TW202334364A - Adhesive composition and laminate with adhesive layer - Google Patents

Abstract

Provided is an epoxy-based adhesive composition excelling in re-dispersibility of a filler, having a re-peelable property in a B-stage state, and capable of forming an adhesive layer exhibiting excellent adhesive strength after a curing reaction. Also provided is a laminate with an adhesive layer in which the adhesive composition is used.

Description

Adhesive composition and laminate with adhesive layer attached

The present invention relates to an adhesive composition and a laminate with an adhesive layer attached thereto.

Flexible printed circuits (FPC) are flexible printed circuit boards that can still achieve three-dimensional and high-density installation in a limited space. As electronic machines become smaller and lighter, FPC-related products have become diversified and their demand has gradually increased. As such related products, there are flexible copper-clad laminated boards in which copper foil is bonded to a polyimide film, flexible printed wiring boards in which an electronic circuit is formed on a flexible copper-clad laminated board, and flexible printed wiring boards and reinforcing boards bonded to each other. A composite flexible printed wiring board with a reinforcing plate, a multilayer board made by overlapping and joining flexible copper-clad laminates or flexible printed wiring boards, and a flexible flat cable with copper wiring bonded to a base film (hereinafter also referred to as "FFC"), etc., for example, when manufacturing a flexible copper-clad laminate, an adhesive is generally used in order to bond a polyimide film and a copper foil.

In addition, when manufacturing FPC, in order to protect the wiring part, a film called a "coverlay film" is usually used. The cover film includes an insulating resin layer and an adhesive layer formed on its surface. When forming the insulating resin layer, polyimide resin compositions are widely used. Then, for example, by using hot pressing or the like, a cover film is attached to the surface having the wiring portion through the adhesive layer, thereby manufacturing the FPC.

As an adhesive used for such FPC-related products, an epoxy-based adhesive composition containing an epoxy resin and a highly reactive thermoplastic resin has been proposed (for example, Patent Document 1).

The adhesive composition is usually coated on a desired base film to obtain a laminate with an adhesive layer, and the laminate is bonded to a target adherend via the adhesive layer. If positional deviation occurs during the bonding, the laminated body together with the adhesive layer must be peeled off from the adhered body, the position must be adjusted again, and the laminated body and the adhered body must be bonded together through the adhesive layer. Therefore, the adhesive layer is required to have re-peelability so that it can be easily peeled off even when bonded in the so-called B-stage state. In order to achieve this re-peelability, it is proposed to blend a filler into the adhesive composition. For example, Patent Document 2 describes improving anti-blocking properties by blending a specific amount of hydrophobic silica with an average particle diameter of 16 nm into the adhesive composition. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent No. 6718148 [Patent Document 2] Japanese Patent Application Publication No. 2018-78337

[Problem to be solved by the invention]

The present inventors studied an epoxy-based adhesive composition that can form an adhesive layer that has re-peelability in the B-stage state and exhibits excellent adhesion after the hardening reaction. As a result, it was found that when a filler is added to an epoxy adhesive composition, the redispersibility of the filler in the adhesive layer formed using the adhesive composition is poor. If the adhesive composition is stored with filler mixed in, the filler will settle over time. During use, the settled filler needs to be redispersed to make it uniform. However, if the redispersibility is insufficient, redispersion will take a long time, or a special mixer will be required, or the improvement of uniformity after redispersion will be limited. In other words, improvement in redispersibility is an important factor in improving work efficiency or splicing reliability.

The present invention was accomplished in view of the above situation, and its object is to provide an epoxy-based adhesive composition which has excellent redispersibility of the filler, and when used for layer formation, can form an epoxy adhesive composition that has excellent re-peelability and exhibits excellent performance after the hardening reaction. The adhesive layer has strong adhesion. Furthermore, an object of the present invention is to provide a laminate of an adhesive layer using the adhesive composition. [Technical means to solve the problem]

The above-mentioned problems of the present inventors were solved by the following means. [1] An adhesive composition containing a graft-modified thermoplastic resin (A) using an α,β-unsaturated carboxylic acid compound, an epoxy resin (B), and a filler liquid crystal polymer (C), and In the total solid content, the content of the above-mentioned graft-modified thermoplastic resin (A) is 30% by mass or more, The content of the epoxy resin (B) is 1 to 20 parts by mass relative to 100 parts by mass of the graft-modified thermoplastic resin (A). [2] The adhesive composition according to [1], wherein the proportion of the structural part derived from the α,β-unsaturated carboxylic acid compound in the graft-modified thermoplastic resin (A) is 0.1 to 20% by mass. . [3] The adhesive composition according to [1] or [2], wherein the thermoplastic resin constituting the graft-modified thermoplastic resin (A) is an ethylene-propylene copolymer, a propylene-butene copolymer, an ethylene-propylene- At least one of butene copolymer and styrenic elastomer. [4] The adhesive composition according to any one of [1] to [3], wherein the weight average molecular weight of the graft-modified thermoplastic resin (A) is 30,000 to 250,000. [5] The adhesive composition according to any one of [1] to [4], wherein the acid value of the graft-modified thermoplastic resin (A) is 0.1 to 50 mgKOH/g. [6] The adhesive composition according to any one of [1] to [5], wherein the epoxy resin (B) is a polyfunctional epoxy resin having an alicyclic skeleton. [7] A laminate with an adhesive layer attached, which has: An adhesive layer formed from the adhesive composition described in any one of [1] to [6], and A base film in contact with at least one side of the adhesive layer.

In the present invention, the numerical range represented by "～" means a range including the numerical values described before and after "～" as the lower limit and upper limit. For example, when it is described as "A～B", the numerical range is "A or more and B or less".

In the present invention and this specification, the "adhesive layer" means a state before hardening, a state in the B stage (that is, a semi-hardened state in which a part of the adhesive composition begins to harden, and the adhesive composition is further hardened by heating or the like). The layer is in a state where the curing reaction is in progress), or in a state where the cross-linked structure has been fully formed. In addition, the "cured product" means a state in which the adhesive composition is subjected to a curing reaction to fully form a cross-linked structure. In the present invention, the term "resin" is used in a broader sense than usual. That is, in the present invention, when "resin" is mentioned, its meaning includes elastomers in addition to ordinary resins unless otherwise specified. [Effects of the invention]

The adhesive composition of the present invention is an epoxy-based adhesive composition, which has excellent filler redispersibility. The adhesive layer formed using the composition has excellent re-peelability and exhibits excellent adhesive strength after the hardening reaction. Furthermore, the laminate with an adhesive layer attached to the present invention has excellent removability of the adhesive layer and exhibits excellent adhesion after the curing reaction.

Preferred embodiments of the adhesive composition of the present invention will be described below, but the present invention is not limited to the following embodiments unless otherwise specified in the present invention.

[Adhesive composition] The adhesive composition of the present invention contains a graft-modified thermoplastic resin (A) using an α,β-unsaturated carboxylic acid compound, an epoxy resin (B), and a filler liquid crystal polymer (C). In the total solid content of the adhesive composition of the present invention (components other than the solvent), the content of the graft-modified thermoplastic resin (A) is 30 mass % or more. Moreover, the content of the above-mentioned epoxy resin (B) is 1 to 20 parts by mass relative to 100 parts by mass of the content of the above-mentioned graft-modified thermoplastic resin (A). Each component constituting the adhesive composition of the present invention will be described in order.

