TW202248387A - Curable adhesive composition and cured product - Google Patents

Abstract

The present invention provides a curable adhesive composition which contains (A) a binder resin that has a reactive functional group and (B) a crosslinking agent that is reactive with the component (A), while having a molecular weight of 1000 or less, wherein the content of the component (B) is 0.1% by mass or more relative to the total amount of the active ingredients of this curable adhesive composition. A cured product that has a dielectric loss tangent of less than 0.0050 at 23 DEG C at a frequency of 1 GHz is obtained by curing this curable adhesive composition. The present invention also provides a cured product of this curable adhesive composition.

Description

Curable adhesive composition, and hardened product

The present invention relates to a curable adhesive composition and its cured product which provide a cured product with excellent low dielectric properties in a high-frequency region and are less likely to contaminate the surroundings in the subsequent step. In this specification, the so-called high frequency region refers to the region from 300MHz to 300GHz.

In recent years, with the miniaturization and weight reduction of electronic equipment, the use of flexible printed circuit boards (FPC) as wiring members has been increasing. FPC can be obtained, for example, by etching the copper foil of a board (copper-clad laminate) obtained by bonding copper foil to an insulating resin film such as polyimide to form an electric circuit. Furthermore, the electric circuit is usually protected by laminating a cover layer film having an insulating resin base material and an adhesive layer to the copper foil on which the electric circuit is formed.

Furthermore, in recent years, for communication devices such as smart phones, in order to process larger-capacity data, the frequency of electrical signals is being promoted. However, electrical signals in the high-frequency region tend to become hot, so if the frequency of the electrical signal is increased, the transmission loss tends to increase.

In order to transmit electrical signals in the high-frequency region at high speed and with reduced transmission loss, improvement of the dielectric properties (lower dielectric constant and lower dielectric tangent) of insulators (substrates or adhesives, etc.) constituting wiring members has been carried out so far.

Patent Document 1 describes an adhesive composition and a thermosetting adhesive sheet. The adhesive composition contains a styrene-based elastomer, a modified polyphenylene ether resin, an epoxy resin, and an epoxy resin hardener. The thermosetting The adhesive sheet is formed by forming a thermosetting adhesive layer composed of the adhesive composition on a substrate. It is also described in Patent Document 1 that the adhesive composition has a low dielectric constant or a low dielectric tangent. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2019-135280.

[Problem to be Solved by the Invention]

The adhesive composition or its cured product described in Patent Document 1 has low dielectric properties (in this specification, the so-called "low dielectric properties" means "low dielectric constant and low dielectric tangent"). However, in order to cope with the further increase in frequency of electric signals expected in the future, it is desired to form a cured product with better low dielectric properties in the high frequency region. Furthermore, with regard to the conventional curable adhesive composition, as a result of the fluidity before curing being too high, the environment may be polluted in the following step.

The present invention is made in view of the above circumstances, and an object of the present invention is to provide a cured adhesive composition and a cured product thereof which provide a cured product having excellent low dielectric properties in a high-frequency region and which are less likely to contaminate the surroundings in the subsequent step. [Means to solve the problem]

The inventors of the present invention conducted intensive research to solve the above-mentioned problems. As a result, it has been found that by formulating a crosslinking agent that reacts with the binder resin to a curable adhesive composition that contains the binder resin and provides a cured product having excellent low dielectric properties, it is possible to suppress contamination of the surrounding area during the bonding step, So as to complete the present invention.

Therefore, according to the present invention, the curable adhesive composition of the following [1] to [10] and the cured product of [11] to [15] can be provided.

[1] A curable adhesive composition comprising the following components (A) and (B), wherein the content of component (B) is 0.1% by mass relative to the total amount of active ingredients in the curable adhesive composition The above; and the aforementioned curable adhesive composition is cured to provide a cured product with a dielectric tangent of less than 0.0050 at 23°C and a frequency of 1 GHz. (A) Component: Binder resin with reactive functional groups. (B) component: the crosslinking agent whose molecular weight is 1000 or less which can react with said (A) component. [2] The curable adhesive composition according to [1], wherein the component (A) is a polyolefin resin. [3] The curable adhesive composition according to [1] or [2], wherein the component (A) is an acid-modified resin. [4] The curable adhesive composition according to any one of [1] to [3], wherein the component (B) is a compound having an isocyanurate skeleton. [5] The curable adhesive composition according to any one of [1] to [4], wherein the component (B) is a compound having two or more isocyanate groups. [6] The curable adhesive composition according to any one of [1] to [5], which further contains the following component (C). Component (C): A non-aromatic hardening compound that is liquid at 25°C. [7] The curable adhesive composition according to [6], wherein the component (C) is a compound having two or more hydrocarbon groups having a double bond at the terminal. [8] The curable adhesive composition according to any one of [1] to [7], which further contains the following component (D). (D) Component: polyphenylene ether resin with reactive functional groups. [9] The curable adhesive composition according to any one of [1] to [8], which further contains the following component (E). (E) component: a cationic polymerization initiator. [10] The curable adhesive composition as described in any one of [1] to [9], wherein the curable adhesive composition is cured and supplied at 23° C., at a frequency of 1 GHz, and has a dielectric constant of 3.00. The following hardened products. [11] A cured product obtained by curing the curable adhesive composition according to any one of [1] to [10]. [12] The cured product as described in [11], wherein the cured product has thermosetting properties. [13] The cured product as described in [11] or [12], wherein the cured product has a sheet-like shape. [14] The cured product according to any one of [11] to [13], wherein the cured product is a sheet-like adhesive for electronic components. [15] The cured product according to any one of [11] to [13], wherein the cured product is a sheet-like adhesive for a cover film. [Efficacy of the invention]

According to the present invention, it is possible to provide a cured adhesive composition and a cured product thereof which provide a cured product excellent in low dielectric properties in a high-frequency region and which are less likely to contaminate the surroundings in a subsequent step.

Hereinafter, the present invention will be described in detail in terms of (1) curable adhesive composition and (2) cured product.

Regarding the numerical range described in this specification, the upper limit and the lower limit can be combined arbitrarily. For example, when "preferably 30 to 100, more preferably 40 to 80" is described as a numerical range, the range of "30 to 80" or the range of "40 to 100" is also included in the description in this specification. the value range. Furthermore, for example, when the numerical range is described as "preferably 30 or more, more preferably 40 or more, and preferably 100 or less, more preferably 80 or less", the range of "30 to 80" or "40 to The range of 100" is also included in the numerical range recorded in this manual. Moreover, as a numerical range described in this specification, description of "60 to 100", for example, means the range of "60 or more and 100 or less". Furthermore, in the specification of the upper limit and the lower limit described in this specification, it is possible to appropriately select from the respective options and combine them arbitrarily to define the numerical range from the lower limit to the upper limit. In addition, various requirements described as preferred aspects described in this specification may be combined in plural.

In this specification, the number average molecular weight (Mn) can be calculated|required as a standard polystyrene conversion value by performing gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent, and can measure it, for example under the following conditions. [Example of measurement conditions] ・Gel permeation chromatography device: manufactured by Tosoh Co., Ltd., product name "HLC-8020" ·Tube column: Connect "TSK guard column HXL-L", "TSK gel G2500HXL", "TSK gel G2000HXL" and "TSK gel G1000HXL" in sequence (all manufactured by Tosoh Co., Ltd.) ·Column temperature: 40℃ Developing solvent: tetrahydrofuran ·Flow rate: 1.0mL/min

(1) Hardening adhesive composition The curable adhesive composition of the present invention contains the following components (A) and (B), and the content of the component (B) is 0.1% by mass or more relative to the total amount of active ingredients in the curable adhesive composition. (A) Component: Binder resin with reactive functional groups. (B) component: the crosslinking agent whose molecular weight is 1000 or less which can react with said (A) component. The curable adhesive composition of the present invention is cured at 23° C. and a frequency of 1 GHz to provide a cured product whose dielectric tangent is less than 0.0050. In this specification, the so-called "active ingredient" refers to an ingredient in a composition, and refers to an ingredient other than a solvent.

