Curable resin laminates, dry films, cured products, and electronic components

Abstract

Provided: A curable resin laminate with low dielectric properties, capable of easily fabricating an insulating layer with excellent adhesion (peel strength) to the conductor layer. A curable resin laminate comprising: a first resin layer formed of a first curable composition; and a second resin layer laminated on the first resin layer and formed of a second curable composition, the second resin layer having a thickness of 5-35% relative to the total thickness of the first and second resin layers, the first curable composition comprising (A1) polyphenylene ether and filler, wherein the filler content (M) as a total solid component is... B1 The content of the second curable composition is 30% or more by mass, and the content of the filler as a solid component is (M). B2 () is less than 40% by mass, which is M B1 >M B2 The slopes of (A1) and (A2) calculated from the conformation diagrams are less than 0.6.

Description

Technical Field

[0001] This invention relates to: a curable resin laminate useful for manufacturing interlayer insulating layers in electronic components such as printed circuit boards (hereinafter also simply referred to as "circuit boards"), a dry film having the curable resin laminate, and a cured product of the curable resin laminate obtained using the curable resin laminate or the dry film, and electronic components. Background Technology

[0002] In recent years, the high-frequency transmission of electronic devices has been driven by the widespread adoption of high-capacity, high-speed communication systems such as 5G and millimeter-wave lasers for automotive ADAS (Advanced Driver Assistance Systems).

[0003] The circuit boards embedded in these electronic devices use curable resin compositions with epoxy resin as the main component as insulating materials. However, the cured products formed from these compositions have high relative permittivity (Dk) and dielectric loss tangent (Df), leading to increased signal transmission loss in high-frequency digital bands, signal attenuation, and heat generation. Therefore, polyphenylene ether (PPE), with its excellent low dielectric properties, has attracted much attention.

[0004] Non-patent literature 1 proposes a method to improve the heat resistance of polyphenylene ether by introducing allyl groups into the molecule of polyphenylene ether to form a thermosetting resin.

[0005] Existing technical documents

[0006] Non-patent literature

[0007] Non-patent literature 1: J. Nunoshige, H. Akahoshi, Y. Shibasaki, M. Ueda, J. Polym. Sci. Part A: Polym. Chem. 2008, 46, 5278-3223. Summary of the Invention

[0008] The problem the invention aims to solve

[0009] However, when polyphenylene ether is used as an insulating film for circuit boards, such as as an interlayer insulating material sandwiched between the upper and lower conductor layers of copper clad laminates (CCLs), there is a problem that the adhesion to the copper foil used in the conductor layer, or the so-called peel strength, cannot be adequately obtained.

[0010] Therefore, the object of the present invention is to provide a curable resin laminate having low dielectric properties and being useful for forming an insulating layer that has excellent adhesion (peel strength) to the conductor layer.

[0011] Solution for solving the problem

[0012] The inventors discovered that the thickness of each layer is configured as a multilayer structure within a specific range, and that the curable composition forming each layer contains polyphenylene ether with a branched structure, further specifying the filler content within a specific range, thereby solving the aforementioned problems and thus completing the present invention. In other words, the present invention is as described below.

[0013] This invention relates to a curable resin laminate, characterized in that,

[0014] It comprises: a first resin layer formed of a first curable composition; and a second resin layer laminated on at least one side of the main surface of the aforementioned first resin layer and formed of a second curable composition.

[0015] The aforementioned second resin layer has a thickness of 5% to 35% relative to the total thickness of the aforementioned first resin layer and the aforementioned second resin layer.

[0016] The aforementioned first curable composition comprises (A1) polyphenylene ether and (B1) filler, wherein the content (M) of the aforementioned (B1) filler is... B1 The content of solid components in the composition is 30% or more by mass relative to the total solid content.

[0017] The aforementioned second curable composition contains (A2) polyphenylene ether and does not contain (B2) filler, or the content of (B2) filler is (M) B2 The content of solid components in the composition is less than 40% by mass relative to the total solid content.

[0018] The content (M) of the aforementioned (B1) filler B1 The content of the aforementioned (B2) filler (M) B2 The relationship is M. B1 >M B2 ,

[0019] The aforementioned (A1) polyphenylene ether and (A2) polyphenylene ether are polyphenylene ethers obtained from raw material phenols containing at least phenols satisfying condition 1, and whose slope calculated from the conformation diagram is less than 0.6.

[0020] (Condition 1)

[0021] It has hydrogen atoms in the ortho and para positions.

[0022] The present invention can be a dry film having the aforementioned curable resin laminate.

[0023] The present invention is a cured material formed from the aforementioned cured laminate.

[0024] The present invention is an electronic component having the aforementioned cured material.

[0025] The effects of the invention

[0026] According to the present invention, a curable resin laminate having low dielectric properties and useful for forming an insulating layer with excellent adhesion (peel strength) to the conductor layer can be provided. Detailed Implementation

[0027] Hereinafter, a cured resin laminate, which is a laminated structure comprising at least two resin layers, will be described, but the present invention is not limited thereto.

[0028] In the case of isomers present in the compound described, other isomers that can exist may be used in this invention unless otherwise specified.

[0029] In this invention, phenols that are used as raw materials for polyphenylene ether (PPE) and can become structural units of PPE are referred to as "raw material phenols".

[0030] In this invention, when describing the raw material phenols, if they are referred to as "ortho", "para", etc., the position of the phenolic hydroxyl group is used as the reference (in situ) unless otherwise specified.

[0031] In this invention, when simply referred to as "adjacent", it means "at least one of the adjacent". Therefore, as long as there is no particular contradiction, when simply written as "adjacent", it can be interpreted as referring to any one of the adjacent, or it can be interpreted as referring to both adjacent.

[0032] In this invention, polyphenylene ethers in which some or all of the functional groups (e.g., hydroxyl groups) have been modified are sometimes simply referred to as "polyphenylene ether". Therefore, when referred to as "polyphenylene ether", it includes both unmodified polyphenylene ether and modified polyphenylene ether, unless there is a particular contradiction.

[0033] In this specification, monohydric phenols are mainly disclosed as raw material phenols, but polyhydric phenols may also be used as raw material phenols without affecting the effect of the present invention.

[0034] In this specification, while the upper and lower limits of the numerical range are recorded separately, within the range that is not contradictory, all combinations of each lower limit and each upper limit are actually recorded.

[0035] In this specification, solid components are used to mean non-volatile components (components other than solvents and other volatile components).

[0036] The following describes the composition and components of curable resin laminates, their effects, manufacturing methods, and applications.

[0037] It should be noted that the following descriptions sometimes do not distinguish between the components contained in the curing composition and the components contained in the cured resin layer that forms the dried coating of the curing composition.

[0038] <<<<<<Composition and Components of Curable Resin Layer>>>>>>

[0039] The curable resin laminate of the present invention comprises: a first resin layer; and a second resin layer (directly) laminated on at least one side of the main surface of the first resin layer.

[0040] The second resin layer has a thickness of 5 to 35% relative to the total thickness of the first and second resin layers.

[0041] The first and second resin layers contain polyphenylene ether.

[0042] In addition, the first resin layer must contain filler, but the second resin layer may or may not contain filler.

[0043] The second resin layer is preferably configured such that (1) it does not contain filler, or (2) when the second resin layer contains filler, the filler content of the second resin layer becomes less than the filler content of the first resin layer.

[0044] The curable resin laminate of the present invention is typically used such that the second resin layer is in contact with the object to be bonded, such as copper foil (copper circuit). Therefore, in the case of a laminate comprising two layers including a first resin layer and a second resin layer, the first resin layer is arranged in contact with a substrate such as a circuit board, and the second resin layer is used in contact with the object to be bonded, such as copper foil (copper circuit).

[0045] The curable resin laminate of the present invention may consist of a substrate film formed of polyethylene terephthalate, polypropylene, etc., and other resin layers laminated on the outer layer of the first resin layer and / or the second resin layer. Furthermore, two or more substrate films and other layers may be provided.

[0046] It should be noted that the curable resin laminate of the present invention can be any laminate that satisfies the above-described structure. For example, it can also be a laminate of at least 3 layers formed by stacking the second resin layer / the first resin layer / the second resin layer in that order.

[0047] When the curable resin laminate of the present invention has two second resin layers, for example, within the range of satisfying the following conditions A, B and / or C, the thickness, material, etc. of each second resin layer may be the same or different.

[0048] (Condition A)

[0049] It is configured in such a way that, for the thickness of the combined second resin layer, (1) the thickness is 10 to 70% relative to the thickness of the combined first and second resin layers, and the individual layer (2) of the second resin layer does not contain filler, or the filler content in the second resin layer is less than 40% by mass relative to the total solid components in the composition, and the filler content in the second resin layer becomes less than the filler content in the first resin layer.

[0050] (Condition B)

[0051] It is configured such that the thickness of the combined second resin layer is 10 to 70% of the thickness of the combined first and second resin layers, and each resin layer satisfies the specified melt viscosity as a cured product.

[0052] (Condition C)

[0053] It is configured such that the thickness of the combined second resin layer is 10 to 70% of the thickness of the combined first and second resin layers, and each resin layer satisfies the specified Young's modulus limit as a cured product.

[0054] <<<<<Composition>>>>>

[0055] <<<<Composition: First Resin Layer>>>>

[0056] The first resin layer of the present invention comprises (A1) polyphenylene ether and (B1) filler.

[0057] In addition, relative to the total solid components in the first resin layer, the content M of filler (B1) is... B1 Preferably, it contains 30% or more by mass.

[0058] According to other performance characteristics, the first resin layer is a dried coating film obtained from a first curable composition comprising (A1) polyphenylene ether and (B1) filler.

[0059] Preferably, the content M of (B1) filler relative to the total solids in the first curable composition B1 A dry coating of 30% or more by mass.

[0060] From the perspective of low thermal expansion, the content M of (B1) filler B1 More preferably 30-80% by mass, even more preferably 50-80% by mass, and particularly preferably 65-80% by mass.

[0061] The content M of (A1) polyphenylene ether relative to the total solid components in the first resin layer A1 Preferably 3-40% by mass, more preferably 5-30% by mass, even more preferably 7-25% by mass, and particularly preferably 9-20% by mass.

[0062] In addition, the first resin layer may also contain other components (C1).

[0063] (A1) polyphenylene ether, (B1) filler, and (C1) other components will be described later.

[0064] The thickness T1 of the first resin layer is greater than the thickness T2 of the second resin layer. The thickness T1 of the first resin layer is preferably 1 to 50 μm, more preferably 10 to 45 μm, even more preferably 20 to 30 μm, and particularly preferably 24 to 29 μm.

[0065] <<<<Composition: Second Resin Layer>>>>

[0066] The second resin layer of the present invention comprises (A2) polyphenylene ether.

