member for internal wiring of devices and component mounting boards. As a flexible printed circuit board, there are two-layer CCL (Copper Clad Laminate) in which an insulating film represented by polyimide film and copper foil are directly bonded, and three-layer CCL in which the insulating film and copper foil are bonded via an adhesive. Are known. The two-layer CCL is superior in reliability at high temperatures because it does not involve an adhesive, but requires a process such as applying a polyamic acid solution, which is a polyimide precursor, to a copper foil, drying, and heating imidization. However, its manufacture is not always easy. On the other hand, the three-layer CCL is made by adhering an insulating film such as a polyimide film and a copper foil with an adhesive, so that it is industrially easy to manufacture and inexpensive, and the insulating film and the copper foil are bonded. Excellent in properties. For this reason, three-layer CCL is mainly used in general purpose applications.

The adhesive used for the production of the three-layer CCL is required to have properties such as adhesion, electrical insulation, chemical resistance, and solder heat resistance. Conventionally, polyamide (nylon) / epoxy system, polyester / epoxy system, phenol / butyral system, nitrile rubber / epoxy system, acrylic system, urethane system, and the like have been used as adhesives that satisfy these requirements.
However, in order to firmly bond a copper foil having a small surface roughness to a polyimide film using these adhesives, for example, when using a polyamide / epoxy adhesive, Must be treated with an aminosilane coupling agent (Patent Document 7).

  In relation to the present invention, Patent Document 8 discloses that a modified block copolymer hydride (E) in which an alkoxysilyl group is introduced into a block copolymer hydride has adhesion to glass or metal, Since it is excellent also in insulation, it is disclosed that it can utilize for the sealing material of a solar cell.

Japanese Patent Publication No. 60-15654 Japanese Patent Publication No. 2-19994 JP 63-183178 A JP-A-2-26097 JP-A-5-230667 JP-A-10-226209 JP 2003-298230 A WO2012 / 043708 pamphlet

  The present invention has been made in view of the above-described prior art, and its purpose is to provide excellent adhesion between a metal layer having a small surface roughness and a heat-resistant resin layer, and a low dielectric constant and electrical insulation. It is an object of the present invention to provide a novel bonded adhesive and a composite joined body in which a metal layer and a heat-resistant resin layer are firmly bonded by the adhesive.

  As a result of intensive studies to achieve the above object, the present inventors have found that an adhesive containing a specific modified block copolymer hydride having an alkoxysilyl group introduced as a main component (E) is a metal layer. And it discovered that it showed strong adhesiveness with respect to a heat resistant resin layer, and came to complete this invention.

Thus, according to the present invention, the following adhesives (1) to (3) and the composite assembly (4) are provided.
(1) An adhesive used for bonding a metal layer and a heat resistant resin layer,
At least two polymer blocks (A) mainly comprising a structural unit derived from an aromatic vinyl compound, and at least one polymer block (B) mainly comprising a structural unit derived from a chain conjugated diene compound. The weight fraction of the entire polymer block (A) in the entire block copolymer (C) is wA, and the weight fraction of the entire polymer block (B) in the entire block copolymer (C) is The ratio of wA to wB, wA: wB is 30: 70-60: 40, and the main chain and side chain carbon-carbon unsaturated bonds and aromatic rings of the block copolymer (C) Adhesive mainly comprising a modified block copolymer hydride (E) in which an alkoxysilyl group is introduced into a block copolymer hydride (D) obtained by hydrogenating 90% or more of carbon-carbon unsaturated bonds. .
(2) The adhesive according to (1), wherein the silane coupling agent is blended at a ratio of 0.1 to 10 parts by weight with respect to 100 parts by weight of the modified block copolymer hydride (E).
(3) An organic solvent having a boiling point of 90 ° C. or higher is further included, and 100 parts by weight of the modified block copolymer hydride (E) is dissolved in the organic solvent having a boiling point of 90 ° C. or higher in a proportion of 100 to 1000 parts by weight. The adhesive according to (1) or (2).
(4) A composite joined body in which a heat-resistant resin layer and a metal layer are bonded with the adhesive according to any one of (1) to (3).

  According to the present invention, an adhesive having a low dielectric constant and a low dielectric loss tangent that can be used for the production of a high-density printed circuit board, etc., capable of firmly adhering a metal layer having a small surface roughness and a heat-resistant resin layer, And the composite conjugate | bonded_body by which a metal layer and a heat resistant resin layer are adhere | attached firmly with the said adhesive agent is provided.

Hereinafter, the present invention will be described in detail by dividing it into 1) an adhesive and 2) a composite joined body.
1) Adhesive The adhesive of the present invention is an adhesive used for adhesion between a metal layer and a heat-resistant resin layer,
At least two polymer blocks (A) mainly comprising a structural unit derived from an aromatic vinyl compound, and at least one polymer block (B) mainly comprising a structural unit derived from a chain conjugated diene compound. The weight fraction of the entire polymer block (A) in the entire block copolymer (C) is wA, and the weight fraction of the entire polymer block (B) in the entire block copolymer (C) is The ratio of wA to wB, wA: wB is 30: 70-60: 40, and the main chain and side chain carbon-carbon unsaturated bonds and aromatic rings of the block copolymer (C) The main component is a modified block copolymer hydride (E) in which an alkoxysilyl group is introduced into a block copolymer hydride (D) obtained by hydrogenating 90% or more of carbon-carbon unsaturated bonds. is there.

(1) Block copolymer (C)
The block copolymer (C) has at least two polymer blocks (A) having a structural unit derived from an aromatic vinyl compound as a main component, and a structural unit derived from a chain conjugated diene compound as a main component, at least It is a block copolymer composed of one polymer block (B).

The polymer block (A) has a structural unit derived from an aromatic vinyl compound as a main component. The content of the structural unit derived from the aromatic vinyl compound in the polymer block (A) is usually 95% by weight or more, preferably 97% by weight or more, more preferably 99% by weight or more. The polymer block (A) can contain a structural unit derived from a chain conjugated diene and / or a structural unit derived from another vinyl compound as a component other than the structural unit derived from the aromatic vinyl compound. The content is usually 5% by weight or less, preferably 3% by weight or less, more preferably 1% by weight or less.
When there are too few structural units derived from the aromatic vinyl compound in the polymer block (A), the heat resistance of the adhesive may be lowered.

