CN117222721A

CN117222721A - Curable adhesive composition, cured product, and method for producing cured product

Info

Publication number: CN117222721A
Application number: CN202280025752.6A
Authority: CN
Inventors: 西嶋健太; 樫尾干广
Original assignee: Lintec Corp
Current assignee: Lintec Corp
Priority date: 2021-03-30
Filing date: 2022-03-29
Publication date: 2023-12-12
Also published as: TW202244222A; KR20230163357A; JPWO2022210673A1; WO2022210673A1

Abstract

The present invention provides a curable adhesive composition, a cured product thereof, and a method for producing the cured product, wherein the curable adhesive composition comprises: a 1 st curing system in which a binder resin having a reactive functional group is reacted with a crosslinking agent, the curing system being reacted at a temperature of 120 ℃ or lower; and a 2 nd curing system in which 1 or 2 or more compounds having a carbon-carbon double bond are reacted, the reaction being performed at a temperature exceeding 120 ℃.

Description

Curable adhesive composition, cured product, and method for producing cured product

Technical Field

The present invention relates to a curable adhesive composition which is less likely to contaminate the surroundings in an adhesion step, a cured product thereof, and a method for producing the cured product.

Background

In recent years, curable adhesives have been used as materials for forming insulating resin layers, sealant layers, adhesive members, and the like for electronic devices and the like.

For example, patent document 1 describes a thermosetting adhesive sheet comprising an epoxy resin, wherein the cured product of the thermosetting adhesive sheet has a storage elastic modulus (x 1) at 25 ℃ of 1GPa or more and a storage elastic modulus (x 2) at 100 ℃ of 1GPa or more. In addition, this document also describes: the thermosetting adhesive sheet described in this document can effectively suppress the minute deformation or displacement of the adherend at high temperature, and even when used for fixing an adherend that can repeatedly undergo minute deformation, it is difficult to cause peeling with time.

Prior art literature

Patent literature

Patent document 1: japanese patent application laid-open No. 2017-110128.

Disclosure of Invention

Problems to be solved by the invention

When the adhesive composition is used, a coating film of the adhesive composition is generally subjected to a heat treatment. In this case, depending on the processing conditions, the adhesive component may bleed out and cause contamination of the surroundings.

The present invention has been made in view of the above circumstances, and an object thereof is to: provided are a curable adhesive composition, a cured product thereof, and a method for producing the cured product, wherein the surrounding is less likely to be contaminated in an adhesion step.

Means for solving the problems

In order to solve the above problems, the present inventors have conducted intensive studies on a curable adhesive composition. As a result, it was found that: the present invention has been completed by blending curable components so as to have a 1 st curing system that reacts at a temperature of 120 ℃ or less and a 2 nd curing system that reacts at a temperature exceeding 120 ℃ to obtain a curable adhesive composition that is less likely to contaminate the surroundings in the bonding step.

Thus, according to the present invention, there are provided the following curable adhesive compositions [1] to [10], cured products of [11] to [14] and [16], and methods for producing cured products of [15] and [17 ].

[1] A curable adhesive composition comprising:

a 1 st curing system in which a binder resin having a reactive functional group is reacted with a crosslinking agent, the curing system being reacted at a temperature of 120 ℃ or lower; and

the 2 nd curing system is a curing system in which 1 or 2 or more kinds of compounds having a carbon-carbon double bond are reacted, and the reaction is performed at a temperature exceeding 120 ℃.

[2] The curable adhesive composition according to [1], wherein the adhesive resin having the reactive functional group is a polyolefin resin.

[3] The curable adhesive composition according to [1] or [2], wherein the adhesive resin having a reactive functional group is an acid-modified resin.

[4] The curable adhesive composition according to any one of [1] to [3], wherein the crosslinking agent is a compound having an isocyanurate skeleton.

[5] The curable adhesive composition according to any one of [1] to [4], wherein the crosslinking agent is a compound having 2 or more isocyanate groups.

[6] The curable adhesive composition according to any one of [1] to [5], wherein the compound having a carbon-carbon double bond is a non-aromatic compound having 2 or more hydrocarbon groups having a double bond at the terminal and being liquid at 25 ℃.

[7] The curable adhesive composition according to any one of [1] to [6], wherein the compound having a carbon-carbon double bond is a modified polyphenylene ether resin having a hydrocarbon group having a double bond at a terminal.

[8] The curable adhesive composition according to any one of [1] to [7], wherein the curable adhesive composition further comprises a cationic polymerization initiator, and the 2 nd curing system initiates a reaction by the cationic polymerization initiator.

[9] The curable adhesive composition according to any one of [1] to [8], wherein the curable adhesive composition is a composition which, upon curing, provides a cured product having a dielectric loss tangent of less than 0.0050 at 23 ℃ and a frequency of 1 GHz.

[10] The curable adhesive composition according to any one of [1] to [9], wherein the curable adhesive composition is a composition which, upon curing, provides a cured product having a relative dielectric constant of 3.00 or less at 23 ℃ and a frequency of 1 GHz.

[11] A cured product obtained by curing the curable adhesive composition according to any one of [1] to [10], which satisfies the following requirements 1 and 2:

element 1: gel fraction (gel fraction) of 10 mass% or more;

element 2: with further thermosetting properties.

[12] The cured product according to [11], wherein the cured product is a cured product having a sheet-like shape.

[13] The cured product of [11] or [12], wherein the cured product is a sheet-like adhesive for electronic devices.

[14] The cured product of [11] or [12], wherein the cured product is a sheet-like adhesive for a cover film.

[15] The method for producing a cured product according to any one of [11] to [14], comprising the following step I:

procedure I: the step of curing the curable adhesive composition of any one of [1] to [10] at a temperature of 120 ℃ or lower.

[16] A cured product obtained by curing the curable adhesive composition according to any one of [1] to [10], which satisfies the following requirement 3:

element 3: the gel fraction is 50 mass% or more.

[17] The method for producing a cured product according to [16], comprising the following steps IIa and IIb:

procedure IIa: a step of curing the curable adhesive composition of any one of [1] to [10] at a temperature of 120 ℃ or lower to form a cured product;

procedure IIb: and (c) a step of further curing the cured product formed in step IIa at a temperature exceeding 120 ℃.

Effects of the invention

According to the present invention, there are provided a curable adhesive composition, a cured product thereof, and a method for producing the cured product, which hardly contaminates the surroundings in the bonding step.

Drawings

FIG. 1 is a schematic view (plan view) of a part of a laminate used in evaluating the bleeding of an adhesive component.

FIG. 2 is a schematic diagram showing a section A-A of FIG. 1.

Detailed Description

The numerical ranges described in the present specification may be arbitrarily combined with the upper limit value and the lower limit value. For example, when the numerical range is described as "preferably 30 to 100, more preferably 40 to 80", the numerical range of "30 to 80" or the numerical range of "40 to 100" is also included in the numerical range described in the present specification. For example, when the numerical range is "preferably 30 or more, more preferably 40 or more, and further preferably 100 or less, more preferably 80 or less," the range of "30 to 80" or the range of "40 to 100" is included in the numerical range described in the present specification.

In addition, as the numerical ranges described in the present specification, for example, the description of "60 to 100" means a range of "60 or more and 100 or less".

In the specification of the upper limit and the lower limit described in the present specification, the numerical ranges from the lower limit to the upper limit may be defined by appropriately selecting from the respective options and arbitrarily combining them.

In addition, a plurality of various elements described as preferable embodiments described in the present specification may be combined.

In the present specification, the number average molecular weight (Mn) can be obtained by Gel Permeation Chromatography (GPC) using Tetrahydrofuran (THF) as a solvent and as a standard polystyrene equivalent, and can be measured under the following conditions, for example.

(examples of measurement conditions)

Gel permeation chromatography apparatus: manufactured by Tosoh corporation, product name "HLC-8020";

column: columns (all manufactured by Tosoh Co., ltd.) obtained by sequentially connecting "TSK guard column HXL-L", "TSK gel G2500HXL", "TSK gel G2000HXL" and "TSK gel G1000 HXL";

column temperature: 40 ℃;

developing solvent: tetrahydrofuran;

flow rate: 1.0 mL/min.

Hereinafter, the present invention will be described in detail with reference to (1) a curable adhesive composition, and (2) a cured product and a method for producing the cured product.

(1) Curable adhesive composition

The curable adhesive composition of the present invention comprises: a 1 st curing system in which a binder resin having a reactive functional group is reacted with a crosslinking agent, the curing system being reacted at a temperature of 120 ℃ or lower; and a 2 nd curing system in which 1 or 2 or more compounds having a carbon-carbon double bond are reacted, the reaction being performed at a temperature exceeding 120 ℃.

The curable adhesive composition of the present invention may contain one of the components classified into the 1 st curing system and the 2 nd curing system, or may contain both of the components classified into the 1 st curing system and the 2 nd curing system.

The curable adhesive composition of the present invention may contain components not classified into any of the 1 st curing system and the 2 nd curing system, within a range that does not impair the effects of the present invention.

Curing System 1

The 1 st curing system contained in the curable adhesive composition of the present invention is a curing system in which a binder resin having a reactive functional group and a crosslinking agent react, and the reaction is performed at a temperature of 120 ℃ or lower.

The 1 st curing system is a system in which the reaction is carried out at a temperature of 120℃or lower. Since the 1 st curing system is a system that reacts at a temperature of 120 ℃ or lower, the reaction of the 1 st curing system can be performed under relatively mild conditions when the curable adhesive composition of the present invention is used. Therefore, the crosslinked structure can be efficiently formed in the coating film of the curable adhesive composition without performing the reaction of the 2 nd curing system.