[0067] The second resin layer may or may not contain (B2) filler.

[0068] The second resin layer is preferably free of (B2) filler, or the content of (B2) filler is (M). B2 The content (M) of the aforementioned (B1) filler is less than 40% by mass relative to the total solid content in the composition. B1 The content of the aforementioned (B2) filler (M) B2 The relationship is M. B1 >M B2 .

[0069] Based on other performance characteristics, the second resin layer is a dried coating film obtained from a second curable composition containing (A2) polyphenylene ether.

[0070] The second resin layer is preferably a dried coating film obtained from a second curable composition that does not contain (B2) filler, or a mixture of (B2) filler content M relative to the total solid components in the second curable composition. B2 The content (M) of the aforementioned (B1) filler is less than 40% by mass. B1 The content of the aforementioned (B2) filler (M) B2 The relationship is M. B1 >M B2 The dried coating film obtained from the second curing composition.

[0071] From the perspective of low dielectric properties, [the content M of (B2) filler relative to all solid components in the second curable composition] B2 [Relative to the total solids in the first curing composition, the content of (B1) filler M] B1 The ratio of ] (M) B2 / M B1More preferably, it is 50% or less; even more preferably, it is 45% or less; and even more preferably, it is 15% or less.

[0072] The content M of filler (B2) in the second resin layer and the second curable composition B2 More preferably, less than 35% by mass.

[0073] When the second resin layer and the second curable composition contain filler (B2), the content of filler M is optimal due to its excellent balance between low thermal expansion and good adhesion to the conductor layer. B2 Preferably 5-35% by mass, more preferably 20-35% by mass.

[0074] The content M of (A2) polyphenylene ether relative to the total solids in the second resin layer (or the total solids in the second curable composition) A2 Preferably 10-50% by mass, more preferably 30-50% by mass.

[0075] In addition, the second resin layer may contain other components (C2).

[0076] (A2) polyphenylene ether, (B2) filler, and (C2) other components will be described later.

[0077] For the thickness T2 of the second resin layer, the ratio of [the thickness T2 of the second resin layer] to [the total thickness (T1+T2) of the first resin layer (T1) and the second resin layer (T2)] (T2 / (T1+T2)) is 5 to 35%, preferably 10 to 25%, and more preferably 15 to 25%. By setting the ratio of the thickness T2 of the second resin layer to the above range, stable adhesion to the conductor layer can be obtained.

[0078] The thickness T2 of the second resin layer is thinner than the thickness T1 of the first resin layer, for example, preferably 0.5 to 40 μm, more preferably 0.7 to 30 μm, even more preferably 1 to 20 μm, and particularly preferably 3 to 10 μm.

[0079] <<<<<Physical Properties>>>>

[0080] <<<<Melt viscosity>>>>

[0081] The melt viscosity (MV1) of the first resin layer at 140°C is preferably greater than 20,000 dPa·s, more preferably greater than 25,000 dPa·s, and particularly preferably greater than 30,000 dPa·s. There is no particular upper limit to the melt viscosity (MV1), for example, it is 500,000 dPa·s.

[0082] The melt viscosity (MV2) of the second resin layer at 140°C is preferably below 40,000 dPa·s. The lower limit of the melt viscosity (MV2) is not particularly limited, for example, it is 10,000 dPa·s.

[0083] Furthermore, the relationship between the melt viscosity (MV1) of the first resin layer at 140°C and the melt viscosity (MV2) of the second resin layer is preferably MV1 > MV2.

[0084] More specifically, the difference in melt viscosity (MV1-MV2) between the melt viscosity (MV1) of the first resin layer at 140°C and the melt viscosity (MV2) of the second resin layer at 140°C is preferably 2000 dPa·s or more, and more preferably 5000 dPa·s or more. There is no particular upper limit to the melt viscosity difference (MV1-MV2), but it can be, for example, 450000 dPa·s, 400000 dPa·s, or 300000 dPa·s.

[0085] The melt viscosity of the resin layer at 140°C can be adjusted by changing the molecular structure, molecular weight, and content of the resin component (polyphenylene ether), or by changing the content of the filler component. Specifically, increasing the filler content in the resin layer tends to increase the melt viscosity at 140°C.

[0086] The melt viscosity of the first resin layer and the second resin layer can be determined by the following method.

[0087] Using a vacuum laminator MVLP-500 manufactured by Meiki Manufacturing Co., Ltd., individual resin layers (e.g., dry films with individual resin layers of 25 μm thickness) were repeatedly laminated to a thickness of 500 μm to serve as test pieces for melt viscosity measurement. The test pieces were then placed into a melt viscosity measuring device to measure the melt viscosity at 140°C [unit: dPa·s].

[0088] It should be noted that a HAAKE rheometer (MARS 40) was used as the melt viscosity measuring device, and the measurement was performed under the following conditions: oscillating heating method (5℃ / min), measuring temperature range: 70~200℃, frequency: 1Hz, stress control: 2.5N, parallel plate: diameter 20mm, gap: 450μm, sample size: 2.5×2.5cm.

[0089] <<<<Young's Modulus>>>>

[0090] The Young's modulus (YM1) of the first resin layer as a cured product is preferably greater than 2.0 GPa, more preferably greater than 3.0 GPa, even more preferably greater than 3.5 GPa, and particularly preferably greater than 5.0 GPa.

[0091] The Young's modulus (YM2) of the second resin layer as a cured product is preferably 3.0 GPa or less, more preferably 2.0 GPa or less.

[0092] Furthermore, the Young's modulus (YM1) of the cured first resin layer and the Young's modulus (YM2) of the cured second resin layer are preferably YM1>YM2.

[0093] More specifically, the difference in Young's modulus (YM1-YM2) between the cured Young's modulus (YM1) of the first resin layer and the cured Young's modulus (YM2) of the second resin layer is preferably 0.5 GPa or more, more preferably 1.0 GPa or more, and particularly preferably 1.5 Pa or more. Furthermore, the upper limit of the Young's modulus difference (YM1-YM2) is not particularly limited, and may be 8 GPa, 6 GPa, or 5 GPa, etc.

[0094] The Young's modulus of the resin layer as a cured product can be adjusted by changing the molecular structure, molecular weight, and content of the resin component (polyphenylene ether), changing the number of curing reactive functional groups contained in the composition, and changing the filler content. Specifically, increasing the filler content in the resin layer tends to increase the Young's modulus.

[0095] The Young's modulus of the resin layer as a cured product can be determined by the following method.

[0096] The cured resin layer with a thickness of 25 μm was cut into pieces with a length of 8 cm and a width of 0.5 cm, and the Young's modulus was determined under the following conditions.

[0097] It should be noted that Young's modulus is calculated based on the slope of strain at stresses ranging from 5 MPa to 10 MPa in the obtained stress-strain curve.

[0098] [Measurement Conditions]

[0099] Testing machine: Tensile testing machine EZ-SX (manufactured by Shimadzu Corporation)

[0100] Chuck pitch: 50mm

[0101] Test speed: 1 mm / min

[0102] Elongation calculation: (Extension movement / Chuck spacing) × 100

[0103] <<<<Composition: Other Layers>>>>

[0104] Other layers include, for example, substrate films such as polyethylene terephthalate and polypropylene, and protective films that protect the surface of curable resin layers.

[0105] <<<<<Ingredients>>>>

[0106] The components of the first and second resin layers described above, namely (A1) polyphenylene ether, (A2) polyphenylene ether, (B1) filler, (B2) filler, (C1) other components, and (C2) other components, will be described.

[0107] <<<<Ingredients: Polyphenylene ether (A1) and (A2)>>>>

[0108] The (A1) polyphenylene ether contained in the first curable composition and resin layer and the (A2) polyphenylene ether contained in the second curable composition and resin layer may be the same component or different components. Here, (A1) polyphenylene ether and (A2) polyphenylene ether are described as polyphenylene ether (specified polyphenylene ether).

[0109] <<<Polyphenylene ether (specified polyphenylene ether)>>>

[0110] The polyphenylene ether of the present invention is a polyphenylene ether obtained from a raw material phenol containing at least one phenol satisfying condition 1, and having a branched structure. This polyphenylene ether is designated as a specified polyphenylene ether.

[0111] (Condition 1)

[0112] It has hydrogen atoms in the ortho and para positions.

[0113] Phenolic compounds that satisfy condition 1 {e.g., phenols (A) and (B) described later} have hydrogen atoms in the ortho position. Therefore, during oxidative polymerization with phenols, ether bonds can be formed not only in the in-situ, para position, but also in the ortho position, thus forming a branched structure.

[0114] Thus, polyphenylene ethers with branched structures are sometimes referred to as specified polyphenylene ether branched polyphenylene ethers.

[0115] Thus, it is defined that polyphenylene ether is branched by at least three ether-bonded benzene rings at the in-situ, ortho, and para positions, as part of its structure. It is considered that the defined polyphenylene ether is, for example, a polyphenylene ether compound having at least the branched structure shown in formula (i) in its backbone.

[0116]

[0117] In equation (i), R a ~R k It is a hydrogen atom or a hydrocarbon group having 1 to 15 carbon atoms (preferably 1 to 12 carbon atoms).

[0118] Here, the phenolic raw materials constituting the specified polyphenylene ether may also include other phenolic compounds that do not satisfy condition 1, to the extent that they do not impair the effects of the present invention.

[0119] Other examples of such phenols include phenols (C) and (D) described later, and phenols that do not have hydrogen atoms at the para position. In particular, when phenols (C) and (D) described later undergo oxidative polymerization, ether bonds are formed in situ and at the para position, gradually polymerizing in a linear fashion. Therefore, for the purpose of increasing the molecular weight of polyphenylene ether, it is preferable to also include phenols (C) and (D) as raw material phenols.

[0120] Furthermore, it is specified that polyphenylene ether may also have functional groups containing unsaturated carbon bonds. By having the above-mentioned functional groups, the properties of the cured product are improved due to the effect of imparting crosslinking and excellent reactivity.

[0121] It should be noted that, unless otherwise specified, "unsaturated carbon bond" in this invention refers to multiple bonds (double or triple bonds) between carbon atoms in alkenes or alkynes.

[0122] The functional group containing unsaturated carbon bonds is not particularly limited, but alkenyl (e.g., vinyl, allyl), alkynyl (e.g., ethynyl), or (meth)acryloyl is preferred. From the viewpoint of excellent curability, vinyl, allyl, and (meth)acryloyl are more preferred, and from the viewpoint of excellent low dielectric properties, allyl is even more preferred. These functional groups having unsaturated carbon bonds can have, for example, 15 or less, 10 or less, 8 or less, 5 or less, 3 or less, etc.

