KR20220089694A - Adhesive composition and adhesive sheet - Google Patents

Abstract

It is an adhesive sheet which has the adhesive composition containing the following (A) component and (B) component, and the adhesive bond layer formed using this adhesive composition. This adhesive composition provides the hardened|cured material which has the low dielectric characteristic in a high frequency range, and is excellent in adhesive strength.
(A) component: modified polyolefin resin
(B) component: a compound having a polyphenylene ether skeleton and a crosslinkable functional group

Description

Adhesive composition and adhesive sheet

The present invention relates to an adhesive composition having a low dielectric property in a high frequency region and providing a cured product excellent in adhesive strength, and an adhesive sheet having an adhesive layer formed using the adhesive composition. In this specification, a high frequency area shall refer to the area|region of 300 MHz - 300 GHz.

In recent years, with size reduction and weight reduction of an electronic device, the case of using a flexible printed wiring board (FPC) as a wiring member is increasing.

FPC can be obtained by, for example, performing an etching process with respect to the copper foil of what bonded copper foil to insulating resin films, such as a polyimide (copper-clad laminated board), and forming an electric circuit.

Moreover, it is performed normally by bonding together the coverlay film which has an insulating resin base material and an adhesive bond layer to the copper foil with an electric circuit, and protecting an electric circuit.

By the way, with respect to communication devices, such as a smart phone, in recent years, in order to handle larger-capacity data, the frequency increase of an electrical signal is progressing.

However, since the electrical signal in the high-frequency region is easily converted into heat, the transmission loss tends to increase when the electrical signal is made high-frequency.

In order to transmit electric signals in the high-frequency region at high speed and with reduced transmission loss, it is desirable to improve the dielectric properties (low dielectric constant and low dielectric loss tangent) of insulators (base materials, adhesives, etc.) constituting the wiring member. has been done

Moreover, in order to further reduce transmission loss, planarization of the copper foil surface and use of a non-adhesive base material are also examined, In order to respond to this, development of the adhesive agent which was more excellent in adhesiveness has also been performed.

Patent Document 1 describes a laminate with an adhesive layer comprising a base film and an adhesive layer on at least one surface of the base film, wherein the adhesive layer is made of a specific adhesive composition.

Patent Document 1 also describes that the laminate with an adhesive layer is excellent in adhesiveness to a base film or copper foil, electrical properties (low dielectric constant, low dielectric loss tangent), and the like.

Japanese Laid-Open Patent Publication No. 2018-150541

The cured product of the adhesive composition described in Patent Document 1 has sufficient adhesive strength and has a low dielectric property (in the present specification, "having a low dielectric property" means "having a low dielectric constant and a low dielectric loss tangent") ' says something).

However, in order to cope with the further increase in frequency of electric signals expected in the future, there has been a demand for an adhesive composition that provides a cured product having further excellent low dielectric properties and adhesive strength in a high frequency region.

The present invention has been made in view of the above circumstances, and has an adhesive composition for providing a cured product having low dielectric properties in a high frequency region and excellent adhesive strength, and an adhesive having an adhesive layer formed using the adhesive composition The purpose is to provide a sheet.

The present inventors earnestly studied the adhesive composition in order to solve the said subject. As a result, it was found that an adhesive composition containing a modified polyolefin resin and a polyphenylene ether resin having a reactive group provides a cured product having low dielectric properties in a high frequency region and excellent adhesive strength, and the present invention came to complete.

In this way, according to the present invention, the following [1] to [7] adhesive compositions and [8] adhesive sheets are provided.

[1] An adhesive composition comprising the following component (A) and component (B).

(A) component: modified polyolefin resin

(B) component: polyphenylene ether resin having a reactive group

[2] The adhesive composition according to [1], wherein the content of the modified polyolefin resin is more than 50 mass% of the total amount of the active ingredient of the adhesive composition.

[3] The adhesive composition according to [1] or [2], wherein the reactive group of the polyphenylene ether resin having a reactive group is a group having an ethylenically unsaturated bond.

[4] The adhesive composition according to any one of [1] to [3], further comprising the following component (C).

(C) component: a compound having an alicyclic skeleton and a cyclic ether group

[5] The adhesive composition according to [4], wherein the content of the compound having an alicyclic skeleton and a cyclic ether group is 10 mass% or less based on the total amount of the active ingredient of the adhesive composition.

[6] At least one of the compounds having an alicyclic skeleton and a cyclic ether group is a compound that is liquid at 25°C, and the content of the compound having an alicyclic skeleton and a cyclic ether group that is liquid at 25°C is effective for the adhesive composition The adhesive composition according to [4] or [5], which is 10 mass% or less of the total amount of the component.

[7] The adhesive composition according to any one of [1] to [6], further comprising the following (D) component.

(D) component: curing agent

[8] The adhesive composition according to [7], wherein the curing agent contains a cationic polymerization initiator.

[9] The adhesive composition according to any one of [1] to [8], further comprising the following component (E).

(E) component: silane coupling agent

[10] An adhesive sheet having an adhesive layer formed by using the adhesive composition according to any one of [1] to [9].

Advantageous Effects of Invention According to the present invention, there is provided an adhesive composition having a low dielectric property in a high frequency region and providing a cured product excellent in adhesive strength, and an adhesive sheet having an adhesive layer formed using the adhesive composition.

Hereinafter, the present invention will be described in detail by classifying it into 1) an adhesive composition, and 2) an adhesive sheet.

1) Adhesive composition

The adhesive composition of this invention contains the following (A) component and (B) component.

(A) component: modified polyolefin resin

(B) component: polyphenylene ether resin having a reactive group

[Component (A): Modified polyolefin resin]

The adhesive composition of this invention contains a modified polyolefin resin as (A) component.

