JP2023180707A - Resin composition, cured product, sheet, laminate, and printed wiring board - Google Patents

Abstract

To provide a resin composition capable of forming a cured product having excellent press moldability, sufficiently maintaining low dielectric constant and low dielectric loss tangent, and having excellent adhesiveness to copper foil.SOLUTION: A resin composition according to the present disclosure includes a bismaleimide resin (A) obtained by reacting tetracarboxylic dianhydride (a1), a diamine containing dimer diamine (a2), and maleic anhydride (a3), inorganic hollow particles (B), a rubber (C), and a polymerization initiator (D).SELECTED DRAWING: None

Description

The present disclosure relates to a resin composition, a cured product, a sheet, a laminate, and a printed wiring board.

Printed wiring boards and multilayer wiring boards using them are used in products such as mobile communication devices such as mobile phones and smartphones, their base station equipment, network-related electronic equipment such as servers and routers, and large computers.

In recent years, high-frequency electrical signals have been used in these products to transmit and process large amounts of information at high speed. However, since high-frequency signals are extremely susceptible to attenuation, the above-mentioned Insulating materials with excellent dielectric properties are required for use in printed wiring boards, multilayer wiring boards, and the like.

Epoxy resin compositions disclosed in Patent Documents 1 to 3 are known as the above-mentioned insulating material. This Patent Document 1 discloses that an epoxy resin composition containing an epoxy resin, an active ester compound, and a triazine-containing cresol novolac resin is effective for lowering the dielectric loss tangent. Further, Patent Documents 2 and 3 disclose that a resin composition containing an epoxy resin and an active ester compound as essential components can form a cured product with a low dielectric loss tangent, and is useful as an insulating material. However, it has been found that these epoxy resin compositions are not satisfactory for high frequency band applications.

On the other hand, in Patent Document 4, a resin film made of a resin composition containing a bismaleimide resin having a long-chain alkyl group and an inorganic filler as a non-epoxy material has excellent dielectric properties (low relative permittivity and low dielectric constant). It has been reported that the However, since such a resin composition has a low melt viscosity, resin flow increases during pressing, and press molding tends to be difficult.

Japanese Patent Application Publication No. 2011-132507 Japanese Patent Application Publication No. 2015-101626 JP2017-210527A International Publication No. 2022/025123

An object of the present disclosure is to provide a resin composition that can form a cured product that has excellent press moldability, sufficiently maintains low dielectric constant and low dielectric loss tangent, and has excellent adhesion to copper foil. shall be. Another object of the present disclosure is to provide a cured product, sheet, laminate, and printed wiring board using the resin composition.

As a result of intensive studies to solve the above problems, the present inventors have discovered that a bishydride prepared by reacting a tetracarboxylic dianhydride (a1), a diamine containing dimer diamine (a2), and maleic anhydride (a3) A resin composition containing a maleimide resin (A), an inorganic hollow particle (B), a rubber (C), and a polymerization initiator (D) has excellent press moldability and has a sufficiently low dielectric constant and low dielectric loss tangent. The present inventors have discovered that it is possible to form a cured product having excellent adhesion to copper foil while maintaining the same properties, and have completed the present invention.

One aspect of the present disclosure relates to the following resin compositions, sheets, laminates, and printed wiring boards.
[1] Bismaleimide resin (A) obtained by reacting tetracarboxylic dianhydride (a1), diamine containing dimer diamine (a2), and maleic anhydride (a3), and inorganic hollow particles (B). , a resin composition comprising a rubber (C) and a polymerization initiator (D).
[2] The tetracarboxylic dianhydride (a1) is pyromellitic anhydride, 4,4'-oxydiphthalic anhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, bisphenol A type acid dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1 , 2-dicarboxylic anhydride, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, dicyclohexyl-3,4,3',4'- At least one member selected from the group consisting of tetracarboxylic dianhydride and bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic acid 2,3:5,6-dianhydride. The resin composition according to [1] above, which contains:
[3] The resin composition according to [1], wherein the dimer diamine (a2) contains at least one of a compound represented by the following formula (1) and a compound represented by the following formula (2).


[In formulas (1) and (2), m, n, p and q each represent an integer of 1 or more selected so that m+n=6 to 17 and p+q=8 to 19, and the bonds indicated by broken lines means a carbon-carbon single bond or a carbon-carbon double bond. However, when the bond shown by the broken line is a carbon-carbon double bond, formulas (1) and (2) calculate the number of hydrogen atoms bonded to each carbon atom constituting the carbon-carbon double bond using the formula The structure is obtained by subtracting one from the numbers shown in (1) and (2). ]
[4] The resin composition according to any one of [1] to [3] above, wherein the bismaleimide resin has a weight average molecular weight of 3,000 or more and less than 30,000.
[5] The resin composition according to any one of [1] to [4] above, wherein the inorganic hollow particles (B) are hollow silica.
[6] The resin composition according to any one of [1] to [5] above, wherein the inorganic hollow particles (B) have an average particle size of 50 nm to 2.5 μm.
[7] The resin according to any one of [1] to [6] above, wherein the content of the inorganic hollow particles (B) is 15 to 70% by mass based on the total amount of nonvolatile components in the resin composition. Composition.
[8] The rubber (C) contains at least one selected from the group consisting of butadiene rubber, isoprene rubber, styrene-butadiene rubber, and acrylic rubber, according to any one of [1] to [7] above. resin composition.
[9] Any of the above [1] to [8], wherein the polymerization initiator (D) contains at least one selected from the group consisting of organic peroxides, imidazole compounds, phosphine compounds, and phosphonium salt compounds. The resin composition according to claim 1.
[10] The resin composition according to any one of [1] to [9] above, further comprising monomer (E).
[11] The resin composition according to [10] above, wherein the monomer (E) contains at least one selected from the group consisting of acrylate compounds, methacrylate compounds, and allyl compounds.
[12] A cured product of the resin composition according to any one of [1] to [11] above.
[13] A sheet comprising the resin composition and base material according to any one of [1] to [11] above.
[14] A laminate obtained by thermocompression-bonding a base material to the adhesive surface of the sheet according to [13] above.
[15] A printed wiring board using the sheet described in [13] above.
[16] A printed wiring board using the laminate of [14] above.

