Resin composition, and prepreg, resin-coated film, resin-coated metal foil, metal-clad laminate, and wiring board using the same

Abstract

An aspect of the present invention relates to a resin composition characterized by comprising a poly(phenylene ether) compound having at least one of groups represented by formulae (1) and (2) and an allyl compound having a group represented by formula (3).

Description

[Technical Field]

[0001] The present invention relates to a resin composition, and to a prepreg, a resin-coated film, a resin-coated metal foil, a metal-clad laminate, and a wiring board using the same. [Background technology]

[0002] In recent years, with the increase in the amount of information processed in various electronic devices, there has been rapid progress in packaging technologies such as higher integration of mounted semiconductor devices, higher density wiring, and multi-layering. Substrate materials for constituting the base material of wiring boards used in various electronic devices are required to have low dielectric constants and dielectric loss tangents in order to increase signal transmission speeds and reduce loss during signal transmission.

[0003] Polyphenylene ether (PPE) is known to have excellent dielectric properties, such as a low dielectric constant and a low dielectric loss tangent, even in high frequency bands (high frequency regions) from the MHz band to the GHz band. For this reason, polyphenylene ether is being considered for use as, for example, a molding material for high frequencies. More specifically, it is preferably used as a substrate material for constituting the base material of a wiring board included in an electronic device that uses high frequencies.

[0004] For example, Patent Document 1 discloses a resin composition containing a modified polyphenylene ether compound and a cross-linking curing agent having a carbon-carbon unsaturated double bond, such as triallyl isocyanurate (TAIC) or divinylbenzene. The resin composition disclosed in Patent Document 1 can provide a cured product with a low dielectric constant, a low dielectric loss tangent, and excellent heat resistance.

[0005] The resin composition described in Patent Document 1 is an excellent resin composition in terms of low dielectric properties and heat resistance, but research by the present inventors has revealed that when a copper-clad laminate is made with an insulating layer containing a cured product of a resin composition containing the above-mentioned crosslinking curing agent and metal foil on both sides of the insulating layer, the crosslink density increases due to the three-dimensional crosslinking of the resin. As this crosslink density increases, the toughness of the resin is thought to be insufficient, and for example, when a resin composition that does not contain glass cloth is cured, problems such as cracking occur during etching to form wiring, etc.

[0006] For these reasons, there has been a need for the development of a resin composition that can give a cured product that has properties such as low dielectric properties and heat resistance, and also has enough toughness to withstand etching treatment. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-86330 Summary of the Invention

[0008] The present invention has been made in view of the above circumstances, and aims to provide a resin composition that can improve the toughness and handleability of a cured product while maintaining properties such as low dielectric properties and a high Tg. Another aim is to provide a prepreg, a resin-coated film, a resin-coated metal foil, a metal-clad laminate, and a wiring board that use the resin composition.

[0009] A resin composition according to one embodiment of the present invention is characterized by containing a polyphenylene ether compound having at least one group represented by the following formula (1) or formula (2), and an allyl compound represented by the following formula (3).

[0010] [ka] (In formula (1), p represents an integer of 0 to 10. Z represents an arylene group. R1 to R3 each independently represent a hydrogen atom or an alkyl group.)

[0011] [ka] (In formula (2), R4 represents a hydrogen atom or an alkyl group.)

[0012] [ka] (In formula (3), R A represents an alkyl or alkenyl group having 8 to 22 carbon atoms) [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic cross-sectional view showing the configuration of a prepreg according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view showing the configuration of a metal-clad laminate according to one embodiment of the present invention. [Figure 3] FIG. 3 is a schematic cross-sectional view showing the configuration of a wiring board according to one embodiment of the present invention. [Figure 4] FIG. 4 is a schematic cross-sectional view showing the structure of a resin-coated metal foil according to one embodiment of the present invention. [Figure 5] FIG. 5 is a schematic cross-sectional view showing the structure of a resin film according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] The resin composition according to an embodiment of the present invention (hereinafter also simply referred to as the resin composition) is characterized by containing a polyphenylene ether compound having at least one of the groups represented by the formula (1) and the formula (2), and an allyl compound represented by the formula (3).

[0015] By including the allyl compound in addition to the polyphenylene ether compound, it is possible to provide a resin composition that not only has low dielectric properties and a high Tg (glass transition temperature), but also has excellent handleability and toughness in the cured product. This is thought to be because the allyl compound can suppress to some extent the increase in crosslink density due to the three-dimensional crosslinking of the resin.

[0016] That is, the present invention can provide a resin composition that has low dielectric properties and can improve the toughness and handleability of a cured product while maintaining excellent properties such as a high Tg. Furthermore, by using the resin composition, it is possible to provide a prepreg, a resin-coated film, a resin-coated metal foil, a metal-clad laminate, and a wiring board that have high toughness and excellent handleability, as well as properties such as a low dielectric property and a high Tg.

[0017] Furthermore, as a material property, a material with a high Tg in the cured product is one factor that contributes to improved heat resistance (e.g., solder heat resistance). Furthermore, a material with a high Tg in the cured product has the advantage of having a low coefficient of thermal expansion at higher temperatures. This is because thermal expansion generally increases rapidly at temperatures above the glass transition temperature. In other words, a low glass transition temperature results in a high coefficient of thermal expansion at higher temperatures above the glass transition temperature. A low glass transition temperature results in increased thermal expansion at higher temperatures, which can lead to poor interlayer connection reliability in wiring boards (e.g., barrel cracking in through-holes) and potentially impaired functionality as a printed circuit board. This is thought to be due to the large difference in thermal expansion coefficients at high temperatures between the insulating layer made of the cured resin composition in the board and the metal through-holes, which can lead to cracks in the walls of the metal through-holes and reduced connection reliability.

[0018] First, each component of the resin composition according to this embodiment will be specifically described below.

[0019] <Polyphenylene ether compound> The polyphenylene ether compound used in this embodiment is a modified polyphenylene ether compound that can exhibit excellent low dielectric properties when cured, and is not particularly limited as long as it is a polyphenylene ether compound having at least one of the groups represented by the following formula (1) and formula (2). It is believed that the inclusion of such a modified polyphenylene ether compound results in a resin composition that can give a cured product with low dielectric properties and high heat resistance.

[0020] [ka]

[0021] In formula (1), p represents an integer of 0 to 10. Z represents an arylene group. R1 to R3 are each independent. That is, R1 to R3 may be the same group or different groups. R1 to R3 represent a hydrogen atom or an alkyl group.

[0022] In addition, in formula (1), when s is 0, it means that Z is directly bonded to the end of the polyphenylene ether.

[0023] The arylene group of Z is not particularly limited. Examples of the arylene group include monocyclic aromatic groups such as a phenylene group, and polycyclic aromatic groups in which the aromatic ring is not monocyclic but is polycyclic, such as a naphthalene ring. The arylene group also includes derivatives in which a hydrogen atom bonded to the aromatic ring is substituted with a functional group such as an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group. The alkyl group is not particularly limited, and is preferably an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group.

[0024] [ka]

[0025] In formula (2), R4 represents a hydrogen atom or an alkyl group. The alkyl group is not particularly limited, and is preferably, for example, an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group.

[0026] Preferred specific examples of the substituent represented by the formula (1) include, for example, a substituent containing a vinylbenzyl group. Examples of the substituent containing a vinylbenzyl group include, for example, a substituent represented by the following formula (4). Furthermore, examples of the substituent represented by the formula (2) include an acrylate group and a methacrylate group.

[0027] [ka]

[0028] More specific examples of the substituent include vinylbenzyl groups (ethenylbenzyl groups) such as p-ethenylbenzyl and m-ethenylbenzyl groups, vinylphenyl groups, acrylate groups, and methacrylate groups.

[0029] The polyphenylene ether compound has a polyphenylene ether chain in the molecule, and preferably has, for example, a repeating unit represented by the following formula (5) in the molecule.

[0030] [ka]

[0031] In formula (5), t represents 1 to 50. R5 to R8 are each independent. That is, R5 to R8 may be the same group or different groups. R5 to R8 represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group. Of these, a hydrogen atom and an alkyl group are preferred.

[0032] Specific examples of the functional groups listed for R5 to R8 include the following.