Modified polyolefin resin is the olefin resin into which the functional group was introduce|transduced to the olefin resin as a precursor, and is obtained by performing a modification process using a modifier.

Since the modified polyolefin resin has a polyolefin skeleton, the cured product of the adhesive composition of the present invention containing the modified polyolefin resin has low dielectric properties.

Moreover, since the modified polyolefin resin has a functional group, the hardened|cured material of the adhesive composition of this invention containing a modified polyolefin resin is excellent in adhesive strength.

The olefin-based resin refers to a polymer including a repeating unit derived from an olefin-based monomer. The olefinic resin may be a polymer composed of only repeating units derived from an olefinic monomer, or may be a polymer composed of a repeating unit derived from an olefinic monomer and a repeating unit derived from a monomer copolymerizable with the olefinic monomer. From a viewpoint of being easy to obtain the hardened|cured material excellent in a low dielectric characteristic, it is preferable that the olefin resin is a polymer which consists only of repeating units derived from an olefinic monomer.

As an olefinic monomer, a C2-C8 alpha-olefin is preferable, ethylene, propylene, 1-butene, isobutylene, or 1-hexene is more preferable, ethylene or propylene is still more preferable. These olefinic monomers can be used individually by 1 type or in combination of 2 or more type.

As a monomer copolymerizable with an olefinic monomer, vinyl acetate, (meth)acrylic acid ester, styrene, etc. are mentioned. Here, "(meth)acrylic acid" means acrylic acid or methacrylic acid (the same applies hereinafter).

These olefinic monomers and the monomer copolymerizable can be used individually by 1 type or in combination of 2 or more type.

Examples of the olefin-based resin include ultra-low-density polyethylene (VLDPE), low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear low-density polyethylene, polypropylene (PP), ethylene-propylene copolymer, An olefin-based elastomer (TPO), an ethylene-vinyl acetate copolymer (EVA), an ethylene-(meth)acrylic acid copolymer, an ethylene-(meth)acrylic acid ester copolymer, etc. are mentioned.

The modifier used for the modification process of an olefin resin is a compound which has a functional group in a molecule|numerator.

Examples of the functional group include a carboxyl group, a carboxylic acid anhydride group, a carboxylate ester group, a hydroxyl group, an epoxy group, an amide group, an ammonium group, a nitrile group, an amino group, an imide group, an isocyanate group, an acetyl group, a thiol group, an ether group, and a thioether group. , a sulfone group, a phosphonic group, a nitro group, a urethane group, an alkoxysilyl group, a silanol group, and a halogen atom. The compound which has a functional group may have 2 or more types of functional groups in a molecule|numerator.

Modified polyolefin resin can be used individually by 1 type or in combination of 2 or more type.

The number average molecular weight (Mw) of the modified polyolefin resin is preferably 10,000 to 150,000, more preferably 30,000 to 100,000.

The number average molecular weight (Mw) of modified polyolefin resin can be calculated|required as standard polystyrene conversion value by performing gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

The content of the modified polyolefin resin is preferably more than 50 mass%, more preferably more than 50 mass% and 90 mass% or less, still more preferably 55 mass% or more and 85 mass% or less in the total amount of the active ingredient of the adhesive composition. .

When the content of the modified polyolefin resin is more than 50% by mass in the total amount of the active ingredient of the adhesive composition, an adhesive composition that has a low dielectric property in a high frequency region and provides a cured product excellent in adhesive strength is easily obtained lose

As used herein, the term “active ingredient” refers to a component constituting the adhesive composition excluding the solvent.

As modified polyolefin resin, an acid-modified polyolefin resin is preferable at the point from which the hardened|cured material more excellent in adhesive strength is formed.

An acid-modified polyolefin resin means what graft-modified the olefin resin with an acid or an acid anhydride. For example, an olefin resin is reacted with an unsaturated carboxylic acid or an unsaturated carboxylic acid anhydride (hereinafter referred to as "unsaturated carboxylic acid etc.") to introduce a carboxyl group or a carboxylic acid anhydride group (graft modification). ) can be cited.

As an unsaturated carboxylic acid made to react with olefin resin, etc., Unsaturated carboxylic acids, such as maleic acid, a fumaric acid, itaconic acid, a citraconic acid, glutaconic acid, tetrahydrophthalic acid, and aconitic acid; Unsaturated carboxylic acid anhydrides, such as maleic anhydride, itaconic anhydride, glutaconic acid anhydride, citraconic acid anhydride, aconitic anhydride, norbornene dicarboxylic acid anhydride, tetrahydrophthalic anhydride; can be heard

These can be used individually by 1 type or in combination of 2 or more type. Among these, maleic anhydride is preferable at the point that the hardened|cured material more excellent in adhesive strength is easy to be obtained.

To [ the quantity of unsaturated carboxylic acid etc. made to react with olefin resin / 100 mass parts of olefin resin / olefin resin ], Preferably it is 0.1-5 mass parts, More preferably, it is 0.2-3 mass parts, More preferably, it is 0.2-1 mass part. is wealth By hardening the adhesive composition containing the acid-modified polyolefin resin obtained in this way, the hardened|cured material more excellent in adhesive strength can be formed.

The method of introduce|transducing an unsaturated carboxylic acid unit or an unsaturated carboxylic acid anhydride unit into an olefin resin is not specifically limited. For example, in the presence of radical generators such as organic peroxides or azonitriles, a method in which an olefinic resin and an unsaturated carboxylic acid are heated and melted above the melting point of the olefinic resin to react, or an olefinic resin and a method in which an unsaturated carboxylic acid or the like is dissolved in an organic solvent, followed by heating and stirring in the presence of a radical generating agent to react with, for example, a method of graft copolymerizing an unsaturated carboxylic acid or the like with an olefinic resin.

