JP2017149859A - Thermosetting resin composition, prepreg, copper-clad laminate and printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermosetting resin composition, a prepreg, a copper-clad laminate and a printed wiring board which can achieve high adhesiveness to a copper foil, excellent dielectric properties, high glass-transition temperatures, low thermal expansion coefficients, and excellent moldability.SOLUTION: A thermosetting resin composition comprises (A) a copolymer resin comprising a structural unit derived from an aromatic vinyl compound and a structural unit derived from maleic anhydride, (B) a compound having a dihydrobenzoxazine ring, and (C) a maleimide compound.SELECTED DRAWING: None

Description

  The present invention relates to a thermosetting resin composition, a prepreg, a copper clad laminate, and a printed wiring board that are suitable as materials for electronic devices and the like.

  Thermosetting resins are widely used in fields that require high reliability, such as electronic parts, because their unique cross-linked structure exhibits high heat resistance and dimensional stability. In particular, a copper-clad laminate and an interlayer insulating material require high copper foil adhesion for forming fine wiring due to the recent demand for higher wiring density.

  Mobile communication devices such as mobile phones, base station devices, network-related electronic devices such as servers and routers, and large computers are required to transmit and process large amounts of information with low loss and high speed. ing. When transmitting and processing a large amount of information, the electrical signal having a higher frequency can be transmitted and processed at a higher speed. However, an electrical signal basically has a property that the higher the frequency, the easier it is to attenuate, and the output tends to be weak at a shorter transmission distance and the loss tends to increase. Therefore, in order to satisfy the above-mentioned requirements for low loss and high-speed communication, in the characteristics of the printed wiring board itself that performs transmission and processing mounted on the device, dielectric characteristics (relative permittivity, dielectric loss tangent), particularly in a high frequency band. Therefore, it is required to reduce the relative dielectric constant and the dielectric loss tangent.

  Conventionally, in order to obtain a printed wiring board capable of transmitting information with low loss, a substrate material using a fluorine-based resin having a low relative dielectric constant and dielectric loss tangent has been used. However, since the fluorine-based resin generally has a high melting temperature and melt viscosity and relatively low fluidity, there is a problem that it is necessary to set high-temperature and high-pressure conditions during press molding. In addition, the processability, dimensional stability, and adhesion to metal plating are insufficient for use in high-layer printed wiring boards used in the above communication devices, network-related electronic devices, and large computers. There is a problem.

Accordingly, research is being made on thermosetting resin materials that can be used for high-frequency printed wiring boards instead of fluororesins. For example, a resin composition containing an epoxy resin (see Patent Document 1), a resin composition containing polyphenylene ether and bismaleimide (see Patent Document 2), a styrene-butadiene copolymer or polystyrene, and triallyl cyanurate Alternatively, resin compositions containing triallyl isocyanurate (see, for example, Patent Documents 3 and 4) have been proposed.
Furthermore, a resin composition containing a reaction product of polyphenylene ether and an unsaturated carboxylic acid or an unsaturated acid anhydride and a polyfunctional maleimide or the like (see, for example, Patent Document 5) has been proposed.

Japanese Patent Laid-Open No. 58-069046 JP-A-56-133355 JP-A-61-286130 Japanese Patent Laid-Open No. 03-275760 Japanese Patent Laid-Open No. 06-179734

However, the resin composition described in Patent Document 1, 2, or 5 is inferior in dielectric properties after curing due to the influence of a highly polar epoxy resin, and is unsuitable for high frequency applications.
In the resin composition described in Patent Document 3 or 4, there was a tendency that the relative dielectric constant was slightly high.
Further, the resin composition described in Patent Document 5 has a problem that the dielectric properties are deteriorated as compared with the case of using polyphenylene ether before modification due to the influence of modification with highly polar unsaturated carboxylic acid and unsaturated anhydride. It has been found that the use of a compound having a large number of polar groups in order to improve the adhesion to the copper foil results in a decrease in dielectric properties.

  Accordingly, an object of the present invention is to provide a thermosetting resin composition, a prepreg, and a copper clad that can achieve high adhesion to copper foil, excellent dielectric properties, high glass transition temperature, low thermal expansion coefficient, and good moldability. It is providing a laminated board and a printed wiring board.

  As a result of diligent research to solve the above problems, the present inventors have found that (A) a copolymer resin having a structural unit derived from an aromatic vinyl compound and a structural unit derived from maleic anhydride, (B) dihydro It has been found that a thermosetting resin composition comprising a compound having a benzoxazine ring and (C) a maleimide compound can solve the above-mentioned problems, and has completed the present invention. The present invention has been completed based on such knowledge.

The present invention relates to the following [1] to [13].
[1] (A) a copolymer resin having a structural unit derived from an aromatic vinyl compound and a structural unit derived from maleic anhydride,
(B) a compound having a dihydrobenzoxazine ring, and (C) a maleimide compound,
A thermosetting resin composition comprising:
[2] The thermosetting resin composition according to [1], wherein the component (B) includes a compound represented by the following general formula (B).

(In the formula, R ^B1 is an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 4 to 8 carbon atoms, or an aryl group having 6 to 14 carbon atoms, or an alkyl group having 1 to 3 carbon atoms. And an aryl group having 6 to 14 carbon atoms substituted with at least one organic group selected from the group consisting of alkoxyl groups having 1 to 3 carbon atoms.)
[3] A structure in which the component (A) is derived from a structural unit derived from an aromatic vinyl compound represented by the following general formula (Ai) and a maleic anhydride represented by the following formula (A-ii) The thermosetting resin composition according to the above [1] or [2], which is a copolymer resin having units.

(In the formula, R ^A1 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ^A2 is an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or 6 to 20 carbon atoms. An aryl group, a hydroxyl group or a (meth) acryloyl group, wherein x is an integer of 0 to 3. However, when x is 2 or 3, a plurality of R ^A2 may be the same or different. May be.)
[4] In the component (A), the content ratio of the structural unit derived from the aromatic vinyl compound to the structural unit derived from maleic anhydride [the structural unit derived from the aromatic vinyl compound / the structure derived from maleic anhydride The thermosetting resin composition according to any one of [1] to [3], wherein the unit (molar ratio) is 2 to 9.
[5] The thermosetting resin composition according to any one of [1] to [4], wherein the component (C) is a maleimide compound having at least two N-substituted maleimide groups in one molecule. .
[6] Maleimide in which the component (C) is a maleimide compound (c1) represented by the following general formula (c1-1) or (c1-2) and is modified with a monoamine compound (c2) having an acidic substituent The thermosetting resin composition according to any one of [1] to [5], which is a compound.

(Wherein R ^{C1 to} R ^C3 each independently represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom. X ^C1 is an alkylene group having 1 to 5 carbon atoms and 2 to 5 carbon atoms. An alkylidene group, -O-, -C (= O)-, -S-, -SS- or a sulfonyl group, wherein p, q and r are each independently an integer of 0 to 4; )
[7] The thermosetting resin composition according to [6], wherein the monoamine compound (c2) having the acidic substituent is represented by the following general formula (c2-1).

(Wherein R ^C4 represents an acidic substituent selected from a hydroxyl group, a carboxy group, and a sulfonic acid group. R ^C5 represents an alkyl group having 1 to 5 carbon atoms or a halogen atom. T represents 1 to 5) Integer, u is an integer of 0 to 4 and satisfies 1 ≦ t + u ≦ 5, provided that when t is an integer of 2 to 5, a plurality of R ^C4 may be the same or different. In addition, when u is an integer of 2 to 4, a plurality of R ^C5 may be the same or different.
[8] The heat according to any one of [1] to [7], wherein the component (C) includes a compound represented by the following general formula (C-1) or the following general formula (C-2). Curable resin composition.

(Wherein R ^{C1 to} R ^C3 each independently represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom. X ^C1 is an alkylene group having 1 to 5 carbon atoms and 2 to 5 carbon atoms. An alkylidene group, -O-, -C (= O)-, -S-, -SS- or a sulfonyl group, wherein p, q and r are each independently an integer of 0 to 4;
R ^C4 represents an acidic substituent selected from a hydroxyl group, a carboxy group, and a sulfonic acid group. R ^C5 represents an alkyl group having 1 to 5 carbon atoms or a halogen atom. t is an integer of 1 to 5, u is an integer of 0 to 4, and 1 ≦ t + u ≦ 5 is satisfied. However, when t is an integer of 2 to 5, the plurality of R ^C4 may be the same or different. Moreover, when u is an integer of 2-4, several ^RC5 may be the same and may differ. )
[9] The thermosetting resin composition according to any one of [1] to [8], further including (D) a hydrogenated styrene-based thermoplastic elastomer.
[10] The above [10] further comprising at least one selected from the group consisting of (E) a radical reaction initiator, (F) a curing accelerator, (G) a flame retardant, and (H) an inorganic filler. The thermosetting resin composition according to any one of [1] to [9].
[11] A prepreg comprising the thermosetting resin composition according to any one of [1] to [10].
[12] A copper-clad laminate obtained by laminating the prepreg according to [11] and a copper foil.
[13] A printed wiring board using the copper-clad laminate according to [12].

  According to the present invention, it is possible to provide a thermosetting resin composition that can achieve high adhesion to copper foil, high heat resistance, excellent dielectric properties, high glass transition temperature, low thermal expansion coefficient, and good moldability. it can. The thermosetting resin composition is also excellent in solubility in an organic solvent. Also provided are a prepreg comprising the thermosetting resin composition, a copper-clad laminate obtained by laminating the prepreg and a copper foil, and a printed wiring board using the copper-clad laminate. it can.

Hereinafter, the present invention will be described in detail.
[Thermosetting resin composition]
The thermosetting resin composition of the present invention is
(A) a copolymer resin having a structural unit derived from an aromatic vinyl compound and a structural unit derived from maleic anhydride,
(B) a compound having a dihydrobenzoxazine ring, and (C) a maleimide compound,
Is a thermosetting resin composition.
Hereinafter, each component contained in the thermosetting resin composition of the present invention will be described in detail.

<(A) Copolymer resin having a structural unit derived from an aromatic vinyl compound and a structural unit derived from maleic anhydride>
The component (A) is a copolymer resin [hereinafter sometimes referred to as copolymer resin (A)] having a structural unit derived from an aromatic vinyl compound and a structural unit derived from maleic anhydride. The dielectric property is particularly improved by the component (A).
Examples of the aromatic vinyl compound include styrene, 1-methylstyrene, vinyltoluene, dimethylstyrene and the like. Among these, styrene is preferable.
As the component (A), in particular, a structural unit derived from an aromatic vinyl compound represented by the following general formula (Ai) and a structural unit derived from maleic anhydride represented by the following formula (A-ii) Are preferable.