[0123] There are no particular limitations on the method for introducing such functional groups containing unsaturated carbon bonds into a specified polyphenylene ether, and examples such as [Method 1] or [Method 2] can be given below.

[0124] [Method 1]

[0125] Method 1 is as follows:

[0126] Phenols as raw materials

[0127] A method comprising phenols (A) that at least satisfy both of the following conditions 1 and 2 (method 1), or a mixture comprising phenols (B) that at least satisfy the following condition 1 and do not satisfy the following condition 2, and phenols (C) that do not satisfy the following condition 1 and satisfy the following condition 2 (method 2).

[0128] (Condition 1)

[0129] It has hydrogen atoms in the ortho and para positions.

[0130] (Condition 2)

[0131] It has a hydrogen atom in the para position and a functional group containing an unsaturated carbon bond.

[0132] According to Method 1, a specified polyphenylene ether containing unsaturated carbon bonds with functional groups derived from raw phenols can be obtained.

[0133] [Method 2]

[0134] Method 2 is as follows:

[0135] The terminal hydroxyl groups of branched polyphenylene ethers are modified by using functional groups containing unsaturated carbon bonds to form terminal-modified polyphenylene ethers.

[0136] According to Method 2, even if the raw material phenol does not have a functional group containing an unsaturated carbon bond, a specified polyphenylene ether containing an unsaturated carbon bond can still be obtained.

[0137] Method 1 and Method 2 can also be implemented simultaneously.

[0138] <<Specified polyphenylene ether obtained by method 1>>

[0139] The specified polyphenylene ether obtained by method 1 uses at least one phenolic raw material (e.g., any one of phenolic (A) and phenolic (C)) that satisfies condition 2, and thus becomes crosslinkable based on a hydrocarbon group containing at least an unsaturated carbon bond. When the specified polyphenylene ether has such a hydrocarbon group containing an unsaturated carbon bond, it can also be reacted with this hydrocarbon group, and modifications such as epoxidation can be performed using compounds with reactive functional groups such as epoxy groups.

[0140] That is, the specified polyphenylene ether obtained by method 1 is, for example, a polyphenylene ether having at least the branched structure shown in formula (i) in its backbone, and is considered to be a compound having a hydrocarbon group containing at least one unsaturated carbon bond as a functional group. Specifically, R in formula (i) above is considered to be... a ~R k At least one of them is a hydrocarbon group with an unsaturated carbon bond.

[0141] In particular, in the above-mentioned method 2, from an industrial / economic point of view, the preferred phenol (B) is at least one of o-cresol, 2-phenylphenol, 2-dodecylphenol and phenol, and the preferred phenol (C) is 2-allyl-6-methylphenol.

[0142] The following is a more detailed explanation of phenols (A) to (D).

[0143] Phenolic class (A) as described above is a phenol that satisfies both conditions 1 and 2, that is, a phenol that has hydrogen atoms in the ortho and para positions and has functional groups containing unsaturated carbon bonds, preferably a phenol (a) as shown in the following formula (1).

[0144]

[0145] In formula (1), R1 to R3 are hydrogen atoms or hydrocarbon groups with 1 to 15 carbon atoms. Among them, at least one of R1 to R3 is a hydrocarbon group with unsaturated carbon bonds. It should be noted that, from the viewpoint that polymerization is easier during oxidative polymerization, hydrocarbon groups with 1 to 12 carbon atoms are preferred.

[0146] Examples of phenols (a) represented by formula (1) include o-vinylphenol, m-vinylphenol, o-allylphenol, m-allylphenol, 3-vinyl-6-methylphenol, 3-vinyl-6-ethylphenol, 3-vinyl-5-methylphenol, 3-vinyl-5-ethylphenol, 3-allyl-6-methylphenol, 3-allyl-6-ethylphenol, 3-allyl-5-methylphenol, and 3-allyl-5-ethylphenol. Only one phenol represented by formula (1) may be used, or two or more may be used.

[0147] Phenolic compounds (B) are those that satisfy condition 1 but not condition 2, i.e., those that have hydrogen atoms in the ortho and para positions and do not have functional groups containing unsaturated carbon bonds. Phenolic compounds (B) as shown in the following formula (2) are preferred.

[0148]

[0149] In formula (2), R4 to R6 are hydrogen atoms or hydrocarbon groups with 1 to 15 carbon atoms. R4 to R6 do not have unsaturated carbon bonds. It should be noted that, from the viewpoint that polymerization is easier during oxidative polymerization, hydrocarbon groups with 1 to 12 carbon atoms are preferred.

[0150] Examples of phenols (b) represented by formula (2) include phenol, o-cresol, m-cresol, o-ethylphenol, m-ethylphenol, 2,3-xylenol, 2,5-xylenol, 3,5-xylenol, o-tert-butylphenol, m-tert-butylphenol, o-phenylphenol, m-phenylphenol, 2-dodecylphenol, etc. Only one type of phenol may be used in formula (2), or two or more types may be used.

[0151] Phenolic compounds (C) as described above are phenolic compounds that do not satisfy condition 1 but satisfy condition 2, that is, phenolic compounds that have hydrogen atoms in the para position, do not have hydrogen atoms in the ortho position, and have functional groups containing unsaturated carbon bonds, preferably phenolic compounds (c) as shown in the following formula (3).

[0152]

[0153] In equation (3), R7 and R 10 R7 to R9 are hydrocarbon groups with 1 to 15 carbon atoms, with R8 and R9 being hydrogen atoms or hydrocarbon groups with 1 to 15 carbon atoms. 10At least one of them is a hydrocarbon group with an unsaturated carbon bond. It should be noted that, from the viewpoint that polymerization is easier during oxidative polymerization, the hydrocarbon group preferably has 1 to 12 carbon atoms.

[0154] Examples of phenols (c) represented by formula (3) include 2-allyl-6-methylphenol, 2-allyl-6-ethylphenol, 2-allyl-6-phenylphenol, 2-allyl-6-styrylphenol, 2,6-divinylphenol, 2,6-diallylphenol, 2,6-diisopropenylphenol, 2,6-dibutenylphenol, 2,6-diisobutenylphenol, 2,6-diisopentenylphenol, 2-methyl-6-styrylphenol, 2-vinyl-6-methylphenol, and 2-vinyl-6-ethylphenol. Only one phenol represented by formula (3) may be used, or two or more may be used.

[0155] Phenolic compounds (D) as described above are phenolic compounds that have hydrogen atoms at the para position, no hydrogen atoms at the ortho position, and no functional groups containing unsaturated carbon bonds. Phenolic compounds (d) as shown in the following formula (4) are preferred.

[0156]

[0157] In equation (4), R 11 and R 14 R is a hydrocarbon group with 1 to 15 carbon atoms that does not have unsaturated carbon bonds. 12 and R 13 It is a hydrogen atom or a hydrocarbon group with 1 to 15 carbon atoms that does not have unsaturated carbon bonds. It should be noted that, from the viewpoint that polymerization is easier during oxidative polymerization, the hydrocarbon group preferably has 1 to 12 carbon atoms.

[0158] Examples of phenols (d) represented by formula (4) include 2,6-dimethylphenol, 2,3,6-trimethylphenol, 2-methyl-6-ethylphenol, 2-ethyl-6-n-propylphenol, 2-methyl-6-n-butylphenol, 2-methyl-6-phenylphenol, 2,6-diphenylphenol, and 2,6-xylylphenol. Only one phenol represented by formula (4) may be used, or two or more may be used.

[0159] In this invention, alkyl, cycloalkyl, aryl, alkenyl, and alkynyl groups can be cited as hydrocarbon groups, with alkyl, aryl, and alkenyl groups being preferred. Alkenyl and alkynyl groups can be cited as hydrocarbon groups having unsaturated carbon bonds. It should be noted that these hydrocarbon groups can be linear or branched.

[0160] <<Specified polyphenylene ether obtained by method 2>>

[0161] The specified polyphenylene ether obtained by method 2 is a terminal-modified branched polyphenylene ether.

[0162] This end-modified branched polyphenylene ether has a branched structure and modified terminal hydroxyl groups, thus yielding a cured product that is soluble in various solvents and further reduces low dielectric properties. Furthermore, the end-modified branched polyphenylene ether positions unsaturated carbon bonds at the ends, resulting in extremely good reactivity and improved properties of the cured product.

[0163] In cases where the terminal hydroxyl group is modified by a modifying compound, an ether bond or an ester bond is typically formed between the terminal hydroxyl group and the modifying compound.

[0164] Here, as a compound for modification, there are no particular limitations as long as it contains a functional group with an unsaturated carbon bond, can react with phenolic hydroxyl groups in the presence or absence of a catalyst.

[0165] Suitable examples of compounds for modification include organic compounds represented by the following formula (11).

[0166]

[0167] In equation (11), R A R B R C Each is independently a hydrogen or a hydrocarbon group having 1 to 9 carbon atoms, R D It is a hydrocarbon group with 1 to 9 carbon atoms, and X is a group such as F, Cl, Br, I or CN that can react with phenolic hydroxyl groups.

[0168] Alternatively, from another perspective, suitable examples of compounds for modification can be found in organic compounds represented by the following formula (11-1).

[0169] RX (11-1)

[0170] In formula (11-1), R is vinyl, allyl, or (meth)acryloyl, and X is a group such as F, Cl, Br, or I that can react with phenolic hydroxyl groups.

[0171] The modification of the terminal hydroxyl groups in branched polyphenylene ethers can be confirmed by comparing the hydroxyl values ​​of the branched polyphenylene ether with those of the terminally modified branched polyphenylene ether. It should be noted that a portion of the terminally modified branched polyphenylene ether can be directly composed of unmodified hydroxyl groups.

[0172] The reaction temperature, reaction time, presence or absence of catalyst, and type of catalyst during modification can be appropriately designed. Two or more compounds can also be used as the modifying compound.

[0173] When polyphenylene ether is used as a component of the curable composition as specified above, it may be used alone or in combination with two or more components.

[0174] It should be noted that, relative to the total amount of phenols used in the synthesis of polyphenylene ether, the ratio of phenols satisfying condition 1 is preferably 1 to 50 mol.

[0175] Alternatively, phenols that satisfy condition 2 above may not be used, but when they are used, the ratio of phenols that satisfy condition 2 relative to the total amount of raw material phenols is preferably 0.5 to 99 mol%, more preferably 1 to 99 mol%.

[0176] Specifications for the physical properties and characteristics of polyphenylene ether

[0177] <branching degree>

[0178] The branched structure (degree of branching) of polyphenylene ether can be confirmed based on the following analytical steps.

