JP2023180373A - Copper-clad laminate and circuit board including the same - Google Patents

Abstract

To provide a laminate that comprises a low-roughness copper foil and a resin layer composed of a polyarylene sulfide resin with superior adhesion, laminated through an adhesion layer, and achieves reduction in transmission loss, and a circuit board including the same.SOLUTION: The foregoing problem is solved by laminating a low-roughness copper foil and a resin layer through an adhesion layer, wherein the resin layer is primarily composed of a polyarylene sulfide resin (A) and comprises a fluorine-based resin (B) and a thermoplastic resin (C) that is different from the fluorine-based resin (B) and has a glass transition temperature of 140°C or higher or a melting point of 230°C or higher.SELECTED DRAWING: None

Description

The present invention relates to a laminate in which copper foil, an adhesive layer, and a resin layer having low dielectric properties and excellent adhesiveness mainly composed of polyarylene sulfide resin are laminated, and a circuit board using the same.

In recent years, in electronic devices such as personal computers and mobile terminals, the frequency of electrical signals has been increasing as communication speeds and capacities have increased, and printed wiring boards compatible with this have been required. In particular, the higher the frequency of an electrical signal, the greater the loss and attenuation of signal power, and a printed wiring board that can reduce signal power loss (transmission loss) is required. Transmission loss includes conductor loss on the copper foil side and dielectric loss on the board side. Conductor loss has a skin effect in the high frequency range, and since signals have the characteristic of flowing on the surface of the conductor, it is preferable that the surface roughness of the copper foil used as the conductor is reduced. On the other hand, for dielectric loss, the resin base material preferably has low dielectric properties, and a film made of liquid crystal polymer (LCP) or the like is used. However, since the LCP film has poor adhesion to low-roughness copper foil, it is necessary to roughen the surface of the copper foil, which has the disadvantage of worsening transmission loss.

On the other hand, polyarylene sulfide resins such as polyphenylene sulfide resins (PPS) have excellent heat resistance, flame retardancy, chemical resistance, electrical insulation properties, and low dielectric properties, so they are used in the field of printed wiring boards. can be applied. However, polyarylene sulfide resins generally have a problem in that they have low adhesion and adhesion to metals and other resins, and they also have poor reactivity with adhesives. To improve this, for example, Patent Document 1 describes that a layer made of a polyarylene sulfide resin having a melting point of 275° C. or less is laminated on at least one side of a metal plate by thermal lamination. ing.
However, Patent Document 1 discloses a laminate in which a layer made of a copolymerized polyarylene sulfide resin with a low melting point and a metal plate are directly laminated, and the polyarylene sulfide resin layer is made of a copolymerized polyarylene sulfide resin. Multi-layering or lamination of co-extrusion layers is required, resulting in poor productivity and problems of deteriorating the heat resistance of the laminate.

JP2020-6678A

Therefore, the present invention provides a laminate that can reduce transmission loss by laminating a low-roughness copper foil and a resin layer made of polyarylene sulfide resin with excellent adhesive properties via an adhesive layer, and a circuit board using the same. It is about providing.

As a result of a sincere study, the present inventors found that a fluorine-containing resin (B) containing a low-roughness copper foil and a polyarylene sulfide resin (A) as the main components, a glass transition temperature of 140°C or higher, or a melting point of It has been discovered that the above problem can be solved by laminating a resin layer made of a thermoplastic resin (C) other than the fluorine-containing resin (B) at 230°C or higher via an adhesive layer, and the present invention has been completed. reached.

That is, the present invention relates to the following (1) to (16).

(1) A laminate in which at least a copper foil, an adhesive layer, and a resin layer containing polyarylene sulfide resin (A) as a main component are laminated in this order,
In the copper foil, the surface roughness (Rz) of the copper foil on the side on which the adhesive layer is laminated is 2.0 μm or less and the thickness is 1 μm to 50 μm,
The resin layer contains a polyarylene sulfide resin (A) as the main components, a fluorine-containing resin (B), and a resin other than the fluorine-containing resin (B) having a glass transition temperature of 140°C or higher or a melting point of 230°C or higher. A laminate comprising a resin layer containing a thermoplastic resin (C), having a continuous phase and a dispersed phase, and having a dielectric constant of 3.5 or less and a dielectric loss tangent of 0.005 or less.
(2) The fluorine-containing resin (B) is a fluorine-containing resin having at least one functional group selected from the group consisting of a carbonyl group-containing group, a hydroxyl group, an epoxy group, and an isocyanate group (1) The laminate described in .
(3) The average dispersion diameter of the fluorine-containing resin (B) as the dispersed phase and the thermoplastic resin (C) other than the fluorine-containing resin (B) having a glass transition temperature of 140°C or higher or a melting point of 230°C or higher is 5 μm. The laminate according to any one of (1) to (2), which is preferably as follows.
(4) The proportion of the fluorine-containing resin (B) is based on 100% by mass of the total amount of the polyarylene sulfide resin (A), the fluorine-containing resin (B), and the thermoplastic resin (C). , 3 is preferably in the range of 49% by mass, and the laminate according to any one of (1) to (3).
(5) The thermoplastic resin (C) other than the fluorine-containing resin is preferably a polyphenylene ether resin, a polycarbonate resin, a polyether sulfone resin, a polyphenylene sulfone resin, a polyetherimide resin, a polysulfone resin, or a liquid crystal resin, (1 ) to (4).
(6) The proportion of the thermoplastic resin (C) other than the fluorine-containing resin having a glass transition temperature of 140°C or higher or a melting point of 230°C or higher is polyarylene sulfide resin (A), fluorine-containing resin (B), The amount is preferably 1 to 40% by mass based on 100% by mass of the total amount of the thermoplastic resin (C) other than the fluorine-containing resin, and the laminate according to any one of (1) to (5). .
(7) It is preferable that the dielectric constant of the laminate consisting of the adhesive layer and the resin layer at a frequency of 5 GHz is 3.5 or less, and the dielectric loss tangent is 0.03 or less, and any of (1) to (6) The laminate according to any one of the above.
(8) The laminate according to any one of (1) to (7), which preferably further contains a modified elastomer (D) provided with a reactive group.
(9) The laminate according to (8), wherein the modified elastomer (D) is preferably made of an olefin polymer having at least one functional group selected from the group consisting of an epoxy group and an acid anhydride group.
(10) The blending ratio of the modified elastomer (D) is the polyarylene sulfide resin (A), the fluorine-containing resin (B), the thermoplastic resin other than the fluorine-containing resin (C), and the modified elastomer (D). ) is preferably in the range of 1 to 15% by mass based on the total of 100% by mass, and the laminate according to (8) or (9).
(11) The α-olefin content of the modified elastomer (D) is preferably 50 to 95% by mass based on the total mass of the modified elastomer, and any one of (8) to (10) The laminate described in .
(12) Furthermore, it is preferable that the silane coupling agent (E) containing at least one functional group selected from an epoxy group, an amino group, and an isocyanate group contains 0.01 to 5% by mass, and (1 ) to (11).
(13) The laminate according to any one of (1) to (12), wherein the resin layer is a biaxially stretched film.
(14) The laminate according to any one of (1) to (13), wherein the adhesive layer preferably has a thickness of 30 μm or less.
(15) The laminate according to any one of (1) to (14), wherein the adhesive layer preferably has a dielectric constant of 3.5 or less and a dielectric loss tangent of 0.01 or less at a frequency of 5 GHz.
(16) A circuit board using the laminate according to any one of items (1) to (15) above.
(17) A high-frequency circuit board using the laminate according to any one of items (1) to (15) above.
It provides:

According to the present invention, polyarylene sulfide resin (A), fluorine-containing resin (B), thermoplastic resin other than fluorine-containing resin (B) having a glass transition temperature of 140°C or higher or a melting point of 230°C or higher ( Copper-clad laminates and prints that use a resin composition consisting of C) improve adhesion with adhesives, enable lamination with low-roughness copper foil, and reduce transmission loss in high frequency bands. Wiring boards can be provided.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated in detail.

[Resin layer]
The resin composition constituting the resin layer has a polyarylene sulfide resin (hereinafter sometimes referred to as "PAS resin") as a main component, a fluorine-containing resin, and a glass transition temperature of 140°C or higher or a melting point of 230°C. The raw material is a thermoplastic resin other than fluorine-containing resin with a temperature of ℃ or higher. In this case, the resin composition has a continuous phase and a dispersed phase, the continuous phase includes a polyarylene sulfide resin, and the dispersed phase includes a fluorine-containing resin and a glass transition temperature of 140°C or higher, or Contains thermoplastic resins other than fluorine-containing resins with a melting point of 230°C or higher.