In this specification, the cross-linking reaction in which the binder resin (A) and the cross-linking agent (B) participate is sometimes described as "curing reaction (I)", and the hardened product obtained mainly through the curing reaction (I) is described. It is "hardened product (I)". In addition, the hardened|cured material (I) should just harden at least to the extent which suppresses the bleeding of the adhesive agent component in a coating film. Therefore, the cured product (I) may be almost complete of the curing reaction (I), may contain unreacted binder resin (A) and crosslinking agent (B), and has curability derived from the curing reaction (I).

The curable adhesive composition of the present invention may contain curable components other than the binder resin (A) and the crosslinking agent (B) (hereinafter sometimes referred to as "curable component (X)").

The hardening component (X) may be a compound that participates in the hardening reaction (I), or may be a compound that does not participate in the hardening reaction (I). It is preferable that the curable component (X) does not participate in hardening in terms of the fact that multiple times of hardening reactions can be reliably performed and a curable adhesive composition can be obtained that can more reliably suppress the bleeding of the adhesive component in the coating film. Compounds of Reaction (I). That is, when the hardening component (X) is a compound that participates in the hardening reaction (I), both the step of building a crosslinked structure in the coating film and the step of bonding the two adherends more firmly The hardening reaction (I) is required in the step, and the hardening reaction (I) that starts to build a cross-linked structure in the coating film must be temporarily stopped halfway, and the hardening reaction (I) must be highly controlled. On the other hand, when the hardening component (X) is a compound that does not participate in the hardening reaction (I), even if the hardening reaction (I) is almost completed, the obtained hardened product (I) also has (X) has curability, so the step of bonding two adherends more firmly can be performed by utilizing this curability. In this way, the curable adhesive composition containing the curable component (X) that does not participate in the curing reaction (I) can surely perform multiple curing reactions without highly controlling the curing reaction (I), and can more reliably Inhibit the leakage of adhesive ingredients in the coating film.

In this specification, the hardening reaction in which the curable component (X) which does not participate in the hardening reaction (I) participates may be described as "hardening reaction (II)".

Examples of the curable component (X) include the following (C)component, (D)component, and (F)component. (C) Component: non-aromatic hardening compound that is liquid at 25°C (D) Component: polyphenylene ether resin with reactive functional groups (F) Component: Silane coupling agent

When the curing reaction (I) or curing reaction (II) is a cationic polymerization reaction, the curable adhesive composition of one aspect of the present invention may further contain the following component (E). Component (E): Cationic polymerization initiator Furthermore, the curable adhesive composition of one aspect of the present invention may further contain components other than the above-mentioned components (A) to (F) within a range that does not impair the effects of the present invention.

In the curable adhesive composition of one aspect of the present invention, the total content of (A) component and (B) component can be 40% by mass or more, 50% by mass or more, 60% by mass or more, 65% by mass or more, or 70% by mass or more, and may be 100% by mass or less, 99% by mass or less, 95% by mass or less, or 90% by mass or less , 85% by mass or less than 80% by mass.

In the curable adhesive composition according to one aspect of the present invention, the total content of components (A) to (E) may be 45% by mass or more, 55% by mass or more, 65% by mass or more, 75% by mass or more, 80% by mass or more, 85% by mass or more, 90% by mass or more, or 95% by mass or more, or 100% by mass less than, 99.9% by mass or less than 99.8% by mass.

In the curable adhesive composition of one aspect of the present invention, the total content of the components (A) to (F) may be Set to 45% by mass to 100% by mass, 55% by mass or more, 65% by mass or more, 75% by mass or more, 80% by mass or more, 85% by mass or more, 90% by mass or more, or 95% by mass or more, and can be set to 100% by mass Mass % or less, 99.9 mass % or less, or 99.8 mass % or less.

[Component (A): Binder resin with reactive functional groups] The curable adhesive composition of the present invention contains an adhesive resin (hereinafter sometimes referred to as "adhesive resin (A)") having a reactive functional group as the (A) component. Since the curable adhesive composition of the present invention contains the adhesive resin (A), as will be described later, it is possible to suppress contamination of the surrounding area in the bonding step. Binder resin (A) can be used individually by 1 type or in combination of 2 or more types.

The number average molecular weight (Mn) of the adhesive resin (A) is not particularly limited, but it is usually 10,000 or more, preferably 10,000 to 150,000, and more preferably 10,000 to 100,000. The number average molecular weight (Mn) of the binder resin (A) can be obtained by performing gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent, and as a standard polystyrene conversion value. As a specific measurement condition, the above described in the text.

The content of the adhesive resin (A) contained in the curable adhesive composition relative to the total amount of active ingredients (100% by mass) of the curable adhesive composition (when two or more adhesive resins (A) are included When the total amount of these binder resins (A)) is preferably at least 50% by mass, more preferably at least 60% by mass, further preferably at least 65% by mass, and is more preferably at most 95% by mass, more preferably at least 95% by mass. 90 mass % or less, More preferably, it is 85 mass % or less, More preferably, it is 80 mass % or less. When the content of the adhesive resin (A) is 50% by mass or more, it is easy to obtain a curable adhesive composition that does not easily contaminate the surroundings. When the content of the binder resin (A) is 95% by mass or less, it is easy to obtain a curable adhesive composition that provides a cured product excellent in low dielectric properties.

Examples of the binder resin (A) include polyolefin-based resins, phenoxy-based resins, polyimide-based resins, polyamideimide-based resins, polyvinyl butyral-based resins, polycarbonate resins, and polyamide-based resins. Department of resin, etc. Among these binder resins, the binder resin (A) is preferably a polyolefin-based resin. When the adhesive resin (A) is a polyolefin-based resin, it is easy to obtain a curable adhesive composition that provides a cured product excellent in low dielectric properties.

In addition, in the case where the (A) component is a curable adhesive composition of a polyolefin resin, the curable adhesive composition may contain other adhesive resins other than the polyolefin resin as other components. In the aforementioned curable adhesive composition, the content of other adhesive resins is preferably 0 to 50 parts by mass, more preferably 0 to 30 parts by mass, relative to 100 parts by mass of the total amount of the polyolefin resin. , and more preferably 0 parts by mass to 10 parts by mass, and even more preferably 0 parts by mass to 5 parts by mass.

The polyolefin-based resin refers to a polymer containing repeating units derived from olefin-based monomers. Polyolefin-based resins may be polymers composed only of repeating units derived from olefin-based monomers, or may be composed of repeating units derived from olefin-based monomers and monomers that can be copolymerized with olefin-based monomers A polymer composed of repeating units.

The olefin-based monomer is preferably an α-olefin having 2 to 8 carbon atoms, more preferably ethylene, propylene, 1-butene, isobutene or 1-hexene, and still more preferably ethylene or propylene. These olefinic monomers may be used alone or in combination of two or more. Vinyl acetate, (meth)acrylate, styrene, etc. are mentioned as a monomer copolymerizable with an olefin type monomer. Here, "(meth)acrylic acid" means acrylic acid or methacrylic acid (the same applies hereinafter). These "monomers copolymerizable with olefin-based monomers" can be used alone or in combination of two or more.

Examples of polyolefin-based resins 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, olefin-based elastomer (TPO), ethylene-vinyl acetate copolymer (EVA), ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate copolymer things etc.

Examples of reactive functional groups contained in the binder resin (A) include carboxyl groups, carboxylic acid anhydride groups, carboxylate groups, hydroxyl groups, epoxy groups, amido groups, ammonium groups, nitrile groups, amino groups, and imide groups. Amino group, isocyanate group, acetyl group, thiol group, ether group, thioether group, phosphono group, nitro group, carbamate group, halogen atom, alkoxysilyl group, etc.

The binder resin (A) is preferably a modified resin. The modified resin is a resin with reactive functional groups introduced by using a modifier to modify the resin as a precursor. The modifier used in the modification treatment of the binder resin is a compound having a reactive functional group in the molecule. As a reactive functional group, what was demonstrated above is mentioned.

Examples of the modified resin include resins into which acid groups have been introduced (acid-modified resins), or resins into which hydroxyl groups have been introduced, and acid-modified resins are preferred. Among the acid-modified resins, those introduced with an acid anhydride structure are also preferable. By using an acid-modified resin as the component (A), it is easy to obtain a curable adhesive composition that provides a cured product excellent in low dielectric properties. Furthermore, by using a resin into which an acid anhydride structure is introduced as an acid-modified resin, it tends to be easy to maintain a long service life.