[0179] (Analysis Steps)

[0180] After preparing chloroform solutions of polyphenylene ether at intervals of 0.1, 0.15, 0.2, and 0.25 mg / mL, a graph of refractive index difference versus concentration was plotted while the solution was fed at a rate of 0.5 mL / min. The refractive index increment dn / dc was calculated from the slope. Next, the absolute molecular weight was determined under the following operating conditions. Using the chromatograms from the RI detector and the MALS detector as references, a regression line based on the least squares method was obtained from the logarithmic graph (conformation diagram) of molecular weight versus radius of rotation, and its slope was calculated.

[0181] (Measurement conditions)

[0182] Device Name: HLC8320GPC

[0183] Mobile phase: chloroform

[0184] Column: TOSOH TSKguardcolumnHHR-H

[0185] +TSKgelGMHHR-H (2 sticks)

[0186] +TSKgelG2500HHR

[0187] Flow rate: 0.6 mL / min

[0188] Detector: DAWN HELEOS (MALS detector)

[0189] +Optilab rEX (RI detector, wavelength 254nm)

[0190] Sample concentration: 0.5 mg / mL

[0191] Sample solvent: Same as mobile phase. Dissolve 5 mg of sample in 10 mL of mobile phase.

[0192] Injection volume: 200μL

[0193] Filter: 0.45μm

[0194] STD reagent: Standard polystyrene Mw 37900

[0195] STD concentration: 1.5 mg / mL

[0196] STD solvent: Same as mobile phase. Dissolve 15 mg of sample in 10 mL of mobile phase.

[0197] Analysis time: 100 minutes

[0198] In resins with the same absolute molecular weight, the more branched the polymer chains, the smaller the distance (radius of gyration) from the center of gravity to each chain segment. Therefore, the slope of the logarithmic graph of absolute molecular weight versus radius of gyration obtained by GPC-MALS indicates the degree of branching; the smaller the slope, the more branching occurs. In this invention, the smaller the slope calculated from the conformation diagram, the more branches the polyphenylene ether has; the larger the slope, the fewer branches the polyphenylene ether has.

[0199] In the specified polyphenylene ether constituting the curable composition of the present invention, the slope is less than 0.6, preferably less than 0.55, less than 0.50, less than 0.45, less than 0.40, or less than 0.35. When the slope is within this range, the polyphenylene ether is considered to have sufficient branching. It should be noted that the lower limit of the above slope is not particularly limited, and for example, it is 0.05 or more, 0.10 or more, 0.15 or more, or 0.20 or more.

[0200] It should be noted that the slope of the conformational diagram can be adjusted by changing the temperature, catalyst amount, stirring speed, reaction time, oxygen supply, and solvent amount during the synthesis of polyphenylene ether. More specifically, increasing the temperature, increasing the catalyst amount, increasing the stirring speed, extending the reaction time, increasing the oxygen supply, and / or decreasing the solvent amount tends to result in a lower slope of the conformational diagram (making the polyphenylene ether more prone to branching).

[0201] <Specify the molecular weight of polyphenylene ether>

[0202] The number-average molecular weight of the specified polyphenylene ether constituting the curable composition of the present invention is preferably 2,000 to 30,000, more preferably 5,000 to 30,000, further preferably 8,000 to 30,000, and particularly preferably 8,000 to 25,000. By maintaining the molecular weight within this range, solubility in solvents can be maintained, and the film-forming properties of the curable composition can be improved. Furthermore, the polydispersity index (PDI: weight-average molecular weight / number-average molecular weight) of the specified polyphenylene ether constituting the curable composition of the present invention is preferably 1.5 to 20.

[0203] In this invention, the number-average molecular weight and weight-average molecular weight are determined by gel permeation chromatography (GPC) and converted according to a standard curve made of standard polystyrene.

[0204] <Specify the hydroxyl value of polyphenylene ether>

[0205] The number-average molecular weight (Mn) of the specified polyphenylene ether constituting the curable composition of the present invention is in the range of 2,000 to 30,000, preferably 15 or less, more preferably 2 or more and 10 or less, and even more preferably 3 or more and 8 or less.

[0206] It should be noted that when the polyphenylene ether is specified as the polyphenylene ether obtained by method 2, the hydroxyl value may sometimes be lower than the above value.

[0207] <Specify the solvent solubility of polyphenylene ether>

[0208] The specified polyphenylene ether 1g constituting the curable composition of the present invention is soluble in 100g of cyclohexanone (more preferably in 100g of cyclohexanone, DMF, and PMA) at 25°C. It should be noted that 1g of polyphenylene ether being soluble in 100g of solvent (e.g., cyclohexanone) means that when 1g of polyphenylene ether is mixed with 100g of solvent, turbidity and precipitation cannot be visually confirmed. More preferably, the specified polyphenylene ether is soluble in more than 1g of 100g of cyclohexanone at 25°C.

[0209] The specified polyphenylene ether constituting the curable composition of the present invention has a branched structure, thereby improving its solubility in various solvents, the dispersibility of the components in the composition, and their compatibility. Therefore, the components of the composition can be uniformly dissolved or dispersed, resulting in a uniform cured product. Consequently, the cured product exhibits excellent mechanical properties. In particular, the specified polyphenylene ether can crosslink with each other. As a result, the mechanical properties and low thermal expansion of the obtained cured product are further improved.

[0210] <<Prescribed Methods for Manufacturing Polyphenylene Ether>>

[0211] The specified polyphenylene ether constituting the curable composition of the present invention uses a specific type of phenol as the raw material. Otherwise, it can be manufactured using conventionally known methods for the synthesis of polyphenylene ether (polymerization conditions, presence or absence of catalyst, and type of catalyst, etc.).

[0212] Next, an example of the manufacturing method of the specified polyphenylene ether will be described.

[0213] Polyphenylene ether can be manufactured, for example, by preparing a polymerization solution containing specific phenols, a catalyst, and a solvent (polymerization solution preparation step), venting oxygen into the aforementioned solvent at least (oxygen supply step), and oxidizing and polymerizing the phenols in the aforementioned polymerization solution containing oxygen (polymerization step).

[0214] The following describes the polymerization solution preparation step, the oxygen supply step, and the polymerization step. It should be noted that the steps can be performed continuously, or a part or all of a step can be performed simultaneously with a part or all of other steps, or a step can be interrupted while other steps are performed during this period. For example, the oxygen supply step can be performed during the polymerization solution preparation step and the polymerization step. Furthermore, the method for manufacturing polyphenylene ether of the present invention may include other steps as needed. Examples of other steps include, for instance, the step of extracting the polyphenylene ether obtained through the polymerization step (e.g., the steps of reprecipitation, filtration, and drying), and the aforementioned modification step.

[0215] <Polymerization Solution Preparation Process>

[0216] The polymerization solution preparation process involves mixing various raw materials, including the phenols to be polymerized in the polymerization process described later, to prepare a polymerization solution. Examples of raw materials for the polymerization solution include phenols, catalysts, and solvents.

[0217] (catalyst)

[0218] There are no particular limitations on the catalyst; it can be any suitable catalyst used in the oxidative polymerization of polyphenylene ether.

[0219] Examples of catalysts include amine compounds and metal amine compounds formed by combining heavy metal compounds such as copper, manganese, and cobalt with amine compounds such as tetramethylethylenediamine. For obtaining copolymers with sufficient molecular weight, copper-amine compounds in which copper compounds are coordinated to the amine compound are particularly preferred. One type of catalyst may be used, or two or more types may be used.

[0220] There is no particular limit to the content of the catalyst. In the polymerization solution, relative to the total amount of phenols in the raw materials, it can be set to 0.1 to 0.6 mol%.

[0221] This catalyst can also be pre-dissolved in a suitable solvent.

[0222] (solvent)

[0223] The solvent is not particularly limited and can be any suitable solvent used in the oxidative polymerization of polyphenylene ether. Preferably, the solvent is one that can dissolve or disperse phenolic compounds and catalysts.

[0224] Specifically, solvents include aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; halogenated aromatic hydrocarbons such as chloroform, dichloromethane, chlorobenzene, dichlorobenzene, and trichlorobenzene; nitro compounds such as nitrobenzene; methyl ethyl ketone (MEK); cyclohexanone; tetrahydrofuran; ethyl acetate; N-methyl-2-pyrrolidone (NMP); N,N-dimethylformamide (DMF); propylene glycol monomethyl ether acetate (PMA); and diethylene glycol monoethyl ether acetate (CA). One solvent or two or more can be used.

[0225] It should be noted that the solvent can include water, solvents that are miscible with water, etc.

[0226] There is no particular limit to the solvent content in the polymerization solution; it can be adjusted appropriately.

[0227] (Other raw materials)

[0228] The polymerization solution may also contain other raw materials to the extent that it does not impair the effects of the present invention.

[0229] <Oxygen Supply Process>

[0230] The oxygen supply process is the process of venting oxygen-containing substances into the polymerization solution.

[0231] The ventilation time and oxygen concentration in the oxygen-containing container can be appropriately adjusted according to factors such as air pressure and temperature.

[0232] <Polymerization Process>

[0233] The polymerization process is a process in which phenols in a polymerization solution undergo oxidative polymerization under the condition of oxygen supply.

[0234] There are no particular limitations on the specific conditions for polymerization; for example, stirring can be carried out at 25–100°C for 2–24 hours.

[0235] When manufacturing the specified polyphenylene ether using the processes described above, by referring to Method 1 and Method 2 above, the specific methods for introducing functional groups containing unsaturated carbon bonds into the branched polyphenylene ether can be understood. That is, by specifying the type of raw phenol or by further adding a process to modify the terminal hydroxyl groups after the polymerization process (modification process), a specified polyphenylene ether having functional groups containing unsaturated carbon bonds can be obtained.

[0236] <<<<Composition: Fillers (B1) and (B2)>>>>

[0237] The filler (B1) contained in the first curable composition and resin layer of the present invention and the filler (B2) contained in the second curable composition and resin layer may be the same component or different components. Here, filler (B1) and filler (B2) are described as fillers in general.

[0238] Examples of fillers include inorganic fillers and organic fillers.

[0239] As inorganic fillers, metal oxides such as silicon dioxide, aluminum oxide, and titanium oxide can be used; metal hydroxides such as aluminum hydroxide and magnesium hydroxide; clay minerals such as talc and mica; fillers with perovskite-type crystal structures such as barium titanate and strontium titanate; and boron nitride, aluminum borate, barium sulfate, and calcium carbonate.

[0240] As organic fillers, fluoropolymers such as polytetrafluoroethylene (PTFE), tetrafluoroethylene / ethylene copolymer (ETFE), tetrafluoroethylene / perfluoroalkyl ethylene ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), polyvinyl chloride trifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), and polyvinyl fluoride (PVF) can be used; hydrocarbon resin fillers such as cyclic olefin polymers (COP) and cyclic olefin copolymers (COC) can also be used.