The resin layer of the present invention preferably has a dielectric constant of 3.5 or less and a dielectric loss tangent of 0.005 or less at a frequency of 5 GHz. Furthermore, a dielectric constant of 3.3 or less and a dielectric loss tangent of 0.004 or less are more preferable. If the dielectric constant is 3.5 or less and the dielectric loss tangent is 0.005 or less, it can be suitably used for FPC-related products with strict electrical characteristics requirements. In addition, if the dielectric constant and dielectric loss tangent are within the above ranges, the layer structure and layer ratio of the resin layer/adhesive layer should be such that the dielectric constant and dielectric loss tangent after laminating the adhesive layer are 3.5 or less and the dielectric loss tangent 0.03 or less. Transmission loss can be suppressed in a laminate made by laminating copper foil with low roughness, and it can be suitably used in FPC-related products for high frequency applications.

The average dispersed diameter of the dispersed phase is 5 μm or less, preferably 0.5 μm or more and 5 μm or less, and more preferably 0.5 μm or more and 3 μm or less. When the average dispersed diameter of the dispersed phase is 5 μm or less, the mechanical properties of the resin layer can be maintained and a resin layer with excellent adhesiveness to metal can be obtained. In addition, in the present invention specification, the value measured by the method described in the Examples shall be adopted as the "average dispersion diameter of the dispersed phase".

[Polyarylene sulfide resin (A)]
The polyarylene sulfide resin (A) (PAS resin (A)) is the main component of the resin composition, and is basically contained in the continuous phase of the resin composition.
The PAS resin (A) is a polymer containing a structure in which an aromatic ring and a sulfur atom are bonded (specifically, a structure represented by the following formula (1)) as a repeating unit.

上記式中、Ｒ^１は、それぞれ独立して、水素原子、炭素原子数１～４のアルキル基、ニトロ基、アミノ基、フェニル基、メトキシ基、エトキシ基を表し、ｎは、それぞれ独立して、１～４の整数である。

In the above formula, R ¹ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a nitro group, an amino group, a phenyl group, a methoxy group, or an ethoxy group; , an integer from 1 to 4.

Here, R ¹ in the structure represented by formula (1) is preferably a hydrogen atom. With this configuration, the mechanical strength of the PAS resin (A) can be further increased. A structure represented by the formula (1) in which R ¹ is a hydrogen atom is a structure represented by the following formula (2) (i.e., a structure in which a sulfur atom is bonded to the aromatic ring at the para position) , and a structure represented by the following formula (3) (that is, a structure in which a sulfur atom is bonded to an aromatic ring at a meta position).

これらの中でも、式（１）で表される構造は、式（２）で表される構造であることが好ましい。式（２）で表される構造を有するＰＡＳ系樹脂（Ａ）であれば、耐熱性や結晶性をより向上させることができる。

Among these, the structure represented by formula (1) is preferably the structure represented by formula (2). PAS resin (A) having the structure represented by formula (2) can further improve heat resistance and crystallinity.

Furthermore, the PAS resin (A) may contain not only the structure represented by the above formula (1) but also structures represented by the following formulas (4) to (7) as repeating units.

The structures represented by formulas (4) to (7) are preferably contained in an amount of 30 mol% or less, more preferably 10 mol% or less in all repeating units constituting the PAS resin (A). . With this configuration, the heat resistance and mechanical strength of the PAS resin (A) can be further improved.
Further, the bonding mode of the structures represented by formulas (4) to (7) may be either random or block.

Further, the PAS resin (A) may include a trifunctional structure represented by the following formula (8), a naphthyl sulfide structure, etc. as a repeating unit in its molecular structure.

The structure represented by formula (8), the naphthyl sulfide structure, etc. are preferably contained in the total repeating units constituting the PAS resin (A) in an amount of 1 mol% or less, and are not substantially contained. More preferred. With this configuration, the content of chlorine atoms in the PAS resin (A) can be reduced.
Further, the properties of the PAS resin (A) are not particularly limited as long as they do not impair the effects of the present invention, but the melt viscosity (V6) at 300°C is preferably 100 to 2000 Pa·s, and It is more preferably 120 to 1600 Pa·s because it provides a good balance between properties and mechanical strength.

Furthermore, PAS resin (A) has a peak in the molecular weight range of 25,000 to 40,000 when measured using gel permeation chromatography (GPC), and has a weight average molecular weight (Mw) and a number average molecular weight ( It is particularly preferable that the ratio (Mw/Mn) to Mn) is in the range of 5 to 10 and the non-Newtonian index is in the range of 0.9 to 1.3. By using such a PAS resin (A), the content of chlorine atoms in the PAS resin (A) itself can be reduced to a range of 700 to 2,000 ppm without reducing the mechanical strength of the insulating film 4. , it can be easily applied to halogen-free electronic and electrical component applications.

In this specification, values measured by gel permeation chromatography (GPC) are used for weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw/Mn), respectively. Note that the measurement conditions for GPC are as follows.
[Measurement conditions by gel permeation chromatography]
Equipment: Ultra-high temperature polymer molecular weight distribution measuring device (SSC-7000 manufactured by Senshu Kagaku Co., Ltd.)
Column: UT-805L (manufactured by Showa Denko)
Column temperature: 210℃
Solvent: 1-chloronaphthalene Measurement method: Calibration of 6 types of monodisperse polystyrene using UV detector (360 nm)
to measure the molecular weight distribution and peak molecular weight.

The method for producing the PAS resin (A) is not particularly limited, but includes, for example, 1) a dihalogeno aromatic compound, and if necessary a polyhalogeno aromatic compound or other copolymer component, in the presence of sulfur and sodium carbonate; In addition, a method of polymerization, 2) a method of polymerizing a dihalogeno aromatic compound in the presence of a sulfidating agent, etc. in a polar solvent, and adding a polyhalogeno aromatic compound or other copolymerization component if necessary, 3. ) A method of self-condensing p-chlorothiophenol by adding other copolymerization components if necessary, and the like. Among these manufacturing methods, method 2) above is preferred because it is versatile.
In addition, during the reaction, an alkali metal salt of carboxylic acid or sulfonic acid, or an alkali hydroxide may be added in order to adjust the degree of polymerization.

Among the methods 2) above, the following methods 2-1) or 2-2) are particularly preferred.
In method 2-1), a hydrous sulfidating agent is introduced into a heated mixture containing an organic polar solvent and a dihalogeno aromatic compound at a rate that allows water to be removed from the reaction mixture, and the dihalogeno aromatic compound is dissolved in the organic polar solvent. When the group compound and the sulfidating agent are added and reacted with the polyhalogeno aromatic compound as necessary, the amount of water in the reaction system is adjusted to 0.02 to 0.5 mol per mol of the organic polar solvent. PAS resin (A) is produced by controlling the amount within the range (see JP-A-07-228699).
In method 2-2), in the presence of a solid alkali metal sulfide and an aprotic polar organic solvent, a dihalogeno aromatic compound and, if necessary, a polyhalogeno aromatic compound or other copolymer components are added, and the alkali metal When reacting hydrosulfide and an organic acid alkali metal salt, the amount of the organic acid alkali metal salt should be controlled within the range of 0.01 to 0.9 mol per 1 mol of the sulfur source, and the amount within the reaction system should be controlled. The PAS resin (A) is produced by controlling the water content in the range of 0.02 mol or less per 1 mol of the aprotic polar organic solvent (see WO2010/058713 pamphlet).

Specific examples of dihalogeno aromatic compounds include p-dihalobenzene, m-dihalobenzene, o-dihalobenzene, 2,5-dihalotoluene, 1,4-dihalonaphthalene, 1-methoxy-2,5-dihalobenzene, 4,4' -dihalobiphenyl, 3,5-dihalobenzoic acid, 2,4-dihalobenzoic acid, 2,5-dihalonitrobenzene, 2,4-dihalonitrobenzene, 2,4-dihaloanisole, p,p'- Dihalodiphenyl ether, 4,4'-dihalobenzophenone, 4,4'-dihalodiphenylsulfone, 4,4'-dihalodiphenylsulfoxide, 4,4'-dihalodiphenylsulfide, and aromatic rings of each of the above compounds Examples include compounds having an alkyl group having 1 to 18 carbon atoms.
In addition, examples of polyhalogeno aromatic compounds include 1,2,3-trihalobenzene, 1,2,4-trihalobenzene, 1,3,5-trihalobenzene, 1,2,3,5-tetrahalobenzene, 1, Examples include 2,4,5-tetrahalobenzene and 1,4,6-trihalonaphthalene.
Note that the halogen atom contained in the above compound is preferably a chlorine atom or a bromine atom.