＜Graft-modified thermoplastic resin (A)＞ The adhesive composition of the present invention contains one or more than two of the above-mentioned graft-modified thermoplastic resins (A). The graft-modified thermoplastic resin (A) contained in the adhesive composition of the present invention is a resin obtained by subjecting a thermoplastic resin to a graft polymerization reaction using an α,β-unsaturated carboxylic acid compound as a modifier. . The method of graft modification (graft polymerization) is known per se and can be carried out according to common practice. Graft polymerization of an α,β-unsaturated carboxylic acid compound and a thermoplastic resin is usually carried out through a free radical reaction using a radical initiator (radical generator). For example, a solution method in which a thermoplastic resin is heated and dissolved in a solvent such as toluene, and an α,β-unsaturated carboxylic acid compound and a radical initiator are added, using a Bambry mixer, a kneader, an extruder, etc. The target graft-modified thermoplastic resin (A) can be obtained by the melting method of melting and kneading thermoplastic resin, α,β-unsaturated carboxylic acid compound and free radical initiator. The thermoplastic resin, α,β-unsaturated carboxylic acid compound and free radical initiator can be added to the reaction system of the graft polymerization reaction at once, or they can be added successively. In addition, modification aids for improving the grafting efficiency of α,β-unsaturated carboxylic acid compounds, stabilizers for adjusting resin stability, etc. can be further used.

The thermoplastic resin constituting the graft-modified thermoplastic resin (A) (the thermoplastic resin before graft modification, in the present invention, when it is only called "thermoplastic resin" means the thermoplastic resin before graft modification) only It is not particularly limited as long as it is a thermoplastic resin. Examples of the thermoplastic resin include polyolefin resin, polystyrene resin, polyester resin, acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-styrene copolymer (AS resin), Polyamide resin, styrene elastomer, etc., one or more of these may be used. Among them, at least one kind among polyolefin resin, polystyrene resin, and styrenic elastomer is preferable, and at least one kind among polyolefin resin and styrene elastomer is more preferable.

The polyolefin resin is preferably a homopolymer of an olefin having 2 to 20 carbon atoms such as ethylene, propylene, butene, pentene, hexene, heptene, octene, or 4-methyl-1-pentene, or copolymer. Among them, the polyolefin resin is particularly preferably a homopolymer or copolymer of an olefin having 2 to 6 carbon atoms. The content ratio of each structural unit in the polyolefin resin is not particularly limited. Taking into consideration the adhesion to a difficult-to-adhere adherend, the polyolefin resin is preferably at least one of an ethylene-propylene copolymer, a propylene-butylene copolymer, and an ethylene-propylene-butylene copolymer. The polyolefin resin preferably contains propylene units. In this case, the polyolefin resin may be a homopolymer composed of propylene units or a copolymer including propylene units. When the polyolefin resin contains a propylene unit, the content ratio of the propylene unit in all structural units is preferably 50 mol% or more, more preferably 60 mol% or more. When the polyolefin resin is a copolymer containing a propylene unit as a structural unit, the content ratio of the propylene unit in all structural units is preferably 50 to 98 mol%, more preferably 60 to 98 mol%. By setting the content ratio of the propylene unit in the copolymer within the above range, further flexibility can be imparted to the joint portion after joining two members.

The above-mentioned styrenic elastic system is a copolymer mainly composed of a block copolymer structure or a random copolymer structure of a conjugated diene compound and a styrene compound, or a hydrogenated product thereof. Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, and the like. Examples of the styrene compound include styrene, tert-butylstyrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylstyrene, N , N-diethyl p-aminoethylstyrene, vinyl toluene, p-tert-butylstyrene, etc. Specific examples of the styrenic elastomer include: styrene-butadiene block copolymer, styrene-ethylene-propylene block copolymer, styrene-butadiene-styrene block copolymer, Styrene-isoprene-styrene block copolymer, styrene-ethylene butylene-styrene block copolymer and styrene-ethylene propylene-styrene block copolymer, one of these or Two or more types. Among them, at least one of styrene-ethylene butylene-styrene block copolymer and styrene-ethylene propylene-styrene block copolymer is preferred.

The molecular weight of the thermoplastic resin is not particularly limited. For example, the weight average molecular weight (Mw) is preferably 30,000 to 250,000, more preferably 50,000 to 200,000. In the present invention, the weight average molecular weight can be determined according to the method described in the following examples.

The above-mentioned α,β-unsaturated carboxylic acid compound means including α,β-unsaturated carboxylic acid and compounds derived from α,β-unsaturated carboxylic acid. Specific examples of α,β-unsaturated carboxylic acid compounds include maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, and aconitic acid. Norbornene dicarboxylic acid, its anhydrides, halides, amides, imines, esters, etc. From the viewpoint of realizing higher adhesion, the α,β-unsaturated carboxylic acid compound is preferably at least one of itaconic anhydride, maleic anhydride, aconitic anhydride and citraconic anhydride, and more preferably At least one of itaconic anhydride and maleic anhydride. In the graft modification of thermoplastic resin, one or more than two kinds of α,β-unsaturated carboxylic acid compounds can be used in the reaction system of graft polymerization.

In the present invention, in the graft modification of the above-mentioned thermoplastic resin, as the modifier, in addition to α,β-unsaturated carboxylic acid compounds, one or two or more other modifiers can also be used. Examples of other modifiers include (meth)acrylate compounds, (meth)acrylic acid compounds, aromatic vinyl compounds, cycloalkyl vinyl ether compounds, and the like. These other compounds may be used individually or in combination of two or more types.

Examples of the (meth)acrylate compound include: (meth)acrylate methyl ester, (meth)ethyl acrylate, (meth)propyl acrylate, (meth)butyl acrylate, (meth)acrylate Amyl acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, ten (meth)acrylate Tryster, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, hydroxyethyl (meth)acrylate, epoxypropyl (meth)acrylate, isopropyl acrylate Cyanate group (meth)acrylic acid, etc. Examples of the aromatic vinyl compound include styrene, o-methylstyrene, p-methylstyrene, α-methylstyrene, and the like. These compounds may be used alone, or two or more types may be used in combination. When a modifier other than an α,β-unsaturated carboxylic acid compound is used in combination, among the above, it is preferable to use octyl (meth)acrylate, lauryl (meth)acrylate, and (meth)acrylate. At least one of tridecyl acrylate and stearyl (meth)acrylate.

Regarding the graft-modified thermoplastic resin (A), the proportion of the structural part derived from the α,β-unsaturated carboxylic acid compound (called "graft part I") in the graft-modified thermoplastic resin (A) is relatively Preferably, it is 0.1-20 mass %, More preferably, it is 0.2-18 mass %. Moreover, this ratio may be 0.2-15 mass %, and may be 0.3-10 mass %. By controlling the amount of the graft portion I as described above, the solubility in a solvent can be further improved, and the adhesion to an adherend made of metal, resin, etc. can be further improved.

The ratio of the above-mentioned graft portion I in the graft-modified thermoplastic resin (A) can be determined by an alkali quantitative method. In addition, when the α,β-unsaturated carboxylic acid compound does not have an acid group (for example, in the case of an amide imine), it can also be determined by Fourier transform infrared spectroscopy, for example.