[0033] The alkyl group is not particularly limited, but is preferably an alkyl group having 1 to 18 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group.

[0034] The alkenyl group is not particularly limited, but is preferably an alkenyl group having 2 to 18 carbon atoms, and more preferably an alkenyl group having 2 to 10 carbon atoms. Specific examples include a vinyl group, an allyl group, and a 3-butenyl group.

[0035] The alkynyl group is not particularly limited, but is preferably an alkynyl group having 2 to 18 carbon atoms, and more preferably an alkynyl group having 2 to 10 carbon atoms. Specific examples include an ethynyl group and a prop-2-yn-1-yl group (propargyl group).

[0036] The alkylcarbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkyl group, but for example, an alkylcarbonyl group having 2 to 18 carbon atoms is preferred, and an alkylcarbonyl group having 2 to 10 carbon atoms is more preferred. Specific examples include an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a pivaloyl group, a hexanoyl group, an octanoyl group, and a cyclohexylcarbonyl group.

[0037] The alkenylcarbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkenyl group, but for example, an alkenylcarbonyl group having 3 to 18 carbon atoms is preferred, and an alkenylcarbonyl group having 3 to 10 carbon atoms is more preferred. Specific examples include an acryloyl group, a methacryloyl group, and a crotonoyl group.

[0038] The alkynylcarbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkynyl group, but for example, an alkynylcarbonyl group having 3 to 18 carbon atoms is preferred, and an alkynylcarbonyl group having 3 to 10 carbon atoms is more preferred. Specific examples include a propioloyl group.

[0039] The weight-average molecular weight (Mw) of the polyphenylene ether compound is not particularly limited. Specifically, it is preferably 500 to 5,000, more preferably 800 to 4,000, and even more preferably 1,000 to 3,000. The weight-average molecular weight may be measured by a general molecular weight measurement method, specifically, a value measured using gel permeation chromatography (GPC), etc. Furthermore, when the polyphenylene ether compound has a repeating unit represented by the formula (5) in the molecule, t is preferably a numerical value such that the weight-average molecular weight of the polyphenylene ether compound falls within this range. Specifically, t is preferably 1 to 50.

[0040] When the weight-average molecular weight of the polyphenylene ether compound is within this range, the compound has the excellent low dielectric properties of polyphenylene ether, and the cured product not only has excellent heat resistance but also has excellent moldability. This is believed to be due to the following reasons. When the weight-average molecular weight of a typical polyphenylene ether is within this range, the compound has a relatively low molecular weight, which tends to reduce the heat resistance of the cured product. In this regard, the polyphenylene ether compound according to this embodiment has one or more unsaturated double bonds at its terminals, which is believed to result in a cured product with sufficiently high heat resistance. Furthermore, when the weight-average molecular weight of the polyphenylene ether compound is within this range, the compound has a relatively low molecular weight, which is believed to result in excellent moldability. Therefore, it is believed that such a polyphenylene ether compound not only has excellent heat resistance but also has excellent moldability.

[0041] The average number of the substituents (number of terminal functional groups) at the molecular terminals per molecule of the polyphenylene ether compound is not particularly limited. Specifically, it is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1.5 to 3. If the number of terminal functional groups is too small, it tends to be difficult to obtain a cured product with sufficient heat resistance. On the other hand, if the number of terminal functional groups is too large, the reactivity becomes too high, which may cause problems such as reduced shelf life and reduced fluidity of the resin composition. That is, when such a polyphenylene ether compound is used, insufficient fluidity may cause molding defects such as the generation of voids during multilayer molding, which may lead to moldability problems such as difficulty in obtaining a highly reliable printed wiring board.

[0042] The number of terminal functional groups of a polyphenylene ether compound may be, for example, a numerical value representing the average number of the above-mentioned substituents per molecule of all modified polyphenylene ether compounds present in 1 mole of the polyphenylene ether compound. The number of terminal functional groups can be measured, for example, by measuring the number of hydroxyl groups remaining in the obtained modified polyphenylene ether compound and calculating the difference from the number of hydroxyl groups in the polyphenylene ether before modification. This difference from the number of hydroxyl groups in the polyphenylene ether before modification is the number of terminal functional groups. The number of hydroxyl groups remaining in the modified polyphenylene ether compound can be measured by adding a quaternary ammonium salt (tetraethylammonium hydroxide) that associates with hydroxyl groups to a solution of the modified polyphenylene ether compound and measuring the UV absorbance of the resulting mixed solution.

[0043] The intrinsic viscosity of the polyphenylene ether compound of this embodiment is not particularly limited. Specifically, it is preferably 0.03 to 0.12 dL / g, more preferably 0.04 to 0.11 dL / g, and even more preferably 0.06 to 0.095 dL / g. If the intrinsic viscosity is too low, the molecular weight tends to be low, and it tends to be difficult to achieve low dielectric properties such as a low dielectric constant and a low dielectric loss tangent. On the other hand, if the intrinsic viscosity is too high, the viscosity is high, sufficient fluidity cannot be achieved, and the moldability of the cured product tends to be reduced. Therefore, if the intrinsic viscosity of the polyphenylene ether compound is within the above range, excellent heat resistance and moldability can be achieved in the cured product.

[0044] The intrinsic viscosity here is the intrinsic viscosity measured in methylene chloride at 25°C, and more specifically, it is the value measured, for example, with a viscometer using a 0.18 g / 45 ml methylene chloride solution (liquid temperature: 25°C). Examples of such viscometers include the AVS500 Visco System manufactured by Schott.

[0045] Examples of the polyphenylene ether compound of the present embodiment include modified polyphenylene ether compounds represented by the following formulas (6) to (8). Furthermore, as the polyphenylene ether compound of the present embodiment, these modified polyphenylene ether compounds may be used alone or in combination.

[0046] [ka]

[0047] [ka]

[0048] [ka]

[0049] In formulas (6) to (8), R9 to R 16 , R 17 ~R 24 and R 25 ~R 28 are independent of each other. That is, R9 to R 16 , R 17 ~R 24 and R 25 ~R 28 may be the same group or different groups. 16 , R 17 ~R 24 and R 25 ~R 28 represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group.

[0050] In the above formula (8), s represents an integer of 1-100.

[0051] The above R9 to R 16 , R 17 ~R 24and R 25 ~R 28 Regarding the above, specific examples of the functional groups include the following:

[0052] The alkyl group is not particularly limited, but is preferably an alkyl group having 1 to 18 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group.

[0053] The alkenyl group is not particularly limited, but is preferably an alkenyl group having 2 to 18 carbon atoms, and more preferably an alkenyl group having 2 to 10 carbon atoms. Specific examples include a vinyl group, an allyl group, and a 3-butenyl group.

[0054] The alkynyl group is not particularly limited, but is preferably an alkynyl group having 2 to 18 carbon atoms, and more preferably an alkynyl group having 2 to 10 carbon atoms. Specific examples include an ethynyl group and a prop-2-yn-1-yl group (propargyl group).

[0055] The alkylcarbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkyl group, but for example, an alkylcarbonyl group having 2 to 18 carbon atoms is preferred, and an alkylcarbonyl group having 2 to 10 carbon atoms is more preferred. Specific examples include an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a pivaloyl group, a hexanoyl group, an octanoyl group, and a cyclohexylcarbonyl group.

[0056] The alkenylcarbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkenyl group, but for example, an alkenylcarbonyl group having 3 to 18 carbon atoms is preferred, and an alkenylcarbonyl group having 3 to 10 carbon atoms is more preferred. Specific examples include an acryloyl group, a methacryloyl group, and a crotonoyl group.

[0057] The alkynylcarbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkynyl group, but for example, an alkynylcarbonyl group having 3 to 18 carbon atoms is preferred, and an alkynylcarbonyl group having 3 to 10 carbon atoms is more preferred. Specific examples include a propioloyl group.

[0058] In the above formulas (6) and (8), A and B represent repeating units represented by the following formulas (9) and (10), respectively. In the formula (7), Y represents a linear, branched, or cyclic hydrocarbon having 20 or less carbon atoms.

