Adhesive composition

Abstract

To provide an adhesive composition which gives a cured product excellent in low dielectric characteristics and heat resistance and also excellent in adhesiveness to a resin and a metal.SOLUTION: As a result of intensive studies, the inventors have found that the problem can be solved by an adhesive composition which contains a component (A): a resin obtained by converting terminals of a bifunctional polyphenylene ether resin to vinyl groups, a component (B): a maleimide compound having two or more maleimide groups in one molecule, a component (C): an acid-modified styrenic elastomer, and a component (D): an isocyanate compound having two or more isocyanate groups in one molecule in a specific ratio.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an adhesive composition that provides a cured product with excellent low dielectric properties (low dielectric constant, low dielectric loss tangent), heat resistance, and adhesion, and is suitable for the manufacture of electronic components, particularly related components for flexible printed circuit boards (hereinafter referred to as FPCs). [Background technology]

[0002] In recent years, with the advancement of wireless communication technologies such as smartphones and mobile computers, there has been a demand for high-speed processing of large amounts of information, leading to an increase in the frequency of transmitted signals. Along with this increase in frequency, FPCs and related components, which are one of the components of wireless communication devices, are required to have low dielectric properties (low dielectric constant, low dielectric loss tangent) in the high-frequency band (for example, Patent Document 1).

[0003] As a related component, for example, in a laminate with an adhesive layer called a "coverlay film" used to protect the wiring portion when manufacturing an FPC, it is also required that the adhesive layer has strong adhesion to the wiring portion and the base film.

[0004] Furthermore, FPCs are required to have excellent heat resistance to prevent damage from thermal shock during processing such as soldering. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2016 / 017473 brochure [Overview of the project] [Problems that the invention aims to solve]

[0006] This invention has been made in view of these circumstances, and aims to provide an adhesive composition that yields a cured product with excellent low dielectric properties, heat resistance, and adhesion to resins and metals. [Means for solving the problem]

[0007] As a result of diligent research, the inventors have found that the above problems can be solved by an adhesive composition containing the following components (A) to (D) in specific proportions. Specifically, the present invention includes the following inventions.

[0008] [1] Component (A): A resin obtained by converting the ends of a bifunctional polyphenylene ether resin to vinyl groups. Component (B): A maleimide compound having two or more maleimide groups in one molecule. Component (C): Acid-modified styrene elastomer, and Component (D): An isocyanate compound having two or more isocyanate groups in one molecule. It contains, The molar ratio (maleimide group / vinyl group) of vinyl groups in component (A) to maleimide groups in component (B) is 0.4 to 6.0. The molar ratio (isocyanate groups / total acidic groups) of the total acidic groups in component (C) to the isocyanate groups in component (D) is 0.2 to 4.0. The content of component (C) is 40 to 100 parts by weight per 100 parts by weight of component (A). Adhesive composition.

[0009] [2] The adhesive composition according to [1], wherein component (A) is a resin represented by the following general formula (1).

[0010] [ka] (In the above general formula (1), R1, R2, R3, R4, R5, R6, R7, and R8 are each independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, or a phenyl group, and X represents a divalent aromatic hydrocarbon group represented by the following general formula (2). m is an integer from 0 to 20. n is an integer from 0 to 20. However, m and n cannot both be 0 at the same time.)

[0011] [Chemical formula] (In the above general formula (2), each of R9, R 51 , 49 , 50 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, or a phenyl group independently. Y represents a single bond or a divalent hydrocarbon group having 20 or less carbon atoms.)

[0012] [3] The adhesive composition according to [1], wherein component (B) is a maleimide compound having two or more maleimide groups in at least one selected from the group consisting of compounds represented by the following general formulas (4), (7), and (8).

[0013] [Chemical formula] (In the above general formula (4), each of R 17 , R 18 , R 19 , R 20 , R 21 , R 22 , R 23 and R 24 represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 6 carbon atoms independently. A1 represents a single bond, a divalent hydrocarbon group having 1 to 20 carbon atoms, or an oxygen atom.)

[0014] [Chemical formula] (In the above general formula (7), each of R 41 , R 42 , R 43 , R 44 , R 45 , R 46 , R 47 , R 48 , R 49 , R 50 and R 51 represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 6 carbon atoms independently. p represents an integer of 1 to 20.)

[0015] [ka] (In the above general formula (8), A3 represents a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms.)

[0016] [4] The adhesive composition according to [1], wherein component (C) is at least one styrene-based elastomer selected from the group consisting of styrene-ethylenebutylene-styrene block copolymer and styrene-ethylenepropylene block copolymer, modified with at least one selected from the group consisting of unsaturated carboxylic acids and unsaturated carboxylic acid anhydrides.

[0017] [5] The adhesive composition according to [1], wherein component (D) is an isocyanate compound having two or more isocyanate groups in one molecule, selected from the group consisting of aliphatic polyisocyanates, alicyclic polyisocyanates, and derivatives thereof.