As acid-modified polyolefin resin, a commercial item can also be used. Commercially available products include, for example, Admer (registered trademark) (manufactured by Mitsui Chemicals Corporation), Unistol (registered trademark) (manufactured by Mitsui Chemicals Corporation), BondyRam (manufactured by Polyram Corporation), orevac (registered trademark) (manufactured by ARKEMA), Modique (trademark) (made by Mitsubishi Chemical) etc. are mentioned.

[Component (B): Polyphenylene ether resin having a reactive group]

The adhesive composition of this invention contains the polyphenylene ether resin (Hereinafter, it may be called "polyphenylene ether resin (B)") which has a reactive group as (B) component.

Polyphenylene ether resin means resin which has polyphenylene skeleton in a principal chain.

Polyphenylene skeleton is the following formula

[Formula 1]

It refers to a skeleton having a repeating unit represented by , or a repeating unit in which a hydrogen atom in the formula is substituted.

The polyphenylene ether resin (B) is a compound having a polyphenylene ether skeleton and a reactive group.

Since the polyphenylene ether resin (B) has a polyphenylene ether skeleton, the cured product of the adhesive composition of the present invention containing the polyphenylene ether resin (B) has a low dielectric property.

Moreover, since polyphenylene ether resin (B) has a reactive group, the hardened|cured material of the adhesive composition of this invention containing polyphenylene ether resin (B) is excellent in heat resistance.

As polyphenylene ether skeleton in polyphenylene ether resin (B), what is represented by following formula (1) is mentioned.

[Formula 2]

In formula (1), X is a divalent group represented by the following formula (2) or (3), Y is each independently a divalent group represented by the following formula (4), a and b are, It is an integer of 0-100, and at least either one of a and b is 1 or more. * represents a bond (hereinafter the same).

[Formula 3]

In formula (2), R ¹ to R ⁸ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group, and preferably a hydrogen atom or a methyl group.

[Formula 4]

In formula (3), R ⁹ to R ¹⁶ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group, and preferably a hydrogen atom or a methyl group. A represents a C20 or less linear, branched, or cyclic divalent hydrocarbon group.

[Formula 5]

In formula (4), R ¹⁷ to R ²⁰ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group, and preferably a hydrogen atom or a methyl group.

As polyphenylene ether skeleton in polyphenylene ether resin (B), what is represented by following formula (5) is mentioned.

[Formula 6]

Examples of the reactive group in the polyphenylene ether resin (B) include groups having an ethylenically unsaturated bond such as a vinyl group, an allyl group, an acryloyl group, a methacryloyl group, a cyclopentenyl group, a vinylbenzyl group, and a vinylnaphthyl group; epoxy group; hydroxyl group; and the like.

Among these, the group which has an ethylenically unsaturated bond is preferable and, as for a reactive group, the group which has an ethylenically unsaturated bond is more preferable at the point which hardened|cured material which has a low dielectric characteristic is obtained easily.

The polyphenylene ether resin (B) preferably has a reactive group at both terminals of the polyphenylene ether skeleton from the viewpoint of easily obtaining a cured product having a low dielectric characteristic.

Polyphenylene ether resin (B) can be obtained by introduce|transducing a reactive group into the terminal, after forming polyphenylene ether skeleton.

For example, a polyphenylene ether resin (B) having vinylbenzyl groups at both terminals as a reactive group is obtained by reacting a bifunctional phenol compound and a monofunctional phenol compound to obtain a polymer having phenolic hydroxyl groups at both terminals, It can be obtained by vinylbenzyl etherification of a terminal phenolic hydroxyl group using 4-(chloromethyl)styrene.

As polyphenylene ether resin (B), what is represented by following formula (6) is mentioned.

[Formula 7]

As polyphenylene ether resin (B), a commercial item can also be used. Commercially available products include, for example, OPE-2St (modified polyphenylene ether resin having vinylbenzyl groups at both ends), OPE-2Gly (modified polyphenylene ether resin having epoxy groups at both ends), OPE-2EA (both ends) Modified polyphenylene ether resin having an acryloyl group at the terminal, the above, manufactured by Mitsubishi Gas Chemical Co., Ltd.), Noryl SA9000 (modified polyphenylene ether resin having methacryloyl groups at both terminals, manufactured by SABIC), etc. are mentioned. .

The weight average molecular weight (Mw) of polyphenylene ether resin (B) becomes like this. Preferably it is 500-5,000, More preferably, it is 500-3,000.

The weight average molecular weight (Mw) of polyphenylene ether resin (B) can be calculated|required as a standard polystyrene conversion value by performing gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

Polyphenylene ether resin (B) can be used individually by 1 type or in combination of 2 or more type.

Content of polyphenylene ether resin (B) in the total amount of the active ingredient of an adhesive composition, Preferably it is 1 mass % or more, More preferably, it is 10-50 mass %, More preferably, it is 15-40 mass %. .

When content of polyphenylene ether resin (B) is 1 mass % or more in the total amount of the active ingredient of an adhesive composition, the hardened|cured material which has a low dielectric characteristic becomes easy to be obtained.

[Component (C): A compound having an alicyclic skeleton and a cyclic ether group]

The adhesive composition of this invention may contain the compound which has an alicyclic skeleton and a cyclic ether group as (C)component.

A compound having an alicyclic skeleton and a cyclic ether group (hereinafter sometimes referred to as “cyclic ether group-containing compound (C)”) refers to a compound having an alicyclic skeleton in a molecule and at least one in the molecule, preferably refers to a compound having two or more cyclic ether groups.