The 1 st curing system is preferably a curing system in which a binder resin having a reactive functional group (hereinafter, sometimes referred to as "binder resin (a)") and a crosslinking agent (B) (hereinafter, sometimes referred to as "crosslinking agent (B)") which is reactive with the binder resin (a) react. Therefore, the 1 st curing system preferably comprises a binder resin (a) and a crosslinking agent (B).

The 1 st curing system may contain curable components other than the binder resin (a) and the crosslinking agent (B). The other curable components other than the binder resin (a) and the crosslinking agent (B) contained in the 1 st curing system may be appropriately selected according to the reaction characteristics of the 1 st curing system. The other curable component may be a component classified as a 2 nd curing system.

The reaction temperature of the 1 st curing system can be adjusted by appropriately combining the binder resin (a) and the crosslinking agent (B) in consideration of the reactivity of the reactive functional group in the binder resin (a) with the crosslinking agent (B).

In the curable adhesive composition according to one embodiment of the present invention, the total content of the (a) component and the (B) component as the 1 st curing system may be 40 mass% or more, 50 mass% or more, 60 mass% or more, 65 mass% or more, or 70 mass% or more, and 94 mass% or less, 90 mass% or less, 85 mass% or less, 80 mass% or less, or 77 mass% or less, with respect to the total amount (100 mass%) of the active components of the curable adhesive composition.

In the present specification, the "active ingredient" refers to a component in a composition, and refers to a component other than a solvent.

[ (A) component: binder resin having reactive functional group ]

The 1 st curing system contains a binder resin (a) having a reactive functional group as a curable component.

Since the 1 st curing system contains the binder resin (a), contamination around the bonding step can be suppressed as described below.

The binder resin (a) may be used alone or in combination of 2 or more.

The number average molecular weight (Mn) of the binder resin (a) is not particularly limited, but is usually 10,000 or more, preferably 10,000 ～ 150,000, and more preferably 10,000 ～ 100,000, from the viewpoint of easily obtaining a curable adhesive composition which is less likely to contaminate the surroundings.

The number average molecular weight (Mn) of the binder resin (a) can be determined by Gel Permeation Chromatography (GPC) using Tetrahydrofuran (THF) as a solvent, as a standard polystyrene equivalent, and as specific measurement conditions, as described above.

The content of the binder resin (a) (when the binder resin (a) is contained in an amount of 2 or more kinds, the total amount thereof) is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 65% by mass or more, and further preferably 95% by mass or less, more preferably 90% by mass or less, still more preferably 85% by mass or less, still more preferably 80% by mass or less, relative to the total amount (100% by mass) of the active ingredients of the curable adhesive composition.

When the content of the binder resin (a) is 50 mass% or more, a curable adhesive composition which is less likely to contaminate the surroundings is easily obtained.

When the content of the binder resin (a) is 95 mass% or less, a curable adhesive composition providing a cured product excellent in low dielectric characteristics (in this specification, "low dielectric characteristics" means "low dielectric constant and low dielectric loss tangent") is easily obtained.

As the binder resin (a), there may be mentioned: polyolefin resins, phenoxy resins, polyimide resins, polyamideimide resins, polyvinyl butyral resins, polycarbonate resins, and the like.

Of these, as the binder resin (a), a polyolefin-based resin is preferable. By making the binder resin (a) a polyolefin resin, a curable adhesive composition that provides a cured product excellent in low dielectric characteristics can be easily obtained.

In the case of preparing the curable adhesive composition containing the polyolefin resin as the component (a), the curable adhesive composition may contain other adhesive resins other than the polyolefin resin as other components.

In the curable adhesive composition, the content of the other binder resin is preferably 0 to 50 parts by mass, more preferably 0 to 30 parts by mass, still more preferably 0 to 10 parts by mass, and still more preferably 0 to 5 parts by mass, relative to 100 parts by mass of the total amount of the polyolefin resin.

The polyolefin-based resin means a polymer containing a repeating unit derived from an olefin-based monomer. The polyolefin resin may be a polymer composed of only repeating units derived from an olefin monomer, or may be a polymer composed of repeating units derived from an olefin monomer and repeating units derived from a monomer copolymerizable with an olefin monomer.

The olefin monomer is preferably an α -olefin having 2 to 8 carbon atoms, more preferably ethylene, propylene, 1-butene, isobutylene or 1-hexene, and still more preferably ethylene or propylene. These olefinic monomers may be used singly or in combination of 1 or more than 2.

Examples of the monomer copolymerizable with the olefin monomer include: vinyl acetate, (meth) acrylate, styrene, and the like. Here, "(meth) acrylic" means acrylic acid or methacrylic acid (hereinafter the same).

These "monomers copolymerizable with the olefin-based monomer" may be used singly or in combination of 1 or more than 2.

Examples of the polyolefin 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 copolymers, olefin-based elastomers (TPO), ethylene-vinyl acetate copolymers (EVA), ethylene- (meth) acrylic acid copolymers, ethylene- (meth) acrylate copolymers, and the like.

The reactive functional group contained in the binder resin (a) includes: carboxyl group, carboxylic anhydride group, carboxylic ester group, hydroxyl group, epoxy group, amide group, ammonium group, nitrile group, amino group, imide group, isocyanate group, acetyl group, thiol group, ether group, thioether group, sulfo group, phosphine group, nitro group, urethane group, halogen atom, alkoxysilyl group, etc.

The binder resin (a) is preferably a modified resin. The modified resin is a resin having a reactive functional group introduced therein, which is obtained by modifying a resin as a precursor with a modifier.

The modifier used for the modification treatment of the binder resin is a compound having a reactive functional group in the molecule. As the reactive functional group, there may be mentioned: the functional groups described previously.

The modified resins include: the acid group-introduced resin (acid-modified resin) or the hydroxyl group-introduced resin is preferably an acid-modified resin. Among the acid-modified resins, resins incorporating an acid anhydride structure are preferred.

By using the acid-modified resin as the binder resin (a), a curable adhesive composition providing a cured product excellent in low dielectric characteristics can be easily obtained. Further, the use of a resin having an acid anhydride structure as the acid-modified resin tends to facilitate the maintenance of a long pot life.

In the case of preparing the curable adhesive composition containing the acid-modified resin as the component (a), the curable adhesive composition may contain other adhesive resins other than the acid-modified resin as other components.

In the curable adhesive composition, the content of the other binder resin is preferably 0 to 50 parts by mass, more preferably 0 to 30 parts by mass, still more preferably 0 to 10 parts by mass, and still more preferably 0 to 5 parts by mass, relative to 100 parts by mass of the total amount of the acid-modified resin.

Examples of the acid-modified resin include: an acid-modified resin in which an unsaturated carboxylic acid or unsaturated carboxylic acid anhydride (hereinafter, sometimes referred to as "unsaturated carboxylic acid or the like") is reacted with a resin to introduce (graft-modify) a carboxyl group or carboxylic acid anhydride group.

Examples of the unsaturated carboxylic acid that reacts with the resin include: unsaturated carboxylic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid, glutaconic acid, tetrahydrophthalic acid, aconitic acid, and the like; unsaturated carboxylic acid anhydrides such as maleic anhydride, itaconic anhydride, glutaconic anhydride, citraconic anhydride, aconitic anhydride, norbornene dicarboxylic anhydride, tetrahydrophthalic anhydride, and the like.

These may be used singly or in combination of 1 or more than 2. Among these, maleic anhydride is preferable from the viewpoint of easy availability of a curable adhesive composition which provides a cured product having higher adhesive strength.

The amount of the unsaturated carboxylic acid or the like to be reacted with the resin is preferably 0.1 to 5 parts by mass, more preferably 0.2 to 3 parts by mass, and still more preferably 0.2 to 1 part by mass, per 100 parts by mass of the resin. By curing the curable adhesive composition containing the acid-modified resin obtained in this way, a cured product having higher adhesive strength can be easily obtained.

The method of introducing the unsaturated carboxylic acid unit or the unsaturated carboxylic acid anhydride unit into the resin is not particularly limited. For example, the following methods may be mentioned: the unsaturated carboxylic acid and the like are graft-copolymerized with the resin by a method of melting and reacting the resin and the unsaturated carboxylic acid and the like by heating them to a temperature equal to or higher than the melting point of the resin in the presence of a radical generator such as an organic peroxide or an azonitrile, or a method of dissolving the resin and the unsaturated carboxylic acid and the like in an organic solvent, and then heating them in the presence of a radical generator and stirring them to react them.

As the binder resin (a), a modified polyolefin-based resin is preferable, and an acid-modified polyolefin-based resin is more preferable. By making the binder resin (a) an acid-modified polyolefin-based resin, a curable adhesive composition that provides a cured product excellent in low dielectric characteristics and low contamination can be easily obtained.

The modified polyolefin resin is a polyolefin resin having a reactive functional group introduced therein, which is obtained by modifying a polyolefin resin as a precursor with a modifier.

In the case of preparing the curable adhesive composition containing the acid-modified polyolefin resin as the component (a), the curable adhesive composition may contain other adhesive resins other than the acid-modified polyolefin resin as other components.

In the curable adhesive composition, the content of the other binder resin is preferably 0 to 50 parts by mass, more preferably 0 to 30 parts by mass, still more preferably 0 to 10 parts by mass, and still more preferably 0 to 5 parts by mass, relative to 100 parts by mass of the total amount of the acid-modified polyolefin resin.

[ (B) component: crosslinking agent ]

The 1 st curing system contains a crosslinking agent (B) reactive with the binder resin (a) as a curable component.

