JP2022111423A - Thermosetting cyclic imide resin composition - Google Patents

Abstract

To provide a thermosetting cyclic imide resin composition whose cured product is excellent in dielectric characteristics and has strong adhesive force to an organic resin and copper.SOLUTION: A thermosetting cyclic imide resin composition contains: (A) a styrenic elastomer; (B) a cyclic imide compound containing at least one dimer acid skeleton, at least one C6 or higher linear alkylene group, and at least two cyclic imide groups in one molecule; (C) an epoxy resin having two or more epoxy groups in one molecule; and (D) a reaction accelerator. The mass ratio of the components (A), (B), and (C) is such that the total amount of the component (B) and the component (C) is 1-50 pts. mass based on 100 pts. mass of the component (A), and the amount of the component (B) is greater than the amount of the component (C).SELECTED DRAWING: None

Description

The present invention relates to a thermosetting cyclic imide resin composition, uncured and cured resin films comprising the resin composition, adhesives, and substrates containing the thermosetting cyclic imide resin composition.

In recent years, 5G, a next-generation mobile communication system, has become popular, and attempts are being made to realize high-speed, large-capacity, low-delay communication. In order to achieve these, materials for high-frequency bands are necessary, and since reduction of transmission loss is essential as a countermeasure against noise, the development of insulating materials with excellent dielectric properties is required.

Among them, there is a demand for an insulating material having such excellent dielectric properties for use as a substrate. There is a demand for insulating materials with excellent dielectric properties for substrates such as rigid substrates and flexible substrates. For rigid substrates, reactive polyphenylene ether resin (PPE) A product called modified polyimide (MPI), which is an improved polyimide, has come to be used.

When manufacturing the above-mentioned FPC, an adhesive is required for attaching the base film or the coverlay film to the surface having the wiring portion using a hot press or the like. Conventionally, an adhesive mainly using an epoxy resin has been used, but recently, adhesives with excellent dielectric properties have been required.

Against this background, adhesives with excellent dielectric properties have been reported (for example, Patent Documents 1 to 4), but most of them are combinations of epoxy resins, other thermosetting resins and thermoplastic resins. These compositions have excellent dielectric properties in the frequency range of 10 GHz or less, but 5G is required to have dielectric properties in the frequency range of 28 GHz or higher, which is called millimeter waves. At present, many of the said adhesives cannot be said to have sufficient dielectric properties.

Further, a resin composition containing a special maleimide compound and a thermoplastic resin is disclosed as a composition having excellent high-frequency characteristics and a high level of adhesion to conductors (Patent Document 5).

JP 2008-248141 A JP 2011-68713 A International Publication No. 2016-17473 JP 2016-79354 A WO2018-16489

However, the resin composition described in Patent Document 5 is in the form of a varnish and does not have compatibility between the resins, and the varnish is separated. It was confirmed that the properties did not appear, and it was found that it was not suitable for use as a substrate.
Therefore, the present invention provides a thermosetting cyclic imide resin composition having excellent dielectric properties and strong adhesion to organic resins such as LCP and MPI and copper, as well as uncured and cured resin films and adhesive An object of the present invention is to provide a substrate containing a thermosetting cyclic imide resin composition.

Means for Solving the Problems As a result of earnest research to solve the above problems, the present inventors have found that the following thermosetting cyclic imide resin composition can achieve the above objects, and completed the present invention.

（式（１）中、
Ａは独立して環状構造を有する４価の有機基であり、
Ｂは独立して炭素数６～２００の２価炭化水素基であり、
Ｑは独立して下記式（２）

（式（２）中、Ｒ¹は独立して、水素原子又は炭素数１～５のアルキル基であって、ｘ１及びｘ２はそれぞれ独立に０～４の数である。）
で示されるシクロヘキサン骨格を有する炭素数６～６０の２価の脂環式炭化水素基であり、
ＷはＢ又はＱであり、
ｎは０～１００であり、ｍは０～２００であるが、ｎ及びｍは同時に０とはならず、
ｎ及びｍで括られた各繰り返し単位の順序は限定されず、結合様式は、交互であっても、ブロックであっても、ランダムであってもよい。）

＜４＞
式（１）中のＡが下記構造式で示される４価の有機基のいずれかである＜３＞に記載の熱硬化性環状イミド樹脂組成物。

（上記構造式中の置換基が結合していない結合手は、式（１）において環状イミド構造を形成するカルボニル炭素と結合するものである。）

＜５＞
（Ｄ）成分の反応促進剤が少なくともアニオン重合開始触媒及びラジカル重合開始剤のいずれである＜１＞から＜４＞のいずれかに１項に記載の熱硬化性環状イミド樹脂組成物。