When the graft-modified thermoplastic resin (A) contains a structural part derived from a (meth)acrylate compound in the graft part (referred to as "graft part II"), the graft part II is The proportion of the thermoplastic resin (A) is preferably 30 mass% or less, more preferably 25 mass% or less. Moreover, this ratio may be 15 mass % or less, 10 mass % or less, and further may be 5 mass % or less. The lower limit of the ratio is not particularly limited, but for example, it is preferably 0.1 mass% or more, and more preferably 0.3 mass% or more. By controlling the amount of the graft part II as described above, the solubility in the solvent can be further improved. The adhesive composition of the present invention contains a resin or elasticity other than the graft-modified thermoplastic resin (A). In the case of a body, the compatibility with the body can be further improved, and the adhesion to the body to be adhered can also be further improved.

The proportion of the graft portion II in the graft-modified thermoplastic resin (A) can be determined, for example, by Fourier transform infrared spectroscopy.

The free radical initiator used in the graft polymerization reaction to obtain the graft-modified thermoplastic resin (A) is not particularly limited. For example, organic peroxides can be used. Examples of organic peroxides include benzyl peroxide, dicumyl peroxide, lauryl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (Third-butylperoxy)hexane, cumene hydroperoxide, etc. One or more than two free radical initiators may be used in the above graft polymerization reaction.

Examples of the above-mentioned modifying aid include divinylbenzene, hexadiene, dicyclopentadiene, and the like. Examples of the stabilizer include hydroquinone, benzoquinone, nitrosophenylhydroxy compounds, and the like, and one or two or more of these may be used.

The weight average molecular weight (Mw) of the graft-modified thermoplastic resin (A) is not particularly limited, but is preferably 30,000 to 250,000, more preferably 50,000 to 200,000. By controlling the molecular weight within this range, the solubility in solvents can be fully ensured, the initial adhesion to the adherend can be further improved, and sufficient solvent resistance can be produced after the hardening reaction. In the present invention, the weight average molecular weight can be determined according to the method described in the following examples.

The acid value of the graft-modified thermoplastic resin (A) is preferably 0.1 to 50 mgKOH/g, more preferably 0.5 to 40 mgKOH/g, and further preferably 1.0 to 30 mgKOH/g. By controlling the acid value within this range, sufficient hardening reactivity can be expressed in the adhesive composition. The acid value can be determined according to the method described in the section [Examples] below.

The content of the graft-modified thermoplastic resin (A) is 30 mass % or more, preferably 30 to 97 mass %, more preferably 30 to 95 mass % in the total solid content of the adhesive composition, and further Preferably, it is 40-90 mass %, especially preferably 50-88 mass %.

＜Epoxy resin (B)＞ The adhesive composition of the present invention contains one or more than two of the above-mentioned epoxy resins (B). Epoxy resin (B) is a component that reacts with reactive groups such as carboxyl groups in the graft-modified thermoplastic resin (A) to improve the adhesion to the adherend and further improves the heat resistance of the cured adhesive material.

The epoxy resin (B) is not particularly limited, and any epoxy resin that can be used in this adhesive composition can be widely used. The epoxy resin (B) usually has two or more (preferably 2 to 6, more preferably 2 to 4) epoxy groups per molecule when crosslinking properties, heat resistance, etc. are considered. Multifunctional epoxy resin. Examples of the epoxy resin (B) include bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, or hydrogenated products thereof; diepoxypropyl phthalate, isophthalate Diglycidyl formate, Diglycidyl terephthalate, Diglycidyl p-hydroxybenzoate, Diglycidyl tetrahydrophthalate, Diglycidyl succinate, Hexyl Epoxypropyl ester-based epoxy resins such as dialpoxypropyl diacid, dialpoxypropyl sebacate, and trimepoxypropyl 1,2,4-benzenetricarboxylate (epoxypropyl ester Compounds); Ethylene glycol diepoxypropyl ether, propylene glycol diepoxypropyl ether, 1,4-butanediol diepoxypropyl ether, 1,6-hexanediol diepoxypropyl ether, triglyceride Hydroxymethylpropane triglycidyl ether, neopentyl tetraglycidyl ether, tetraphenylglycidyl ether ethane, triphenylglycidyl ether ethane, sorbitol polyepoxy Glycidyl ethers such as propyl ether and polyglycerol polyglycidyl ether are epoxy resins (glycidyl ether compounds); tripoxypropyl isocyanurate, tetraepoxypropyldiamine diamine Glycidylamine-based epoxy resins (glycidylamine compounds) such as benzene methane; linear aliphatic epoxy resins such as epoxidized polybutadiene and epoxidized soybean oil, etc. Furthermore, novolak-type epoxy resins such as phenol novolac epoxy resin, o-cresol novolac epoxy resin, and bisphenol A novolac epoxy resin can be used.

Furthermore, as examples of the epoxy resin (B), brominated bisphenol A type epoxy resin, phosphorus-containing epoxy resin, dicyclopentadiene skeleton-containing epoxy resin, naphthalene skeleton-containing epoxy resin can be used. , anthracene-type epoxy resin, tert-butylcatechol-type epoxy resin, triphenylmethane-type epoxy resin, tetraphenylethane-type epoxy resin, biphenyl-type epoxy resin, bisphenol S-type epoxy resin wait. The epoxy resin (B) is preferably a multifunctional epoxy resin having an alicyclic skeleton, and more preferably a multifunctional epoxy resin having a dicyclopentadiene skeleton.

In the adhesive composition of the present invention, the content of epoxy resin (B) is 1 to 20 parts by mass, preferably 2 to 18 parts by mass, and more preferably 100 parts by mass of the graft-modified thermoplastic resin (A). It is 2-17 parts by mass, and it is also preferable that it is 3-15 parts by mass. By controlling the content of the epoxy resin (B) within the above range, sufficient adhesiveness and heat resistance can be exhibited, and peel adhesion strength or electrical characteristics can also be fully exhibited.

＜Filled liquid crystal polymer (C)＞ The adhesive composition of the present invention contains one or more than two of the above-mentioned filler liquid crystal polymers (C). The filler liquid crystal polymer (C) has excellent re-dispersibility even after settling during storage of the adhesive composition, and can effectively improve the re-peelability of the adhesive layer formed by the adhesive composition, and Sufficient adhesion can also be achieved after the hardening reaction. That is, compared with the case where the filler-like liquid crystal polymer (C) is not contained, the working efficiency and the bonding reliability are improved. Liquid crystal polymers themselves are known, and as long as ordinary liquid crystal polymers are processed into filler (microparticle) form, they can be used as the filler-form liquid crystal polymer (C) in the present invention without particular limitations.

As a filler liquid crystal polymer that can be used in the present invention, for example, a filler composed of a liquid crystal polymer having a structural unit derived from p-hydroxybenzoic acid and a structural unit derived from 6-hydroxy-2-naphthoic acid can be used. The liquid crystal polymer further preferably has at least one of a structural unit derived from an aromatic diol compound and a structural unit derived from an aromatic dicarboxylic acid, and more preferably has a structural unit derived from an aromatic diol compound and a structural unit derived from an aromatic diol compound. Both structural units of dicarboxylic acid. The liquid crystal polymer preferably has 10 to 40 mol%, more preferably 15 to 35 mol% of structural units derived from p-hydroxybenzoic acid, and preferably 60 to 90 mol%, more preferably 65 to 65 mol%. 85 mol% of structural units derived from 6-hydroxy-2-naphthoic acid. In a form in which the liquid crystal polymer further contains an aromatic diol compound, the content is preferably 1 to 20 mol%, more preferably 1 to 15 mol%. Moreover, in the form where the liquid crystal polymer further contains an aromatic dicarboxylic acid, the content is preferably 1 to 20 mol%, more preferably 1 to 15 mol%.