Since the cyclic ether group-containing compound (C) has a cyclic ether group, the cured product of the adhesive composition containing the cyclic ether group-containing compound (C) is excellent in adhesive strength.

It is preferable that it is 2-6, as for the number of cyclic ether groups which the cyclic ether group containing compound (C) has in a molecule|numerator, it is more preferable that it is 2-4, It is still more preferable that it is 2. The cyclic ether group-containing compound (C) is a compound having two cyclic ether groups, thereby exhibiting curability and reducing curing shrinkage of the curable adhesive layer even when the compounding amount of the cyclic ether group-containing compound (C) is large. can be suppressed Therefore, for example, when an adhesive composition is used for adhesion|attachment of plate-shaped members, such as a circuit board, the curvature of a plate-shaped member can be reduced.

The molecular weight of the cyclic ether group-containing compound (C) is usually 100 to 5,000, preferably 200 to 3,000.

The cyclic ether equivalent of the cyclic ether group-containing compound (C) is preferably 50 g/eq or more and 1000 g/eq or less, more preferably 100 g/eq or more and 800 g/eq or less.

By curing the adhesive composition containing the cyclic ether group-containing compound (C) having a cyclic ether equivalent in the above range, a cured product having more excellent adhesive strength can be formed more efficiently.

The cyclic ether equivalent in the present invention means a value obtained by dividing the molecular weight by the number of cyclic ether groups.

Examples of the cyclic ether group include an oxirane group (epoxy group), oxetane group (oxetanyl group), tetrahydrofuryl group, and tetrahydropyranyl group.

Among these, as a cyclic ether group, an oxirane group is preferable.

In addition, in this specification, the group which has oxirane structures, such as a glycidyl group, a glycidyl ether group, and an epoxycyclohexyl group, is contained in an oxirane group.

Examples of the cyclic ether group-containing compound (C) include polyglycidyl ether products of polyhydric alcohols having at least one or more alicyclic structures, cyclohexene oxides obtained by epoxidizing cyclohexene or cyclopentene ring-containing compounds with an oxidizing agent; Cycloalkenoxide compounds, such as a cyclopentene oxide containing compound, are mentioned.

Representative compounds of the cyclic ether group-containing compound (C) include hydrogenated bisphenol A diglycidyl ether, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and 3,4-epoxy -1-methylcyclohexyl-3,4-epoxy-1-methylhexanecarboxylate, 6-methyl-3,4-epoxycyclohexylmethyl-6-methyl-3,4-epoxycyclohexanecarboxylate, 3 ,4-Epoxy-3-methylcyclohexylmethyl-3,4-epoxy-3-methylcyclohexanecarboxylate, 3,4-epoxy-5-methylcyclohexylmethyl-3,4-epoxy-5-methylcyclo Hexanecarboxylate, bis(3,4-epoxycyclohexylmethyl)adipate, 3,4-epoxy-6-methylcyclohexanecarboxylate, methylenebis(3,4-epoxycyclohexane), propane-2, 2-diyl-bis(3,4-epoxycyclohexane), 2,2-bis(3,4-epoxycyclohexyl)propane, dicyclopentadiene diepoxide, ethylenebis(3,4-epoxycyclohexanecar) carboxylate), epoxyhexahydrophthalate dioctyl, epoxyhexahydrophthalate di-2-ethylhexyl, 1-epoxyethyl-3,4-epoxycyclohexane, 1,2-epoxy-2-epoxyethylcyclohexane, α- Pinene oxide, limonene dioxide, etc. are mentioned.

Moreover, a commercial item can also be used as a cyclic ether group containing compound (C). As a commercial item, Celoxide 2021P, Celoxide 2081, Celoxide 2000, Celoxide 8010 (above, the Daicel company make); Eporite 4000 (manufactured by Kyoeisha Chemical Co., Ltd.); YX8000, YX8034 (above, the Mitsubishi Chemical company make); Adeka Resin EP-4088S, Adeka Resin EP-4088L, Adeka Resin EP-4080E (above, manufactured by ADEKA); and the like.

A cyclic ether group containing compound (C) can be used individually by 1 type or in combination of 2 or more type.

When the adhesive composition of the present invention contains the cyclic ether group-containing compound (C), the content of the cyclic ether group-containing compound (C) is preferably 1 mass% or more in the total amount of the active ingredient of the adhesive composition. , More preferably, it is 2-15 mass %.

When the content of the cyclic ether group-containing compound (C) is 1 mass % or more in the total amount of the active ingredient of the adhesive composition, tackiness is easily imparted, and the adhesive composition is excellent in adhesiveness, and the adhesive strength is more An excellent hardened|cured material becomes easy to be obtained.

In addition, the content of the cyclic ether group-containing compound (C) is preferably 10% by mass or less based on the total amount of the active ingredient of the adhesive composition from the viewpoint of easily obtaining a cured product having low dielectric properties, It is more preferable to set it as 2-10 mass %.

As for at least 1 sort(s) of a cyclic ether group containing compound (C), the compound which is liquid at 25 degreeC is preferable.

"Liquid at 25 degreeC" means having fluidity|liquidity in 25 degreeC. It is preferable that the viscosity of a cyclic ether group containing compound (B) measured at 25 degreeC and 1.0 rpm using an E-type viscometer is 2-10000 mPa*s.

As described above, the adhesive composition of the present invention contains the polyphenylene ether resin (B). Since polyphenylene ether resin (B) has a comparatively rigid molecular structure, there exists a possibility that the adhesive composition containing polyphenylene ether resin (B) may be inferior in coatability or adhesiveness.

In this respect, by making an adhesive composition contain the cyclic ether group containing compound (C) liquid at 25 degreeC, coatability, adhesiveness, and tackiness can be improved efficiently.