(In the formula, R ^A1 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ^A2 is an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or 6 to 20 carbon atoms. An aryl group, a hydroxyl group or a (meth) acryloyl group, wherein x is an integer of 0 to 3. However, when x is 2 or 3, a plurality of R ^A2 may be the same or different. May be.)

Examples of the alkyl group having 1 to 5 carbon atoms represented by R ^A1 and R ^A2 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, and an n-pentyl group. Groups and the like. The alkyl group is preferably an alkyl group having 1 to 3 carbon atoms.
Examples of the alkenyl group having 2 to 5 carbon atoms represented by R ^A2 include an allyl group and a crotyl group. The alkenyl group is preferably an alkenyl group having 3 to 5 carbon atoms, more preferably an alkenyl group having 3 or 4 carbon atoms.
Examples of the aryl group having 6 to 20 carbon atoms represented by R ^A2 include a phenyl group, a naphthyl group, an anthryl group, and a biphenylyl group. The aryl group is preferably an aryl group having 6 to 12 carbon atoms, more preferably an aryl group having 6 to 10 carbon atoms.
x is preferably 0 or 1, more preferably 0.
In the structural unit derived from the aromatic vinyl compound represented by the general formula (A-i), R ^A1 is a hydrogen atom and x is 0, and is represented by the following formula (A-i-1). Structural units are preferred.

Content ratio of structural unit derived from aromatic vinyl compound to structural unit derived from maleic anhydride in copolymer resin (A) [structural unit derived from aromatic vinyl compound / structural unit derived from maleic anhydride ] (Molar ratio) is preferably 2 to 9, more preferably 4 to 9, and further preferably 6 to 9. The content ratio of the structural unit derived from the aromatic vinyl compound represented by the general formula (Ai) to the structural unit derived from maleic anhydride represented by the formula (A-ii) [(A- i) / (A-ii)] (molar ratio) is also preferably 2 to 9, more preferably 4 to 9, and still more preferably 6 to 9. If the content ratio is 2 or more, the effect of improving the dielectric properties and heat resistance tends to be sufficient, and if it is 9 or less, the compatibility tends to be good.
The total content of the structural unit derived from the aromatic vinyl compound and the structural unit derived from maleic anhydride in the copolymer resin (A), and the aromatic vinyl compound represented by the general formula (Ai) The total content of the structural unit derived from the structural unit derived from maleic anhydride represented by the formula (A-ii) is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably Is 90% by mass or more, particularly preferably substantially 100% by mass.
The weight average molecular weight (Mw) of the copolymer resin (A) is preferably 5,000 to 18,000, more preferably 6,000 to 17,000, still more preferably 8,000 to 16,000, particularly preferably. It is 10,000 to 16,000, most preferably 12,000 to 16,000. In addition, all the weight average molecular weights in this specification are values measured by gel permeation chromatography (GPC) method (standard polystyrene conversion) using tetrahydrofuran as an eluent.

  As a method for reducing the dielectric constant of an epoxy resin, there is a method using a copolymer resin of styrene and maleic anhydride. When this method is applied to a printed wiring board material, the impregnation property to the substrate and the copper Generally, it tends to be avoided due to insufficient adhesion to the foil. For this reason, it is apt to be avoided to use the copolymer resin (A), but the present invention contains both the component (B) and the component (C) while using the copolymer resin (A). This makes it possible to improve the adhesiveness with copper foil while having excellent dielectric properties, and furthermore, the thermosetting resin composition is also excellent in dielectric properties, glass transition temperature, thermal expansion coefficient and moldability. It was proved to be achieved.

(Method for producing copolymer resin (A))
The copolymer resin (A) can be produced by copolymerizing an aromatic vinyl compound and maleic anhydride.
Examples of the aromatic vinyl compound include styrene, 1-methylstyrene, vinyltoluene, and dimethylstyrene as described above. These may be used individually by 1 type and may use 2 or more types together.
In addition to the aromatic vinyl compound and maleic anhydride, various polymerizable components may be copolymerized. Examples of various polymerizable components include vinyl compounds such as ethylene, propylene, butadiene, isobutylene and acrylonitrile; compounds having a (meth) acryloyl group such as methyl acrylate and methyl methacrylate.
In addition, substitution of alkenyl groups such as allyl groups, (meth) acryloyl groups, hydroxyl groups, etc., through Friedel-Crafts reaction or reaction using a metal catalyst such as lithium to the copolymer obtained by the above copolymerization A group (corresponding to R ^A2 in formula (Ai)) may be introduced.

  As the copolymer resin (A), a commercially available product can be used. Examples of the commercially available product include “SMA (registered trademark) EF30” (styrene / maleic anhydride = 3, Mw = 9,500), “SMA”. (Registered trademark) EF40 "(styrene / maleic anhydride = 4, Mw = 11,000)," SMA (registered trademark) EF60 "(styrene / maleic anhydride = 6, Mw = 11,500)," SMA (registered) Trademark) EF80 "(styrene / maleic anhydride = 8, Mw = 14,400) [above, manufactured by Sartomer]. Among these, “SMA (registered trademark) EF80” is preferable.

<(B) Compound having dihydrobenzoxazine ring>
The component (B) is a compound having a dihydrobenzoxazine ring [hereinafter sometimes referred to as a compound (B) having a dihydrobenzoxazine ring]. The component (B) exhibits the effect of improving the adhesiveness with the copper foil while maintaining the dielectric characteristics. In order to improve the adhesiveness with the copper foil, for example, phenol resin or the like can be used, but in this case, the dielectric characteristics tend to deteriorate. However, if it is (B) component used by this invention, as above-mentioned, adhesiveness with copper foil can be improved, without producing such a problem.
The compound (B) having a dihydrobenzoxazine ring undergoes a ring-opening polymerization reaction by heating, and forms a crosslinked structure while generating a phenolic hydroxyl group without generating a volatile component. It is presumed that this leads to the effect of increasing the adhesion with the copper foil while maintaining the dielectric properties of the thermosetting resin composition of the present invention, and to obtaining a high glass transition temperature.

The compound (B) having a dihydrobenzoxazine ring is not particularly limited as long as it has a dihydrobenzoxazine ring, but is preferably a compound having 1 to 3 dihydrobenzoxazine rings, more preferably A compound having one or two dihydrobenzoxazine rings, more preferably a compound having one dihydrobenzoxazine ring.
Specifically, the component (B) preferably contains a compound represented by the following general formula (B), more preferably contains 80% by mass or more of a compound represented by the following general formula (B). More preferably, 90% by mass or more of the compound represented by the following general formula (B) is contained, and it is further more preferred that the compound represented by the following general formula (B) is substantially 100% by mass.
The compound represented by general formula (B) may be used individually by 1 type, and may use 2 or more types together.

(In the formula, R ^B1 is an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 4 to 8 carbon atoms, or an aryl group having 6 to 14 carbon atoms, or an alkyl group having 1 to 3 carbon atoms. And an aryl group having 6 to 14 carbon atoms substituted with at least one organic group selected from the group consisting of alkoxyl groups having 1 to 3 carbon atoms.)

In the general formula (B), examples of the alkyl group having 1 to 6 carbon atoms represented by R ^B1 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. Group, n-pentyl group and the like. The alkyl group is preferably an alkyl group having 1 to 3 carbon atoms.
Examples of the cycloalkyl group having 4 to 8 carbon atoms represented by R ^B1 include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. The cycloalkyl group is preferably a cycloalkyl group having 5 to 8 carbon atoms.
Examples of the aryl group having 6 to 14 carbon atoms represented by R ^B1 include a phenyl group, a naphthyl group, a biphenylyl group, and an anthryl group. The aryl group is preferably an aryl group having 6 to 10 carbon atoms, and more preferably a phenyl group.
Examples of the aryl group having 6 to 14 carbon atoms substituted by at least one organic group selected from the group consisting of an alkyl group having 1 to 3 carbon atoms and an alkoxyl group having 1 to 3 carbon atoms, represented by R ^B1 include , Tosyl group, dimethylphenyl group, methoxyphenyl group, dimethoxyphenyl group, ethoxyphenyl group, diethoxyphenyl group, n-propoxyphenyl group, isopropoxyphenyl group and the like.
Among the above, R ^B1 is an aryl group having 6 to 14 carbon atoms, or at least one organic group selected from the group consisting of an alkyl group having 1 to 3 carbon atoms and an alkoxyl group having 1 to 3 carbon atoms. A substituted aryl group having 6 to 14 carbon atoms is preferred, and an aryl group having 6 to 14 carbon atoms is more preferred.

(Method for producing compound (B) having a dihydrobenzoxazine ring)
The production method of the compound (B) having a dihydrobenzoxazine ring is not particularly limited. For example, (b1) a compound having a phenolic hydroxyl group having a hydrogen atom bonded to at least one of the ortho positions [hereinafter referred to as a phenolic hydroxyl group. (B1) may be abbreviated as compound (b1)], (b2) primary amine [hereinafter referred to as primary amine (b2)] and (b3) formaldehyde [hereinafter referred to as formaldehyde (b3)]. It can be produced by reaction. When the compound (b1) having a phenolic hydroxyl group is phenol, it is represented by the following reaction formula.

(Wherein R ^B1 is as defined above.)

As the compound (b1) having a phenolic hydroxyl group, which is one of the raw materials of the compound (B) having a dihydrobenzoxazine ring, for example, phenols, polyfunctional phenols, biphenol compounds, bisphenols, trisphenols, Examples include tetraphenols and phenol resins. Among these, phenols are preferable, and phenol is more preferable. Examples of phenols include phenol, 2-methylphenol, 4-methylphenol, 2-ethylphenol, 3-methyl-4-isopropylphenol, and the like.
The compound (b1) having a phenolic hydroxyl group may be a compound having two or more phenolic hydroxyl groups in which hydrogen is bonded to at least one of the ortho positions in one molecule. Specifically, examples of polyfunctional phenols include catechol, resorcinol, hydroquinone and the like. Examples of bisphenols include bisphenol A, bisphenol S, bisphenol F, and hexafluorobisphenol A. Examples of trisphenols include 1,1,1-tris (4-hydroxyphenyl) ethane.
As the compound (b1) having a phenolic hydroxyl group, one type may be used alone, or two or more types may be used in combination, but it is usually preferable to use one type alone.