According to the present disclosure, there is provided a resin composition capable of forming a cured product that has excellent press moldability, sufficiently maintains low dielectric constant and low dielectric loss tangent, and has excellent adhesion to copper foil, and uses the same. Cured products, sheets, laminates, and printed wiring boards can be provided.

The resin composition according to the present disclosure not only has excellent low dielectric properties in a high frequency band, but also has adhesion to copper foil and further has excellent press moldability. In addition, the resin composition can be used not only as an adhesive for manufacturing printed circuit boards (build-up boards, flexible printed wiring boards, etc.) and copper-clad boards for flexible printed wiring boards, but also as semiconductor interlayer materials, coating agents, and resists. It is also useful as ink, conductive paste, etc.

Embodiments of the present disclosure will be described in detail below.

[Resin composition]
The resin composition of the present embodiment includes a diamine (a2) containing a tetracarboxylic dianhydride (a1) (hereinafter also referred to as the (a1) component) and a dimer diamine (hereinafter also referred to as the (a2) component). , and maleic anhydride (a3) (hereinafter also referred to as component (a3)), bismaleimide resin (A) (hereinafter also referred to as component (A)), and inorganic hollow particles (B) ( (hereinafter also referred to as (B) component), rubber (C) (hereinafter also referred to as (C) component), and polymerization initiator (D) (hereinafter also referred to as (D) component). . The resin composition of the present embodiment may further contain a monomer (E) (hereinafter also referred to as "component (E)"). Moreover, the resin composition of this embodiment may further contain an organic solvent (F) (hereinafter also referred to as "(F) component").

((A) component: bismaleimide resin)
Component (A) can be obtained by reacting component (a1), component (a2), and component (a3).

As the tetracarboxylic dianhydride of component (a1), those known as raw materials for polyimide can be used. Component (a1) includes, for example, pyromellitic anhydride, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, 1,3,3a,4,5,9b-hexahydro-5(tetrahydro-2, 5-dioxo-3-furanyl) naphtho[1,2-C]furan-1,3-dione, 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-diphenylsulfone tetracarboxylic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 4,4'-(4,4' -isopropylidene diphenoxy) diphthalic anhydride, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, 1,2,3,4-butanetetracarboxylic dianhydride, 1,3,3a,4 , 5,9b-hexahydro-5(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-C]furan-1,3-dione, 1,2,3,4-cyclobutanetetracarboxylic acid di Anhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, bicyclo[2 .2.2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid) 1,4 -phenylene, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 4,4'-(ethyne-1,2-diyl)diphthalic anhydride, 5-(2,5-dioxo (tetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, dicyclohexyl-3,4,3',4'-tetracarboxylic dianhydride, 3,4'-oxydiphthalic anhydride, 3,4'-biphthalic anhydride, and norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid di Examples include anhydrides. These can be used alone or in combination of two or more.

From the viewpoint of low dielectric properties and heat resistance, component (a1) is pyromellitic anhydride, 4,4'-oxydiphthalic anhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, bisphenol. Type A acid dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene- 1,2-dicarboxylic anhydride, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, dicyclohexyl-3,4,3',4' - at least one member selected from the group consisting of tetracarboxylic dianhydride and bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic acid 2,3:5,6-dianhydride It is preferable to contain, and it is more preferable to contain pyromellitic anhydride.

Component (a2) contains dimer diamine as an essential component. Dimer diamine is a compound derived from dimer acid, which is a dimer of unsaturated fatty acids such as oleic acid, as described in, for example, JP-A-9-12712. By using dimer diamine as the component (a2), the dielectric properties of the cured product can be lowered. In this embodiment, known dimer diamines can be used without any particular limitations. The component (a2) preferably includes, for example, at least one of a compound represented by the following formula (1) and a compound represented by the following formula (2).

In formulas (1) and (2), m, n, p and q each represent an integer of 1 or more selected so that m+n=6 to 17 and p+q=8 to 19, and the bonds shown by broken lines are , means a carbon-carbon single bond or a carbon-carbon double bond. However, when the bond shown by the broken line is a carbon-carbon double bond, formulas (1) and (2) calculate the number of hydrogen atoms bonded to each carbon atom constituting the carbon-carbon double bond using the formula The structure is obtained by subtracting one from the numbers shown in (1) and (2).

From the viewpoint of solubility in organic solvents, heat resistance, heat-resistant adhesiveness, low viscosity, etc., the dimer diamine is preferably a compound represented by the above formula (2), and particularly a compound represented by the following formula (3). is preferred.

Examples of commercially available dimer diamines include PRIAMINE 1075 and PRIAMINE 1074 (both manufactured by Croda Japan Co., Ltd.).