Since the 1 st curing system contains the crosslinking agent (B), the contamination of the surroundings can be suppressed in the bonding step as described below.

The crosslinking agent (B) may be used alone or in combination of 1 or more than 2.

The molecular weight of the crosslinking agent (B) is preferably 1000 or less, more preferably 800 or less, further preferably 700 or less, further preferably 600 or less, particularly preferably 500 or less.

By setting the molecular weight of the crosslinking agent (B) to 1000 or less, the probability of collision of the reaction with the binder resin (a) is increased, and a crosslinked structure is easily formed, whereby the curable adhesive composition having a high effect of suppressing contamination around the periphery in the bonding step can be obtained.

The lower limit of the molecular weight of the crosslinking agent (B) is not particularly limited, but is usually 100 or more, preferably 200 or more.

The molecular weight of the crosslinking agent (B) is a formula weight determined by the structural formula of the compound used as the crosslinking agent (B).

The content of the crosslinking agent (B) (when 2 or more crosslinking agents (B) are contained, the total amount thereof) is preferably 0.1 mass% or more, more preferably 0.2 mass% or more, still more preferably 0.3 mass% or more, still more preferably 0.5 mass% or more, still more preferably 0.7 mass% or more, particularly preferably 0.9 mass% or more, and further preferably 5 mass% or less, more preferably 4 mass% or less, still more preferably 3 mass% or less, still more preferably 2 mass% or less, relative to the total amount (100 mass%) of the active ingredients of the curable adhesive composition.

The content of the crosslinking agent (B) is 0.1 mass% or more with respect to the total amount of the active ingredients of the curable adhesive composition, whereby a curable adhesive composition which is less likely to contaminate the surroundings can be easily obtained.

In addition, the content of the crosslinking agent (B) is 5 mass% or less with respect to the total amount of the active ingredients of the curable adhesive composition, so that a curable adhesive composition providing a cured product excellent in low dielectric characteristics can be easily obtained.

The content of the crosslinking agent (B) (when the crosslinking agent (B) is contained in an amount of 2 or more kinds, the total amount thereof) is preferably 0.1 part by mass or more, more preferably 0.3 part by mass or more, further preferably 0.5 part by mass or more, further preferably 0.8 part by mass or more, particularly preferably 1.2 part by mass or more, further preferably 10 parts by mass or less, more preferably 7 parts by mass or less, further preferably 5 parts by mass or less, further preferably 3 parts by mass or less, relative to 100 parts by mass of the component (a).

The crosslinking agent (B) is a compound that can react with the binder resin (a). Therefore, as the crosslinking agent (B), a substance having a reactive group or a reactive site reactive to the reactive functional group in the binder resin (a) needs to be appropriately selected.

For example, as the crosslinking agent (B), an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, a metal chelate-based crosslinking agent, an aziridine-based crosslinking agent, or the like can be used. Among these, 1 or more selected from the group consisting of isocyanate-based crosslinking agents, epoxy-based crosslinking agents and metal chelate-based crosslinking agents is preferable from the viewpoint of storage stability.

In one embodiment of the present invention, for example, the binder resin (a) is an acid-modified resin, and when the reactive functional group in the binder resin (a) is a carboxyl group or a carboxylic acid anhydride group, the crosslinking agent (B) is preferably 1 or more selected from an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent and a metal chelate-based crosslinking agent.

The isocyanate-based crosslinking agent is a compound having 2 or more isocyanate groups in the molecule.

Examples of the isocyanate-based crosslinking agent include: 2, 4-toluene diisocyanate, 2, 6-toluene diisocyanate, hydrogenated xylene diisocyanate, 1, 5-pentamethylene diisocyanate, 1, 6-hexamethylene diisocyanate, diphenylmethane-4, 4-diisocyanate, isophorone diisocyanate, 1, 3-bis (isocyanatomethyl) cyclohexane, tetramethylxylylene diisocyanate, 1, 5-naphthalene diisocyanate, triphenylmethane triisocyanate, adducts of these polyisocyanate compounds with polyol compounds such as trimethylolpropane, biuret or isocyanurate of these polyisocyanate compounds, and the like.

The epoxy crosslinking agent is a compound having 2 or more epoxy groups in the molecule.

Examples of the epoxy-based crosslinking agent include: 1, 3-bis (N, N-diglycidyl aminomethyl) cyclohexane, N, N, N ', N' -tetraglycidyl-m-xylylenediamine, ethylene glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidyl aniline, diglycidyl amine, and the like.

The metal chelate crosslinking agent is a chelate compound having a metal ion that functions as a crosslinking point.

As the metal chelate crosslinking agent, for example, a metal chelate compound in which metal ions are aluminum ions, zirconium ions, titanium ions, zinc ions, iron ions, tin ions, or the like can be used. Among these, aluminum chelate compounds are preferable.

Examples of the aluminum chelate compound include: aluminum tris (acetylacetonate), aluminum bis (ethylacetoacetate), diisopropoxyaluminum monooleyl acetoacetate, monoisopropoxyaluminum dioleylacetoacetate, and the like.

In one embodiment of the present invention, the crosslinking agent (B) is preferably a compound having an isocyanurate skeleton, more preferably a compound having an isocyanurate skeleton and having 2 or more isocyanate groups.

By making the crosslinking agent (B) a compound having an isocyanurate skeleton, a curable adhesive composition which provides a cured product excellent in low dielectric characteristics can be easily obtained.

In the case of preparing a curable adhesive composition containing a compound having an isocyanurate skeleton as the component (B), the curable adhesive composition may contain a crosslinking agent other than the compound having an isocyanurate skeleton as the other component.

In the curable adhesive composition, the content of the other crosslinking agent is preferably 0 to 100 parts by mass, more preferably 0 to 50 parts by mass, still more preferably 0 to 30 parts by mass, still more preferably 0 to 10 parts by mass, and particularly preferably 0 to 5 parts by mass, relative to 100 parts by mass of the total amount of the compound having an isocyanurate skeleton.

In one embodiment of the present invention, the crosslinking agent (B) is preferably an isocyanate-based crosslinking agent which is a compound having 2 or more isocyanate groups, more preferably an isocyanurate of a polyisocyanate compound, still more preferably an isocyanurate of 1, 5-pentamethylene diisocyanate [1,3, 5-tris (5-isocyanatopentyl) -1,3, 5-triazine-2, 4, 6-trione ] or an isocyanurate of 1, 6-hexamethylene diisocyanate [1,3, 5-tris (6-isocyanatohexyl) -1,3, 5-triazine-2, 4, 6-trione ] from the viewpoint of easy availability of a curable adhesive composition which provides a cured product excellent in low dielectric characteristics.

In the case of preparing a curable adhesive composition containing an isocyanate-based crosslinking agent as component (B), the curable adhesive composition may contain a crosslinking agent other than the isocyanate-based crosslinking agent as another component.

In the curable adhesive composition, the content of the other crosslinking agent is preferably 0 to 100 parts by mass, more preferably 0 to 50 parts by mass, still more preferably 0 to 30 parts by mass, still more preferably 0 to 10 parts by mass, and particularly preferably 0 to 5 parts by mass, relative to 100 parts by mass of the total amount of the isocyanate-based crosslinking agent.

In one embodiment of the present invention, the crosslinking agent (B) is preferably an epoxy crosslinking agent in view of easy availability of a curable adhesive composition capable of suppressing contamination around the bonding step.

In the case of preparing a curable adhesive composition containing an epoxy-based crosslinking agent as component (B), the curable adhesive composition may contain a crosslinking agent other than the epoxy-based crosslinking agent as another component.

In the curable adhesive composition, the content of the other crosslinking agent is preferably 0 to 100 parts by mass, more preferably 0 to 50 parts by mass, still more preferably 0 to 30 parts by mass, still more preferably 0 to 10 parts by mass, and particularly preferably 0 to 5 parts by mass, relative to 100 parts by mass of the total amount of the epoxy crosslinking agent.

Since the crosslinking agent (B) is a compound reactive with the binder resin (a), the binder resin (a) and the crosslinking agent (B) can be reacted in the coating film obtained by applying the curable adhesive composition of the present invention, and a crosslinked structure can be formed in the coating film. The coating film having a crosslinked structure inside is difficult to flow even when heated. Therefore, by constructing the crosslinked structure in the coating film before bonding 2 adherends, even if the heat treatment is performed at the time of bonding 2 adherends, the coating film can be completely cured while suppressing the oozing out of the adhesive component in the coating film.

In this way, in the curable adhesive composition of the present invention, by performing the reaction (reaction of the 1 st curing system) of the binder resin (a) and the crosslinking agent (B) before the bonding step, the contamination of the surroundings in the bonding step can be suppressed.

Curing System No. 2

The 2 nd curing system contained in the curable adhesive composition of the present invention is a curing system in which 1 or 2 or more compounds having a carbon-carbon double bond are reacted, and the reaction is carried out at a temperature exceeding 120 ℃.

Since the 2 nd curing system is reacted at a temperature exceeding 120 ℃, the curable adhesive composition of the present invention has sufficient adhesive ability even after the reaction of the 1 st curing system is completed.

The 2 nd curing system is a system containing a compound having a carbon-carbon double bond as a curable component. Since the reaction starting time of the reaction involving the compound having a carbon-carbon double bond can be controlled relatively easily, the reaction of the 2 nd curing system is not performed during the reaction of the 1 st curing system, and the reaction of the 2 nd curing system can be performed reliably after the reaction of the 1 st curing system is completed.

In addition, cured products of the curable adhesive composition containing a compound having a carbon-carbon double bond tend to be excellent in low dielectric characteristics.

The 2 nd curing system may contain 1 or 2 or more compounds having carbon-carbon double bonds.