Examples of the primary amine (b2) that is one of the raw materials of the compound (B) having a dihydrobenzoxazine ring include aliphatic amines such as methylamine, butylamine, and cyclohexylamine; aniline, substituted aniline, toluidine, and anisidine Aromatic amines such as can be used. Among these, aromatic amines are preferable, aniline and substituted anilines are more preferable, and aniline is more preferable. Examples of the substituted aniline include 2-methoxyaniline and 4-methoxyaniline.
As the primary amine (b2), one type may be used alone, or two or more types may be used in combination, but it is usually preferable to use one type alone.

  Formaldehyde (b3), which is one of the raw materials of the compound (B) having a dihydrobenzoxazine ring, can be used as formalin (formaldehyde aqueous solution), or can be used as a solid paraformaldehyde.

  In the production of the compound (B) having a dihydrobenzoxazine ring, the amount of each raw material used is not particularly limited, but a primary amine (1 mol) with respect to 1 mol of the phenolic hydroxyl group of the compound (b1) having a phenolic hydroxyl group. It is preferable to use 2 mol or more of formaldehyde (b3) with respect to 0.5 to 1 mol of b2) and 1 mol of primary amine (b2). By using the amount of the primary amine (b2) as described above, a part of the phenolic hydroxyl group of the compound (b1) having a phenolic hydroxyl group is likely to remain unreacted, and adhesion and glass transition. Temperature tends to improve.

As a more specific production method of the compound (B) having a dihydrobenzoxazine ring, a mixture of the compound (b1) having a phenolic hydroxyl group and the primary amine (b2) is preferably 70 ° C. or more, more preferably Is added to formaldehyde (b3) heated to 70 to 110 ° C., preferably 70 to 110 ° C., more preferably 90 to 100 ° C., preferably 20 minutes to 8 hours, more preferably 20 minutes to 2 hours. Then, the compound (B) having a dihydrobenzoxazine ring can be obtained by drying under reduced pressure at 120 ° C. or lower.
The mixing procedure of the raw materials is not limited to the above procedure, and the primary amine (b2) is added to the mixture of the compound (b1) having phenolic hydroxyl group and formaldehyde (b3), preferably 70 ° C. or higher. More preferably, you may make it react at 70-110 degreeC.
You may implement the manufacturing method of the compound (B) which has a dihydrobenzoxazine ring in presence of a solvent. Examples of the solvent include alcohol solvents such as methanol, ethanol, propanol, butanol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ethers such as tetrahydrofuran. A solvent etc. are mentioned.
After completion of the reaction, the product is separated by a technique generally used in organic synthetic chemistry such as extraction, and volatile components such as condensed water are removed by drying to obtain a compound (B) having a dihydrobenzoxazine ring. It is done.

<(C) Maleimide compound>
As the component (C), a maleimide compound [hereinafter referred to as a maleimide compound (C)] is used. By this (C) component, especially adhesiveness with copper foil improves. As the maleimide compound (C), a compound having at least two N-substituted maleimide groups in one molecule is preferable.
The weight average molecular weight (Mw) of the maleimide compound (C) is preferably 400 to 3,500, more preferably 600 to 1,000, and still more preferably 650, from the viewpoints of solubility in organic solvents and mechanical strength. ~ 950.
Moreover, it is preferable that a maleimide compound (C) has an acidic substituent from a viewpoint of the rigidity and mechanical strength of the hardened | cured material of a thermosetting resin composition. Specifically, the maleimide compound (C) is preferably a maleimide compound obtained by modifying a maleimide compound (c1) described later with a monoamine compound (c2) having an acidic substituent.

(Maleimide compound (c1))
The maleimide compound (c1) is a maleimide compound having at least two N-substituted maleimide groups in one molecule.
Whether the maleimide compound (c1) is a maleimide compound having an aliphatic hydrocarbon group between any two maleimide groups among a plurality of maleimide groups [hereinafter referred to as an aliphatic hydrocarbon group-containing maleimide] Or a maleimide compound containing an aromatic hydrocarbon group between any two maleimide groups of the plurality of maleimide groups [hereinafter referred to as an aromatic hydrocarbon group-containing maleimide]. Among these, an aromatic hydrocarbon group-containing maleimide is preferable from the viewpoints of adhesion to copper foil, dielectric properties, glass transition temperature, thermal expansion coefficient, and moldability. The aromatic hydrocarbon group-containing maleimide only needs to contain an aromatic hydrocarbon group between any combination of two maleimide groups selected arbitrarily.
The maleimide compound (c1) is a maleimide having 2 to 5 N-substituted maleimide groups in one molecule from the viewpoints of adhesion to copper foil, dielectric properties, glass transition temperature, thermal expansion coefficient and moldability. A compound is preferable, and a maleimide compound having two N-substituted maleimide groups in one molecule is more preferable. The maleimide compound (c1) is represented by the following general formula (c1-1) or (c1-2) from the viewpoints of adhesion to copper foil, dielectric properties, glass transition temperature, thermal expansion coefficient, and moldability. An aromatic hydrocarbon group-containing maleimide is more preferable, and an aromatic hydrocarbon group-containing maleimide represented by the following general formula (c1-2) is more preferable.

In the above formula, R ^{C1 to} R ^C3 each independently represent an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom. X ^C1 represents an alkylene group having 1 to 5 carbon atoms, an alkylidene group having 2 to 5 carbon atoms, —O—, —C (═O) —, —S—, —SS— or a sulfonyl group. p, q, and r are each independently an integer of 0-4.
Examples of the aliphatic hydrocarbon group having 1 to 5 carbon atoms represented by R ^{C1 to} R ^C3 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, An n-pentyl group and the like can be mentioned. The aliphatic hydrocarbon group is preferably an aliphatic hydrocarbon group having 1 to 3 carbon atoms from the viewpoint of adhesiveness with copper foil, dielectric properties, glass transition temperature, thermal expansion coefficient, and moldability, and more A methyl group and an ethyl group are preferred.
Examples of the halogen atom represented by R ^{C1 to} R ^C3 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the alkylene group having 1 to 5 carbon atoms represented by X ^C1 include a methylene group, a 1,2-dimethylene group, a 1,3-trimethylene group, a 1,4-tetramethylene group, a 1,5-pentamethylene group, and the like. Is mentioned. The alkylene group is preferably an alkylene group having 1 to 3 carbon atoms, more preferably a methylene group, from the viewpoints of adhesion to copper foil, dielectric properties, glass transition temperature, thermal expansion coefficient, and moldability. .
Examples of the alkylidene group having 2 to 5 carbon atoms represented by X ^C1 include an ethylidene group, a propylidene group, an isopropylidene group, a butylidene group, an isobutylidene group, a pentylidene group, and an isopentylidene group. Among these, an isopropylidene group is preferable from the viewpoints of adhesion to copper foil, dielectric properties, glass transition temperature, thermal expansion coefficient, and moldability.
X ^C1 is preferably an alkylene group having 1 to 5 carbon atoms or an alkylidene group having 2 to 5 carbon atoms, and more preferably an alkylene group having 1 to 5 carbon atoms, among the above options. Further preferred are as described above.
p, q and r are each independently an integer of 0 to 4, and from the viewpoints of adhesion to copper foil, dielectric properties, glass transition temperature, thermal expansion coefficient and formability, all preferably 0 to It is an integer of 2, more preferably 0 or 1, and still more preferably 0.

  Examples of the maleimide compound (c1) include N, N′-ethylene bismaleimide, N, N′-hexamethylene bismaleimide, bis (4-maleimidocyclohexyl) methane, and 1,4-bis (maleimidomethyl) cyclohexane. Aliphatic hydrocarbon group-containing maleimide; m-phenylene bismaleimide, N, N ′-(2-methyl-1,3-phenylene) bismaleimide, N, N ′-(4-methyl-1,3-phenylene) bis Maleimide, N, N ′-(1,4-phenylene) bismaleimide, 4,4′-diphenylmethane bismaleimide, bis (3-methyl-4-maleimidophenyl) methane, 3,3′-dimethyl-5,5 ′ -Diethyl-4,4'-diphenylmethane bismaleimide, bis (4-maleimidophenyl) ether, bis (4-ma Imidophenyl) sulfone, bis (4-maleimidophenyl) sulfide, bis (4-maleimidophenyl) ketone, 1,4-bis (4-maleimidophenyl) cyclohexane, 1,4-bis (maleimidomethyl) cyclohexane, 1,3 -Bis (4-maleimidophenoxy) benzene, 1,3-bis (3-maleimidophenoxy) benzene, bis [4- (3-maleimidophenoxy) phenyl] methane, bis [4- (4-maleimidophenoxy) phenyl] methane 1,1-bis [4- (3-maleimidophenoxy) phenyl] ethane, 1,1-bis [4- (4-maleimidophenoxy) phenyl] ethane, 1,2-bis [4- (3-maleimidophenoxy) ) Phenyl] ethane, 1,2-bis [4- (4-maleimidophenoxy) pheny ] Ethane, 2,2-bis [4- (3-maleimidophenoxy) phenyl] propane, 2,2-bis [4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [4- (3- Maleimidophenoxy) phenyl] butane, 2,2-bis [4- (4-maleimidophenoxy) phenyl] butane, 2,2-bis [4- (3-maleimidophenoxy) phenyl] -1,1,1,3 3,3-hexafluoropropane, 2,2-bis [4- (4-maleimidophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 4,4-bis (3-maleimide) Phenoxy) biphenyl, 4,4-bis (4-maleimidophenoxy) biphenyl, bis [4- (3-maleimidophenoxy) phenyl] ketone, bis [4- (4-maleimi) Dophenoxy) phenyl] ketone, 2,2′-bis (4-maleimidophenyl) disulfide, bis (4-maleimidophenyl) disulfide, bis [4- (3-maleimidophenoxy) phenyl] sulfide, bis [4- (4 -Maleimidophenoxy) phenyl] sulfide, bis [4- (3-maleimidophenoxy) phenyl] sulfoxide, bis [4- (4-maleimidophenoxy) phenyl] sulfoxide, bis [4- (3-maleimidophenoxy) phenyl] sulfone, Bis [4- (4-maleimidophenoxy) phenyl] sulfone, bis [4- (3-maleimidophenoxy) phenyl] ether, bis [4- (4-maleimidophenoxy) phenyl] ether, 1,4-bis [4- (4-Maleimidophenoxy) -α, α-dimethyl Rubenzyl] benzene, 1,3-bis [4- (4-maleimidophenoxy) -α, α-dimethylbenzyl] benzene, 1,4-bis [4- (3-maleimidophenoxy) -α, α-dimethylbenzyl] Benzene, 1,3-bis [4- (3-maleimidophenoxy) -α, α-dimethylbenzyl] benzene, 1,4-bis [4- (4-maleimidophenoxy) -3,5-dimethyl-α, α -Dimethylbenzyl] benzene, 1,3-bis [4- (4-maleimidophenoxy) -3,5-dimethyl-α, α-dimethylbenzyl] benzene, 1,4-bis [4- (3-maleimidophenoxy) -3,5-dimethyl-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (3-maleimidophenoxy) -3,5-dimethyl-α, α-dimethylbenzyl] ben Examples thereof include aromatic hydrocarbon group-containing maleimides such as zen and polyphenylmethanemaleimide.