As the aromatic vinyl compound, styrene; 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, 4-t-butylstyrene, 5-t-butyl Styrenes having an alkyl group as a substituent such as 2-methylstyrene; Styrenes having a halogen atom as a substituent such as 4-monochlorostyrene, dichlorostyrene, 4-monofluorostyrene; Substituents such as 4-phenylstyrene And styrenes having an aryl group; and the like. Among them, those having no polar group are preferable in terms of low dielectric constant and low hygroscopicity, and styrene is particularly preferable from the viewpoint of industrial availability.
Examples of the chain conjugated diene and other vinyl compounds that can be copolymerized with the aromatic vinyl compound include those similar to the chain conjugated diene and other vinyl compounds that form the structural unit of the polymer block (B) described later. can give.

The polymer block (B) has a structural unit derived from a chain conjugated diene compound as a main component. The content of the structural unit derived from the chain conjugated diene compound in the polymer block (B) is usually 95% by weight or more, preferably 97% by weight or more, more preferably 99% by weight or more. The polymer block (B) can contain a structural unit derived from an aromatic vinyl compound and / or a structural unit derived from another vinyl compound as a component other than the structural unit derived from the chain conjugated diene compound. Its content is usually 5% by weight or less, preferably 3% by weight or less, more preferably 1% by weight or less.
When the structural unit derived from the chain conjugated diene compound is in the above range, the adhesiveness of the adhesive is excellent.

  Examples of the chain conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene and the like. Of these, a chain conjugated diene compound containing no polar group is preferable from the viewpoint of hygroscopicity, and 1,3-butadiene and isoprene are particularly preferable from the viewpoint of industrial availability.

  Examples of other vinyl compounds include chain vinyl compounds, cyclic vinyl compounds, unsaturated cyclic acid anhydrides, and unsaturated imide compounds. These compounds may have a substituent such as a nitrile group, an alkoxycarbonyl group, a hydroxycarbonyl group, or a halogen atom. Among these, from the viewpoint of hygroscopicity, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-eicosene, C2-C20 chain olefins such as 4-methyl-1-pentene and 4,6-dimethyl-1-heptene; C5-C20 cyclic olefins such as vinylcyclohexane and norbornene; 1,3-cyclohexadiene And those containing no polar group such as cyclic diene compounds such as norbornadiene;

  In the block copolymer (C), the weight fraction of the whole block copolymer (C) in the whole polymer block (A) is wA, and the whole block copolymer (C) in the whole polymer block (B). When the weight fraction of wA is wB, the ratio wA: wB of wA: wB is 20: 80-60: 40, preferably 25: 75-55: 45, more preferably 30: 70-50: 50. belongs to. If the ratio wA: wB of wA and wB is in this range, an adhesive having good adhesive strength can be obtained.

The number of polymer blocks (A) in the block copolymer (C) is usually 3 or less, preferably 2 and the number of polymer blocks (B) is usually 2 or less, preferably 1 It is.
The form of the block of the block copolymer (C) may be a chain type block or a radial type block, but a chain type block is preferred because of excellent mechanical strength. The most preferable form of the block copolymer (C) is a (A)-(B)-(A) type triblock copolymer in which the polymer block (A) is bonded to both ends of the polymer block (B). It is.
The plurality of polymer blocks (A) may be the same as or different from each other. When there are a plurality of polymer blocks (B), the polymer blocks (B) may be the same as or different from each other.

  The molecular weight of the block copolymer [C] is a polystyrene-reduced weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent, and usually 40,000 to 200. , Preferably 45,000 to 150,000, more preferably 50,000 to 100,000. Further, the molecular weight distribution (Mw / Mn) of the block copolymer [C] is preferably 3 or less, more preferably 2 or less, and particularly preferably 1.5 or less. When Mw and Mw / Mn are within the above ranges, an adhesive having good mechanical strength can be obtained.

  As a method for producing the block copolymer [C], for example, a monomer mixture (a) containing an aromatic vinyl compound as a main component and a chain conjugated diene compound as a main component by a method such as living anion polymerization. A method of alternately polymerizing the monomer mixture (b) to be polymerized; a monomer mixture (a) containing an aromatic vinyl compound as a main component and a monomer mixture (b) containing a chain conjugated diene compound as a main component in order. Then, the method etc. of coupling the terminal of polymer block [B] with a coupling agent are mentioned.

(2) Block copolymer hydride (D)
The block copolymer hydride (D) is obtained by hydrogenating the carbon-carbon unsaturated bond of the main chain and the side chain and the carbon-carbon unsaturated bond of the aromatic ring of the block copolymer (C). Is a molecule. The hydrogenation rate is usually 90% or more, preferably 97% or more, more preferably 99% or more. As the hydrogenation rate is higher, an adhesive having better oxidation resistance and light resistance can be obtained.
The hydrogenation rate of the block copolymer hydride (D) can be determined by measuring ¹ H-NMR of the block copolymer hydride (D).

  There are no particular limitations on the method for hydrogenating unsaturated bonds, the reaction mode, and the like, and known methods can be used. Among these, a hydrogenation method that can increase the hydrogenation rate and has few polymer chain scission reactions is preferable. Examples of such a hydrogenation method include the methods described in WO 2011/096389 pamphlet, WO 2012/043708 pamphlet and the like.

  The block copolymer hydride (D) obtained by the above method is recovered from the reaction solution after removing the hydrogenation catalyst and / or the polymerization catalyst from the reaction solution containing the block copolymer hydride (D). The Although the form of the recovered block copolymer hydride (D) is not limited, it can usually be formed into a pellet shape and subjected to subsequent alkoxysilyl group introduction reaction.

  The molecular weight of the block copolymer hydride (D) is a polystyrene-equivalent weight average molecular weight (Mw) measured by GPC using THF as a solvent, and is usually 40,000 to 200,000, preferably 45,000 to 150. 1,000, more preferably 50,000 to 100,000. The molecular weight distribution (Mw / Mn) of the block copolymer hydride (D) is preferably 3 or less, more preferably 2 or less, and particularly preferably 1.5 or less. When Mw and Mw / Mn are within the above ranges, an adhesive having good mechanical strength can be obtained.

(3) Modified block copolymer hydride (E)
The modified block copolymer hydride (E) is obtained by introducing an alkoxysilyl group into the above block copolymer hydride (D).
By introducing an alkoxysilyl group into the block copolymer hydride (D), it is possible to impart strong adhesion to the metal layer and the heat-resistant resin layer.