In the case where the component (A) is a curable adhesive composition of an acid-modified resin, the curable adhesive composition may contain other adhesive resins other than the acid-modified resin as other components. In the aforementioned curable adhesive composition, the content of other adhesive resins is preferably 0 to 50 parts by mass, more preferably 0 to 30 parts by mass, relative to 100 parts by mass of the total amount of the acid-modified resin , and more preferably 0 parts by mass to 10 parts by mass, and even more preferably 0 parts by mass to 5 parts by mass.

Examples of acid-modified resins include: reacting unsaturated carboxylic acid or unsaturated carboxylic acid anhydride (hereinafter sometimes referred to as "unsaturated carboxylic acid, etc.") with the resin to introduce (graft modification) carboxyl group or carboxylic anhydride base resin.

Examples of unsaturated carboxylic acids that react with resins include unsaturated carboxylic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid, glutaconic acid, tetrahydrophthalic acid, and aconitic acid; Unsaturated carboxylic anhydrides such as maleic anhydride, itaconic anhydride, glutaconic anhydride, citraconic anhydride, aconitic anhydride, norbornene dicarboxylic anhydride, tetrahydrophthalic anhydride, etc. These unsaturated carboxylic acids etc. can be used individually by 1 type or in combination of 2 or more types. Among these unsaturated carboxylic acids, maleic anhydride is preferable in terms of easily obtaining a curable adhesive composition that provides a cured product with higher adhesive strength.

The amount of the unsaturated carboxylic acid 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, relative to 100 parts by mass of the resin. share. By curing the curable adhesive composition containing the acid-modified resin obtained in this manner, it is easy to obtain a cured product with higher adhesive strength.

The method of introducing the unsaturated carboxylic acid unit or the unsaturated carboxylic anhydride unit into the resin is not particularly limited. For example, the method of graft-copolymerizing unsaturated carboxylic acid and the like with the resin by the following method: in the presence of free radical generators such as organic peroxides and azonitriles, resin and unsaturated carboxylic acid A method in which an acid, etc. is heated and melted above the melting point of the resin and reacted; or a method in which a resin and an unsaturated carboxylic acid, etc. are dissolved in an organic solvent, and then heated and stirred in the presence of a free radical generator to react.

The binder resin (A) is preferably a modified polyolefin resin, more preferably an acid modified polyolefin resin. When the adhesive resin (A) is an acid-modified polyolefin-based resin, it is easy to obtain a curable adhesive composition that provides a cured product excellent in low dielectric properties and low contamination.

The modified polyolefin-based resin is a polyolefin-based resin with reactive functional groups introduced therein, which is obtained by modifying the polyolefin-based resin as a precursor with a modifying agent.

In the case where the component (A) is a curable adhesive composition of an acid-modified polyolefin resin, the curable adhesive composition may also contain other adhesive resins other than the acid-modified polyolefin resin. other ingredients. In the aforementioned curable adhesive composition, the content of other adhesive resins is preferably from 0 to 50 parts by mass, more preferably from 0 to 50 parts by mass, relative to 100 parts by mass of the total amount of the acid-modified polyolefin resin. 30 parts by mass, more preferably 0 to 10 parts by mass, even more preferably 0 to 5 parts by mass.

[Component (B): A crosslinking agent with a molecular weight of 1000 or less that can react with component (A)] The curable adhesive composition of the present invention contains, as the (B) component, a crosslinking agent having a molecular weight of 1000 or less (hereinafter sometimes referred to as "crosslinking agent (B)") capable of reacting with the (A) component. Since the curable adhesive composition of the present invention contains the crosslinking agent (B), it is possible to suppress contamination of the surrounding area in the bonding step as will be described later. In addition, the crosslinking agent (B) can be used individually by 1 type or in combination of 2 or more types.

The molecular weight of the crosslinking agent (B) is 1000 or less, preferably 800 or less, more preferably 700 or less, still more preferably 600 or less, still more preferably 500 or less. When the molecular weight of the crosslinking agent (B) is 1000 or less, the collision probability of the reaction with the component (A) increases, and the crosslinking structure is easily formed, and it can be used as a hardening adhesive with a high effect of suppressing surrounding contamination in the adhesion step Composition. The lower limit of the molecular weight of the crosslinking agent (B) is not particularly present, and is usually 100 or more, preferably 200 or more. Furthermore, 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) relative to the total amount of active ingredients (100% by mass) of the curable adhesive composition (when two or more crosslinking agents (B) are included, these crosslinking agents (B) The total amount) is 0.1% by mass or more, preferably 0.2% by mass or more, more preferably 0.3% by mass or more, more preferably 0.5% by mass or more, more preferably 0.7% by mass or more, especially preferably 0.9% by mass Above, and 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. When content of a crosslinking agent (B) is 0.1 mass % or more with respect to the active ingredient total amount of a curable adhesive composition, the hardenable adhesive composition which does not easily contaminate the surrounding can be obtained. Furthermore, when the content of the crosslinking agent (B) is 5% by mass or less with respect to the total amount of active ingredients of the curable adhesive composition, it is easy to obtain a curable adhesive composition that provides a cured product excellent in low dielectric properties .

The content of the crosslinking agent (B) (the total amount of these crosslinking agents (B) when two or more kinds of crosslinking agents (B) are included) is preferably 0.1 parts by mass or more with respect to 100 parts by mass of the component (A) , more preferably more than 0.3 parts by mass, more preferably more than 0.5 parts by mass, more preferably more than 0.8 parts by mass, especially preferably more than 1.2 parts by mass, and preferably less than 10 parts by mass, more preferably 7 parts by mass or less, more preferably 5 parts by mass or less, still more preferably 3 parts by mass or less.

The crosslinking agent (B) is a compound which can react with (A) component. Therefore, as the crosslinking agent (B), it is necessary to appropriately select a compound having a reactive group or a reactive site that is reactive to the reactive functional group in the binder resin (A). For example, as a crosslinking agent (B), an isocyanate type crosslinking agent, an epoxy type crosslinking agent, a metal chelate type crosslinking agent, an aziridine type crosslinking agent etc. can be used. Among these crosslinking agents (B), from the viewpoint of storage stability, one or more kinds selected from isocyanate crosslinking agents, epoxy crosslinking agents, and metal chelate crosslinking agents are preferred. Moreover, in one aspect of the present invention, for example, when the binder resin (A) is an acid-modified resin, and the reactive functional group in the binder resin (A) is a carboxyl group or a carboxylic acid anhydride group, as a crosslinking The agent (B) is preferably at least one selected from isocyanate-based crosslinking agents, epoxy-based crosslinking agents, and metal chelate-based crosslinking agents.

The isocyanate-based crosslinking agent is a compound having two or more isocyanate groups in the molecule. Examples of isocyanate-based crosslinking agents include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, hydrogenated toluene diisocyanate, hydrogenated xylene diisocyanate, 1,5-pentamethylene diisocyanate, 1 , 6-hexamethylene diisocyanate, diphenylmethane-4,4-diisocyanate, isophorone diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, tetramethylbenzene Dimethyl diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, adducts of these polyisocyanate compounds and polyol compounds such as trimethylolpropane, and biuret forms of these polyisocyanate compounds or isocyanurate body, etc.

The epoxy-based crosslinking agent is a compound having two or more epoxy groups in the molecule. Examples of epoxy-based crosslinking agents include: 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-meta Xylylenediamine, ethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidyl aniline, diglycidylamine, etc.

The metal chelate type crosslinking agent is a chelate compound having a metal ion functioning as a crosslinking point. As a metal chelate type crosslinking agent, the metal chelate compound whose metal ion is aluminum ion, zirconium ion, titanium ion, zinc ion, iron ion, tin ion, etc. can be used, for example. Among these metal chelate compounds, aluminum chelate compounds are preferred.

Examples of aluminum chelate compounds include: tris(acetylacetonate)aluminum, acetylacetonate bis(ethyl acetate)aluminum, diisopropoxymonoacetylacetate oleyl aluminum, monoisopropoxybis Acetyl oleyl acetate, aluminum, etc.

