Resin composition, and prepregs, resin-coated films, resin-coated metal foils, metal-clad laminates, and wiring boards using the same.

Abstract

As aspect of the present invention relates to a resin composition comprising a compound (A) represented by the formula X-Y　(In the formula, X is 9,10-dihydro-9-oxa-10-phosphaphenanthren-10-yl-10-oxide, and Y is a protecting group.) and a thermosetting resin (B) comprising at least one selection from epoxy resins, polyphenylene ether resins, cyanate ester resins, phenolic resins, active ester resins, benzoxazine resins, maleimide resins, acrylic resins, methacrylic resins, vinyl resins, allyl resins, propenyl resins, and hydrocarbon resins having an unsaturated double bond.

Description

Technical Field

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

Background Art

[0002] In recent years, with the increase in the amount of information processing in various electronic devices, mounting technologies such as high integration of semiconductor devices, high density of wirings, and multilayerization have been rapidly advancing. Generally, thermosetting resins are used as the substrate materials for the base materials of wiring boards used in various electronic devices. In order to cope with high temperatures such as reflow and multilayerization, high heat resistance (glass transition temperature) is required, and low dielectric constant and dielectric tangent are required to increase the signal transmission speed and reduce the loss during signal transmission.

[0003] Since high flame retardancy is required for substrate materials for printed wiring boards and semiconductor packages, generally, flame retardants are added to the resin compositions used as their insulating materials. As flame retardants, halogen-based flame retardants such as bromine-based flame retardants are also known. However, cured products of resin compositions containing such halogens may generate harmful substances such as hydrogen halide during combustion, and have the drawback of having an adverse effect on the human body and the natural environment. Under such circumstances, non-halogenation is also required for insulating materials such as printed wiring boards.

[0004] Phosphorus-based flame retardants known as non-halogen flame retardants are said to exhibit a flame retardant effect by blocking the thermal energy of the ignition source by the carbonized layer formed on the surface during combustion or blocking the air required for combustion due to the carbonization promoting effect of phosphorus compounds on synthetic resins.

[0005] So far, it has been reported that by adding a predetermined phosphorus compound to a thermosetting resin such as a PPE compound or a maleimide compound, flame retardancy can be ensured while maintaining the performance as a printed wiring board to some extent (Patent Documents 1 to 3, etc.).

[0006] However, with conventional non-halogen flame retardants, it is necessary to use a large amount of flame retardant to ensure sufficient flame retardancy. As a result, there is a risk that the glass transition temperature (Tg) of the cured resin composition may decrease or that the dielectric properties may become insufficient. Furthermore, there is a need for resin compositions using novel flame retardants that have flame-retardant effects, different from conventional non-halogen flame retardants, which are suitable for the increasing functionality of substrate materials in recent years.

[0007] The present invention has been made in view of these circumstances, and aims to provide a resin composition that has flame retardancy equivalent to or better than conventional resin compositions containing phosphorus-based flame retardants, while maintaining or having even better performance in properties such as low dielectric properties and high glass transition temperature (Tg) as a wiring board. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2011-46816 [Patent Document 2] International Publication No. 2020 / 204175 [Patent Document 3] Japanese Patent Publication No. 2011-52165 [Overview of the Initiative]

[0009] A resin composition according to one aspect of the present invention is given by the following formula: X-Y (In the formula, X is 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-yl-10-oxide, and Y is a protecting group.) Compound (A) represented by, The present invention is characterized by comprising a thermosetting resin (B) containing at least one selected from epoxy resins, polyphenylene ether resins, cyanate ester resins, phenol resins, activated ester resins, benzoxazine resins, maleimide resins, acrylic resins, methacrylic resins, vinyl resins, allyl resins, propenyl resins, and hydrocarbon resins having unsaturated double bonds. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a schematic cross-sectional view showing the configuration of a prepreg according to one embodiment of the present invention. [Figure 2] Figure 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] Figure 3 is a schematic cross-sectional view showing the configuration of a wiring board according to one embodiment of the present invention. [Figure 4] Figure 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] Figure 5 is a schematic cross-sectional view showing the structure of a resin film according to one embodiment of the present invention. [Figure 6] Figure 6 shows the infrared absorption spectrum (IR) of organic compound 1 obtained in Production Example 1. [Figure 7] Figure 7 shows the 1H-NMR spectrum of organic compound 1 obtained in Production Example 1. [Figure 8] Figure 8 shows the FD-MS of organic compound 1 obtained in Production Example 1. [Modes for carrying out the invention]

[0011] The resin composition according to an embodiment of the present invention (hereinafter also simply referred to as the resin composition) is the following formula: X-Y (In the formula, X is 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-yl-10-oxide, and Y is a protecting group.) Compound (A) represented by, It is characterized by containing a thermosetting resin (B) containing at least one selected from epoxy resins, polyphenylene ether resins, cyanate ester resins, phenol resins, active ester resins, benzoxazine resins, maleimide resins, acrylic resins, methacrylic resins, vinyl resins, allyl resins, propenyl resins, and hydrocarbon resins having unsaturated double bonds.

[0012] With the above configuration, it is possible to provide a resin composition that exhibits high flame retardancy despite not containing halogen atoms, and has properties such as low dielectric characteristics and a high glass transition temperature (Tg).

[0013] It is considered that in the resin composition of this embodiment, the protecting group cleaves from the compound (A) to generate radicals, and the flame retardant effect is exerted by the digestion effect of the stable radicals.

[0014] Therefore, according to the present invention, it is possible to provide a resin composition that exhibits high flame retardancy without containing halogen atoms, and has properties such as low dielectric characteristics and a high Tg in the cured product. Further, by using the resin composition, it is possible to provide a prepreg, a film with resin, a metal foil with resin, a metal-clad laminate, and a wiring board having properties such as high flame retardancy, low dielectric characteristics, and a high Tg.

[0015] Hereinafter, each component of the resin composition according to this embodiment will be specifically described.

[0016] <Compound (A)> The compound (A) according to this embodiment has the following formula: X―Y (In the formula, X is 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-yl-10-oxide, and Y is a protecting group.) It is a compound represented by this.