  Examples of the alkoxysilyl group include tri (C1-C6 alkoxy) silyl groups such as trimethoxysilyl group and triethoxysilyl group; methyldimethoxysilyl group, methyldiethoxysilyl group, ethyldimethoxysilyl group, ethyldiethoxysilyl group Group, propyldimethoxysilyl group, propyldiethoxysilyl group, (C1-C20 alkyl) di (C1-C6 alkoxy) silyl group; phenyldimethoxysilyl group, phenyldiethoxysilyl group, (aryl ) Di (C1-C6 alkoxy) silyl group; and the like. The alkoxysilyl group is bonded to the block copolymer hydride (D) via a divalent organic group such as an alkylene group having 1 to 20 carbon atoms or an alkyleneoxycarbonylalkylene group having 2 to 20 carbon atoms. You may do it.

  The amount of the alkoxysilyl group introduced into the block copolymer hydride (D) is usually 0.1 to 10 parts by weight, preferably 0.2 to 100 parts by weight with respect to 100 parts by weight of the block copolymer hydride (D). 5 parts by weight, more preferably 0.5 to 3 parts by weight. When the introduction amount of alkoxysilyl groups is too large, the resulting modified block copolymer hydride (E) is cross-linked with alkoxysilyl groups that have been decomposed with a small amount of moisture during storage, resulting in gelation or melt molding. There is a possibility that the fluidity at the time is lowered and the adhesiveness as an adhesive is lowered. Moreover, when there is too little introduction amount of an alkoxy silyl group, there exists a possibility that the adhesiveness with respect to a metal layer and a heat resistant resin layer as an adhesive agent may fall.

  The modified block copolymer hydride (E) can be produced according to a known method. As a manufacturing method, the method described in WO2012 / 043708 pamphlet, country WO2013 / 176258 pamphlet, etc. are mentioned, for example. More specifically, a method of reacting the block copolymer hydride (D) with an ethylenically unsaturated silane compound in the presence of an organic peroxide can be mentioned.

The ethylenically unsaturated silane compound to be used is not particularly limited as long as it is graft-polymerized with the block copolymer hydride [D] and introduces an alkoxysilyl group into the block copolymer hydride [D]. For example, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, dimethoxymethylvinylsilane, diethoxymethylvinylsilane, p-styryltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acrylic Loxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysila, 3-acryloxypropyltrimethoxy Silane and the like are preferably used. These ethylenically unsaturated silane compounds may be used alone or in combination of two or more.
The amount of the ethylenically unsaturated silane compound used is usually 0.1 to 10 parts by weight, preferably 0.2 to 5 parts by weight, and more preferably 0 to 100 parts by weight of the block copolymer hydride (D). 0.5 to 3 parts by weight.

  As the organic peroxide, those having a 1-minute half-life temperature of 170 to 190 ° C. are preferably used. For example, t-butyl cumyl peroxide, dicumyl peroxide, di-t-hexyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, di-t-butyl peroxide, Di (2-t-butylperoxyisopropyl) benzene or the like is preferably used. These peroxides may be used alone or in combination of two or more. The amount of peroxide used is usually 0.05 to 2 parts by weight, preferably 0.1 to 1 part by weight, more preferably 0.2 to 100 parts by weight with respect to 100 parts by weight of the block copolymer hydride (D). 0.5 weight.

  The method for reacting the block copolymer hydride (D) with the ethylenically unsaturated silane compound in the presence of peroxide is not particularly limited. For example, an alkoxysilyl group can be introduced into the block copolymer hydride (D) by kneading for a desired time at a desired temperature in a biaxial kneader. The kneading temperature by the biaxial kneader is usually 180 to 220 ° C, preferably 185 to 210 ° C, more preferably 190 to 200 ° C. The heat kneading time is usually about 0.1 to 10 minutes, preferably about 0.2 to 5 minutes, and more preferably about 0.3 to 2 minutes. What is necessary is just to knead | mix and extrude continuously so that temperature and residence time may become the said range. Although the form of the obtained modified block copolymer hydride (E) is not limited, it can usually be formed into a pellet shape and used for the subsequent production of an adhesive.

  The molecular weight of the modified block copolymer hydride (E) is substantially the same as the molecular weight of the block copolymer hydride (D) used as a raw material because the amount of alkoxysilyl groups introduced is small. On the other hand, in order to react with the ethylenically unsaturated silane compound in the presence of peroxide, the cross-linking reaction and cleavage reaction of the polymer occur simultaneously, and the molecular weight distribution value of the modified block copolymer hydride (E) is large. Become.

  The molecular weight of the modified block copolymer hydride (E) is a polystyrene-reduced weight average molecular weight (Mw) measured by GPC using THF as a solvent, and is usually 40,000 to 200,000, preferably 50,000 to 150,000, more preferably 60,000 to 100,000. The molecular weight distribution (Mw / Mn) is preferably 3.5 or less, more preferably 2.5 or less, and particularly preferably 2.0 or less. When Mw and Mw / Mn are within the above ranges, the mechanical strength of the modified block copolymer hydride (E) is maintained.

(4) Adhesive The adhesive containing the modified block copolymer hydride (E) of the present invention as a main component is excellent in adhesion to the metal layer and the heat-resistant resin layer.
In the adhesive of the present invention, the content of the modified block copolymer hydride (E) is usually 9% by weight or more, preferably from the viewpoint of firmly bonding the metal layer having a small surface roughness and the heat-resistant resin layer. Is 11% by weight or more, more preferably 14% by weight or more.

  The adhesive of the present invention preferably contains a silane coupling agent in addition to the modified block copolymer hydride (E) as a main component in order to further increase the adhesive strength with the heat resistant resin layer.

  As the silane coupling agent to be blended, from the viewpoint of further improving the properties of the adhesive, an epoxy silane coupling agent and an amino silane coupling agent are preferable, and an epoxy silane coupling agent is particularly preferable.

Specific examples of the epoxysilane coupling agent include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-glycol. Sidoxypropyltriethoxysilane etc. are mentioned.
Specific examples of the aminosilane coupling agent include N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- ( Aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N- Examples include phenyl-3-aminopropyltrimethoxysilane, N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane, and the like.