In one aspect 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 two or more isocyanate groups . When the crosslinking agent (B) is a compound having an isocyanurate skeleton, it is easy to obtain a curable adhesive composition that provides a cured product excellent in low dielectric properties. Furthermore, in the case of a curable adhesive composition in which the component (B) is a compound having an isocyanurate skeleton, the curable adhesive composition may contain a compound having an isocyanurate skeleton. other cross-linking agents as other components. In the aforementioned curable adhesive composition, the content of other crosslinking agents is preferably 0 to 100 parts by mass, more preferably 0 parts by mass, relative to 100 parts by mass of the total amount of the compound having an isocyanurate skeleton. Parts to 50 parts by mass, more preferably 0 parts by mass to 30 parts by mass, even more preferably 0 parts by mass to 10 parts by mass, especially preferably 0 parts by mass to 5 parts by mass.

In one aspect of the present invention, it is preferable to have two or more crosslinking agents (B) from the viewpoint of easily obtaining a curable adhesive composition that provides a cured product having excellent low dielectric properties. Isocyanate-based crosslinking agent for isocyanate-based compounds, more preferably isocyanurate form of polyisocyanate compound, further preferably isocyanurate form of 1,5-pentamethylene diisocyanate [1,3 ,5-tris(5-isocyanatopentyl)-1,3,5-triazine-2,4,6-trione] or 1,6-hexamethylene diisocyanate isocyanurate [1 ,3,5-tris(6-isocyanatohexyl)-1,3,5-triazine-2,4,6-trione]. Furthermore, in the case of a curable adhesive composition in which the component (B) is an isocyanate-based cross-linking agent, the curable adhesive composition may contain other cross-linking agents other than the isocyanate-based cross-linking agent as other ingredients. In the aforementioned curable adhesive composition, the content of other crosslinking agents is preferably 0 to 100 parts by mass, more preferably 0 to 50 parts by mass, relative to 100 parts by mass of the total amount of the isocyanate-based crosslinking agent. parts by mass, more preferably 0 to 30 parts by mass, more preferably 0 to 10 parts by mass, especially preferably 0 to 5 parts by mass.

In one aspect of the present invention, the cross-linking agent (B) is preferably an epoxy-based cross-linking agent from the viewpoint of easily obtaining a curable adhesive composition capable of suppressing surrounding contamination in the following step. In the case of a curable adhesive composition in which the component (B) is an epoxy-based cross-linking agent, the curable adhesive composition may contain other cross-linking agents other than the epoxy-based cross-linking agent as other components . In the aforementioned curable adhesive composition, the content of other crosslinking agents is preferably 0 to 100 parts by mass, more preferably 0 to 50 parts by mass, relative to 100 parts by mass of the total amount of the epoxy-based crosslinking agent. parts by mass, more preferably 0 to 30 parts by mass, more preferably 0 to 10 parts by mass, especially preferably 0 to 5 parts by mass.

The crosslinking agent (B) is a compound that can react with the binder resin (A), so it is possible to combine the binder resin (A) and the crosslinking agent in the coating film obtained by coating the curable adhesive composition of the present invention. (B) Reaction to build a cross-linked structure in the coating film. A coating film with a cross-linked structure inside is difficult to flow even when heated. Therefore, by constructing a cross-linked structure in the coating film before bonding the two adherends, even if heat treatment is performed when the two adherends are bonded, it is possible to keep suppressing the separation of the adhesive components in the coating film. The oozing state completely hardens the coating film. In this way, in the curable adhesive composition of the present invention, by appropriately controlling the reaction between the adhesive resin (A) and the crosslinking agent (B), it is possible to suppress contamination of the surrounding area in the adhesive step.

[Component (C): non-aromatic hardening compound that is liquid at 25°C] The component (C) is a non-aromatic curable compound (hereinafter sometimes referred to as "hardenable compound (C)") that is liquid at 25°C. The curable compound (C) can be used individually by 1 type or in combination of 2 or more types.

The curable compound (C) is a curable compound. Therefore, when the curable compound (C) is a curable component (X) that does not participate in the curing reaction (I), the curable adhesive composition containing the curable compound (C) undergoes the curing reaction (I) to The resulting hardened product can undergo hardening reaction (II), and can function as a solid adhesive.

The curable compound (C) is a liquid compound at 25°C. Therefore, when the curable compound (C) is a curable component (X) that does not participate in the hardening reaction (I), the cured product (the curable adhesive composition containing the curable compound (C) undergoes a hardening reaction The solid adhesive formed by (I) has good moisture spreading property during lamination process, and the layer suitability is more excellent. The term "liquid at 25°C" means fluidity at 25°C. For example, a compound that is liquid at 25°C is a compound having a viscosity of 2 mPa·s to 10000 mPa·s measured at 25°C and 1.0 rpm using an E-type viscometer.

The hardening compound (C) is a non-aromatic compound. The term "non-aromatic compound" means a compound that does not have an aromatic ring. Since the curable compound (C) is a non-aromatic compound, the cured product of the curable adhesive composition containing the curable compound (C) tends to have better low dielectric properties.

The curable compound (C) is preferably a compound having a heterocyclic skeleton. When the curable compound (C) is a compound having a heterocyclic skeleton, it is easy to obtain a curable adhesive composition that provides a cured product that is more excellent in adhesive strength and low dielectric properties. In the case of a curable adhesive composition in which component (C) is a compound having a heterocyclic skeleton, the curable adhesive composition may contain other curable compounds other than the compound having a heterocyclic skeleton as other Element. In the above curable adhesive composition, the content of other curable compounds is preferably 0 to 50 parts by mass, more preferably 0 to 50 parts by mass, relative to 100 parts by mass of the total amount of the compound having a heterocyclic skeleton. 30 parts by mass, more preferably 0 to 10 parts by mass, even more preferably 0 to 5 parts by mass. As a heterocyclic skeleton, an isocyanurate skeleton or a glycoluril skeleton is mentioned. The heterocyclic skeleton preferably has n-fold rotation axes as symmetry elements. The cured product of the curable adhesive composition containing the curable compound (C) having such a heterocyclic skeleton tends to be more excellent in low dielectric properties.

The molecular weight of the curable compound (C) is preferably at most 1,000, more preferably at most 800, further preferably at most 650, even more preferably at most 500. Curable compounds with a molecular weight of 1,000 or less tend to satisfy the requirement of being liquid at 25°C. Furthermore, the molecular weight of the curable compound (C) is preferably at least 100, more preferably at least 200, and still more preferably at least 275. The curable compound (C) having a molecular weight of 100 or more does not volatilize easily even in the drying step or thermal curing step of the curable adhesive composition, so it is easy to obtain a cured product having the desired physical properties.

Examples of the curable compound (C) include compounds having two or more hydrocarbon groups having a double bond at the terminal (hereinafter, this compound may be referred to as "hardenable compound (C')"). By using the curable compound (C') as the curable compound (C), it is easy to obtain a curable adhesive composition that provides a cured product having more excellent low dielectric properties. In the case of a curable adhesive composition in which the component (C) is the aforementioned curable compound (C'), the curable adhesive composition may contain other curable compounds other than the curable compound (C'). compounds as other ingredients. In the curable adhesive composition, the content of other curable compounds is preferably 0 to 50 parts by mass, more preferably 0 parts by mass, relative to 100 parts by mass of the total amount of the curable compound (C'). to 30 parts by mass, more preferably 0 to 10 parts by mass, and more preferably 0 to 5 parts by mass.

The carbon number of the hydrocarbon group having a double bond at the terminal contained in the curable compound (C') is preferably 2-10, more preferably 2-5. 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, etc. Among these hydrocarbon groups having a double bond at the terminal, an allyl group is preferable.

The number of hydrocarbon groups having a double bond at the terminal contained in the curable compound (C') is 2 or more. When the number of hydrocarbon groups having a double bond at the terminal is 2 or more, it is easy to obtain a curable adhesive composition that provides a cured product having superior adhesive strength or heat resistance. Furthermore, since the crosslinked structure formed in the cured product is moderately sparse, there is a tendency to suppress the occurrence of cracks in the cured product. Therefore, the number of hydrocarbon groups having a double bond at the terminal is preferably 2 to 4, more preferably 2.