A known and commonly used method is used for post-treatment of the reaction mixture containing the PAS resin (A) obtained in the polymerization step. Such post-processing methods are not particularly limited, but include, for example, the following methods (1) to (5).
In method (1), after the polymerization reaction is completed, the reaction mixture is used as it is, or after adding an acid or a base, the solvent is distilled off under reduced pressure or normal pressure, and then the solid after the solvent distillation is mixed with water, It is washed once or twice or more with a reaction solvent (or an organic solvent having an equivalent solubility for the low-molecular polymer), acetone, methyl ethyl ketone, alcohols, etc., and then neutralized, washed with water, filtered, and dried.
In method (2), after the polymerization reaction is completed, the reaction mixture is mixed with a solvent such as water, acetone, methyl ethyl ketone, alcohols, ethers, halogenated hydrocarbons, aromatic hydrocarbons, aliphatic hydrocarbons (depending on the polymerization solvent used). A solvent that is soluble and at least a poor solvent for the PAS resin (A) is added as a precipitant to precipitate solid products such as the PAS resin (A) and inorganic salts, These are separated by filtration, washed and dried.

In method (3), after the polymerization reaction is completed, a reaction solvent (or an organic solvent having an equivalent solubility for low-molecular-weight polymers) is added to the reaction mixture, stirred, and then filtered to remove low-molecular-weight polymers. Afterwards, it is washed once or twice or more with a solvent such as water, acetone, methyl ethyl ketone, alcohol, etc., and then neutralized, washed with water, filtered, and dried.
In method (4), after the polymerization reaction is completed, water is added to the reaction mixture, followed by water washing, filtration, and if necessary, an acid is added during the water washing for acid treatment, followed by drying.
In method (5), after the completion of the polymerization reaction, the reaction mixture is filtered, washed once or twice or more with a reaction solvent, if necessary, and further washed with water, filtered, and dried.

Examples of acids that can be used in the method (4) above include saturated fatty acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, and monochloroacetic acid; unsaturated fatty acids such as acrylic acid, crotonic acid, and oleic acid. Fatty acids, aromatic carboxylic acids such as benzoic acid, phthalic acid, and salicylic acid, dicarboxylic acids such as maleic acid and fumaric acid, organic acids such as sulfonic acids such as methanesulfonic acid and para-toluenesulfonic acid, hydrochloric acid, sulfuric acid, sulfurous acid, and nitric acid. , nitrous acid, phosphoric acid, and other inorganic acids.
Examples of hydrogen salts include sodium hydrogen sulfide, disodium hydrogen phosphate, and sodium hydrogen carbonate. However, when used in actual equipment, organic acids are preferred because they are less corrosive to metal members.
In addition, in the methods (1) to (5) above, the PAS resin (A) may be dried in a vacuum, in the air, or in an inert gas atmosphere such as nitrogen. .

In particular, the PAS resin (A) post-treated by the method (4) above has a glass transition temperature of 140°C or higher due to an increase in the amount of acid groups bonded to its molecular terminals. , or when mixed with a thermoplastic resin (C) other than a fluorine-containing resin with a melting point of 230°C or higher, a modified elastomer (D), or a silane coupling agent (E), it reacts with those components and has the effect of increasing dispersibility. is obtained. The acid group is particularly preferably a carboxyl group.
The content of the PAS resin (A) in the resin composition may be 51 to 95% by mass, but preferably 55 to 90% by mass. When the content of the PAS resin (A) is within the above range, the heat resistance and chemical resistance of the resin layer can be further improved. In the present invention, the term "main component" means that the specific resin is contained in an amount of 50% by mass or more based on the total mass of the resin components used to form the base resin layer. Preferably, the content is 55% by mass or more.

[Fluorine-containing resin (B)]
The structure of the fluorine-containing resin (B) is not particularly limited, but it is composed of at least one type of fluoroolefin unit. For example, tetrafluoroethylene polymers, copolymers with perfluoro(alkyl vinyl ether), hexafluoropropylene, vinylidene fluoride, vinyl fluoride, trifluoroethylene, and chlorotrifluoroethylene, as well as ethylene, propylene, and butene. Copolymers with non-fluorine ethylene monomers containing no fluorine, such as alkyl vinyl ethers, may also be mentioned. Specifically, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene- Examples include hexafluoropropylene copolymer, polyvinylidene fluoride, and polychlorotrifluoroethylene. Among these, ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer, and tetrafluoroethylene-hexafluoropropylene copolymer are preferred from the viewpoint of easy melt extrudability.

Among the fluorine-containing resins (B), fluorine-containing resins (B) having functional groups are preferred. The fluorine-containing resin (B) having a functional group has at least one reactive functional group selected from the group consisting of a carbonyl group-containing group, a hydroxy group, an epoxy group, and an isocyanate group. Two or more types of these reactive functional groups may be included. Among these, carbonyl group-containing groups are preferred from the viewpoint of excellent compatibility and reactivity with the PAS resin (A). Examples of the carbonyl group-containing group include a group having a carbonyl group between carbon atoms of a hydrocarbon group, a carbonate group, a carboxy group, a haloformyl group, an alkoxycarbonyl group, an acid anhydride group, a polyfluoroalkoxycarbonyl group, and the like.

As a method for introducing a reactive functional group into the fluorine-containing resin (B) having a functional group, (1) when producing the main chain of the fluorine-containing resin having a functional group in a polymerization reaction, the reactive functional group A monomer having the following is used. (2) A fluorine-containing resin (B) having a functional group is produced by a polymerization reaction using a chain transfer agent that generates a radical having a reactive functional group. (3) A fluorine-containing resin (B) having a functional group is produced by a polymerization reaction using a polymerization initiator that generates a radical having a reactive functional group. (4) Examples include methods of modifying fluororesin by methods such as oxidation and thermal decomposition. (5) A method of blending a compound or resin that is compatible with the fluororesin and contains the above-mentioned functional group can be mentioned.

Examples of the reactive functional group-containing monomer include a monomer having a carbonyl group-containing group, an epoxy group-containing monomer, a hydroxy group-containing monomer, an isocyanate group-containing monomer, and the like.

Examples of monomers having a carboxyl group-containing group include unsaturated dicarboxylic acids (maleic acid, itaconic acid, citraconic acid, crotonic acid, hemic acid, 5-norbornene-2,3-dicarboxylic acid, maleic acid), Saturated dicarboxylic acid anhydrides, unsaturated monocarboxylic acids (acrylic acid, methacrylic acid), vinyl esters (vinyl acetate, vinyl chloroacetate, vinyl butanoate, vinyl pivalate, vinyl benzoate, vinyl crotonate), and the like.

Examples of the hydroxy group-containing monomer include hydroxy group-containing vinyl ester, hydroxy group-containing vinyl ether, hydroxy-containing allyl ether, hydroxy-containing (meth)acrylate, hydroxyethyl crotonate, allyl alcohol, and the like.

Examples of the epoxy group-containing monomer include unsaturated glycidyl ethers (allyl glycidyl ether, 2-methylallyl glycidyl ether, vinyl glycidyl ether, etc.) and unsaturated glycidyl esters (glycidyl acrylate, glycidyl methacrylate, etc.).

Isocyanate group-containing monomers include 2-(meth)acryloyloxyethyl isocyanate, 2-(2-(meth)acryloyloxyethoxy)ethyl isocyanate, 1,1-bis((meth)acryloyloxymethyl)ethyl isocyanate, etc. can be mentioned.

The amount of reactive functional groups contained in the fluorine-containing resin (B) having a functional group is preferably 0.01 to 3 mol% of the total units constituting the fluorine-containing resin (B) having a functional group. , more preferably 0.03 to 2 mol%, and even more preferably 0.05 to 1 mol%. When the amount of reactive functional groups is within the above range, compatibility and reactivity with the PAS resin are excellent, and deterioration of fluidity can be suppressed.

The melting point of the fluorine-containing resin (B) used in the present invention is not particularly limited, but is 170°C to 330°C, preferably 180°C to 320°C, and more preferably 190°C to 310°C. When the melting point of the fluorine-containing resin (B) is within the above range, heat resistance can be maintained and good melt extrusion stability can be obtained.

The glass transition temperature of the fluorine-containing resin (B) used in the present invention is not particularly limited, but is 120°C or lower, more preferably 110°C or lower. If the fluorine-containing resin (B) has the above-mentioned glass transition temperature, in the stretching process after mixing with the PAS resin (A), at the stretching temperature of the PAS resin (A) of the present invention, the fluorine-containing resin (B) Since the dispersed phase of the resin (B) is also stretched, peeling at the interface between the PAS resin (A) as the continuous phase and the fluorine-containing resin (B) as the dispersed phase can be suppressed. Thereby, breakage during stretching can be suppressed, and furthermore, a film having excellent mechanical properties can be obtained.