[0017] Generally, compounds that undergo homogeneous cleavage easily, such as organic peroxides, are known to have low decomposition temperatures, making them unsuitable for addition to various synthetic resins as flame retardants. In contrast, compound (A) of this embodiment has a decomposition temperature of over 200°C at which stable radicals are generated, and it is believed that a very high flame retardant effect can be obtained.

[0018] Furthermore, the resin composition of this embodiment, by containing the above compound (A), has the advantage of not only being flame-retardant but also having a high Tg and low dielectric properties in its cured product.

[0019] The aforementioned compound (A) is a compound having at least one selected from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-yl-10-oxide. Compounds having such a group are thought to have a radical trapping effect and therefore can be obtained to have a higher flame retardant effect.

[0020] Furthermore, the protecting group of compound (A) is a substituent that is temporarily introduced to a specific functional group of a compound having a functional group, with the understanding that it will be removed at a later stage, thereby inactivating its reactivity and improving the chemical stability of the compound. In this embodiment, the later stage refers to the combustion of the resin composition containing the compound.

[0021] In this embodiment, any protecting group introduced by a protecting reagent can be used without any particular problem. Such protecting reagents generally refer to those derived from protecting reagents that are available (for example, commercially) or can be synthesized.

[0022] Specifically, examples of protecting group Y include silyl group, acyl group, allyl group, allyloxycarbonyl group, benzyl group, benzyloxycarbonyl group, acetal group, thioacetal group, 2,2,2-trichloroethoxycarbonyl group, alkoxymethyl group, tert-butoxycarbonyl group, 9-fluorenylmethyloxycarbonyl group, trityl group, sulfonyl group, etc. In particular, among these, it is preferable that the total molecular weight of the compound of formula (1) is 250 or more, and that when the bond between X and Y is cleaved, the radical atom of Y, like the radical atom of X, undergoes resonance stabilization by at least one adjacent aromatic ring, and is a group that readily generates a stable radical.

[0023] Furthermore, it is preferable that the protecting group Y is a group represented by the following formula (1).

[0024] [ka]

[0025] In formula (1) above, R1, R2, and R3 are each independently hydrogen, a benzoyloxy group, a vinylbenzyl group, an alkoxy group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms, and m is each independently an integer from 1 to 5.

[0026] In compound (A), when the protecting group Y is the group represented by formula (1), each radical atom generated by the cleavage of the organic compound undergoes resonance stabilization by at least one aromatic ring on one side (X side) and by three aromatic rings on the other side (protecting group Y side). Therefore, it is considered that the cleavage into radical pairs proceeds more smoothly. As a result, the flame retardant effect described above can be obtained more reliably.

[0027] More specific examples of the group represented by formula (1) include, for example, the trityl group, the 4-methoxytrityl group, the 4,4'-dimethoxytrityl group, and the 4,4',4''-tris(benzoyloxy)trityl group.

[0028] For example, when the protecting group is a trityl group, compound (A) of this embodiment is as follows (however, compounds (1-2) to (1-4) other than compound (1-1) are reference compounds): [ka]

[0029] Furthermore, for example, when the protecting group is a 4-methoxytrityl group, compound (A) of this embodiment is as follows (however, compounds (2-2) to (2-4) other than compound (2-1) are reference compounds): [ka]

[0030] Furthermore, for example, when the protecting group is a 4,4'-dimethoxytrityl group, compound (A) of this embodiment is as follows (however, compounds (3-2) to (3-4) other than compound (3-1) are reference compounds): [ka]

[0031] Furthermore, when the protecting group is a 4,4',4''-tris(benzoyloxy)trityl group, compound (A) of this embodiment is as follows (however, compounds (4-2) to (4-4) other than compound (4-1) are reference compounds): [ka]

[0032] Furthermore, it is preferable that compound (A) in this embodiment has a weight-average molecular weight of 250 or more. This has the advantage that even when added and mixed with synthetic resin at high temperatures, volatility can be suppressed and its additive effect can be fully exerted. Moreover, it is more preferable that the weight-average molecular weight of compound (A) be 300 or more, and even more preferable that it be 400 or more. There is no particular upper limit to the molecular weight, but from the viewpoint of the number of radical sources per molecular weight, it is preferable that it be 1000 or less, and more preferably 900 or less.

[0033] The method for synthesizing compound (A) in this embodiment is not particularly limited, but for example, compound (A) can be obtained by condensing compound X (9,10-dihydro-9-oxa-10-phosphaphenanthren-10-yl-10-oxide) with a protecting reagent having a group that specifically reacts with the functional group of compound X, in the presence or absence of a base. Specific protecting reagents that can be used include, for example, trityl chloride, 4-methoxytrityl chloride, 4,4'-dimethoxytrityl chloride, and 4,4',4''-tris(benzoyloxy)trityl bromide.

[0034] <Thermosetting resin (B)> The thermosetting resin (B) used in this embodiment is not particularly limited as long as it is a thermosetting resin that can be used as a wiring board material, but specifically, examples include epoxy resins, polyphenylene ether resins, cyanate ester resins, phenol resins, benzoxazine resins, activated ester resins, and resins having unsaturated groups. Examples of resins having unsaturated groups include acrylic resins, methacrylic resins, vinyl resins, allyl resins, propenyl resins, maleimide resins, and hydrocarbon resins having unsaturated double bonds, and it is preferable to include at least one of these.

[0035] Among these, it is more preferable to use a resin that yields a low dielectric constant, low dielectric loss tangent, and high Tg in the cured product. Specifically, it is preferable to contain at least one selected from polyphenylene ether compounds, maleimide compounds, and hydrocarbon resins having unsaturated double bonds.

[0036] (Polyphenylene ether resin) As the polyphenylene ether resin, it is preferable to use, for example, a terminal-modified polyphenylene ether compound that exhibits excellent low dielectric properties when cured, and further, it is preferable to use a modified polyphenylene ether compound that is terminally modified by substituents having carbon-carbon unsaturated double bonds.

[0037] Examples of substituents having a carbon-carbon unsaturated double bond include groups exhibiting a styrene structure or a (meth)acrylate structure, as shown in formula (2) or (3) below.

[0038] [ka]

[0039] [ka]

[0040] In formula (3), R1 represents a hydrogen atom or an alkyl group. The alkyl group is not particularly limited, but for example, alkyl groups having 1 to 18 carbon atoms are preferred, and alkyl groups having 1 to 10 carbon atoms are more preferred. Specifically, examples include methyl groups, ethyl groups, propyl groups, hexyl groups, and decyl groups.