Among these, 4,4′-diphenylmethane bismaleimide, m-phenylene bismaleimide, bis (4-maleimidophenyl) from the viewpoints of adhesion to copper foil, dielectric properties, glass transition temperature, thermal expansion coefficient and moldability. ) Sulfone and bis (4-maleimidophenyl) ether are preferred, and bis (4-maleimidophenyl) ether is more preferred.
As the maleimide compound (c1), one type may be used alone, or two or more types may be used in combination, but it is preferable to use one type alone.

(Monoamine compound having acidic substituent (c2))
The monoamine compound (c2) having an acidic substituent is preferably a monoamine compound represented by the following general formula (c2-1).

In the general formula (c2-1), R ^C4 represents an acidic substituent selected from a hydroxyl group, a carboxy group, and a sulfonic acid group. R ^C5 represents an alkyl group having 1 to 5 carbon atoms or a halogen atom. t is an integer of 1 to 5, u is an integer of 0 to 4, and 1 ≦ t + u ≦ 5 is satisfied. However, when t is an integer of 2 to 5, the plurality of R ^C4 may be the same or different. Moreover, when u is an integer of 2-4, several ^RC5 may be the same and may differ.
The acidic substituent represented by R ^C4 is preferably a hydroxyl group or a carboxy group from the viewpoint of solubility and reactivity, and more preferably a hydroxyl group in consideration of heat resistance.
t is an integer of 1 to 5, and is preferably an integer of 1 to 3, more preferably 1 or 2, from the viewpoints of adhesion to copper foil, dielectric properties, glass transition temperature, thermal expansion coefficient, and moldability. Preferably it is 1.
Examples of the alkyl group having 1 to 5 carbon atoms represented by R ^C5 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, and an n-pentyl group. Can be mentioned. The alkyl group is preferably an alkyl group having 1 to 3 carbon atoms.
Examples of the halogen atom represented by R ^C5 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
u is an integer of 0 to 4, and preferably an integer of 0 to 3, more preferably an integer of 0 to 2, from the viewpoints of adhesion to copper foil, dielectric properties, glass transition temperature, thermal expansion coefficient, and moldability. More preferably, it is 0 or 1, particularly preferably 0.
As the monoamine compound (c2) having an acidic substituent, from the viewpoints of adhesion to copper foil, dielectric properties, glass transition temperature, thermal expansion coefficient and moldability, the following general formula (c2-2) or ( c2-3), and more preferably monoamine compounds represented by the following general formula (c2-2). However, R ^C4 , R ^C5 and u in the general formulas (c2-2) and (c2-3) are the same as those in the general formula (c2-1), and preferable ones are also the same.

Examples of the monoamine compound (c2) having an acidic substituent include o-aminophenol, m-aminophenol, p-aminophenol, o-aminobenzoic acid, m-aminobenzoic acid, p-aminobenzoic acid, o- Aminobenzenesulfonic acid, m-aminobenzenesulfonic acid, p-aminobenzenesulfonic acid, 3,5-dihydroxyaniline, 3,5-dicarboxyaniline and the like can be mentioned. Among these, m-aminophenol, p-aminophenol, p-aminobenzoic acid, and 3,5-dihydroxyaniline are preferable from the viewpoint of solubility and reactivity, and o-aminophenol from the viewpoint of heat resistance. , M-aminophenol and p-aminophenol are preferable, and p-aminophenol is more preferable in consideration of dielectric properties, thermal expansion coefficient and production cost.
The monoamine compound (c2) having an acidic substituent may be used alone or in combination of two or more.

The reaction between the maleimide compound (c1) and the monoamine compound (c2) having an acidic substituent is preferably carried out by reacting at a reaction temperature of 50 to 200 ° C. for 0.1 to 10 hours in the presence of an organic solvent described later. Is preferred.
The reaction temperature is more preferably 70 to 200 ° C, still more preferably 70 to 160 ° C, particularly preferably 70 to 130 ° C, and most preferably 80 to 120 ° C. The reaction time is more preferably 1 to 6 hours, still more preferably 1 to 4 hours.

In the reaction of the maleimide compound (c1) and the monoamine compound (c2) having an acidic substituent, the amount of both used is the primary amino group equivalent [—NH ₂ group equivalent] of the monoamine compound (c2) having an acidic substituent. And the maleimide group equivalent of the maleimide compound (c1) preferably satisfies the following formula.
1.0 <[maleimide group equivalent] / [-NH ₂ group equivalent] ≦ 10
[Maleimide group equivalent] / - With [NH ₂ group equivalents] of 0.1 or more, it is difficult to gel, and heat resistance tend to hardly reduced also by 10 or less, an organic solvent This is preferable because the solubility, the adhesiveness with copper foil, and the heat resistance tend not to decrease.
From the same viewpoint, more preferably,
2 ≦ [maleimide group equivalent] / [— NH ₂ group equivalent] ≦ 10
More preferably,
3 ≦ [maleimide group equivalent] / [— NH ₂ group equivalent] ≦ 9
More preferably,
5 ≦ [maleimide group equivalent] / [— NH ₂ group equivalent] ≦ 9.

The maleimide compound (C) preferably contains a compound represented by the following general formula (C-1) or the following general formula (C-2). Any of the compounds represented by the following general formula (C-1) or the following general formula (C-2) is a compound having a maleimide group not modified in the molecule.
(Wherein R ^{C1 to} R ^C3 each independently represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom. X ^C1 is an alkylene group having 1 to 5 carbon atoms and 2 to 5 carbon atoms. An alkylidene group, -O-, -C (= O)-, -S-, -SS- or a sulfonyl group, wherein p, q and r are each independently an integer of 0 to 4;
R ^C4 represents an acidic substituent selected from a hydroxyl group, a carboxy group, and a sulfonic acid group. R ^C5 represents an alkyl group having 1 to 5 carbon atoms or a halogen atom. t is an integer of 1 to 5, u is an integer of 0 to 4, and 1 ≦ t + u ≦ 5 is satisfied. However, when t is an integer of 2 to 5, the plurality of R ^C4 may be the same or different. Moreover, when u is an integer of 2-4, several ^RC5 may be the same and may differ. )
About each group, it is the same as that of the said general formula (c1-1), (c1-2), or (c2-1), respectively, A preferable thing is also the same.

(Organic solvent)
As described above, the reaction between the maleimide compound (c1) and the monoamine compound (c2) having an acidic substituent is preferably performed in an organic solvent.
The organic solvent is not particularly limited as long as it does not adversely affect the reaction. For example, alcohol solvents such as ethanol, propanol, butanol, methyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; ether solvents such as tetrahydrofuran; toluene, xylene, mesitylene Aromatic solvents such as dimethylformamide, N, N-dimethylacetamide, nitrogen atom-containing solvents including amide solvents such as N-methylpyrrolidone; sulfur atom-containing solvents including sulfoxide solvents such as dimethyl sulfoxide; Examples thereof include ester solvents such as ethyl and γ-butyrolactone.
Among these, from the viewpoint of solubility, alcohol solvents, ketone solvents, ester solvents, and nitrogen atom-containing solvents are preferable, and from the viewpoint of low toxicity, cyclohexanone and propylene glycol monomethyl ether are more preferable and volatile. Considering that it is high and hardly remains as a residual solvent during the production of the prepreg, propylene glycol monomethyl ether and N, N-dimethylacetamide are more preferable, and N, N-dimethylacetamide is particularly preferable.
An organic solvent may be used individually by 1 type, and may use 2 or more types together.
Although there is no restriction | limiting in particular in the usage-amount of an organic solvent, Preferably from a viewpoint of solubility and reaction efficiency with respect to a total of 100 mass parts of maleimide compound (c1) and the monoamine compound (c2) which has an acidic substituent, What is necessary is just to make it become 1000 mass parts, More preferably, it is 40-700 mass parts, More preferably, it is 50-250 mass parts, Most preferably, it is 50-150 mass parts. There exists a tendency which becomes easy to ensure solubility by setting it as 10 mass parts or more with respect to a total of 100 mass parts of a maleimide compound (c1) and the monoamine compound (c2) which has an acidic substituent, and shall be 1000 mass parts or less. Therefore, there is a tendency that a significant decrease in reaction efficiency is easily suppressed.

(Reaction catalyst)
The reaction between the maleimide compound (c1) and the monoamine compound (c2) having an acidic substituent may be carried out in the presence of a reaction catalyst, if necessary. Examples of the reaction catalyst include amine-based catalysts such as triethylamine, pyridine, and tributylamine; imidazole-based catalysts such as methylimidazole and phenylimidazole; and phosphorus-based catalysts such as triphenylphosphine.
A reaction catalyst may be used individually by 1 type, and may use 2 or more types together.
When the reaction catalyst is used, the amount used is not particularly limited, but is preferably 0.001 to 100 parts by mass of the total mass of the maleimide compound (c1) and the monoamine compound (c2) having an acidic substituent. 5 parts by mass.
The reaction proceeds sufficiently even without using a reaction catalyst.

[Contents of components (A) to (C) in the thermosetting resin composition]
The thermosetting resin composition of the present invention comprises the components (A) to (C). Content of each component (however, each component is not necessarily contained in the thermosetting resin composition in the structure as it is, that is, some components are reacted, but here, for convenience, use of each component is used. The amount is referred to as “content”.) Is preferably 5 to 25 parts by mass of component (A) with respect to 100 parts by mass of the total mass of components (A) to (C) in terms of solid content. 10-20 parts by mass, component (B) is preferably 5-30 parts by mass, more preferably 10-30 parts by mass, and component (C) is preferably 45-75 parts by mass, more preferably 60-70 parts by mass. It is.
If the content of the component (A) is 5 parts by mass or more with respect to 100 parts by mass of the total mass of the components (A) to (C) in terms of solid content, the dielectric properties tend to be good, and further Solubility is ensured and it tends to be difficult to deposit during the production of the resin varnish. Moreover, since it is hard to remain an unreacted component if it is 25 mass parts or less, it exists in the tendency which can suppress the adhesive fall with copper foil.
If the content of the component (B) is 5 parts by mass or more with respect to 100 parts by mass of the total mass of the components (A) to (C) in terms of solid content, the adhesiveness with the copper foil tends to be good. It is in. Moreover, if it is 30 mass parts or less, it exists in the tendency for heat resistance to become favorable.
If the content of the component (C) is 45 parts by mass or more with respect to 100 parts by mass of the total mass of the components (A) to (C) in terms of solid content, the heat resistance tends to be excellent. Moreover, if it is 75 mass parts or less, it exists in the tendency for the fluidity | liquidity and moldability of a thermosetting resin composition to become favorable.