＜６＞
（Ｅ）成分としてさらに接着助剤を含む＜１＞から＜５＞のいずれかに１項に記載の熱硬化性環状イミド樹脂組成物。

＜７＞
＜１＞に記載の熱硬化性環状イミド樹脂組成物からなる未硬化樹脂フィルム。

＜８＞
＜１＞に記載の熱硬化性環状イミド樹脂組成物からなる硬化樹脂フィルム。

＜９＞
＜１＞に記載の熱硬化性環状イミド樹脂組成物からなる接着剤。

＜１０＞
＜１＞に記載の熱硬化性環状イミド樹脂組成物を含む基板。 <1>
(A) a styrene-based elastomer,
(B) a cyclic imide compound containing, in one molecule, at least one dimer acid skeleton, at least one linear alkylene group having 6 or more carbon atoms, and at least two cyclic imide groups;
(C) an epoxy resin having two or more epoxy groups in one molecule and (D) a reaction accelerator,
The mass ratio of components (A), (B) and (C) is 1 to 50 parts by mass per 100 parts by mass of component (A), and the total amount of components (B) and (C) is 1 to 50 parts by mass, and , a thermosetting cyclic imide resin composition, wherein the amount of component (B) is greater than the amount of component (C).

<2>
The thermosetting according to <1>, wherein the styrene-based elastomer of component (A) is a partially or completely hydrogenated copolymer of styrene and an alkene and/or a non-conjugated diene. cyclic imide resin composition.

<3>
<1> or <2>, wherein the cyclic imide compound of component (B) is a maleimide compound represented by the following formula (1) and having at least one dimer acid skeleton in one molecule. A thermosetting cyclic imide resin composition.

(In formula (1),
A is independently a tetravalent organic group having a cyclic structure,
B is independently a divalent hydrocarbon group having 6 to 200 carbon atoms,
Q is independently the following formula (2)

(In formula (2), R ¹ is independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and x1 and x2 are each independently a number of 0 to 4.)
A divalent alicyclic hydrocarbon group having 6 to 60 carbon atoms and having a cyclohexane skeleton represented by
W is B or Q;
n is 0 to 100 and m is 0 to 200, but n and m are not 0 at the same time,
The order of each repeating unit bracketed by n and m is not limited, and the binding mode may be alternating, block, or random. )

<4>
The thermosetting cyclic imide resin composition according to <3>, wherein A in formula (1) is any one of tetravalent organic groups represented by the following structural formulas.

(The bond to which no substituent is bonded in the above structural formula is bonded to the carbonyl carbon that forms the cyclic imide structure in formula (1).)

<5>
The thermosetting cyclic imide resin composition according to any one of <1> to <4>, wherein the reaction accelerator of component (D) is at least one of an anionic polymerization initiation catalyst and a radical polymerization initiator.

<6>
The thermosetting cyclic imide resin composition according to any one of <1> to <5>, further comprising an adhesion aid as component (E).

<7>
An uncured resin film made of the thermosetting cyclic imide resin composition according to <1>.

<8>
A cured resin film comprising the thermosetting cyclic imide resin composition according to <1>.

<9>
An adhesive comprising the thermosetting cyclic imide resin composition according to <1>.

<10>
A substrate containing the thermosetting cyclic imide resin composition according to <1>.

The thermosetting cyclic imide resin composition of the present invention does not separate even if it is a varnish, and the cured product thereof has excellent dielectric properties and adhesive strength. It has strong adhesion. Therefore, the thermosetting cyclic imide resin composition of the present invention is particularly useful as an FPC material.

The present invention will be described in more detail below.

(A) Styrene-based elastomer The styrene-based elastomer of component (A) mainly has low dielectric properties at high frequencies of the cured composition, improves heat resistance and adhesiveness, and improves flexibility when the composition is made into a film. is not particularly limited as long as it is a thermoplastic elastomer having a structural unit derived from a styrene-based compound, and a thermoplastic elastomer having a structural unit derived from styrene may be used.

In the present invention, the styrenic elastomer is preferably a copolymer of styrene and an alkene and/or a non-conjugated diene, which is partially or completely hydrogenated. That is, block copolymers and/or random copolymers having styrene as a hard segment and alkenes and/or non-conjugated dienes as soft segments. Examples of styrene-based elastomers include styrene/butadiene/styrene block/random Copolymers, styrene/isoprene/styrene block/random copolymers, styrene/ethylene/butylene/styrene block/random copolymers, styrene/ethylene/propylene/styrene block/random copolymers, styrene/butadiene - Block/random copolymers and the like can be mentioned. Block copolymers are preferred for quality stability.

From the viewpoint of heat resistance, styrene/ethylene/butylene/styrene block/random copolymers, styrene/ethylene/propylene/styrene block/ Random copolymers, styrene/butadiene block/random copolymers and the like are preferably used. Hydrogenation may be partial hydrogenation or complete hydrogenation, but from the viewpoint of heat resistance, complete hydrogenation or a high degree of hydrogenation is more preferable.

The mass ratio of styrene/conjugated diene and hydrogenated double bonds thereof in the styrene copolymer is preferably from 10/90 to 70/30, more preferably from 20/80 to 67/33. If the mass ratio is within this range, a composition with excellent compatibility and dispersibility and stable quality can be obtained. That is, the styrene content based on mass in the styrene elastomer is preferably 10 to 90%, more preferably 20 to 67%.