As the compound having a carbon-carbon double bond of the 2 nd curing system, there may be mentioned: a compound having 2 or more hydrocarbon groups having a double bond at the terminal and being liquid at 25 ℃ (hereinafter, sometimes referred to as "liquid compound (C) having a carbon-carbon double bond)"; or a polymer having a hydrocarbon group having a double bond at the terminal (hereinafter, sometimes referred to as "polymer (D) having a carbon-carbon double bond)").

In the curable adhesive composition according to one embodiment of the present invention, the total content of the (C) component and the (D) component as the 2 nd curing system may be 6 mass% or more, 10 mass% or more, 15 mass% or more, 20 mass% or more, or 23 mass% or more, and may be 60 mass% or less, 50 mass% or less, 40 mass% or less, 35 mass% or less, or 30 mass% or less, with respect to the total amount (100 mass%) of the active components of the curable adhesive composition.

[ (C) component: liquid Compounds containing carbon-carbon double bonds

The liquid compound (C) having a carbon-carbon double bond has 2 or more hydrocarbon groups having a double bond at the terminal. Since the liquid compound (C) having a carbon-carbon double bond has 2 or more hydrocarbon groups having a double bond at the terminal, a curable adhesive composition which provides a cured product having more excellent adhesive strength or heat resistance can be easily obtained.

The liquid compound (C) having a carbon-carbon double bond may be used alone or in combination of 1 or more than 2.

Further, since the crosslinked structure formed in the cured product is moderately sparse, the occurrence of cracks in the cured product tends to be suppressed. Therefore, the number of hydrocarbon groups having a double bond at the terminal of the liquid compound (C) containing a carbon-carbon double bond is preferably 2 to 4, more preferably 2.

The number of carbon atoms of the hydrocarbon group having a double bond at the terminal contained in the liquid compound (C) having a carbon-carbon double bond is preferably 2 to 10, more preferably 2 to 5.

Examples of the hydrocarbon group having a double bond at the terminal include: vinyl, allyl, 3-butenyl, 4-pentenyl, 5-hexenyl, isopropenyl, 1-methyl-2-propenyl, vinylbenzyl, vinylnaphthyl, and the like. Among these, allyl is preferable.

The liquid compound (C) having a carbon-carbon double bond is a compound which is liquid at 25 ℃. Since the liquid compound (C) having a carbon-carbon double bond is a compound which is liquid at 25 ℃, the curable adhesive composition of the present invention has good wetting expansibility at the time of lamination treatment even after the reaction of the 1 st curing system, and is more excellent in lamination suitability.

"liquid at 25 ℃ means having fluidity at 25 ℃. For example, a compound that is liquid at 25℃means a compound having a viscosity of 2 to 10000 mPas measured at 25℃and 1.0rpm using an E-type viscometer.

The liquid compound (C) having a carbon-carbon double bond is preferably a non-aromatic compound. Non-aromatic compounds refer to compounds that do not have an aromatic ring. Since the liquid compound (C) having a carbon-carbon double bond is a non-aromatic compound, a cured product of the curable adhesive composition containing the liquid compound (C) having a carbon-carbon double bond tends to be more excellent in low dielectric characteristics.

The liquid compound (C) having a carbon-carbon double bond is preferably a compound having a heterocyclic skeleton. By making the liquid compound (C) having a carbon-carbon double bond a compound having a heterocyclic skeleton, a curable adhesive composition which provides a cured product having more excellent adhesive strength and low dielectric characteristics can be easily obtained.

In the case of preparing the curable adhesive composition in which the component (C) is a compound having a heterocyclic skeleton, the curable adhesive composition may contain, as the other component, another liquid compound containing a carbon-carbon double bond other than the compound having a heterocyclic skeleton.

In the curable adhesive composition, the content of the other liquid compound having a carbon-carbon double bond is preferably 0 to 50 parts by mass, more preferably 0 to 30 parts by mass, still more preferably 0 to 10 parts by mass, and still more preferably 0 to 5 parts by mass, relative to 100 parts by mass of the total amount of the compound having a heterocyclic skeleton.

Examples of the heterocyclic skeleton include: isocyanurate or glycoluril backbones.

The heterocyclic skeleton preferably has n times of rotation as a symmetrical element. The cured product of the curable adhesive composition containing the liquid compound (C) having a carbon-carbon double bond having such a heterocyclic skeleton tends to be more excellent in low dielectric characteristics.

The molecular weight of the liquid compound (C) having a carbon-carbon double bond is preferably 1,000 or less, more preferably 800 or less, further preferably 650 or less, and still further preferably 500 or less.

Compounds having a molecular weight of 1,000 or less tend to satisfy the requirement of being liquid at 25 ℃.

The molecular weight of the liquid compound (C) having a carbon-carbon double bond is preferably 100 or more, more preferably 200 or more, and still more preferably 275 or more.

In the case of a compound having a molecular weight of 100 or more, the liquid compound (C) having a carbon-carbon double bond is less likely to volatilize even in the drying step or the thermosetting step of the curable adhesive composition, and thus a cured product having target physical properties can be easily obtained.

As the liquid compound (C) containing a carbon-carbon double bond, there may be mentioned: a compound having an isocyanurate skeleton or a compound having a glycoluril skeleton.

Examples of the liquid compound (C) having a carbon-carbon double bond of an isocyanurate skeleton include compounds represented by the following formula (1) or (2).

[ chemical formula 1]

[ chemical formula 2]

In the formula (1), R ¹ 、R ² Each independently represents a hydrocarbon group having a double bond at the end, R ³ Represents a saturated hydrocarbon group having 1 to 15 carbon atoms and an alkoxy-substituted alkyl group having 1 to 15 carbon atoms.

In the formula (2), R ⁴ ～R ⁶ Each independently represents a hydrocarbon group having a double bond at the terminal.

R ¹ 、R ² 、R ⁴ 、R ⁵ 、R ⁶ The hydrocarbon group represented having a double bond at the terminal is as previously described.

R ³ The carbon number of the saturated hydrocarbon group represented is 1 to 15, preferably 5 to 15, more preferably 8 to 15. As R ³ Examples of the saturated hydrocarbon group include: methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, sec-butyl, isobutyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, and the like.

R ³ The carbon number of the alkoxy-substituted alkyl group represented is 2 to 15, preferably 2 to 12, more preferably 3 to 10. As R ³ The alkoxy-substituted alkyl groups represented may be exemplified by: methoxymethyl, ethoxymethyl, 2-methoxyethoxymethyl, benzyloxymethyl, and the like.

As the liquid compound (C) having a carbon-carbon double bond of glycoluril skeleton, there may be mentioned: a compound represented by the following formula (3).

[ chemical formula 3]

In the formula (3), R ⁷ ～R ¹⁰ Each independently represents a hydrocarbon group having 1 to 15 carbon atoms, and at least 2 of these are hydrocarbon groups having a double bond at the terminal. R is R ¹¹ 、R ¹² Represents a hydrogen atom or a saturated hydrocarbon group having 1 to 15 carbon atoms。

Among these, the liquid compound (C) having a carbon-carbon double bond is preferably a compound having an isocyanurate skeleton, more preferably a compound represented by the formula (1), and even more preferably a compound represented by the following formula, from the viewpoint of easy obtaining of a cured product having a suitable crosslink density and excellent low dielectric characteristics.

[ chemical formula 4]

Wherein R represents a saturated hydrocarbon group having 5 to 15 carbon atoms, preferably a saturated hydrocarbon group having 8 to 15 carbon atoms.

When the curable adhesive composition of the present invention contains the liquid compound (C) having a carbon-carbon double bond, the content of the liquid compound (C) having a carbon-carbon double bond (when the content of the (C) component is 2 or more, the total amount thereof) is preferably 5% by mass or more, more preferably 7% by mass or more, still more preferably 8.5% by mass or more, and further preferably 25% by mass or less, more preferably 20% by mass or less, still more preferably 15% by mass or less, relative to the total amount (100% by mass) of the active ingredient of the curable adhesive composition.

The content of the liquid compound (C) having a carbon-carbon double bond is 5 mass% or more based on the total amount of the active ingredients of the curable adhesive composition, whereby the curable adhesive composition providing a cured product excellent in adhesive strength can be easily obtained.

The content of the liquid compound (C) having a carbon-carbon double bond in the total amount of the active ingredients of the curable adhesive composition is 25 mass% or less, whereby the curable adhesive composition which provides a cured product excellent in low dielectric characteristics can be easily obtained.

When the curable adhesive composition of the present invention contains the curable compound (C), the content of the curable compound (C) (when the curable compound (C) is contained in an amount of 2 or more kinds, the total amount thereof) is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, still more preferably 7 parts by mass or more, still more preferably 10 parts by mass or more, and further preferably 30 parts by mass or less, more preferably 25 parts by mass or less, still more preferably 20 parts by mass or less, still more preferably 16 parts by mass or less, relative to 100 parts by mass of the component (a).

[ (D) component: polymers containing carbon-carbon double bonds

The polymer (D) having carbon-carbon double bonds is a polymer having a hydrocarbon group having a double bond at the terminal. Since the 2 nd curing system contains the polymer (D) having a carbon-carbon double bond, a curable adhesive composition which provides a cured product having more excellent adhesive strength or heat resistance can be easily obtained.

The polymer (D) having carbon-carbon double bonds may be used singly or in combination of 1 or more than 2.

The number of hydrocarbon groups having a double bond at the terminal contained in the polymer (D) containing a carbon-carbon double bond is preferably 2 to 4, more preferably 2.