Component (a2) may further contain a diamine other than dimer diamine as the second diamine. By using an alicyclic diamine as the second diamine, the dielectric constant can be lowered. By using an aromatic diamine as the second diamine, the elastic modulus and Tg of the cured product can be improved.

Examples of the second diamine include 1,3-diaminopropane, norbornane diamine, 4,4-methylene dianiline, 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene, 4, 4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 9,9-bis(4-aminophenyl)fluorene , 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(aminomethyl)norbornane, 4,4'-(hexafluoroisopropylidene)dianiline, 3(4),8( 9)-Bis(aminomethyl)tricyclo[5.2.1.02,6]decane, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, isophoronediamine, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), 1,1-bis(4-aminophenyl)cyclohexane, 2,7-diaminofluorene, 4,4'-ethylenedianiline, 4,4'-methylenebis( 2,6-diethylaniline), 4,4'-methylenebis(2-ethyl-6-methylaniline), 2,2-bis[4-(4-aminophenoxy)phenyl]propane, bis[4-(4- aminophenoxy)phenyl]methane, 4,4'-bis(4-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]ketone, 1 , 3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2,2'-dimethylbiphenyl-4,4'-diamine, (4,4'-diamino)diphenyl ether, (3,3'-diamino)diphenylethe, paraphenylenediamine, orthophenylenediamine, metaphenylenediamine, 2,2'-dimethylbiphenyl-4,4'-diamine, bis[4-(3-aminophenoxy)phenyl]sulfone , and bis[4-(4-aminophenoxy)phenyl]sulfone. These can be used alone or in combination of two or more.

In component (a2), the molar ratio of dimer diamine is preferably 50 mol% or more, more preferably 70 mol% or more, based on the total diamine. By setting the molar ratio of dimer diamine to 50 mol % or more, the low dielectric properties of the cured product of the resin composition can be further improved.

Component (A) can be produced by various known methods. For example, first, components (a1) and (a2) are heated at a temperature of about 60 to 120°C, preferably 70 to 90°C, for usually about 0.1 to 2 hours, preferably 0.1 to 1.0 hours. Perform polyaddition reaction. Next, the obtained polyadduct is further subjected to an imidization reaction, that is, a dehydration ring closure reaction, at a temperature of about 80 to 250°C, preferably 100 to 200°C, for about 0.5 to 30 hours, preferably 0.5 to 10 hours. let Subsequently, the product subjected to the dehydration ring-closing reaction and component (a3) are subjected to a maleimidation reaction at a temperature of about 60 to 250°C, preferably 80 to 200°C, for about 0.5 to 30 hours, preferably 0.5 to 10 hours. In other words, the desired component (A) is obtained by carrying out a dehydration ring closure reaction.

In the imidization reaction or the maleimidization reaction, various known reaction catalysts, dehydrating agents, and organic solvents described below can be used. As a reaction catalyst, aliphatic tertiary amines such as triethylamine, aromatic tertiary amines such as dimethylaniline, heterocyclic tertiary amines such as pyridine, picoline, and isoquinoline, or methanesulfonic acid, para Examples include organic acids such as toluenesulfonic acid monohydrate. Examples of the dehydrating agent include aliphatic acid anhydrides such as acetic anhydride, aromatic acid anhydrides such as benzoic anhydride, and the like.

Component (A) can be purified by various known methods to increase its purity. For example, first, component (A) dissolved in an organic solvent and pure water are placed in a separating funnel. Next, shake the separating funnel and let it stand. Subsequently, after the aqueous layer and organic layer are separated, component (A) can be purified by collecting only the organic layer.

The molecular weight of component (A) can be controlled by the number of moles of component (a1) and component (a2), and the smaller the number of moles of component (a1) than the number of moles of component (a2), the smaller the molecular weight. be able to. For the purpose of easily achieving the effects of the present invention, the ratio of [number of moles of component (a1)]/[number of moles of component (a2)] is usually about 0.30 to 0.85, preferably 0.50 to 0. A range of .80 is good.

The molecular weight of component (A) may be 3,000 or more and less than 30,000, 5,000 or more and 25,000 or less, or 7,000 or more and 20,000 or less in terms of weight average molecular weight, from the viewpoint of solubility in a solvent and heat resistance. When the weight average molecular weight is less than 30,000, solubility in organic solvents becomes good, and when it is 3,000 or more, the effect of improving heat resistance tends to be sufficiently obtained.

As component (A), a commercially available compound can also be used, and a preferable example is a compound manufactured by DESIGNER MOLECURES Inc. BMI-3000CG (synthesized from dimer diamine, pyromellitic anhydride, and maleic anhydride), BMI-1500, BMI-1700, BMI-5000, and the like manufactured by the company can be suitably used.

((B) component: inorganic hollow particles)
As component (B), various known inorganic hollow particles that can be used in resin compositions can be used without particular limitation. Inorganic hollow particles are particles that have voids inside. Inorganic materials constituting the outer shell of the hollow inorganic particles include, for example, silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, Boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate , titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, zirconium tungstate phosphate, and aluminosilicate. Among these, since silica is particularly excellent in low dielectric loss tangent, it is preferable to use hollow silica as the component (B).

The average particle size of component (B) may be 50 nm or more, 100 nm or more, or 200 nm or more, and may be 2.5 μm or less, 2.0 μm or less, or 1.0 μm or less. The average particle size of component (B) is preferably 50 nm to 2.5 μm, more preferably 100 nm to 2.0 μm, and even more preferably 200 nm to 1.0 μm. When the average particle size of the component (B) is within the above range, the surface roughness of the sheet can be reduced and the adhesiveness with base materials such as copper foil and polyimide film can be improved. As the average particle diameter of component (B), the value of the median diameter (d50) that is 50% is adopted. The above average particle size can be measured using a laser diffraction scattering type particle size distribution measuring device.