Examples of the curable compound (C') include a curable compound (C') having an isocyanurate skeleton and a curable compound (C') having a glycoluril skeleton. Examples of the curable compound (C') having an isocyanurate skeleton include compounds represented by the following formula (1) or formula (2).

In formula (1), R ¹ and R ² independently represent a hydrocarbon group having a double bond at the end, and R ³ represents a saturated hydrocarbon group with 1 to 15 carbons, or an alkoxy-substituted alkyl group with 1 to 15 carbons. In formula (2), R ⁴ to R ⁶ each independently represent a hydrocarbon group having a double bond at the end.

The hydrocarbon group having a double bond at the terminal represented by R ¹ , R ² , R ⁴ , R ⁵ , and R ⁶ is as described above.

The saturated hydrocarbon group represented by R ³ has a carbon number of 1 to 15, preferably 5 to 15, more preferably 8 to 15. Examples of the saturated hydrocarbon group represented by ^R include: methyl, ethyl, n-propyl, isopropyl, n-butyl, tertiary butyl, secondary butyl, isobutyl, n-pentyl, n-hexyl , n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, etc.

The carbon number of the alkoxy-substituted alkyl represented by R ³ is 2-15, preferably 2-12, more preferably 3-10. Examples of the alkoxy-substituted alkyl represented by ^R3 include methoxymethyl, ethoxymethyl, 2-methoxyethoxymethyl, benzyloxymethyl and the like.

Examples of the curable compound (C') having a glycoluril skeleton include compounds represented by the following formula (3).

In formula (3), R ⁷ to R ¹⁰ each independently represent a hydrocarbon group having 1 to 15 carbon atoms, and at least two of these hydrocarbon groups are hydrocarbon groups having a double bond at the end. R ¹¹ and R ¹² represent a hydrogen atom or a saturated hydrocarbon group with 1 to 15 carbons.

Among these hydrocarbon groups, the curable compound (C') is preferably a compound having an isocyanurate skeleton in terms of easily obtaining a cured product having an appropriate crosslink density and excellent low dielectric properties. A compound represented by formula (1) is preferable, and a compound represented by the following formula is more preferable.

In the formula, R represents a saturated hydrocarbon group having 5 to 15 carbons, preferably a saturated hydrocarbon group having 8 to 15 carbons.

When the curable adhesive composition of the present invention contains the curable compound (C), the content of the curable compound (C) relative to the total amount of active ingredients (100% by mass) of the curable adhesive composition ( When two or more curable compounds (C) are contained, the total amount of these curable compounds (C) is preferably at least 5% by mass, more preferably at least 7% by mass, still more preferably at least 8.5% by mass, Moreover, it is preferably at most 25% by mass, more preferably at most 20% by mass, and still more preferably at most 15% by mass. When the content of the curable compound (C) is 5% by mass or more in the total amount of active ingredients of the curable adhesive composition, it is easy to obtain a curable adhesive composition that provides a cured product excellent in adhesive strength. When the content of the curable compound (C) is 25% by mass or less in the total active ingredients of the curable adhesive composition, it is easy to obtain a curable adhesive composition that provides a cured product excellent in low dielectric properties.

When the curable adhesive composition of the present invention contains a curable compound (C), the content of the curable compound (C) (when two or more curable compounds (C) are included, these curable compounds (C) ) is preferably at least 3 parts by mass, more preferably at least 5 parts by mass, further preferably at least 7 parts by mass, and still more preferably at least 10 parts by mass, with respect to 100 parts by mass of component (A). Preferably, it is 30 mass parts or less, More preferably, it is 25 mass parts or less, More preferably, it is 20 mass parts or less, More preferably, it is 16 mass parts or less.

[Component (D): Polyphenylene ether resin with reactive functional groups] The component (D) is a polyphenylene ether resin (hereinafter sometimes referred to as "polyphenylene ether resin (D)") having a reactive functional group. The polyphenylene ether resin refers to a resin having a polyphenylene skeleton in the main chain. The polyphenylene skeleton refers to a skeleton having a repeating unit represented by the following formula, or a repeating unit in which hydrogen atoms in the above formula are substituted.

The polyphenylene ether resin (D) is a compound having a polyphenylene ether skeleton and reactive functional groups. The polyphenylene ether resin (D) has a polyphenylene ether skeleton, so the cured product of the curable adhesive composition containing the polyphenylene ether resin (D) has excellent low dielectric properties. Furthermore, since the polyphenylene ether resin (D) has a reactive functional group, the cured product of the curable adhesive composition containing the polyphenylene ether resin (D) is excellent in heat resistance. The polyphenylene ether resin (D) may be used alone or in combination of two or more.

Examples of the polyphenylene ether skeleton in the polyphenylene ether resin (D) include skeletons represented by the following formula (4).

In formula (4), X is a divalent group represented by the following formula (5) or formula (6), Y is independently a divalent group represented by the following formula (7), and a and b are 0 to 100 Integers, at least one of a and b is 1 or more. * indicates a bonding site (the same applies hereinafter).

In formula (5), R ¹³ 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, preferably a hydrogen atom or a methyl group.

In formula (6), R ²¹ to R ²⁸ each independently represent 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 divalent hydrocarbon group having 20 or less carbon atoms.

In formula (7), R ²⁹ to R ³² each independently represent 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 polyphenylene ether resin (D) include a skeleton represented by the following formula (8).

(a及b為0至100之整數，a與b的至少任一者為1以上)。

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

Examples of reactive functional groups in the polyphenylene ether resin (D) include vinyl, allyl, acryl, methacryl, cyclopentenyl, vinylbenzyl, vinylnaphthyl, etc. A group with an ethylenically unsaturated bond; an epoxy group; a hydroxyl group, etc. Among these reactive functional groups, the reactive functional group is preferably a group having an ethylenically unsaturated bond, more preferably a vinylbenzyl group, from the viewpoint of easily obtaining a cured product having excellent low dielectric properties.

The polyphenylene ether resin (D) is preferably a resin having a reactive functional group at both ends of the polyphenylene ether skeleton in terms of being easy to obtain a cured product having excellent low dielectric properties. In the case of a curable adhesive composition in which the component (D) is a resin having reactive functional groups at both ends of the polyphenylene ether skeleton, the curable adhesive composition may also contain the polyphenylene ether skeleton. Other polyphenylene ether resins other than resins with reactive functional groups at both ends are used as other components. In the aforementioned curable adhesive composition, the content of other polyphenylene ether resins is preferably 0 to 50 parts by mass relative to the total amount of 100 parts by mass of the resin having reactive functional groups at both ends of the polyphenylene ether skeleton. parts by mass, more preferably 0 to 30 parts by mass, further preferably 0 to 10 parts by mass, further preferably 0 to 5 parts by mass.

The polyphenylene ether resin (D) can be obtained by introducing a reactive functional group into a terminal after forming a polyphenylene ether skeleton. For example, a polyphenylene ether resin (D) having vinylbenzyl groups as reactive functional groups at both ends can be obtained by reacting a difunctional phenolic compound with a monofunctional phenolic compound to obtain a polyphenylene ether resin (D) having phenolic properties at both ends. After polymerizing the hydroxyl groups, the terminal phenolic hydroxyl groups were vinylbenzyl etherified using 4-(chloromethyl)styrene.

Examples of the polyphenylene ether resin (D) include compounds represented by the following formula (9).

(上述式中，a及b為0至100之整數，a與b中的至少任一者為1以上)。

(In the above formula, a and b are integers from 0 to 100, and at least one of a and b is 1 or more).

In the case of a curable adhesive composition in which the component (D) is a compound represented by the above formula (9), the curable adhesive composition may contain compounds other than the compound represented by the above formula (9) Other polyphenylene ether resins as other components. In the aforementioned curable adhesive composition, the content of other polyphenylene ether resins is preferably 0 to 50 parts by mass, more preferably 0 to 30 parts by mass, more preferably 0 to 10 parts by mass, even more preferably 0 to 5 parts by mass.

The number average molecular weight (Mn) of the polyphenylene ether resin (D) is preferably 500 to 5,000, more preferably 500 to 3,000, further preferably 700 to 2,500, further preferably 1,000 to 2,000. The number average molecular weight (Mn) of the polyphenylene ether resin (D) can be obtained by performing gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent, and as a standard polystyrene conversion value. As a specific measurement condition, As mentioned above.