[0241] Among these considerations, considering low dielectric loss tangent and low thermal expansion, silica is the preferred filler component. The following explains the preferred choice of silica as a filler component.

[0242] <<Silicon Dioxide>>

[0243] The average particle size of silica is preferably 0.01 to 10 μm, more preferably 0.1 to 3 μm. The average particle size can be determined as follows: using a commercially available laser diffraction-scattering particle size distribution measuring device, the measured value of particle size distribution based on laser diffraction-scattering method is used as the median particle size (d50, volume basis) based on cumulative distribution.

[0244] It is also possible to use silica with different average particle sizes. In the case of achieving high silica filling, for example, it is also possible to use nanoscale silica with an average particle size of less than 1 μm in combination with silica with an average particle size of more than 1 μm.

[0245] Silica can be surface-treated with coupling agents. Treating the surface with a silane coupling agent improves its dispersibility with polyphenylene ethers. Additionally, it improves its affinity for organic solvents.

[0246] Examples of silane coupling agents include epoxy silane coupling agents, mercaptosilane coupling agents, and vinyl silane coupling agents. Examples of epoxy silane coupling agents include γ-epoxypropoxypropyltrimethoxysilane and γ-epoxypropoxypropylmethyldimethoxysilane. Examples of mercaptosilane coupling agents include γ-mercaptopropyltriethoxysilane. Examples of vinyl silane coupling agents include vinyltriethoxysilane.

[0247] The amount of silane coupling agent used, for example, relative to 100 parts by mass of silicon dioxide, can be set to 0.1 to 5 parts by mass or 0.5 to 3 parts by mass.

[0248] <<<<Ingredients: Other ingredients (C1) and (C2)>>>>

[0249] The first curable composition and resin layer may also contain other components (C1), and the second curable composition and resin layer may also contain other components (C2). Other components (C1) and other components (C2) may be the same or different components. Here, other components (C1) and other components (C2) are collectively referred to as "other components."

[0250] Other components include conventionally known additives that can be composable in the first and second curing compositions. More specifically, peroxides, cross-linking curing agents, elastomers, maleimide compounds, etc., are preferred.

[0251] In addition, other components may include flame retardant improvers (phosphorus compounds, etc.), cellulose nanofibers, polymer components (cyanate ester resins, epoxy resins, phenolic varnish resins, etc., unbranched polyphenylene ethers, polyimides, polyamides, etc.), dispersants, thermosetting catalysts, thickeners, defoamers, antioxidants, rust inhibitors, and adhesion promoters, etc., without impairing the effects of the present invention.

[0252] They can use only one type, or they can use two or more types.

[0253] <<<Peroxides>>>

[0254] In the case where the polyphenylene ether has unsaturated carbon bonds as specified above, the curable composition and even the curable resin laminate preferably contain peroxide.

[0255] Examples of peroxides include methyl ethyl ketone peroxide, methyl acetoacetate peroxide, acetyl acetyl peroxide, 1,1-bis(tert-butyl peroxide)cyclohexane, 2,2-bis(tert-butyl peroxide)butane, tert-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, di-tert-butyl hydroperoxide, tert-butyl hydroperoxide, dicumyl peroxide, 2,5- Dimethyl-2,5-di(tert-butylperoxide)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxide)hexyne, 2,5-dimethyl-2,5-di(tert-butylperoxide)-3-butene, acetyl peroxide, octylperoxide, lauroyl peroxide, benzoyl peroxide, m-toluyl peroxide, diisopropyl percarbonate, tert-butyl peroxide, di-tert-butyl peroxide, tert-butyl percarbonate, α,α'-bis(tert-butylperoxide-m-isopropyl)benzene, etc. One or more peroxides may be used.

[0256] Among these peroxides, those with a half-life temperature of 130°C to 180°C within one minute are desirable from the viewpoints of ease of handling and reactivity. Such peroxides have a relatively high reactivity temperature, therefore they do not readily promote curing during drying or other times when curing is not required, thus negatively impacting the shelf life of curable compositions containing polyphenylene ether. Furthermore, they have low volatility, therefore they do not volatilize during drying or storage, exhibiting good stability.

[0257] The content of peroxide in the curable composition and even in the curable resin laminate, based on the total amount of peroxide and relative to the total solid content of the curable composition and even the curable resin laminate, is preferably set to 0.01 to 20% by mass, more preferably 0.05 to 10% by mass, and particularly preferably 0.1 to 10% by mass. By setting the total amount of peroxide within this range, sufficient effect at low temperatures can be achieved, and film deterioration during coating is prevented.

[0258] In addition, depending on the requirements, it may also contain azo compounds such as azobisisobutyronitrile and azobisisovalerate, as well as free radical initiators such as dicumyl and 2,3-diphenylbutane.

[0259] <<<Cross-linking curing agents>>>

[0260] When polyphenylene ether is specified to have unsaturated carbon bonds, the curable composition or even the curable resin laminate preferably contains a cross-linking curing agent.

[0261] As a crosslinking curing agent, those with good compatibility with polyphenylene ether are preferred, but polyfunctional vinyl compounds such as divinylbenzene, divinylnaphthalene, and divinylbiphenyl; vinyl benzyl ether compounds synthesized by the reaction of phenol with vinyl benzyl chloride; allyl ether compounds synthesized by the reaction of styrene monomer, phenol, and allyl chloride; and further, triallyl isocyanurate is preferred. As a crosslinking curing agent, triallyl isocyanurate, which has particularly good compatibility with polyphenylene ether, is preferred, specifically, triallyl isocyanurate (hereinafter, TAIC (registered trademark)) and triallyl cyanurate (hereinafter, TAC). They exhibit low dielectric properties and can improve heat resistance. TAIC (registered trademark) is particularly preferred due to its excellent compatibility with polyphenylene ether.

[0262] Alternatively, (meth)acrylate compounds (methacrylate compounds and acrylate compounds) can also be used as crosslinking curing agents. Three- to five-functional (meth)acrylate compounds are particularly preferred. Examples of three- to five-functional methacrylate compounds include trimethylolpropane trimethacrylate, while examples of three- to five-functional acrylate compounds include trimethylolpropane triacrylate. Using these crosslinking curing agents can improve heat resistance. Only one type of crosslinking curing agent can be used, or two or more types can be used.

[0263] When the components in a curable composition containing a specified polyphenylene ether or even a curable resin laminate contain hydrocarbon groups with unsaturated carbon bonds, a cured product with excellent dielectric properties can be obtained, especially by curing with a crosslinking curing agent.

[0264] In curable compositions and even curable resin laminates, the mixing ratio of polyphenylene ether to crosslinking curing agent (e.g., trimeryl isocyanurate) is specified as a solids ratio (specifying polyphenylene ether: crosslinking curing agent), preferably 20:80 to 90:10, more preferably 30:70 to 90:10. By setting it within this range, a cured product with low dielectric properties and excellent heat resistance is obtained.

[0265] <<<Maleimide Compounds>>>

[0266] There are no particular restrictions on maleimide compounds as long as they contain at least one maleimide group in one molecule.

[0267] Examples of maleimide compounds include:

[0268] (1) Monofunctional aliphatic / alicyclic maleimide,

[0269] (2) Monofunctional aromatic maleimides,

[0270] (3) Multifunctional aliphatic / alicyclic maleimides,

[0271] (4) Polyfunctional aromatic maleimide.

[0272] <<(1) Monofunctional aliphatic / alicyclic maleimide>>

[0273] Examples of monofunctional aliphatic / alicyclic maleimides (1) include N-methylmaleimide, N-ethylmaleimide, and the reaction product of maleimide carboxylic acid and tetrahydrofurfuryl alcohol disclosed in Japanese Patent Application Publication No. 11-302278.

[0274] <<(2) Monofunctional aromatic maleimides>>

[0275] Examples of monofunctional aromatic maleimides (2) include N-phenylmaleimide and N-(2-methylphenyl)maleimide.

[0276] <<(3) Multifunctional aliphatic / alicyclic maleimides>>

[0277] Examples of multifunctional aliphatic / alicyclic maleimides (3) include: N,N'-methylene bismaleimide, N,N'-ethylene bismaleimide, maleimide ester compounds with an isocyanurate skeleton obtained by dehydration esterification of tri(hydroxyethyl) isocyanurate with aliphatic / alicyclic maleimide carboxylic acid, maleimide carboxylate compounds with an isocyanurate skeleton obtained by carbamate esterification of tri(hexyl) isocyanurate with aliphatic / alicyclic maleimide alcohol, etc., polymaleimides with isocyanurate skeletons, isophorone biscarbamate bis(N-ethylmaleimide), triethylene glycol bis(maleimide ethyl carbon) These compounds include: aliphatic / alicyclic maleimide esters, obtained by dehydration and esterification of aliphatic / alicyclic maleimide carboxylic acids with various aliphatic / alicyclic polyols, or by transesterification of aliphatic / alicyclic maleimide carboxylic acid esters with various aliphatic / alicyclic polyols; aliphatic / alicyclic maleimide esters, obtained by ether ring-opening reaction of aliphatic / alicyclic maleimide carboxylic acids with various aliphatic / alicyclic polyepoxides; and aliphatic / alicyclic maleimide urethane compounds, obtained by urethane esterification of aliphatic / alicyclic maleimide alcohols with various aliphatic / alicyclic polyisocyanates.

[0278] Specifically, examples include aliphatic bismaleimide compounds of the following general formulas (X1) and (X2) obtained by subjecting maleimide alkyl carboxylic acids or maleimide alkyl carboxylic acid esters having 1 to 6 carbon alkyl groups, more preferably having straight-chain alkyl groups, to polyethylene glycol and / or polypropylene glycol and / or polytetramethylene glycol with a number average molecular weight of 100 to 1000 and a number average molecular weight of 100 to 1000.

[0279]

[0280] (In the formula, m represents an integer from 1 to 6, n represents a value from 2 to 23, and R1 represents a hydrogen atom or a methyl group.)

[0281]

[0282] (In the formula, m represents an integer from 1 to 6, and p represents a value from 2 to 14.)

[0283] <<(4) Polyfunctional aromatic maleimides>>

[0284] Examples of multifunctional aromatic maleimides (4) include: N,N'-(4,4'-diphenylmethane)bismaleimide, bis-(3-ethyl-5-methyl-4-maleimidephenyl)methane, 2,2'-bis-(4-(4-maleimidephenoxy)propane, N,N'-(4,4'-diphenyloxy)bismaleimide, N,N'-p-phenylene bismaleimide, N,N'-m-phenylene bismaleimide, N,N'-2,4-methylphenylene bismaleimide, N,N'- 2,6-Methylphenylene bismaleimide, aromatic polymaleimide ester compounds obtained by dehydration and esterification of maleimide carboxylic acid with various aromatic polyols, or by transesterification of maleimide carboxylic acid ester with various aromatic polyols, aromatic polymaleimide ester compounds obtained by ether ring-opening reaction of maleimide carboxylic acid with various aromatic polyepoxides, and aromatic polymaleimide carbamate compounds obtained by carbamate reaction of maleimide alcohol with various aromatic polyisocyanates, etc.