[0059] [ka]

[0060] [ka]

[0061] In formula (9) and formula (10), m and n each represent an integer of 0 to 20. Preferably, m and n represent a numerical value such that the sum of m and n is 1 to 30. Therefore, it is more preferable that m represents an integer of 0 to 20, n represents an integer of 0 to 20, and the sum of m and n represents an integer of 1 to 30.

[0062] In addition, in formulas (9) and (10), R 29 ~R 32 and R 33 ~R 36 are independent of each other, and R 29 ~R 32 and R 33 ~R 36 may be the same or different groups and represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group.

[0063] In the formula (7), Y is, as described above, a linear, branched, or cyclic hydrocarbon having 20 or less carbon atoms. Examples of Y include a group represented by the following formula (11).

[0064] [ka]

[0065] In the formula (11), R 37 and R 38 are each independently a hydrogen atom or an alkyl group. Examples of the alkyl group include a methyl group. Examples of the group represented by formula (11) include a methylene group, a methylmethylene group, and a dimethylmethylene group, and among these, a dimethylmethylene group is preferred.

[0066] In the formulas (6) to (8), X1 to X3 each independently represent a substituent represented by the formula (1) and / or a substituent represented by the formula (2). In the modified polyphenylene ether compounds represented by the formulas (6) to (8), X1 to X3 may be the same or different substituents.

[0067] More specific examples of the modified polyphenylene ether compound represented by the formula (6) include modified polyphenylene ether compounds represented by the following formula (12).

[0068] [ka]

[0069] More specific examples of the modified polyphenylene ether compound represented by the formula (7) include a modified polyphenylene ether compound represented by the following formula (13) and a modified polyphenylene ether compound represented by the following formula (14).

[0070] [ka]

[0071] [ka]

[0072] In the above formulas (12) to (14), m and n are the same as m and n in the above formulas (9) and (10). In addition, in the above formulas (12) and (13), R1 to R3, p, and Z are the same as R1 to R3, p, and Z in the above formula (1), respectively. In addition, in the above formulas (13) and (14), Y is the same as Y in the above formula (7). In addition, in the above formula (14), R4 is the same as R4 in the above formula (2).

[0073] The method for synthesizing the polyphenylene ether compound used in the present embodiment is not particularly limited as long as it is possible to synthesize a polyphenylene ether compound terminally modified with a group represented by the formula (1) and / or the formula (2). Specific examples include a method of reacting polyphenylene ether with a compound in which a substituent having a carbon-carbon unsaturated double bond and a halogen atom are bonded.

[0074] Examples of compounds in which a substituent having a carbon-carbon unsaturated double bond is bonded to a halogen atom include compounds in which a substituent represented by the formulas (1), (2), and (5) is bonded to a halogen atom. Specific examples of the halogen atom include a chlorine atom, a bromine atom, an iodine atom, and a fluorine atom, with a chlorine atom being preferred. More specific examples of compounds in which a substituent having a carbon-carbon unsaturated double bond is bonded to a halogen atom include p-chloromethylstyrene and m-chloromethylstyrene.

[0075] The polyphenylene ether used as the raw material is not particularly limited as long as it can ultimately synthesize a predetermined modified polyphenylene ether compound. Specific examples include polyphenylene ethers composed of 2,6-dimethylphenol and at least one of a bifunctional phenol and a trifunctional phenol, and those containing polyphenylene ether as the main component, such as poly(2,6-dimethyl-1,4-phenylene oxide). Furthermore, a bifunctional phenol is a phenolic compound having two phenolic hydroxyl groups per molecule, such as tetramethylbisphenol A. Furthermore, a trifunctional phenol is a phenolic compound having three phenolic hydroxyl groups per molecule.

[0076] The polyphenylene ether compound of this embodiment can be synthesized by the method described above. Specifically, the polyphenylene ether described above and a compound in which a substituent having a carbon-carbon unsaturated double bond and a halogen atom are bonded are dissolved in a solvent and stirred. By doing so, the polyphenylene ether reacts with the compound in which a substituent having a carbon-carbon unsaturated double bond and a halogen atom are bonded, thereby obtaining the polyphenylene ether compound used in this embodiment.

[0077] The reaction is preferably carried out in the presence of an alkali metal hydroxide. It is believed that this allows the reaction to proceed smoothly. This is believed to be because the alkali metal hydroxide functions as a dehydrohalogenating agent, specifically, a dehydrochlorinating agent. That is, it is believed that the alkali metal hydroxide eliminates hydrogen halide from the phenol group of the polyphenylene ether and a compound in which a substituent having a carbon-carbon unsaturated double bond and a halogen atom are bonded, and as a result, the substituent having a carbon-carbon unsaturated double bond is bonded to the oxygen atom of the phenol group in place of the hydrogen atom of the phenol group of the polyphenylene ether.

[0078] The alkali metal hydroxide is not particularly limited as long as it can act as a dehalogenating agent, and examples thereof include sodium hydroxide, etc. The alkali metal hydroxide is usually used in the form of an aqueous solution, specifically, an aqueous sodium hydroxide solution.

[0079] Reaction conditions such as reaction time and reaction temperature vary depending on the compound in which a substituent having a carbon-carbon unsaturated double bond is bonded to a halogen atom, and are not particularly limited as long as the conditions are such that the above-mentioned reaction proceeds favorably. Specifically, the reaction temperature is preferably room temperature to 100°C, more preferably 30 to 100°C. The reaction time is preferably 0.5 to 20 hours, more preferably 0.5 to 10 hours.

[0080] The solvent used in the reaction is not particularly limited as long as it can dissolve the polyphenylene ether and the compound in which a substituent having a carbon-carbon unsaturated double bond and a halogen atom are bonded, and does not inhibit the reaction between the polyphenylene ether and the compound in which a substituent having a carbon-carbon unsaturated double bond and a halogen atom are bonded. Specific examples include toluene.

[0081] The above reaction is preferably carried out in the presence of not only an alkali metal hydroxide but also a phase transfer catalyst. That is, the above reaction is preferably carried out in the presence of an alkali metal hydroxide and a phase transfer catalyst. Doing so is believed to allow the reaction to proceed more smoothly. This is believed to be due to the following: A phase transfer catalyst has the function of incorporating an alkali metal hydroxide, is soluble in both a polar solvent phase such as water and a nonpolar solvent phase such as an organic solvent, and is capable of transferring between these phases. Specifically, when an aqueous solution of sodium hydroxide is used as the alkali metal hydroxide and an organic solvent such as toluene, which is incompatible with water, is used as the solvent, even if the aqueous solution of sodium hydroxide is added dropwise to the solvent being used for the reaction, the solvent and the aqueous solution of sodium hydroxide separate, and it is believed that the sodium hydroxide is unlikely to migrate to the solvent. In this case, it is believed that the aqueous solution of sodium hydroxide added as the alkali metal hydroxide is unlikely to contribute to promoting the reaction. On the other hand, when the reaction is carried out in the presence of an alkali metal hydroxide and a phase transfer catalyst, the alkali metal hydroxide is transferred to the solvent while being incorporated into the phase transfer catalyst, and the aqueous sodium hydroxide solution is thought to contribute more to promoting the reaction. Therefore, when the reaction is carried out in the presence of an alkali metal hydroxide and a phase transfer catalyst, the reaction is thought to proceed more smoothly.

[0082] The phase transfer catalyst is not particularly limited, but examples thereof include quaternary ammonium salts such as tetra-n-butylammonium bromide.

[0083] The resin composition used in the present embodiment preferably contains, as the polyphenylene ether compound, the modified polyphenylene ether compound obtained as described above.

[0084] <Allyl compounds> The allyl compound in this embodiment functions as a so-called curing agent, and can be used without any particular limitation as long as it is represented by the following formula (3).

[0085] [ka]

[0086] In formula (3), R A represents an alkyl group or alkenyl group having 8 to 22 carbon atoms. By using the allyl compound having an alkyl group or alkenyl group with such a carbon number, a resin composition can be provided that has excellent crosslinkability and can give a cured product with high toughness. As a result, even if the resin composition does not contain a substrate such as glass cloth, cracking during etching or the like can be suppressed.