  The amount of the silane coupling agent is usually 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, more preferably 100 parts by weight of the modified block copolymer hydride (E). It mix | blends in the ratio of 0.5-3 weight part. By making the compounding quantity of a silane coupling agent into the said range, the adhesiveness of the adhesive of this invention and the heat resistant resin layer which has a polar group can further be improved, and block copolymer hydride (D) becomes The low dielectric constant characteristics are maintained.

In order to further improve the heat distortion resistance of the adhesive of the present invention, a crosslinking assistant and an organic peroxide can be blended with the modified block copolymer hydride (E).
Examples of the crosslinking aid include triallyl isocyanurate, polyvalent acrylic acid ester, and polyvalent methacrylate acid. These crosslinking aids may be used alone or in combination of two or more.
The amount of the crosslinking aid is usually 5 parts by weight or less, preferably 3 parts by weight or less, more preferably 2 parts by weight or less with respect to 100 parts by weight of the modified block copolymer hydride (E). If it is this range, the heat-resistant deformation property of an adhesive agent can be improved and the increase in a dielectric constant can be suppressed small.

Examples of the organic peroxide include 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-di (t-butylperoxy) -2-methylcyclohexane, 1-di (t-butylperoxy) cyclohexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,2-di (t-butylperoxy) butane, n-butyl-4, 4-di (t-butylperoxy) valerate, t-butylperoxybenzoate, t-butylcumyl peroxide, dicumyl peroxide, di-t-hexyl peroxide, 2,5-dimethyl-2,5-di (T-butylperoxy) hexane, di-t-butyl peroxide, t-butylperoxyisobutyrate, lauroyl peroxide, dipropionyl peroxide, - menthane hydroperoxide, and the like. These organic peroxides may be used alone or in combination of two or more.
The amount of the crosslinking agent used is usually 1 part by weight or less, preferably 0.5 parts by weight or less, more preferably 0.3 parts by weight or less with respect to 100 parts by weight of the modified block copolymer hydride [E]. If it is this range, the heat-resistant deformation property of an adhesive agent can be improved and the increase in a dielectric constant can be suppressed small.

  In the adhesive of the present invention, an antioxidant can be blended in order to further improve the heat deterioration resistance. As the antioxidant, a phenol-based antioxidant, a phosphorus-based antioxidant, a sulfur-based antioxidant, and the like can be used. The blending amount of the antioxidant is 0.3 parts by weight or less, preferably 0.2 parts by weight or less, more preferably 0.1 parts by weight or less with respect to 100 parts by weight of the modified block copolymer hydride (E). is there. If it is this range, the heat-resistant deterioration property of an adhesive agent can be improved and the increase in a dielectric constant can be suppressed.

  In order to impart flame retardancy, a flame retardant can be blended in the adhesive of the present invention. As the flame retardant, a halogen flame retardant, a phosphorus flame retardant, a metal hydroxide flame retardant, or the like can be used. The blending amount of the flame retardant is 10 parts by weight or less, preferably 5 parts by weight or less, and more preferably 2 parts by weight or less with respect to 100 parts by weight of the modified block copolymer hydride (E). If it is this range, the increase in a dielectric constant can be suppressed, improving the flame retardance of an adhesive agent.

The adhesive of the present invention usually comprises an organic solvent, a modified block copolymer hydride (E), and, if necessary, a compounding agent.
As the organic solvent, an organic solvent capable of dissolving the modified block copolymer hydride (E) can be used. Specifically, for example, aromatic solvents such as toluene, xylene and solvent naphtha; saturated hydrocarbon solvents such as decalin; alicyclic hydrocarbon solvents such as cyclohexane, methylcyclohexane and dimethylcyclohexane; ethers such as tetrahydrofuran Solvent; terpene solvents such as limonene; ketone solvents such as cyclohexanone; and the like.
These organic solvents may be used alone or in combination of two or more.
Among these, from the viewpoint of the volatility of the solvent from the adhesive applied to the substrate and the workability in the coating process, an organic solvent having a boiling point (boiling point at 1 atm = 1024 hPa) of 90 ° C. or higher is preferable, and the boiling point is 100 An organic solvent of ˜150 ° C. is particularly preferred. These solvents can also be used by mixing with an organic solvent having a boiling point lower than 90 ° C.

  When the adhesive of the present invention contains an organic solvent, the amount of the organic solvent used may be appropriately selected in consideration of workability in the step of applying the adhesive of the present invention to a substrate. Various other compounding agents of the modified block copolymer hydride (E) can also be used by dissolving or mixing in the solution. The content of the organic solvent is usually 100 to 1000 parts by weight, preferably 150 to 800 parts by weight, and more preferably 200 to 600 parts by weight with respect to 100 parts by weight of the modified block copolymer hydride (E). .

The adhesive of the present invention has excellent adhesion between a metal layer having a small surface roughness and a heat-resistant resin layer, and has a low dielectric constant and excellent electrical insulation.
It can be confirmed that the adhesive of the present invention is excellent in adhesiveness because, for example, the peel strength measured as described in Examples is 4 N / cm or more. The adhesive of the present invention has a low dielectric constant and excellent electrical insulation. For example, the dielectric constant at 5 GHz measured by the cavity resonator perturbation method (ASTM D2520) described in the Examples is 2.5 or less. Since the dielectric loss tangent is 0.002 or less, it can be confirmed.

(5) Method of using the adhesive The adhesive containing the organic solvent of the present invention is usually applied to the heat-resistant resin layer and / or the metal layer, and then the solvent is removed by volatilization and the adhesive is used as a coating. To do.
The heat resistant resin layer and / or metal layer on which the coating film of the adhesive of the present invention is formed is heated by laminating the metal layer and / or heat resistant resin layer as the other adherend on the coating film surface. And by applying pressure, a composite joined body in which the heat-resistant resin layer and the metal layer are bonded with the adhesive of the present invention is obtained.

  When using the adhesive agent containing the organic solvent of this invention, the thickness of the adhesive agent after volatilizing and removing a solvent is 5-100 micrometers normally, Preferably it is 8-70 micrometers, More preferably, it is 10-50 micrometers. If the thickness of the adhesive is within this range, the remaining organic solvent is small and good adhesion to other adherend layers can be obtained.