<Other ingredients>
The thermosetting resin composition of the present invention may contain other components other than the components (A) to (C). Examples of other components include (D) hydrogenated styrene-based thermoplastic elastomer, (E) radical reaction initiator, (F) curing accelerator, (G) flame retardant, (H) inorganic filler, colorant, Antioxidants, reducing agents, ultraviolet absorbers, fluorescent brighteners, adhesion improvers, organic fillers and the like can be mentioned, but are not particularly limited thereto. These may be used individually by 1 type and may use 2 or more types together.
In particular, the thermosetting resin composition of the present invention includes (D) a hydrogenated styrene-based thermoplastic elastomer, (E) a radical reaction initiator, (F), in addition to the components (A) to (C). It is preferable to contain at least one selected from the group consisting of a curing accelerator, (G) a flame retardant, and (H) an inorganic filler.

((D) Hydrogenated styrene thermoplastic elastomer)
By including a hydrogenated styrene-based thermoplastic elastomer [hereinafter referred to as hydrogenated styrene-based thermoplastic elastomer (D)], the dielectric properties can be further improved.
The hydrogenated styrenic thermoplastic elastomer (D) is preferably a hydrogenated product of a copolymer having a structural unit derived from a styrenic compound and a structural unit derived from a conjugated diene compound, more preferably styrene. It is a hydrogenated product of a block copolymer having a structural unit derived from a system compound and a structural unit derived from a conjugated diene compound. Examples of the styrene compound include styrene and p-methylstyrene. Examples of the conjugated diene compound include butadiene and isoprene.
Specific examples of the hydrogenated styrene-based thermoplastic elastomer (D) include a hydrogenated product of styrene-butadiene-styrene block copolymer (SEBS) and a hydrogenated product of styrene-isoprene-styrene block copolymer (SEPS). ), Hydrogenated product of styrene- (isoprene / butadiene) -styrene block copolymer (SEEPS), and the like. Among these, a hydrogenated product (SEBS) of a styrene-butadiene-styrene block copolymer is preferable.

In the hydrogenated styrene thermoplastic elastomer (D), the content of the structural unit derived from the styrene compound is preferably 10 to 70% by mass, more preferably 15 to 70% by mass, and still more preferably 20 to 70% by mass. Especially preferably, it is 20-50 mass%.
The weight average molecular weight of the hydrogenated styrene-based thermoplastic elastomer (D) is preferably 50,000 to 1,000,000, more preferably 50,000 to 450,000. Further, the hydrogenation rate of the hydrogenated styrene-based thermoplastic elastomer (D) is preferably 80 mol% or more, more preferably 90 mol% or more, and further preferably 95 mol% or more.
Commercially available products may be used as the hydrogenated styrene-based thermoplastic elastomer (D). Examples of commercially available products include “Tuftec (registered trademark) H1043”, “Tuftec (registered trademark) H1051”, and “Tuftec (registered). Trademark) H1053 "(all manufactured by Asahi Kasei Chemicals Corporation) and the like.

  When the thermosetting resin composition of the present invention contains the hydrogenated styrene-based thermoplastic elastomer (D), the content is the mass of the components (A) to (D) in terms of solid content. Preferably it is 0.1-30 mass parts with respect to 100 mass parts of total, More preferably, it is 1-20 mass parts, More preferably, it is 3-15 mass parts.

((E) radical reaction initiator)
By containing a radical reaction initiator [hereinafter referred to as radical reaction initiator (E)], the curing reaction of the thermosetting resin composition of the present invention is likely to occur.
The radical reaction initiator (E) has an effect of initiating or accelerating the curing reaction of the cured product of the thermosetting resin composition when producing a metal-clad laminate or a multilayer printed wiring board.
Examples of the radical reaction initiator (E) include α, α′-bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, di-t-hexyl peroxide, 2,5-dimethyl-2,5. A dialkyl peroxide radical initiator such as bis (t-butylperoxy) hexane, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne, di-t-butyl peroxide; p -Hydroperoxide radical initiators such as mentahydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, etc. Although it is mentioned, it is not particularly limited to these. A radical reaction initiator (E) may be used individually by 1 type, and may use 2 or more types together.
Moreover, the radical reaction initiator (E) from which a half-life temperature differs can also be combined from a viewpoint of improving the moldability when it is set as a prepreg. From the viewpoints of dielectric properties, thermal expansion coefficient, etc., p- having a reaction initiation temperature higher than dialkyl peroxide radical initiators such as α, α′-bis (t-butylperoxy) diisopropylbenzene and the like. It is preferable to use one or more radical reaction initiators selected from hydroperoxide-based radical reaction initiators such as mentahydroperoxide, diisopropylbenzene hydroperoxide and t-hexyl hydroperoxide.
When the thermosetting resin composition of the present invention contains a radical reaction initiator (E), the content is 100 mass of the total mass of components (A) to (D) in terms of solid content. Preferably it is 0.01-5 mass parts with respect to a part, More preferably, it is 0.1-3 mass part.

((F) curing accelerator)
By containing a curing accelerator [hereinafter referred to as curing accelerator (F)], the curing reaction of the thermosetting resin composition of the present invention can be promoted.
Examples of the curing accelerator (F) include imidazoles and derivatives thereof; phosphines and phosphonium salts; organophosphorus compounds such as adducts of tertiary phosphines and quinones; secondary amines and tertiary amines. And quaternary ammonium salts. A hardening accelerator may be used individually by 1 type, and may use 2 or more types together.
As the curing accelerator, for example, imidazoles and derivatives thereof are preferable from the viewpoints of adhesion to copper foil and flame retardancy.
A commercial item may be used as a hardening accelerator. Commercially available products include, for example, isocyanate mask imidazole (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: G-8809L), tetraphenylphosphonium tetra-p-tolylborate (manufactured by Hokuko Chemical Co., Ltd., trade name: TPP-MK). ), Triphenylphosphine triphenylborane (made by Hokuko Chemical Co., Ltd., trade name: TPP-S), and the like.
In the case where the thermosetting resin composition of the present invention contains a curing accelerator (F), the content thereof is (A) to (A) to solid content conversion from the viewpoint of curing acceleration effect and storage stability. (D) Preferably it is 0.01-3 mass parts with respect to 100 mass parts of total of the mass of a component, More preferably, it is 0.05-1.5 mass parts, More preferably, it is 0.1-0.8 mass parts. It is.

((G) Flame retardant)
By containing a flame retardant [hereinafter referred to as a flame retardant (G)], the flame retardancy of the thermosetting resin composition of the present invention is improved.
Examples of the flame retardant (G) include metal hydrates such as aluminum hydroxide and magnesium hydroxide having a thermal decomposition temperature of less than 300 ° C .; halogen-containing flame retardants containing bromine, chlorine, etc .; phosphorus flame retardants; Nitrogen flame retardants such as guanidine sulfamate, melamine sulfate, melamine polyphosphate, melamine cyanurate; phosphazene flame retardants such as cyclophosphazene and polyphosphazene; inorganic flame retardants such as antimony trioxide and zinc molybdate Can be mentioned. Among these, from the viewpoint of environmental protection, flame retardants other than halogen-containing flame retardants are preferable, the adhesiveness with copper foil, the elastic modulus, the thermal expansion coefficient and the like are less reduced, and high flame retardancy is imparted Is more preferably a phosphorus-based flame retardant. A flame retardant may be used individually by 1 type, and may use 2 or more types together.
Examples of the phosphorus flame retardant include an inorganic phosphorus flame retardant and an organic phosphorus flame retardant.
Examples of inorganic phosphorus flame retardants include red phosphorus; ammonium phosphates such as monoammonium phosphate, diammonium phosphate, triammonium phosphate and ammonium polyphosphate; inorganic nitrogen-containing phosphorus compounds such as phosphate amides Phosphoric acid; phosphine oxide and the like.
Examples of organic phosphorus flame retardants include aromatic phosphate esters, monosubstituted phosphonic acid diesters, disubstituted phosphinic acid esters, disubstituted phosphinic acid metal salts, organic nitrogen-containing phosphorus compounds, cyclic organophosphorus compounds, Examples thereof include phosphorus-containing phenol resins. Among these, aromatic phosphate esters and metal salts of disubstituted phosphinic acids are preferred. Here, the metal salt is preferably any one of a lithium salt, a sodium salt, a potassium salt, a calcium salt, a magnesium salt, an aluminum salt, a titanium salt, and a zinc salt, and preferably an aluminum salt. Among organic phosphorus flame retardants, aromatic phosphates are more preferable.

Examples of the aromatic phosphate ester include triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, cresyl di-2,6-xylenyl phosphate, resorcinol bis (diphenyl phosphate), 1,3 -Phenylenebis (di-2,6-xylenyl phosphate), bisphenol A-bis (diphenyl phosphate), 1,3-phenylenebis (diphenyl phosphate) and the like.
Examples of monosubstituted phosphonic acid diesters include divinyl phenylphosphonate, diallyl phenylphosphonate, and bis (1-butenyl) phenylphosphonate.
Examples of the disubstituted phosphinic acid ester include phenyl diphenylphosphinate and methyl diphenylphosphinate.
Examples of the metal salt of disubstituted phosphinic acid include a metal salt of dialkylphosphinic acid, a metal salt of diallylphosphinic acid, a metal salt of divinylphosphinic acid, a metal salt of diarylphosphinic acid, and the like. As described above, these metal salts are preferably any of lithium salt, sodium salt, potassium salt, calcium salt, magnesium salt, aluminum salt, titanium salt, and zinc salt.
Examples of the organic nitrogen-containing phosphorus compound include phosphazene compounds such as bis (2-allylphenoxy) phosphazene and dicresyl phosphazene; melamine phosphate, melamine pyrophosphate, melamine polyphosphate, melam polyphosphate, and the like.
Examples of the cyclic organophosphorus compound include 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10- (2,5-dihydroxyphenyl) -9,10-dihydro-9-oxa- Examples thereof include 10-phosphaphenanthrene-10-oxide.
Among these, from the viewpoint of dielectric properties and glass transition temperature, at least one selected from an aromatic phosphate ester, a metal salt of a disubstituted phosphinic acid, and a cyclic organic phosphorus compound is preferable. More preferred is at least one selected from metal salts of phosphinic acid.