[0087] From the viewpoint of improving handleability, the number of carbon atoms is more preferably 12 or more and even more preferably 18 or less. This improves the resin flow properties of the resin composition, and is thought to result in better circuit filling properties when a multilayer circuit board or the like is produced using the resin composition of the present embodiment.

[0088] In a preferred embodiment, the reactive group (allyl group) equivalent of the allyl compound is desirably not more than 1000. If the equivalent is not more than 1000, it is believed that a high Tg can be more reliably obtained.

[0089] Examples of the alkyl group having 8 to 22 carbon atoms include linear or branched alkyl groups, such as octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, and docosyl groups. Examples of the alkenyl group having 8 to 22 carbon atoms include decenyl.

[0090] Specific examples of the allyl compound used in this embodiment include 5-octyl-1,3-diallyl isocyanurate, 5-dodecyl-1,3-diallyl isocyanurate, 5-tetradecyl-1,3-diallyl isocyanurate, 5-hexadecyl-1,3-diallyl isocyanurate, 5-octadecyl-1,3-diallyl isocyanurate, 5-eicosyl-1,3-diallyl isocyanurate, 5-docosyl-1,3-diallyl isocyanurate, and 5-decenyl-1,3-diallyl isocyanurate.

[0091] The method for producing such an allyl compound of the present embodiment is not particularly limited, but for example, the allyl compound can be obtained by reacting diallyl isocyanurate with an alkyl halide in an aprotic polar solvent such as N,N'-dimethylformamide in the presence of a basic substance such as sodium hydroxide, potassium carbonate, or triethylamine at a temperature of about 60°C to 150°C.

[0092] (inorganic filler) The resin composition according to the present embodiment may further contain an inorganic filler. Examples of inorganic fillers include those added to enhance the heat resistance and flame retardancy of the cured product of the resin composition, and are not particularly limited. It is believed that the inclusion of an inorganic filler can further enhance the heat resistance and flame retardancy, and also suppress an increase in the coefficient of thermal expansion.

[0093] Specific examples of inorganic fillers that can be used in this embodiment include silica such as spherical silica, metal oxides such as alumina, titanium oxide, and mica, metal hydroxides such as aluminum hydroxide and magnesium hydroxide, talc, aluminum borate, barium sulfate, and calcium carbonate. Among these, silica, mica, and talc are preferred, and spherical silica is more preferred. The inorganic fillers may be used alone or in combination of two or more. The inorganic fillers described above may be used as is, or may be surface-treated with an epoxysilane-type, vinylsilane-type, methacrylsilane-type, or aminosilane-type silane coupling agent. This silane coupling agent can be added to the filler by integral blending rather than by pre-surface treatment.

[0094] (styrene polymer) The resin composition of the present embodiment may contain a styrene polymer in addition to the components described above. The inclusion of a styrene polymer is considered to have advantages such as improved handleability (resin flowability) when the resin composition is made into a varnish and further reducing the dielectric constant of the resin.

[0095] The styrene polymer used in this embodiment is, for example, a polymer obtained by polymerizing a monomer containing a styrene monomer, and may be a styrene copolymer. Examples of the styrene copolymer include copolymers obtained by copolymerizing one or more styrene monomers with one or more other monomers copolymerizable with the styrene monomer. Examples of the styrene monomer include styrene and styrene derivatives.

[0096] As a specific styrene-based polymer, a wide variety of conventionally known polymers can be used, and there is no particular limitation. For example, a polymer having a structural unit (structure derived from a styrene-based monomer) represented by the following formula (15) in the molecule can be used.

[0097] [ka]

[0098] In formula (15), R 39 ~R 41 each independently represents a hydrogen atom or an alkyl group, and R 42 represents a group selected from the group consisting of a hydrogen atom, an alkyl group, an alkenyl group, and an isopropenyl group. The alkyl group is not particularly limited, and is preferably, for example, an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms. The alkenyl group is preferably an alkenyl group having 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group.

[0099] The styrene-based polymer of the present embodiment preferably contains at least one structural unit represented by the above formula (15), but may contain a combination of two or more different structural units, or may contain a structure in which the structural unit represented by the above formula (15) is repeated.

[0100] Furthermore, the styrene-based polymer of the present embodiment may have, in addition to the structural unit represented by the above formula (15), at least one of structural units represented by the following formulas (16), (17), and (18) as another monomer copolymerizable with the styrene-based monomer.

[0101] [ka]

[0102] [ka]

[0103] [ka]

[0104] In the formulas (16), (17) and (18), R 43 ~R 60are each independently a group selected from the group consisting of a hydrogen atom, an alkyl group, an alkenyl group, and an isopropenyl group. The alkyl group is not particularly limited, and is preferably, for example, an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms. The alkenyl group is preferably an alkenyl group having 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group. The styrene-based polymer of this embodiment preferably contains at least one structural unit represented by the above formula (16), formula (17), or formula (18), and may contain two or more different structural units in combination. The styrene-based polymer may also contain a structure in which the structural units represented by the above formula (16), formula (17), and / or formula (18) are repeated.

[0105] More specifically, examples of the structural unit represented by the formula (15) include structural units represented by the following formulas (19) to (21). The structural unit represented by the formula (15) may be one of these alone or a combination of two or more different types. Furthermore, the structural unit may be a structure in which each of the structural units represented by the formulas (19) to (21) is repeated.

[0106] [ka]

[0107] More specifically, examples of the structural unit represented by the above formula (16) include structural units represented by the following formulas (22) to (28). The structural unit represented by the above formula (16) may be one of these alone or a combination of two or more different types. Furthermore, the structural unit may be a structure in which each of the structural units represented by the above formulas (22) to (28) is repeated.

[0108] [ka]

[0109] [ka]

[0110] [ka]

[0111] [ka]

[0112] [ka]

[0113] [ka]

[0114] [ka]

[0115] More specifically, examples of the structural unit represented by the formula (17) include structural units represented by the following formulas (29) to (30). The structural unit represented by the formula (17) may be one of these alone or a combination of two or more different types. Furthermore, the structural unit may be a structure in which each of the structural units represented by the formulas (29) to (30) is repeated.

[0116] [ka]

[0117] [ka]

[0118] More specifically, examples of the structural unit represented by the formula (18) include structural units represented by the following formulas (31) to (32). The structural unit represented by the formula (18) may be one of these alone or a combination of two or more different types. Furthermore, the structural unit may be a structure in which each of the structural units represented by the formulas (31) to (32) is repeated.

[0119] [ka]

[0120] [ka]

[0121] Preferred examples of styrene-based polymers include polymers or copolymers obtained by polymerizing or copolymerizing one or more styrene-based monomers such as styrene, vinyltoluene, α-methylstyrene, isopropenyltoluene, divinylbenzene, and allylstyrene. More specific examples include styrene-butadiene copolymer, styrene-isobutylene copolymer, and styrene-isobutylene-styrene copolymer. Hydrogenated styrene-based polymers are also acceptable, including, for example, hydrogenated methylstyrene (ethylene / butylene) methylstyrene copolymer, hydrogenated methylstyrene (ethylene-ethylene / propylene) methylstyrene copolymer, hydrogenated styrene-isoprene copolymer, hydrogenated styrene-isoprene styrene copolymer, hydrogenated styrene (ethylene / butylene) styrene copolymer, and hydrogenated styrene (ethylene-ethylene / propylene) styrene copolymer.

[0122] As the styrene-based polymer, the above-exemplified ones may be used alone or in combination of two or more kinds.

[0123] When the styrene polymer contains at least one of the structural units represented by the formulas (19) to (21), the molar fraction thereof is preferably about 10 to 40%, more preferably about 15 to 35%, of the entire polymer, which has the additional advantage of maintaining compatibility with the resin and thereby maintaining uniformity of properties within the resin composition.

[0124] The polymerization form of the styrene-based polymer is not particularly limited, and may be a block copolymer, an alternating copolymer, a random copolymer, a graft copolymer, etc. The form of the styrene-based polymer may be a liquid, a solid, an elastomer, etc., and may be hydrogenated.

[0125] The number-average molecular weight of the styrene-based polymer of this embodiment is preferably about 50,000 to 200,000, and more preferably about 50,000 to 150,000. A number-average molecular weight within this range has the advantage of ensuring appropriate resin fluidity in the B-stage of the cured resin. The number-average molecular weight may be measured by a general molecular weight measurement method, and specific examples include values ​​measured using gel permeation chromatography (GPC).