When the adhesive composition contains the liquid cyclic ether group-containing compound (C) at 25°C, the content is preferably 15% by mass or less in the total amount of the active ingredient of the adhesive composition, more preferably , 2 to 10 mass%. From the viewpoint of improving sticking ability when the adhesive composition of the present invention is used as an adhesive layer, the content of the cyclic ether group-containing compound (C) is 3 to 10 mass% in the total amount of the active ingredient of the adhesive composition desirable.

When content of the cyclic ether group containing compound (C) liquid at 25 degreeC shall be 15 mass % or less with respect to the total amount of the active ingredient of an adhesive composition, the hardened|cured material which has a low dielectric characteristic becomes easy to be obtained.

The curable adhesive layer may contain a compound having a cyclic ether group other than the cyclic ether group-containing compound (C), that is, a compound having a cyclic ether group without an alicyclic skeleton, but the dielectric constant of the cured product of the adhesive composition And in order to further reduce a dielectric loss tangent, it is preferable to reduce the usage-amount. From such a viewpoint, the ratio of the mass of the cyclic ether group-containing compound (C) to the mass of the compound having a cyclic ether group contained in the adhesive composition is preferably 90 mass% or more, and more preferably 95 mass% or more desirable.

[(D) component: curing agent]

The adhesive composition of this invention may contain a hardening|curing agent as (D)component.

The adhesive composition containing a hardening|curing agent is preferable since hardening reaction advances more efficiently.

As a hardening|curing agent, if hardening reaction is started, it will not specifically limit. A cationic polymerization initiator is preferably used as the curing agent from the viewpoint of efficiently reacting the polyphenylene ether resin (B) and the cyclic ether group-containing compound (C) to obtain a cured product having a high elastic modulus. . From the viewpoints of excellent stability and productivity over time, the curing agent is preferably used to initiate curing reaction by heating.

As a hardening|curing agent which initiates hardening reaction by heating, a thermal cationic polymerization initiator and other heat-reactive hardening|curing agents are mentioned. When using a thermal cationic polymerization initiator, in a thermosetting process, since heating is accompanied, polyphenylene ether resin (B) and a cyclic ether group containing compound (C) become easy to flow. As a result, compared with photocationic polymerization, a reactive functional group becomes easy to associate, and since reaction advances more efficiently, it is preferable.

A thermal cationic polymerization initiator is a compound which can generate|occur|produce the cationic species which initiate superposition|polymerization by heating.

As a thermal cationic polymerization initiator, a sulfonium salt, a quaternary ammonium salt, a phosphonium salt, a diazonium salt, an iodonium salt, etc. are mentioned.

As the sulfonium salt, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluoroarsinate, tris (4-methoxyphenyl) sulfonium hexafluoroar Cinate, diphenyl (4-phenylthiophenyl) sulfonium hexafluoro arsinate, etc. are mentioned.

A commercial item can also be used as a sulfonium salt. Commercially available products include adecaopton SP-150, adecaopton SP-170, adecaopton CP-66, adecaopton CP-77 (above, manufactured by ADEKA Corporation), San-Aid SI-60L, and San-Aid SI-80L. , San-Aid SI-100L, San-Aid SI-B2A, San-Aid SI-B3 (above, manufactured by Sanshin Chemical), CYRACURE UVI-6974, CYRACURE UVI-6990 (above, manufactured by Union Carbide), UVI-508, UVI -509 (above, manufactured by General Electric), FC-508, FC-509 (above, manufactured by Minnesota Mining and Manufacturing), CD-1010, CD-1011 (above, manufactured by Saastomer), CI series products (manufactured by Nippon Soda Corporation); and the like.

Examples of the quaternary ammonium salt include tetrabutylammonium tetrafluoroborate, tetrabutylammonium hexafluorophosphate, tetrabutylammonium hydrogen sulfate, tetraethylammonium tetrafluoroborate, tetraethylammonium p-toluenesulfonate, N,N -dimethyl-N-benzylanilinium hexafluoroantimonate, N,N-dimethyl-N-benzylanilinium tetrafluoroborate, N,N-dimethyl-N-benzylpyridinium hexafluoroantimonate, N ,N-diethyl-N-benzyltrifluoromethanesulfonate, N,N-dimethyl-N-(4-methoxybenzyl)pyridiniumhexafluoroantimonate, N,N-diethyl-N-( 4-methoxybenzyl) toluidinium hexafluoroantimonate, etc. are mentioned.

Examples of the phosphonium salt include ethyltriphenylphosphonium hexafluoroantimonate and tetrabutylphosphonium hexafluoroantimonate.

As a diazonium salt, AMERICURE (made by American Kan Corporation), ULTRASET (made by Adeka Corporation), etc. are mentioned.

Examples of the iodonium salt include diphenyliodonium hexafluoroarsinate, bis(4-chlorophenyl)iodonium hexafluoroarsinate, and bis(4-bromophenyl)iodonium hexafluoroarcinate. Cinate, phenyl (4-methoxyphenyl) iodonium hexafluoroarsinate, etc. are mentioned. Also, commercially available products include UV-9310C (manufactured by Toshiba Silicone), Photoinitiator2074 (manufactured by Long Plane), UVE series products (manufactured by General Electric), and FC series products (manufactured by Minnesota Mining & Manufacturing). etc. can also be used.

Examples of the thermally reactive curing agent other than the thermal cationic polymerization initiator include amine compounds such as benzylmethylamine and 2,4,6-trisdimethylaminomethylphenol; imidazole compounds such as 2-methylimidazole, 2-ethyl-4-methylimidazole, and 2-heptadecylimidazole; Lewis acids, such as a boron trifluoride-monoethylamine complex and a boron trifluoride-piperazine complex; and the like.