The styrene elastomer may be modified with a carboxyl group, an amino group, or the like. The styrenic elastomer can be modified, for example, by copolymerizing an unsaturated carboxylic acid during polymerization of the styrenic elastomer. It can also be carried out by heating and kneading a styrene-based elastomer and an unsaturated carboxylic acid in the presence of an organic peroxide. Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, maleic anhydride, itaconic anhydride, and fumaric anhydride.

The number average molecular weight (Mn) of the styrene elastomer (A) is preferably 10,000 to 300,000, more preferably 10,000 to 200,000. If the number average molecular weight is within the specified range, the resulting composition has excellent film properties, and has excellent compatibility and dispersibility with other components such as component (B) and component (C). Shows adhesion.
The number average molecular weight referred to in the present invention refers to the number average molecular weight measured by gel permeation chromatography (GPC) under the following conditions using polystyrene as a standard substance.

[Measurement condition]
Developing solvent: tetrahydrofuran (THF)
Flow rate: 0.35mL/min
Detector: Differential Refractive Index Detector (RI)
Column: TSK Guard column SuperH-L
TSKgel SuperHZ4000 (4.6mm ID x 15cm x 1)
TSKgel SuperHZ3000 (4.6mm ID x 15cm x 1)
TSKgel SuperHZ2000 (4.6mm I.D. x 15cm x 2)
(both manufactured by Tosoh Corporation)
Column temperature: 40°C
Sample injection volume: 5 μL (THF solution with a concentration of 0.2% by mass)

(A) A commercially available styrene-based elastomer may be used. Specific examples include the Tuftec series manufactured by Asahi Kasei Corporation and the Hybler series manufactured by Kuraray. In the composition of the present invention, one type of styrene elastomer may be used alone, or two or more types may be mixed and used.

(B) Specific cyclic imide compound The component (B) used in the present invention is a specific cyclic imide compound having at least one dimer acid skeleton and at least one linear alkylene group having 6 or more carbon atoms in one molecule. , and at least two cyclic imido groups.

The dimer acid referred to here is a liquid dibasic acid mainly composed of dicarboxylic acid having 36 carbon atoms, which is produced by dimerization of unsaturated fatty acid having 18 carbon atoms obtained from natural products such as vegetable oils and fats. It is an acid, and a dimer acid (dimer diamine) skeleton refers to a structure obtained by removing the carboxy group (amino group) from the dimer acid. Therefore, it is known that the dimer acid skeleton is not a single skeleton, but has multiple structures and several isomers. Typical dimer acids are classified under the names of straight chain type (a), monocyclic type (b), aromatic ring type (c), and polycyclic type (d).
That is, the component (B) preferably has, as a dimer acid skeleton, groups obtained by removing two carboxyl groups from the dimer acids shown in (a) to (d) below.

As the cyclic imide compound (B), a maleimide compound represented by the following formula (1) and having at least one dimer acid skeleton in one molecule is preferable. When the maleimide compound represented by the following formula (1) is used, the resulting film has good mechanical properties both before and after curing, is easy to handle, and has high compatibility with component (C) described later. It is possible to obtain a composition with uniform properties depending on the location. Moreover, by blending the component (B), the composition has strong adhesion to the copper foil and is highly reliable.

（式（１）中、
Ａは独立して環状構造を有する４価の有機基であり、
Ｂは独立して炭素数６～２００の２価炭化水素基であり、
Ｑは独立して下記式（２）

（式（２）中、Ｒ¹は独立して、水素原子又は炭素数１～５のアルキル基であって、ｘ１及びｘ２はそれぞれ独立に０～４の数である。）
で示されるシクロヘキサン骨格を有する炭素数６～６０の２価の脂環式炭化水素基であり、
ＷはＢ又はＱであり、
ｎは０～１００であり、ｍは０～２００であるが、ｎ及びｍは同時に０とはならず、
ｎ及びｍで括られた各繰り返し単位の順序は限定されず、結合様式は、交互であっても、ブロックであっても、ランダムであってもよい。）

(In formula (1),
A is independently a tetravalent organic group having a cyclic structure,
B is independently a divalent hydrocarbon group having 6 to 200 carbon atoms,
Q is independently the following formula (2)

(In formula (2), R ¹ is independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and x1 and x2 are each independently a number of 0 to 4.)
A divalent alicyclic hydrocarbon group having 6 to 60 carbon atoms and having a cyclohexane skeleton represented by
W is B or Q;
n is 0 to 100 and m is 0 to 200, but n and m are not 0 at the same time,
The order of each repeating unit bracketed by n and m is not limited, and the binding mode may be alternating, block, or random. )

（上記構造式中の置換基が結合していない結合手は、一般式（１）において環状イミド構造を形成するカルボニル炭素と結合するものである。） Here, in the above formula (1), A independently represents a tetravalent organic group having a cyclic structure, preferably any one of the tetravalent organic groups represented by the following structural formulas.

(The bond to which no substituent is bonded in the above structural formula is bonded to the carbonyl carbon that forms the cyclic imide structure in general formula (1).)