In the adhesive composition of the present invention, the content of the filler liquid crystal polymer (C) is higher than that of the graft-modified thermoplastic resin from the viewpoint of improving the redispersibility and repeelability of the adhesive composition. (A) 100 parts by mass is preferably 1 to 250 parts by mass, more preferably 1 to 200 parts by mass, further preferably 5 to 100 parts by mass, and still more preferably 5 to 80 parts by mass.

The filler liquid crystal polymer (C) mostly has a low dielectric constant or dielectric loss tangent, and has the advantage of being able to reduce the dielectric constant or dielectric loss tangent of the hardened material formed from the adhesive composition of the present invention. . Furthermore, the dielectric constant or dielectric loss tangent of the filler liquid crystal polymer (C) can be measured by the split column dielectric resonator method (SPDR method) using Network analyzer N5247A of Agilent, etc. Specifically, the filler-like liquid crystal polymer (C) was heated and melted under the conditions of melting point to melting point + 30°C and injection molded to produce a flat test piece of 30 mm × 30 mm × 0.4 mm. Secondly, Keysight Technologies' Network analyzer N5247A was used to measure the dielectric loss tangent and dielectric constant of the test piece using the split column dielectric resonator method (SPDR method) at a frequency of 10 GHz.

The average particle diameter (d50) of the filler liquid crystal polymer (C) is preferably 0.1 to 50 μm, more preferably 0.1, from the viewpoint of further improving the redispersibility and repeelability of the adhesive composition. ~20 μm, and more preferably 1 ~ 10 μm. The average particle size (d50) refers to the so-called median particle size, which is the particle size distribution measured by the laser diffraction/scattering method. In the cumulative distribution, the total volume of the particles is set to 100% and the particle size accumulates to 50%. .

The water absorption rate of the filler liquid crystal polymer (C) is preferably 0.1% or less, more preferably 0.05% or less, further preferably 0.03% or less, particularly preferably 0.02% or less. The lower limit of the water absorption rate is not particularly limited, but is usually 0.002% or more, and preferably 0.005% or more. Therefore, the water absorption rate of the filler liquid crystal polymer (C) is preferably 0.002 to 0.05%, more preferably 0.005 to 0.03%, and still more preferably 0.01 to 0.02%. Furthermore, regarding the water absorption rate of the filled liquid crystal polymer (C), the filled liquid crystal polymer (C) can be heated and melted, and then injection molded, press molded, or film formed to obtain a molded product. According to ASTM D570 The test method is to immerse the molded product in water at room temperature (23°C) for 24 hours, measure the weight of the molded product before immersion and the weight of the molded product after 24 hours of immersion, and calculate according to the following formula (2). Water absorption rate (%) = [(weight of the molded product after 24 hours of immersion - weight of the molded product before immersion)/weight of the test piece before immersion] × 100... (2)

The melting point of the filler liquid crystal polymer (C) is preferably 280 to 350°C, more preferably 300 to 350°C, and further preferably 305 to 335°C. By setting the melting point of the filler liquid crystal polymer (C) within the above numerical range, sufficient heat resistance can be imparted to the cured product. Furthermore, the melting point of the filler liquid crystal polymer (C) can be determined according to the test methods of ISO11357 and ASTM D3418. Specifically, the polymer is heated from room temperature to 360-380°C at a heating rate of 10°C/min to completely melt it, then cooled to 30°C at a rate of 10°C/min, and then heated to 360°C at a rate of 10°C/min. 380°C, and the peak of the endothermic wave peak obtained at this time is regarded as the melting point.

The glass transition temperature of the filler liquid crystal polymer (C) is preferably 120 to 150°C. By setting the glass transition temperature of the filler liquid crystal polymer (C) within the above numerical range, sufficient heat resistance can be imparted to the cured product. In addition, in this specification, the glass transition temperature of the filler liquid crystal polymer (C) can be determined in accordance with JIS K7244 using a dynamic viscoelasticity measuring device (Hitachi High-Tech Science Co., Ltd., trade name: DMA7100), etc. It is calculated from the peak temperature of tan δ obtained by dynamic viscoelasticity measurement.

After the adhesive layer formed using the adhesive composition of the present invention adheres to the adherend and undergoes a hardening reaction, the bonding strength with the adherend is preferably 0.7 N/mm or more, more preferably 1.0 N/mm or more. The upper limit of the above-mentioned bonding strength is not particularly limited, but is usually 2.0 N/mm or less. The above-mentioned bonding strength can be measured by the following method. Furthermore, in the present invention, the hardening reaction conditions of the adhesive layer for measuring the bonding strength are set to 180° C. for 30 minutes. In addition, the hardening reaction conditions of the adhesive layer used to determine the various characteristics or physical properties described in this specification other than the bonding strength are also set to 180° C. for 30 minutes.

Prepare a release PET film with a thickness of 38 μm, and roll-coat the liquid adhesive composition described in Table 1 on one surface. Next, the film with the adhesive layer was allowed to stand in an oven and dried at 90° C. for 3 minutes to form a B-stage adhesive layer (thickness: 25 μm). Next, the adhesive layer of the film with an adhesive layer was overlapped on the polyimide surface of the flexible substrate material (manufactured by Panasonic Co., Ltd., product name "FELIOS R-F770") at a temperature of 120°C, a pressure of 0.4 MPa, and Lamination is carried out at a speed of 0.5 m/min. Next, peel off the release PET, overlap the adhesive layer and the rolled copper foil (thickness 35 μm), and perform lamination at a temperature of 120°C, a pressure of 0.4 MPa, and a speed of 0.5 m/min. Thereafter, the laminate (flexible substrate material/adhesive layer/copper foil) was heat-pressed and bonded for 30 minutes at a temperature of 180°C and a pressure of 3 MPa. After heating and crimping, cut out 10 mm × 100 mm from the laminate to obtain a bonded test piece. In order to evaluate the adhesion, according to JIS C6481 "Test method for copper-clad laminates for printed wiring boards", the flexible substrate material of each adhered test piece was peeled off from the copper foil at a temperature of 23°C and a tensile speed of 50 mm/min. , measure the 90° peel adhesion strength (N/mm) at this time. Set the width of the bonded test piece during measurement to 10 mm.

The dielectric constant (ε) and The dielectric loss tangent (tanδ) is preferably less than 3.0 and less than 0.01, respectively, and more preferably less than 2.8 and less than 0.01. Furthermore, the dielectric loss tangent is preferably lower than that obtained by measuring the cured product of the adhesive composition in which the filler-like liquid crystal polymer (C) is removed from the above-mentioned adhesive composition at a frequency of 10 GHz. The dielectric loss tangent. In this case, the reduction rate of the dielectric loss tangent (100 × {[dielectric loss tangent without filler liquid crystal polymer (C)] - [dielectric loss tangent with filler liquid crystal polymer (C) Loss tangent]}/[dielectric loss tangent without filler liquid crystal polymer (C)]) is, for example, 5% or more, and the reduction rate is preferably 6 to 100%. The dielectric constant (ε) and dielectric loss tangent (tanδ) of the hardened material of the adhesive composition can be measured, for example, by the following method.