The porosity of component (B) is preferably 20 to 80%, more preferably 25 to 70%, even more preferably 30 to 60%. When the porosity of component (B) is within the above range, the effect of low dielectric properties (particularly low dielectric constant) can be sufficiently obtained. The specific gravity of component (B) is preferably 0.4 to 1.9 g/cm ³ , more preferably 0.5 to 1.8 g/cm ³ , even more preferably 0.6 to 1.6 g/cm ³ . When the specific gravity of component (B) is within the above range, it is easy to obtain sufficient press workability effects.

Component (B) may further contain inorganic particles having no internal voids as component (B'). Component (B') is preferably surface-treated, preferably a surface-treated product using a coupling agent, and more preferably a surface-treated product using a silane coupling agent. By surface-treating component (B'), not only can the dispersibility in the resin composition be improved, but also the surface roughness of the sheet surface can be further reduced, making it suitable for use with copper foil, polyimide film, etc. Adhesion to the base material can be improved.

Examples of the coupling agent include a silane coupling agent, a titanium coupling agent, and an aluminum coupling agent. Examples of the silane coupling agent include methacrylsilane, acrylicsilane, aminosilane, aminophenylsilane, imidazolesilane, phenylsilane, vinylsilane, and epoxysilane.

The content of component (B) is not particularly limited, but is 15 to 70% by mass, 20 to 60% by mass, or 30 to 55% by mass based on the total amount of nonvolatile components (100% by mass) in the resin composition. It may be. When the content of component (B) is 15% by mass or more, it becomes easier to improve the low dielectric properties and press formability, and when it is 70% by mass or less, it becomes easier to suppress a decrease in adhesive properties. The content of component (B) may be 15 to 60% by volume, 20 to 55% by volume, or 25 to 50% by volume based on the volume of the resin composition. When the content of the component (B) is 15% by volume or more, it becomes easier to improve the low dielectric properties and press formability, and when it is less than 60% by volume, it becomes easier to suppress a decrease in adhesive properties.

((C) component: rubber)
As component (C), various known rubbers can be used without particular limitation as long as they can be used in resin compositions. Component (C) includes, for example, hydrogenated nitrile rubber (HNBR), styrene-butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), acrylonitrile butadiene rubber (NBR), epichlorohydrin rubber (ECO), and acrylic rubber (ACM). Among these, butadiene rubber, isoprene rubber, and styrene-butadiene rubber are particularly easy to improve low dielectric properties.

Component (C) may have a reactive polymerizable group added to its side chain, such as an acryloyl group, a methacryloyl group, a vinyl group, a maleimide group, an epoxy group, etc. In particular, from the viewpoint of reactivity or low dielectric properties, an acryloyl group Alternatively, it is preferable that a methacryloyl group is added.

((D) component: polymerization initiator)
As component (D), various known polymerization initiators that can be used in resin compositions can be used without particular limitation. Examples of the component (D) include organic peroxides, imidazole compounds, phosphine compounds, and phosphonium salt compounds. These can be used alone or in combination of two or more. Among these, organic peroxides are particularly preferred since they are excellent in terms of excellent curability and low dielectric properties.

Examples of organic peroxides include methyl ethyl ketone peroxide, methyl cyclohexanone peroxide, methyl acetoacetate peroxide, acetylacetone peroxide, 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, 1 , 1-bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-hexylperoxy)3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, 2, 2-bis(4,4-di-t-butylperoxycyclohexyl)propane, 1,1-bis(t-butylperoxy)cyclododecane, n-butyl 4,4-bis(t-butylperoxy)valerate , 2,2-bis(t-butylperoxy)butane, 1,1-bis(t-butylperoxy)-2-methylcyclohexane, t-butyl hydroperoxide, P-menthane hydroperoxide, 1,1 , 3,3-tetramethylbutyl hydroperoxide, t-hexyl hydroperoxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, α,α'-bis (t-butylperoxy) diisopropylbenzene, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexine-3, isobutyl peroxide oxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, cinnamic acid peroxide, m-toluoyl peroxide, benzoyl peroxide, diisopropyl peroxydicarbonate, bis(4-t -butylcyclohexyl) peroxydicarbonate, di-3-methoxybutyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, di(3-methyl-3-methoxybutyl) ) peroxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, α,α'-bis(neodecanoylperoxy)diisopropylbenzene, cumylperoxyneodecanoate, 1,1,3, 3,-Tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t- Hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, 1,1,3,3-tetramethylbutylperoxy- 2-ethylhexanoate, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-Butylperoxyisobutyrate, t-butylperoxymaleic acid, t-butylperoxylaurate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxyisopropyl mono carbonate, t-butylperoxy-2-ethylhexyl monocarbonate, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, t-butylperoxyacetate, t-hexylperoxybenzoate, t-butylperoxy Oxy-m-toluoylbenzoate, t-butylperoxybenzoate, bis(t-butylperoxy)isophthalate, t-butylperoxyallyl monocarbonate, and 3,3',4,4'-tetra(t- butylperoxycarbonyl)benzophenone. These can be used alone or in combination of two or more. Among these organic peroxides, dicumyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, α,α'-bis(t-butylperoxy)diisopropylbenzene, etc. is preferred.