[0041] More specifically, examples of the substituents include vinyl benzyl groups (ethenyl benzyl groups) such as p-ethenylbenzyl groups and m-ethenylbenzyl groups, vinylphenyl groups, acrylate groups, and methacrylate groups.

[0042] By using such modified polyphenylene ether compounds, it is believed that it is possible to improve high Tg and adhesion while maintaining low dielectric properties such as low dielectric constant and low dielectric loss tangent, as well as excellent heat resistance.

[0043] Furthermore, modified polyphenylene ether compounds can be used individually or in combination of two or more types.

[0044] In this embodiment, the weight-average molecular weight (Mw) of the modified polyphenylene ether compound used as the thermosetting resin is not particularly limited, but is preferably 1000 to 5000, and more preferably 1000 to 4000. Here, the weight-average molecular weight can be measured by a general molecular weight measurement method, specifically, a value measured using gel permeation chromatography (GPC). Furthermore, if the modified polyphenylene ether compound has repeating units (s, m, n) in the molecule, it is preferable that these repeating units are such that the weight-average molecular weight of the modified polyphenylene ether compound falls within this range.

[0045] When the weight-average molecular weight of a modified polyphenylene ether compound is within this range, it possesses the excellent low dielectric properties of the polyphenylene ether skeleton, resulting in not only superior heat resistance of the cured product but also excellent moldability. This is thought to be due to the following: Compared to ordinary polyphenylene ether, if the weight-average molecular weight is within the range described above, it is relatively low molecular weight, so the heat resistance of the cured product tends to decrease. In this respect, the modified polyphenylene ether compound according to this embodiment has a styrene structure or (meth)acrylate structure at the terminal, so it has high reactivity, and it is thought that a cured product with sufficiently high heat resistance can be obtained. Furthermore, when the weight-average molecular weight of a modified polyphenylene ether compound is within this range, it is high molecular weight compared to styrene and divinylbenzene, but relatively low molecular weight compared to general polyphenylene ether, so it is thought to have excellent moldability. Therefore, it is thought that such a modified polyphenylene ether compound can be obtained that not only has superior heat resistance of the cured product but also excellent moldability.

[0046] Furthermore, in this embodiment, the average number of substituents (number of terminal functional groups) at the molecular ends of the modified polyphenylene ether compound used as a thermosetting resin is not particularly limited. Specifically, it is preferably 1 to 5, and more preferably 1 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 a decrease in the shelf life of the resin composition or a decrease in the fluidity of the resin composition. In other words, using such a modified polyphenylene ether may result in molding defects such as voids occurring during multilayer molding due to insufficient fluidity, making it difficult to obtain a highly reliable printed circuit board.

[0047] The number of terminal functional groups in a modified polyphenylene ether compound can be expressed as a numerical value representing the average number of substituents per molecule of the modified polyphenylene ether compound present in 1 mole of the modified polyphenylene ether compound. This 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 decrease from the number of hydroxyl groups in the polyphenylene ether before modification. This decrease 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 a 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 mixed solution.

[0048] Furthermore, the intrinsic viscosity of the modified polyphenylene ether compound used in this embodiment is not particularly limited. Specifically, it may be 0.03 to 0.12 dl / g, but preferably 0.04 to 0.11 dl / g, and 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 obtain low dielectric properties such as low dielectric constant and low dielectric loss tangent. On the other hand, if the intrinsic viscosity is too high, the viscosity is high, sufficient fluidity cannot be obtained, and the moldability of the cured product tends to decrease. Therefore, if the intrinsic viscosity of the modified polyphenylene ether compound is within the above range, excellent heat resistance and moldability of the cured product can be achieved.

[0049] The intrinsic viscosity referred to here is the intrinsic viscosity measured in methylene chloride at 25°C. More specifically, it is the value measured using a viscometer in a 0.18 g / 45 ml methylene chloride solution (at a liquid temperature of 25°C). Examples of such viscometers include the Schott AVS500 Visco System.

[0050] The polyphenylene ether compound used in the resin composition of this embodiment can be synthesized by known methods or a commercially available compound can be used. Examples of commercially available compounds include "OPE-2st 1200" and "OPE-2st 2200" from Mitsubishi Gas Chemical Company, Inc., and "SA9000" from SABIC Innovative Plastics Corporation.

[0051] (Maleimide resin) The maleimide resin usable in this embodiment is not particularly limited as long as it is a compound having a maleimide group in its molecule. Specifically, examples of the maleimide compound include monofunctional maleimide compounds having one maleimide group in its molecule, polyfunctional maleimide compounds having two or more maleimide groups in its molecule, and modified maleimide compounds. Examples of the modified maleimide compound include modified maleimide compounds in which part of the molecule is modified with an amine compound, modified maleimide compounds in which part of the molecule is modified with a silicone compound, and modified maleimide compounds in which part of the molecule is modified with both an amine compound and a silicone compound.

[0052] More specifically, examples include maleimide compounds having two or more N-substituted maleimide groups in one molecule, maleimide compounds having an indan structure, maleimide compounds having at least one selected from alkyl groups having 6 or more carbon atoms and alkylene groups having 6 or more carbon atoms, and maleimide compounds having a benzene ring in the molecule.

[0053] The maleimide compound used in this embodiment may be a commercially available product, for example, BMI-4000, BMI-2300, BMI-TMH, BMI-4000, BMI-5100 etc. manufactured by Yamato Chemical Industries, Ltd.; MIR-3000-70MT, MIR-5000 manufactured by Nippon Kayaku Co., Ltd.; BMI-689, BMI-1500, BMI-3000J, BMI-5000 etc. manufactured by Designer Molecules Inc.

[0054] (Hydroxide resins containing unsaturated double bonds) The hydrocarbon resins usable in this embodiment are not particularly limited as long as they are hydrocarbon resins having unsaturated double bonds, but preferred examples include hydrocarbon resins such as polyfunctional vinyl aromatic polymers, cyclic polyolefin resins, and vinyl aromatic compound-conjugated diene compound copolymers.