The heating temperature when the heat-resistant resin layer and the metal layer are bonded using the adhesive of the present invention is usually 100 to 200 ° C, preferably 110 to 190 ° C, more preferably 120 to 180 ° C. The pressure applied to the adherend when the heat-resistant resin layer and the metal layer are bonded using the adhesive of the present invention is usually 0.01 to 10 MPa, preferably 0.05 to 5 MPa, more preferably 0.00. 1 to 1 MPa. Moreover, the time to heat and pressurize is 1 to 90 minutes normally, Preferably it is 3 to 60 minutes, More preferably, it is 5 to 30 minutes.
When the temperature, pressure and time are within this range, good adhesion between the heat-resistant resin layer and the metal layer can be obtained.

The adhesive of the present invention can be firmly bonded to the metal layer and the ceramic layer.
The ceramic layer is usually formed into a molded product by press molding or the like as a uniform mixture by appropriately mixing a sintering aid or a mixing aid such as an organic solvent or water with inorganic powder, and further adding a mixing aid. After removing by drying, heating or the like, a sheet-like product produced by firing and sintering can be used.

  Specific examples of ceramics used include aluminum nitride-boron nitride composite, alumina-boron nitride composite, zirconium oxide-boron nitride composite, silicon nitride-boron nitride composite, β-wollastonite, cordierite, Sintered body mainly composed of mica, etc .; ceramics mainly composed of aluminum, silicon, strontium, etc., and titanium, bismuth, copper, manganese, sodium, potassium, etc. as minor components; ceramics containing aluminum, magnesium and silicon; Ceramics containing aluminum, silicon, zirconium and magnesium; alumina, barium titanate, aluminum nitride and the like.

  Although the thickness of a ceramic layer is not specifically limited, Usually, 0.5-2 mm, Preferably it is 0.6-1.5 mm, More preferably, it is 0.7-1.2 mm. If the thickness is within this range, the handling workability, mechanical strength, etc. are good.

  Examples of composite joints obtained by bonding a metal layer and a ceramic layer with the adhesive of the present invention include three-layer composite joints such as ceramic layer / adhesive layer / copper layer; copper layer / adhesive 5-layer composite joined body such as layer / ceramic layer / adhesive layer / copper layer; and the like.

2) Composite bonded body The composite bonded body of the present invention is characterized in that a heat-resistant resin layer and a metal layer are bonded with the adhesive of the present invention.

(1) Metal layer The metal layer of the composite joined body of the present invention is an adherend bonded with the adhesive of the present invention. As the metal layer, a metal layer laminated on a substrate by a method such as plating or vapor deposition, a metal layer in which a metal foil is adhered to the substrate with an adhesive, a single layer or a multilayer sheet made of metal And the like. Further, the metal layer may have a linear or planar pattern formed on a base material like an electric circuit.

  Specific examples of the metal constituting the metal layer include metals such as aluminum, gallium, indium, titanium, vanadium, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, palladium, platinum, copper, silver, gold, and zinc. An alloy such as iron alloy, copper alloy, aluminum alloy, nickel alloy, solder, wood metal, super steel alloy, and white gold;

  Although the thickness of a metal layer is not specifically limited, Usually, 0.01-300 micrometers, Preferably it is 0.05-200 micrometers, More preferably, it is 0.1-100 micrometers. The thickness of the metal layer is appropriately selected according to the purpose such as an electric circuit, a conductive layer, an electromagnetic wave shielding layer, a barrier layer such as oxygen and water, and a selective light reflecting layer.

  The surface roughness of the metal layer is also appropriately selected depending on the purpose. For example, when the metal layer is a high-frequency electric circuit, the surface roughness of the metal layer is usually 3.0 μm or less, preferably 1.5 μm or less, more preferably 1.0 μm or less in terms of the maximum height roughness Rz. . If the maximum height roughness Rz is within this range, transmission loss in the high frequency region is reduced. As described above, by using the adhesive of the present invention, a metal layer having a small surface roughness such as a maximum height roughness Rz of usually 3.0 μm or less, preferably 1.5 μm or less, more preferably 1.0 μm or less. And a composite bonded body in which the heat-resistant resin layer is firmly bonded.

(2) Heat-resistant resin layer The heat-resistant resin layer of the composite joined body of the present invention is an adherend bonded with the adhesive of the present invention. The heat-resistant resin layer is a layer made of a heat-resistant resin having a heat-deformability that is usually 180 ° C. or higher, preferably 220 ° C. or higher, more preferably 260 ° C. or higher.
The heat deformation resistance can be evaluated by a load deflection temperature obtained according to JIS K7919-1 method (plastic-method for obtaining a deflection temperature under load).
If the deflection temperature under load of the heat resistant resin is in the above range, it is useful as an electrically insulating material.

The heat-resistant resin layer may be a layer made of a heat-resistant resin laminated on a base material, or may be a single layer or multilayer film made of a heat-resistant resin.
Specific examples of the heat resistant resin constituting the heat resistant resin layer include polyimide resin, polyamideimide resin, polyether imide resin, aromatic polyamide resin, polyarylate resin, polyether sulfone resin, liquid crystal polymer, polyphenylene sulfide resin. , Bismaleimide resin, epoxy resin, unsaturated polyester resin and the like.

  Although the thickness of a heat resistant resin layer is not specifically limited, Usually, 1-500 micrometers, Preferably it is 10-300 micrometers, More preferably, it is 20-200 micrometers. When the thickness is within this range, the electrical insulation property, mechanical strength, etc. of the heat resistant resin layer are good.

(3) Composite Joint The composite joint of the present invention is a laminate in which a heat resistant resin layer and a metal layer are bonded with the adhesive of the present invention.
If the composite joined body of this invention is a laminated body which has a heat resistant resin layer, an adhesive bond layer, and a metal layer in this order at least, it will not restrict | limit especially in the layer structure.
Specific examples of the composite joined body of the present invention include polyimide resin layer / adhesive layer / copper layer, liquid crystal polymer layer / adhesive layer / copper layer, polyethersulfone resin layer / adhesive layer / copper layer, and the like. Such a three-layer composite joint; copper layer / adhesive layer / glass fiber / epoxy resin layer / adhesive layer / copper layer, copper layer / adhesive layer / polyimide resin layer / adhesive layer / copper layer, etc. 5 layer laminates; and the like.