Since the number of hydrocarbon groups having a double bond at the terminal is within the above range, a curable adhesive composition which provides a cured product having more excellent adhesive strength and heat resistance and suppressed occurrence of cracks can be easily obtained.

The number of carbons of the hydrocarbon group having a double bond at the terminal contained in the polymer (D) having a carbon-carbon double bond is preferably 2 to 20, more preferably 2 to 15.

Examples of the hydrocarbon group having a double bond at the terminal include: vinyl, allyl, 3-butenyl, 4-pentenyl, 5-hexenyl, isopropenyl, 1-methyl-2-propenyl, vinylbenzyl, vinylnaphthyl, and the like. Among these, vinylbenzyl is preferable from the viewpoint of obtaining a cured product excellent in low dielectric characteristics.

The number average molecular weight (Mn) of the polymer (D) containing carbon-carbon double bonds is preferably 500 to 5,000, more preferably 500 to 3,000.

The number average molecular weight (Mn) of the polymer (D) having carbon-carbon double bonds can be determined by Gel Permeation Chromatography (GPC) using Tetrahydrofuran (THF) as a solvent, as a standard polystyrene equivalent, and as specific measurement conditions, as described above.

Examples of the polymer (D) having carbon-carbon double bonds include: polyolefin-based resins, phenoxy-based resins, polyimide-based resins, polyamideimide-based resins, polyvinyl butyral-based resins, polycarbonate-based resins, polyphenylene ether-based resins, and the like.

When the curable adhesive composition of the present invention contains the polymer (D) having a carbon-carbon double bond, the content of the polymer (D) having a carbon-carbon double bond (when the total amount of the (D) components is 2 or more) is preferably 1% by mass or more, more preferably 5% by mass or more, still more preferably 10% by mass or more, still more preferably 15% by mass or more, and still more preferably 30% by mass or less, still more preferably 25% by mass or less, relative to the total amount (100% by mass) of the active ingredients of the curable adhesive composition.

The content of the polymer (D) having a carbon-carbon double bond is 1 mass% or more based on the total amount of the active ingredients of the curable adhesive composition, whereby the curable adhesive composition providing a cured product excellent in adhesive strength can be easily obtained.

The content of the polymer (D) having a carbon-carbon double bond is 30 mass% or less based on the total amount of the active ingredients of the curable adhesive composition, whereby adhesion is easily imparted.

When the curable adhesive composition of the present invention contains the polymer (D) having a carbon-carbon double bond, the content of the polymer (D) having a carbon-carbon double bond (when 2 or more (D) components are contained, the total amount thereof) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, still more preferably 15 parts by mass or more, still more preferably 20 parts by mass or more, and further preferably 50 parts by mass or less, more preferably 40 parts by mass or less, still more preferably 35 parts by mass or less, still more preferably 30 parts by mass or less, relative to 100 parts by mass of the component (a).

From the viewpoint of easy availability of a curable adhesive composition which provides a cured product having more excellent low dielectric characteristics, the polymer (D) having a carbon-carbon double bond is preferably a modified polyphenylene ether resin having a hydrocarbon group having a double bond at the terminal (hereinafter, sometimes referred to as "polymer (D') having a carbon-carbon double bond").

In the case of preparing a curable adhesive composition in which the component (D) is a polymer (D ') having carbon-carbon double bonds, the curable adhesive composition may contain, as other components, other polymers having carbon-carbon double bonds than the component (D').

In the curable adhesive composition, the content of the other polymer having a carbon-carbon double bond is preferably 0 to 50 parts by mass, more preferably 0 to 30 parts by mass, still more preferably 0 to 10 parts by mass, and still more preferably 0 to 5 parts by mass, relative to 100 parts by mass of the total amount of the component (D').

The polyphenylene ether resin means a resin having a polyphenylene skeleton in the main chain.

The polyphenyl skeleton is a skeleton having a repeating unit represented by the following formula or a repeating unit in which a hydrogen atom in the above formula is substituted.

[ chemical formula 5]

The polymer (D') having carbon-carbon double bonds is a compound having a polyphenylene ether skeleton and a hydrocarbon group having a double bond at the terminal.

Since the polymer (D ') having a carbon-carbon double bond has a polyphenylene ether skeleton, the cured product of the curable adhesive composition of the polymer (D') having a carbon-carbon double bond is excellent in low dielectric characteristics.

Examples of the polyphenylene ether skeleton in the polymer (D') having carbon-carbon double bonds include: a polyphenylene ether skeleton represented by the following formula (4).

[ chemical formula 6]

In the formula (4), X is a 2-valent group represented by the following formula (5) or formula (6), Y is a 2-valent group represented by the following formula (7), a and b are integers of 0 to 100, and at least one of a and b is 1 or more. * Indicating a bond (the same applies below).

[ chemical formula 7]

In the formula (5), R ¹³ ～R ²⁰ Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group, preferably a hydrogen atom or a methyl group.

[ chemical formula 8]

In the formula (6), R ²¹ ～R ²⁸ Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group, preferably a hydrogen atom or a methyl group. A represents a linear, branched or cyclic 2-valent hydrocarbon group having 20 or less carbon atoms.

[ chemical formula 9]

In the formula (7), R ²⁹ ～R ³² Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group, preferably a hydrogen atom or a methyl group.

Examples of the polyphenylene ether skeleton in the polymer (D') having carbon-carbon double bonds include: a polyphenylene ether skeleton represented by the following formula (8).

[ chemical formula 10]

a and b are integers of 0 to 100, and at least one of a and b is 1 or more.

Examples of the hydrocarbon group having a double bond at the terminal in the polymer (D') having a carbon-carbon double bond include: the hydrocarbon groups described previously. Among them, vinylbenzyl is more preferable in view of easy obtaining of a cured product excellent in low dielectric characteristics.

As the polymer (D') having a carbon-carbon double bond, a resin having hydrocarbon groups having double bonds at both ends of the polyphenylene ether skeleton is preferable from the viewpoint of easy obtaining of a cured product excellent in low dielectric characteristics.

In the case where the component (D) is a curable adhesive composition comprising a resin having a hydrocarbon group having a double bond at both ends of the polyphenylene ether skeleton, the curable adhesive composition may contain, as the other component, a polymer having a carbon-carbon double bond other than the resin.

In the curable adhesive composition, the content of the other carbon-carbon double bond-containing polymer is preferably 0 to 50 parts by mass, more preferably 0 to 30 parts by mass, still more preferably 0 to 10 parts by mass, and still more preferably 0 to 5 parts by mass, relative to 100 parts by mass of the total amount of the resin.

The polymer (D') having carbon-carbon double bonds can be obtained by introducing "hydrocarbon group having double bonds at the terminal" to the terminal after the formation of the polyphenylene ether skeleton.

For example, the polymer (D') having a carbon-carbon double bond of a vinylbenzyl group at both terminals can be obtained by reacting a bifunctional phenol compound with a monofunctional phenol compound to obtain a polymer having phenolic hydroxyl groups at both terminals, and then subjecting the terminal phenolic hydroxyl groups to vinylbenzyl etherification using 4- (chloromethyl) styrene.

As the polymer (D') having carbon-carbon double bonds, there may be mentioned: a polymer represented by the following formula (9).

[ chemical formula 11]

[ cationic polymerization initiator ]

The curable adhesive composition of the present invention is a composition containing a cationic polymerization initiator, preferably a composition in which the reaction of the 2 nd curing system is initiated by the cationic polymerization initiator.

In the curable adhesive composition containing the cationic polymerization initiator, the stability or reactivity of the 2 nd curing system can be adjusted by appropriately selecting the cationic polymerization initiator having reactivity in accordance with the purpose.

The cationic polymerization initiator may be used singly or in combination of 1 or more than 2.

As the cationic polymerization initiator, a thermal cationic polymerization initiator is preferable.

Thermal cationic polymerization initiators are compounds that can generate cationic species that initiate polymerization by heating.

Examples of the thermal cationic polymerization initiator include: sulfonium salts, quaternary ammonium salts, phosphonium salts, diazonium salts, iodonium salts, and the like.

As the sulfonium salt, there can be mentioned: triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluoroarsonate, tris (4-methoxyphenyl) sulfonium hexafluoroarsonate, diphenyl (4-thiophenylphenyl) sulfonium hexafluoroarsonate, and the like.

As the quaternary ammonium salt, there may be mentioned: tetrabutylammonium tetrafluoroborate, tetrabutylammonium hexafluorophosphate, tetrabutylammonium bisulfate, tetraethylammonium tetrafluoroborate, tetraethylammonium p-toluenesulfonate, N-dimethyl-N-benzylanilinium hexafluoroantimonate, N-dimethyl-N-benzylanilinium tetrafluoroborate, N, N-dimethyl-N-benzylpyridinium hexafluoroantimonate, N-diethyl-N-benzyltriflate, N-dimethyl-N- (4-methoxybenzyl) pyridinium hexafluoroantimonate, N-diethyl-N- (4-methoxybenzyl) toluidinium hexafluoroantimonate, and the like.

Examples of phosphonium salts include: ethyl triphenyl phosphonium hexafluoroantimonate, tetrabutylphosphonium hexafluoroantimonate, and the like.

Examples of the iodonium salt include: diphenyliodonium hexafluoroarsenate, bis (4-chlorophenyl) iodonium hexafluoroarsenate, bis (4-bromophenyl) iodonium hexafluoroarsenate, phenyl (4-methoxyphenyl) iodonium hexafluoroarsenate, and the like.

In the case where the curable adhesive composition of the present invention contains a cationic polymerization initiator, at least a part of the cationic polymerization initiator is preferably a high-temperature reactive thermal cationic polymerization initiator having a peak top temperature of a heat generation peak exceeding 120 ℃ obtained by differential scanning calorimetric measurement under the following conditions.