[0055] The polyfunctional vinyl aromatic polymer is preferably a polymer containing at least a polyfunctional vinyl aromatic compound and / or its derivatives polymerized together, and is not particularly limited as long as it contains structures derived from a polyfunctional vinyl aromatic compound and / or its derivatives, and may be a polymer containing structures derived from one or more polyfunctional vinyl aromatic compounds and / or their derivatives.

[0056] Preferably, a polyfunctional vinyl aromatic copolymer having a monomer-derived structural unit consisting of a divinyl aromatic compound and an ethyl vinyl aromatic compound can be used.

[0057] In the resin composition of this embodiment, in addition to the above, epoxy resins, cyanate ester resins, phenolic resins, activated ester resins, benzoxazine resins, and other resins having unsaturated groups (acrylic, methacrylic, vinyl, allyl, propenyl) can also be used as the thermosetting resin (B).

[0058] As epoxy resins, compounds having epoxy groups in their molecules can be used. Specifically, examples include bixylenol-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, bisphenol AF-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol novolac-type epoxy resins, phenol novolac-type epoxy resins, tert-butyl-catechol-type epoxy resins, naphthalene-type epoxy resins, naphthol-type epoxy resins, anthracene-type epoxy resins, glycidylamine-type epoxy resins, glycidyl ester-type epoxy resins, cresol novolac-type epoxy resins, biphenyl-type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro-ring-containing epoxy resins, cyclohexane-type epoxy resins, cyclohexanedimethanol-type epoxy resins, naphthylene ether-type epoxy resins, trimethylol-type epoxy resins, tetraphenylethane-type epoxy resins, and the like. Furthermore, the epoxy compound also includes epoxy resins, which are polymers of each of the epoxy compounds.

[0059] As the cyanate ester resin, compounds having a cyanate group in the molecule can be used. Specifically, for example, phenol novolac type cyanate ester compounds, naphthol aralkyl type cyanate ester compounds, biphenyl aralkyl type cyanate ester compounds, naphthylene ether type cyanate ester compounds, xylene resin type cyanate ester compounds, adamantane skeleton type cyanate ester compounds, etc., can be used.

[0060] As the benzoxazine resin, for example, a benzoxazine compound represented by the following general formula (CI) can be used.

[0061] [ka]

[0062] In formula (C-1), Ra The 'k' represents a k-valent group, and 'Rb' independently represents a halogen atom, alkyl group, or aryl group. 'k' represents an integer from 2 to 4, and 'l' represents an integer from 0 to 4.

[0063] Commercially available products include "JBZ-OP100D" and "ODA-BOZ" from JFE Chemical Corporation; "Pd," "Fa," and "ALP-d" from Shikoku Chemicals Corporation; and "HFB2006M" from Showa Polymer Co., Ltd.

[0064] As the acrylic resin, compounds having an acryloyl group in the molecule can be used. Examples include monofunctional acrylate compounds having one acryloyl group in the molecule, and polyfunctional acrylate compounds having two or more acryloyl groups in the molecule. Examples of the monofunctional acrylate compounds include methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate. Examples of the polyfunctional acrylate compounds include diacrylate compounds such as tricyclodecanedimethanol diacrylate.

[0065] As the methacrylic resin, compounds having a methacryloyl group in the molecule can be used. Examples include monofunctional methacrylate compounds having one methacryloyl group in the molecule, and polyfunctional methacrylate compounds having two or more methacryloyl groups in the molecule. Examples of the monofunctional methacrylate compounds include methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate. Examples of the polyfunctional methacrylate compounds include dimethacrylate compounds such as tricyclodecanedimethanol dimethacrylate (DCP).

[0066] As vinyl resins, compounds having vinyl groups in their molecules can be used. Examples include monofunctional vinyl compounds (monovinyl compounds) having one vinyl group in their molecule, and polyfunctional vinyl compounds having two or more vinyl groups in their molecule. Examples of the polyfunctional vinyl compounds include divinylbenzene, curable polybutadiene having a carbon-carbon unsaturated double bond in its molecule, and curable butadiene-styrene copolymer having a carbon-carbon unsaturated double bond in its molecule.

[0067] As the active ester resin, compounds having highly reactive ester groups in the molecule can be used, such as benzenecarboxylic acid active esters, benzenedicarboxylic acid active esters, benzenetricarboxylic acid active esters, benzenetetracarboxylic acid active esters, naphthalenecarboxylic acid active esters, naphthalenedicarboxylic acid active esters, naphthalenetricarboxylic acid active esters, naphthalenetetracarboxylic acid active esters, fluorenecarboxylic acid active esters, fluorenocarboxylic acid active esters, fluorentricarboxylic acid active esters, and fluorenetetracarboxylic acid active esters.

[0068] As allyl resins, compounds having an allyl group in their molecule can be used, such as triallyl isocyanurate compounds like triallyl isocyanurate (TAIC), diallyl bisphenol compounds, and diallyl phthalate (DAP).

[0069] As phenolic resins, compounds containing a hydroxyl group bonded to an aromatic ring in their molecule can be used. Examples include bisphenol A type phenolic resin, bisphenol E type phenolic resin, bisphenol F type phenolic resin, bisphenol S type phenolic resin, phenol novolac resin, bisphenol A novolac type phenolic resin, glycidyl ester type phenolic resin, aralkyl novolac type phenolic resin, biphenyl aralkyl type phenolic resin, cresol novolac type phenolic resin, polyfunctional phenolic resin, naphthol resin, naphthol novolac resin, polyfunctional naphthol resin, anthracene type phenolic resin, naphthalene skeleton-modified novolac type phenolic resin, phenol aralkyl type phenolic resin, naphthol aralkyl type phenolic resin, dicyclopentadiene type phenolic resin, biphenyl type phenolic resin, alicyclic phenolic resin, polyol type phenolic resin, phosphorus-containing phenolic resin, polymerizable unsaturated hydrocarbon group-containing phenolic resin, and hydroxyl group-containing silicone resins.

[0070] As propenyl resins, for example, propenylbenzene and BPN manufactured by Gun-ei Chemical Industry Co., Ltd. can be used.

[0071] (Blending ratio) The blending ratio of compound (A) and thermosetting resin (B) in the resin composition described above can be appropriately set to an optimal range depending on the type of compound (A) and / or thermosetting resin (B). For example, the content of compound (A) is preferably 1 to 100 parts by weight, and more preferably 5 to 60 parts by weight, based on 100 parts by weight of thermosetting resin (B).