When the curable adhesive composition of the present invention contains polyphenylene ether resin (D), the amount of polyphenylene ether resin (D) relative to the total amount of active ingredients (100% by mass) of the curable adhesive composition The content (the total amount of these (D) components when two or more (D) components are included) is preferably at least 1% by mass, more preferably at least 5% by mass, further preferably at least 10% by mass, and still more preferably It is preferably at least 15% by mass, more preferably at most 30% by mass, more preferably at most 25% by mass. When the content of the polyphenylene ether resin (D) is 1% by mass or more in the total active ingredients of the curable adhesive composition, it is easy to obtain a curable adhesive composition that provides a cured product excellent in low dielectric properties. When the content of the polyphenylene ether resin (D) is 30% by mass or less in the total amount of active ingredients of the curable adhesive composition, it is easy to provide adhesiveness.

In the case where the curable adhesive composition of the present invention contains polyphenylene ether resin (D), the content of polyphenylene ether resin (D) (when two or more (D) components are included is the total of these (D) components The total amount) is preferably at least 5 parts by mass, more preferably at least 10 parts by mass, further preferably at least 15 parts by mass, further preferably at least 20 parts by mass, and more preferably at least 20 parts by mass with respect to 100 parts by mass of component (A). 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.

[(F) component: silane coupling agent] The curable adhesive composition of the present invention may also contain a silane coupling agent (F) as the curable component (X). A silane coupling agent (F) can be used individually by 1 type or in combination of 2 or more types.

As the silane coupling agent (F), known silane coupling agents can be used. Among them, organosilicon compounds having at least one alkoxysilyl group in the molecule are preferred. Examples of the silane coupling agent (F) include: 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyl Oxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, etc. Silane coupling agent; vinyltrimethoxysilane, vinyltriethoxysilane, dimethoxymethylvinylsilane, diethoxymethylvinylsilane, trichlorovinylsilane, vinyl tri(2 -Methoxyethoxy)silane and other silane coupling agents with vinyl groups; 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 8-glycidyloxyoctyltrimethoxysilane, etc. Mixture; p-styryltrimethoxysilane, p-styryltriethoxysilane and other styryl-based silane coupling agents; N-(2-aminoethyl)-3-aminopropylmethyl di Methoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, hydrochloride of N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane, etc. have amino groups silane coupling agent; 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane and other silane coupling agents with ureido groups; 3-chloropropyltrimethoxysilane, 3-chloropropyl Silane coupling agents with halogen atoms, such as triethoxysilane; silane coupling agents with mercapto groups, such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane; bis(trimethoxy Silane coupling agents with sulfide groups such as silylpropyl) tetrasulfide and bis(triethoxysilylpropyl) tetrasulfide; 3-isocyanate propyl trimethoxysilane, 3-isocyanate propyl triethyl Silane coupling agents with isocyanate groups such as oxysilane; silane coupling agents with allyl groups such as allyltrichlorosilane, allyltriethoxysilane, and allyltrimethoxysilane; 3-hydroxypropyl Hydroxyl trimethoxysilane, 3-hydroxypropyltriethoxysilane and other silane coupling agents with hydroxyl groups.

When the curable adhesive composition contains the silane coupling agent (F), the content of the silane coupling agent (F) relative to the total amount of active ingredients (100% by mass) of the curable adhesive composition (including two When more than one silane coupling agent (F) is the total amount of these silane coupling agents (F), it is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, further preferably 0.08% by mass or more, and more preferably It is 5 mass % or less, More preferably, it is 3 mass % or less, More preferably, it is 1 mass % or less, More preferably, it is 0.5 mass % or less. When the content of the silane coupling agent (F) is 0.01% by mass or more in the total amount of active ingredients of the curable adhesive composition, it is easy to maintain the adhesiveness after the high temperature and high humidity test. When the content of the silane coupling agent (F) is 5% by mass or less in the total amount of active ingredients of the curable adhesive composition, it is easy to maintain the adhesiveness after the high temperature and high humidity test.

When the curable adhesive composition of the present invention contains a silane coupling agent (F), the content of the silane coupling agent (F) (when two or more silane coupling agents (F) are included is the amount of these silane coupling agents (F) ) is preferably at least 0.01 parts by mass, more preferably at least 0.05 parts by mass, further preferably at least 0.1 parts by mass, further preferably at least 0.15 parts by mass, and more preferably at least 0.15 parts by mass with respect to 100 parts by mass of component (A). It is preferably at most 3 parts by mass, more preferably at most 1 part by mass, still more preferably at most 0.7 parts by mass, still more preferably at most 0.5 parts by mass.

[(E) component: cationic polymerization initiator] The curable adhesive composition of this invention may contain a cationic polymerization initiator as (E) component. When the curing reaction (I) or the curing reaction (II) is a cationic polymerization reaction, these curing reactions can be efficiently performed by adding a cationic polymerization initiator to the curable adhesive composition. The cationic polymerization initiators can be used alone or in combination of two or more. As a cationic polymerization initiator (E), a thermal cationic polymerization initiator or a photocationic polymerization initiator is mentioned, Preferably it is a thermal cationic polymerization initiator which can polymerize by a simple process.

A thermal cationic polymerization initiator is a compound that generates a cationic species that initiates polymerization by heating. As a thermal cationic polymerization initiator, a permeic salt, a quaternary ammonium salt, a phosphonium salt, a diazonium salt, an iodonium salt, etc. are mentioned.

Examples of columium salts include: triphenylcolumbitium tetrafluoroborate, triphenylcolumbitium hexafluoroantimonate, triphenylcolumbitium hexafluoroarsenate, tris(4-methoxyphenyl)columbitium hexafluoroarsenate acid salt, diphenyl(4-phenylthiophenyl) percilium hexafluoroarsenate, etc.

Examples of quaternary ammonium salts include: tetrabutylammonium tetrafluoroborate, tetrabutylammonium hexafluorophosphate, tetrabutylammonium bisulfate, tetraethylammonium tetrafluoroborate, tetraethylammonium p-toluene Sulfonate, N,N-Dimethyl-N-benzylanilinium hexafluoroantimonate, N,N-Dimethyl-N-benzylanilinium tetrafluoroborate, N,N-Dimethyl-N-benzylanilinium tetrafluoroborate -N-benzylpyridinium hexafluoroantimonate, N,N-diethyl-N-benzyl trifluoromethanesulfonate, N,N-dimethyl-N-(4-methoxybenzyl ) pyridinium hexafluoroantimonate, N,N-diethyl-N-(4-methoxybenzyl) toluidine hexafluoroantimonate, etc.

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

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

When the curable adhesive composition contains a cationic polymerization initiator (E), the cationic polymerization initiator (E) will ) content (the total amount of these (E) components when two or more (E) components are included) is preferably at least 0.01 parts by mass, more preferably at least 0.05 parts by mass, and still more preferably at least 0.1 parts by mass, More preferably, it is 0.2 mass parts or more, and it is more preferable that it is 6 mass parts or less, More preferably, it is 5 mass parts or less, More preferably, it is 4 mass parts or less. When content of a cationic polymerization initiator is 0.01 mass part or more, it becomes easy to prevent reactivity fall. When content of a cationic polymerization initiator is 6 mass parts or less, corrosion of an adherend can be suppressed easily.

[solvent] The curable adhesive composition of the present invention may also contain a solvent and be in the form of a solution. Examples of solvents include: aromatic hydrocarbon 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; n-pentane , n-hexane, n-heptane and other aliphatic hydrocarbon solvents; cyclopentane, cyclohexane, methylcyclohexane and other alicyclic hydrocarbon solvents, etc. These solvents may be used alone or in combination of two or more. When the curable adhesive composition contains a solvent, the content of the solvent can be appropriately determined in consideration of applicability and the like.

[other ingredients] The curable adhesive composition of the present invention may contain components (other components) other than those described so far within a range that does not interfere with the effects of the present invention. Examples of other components include additives such as ultraviolet absorbers, antistatic agents, light stabilizers, antioxidants, resin stabilizers, fillers, pigments, extenders, and softeners. These other components may be used alone or in combination of two or more. When the curable adhesive composition of the present invention contains these additives, the content of the additives can be appropriately determined according to the purpose.