A hardening|curing agent can be used individually by 1 type or in combination of 2 or more type.

When the adhesive composition of this invention contains a hardening|curing agent, content of a hardening|curing agent becomes like this with respect to 100 mass parts of cyclic ether group containing compound (C), Preferably it is 1-10 mass parts, More preferably, it is 2-9 mass parts. , More preferably, it is 3-8 mass parts.

[Component (E): Silane Coupling Agent]

The adhesive composition of this invention may contain a silane coupling agent as (E) component.

By using a silane coupling agent, the hardened|cured material more excellent in adhesive strength becomes easy to be obtained.

As a silane coupling agent, a well-known silane coupling agent can be used. Especially, the organosilicon compound which has at least 1 alkoxysilyl group in a molecule|numerator is preferable.

Examples of the silane coupling agent include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, Silane coupling agents which have (meth)acryloyl groups, such as 3-acryloxypropyl trimethoxysilane;

Silane coupling agents having a vinyl group, such as vinyl trimethoxysilane, vinyl triethoxysilane, dimethoxymethylvinylsilane, diethoxymethylvinylsilane, trichlorovinylsilane, and vinyltris(2-methoxyethoxy)silane;

2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, Silane coupling agent which has epoxy groups, such as 8-glycidoxy octyl trimethoxysilane;

silane coupling agents having a styryl group such as p-styryltrimethoxysilane and p-styryltriethoxysilane;

N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltri Ethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl butylidene)propylamine, N-phenyl-3 - a silane coupling agent having an amino group, such as hydrochloride salt of -aminopropyltrimethoxysilane and N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane;

silane coupling agents having a ureido group such as 3-ureidopropyltrimethoxysilane and 3-ureidopropyltriethoxysilane;

silane coupling agents having halogen atoms such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane;

silane coupling agents having a mercapto group such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane;

silane coupling agents having a sulfide group such as bis(trimethoxysilylpropyl)tetrasulfide and bis(triethoxysilylpropyl)tetrasulfide;

Silane coupling agents which have isocyanate groups, such as 3-isocyanate propyl trimethoxysilane and 3-isocyanate propyl triethoxysilane;

Silane coupling agents having an allyl group, such as allyltrichlorosilane, allyltriethoxysilane, and allyltrimethoxysilane;

Silane coupling agents which have hydroxyl groups, such as 3-hydroxypropyl trimethoxysilane and 3-hydroxypropyl triethoxysilane; and the like.

These silane coupling agents can be used individually by 1 type or in combination of 2 or more type.

When the adhesive composition of this invention contains a silane coupling agent, content of a silane coupling agent is in the total amount of the active ingredient of an adhesive composition, Preferably it is 0.01-5 mass %, More preferably, it is 0.05-1 mass %. .

〔menstruum〕

The adhesive composition of this invention may contain a solvent.

As a solvent, Aromatic hydrocarbon type solvents, such as benzene and toluene; ester solvents such as ethyl acetate and butyl acetate; Ketone solvents, such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as n-pentane, n-hexane, and n-heptane; alicyclic hydrocarbon solvents such as cyclopentane, cyclohexane and methylcyclohexane; and the like.

These solvents can be used individually by 1 type or in combination of 2 or more type.

When the adhesive composition of this invention contains a solvent, content of a solvent can consider coatability etc. and can determine it suitably.

[Other ingredients]

The adhesive composition of this invention may contain other components in the range which does not impair the effect of this invention.

As other components, additives, such as a ultraviolet absorber, antistatic agent, a light stabilizer, antioxidant, a resin stabilizer, a filler, a pigment, an extender, and a softener, are mentioned.

These can be used individually by 1 type or in combination of 2 or more type.

When the adhesive composition of this invention contains these additives, the content can be suitably determined according to the objective.

[Adhesive composition]

The adhesive composition of this invention can be prepared by mixing and stirring the said (A) component and (B) component, and another arbitrary component suitably according to a conventional method.

The cured product of the adhesive composition of the present invention has low dielectric properties in a high-frequency region.

The cured product of the adhesive composition has a relative dielectric constant at 23° C. and a frequency of 1 GHz (hereinafter, this relative dielectric constant may be referred to as “relative dielectric constant (α)”) is preferably 2.66 or less, more preferably is 2.50 or less, particularly preferably 2.45 or less.

Although there is no particular lower limit of the dielectric constant (?), it is usually 2.00 or more.

The adhesive composition which can form the hardened|cured material whose dielectric constant ((alpha)) is 2.66 or less is used suitably as an adhesive agent for flexible printed wiring board connection.

The measurement sample of the relative dielectric constant (α) will not be particularly limited as long as the adhesive composition is sufficiently cured.

For example, when the adhesive composition has curability, the adhesive after curing is used as a measurement sample for the relative dielectric constant (?). When the adhesive composition to be measured has recommended curing conditions, the cured adhesive cured under the recommended conditions is used as a measurement sample for the relative dielectric constant (?). When there is no recommended curing conditions in the adhesive composition or is unknown, for example, a cured product obtained under curing conditions of 160°C for 1 hour may be used as a measurement sample for the relative dielectric constant (α).

The dielectric constant (α) can be measured according to the method described in Examples.

The cured product of the adhesive composition has a dielectric loss tangent at 23° C. and a frequency of 1 GHz (hereinafter, this dielectric loss tangent may be referred to as “dielectric loss tangent (β)”) is preferably 0.0100 or less, more preferably Preferably it is 0.0075 or less, More preferably, it is 0.0050 or less.

Although there is no particular lower limit of the dielectric loss tangent (?), it is usually 0.0001 or more.