[0072] <Thermoplastic resin> Furthermore, thermoplastic resins may be added to the resin composition of this embodiment to more reliably ensure low dielectric properties and adhesive strength.

[0073] Examples of thermoplastic resins include thermoplastic polyphenylene ether resin, polyphenylene sulfide resin, liquid crystal polymer, polyethylene resin, polystyrene resin, polyurethane resin, polypropylene resin, ABS resin, acrylic resin, polyethylene terephthalate resin, polycarbonate resin, polyacetal resin, polyimide resin, polyamide-imide resin, polytetrafluoroethylene resin, cycloolefin polymer, cycloolefin copolymer, and styrene-based elastomer. These resins may be used individually or in combination of two or more types.

[0074] Among these, the styrene-based elastomer is a polymer obtained by polymerizing monomers containing a styrene-based monomer, and may also be a styrene-based copolymer. Examples of the styrene-based copolymer include copolymers obtained by copolymerizing one or more of the styrene-based monomers with one or more other monomers copolymerizable with the styrene-based monomers. The styrene-based copolymer may be a random copolymer or a block copolymer, as long as it has a structure derived from the styrene-based monomer in its molecule. Examples of the block copolymer include a binary copolymer of a structure (repeating unit) derived from the styrene-based monomer and the copolymerizable other monomer (repeating unit), and a ternary copolymer of a structure (repeating unit) derived from the styrene-based monomer and the copolymerizable other monomer (repeating unit).

[0075] The styrene-based elastomer may be a hydrogenated styrene-based copolymer obtained by hydrogenating the styrene-based copolymer.

[0076] The styrene-based elastomer may be made by using one type of styrene-based polymer alone, or by using two or more types in combination.

[0077] The styrene-based elastomer may also be an acid anhydride-modified styrene-based elastomer, in which a portion of the molecule is modified with an acid anhydride.

[0078] The styrene-based elastomer preferably has a weight-average molecular weight of 1,000 to 300,000, and more preferably 1,200 to 200,000. If the molecular weight is too low, the glass transition temperature of the cured resin composition tends to decrease, and the heat resistance tends to decrease. If the molecular weight is too high, the viscosity of the resin composition when it is made into a varnish, and the viscosity of the resin composition during heat molding, tend to become too high. The weight-average molecular weight can be measured by any general molecular weight measurement method, specifically, values ​​measured using gel permeation chromatography (GPC), etc.

[0079] As the styrene-based elastomer, commercially available products may be used, for example, V9827, V9461, 2002, 8007, 8076, 7125F from Kuraray Co., Ltd., FTR2140, FTR6125 from Mitsui Chemicals, Inc., and H1517, H1041, H1221 from Asahi Kasei Corporation.

[0080] <Inorganic fillers> The resin composition according to this 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 resin composition, and are not particularly limited. It is believed that by including an inorganic filler, it is possible to enhance the heat resistance and flame retardancy, as well as further suppress the coefficient of thermal expansion.

[0081] Specific examples of inorganic fillers that can be used in this embodiment include, for example, silica, alumina, titanium oxide, magnesium oxide and mica, metal oxides such as magnesium hydroxide and aluminum hydroxide, talc, aluminum borate, barium sulfate, aluminum nitride, boron nitride, titanium oxide, barium titanate, strontium titanate, calcium titanate, aluminum titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, zirconium tungstate phosphate, magnesium carbonate such as anhydrous magnesium carbonate, and calcium carbonate, as well as boehmite-treated versions thereof. Among these, silica, metal hydroxides such as magnesium hydroxide and aluminum hydroxide, aluminum oxide, boron nitride, barium titanate, and strontium titanate are preferred, with silica being more preferred. The silica is not particularly limited and examples include crushed silica, spherical silica, and silica particles.

[0082] These inorganic fillers may be used individually or in combination of two or more types. Furthermore, while the inorganic fillers described above may be used as is, they may also be surface-treated with epoxysilane, vinylsilane, methacrylicsilane, phenylaminosilane, or aminosilane type silane coupling agents. These silane coupling agents can be added using an integral blending method, rather than being pre-surface-treated with the fillers.

[0083] If the resin composition of this embodiment contains an inorganic filler, its content is preferably about 10 to 300 parts by mass, and more preferably about 40 to 250 parts by mass, based on 100 parts by mass of the total mass of compound (A), thermosetting resin (B), and thermoplastic resin.

[0084] <Other ingredients> The resin composition according to this embodiment may further contain components other than those described above (other components) as necessary, as long as they do not impair the effects of the present invention. Other components contained in the resin composition according to this embodiment may further include, for example, catalysts such as reaction initiators and reaction accelerators, silane coupling agents, polymerization inhibitors, polymerization retarders, defoamers, leveling agents, antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, dyes and pigments, dispersants and lubricants and other additives.

[0085] As described above, the resin composition according to this embodiment may contain a catalyst. The catalyst is not particularly limited as long as it can promote the curing reaction of the resin composition. Specifically, examples include metal oxides, azo compounds, peroxides, imidazole compounds, phosphorus-based curing accelerators, amine-based curing accelerators, and the like.

[0086] Examples of metal oxides include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0087] Examples of peroxides include α,α'-di(t-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexine, benzoyl peroxide, 3,3',5,5'-tetramethyl-1,4-diphenoquinone, chloranil, 2,4,6-tri-t-butylphenoxyl, t-butylperoxyisopropyl monocarbonate, and azobisisobutyronitrile.

[0088] Examples of azo compounds include 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(N-butyl-2-methylpropionamide), and 2,2'-azobis(2-methylbutyronitrile).

[0089] Among the preferred reaction initiators, α,α'-di(t-butylperoxy)diisopropylbenzene is preferably used. α,α'-di(t-butylperoxy)diisopropylbenzene has low volatility, so it does not volatilize during drying or storage, resulting in good stability. Furthermore, because α,α'-di(t-butylperoxy)diisopropylbenzene has a relatively high reaction initiation temperature, it can suppress the acceleration of the curing reaction at points where curing is not required, such as during prepreg drying. This suppression of the curing reaction helps to prevent a decrease in the shelf life of the resin composition.

[0090] Examples of phosphorus-based curing accelerators include triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate.

[0091] Examples of amine-based curing accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine (DMAP), benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene.