[0126] As the styrene-based polymer of the present embodiment, commercially available products may be used, and examples thereof include "SIBSTAR (registered trademark) 073T" manufactured by Kaneka Corporation, "Septon V9827" and "Septon 2002" manufactured by Kuraray Co., Ltd., and "Tuftec (registered trademark) H1041" manufactured by Asahi Kasei Corporation.

[0127] (Content of each ingredient) In the resin composition of this embodiment, the content of the polyphenylene ether compound is preferably 10 to 90 parts by mass, more preferably 15 to 80 parts by mass, and even more preferably 20 to 70 parts by mass, relative to 100 parts by mass of the total of the polyphenylene ether compound and the allyl compound (and the styrene-based polymer, if the styrene-based polymer is included). That is, the content of the polyphenylene ether compound is preferably 10 to 90% by mass relative to the components other than the inorganic filler in the resin composition. It is believed that if the content of the polyphenylene ether compound is within the above range, a resin composition that can yield a cured product with low dielectric properties and high heat resistance can be more reliably obtained.

[0128] The content of the allyl compound is preferably 10 to 50 parts by mass, more preferably 15 to 50 parts by mass, relative to 100 parts by mass of the total of the polyphenylene ether compound and the allyl compound (and the styrene-based polymer, if the styrene-based polymer is contained) in the resin composition. If the content of the allyl compound is within the above range, it is believed that the resin composition will have superior toughness in the cured product.

[0129] Furthermore, when the resin composition of the present embodiment contains the styrene-based polymer, the content of the styrene-based polymer is preferably 10 to 60 parts by mass, more preferably 15 to 60 parts by mass, relative to 100 parts by mass of the total of the polyphenylene ether compound, the allyl compound, and the styrene-based polymer in the resin composition. When the content of the styrene-based polymer is within the above range, it is believed that resin flowability and varnish handleability are further improved.

[0130] Furthermore, when the resin composition of the present embodiment contains an inorganic filler, the content of the inorganic filler is preferably 50 to 300 parts by mass, more preferably 70 to 300 parts by mass, and even more preferably 100 to 300 parts by mass, relative to 100 parts by mass of the total of the polyphenylene ether compound and the allyl compound (and the styrene polymer, if the styrene polymer is included). When the content of the inorganic filler is within the above range, it is believed that an increase in the thermal expansion coefficient of the cured product can be suppressed, and an increase in resin flowability can also be suppressed.

[0131] <Other ingredients> The resin composition according to this embodiment may contain other components (other components) in addition to the components described above, as necessary, as long as the effects of the present invention are not impaired. Examples of other components contained in the resin composition according to this embodiment include additives such as a reaction initiator, a silane coupling agent, a flame retardant, an antifoaming agent, an antioxidant, a heat stabilizer, an antistatic agent, an ultraviolet absorber, a dye or pigment, a dispersant, and a lubricant. Furthermore, the resin composition according to this embodiment may contain, in addition to the polyphenylene ether compound, the allyl compound, and the heavy styrene-based polymer, other thermosetting resins such as epoxy resins, maleimide resins, aromatic hydrocarbon resins, and aliphatic hydrocarbon resins.

[0132] As described above, the resin composition according to the present embodiment may contain a reaction initiator (initiator). Even if the resin composition contains the polyphenylene ether compound, the curing agent, and the polymer, the curing reaction can proceed. However, depending on the process conditions, it may be difficult to raise the temperature high enough for curing to proceed, so a reaction initiator may be added.

[0133] The reaction initiator is not particularly limited as long as it can accelerate the curing reaction of the resin composition, and specific examples thereof include metal oxides, azo compounds, and peroxides.

[0134] Specific examples of metal oxides include metal carboxylates.

[0135] Examples of peroxides include α,α'-di(t-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne, benzoyl peroxide, 3,3',5,5'-tetramethyl-1,4-diphenoquinone, chloranil, 2,4,6-tri-t-butylphenoxyl, t-butylperoxyisopropyl monocarbonate, and azobisisobutyronitrile.

[0136] Specific examples of the azo compound include 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(N-butyl-2-methylpropionamide), and 2,2'-azobis(2-methylbutyronitrile).

[0137] Among these, α,α'-di(t-butylperoxy)diisopropylbenzene is preferably used as a preferred reaction initiator. α,α'-Di(t-butylperoxy)diisopropylbenzene has low volatility and therefore does not volatilize during drying or storage, resulting in good stability. Furthermore, α,α'-Di(t-butylperoxy)diisopropylbenzene has a relatively high reaction initiation temperature, which can suppress the promotion of the curing reaction when curing is not required, such as during prepreg drying. This suppression of the curing reaction can prevent a decrease in the shelf life of the resin composition.

[0138] The above-mentioned reaction initiators may be used alone or in combination of two or more kinds.

[0139] When the resin composition of the present embodiment contains the reaction initiator, the content thereof is not particularly limited, but is preferably 0.5 to 2.0 parts by mass, more preferably 0.8 to 1.5 parts by mass, and even more preferably 0.9 to 1.0 parts by mass, relative to 100 parts by mass of the total of the polyphenylene ether compound and the allyl compound (and, when the styrene-based polymer is contained, further the styrene-based polymer).

[0140] (Prepreg, resin-coated film, metal-clad laminate, wiring board, and resin-coated metal foil) Next, a prepreg for a wiring board, a metal-clad laminate, a wiring board, and a resin-coated metal foil using the resin composition of this embodiment will be described.

[0141] 1 is a schematic cross-sectional view showing an example of a prepreg 1 according to an embodiment of the present invention. In the following description, the following reference numerals represent: 1 prepreg, 2 resin composition or semi-cured resin composition, 3 fibrous base material, 11 metal-clad laminate, 12 insulating layer, 13 metal foil, 14 wiring, 21 wiring board, 31 resin-coated metal foil, 32 and 42 resin layer, 41 resin-coated film, and 43 support film.

[0142] As shown in Fig. 1, the prepreg 1 according to this embodiment comprises the resin composition containing the thermally expandable microcapsules or a semi-cured product of the resin composition 2, and a fibrous base material 3. Examples of this prepreg 1 include those in which the fibrous base material 3 is present in the resin composition or semi-cured product 2. That is, this prepreg 1 comprises the resin composition or semi-cured product thereof, and the fibrous base material 3 present in the resin composition or semi-cured product 2.

[0143] In this embodiment, the term "semi-cured product" refers to a resin composition that has been partially cured to the extent that it can be further cured. That is, the semi-cured product is a resin composition that has been semi-cured (B-staged). For example, when a resin composition is heated, the viscosity initially gradually decreases, and then curing begins, and the viscosity gradually increases. In such a case, the semi-cured state can be exemplified by the state between when the viscosity starts to increase and when the composition is completely cured.

[0144] The prepreg obtained using the resin composition according to this embodiment may comprise a semi-cured product of the resin composition as described above, or may comprise the uncured resin composition itself. That is, it may be a prepreg comprising a semi-cured product of the resin composition (the resin composition in B stage) and a fibrous substrate, or a prepreg comprising the resin composition before curing (the resin composition in A stage) and a fibrous substrate. Specific examples include those in which a fibrous substrate is present in the resin composition. The resin composition or a semi-cured product thereof may be obtained by heating and drying the resin composition.

[0145] The resin composition according to the present embodiment is often prepared in the form of a varnish and used as a resin varnish when producing the prepreg, or the resin-coated metal foil or metal-clad laminate described below. Such a resin varnish is prepared, for example, as follows.

[0146] First, components soluble in organic solvents, such as resin components and reaction initiators, are added to an organic solvent and dissolved. Heating may be performed as necessary. Subsequently, inorganic fillers and other components insoluble in organic solvents are added and dispersed using a ball mill, bead mill, planetary mixer, roll mill, or the like until a predetermined dispersion state is achieved, thereby preparing a varnish-like resin composition. The organic solvent used here is not particularly limited as long as it dissolves the modified polyphenylene ether compound, the allyl compound, the styrene-based polymer, and the like and does not inhibit the curing reaction. Specific examples include toluene, methyl ethyl ketone, cyclohexanone, and propylene glycol monomethyl ether acetate. These may be used alone or in combination of two or more.