In the above formula (1), B is independently a divalent hydrocarbon group having 6 to 200 carbon atoms, preferably 8 to 100 carbon atoms, more preferably 10 to 50 carbon atoms. Among them, branched 2 in which one or more hydrogen atoms in the divalent hydrocarbon group are substituted with an alkyl or alkenyl group having 6 to 200 carbon atoms, preferably 8 to 100 carbon atoms, more preferably 10 to 50 carbon atoms. A valent hydrocarbon group is preferred. The branched divalent hydrocarbon group may be either a saturated aliphatic hydrocarbon group or an unsaturated hydrocarbon group, and may have an alicyclic structure or an aromatic ring structure in the middle of the molecular chain.
Specific examples of the branched divalent hydrocarbon group include divalent hydrocarbon groups derived from diamines at both ends, called dimer diamine. Dimer diamine is a compound derived from a dimer (dimer acid) of an unsaturated fatty acid such as oleic acid. Particularly preferred are groups that exclude two carboxy groups.

（式（２）中、Ｒ¹は独立して、水素原子又は炭素数１～５のアルキル基であって、ｘ１及びｘ２はそれぞれ独立に０～４の数である。）
で示されるシクロヘキサン骨格を有する炭素数６～６０、好ましくは８～３０、より好ましくは１０～２０の２価の脂環式炭化水素基である。 Further, in the above formula (1), Q is independently the following formula (2)

(In formula (2), R ¹ is independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and x1 and x2 are each independently a number of 0 to 4.)
is a divalent alicyclic hydrocarbon group having 6 to 60, preferably 8 to 30, more preferably 10 to 20 carbon atoms and having a cyclohexane skeleton represented by

Here, specific examples of R ¹ include hydrogen atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and t-butyl group. Among them, a hydrogen atom and a methyl group are preferred. Each R ¹ may be the same or different.
In addition, x1 and x2 are each independently a number from 0 to 4, preferably a number from 0 to 2. Note that x1 and x2 may be the same or different.

（上記構造式中の置換基が結合していない結合手は、式（１）において環状イミド構造を形成する窒素原子と結合するものである。） Specific examples of Q include divalent alicyclic hydrocarbon groups represented by the following structural formulas.

(The bond to which no substituent is bonded in the above structural formula is the one that bonds to the nitrogen atom that forms the cyclic imide structure in formula (1).)

In the above formula (1), W is B or Q. Regarding W, it is determined whether it is a structural unit having B or Q depending on the manufacturing method.

In the formula (1), n is 0 to 100, preferably 2 to 60, more preferably 5 to 50, m is 0 to 200, preferably 1 to 50, more preferably is 3 to 40, but n and m are not 0 at the same time. If n or m is too large, the fluidity may decrease and the moldability may deteriorate.

In addition, in the maleimide compound represented by formula (1), the order of each repeating unit bracketed by n and m in the formula is not limited, and the binding mode may be alternating, block, or random. , but block bonding is preferred.

The cyclic imide compound of component (B) further includes a maleimide compound represented by the following formula (1′), which has at least one dimer acid skeleton in one molecule, or a maleimide compound represented by the following formula (3). A maleimide compound having at least one dimer acid skeleton in one molecule is preferable.

（式（１’）中、
Ａは独立して環状構造を有する４価の有機基であり、
Ｂは独立して炭素数６～２００の２価炭化水素基であり、
Ｑは独立して下記式（２）

（式（２）中、Ｒ¹は独立して、水素原子又は炭素数１～５のアルキル基であって、ｘ１及びｘ２はそれぞれ独立に０～４の数である。）
で示されるシクロヘキサン骨格を有する炭素数６～６０の２価の脂環式炭化水素基であり、
ＷはＢ又はＱであり、
ｎ’は１～１００であり、ｍは０～２００であり、
ｎ及びｍで括られた各繰り返し単位の順序は限定されず、結合様式は、交互であっても、ブロックであっても、ランダムであってもよい。）

(In formula (1′),
A is independently a tetravalent organic group having a cyclic structure,
B is independently a divalent hydrocarbon group having 6 to 200 carbon atoms,
Q is independently the following formula (2)

(In formula (2), R ¹ is independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and x1 and x2 are each independently a number of 0 to 4.)
A divalent alicyclic hydrocarbon group having 6 to 60 carbon atoms and having a cyclohexane skeleton represented by
W is B or Q;
n' is 1 to 100, m is 0 to 200,
The order of each repeating unit bracketed by n and m is not limited, and the binding mode may be alternating, block, or random. )

Specific examples of A, B, Q and W in formula (1′) are the same as those exemplified for A, B, Q and W in formula (1), and n′ is 1 ~100, preferably 2-60, more preferably 5-50, m is 0-200, preferably 1-50, more preferably 3-40.

（式（３）中、
Ａは独立して環状構造を有する４価の有機基であり、
Ｂは独立して炭素数６～２００の２価炭化水素基であり、
ｍは１～２００である。）

(In formula (3),
A is independently a tetravalent organic group having a cyclic structure,
B is independently a divalent hydrocarbon group having 6 to 200 carbon atoms,
m is 1-200. )

Specific examples of A and B in formula (3) are the same as those exemplified for A and B in formula (1), m is 1 to 200, preferably 1 to 50 and more preferably 3-40.