[0018] [6] Furthermore, the adhesive composition according to any one of [1] to [5], further comprising (E) fluorine polymer fine particles.

[0019] [7] Furthermore, an adhesive composition according to any one of [1] to [5], comprising (F) an organic solvent.

[0020] [8] Furthermore, the adhesive composition according to [6], comprising (F) an organic solvent.

[0021] [9] An adhesive film made using the adhesive composition described in [1].

[0022]

[10] A laminate made using the adhesive composition described in [1]. [Effects of the Invention]

[0023] The adhesive composition of the present invention exhibits excellent low dielectric properties and heat resistance in its cured product, and also provides improved adhesion compared to conventionally known adhesive compositions (for example, the adhesive composition of Comparative Example 1 described in the Examples section below). Therefore, the adhesive composition of the present invention can be suitably used in the manufacture of FPC-related components such as laminates with adhesive layers (coverlay films, bonding sheets), resin-coated copper foil, flexible copper-clad laminates, and flexible flat cables. [Modes for carrying out the invention]

[0024] The present invention will be described in detail below. However, the present invention is not limited to the following embodiments and can be implemented with various modifications within the scope of its essence.

[0025] <Adhesive composition of the present invention> The adhesive composition of the present invention, Component (A): A resin obtained by converting the ends of a bifunctional polyphenylene ether resin to vinyl groups. Component (B): A maleimide compound having two or more maleimide groups in one molecule. Component (C): Acid-modified styrene elastomer, and Component (D): An isocyanate compound having two or more isocyanate groups in one molecule. It contains the following. The above components (A) to (D) will be explained in detail below.

[0026] [Component (A): A resin obtained by converting the ends of a bifunctional polyphenylene ether resin to vinyl groups] Component (A) is preferably the structure shown in the following general formula (1).

[0027] [ka] (In the above general formula (1), R1, R2, R3, R4, R5, R6, R7, and R8 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, or a phenyl group. X represents a divalent aromatic hydrocarbon group represented by the following general formula (2). m represents an integer from 0 to 20. n represents an integer from 0 to 20. However, m and n cannot both be 0 at the same time.)

[0028] [ka] (In the above general formula (2), R9, R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 Each of the following independently represents a hydrogen atom, an aliphatic hydrocarbon group with 1 to 6 carbon atoms, or a phenyl group. Y represents a single bond or a divalent hydrocarbon group with 1 to 20 carbon atoms.

[0029] Examples of C1-C6 aliphatic hydrocarbon groups in substituents R1, R2, R3, R4, R5, R6, R7, and R8 of the above general formula (1) include branched C1-C6 linear aliphatic hydrocarbon groups such as methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, and hexyl groups, and C3-C6 cyclic aliphatic hydrocarbon groups which may have substituents such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups. From the viewpoint of ease of obtaining raw materials, hydrogen atoms or methyl groups are preferred as substituents R1, R2, R3, R4, R5, R6, R7, and R8 of the above general formula (1).

[0030] Among the compounds represented by the above general formula (1), compounds represented by the following general formula (3) (i.e., compounds in which R2, R4, R5, and R7 are hydrogen atoms and R1, R3, R6, and R8 are methyl groups) are preferred.

[0031] [ka] (In the above general formula (3), X, m, and n are as described above.)

[0032] The substituents R9 and R in the above general formula (2) 10 , R 11 , R 12 , R 13 , R 14 , R 15 and R 16 Examples of aliphatic hydrocarbon groups having 1 to 6 carbon atoms in the above general formula (1) include the same aliphatic hydrocarbon groups having 1 to 6 carbon atoms as those in substituents R1, R2, R3, R4, R5, R6, R7, and R8, and the preferred embodiments are also the same.

[0033] Examples of divalent hydrocarbon groups having 1 to 20 carbon atoms in Y of the above general formula (2) include branched divalent linear aliphatic hydrocarbon groups having 1 to 20 carbon atoms, branched divalent cyclic aliphatic hydrocarbon groups having 3 to 20 carbon atoms, branched divalent aromatic hydrocarbon groups having 6 to 20 carbon atoms, branched divalent aromatic hydrocarbon groups having 6 to 20 carbon atoms, branched divalent aliphatic hydrocarbon groups having 13 to 20 carbon atoms, branched divalent aliphatic hydrocarbon groups having 3 to 20 carbon atoms, branched divalent aliphatic hydrocarbon groups having 3 to 20 carbon atoms, branched divalent aliphatic hydrocarbon groups having 3 to 20 carbon atoms, branched divalent aliphatic hydrocarbon groups having 3 to 20 carbon atoms, branched divalent aliphatic hydrocarbon groups having 3 to 20 carbon atoms, branched divalent aliphatic hydrocarbon groups having 3 to 20 carbon atoms, branched divalent aliphatic hydrocarbon groups having 3 to 20 carbon atoms, branched divalent aliphatic Examples of divalent aromatic hydrocarbon groups having 6 to 20 carbon atoms that may have substituents include phenylene groups, torylene groups, dimethylphenylene groups, and naphthylene groups. Among the Y groups in the above general formula (2), divalent linear aliphatic hydrocarbon groups having 1 to 5 carbon atoms that may have single bonds or branching are preferred from the viewpoint of ease of obtaining raw materials.