The aromatic phosphate is preferably an aromatic phosphate represented by the following general formula (G-1) or (G-2) from the viewpoint of dielectric properties and glass transition temperature, The metal salt of disubstituted phosphinic acid is preferably a metal salt of disubstituted phosphinic acid represented by the following general formula (G-3).

(Wherein R ^{G1 to} R ^G5 are each independently an alkyl group having 1 to 5 carbon atoms or a halogen atom. E and f are each independently an integer of 0 to 5, and g, h, and i are each It is an integer of 0-4 independently.
R ^G6 and R ^G7 are each independently an alkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 14 carbon atoms. M is a lithium atom, sodium atom, potassium atom, calcium atom, magnesium atom, aluminum atom, titanium atom or zinc atom. j is an integer of 1 to 4. )

Examples of the alkyl group having 1 to 5 carbon atoms represented by R ^{G1 to} R ^G5 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, and an n-pentyl group. Groups and the like. The alkyl group is preferably an alkyl group having 1 to 3 carbon atoms. Examples of the halogen atom represented by R ^{G1 to} R ^G5 include a fluorine atom.
e and f are preferably integers of 0 to 2, and more preferably 2. g, h and i are preferably integers of 0 to 2, more preferably 0 or 1, and still more preferably 0.
Examples of the alkyl group having 1 to 5 carbon atoms represented by R ^G6 and R ^G7 include the same groups as in R ^{G1 to} R ^G5 .
Examples of the aryl group having 6 to 14 carbon atoms represented by R ^G6 and R ^G7 include a phenyl group, a naphthyl group, a biphenylyl group, and an anthryl group. The aromatic hydrocarbon group is preferably an aryl group having 6 to 10 carbon atoms.
j represents the valence of the metal ion, that is, changes within a range of 1 to 4 corresponding to the type of M.
M is preferably an aluminum atom. In addition, j is 3 when M is an aluminum atom.

  A commercially available product may be used as the flame retardant (G). Examples of commercially available products include “PX-200” (1,3-phenylenebis (di-2,6-xylenyl phosphate), phosphorus content = 9% by mass, manufactured by Daihachi Chemical Industry Co., Ltd.), “ OP-935 "(a dialkylphosphinic acid aluminum salt, phosphorus content = 23.5% by mass, manufactured by Clariant).

  When the thermosetting resin composition of the present invention contains the flame retardant (G), the content is from the viewpoint of flame retardancy of the components (A) to (D) in terms of solid content. Preferably it is 0.01-15 mass parts with respect to 100 mass parts of total mass, More preferably, it is 0.1-10 mass parts, More preferably, it is 1-8 mass parts.

((H) inorganic filler)
With the inorganic filler [hereinafter referred to as inorganic filler (H)], the thermal expansion coefficient of the thermosetting resin composition of the present invention can be reduced, and the elastic modulus, heat resistance and flame retardancy can be improved.
Examples of the inorganic filler (H) include silica, alumina, titanium oxide, mica, beryllia, barium titanate, potassium titanate, strontium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum hydroxide, and silica. Aluminum clay, calcium carbonate, calcium silicate, magnesium silicate, silicon nitride, boron nitride, calcined clay, talc, aluminum borate, silicon carbide, quartz powder, short glass fiber, fine glass powder, hollow glass, etc. Can be mentioned. Preferred examples of the glass include E glass, T glass, and D glass. An inorganic filler (H) may be used individually by 1 type, and may use 2 or more types together. Among these, silica, alumina, mica, and talc are preferable, silica and alumina are more preferable, and silica is more preferable from the viewpoints of adhesion to copper foil and flame retardancy. Examples of silica include crushed silica, fumed silica, and spherical silica. The silica is preferably spherical silica from the viewpoint of thermal expansion coefficient and fluidity when filled into the thermosetting resin composition.
Although there is no restriction | limiting in particular in the average particle diameter of a silica, 0.01-30 micrometers is preferable, 0.1-10 micrometers is more preferable, 0.3-7 micrometers is more preferable, 0.5-6 micrometers is especially preferable. By making the average particle diameter of silica 0.01 μm or more, there is a tendency to maintain good fluidity even when highly packed, and by making it 30 μm or less, the mixing probability of coarse particles is reduced and coarse particles It tends to be possible to suppress the occurrence of defects due to. Here, the average particle size is a particle size at a point corresponding to a volume of just 50% when the cumulative frequency distribution curve based on the particle size is obtained with the total volume of the particles being 100%, and the laser diffraction scattering method is used. It can be measured with the used particle size distribution measuring device or the like.
The specific surface area of silica is preferably 4 cm ² / g or more, more preferably 4 to 9 cm ² / g, and still more preferably 5 to 7 cm ² / g.

What was surface-treated with a coupling agent as an inorganic filler (H) may be used. That is, it is also preferable to employ a method in which the inorganic filler (H) such as silica is directly subjected to a surface treatment in a dry or wet manner and then used as it is or in a slurry state during blending. On the other hand, an inorganic filler (H) such as untreated silica is blended in a resin composition containing the component (A) and the component (B), and then a surface treatment agent is added to the resin composition. A blending method may be employed.
Examples of the coupling agent include amino silane coupling agents, epoxy silane coupling agents, phenyl silane coupling agents, alkyl silane coupling agents, alkenyl silane coupling agents, alkynyl silane coupling agents, Haloalkylsilane coupling agents, siloxane coupling agents, hydrosilane coupling agents, silazane coupling agents, alkoxysilane coupling agents, chlorosilane coupling agents, (meth) acrylsilane coupling agents, aminosilanes Examples include coupling agents, isocyanurate silane coupling agents, ureido silane coupling agents, mercapto silane coupling agents, sulfide silane coupling agents, and isocyanate silane coupling agents. It is. Of these, aminosilane coupling agents are preferred.
From the viewpoint of the thermal expansion coefficient and the adhesion to other components, the inorganic filler (H) is preferably silica treated with an aminosilane coupling agent, and treated with an aminosilane coupling agent. More preferred is spherical silica. By using silica treated with an aminosilane coupling agent, it is possible not only to suppress defects such as silica aggregation, but also to improve the reactivity and adhesion of silica and resin components while improving the curability of the resin components. In addition, there is a tendency that chemical resistance against various acidic aqueous solutions and basic aqueous solutions used in the printed wiring board manufacturing process is improved while improving dielectric properties, a low thermal expansion coefficient, heat resistance, and the like.

As the aminosilane coupling agent, specifically, a silane coupling agent having a silicon-containing group represented by the following general formula (H-1) and an amino group is preferable.

(In the formula, R ^H1 is an alkyl group having 1 to 3 carbon atoms or an acyl group having 2 to 4 carbon atoms. Z is an integer of 0 to 2)

Examples of the alkyl group having 1 to 3 carbon atoms represented by R ^H1 include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. Among these, a methyl group is preferable.
Examples of the acyl group having 2 to 4 carbon atoms represented by R ^H1 include an acetyl group, a propionyl group, and an acrylic group. Among these, an acetyl group is preferable.
z is preferably 0 or 1, more preferably 0.

The aminosilane coupling agent may have one amino group, two amino groups, or three or more, but usually one amino group or Have two.
Examples of the aminosilane coupling agent having one amino group include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-trimethoxysilyl- N- (1,3-dimethyl-butylidene) propylamine and its partial hydrolyzate, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine and its partial hydrolyzate, 2-propynyl [ 3- (trimethoxysilyl) propyl] carbamate and the like can be mentioned, but the invention is not particularly limited thereto.
Examples of the aminosilane coupling agent having two amino groups include N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, 1- [3- (trimethoxysilyl) propyl] urea, 1- [3- (triethoxysilyl) propyl] urea However, it is not particularly limited thereto.

As the aminosilane-based coupling agent, from the viewpoint of dispersibility of the inorganic filler (H) such as silica in the resin composition, and the reactivity and adhesiveness between the inorganic filler (H) and the resin component, the following formula N-phenyl-3-aminopropyltrimethoxysilane represented by (H1) is particularly preferred.

  When the thermosetting resin composition of this invention contains an inorganic filler (H), the content is the sum total 100 of the mass of (A)-(D) component of solid content conversion from a flame-retardant viewpoint. Preferably it is 20-110 mass parts with respect to a mass part, More preferably, it is 20-80 mass parts, More preferably, it is 30-80 mass parts, Most preferably, it is 30-70 mass parts, Most preferably, it is 40-70 mass parts. is there.

(Organic solvent)
The thermosetting resin composition of the present invention may contain an organic solvent from the viewpoint of facilitating handling by dilution and easy manufacture of a prepreg described later. In this specification, the thermosetting resin composition containing an organic solvent may be referred to as a resin varnish.
The organic solvent is not particularly limited. For example, methanol, ethanol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol, Alcohol solvents such as propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; ether solvents such as tetrahydrofuran ; Aromatic solvents such as toluene, xylene, mesitylene; Form N-methylformamide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone and other nitrogen atom-containing solvents; dimethylsulfoxide and other sulfur atom-containing solvents; methoxyethyl acetate, ethoxyethyl acetate, butoxy Examples thereof include ester solvents such as ethyl acetate, propylene glycol monomethyl ether acetate, ethyl acetate, and γ-butyrolactone.
Among these, from the viewpoint of solubility, alcohol solvents, ketone solvents, aromatic solvents, nitrogen atom-containing solvents are preferable, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl cellosolve, propylene glycol monomethyl ether, γ-butyrolactone, Toluene, dimethylformamide, and N, N-dimethylacetamide are more preferable, and methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monomethyl ether, toluene, and N, N-dimethylacetamide are more preferable, and methyl isobutyl ketone, toluene, and N, N-dimethylacetamide Is particularly preferred.
An organic solvent may be used individually by 1 type, and may use 2 or more types together. When an organic solvent is used in combination, a ketone solvent and an aromatic solvent are particularly preferable, and methyl isobutyl ketone and toluene are more preferable.
The content of the organic solvent in the thermosetting resin composition of the present invention may be appropriately adjusted to such an extent that the thermosetting resin composition can be easily handled, and the range in which the coating property of the resin varnish is good. If it is, there will be no restriction | limiting in particular, However, Solid content concentration (concentration of components other than an organic solvent) of a thermosetting resin composition becomes like this. Preferably it is 30-90 mass%, More preferably, it is 40-80 mass%, More preferably, it is 50 ˜80 mass%.