The content of the fluorine-containing resin (B) in the resin composition may be 3 to 49% by mass, but preferably 5 to 40% by mass. When the content of the fluorine-containing resin (B) is within the above range, the effect of improving the dielectric properties (lowering the dielectric constant) of the film is more markedly exhibited.

In the present invention, it is also possible to use a fluorine-containing resin containing a reactive functional group together with a fluorine-containing resin having no reactive functional group.

[Thermoplastic resin (C) other than fluorine-containing resin (B)]
The thermoplastic resin (C) other than the fluorine-containing resin (B) of the present invention (hereinafter sometimes referred to as "thermoplastic resin (C)") has a glass transition temperature of 140°C or higher or a melting point of 230°C or higher. Any thermoplastic resin containing no fluorine atoms in its molecules may be used. If the thermoplastic resin (C) has a glass transition temperature of 140°C or higher or a melting point of 230°C or higher, it is possible to suppress a significant decrease in the heat resistance of PPS resin and enhance the modification effect of corona treatment and plasma treatment. Therefore, when laminating the resin layer obtained from the resin composition of the present invention and the copper foil, a laminate with higher adhesion can be obtained via the adhesive. Furthermore, since the layer is laminated using an adhesive, it is possible to layer it with copper foil having a low roughness, thereby suppressing conductor loss.

The thermoplastic resin (C) other than the fluorine-containing resin (B) may be any thermoplastic resin having a glass transition temperature of 140°C or higher or a melting point of 230°C or higher, such as polycarbonate, polyphenylene ether, polyether salt, etc. Various polymers such as phon, polyphenylene sulfone, polyetherimide, polysulfone, liquid crystal resin, and blends containing at least one of these polymers can be used. Among these, polyphenylene ether resins are preferred from the viewpoint of low dielectric properties, miscibility with PAS resins, and low hygroscopicity.

The content of the thermoplastic resin (C) in the resin composition constituting the resin layer may be 1 to 40% by mass, but preferably 3 to 40% by mass. When the content of the thermoplastic resin (C) is within the above range, the physical properties of the laminate can be maintained and the adhesiveness with the adhesive can be improved.

Polyphenylene ether resin (hereinafter sometimes referred to as "PPE resin") is a component that also provides the resin layer with the function of providing a low dielectric constant and low dielectric loss tangent.
The PPE resin is a polymer containing a structure represented by the following formula (9) as a repeating unit.

In the above formula, R ² is each independently a hydrogen atom, a halogen atom, a primary alkyl group having 1 to 7 carbon atoms, a secondary alkyl group having 1 to 7 carbon atoms, a phenyl group, a haloalkyl group, an amino an alkyl group, a hydrocarbonoxy group, a halohydrocarbonoxy group in which at least two carbon atoms separate a halogen atom and an oxygen atom, and m is each independently an integer from 1 to 4.

Specific examples of PPE resins include poly(2,6-dimethyl-1,4-phenylene ether), poly(2-methyl-6-ethyl-1,4-phenylene ether), and poly(2-methyl-6-phenylene ether). -phenyl-1,4-phenylene ether), poly(2,6-dichloro-1,4-phenylene ether), 2,6-dimethylphenol and other phenols (e.g. 2,3 , 6-trimethylphenol and 2-methyl-6-butylphenol).
Among these, PPE resins include poly(2,6-dimethyl-1,4-phenylene ether) and a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol. Preferably, poly(2,6-dimethyl-1,4-phenylene ether) is more preferable.

The number average molecular weight of the PPE resin is preferably 1,000 or more, more preferably 1,500 to 50,000, and even more preferably 1,500 to 30,000.

[Modified elastomer (D)]
The modified elastomer (D) is, in principle, contained in the dispersed phase of the resin composition constituting the resin layer. The modified elastomer (D) has a reactive group capable of reacting with at least one of the PAS resin (A), the fluorine-containing resin (B), and the thermoplastic resin (C). The adhesiveness of the interface between the resin (A), the fluorine-containing resin (B), and the thermoplastic resin (C) is further improved, and the mechanical strength (tensile properties, bending strength, etc.) of the laminate is further improved. It is a component that provides functionality.
The reactive group possessed by the modified elastomer (D) is preferably at least one selected from the group consisting of an epoxy group and an acid anhydride group, and more preferably an epoxy group. These reactive groups can rapidly react with functional groups at the molecular terminals of the PAS resin (A), fluorine-containing resin (B), and thermoplastic resin (C).

Such a modified elastomer (D) includes a copolymer containing a repeating unit based on an α-olefin and a repeating unit based on a vinyl polymerizable compound having the above-mentioned functional group, a repeating unit based on an α-olefin, and a repeating unit containing the above-mentioned functional group. A copolymer containing a repeating unit based on a vinyl polymerizable compound having the following and a repeating unit based on an acrylic ester can be mentioned.

Examples of the α-olefin include α-olefins having 2 to 8 carbon atoms such as ethylene, propylene, and butene-1.
In addition, vinyl polymerizable compounds having functional groups include α,β-unsaturated carboxylic acids and their esters such as acrylic acid, methacrylic acid, acrylic esters, and methacrylic esters, maleic acid, fumaric acid, itaconic acid, and others. Examples include unsaturated dicarboxylic acids having 4 to 10 carbon atoms, their mono- or diesters, their acid anhydrides, α,β-unsaturated dicarboxylic acids, their esters and their acid anhydrides, α,β-unsaturated glycidyl esters, etc. It will be done.

Examples of the α,β-unsaturated glycidyl ester include, but are not particularly limited to, compounds represented by the following formula (10).

In the above formula, R ³ is an alkenyl group having 1 to 6 carbon atoms.
Examples of the alkenyl group having 1 to 6 carbon atoms include vinyl group, 1-propenyl group, 2-propenyl group, 1-methylethenyl group, 1-butenyl group, 2-butenyl group, 1-methyl-1-propenyl group, 1- Methyl-2-propenyl group, 2-methyl-1-propenyl group, 2-methyl-2-propenyl group, 1-pentenyl group, 2-pentenyl group, 3-pentenyl group, 4-pentenyl group, 1-methyl-1- Examples include pentenyl group, 1-methyl-3-pentenyl group, 1,1-dimethyl-1-butenyl group, 1-hexenyl group, and 3-hexenyl group.

Each R ⁴ is independently a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of alkyl groups having 1 to 6 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, 2-methylbutyl group, 3-methylbutyl group. group, 2,2-dimethylpropyl group, hexyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 2,2-dimethylbutyl group, 2,3-dimethyl Examples include butyl group, 2,4-dimethylbutyl group, 3,3-dimethylbutyl group, and 2-ethylbutyl group.

Specific examples of α,β-unsaturated glycidyl esters include glycidyl acrylate, glycidyl methacrylate, and the like, with glycidyl methacrylate being preferred.
The proportion of α-olefin-based repeating units in the modified elastomer (D) is preferably 50 to 95% by mass, more preferably 50 to 80% by mass. When the proportion of repeating units based on α-olefin is within the above range, the stretching uniformity, bending strength, and adhesive strength with the adhesive layer of the film serving as the resin layer can be improved.
Further, the proportion of repeating units based on a vinyl polymerizable compound having a functional group in the modified elastomer (D) is preferably 1 to 30% by mass, more preferably 2 to 20% by mass. If the proportion of the repeating unit based on the vinyl polymerizable compound having a functional group is within the above range, not only the desired improvement effect but also good extrusion stability can be obtained.

The content of the modified elastomer (D) in the resin composition constituting the resin layer is preferably 1 to 15% by mass, more preferably 2 to 10% by mass. If the content of the modified elastomer (D) is within the above range, the effect of improving the folding strength, adhesive strength, etc. of the laminate will be significantly exhibited.

[Silane coupling agent (E)]
In the present invention, the compatibility and interaction between the PAS resin (A) and other components (fluorine-containing resin (B), thermoplastic resin other than fluorine-containing resin (C), and modified elastomer (D)) It is preferable to use a silane coupling agent as a component having the function of increasing the PAS resin (A), and the dispersibility of other components in the PAS resin (A) can be dramatically improved and a good morphology can be formed.

The silane coupling agent (E) is preferably a compound having a functional group that can react with a carboxyl group. Such a silane coupling agent reacts with other components to firmly bond with them. As a result, the effect of the silane coupling agent is more significantly exhibited, and the dispersibility of other components in the PAS resin (A) can be particularly improved.
Examples of such silane coupling agents include compounds having an epoxy group, an isocyanate group, an amino group, or a hydroxyl group.