(differential scanning calorimetric conditions)

A mixture of 0.1 part by mass of a cationic polymerization initiator, 100 parts by mass of bisphenol A diglycidyl ether, and 0.1 part by mass of gamma-butyrolactone, which were the objects of measurement, was used as a measurement sample, and a differential scanning calorimeter measurement was performed at a temperature rise rate of 10 ℃/min from 30℃to 300℃to measure the peak temperature of the exothermic peak.

In a curable adhesive composition containing a high-temperature reactive thermal cationic polymerization initiator, the reaction of the 2 nd curing system is likely to proceed at a temperature exceeding 120 ℃. The peak top temperature of the heat generating peak of the high temperature reactive thermal cationic polymerization initiator is preferably 250 ℃ or less, from the viewpoint that the temperature at the time of curing the curable adhesive composition does not become excessively high.

Examples of commercial products of the high-temperature reactive thermal cationic polymerization initiator include: san-Aid SI-B3, san-Aid SI-B4, san-Aid SI-B5, san-Aid SI-150 (all manufactured by Sanxinshi chemical Co., ltd.), and the like.

When the curable adhesive composition contains a cationic polymerization initiator, the content of the cationic polymerization initiator is preferably 0.01 part by mass or more, more preferably 0.05 part by mass or more, still more preferably 0.1 part by mass or more, still more preferably 0.2 part by mass or more, and further preferably 6 parts by mass or less, more preferably 5 parts by mass or less, still more preferably 4 parts by mass or less, based on 100 parts by mass of the total of the component (C) and the component (D) as the cationic overlap compound.

By setting the content of the cationic polymerization initiator to 0.01 part by mass or more, the decrease in reactivity can be easily prevented.

By setting the content of the cationic polymerization initiator to 6 parts by mass or less, corrosion of the adherend is easily suppressed.

When a thermal cationic polymerization initiator is used as the cationic polymerization initiator, it is preferable to perform differential scanning calorimetric measurement under the following conditions, grasp the thermal stability or reactivity of the thermal cationic polymerization initiator, and adjust the reaction initiation temperature of the 2 nd curing system reaction.

(differential scanning calorimetric conditions)

Using a mixture of 0.1 part by mass of a thermal cationic polymerization initiator, 100 parts by mass of bisphenol a diglycidyl ether, and 0.1 part by mass of γ -butyrolactone as a measurement sample, differential scanning calorimetric measurement was performed at a heating rate of 10 ℃/min from 30 ℃ to 300 ℃, and the peak top temperature of the heat generation peak was detected.

For example, the peak top temperature of the exothermic peak of benzyl (4-hydroxyphenyl) (methyl) sulfonium tetrakis (pentafluorophenyl) borate is 140 ℃.

The peak top temperature of the heat generation peak of the thermal cationic polymerization initiator measured by the above measurement is preferably 120 to 180 ℃, more preferably 130 to 160 ℃.

[ silane coupling agent ]

The curable adhesive composition of the present invention may contain a silane coupling agent.

The silane coupling agent may participate in the reaction of the 1 st cure system, may participate in the reaction of the 2 nd cure system, or may not participate in any of these cure systems. Whether the silane coupling agent used participates in the reaction of the 1 st cure system or the 2 nd cure system is generally determined by the reactivity of the substituents in the silane coupling agent.

The silane coupling agent may be used alone or in combination of 1 or more than 2.

As the silane coupling agent, a known silane coupling agent can be used. Among them, an organosilicon compound having at least 1 alkoxysilyl group in the molecule is preferable.

As the silane coupling agent, there may be mentioned: silane coupling agents having a (meth) acryloyl group, such as 3-methacryloxypropyl methyl dimethoxy silane, 3-methacryloxypropyl trimethoxy silane, 3-methacryloxypropyl methyl diethoxy silane, 3-methacryloxypropyl triethoxy silane, and 3-acryloxypropyl trimethoxy silane;

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

silane coupling agents having an epoxy group, such as 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane, 3-epoxypropoxypropyltriethoxysilane, 8-epoxypropoxyoctyltrimethoxysilane;

silane coupling agents having a styrene group such as p-styryl trimethoxysilane and p-styryl triethoxysilane;

silane coupling agents having an amino group such as hydrochloride salts of N- (2-aminoethyl) -3-aminopropyl methyldimethoxy silane, N- (2-aminoethyl) -3-aminopropyl trimethoxy silane, N- (2-aminoethyl) -3-aminopropyl triethoxy silane, 3-aminopropyl trimethoxy silane, 3-triethoxysilyl-N- (1, 3-dimethyl/butylene) propylamine, N-phenyl-3-aminopropyl trimethoxy silane, N- (vinylbenzyl) -2-aminoethyl-3-aminopropyl trimethoxy silane;

Silane coupling agents having an ureido group such as 3-ureidopropyltrimethoxysilane and 3-ureidopropyltriethoxysilane;

silane coupling agents having halogen atoms such as 3-chloropropyl trimethoxysilane and 3-chloropropyl triethoxysilane;

mercapto silane coupling agents such as 3-mercaptopropyl methyl dimethoxy silane and 3-mercaptopropyl trimethoxy silane;

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

silane coupling agents having an isocyanate group, such as 3-isocyanatopropyl trimethoxysilane and 3-isocyanatopropyl triethoxysilane;

silane coupling agents having an allyl group, such as allyl trichlorosilane, allyl triethoxysilane, and allyl trimethoxysilane;

and silane coupling agents having a hydroxyl group such as 3-hydroxypropyl trimethoxysilane and 3-hydroxypropyl triethoxysilane.

When the curable adhesive composition contains a silane coupling agent, the content of the silane coupling agent (when the curable adhesive composition contains 2 or more types of silane coupling agents, the total amount of the silane coupling agents is preferably 0.01 mass% or more, more preferably 0.05 mass% or more, still more preferably 0.08 mass% or more, preferably 5 mass% or less, still more preferably 1 mass% or less, still more preferably 0.5 mass% or less, based on the total amount (100 mass%) of the active ingredients of the curable adhesive composition.

The content of the silane coupling agent is 0.01 mass% or more based on the total amount of the active ingredients of the curable adhesive composition, and thus the adhesiveness after the high-temperature and high-humidity test can be easily maintained.

The content of the silane coupling agent in the total amount of the active ingredients of the curable adhesive composition is 5 mass% or less, so that the adhesiveness after the high-temperature high-humidity test can be easily maintained.

When the curable adhesive composition of the present invention contains a silane coupling agent, the content of the silane coupling agent (when the total amount of the silane coupling agents is 2 or more kinds of the silane coupling agent is included) is preferably 0.01 part by mass or more, more preferably 0.05 part by mass or more, still more preferably 0.1 part by mass or more, still more preferably 0.15 part by mass or more, and further preferably 3 parts by mass or less, still more preferably 1 part by mass or less, still more preferably 0.7 part by mass or less, still more preferably 0.5 part by mass or less, relative to 100 parts by mass of the component (a).

[ solvent ]

The curable adhesive composition of the present invention contains a solvent and may be in the form of a solution.

As the solvent, there may be mentioned: aromatic hydrocarbon solvents such as benzene and toluene; ester solvents such as ethyl acetate and butyl acetate; ketone solvents such as acetone, butanone, 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.

These solvents may be used singly or in combination of 1 or more than 2.

When the curable adhesive composition contains a solvent, the content of the solvent can be appropriately determined in consideration of coatability and the like.

[ other Components ]

The curable adhesive composition of the present invention may contain components (other components) other than the components described above, within a range that does not hinder the effects of the present invention.

As other components, there may be mentioned: additives such as ultraviolet light absorbers, antistatic agents, light stabilizers, antioxidants, resin stabilizers, fillers, pigments, extenders, and softeners.

These may be used singly or in combination of 1 or more than 2.

When the curable adhesive composition of the present invention contains these additives, the content thereof can be appropriately determined according to the purpose.

Method for producing curable adhesive composition and method for using the same

The curable adhesive composition of the present invention can be prepared by appropriately mixing and stirring the binder resin (a), the crosslinking agent (B), the compound having a carbon-carbon double bond, and other optional components according to a conventional method.

The method of using the curable adhesive composition of the present invention is not particularly limited.

For example, the curable adhesive composition of the present invention is applied to an adherend, the obtained coating film is dried, and the reaction of the 1 st curing system is performed to form a crosslinked structure in the coating film. Then, another adherend is superimposed on the coating film, and then the reaction of the 2 nd curing system is performed, whereby the adherends can be adhered.

Examples of the method for applying the curable adhesive composition include: spin coating, spray coating, bar coating, blade coating, roll coating, blade coating, die coating, gravure coating, and the like.

The method of drying the coating film includes: conventionally known drying methods such as hot air drying, hot roll drying, and infrared irradiation.

The conditions for drying the coating film are, for example, 80 to 120℃for 30 seconds to 5 minutes.

Depending on the drying conditions of the coating film, the drying treatment of the coating film and the reaction of the 1 st curing system may be compatible.

The thickness of the coating film is not particularly limited, but is usually 1 to 50. Mu.m, preferably 1 to 25. Mu.m, more preferably 5 to 25. Mu.m.

The curable adhesive composition of the present invention can be used to produce an adhesive sheet, and 2 adherends can be bonded to each other using the adhesive sheet.

For example, the curable adhesive composition of the present invention may be applied to a release film, and the obtained coating film may be dried and reacted with the 1 st curing system to obtain a coating film (adhesive layer of adhesive sheet) having a crosslinked structure.

