JPH05309785A - Heat-resistant laminate - Google Patents

Abstract

PURPOSE:To enhance adhesiveness and durability, in a laminate wherein metal foil and an aromatic polyamide film are laminated through a heat-resistant adhesive layer, by forming the heat-resistant adhesive layer from a specific curable polyphenylene ether resin compsn. CONSTITUTION:A laminate is obtained by laminating metal foil and an aromatic polyamide film through a heat-resistant adhesive layer. In this case, the heat- resistant adhesive layer is formed from a curable polyphenylene ether resin compsn. consisting of a polyphenylene ether resin (a) having an unsaturated bond and triallylisocyanurate and/or triallylcyanurate (b). In this resin compsn., the component (a) is set to 100-400 pts.wt. and the component (b) is set to 0-60 pts.wt. on the basis of 100 pts.wt. of the sum of the components (a), (b). By this constitution, the laminate is enhanced in adhesiveness and durability and adapted, for example, to a dielectric material in the electronic industry.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a laminate comprising a heat resistant film, a heat resistant adhesive layer, and a metal foil. The laminate of the present invention exhibits excellent heat resistance, chemical resistance, and low dielectric constant, and can be used as an excellent material in the fields of electronic industry, space / aircraft industry and the like. It is particularly suitable as a flexible printed circuit board.

[0002]

2. Description of the Related Art A flexible printed circuit board has a structure in which a copper foil is bonded to one or both sides of a flexible insulating base material with an adhesive. An aromatic polyamide (aramid) film has been recently attracting attention as an insulating base material. The aramid film has excellent heat resistance, mechanical strength, and solvent resistance. However, while the aramid film has excellent releasability with other substances, it has a drawback that it is very difficult to adhere to a metal because of its very poor surface activity, and the conventional treatment methods such as caustic soda, corona discharge, Even if the surface of the film is chemically or mechanically treated by sanding or the like and then adhered with an ordinary adhesive, a sufficient adhesive force as a printed wiring board cannot be obtained.

Further, as a method for adhering the aramid film and the metal foil, there is a method in which a film obtained by applying a film to an adhesive is superposed on the metal foil and then heat-pressed. The main components of the adhesive used here are acrylonitrile-
Since a polymer having low heat resistance such as butadiene, acryl, polyamide, and epoxy is used, the heat resistance of aromatic polyamide is not fully utilized.

[0004]

The problem to be solved by the present invention is to provide a laminate having excellent adhesion and excellent heat resistance, chemical resistance, low dielectric constant and electrical insulation. It is in.

[0005]

As a result of intensive studies to solve the above problems, the present invention has completed a present invention by finding a laminated body in accordance with the object of the present invention. That is, the present invention is a laminate in which a metal foil and an aromatic polyamide film are laminated via a heat-resistant adhesive layer, the adhesive layer being (a) a polyphenylene ether resin having an unsaturated bond group, b) A curable polyphenylene ether resin composition comprising triallyl isocyanurate and / or triallyl cyanurate,
Based on 100 parts by weight of the sum of the components (a) and (b), 100 to 40 parts by weight of the component (a) and 0 of the component (b) are used.
It is a laminated body characterized by using the resin composition for adhesives which consists of -60 parts by weight.

The present invention will be described in detail below. The polyphenylene ether resin having an unsaturated group used as the component (a) of the adhesive layer of the present invention means a carbon-carbon double bond and / or a carbon-carbon triple bond as a side chain with respect to polyphenylene ethers. Refers to those having introduced a functional group containing. An example thereof is a resin comprising a reaction product of a polyphenylene ether resin represented by the following formula (1) and an alkenyl halide and / or alkynyl halide of the formula (2),

[0007]

[Chemical 1]

[0008]

[Chemical 2]

The resin of the formula (3) in which X and / or Y, the following alkenyl group and / or alkynyl group are covalently bonded to the polyphenylene ether resin can be mentioned.

[0010]

[Chemical 3]

Explaining the polyphenylene ether resin of the formula (1), typical examples of Q include the following four kinds of compounds represented by the formula (4).