Examples of the imidazole compound include 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-ethylimidazole, 2,4-dimethylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 1-vinyl-2- Methylimidazole, 1-propyl-2-methylimidazole, 2-isopropylimidazole, 1-cyanomethyl-2-methyl-imidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, Examples include 1-cyanoethyl-2-phenylimidazole. Among them, 1-cyanoethyl-2-phenylimidazole and 2-ethyl-4-methylimidazole are preferred because they have high solubility in the resin composition according to the present embodiment. These can be used alone or in combination of two or more.

Examples of phosphine compounds include primary phosphines such as alkylphosphines such as ethylphosphine and propylphosphine, and phenylphosphine; dialkylphosphines such as dimethylphosphine and diethylphosphine; secondary phosphines such as diphenylphosphine, methylphenylphosphine, and ethylphenylphosphine; and trimethylphosphine, triethylphosphine, tributylphosphine, trioctylphosphine, tricyclohexylphosphine, triphenylphosphine, alkyldiphenylphosphine, dialkylphenylphosphine, tribenzylphosphine, tritolylphosphine, tri-p-styrylphosphine, tris( Examples include tertiary phosphines such as 2,6-dimethoxyphenylphosphine, tri-4-methylphenylphosphine, tri-4-methoxyphenylphosphine, and tri-2-cyanoethylphosphine. Among them, tertiary phosphine is preferably used. These can be used alone or in combination of two or more.

Examples of phosphonium salt compounds include compounds having tetraphenylphosphonium salt, alkyltriphenylphosphonium salt, tetraalkylphosphonium, etc. Specifically, tetraphenylphosphonium-thiocyanate, tetraphenylphosphonium-tetra-p-methyl Phenylborate, butyltriphenylphosphonium-thiocyanate, tetraphenylphosphonium-phthalic acid, tetrabutylphosphonium-1,2-cyclohexyldicarboxylic acid, tetrabutylphosphonium-1,2-cyclohexyldicarboxylic acid, and tetrabutylphosphonium- Examples include lauric acid.

The content of component (D) is not particularly limited, but is preferably 0.1 to 10.0 parts by mass, more preferably 1.0 to 5.0 parts by mass, per 100 parts by mass of component (A).

((E) component: monomer)
As component (E), various known monomers that can be used in resin compositions can be used. Examples of the component (E) include acrylate compounds, methacrylate compounds, allyl compounds, and benzoxazine compounds. These can be used alone or in combination of two or more. Among these, from the viewpoint of reactivity with the maleimide group of component (A) and low dielectric properties, component (E) contains at least one member selected from the group consisting of acrylate compounds, methacrylate compounds, and allyl compounds. May be contained.

Examples of acrylate compounds include isobornyl acrylate, dimethyloltricyclodecane dimethacrylate, 2-acryloyloxyethylhexahydrophthalic acid, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, dicyclopentanyl acrylate, and adamantane. Cyclic hydrocarbon acrylates such as acrylate, dimethyltricyclodecane diacrylate, tricyclodecane dimethanol diacrylate; benzyl acrylate, phenoxyethyl acrylate, phenoxypolyethylene glycol acrylate, nonylphenol ethylene oxide adduct acrylate, 2-acryloyloxyethylphthal acids, aromatic acrylates such as 2-acryloyloxyethyl-2-hydroxyethylphthalate, neopentyl glycol acrylic acid benzoate; and trimethylolpropane triacrylate, tris-(2-acryloxyethyl) isocyanurate, Bis(2-acryloxyethyl) isocyanurate, tris-(2-acryloxyethyl) isocyanurate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol polyacrylate, etc. Examples include polyfunctional acrylates.

Examples of methacrylate compounds include methacrylic acid, methyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, tridecyl methacrylate, and stearyl methacrylate. , glycidyl methacrylate, and hydroxypropyl methacrylate.

Examples of allyl compounds include allyl isonicotinate, allyl phenyl ether, allyl p-tolyl ether, allyl phenoxyacetate, 1-allylnaphthalene, allyl phenylacetate, triallyl(methyl)silane, triallyl(phenyl)silane, and allyl benzoate. , allyl benzyl ether, allyl o-tolyl ether, N-allyloxyphthalimide, allylcyclohexane, allylbenzene, 9,9-bis(4-allyloxyphenyl)fluorene, and triallyl isocyanurate.

The content of component (E) is not particularly limited, but is 1.0 to 30.0 parts by mass, 3.0 to 20.0 parts by mass, or 5.0 to 20.0 parts by mass, based on 100 parts by mass of component (A). It may be 10.0 parts by mass.

((F) component: organic solvent)
Component (F) is not particularly limited as long as it dissolves component (A). Component (F) includes, for example, aromatic hydrocarbons such as benzene, toluene, xylene, and mesitylene; alcoholic solvents such as methanol, ethanol, isopropyl alcohol, butanol, pentanol, hexanol, propanediol, and phenol; acetone, methyl Ketone solvents such as isobutyl ketone, methyl ethyl ketone, pentanone, hexanone, cyclopentanone, cyclohexanone, isophorone, acetophenone; cellosolves such as methyl cellosolve, ethyl cellosolve, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, formic acid Ester solvents such as butyl; and ethylene glycol mono-n-butyl ether, ethylene glycol mono-iso-butyl ether, ethylene glycol mono-tert-butyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-iso-butyl ether, triethylene glycol mono-n-butyl ether, and tetraethylene glycol mono-n-butyl ether; Examples include glycol ether solvents such as ethylene glycol mono-n-butyl ether. These can be used alone or in combination of two or more. Aromatic hydrocarbons such as toluene and mesitylene in which component (A) is highly soluble may be used in combination with ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone in which component (B) is highly dispersible.