[0034] Examples of commercially available components (A) include OPE-2St1200 and OPE-2St2200 manufactured by Mitsubishi Gas Chemical Company.

[0035] The molecular weight of component (A) is, for example, 500 to 5,000, calculated using a polystyrene standard based on gel permeation chromatography (GPC) measurement.

[0036] Component (A) may be used alone or in combination of two or more components.

[0037] [Component (B): Maleimide compound having two or more maleimide groups in one molecule] Examples of component (B) include compounds represented by general formulas (4), (5), (7), and (8).

[0038] [ka] (In the above general formula (4), R 17 , R 18 , R 19 , R 20 , R 21 , R 22 , R 23 and R 24 Each of these independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 6 carbon atoms. A1 represents a single bond, a divalent hydrocarbon group having 1 to 20 carbon atoms, or an oxygen atom.

[0039] R in the above general formula (4) 17 , R 18 , R 19 , R 20 , R 21 , R 22 , R 23 and R 24Examples of C1-C6 aliphatic hydrocarbon groups in this context include branched C1-C6 chain aliphatic hydrocarbon groups such as methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, and hexyl groups, and C3-C6 cyclic aliphatic hydrocarbon groups that may have substituents such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups. Among these substituents, hydrogen atoms, methyl groups, or ethyl groups are preferred.

[0040] Examples of divalent hydrocarbon groups having 1 to 20 carbon atoms in A1 include divalent linear aliphatic hydrocarbon groups having 1 to 4 carbon atoms that may be branched. Specifically, examples include methylene, ethylene, trimethylene, tetramethylene, propylene, 2,2-propanediyl, 2,2-dimethylethylene, 1,2-butanediyl, 1,3-butanediyl, and 2,3-butanediyl groups. Among these substituents, divalent linear aliphatic hydrocarbon groups having 1 to 4 carbon atoms that may be branched are preferred, with methylene and 2,2-propanediyl groups being more preferred.

[0041] [ka] (In the above general formula (5), R 25 , R 26 , R 27 , R 28 , R 29 , R 30 , R 31 and R 32 A1 independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 6 carbon atoms. A2 represents a divalent hydrocarbon group having 1 to 20 carbon atoms.

[0042] R in the above general formula (5) 25 , R 26 , R 27 , R 28 , R 29 , R 30 , R 31 and R 32Examples of C1-C6 aliphatic hydrocarbon groups in A2 include branched C1-C6 chain aliphatic hydrocarbon groups such as methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, and hexyl groups, and C3-C6 cyclic aliphatic hydrocarbon groups that may have substituents such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups. Among these substituents, hydrogen atoms or methyl groups are preferred. Among the C1-C20 divalent hydrocarbon groups in A2, hydrocarbon groups represented by the following general formula (6) are preferred.

[0043] [ka] (In the above general formula (6), R 33 , R 34 , R 35 , R 36 , R 37 , R 38 , R 39 and R 40 Each of these independently represents a hydrogen atom or a branched, potentially branched, C1-C4 linear aliphatic hydrocarbon group. B1 represents a branched, potentially branched, C1-C4 divalent linear aliphatic hydrocarbon group.

[0044] R in the above general formula (6) 33 , R 34 , R 35 , R 36 , R 37 , R 38 , R 39 and R 40Examples of the linear aliphatic hydrocarbon group having 1 to 4 carbon atoms which may have a branch in A1 include a methyl group, an ethyl group, a propyl group, an iso-propyl group, a butyl group, an iso-butyl group, a sec-butyl group, and a tert-butyl group. Examples of the divalent linear aliphatic hydrocarbon group having 1 to 4 carbon atoms which may have a branch in B1 include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a propylene group, a 2,2-propanediyl group, a 2,2-dimethylethylene group, a 1,2-butanediyl group, a 1,3-butanediyl group, and a 2,3-butanediyl group.

[0045] [Chemical formula] (In the above general formula (7), R 41 , R 42 , R 43 , R 44 , R 45 , R 46 [[ID=2l]], R 47 , R 48 , R 49 , R 50 and R 51 each independently represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 6 carbon atoms. p represents an integer of 1 to 20.)

[0046] R 41 , R 42 , R 43 , R 44 , R 45 , R 46 , R 47 , R 48 , R 49 , R 50 and R 51Examples of C1-C6 aliphatic hydrocarbon groups in this formula include branched C1-C6 linear aliphatic hydrocarbon groups such as methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, and hexyl groups, and C3-C6 cyclic aliphatic hydrocarbon groups that may have substituents such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups. Among these substituents, hydrogen atoms or methyl groups are preferred. Also, p represents an integer from 1 to 20.

[0047] [ka] (In the above general formula (8), A3 represents a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms.)