[0012]

[Chemical 4]

As a concrete example, equations (5), (6),

[0014]

[Chemical 5]

[0015]

[Chemical 6]

Etc. In the polyphenylene ether chain represented by J in the formula (1), among the units or terminal groups described in i) to iv) below, unless heat resistance and thermal stability of the polyphenylene ether resin are decreased, One kind or two or more kinds may be contained.

I) A unit represented by the following formula (7) other than (A) in the formula (1),

[0018]

[Chemical 7]

Ii) a unit represented by the following equation (8),

[0020]

[Chemical 8]

Iii) an end group represented by the following formula (9),

[0022]

[Chemical 9]

Iv) A polymerizable monomer having an unsaturated bond such as styrene or methyl methacrylate with respect to the unit or terminal group of (A) and formulas (7), (8) and (9) of the above formula (1). A unit or terminal group obtained by graft polymerization of. As an example of the unit of formula (7),

[0024]

[Chemical 10]

And the like. As an example of the unit of the formula (8),

[0026]

[Chemical 11]

And the like. Examples of the terminal group of the formula (9) include those of the formula (12).

[0028]

[Chemical formula 12]

And the like. Next, specific examples of the alkenyl halide of the formula (2) will be listed below: allyl chloride, allyl bromide, allyl iodide, 4-bromo-1-butene, trans- and / or cis-1-.
Bromo-2-butene, trans- and / or cis-
1-chloro-2-butene, 1-chloro-2-methyl-2
-Propene, 5-bromo-1-pentene, 4-bromo-
2-methyl-2-butene, 6-bromo-1-hexene,
5-bromo-2-methyl-2-pentene and the like.

Specific examples of the alkynyl halide of the formula (2) include propargyl chloride, propargyl bromide, propargyl iodide and 4-bromo-1.
-Butyne, 4-bromo-2-butyne, 5-bromo-1-
Pentin, 5-bromo-2-pentyne, 1-iodo-2
-Pentin, 1-iodo-3-hexyne, 6-bromo-
1-hexyne and the like.

These alkenyl halides and alkynyl halides can be used alone or in combination of two or more. The unsaturated group-introduced polyphenylene ether resin used in the component (a) of the present invention is
For example, JP-A-64-69628 and JP-A-64-696.
29, JP-A-1-113425, 1-1.
No. 13426, No. 2-232260, and No. 2-
According to the method disclosed in Japanese Patent No. 233759, formula (1)
Can be produced by metallizing the polyphenylene ether resin of (1) with an organic metal, and subsequently subjecting the alkenyl halide of the formula (2) and / or a substitution reaction to the alkenyl halide. The polyphenylene ether resin produced according to this method is composed of at least two or three units represented by the following formula (13).

[0032]

[Chemical 13]

Further, in addition to the above, the unit of the following formula (14) may be included.

[0034]

[Chemical 14]

The content of halogen derived from the above formula (14) is 30 based on the polyphenylene ether resin.
It is in the range of not more than 20% by weight, more preferably 20% by weight
The range is as follows. The unsaturated group-introduced polyphenylene ether resin used in the present invention does not necessarily need to contain halogen. However, particularly when halogen is chlorine or bromine, there is an effect that flame retardancy can be imparted to the curable polyphenylene ether resin composition of the present invention. A preferable halogen content for imparting flame retardancy is 1% by weight or more. However, if it exceeds 30% by weight, the thermal stability of the polyphenylene ether resin itself is deteriorated, which is not preferable.

Preferred examples of the unsaturated group-introduced polyphenylene ether resin obtained by the above method include:
The resin which consists of the reaction product of polyphenylene ether-type resin and allyl bromide, allyl chloride, propargyl bromide, and propargyl chloride described below can be mentioned. Examples of the polyphenylene ether resin include poly (2,6-dimethyl-1,4-phenylene ether) and poly (2,6-dimethyl-1,4-phenylene ether) obtained by homopolymerization of 2,6-dimethylphenol. Polystyrene graft copolymer of 2,6
-Copolymer of dimethylphenol and 2,3,6-trimethylphenol, 2,6-dimethylphenol and 2,6
-Dimethyl-3-phenylphenol copolymer, 2,
6-Dimethylphenol is a polyfunctional phenol compound:
Formula (15),

[0037]

[Chemical 15]

A polyfunctional polyphenylene ether resin obtained by polymerization in the presence of, for example, JP-A-63-3012.
No. 22, a copolymer containing units of the formulas (7) and (8) as disclosed in JP-A-1-297748, for example, as disclosed in Japanese Patent Application No. 1-135763. Examples thereof include a resin containing the unit of formula (7) and the terminal group of formula (9).