The amount of component (F) to be used is not particularly limited, but it should normally be used within a range such that the nonvolatile content of the resin composition of the present embodiment is about 20 to 70% by mass.

The resin composition of this embodiment is prepared according to a generally employed method. Examples include methods such as melt mixing, powder mixing, and solution mixing. In addition, in this case, other than the essential components according to this embodiment, such as a mold release agent, a flame retardant, an ion trapping agent, an antioxidant, an adhesion promoter, a low stress agent, a coloring agent, a coupling agent, etc. may be blended within a range that does not impair the effects of the present disclosure.

A mold release agent is added to improve mold releasability from a mold. Examples of mold release agents include carnauba wax, rice wax, candelilla wax, polyethylene, oxidized polyethylene, polypropylene, montanic acid, montanic acid and saturated alcohol, 2-(2-hydroxyethylamino)ethanol, ethylene glycol, glycerin, etc. All known ester compounds such as montan wax, stearic acid, stearic acid ester, and stearic acid amide can be used. These can be used alone or in combination of two or more.

The flame retardant is added to impart flame retardancy, and all known flame retardants can be used without particular limitation. Examples of the flame retardant include phosphazene compounds, silicon compounds, talc supporting zinc molybdate, zinc oxide supporting zinc molybdate, aluminum hydroxide, magnesium hydroxide, molybdenum oxide, and the like. These can be used alone or in combination of two or more.

The ion trap agent is added in order to trap ionic impurities contained in the liquid resin composition and prevent thermal deterioration and moisture absorption deterioration. All known ion trapping agents can be used and are not particularly limited. Examples of the ion trapping agent include hydrotalcites, bismuth hydroxide compounds, and rare earth oxides. These can be used alone or in combination of two or more.

[Cured product]
The cured product of this embodiment is obtained by curing the resin composition of this embodiment. Specifically, it can be obtained by heat-treating the composition at about 150 to 250°C for about 10 minutes to 3 hours.

The shape of the cured product is not particularly limited, but when used for adhesion of base materials, it can be in the form of a sheet with a film thickness of usually about 1 to 100 μm, preferably about 3 to 50 μm, and the film thickness can be determined depending on the application. It can be adjusted accordingly.

[Sheet]
The sheet of this embodiment includes the resin composition of this embodiment and a base material. In the sheet, a resin layer containing the above-mentioned resin composition is formed on a base material. The resin layer becomes the adhesive surface of the sheet. The sheet of this embodiment can be obtained, for example, by applying the resin composition of this embodiment to a base material (sheet base material) and drying it.

Examples of the base material include polyimide, polyimide-silica hybrid, polyamide, polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polymethyl methacrylate resin (PMMA), and polystyrene resin. (PSt), polycarbonate resin (PC), acrylonitrile-butadiene-styrene resin (ABS), ethylene terephthalate, phenol, phthalic acid, hydroxynaphthoic acid, etc., and aromatic polyester resin (so-called liquid crystal polymer ; manufactured by Kuraray Co., Ltd., "Vexter", etc.), and among these, polyimide films, particularly polyimide-silica hybrid films, are preferred from the viewpoint of heat resistance and dimensional stability. Furthermore, as the base material, metals such as glass, iron, aluminum, 42 alloy, and copper, and inorganic base materials such as ITO, silicon, and silicon carbide may be used. The thickness of the base material can be appropriately set depending on the application.

[Laminated body]
In the laminate of this embodiment, a base material is further thermocompression bonded to the adhesive surface of the sheet. The laminate is obtained by further thermocompressing a base material onto the adhesive surface of the sheet. The base material is preferably a metal such as glass, iron, aluminum, 42 alloy, or copper; or an inorganic base material such as ITO, silicon, or silicon carbide. The thickness of the base material can be appropriately set depending on the application. The laminate may be further heat-treated.

[Printed circuit boards and printed wiring boards]
The printed circuit board of this embodiment uses the sheet described above or the laminate described above. The printed circuit board of this embodiment is obtained, for example, by further bonding the adhesive surface of the sheet to the inorganic base material surface of the laminate. The printed circuit board preferably uses a polyimide film as an organic base material and a metal foil (especially copper foil) as an inorganic base material. Then, a circuit is formed by soft etching the metal surface of the printed circuit board, and the sheet is further bonded thereon and hot pressed to obtain a printed wiring board.

The resin composition according to this embodiment not only has excellent low dielectric properties in a high frequency band, but also has high adhesiveness to copper foil and excellent press moldability. Therefore, the adhesive composition can be used not only as an adhesive for manufacturing printed circuit boards (build-up boards, flexible printed wiring boards, etc.) and copper-clad boards for flexible printed wiring boards, but also as semiconductor interlayer materials, coating agents, etc. It is also useful as resist ink, conductive paste, etc.

Hereinafter, the present disclosure will be specifically explained using Examples and Comparative Examples, but the present invention is not limited thereto.