[0048] The divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms in A3 of the above general formula (8) is preferably a divalent chain aliphatic hydrocarbon group having 1 to 10 carbon atoms, which may have substituents. Specifically, examples include methylene group, ethylene group, trimethylene group, tetramethylene group, propylene group, 2,2-propanediyl group, 2,2-dimethylethylene group, 1,2-butanediyl group, 1,3-butanediyl group, 2,3-butanediyl group, pentamethylene group, hexamethylene group, 2,2,4-trimethylhexamethylene group, and the like.

[0049] Among the maleimide compounds having two or more maleimide groups in one molecule represented by the above general formulas (4), (5), (7), and (8), the compounds represented by the above general formulas (4), (7), and (8) are preferred, and phenylmethane maleimide oligomer, bis(3-ethyl-5-methyl-4-maleimidophenyl)methane, and 1,6-bismaleimide-(2,2,4-trimethyl)hexane are more preferred.

[0050] Examples of commercially available products containing component (B) include BMI-70 manufactured by K.I. Chemicals Co., Ltd., and BMI-1000, BMI-2300, BMI-4000, and BMI-TMH manufactured by Yamato Chemicals Co., Ltd.

[0051] The maleimide compounds listed as component (B), each having two or more maleimide groups in a single molecule, may be used individually or in combination of two or more.

[0052] In the adhesive composition of the present invention, the molar ratio (maleimide group / vinyl group) of vinyl groups in component (A) to maleimide groups in component (B) is usually 0.4 to 6.0, preferably 0.5 to 4.0, and more preferably 0.7 to 2.0.

[0053] [Ingredient (C): Acid-modified styrene elastomer] Component (C) is a styrene elastomer (acid-modified styrene elastomer) modified with at least one selected from the group consisting of unsaturated carboxylic acids and unsaturated carboxylic acid anhydrides. Methods for modifying the styrene elastomer include, for example, a grafting reaction between the styrene elastomer and at least one selected from the group consisting of unsaturated carboxylic acids and unsaturated carboxylic acid anhydrides.

[0054] Specific examples of styrene-based elastomers include styrene-butadiene block copolymer, styrene-ethylenepropylene block copolymer, styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylenebutylene-styrene block copolymer (SEBS), and styrene-ethylenepropylene-styrene block copolymer (SEPS). Among these styrene-based elastomers, styrene-ethylenebutylene-styrene block copolymer (SEBS) and styrene-ethylenepropylene-styrene block copolymer (SEPS) are preferred from the viewpoint of adhesion and low dielectric properties.

[0055] Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, itaconic acid, and fumaric acid. Examples of unsaturated carboxylic acid anhydrides include maleic anhydride, itaconic anhydride, and fumaric anhydride. Among these unsaturated carboxylic acids and unsaturated carboxylic acid anhydrides, maleic acid, fumaric acid, and maleic anhydride are preferred, with maleic anhydride being more preferred. The amount of modification by at least one selected from the group consisting of unsaturated carboxylic acids and unsaturated carboxylic acid anhydrides is usually about 0.1 to 10% by weight of the total acid-modified styrene elastomer. Furthermore, it is preferable that at least a portion of the total acidic groups in the acid-modified styrene elastomer are acid anhydrides.

[0056] The acid value of component (C) is, for example, 0.1 mg CH3ONa / g or more, preferably 0.5 mg CH3ONa / g or more, more preferably 1.0 mg CH3ONa / g or more, and also, for example, 20 mg CH3ONa / g or less, preferably 18 mg CH3ONa / g or less, more preferably 15 mg CH3ONa / g or less.

[0057] The molecular weight of component (C) is, for example, 10,000 or more, preferably 30,000 or more, more preferably 50,000 or more, and also, for example, 500,000 or less, preferably 300,000 or less, more preferably 200,000 or less, based on a weight-average molecular weight. In this invention, the weight-average molecular weight is the molecular weight on a polystyrene basis measured by gel permeation chromatography (GPC).

[0058] Examples of commercially available products containing component (C) include Asahi Kasei's ToughTec M series and Kraton Polymer Japan's Kraton FG series.

[0059] These acid-modified styrene elastomers listed as component (C) may be used individually or in combination of two or more types.

[0060] In the adhesive composition of the present invention, the content of component (C) is usually 40 to 100 parts by weight per 100 parts by weight of component (A).