[Manufacturing method and usage method of curable adhesive composition] The curable adhesive composition of the present invention can be prepared by appropriately mixing and stirring the adhesive resin (A) and the crosslinking agent (B) 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, one of the adherends is coated with the curable adhesive composition of the present invention, the obtained coating film is dried, and the hardening reaction (I) proceeds to form the hardened product (I). Then, after another adherend is laminated on this cured product (I), these adherends can be bonded by further curing the coating film. As described above, when the hardening reaction (I) started to build a crosslinked structure in the coating film is stopped midway, the unreacted binder resin (A) in the hardened product (I) can be used together with The crosslinking agent (B) starts the hardening reaction (I) again, and the two adherends are bonded together. Furthermore, when the cured product (I) contains a curable component (X) that does not participate in the curing reaction (I), two adherends can be bonded by the curing reaction (II).

Examples of methods for applying the curable adhesive composition include spin coating, spray coating, bar coating, blade coating, roll coating, knife coating, die coating, and gravure coating. law etc.

As a method of drying a coating film, conventionally known drying methods, such as hot-air drying, hot-roll drying, and infrared-ray irradiation, are mentioned. The conditions for drying the coating film are, for example, 80° C. to 150° C. and 30 seconds to 5 minutes.

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

When the hardening reaction (I) is a reaction initiated by heat, the drying treatment of the coating film and the hardening reaction (I) can be combined. For example, the reactive functional group in the binder resin (A) is a carboxyl group or carboxylic anhydride group, and the crosslinking agent (B) is an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, or a metal chelate-based crosslinking agent In the case of etc., by heating the coating film to about 100° C., the drying treatment and the curing reaction (I) can be performed simultaneously, and the cured product (I) can be obtained.

Furthermore, an adhesive sheet can be produced using the curable adhesive composition of the present invention, and two adherends can be bonded using the adhesive sheet. For example, the curable adhesive composition of the present invention is coated on a peeling film, and the obtained coating film is dried, and then the hardening reaction (I) is carried out, whereby the cured product (I) (adhesive agent for adhesive sheet) can be obtained. Floor). The coating method and drying method of the curable adhesive composition can utilize the methods described above. Moreover, the preferred thickness of the coating film, or the aspects of both the drying treatment and the hardening reaction (I) of the coating film are also as described above.

[Physical properties of cured product obtained from curable adhesive composition] The curable adhesive composition of the present invention is cured by the curable adhesive composition, and the cured product with a dielectric tangent of less than 0.0050 at 23°C and a frequency of 1 GHz is preferably supplied with a dielectric tangent of 0.0030 or less. It is more preferable to provide a cured product with a dielectric tangent of 0.0020 or less, more preferably a cured product with a dielectric tangent of 0.0015 or less, and more preferably a cured product with a dielectric tangent of 0.0012 or less. Furthermore, it is more preferable to provide a cured product having a dielectric tangent of 0.0010 or less, and it is particularly preferable to provide a cured product having a dielectric tangent of 0.0008 or less. The lower limit of the dielectric tangent under this condition does not particularly exist, and is usually 0.0001 or more.

The curable adhesive composition of the present invention is preferably cured by the curable adhesive composition, and a cured product with a relative dielectric constant of 3.00 or less at 23°C and a frequency of 1 GHz is supplied, and more preferably the above-mentioned relative dielectric constant is supplied. A cured product having a dielectric constant of 2.75 or less, and more preferably a cured product having a relative dielectric constant of 2.50 or less. The lower limit of the relative permittivity under this condition does not particularly exist, and is usually 2.00 or more.

In addition, as long as the sample used for measuring the above-mentioned dielectric tangent or relative permittivity can be measured, the hardened state of the sample is not limited. For example, it may or may not have further curability. As an example of the measurement sample of a dielectric tangent and a relative dielectric constant, the sheet-shaped adhesive agent heat-processed at 100 degreeC for 2 minutes as drying process and hardening reaction (I) is mentioned.

The curable adhesive composition of the present invention provides a hardened product having the above-mentioned dielectric properties through a curing reaction, whereby the curable adhesive composition of the present invention can be preferably used as an adhesive member, protection member in an electronic component Forming materials of components, insulating components, etc.

(2) Hardened The cured product of the present invention is characterized in that the raw material composition is the curable adhesive composition of the present invention. That is, the cured product of the present invention is formed by at least the hardening reaction (I), and the viscosity of the curable adhesive composition is increased or solidified.

Examples of the cured product of the present invention include the following cured products. Cured product (α1): A hardened adhesive composition that can only undergo curing reaction (I) as a curing reaction is used as a raw material composition, and the curing reaction (I) is interrupted midway to have further curable properties. Cured product (β1): A curable adhesive composition capable of undergoing curing reaction (I) and curing reaction (II) as a raw material composition, and having at least curability derived from curing reaction (II) Hardened. Cured product (α2): A cured adhesive composition that can undergo only curing reaction (I) as a curing reaction is used as a raw material composition, and the curing reaction (I) is completed without further curing properties. Hardened product (β2): The hardening adhesive composition that can undergo hardening reaction (I) and hardening reaction (II) as the hardening reaction is used as the raw material composition, and the hardening reaction (I) and hardening reaction (II) are completed, not A hardened product with further hardening properties.

Cured product (α1) and cured product (β1) are cured products with curability. The cured product (α1) and the cured product (β1) are useful as solid adhesives. It is preferable that the hardened|cured material which has these hardening properties has thermosetting property from the point which can carry out the following process more efficiently. Furthermore, it is preferable that the hardened|cured material which has this thermosetting property has a sheet shape. Since the cured product having thermosetting properties has a sheet-like shape, two adherends can be efficiently bonded by hot pressing or the like.

Thermosetting cured products having a sheet-like shape (hereinafter sometimes referred to as "thermosetting sheet adhesive") may also have protective sheets on one or both sides for protection during storage or transportation. .

The thermosetting sheet adhesive of the present invention uses the curable adhesive composition of the present invention as a raw material composition. Therefore, the cured product obtained by curing the thermosetting sheet-like adhesive of the present invention has excellent low dielectric properties. Therefore, the thermosetting sheet adhesive of the present invention can be suitably used as a sheet adhesive for electronic components or a sheet adhesive for cover films.

The sheet adhesive for electronic components is a sheet adhesive used for the bonding of various parts in electronic components, or the protection or insulation of circuits in electronic components. Examples of electronic components include communication devices such as smartphones and tablet terminals.

The sheet adhesive for the cover film is a sheet adhesive used in the manufacture of the cover film. The cover film is, for example, a laminated film used to protect the surface of a flexible printed wiring board, and usually has an insulating resin layer and an adhesive layer. The thermosetting sheet-like adhesive of the present invention is useful as the adhesive layer.

Cured product (α2) and cured product (β2) are cured products that do not have curability. Examples of the cured product (α2) and the cured product (β2) include: a state in which the cured product (α1) or the cured product (β1) functions as an adhesive and is completely cured; or the cured adhesive composition of the present invention is completely cured. Formed body obtained by hardening. [Example]

Hereinafter, examples are given and the present invention will be described in more detail. However, the present invention is by no means limited to the following examples.

[Compounds used in Examples or Comparative Examples] Binder resin (A1): maleic anhydride modified α-olefin polymer [manufactured by Mitsui Chemicals Co., Ltd., trade name: Unistole 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, [manufactured by Mitsui Chemicals Co., Ltd. , trade name: Stabio D-370N, molecular weight: 462] Epoxy-based crosslinking agent (B2): 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, [manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name: TETRAD-C, Molecular weight: 362] ・Metal chelate crosslinking agent (B3): aluminum tris(acetylacetonate), [manufactured by Soken Chemical Co., Ltd., trade name: M-5A, molecular weight: 324] · Hardening compound (C1): a compound having an isocyanurate skeleton and two allyl groups [manufactured by Shikoku Chemical Industry Co., Ltd., trade name: L-DAIC] · Polyphenylene ether resin (D1): vinylbenzyl modified polyphenylene ether [manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name: OPE-2St 1200, number average molecular weight: 1200] Cationic polymerization initiator (E1): Thermal cationic polymerization initiator [manufactured by Sanshin Chemical Industry Co., Ltd., trade name: San-aid SI-B3] · Silane coupling agent (F1): 8-glycidyloxyoctyltrimethoxysilane [manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM4803]

[Example 1] 100 parts by mass of binder resin (A1), 0.5 parts by mass of isocyanate crosslinking agent (B1), 12.5 parts by mass of hardening compound (C1), 25 parts by mass of polyphenylene ether resin (D1), cationic polymerization initiator (E1 ) and 0.12 parts by mass of the silane coupling agent (F1) were dissolved in toluene to prepare a curable adhesive composition. On the release-treated surface of the release sheet (the first release sheet, manufactured by Lintec Co., Ltd., trade name: SP-PET752150), the obtained curable adhesive composition was applied to form a coating film, and the obtained The coating film was dried at 100°C for 2 minutes to form an adhesive layer with a thickness of 15 μm. On the exposed surface of the adhesive layer, the release-treated surface of another release sheet (second release sheet, manufactured by Lintec Co., Ltd., trade name: SP-PET381130) was attached to obtain an adhesive sheet.