[0285] Among these, maleimide compounds are preferably multifunctional. Maleimide compounds preferably have a bismaleimide skeleton. Maleimide compounds can be used alone or in combination of two or more.

[0286] There is no particular limitation on the weight-average molecular weight of maleimide compounds; it can be set to 100 or more, 200 or more, 500 or more, 750 or more, 1000 or more, 2000 or more, or less than 100,000, less than 50,000, less than 10,000, less than 5,000, less than 4,000, or less than 3,500.

[0287] The content of maleimide compounds in curable compositions and even curable resin laminates can typically be set at 0.5–50% by mass, 1–40% by mass, or 1.5–30% by mass, based on the total amount of solids.

[0288] In other viewpoints, the mixing ratio of polyphenylene ether to maleimide compound in a curable composition or even a curable resin laminate, in terms of solid content ratio, can be set as 9:91 to 99:1, 17:83 to 95:5, or 25:75 to 90:10.

[0289] Furthermore, when the curable composition or even the curable resin laminate contains a maleimide compound and a crosslinking curing agent, the mixing ratio of the maleimide compound to the crosslinking curing agent, in terms of solid component ratio (maleimide compound: crosslinking curing agent), is preferably set to 80:20 to 10:90, more preferably to 70:30 to 20:80. By setting it within this range, a cured product with low dielectric properties and excellent heat resistance is obtained.

[0290] <<<Elastomers>>>

[0291] Examples of elastomers include diene-based synthetic rubbers such as polyisoprene rubber, polybutadiene rubber, styrene-butadiene rubber, polychloroprene rubber, nitrile rubber, and ethylene-propylene rubber; non-dien-based synthetic rubbers such as ethylene-propylene rubber, butyl rubber, acrylate rubber, polyurethane rubber, fluororubber, silicone rubber, and epichlorohydrin rubber; natural rubber; styrene-based elastomers; olefin-based elastomers; urethane-based elastomers; polyester-based elastomers; polyamide-based elastomers; acrylic elastomers; and silicone-based elastomers.

[0292] From the viewpoint of compatibility with polyphenylene ether and dielectric properties, at least a portion of the elastomer is preferably a styrene-based elastomer. Examples of styrene-based elastomers include styrene-butadiene-styrene block copolymers, styrene-butadiene-butene-styrene block copolymers, and other styrene-butadiene copolymers; styrene-isoprene-styrene block copolymers, and other styrene-isoprene copolymers; styrene-ethylene-butene-styrene block copolymers, styrene-ethylene-propylene-styrene block copolymers, and the like. For the sake of particularly good dielectric properties of the resulting cured product, styrene-based elastomers without unsaturated carbon bonds, such as styrene-ethylene-butene-styrene block copolymers, are preferred.

[0293] The preferred content of styrene blocks in styrene-based elastomers is 10–70% by mass, 30–60% by mass, or 40–50% by mass. The content of the styrene blocks can be determined according to… 1 The integral ratio of the spectrum measured by H-NMR is obtained.

[0294] The raw material monomers for the styrene-based elastomers here include not only styrene, but also styrene derivatives such as α-methylstyrene, 3-methylstyrene, 4-propylstyrene, and 4-cyclohexylstyrene.

[0295] The percentage of styrene-based elastomers in 100% by mass of the elastomer can be set as, for example, 10% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, or 100% by mass.

[0296] Elastomers can also have functional groups (including bonds) that react with other components.

[0297] For example, it can have unsaturated carbon bonds as reactive functional groups. By constructing the elastomer in this way, it can be crosslinked with unsaturated carbon bonds (such as the unsaturated carbon bonds present in branched polyphenylene ethers), which has the effect of reducing the risk of leakage.

[0298] The elastomer can be modified using (meth)acrylic acid, maleic acid, their anhydrides or esters, etc. Alternatively, it can be obtained by further adding water to the residual unsaturated bonds of the diene elastomer.

[0299] The number-average molecular weight of the elastomer can be set to 1,000 to 150,000. If the number-average molecular weight is above the aforementioned lower limit, it exhibits excellent low thermal expansion properties; if it is below the aforementioned upper limit, it exhibits excellent compatibility with other components.

[0300] The content of the elastomer in the curable composition or even the curable resin laminate, relative to 100 parts by weight of the specified polyphenylene ether, can be set to 10 to 300 parts by weight. Alternatively, the content of the elastomer, based on the total amount of solid components in the curable composition or even the curable resin laminate, can be set to 3 to 65% by weight. Within the above range, good tensile properties, adhesion, and heat resistance can be achieved in a balanced manner.

[0301] <<<<<<Effects of Curing Resin Laminates>>>>>

[0302] The curable resin laminate of the present invention is disposed on the object to be bonded (such as copper foil) in such a way that the aforementioned second resin layer is in contact with the object to be bonded, and then heated and pressed together, so that the second resin layer can be filled into the uneven parts of the object to be bonded (such as copper foil) without gaps. Afterwards, the curable resin laminate is cured, thereby generating a cross-linking reaction at the interface between the first resin layer, the second resin layer, and the aforementioned resin layers, so that the object to be bonded and the curable resin laminate are firmly and tightly bonded, thereby obtaining excellent peel strength.

[0303] <<<<<<Method for manufacturing curable resin laminates>>>>>>

[0304] <<<<<Raw Materials>>>>>

[0305] The curable resin laminate can be obtained as follows: the first curable composition and the second curable composition described above are diluted with a solvent or the like to form a solution, which is then coated onto a substrate film or a substrate and dried.

[0306] There is no particular limitation on the amount of solvent used in the dilution of the curable composition, and it can be appropriately adjusted according to the intended use of the curable composition and the desired viscosity.

[0307] <<<<Solvents>>>>

[0308] Examples of solvents that can be used in the curable compositions of the present invention include, in addition to conventionally used solvents such as chloroform, dichloromethane, and toluene, solvents with relatively high safety such as N-methyl-2-pyrrolidone (NMP), tetrahydrofuran (THF), cyclohexanone, propylene glycol monomethyl ether acetate (PMA), diethylene glycol monoethyl ether acetate (CA), methyl ethyl ketone, and ethyl acetate. It should be noted that the solvent can be N,N-dimethylformamide (DMF). Only one solvent may be used, or two or more solvents may be used.

[0309] <<<<<Manufacturing Processes>>>>>

[0310] The following describes an example of the manufacturing process of a curable resin laminate.

[0311] <<<<Dry Film>>>>

[0312] The dry film of the present invention is characterized in that it is formed by at least one side of a curable resin laminate being supported or protected by a film.

[0313] The film used as the support (substrate film) is not particularly limited and can be made of metal foil such as copper foil, polyimide film, polyester film, polyethylene naphthalate (PEN) film, etc. It should be noted that these films can also be used as supports or protective films for dry films.

[0314] The method for manufacturing a dry film is as follows: using an applicator or the like, a solution of a second curable composition is applied to a substrate film and dried to form a second resin layer. Then, a solution of a first curable composition is applied to the second resin layer and dried to form a first resin layer, thereby forming a dry film having two layers of a curable resin laminate having a second resin layer and a first resin layer sequentially stacked on a substrate film.

[0315] Furthermore, by further forming a second resin layer on the first resin layer of the aforementioned two-layer curable resin laminate, a dry film of a three-layer curable resin structure having a second resin layer on both sides of the first resin layer can be formed.

[0316] After the resin layer is formed, other layers (such as a protective film) can be added as needed.

[0317] For a dry film having a curable resin laminate, instead of the process of sequentially laminating resin layers on the aforementioned substrate film, a first dry film having a first resin layer and / or a second dry film having a second resin layer are prepared in advance and bonded together. The substrate film is then further peeled off and bonded together, thereby producing a dry film with a structure in which the aforementioned two-layer curable resin laminate and the aforementioned three-layer curable resin laminate are sandwiched by the substrate film.

[0318] The coating and drying of the curable composition can be carried out according to known methods and conditions. For example, a curable composition with uniform thickness can be obtained by known coating methods such as comma coaters, blade coaters, lip coaters, bar coaters, pressure coaters, reverse coaters, transfer roller coaters, gravure coaters, and spray coaters.

[0319] The coating film of the curable composition obtained by coating is then heated and dried at a temperature of 60–130°C for 1–30 minutes to form a resin layer from the dried coating film. Heating and drying can be carried out using known heating methods such as hot air circulating drying ovens, IR ovens, hot plates, and convection ovens.

[0320] The thickness of the resin layer can be adjusted by changing the coating conditions and the viscosity of the curing composition.

[0321] <<<<<<Usage and Applications of Curing Resin Laminates>>>>>>

[0322] As an example of the curable resin laminate of the present invention, after being formed on a suitable substrate with the second resin layer as the surface layer, a conductor layer (such as copper foil) is pressed onto the second resin layer for use. As a method of forming on the substrate, the first curable composition and the second curable composition can be coated on the substrate and dried to form the laminate, or it can be formed on the substrate by means of the above-described dry film method.

[0323] As substrates, in addition to pre-formed circuit boards and flexible printed circuit boards, examples include: all grades (FR-4, etc.) of copper-clad laminates, polyimide films, PET films, glass substrates, ceramic substrates, wafer boards, etc. The copper-clad laminates use composite materials such as paper-phenolic resin, paper-epoxy resin, glass cloth-epoxy resin, glass-polyimide, glass cloth / non-woven fabric-epoxy resin, glass cloth / paper-epoxy resin, synthetic fiber-epoxy resin, fluoropolymer, polyethylene, PPO, cyanate ester, etc.

[0324] In the case of coating and drying on a substrate, for example, coating a solution of a first curable composition on the substrate and drying to form a first resin layer, and then coating a solution of a second curable composition on the first resin layer and drying to form a second resin layer, a curable resin laminate in which the first resin layer and the second resin layer are sequentially stacked on the substrate can be formed.

[0325] The coating and drying can be carried out according to known methods and conditions, and the same coating and drying methods as those used in the above-described dry film manufacturing method can be used.