(Physical properties and properties of thermosetting resin composition)
The thermosetting resin composition of the present invention is excellent in adhesiveness and dielectric properties with copper foil, has a high glass transition temperature, a low thermal expansion coefficient, and is excellent in moldability. Moreover, this thermosetting resin composition is excellent also in the solubility with respect to the organic solvent.
About the adhesiveness with the copper foil of the thermosetting resin composition of this invention, when it says with the peel strength of the copper foil measured by the method as described in an Example, it is 0.50 kN / m or more, and it is 0 in detail. .60 kN / m or more, more specifically in the range of 0.60 to 0.80 kN / m.
The dielectric property of the thermosetting resin composition of the present invention is 4.0 or less, specifically 3.95 or less in terms of relative dielectric constant measured by the method described in Examples, and more specifically. Is in the range of 3.80 to 3.95. The dielectric loss tangent measured by the method described in the examples is 0.0070 or less, specifically 0.0063 or less, and more specifically in the range of 0.0045 to 0.0063.
The glass transition temperature of the thermosetting resin composition of the present invention is 170 ° C. or higher, specifically 175 ° C. or higher, more specifically 175 to 186 ° C., as measured by the method described in the examples. It is in.
The thermal expansion coefficient of the thermosetting resin composition of the present invention is 48 ppm / ° C. or less, specifically in the range of 42 to 47.5 ppm / ° C., as measured by the method described in the examples. Preferably it is 48 ppm / degrees C or less, More preferably, it is 40-48 ppm / degrees C.

[Prepreg]
The present invention also provides a prepreg comprising the thermosetting resin composition.
The prepreg of the present invention can be produced by impregnating or coating the thermosetting resin composition on a sheet-like reinforcing base material and semi-curing (B-stage) by heating or the like.
As the prepreg sheet-like reinforcing substrate, known materials used for various types of laminates for electrical insulating materials can be used. The material of the sheet-like reinforcing substrate includes natural fibers such as paper and cotton linter; inorganic fibers such as glass fiber and asbestos; organic fibers such as aramid, polyimide, polyvinyl alcohol, polyester, polytetrafluoroethylene, and acrylic; And the like. Among these, glass fiber is preferable from the viewpoint of flame retardancy. Glass fiber base materials include woven fabrics using E glass, C glass, D glass, S glass, etc., or glass woven fabrics in which short fibers are bonded with an organic binder; Can be mentioned. More preferably, it is a glass woven fabric using E glass.
These sheet-like reinforcement base materials have shapes, such as a woven fabric, a nonwoven fabric, a robink, a chopped strand mat, or a surfacing mat, for example. In addition, a material and a shape are selected by the use and performance of the target molding, and 1 type may be used independently and 2 or more types of materials and shapes can also be combined as needed.

As a method for impregnating or applying the thermosetting resin composition to the sheet-like reinforcing base material, the following hot melt method or solvent method is preferable.
The hot melt method is a method in which an organic solvent is not contained in a thermosetting resin composition, and (1) a coated paper having good peelability from the composition is once coated and laminated on a sheet-like reinforcing substrate. Or (2) A method of directly coating the sheet-like reinforcing substrate with a die coater.
On the other hand, in the solvent method, a resin varnish is prepared by adding an organic solvent to a thermosetting resin composition, and a sheet-like reinforcing base material is immersed in the resin varnish to impregnate the sheet-like reinforcing base material. Then, it is a method of drying.

The thickness of the sheet-like reinforcing base material is not particularly limited, and for example, about 0.03 to 0.5 mm can be used, and the surface treatment with a silane coupling agent or the like or mechanical fiber opening treatment is performed. What has been applied is preferred from the viewpoints of heat resistance, moisture resistance and processability. After impregnating or coating the base material with the thermosetting resin composition, it is usually preferably dried by heating at 100 to 200 ° C. for 1 to 30 minutes and semi-curing (B-stage). A prepreg can be obtained.
The obtained prepreg is used as a single sheet, or preferably 2 to 20 sheets are used in an overlapping manner as necessary.

[Copper laminate]
The copper clad laminate of the present invention is obtained by laminating the prepreg and copper foil. For example, it can be manufactured by using one sheet of the prepreg or stacking 2 to 20 sheets as necessary, and laminating with a structure in which a copper foil is disposed on one or both sides.
As the molding conditions for the copper clad laminate, a known molding technique for laminates for electrical insulation materials and multilayer plates can be applied. For example, a multistage press, a multistage vacuum press, continuous molding, an autoclave molding machine, etc. are used. It can be molded at a temperature of 100 to 250 ° C., a pressure of 0.2 to 10 MPa, and a heating time of 0.1 to 5 hours.
Moreover, the prepreg of the present invention and the printed wiring board for inner layer can be combined and laminated to produce a multilayer board.
There is no restriction | limiting in particular in the thickness of copper foil, According to the use etc. of a printed wiring board, it can select suitably. The thickness of the copper foil is preferably 0.5 to 150 μm, more preferably 1 to 100 μm, still more preferably 5 to 50 μm, and particularly preferably 5 to 30 μm.

In addition, it is also preferable to form a plating layer by plating copper foil.
The metal of the plating layer is not particularly limited as long as it can be used for plating. The metal of the plating layer is preferably made of copper, gold, silver, nickel, platinum, molybdenum, ruthenium, aluminum, tungsten, iron, titanium, chromium, or an alloy containing at least one of these metal elements. Preferably it is selected.
There is no restriction | limiting in particular as a plating method, For example, a well-known method, for example, the electroplating method and the electroless-plating method, can be utilized.

[Printed wiring board]
The present invention also provides a printed wiring board using the copper clad laminate.
The printed wiring board of the present invention can be produced by subjecting a metal foil of a copper-clad laminate to circuit processing. For example, after forming a resist pattern on the surface of the copper foil, the unnecessary portion of the copper foil is removed by etching, the resist pattern is peeled off, a necessary through hole is formed by a drill, and a resist pattern is formed again. It can be performed by plating for conducting through holes and finally peeling off the resist pattern. The copper-clad laminate is further laminated on the surface of the printed wiring board thus obtained under the same conditions as described above, and further, the circuit is processed in the same manner as described above to obtain a multilayer printed wiring board. Can do. In this case, it is not always necessary to form a through hole, a via hole may be formed, and both can be formed. Such multi-layering is performed as many times as necessary.

  Next, the present invention will be described in more detail with reference to the following examples, but these examples are not intended to limit the present invention in any way. Using the thermosetting resin composition according to the present invention, a prepreg and a copper-clad laminate were produced, and the produced copper-clad laminate was evaluated. The evaluation method is shown below.

[Evaluation method]
<1. Presence or absence of precipitates in resin varnish>
The resin varnish produced in each example was passed through a nylon # 200 sieve “N-NO. 200HD” (manufactured by NBC Meshtec Co., Ltd.), and the presence or absence of precipitates was visually confirmed.

<2. Adhesiveness with copper foil (copper foil peel strength)>
The copper clad laminate produced in each example was immersed in a copper etching solution “ammonium persulfate (APS)” (manufactured by ADEKA Corporation) to form a copper foil having a width of 3 mm to produce an evaluation board, and a tensile tester “ The peel strength of the copper foil was measured using “Ez-Test” (manufactured by Shimadzu Corporation) and used as an index of adhesiveness with the copper foil. It shows that it is excellent in adhesiveness with copper foil, so that a value is large. In particular, 0.50 kN / m or more is preferable, and 0.60 kN / m or more is more preferable.

<3. Dielectric properties (dielectric constant Dk, dielectric loss tangent Df)>
The copper clad laminate produced in each example was immersed in a copper etching solution “Ammonium Persulfate (APS)” (manufactured by ADEKA Corporation) to remove the copper foil, and then cut to 2 mm × 85 mm to obtain a network analyzer “E8364B”. The relative permittivity and dielectric loss tangent of the copper-clad laminate at 5 GHz were measured by a cavity resonator perturbation method using (Agilent Technologies).
The smaller the relative dielectric constant and the dielectric loss tangent, the better. In particular, the relative dielectric constant is preferably 4.0 or less, and the dielectric loss tangent is preferably 0.0070 or less.

<4. Glass transition temperature (Tg)>
The copper-clad laminate produced in each example was immersed in a copper etching solution “Ammonium Persulfate (APS)” (manufactured by ADEKA Corporation) to produce a 5 mm square evaluation board from which the copper foil was removed, and a TMA test apparatus “Q400EM ”(Manufactured by TA Instruments Co., Ltd.), the thermal expansion characteristics in the surface direction (Z direction) of the evaluation substrate in the range of 25 to 330 ° C. (temperature increase rate: 10 ° C./min) are observed, and the inflection point of the expansion amount is made of glass. The transition temperature was used.
The glass transition temperature is preferably 170 ° C. or higher, and more preferably 175 ° C. or higher.

<5. Thermal expansion coefficient>
The copper-clad laminate produced in each example was immersed in a copper etching solution “Ammonium Persulfate (APS)” (manufactured by ADEKA Corporation) to produce a 5 mm square evaluation board from which the copper foil was removed, and a TMA test apparatus “Q400EM ”(Manufactured by TA Instruments) was used to measure the coefficient of thermal expansion (linear expansion coefficient) in the surface direction (Z direction) of the evaluation substrate. In addition, in order to remove the influence of the thermal strain which a sample has, the temperature rising-cooling cycle was repeated twice, and the thermal expansion coefficient [ppm / ° C.] of 30 ° C. to 260 ° C. in the second temperature displacement chart was measured. The smaller the value, the better.
Measurement conditions 1st Run: room temperature → 210 ° C. (temperature increase rate 10 ° C./min)
2nd Run: 0 ° C. → 270 ° C. (temperature increase rate: 10 ° C./min)
The copper-clad laminate is desired to be further reduced in thickness, and in conjunction with this, the prepreg constituting the copper-clad laminate is also being considered to be thinner. Since the thinned prepreg is likely to warp, it is desired that the prepreg warp during heat treatment be small. In order to reduce the warpage, it is effective that the thermal expansion coefficient in the surface direction of the base material is small.
The thermal expansion coefficient is particularly preferably 48 ppm / ° C. or less.

<6. Formability>
A prepreg with a thickness of 0.05 mm is stacked on each side of a moldability confirmation substrate on which a pattern having a copper thickness of 18 μm and a residual copper ratio of 60% is fabricated, and further, a 18 μm copper foil “YGP-18” (NIPPON ELECTRIC CO., LTD.) One by one was piled up one by one, and heat-pressed for 90 minutes at a temperature of 200 ° C. and a pressure of 25 kgf / cm ² (= 2.45 MPa) to produce a four-layer copper-clad laminate. After removing the outer layer copper of the four-layer copper-clad laminate, the resin embedding property, void, fading, and the like were visually confirmed. When the embedding property of the resin was good and there was no void or blur, the moldability was evaluated as good. If there were voids or faintness, this was indicated.