Although the number average molecular weight of the cyclic imide compound (B) is not particularly limited, it is preferably from 2,000 to 50,000, more preferably from 5,000 to 40,000, from the viewpoint of handleability of the composition. Moreover, (B) component may be used individually by 1 type, or may be used in mixture of 2 or more types.

(C) Epoxy Resin Having Two or More Epoxy Groups in One Molecule The component (C) used in the present invention is an epoxy resin having two or more epoxy groups in one molecule. Epoxy resins improve or improve fluidity and mechanical properties of the thermosetting cyclic imide resin composition of the present invention, and improve adhesion to organic resins such as LCP and MPI. Any epoxy resin having two or more epoxy groups in one molecule can be used without particular limitation. Preferably, it is a solid with a melting point of 40° C. or higher and 150° C. or lower or a softening point of 50° C. or higher and 160° C. or lower.

Specific examples of epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, 3,3',5,5'-tetramethyl-4,4'-biphenol type epoxy resin and 4,4'-biphenol type epoxy resin. Biphenol-type epoxy resins such as epoxy resins, phenol novolac-type epoxy resins, cresol novolac-type epoxy resins, bisphenol A novolac-type epoxy resins, naphthalene diol-type epoxy resins, trisphenylolmethane-type epoxy resins, tetrakisphenylolethane-type epoxy resins, Examples include phenol biphenyl type epoxy resin, dicyclopentadiene type epoxy resin, biphenyl aralkyl type epoxy resin, epoxy resin obtained by hydrogenating the aromatic ring of phenol dicyclopentadiene novolac type epoxy resin, triazine derivative epoxy resin and alicyclic epoxy resin. be done. Among them, dicyclopentadiene-type epoxy resins and biphenylaralkyl-type epoxy resins are preferably used.

The mass ratio of the components (A), (B) and (C) is 1 to 50 parts by mass of the total amount of the components (B) and (C) with respect to 100 parts by mass of the component (A). The total amount of components B) and (C) is preferably 2 to 40 parts by mass. If the amount of component (B) and component (C) exceeds this range, for example, when the varnish is made into a varnish, separation occurs, resulting in a partially gelled state and loss of fluidity. Furthermore, even if it is made into a film, there is a possibility that unevenness will occur in the film. Conversely, if the amounts of components (B) and (C) are less than this range, the resulting composition may have poor adhesive strength.
Also, if the amount of component (B) is greater than the amount of component (C), and if the amount of component (B) is less than component (C), not only will the adhesive strength to metals decrease, but component (C) will also cause dielectric There is a risk that the properties will deteriorate or the curing balance will be lost. The amount of component (C) is preferably 1 to 50 parts by mass per 100 parts by mass of component (B).
Furthermore, based on the total amount of components (A), (B) and (C), the amount of component (A) is preferably 70 to 95% by mass, more preferably 71 to 93% by mass. , 72 to 90% by weight.

(D) Reaction Accelerator The reaction accelerator, which is component (D), reacts mainly with the crosslinking reaction of the cyclic imide compound, which is component (B), and the epoxy group in the epoxy resin, which is component (C). Initiating the cross-linking reaction of the imide, or if there is a functional group in the styrene elastomer of the component (A), reacts the functional group with the cyclic imide of the component (B) or the epoxy group in the component (C). It is added to promote
Component (D) is not particularly limited as long as it promotes the cross-linking reaction. Examples include ionic catalysts such as phosphonium salts, organic peroxides such as diallyl peroxide, dialkyl peroxide, peroxide carbonate and hydroperoxide, and radical polymerization initiators such as azoisobutyronitrile. Among these, a radical polymerization initiator such as an organic peroxide that promotes the reaction of the component (B) alone, and an epoxy group in the component (C) that opens the ring and then the adduct with the epoxy resin is a cyclic imide. Anionic polymerization initiation catalysts such as imidazoles and tertiary amines, which promote the cross-linking reaction of the compound, are preferred.

When the (A) component is non-functional (when the styrene-based elastomer does not have a functional group), the total amount of the thermosetting resin components such as (B) and (C) is 100 parts by mass. 0.05 to 10 parts by mass, particularly preferably 0.1 to 5 parts by mass. When the (A) component has a functional group, the reaction accelerator is 0.05 to 10 parts by mass with respect to 100 parts by mass of the total resin components such as the (A), (B) and (C) components, In particular, it is preferable to blend within the range of 0.1 to 5 parts by mass.
If it is out of the above range, the thermosetting cyclic imide resin composition may be cured very slowly or rapidly during molding, which is not preferable. In addition, the balance between the heat resistance and moisture resistance of the obtained cured product may be deteriorated.