The adhesive composition which can form the hardened|cured material whose dielectric loss tangent ((beta)) is 0.0100 or less is used suitably as an adhesive agent for flexible printed wiring board connection.

The dielectric loss tangent (β) can be measured according to the method described in Examples.

The hardened|cured material of the adhesive composition of this invention is excellent in adhesive strength.

When peel adhesive strength is measured by the method as described in an Example, it is 8 N/cm or more normally. In addition, although an upper limit in particular is not provided, Usually, it is 50 N/cm or less.

The adhesive composition of this invention is used suitably as an adhesive agent for flexible printed wiring board association. As an adhesive agent for flexible printed wiring board connection, the adhesive composition for formation of the adhesive bond layer which comprises an adhesive film with copper foil and a coverlay film is mentioned.

2) Adhesive sheet

The adhesive sheet of this invention has the adhesive bond layer formed using the adhesive composition of this invention.

Although the thickness of an adhesive bond layer is not specifically limited, Usually, it is 1-50 micrometers, Preferably it is 1-25 micrometers, More preferably, it is 5-25 micrometers. The adhesive bond layer whose thickness exists in the said range is used suitably as a forming material of a flexible printed wiring board-related product.

The thickness of an adhesive bond layer can be measured according to JISK7130 (1999) using a well-known thickness gauge.

The adhesive sheet of this invention may have a base material other than an adhesive bond layer.

As a base material, a resin film can be used normally.

As the resin component of the resin film, polyimide, polyamide, polyamideimide, polyphenylene ether, polyether ketone, polyether ether ketone, polyolefin, polyester, polycarbonate, polysulfone, polyethersulfone, polyphenylene sulfone pids, polyarylates, acrylic resins, cycloolefin polymers, aromatic polymers, polyurethane polymers, liquid crystal polymer films, and the like.

Although there is no restriction|limiting in particular as for the thickness of a base material, Preferably it is 10-500 micrometers, More preferably, it is 10-300 micrometers, More preferably, it is 15-200 micrometers.

The adhesive sheet of this invention may have a peeling sheet other than an adhesive bond layer.

The release sheet functions as a protective sheet for the adhesive layer until the adhesive sheet is used. Moreover, when an adhesive sheet does not have a base material, a peeling sheet functions as a support body in the manufacturing process of an adhesive sheet.

In addition, when using the adhesive sheet of this invention, a peeling sheet is peeled and removed normally.

As a release sheet, a conventionally well-known thing can be used. For example, on the base material for peeling sheets, what has the peeling layer by which the peeling process was carried out with the release agent is mentioned.

As a base material for release sheets, Paper base materials, such as glassine paper, coated paper, and quality paper; laminated paper in which a thermoplastic resin such as polyethylene is laminated on these paper substrates; plastic films such as polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, polypropylene resin, and polyethylene resin; and the like.

Examples of the release agent include rubber-based elastomers such as silicone-based resins, olefin-based resins, isoprene-based resins and butadiene-based resins, long-chain alkyl-based resins, alkyd-based resins, and fluorine-based resins.

Although there is no restriction|limiting in particular as for the thickness of a peeling sheet, Usually, it is about 20-250 micrometers.

When the adhesive sheet of this invention has a peeling sheet, you may have a peeling sheet of 1 sheet, a total of 2 sheets, respectively on both sides of an adhesive bond layer, and you may have a peeling sheet only on one side of an adhesive bond layer.

The manufacturing method of an adhesive sheet is not specifically limited. For example, an adhesive sheet can be manufactured using the casting method.

When the adhesive sheet is produced by the casting method, by using a known method, the adhesive composition of the present invention is applied to the surface of the release-treated release layer of the base material or release sheet, and the obtained coating film is dried to prepare the adhesive sheet. can

As a method of coating the adhesive composition, for example, a spin coat method, a spray coat method, a bar coat method, a knife coat method, a roll coat method, a blade coat method, a die coat method, a gravure coat method, etc. are mentioned.

As a method of drying a coating film, conventionally well-known drying methods, such as hot air drying, hot roll drying, and infrared irradiation, are mentioned.

As conditions at the time of drying a coating film, it is 30 second to 5 minutes at 80-150 degreeC, for example.

When an adhesive bond layer has thermosetting property, an adhesive bond layer is hardened by heating an adhesive bond layer.

The conditions at the time of thermosetting an adhesive bond layer are not specifically limited.

Heating temperature is 80-200 degreeC normally, Preferably it is 90-150 degreeC.

The heating time is usually 30 minutes to 12 hours, and preferably 1 to 6 hours.

The hardened|cured material of the adhesive bond layer of this invention has a low dielectric characteristic in a high frequency range, and is excellent in adhesive strength.

Therefore, the hardened|cured material of the adhesive bond layer of this invention is used suitably as an adhesive agent hardened|cured material layer which comprises a flexible printed wiring board.

Example

Hereinafter, the present invention will be described in more detail by way of Examples. However, the present invention is not limited to the following examples at all.