  Hereinafter, each component used in Examples and Comparative Examples will be described.

(A) component:
"SMA (registered trademark) EF80" (styrene / maleic anhydride = 8, Mw = 14,400, manufactured by Sartomer)

Component (B): A compound having a dihydrobenzoxazine ring produced according to the following Production Example 1 was used.
[Production Example 1]
1,000 g (10.6 mol) of phenol was added to 920 g of methanol and dissolved while stirring. To this, 652 kg of formaldehyde was added. Next, 930 g (9.99 mol) of aniline was added dropwise over 1 hour with stirring, and the temperature was adjusted to 78 to 80 ° C. after 1 hour. After reacting for 7 hours under reflux, concentration under reduced pressure was started at 60 mmHg (80 hPa). Concentration was continued while maintaining the reduced pressure, and when the temperature reached 110 ° C., the reduced pressure was set to 90 mmHg (120 hPa). After confirming that the distillate was gone, the product was taken out into a vat. Thus, a compound having a dihydrobenzoxazine ring was obtained.

(B) Component phenol resin for comparison, “KA-1165” (cresol novolac resin, manufactured by DIC Corporation)
・ "HP-350N" (phenol resin, manufactured by Hitachi Chemical Co., Ltd.)

(C) Component: The maleimide compound manufactured according to the following manufacture example 2 was used.
[Production Example 2]
In a reaction vessel with a volume of 2 liters that can be heated and cooled, equipped with a thermometer, a stirrer, and a moisture meter with a reflux condenser, 1,000 g (2) of the following bis (4-maleimidophenyl) ether [(c1) component] .90 mol), p-aminophenol (manufactured by Ihara Chemical Industry Co., Ltd.) [component (c2)] 80 g (0.73 mol) and N, N-dimethylacetamide 850 g ([maleimide group equivalent] / [— NH ₂ group] Equivalent]] = 7.9) and reacted at 100 ° C. for 2 hours to obtain a solution of the maleimide compound, which was used as the maleimide compound (C).

Component (D): Hydrogenated styrene-based thermoplastic elastomer “Tuftec (registered trademark) H1053” (SEBS, styrene content = 29 mass%, manufactured by Asahi Kasei Chemicals Corporation)
・ "Tuftec (registered trademark) H1051" (SEBS, styrene content = 42% by mass, manufactured by Asahi Kasei Chemicals Corporation)
・ "Tuftec (registered trademark) H1043" (SEBS, styrene content = 67 mass%, manufactured by Asahi Kasei Chemicals Corporation)

(E) Component: Radical reaction initiator “Perbutyl (registered trademark) P” (α, α′-bis (t-butylperoxy) diisopropylbenzene, manufactured by NOF Corporation)

(F) Component: Curing accelerator “G-8809L” (isocyanate mask imidazole (addition reaction product of hexamethylene diisocyanate resin and 2-ethyl-4-methylimidazole), manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)

Component (G): Flame retardant / Flame retardant 1: “PX-200” (1,3-phenylenebis (di-2,6-xylenyl phosphate), phosphorus content = 9 mass%, Daihachi Chemical Industry Co., Ltd. Company-made)
Flame retardant 2: “OP-935” (aluminum salt of dialkylphosphinic acid, phosphorus content = 23.5% by mass, manufactured by Clariant)

Component (H): Inorganic filler / Inorganic filler 1: “Megasil 525 ARI” (spherical silica treated with an aminosilane coupling agent, average particle size = 1.9 μm, specific surface area = 5.8 m ² / g, Sibelco Japan Co., Ltd.)
Inorganic filler 2: “F05-30” (untreated crushed silica, average particle size = 4.2 μm, specific surface area = 5.8 m ² / g, manufactured by Fukushima Ceramics Co., Ltd.)

[Examples 1-6, Comparative Examples 1-4]
Each component shown above was blended as shown in Table 1 below (unit: parts by mass. However, in the case of a solution, the amount in terms of solid content is shown), and toluene was added so that the nonvolatile content of the solution was 56% by mass. And methyl ethyl ketone was added and the thermosetting resin composition (resin varnish) of each Example and each comparative example was prepared. Using the thermosetting resin composition, the presence or absence of precipitates was confirmed according to the method described above.
Each of the obtained thermosetting resin compositions was impregnated into 0.1 mm thick E glass cloth “# 3313” (model number, manufactured by Nitto Boseki Co., Ltd.), dried by heating at 140 ° C. for 5 minutes, and a prepreg ( Resin content: 54 ± 2% by mass).
18 μm copper foil “3EC-VLP-18” (manufactured by Mitsui Kinzoku Co., Ltd.) was layered on both sides of the 8 prepregs stacked, and heated and pressed at a temperature of 200 ° C. and a pressure of 2.5 MPa for 80 minutes. A double-sided copper-clad laminate having a thickness of 0.8 mm (eight prepregs) was produced.
Using the copper-clad laminate or resin plate thus produced, measurement and evaluation of adhesion to copper foil, heat resistance, dielectric properties, glass transition temperature, thermal expansion coefficient, and moldability were carried out according to the above-described methods. The results are shown in Table 1.

From Table 1, in Examples 1-6, the outstanding dielectric characteristic was shown, maintaining high adhesiveness with copper foil. Furthermore, it has a high glass transition temperature and a low coefficient of thermal expansion. Moreover, abnormality, such as a void and a blur, is not confirmed but it turns out that a moldability is also favorable. Excellent solubility in organic solvents.
On the other hand, in Comparative Examples 1 to 4 using a phenol resin instead of the component (B), the adhesiveness with the copper foil is lowered, the dielectric properties are deteriorated, the glass transition temperature is lowered, and the thermal expansion coefficient is Increased and moldability decreased.

  The thermosetting resin composition of the present invention and the prepreg formed using the thermosetting resin composition have high adhesion to copper foil, excellent dielectric properties, high glass transition temperature, low thermal expansion coefficient, and good Therefore, it is useful as a copper-clad laminate and printed wiring board for electronic equipment.

Claims (13)

(A) a copolymer resin having a structural unit derived from an aromatic vinyl compound and a structural unit derived from maleic anhydride,
(B) a compound having a dihydrobenzoxazine ring, and (C) a maleimide compound,
A thermosetting resin composition comprising: The thermosetting resin composition according to claim 1, wherein the component (B) includes a compound represented by the following general formula (B).

(In the formula, R ^B1 is an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 4 to 8 carbon atoms, or an aryl group having 6 to 14 carbon atoms, or an alkyl group having 1 to 3 carbon atoms. And an aryl group having 6 to 14 carbon atoms substituted with at least one organic group selected from the group consisting of alkoxyl groups having 1 to 3 carbon atoms.) The component (A) includes a structural unit derived from an aromatic vinyl compound represented by the following general formula (Ai) and a structural unit derived from maleic anhydride represented by the following formula (A-ii). The thermosetting resin composition according to claim 1, which is a copolymer resin.

(In the formula, R ^A1 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ^A2 is an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or 6 to 20 carbon atoms. An aryl group, a hydroxyl group or a (meth) acryloyl group, wherein x is an integer of 0 to 3. However, when x is 2 or 3, a plurality of R ^A2 may be the same or different. May be.)   In the component (A), the content ratio of the structural unit derived from the aromatic vinyl compound to the structural unit derived from maleic anhydride [structural unit derived from the aromatic vinyl compound / structural unit derived from maleic anhydride] ( The thermosetting resin composition of any one of Claims 1-3 whose molar ratio is 2-9.   The thermosetting resin composition according to any one of claims 1 to 4, wherein the component (C) is a maleimide compound having at least two N-substituted maleimide groups in one molecule. The component (C) is a maleimide compound in which the maleimide compound (c1) represented by the following general formula (c1-1) or (c1-2) is modified with a monoamine compound (c2) having an acidic substituent. The thermosetting resin composition according to any one of claims 1 to 5.

(Wherein R ^{C1 to} R ^C3 each independently represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom. X ^C1 is an alkylene group having 1 to 5 carbon atoms and 2 to 5 carbon atoms. An alkylidene group, -O-, -C (= O)-, -S-, -SS- or a sulfonyl group, wherein p, q and r are each independently an integer of 0 to 4; ) The thermosetting resin composition according to claim 6, wherein the monoamine compound (c2) having an acidic substituent is represented by the following general formula (c2-1).

(Wherein R ^C4 represents an acidic substituent selected from a hydroxyl group, a carboxy group, and a sulfonic acid group. R ^C5 represents an alkyl group having 1 to 5 carbon atoms or a halogen atom. T represents 1 to 5) Integer, u is an integer of 0 to 4 and satisfies 1 ≦ t + u ≦ 5, provided that when t is an integer of 2 to 5, a plurality of R ^C4 may be the same or different. In addition, when u is an integer of 2 to 4, a plurality of R ^C5 may be the same or different. The thermosetting resin composition according to claim 1, wherein the component (C) includes a compound represented by the following general formula (C-1) or the following general formula (C-2). object.

(Wherein R ^{C1 to} R ^C3 each independently represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom. X ^C1 is an alkylene group having 1 to 5 carbon atoms and 2 to 5 carbon atoms. An alkylidene group, -O-, -C (= O)-, -S-, -SS- or a sulfonyl group, wherein p, q and r are each independently an integer of 0 to 4;
R ^C4 represents an acidic substituent selected from a hydroxyl group, a carboxy group, and a sulfonic acid group. R ^C5 represents an alkyl group having 1 to 5 carbon atoms or a halogen atom. t is an integer of 1 to 5, u is an integer of 0 to 4, and 1 ≦ t + u ≦ 5 is satisfied. However, when t is an integer of 2 to 5, the plurality of R ^C4 may be the same or different. Moreover, when u is an integer of 2-4, several ^RC5 may be the same and may differ. )   The thermosetting resin composition according to claim 1, further comprising (D) a hydrogenated styrene-based thermoplastic elastomer.   Furthermore, it contains at least one selected from the group consisting of (E) a radical reaction initiator, (F) a curing accelerator, (G) a flame retardant and (H) an inorganic filler. The thermosetting resin composition according to any one of the above.   The prepreg containing the thermosetting resin composition of any one of Claims 1-10.   A copper-clad laminate obtained by laminating the prepreg according to claim 11 and a copper foil.   The printed wiring board formed using the copper clad laminated board of Claim 12.