Specific examples of the silane coupling agent include epoxy group-containing alkoxysilane such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. Silane compound, γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-isocyanatopropylmethyldimethoxysilane, γ-isocyanatopropylmethyldiethoxysilane, γ-isocyanatopropylethyldimethoxysilane, γ - Isocyanato group-containing alkoxysilane compounds such as isocyanatopropylethyldiethoxysilane, γ-isocyanatopropyltrichlorosilane, γ-(2-aminoethyl)aminopropylmethyldimethoxysilane, γ-(2-aminoethyl)aminopropyltrichlorosilane, etc. Examples include amino group-containing alkoxysilane compounds such as methoxysilane and γ-aminopropyltrimethoxysilane, and hydroxyl group-containing alkoxysilane compounds such as γ-hydroxypropyltrimethoxysilane and γ-hydroxypropyltriethoxysilane.

The content of the silane coupling agent in the resin composition constituting the resin layer is preferably 0.01 to 5% by mass, more preferably 0.01 to 3% by mass. When the content of the silane coupling agent is within the above range, the effect of improving the dispersibility of other components in the PAS resin (A) is significantly exhibited.

[Styrenic resin]
The resin composition constituting the resin layer may contain a styrene resin. In principle, the styrenic resin is contained in the dispersed phase of the resin composition. Note that the styrene resin has particularly high compatibility with the polyphenylene ether resin, and therefore may be included in a form that is compatible with the polyphenylene ether resin or in a form similar to this. The styrene resin has a function of improving fluidity during melting. In addition, in this specification, "styrenic resin" means a resin whose main monomer unit is a styrene monomer.

The styrene resin is not particularly limited, but includes polymers of styrene monomers. Styrenic monomers include, but are not particularly limited to, styrene and derivatives thereof. Examples of styrene derivatives include alkylstyrenes such as methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, and octylstyrene; fluorostyrene, chlorostyrene, and bromostyrene. , dibromostyrene, iodostyrene, and other halogenated styrenes; nitrostyrene; acetylstyrene; methoxystyrene; and the like. These styrene monomers may be used alone or in combination of two or more.

The styrene resin may be a homopolymer of styrene monomers, or a copolymer obtained by copolymerizing two or more types of styrene monomers. For example, a copolymer of an unsaturated monomer having a glycidyl group and/or an oxazoline group and a monomer whose main component is styrene, a block copolymer obtained by copolymerizing a styrene monomer and a conjugated diene compound, and this block copolymer. Examples include hydrogenated block copolymers obtained by further hydrogenating the polymer. Furthermore, rubber-modified styrene (high-impact styrene) may be used using a rubber component such as polybutadiene, styrene-butadiene copolymer, polyisoprene, butadiene-isoprene copolymer, or the like.

In addition, the above-mentioned styrene resins may be used alone or in combination of two or more types.

[Copper foil]
Examples of the copper foil include rolled copper foil, electrolytic copper foil, and the like. The thickness of the copper foil is preferably 1 μm or more and 50 μm or less, and more preferably 1 μm or more and 30 μm or less. Further, the copper foil may be subjected to various surface treatments (roughening, rust prevention treatment, etc.). Examples of the rust prevention treatment include plating treatment containing Ni, Zn, Sn, etc., and mirror finishing treatment such as chromate treatment.

In order for a circuit board using a copper-clad laminate obtained by the present invention to exhibit good high-frequency characteristics, the surface roughness of the copper foil on the side in contact with the adhesive layer is preferably low. The surface roughness Rz of the copper foil on the side in contact with the adhesive layer is preferably 2 μm or less, more preferably 1.5 μm or less, and even more preferably no roughening.

[Adhesive layer]
The adhesive layer is not particularly limited as long as it is composed of a resin component that can bond the copper foil and the polyarylene sulfide resin composition layer, but it must contain a thermosetting resin as a main component. is preferred. Further, in addition to the thermosetting resin, additives such as a curing agent, a curing accelerator, a flexible component, an inorganic filler, and a flame retardant may be included as necessary.

Compounds used in the adhesive layer include adhesives typified by epoxy compounds, isocyanate compounds, acrylic compounds, and urethane compounds; single substances or mixtures of various resins such as olefins, polyesters, polyamides, and polyimides; Compounds, modified products, etc. can be used, and it does not matter if it is a solution type or a film type.

As the thermosetting resin, one or a combination of two or more known thermosetting resins can be used. In particular, epoxy compounds are preferably used from the viewpoint of heat resistance. The epoxy compound may contain at least two epoxy groups in its molecule, such as bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol AD epoxy resin, resorcinol epoxy resin, etc. resin, hydroquinone type epoxy resin, catechol type epoxy resin, hydroxynaphthalene type epoxy resin, biphenyl type epoxy resin, tetramethylbiphenyl type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, etc.

In addition, as curing agents, amine compounds such as dicyandiamide, diaminodiphenylmethane, diaminodiphenyl sulfide, diaminobenzophenone, diaminodiphenylsulfone, diethyltriamine, 2-alkyl-4-methylimidazole, 2-phenyl-4- Imidazole derivatives such as alkylimidazole, 2-phenyl-4-alkylimidazole, 1-cyanoethyl-2-methylimidazole, 1,8-diazabicyclo[5,4,0]undecene, 7,1,4-diazabicyclo[2,2 , 2] DBU compounds such as octane, phosphorus compounds such as triphenylphosphine and triethylphosphine, aromatic compounds such as benzyldimethylamine, 2-(dimethylamino)phenol, and 2,4,6-tris(diaminomethyl)phenol. Tertiary amines, alicyclic tertiary amines such as dimethylcyclohexylamine, organic acids such as phthalic anhydride, trimellitic anhydride, pyromellitic acid, boron trifluoride triethylamine complex, boron trifluoride piperazine complex, etc. Boron trifluoride amine complexes, boron trifluoride amine complexes, phosphorus pentafluoride, arsenic pentafluoride, antimony pentafluoride, boron tetrafluoride amine complexes, boron trifluoride piperazine complexes, etc. Examples include amine complexes, amine complexes of boron trichloride, phosphorous pentafluoride, arsenic pentafluoride, antimony pentafluoride, boron tetrafluoride amine salts, metal borofluorides such as zinc borofluoride, etc. You may use a mixture of more than one species. In addition, phenolic resins such as resol type and novolak type phenolic resins may be used. Examples of phenolic resins include alkyl-substituted phenols such as phenol, biphenol, and cresol, terpenes, cyclic alkyl-modified phenols such as dicyclopentadiene, nitro group, Examples include those having a functional group containing a hetero atom such as an amino group, and those having a skeleton such as naphthalene and anthracene.

Further, a curing accelerator, a flexible component, an inorganic filler, and a flame retardant can be added together with the above-mentioned thermosetting resin as necessary.

Known materials can be used as the flexible component. For example, various synthetic rubbers such as acrylic rubber, acrylonitrile butadiene rubber, carboxyl-containing acrylonitrile butadiene rubber, rubber-modified high molecular weight compounds, modified polyimides, modified polyamideimides, polyurethane resins, polyester resins, polyurethane polyester resins, polyvinyl butyral resins, polyvinyl acetate resins, etc. Acetal resin, phenoxy resin, etc. can be used. These components may be used alone or in combination of two or more.

As the inorganic filler, known ones can be used. Examples include silica, alumina, silicon nitride, aluminum hydroxide, magnesium hydroxide, talc, and clay. These fillers can be used alone or in combination of two or more.

As the flame retardant, known ones can be used. Examples include phosphorus atom-containing compounds, nitrogen atom-containing compounds, and inorganic flame retardant compounds. Specifically, phosphoric acid esters such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, tricylenyl phosphate, and ammonium polyphosphate. , phosphorus atom-containing compounds such as polyphosphoric acid amide, red phosphorus, guanidine phosphate, condensed phosphoric acid ester compounds such as dialkyl hydroxymethyl phosphonate, nitrogen atom-containing compounds such as melamine, aluminum hydroxide, magnesium hydroxide, zinc borate, Examples include inorganic flame retardant compounds such as calcium borate. These components can be used alone or in combination of two or more.

As a method for applying the adhesive layer, for example, gravure coating, die coating, knife coating, etc., and as a method for laminating a film-like adhesive layer such as a bonding sheet, a well-known method such as thermal lamination can be applied. .

The thickness of the adhesive layer after curing is preferably 0.5 μm or more and 50 μm or less, more preferably 1 μm or more and 40 μm or less, and even more preferably 1 μm or more and 30 μm or less. When the adhesive layer thickness is within the above range, adhesiveness between members can be ensured. If it exceeds 50 μm, the dielectric properties of the adhesive layer components will be affected and transmission loss may become large, which is not preferable.