[0147] An example of a method for producing the prepreg 1 of this embodiment using the varnish-like resin composition of this embodiment is a method in which the fibrous base material 3 is impregnated with the resin composition 2 in the form of a resin varnish, and then dried.

[0148] Specific examples of fibrous substrates used in producing prepregs include glass cloth, aramid cloth, polyester cloth, LCP (liquid crystal polymer) nonwoven fabric, glass nonwoven fabric, aramid nonwoven fabric, polyester nonwoven fabric, pulp paper, and linter paper. The use of glass cloth results in a laminate with excellent mechanical strength, and flattened glass cloth is particularly preferred. The glass cloth used in this embodiment is not particularly limited, but examples include low-dielectric-constant glass cloths such as E glass, S glass, NE glass, Q glass, and L glass. Flattening can be performed, for example, by continuously pressing the glass cloth with a press roll at an appropriate pressure to compress the yarns flat. The thickness of the fibrous substrate can generally be, for example, 0.01 to 0.3 mm.

[0149] The resin varnish (resin composition 2) is impregnated into the fibrous substrate 3 by immersion, coating, or the like. This impregnation can be repeated multiple times as necessary. In this case, it is also possible to repeat the impregnation using multiple resin varnishes with different compositions and concentrations, and to adjust the final composition (content ratio) and resin amount to the desired one.

[0150] The fibrous substrate 3 impregnated with the resin varnish (resin composition 2) is heated under desired heating conditions, for example, at a temperature of 80°C or higher and 180°C or lower for 1 minute or longer and 10 minutes or shorter. By heating, the solvent is volatilized from the varnish, reducing or removing the solvent, and a prepreg 1 in an uncured (A-stage) or semi-cured (B-stage) state is obtained.

[0151] 4, the resin-coated metal foil 31 of this embodiment has a configuration in which a resin layer 32 containing the above-mentioned resin composition or a semi-cured product of the resin composition is laminated with a metal foil 13. That is, the resin-coated metal foil of this embodiment may be a resin-coated metal foil comprising a resin layer containing the resin composition before curing (the resin composition in A stage) and a metal foil, or a resin-coated metal foil comprising a resin layer containing a semi-cured product of the resin composition (the resin composition in B stage) and a metal foil.

[0152] An example of a method for producing such a resin-coated metal foil 31 is a method in which the resin composition in the form of a resin varnish as described above is applied to the surface of a metal foil 13 such as a copper foil, followed by drying. Examples of the application method include a bar coater, a comma coater, a die coater, a roll coater, a gravure coater, and the like.

[0153] As the metal foil 13, any metal foil that is used in metal-clad laminates, wiring boards, etc. can be used without any limitation, and examples thereof include copper foil and aluminum foil.

[0154] 5, a resin-coated film 41 of this embodiment has a configuration in which a resin layer 42 containing the above-mentioned resin composition or a semi-cured product of the resin composition is laminated on a film support substrate 43. That is, the resin-coated film of this embodiment may be a resin-coated film comprising the resin composition before curing (the resin composition in A stage) and a film support substrate, or may be a resin-coated film comprising a semi-cured product of the resin composition (the resin composition in B stage) and a film support substrate.

[0155] A method for producing such a resin-coated film 41 is, for example, to apply a resin composition in the form of a resin varnish as described above to the surface of the film support substrate 43, and then evaporate the solvent from the varnish to reduce or remove the solvent, thereby obtaining a resin-coated film in a pre-cured (A stage) or semi-cured (B stage) state.

[0156] Examples of the film support substrate include electrically insulating films such as polyimide film, PET (polyethylene terephthalate) film, polyester film, polyparabanic acid film, polyether ether ketone film, polyphenylene sulfide film, aramid film, polycarbonate film, and polyarylate film.

[0157] In the resin-coated film and resin-coated metal foil of this embodiment, the resin composition or a semi-cured product thereof may be obtained by drying or heat-drying the resin composition, as in the case of the prepreg described above.

[0158] The thickness of the metal foil 13 and the film support substrate 43 can be appropriately set depending on the desired purpose. For example, a metal foil 13 having a thickness of about 0.2 to 70 μm can be used. When the thickness of the metal foil is, for example, 10 μm or less, a carrier-attached copper foil having a release layer and a carrier for improved handleability may be used. The resin varnish is applied to the metal foil 13 and the film support substrate 43 by coating or the like, which can be repeated multiple times as necessary. In this case, it is also possible to repeatedly apply multiple resin varnishes with different compositions and concentrations to adjust the final composition (content ratio) and resin amount to the desired one.

[0159] There are no particular limitations on the drying or heating drying conditions in the manufacturing method of the resin-coated metal foil 31 or the resin film 41, but after applying a resin varnish-like resin composition to the above-mentioned metal foil 13 or film support substrate 43, it is heated under the desired heating conditions, for example, at 80 to 170°C for about 1 to 10 minutes, to volatilize the solvent from the varnish and reduce or remove the solvent, thereby obtaining the resin-coated metal foil 31 or resin film 41 in an uncured (A stage) or semi-cured (B stage) state.

[0160] The resin-coated metal foil 31 and the resin film 41 may be provided with a cover film or the like as necessary. The provision of a cover film can prevent the inclusion of foreign matter, etc. The cover film is not particularly limited as long as it can be peeled off without damaging the shape of the resin composition. For example, a polyolefin film, a polyester film, a TPX film, a film formed by providing a release agent layer on any of these films, or even paper formed by laminating any of these films onto a paper substrate can be used.

[0161] 2, the metal-clad laminate 11 of this embodiment is characterized by having an insulating layer 12 containing a cured product of the above-mentioned resin composition or a cured product of the above-mentioned prepreg, and a metal foil 13. Note that the metal foil 13 used in the metal-clad laminate 11 may be the same as the metal foil 13 described above.

[0162] The metal-clad laminate 11 of this embodiment can also be produced using the resin-coated metal foil 31 or resin film 41 described above.

[0163] A method for producing a metal-clad laminate using the prepreg 1, resin-coated metal foil 31, or resin film 41 obtained as described above involves stacking one or more prepregs 1, resin-coated metal foil 31, or resin film 41, and then stacking a metal foil 13 such as copper foil on either or both sides of the prepreg 1, and then heat-pressure molding the stack to form an integrated laminate, thereby producing a double-sided or single-sided metal foil-clad laminate. The heat-pressure conditions can be set appropriately depending on the thickness of the laminate to be produced, the type of resin composition, and other factors, but can be, for example, a temperature of 170 to 220°C, a pressure of 1.5 to 5.0 MPa, and a time of 60 to 150 minutes.

[0164] Alternatively, the metal-clad laminate 11 may be produced by forming a film-like resin composition on the metal foil 13 and applying heat and pressure, without using the prepreg 1 or the like.

[0165] As shown in FIG. 3, wiring board 21 of this embodiment has insulating layer 12 containing a cured product of the above-mentioned resin composition or a cured product of the above-mentioned prepreg, and wiring 14.

[0166] The resin composition of this embodiment is suitable for use as a material for an insulating layer of a wiring board. For example, a method for producing a wiring board 21 is to form a circuit (wiring) by etching the metal foil 13 on the surface of the metal clad laminate 13 obtained above, thereby obtaining a wiring board 21 having a conductor pattern (wiring 14) provided as a circuit on the surface of the laminate. Examples of the method for forming a circuit include, in addition to the above-described methods, circuit formation by a semi-additive process (SAP) or a modified semi-additive process (MSAP).

[0167] The prepreg, resin-coated film, and resin-coated metal foil obtained using the resin composition of this embodiment have low dielectric properties, a high Tg, and excellent toughness and handleability when cured, making them extremely useful for industrial applications. Furthermore, the metal-clad laminates and wiring boards obtained by curing them have the advantages of low dielectric properties, a high Tg, and excellent handleability.

[0168] The present invention will be explained in more detail below with reference to examples, but the scope of the present invention is not limited to these examples. [Example]

[0169] First, in this example, each component used in preparing the resin composition will be described.