[0092] Examples of imidazole compounds include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[ 2'-methylimidazolyl-(1')-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanurate adduct, 2-F Examples of imidazole compounds include phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline.

[0093] The catalysts described above may be used individually or in combination of two or more types.

[0094] <Prepregs, resin-coated films, metal-clad laminates, wiring boards, and resin-coated metal foils> Next, a prepreg, metal-clad laminate, wiring board, and resin-coated metal foil for a wiring board using the resin composition of this embodiment will be described. In the following description, each reference numeral indicates the following: 1 prepreg, 2 resin composition or semi-cured resin composition, 3 fibrous substrate, 11 metal-clad laminate, 12 insulating layer, 13 metal foil, 14 wiring, 21 wiring board, 31 resin-coated metal foil, 32, 42 resin layer, 41 resin-coated film, and 43 support film.

[0095] Figure 1 is a schematic cross-sectional view showing an example of prepreg 1 according to an embodiment of the present invention.

[0096] As shown in Figure 1, the prepreg 1 according to this embodiment comprises the resin composition or a semi-cured product 2 of the resin composition and a fibrous base material 3. An example of this prepreg 1 is one in which the fibrous base material 3 is present within the resin composition or its semi-cured product 2. That is, this prepreg 1 comprises the resin composition or its semi-cured product and the fibrous base material 3 present within the resin composition or its semi-cured product 2.

[0097] In this embodiment, "semi-cured product" refers to a resin composition that has been partially cured to the extent that it can be further cured. In other words, a semi-cured product is a resin composition that has been partially cured (stage B). For example, when a resin composition is heated, its viscosity gradually decreases at first, then curing begins, and the viscosity gradually increases. In such a case, a semi-cured state would be the state between when the viscosity begins to increase and when it is not yet completely cured.

[0098] The prepreg obtained using the resin composition according to this embodiment may include a semi-cured product of the resin composition as described above, or it may include 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 stage B) and a fibrous substrate, or it may be a prepreg comprising the uncured resin composition (the resin composition in stage A) and a fibrous substrate. Specifically, for example, a resin composition may contain a fibrous substrate. The resin composition or its semi-cured product may be obtained by heat-drying the resin composition.

[0099] The resin composition according to this embodiment is often prepared in a varnish-like form and used as a resin varnish when manufacturing the prepreg, or resin-coated metal foil or metal-clad laminate described later. Such a resin varnish is prepared, for example, as follows.

[0100] First, each component that can be dissolved in an organic solvent, such as the resin component and the reaction initiator, is added to the organic solvent and dissolved. Heating may be performed as needed during this process. Subsequently, an inorganic filler or the like, which is a component that does not dissolve in the organic solvent, is added, and the mixture is dispersed using a ball mill, bead mill, planetary mixer, roll mill, etc., until a predetermined dispersion state is reached, thereby preparing a varnish-like resin composition. The organic solvent used here is not particularly limited as long as it dissolves the compound (A), the thermosetting resin (B), and the reactive compound, etc., as needed, without inhibiting the curing reaction. Specifically, examples include toluene, methyl ethyl ketone, cyclohexanone, cyclopentanone, methylcyclohexane, dimethylformamide, and propylene glycol monomethyl ether acetate. These may be used individually or in combination of two or more.

[0101] A method for producing the prepreg 1 of this embodiment using the varnish-like resin composition of this embodiment is, for example, to impregnate a fibrous substrate 3 with the resin varnish-like resin composition 2 and then dry it.

[0102] Specific examples of fibrous base materials used in the manufacture of 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. When glass cloth is used, a laminate with excellent mechanical strength can be obtained, 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. Specifically, the flattening process can be carried out, for example, by continuously pressing the glass cloth with a press roll at an appropriate pressure to flatten the yarn. The thickness of the fibrous base material can generally be 0.01 to 0.3 mm.

[0103] The resin varnish (resin composition 2) is impregnated into the fibrous substrate 3 by dipping, coating, etc. This impregnation can be repeated multiple times as needed. Furthermore, it is possible to repeat the impregnation using multiple resin varnishes with different compositions and concentrations to finally adjust to the desired composition (content ratio) and resin amount.

[0104] A fibrous substrate 3 impregnated with resin varnish (resin composition 2) is heated under desired heating conditions, for example, at 80°C or higher and 180°C or lower for 1 minute or more and 10 minutes or less. Heating causes the solvent to evaporate from the varnish, reducing or removing the solvent to obtain a prepreg 1 in a pre-cured state (Stage A) or a semi-cured state (Stage B).

[0105] Furthermore, as shown in Figure 4, the resin-coated metal foil 31 of this embodiment has a structure in which a resin layer 32 containing the above-mentioned resin composition or a semi-cured product of the resin composition and a metal foil 13 are laminated together. 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 stage A) and a metal foil, or it may be a resin-coated metal foil comprising a resin layer containing a semi-cured product of the resin composition (the resin composition in stage B) and a metal foil.

[0106] One method for producing such resin-coated metal foil 31 is to apply a resin varnish-like resin composition, as described above, to the surface of a metal foil 13 such as copper foil, and then dry it. Examples of such application methods include bar coaters, comma coaters, die coaters, roll coaters, gravure coaters, and the like.

[0107] The metal foil 13 can be any metal foil used in metal-clad laminates, wiring boards, etc., for example, copper foil and aluminum foil.

[0108] Furthermore, as shown in Figure 5, the resin-coated film 41 of this embodiment has a structure in which a resin layer 42 containing the above-mentioned resin composition or a semi-cured product of the resin composition and a film support substrate 43 are laminated together. 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 stage A) and a film support substrate, or it may be a resin-coated film comprising a semi-cured product of the resin composition (the resin composition in stage B) and a film support substrate.

[0109] As a method for producing such a resin-coated film 41, for example, a resin varnish-like resin composition as described above can be applied to the surface of a film support substrate 43, and then the solvent can be evaporated from the varnish to reduce the amount of solvent, or the solvent can be removed, thereby obtaining a resin-coated film in a pre-cured state (Stage A) or a semi-cured state (Stage B).

[0110] 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.

[0111] In addition, in the resin-coated film and resin-coated metal foil of this embodiment, similar to the prepreg described above, the resin composition or its semi-cured product may be obtained by drying or heat-drying the resin composition.