The adhesive layer after curing preferably has a dielectric constant of 3.5 or less and a dielectric loss tangent of 0.01 or less at a frequency of 5 GHz. Furthermore, a dielectric constant of 3.5 or less and a dielectric loss tangent of 0.007 or less are more preferable. If the dielectric constant is 3.5 or less and the dielectric loss tangent is 0.01 or less, it can be suitably used for FPC-related products with strict electrical characteristics requirements.

[Additives for resin layer]
The resin composition may contain plasticizers, weathering agents, antioxidants, heat stabilizers, ultraviolet stabilizers, lubricants, antistatic agents, colorants, conductive agents, flame retardants, etc., as long as they do not impede the effects of the present invention. May contain.

The method for producing the composition of the resin layer is not particularly limited, but includes PAS resin (A) and other components (fluorine-containing resin (B), thermoplastic resin other than fluorine-containing resin (C)), A method of uniformly mixing other components (modified elastomer (D), silane coupling agent (E), etc.) with a tumbler or Henschel mixer, etc. as necessary, and then introducing the mixture into a twin-screw extruder for melt-kneading. This melt kneading may be kneading in a shear flow field, kneading in an extensional flow field, or both.
In this melt-kneading, the ratio between the discharge amount (kg/hr) of the kneaded material and the screw rotation speed (rpm) (discharge amount/screw rotation speed) is 0.02 to 0.2 (kg/hr・rpm). It is preferable to carry out under the following conditions.

More specifically, it is preferable to put each component into a twin-screw extruder and melt-knead it under temperature conditions of a set temperature of 300°C and a resin temperature of about 330°C in a strand die. At this time, the discharge rate of the kneaded material is in the range of 5 to 50 kg/hr at a rotation speed of 250 rpm. Particularly from the viewpoint of improving the dispersibility of each component, the discharge rate of the kneaded material is preferably 20 to 35 kg/hr at a rotational speed of 250 rpm. Therefore, the ratio between the discharge amount (kg/hr) of the kneaded material and the screw rotation speed (rpm) (discharge amount/screw rotation speed) is 0.08 to 0.14 (kg/hr・rpm). More preferred.

[Film mainly composed of PAS resin (A)]
One of the forms of the resin layer of the present invention is a film obtained from a composition containing the above-mentioned PAS resin (A) as a main component, and among them, a biaxially stretched film is preferable. The heat resistance of the resin layer can be improved by laminating molecularly oriented biaxially stretched films.
In one embodiment of such a film, particles containing a PAS resin (A) as a matrix (continuous phase), and a fluorine-containing resin (B) and a thermoplastic resin other than the fluorine-containing resin (C) in this matrix. (dispersed phase) is dispersed.
In addition, the modified elastomer (D) is applied to the surface of the particles of the fluorine-containing resin (B) or the thermoplastic resin (C) (i.e., the interface between the matrix and the particles), the fluorine-containing resin (B) or the thermoplastic resin (C). ) or as separate particles (dispersed phase) from the particles of the fluorine-containing resin (B) or thermoplastic resin (C).

In addition, the present inventors have discovered that the modified elastomer (D) also functions as a compatibilizer for the PAS resin (A), the fluorine-containing resin (B), and the thermoplastic resin (C), thereby improving particle By being finely dispersed in the matrix, it is possible to suppress the tearing of the film during stretching, improve the mechanical strength (folding strength, etc.) of the biaxially stretched film, and improve the mechanical strength of the laminate. This is expected to improve. Furthermore, the present inventors have found that the use of a silane coupling agent in combination with the modified elastomer (D) further improves the adhesion at the interface between the matrix and the particles through the modified elastomer (D), thereby increasing the mechanical strength of the biaxially stretched film and the laminate. We also believe that this will further improve (folding strength, etc.).

The average particle diameter (average dispersion diameter) of the particles (dispersed phase) dispersed in the matrix in a film state is preferably 5 μm or less, more preferably 0.5 μm or more and 5 μm or less, and 0.5 μm or more. More preferably, it is 3 μm or less. If the average particle diameter of the particles is within the above range, the mechanical properties of the film and resin layer will be maintained and the adhesion to the adhesive will be good.

The film is preferably a biaxially stretched film obtained by biaxially stretching an unstretched sheet obtained from the composition of the resin layer. Biaxial stretching can improve the mechanical properties and heat resistance of the resin layer.

The biaxially stretched film should have at least one layer made of the resin layer composition of the present invention as the outermost layer, and layers made of other resin compositions may be laminated directly or via an adhesive layer or the like. A biaxially stretched laminated film may also be used.

The method for producing the biaxially stretched laminated film used in the present invention is not particularly limited, but for example, in the case of a laminated structure, the resin or resin mixture used for each resin layer is heated and melted in separate extruders, and the Examples include a coextrusion method in which the materials are laminated in a desired laminated configuration in a molten state by a method such as an extrusion lamination die method or a feed block method, and then formed into a sheet shape by an inflation method, a T-die/chill roll method, or the like. This coextrusion method is preferable because it allows the ratio of the thickness of each layer to be adjusted relatively freely and provides an unstretched laminated sheet with excellent cost performance.

Next, in the case of biaxial stretching, the unstretched sheet and unstretched laminated sheet obtained above are biaxially stretched.
As the stretching method, a sequential biaxial stretching method, a simultaneous biaxial stretching method, or a combination thereof can be used.
When biaxially stretching is performed by the sequential biaxial stretching method, for example, the obtained unstretched sheet is heated with a group of heating rolls, and the width is increased by 1.5 to 4 times (preferably 2 to 3 times) in the longitudinal direction (MD direction). .8 times) in one or more stages, and then cooled with a group of cooling rolls at 30 to 60°C.
The stretching temperature is preferably from the glass transition temperature (Tg) of the PAS resin (A) to Tg+40°C, more preferably from Tg+5°C to Tg+30°C, and even more preferably from Tg+5°C to Tg+20°C. preferable.

Next, it is stretched in the width direction (TD direction) by a method using a tenter. Both ends of the film stretched in the MD direction are held with clips and guided into a tenter, where it is stretched in the TD direction.
Note that the stretching ratio is preferably 1.5 to 4 times, more preferably 2 to 3.8 times.
Further, the stretching temperature is preferably from the glass transition temperature (Tg) of the PAS resin (A) to Tg+40°C, more preferably from Tg+5°C to Tg+30°C, and even more preferably from Tg+5°C to Tg+20°C. preferable.

Next, this stretched film is heat set under tension or while relaxing in the width direction.
The heat setting temperature is not particularly limited, but is preferably 200 to 280°C, more preferably 220 to 280°C, and even more preferably 240 to 275°C. Note that heat setting may be performed in two stages by changing the heat setting temperature. In this case, it is preferable that the second stage heat setting temperature is +10 to 40°C higher than the first stage heat setting temperature. A stretched film heat-set at a heat-setting temperature within this range has improved heat resistance and mechanical strength.
Further, the heat setting time is preferably 1 to 60 seconds.

Further, this film is cooled in a temperature zone of 50 to 275° C. while relaxing in the width direction. The relaxation rate is preferably 0.5 to 10%, more preferably 2 to 8%, even more preferably 3 to 7%.

The thickness of the biaxially stretched film or the biaxially stretched laminated film (hereinafter both biaxially stretched films may be referred to as "stretched film") is not particularly limited, but is preferably 10 to 300 μm. , more preferably from 10 to 200 μm, even more preferably from 10 to 150 μm. With a stretched film having such a thickness, a resin layer with sufficient mechanical strength and insulation properties can be obtained.

It is preferable to subject the stretched film of the present invention to a surface treatment in order to improve the adhesiveness between the stretched film and the copper foil or adhesive layer. Such surface treatments include corona discharge treatment (including corona treatment under various gas atmospheres), plasma treatment (including plasma treatment under various gas atmospheres), oxidation treatment using chemicals, ultraviolet rays, electron irradiation, etc. can be mentioned. Among these, plasma treatment is preferred.

[Laminated body]
According to the present invention, there is provided a laminate in which the above-mentioned stretched film and a copper foil are laminated on at least one outermost resin layer surface of the stretched film via an adhesive layer.

The laminate of the present invention can be produced, for example, by the following procedure. First, a resin solution for forming an adhesive layer is applied to the surface of a stretched film and dried, or a film made of an adhesive is heat laminated to form a film with an uncured adhesive layer formed on the surface of the stretched film. Create.

Next, the adhesive layer side of the film and the copper foil are bonded together. Although known methods can be used for bonding, a method of laminating using rolls is preferred. After bonding, heat treatment is performed to harden the uncured adhesive layer.