[0170] (Polyphenylene ether compound) PPE1: Modified polyphenylene ether in which the terminal hydroxyl groups of polyphenylene ether have been modified with methacrylic groups (SABIC Innovative Plastics SA9000, intrinsic viscosity (IV) in methylene chloride at 25°C: 0.085 dl / g, weight-average molecular weight Mw: 1700, number of terminal functional groups: 1.8)

[0171] The intrinsic viscosity is a viscosity obtained by measuring a 0.18 g / 45 ml methylene chloride solution (liquid temperature 25° C.) of the modified polyphenylene ether with a viscometer (AVS500 Visco System manufactured by Schott).

[0172] PPE2: Difunctional vinylbenzyl-modified PPE (Mw: 1700) First, modified polyphenylene ether (modified PPE-1) was synthesized. The average number of phenolic hydroxyl groups at the molecular terminals per polyphenylene ether molecule is referred to as the terminal hydroxyl group number.

[0173] Modified polyphenylene ether 1 (modified PPE-1) was obtained by reacting polyphenylene ether with chloromethylstyrene. Specifically, 200 g of polyphenylene ether (SA90 manufactured by SABIC Innovative Plastics, intrinsic viscosity (IV) 0.083 dl / g, number of terminal hydroxyl groups 1.9, weight molecular weight Mw 1700), 30 g of a 50:50 mass ratio mixture of p-chloromethylstyrene and m-chloromethylstyrene (chloromethylstyrene: CMS manufactured by Tokyo Chemical Industry Co., Ltd.), 1.227 g of tetra-n-butylammonium bromide as a phase transfer catalyst, and 400 g of toluene were charged into a 1-liter three-neck flask equipped with a temperature controller, a stirrer, a cooling device, and a dropping funnel, and the mixture was stirred. The mixture was then gradually heated until the liquid temperature reached 75 °C. Then, an aqueous solution of sodium hydroxide (20 g sodium hydroxide / 20 g water) was added dropwise to the solution over 20 minutes as an alkali metal hydroxide. The mixture was then stirred at 75°C for another 4 hours. Next, the contents of the flask were neutralized with 10% by mass of hydrochloric acid, and a large amount of methanol was added. This caused a precipitate to form in the liquid within the flask. In other words, the product contained in the reaction solution within the flask was reprecipitated. The precipitate was then filtered out, washed three times with a mixture of methanol and water in a mass ratio of 80:20, and then dried under reduced pressure at 80°C for 3 hours.

[0174] The obtained solid is 1 The solid was analyzed by H-NMR (400 MHz, CDCl3, TMS). NMR measurements confirmed peaks at 5 to 7 ppm attributable to ethenylbenzyl. This confirmed that the solid obtained was polyphenylene ether ethenylbenzylated at the molecular terminals.

[0175] The molecular weight distribution of the modified polyphenylene ether was measured using GPC, and the weight average molecular weight (Mw) was calculated from the obtained molecular weight distribution, resulting in Mw of 1,700.

[0176] The number of terminal functional groups of the modified polyphenylene ether was measured as follows.

[0177] First, the modified polyphenylene ether was accurately weighed. The weight at that time was designated X (mg). Then, this weighed modified polyphenylene ether was dissolved in 25 mL of methylene chloride, and 100 μL of a 10 mass% ethanol solution of tetraethylammonium hydroxide (TEAH) (TEAH:ethanol (volume ratio) = 15:85) was added to the solution, and the absorbance (Abs) at 318 nm was measured using a UV spectrophotometer (UV-1600, manufactured by Shimadzu Corporation). Then, from the measurement results, the number of terminal hydroxyl groups of the modified polyphenylene ether was calculated using the following formula.

[0178] Residual OH amount (μmol / g) = [(25×Abs) / (ε×OPL×X)]×10 6 where ε is the extinction coefficient, 4700 L / mol cm, and OPL is the cell path length, 1 cm.

[0179] The calculated residual OH amount (number of terminal hydroxyl groups) of the modified polyphenylene ether was almost zero, which indicated that the hydroxyl groups of the polyphenylene ether before modification had been almost entirely modified. This indicated that the decrease in the number of terminal hydroxyl groups from the polyphenylene ether before modification was the number of terminal hydroxyl groups of the polyphenylene ether before modification. In other words, the number of terminal hydroxyl groups of the polyphenylene ether before modification was the number of terminal functional groups of the modified polyphenylene ether. In other words, the number of terminal functional groups was 1.8. This was designated "PPE2."

[0180] (allyl compounds) Production of allyl compound A A 1 L three-necked round-bottom flask equipped with a stirrer and condenser was charged with 104.5 g (0.5 mol) of diallyl isocyanurate, 0.5 mol of a C8 alkyl halide, 48.4 g (0.35 mol) of potassium carbonate, and 400 mL of N,N'-dimethylformamide as a solvent. The mixture was heated with stirring and maintained at 140°C for 4 hours. The solvent was then distilled off under reduced pressure, and 400 mL of benzene was added to the reaction product to extract the target product. The extract was washed with water, dried over anhydrous magnesium sulfate, and the benzene was distilled off to obtain allyl compound A: long-chain alkyl-modified diallyl isocyanurate (C8). Production of allyl compound B Allyl compound B: long-chain alkyl-modified diallyl isocyanurate (carbon number: 12) was obtained in the same manner as allyl compound A, except that the alkyl halide was changed to an alkyl halide having 12 carbon atoms. Preparation of allyl compound C Allyl compound C: long-chain alkyl-modified diallyl isocyanurate (carbon number 14) was obtained in the same manner as allyl compound A, except that the alkyl halide was changed to an alkyl halide having 14 carbon atoms. Preparation of allyl compound D Allyl compound D: long-chain alkyl-modified diallyl isocyanurate (carbon number: 18) was obtained in the same manner as allyl compound A, except that the alkyl halide was changed to an alkyl halide having 18 carbon atoms. Production of allyl compound E Allyl compound E: long-chain alkylene-modified diallyl isocyanurate (carbon number 10) was obtained in the same manner as allyl compound A, except that the alkyl halide was changed to an alkylene halide having 10 carbon atoms.

[0181] (Other hardeners) TAIC: Triallyl isocyanurate (manufactured by Nippon Kasei Co., Ltd.) MeDAIC: Methyl diallyl isocyanurate (manufactured by Shikoku Chemicals Corporation) TMAIC: Trimethallyl isocyanurate (manufactured by Nippon Kasei Co., Ltd.) DVB-810: Divinylbenzene (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)

[0182] (styrene polymer) Septon V9827: Hydrogenated methylstyrene (ethylene / butylene) methylstyrene copolymer (Kuraray Co., Ltd., weight-average molecular weight 92,000) Septon 2002: Hydrogenated styrene (ethylene / propylene) styrene copolymer (Kuraray Co., Ltd., weight average molecular weight 54,000) Tuftec H1041: Hydrogenated styrene (ethylene / butylene) styrene copolymer (Asahi Kasei Corporation, 75,000) SIBSTAR073T: Styrene-isobutylene-styrene triblock copolymer (Kaneka Corporation, weight-average molecular weight 80,000)

[0183] (Reaction initiator) Peroxide: "Perbutyl P", 1,3-bis(butylperoxyisopropyl)benzene (manufactured by NOF Corporation)

[0184] (Inorganic filler) Silica particles: "SC2300-SVJ" vinylsilane-treated spherical silica (manufactured by Admatechs Co., Ltd.)

[0185] <Examples 1 to 15 and Comparative Examples 1 to 6> [Preparation method] (resin varnish) First, the resin components (PPE, allyl compound, styrene polymer, etc.) were added to toluene and mixed to a solids concentration of 60% by mass in the blending ratios (parts by mass) shown in Tables 1 and 2. To this mixture were added peroxide, inorganic filler, etc., and after stirring for 60 minutes, the mixture was dispersed in a bead mill to obtain a resin varnish.