(E) Adhesion aid The thermosetting cyclic imide resin composition of the present invention contains the resin components (A) to (C) in order to increase the adhesion between the resin components (A) to (C) and copper foil or organic resins such as LCP and MPI. , an adhesion aid can be added.
As the adhesion aid, a coupling agent such as a silane coupling agent or a titanate coupling agent, or a monomer having a (meth)acrylic group can be blended.
Examples of silane coupling agents include epoxy-functional alkoxys such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and the like. silanes, mercapto-functional alkoxysilanes such as γ-mercaptopropyltrimethoxysilane, amine-functional alkoxysilanes such as γ-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, and the like. mentioned.
Titanium coupling agents include isopropyltriisostearoyl titanate, isopropyltridodecylbenzenesulfonyltitanate, isopropyltris(dioctylpyrophosphate)titanate, tetraisopropylbis(dioctylphosphite)titanate, tetraoctylbis(ditridecylphosphite)titanate, Bis(dioctyl pyrophosphate) oxyacetate titanate, isopropyl trioctanoyl titanate, isopropyl dimethacryl isostearoyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl tri(dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, isopropyl tri(N-amino ethyl aminoethyl) titanate and the like.
(Meth) acrylic group-containing monomers include 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, dipropylene glycol diacrylate, tricyclodecanedimethanol diacrylate, 9,9-bis[4-(2 -hydroxyethoxy)phenyl]fluorene diacrylate, bisphenol A type diacrylate, trimethylolpropane triacrylate, tris(2-acryloxymethyl)isocyanurate, ditrimethylolpropane tetraacrylate, 1,6-hexanediol dimethacrylate, neopentyl Glycol methacrylate, dipropylene glycol methacrylate, tricyclodecanedimethanol methacrylate, 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene methacrylate, bisphenol A type dimethacrylate, trimethylolpropane trimethacrylate, tris(2- methacryloxymethyl)isocyanurate, ditrimethylolpropane tetramethacrylate and the like.

The amount of component (E) to be blended is preferably 0.1 to 8.0% by mass, particularly 0.5 to 6.0%, based on the sum of components (A), (B) and (C). % by mass is preferable. When the amount is 0.1% by mass or more, a sufficient adhesive effect to the substrate can be obtained, and when the amount is 8.0% by mass or less, the viscosity does not become too low, so voids are less likely to occur, which is preferable.

<Other additives>
Various additives can be added to the thermosetting cyclic imide resin composition of the present invention as necessary within a range that does not impair the effects of the present invention. Examples of the additive include inorganic fillers such as silica, alumina, and boron nitride, resin powder such as PTFE powder, metal particles such as silver, organopolysiloxane having a reactive functional group, non-functional silicone oil, Examples include thermoplastic resins, thermoplastic elastomers other than styrene, organic synthetic rubbers, photosensitizers, light stabilizers, polymerization inhibitors, flame retardants, pigments, and dyes. Further, in order to improve the electrical properties of the cured product of the thermosetting cyclic imide resin composition, an ion trapping agent or the like may be blended as other additives.

The thermosetting cyclic imide resin composition of the present invention comprises (A) component, (B) component, (C) component and (D) component, and optionally added (E) component and other additives. It can be manufactured by mixing.
The thermosetting cyclic imide resin composition of the present invention can also be dissolved in an organic solvent and treated as a varnish. The thermosetting cyclic imide resin composition can be easily formed into a sheet or film by forming it into a varnish. Any organic solvent can be used without limitation as long as it dissolves the thermosetting resin components of components (A), (B) and (C). As the organic solvent, for example, toluene, xylene, anisole, cyclohexanone, cyclopentanone, etc. can be preferably used. The above organic solvents may be used alone or in combination of two or more. The concentration of the thermosetting cyclic imide resin composition of the present invention in the varnish is preferably 5-80% by mass, more preferably 10-75% by mass.

This thermosetting cyclic imide resin composition can be suitably used mainly as adhesives, primers, bonding films and sheet materials for substrates, and adhesive layers for coverlay films for FPC. It can be used without limitation in the usage method and form. For example, it can be used as an uncured resin film, a cured resin film, or as an adhesive. Examples of use are shown below, but are not limited to these.

For example, after coating a support sheet with a thermosetting cyclic imide resin composition (varnish) dissolved in an organic solvent, it is usually heated at a temperature of 80° C. or higher, preferably 100° C. or higher for 0.5 to 5 hours. The organic solvent is removed, and an uncured film-like or sheet-like composition can be obtained. As the support sheet, commonly used ones may be used, for example, polyethylene (PE) resin, polypropylene (PP) resin, polyolefin resin such as polystyrene (PS) resin, polyethylene terephthalate (PET) resin, polybutylene terephthalate. (PBT) resin, polyester resin such as polycarbonate (PC) resin, etc., and the like, and the surface of these support sheets may be subjected to release treatment. Also, the coating method is not particularly limited, and examples thereof include a gap coater, a curtain coater, a roll coater, a laminator, and the like. Also, the thickness of the coating layer is not particularly limited, but the thickness after removal of the solvent is in the range of 1 to 100 μm, preferably 3 to 80 μm. Furthermore, a cover film may be used on the coating layer.

Moreover, it can also be used as a substrate material by attaching a copper foil on the coating layer.

Furthermore, the varnish is applied to the substrate, and the organic solvent is removed by heating at a temperature of usually 80° C. or higher, preferably 100° C. or higher for 0.5 to 5 hours, and the object to be adhered to the substrate is pressed while heating. Then, they can be bonded by heating at a temperature of 130° C. or higher, preferably 150° C. or higher for 0.5 to 10 hours. A spin coater, a slit coater, a spray, a dip coater, a bar coater and the like can be used as the coating method, but there is no particular limitation.
In addition, it can also be used for flexible flat cables.