[Example 2 to Example 5, Comparative Example 1] Except having changed the compounding quantity or kind of a component into Table 1, the curable adhesive composition was prepared similarly to Example 1, and the adhesive sheet was obtained.

[Evaluation of exudation of ingredients] Peel off one piece of the release sheet of the adhesive sheet obtained in the examples or comparative examples, and use a thermal laminator to bond the exposed adhesive layer with a polyimide film (Toray-DuPont) at 100°C. Manufactured, Kapton, thickness 25 μm) crimping to obtain a laminate with a structure of release sheet/adhesive layer/polyimide film. Then, the release sheet of the laminate was peeled off, and the exposed adhesive layer was bonded to the copper foil at 100°C using a thermal laminator to obtain a laminate with a structure of copper foil/adhesive layer/polyimide film body. Furthermore, since the copper foil has a wider area than the other two layers, when the adhesive component of the adhesive layer seeps out, it will adhere to the copper foil. This laminate was subjected to hot press treatment at 171° C. and 1.38 MPa for 20 minutes. After cooling, the length of the adhesive component that oozes out the most from the adhesive layer (cured product) in plan view was measured using a digital microscope [the length of the portion indicated by X in FIG. 1 (μm)]. The results are shown in Table 1. In addition, FIG. 1 is a schematic plan view of the laminated body used for evaluating the exudation of an adhesive agent component in an Example, and seeing it from above after hot-pressing. As shown in Fig. 1, due to the hot pressing process, a part of the adhesive layer (cured product) sandwiched between the copper foil 1 and the polyimide film 3 of the above-mentioned laminate oozes out, and the oozing adhesive component 2 adheres to it. on copper foil 1. At this time, as shown in FIG. 1 , the maximum value X of the distance X between the adhesive agent component 2 and the polyimide film 3 that exuded in plan view was set as "the exudation length of the adhesive agent component", and described in Table 1.

[relative permittivity, dielectric tangent] After the adhesive layer of the adhesive sheet obtained in the example or comparative example is laminated to a thickness of about 1mm, it is welded at 100°C using a heat laminator to obtain a release sheet/thickness of about 1mm. A laminate with a structure of adhesive layer/release sheet. The release sheets on both sides of the laminate were peeled off to obtain a measurement sample. The relative permittivity and dielectric tangent at 23° C. and 1 GHz were measured for the obtained measurement sample using an RF (radio frequency) impedance-material analyzer (manufactured by Keysight Technologies, E4991A). Furthermore, 1 GHz is used as an example of the high-frequency region this time. The results are shown in Table 1.

[Table 1] Composition of Adhesive Composition Mixing ratio (parts by mass) The content (mass %) of each component relative to the total amount of active ingredients (100 mass %) of the adhesive composition Exudation length of adhesive components [μm] Relative permittivity Dielectric tangent Binder resin (A1) Isocyanate-based crosslinking agent (B1) Epoxy crosslinking agent (B2) Metal chelate crosslinking agent (B3) Hardening compound (C1) Polyphenylene ether resin (D1) Cationic polymerization initiator (E1) Silane coupling agent (F1) (A1) (B1) (B2) (B3) (C1) (D1) (E1) (F1) Example 1 100 0.5 - - 12.5 25 0.12 0.2 72.3 0.36 9.0 18.1 0.087 0.145 98 2.36 0.0008 Example 2 100 1.0 - - 12.5 25 0.12 0.2 72.0 0.72 9.0 18.0 0.086 0.144 14 2.37 0.0009 Example 3 100 1.5 - - 12.5 25 0.12 0.2 71.8 1.08 9.0 17.9 0.086 0.144 14 2.38 0.0010 Example 4 100 - 0.5 - 12.5 25 0.12 0.2 72.3 0.36 9.0 18.1 0.087 0.145 16 2.38 0.0011 Example 5 100 - - 0.5 12.5 25 0.12 0.2 72.3 0.36 9.0 18.1 0.087 0.145 95 2.38 0.0012 Comparative example 1 100 - - - 12.5 25 0.12 0.2 72.6 0.00 9.1 18.1 0.087 0.145 574 2.39 0.0010

The cured products of the curable adhesive compositions obtained in Examples 1 to 5 and Comparative Example 1 all have excellent low dielectric properties. However, when the laminate was manufactured using the curable adhesive composition of Comparative Example 1, the adhesive component oozes out largely when hot pressing is performed under the conditions of 171° C., 1.38 MPa, and 20 minutes. On the other hand, since the curable adhesive compositions of Examples 1 to 5 contain a crosslinking agent (B), drying of the coating film of the curable adhesive composition at 100°C, or drying at 100°C Thermal lamination treatment to form a cross-linked structure in the coating film. Therefore, even if hot pressing is carried out under the conditions of 171°C, 1.38MPa, and 20 minutes, the exudation of adhesive components is still suppressed.

1: copper foil 2: Exuding adhesive ingredients 3: Polyimide film

[ Fig. 1 ] is a schematic diagram (plan view) of a part of a laminate used for evaluation of exudation of adhesive components. [ Fig. 2 ] is a schematic view showing a section A-A of Fig. 1 .

Claims (15)

A curable adhesive composition comprising the following components (A) and (B), wherein the content of component (B) is 0.1% by mass or more relative to the total amount of active ingredients in the curable adhesive composition; In addition, the curable adhesive composition is cured to provide a cured product with a dielectric tangent of less than 0.0050 at 23°C and a frequency of 1 GHz; (A) Component: a binder resin with reactive functional groups; (B) component: the crosslinking agent whose molecular weight is 1000 or less which can react with said (A) component. The curable adhesive composition as described in claim 1, wherein the aforementioned component (A) is a polyolefin resin. The curable adhesive composition as described in claim 1 or 2, wherein the aforementioned component (A) is an acid-modified resin. The curable adhesive composition according to any one of claims 1 to 3, wherein the aforementioned component (B) is a compound having an isocyanurate skeleton. The curable adhesive composition according to any one of claims 1 to 4, wherein the aforementioned component (B) is a compound having two or more isocyanate groups. The curable adhesive composition described in any one of Claims 1 to 5 further contains the following (C) component; Component (C): A non-aromatic hardening compound that is liquid at 25°C. The curable adhesive composition as described in claim 6, wherein the aforementioned component (C) is a compound having two or more hydrocarbon groups having double bonds at the ends. The curable adhesive composition described in any one of Claims 1 to 7 further contains the following (D) component; (D) Component: polyphenylene ether resin with reactive functional groups. The curable adhesive composition described in any one of Claims 1 to 8 further contains the following (E) component; (E) component: a cationic polymerization initiator. The curable adhesive composition according to any one of Claims 1 to 9, wherein the curable adhesive composition is cured at 23° C. and at a frequency of 1 GHz with a dielectric constant of 3.00 or less. things. A cured product obtained by curing the curable adhesive composition described in any one of claims 1 to 10. The cured product according to claim 11, wherein the cured product has thermosetting properties. The cured product as described in claim 11 or 12, wherein the cured product has a sheet shape. The cured product as described in any one of Claims 11 to 13, wherein the cured product is a sheet-like adhesive for electronic components. The cured product as described in any one of claims 11 to 13, wherein the cured product is a sheet-like adhesive for a cover film.

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