Prepare a release polyethylene terephthalate film with a thickness of 38 μm, and roll-coat the adhesive composition on one surface. Next, the coated film was placed in an oven and dried at 90° C. for 3 minutes to form a film (adhesive layer) with a thickness of 50 μm to obtain a bonding sheet. Next, the adhesive sheet is placed in an oven and heated at 180° C. for 30 minutes to harden it. Thereafter, the release film was peeled off to prepare a test piece (60 mm × 60 mm × thickness 0.2 mm). Regarding the dielectric constant (ε) and dielectric loss tangent (tanδ), Network analyzer E5071C (manufactured by Agilent Corporation) was used and the separated column dielectric resonator method (SPDR method) was used at a temperature of 23°C and a frequency of 10 GHz. Make a determination. In addition, in the present invention and this specification, when it is simply called "dielectric constant", it means the relative dielectric constant.

＜Other ingredients＞ In addition to the graft-modified thermoplastic resin (A), epoxy resin (B) and filler liquid crystal polymer (C), the above-mentioned adhesive composition may appropriately contain materials different from the graft-modified thermoplastic resin (A), epoxy resin (B) and filler liquid crystal polymer (C) within the scope that does not impair the effect of the present invention. Thermoplastic resin (other thermoplastic resin), adhesion imparting agent, flame retardant, hardener, hardening accelerator, coupling agent, thermal aging inhibitor, leveling agent, defoaming agent, different from branch-modified thermoplastic resin (A) Other components such as filler, pigment, and solvent of the filler liquid crystal polymer (C).

Examples of the other thermoplastic resins include phenoxy resin, polyamide resin, polyester resin, polycarbonate resin, polyphenylene ether resin, polyurethane resin, polyacetal resin, and polyethylene-based resin. , polypropylene resin and polyvinyl resin, etc. These thermoplastic resins may be used alone, or two or more types may be used in combination.

Examples of the tackifier include benzofuran-indene resin, terpene resin, terpene-phenol resin, rosin resin, p-tert-butylphenol-acetylene resin, phenol-formaldehyde resin, and xylene-formaldehyde. Resin, petroleum-based hydrocarbon resin, hydrogenated hydrocarbon resin, turpentine-based resin, etc. These adhesive imparting agents may be used alone, or two or more types may be used in combination.

The above flame retardant may be either an organic flame retardant or an inorganic flame retardant. Examples of organic flame retardants include: melamine phosphate, melamine polyphosphate, guanidine phosphate, guanidine polyphosphate, ammonium phosphate, ammonium polyphosphate, ammonium phosphatamide, ammonium polyphosphatamide, phosphate urethane, Polyphosphate urethane, aluminum tris(diethylphosphinate), aluminum tris(methylethylphosphinate), aluminum tris(diphenylphosphinate), bis(diethylphosphinic acid) ) zinc, bis(methylethylphosphinic acid)zinc, bis(diphenylphosphinic acid)zinc, bis(diethylphosphinic acid)titanium oxide, tetrakis(diethylphosphinic acid)titanium, bis(diethylphosphinic acid)titanium Phosphorus-based difficult titaniums such as (methylethylphosphinic acid) titanium, tetrakis (methylethylphosphinic acid) titanium, bis (diphenylphosphinic acid) titanium, and tetrakis (diphenylphosphinic acid) titanium Fuel; melamine, melam, melamine cyanurate, etc. Compounds, cyanuric acid compounds, isocyanuric acid compounds, triazole compounds, tetrazole compounds, diazo compounds, urea and other nitrogen-based flame retardants; polysiloxy compounds, silane compounds and other silicon-based flame retardants, etc. Examples of inorganic flame retardants include metal hydroxides such as aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, barium hydroxide, and calcium hydroxide; tin oxide, aluminum oxide, magnesium oxide, zirconium oxide, Metal oxides such as zinc, molybdenum oxide, nickel oxide; zinc carbonate, magnesium carbonate, barium carbonate, zinc borate, hydrated glass, etc. Two or more types of these flame retardants may be used in combination.

Examples of the curing agent include, but are not limited to, amine curing agents (amine compounds), acid anhydride curing agents, and the like. Examples of the amine-based hardening agent include: melamine resins such as methylated melamine resin, butylated melamine resin, and benzoguanamine resin; dicyandiamine; 4,4'-diphenyldiaminetrine, etc. . Moreover, examples of the acid anhydride include aromatic acid anhydride and aliphatic acid anhydride. These hardeners may be used alone, or two or more types may be used in combination. The content of the hardener is preferably 1 to 100 parts by mass, and more preferably 5 to 70 parts by mass based on 100 parts by mass of the epoxy resin (B).

The above-mentioned hardening accelerator is used to promote the reaction between the graft-modified thermoplastic resin (A) and the epoxy resin (B). You can use: tertiary amine hardening accelerator (tertiary amine compound), tertiary amine salt It is a hardening accelerator (tertiary amine salt compound) and an imidazole hardening accelerator (imidazole compound).

Examples of the tertiary amine-based hardening accelerator include: dimethylbenzylamine, 2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethylaminomethyl)phenol, tetramethylguanidine, Triethanolamine, N,N'-dimethylpiperdine , triethylenediamine, 1,8-diazabicyclo[5.4.0]undecene, etc.

Examples of tertiary amine salt-based hardening accelerators include: 1,8-diazabicyclo[5.4.0]undecene formate, octanoate, p-toluenesulfonate, and phthalate , phenoxide or phenol novolak resin salt; 1,5-diazabicyclo[4.3.0]nonene formate, octanoate, p-toluenesulfonate, phthalate, phenoxide or phenol Novolac resin salt, etc.

Examples of the imidazole-based hardening accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecanylimidazole, 1,2-dimethylimidazole, and 2-methyl-4-ethylimidazole. , 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2,4-diamino-6- [2'-Methylimidazolyl-(1')]ethyl symmetry , 2,4-diamino-6-[2'-undecylimidazolyl-(1')]ethyl symmetric tris , 2,4-Diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]ethyl symmetric tris , 2,4-diamino-6-[2'-methylimidazolyl-(1')]ethyl symmetric tris Isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5- Hydroxymethylimidazole, etc. These hardening accelerators may be used alone, or two or more types may be used in combination.

When the adhesive composition contains a hardening accelerator, the content of the hardening accelerator may be appropriately set according to the type of the hardening accelerator. The content of the hardening accelerator is preferably 0.1 to 10 parts by mass relative to 100 parts by mass of the epoxy resin (B).

Examples of the coupling agent include vinyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, p-styryltrimethoxysilane, and 3-methacryloxypropyl. Methyldimethoxysilane, 3-propenyloxypropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-urea Propyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, 3-isocyanatopropyltriethoxysilane , imidazole silane and other silane coupling agents; titanate coupling agents; aluminate coupling agents; zirconium coupling agents, etc. These may be used individually, or two or more types may be used in combination.