The method for applying and drying the curable adhesive composition may be the same as described above.

The preferable thickness of the coating film or the combination of the drying treatment of the coating film and the reaction of the 1 st curing system is also as described above.

The curable adhesive composition of the present invention is cured by the curable adhesive composition, and preferably provides a cured product having a dielectric loss tangent of less than 0.0050 at 23 ℃ and a frequency of 1GHz, more preferably provides a cured product having a dielectric loss tangent of 0.0030 or less, more preferably provides a cured product having a dielectric loss tangent of 0.0020 or less, more preferably provides a cured product having a dielectric loss tangent of 0.0015 or less, more preferably provides a cured product having a dielectric loss tangent of 0.0012 or less, still more preferably provides a cured product having a dielectric loss tangent of 0.0010 or less, and particularly preferably provides a cured product having a dielectric loss tangent of 0.0008 or less. The lower limit of the dielectric loss tangent under such conditions is not particularly limited, and is usually 0.0001 or more.

The curable adhesive composition of the present invention is cured by the curable adhesive composition, and preferably provides a cured product having a relative dielectric constant of 3.00 or less, more preferably provides a cured product having a relative dielectric constant of 2.75 or less, and still more preferably provides a cured product having a relative dielectric constant of 2.50 or less at 23 ℃ and a frequency of 1 GHz. The lower limit of the relative dielectric constant under such conditions is not particularly limited, and is usually 2.00 or more.

The sample for measuring the dielectric loss tangent and the relative permittivity is not limited as long as it can be measured, and the cured state thereof is not limited.

As an example of the measurement sample of dielectric loss tangent and relative permittivity, there can be mentioned: the coating film was subjected to a heat treatment at 100℃for 2 minutes as a reaction between the drying treatment and the 1 st curing system.

In the case where the curable adhesive composition of the present invention is a composition which provides a cured product having the above dielectric characteristics by a curing reaction, the curable adhesive composition of the present invention is preferably used as a material for forming an adhesive member, a protective member, an insulating member, or the like in an electronic device.

(2) Cured product and method for producing cured product

The cured product of the present invention is the following cured product (α) or (β).

Cured product (α): the raw material composition is a cured product of the curable adhesive composition of the present invention, and the cured product satisfies the following requirements 1 and 2:

element 1: gel fraction of 10 mass% or more;

element 2: with further thermosetting properties.

Cured product (β): the raw material composition is a cured product of the curable adhesive composition of the present invention, and the cured product satisfies the following requirement 3:

Element 3: the gel fraction is 50 mass% or more.

Cured product (alpha)

The cured product (α) is a cured product of the curable adhesive composition of the present invention, which satisfies the above-mentioned requirements 1 and 2.

The gel fraction of the cured product (α) is 10% by mass or more, preferably 15% by mass or more, more preferably 20% by mass or more, and particularly preferably 25% by mass or more.

The cured product having a gel fraction of 10 mass% or more has a crosslinked structure formed therein. Therefore, even if such a cured product is subjected to a heat treatment such as a hot press treatment, the adhesive component does not bleed out in large amounts, and contamination of the surroundings is suppressed.

The gel fraction of the cured product (α) is usually 70 mass% or less, preferably 60 mass% or less, and more preferably less than 50 mass%.

The cured product (α) having a gel fraction of 70 mass% or less tends to be excellent in curability and adhesion to an adherend.

As described in the examples, the gel fraction of the cured product (. Alpha.) was calculated by conducting an experiment in which the measurement sample was immersed in toluene at 23℃for 168 hours.

The cured product (α) has further thermosetting properties. The curability of the cured product (α) is usually caused by both the reaction of the 1 st curing system and the reaction of the 2 nd curing system (in the case where some of the constituent components of the 1 st curing system remain unreacted), or is caused by only the reaction of the 2 nd curing system (in the case where the reaction of the 1 st curing system has been completed).

The cured product (α) preferably has a sheet-like shape.

Since the cured product (α) has a sheet-like shape, the bonding of 2 adherends can be efficiently performed by heat press treatment or the like.

The cured product (α) having a sheet-like shape (hereinafter, sometimes referred to as "thermosetting sheet-like adhesive") may have a protective sheet or the like on one or both sides to protect it during storage or transportation.

When the thermosetting sheet-like adhesive is excellent in low dielectric characteristics, the thermosetting sheet-like adhesive is suitable for use as a sheet-like adhesive for electronic devices or a sheet-like adhesive for cover films.

The sheet-like adhesive for electronic devices is a sheet-like adhesive for adhesion of various parts in electronic devices or protection or insulation of circuits in electronic devices.

As the electronic device, there may be mentioned: smart phone, tablet terminal's communication device.

The sheet-like adhesive for the cover film is one used in manufacturing the cover film. The cover film is a laminated film used for protecting the surface of a flexible printed wiring board, and generally has an insulating resin layer and an adhesive layer.

A thermosetting sheet-like adhesive can be used as the adhesive layer.

Method for producing cured product (alpha)

The "method for producing a cured product (α)" of the present invention comprises the following step I:

step I: and curing the curable adhesive composition of the present invention at a temperature of 120 ℃ or lower.

As described above, the curable adhesive composition of the present invention has the 1 st curing system that reacts at a temperature of 120 ℃ or lower.

Step I is to perform the reaction of the 1 st curing system to construct a crosslinked structure in the curable adhesive composition.

The heating temperature in step I is 120℃or lower, preferably 110℃or lower.

The heating temperature in step I is usually 0℃or higher, preferably 20℃or higher.

The heating time in step I is usually 0.5 to 5 minutes, preferably 1 to 3 minutes.

Cured product (. Beta.) (cured product (. Beta.))

The cured product (β) is a cured product of the curable adhesive composition of the present invention, which satisfies the above requirement 3.

The gel fraction of the cured product (. Beta.) is 50% by mass or more, preferably 55% by mass or more.

The cured product (β) is used, for example, as an adhesive member, a protective member, an insulating member, or the like for electronic devices and the like. Since the gel fraction of the cured product (. Beta.) is 50% by mass or more, the properties are sufficient for these applications.

The upper limit of the gel fraction of the cured product (. Beta.) is not particularly limited, but is usually 95% by mass or less, preferably 90% by mass or less.

The gel fraction of the cured product (β) can be obtained by the same method as the method for calculating the gel fraction of the cured product (α).

Method for producing cured product (. Beta.)

The "method for producing a cured product (. Beta.)" of the present invention comprises the following steps IIa and IIb. In addition, the following step III may be provided.

Procedure IIa: a step of curing the curable adhesive composition of the present invention at a temperature of 120 ℃ or lower to form a cured product;

procedure IIb: a step of further curing the cured product formed in step IIa at a temperature exceeding 120 ℃;

step III: and curing the curable adhesive composition of the present invention under a heating condition in which the reaction initiation temperature is 120 ℃ or lower and the reaction completion temperature exceeds 120 ℃.

As described above, the curable adhesive composition of the present invention comprises: a 1 st cure system that reacts at a temperature below 120 ℃ and a 2 nd cure system that reacts at a temperature exceeding 120 ℃.

The "method for producing a cured product (β)" of the present invention is a method for producing a cured product by using the reaction of the 1 st curing system and the reaction of the 2 nd curing system.

The method for producing the curable adhesive composition having the steps IIa and IIb is a method for producing a cured product (β) from the curable adhesive composition in 2 stages. That is, the curable adhesive composition of the present invention is cured at a temperature of 120 ℃ or lower to obtain the cured product (α). Then, the cured product (. Alpha.) is heated at a temperature exceeding 120℃to effect the reaction of the 2 nd curing system, thereby obtaining a cured product (. Beta.).

Step IIa is described as a method for producing the cured product (. Alpha.).

The heating temperature in step IIb exceeds 120 ℃, preferably 140 ℃ or higher, more preferably 150 ℃ or higher, and further preferably 180 ℃ or lower.

The heating time in the step IIb is usually 0.5 to 3 hours, preferably 1 to 2 hours.

Step III is a method for producing a cured product (. Beta.) from the curable adhesive composition in 1 stage. That is, the curable adhesive composition of the present invention can be cured under a heating condition in which the reaction initiation temperature is 120 ℃ or lower and the reaction completion temperature exceeds 120 ℃, whereby the reaction of the 1 st curing system is mainly performed from the initial stage to the intermediate stage, and the reaction of the 2 nd curing system is mainly performed from the intermediate stage to the final stage, to obtain the cured product (. Beta.).

The reaction initiation temperature under the elevated temperature condition in step III is 120℃or lower, preferably 110℃or lower.

The reaction initiation temperature under the elevated temperature condition in step III is usually not less than 0℃and preferably not less than 20 ℃.

The reaction completion temperature at the elevated temperature in step III exceeds 120 ℃, preferably 140 ℃ or higher, and more preferably 150 to 180 ℃.

The heating time in step III is usually 0.5 to 3 hours, preferably 1 to 2 hours.

Examples

The present invention will be described in further detail with reference to the following examples. The present invention is not limited to the following examples.