EXAMPLES The present invention will be specifically described below by showing examples and comparative examples, but the present invention is not limited to the following examples.

Components used in Examples and Comparative Examples are shown below. In the following, the number average molecular weight (Mn) is measured under the following measurement conditions using polystyrene as a standard.
Developing solvent: tetrahydrofuran (THF)
Flow rate: 0.35mL/min
Detector: Differential Refractive Index Detector (RI)
Column: TSK Guard column SuperH-L
TSKgel SuperHZ4000 (4.6mm ID x 15cm x 1)
TSKgel SuperHZ3000 (4.6mm ID x 15cm x 1)
TSKgel SuperHZ2000 (4.6mm I.D. x 15cm x 2)
(both manufactured by Tosoh Corporation)
Column temperature: 40°C
Sample injection volume: 5 μL (THF solution with a concentration of 0.2% by mass)

(A) Styrene-based elastomer (A-1) Hydrogenated styrene/ethylene/butylene/styrene block copolymer, styrene content 30% (Tuftec H1041: manufactured by Asahi Kasei Corporation)
(A-2) Carboxylic acid-modified styrene/ethylene/butylene/styrene block copolymer, styrene content 30% (Tuftec M1913: manufactured by Asahi Kasei Corporation)
(A-3) Amine acid-modified styrene/ethylene/butylene/styrene block copolymer, styrene content 30% (Tuftec MP-10: manufactured by Asahi Kasei Corporation)

Ｈ₂Ｎ－Ｃ₃₆Ｈ₇₀－ＮＨ₂はダイマー酸骨格由来の構造を示す。
ｎ≒３、ｍ≒１
（Ｂ－２）：下記式で示される直鎖アルキレン基含有ビスマレイミド化合物（ＢＭＩ－３０００、Ｄｅｓｉｇｎｅｒ Ｍｏｌｅｃｕｌｅｓ Ｉｎｃ．製）

Ｈ₂Ｎ－Ｃ₃₆Ｈ₇₀－ＮＨ₂はダイマー酸骨格由来の構造を示す。
ｎ≒５（平均値）
（Ｂ－３）：４，４’－ジフェニルメタンビスマレイミド（ＢＭＩ－１０００：大和化成工業（株）製、比較例用） (B) Cyclic imide compound (B-1): a linear alkylene group-containing bismaleimide compound represented by the following formula (SLK-2600, manufactured by Shin-Etsu Chemical Co., Ltd.)

H ₂ N—C ₃₆ H ₇₀ —NH ₂ indicates a structure derived from a dimer acid skeleton.
n≈3, m≈1
(B-2): A linear alkylene group-containing bismaleimide compound represented by the following formula (BMI-3000, manufactured by Designer Molecules Inc.)

H ₂ N—C ₃₆ H ₇₀ —NH ₂ indicates a structure derived from a dimer acid skeleton.
n≈5 (mean value)
(B-3): 4,4′-diphenylmethanebismaleimide (BMI-1000: manufactured by Daiwa Kasei Kogyo Co., Ltd., for comparative example)

(C) Epoxy resin having two or more epoxy groups in one molecule (C-1): biphenyl aralkyl type epoxy resin (NC-3000: manufactured by Nippon Kayaku Co., Ltd.)
(C-2): Bis-A type epoxy resin (jER-828: manufactured by Mitsubishi Chemical Corporation)

(D) Reaction accelerator (D-1): Dicumyl peroxide (Percumyl D: manufactured by NOF Corporation)
(D-2): 2-ethyl-4-methylimidazole (2E4MZ: manufactured by Shikoku Kasei Co., Ltd.)

(E) Adhesion aid (E-1): 3-glycidoxypropyltrimethoxysilane (KBM-403: manufactured by Shin-Etsu Chemical Co., Ltd.)

<Preparation of varnish and varnish appearance, stability>
With the formulations shown in Tables 1 and 2, each component was put into a 500 mL four-necked flask equipped with a Dimroth condenser and a stirring device, and stirred at 50° C. for 2 hours to obtain a varnish-like resin composition.

The results are shown in Tables 1 and 2, with the appearance of the varnish-like composition immediately after stirring and after standing at 25°C for 72 hours being uniform without separation, and being separated, being x.

From the results in Tables 1 and 2, it was confirmed that the varnish compositions of Examples 1-9 were stable without separation. Comparative Examples 1 to 3, 10 and 11 also confirmed the stability of the varnish composition. On the other hand, in Comparative Examples 4 to 9, the varnish was separated. In particular, Comparative Examples 6 to 8 have compositions excluding the inorganic fillers of Examples 1 to 3 of WO 2018-16489, but it was confirmed that they were actually separated.

<Production of uncured film>

The varnish-like thermosetting cyclic imide resin compositions of Examples 1 to 9 and Comparative Examples 1 to 3, 10 and 11 in which the varnish did not separate in Tables 1 and 2 above were coated on a PET film having a thickness of 38 μm. , was coated with a roller coater so that the thickness after drying was 50 μm, and dried at 120° C. for 10 minutes to obtain an uncured resin film.