Examples of the thermal aging inhibitor include: 2,6-di-tert-butyl-4-methylphenol, n-octadecyl-3-(3',5'-di-tert-butyl-4 '-Hydroxyphenyl)propionate, tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane, neopentylerythritol tetrakis[3- (3,5-Di-tert-butyl-4-hydroxyphenol)], triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate ] and other phenolic antioxidants (phenolic compounds); sulfur-based antioxidants (sulfur-containing compounds) such as 3,3'-dilauryl thiodipropionate and 3,3'-dimyristyl dithiodipropionate. ; Phosphorus-based antioxidants (phosphorus-containing compounds) such as tris(nonylphenyl) phosphite and tris(2,4-di-tert-butylphenyl) phosphite. These may be used individually, or two or more types may be used in combination.

Examples of the filler include powders composed of titanium oxide, aluminum oxide, zinc oxide, carbon black, silica, talc, copper, silver, and the like. These may be used individually, or two or more types may be used in combination.

The above adhesive composition can be produced by mixing a graft-modified thermoplastic resin (A), an epoxy resin (B), a filler liquid crystal polymer (C), and other components added as necessary. The mixing method is not particularly limited, as long as the adhesive composition is in a desired uniform state. In order to be preferably used in the form of a solution or a dispersion, a solvent is generally used for the adhesive composition. Examples of the solvent include methanol, ethanol, isopropyl alcohol, n-propanol, isobutanol, n-butanol, benzyl alcohol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, and diethylene glycol monomethyl ether. , diacetone alcohol and other alcohols; acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, cyclohexanone, isophorone and other ketones; toluene, xylene, ethylbenzene, 1 , 3,5-trimethylbenzene and other aromatic hydrocarbons; methyl acetate, ethyl acetate, ethylene glycol monomethyl ether acetate, 3-methoxybutyl acetate and other esters; hexane, heptane, cyclohexane, etc. Aliphatic hydrocarbons such as hexane, methylcyclohexane, etc. These solvents can be used individually or in combination of two or more. Since the adhesive composition contains a solvent, coating on the base film and formation of the adhesive layer can be carried out smoothly.

When the adhesive composition contains a solvent, from the viewpoint of workability including formation of the adhesive layer, the solid content concentration of the adhesive composition is preferably 3 to 80 mass %, more preferably In the range of 10 to 50% by mass.

[Laminated body with adhesive layer attached] The adhesive layer-attached laminate of the present invention has an adhesive layer formed of the above-mentioned adhesive composition, and a base film in contact with at least one side of the adhesive layer.

As an aspect of the laminate of the adhesive layer of the present invention, a cover film can be exemplified. The cover film has an adhesive layer formed on at least one surface of the base film.

Examples of the base film when the laminate to which the adhesive layer is attached is a cover film include polyimide film, polyether ether ketone film, polyphenylene sulfide film, aromatic polyamide film, and polynaphthalene film. Ethylene diformate film, liquid crystal polymer film, etc. Among them, from the viewpoint of adhesiveness and electrical characteristics, polyimide films, polyethylene naphthalate films, and liquid crystal polymer films are preferred.

This type of base film is commercially available. For polyimide films, you can use: "Kapton (registered trademark)" manufactured by Toray DuPont Co., Ltd., "XENOMAX (registered trademark) manufactured by Toyobo Co., Ltd.", "Upilex (registered trademark)-S" manufactured by Ube Kosan Co., Ltd., "Apical (registered trademark)" manufactured by Kaneka Co., Ltd., etc. In addition, for the polyethylene naphthalate film, "Teonex (registered trademark)" manufactured by DuPont Teijin Film Co., Ltd., etc. can be used. Furthermore, as the liquid crystal polymer film, "Vecstar (registered trademark)" manufactured by Kuraray Co., Ltd., "BIAC (registered trademark) manufactured by Primatec Co., Ltd.", etc. can be used. The base film may also be formed by forming a corresponding resin film into a required thickness.

As a method of producing a cover film, for example, the above-mentioned adhesive composition (resin varnish) containing a solvent can be coated on the surface of a base film such as a polyimide film to form a coating film, and then the above-mentioned solvent can be removed from the surface of the base film. The coating film is removed, and a cover film with an adhesive layer formed on the base film is produced. The drying temperature used to remove the above solvent is preferably 40 to 250°C, more preferably 70 to 170°C. Drying can be performed by passing the laminate coated with the adhesive composition through a furnace subjected to hot air drying, far infrared heating, high-frequency induction heating, or the like. Furthermore, if necessary, a release film may be layered on the surface of the adhesive layer for storage, etc. As the above-mentioned release film, polyethylene terephthalate film, polyethylene film, polypropylene film, polysilicone release paper, polyolefin resin-coated paper, and polymethylpentene (TPX) can be used. Films, fluororesin films, and other known materials.

Another aspect of the laminate with an adhesive layer attached thereto is an adhesive sheet. The adhesive sheet also has the above-mentioned adhesive layer formed on the surface of the base film. As the base film, a release film can be used. Moreover, the adhesive sheet may be provided with an adhesive layer between two release films. When using the adhesive sheet, the release film can be peeled off and used. The same thing as mentioned above can be used as a release film.

This type of release film is also commercially available and can be used: "Lumirror (registered trademark)" manufactured by Toray Film Processing Co., Ltd., "Toyobo Ester (registered trademark) film" manufactured by Toyobo Co., Ltd., Asahi Glass ( "Aflex (registered trademark)" manufactured by Mitsui Chemicals Co., Ltd., "Opulent (registered trademark)" manufactured by Mitsui Chemicals Tohcello Co., Ltd., etc.

An example of a method for producing an adhesive sheet is to apply the above-mentioned adhesive composition (resin varnish) containing a solvent to the surface of a release film and dry it in the same manner as in the case of the above-mentioned cover film.

In order to achieve thinning of the laminate with the adhesive layer attached, the thickness of the base film is preferably 5 to 100 μm, more preferably 5 to 50 μm, and still more preferably 5 to 30 μm.

In the laminate with an adhesive layer attached to the present invention, the thickness of the adhesive layer is preferably 5 to 100 μm, more preferably 10 to 70 μm, and still more preferably 10 to 50 μm. The thickness of the above-mentioned base film and adhesive layer can be selected according to the application. In order to improve the electrical properties, the base film tends to become thinner. Generally, if the thickness of the base film is thin and the thickness of the adhesive layer is thick, the laminate of the adhesive layer is prone to warp and the workability is reduced. However, the laminate of the adhesive layer of the present invention is Even when the thickness of the base film is thin and the thickness of the adhesive layer is thick, the laminate hardly warps. In the laminate with an adhesive layer attached to the present invention, the ratio (D1/D2) of the thickness (D1) of the adhesive layer to the thickness (D2) of the base film is preferably 1 to 10, more preferably 1 to 5. the following. Furthermore, the thickness of the adhesive layer is preferably thicker than the thickness of the base film. [Example]

The present invention will be described more specifically based on Examples, but the present invention is not limited thereto. In the following, "parts" and "%" are based on quality unless otherwise stated.