[0326] When a dry film is formed on a substrate, for example, in the case of a dry film comprising a two-layer curable resin laminate sandwiched by a substrate film, after peeling off the substrate film in contact with the first resin layer, the substrate is positioned so that the first resin layer is in contact with the substrate. Next, using a vacuum laminator or similar device, heat and pressure are applied from the side of the substrate film in contact with the second resin layer to press the dry film onto the substrate. After cooling to room temperature, the surface substrate film is peeled off, thereby forming a curable resin laminate in which the first and second resin layers are sequentially laminated on the substrate.

[0327] The lamination of dry film onto a substrate can be carried out according to known methods and conditions. Among these, in order to avoid the generation of voids, a vacuum laminator is preferred, which can perform lamination within a temperature range of 80 to 160°C and a time range of 10 to 120 seconds.

[0328] Next, a copper foil or other bonded object is placed on the second resin layer, which becomes the surface layer of the curable resin laminate. The laminate is then heated and pressurized using a vacuum laminator or vacuum press to form a conductive layer on the second resin layer. Finally, the curable resin laminate is heat-cured using a suitable method.

[0329] The thermosetting process is as follows: a hot air circulating drying oven is used to heat the resin laminate at 100-220°C for 30-120 minutes, thereby causing a thermosetting reaction and forming a cured product.

[0330] The curable resin laminate and dry film of the present invention are suitable for forming insulating films on circuit boards, and are suitable for forming interlayer adhesives, electromagnetic waves; shielding layers or interlayer insulating layers.

[0331] <<<<<Examples of specific methods>>>>>>

[0332] The following describes specific examples of the present invention.

[0333] According to the invention of methods I and II below, a curable resin laminate with low dielectric properties can be provided, which is useful for forming an insulating layer with excellent adhesion (peel strength) to the conductor layer.

[0334] <<<<<Method I>>>>>

[0335] The invention of method I is a curable resin laminate, characterized in that,

[0336] It has: a first resin layer; and a second resin layer laminated on at least one side of the main surface of the aforementioned first resin layer.

[0337] The aforementioned second resin layer has a thickness of 5% to 35% relative to the total thickness of the aforementioned first resin layer and the aforementioned second resin layer.

[0338] The aforementioned first resin layer comprises (A1) polyphenylene ether and (B1) filler.

[0339] The aforementioned second resin layer contains (A2) polyphenylene ether, and the Young's modulus (YM2) of the cured product is below 3.0 GPa.

[0340] The Young's modulus (YM1) of the cured product of the first resin layer and the Young's modulus (YM2) of the cured product of the second resin layer are related as follows: YM1 > YM2.

[0341] The aforementioned (A1) polyphenylene ether and (A2) polyphenylene ether are polyphenylene ethers obtained from raw material phenols containing at least phenols satisfying condition 1, and whose slope calculated from the conformation diagram is less than 0.6.

[0342] (Condition 1)

[0343] It has hydrogen atoms in the ortho and para positions.

[0344] The invention of Method I can be a dry film having the aforementioned curable resin laminate.

[0345] The invention of method I can be a cured material formed from the aforementioned cured laminate.

[0346] The invention of method I can be an electronic component having the aforementioned cured material.

[0347] <<<<<Method II>>>>>

[0348] The invention of method II is a curable resin laminate, characterized in that,

[0349] It has: a first resin layer; and a second resin layer laminated on at least one side of the main surface of the aforementioned first resin layer.

[0350] The aforementioned second resin layer has a thickness of 5% to 35% relative to the total thickness of the aforementioned first resin layer and the aforementioned second resin layer.

[0351] The aforementioned first resin layer comprises (A1) polyphenylene ether and (B1) filler.

[0352] The aforementioned second resin layer contains (A2) polyphenylene ether, with a melt viscosity (MV2) of less than 40,000 dPa·s at 140°C.

[0353] The melt viscosity (MV1) of the first resin layer at 140°C and the melt viscosity (MV2) of the second resin layer at 140°C are related as follows: MV1 > MV2.

[0354] The aforementioned (A1) polyphenylene ether and (A2) polyphenylene ether are polyphenylene ethers obtained from raw material phenols containing at least phenols satisfying condition 1, and whose slope calculated from the conformation diagram is less than 0.6.

[0355] (Condition 1)

[0356] It has hydrogen atoms in the ortho and para positions.

[0357] The invention of Method II can be a dry film having the aforementioned curable resin laminate.

[0358] The invention of method II can be a cured material formed from the aforementioned cured laminate.

[0359] The invention of method II can be an electronic component having the aforementioned cured material.

[0360] Example

[0361] Hereinafter, the present invention will be described in more detail based on examples and comparative examples, but the present invention is not limited by any of the following.

[0362] <<Synthesis of PPE resin>>

[0363] <Synthesis of PPE-1 (branched PPE resin)>

[0364] In a 3 L two-neck eggplant-shaped flask, 2.6 g of bis-μ-hydroxy-bis[(N,N,N’,N’-tetramethylethylenediamine)copper(II)] chloride (Cu / TMEDA) and 3.18 mL of tetramethylethylenediamine (TMEDA) were added and dissolved thoroughly, and oxygen was supplied at 10 ml / minute. 105 g of 2,6-dimethylphenol and 13 g of 2-allylphenol as starting phenolic compounds were dissolved in 1.5 L of toluene to prepare a starting material solution. This starting material solution was added dropwise to the flask, and the reaction was carried out at 40 °C for 6 hours while stirring at a rotation speed of 600 rpm. After the reaction was completed, it was reprecipitated with a mixed solution of 20 L of methanol and 22 mL of concentrated hydrochloric acid, filtered out, and dried at 80 °C for 24 hours to obtain PPE-1 as a branched PPE resin.

[0365] The number-average molecular weight of PPE-1 is 20,000, and the weight-average molecular weight is 60,000.

[0366] The slope of the conformational diagram of PPE-1 is 0.31.

[0367] <Synthesis of PPE-2 (branched PPE resin)>

[0368] In a 3 L two-neck eggplant-shaped flask, 2.6 g of bis-μ-hydroxy-bis[(N,N,N’,N’-tetramethylethylenediamine)copper(II)] chloride (Cu / TMEDA) and 3.18 mL of tetramethylethylenediamine (TMEDA) were added and dissolved thoroughly, and oxygen was supplied at 10 ml / minute. 105 g of 2,6-dimethylphenol and 4.89 g of o-cresol as starting phenolic compounds were dissolved in 1.5 L of toluene to prepare a starting material solution. This starting material solution was added dropwise to the flask, and the reaction was carried out at 40 °C for 6 hours while stirring at a rotation speed of 600 rpm. After the reaction was completed, it was reprecipitated with a mixed solution of 20 L of methanol and 22 mL of concentrated hydrochloric acid, filtered out, and dried at 80 °C for 24 hours to obtain a branched PPE resin.

[0369] In a 1-L two-neck eggplant-shaped flask equipped with a dropping funnel, 50 g of branched PPE resin, 4.8 g of allyl bromide as a modifying compound, and 300 mL of NMP were added, and the mixture was stirred at 60°C. 5 mL of 5 M aqueous NaOH solution was added dropwise to this solution. Then, the mixture was further stirred at 60°C for 5 hours. Subsequently, after neutralizing the reaction solution with hydrochloric acid, it was reprecipitated in 5 L of methanol, filtered and taken out, washed 3 times with a mixed solution of methanol and water with a mass ratio of 80:20, and then dried at 80°C for 24 hours to obtain PPE-2 as the branched PPE resin.

[0370] The number-average molecular weight of PPE-2 was 19,000 and the weight-average molecular weight was 66,500.

[0371] The slope of the conformational diagram of PPE-2 was 0.33.

[0372] <Synthesis of non-branched PPE resin>

[0373] In a raw material solution in which 7.6 g of 2-allyl-6-methylphenol and 34 g of 2,6-dimethylphenol as raw material phenols were dissolved in 0.23 L of toluene, 34 mL of water was added. In addition, based on the same synthesis method as PPE-1, a non-branched PPE resin was obtained.

[0374] The number-average molecular weight of the non-branched PPE resin was 1,000 and the weight-average molecular weight was 2,000.

[0375] The slope of the conformational diagram of the non-branched PPE resin could not be measured. [[ID=X]]

[0376] It should be noted that the number-average molecular weight (Mn) and weight-average molecular weight (Mw) of each PPE resin were determined by gel permeation chromatography (GPC). In GPC, Shodex K-805L was used as the column, the column temperature was 40°C, the flow rate was 1 mL / minute, the eluent was chloroform, and the standard substance was polystyrene.

[0377] <Solvent solubility of PPE resin>

[0378] The solvent solubility of each PPE resin was confirmed.

[0379] Branched PPE resins - 1 and 2 were soluble in cyclohexanone.

[0380] The non-branched PPE resin was insoluble in cyclohexanone and soluble in chloroform.

[0381] <<<Preparation of curable composition / Formation of dry film>>>

[0382] Varnishes and dry films of curable compositions of each example and each comparative example were obtained as follows.

[0383] <<Example 1>>

[0384] <Preparation of Curable Composition for the First Resin Layer>

[0385] To a mixture of 100 parts by weight of PPE-1 and 49 parts by weight of styrene elastomer (manufactured by Asahi Kasei Corporation, trade name "H1051"), 540 parts by weight of cyclohexanone as a solvent were added. The mixture was stirred at 40°C for 30 minutes until completely dissolved. To the resulting PPE resin solution, 60 parts by weight of TAIC (manufactured by Mitsubishi Chemical Corporation) as a crosslinking curing agent, 534 parts by weight of spherical silica filler (manufactured by Admatechs Corporation, trade name "SC2500-SVJ"), and 16 parts by weight of maleimide resin (manufactured by Designer Molecules, trade name "BMI-3000J", Mw=3000) were added. The mixture was then dispersed using a three-roll mill. Finally, 3 parts by weight of α,α'-bis(tert-butylperoxide-m-isopropyl)benzene (manufactured by Nippon Yushi Co., Ltd.: trade name "PERBUTYL P-40") as a peroxide were mixed and stirred with a magnetic stirrer. As above, a varnish of the curable composition for the first resin layer of Example 1 was obtained.

[0386] Next, using a spreader, a varnish of the first resin layer curable composition of Example 1 was applied to a 100 μm thick PET film (manufactured by Toyobo Co., Ltd.: trade name "TN-200"), resulting in a dried resin layer thickness of 29 μm. The film was then dried at 90°C for 5 minutes to produce a dry film having the first resin layer of Example 1. Furthermore, for the purpose of measuring melt viscosity and Young's modulus, a dry film was produced under the same conditions with a dried resin layer thickness of 25 μm.