[Compound used in Examples or Comparative Examples]

Modified polyolefin resin (A1): acid-modified α-olefin polymer [manufactured by Mitsui Chemicals, trade name: Unistol H-200, number average molecular weight: 47,000]

Polyphenylene ether resin (B1): vinylbenzyl-modified polyphenylene ether [manufactured by Mitsubishi Gas Chemical, trade name: OPE-2St 1200, number average molecular weight: 1200]

Polyphenylene ether resin (B2): vinylbenzyl-modified polyphenylene ether [manufactured by Mitsubishi Gas Chemical, trade name: OPE-2St 2200, number average molecular weight: 2200]

Cyclic ether group-containing compound (C1): hydrogenated bisphenol A epoxy resin [manufactured by Mitsubishi Chemical, trade name: YX8000, epoxy equivalent: 205 g/eq, liquid at 25°C]

-Cyclic ether group-containing compound (C2): hydrogenated bisphenol A epoxy resin [manufactured by Mitsubishi Chemical, trade name: YX8034, epoxy equivalent: 270 g/eq, liquid at 25°C]

Curing agent (D1): thermal cationic polymerization initiator [manufactured by Sanshin Chemical, trade name: San-Aid SI-B3]

·Silane coupling agent (E1): 8-glycidoxyoctyltrimethoxysilane [manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM4803]

[Example 1]

Modified polyolefin resin (A1) 100 parts by mass, polyphenylene ether resin (B1) 50 parts by mass, cyclic ether group-containing compound (C1) 3 parts by mass, curing agent (D1) 0.15 parts by mass, silane coupling agent (E1) 0.2 A mass part was melt|dissolved in toluene, and the adhesive composition was prepared.

This adhesive composition was coated on the release-treated surface of a release sheet (first release sheet, manufactured by Lintec, trade name: SP-PET752150), and the resulting coating film was dried at 100°C for 2 minutes, and an adhesive layer having a thickness of 15 µm was formed formed. On this adhesive layer, the peeling-processed surface of another peeling sheet (2nd peeling sheet, the Lintec company make, brand name: SP-PET381130) was pasted together, and the adhesive sheet was obtained.

[Examples 2 to 16, Comparative Example 1]

An adhesive composition and an adhesive sheet were obtained in the same manner as in Example 1 except that the type and amount of each active ingredient constituting the adhesive composition were changed to those shown in Tables 1 and 2.

The following tests were done about the adhesive sheet obtained in Examples 1-16 and Comparative Example 1. A result is shown in Table 1, Table 2.

[Relative permittivity, dielectric loss tangent]

A plurality of adhesive layers of the adhesive sheets obtained in Examples or Comparative Examples were laminated using a thermal laminator heated to 100° C. so that the total thickness was 1 mm, and a release sheet/1 mm thick adhesive layer/release sheet A laminate of the structure was obtained. After heating this laminated body at 160 degreeC for 1 hour and hardening the adhesive bond layer with a thickness of 1 mm, the peeling sheets on both sides were peeled and the sample for a measurement was obtained.

About the obtained sample for measurement, the dielectric constant and dielectric loss tangent in 23 degreeC and 1 GHz were measured using the RF impedance material analyzer (The Keysight company make, E4991A). In the Example or the comparative example, 1 GHz was employ|adopted as an example of a high frequency range.

[Adhesive strength]

One release sheet of the adhesive sheet obtained by the Example or the comparative example was peeled off. Using the thermal laminator, the exposed adhesive bond layer and copper foil were bonded together on 100 degreeC temperature conditions. Then, the sample by which copper foil and the adhesive bond layer with a release sheet were bonded together was processed into 10 mm x 100 mm.

Next, the remaining release sheet was peeled off, the exposed adhesive layer and the polyimide film were bonded together under the temperature condition of 100 ° C. using a laminator, to obtain a laminate having a layer structure of copper foil / adhesive layer / polyimide film.

About this laminated body, on 160 degreeC and 5 Mpa conditions, the thermosetting process by hot pressing was performed for 1 hour, and the sample for a measurement was obtained.

Using a precision universal testing machine (manufactured by Shimadzu Corporation, product name: Autograph AG-IS), the peel adhesive strength of the obtained measurement sample was measured under conditions of a peel angle of 90° and a peel rate of 50 mm/min. The peeling test was performed by peeling copper foil with respect to the sample for a measurement, pulling in the direction of 90 degrees.

Table 1 and Table 2 show the following.

The hardened|cured material of the adhesive composition obtained in Examples 1-16 has the low dielectric characteristic in a high frequency range, and has sufficient adhesive strength.

In particular, since the hardened|cured material of the adhesive composition obtained in Examples 1-16 has a low dielectric loss tangent, the wiring member for high frequency signal transmission formed using the adhesive composition obtained in Examples 1-16 has small transmission loss.

Claims (10)

The adhesive composition containing the following (A) component and (B) component.
(A) component: modified polyolefin resin
(B) component: polyphenylene ether resin having a reactive group The method of claim 1,
Adhesive composition whose content of the said modified polyolefin resin is more than 50 mass % in the total amount of the active ingredient of an adhesive composition. 3. The method according to claim 1 or 2,
The adhesive composition, wherein the reactive group of the polyphenylene ether resin having a reactive group is a group having an ethylenically unsaturated bond. 4. The method according to any one of claims 1 to 3,
Furthermore, the adhesive composition containing the following (C) component.
(C) component: a compound having an alicyclic skeleton and a cyclic ether group 5. The method of claim 4,
The adhesive composition, wherein the content of the compound having an alicyclic skeleton and a cyclic ether group is 10 mass% or less in the total amount of the active ingredient of the adhesive composition. 6. The method according to claim 4 or 5,
At least one of the compounds having an alicyclic skeleton and a cyclic ether group is a compound that is liquid at 25°C, and the content of the compound having an alicyclic skeleton and a cyclic ether group that is liquid at 25°C is the total amount of the active ingredient of the adhesive composition 10% by mass or less of the amount, the adhesive composition. 7. The method according to any one of claims 1 to 6,
Furthermore, the adhesive composition containing the following (D) component.
(D) component: curing agent 8. The method of claim 7,
The curing agent, the adhesive composition comprising a cationic polymerization initiator. 9. The method according to any one of claims 1 to 8,
Furthermore, the adhesive composition containing the following (E) component.
(E) component: silane coupling agent The adhesive sheet which has an adhesive bond layer formed using the adhesive composition in any one of Claims 1-9.