Another example of the polyphenylene ether resin containing an unsaturated group used in the curable polyphenylene ether resin composition of the present invention is a resin containing the following repeating unit represented by the formula (16). Can be mentioned.

[0040]

[Chemical 16]

A specific example is US Pat. No. 3,422.
Copolymers of 2-allyl-6-methylphenol and 2,6-dimethylphenol as disclosed in U.S. Pat. No. 062,2,6-Diallyl-4- as disclosed in U.S. Pat. No. 3,281,393. Bromophenol and 2,6-
Copolymer of dimethyl-4-bromophenol, Japanese Patent Publication No. 6
2,6-as disclosed in Japanese Patent Publication No. 3-47733
A copolymer of diprenylphenol and 2,6-dimethylphenol, a copolymer of 2,6-bis (2-butenyl) phenol and 2,6-dimethylphenol, and a copolymer of 2,6-dicinnamylphenol and 2, Copolymer of 6-dimethylphenol, homopolymer of 2-prenyl-6-methylphenol as disclosed in JP-A-58-27719, and also 2-prenyl-6-methylphenol and 2,6 -Copolymer of dimethylphenol, homopolymer of 2- (2-butenyl) -6-methylphenol, copolymer of 2- (2-butenyl) -6-methylphenol and 2,6-dimethylphenol , A homopolymer of 2-cinnamyl-6-methylphenol, a homopolymer of 2-cinnamyl-6-methylphenol and 2,6-dimethylphenol. A copolymer of Knoll and the like.

A resin obtained by converting the methyl group at the 2,6-position of poly (2,6-dimethyl-1,4-phenylene ether) disclosed in US Pat. No. 4,634,742 into a vinyl group, also poly ( A resin obtained by introducing a vinyl group into the 3,5-position of the phenyl group of (2,6-dimethyl-1,4-phenylene ether) is also a preferable example of the polyphenylene ether resin containing an unsaturated group used in the present invention. Is one.

The range of the unsaturated group content of the polyphenylene ether resin containing an unsaturated group used in the present invention is 0.1 mol% or more and 100 mol% or less, more preferably 0. 5 mol% or more and 50 mol%
The following are preferred:

[0044]

[Equation 1]

When the content of the unsaturated group is less than 0.1 mol%, the chemical resistance after curing is insufficiently improved, which is not preferable. On the contrary, if it exceeds 100 mol%, it becomes very brittle after curing, which is not preferable. Regarding the molecular weight of the unsaturated group-introduced polyphenylene ether resin used in the present invention, the viscosity number ηsp / c measured with a chloroform solution at 30 ° C. and 0.5 g / dl is 0.1 to 1.
Those in the range of 0 can be used favorably.

The triallyl isocyanurate and / or triallyl cyanurate used as the component (b) of the curable polyphenylene ether resin composition of the present invention are trifunctional compounds represented by the following formula (17). It is a monomer.

[0047]

[Chemical 17]

In carrying out the present invention, triallyl isocyanurate and triallyl cyanurate can be used not only individually but also as a mixture of both at an arbitrary ratio. In the present invention, triallyl isocyanurate and triallyl cyanurate exert their effects as a plasticizer and a crosslinking agent. That is, the flow of molten resin at the time of pressing and the crosslink density are improved.

The mixing ratio of the above raw materials is 100 to 60 parts by weight of the component (a) and 0 to 40 parts by weight of the component (b) based on 100 parts by weight of the sum of the components (a) and (b). It is a department. If the amount of the component (b) exceeds 40 parts by weight, the film formability is deteriorated and, at the same time, the dielectric properties, flame retardancy and moisture absorption properties are deteriorated, and after curing, it becomes a very brittle material, which is not preferable.

As a method for mixing the above-mentioned components (a) and (b), a mixing method in which both of them are uniformly dissolved or dispersed in a solvent, or a melt blending method in which they are heated by an extruder or the like can be used. As the solvent used as the mixed solvent, halogen-based solvents such as dichloromethane, chloroform and trichloroethylene, benzene, toluene,
Aromatic solvents such as xylene or tetrahydrofuran are used alone or in combination of two or more.