[0186] (Resin-coated film and evaluation board) Resin-coated films were produced using the resin varnishes of each of the examples and comparative examples prepared above. A PET film ("SP-PETO1" manufactured by Mitsui Chemicals Tohcello, Inc.) was used as the substrate. The resin varnish was applied to the surface of the substrate so that the thickness after drying would be 130 μm or more, and this was heated and dried at 120 to 160°C for approximately 2 to 5 minutes to obtain a resin-coated film. The substrate was then peeled off from the obtained resin-coated film, sandwiched between 35 μm-thick copper foils, and laminated. Heating and pressing at a temperature of 200°C and a pressure of 4 MPa for 2 hours yielded an evaluation substrate with an insulating layer thickness of 130 μm.

[0187] <Evaluation test> (Handling: cutter cut) The blade of a cutter knife was placed at an angle of 20° on the evaluation substrate, and a 10 cm long cut was made at a cutting speed of 2 cm / sec. The area of ​​the resin chip around the cut was measured. ◎: The area of ​​resin chipping around the cut surface is 5mm 2 less than ○: The area of ​​resin chipping around the cut surface is 5mm 2 More than 50mm 2 less than △: The area of ​​resin chipping around the cut surface is 50 mm 2 More than 100mm 2 less than ×: The area of ​​resin chipping around the cut surface is 100 mm 2 End

[0188] (elastic modulus) The elastic modulus of the evaluation substrate was measured using a viscoelasticity spectrometer "DMS100" manufactured by Seiko Instruments Inc. Specifically, dynamic viscoelasticity measurement (DMA) was performed using a tensile module at a frequency of 10 Hz, and the storage modulus E' (GPa) at room temperature (25°C) was measured when the temperature was increased from room temperature to 280°C at a heating rate of 5°C / min.

[0189] In this test, a low modulus of elasticity indicates high toughness, and a modulus of elasticity of 4 GPa or less is the passing grade.

[0190] (glass transition temperature (Tg)) The Tg of the evaluation substrate was measured using a viscoelasticity spectrometer "DMS100" manufactured by Seiko Instruments Inc. Dynamic mechanical analysis (DMA) was performed using a tensile module at a frequency of 10 Hz, and the temperature at which tan δ reached a maximum when the temperature was increased from room temperature to 300°C at a heating rate of 5°C / min was defined as Tg. In this example, a Tg of 160°C or higher was considered to be acceptable.

[0191] (Dielectric properties: dielectric loss tangent (Df)) The dielectric loss tangent (Df) of the evaluation board was measured using a cavity resonator perturbation method. Specifically, the dielectric loss tangent (Df) of the test piece at 10 GHz was measured using a network analyzer (Agilent Technologies N5230A). In this example, a Df of 0.0016 or less was considered to be acceptable.

[0192] (Resin flow) The resin flowability was evaluated using the resin-attached film. The resin varnishes of Examples 1 to 15 were measured in accordance with IPC-TM-650. The molding conditions were 171°C and a pressure of 14 kgf / cm. 2 The film was then hot-pressed for 15 minutes. Two resin films prepared as described above were used for the measurement. The resin flow value indicates the quality of circuit filling. If the resin flow value is too low, the resin composition derived from the resin film does not sufficiently penetrate between the circuits, resulting in the formation of voids. In this example, a resin flow value of 10% or more is considered acceptable.

[0193] The results are shown in Tables 1 and 2.

[0194] [Table 1]

[0195] [Table 2]

[0196] (Consideration) As is clear from the results shown in Table 1, it was confirmed that the resin composition of the present invention can provide a cured product that has low dielectric properties, a high Tg, and excellent handleability and toughness. Furthermore, the resin compositions of the examples of the present invention also have excellent resin flow properties, which is thought to be advantageous for filling circuits when producing multilayer wiring boards, etc.

[0197] In particular, in equation (3), R A It was also confirmed that when an allyl compound in which R is an alkyl or alkenyl group having 8 to 18 carbon atoms is used, or when a styrene polymer is used in combination, the handling properties are better.

[0198] In contrast, as is clear from Table 2, Comparative Examples 1 to 4, which did not use the allyl compound according to the present invention, showed high modulus of elasticity and poor handleability. Furthermore, Comparative Example 5, which did not contain a polyphenylene ether compound and instead added an increased amount of allyl compound, showed a brittle cured product, making it impossible to measure the modulus of elasticity and other properties, and was therefore poor in handleability. Furthermore, Comparative Example 6, which added a styrene-based polymer instead of a polyphenylene ether compound, showed good handleability, but was unable to obtain a sufficient Tg.

[0199] This application is based on Japanese Patent Application No. 2020-146564, filed on September 1, 2020, the contents of which are incorporated herein by reference.

[0200] In order to express the present invention, the present invention has been properly and sufficiently described above through embodiments with reference to specific examples, drawings, etc., but it should be recognized that those skilled in the art can easily make changes and / or improvements to the above-described embodiments. Therefore, unless changes or improvements made by those skilled in the art deviate from the scope of the claims set forth in the claims, such changes or improvements are construed as being encompassed within the scope of the claims. [Industrial Applicability]

[0201] The present invention has wide industrial applicability in the technical fields related to electronic materials and various devices using the same.

Claims

1. a polyphenylene ether compound having at least one group represented by the following formula (1) or formula (2); an allyl compound represented by the following formula (3); and a styrene-based polymer having a structural unit represented by the following formula (15): The resin composition, wherein the styrene polymer is at least one selected from the group consisting of hydrogenated methylstyrene (ethylene / butylene) methylstyrene copolymer, hydrogenated methylstyrene (ethylene-ethylene / propylene) methylstyrene copolymer, hydrogenated styrene-isoprene copolymer, hydrogenated styrene-isoprene styrene copolymer, hydrogenated styrene (ethylene / butylene) styrene copolymer, hydrogenated styrene (ethylene / propylene) styrene copolymer, hydrogenated styrene (ethylene-ethylene / propylene) styrene copolymer, styrene-isobutylene copolymer, and styrene-isobutylene-styrene copolymer. 【Chemistry 1】 (In formula (1), p represents an integer of 0 to 10. Z represents an arylene group. R １ ~R ３ each independently represents a hydrogen atom or an alkyl group. 【Chemistry 2】 (In formula (2), R ４ represents a hydrogen atom or an alkyl group) 【Transformation 3】 (In formula (3), R Ａ represents an alkyl or alkenyl group having 8 to 22 carbon atoms) 【Chemistry 4】 (In formula (15), R 39 to R 41 each independently represent a hydrogen atom or an alkyl group, and R 42 represents a group selected from the group consisting of a hydrogen atom, an alkyl group, an alkenyl group, and an isopropenyl group.)

2. The resin composition according to claim 1 , further comprising an inorganic filler.

3. 3. The resin composition according to claim 1, wherein the allyl compound is contained in an amount of 10 to 50 parts by mass per 100 parts by mass of the polyphenylene ether compound and the allyl compound combined.

4. The resin composition according to any one of claims 1 to 3, wherein the allyl compound is contained in an amount of 10 to 50 parts by mass per 100 parts by mass of the total of the polyphenylene ether compound, the allyl compound, and the styrene-based polymer.

5. The resin composition according to any one of claims 1 to 4, wherein the styrene polymer has a weight average molecular weight of 10,000 to 300,000.

6. The resin composition according to any one of claims 1 to 5, wherein the styrene-based polymer is contained in an amount of 10 to 60 parts by mass per 100 parts by mass of the total of the polyphenylene ether compound, the allyl compound, and the styrene-based polymer.

7. The resin composition according to any one of claims 1 to 6, further comprising a reaction initiator.

8. A prepreg comprising the resin composition according to any one of claims 1 to 7 or a semi-cured product of the resin composition and a fibrous base material.

9. A resin-coated film having a resin layer containing the resin composition according to any one of claims 1 to 7 or a semi-cured product of the resin composition, and a support film.

10. A resin-coated metal foil comprising a resin layer containing the resin composition according to any one of claims 1 to 7 or a semi-cured product of the resin composition, and a metal foil.

11. A metal-clad laminate having an insulating layer containing a cured product of the resin composition according to any one of claims 1 to 7 or a cured product of the prepreg according to claim 8, and a metal foil.

12. A wiring board having an insulating layer containing a cured product of the resin composition according to any one of claims 1 to 7 or a cured product of the prepreg according to claim 8, and wiring.

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