[0112] The thickness of the metal foil 13 and the film support substrate 43 can be set appropriately according to the desired purpose. For example, the metal foil 13 can be approximately 0.2 to 70 μm thick. If the thickness of the metal foil is, for example, 10 μm or less, a carrier-equipped copper foil with a release layer and carrier may be used to improve handling. The resin varnish is applied to the metal foil 13 and the film support substrate 43 by coating, and this can be repeated multiple times as needed. In this case, it is also possible to repeatedly coat using multiple resin varnishes with different compositions and concentrations to finally adjust to the desired composition (content ratio) and amount of resin.

[0113] The drying or heat drying conditions in the manufacturing method of the resin-coated metal foil 31 and resin film 41 are not particularly limited, but after applying the resin varnish-like resin composition to the metal foil 13 or film support substrate 43, the resin is heated under desired heating conditions, for example, at 50 to 180°C for about 0.1 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 a pre-cured state (A stage) or a semi-cured state (B stage).

[0114] The resin-coated metal foil 31 and the resin film 41 may be provided with a cover film or the like, if necessary. Providing a cover film can prevent the incorporation of foreign matter. The cover film is not particularly limited as long as it can be peeled off without damaging the form of the resin composition, but for example, polyolefin film, polyester film, TPX film, films formed by providing a release agent layer on these films, and paper obtained by laminating these films onto a paper substrate can be used.

[0115] As shown in Figure 2, the metal-clad laminate 11 of this embodiment is characterized by having an insulating layer 12 containing a cured product of the resin composition or a cured product of the prepreg described above, and a metal foil 13. The metal foil 13 used in the metal-clad laminate 11 can be the same as the metal foil 13 described above.

[0116] Furthermore, the metal-clad laminate 11 of this embodiment can also be made using the resin-coated metal foil 31 or resin film 41 described above.

[0117] As 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, one or more sheets of the prepreg 1, resin-coated metal foil 31, or resin film 41 are stacked, and then metal foil 13 such as copper foil is stacked on both sides or one side of the stack. This is then heated and pressurized to create a laminate that is metal-clad on both sides or on one side. The heating and pressurizing conditions can be appropriately set depending on the thickness of the laminate to be manufactured and the type of resin composition, but for example, the temperature can be set to 170-230°C, the pressure to 1.5-5.0 MPa, and the time to 60-150 minutes.

[0118] Alternatively, the metal-clad laminate 11 may be manufactured by forming a film-like resin composition on a metal foil 13 and then heating and pressurizing it, without using a prepreg 1 or the like.

[0119] As shown in Figure 3, the wiring board 21 of this embodiment has an insulating layer 12 containing a cured product of the resin composition or a cured product of the prepreg described above, and wiring 14.

[0120] The resin composition of this embodiment is suitably used as a material for the insulating layer of a wiring board. As a method for manufacturing the wiring board 21, for example, a wiring board 21 can be obtained by etching the metal foil 13 on the surface of the metal-clad laminate 11 obtained above to form circuits (wirings), thereby providing a conductor pattern (wirings 14) as a circuit on the surface of the laminate. In addition to the method described above, other methods for forming circuits include, for example, circuit formation by the semi-additive process (SAP) or the modified semi-additive process (MSAP).

[0121] The prepregs, resin-coated films, and resin-coated metal foils obtained using the resin composition of this embodiment are highly useful for industrial applications because their cured products exhibit excellent low dielectric properties and flame retardancy, as well as a high Tg. Furthermore, the metal-clad laminates and wiring boards obtained by curing them also possess the advantages of excellent low dielectric properties, flame retardancy, and a high Tg.

[0122] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited thereto. [Examples]

[0123] <Synthesis of compound (A)> (Manufacturing Example 1) Preparation of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-trityl-10-oxide (organic compound 1) A 300 ml hard glass four-necked flask equipped with a stirrer, thermometer, reflux condenser, and gas inlet was charged with 21.6 g (Mw 216.2 × 0.1 mol) of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 183 g of acetonitrile.

[0124] While blowing nitrogen gas through the gas inlet, the temperature was raised, and when the temperature reached 70°C, the addition of trityl chloride in installments began. After the initial addition of 9.3g of trityl chloride, the process of adding 9.3g of trityl chloride every hour was repeated thereafter, and a total of 27.9g (Mw278.8 × 0.1 moles) of trityl chloride was added in installments.

[0125] After the phased addition was complete, the reaction vessel temperature was set to 80°C, and dehydrochlorination maturation was carried out for 24 hours, after which cooling was started. When the vessel temperature dropped to around 25°C, the precipitated crystals were filtered by suction, and then the filtered crystals were washed with purified water. The washing operation was continued until the pH of the filtrate was nearly neutral, and then it was dried.

[0126] Through the above procedure, 44.4 g of white crystals of organic compound 1 (Mw458.5), which has a melting point of approximately 250°C, was obtained.

[0127] Organic compound 1 was confirmed to have a purity of 99% by liquid chromatography (LC) analysis. Its infrared absorption spectrum (IR) is shown in Figure 6, its 1H-NMR spectrum in Figure 7, and its FD-MS spectrum in Figure 8. The obtained organic compound 1 was confirmed to have the following chemical structure.

[0128] [ka]

[0129] <Other flame retardants> • Flame retardant 1: Aromatic condensed phosphate ester (PX-200, manufactured by Daihachi Chemical Industry Co., Ltd.) • Flame retardant 2: Phosphazene compound (FP-100, manufactured by Fushimi Pharmaceutical Co., Ltd.) • Flame retardant 3: Aluminum phosphinate (Clariant "OP-935") • Flame retardant 4: Melamine polyphosphate (BASF Japan Ltd. "Melapur 200 / 70")

[0130] <Thermosetting resin component> • Polyphenylene ether compound: A modified polyphenylene ether compound obtained by modifying the terminal hydroxyl groups of polyphenylene ether with methacryloyl groups (SA9000 from SABIC Innovative Plastics, weight-average molecular weight Mw2000, number of terminal functional groups: 2). • Allyl compound: Triallyl isocyanurate (TAIC, manufactured by Nippon Chemical Corporation)

[0131] <Thermoplastic resin component> • Styrene-based elastomer resin ("SeptonV9827" manufactured by Kuraray Co., Ltd.)