The method for producing a film made of the resin composition of the present invention is not particularly limited, but a usual solvent film-forming method (casting method) or the like can be used, and a film having a thickness of 0.1 to 1000 μm can be produced. The above-mentioned adhesive layer is cured by causing a crosslinking reaction by means such as heating as described later, but it should be used by containing a radical initiator for the purpose of lowering the temperature at that time or promoting the crosslinking reaction. You can

As the radical initiator, a usual peroxide can be used. The adhesive layer, in addition to the above radical initiator, may be used by blending an amount of a filler or an additive in a range that does not impair the original properties for the purpose of imparting desired performance depending on the application. it can. The filler may be in the form of fiber or powder, glass fiber, aramid fiber, carbon fiber, boron fiber, ceramic fiber, asbestos fiber, carbon black, silica, alumina, talc,
Examples thereof include mica, glass beads and glass hollow spheres. As additives, antioxidants, plasticizers, pigments,
Examples include dyes and colorants. For the purpose of further improving flame retardancy, chlorine-based, bromine-based, phosphorus-based flame retardants,
Sb ₂ O ₃ , Sb ₂ O ₅ , NaSbO ₃ · 1 / 4H ₂ O
It is also possible to use a flame retardant auxiliary such as Furthermore, it is also possible to blend one or more thermoplastic resins or other thermosetting resins.

The adhesive may be preliminarily formed into a film and used as a film-shaped adhesive, or the adhesive resin composition may be dissolved in a solvent and applied as a varnish to an adherend. The adhesive resin composition powder can also be used by pressure bonding. The method of forming the adhesive into a film is not particularly limited, but a solvent film forming method (casting method) or the like can be used, and an adhesive having an arbitrary thickness can be manufactured.

Examples of the metal foil used in the present invention include aluminum foil and copper foil, and usually copper foil is often used. The copper foil may be either electrolytic copper foil or rolled copper foil. These metal foils may be surface-treated in order to improve the adhesion. The method of surface treatment is not particularly limited, and any method such as sand blasting, honing, chemical treatment method, plasma treatment method and the like may be used.

As the aromatic polyamide film used in the present invention, a meta-oriented aromatic polyamide film or a para-oriented polyamide film is used. Particularly preferably, para-oriented aromatic polyamide is used from the viewpoint of mechanical strength and heat resistance. The para-oriented aromatic polyamide is substantially composed of a group selected from the group consisting of the following structural units represented by formula (18).

[0056]

[Chemical 18]

In the present invention, Ar1, Ar2 and Ar3 must each be a so-called linearly oriented group in order to ensure good heat resistance. Here, the linear orientation means that the bond for growing the molecular chain is located coaxially or parallel to the opposite direction of the aromatic.
Specific examples of such a divalent aromatic group include paraphenylene, 4,4′-biphenylene, 1,4-naphthylene,
Examples include 1,5-naphthylene and 2,5-pyridylene. They may be substituted with one or two or more inactive groups such as halogen, lower alkyl, nitro, methoxy and cyano groups.

A special divalent aromatic group is a divalent group of the formula (19).

[0059]

[Chemical 19]

Specific examples of X include the following formula (20).

[0061]

[Chemical 20]

Ar1, Ar2 and Ar3 of the formula (18)
May be two or more, and may be the same as each other. The aromatic polyamide film used in the present invention can be produced from a diamine, a dicarboxylic acid or an aminocarboxylic acid corresponding to each unit by a method known so far. Specifically, a method in which a carboxylic acid group is first derived into an acid halide, an acid imidazole, an ester or the like, and then a method of reacting with an amino group is used, and the method of polymerization is also a so-called low temperature solution polymerization method,
An interfacial polymerization method, a melt polymerization method, a solid phase polymerization method or the like can be used.

The aromatic polyamide used in the present invention may be copolymerized with a group other than those mentioned above, or may be blended with another polymer. Specific examples of the group used for the copolymerization include 3,3′-diaminodiphenyl ether, 3,4-diaminodiphenyl ether, 3,
3'-diamino-4,4 'dichlorodiphenyl, etc. are mentioned.