[0387] <Determination of the melt viscosity of the first resin layer>

[0388] Twenty dry films, each with a 25 μm thick first resin layer as described in Example 1, were prepared. Using a MVLP-500 vacuum laminator manufactured by Meikyo, the resin layers were repeatedly laminated and the PET film was peeled off to produce a 500 μm thick test piece for melt viscosity determination. A HAAKE rheometer (MARS 40) was used to measure the melt viscosity at 140 °C under the following conditions: oscillating heating method (5 °C / min), measurement temperature range: 70–200 °C, frequency: 1 Hz, stress control: 3 Pa, parallel plates: 20 mm, gap: 450 μm, sample size: 2.5 × 2.5 cm.

[0389] <Determination of Young's Modulus of Cured Film of First Resin Layer>

[0390] A dry film with a first resin layer of 25 μm thickness, as described in Example 1, was placed on the glossy surface of a low-roughness copper foil (FV-WS (manufactured by Furukawa Electric Corporation): Rz = 1.2 μm), ensuring contact between the first resin layer and the foil. Lamination was then performed in a vacuum laminator. Next, after peeling off the PET film, the film was completely filled with nitrogen in an inert gas oven and cured at 200°C for 60 minutes to obtain a cured film formed from the first resin layer. This cured film was cut into pieces 8 cm long and 0.5 cm wide, and tensile tests were performed under the following conditions. The Young's modulus was determined from the slope of the strain at stresses ranging from 5 MPa to 10 MPa on the stress-strain curve.

[0391] [Measurement Conditions]

[0392] Testing machine: Tensile testing machine EZ-SX (manufactured by Shimadzu Corporation)

[0393] Chuck pitch: 50mm

[0394] Test speed: 1 mm / min

[0395] Elongation calculation: (Extension movement / Chuck spacing) × 100

[0396] <Preparation of Curable Composition for Second Resin Layer>

[0397] In the curable composition for the first resin layer described above, the content of spherical silica filler is 0 parts by mass. Otherwise, the varnish of the curable composition for the second resin layer of Example 1 is obtained by the same method.

[0398] <Preparation of the second resin layer (dry film with the second resin layer)>

[0399] Next, using a spreader, a varnish of the curable composition for the second resin layer of Example 1 was applied to a 100 μm thick PET film, so that the thickness of the dried resin layer was 2 μm. The film was then dried at 90°C for 5 minutes to produce a dry film having the second resin layer of Example 1. Furthermore, for the purposes of melt viscosity and Young's modulus measurement, a dry film was produced under the same conditions with a dried resin layer thickness of 25 μm.

[0400] <Determination of the melt viscosity of the second resin layer>

[0401] Twenty dry films with a thickness of 25 μm and having the second resin layer of Example 1 described above were prepared, and their melt viscosity at 140°C was measured using the same method as that used for measuring the melt viscosity of the first resin layer described above.

[0402] <Determination of Young's Modulus of Cured Film of Second Resin Layer>

[0403] Using a dry film with a thickness of 25 μm having the second resin layer of Example 1 described above, the Young's modulus of the cured film of the second resin layer was determined using the same method as the Young's modulus determination of the first resin layer described above.

[0404] Fabrication of Curable Resin Laminates (Dry Films with First and Second Resin Layers)

[0405] The dry film having the first resin layer and the dry film having the second resin layer were arranged in such a way that the resin layers were in contact with each other, and then laminated using a vacuum laminator MVLP-500 manufactured by Meiki Manufacturing Co., Ltd. to obtain the dry film of Example 1.

[0406] <<Examples 2-13, Comparative Examples 1-6>>

[0407] The components and contents were adjusted to the values ​​shown in the table. In addition, the curable compositions for the first and second resin layers were adjusted in the same manner as in Example 1. The Young's modulus and melt viscosity of each cured film of the first and second resin layers of Examples 2-13 and Comparative Examples 1-6 were measured. In addition, a dry film having the first and second resin layers was prepared.

[0408] It should be noted that the first and second resin layers of Comparative Example 3 could not be used to prepare a cured film or measure the melt viscosity.

[0409] <<Example 14>>

[0410] After laminating a dry film having a first resin layer and a dry film having a second resin layer, the PET film on the side of the first resin layer is peeled off, and the dry film having the second resin layer is further laminating to produce the dry film of Example 14.

[0411] <<Comparative Example 7-13>>

[0412] A dry film having a first resin layer was prepared, and a PET film was laminated in such a way that it came into contact with the resin layer to prepare the dry film of Comparative Examples 7-13.

[0413] <<<Production of Solidified Materials>>>

[0414] After peeling off the PET film from the first resin layer side of each dry film of the Examples and Comparative Examples, a dry film was placed on the glossy surface of a low-roughness copper foil (FV-WS (manufactured by Furukawa Electric Corporation): Rz = 1.2 μm) to bring the first resin layer into contact, and then laminated using a vacuum laminator. Next, after peeling off the remaining PET film, an inert gas oven was completely filled with nitrogen, heated to 200°C, and cured for 60 minutes to obtain the cured films of the Examples and Comparative Examples.

[0415] It should be noted that a cured film could not be made from the dry film of Comparative Example 3.

[0416] <<<Evaluation>>>

[0417] For the cured film of the aforementioned cured product, the following evaluations are carried out.

[0418] <<CTE: Coefficient of Thermal Expansion>>

[0419] The cured film was cut into a length of 3 cm and a width of 0.3 cm, and measured using a TA Instruments TMA (Thermomechanical Analysis) Q400 in the tensile mode, with a distance between chucks of 16 mm, a load of 30 mN, in a nitrogen atmosphere, heated from 20 °C to 250 °C at 5 °C / min, and then cooled from 250 °C to 20 °C at 5 °C / min. The average coefficient of thermal expansion from 100 °C to 50 °C during cooling was determined.

[0420] <<Young's Modulus and Fracture Strain>>

[0421] The cured film was cut into a length of 8 cm and a width of 0.5 cm, and Young's modulus and fracture strain were measured under the following conditions.

[0422] It should be noted that Young's modulus was obtained from the slope of the strain at a stress of 5 MPa to 10 MPa in the obtained stress-strain diagram.

[0423] [Measurement Conditions]

[0424] Testing machine: Tensile testing machine EZ-SX (manufactured by Shimadzu Corporation)

[0425] Distance between chucks: 50 mm

[0426] Testing speed: 1 mm / min

[0427] Elongation calculation: (Tensile displacement / Distance between chucks) × 100

[0428] <<Dielectric Constant>>

[0429] The relative dielectric constant Dk and the dielectric loss tangent Df were measured according to the following method.

[0430] The cured film was cut into a test piece with a length of 80 mm and a width of 45 mm, and measured according to the SPDR (Split Post Dielectric Resonator) resonator method. A vector network analyzer E5071C and an SPDR resonator manufactured by Keysight Technologies were used in the measuring instrument, and the calculation program was manufactured by QWED. The conditions were set as a frequency of 10 GHz and a measurement temperature of 25 °C.

[0431] <<Peel Strength>>

[0432] The surface of a copper-clad laminate with solid copper (full-sided copper foil) was pretreated using a CZ-8100 manufactured by MEC Co., Ltd. Next, the PET film on the first resin layer side of the dry film of Examples 1-13 and Comparative Examples 1-6, and the single-sided PET film of Examples 14 and Comparative Examples 7-13 were peeled off, and the exposed resin layer was laminated with the previously treated surface using a vacuum laminator. Then, the remaining PET film was peeled off, and the exposed resin layer was laminated with the rough surface of the low-roughness copper foil (FV-WS (manufactured by Furukawa Electric Corporation): Rz = 1.2 μm) was brought into contact with the exposed resin layer using a vacuum laminator. Then, an inert gas oven was completely filled with nitrogen, heated to 200°C, and cured for 60 minutes to produce a substrate for peel strength evaluation.

[0433] A 10 mm wide and 100 mm long cut is made in the low-roughness copper foil portion of the substrate used for peel strength evaluation. One end of the cut is peeled off and held by a gripper. The 90° peel strength is measured under the following conditions.

[0434] [Measurement Conditions]

[0435] Testing machine: Tensile testing machine EZ-SX (manufactured by Shimadzu Corporation)

[0436] Test speed: 1 mm / min

[0437] [Table 1]

[0438]

[0439] [Table 2]

[0440]

Claims

1. A curable resin laminate, characterized by comprising: has a first resin layer formed of a first curable composition, and a second resin layer laminated to at least one of main surfaces of the first resin layer and formed of a second curable composition, the second resin layer has a thickness of 5 to 35% relative to the total thickness of the first resin layer and the second resin layer, The first curable composition contains A1 polyphenylene ether and B1 filler, the content M of the B1 filler is 30% by mass or more relative to the total solid content in the composition B1 30% by mass or more relative to the total solid content in the composition The second curable composition contains A2 polyphenylene ether and does not contain B2 filler, or the content M of B2 filler is 0 B2 40% by mass or less with respect to the total solid content in the composition, The content M of the B1 filler B1 The content M of the B2 filler B2 M B1 > M B2 , the A1 polyphenylene ether and the A2 polyphenylene ether are polyphenylene ethers obtained from a raw material phenol including at least a phenol satisfying Condition 1, and have a slope calculated from a conformational diagram of less than 0.6, Condition 1 having hydrogen atoms at the ortho position and the para position, the slope calculated from the conformational diagram is calculated as follows: After preparing a chloroform solution of the polyphenylene ether at intervals of 0.1, 0.15, 0.2, 0.25 mg / mL, a graph of the difference in refractive index and the concentration was prepared while sending the solution at 0.5 mL / min, the increment in refractive index dn / dc was calculated from the slope, and then, under the following device operation conditions, the absolute molecular weight was measured, the chromatogram of the RI detector and the chromatogram of the MALS detector were used as references, a regression straight line based on the least squares method was obtained from a graph of the logarithm of the molecular weight and the logarithm of the radius of gyration, i.e., a conformational diagram, and the slope was calculated, Measurement conditions Device name: HLC8320 GPC Mobile phase: chloroform Column: TOSOH TSKguardcolumn HHR-H + TSKgel GMHHR-H 2 pieces + TSKgel G2500HHR Flow rate: 0.6 mL / min Detector: MALS detector DAWN HELEOS RI detector, + Optilab rEX wavelength 254 nm Sample concentration: 0.5 mg / mL Sample solvent: the same as the mobile phase, 5 mg of the sample was dissolved in 10 mL of the mobile phase Injection amount: 200 μL Filter: 0.45 μm STD reagent: standard polystyrene Mw 37900 STD concentration: 1.5 mg / mL STD solvent: the same as the mobile phase, 15 mg of the sample was dissolved in 10 mL of the mobile phase Analysis time: 100 minutes.

2. A dry film having the curable resin laminate of claim 1.

3. A cured product obtained by curing the curable resin laminate of claim 1 or the dry film of claim 2.

4. An electronic component having the cured product of claim 3.

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