The composite conjugate | zygote of this invention can be manufactured by passing through following step (I), step (II), and step (III), for example.
Step (I): First, the adhesive (adhesive solution) of the present invention containing an organic solvent is applied to a heat-resistant resin film and / or a metal foil, and the solvent is evaporated and removed from the obtained coating film. An agent layer is formed. The thickness of the adhesive after removing the solvent by evaporation is usually 5 to 100 μm, preferably 8 to 70 μm, more preferably 10 to 50 μm.
Step (II): Next, the adhesive layer surface of the heat-resistant resin layer and / or metal layer on which the adhesive layer (the adhesive coating film of the present invention) is formed, and the metal layer as the other adherend And / or a heat resistant resin layer is laminated | stacked, and a laminated body is obtained.
Step (III): Next, by heating and pressurizing the obtained laminate, a composite joined body in which the heat-resistant resin layer and the metal layer are bonded with the adhesive of the present invention can be obtained.

The temperature which heats the obtained laminated body is 100-200 degreeC normally, Preferably it is 110-190 degreeC, More preferably, it is 120-180 degreeC. The pressurizing pressure is usually 0.01 to 10 MPa, preferably 0.05 to 5 MPa, more preferably 0.1 to 1 MPa. Moreover, the time to heat and pressurize is 1 to 90 minutes normally, Preferably it is 3 to 60 minutes, More preferably, it is 5 to 30 minutes.
When the temperature, pressure and time are within this range, good adhesion between the heat-resistant resin layer and the metal layer can be obtained.

  In the method for producing a composite joined body of the present invention, the step (III) can be more specifically performed as follows. That is, the laminate obtained in step (II) is put in a resin bag having a predetermined thickness (for example, 75 μm) having a layer structure of NY (nylon) / adhesive layer / PP (polypropylene). Next, the center of the opening of the bag is heat-sealed on both sides with a heat sealer while leaving a predetermined width (for example, 200 mm width), and then opened using a commercially available sealed pack device while degassing the inside of the bag Heat seal the part and seal the laminate. After that, the hermetically sealed laminate is put in an autoclave and heated and pressurized at a predetermined temperature and pressure (for example, temperature 150 ° C., pressure 0.8 MPa) for a predetermined time (for example, 30 minutes), and a heat resistant resin film / adhesive layer / A composite assembly having a metal layer structure can be obtained.

  A composite joined body obtained by laminating a polyimide resin layer produced using the adhesive of the present invention and a copper layer having a small surface roughness can be suitably used as a material for a high-frequency flexible printed circuit board.

  The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples. “Parts” and “%” are based on weight unless otherwise specified.

Evaluation in this example is performed by the following method.
(1) Measurement of weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) The molecular weights of the block copolymer and the block copolymer hydride were measured by GPC at 38 ° C. and obtained as standard polystyrene conversion values. As a measuring apparatus, HLC8020GPC manufactured by Tosoh Corporation was used.
(2) Measurement of hydrogenation rate The hydrogenation rate of the main chain, the side chain and the aromatic ring of the block copolymer hydride [D] was calculated by measuring a ¹ H-NMR spectrum.

(3) Evaluation method of dielectric constant and dielectric loss tangent
An adhesive solution was applied onto a releasable PET film (thickness: 100 μm) so that the thickness of the adhesive layer was 20 to 30 μm, and the solvent was removed by evaporation in an inert oven. The adhesive layer was peeled off from the releasable PET film, a large number of adhesive layers were stacked, and vacuum press-molded at 140 ° C. to form an adhesive sheet having a thickness of 700 to 760 μm. The obtained adhesive sheet was heat-treated at 150 ° C. for 1 hour in an inert oven to remove volatile components, and used as a sample for evaluating dielectric constant and dielectric loss tangent.
A test piece having a length of 80 mm and a width of 1.5 mm was prepared from the adhesive sheet, and a dielectric constant and a dielectric loss tangent at 5 GHz were measured by a cavity resonator perturbation method (ASTM D2520).

(4) Adhesive evaluation method The adhesiveness between the heat-resistant resin layer and the adhesive and the adhesiveness between the metal layer and the adhesive were evaluated as follows.
On one side of the heat resistant resin film (thickness 50 to 150 μm) or metal foil (thickness 10 to 50 μm), the part where the adhesive is not applied partially is left, and the thickness of the adhesive layer after removing the solvent is 10 to 10 mm. The adhesive solution was applied to a thickness of 20 μm, and the solvent was removed by evaporation in an inert oven.
Cut the heat-resistant resin film or metal foil to which the adhesive was applied, including the part where the adhesive was not applied, so that the adhesive application surface is 15 mm wide x 150 mm long. did. Next, the two test pieces were overlapped with the adhesive-coated surfaces facing each other, and heated and pressed under predetermined conditions to bond them to prepare a test piece for peel strength measurement.
The portion of the heat-resistant resin film or metal foil that is not coated with the adhesive is fixed to a tensile tester (product name “AGS-10KNX”, manufactured by Shimadzu Corporation) and peeled at a rate of 100 mm / min. JIS K 6854-2 The peel strength was measured by performing a 180 ° peel test.
The adhesiveness was evaluated as good (◯) when the peel strength was 4 N / cm or more, and insufficient (×) when it was below 4 N / cm.

[Production Example 1] Production of pellets of modified block copolymer hydride (E1) Block copolymer hydride (D1) with reference to the method described in WO2012 / 043708 and / or WO2014 / 077267 (Weight average molecular weight (Mw): 55,200, molecular weight distribution (Mw / Mn): 1.05, hydrogenation rate: almost 100%) alkoxy having 1.8 parts of vinyltrimethoxysilane bonded to 100 parts A modified block copolymer hydride (E1) into which a silyl group was introduced was produced.
In the modified block copolymer hydride (E1), in the same manner as in the method described in the above-mentioned patent document, pentaerythrine which is a phenolic antioxidant is used with respect to 100 parts of the modified block copolymer hydride (E1). 0.1 part of lithyl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] was blended to obtain pellets of a modified block copolymer hydride (E1).

[Example 1] Production of adhesive (F1) After 100 parts of the modified block copolymer hydride (E1) obtained in Production Example 1 were dissolved in 300 parts of toluene (boiling point 110 ° C), 3- One part of glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Silicone) was added and dissolved to prepare an adhesive (F1) solution.