The method for forming the aromatic polyamide film used in the present invention is not particularly limited, but wet film formation,
A commonly used method such as dry film formation is used.
The method for laminating the laminate of the present invention is not particularly limited, but the metal foil and the aramid film are superposed via an adhesive layer,
It is preferable to perform thermocompression bonding under the conditions of 80 to 300 ° C., 1 to 100 kg / cm ² , and 1 minute to 5 hours.

[0065]

EXAMPLES Hereinafter, the present invention will be described with reference to examples in order to further clarify the present invention, but the scope of the present invention is not limited to these examples.

[0066]

Reference Example 1 Synthesis of Polyphenylene Ether Resin Containing Unsaturated Group; Average Substitution Rate 14%, ηsp / c = 0.62 (30 ° C., 0.
An allyl group-substituted polyphenylene ether (abbreviated as A-PPE) of 5 g / dl, chloroform solution) was used.
Ηs according to the known method disclosed in Japanese Patent Publication No. 69629.
It was synthesized from poly (2,6-dimethyl-1,4-phenylene ether) with p / c = 0.56.

[0067]

Reference Example 2 Synthesis of Polyphenylene Ether Resin Containing Unsaturated Group; Average Substitution Rate 5%, ηsp / c = 0.40 (30 ° C., 0.5
g / dl, chloroform solution) of a propargyl group-substituted polyphenylene ether (abbreviated as Pr-PPE)
According to the known method disclosed in Japanese Patent Publication No. 4-69629, poly (2,6-dimethyl-1, with ηsp / c = 0.56,
4-phenylene ether).

[0068]

Examples 1 to 6 Polyphenylene ether containing an unsaturated group, triallyl isocyanurate and an initiator were dissolved in trichloroethylene in the respective compositions shown in Table 1. This solution was poured onto a glass plate to form a film. The obtained film had a thickness of 30 μm. The film forming properties were all good.

The film was dried in an air oven. A copper foil having a thickness of 35 μm was superposed on one surface of the obtained film, and an aramid film was superposed on the other surface, and they were thermocompression bonded at 200 ° C. for 30 minutes. Various properties of the thus obtained laminate were measured, and as shown in Table 1, good results were obtained.

[0070]

Example 7 Polyphenylene ether containing an unsaturated group, triallyl isocyanurate, and a composition similar to Example 1
The initiator was dissolved in chloroform with the composition shown in Table 1.
Add this to an aramid film with a thickness of 50 μm and a thickness of 20 μm.
And was dried in an air oven. After drying, a copper foil having a thickness of 35 μm was thermocompression-bonded to the coated surface by a roll method to prepare a laminate.

The physical properties of the laminate thus obtained were measured, and as shown in Table 1, good results were obtained.

[0072]

Comparative Examples 1 and 2 Example 1 using a commercially available adhesive for producing a flexible printed circuit board containing bisphenol A epoxy resin as a main component and a commercially available adhesive for producing a flexible printed circuit board containing acrylonitrile-butadiene as a main component A laminated body was produced by the same operation as that of ~ 6. When the solder heat resistance of this laminate was examined, swelling and warpage were observed.

[0073]

[Table 1]

[0074]

The laminate of the present invention is a material having heat resistance, chemical resistance, adhesiveness, electrical insulation, low dielectric constant and good mechanical properties. Therefore, the laminate of the present invention can be used as a dielectric material, an insulating material, a heat-resistant material, etc. in the fields of electric industry, electronic industry, space / aircraft industry and the like. Particularly, it is preferably used as a single-sided, double-sided, or multilayer flexible printed circuit board.

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Claims (1)

[Claims] 1. A laminate in which a metal foil and an aromatic polyamide film are laminated via a heat-resistant adhesive layer, the heat-resistant adhesive layer being (a) a polyphenylene ether resin having an unsaturated bond group, b) A curable polyphenylene ether resin composition comprising triallyl isocyanurate and / or triallyl cyanurate, wherein (a) is based on 100 parts by weight of the sum of the components (a) and (b).
A laminate comprising a resin composition for a heat-resistant adhesive, which comprises 100 to 40 parts by weight of a component and 0 to 60 parts by weight of a component (b).