(Synthesis of bismaleimide resin)
In a 2L pressure-resistant SUS container (manufactured by Todoroki Sangyo Co., Ltd.) equipped with a cooling tube, a separation tank, a nitrogen introduction tube, a thermocouple, and a stirrer, 111 parts by mass of pyromellitic anhydride (manufactured by Daicel Corporation) and toluene (Fujifilm Co., Ltd.) were placed. 907 parts by mass (manufactured by Wako Pure Chemical Industries, Ltd.) and 200 parts by mass of methanol (manufactured by Taishin Chemical Co., Ltd.) were added. Next, nitrogen gas was introduced into the container to pressurize it to a gauge pressure of 250 kPa, and then the temperature was raised to 80° C. and kept at that temperature for 0.5 hours. Subsequently, 368 parts by mass of dimer diamine (trade name "PRIAMINE1075", manufactured by Croda Japan Co., Ltd.) was added dropwise at a dropping rate of 12.3 g/min. After the dropwise addition, the mixture was kept at 80° C. for 0.5 hours, and then 6.5 parts by mass of methanesulfonic acid was added. Thereafter, the temperature was raised to 160° C., a dehydration ring-closing reaction was performed for 2 hours, water and methanol in the reaction solution were removed, and an intermediate polyimide resin was obtained. Subsequently, the obtained polyimide resin was cooled to 135°C, 50 parts by mass of maleic anhydride (manufactured by Mitsui Chemicals, Inc.) was added, the temperature was raised to 160°C, and a dehydration ring-closing reaction was performed for 2 hours. Water was removed to obtain an imide-extended bismaleimide resin. The dehydration ring closure reaction step was carried out while stirring the reaction solution at a rotational speed of 300 rpm while controlling the gauge pressure in the container to 250±10 kPa.

The obtained bismaleimide resin was placed in a separatory funnel, 2000 parts by mass of pure water was added, and the separatory funnel was shaken and allowed to stand still. After standing still, an aqueous layer and an organic layer were separated, and only the organic layer was collected. The collected organic layer was placed in a 2L glass container equipped with a condenser, nitrogen inlet tube, thermocouple, stirrer, and vacuum pump, heated to 88-93°C, water removed, and heated to 110-120°C. The temperature was raised to 0.degree. C., and a portion of toluene was removed to obtain a solution of bismaleimide resin (A-1) (nonvolatile content: 58.9%).

(Non-volatile content)
After weighing 0.75g ± 0.25g of the solution of bismaleimide resin (A-1) into a metal petri dish using a precision balance, it was dried in a hot air dryer at 150°C for 0.5 hours, and the non-volatile content (NV ) was calculated.
NV (mass%) = {(W3-W1)/W2}×100
W1: Mass of empty metal petri dish (g)
W2: Mass (g) of bismaleimide resin solution before drying
W3: Mass of metal petri dish + bismaleimide resin after drying (g)

(Weight average molecular weight)
The weight average molecular weight (Mw) of (A-1) was measured by GPC (gel permeation chromatography). A sample in which bismaleimide resin (A) was dissolved in tetrahydrofuran (THF) to a concentration of 3% by mass was placed in a column heated to 30°C (GL-R420 x 1, GL-R430 x 1, GL -R440 (manufactured by Hitachi High-Tech Fielding Co., Ltd. x 1 bottle), 50 μL was injected, and measurements were performed at a flow rate of 1.6 mL/min using THF as a developing solvent. An L-3350 RI detector (manufactured by Hitachi, Ltd.) was used as a detector, and Mw was converted from the elution time using a molecular weight/elution time curve prepared using standard polystyrene (manufactured by Tosoh Corporation). The Mw of (A-1) was 16,000.

[Resin composition]
Resin compositions of Examples and Comparative Examples were prepared by blending the components shown below in the compositions (parts by mass) shown in Table 1. The nonvolatile content of the resin composition was measured in the same manner as above.
(A) Component: Bismaleimide resin (A-1)
(B) Component: Hollow silica (particle size 0.5 μm, specific gravity 1.2 g/cm ³ , porosity 40%)
(B') Component: Silica (manufactured by Admatex Co., Ltd., trade name "5SX-CM16", slurry containing 70% by mass of phenylaminosilane-treated silica, particle size 0.5 μm, specific gravity 2.1 g/cm ³ )
(C) Component: Isoprene rubber (manufactured by Kuraray Co., Ltd., product name "UC-102M")
(D) Component: Dicumyl peroxide (manufactured by NOF Corporation, trade name "Percmil D")
(E) Component: A-DCP (manufactured by Shin Nakamura Chemical Co., Ltd., tricyclodecane dimethanol diacrylate), TAIC (manufactured by Tokyo Chemical Industry Co., Ltd., triallyl isocyanurate)
(F) Component: MIBK (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., methyl isobutyl ketone)

[Preparation of sheet (1)]
Using an applicator, apply the above resin composition onto Film Biner (registered trademark) (PET film, manufactured by Fujimori Industries Co., Ltd., product name "NS14", thickness 75 μm) so that the thickness becomes 100 μm after drying. It was applied and dried in a dryer at 130°C for 15 minutes to produce a sheet (1).

[Preparation of laminate and cured sheet]
Copper foil (manufactured by Mitsui Kinzoku Mining Co., Ltd., product name: 3EC-M2S-VLP) was laminated on both sides of the sheet (1) from which the PET film was peeled off, and laminated using a vacuum laminator at 75°C for 30 seconds at -100kPa. After that, a curing treatment was performed at 200° C. for 1 hour in a dryer to obtain a laminate in which copper foil, sheet-shaped cured product, and copper foil were laminated in this order. The copper foil of the laminate was removed by etching with an aqueous ammonium persulfate solution, and dried at 110° C. for 30 minutes to obtain a cured sheet.