[ Compounds used in examples or comparative examples ]

Binder resin (A1): maleic anhydride-modified alpha-olefin polymer [ trade name, manufactured by Mitsui chemical Co., ltd.: unistol H-200, number average molecular weight: 47,000];

isocyanate-based crosslinking agent (B1): 1,3, 5-tris (5-isocyanatopentyl) -1,3, 5-triazine-2, 4, 6-trione [ trade name, manufactured by Mitsui chemical Co., ltd.: stabio D-370N, molecular weight: 462];

epoxy-based crosslinking agent (B2): 1, 3-bis (N, N-diglycidyl aminomethyl) cyclohexane (trade name, manufactured by Mitsubishi gas chemical Co., ltd.): tetra d-C, molecular weight: 362];

Metal chelate crosslinking agent (B3): tris (acetylacetonate) aluminum [ trade name, manufactured by comprehensive chemical Co., ltd.: M-5A, molecular weight: 324];

curable compound (C1): a compound having an isocyanurate skeleton and 2 allyl groups [ trade name, manufactured by four chemical industries, ltd: L-DAIC ];

polyphenylene ether resin (D1): vinyl benzyl modified polyphenylene ether [ Mitsubishi gas chemical Co., ltd., trade name: OPE-2St 1200, number average molecular weight: 1200];

cationic polymerization initiator (E1): thermal cationic polymerization initiator [ trade name, manufactured by Sanxinchemical industries Co., ltd.: san-Aid SI-B3];

silane coupling agent (F1): 8-epoxypropoxyoctyltrimethoxysilane (trade name, manufactured by Xinyue chemical industry Co., ltd.): KBM4803].

[ evaluation of reactivity of thermal cationic polymerization initiator ]

A mixture of 0.1 part by mass of a cationic polymerization initiator (E1), 100 parts by mass of bisphenol A diglycidyl ether (jER 828, manufactured by Mitsubishi chemical corporation) and 0.1 part by mass of gamma-butyrolactone was used as a measurement sample, and when differential scanning calorimetry was performed at a heating rate of 10℃per minute at 30 to 300℃the peak top temperature of the heat generating peak was 140 ℃.

Example 1

100 parts by mass of the binder resin (A1), 0.5 part by mass of the isocyanate crosslinking agent (B1), 12.5 parts by mass of the curable compound (C1), 25 parts by mass of the polyphenylene ether resin (D1), 0.12 part by mass of the cationic polymerization initiator (E1), and 0.2 part by mass of the silane coupling agent (F1) were dissolved in toluene to prepare a curable adhesive composition.

The obtained curable adhesive composition was applied to the release treated surface of a release sheet (release sheet 1, manufactured by LINTEC Co., ltd.; trade name: SP-PET 752150) to form a coating film, and the obtained coating film was dried at 100℃for 2 minutes to form an adhesive layer (cured product (. Alpha.)) having a thickness of 15. Mu.m. An adhesive sheet was obtained by bonding a release-treated surface of another 1 release sheet (release sheet 2, manufactured by LINTEC Co., ltd., trade name: SP-PET 381130) to the exposed surface of the adhesive layer.

Examples 2 to 5 and comparative example 1

A curable adhesive composition was prepared in the same manner as in example 1 except that the blending amount and the type of the components were changed as shown in table 1, and an adhesive sheet was obtained.

[ gel fraction of adhesive layer (cured product (. Alpha.)))

The adhesive sheets obtained in examples or comparative examples were cut into a size of 80mm in the longitudinal direction and 80mm in the transverse direction, and then all of the 2 release sheets were peeled off to obtain adhesive layers. Then, the obtained adhesive layer was wrapped in a polyester net (net size 200) of which the quality was measured in advance, to prepare a test sample. After the test sample was allowed to stand at 23℃and a relative humidity of 50% for 24 hours, the mass of the test sample was measured by a precision balance. From the obtained measurement value, the mass (M1) of the adhesive layer before impregnation was calculated.

Next, the test specimen was immersed in toluene 0.2L at room temperature (23 ℃ C.) for 168 hours. After impregnation, the test sample was taken out, dried in an oven at 100 ℃ for 2 hours, and then allowed to stand at 23 ℃ in an environment of 50% relative humidity for 24 hours. The mass of the dried test sample was weighed with a precision balance. From the obtained measurement value, the mass (M2) of the adhesive layer after impregnation and drying was calculated.

The gel fraction of the adhesive layer was calculated from the value of M1 and the value of M2 by the following formula.

Gel fraction (mass%) = (M2/M1) ×100

[ gel fraction of cured product (. Beta.) ]

The adhesive sheets obtained in examples or comparative examples were cut into a size of 80mm in the longitudinal direction by 80mm in the transverse direction, and then heated in an oven at 160℃for 1 hour. The gel fraction of the cured product (β) was calculated using the cured product (β) obtained by peeling off the release sheet in the same manner as described above.

[ evaluation of exudation of component ]

The 1-piece release sheet of the adhesive sheet obtained in the examples or comparative examples was peeled off, and the exposed adhesive layer was laminated with a polyimide film (Kapton, thickness 25 μm, manufactured by eastern dupont) using a thermocompressor at 100 ℃. Then, the release sheet of the laminate was peeled off, and the exposed adhesive layer was pressed against the copper foil using a thermocompressor at 100 ℃. Since the copper foil has a larger area than the other 2 layers, the adhesive component of the adhesive layer adheres to the copper foil when oozing out.

The laminate was subjected to hot pressing at 171℃and 1.38MPa for 20 minutes.

After cooling, the length of the adhesive component that oozes out most from the adhesive layer in a plan view [ the length (μm) of the portion indicated by X in fig. 1 ] was measured using a digital microscope. The results are shown in Table 1.

Fig. 1 is a schematic plan view of a laminate used in evaluation of bleeding of an adhesive component in the example, after heat press treatment. As shown in fig. 1, a part of an adhesive layer (cured product) sandwiched between the copper foil 1 and the polyimide film 3 of the laminate is oozed out by a heat press treatment, and the oozed adhesive component 2 can be attached to the copper foil 1. At this time, as shown in fig. 1, the maximum value X of the distance between the adhesive component 2 oozing out and the polyimide film 3 in a plan view is shown in table 1 as "oozing-out length of the adhesive component".

[ relative permittivity, dielectric loss tangent ]

The adhesive layers of the adhesive sheets obtained in examples and comparative examples were stacked to a thickness of about 1mm, and then subjected to a heat sealing treatment at 100℃using a heat sealing machine to obtain a laminate of adhesive layers/release sheets having a structure of release sheets/thickness of about 1 mm. The release sheets on both sides of the laminate were peeled off to obtain a sample for measurement.

The obtained measurement sample was subjected to measurement of relative permittivity and dielectric loss tangent at 23℃and 1GHz using a radio frequency impedance/material analyzer (manufactured by Keysight Technologies Co., ltd., E4991A). In the present specification, the high frequency region means a region of 300MHz to 300GHz, and 1GHz is used as an example of the high frequency region in the present embodiment.

The results are shown in Table 1.

TABLE 1

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The curable adhesive compositions obtained in examples 1 to 5 had the 1 st cure system and the 2 nd cure system.

When these curable adhesive compositions are used, the reaction of the 1 st curing system is used to form a crosslinked structure in the coating film, and then the adhesion step is performed, whereby bleeding of the adhesive component can be suppressed.

Symbol description

1: copper foil;

2: an adhesive layer or oozed adhesive component;

3: polyimide film.

Claims

1. A curable adhesive composition comprising:

2. The curable adhesive composition according to claim 1, wherein the binder resin having a reactive functional group is a polyolefin resin.

3. The curable adhesive composition according to claim 1 or 2, wherein the binder resin having a reactive functional group is an acid-modified resin.

4. The curable adhesive composition according to any one of claims 1 to 3, wherein the crosslinking agent is a compound having an isocyanurate skeleton.

5. The curable adhesive composition according to any one of claims 1 to 4, wherein the crosslinking agent is a compound having 2 or more isocyanate groups.

6. The curable adhesive composition according to any one of claims 1 to 5, wherein the compound having a carbon-carbon double bond is a non-aromatic compound having 2 or more hydrocarbon groups having a double bond at the terminal and being liquid at 25 ℃.

7. The curable adhesive composition according to any one of claims 1 to 6, wherein the compound having a carbon-carbon double bond is a modified polyphenylene ether resin having a hydrocarbon group having a double bond at a terminal.

8. The curable adhesive composition according to any one of claims 1 to 7, further comprising a cationic polymerization initiator, wherein the 2 nd curing system initiates a reaction by the cationic polymerization initiator.

9. The curable adhesive composition according to any one of claims 1 to 8, wherein the curable adhesive composition is a composition which, upon curing, provides a cured product having a dielectric loss tangent of less than 0.0050 at 23 ℃ and a frequency of 1 GHz.

10. The curable adhesive composition according to any one of claims 1 to 9, wherein the curable adhesive composition is a composition which, upon curing, provides a cured product having a relative dielectric constant of 3.00 or less at 23 ℃ and a frequency of 1 GHz.

11. A cured product obtained by curing the curable adhesive composition according to any one of claims 1 to 10, wherein the following requirements 1 and 2 are satisfied:

element 1: gel fraction of 10 mass% or more;

element 2: with further thermosetting properties.

12. The cured product according to claim 11, wherein the cured product has a sheet-like shape.

13. The cured product according to claim 11 or 12, wherein the cured product is a sheet-like adhesive for electronic devices.

14. The cured product according to claim 11 or 12, wherein the cured product is a sheet-like adhesive for a cover film.

15. The method for producing a cured product according to any one of claims 11 to 14, comprising the following step I:

Procedure I: a step of curing the curable adhesive composition according to any one of claims 1 to 10 at a temperature of 120 ℃ or lower.

16. A cured product obtained by curing the curable adhesive composition according to any one of claims 1 to 10, satisfying the following requirement 3:

element 3: the gel fraction is 50 mass% or more.

17. The method for producing a cured product according to claim 16, comprising the following steps IIa and IIb:

procedure IIa: a step of curing the curable adhesive composition according to any one of claims 1 to 10 at a temperature of 120 ℃ or lower to form a cured product;