[0061] [Component (D): An isocyanate compound having two or more isocyanate groups in one molecule (hereinafter sometimes referred to as a polyisocyanate compound).] Examples of component (D) include aromatic polyisocyanates, aliphatic polyisocyanates, aromatic aliphatic polyisocyanates, alicyclic polyisocyanates, and derivatives thereof. Examples of aromatic polyisocyanates include aromatic diisocyanates such as 1,3-phenylenediisocyanate, 4,4'-diphenyldiisocyanate, 1,4-phenylenediisocyanate, 4,4'-diphenylmethanediisocyanate, 2,4-tolylenediisocyanate, 2,6-tolylenediisocyanate, 4,4'-toluidinediisocyanate, dianisidinediisocyanate, and 4,4'-diphenyletherdiisocyanate, as well as aromatic triisocyanates such as 2,4,6-triisocyanatetoluene and 1,3,5-triisocyanatebenzene. Examples of aliphatic polyisocyanates include aliphatic diisocyanates such as trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate, as well as aliphatic triisocyanates such as lysine triisocyanate. Examples of aromatic aliphatic polyisocyanates include aromatic aliphatic diisocyanates such as ω,ω'-diisocyanate-1,3-dimethylbenzene, ω,ω'-diisocyanate-1,4-dimethylbenzene, ω,ω'-diisocyanate-1,4-diethylbenzene, 1,4-tetramethylxylylene diisocyanate, and 1,3-tetramethylxylylene diisocyanate, as well as aromatic aliphatic triisocyanates such as 4,4',4”-triphenylmethane triisocyanate.Examples of alicyclic polyisocyanates include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate [also known as isophorone diisocyanate], 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 1,3-bis(isocyanate methyl)cyclohexane, 1,4-bis(isocyanate methyl)cyclohexane, and other alicyclic diisocyanates.

[0062] Examples of derivatives of aromatic polyisocyanates, aliphatic polyisocyanates, aromatic aliphatic polyisocyanates, and alicyclic polyisocyanates include their polymers (e.g., dimers, trimers (e.g., isocyanurate derivatives)), allophanate derivatives, biuret derivatives, uretdione derivatives, and urethane prepolymers obtained by reacting diisocyanate compounds with low molecular weight polyols or polyamines such that the terminal ends are isocyanates.

[0063] Furthermore, blocked isocyanates may be used in which at least a portion of the isocyanate groups of aromatic polyisocyanates, aliphatic polyisocyanates, aromatic aliphatic polyisocyanates, and alicyclic polyisocyanates are blocked by a blocking agent. Specific examples include isocyanate compounds in which the isocyanate groups are blocked with ε-caprolactam, MEK (methyl ethyl ketone) oxime, cyclohexanone oxime, pyrazole, phenol, etc.

[0064] Among these polyisocyanate compounds, aliphatic polyisocyanates, alicyclic polyisocyanates, and their derivatives are preferred, aliphatic diisocyanates, alicyclic diisocyanates, and their trimers are more preferred, and trimers of 1,3-bis(isocyanatemethyl)cyclohexane and hexamethylene diisocyanate are particularly preferred.

[0065] Examples of commercially available components (D) include TrixeneBI7982, TrixeneBI7951, TrixeneBI7961, and TrixeneBI7991 from Baksenden, Takenate B-820NP from Mitsui Chemicals, and VESTAGON B1530 and VESTAGON BF1540 from Evonik. In the present invention, the above-mentioned polyisocyanate compounds may be used alone or in combination of two or more.

[0066] In the adhesive composition of the present invention, the molar ratio (isocyanate groups / total acidic groups) of the total acidic groups in component (C) and the isocyanate groups in component (D) is usually 0.2 to 4.0, preferably 0.4 to 2.5, and more preferably 0.5 to 2.0. The total amount of acidic groups (mol) in the acid-modified styrene elastomer is calculated by dividing the acid value of the acid-modified styrene elastomer (mgCH3ONa / g) by the molecular weight of CH3ONa (sodium methoxide), and then further dividing by 10. 3 This can be determined by dividing by the total amount of acidic groups (mol / g) per gram of acid-modified styrene elastomer, and then multiplying this by the amount (g) of acid-modified styrene elastomer in the adhesive composition.

[0067] [Other ingredients] In addition to the above components (A), (B), (C), and (D), the adhesive composition of the present invention may contain other thermoplastic resins other than component (C), curing accelerators, tackifiers, flame retardants, coupling agents, antioxidants, fillers (especially fluorine-based polymer fine particles (component (E)) described later) and organic solvents (component (F)), etc.

[0068] Examples of the above-mentioned other thermoplastic resins include styrene-based elastomers that do not contain acid anhydride groups, phenoxy resins, polyamide resins, polyester resins, polycarbonate resins, polyphenylene oxide resins, polyurethane resins, polyacetal resins, polyethylene-based resins, polypropylene-based resins, and polyvinyl-based resins. These thermoplastic resins may be used individually or in combination of two or more types.

[0069] Examples of the curing accelerators mentioned above include amines such as triethylamine, lutidine, picoline, and DBU (1,8-diazabicyclo[5.4.0]-7-undecene), alkali metals and alkaline earth metal compounds such as lithium methylate, sodium methylate, sodium ethylate, potassium butoxide, potassium fluoride, and sodium fluoride, or metals and metalloid compounds such as titanium, cobalt, tin, zinc, and aluminum. These curing accelerators may be used individually or in combination of two or more.

[0070] Examples of the tackifiers mentioned above include coumarone-indene resin, terpene resin, terpene-phenol resin, rosin resin, pt-butylphenol-acetylene resin, phenol-formaldehyde resin, xylene-formaldehyde resin, petroleum hydrocarbon resin, hydrogenated hydrocarbon resin, and turpentine-based resin. These tackifiers may be used individually or in combination of two or more.