In one embodiment, the laminate includes copper foil-adhesive layer-stretched film, copper foil-adhesive layer-stretched film-adhesive layer-copper foil, copper foil-adhesive layer-stretched film-adhesive layer-copper foil-adhesive layer- It may have a structure such as a stretched film.

Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.
1. Production of resin composition and biaxially stretched film [Example 1]
MA520 (linear type PPS, manufactured by DIC Corporation, melting point 280°C, melt viscosity (V6) 160 Pa s at 300°C), which is a polyphenylene sulfide resin (hereinafter sometimes referred to as "PPS resin"), 74.5% by mass and 15% by mass of EA-2000 (PFA type, manufactured by AGC Corporation, Tg 94°C), which is a fluorine-containing resin having a functional group (hereinafter sometimes referred to as "fluorine-containing resin"), and polyphenylene ether. 10% by mass of PX100F (manufactured by Mitsubishi Engineering Plastics Co., Ltd., glass transition temperature 210°C), which is a resin (hereinafter sometimes referred to as "PPE resin"), and epoxysilane KBM403, which is 3-glycidoxypropyltriethoxysilane. (manufactured by Shin-Etsu Chemical) and 0.5% by mass were uniformly mixed in a tumbler to obtain a mixture.

Note that the polyphenylene sulfide resin has a carboxyl group at the end of its molecule.
Hereinafter, 3-glycidoxypropyltriethoxysilane will be referred to as a "silane coupling agent."

Next, the mixture obtained above was put into a vented twin-screw extruder (manufactured by Japan Steel Works, Ltd., "TEX-30α"). After that, it was melt-extruded under conditions such as a discharge rate of 20 kg/hr, a screw rotation speed of 300 rpm, a cylinder set temperature of 310 °C, and a resin temperature of about 300 °C in the strand die, and was discharged in the form of a strand, and after cooling with water at a temperature of 30 °C. , and cutting to produce a resin composition.

Next, this resin composition was dried at 140°C for 3 hours, and then put into a full-flight screw single-screw extruder and melted at 280-310°C. After extruding the molten resin composition from a T-die, it was closely cooled with a chill roll set at 40°C to produce an unstretched sheet.
Next, the produced unstretched sheet was biaxially stretched to 3.0×3.0 times at 100°C using a batch type biaxial stretching machine (manufactured by Imoto Seisakusho Co., Ltd.), resulting in a film with a thickness of 50 μm. I got it. Furthermore, the obtained film was fixed to a mold and heat-set in an oven at 275°C to produce a biaxially stretched film.

The side of the obtained biaxially stretched film in contact with the adhesive layer was subjected to corona treatment, and the applicator was adjusted so that the thickness of the adhesive layer was 8 μm on the treated side, and modified epoxy adhesive AS60 (Toagosei Co., Ltd. ) was coated and dried to obtain a semi-cured biaxially stretched film with an adhesive layer.

The obtained biaxially stretched film with an adhesive layer and rolled copper foil (thickness 12 μm, Rz 1.2 μm) were directly stacked and pressed with a heat press machine at 150° C./3 MPa for 15 seconds, and after press bonding, Curing was performed at 150° C. for 30 minutes to produce a copper-clad laminate.

The average particle size of the particles in the produced base film was measured as follows.
Specifically, the produced biaxially stretched film was cut using an ultra-thin section method in (a) a direction parallel to the longitudinal direction and perpendicular to the film surface, and (b) a direction parallel to the width direction and perpendicular to the film surface. . The cut surfaces (A) and (B) of the cut film were each photographed using a scanning electron microscope (SEM) at a magnification of 2000 times, and the resulting images were enlarged to A3 size. Select any 50 dispersed phases in the enlarged SEM photograph, measure the maximum diameter of each dispersed phase on the fracture surfaces (A) and (B), and combine the two directions of the cut surfaces (A) and (B). The average diameter was calculated.
As a result, the average particle size of the particles in the biaxially stretched film was 1.0 μm.

Further, a cut surface of the biaxially stretched film obtained above was analyzed by SEM-EDS to analyze the components constituting the matrix and particles. As a result, it was found that the component constituting the matrix was PPS, and the components constituting the particles were a fluorine-containing resin and a PPE resin.

[Example 2]
A resin composition, a biaxially stretched film, and a copper-clad laminate were prepared in the same manner as in Example 1, except that AH-2000 (ETFE type, Tg 75°C, manufactured by AGC Corporation) was used as the fluororesin having a functional group. Manufactured.
In addition, when the average particle diameter of the particles in the biaxially stretched film was measured by the same method as in Example 1, it was found to be 1.3 μm.
Further, as a result of analyzing the constituent components of the base film in the same manner as in Example 1, it was found that particles of fluorine-containing resin and PPE resin were dispersed in the PPS matrix.

[Example 3]
PPS resin (A) (MA520) 79.5% by mass, thermoplastic resin (C) other than fluorine-containing resin, polycarbonate resin (manufactured by Mitsubishi Engineering Plastics Chemical Co., Ltd., glass transition temperature 145 ° C., hereinafter referred to as "PC") A resin composition, a biaxially stretched film, and a copper-clad laminate were produced in the same manner as in Example 1, except that 5% by mass of 5% by mass.
In addition, when the average particle diameter of the particles in the biaxially stretched film was measured by the same method as in Example 1, it was found to be 1.2 μm.
Further, as a result of analyzing the constituent components of the base film in the same manner as in Example 1, it was found that particles of fluorine-containing resin and PC resin were dispersed in the PPS matrix.

[Example 4]
Example 1 except that polyethersulfone resin (manufactured by BASF Corporation, glass transition temperature 225°C, hereinafter sometimes referred to as "PES") was used as the thermoplastic resin (C) other than the fluorine-containing resin. In the same manner as above, a resin composition, a biaxially stretched film, and a copper-clad laminate were produced.
In addition, when the average particle diameter of the particles in the biaxially stretched film was measured by the same method as in Example 1, it was found to be 1.3 μm.
In addition, as a result of analyzing the constituent components of the base film using the same method as in Example 1, it was found that particles of fluorine-containing resin and PES resin were dispersed in the PPS matrix.

[Example 5]
Example 1 except that polyphenylene sulfone resin (manufactured by BASF Corporation, glass transition temperature 220°C, hereinafter sometimes referred to as "PPSU") was used as the thermoplastic resin (C) other than the fluorine-containing resin. Similarly, a resin composition, a biaxially stretched film, and a copper-clad laminate were produced.
In addition, when the average particle diameter of the particles in the biaxially stretched film was measured by the same method as in Example 1, it was found to be 1.1 μm.
In addition, as a result of analyzing the constituent components of the base film using the same method as in Example 1, it was found that particles of fluorine-containing resin and PPSU resin were dispersed in the PPS matrix.

[Example 6]
PPS resin (A) (MA520) 79.5% by mass, thermoplastic resin (C) other than fluorine-containing resin, polyetherimide resin (manufactured by SABIC Corporation, glass transition temperature 216 ° C., hereinafter referred to as "PEI") A resin composition, a biaxially stretched film, and a copper-clad laminate were produced in the same manner as in Example 1, except that the amount of 5% by mass was 5% by mass.
In addition, when the average particle diameter of the particles in the biaxially stretched film was measured by the same method as in Example 1, it was 1.4 μm.
Furthermore, as a result of analyzing the constituent components of the base film in the same manner as in Example 1, it was found that particles of fluorine-containing resin and PEI resin were dispersed in the PPS matrix.

[Example 7]
Example 1 was carried out in the same manner as in Example 1, except that polysulfone resin (manufactured by SOLVAY Co., Ltd., glass transition temperature 190°C, hereinafter sometimes referred to as "PSU") was used as the thermoplastic resin (C) other than the fluorine-containing resin. A resin composition, a biaxially stretched film, and a copper-clad laminate were produced.
In addition, when the average particle diameter of the particles in the biaxially stretched film was measured by the same method as in Example 1, it was found to be 1.3 μm.
Furthermore, as a result of analyzing the constituent components of the base film in the same manner as in Example 1, it was found that particles of fluorine-containing resin and PSU resin were dispersed in the PPS matrix.

[Example 8]
PPS resin (A) 71.5% by mass of MA520, fluorine-containing resin (B) 15% by mass of EA-2000, PPE resin (C) 10% by mass, modified elastomer having a reactive group (D) with Bondfast 7L. (Manufactured by Sumitomo Chemical Co., Ltd., ethylene/glycidyl methacrylate/methyl acrylate = 70/3/27 (mass%), hereinafter sometimes referred to as "BF7L".) 3% by mass, 3-glycidoxypropyltriethoxysilane 0 A resin composition, a biaxially stretched film, and a copper-clad laminate were produced in the same manner as in Example 1, except that the content was .5% by mass.
In addition, when the average particle diameter of the particles in the biaxially stretched film was measured by the same method as in Example 1, it was 0.7 μm.
Further, as a result of analyzing the constituent components of the base film in the same manner as in Example 1, it was found that particles of a fluorine-containing resin, a PPE resin, and a modified elastomer were dispersed in the PPS matrix.