  The adhesive (F1) sheet produced by removing the solvent from the adhesive (F1) solution has a dielectric constant of 2.14 at a frequency of 5 GHz and a dielectric loss tangent of 0.00098, which is a sufficiently low value as a high-frequency insulating material. there were.

The adhesive (F1) solution was applied to the following heat-resistant resin film or metal foil having a length of 300 mm and a width of 300 mm using a bar coater, and the solvent was evaporated and removed at 50 ° C. in an inert oven. A 15 μm adhesive layer was formed.
The heat-resistant resin film used was a polyimide film (product name “Kapton (registered trademark) 200H”, thickness 50 μm, manufactured by Toray DuPont), polyethersulfone film (product name “Sumilite (registered trademark) FS-1300). And a liquid crystal polymer film (product name “BEXTER (registered trademark) CT-Z”, thickness 100 μm, manufactured by Kuraray Co., Ltd.). The metal foil used was aluminum foil (material (JIS H 4160 alloy number): 1N30, thickness 30 μm), copper foil (trade name “FV-WS”, thickness 18 μm, maximum height roughness Rz: 1). 0.5 μm, manufactured by Furukawa Electric Co., Ltd.) and stainless steel foil (material SUS304, thickness 50 μm).

The same kind of two heat resistant resin films or two metal foils coated with the adhesive (F1) were overlapped with the adhesive layer surface facing each other. The obtained laminate was put in a resin bag having a layer configuration of NY / adhesive layer / PP and having a thickness of 75 μm. The center of the opening of the bag is left 200 mm wide, and both sides are heat-sealed with a heat sealer, and then the opening is heated using a sealed pack device (BH-951, manufactured by Panasonic Corporation) while degassing the inside of the bag. The laminate was sealed and sealed.
Then, the sealed package is put in an autoclave and heated and pressurized at a temperature of 150 ° C. and a pressure of 0.8 MPa for 30 minutes to form a heat resistant resin film / adhesive (F1) layer / heat resistant resin film or metal foil / adhesive. A composite joined body comprising (F1) layer / metal foil was produced.

From the obtained composite joined body, a test piece for peel strength measurement was cut out so as to have a size of 15 mm width × 200 mm length to obtain a test piece for peel strength measurement. Using this test piece, the peel strength of the composite joined body was measured to evaluate the adhesiveness between the adhesive (F1) and the heat-resistant resin layer or adhesive (F1) and the metal layer.
As a result, the value of the adhesive strength with respect to each layer and the evaluation thereof are 24 N / cm between the adhesive (F1) / polyimide layer, the evaluation of adhesiveness is good (◯), and the adhesive (F1) / polyethersulfone layer. Is 13 N / cm, the evaluation of adhesion is good (◯), and between the adhesive (F1) / liquid crystal polymer layer is 11 N / cm, and the evaluation of adhesion is good (◯), adhesive (F1) / aluminum It is 14 N / cm between the layers, and the evaluation of adhesiveness is good (◯), and between the adhesive (F1) / copper layers is 18 N / cm, and the evaluation of adhesiveness is good (◯), and the adhesive (F1) / Stainless steel layer was 15 N / cm, and the evaluation of adhesion was good (◯).

The polyimide film coated with the adhesive (F1) and the copper foil coated with the adhesive (F1) are stacked with the adhesive surfaces facing each other, and in the same manner as described above, the polyimide film / adhesive (F1) layer / copper foil. A composite assembly comprising:
When the peel test of this composite joined body was carried out, it peeled at the interface between the copper foil and the adhesive (F1) layer, the peel strength was 18 N / cm, and the adhesiveness was good (◯).
When this composite joined body was held in an oven at 260 ° C. for 60 seconds, there was no significant deformation in appearance, but partial peeling was observed between the polyimide film and the copper foil, and sufficient heat resistance was not necessarily obtained. It was not shown.

[Example 2] Production of adhesive (F2) After 100 parts of the modified block copolymer hydride (E1) obtained in Production Example 1 were dissolved in 300 parts of toluene, 3-methacryloxypropyltrimethoxy was dissolved. Silane (KBM-503, manufactured by Shin-Etsu Silicone) 1 part, triallyl isocyanurate (product name "TAIC (registered trademark)", manufactured by Nippon Kasei Co., Ltd.), 2,5-dimethyl-2,5-di (t -Butylperoxy) hexane (product name "Perhexa (registered trademark) 25B", manufactured by NOF Corporation) (0.2 parts) was added and mixed uniformly to prepare an adhesive (F2) solution.

  The adhesive (F2) sheet prepared by removing the solvent from the adhesive (F2) solution has a dielectric constant of 2.17 at a frequency of 5 GHz and a dielectric loss tangent of 0.00104, which is a sufficiently low value as a high-frequency insulating material. there were.

  In Example 1, a heat resistant resin film was used in the same manner as in Example 1 except that the adhesive (F2) was used in place of the adhesive (F1) and the heating and pressing conditions in the autoclave were set to 160 ° C. A composite assembly comprising: / adhesive (F2) layer / heat-resistant resin film or metal foil / adhesive (F2) layer / metal foil was produced.

Using the obtained composite joined body, the adhesiveness between the adhesive (F2) and the heat-resistant resin layer or adhesive (F2) and the metal layer was evaluated in the same manner as in Example 1.
As a result, the adhesive strength to each layer was 26 N / cm between the adhesive (F2) / polyimide layer, and the evaluation of adhesiveness was good (◯), and 14 N / cm between the adhesive (F2) / polyethersulfone layer. Yes, the evaluation of adhesiveness is good (◯), 15 N / cm between the adhesive (F2) / liquid crystal polymer layer, and the evaluation of adhesiveness is good (◯), 13 N / cm between the adhesive (F2) / aluminum layer The adhesive evaluation is good (◯), and the adhesive (F2) / copper layer is 16 N / cm, the adhesive evaluation is good (◯), and the adhesive (F2) / stainless layer is 14 N. / Cm, and the evaluation of adhesion was good (◯).

  The polyimide film coated with the adhesive (F2) and the copper foil coated with the adhesive (F2) are stacked with the adhesive layer surfaces facing each other, and in the same manner as described above, polyimide film / adhesive (F2) layer / copper foil. A composite assembly comprising: The manufactured composite joined body was further heat-treated at 160 ° C. for 60 minutes in an inert oven.