[Evaluation method] ＜Weight average molecular weight (Mw)＞ GPC measurement was performed under the following conditions to determine the Mw of the graft-modified thermoplastic resin (A). Mw is calculated by converting the residence time measured by GPC based on the residence time of standard polystyrene. Device: Alliance 2695 (manufactured by Waters Corporation) Column: TSKgel Super Multipore HZ-H…2 pieces, TSKgel Super HZ2500…2 pieces (manufactured by Tosoh Corporation) Tube string temperature: 40℃ Eluent: Tetrahydrofuran 0.35 ml/min Detector: RI (differential refractive index detector)

＜Acid value＞ 1 g of graft-modified thermoplastic resin (A) was dissolved in 30 ml of toluene, and an automatic titration device "AT-510" manufactured by Kyoto Electronics Industry Co., Ltd. was used. An "APB-" manufactured by the same company was connected as a burette. 510-20B". Use 0.01 mol/L benzyl alcoholic KOH solution as the titration reagent to perform potentiometric titration, and calculate the mg of KOH per 1 g of the graft-modified thermoplastic resin (A).

＜Repeelability＞ Prepare a release PET film with a thickness of 38 μm, and roll-coat the liquid adhesive composition described in Table 1 on one surface. Next, the film with the adhesive layer was allowed to stand in an oven and dried at 90° C. for 3 minutes to form a B-stage adhesive layer (thickness: 25 μm). Then, the adhesive layer of the film with the adhesive layer was placed on the polyimide surface of the flexible substrate material (manufactured by Panasonic Co., Ltd., product name "FELIOS R-F770"), and heated at 40°C in an oven. The situation where the film attached to the adhesive layer can still peel off directly after heating for 60 seconds is evaluated as "◎"; the situation where it does not reach ◎, but the situation where the film attached to the adhesive layer can still be peeled off directly after heating for 30 seconds is evaluated as "◎" "○"; when heated for 30 seconds, the film with the adhesive layer adheres closely to the flexible substrate material and does not peel off directly, and is evaluated as "×".

＜Redispersibility＞ Add 10 ml of the liquid adhesive composition described in Table 1 to the test tube and let it stand at room temperature for one day. Thereafter, the liquid was stirred again using a rotary mixer, and roller coating was performed on the PET film so that the coating film thickness after drying became 25 μm. Visually confirm the dried coating film. If there is no agglomeration of filler in the liquid after stirring for 10 minutes, the evaluation will be "◎"; if it does not reach ◎, but there is no agglomeration of filler in the liquid after stirring for 30 minutes. , the evaluation is "○"; if there are agglomerates of filler in the liquid after stirring for 30 minutes, the evaluation is "×".

＜Peel adhesion strength＞ Prepare a release PET film with a thickness of 38 μm, and roll-coat the liquid adhesive composition described in Table 1 on one surface. Next, the film with the adhesive layer was allowed to stand in an oven and dried at 90° C. for 3 minutes to form a B-stage adhesive layer (thickness: 25 μm). Then, the polyimide surface of the flexible substrate material (manufactured by Panasonic Co., Ltd., product name "FELIOS R-F770") was overlapped with the adhesive layer of the film to which the adhesive layer was attached, at a temperature of 120°C, a pressure of 0.4 MPa, Lamination is carried out at a speed of 0.5 m/min. Next, peel off the release PET, overlap the adhesive layer and the rolled copper foil (thickness 35 μm), and perform lamination at a temperature of 120°C, a pressure of 0.4 MPa, and a speed of 0.5 m/min. Thereafter, the laminate (flexible substrate material/adhesive layer/copper foil) was heat-pressed and bonded for 30 minutes at a temperature of 180°C and a pressure of 3 MPa. After heating and crimping, the laminated body was cut into 10 mm × 100 mm pieces to obtain bonded test pieces. In order to evaluate the adhesion, according to JISC6481 "Test method for copper-clad laminates for printed wiring boards", the flexible substrate material of each adhered test piece was peeled off from the copper foil at a temperature of 23°C and a tensile speed of 50 mm/min. The 90° peeling bonding strength (N/mm) at this time was measured. The width of the bonded test piece during measurement is 10 mm.

＜Water Absorption Rate＞ The filler liquid crystal polymer is heated, melted, and injection molded to produce a flat test piece of a specified size. Using the test method of ASTM D570, immerse the test piece in water at room temperature (23°C) for 24 hours, measure the weight of the test piece before immersion and the weight of the test piece after 24 hours of immersion, and calculate the water absorption rate.

[Raw materials for adhesive composition] ＜Graft-modified thermoplastic resin (A)＞ (Graft modified polyolefin resin a1) After heating and melting 100 parts by mass of propylene/1-butene copolymer (mass ratio: propylene/1-butene = 70/30) in a four-necked flask in a nitrogen environment, the temperature in the system was maintained at 170°C. While stirring, 3.0 parts by mass of maleic anhydride as an unsaturated carboxylic acid and 2.5 parts by mass of dicumyl peroxide as a radical generator were added over 1 hour respectively, and then the reaction was carried out for 1 hour. After the reaction is completed, the obtained reactant is poured into a large amount of acetone to solidify the resin. The resin is chopped and processed into pellets. Next, the granular resin was mixed with acetone 3 times the mass of the resin, and the mixture was stirred for 1 hour while maintaining the temperature at 50° C. to wash the resin. After the resin is recovered, the resin is further washed by the same method to remove free maleic anhydride. The washed resin is dried under reduced pressure in a vacuum dryer to obtain graft-modified polyolefin resin a1. The weight average molecular weight of the graft-modified polyolefin resin a1 is 100,000, and the acid value is 30 mgKOH/g.

(Graft modified polyolefin resin a2) Using a twin-screw extruder with the maximum temperature of the cylinder section set to 170°C, propylene composed of 97 mol% of propylene units and 3 mol% of ethylene units was produced using a metallocene catalyst as a polymerization catalyst. 100 parts by mass of ethylene random copolymer, 0.5 parts by mass of maleic anhydride, 0.3 parts by mass of lauryl methacrylate and 0.4 parts by mass of di-tert-butyl peroxide were mixed for a mixing reaction. Thereafter, degassing was performed under reduced pressure in the extruder to remove residual unreacted matter to produce graft-modified polyolefin resin a2. The weight average molecular weight of the graft-modified polyolefin resin a2 is 180,000, and the acid value is 4 mgKOH/g.

(Styrenic elastomer) As acid-modified SEBS (SEBS: styrene-ethylene-butylene-styrene block copolymer), "Tuftec M1913" (maleic acid-modified styrene-ethylene butylene-) manufactured by Asahi Kasei Chemical Co., Ltd. was used. Styrenic block copolymer). The acid value of the copolymer is 10 mgKOH/g, the styrene/ethylene butylene ratio (weight ratio) is 30/70, and the weight average molecular weight is 150,000.

＜Epoxy resin (B)＞ (Epoxy resin b1) Use the trade name "EPICLON HP-7200" (epoxy resin containing dicyclopentadiene skeleton) manufactured by DIC Corporation.

(Epoxy resin b2) Use the trade name "EPICLON N-655EXP" (cresol novolac epoxy resin) manufactured by DIC Corporation.

(Epoxy resin b3) Use the trade name "TETRAD-C" (epoxypropylamino-based epoxy resin) manufactured by Mitsubishi Gas Chemical Co., Ltd.

＜Harding accelerator＞ Use the trade name "Curezol C11Z" (imidazole-based hardening accelerator) manufactured by Shikoku Chemical Industry Co., Ltd.

＜Filling material＞ (Filled liquid crystal polymer (C)) Various physical properties (particle size (d50), water absorption, and melting point) of the filler liquid crystal polymer (C) were measured. The results are shown below. Particle size (d50): 5 μm Water absorption: 0.1% Melting point: 320℃

(Inorganic filler 1) Use the trade name "Excelica SE-1" (silicon dioxide) manufactured by Tokuyama Corporation.