[Example 9]
A resin composition, a biaxially stretched film, and a copper-clad laminate were produced in the same manner as in Example 1, except that the copper foil was changed to a non-roughened copper foil (thickness: 12 μm, Rz: 0.8 μm).

[Example 10]
The resin was prepared in the same manner as in Example 1, except that epoxy silane KBM403 was not added, PPS resin MA520 was 75% by mass, fluorine-containing resin EA-2000 was 15% by mass, and PPE resin PX100F was 10% by mass. A composition, a biaxially oriented film, and a copper-clad laminate were produced.
In addition, when the average particle diameter of the particles in the biaxially stretched film was measured by the same method as in Example 1, it was found to be 1.6 μm.
Further, as a result of analyzing the constituent components of the base film in the same manner as in Example 1, it was found that particles of fluorine-containing resin and PPE resin were dispersed in the PPS matrix.

[Comparative example 1]
A resin composition, a biaxially stretched film, and a copper-clad laminate were produced in the same manner as in Example 1, except that only the PPS resin was charged into the vented twin-screw extruder "TEX-30α" manufactured by Japan Steel Works, Ltd. .

[Comparative example 2]
A resin composition, a biaxially stretched film, and a copper-clad laminate were produced in the same manner as in Comparative Example 1, except that a non-roughened copper foil (thickness: 12 μm, Rz: 0.8 μm) was used as the rolled copper foil.

[Comparative example 3]
A resin composition and biaxial stretching were prepared in the same manner as in Example 1, except that 84.5% by mass of PPS resin MA520, 15% by mass of EA-2000, and 0.5% by mass of silane coupling agent KBM403 were blended. Films and copper-clad laminates were manufactured.
In addition, when the average particle diameter of the particles in the biaxially stretched film was measured in the same manner as in Example 1, it was found to be 1.5 μm.
Furthermore, as a result of analyzing the constituent components of the base film in the same manner as in Example 1, it was found that particles of the fluorine-containing resin were dispersed in the PPS matrix.

[evaluation]
Dielectric properties of the resin layer The dielectric constant and dielectric loss tangent were measured based on the cavity resonance method specified in JIS C 2565:1992. Specifically, a strip of width 3 mm x length 150 mm was produced from a biaxially stretched film. Next, the produced strip was left to stand for 24 hours in an environment of 23°C and 50% Rh, and then the dielectric constant and dielectric loss tangent at a frequency of 5 GHz were measured using the ADMS010c series (manufactured by AET Co., Ltd.) using the cavity resonance method. It was measured.

2. Adhesiveness Adhesiveness was evaluated by measuring the peel strength of copper foil using a copper-clad laminate based on the test method specified in JIS K 6854:1999, and according to the following criteria.
◎: 8N/cm or more ○: 6N/cm or more and less than 8N/cm ×: Less than 6N/cm

3. Dielectric properties of the resin layer/adhesive layer laminate The dielectric constant and dielectric loss tangent were measured based on the cavity resonance method specified in JIS C 2565:1992. Specifically, a strip having a width of 3 mm and a length of 150 mm was produced from a biaxially stretched film with an adhesive layer. Next, the produced strip was left to stand for 24 hours in an environment of 23°C and 50% Rh, and then the dielectric constant and dielectric loss tangent at a frequency of 5 GHz were measured using the ADMS010c series (manufactured by AET Co., Ltd.) using the cavity resonance method. It was measured.

4. A heat-resistant copper-clad laminate is passed through a reflow process with a top temperature of 260°C for 10 seconds three times, and the sample after passing is observed to evaluate the presence or absence of blistering and peeling 〇; No blistering or peeling ×; Blistering or peeling can be

＊ＰＡＲ；ポリアリーレンスルフィド系樹脂
ＰＰＳ；ポリフェニレンスルフィド樹脂
ＰＰＥ；ポリフェニレンエーテル樹脂
ＰＣ；ポリカーボネート樹脂
ＰＥＳ；ポリエーテルサルホン樹脂
ＰＰＳＵ；ポリフェニレンサルホン樹脂
ＰＥＩ；ポリエーテルイミド樹脂
ＰＳＵ；ポリサルホン樹脂

*PAR: Polyarylene sulfide resin PPS: Polyphenylene sulfide resin PPE: Polyphenylene ether resin PC: Polycarbonate resin PES: Polyether sulfone resin PPSU: Polyphenylene sulfone resin PEI: Polyetherimide resin PSU: Polysulfone resin

The copper-clad laminates obtained in Examples 1 to 10 showed excellent adhesiveness and heat resistance.
In contrast, the copper-clad laminates obtained in Comparative Examples 1 to 3 had poor adhesiveness and heat resistance.

Claims (17)

A laminate in which at least a copper foil, an adhesive layer, and a resin layer containing polyarylene sulfide resin (A) as a main component are laminated in this order,
In the copper foil, the surface roughness (Rz) of the copper foil on the side on which the adhesive layer is laminated is 2.0 μm or less and the thickness is 1 μm to 50 μm,
The resin layer contains a polyarylene sulfide resin (A) as a main component, a fluorine-containing resin (B), and a resin other than the fluorine-containing resin (B) having a glass transition temperature of 140°C or higher or a melting point of 230°C or higher. A laminate comprising a resin layer containing a thermoplastic resin (C), having a continuous phase and a dispersed phase, and having a dielectric constant of 3.5 or less and a dielectric loss tangent of 0.005 or less. The laminate according to claim 1, wherein the fluorine-containing resin (B) is a fluorine-containing resin having at least one functional group selected from the group consisting of a carbonyl group-containing group, a hydroxyl group, an epoxy group, and an isocyanate group. body. The average dispersion diameter of the fluorine-containing resin (B) as the dispersed phase and the thermoplastic resin (C) other than the fluorine-containing resin (B) having a glass transition temperature of 140° C. or higher or a melting point of 230° C. or higher is 5 μm or less. The laminate according to claim 1 or 2. The ratio of the blending amount of the fluorine-containing resin (B) is 3 49 with respect to 100% by mass of the total amount of the polyarylene sulfide resin (A), the fluorine-containing resin (B), and the thermoplastic resin (C). The laminate according to claim 1 or 2, wherein the content is in the range of % by mass. 3. The thermoplastic resin (C) other than the fluorine-containing resin is a polyphenylene ether resin, a polycarbonate resin, a polyether sulfone resin, a polyphenylene sulfone resin, a polyetherimide resin, a polysulfone resin, or a liquid crystal resin. laminate. The proportion of the thermoplastic resin (C) other than the fluorine-containing resin (B) having a glass transition temperature of 140° C. or higher or a melting point of 230° C. or higher is the polyarylene sulfide resin (A), the fluorine-containing resin (B), or The laminate according to claim 1 or 2, wherein the amount is 1 to 40% by mass based on 100% by mass of the total amount of the thermoplastic resin (C) other than the fluororesin. The laminate according to claim 1 or 2, wherein the laminate comprising the adhesive layer and the resin layer has a dielectric constant of 3.5 or less and a dielectric loss tangent of 0.03 or less. The laminate according to claim 1 or 2, further comprising a modified elastomer (D) provided with a reactive group. The laminate according to claim 8, wherein the modified elastomer (D) is made of an olefin polymer having at least one functional group selected from the group consisting of an epoxy group and an acid anhydride group. The proportion of the modified elastomer (D) is the same as that of the polyarylene sulfide resin (A), the fluorine-containing resin (B), the thermoplastic resin other than the fluorine-containing resin (C), and the modified elastomer (D). The laminate according to claim 8, containing 1 to 15% by mass based on a total of 100% by mass. The laminate according to claim 8, wherein the α-olefin content of the modified elastomer (D) is 50 to 95% by mass based on the total mass of the modified elastomer. The laminate according to claim 1 or 2, further comprising 0.01 to 5% by mass of a silane coupling agent (E) containing at least one functional group selected from epoxy groups, amino groups, and isocyanate groups. The laminate according to claim 1 or 2, wherein the resin layer is a biaxially stretched film. The laminate according to claim 1 or 2, wherein the adhesive layer has a thickness of 30 μm or less. The laminate according to claim 1 or 2, wherein the adhesive layer has a dielectric constant of 3.5 or less at a frequency of 5 GHz and a dielectric loss tangent of 0.01 or less. A circuit board using the laminate according to claim 1 or 2. A high frequency circuit board comprising the laminate according to claim 1 or 2.