In the peeling test of the obtained composite joined body, peeling occurred at the interface between the copper foil and the adhesive (F2) layer, the peeling strength was 16 N / cm, and the adhesiveness was good (◯).
Moreover, although this composite joined body was hold | maintained at 260 degreeC for 60 second in oven, the abnormality on the external appearance of a test piece was not recognized, but it was confirmed that the heat resistance of an adhesive agent (F2) is high.

[Example 3] Production of adhesive (F3) After 100 parts of the modified block copolymer hydride (E1) obtained in Production Example 1 were dissolved in 300 parts of cyclohexane (boiling point 80 ° C), N- 1 part of 2- (aminoethyl) -3-aminopropyltrimethoxysilane (KBM-603, manufactured by Shin-Etsu Silicone), 2 parts of triallyl isocyanurate (product name “TAIC (registered trademark)”, manufactured by Nippon Kasei Co., Ltd.), Add 0.2 part of 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (product name “Perhexa (registered trademark) 25B”, manufactured by NOF Corporation), mix uniformly, and bond An agent (F3) solution was prepared.

  The adhesive (F2) sheet produced by removing the solvent from the adhesive (F2) solution has a dielectric constant of 2.19 at a frequency of 5 GHz and a dielectric loss tangent of 0.00110, which is a sufficiently low value as a high-frequency insulating material. there were.

  In Example 2, a heat resistant resin film / adhesive (F3) layer / heat resistant resin film or metal is used in the same manner as in Example 2 except that the adhesive (F3) is used instead of the adhesive (F2). A composite joined body comprising foil / adhesive (F3) layer / metal foil was produced. When a cyclohexane solution of adhesive (F3) is used, it is applied to a heat-resistant resin film or metal foil using a bar coater and dried in an inert oven. The top was bad. However, there was no problem in producing a composite joined body by heating and pressing with an autoclave.

Using the obtained composite joined body, the adhesion between the adhesive (F3) and the heat-resistant resin layer or adhesive (F3) and the metal layer was evaluated in the same manner as in Example 1.
As a result, the adhesive strength with respect to each layer is 25 N / cm between the adhesive (F3) / polyimide layer, the evaluation of adhesiveness is good (◯), 14 N / cm between the adhesive (F3) / polyethersulfone layer, Adhesion evaluation is good (◯), 11N / cm between the adhesive (F3) / liquid crystal polymer layer, and adhesive evaluation is good (◯), 15N / cm between the adhesive (F3) / aluminum layer The adhesive evaluation is good (◯), 20N / cm between the adhesive (F3) / copper layer, the adhesive evaluation is good (◯), and 17N / cm between the adhesive (F3) / stainless layer. And the evaluation of adhesiveness was good (◯).

  The polyimide film coated with the adhesive (F3) and the copper foil coated with the adhesive (F3) are stacked with the adhesive layer surfaces facing each other, and in the same manner as described above, polyimide film / adhesive (F3) layer / copper foil. A composite assembly comprising: The manufactured composite joined body was further heat-treated at 160 ° C. for 60 minutes in an inert oven.

In the peeling test of the obtained composite joined body, peeling occurred at the interface between the copper foil and the adhesive (F3) layer, the peeling strength was 19 N / cm, and the adhesiveness was good (◯).
Moreover, although this composite joined body was hold | maintained at 260 degreeC for 60 second in oven, the abnormality on the external appearance of a test piece was not recognized, but it was confirmed that the heat resistance of an adhesive agent (F3) is high.

The following can be seen from the results of this example.
The adhesive mainly composed of a modified block copolymer hydride (E) having an alkoxysilyl group introduced therein has good adhesion to a heat-resistant resin layer and a metal layer and good electrical characteristics even in a high frequency region (low dielectric constant, (Low dielectric loss tangent) is shown (Examples 1 to 3).
The adhesive mainly composed of the modified block copolymer hydride (E) having an alkoxysilyl group introduced exhibits good adhesion even to a metal surface having a small surface roughness (the copper of Examples 1 to 3). Example of adhesion to foil).
By using an adhesive mainly composed of a modified block copolymer hydride (E) introduced with an alkoxysilyl group, a composite joined body of a heat-resistant resin layer and a metal layer can be produced (Examples 1 to 3). .
An adhesive prepared by blending a modified block copolymer hydride (E) introduced with an alkoxysilyl group with a crosslinking aid has sufficient heat resistance even at a heat treatment of 260 ° C. corresponding to the reflow soldering process (Example) 2, 3).
In the case where an adhesive mainly composed of a modified block copolymer hydride (E) introduced with an alkoxysilyl group is used as a solution, the adhesive is applied to the substrate by using an organic solvent having a boiling point of 90 ° C. or higher. Defects in appearance such as foaming in the coating step are reduced (comparison between Examples 1 and 2 and Example 3).

  The adhesive and composite assembly of the present invention are excellent in adhesion to a heat-resistant resin layer and a metal layer having a small surface roughness, and have a low dielectric constant and excellent electrical insulation, and thus are useful for the production of high-frequency circuit boards. .

Claims (3)

An adhesive used for bonding the heat-resistant resin layer and the metal layer,
At least two polymer blocks (A) mainly comprising a structural unit derived from an aromatic vinyl compound, and at least one polymer block (B) mainly comprising a structural unit derived from a chain conjugated diene compound. The weight fraction of the entire polymer block (A) in the entire block copolymer (C) is wA, and the weight fraction of the entire polymer block (B) in the entire block copolymer (C) is The ratio of wA to wB, wA: wB is 30: 70-60: 40, and the main chain and side chain carbon-carbon unsaturated bonds and aromatic rings of the block copolymer (C) The block copolymer hydride (D) in which 90% or more of carbon-carbon unsaturated bonds are hydrogenated is mainly composed of a modified block copolymer hydride (E) in which an alkoxysilyl group is introduced, and has a boiling point of 90 Do not use organic solvents above ℃ Including to,
An adhesive comprising 100 parts by weight of the modified block copolymer hydride (E) dissolved in 100 to 1000 parts by weight of an organic solvent having a boiling point of 90 ° C. or higher .   The adhesive according to claim 1, wherein the silane coupling agent is blended at a ratio of 0.1 to 10 parts by weight with respect to 100 parts by weight of the modified block copolymer hydride (E). A composite joined body in which a heat-resistant resin layer and a metal layer are bonded with the adhesive according to claim 1 or 2 .