[0132] <Other ingredients> • Catalyst 1: PBP (1,3-bis(butylperoxyisopropyl)benzene ("Perbutyl P (PBP)" manufactured by NOF Corporation)) • Inorganic filler 1: Spherical silica treated with vinylsilane (Silica particles "SC2300-SVJ" manufactured by Admatex Co., Ltd.)

[0133] (Examples 1-2 and Comparative Examples 1-4) [Preparation method] (Resin varnish) First, each of the above components, excluding compound (A) and the inorganic filler, was added to toluene in the composition (parts by mass) shown in Table 1, so that the solid content concentration was 40-65% by mass, and the mixture was mixed. The mixture was stirred for 60 minutes. Then, compound (A) and the inorganic filler were added to the resulting liquid, dispersed in a stirrer beforehand, and the filler was dispersed using a bead mill. In this way, a varnish-like resin composition (varnish) was obtained.

[0134] (Evaluation sample) Next, prepregs and evaluation substrates (metal-clad laminates) were obtained as follows.

[0135] The obtained varnish was impregnated into a fibrous substrate (glass cloth: #2116 type, E-glass, manufactured by Nitto Boseki Co., Ltd.), and then heated and dried at 120°C for 3 minutes to produce a prepreg. At that time, the content of the components constituting the resin composition relative to the prepreg (resin content) was adjusted to 45% by mass due to the curing reaction.

[0136] Next, an evaluation substrate (metal-clad laminate) was obtained as follows.

[0137] Four of the obtained prepregs were stacked together, and copper foil (3EC-VLP manufactured by Mitsui Mining & Smelting Co., Ltd., 12 μm thick) was placed on both sides. This was used as the pressure-bearing body, and it was heated to 200°C at a heating rate of 2°C / min. By heating and pressurizing it at 200°C for 120 minutes under a pressure of 2 MPa, an evaluation substrate (metal-clad laminate) with copper foil bonded to both sides and a thickness of approximately 400 μm was obtained.

[0138] <Evaluation Test> Using unclad boards obtained by etching away the copper foil from the evaluation boards described above, the flammability (average time) was evaluated in accordance with the UL94 flammability test. Specifically, five evaluation boards were subjected to flame contact twice for a total of 10 flame contacts, and the average time until the flame went out was measured and the average value was calculated. The evaluation criterion was that 25 seconds or less was considered a passing grade. In the table, "total burning" means that the flame rose from the lower end of the evaluation board that was subjected to flame contact to the upper end that was chucked, indicating that it was completely burned.

[0139] (Dielectric properties: Dielectric loss tangent (Df)) The dielectric loss tangent of the evaluation substrate at 10 GHz was measured using the cavity resonator perturbation method with an unclad board obtained by etching away the copper foil from the aforementioned evaluation substrate. Specifically, the dielectric loss tangent (Df) of the evaluation substrate at 10 GHz was measured using a network analyzer (N5230A manufactured by Agilent Technologies, Inc.). In this test, a Df of 0.006 or less was considered acceptable.

[0140] (Glass transition temperature (Tg)) Using an unclad plate obtained by etching away the copper foil from the aforementioned evaluation substrate, the Tg was measured using a viscoelastic spectrometer "DMS100" manufactured by Seiko Instruments Inc. Dynamic viscoelasticity measurement (DMA) was performed using a tensile module at a frequency of 10 Hz. Tg was defined as the temperature at which tanδ was maximized when the temperature was raised from room temperature to 320°C at a heating rate of 5°C / min. In this test, a Tg of 250°C or higher was considered acceptable.

[0141] The results are shown in Table 1.

[0142] [Table 1]

[0143] (Consideration) As is clear from the results in Table 1, the evaluation substrates using the resin compositions of the examples showed good results in all aspects: flame retardancy, Tg, and low dielectric properties.

[0144] On the other hand, the evaluation substrate using the resin composition of Comparative Example 1, which did not contain a flame retardant, did not exhibit flame retardancy. Furthermore, Comparative Examples 2 to 4, which used conventional flame retardants other than compound (A) of the present invention, could not obtain sufficient low dielectric properties, and Comparative Examples 2 and 3 could not obtain an even higher Tg.

[0145] This application is based on Japanese Patent Application No. 2021-81741, filed on 13 May 2021, the contents of which are included in this application.

[0146] In order to express the present invention, the invention has been adequately and sufficiently described above through embodiments with reference to specific examples and drawings, etc. However, those skilled in the art should recognize that it is easy to modify and / or improve the embodiments described above. Therefore, unless the modifications or improvements implemented by those skilled in the art fall outside the scope of the claims described in the claims, such modifications or improvements shall be interpreted as being included within the scope of the claims. [Industrial applicability]

[0147] The present invention has broad industrial applicability in the technical fields of electronic materials, electronic devices, optical devices, and the like.

Claims

1. The following formula: Compound (A) represented by, A thermosetting resin (B) containing at least one selected from epoxy resins, polyphenylene ether resins, cyanate ester resins, phenol resins, activated ester resins, benzoxazine resins, maleimide resins, acrylic resins, methacrylic resins, vinyl resins, allyl resins, propenyl resins, and hydrocarbon resins having unsaturated double bonds, A resin composition containing the following:

2. The resin composition according to claim 1, wherein the thermosetting resin (B) comprises at least one selected from a polyphenylene ether resin, a maleimide resin, and a hydrocarbon resin having an unsaturated double bond.

3. A prepreg having a resin composition according to claim 1 or 2 or a semi-cured product of the resin composition, and a fibrous substrate.

4. A resin-coated film having a resin layer containing the resin composition described in claim 1 or 2 or a semi-cured product of the resin composition, and a support film.

5. A resin-coated metal foil having a resin layer containing the resin composition described in claim 1 or 2 or a semi-cured product of the resin composition, and a metal foil.

6. A metal-clad laminate having an insulating layer containing a cured product of the resin composition according to claim 1 or 2, and a metal foil.

7. A wiring substrate having an insulating layer containing a cured product of the resin composition according to claim 1 or 2, and wiring.

8. A metal-clad laminate having an insulating layer containing a cured prepreg according to claim 3, and a metal foil.

9. A wiring substrate having an insulating layer containing a cured prepreg according to claim 3, and wiring.

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