[0071] Examples of the above-mentioned flame retardants include organic flame retardants and inorganic flame retardants. Examples of organic flame retardants include phosphorus-based flame retardants such as melamine phosphate, melamine polyphosphate, guanidine phosphate, guanidine polyphosphate, ammonium phosphate, ammonium polyphosphate, ammonium phosphate, ammonium polyphosphate, carbamate phosphate, carbamate polyphosphate, aluminum tris-diethylphosphinate, aluminum tris-methylethylphosphinate, aluminum tris-diphenylphosphinate, zinc bis-diethylphosphinate, zinc bis-methylethylphosphinate, zinc bis-diphenylphosphinate, titanyl bis-diethylphosphinate, titanium tetrakis-diethylphosphinate, titanyl bis-methylethylphosphinate, titanium tetrakis-methylethylphosphinate, titanyl bis-diphenylphosphinate, and titanium tetrakis-diphenylphosphinate; nitrogen-based flame retardants such as triazine compounds like melamine, melam, and melamine cyanurate, as well as cyanuric acid compounds, isocyanuric acid compounds, triazole compounds, tetrazole compounds, diazo compounds, and urea; and silicon-based flame retardants such as silicone compounds and silane compounds. Examples of inorganic flame retardants include metal hydroxides such as aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, barium hydroxide, and calcium hydroxide; metal oxides such as tin oxide, aluminum oxide, magnesium oxide, zirconium oxide, zinc oxide, molybdenum oxide, and nickel oxide; and zinc carbonate, magnesium carbonate, barium carbonate, zinc borate, and hydrated glass. These flame retardants may be used individually or in combination of two or more types.

[0072] Examples of the coupling agents mentioned above include silane-based coupling agents such as vinyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, 3-isocyanethopropyltriethoxysilane, and imidazolesilane; titanate-based coupling agents; aluminate-based coupling agents; and zirconium-based coupling agents. These may be used alone or in combination of two or more.

[0073] Examples of the above antioxidants include 2,6-di-tert-butyl-4-methylphenol, Examples include phenol-based antioxidants such as n-octadecyl-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate, tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane, pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenol), and triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate; sulfur-based antioxidants such as dilauryl-3,3'-thiodipropionate and dimyristyl-3,3'-dithiopropionate; and phosphorus-based antioxidants such as trisnonylphenyl phosphite and tris(2,4-di-tert-butylphenyl)phosphite. These may be used alone or in combination of two or more.

[0074] Examples of the above-mentioned fillers include fluorine-based polymer fine particles, olefin-based polymer fine particles, polyacrylic acid ester powder, epoxy resin powder, polyamide powder, polyurethane powder, polysiloxane powder, and polymer fillers such as multilayer core-shell structures using silicone, acrylic, styrene-butadiene rubber, and butadiene rubber; and inorganic fillers such as silica, mica, talc, kaolin, clay, hydrotalcite, wollastonite, xonotlite, silicon nitride, boron nitride, aluminum nitride, calcium hydrogen phosphate, calcium phosphate, glass flakes, hydrated glass, calcium titanate, sepiolite, magnesium sulfate, aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, barium hydroxide, calcium hydroxide, titanium dioxide, tin oxide, aluminum oxide, magnesium oxide, zirconium oxide, zinc oxide, molybdenum oxide, antimony oxide, nickel oxide, zinc carbonate, magnesium carbonate, calcium carbonate, barium carbonate, zinc borate, and aluminum borate. These fillers may be used individually or in combination of two or more types. Furthermore, the fillers can be in various shapes, such as spherical, powdery, fibrous, needle-shaped, or flaky. Among the fillers described above, it is preferable that the adhesive composition of the present invention contains fluorine-based polymer fine particles (component (E)) because they can improve low dielectric properties and also improve adhesion to resins and metals. The fluorine-based polymer fine particles (component (E)) will be described in detail below.

[0075] [Ingredient (E): Fluorine-based polymer microparticles] Fluorine-based polymer fine particles are fine particles mainly composed of fluorine-based polymers. Examples of such fluorine-based polymers include polytetrafluoroethylene (PTFE), fluoroethylene-propylene copolymer (FEP), perfluoroalkoxy polymer (PFA), chlorotrifluoroethylene (CTFE), tetrafluoroethylene-chlorotrifluoroethylene copolymer (TFE / CTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), and polychlorotrifluoroethylene (PCTFE). Among these fluorine-based polymers, polytetrafluoroethylene (PTFE) is preferred.

[0076] Examples of commercially available products containing component (E) include Fluo400XF from MicroPowders, Rubron L-5F from Daikin Industries, SST-1MG from Shamrock, and PolyMist F5AR from SOLVAY.

[0077] The average particle size of the fluorine-based polymer fine particles is preferably 10 μm or less, more preferably 7 μm or less, and even more preferably 5 μm or less, from the viewpoint of dispersibility and other factors.