(Adhesive strength)
The adhesive strength with copper foil was measured using the laminate. The adhesive strength was measured using a 90° peel measuring machine (RHEONER II CREEP METER RE2-3305B manufactured by Yamaden Co., Ltd.) at room temperature and a tensile speed of 5 mm/sec. "A" if the adhesive strength is 1.0 kN/m or more, "B" if the adhesive strength is 0.5 kN/m or more and less than 1.0 kN/m, and "B" if the adhesive strength is less than 0.5 kN/m. A certain case was determined to be "C".

(permittivity and dielectric loss tangent)
A test piece having a size of 80 mm x 60 mm was prepared from the cured sheet, and the dielectric constant (Dk) and dielectric loss tangent (Df) at 10 GHz were measured using an SPDR dielectric resonator (manufactured by Agilent Technologies).

(Coefficient of linear thermal expansion)
A test piece having a size of 30 mm x 4 mm was prepared from the cured sheet. Using this test piece, the coefficient of linear expansion (CTE) was measured using a thermomechanical analyzer (trade name "TMA/SS7100", manufactured by Hitachi High-Tech Science Co., Ltd.). The measurement mode was tensile mode, the measurement load was 50 mN, the measurement atmosphere was air, the temperature increase rate was 5°C/min, and the measurement result at 100 to 200°C in the 2nd run was taken as the CTE.

[Preparation of sheet (2)]
Using an applicator, apply the above resin composition on Film Biner (registered trademark) (PET film, manufactured by Fujimori Kogyo Co., Ltd., product name "NS14", film thickness 75 μm) to a thickness of 25 μm after drying. It was coated and dried in a dryer at 130°C for 15 minutes to obtain a sheet (2).

(melt viscosity)
The sheets (2) from which the PET films were peeled were pasted together using a vacuum laminator to produce a sheet (3) with a thickness of 600 μm. The sheet (3) was cut into a circle with a diameter of 20 mm, and the melt viscosity was measured using a rheometer device (manufactured by Thermo ELECTRON, product name: HAKKA RheoStress 600). The measurement conditions were a heating rate of 5°C/min and a measurement temperature of 40 to 220°C.

(Press workability)
Copper foil (manufactured by Mitsui Kinzoku Mining Co., Ltd., product name: 3EC-M2S-VLP) was laminated on both sides of the sheet (2) from which the PET film had been peeled off using a vacuum laminator at 75°C for 30 seconds at -100 kPa to form a sheet. (4) was obtained. A test piece having a size of 100 mm x 100 mm was prepared from the sheet (4). The test piece was hot pressed at 200°C, the amount of resin flow was measured, and the press workability was evaluated. A case where the resin flow was less than 1 mm was judged as "A", and a case where the resin flow was 1 mm or more was judged as "B".

As is clear from Table 1, the resin composition according to the present disclosure is a cured product that has excellent press moldability, sufficiently maintains low dielectric constant and low dielectric loss tangent, and has excellent adhesion to copper foil. can be formed.

Claims (16)

A bismaleimide resin (A) obtained by reacting a tetracarboxylic dianhydride (a1), a diamine containing a dimer diamine (a2), and maleic anhydride (a3),
Inorganic hollow particles (B),
Rubber (C) and
A resin composition comprising a polymerization initiator (D). The tetracarboxylic dianhydride (a1) is pyromellitic anhydride, 4,4'-oxydiphthalic anhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, bisphenol A type dianhydride, Anhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2- Dicarboxylic anhydride, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, dicyclohexyl-3,4,3',4'-tetracarboxylic acid Containing at least one selected from the group consisting of dianhydride and bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic acid 2,3:5,6-dianhydride. The resin composition according to claim 1. The resin composition according to claim 1, wherein the diamine (a2) contains at least one of a compound represented by the following formula (1) and a compound represented by the following formula (2).


[In formulas (1) and (2), m, n, p and q each represent an integer of 1 or more selected so that m+n=6 to 17 and p+q=8 to 19, and the bonds indicated by broken lines means a carbon-carbon single bond or a carbon-carbon double bond. However, when the bond shown by the broken line is a carbon-carbon double bond, formulas (1) and (2) calculate the number of hydrogen atoms bonded to each carbon atom constituting the carbon-carbon double bond using the formula The structure is obtained by subtracting one from the numbers shown in (1) and (2). ] The resin composition according to claim 1, wherein the bismaleimide resin (A) has a weight average molecular weight of 3,000 or more and less than 30,000. The resin composition according to claim 1, wherein the inorganic hollow particles (B) are hollow silica. The resin composition according to claim 1, wherein the inorganic hollow particles (B) have an average particle size of 50 nm to 2.5 μm. The resin composition according to claim 1, wherein the content of the inorganic hollow particles (B) is 15 to 70% by mass based on the total amount of nonvolatile components of the resin composition. The resin composition according to claim 1, wherein the rubber (C) contains at least one selected from the group consisting of butadiene rubber, isoprene rubber, styrene-butadiene rubber, and acrylic rubber. The resin composition according to claim 1, wherein the polymerization initiator (D) contains at least one selected from the group consisting of organic peroxides, imidazole compounds, phosphine compounds, and phosphonium salt compounds. The resin composition according to claim 1, further comprising a monomer (E). The resin composition according to claim 10, wherein the monomer (E) contains at least one selected from the group consisting of acrylate compounds, methacrylate compounds, and allyl compounds. A cured product of the resin composition according to any one of claims 1 to 11. A sheet comprising the resin composition according to any one of claims 1 to 11 and a base material. A laminate comprising a base material further bonded by thermocompression to the adhesive surface of the sheet according to claim 13. A printed wiring board using the sheet according to claim 13. A printed wiring board using the laminate according to claim 14.