<Relative permittivity, dielectric loss tangent>

The uncured resin film is placed on a 100 μm thick tetrafluoroethylene-ethylene copolymer resin film (manufactured by AGC Co., Ltd., product name: Aflex), and the resin layer of the uncured resin film is a tetrafluoroethylene-ethylene copolymer resin. A cured resin film was obtained by placing it in contact with the film and curing it at 180° C. for 2 hours.

Using a cured resin film from which the PET film and tetrafluoroethylene-ethylene copolymer resin film were peeled off, a network analyzer (E5063-2D5 manufactured by Keysight Corporation) and a strip line (manufactured by Keycom Co., Ltd.) were connected, and the cured resin film was connected. The dielectric constant and dielectric loss tangent at a frequency of 10 GHz were measured.

<Peel strength>

A slide glass with a length of 75 mm, a width of 25 mm, and a thickness of 1.0 mm was prepared, and the resin composition side of the uncured film with the PET film on which the PET substrate was not attached was placed on one surface of the slide glass. Lamination was performed under the conditions of 3 MPa pressure and 60 seconds. After lamination, the PET substrate is peeled off, and a 18 μm thick copper foil (manufactured by Mitsui Kinzoku Co., Ltd., Ra 0.6 μm), a 50 μm thick LCP (manufactured by Chiyoda Integre Co., Ltd.) or MPI (PIXEO SR, (manufactured by Kaneka Co., Ltd.), and lamination was performed under the conditions of 100° C., 0.3 MPa pressure, and 60 seconds. After lamination, the laminate was cured at 180° C. for 2 hours to prepare an adhesion test piece.

In order to evaluate the adhesion, in accordance with JIS-C-6481 "Test method for copper-clad laminates for printed wiring boards", under the conditions of a temperature of 23 ° C. and a tensile speed of 50 mm / min, copper foil of each adhesion test piece, The 90° peel adhesive strength (kN/m) was measured when the LCP or MPI was peeled off from the slide glass.

Tables 3 and 4 show the above evaluation results.

From the above results, the thermosetting cyclic imide resin composition of the present invention does not separate even if it is a varnish, is excellent in dielectric properties of the cured product, and is not only resistant to metals (e.g., copper), but also to organic resins (e.g., For example, it has a strong adhesion to LCP and MPI), so it was confirmed that it is useful as an insulating material suitable for use as a substrate.

Claims (10)

(A) a styrene-based elastomer,
(B) a cyclic imide compound containing, in one molecule, at least one dimer acid skeleton, at least one linear alkylene group having 6 or more carbon atoms, and at least two cyclic imide groups;
(C) an epoxy resin having two or more epoxy groups in one molecule and (D) a reaction accelerator,
The mass ratio of components (A), (B) and (C) is 1 to 50 parts by mass per 100 parts by mass of component (A), and the total amount of components (B) and (C) is 1 to 50 parts by mass, and , a thermosetting cyclic imide resin composition, wherein the amount of component (B) is greater than the amount of component (C). 2. The thermosetting according to claim 1, wherein the styrenic elastomer of component (A) is a copolymer of styrene and an alkene and/or a non-conjugated diene, which is partially or fully hydrogenated. cyclic imide resin composition. The thermosetting according to claim 1 or 2, wherein the cyclic imide compound of component (B) is a maleimide compound represented by the following formula (1) and having at least one dimer acid skeleton in one molecule. cyclic imide resin composition.

(In formula (1),
A is independently a tetravalent organic group having a cyclic structure,
B is independently a divalent hydrocarbon group having 6 to 200 carbon atoms,
Q is independently the following formula (2)

(In formula (2), R ¹ is independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and x1 and x2 are each independently a number of 0 to 4.)
A divalent alicyclic hydrocarbon group having 6 to 60 carbon atoms and having a cyclohexane skeleton represented by
W is B or Q;
n is 0 to 100 and m is 0 to 200, but n and m are not 0 at the same time,
The order of each repeating unit bracketed by n and m is not limited, and the binding mode may be alternating, block, or random. ) 4. The thermosetting cyclic imide resin composition according to claim 3, wherein A in formula (1) is any one of the tetravalent organic groups represented by the following structural formulas.

(The bond to which no substituent is bonded in the above structural formula is bonded to the carbonyl carbon that forms the cyclic imide structure in formula (1).) 5. The thermosetting cyclic imide resin composition according to any one of claims 1 to 4, wherein the reaction accelerator of component (D) is at least one of an anionic polymerization initiation catalyst and a radical polymerization initiator. 6. The thermosetting cyclic imide resin composition according to any one of claims 1 to 5, further comprising an adhesion aid as component (E). An uncured resin film comprising the thermosetting cyclic imide resin composition according to claim 1 . A cured resin film comprising a cured product of the thermosetting cyclic imide resin composition according to claim 1 . An adhesive comprising the thermosetting cyclic imide resin composition according to claim 1 . A substrate comprising the thermosetting cyclic imide resin composition according to claim 1 .