(Inorganic filler 2) Aluminum hydroxide (particle size 2 μm) was used.

＜Thermal Aging Inhibitor＞ Use the trade name "Adekastab AO-80" manufactured by ADEKA.

＜Solvent＞ In Examples 1 to 10, Comparative Examples 1 to 3, and Comparative Examples 5 to 8, a mixed solvent composed of methylcyclohexane, toluene, and isopropyl alcohol (the mass ratio is methylcyclohexane:toluene:isopropyl alcohol) is used. Propanol = 65:30:5), in Example 11 and Comparative Example 4, a mixed solvent composed of toluene and methyl ethyl ketone (mass ratio: toluene: methyl ethyl ketone = 85:15) was used.

[Preparation of adhesive composition] The ratios shown in Tables 1 and 2 (the values in Table 1 indicate the blending amounts of each component based on 100 parts by mass of the graft-modified thermoplastic resin; Table 2 indicates the amounts of all solid components based on 100% by mass) The blending amount of each component) was added to a flask equipped with a stirring device, and stirred at room temperature (25°C) for 6 hours to dissolve, thereby preparing a liquid adhesive composition with a solid content concentration of 20%. . The evaluation results of the obtained adhesive composition are shown in Table 3. In Table 3, the unit of bonding strength is "N/mm".

[Table 1] Table 1 Composition ratio (mass parts) Graft modified thermoplastic resin (A) Epoxy resin (B) hardening accelerator Filling material (filler) Thermal aging inhibitor Resin a1 Resin a2 Acid modified SEBS Epoxy resin b1 Epoxy resin b2 Epoxy resin b3 C11Z Filler liquid crystal polymer (C) SE-1 (silica) aluminum hydroxide AO-80 Example 1 100 10 0.1 5 1.5 Example 2 100 10 0.1 15 1.5 Example 3 100 10 0.1 30 1.5 Example 4 100 10 0.1 60 1.5 Example 5 100 10 0.1 100 1.5 Example 6 100 10 0.1 200 1.5 Example 7 100 5 0.1 60 1.5 Example 8 100 15 0.1 60 1.5 Example 9 100 3 0.2 30 1.5 Example 10 100 3 0.2 30 1.5 Example 11 100 5 0.1 15 1.5 Comparative example 1 100 10 0.1 1.5 Comparative example 2 100 3 0.2 1.5 Comparative example 3 100 3 0.2 1.5 Comparative example 4 100 5 0.1 1.5 Comparative example 5 100 10 0.1 15 1.5 Comparative example 6 100 10 0.1 15 1.5 Comparative example 7 100 5 0.1 1.5 Comparative example 8 100 15 0.1 1.5

[Table 2] Table 2 Content of all solid components (mass %) Graft modified thermoplastic resin (A) Epoxy resin (B) Filler liquid crystal polymer (C) SE-1 (silica) SG-95 (talc) aluminum hydroxide other total Example 1 85.8 8.6 4.3 1.4 100 Example 2 79.0 7.9 11.9 1.3 100 Example 3 70.6 7.1 21.2 1.1 100 Example 4 58.3 5.8 35.0 0.9 100 Example 5 47.3 4.7 47.3 0.8 100 Example 6 32.1 3.2 64.2 0.5 100 Example 7 60.0 3.0 36.0 1.0 100 Example 8 56.6 8.5 34.0 0.9 100 Example 9 74.2 2.2 22.3 1.3 100 Example 10 74.2 2.2 22.3 1.3 100 Example 11 82.2 4.1 12.3 1.3 100 Comparative example 1 89.6 9.0 1.4 100 Comparative example 2 95.5 2.9 1.6 100 Comparative example 3 95.5 2.9 1.6 100 Comparative example 4 93.8 4.7 1.5 100 Comparative example 5 79.0 7.9 11.9 1.3 100 Comparative example 6 79.0 7.9 11.9 1.3 100 Comparative example 7 93.8 4.7 1.5 100 Comparative example 8 85.8 12.9 1.4 100

[table 3] table 3 Re-peelability Redispersibility Then intensity Example 1 ◎ ◎ 1.7 Example 2 ◎ ◎ 1.6 Example 3 ◎ ◎ 1.7 Example 4 ◎ ◎ 1.5 Example 5 ◎ ○ 1.3 Example 6 ◎ ○ 0.8 Example 7 ◎ ◎ 1.6 Example 8 ◎ ◎ 1.5 Example 9 ◎ ◎ 1.4 Example 10 ◎ ◎ 1.4 Example 11 ○ ○ 1.0 Comparative example 1 × - 1.5 Comparative example 2 × - 1.5 Comparative example 3 × - 1.4 Comparative example 4 × - 1.3 Comparative example 5 Poor redispersibility uncoated × - Not rated yet Comparative example 6 Poor redispersibility uncoated × - Not rated yet Comparative example 7 × - 1.6 Comparative example 8 × - 1.5

As shown in the table above, it can be seen that the adhesive composition of the present invention prepared by blending a liquid crystal polymer as a filler has excellent redispersibility. When used for layer formation, it can form a product that has excellent removability and exhibits excellent performance after the hardening reaction. The adhesive layer has strong adhesion. Furthermore, in the examples, the reduction rate of the dielectric loss tangent (tan δ) obtained by measuring the cured product of the adhesive composition at a frequency of 10 GHz is in the range of 7 to 52%.

The present invention and its embodiments have been described. However, unless otherwise specified by the inventors, they are not intended to limit the invention to any detail in the description. The invention shall be interpreted broadly within the spirit and scope of the invention as shown in the patent application.

This case claims priority based on Japanese Patent Application No. 2021-215243 filed in Japan on December 28, 2021, the contents of which are hereby incorporated by reference as part of the description of this specification.

without

without

Claims (7)

An adhesive composition containing a graft-modified thermoplastic resin (A) using an α,β-unsaturated carboxylic acid compound, an epoxy resin (B), and a filler liquid crystal polymer (C), and In the total solid content, the content of the above-mentioned graft-modified thermoplastic resin (A) is 30% by mass or more, The content of the epoxy resin (B) is 1 to 20 parts by mass relative to 100 parts by mass of the graft-modified thermoplastic resin (A). The adhesive composition of claim 1, wherein the proportion of the structural part derived from the α,β-unsaturated carboxylic acid compound in the graft-modified thermoplastic resin (A) is 0.1 to 20% by mass. The adhesive composition of claim 1 or 2, wherein the thermoplastic resin constituting the graft-modified thermoplastic resin (A) is an ethylene-propylene copolymer, a propylene-butylene copolymer, or an ethylene-propylene-butylene copolymer. , and at least one of styrenic elastomers. The adhesive composition of claim 1 or 2, wherein the weight average molecular weight of the graft-modified thermoplastic resin (A) is 30,000 to 250,000. The adhesive composition of claim 1 or 2, wherein the acid value of the graft-modified thermoplastic resin (A) is 0.1 to 50 mgKOH/g. The adhesive composition of claim 1 or 2, wherein the above-mentioned epoxy resin (B) is a multifunctional epoxy resin having an alicyclic skeleton. A laminate with an adhesive layer attached, which has: An adhesive layer formed from the adhesive composition of any one of claims 1 to 6, and A base film in contact with at least one side of the adhesive layer.