[0078] The fluorine-based polymer fine particles may be composed of these fluorine-based polymers alone, or they may be composed of two or more types in combination. Furthermore, in the present invention, these fluorine-based polymer fine particles described as component (E) may be used alone, or two or more types with different compositions may be used in combination.

[0079] When using component (E), the amount used is, for example, 15 to 100 parts by weight, preferably 20 to 80 parts by weight, per 100 parts by weight of component (A).

[0080] [(F) Organic solvent] Examples of organic solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, cyclohexane, methylcyclohexane, toluene, xylene, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, ethylene glycol monomethyl ether acetate, propylene glycol dimethyl ether, dioxane, cyclopentyl methyl ether, methylene chloride, chloroform, 1,2-dichloroethane, γ-butyrolactone, cellosolve, butyl cellosolve, carbitol, and butyl carbitol. These organic solvents may be used individually or in combination of two or more. When using component (F), the amount used should be such that the solid content concentration of the adhesive composition is, for example, 3 to 80% by weight, preferably 10 to 50% by weight, from the viewpoint of workability, including the formation of the adhesive layer.

[0081] Furthermore, the adhesive composition of the present invention may also contain, for example, stabilizers such as light stabilizers, weather stabilizers, and heat stabilizers; anionic, cationic, and nonionic surfactants such as leveling agents and defoamers; dyes; pigments; plasticizers; and the like.

[0082] The adhesive composition of the present invention can be manufactured by mixing (A), (B), (C), (D) and other components as needed. The mixing method is not particularly limited, as long as the adhesive composition is homogeneous. The adhesive composition is preferably used in a solution state in which fine particles are dispersed (hereinafter referred to as the liquid adhesive composition), and therefore usually includes the above-mentioned (F) organic solvent. By using a liquid adhesive composition, coating the substrate and forming the adhesive layer can be carried out more smoothly when manufacturing FPC-related components, and an adhesive layer of the desired thickness can be obtained more easily.

[0083] <Application> The adhesive composition of the present invention is suitable for use as an adhesive (e.g., adhesive film, etc.) for manufacturing FPC-related components because it exhibits excellent low dielectric properties, adhesion between resin and metal, and heat resistance. Examples of FPC-related components in the present invention include coverlay film, bonding sheet, resin-coated copper foil, flexible copper-clad laminate, and flexible flat cable. [Examples]

[0084] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following examples, Stage B refers to a semi-cured state in which a portion of the adhesive composition has begun to harden, and further hardening of the adhesive composition progresses due to heating, etc. Stage C refers to a state in which the adhesive composition has completely hardened.

[0085] (Examples 1-12) The adhesive composition was prepared by adding each component in the proportions (parts by weight) shown in Table 1 to a 1000 ml flask equipped with a stirring device and stirring at room temperature for 6 hours to disperse the components. The physical properties of the obtained adhesive composition were measured and evaluated using the following method. The results are shown in Table 1.

[0086] (Comparative Examples 1-7) The adhesive composition was prepared by adding each component in the proportions (parts by weight) shown in Table 2 to a 1000 ml flask equipped with a stirring device and stirring at room temperature for 6 hours to disperse the components. The physical properties of the obtained adhesive composition were measured and evaluated using the following method. The results are shown in Table 2.

[0087] (1) Dielectric constant, dielectric loss tangent A glass plate that had been treated with a release agent was prepared, and one surface of the plate was coated with the adhesive compositions described in Tables 1 and 2 to a thickness of 100 μm after drying. Next, this coated film was left in an oven and dried at 100°C for 10 minutes to form a B-stage adhesive layer (thickness 100 μm). Then, this adhesive layer was left in the oven and heat-cured at 200°C for 60 minutes to prepare a test specimen. For this test specimen, the dielectric constant (Dk) and dielectric loss tangent (Df) were determined using the cavity resonator method with a dielectric constant measuring device manufactured by AET Co., Ltd. at a measurement temperature of 25°C and a measurement frequency of 10 GHz. The evaluation criteria are as follows.

[0088] (2) Glass transition temperature A 5mm x 50mm specimen was prepared from the specimen (thickness 100μm) obtained in the above ((1) Dielectric constant, dielectric loss tangent). A thermomechanical analyzer (TMA-7100 (Hitachi High-Tech Science Corporation)) was used to measure the prepared specimen in tensile mode with a temperature range of -15℃ to 230℃ and a flow rate of 5℃ / min. The glass transition temperature (Tg) was determined from the TMA curve. The evaluation criteria are as follows.

[0089] <Evaluation Criteria> (dielectric constant) A: Dielectric constant is 2.50 or less B: Dielectric constant is higher than 2.50

[0090] (Dielectric loss tangent) A: Dielectric loss tangent is 0.0050 or less B: Dielectric loss tangent is greater than 0.0050

[0091] (Glass transition temperature) A: Above 150℃ B: Below 150℃

[0092] (3) Peel bond strength A 25 μm thick polyimide film [Kapton 100EN, manufactured by Toray DuPont] was prepared, and the adhesive compositions described in Tables 1 and 2 were applied to one surface of the film. Next, the coated film was placed in an oven and dried at 100°C for 5 minutes to form a B-stage adhesive layer (approximately 25 μm thick), obtaining a coverlay film. Subsequently, the same polyimide film was laminated to obtain a laminate in which two polyimide films were bonded together via the adhesive composition. The laminate was then heat-pressed at 200°C and 4.5 MPa for 60 minutes, cut to a width of 10 mm and a length of 100 mm, and the peel adhesion strength in the 90° direction (perpendicular to the plane direction of the laminate) was measured using a Shimadzu Autograph AGS-500 under the following measurement conditions. The test speed was set to 50 mm / min. Tables 1 and 2 show the ratio of the adhesive strength of each example and comparative example when the adhesive strength of Comparative Example 1 is set to 100% (the ratio calculated by [peel adhesive strength of each example / comparative example (N / mm)] / [peel adhesive strength of Comparative Example 1 (N / mm)] × 100, %).

[0093] The components listed in Tables 1 and 2 are as follows: [Component (A): A resin obtained by converting the ends of a bifunctional polyphenylene ether resin to vinyl groups] (A-1): OPE-2st-2200 (manufactured by Mitsubishi Gas Chemical Co., Ltd., terminally styrene-modified polyphenylene ether resin, solids content: 63.1%, vinyl group equivalent: 1010 g / eq, number average molecular weight (Mn): 2,200) [Component (B): Maleimide compound having two or more maleimide groups in one molecule] (B-1): BMI-2300 (manufactured by Yamato Kasei Co., Ltd., phenylmethane maleimide oligomer, maleimide equivalent: 179 g / eq) (B-2): BMI-70 (manufactured by K.I. Chemicals Co., Ltd., bis(3-ethyl-5-methyl-4-maleimidophenyl)methane, maleimide equivalent: 221g / eq) (B-3): BMI-TMH (manufactured by Yamato Chemical Co., Ltd., 1,6-bismaleimide-(2,2,4-trimethyl)hexane, maleimide equivalent: 159 g / eq) [Ingredient (C): Acid-modified styrene elastomer] (C-1): ToughTec M1913 (manufactured by Asahi Kasei Chemicals, maleic anhydride-modified styrene-ethylenebutylene-styrene block copolymer, acid value: 10 mgCH3ONa / g, weight-average molecular weight: 150,000) (C-2): ToughTec M1911 (manufactured by Asahi Kasei Chemicals, maleic anhydride-modified styrene-ethylenebutylene-styrene block copolymer, acid value: 2 mgCH3ONa / g, weight-average molecular weight: 150,000)

[0094] [(C'): Unmodified styrene elastomer] (C'-1): ToughTec H1041 (manufactured by Asahi Kasei Chemicals, styrene-ethylenebutylene-styrene block copolymer, weight-average molecular weight: 150,000)

[0095] [(D): Isocyanate compounds having two or more isocyanate groups in one molecule] (D-1): Trixene BI7982 (manufactured by Baksenden, a blocked trimer of hexamethylene diisocyanate, solid content concentration: 70% by weight, isocyanate equivalent (molecular weight per isocyanate group): 410 g / eq)

[0096] [(E): Fluorine-based polymer microparticles] (E-1): PTFE powder (average particle size: 4.0 μm)

[0097] [(F): Organic solvent] (F-1): Toluene (F-2): Methyl ethyl ketone

[0098] [(G): Other] (G-1): NHM-3N (manufactured by Tokuyama Corporation, silica filler)

[0099] [Table 1]

[0100] [Table 2]

Claims

1. Component (A): Terminally styrene-modified polyphenylene ether resin, Component (B): At least one maleimide compound selected from the group consisting of phenylmethane maleimide oligomer, bis(3-ethyl-5-methyl-4-maleimidophenyl)methane, and 1,6-bismaleimide-(2,2,4-trimethyl)hexane. Component (C): Maleic anhydride-modified styrene-ethylenebutylene-styrene block copolymer, and Component (D): Blocked form of the trimer of hexamethylene diisocyanate It contains, The molar ratio (maleimide group / vinyl group) of vinyl groups in component (A) to maleimide groups in component (B) is 0.4 to 6.

0. The molar ratio (isocyanate groups / total acidic groups) of the total acidic groups in component (C) to the isocyanate groups in component (D) is 0.2 to 4.

0. The content of component (C) is 33.0 to 41.5 parts by weight per 100 parts by weight of the total content of components (A), (B), (C), and (D). Adhesive composition.

2. Furthermore, the adhesive composition according to claim 1, further comprising (E) fluorine-based polymer fine particles.

3. Furthermore, the adhesive composition according to claim 1, further comprising (F) an organic solvent.

4. Furthermore, the adhesive composition according to claim 2, comprising (F) an organic solvent.

5. An adhesive film made using the adhesive composition described in claim 1.

6. A laminate comprising the adhesive composition described in claim 1.

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