Resin composition, prepreg, metal foil-clad laminate, resin composite sheet, and printed wiring board

Abstract

The invention relates to a resin composition, a prepreg, a metal foil-clad laminate, a resin composite sheet, and a printed wiring board. The purpose of the present invention is to provide a resin composition having a novel component composition in a resin composition containing a specific maleimide compound, thereby expanding the selection range of a material that can be suitably used in a prepreg for a printed wiring board. Furthermore, the present invention provides, from the aspect of physical properties, a dielectric constant and a dielectric loss tangent are sufficiently suppressed to be low, the amount of change in the dielectric constant and the dielectric loss tangent after long-term heating is sufficiently suppressed to be low, the peeling resistance when formed into a film or a sheet is excellent, and the heat resistance of the film or the sheet is excellent. The present invention relates to a resin composition having practically sufficient heat resistance, and a prepreg, a metal foil-clad laminate, a resin composite sheet, and a printed wiring board using the same. The resin composition contains a polyfunctional vinyl aromatic polymer (A) and a specific maleimide compound (B).

Description

[0001] This application is a divisional application of a Chinese patent application with an application date of February 26, 2020, an application number of 202080016910.2, and an invention title of "Resin Composition, Prepreg, Metal-Clad Laminate, Resin Composite Sheet, and Printed Circuit Board". Technical Field

[0002] The present invention relates to a resin composition, a prepreg using the same, a metal-clad laminate, a resin composite, and a printed circuit board. Background Art

[0003] In recent years, the high integration and miniaturization of semiconductor elements used in electronic devices, communication devices, etc., led by portable terminals, have been accelerating. Along with this, technologies capable of achieving high-density mounting of semiconductor elements are required, and printed circuit boards, which play an important role among them, also need to be improved.

[0004] On the other hand, the uses of electronic devices, etc., are diversifying and continuously expanding. Affected by this, various characteristics required for printed circuit boards, metal-clad laminates used therein, prepregs, etc., are also diversifying and becoming stricter. Considering such required characteristics and in order to obtain an improved printed circuit board, various materials and processing methods have been proposed. As one of them, the improvement and development of resin materials constituting prepregs can be cited.

[0005] For example, Patent Document 1 discloses a resin composition containing: a terminal vinyl compound (a) of a bifunctional phenylene ether oligomer having a polyphenylene ether skeleton, a specific maleimide compound (b), a naphthol aralkyl type cyanate resin (c), and a novolak type epoxy resin (d) having a modified naphthalene skeleton.

[0006] Patent Document 2 discloses a flame-retardant resin composition formed from a resin having a maleimide group at at least one end (an amino bismaleimide resin based on N,N'-4,4'-diphenylmethane bismaleimide and diamine), a copolymer of bromostyrene represented by formula (c1) and divinylbenzene represented by formula (c2).

[0007]

[0008] Prior Art Documents

[0009] Patent Documents

[0010] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2010-138364

[0011] Patent Document 2: Japanese Unexamined Patent Application Publication No. 03-006293 Summary of the Invention

[0012] Problems to be Solved by the Invention

[0013] Including the above examples, various characteristics in semiconductor processes have been improved through the development of their materials. However, in view of the recent technological developments and the expansion of applications, there is a demand for further expanding the material selection range, improving performance, and enhancing manufacturing adaptability.

[0014] Therefore, an object of the present invention is to provide a resin composition having a novel composition in a resin composition containing a specific maleimide compound, thereby expanding the selection range of materials suitable for prepregs for printed circuit boards. Another object is to provide: a resin composition that sufficiently suppresses the dielectric constant and the tangent of the dielectric loss angle to a low level from the aspect of physical properties, sufficiently suppresses the change amounts of the dielectric constant and the tangent of the dielectric loss angle after long-term heating to a low level, has excellent peel resistance when formed into a film or sheet, and has sufficient heat resistance in practice, and a prepreg, a metal-clad laminate, a resin composite sheet, and a printed circuit board using the same.

[0015] Solutions for Solving the Problems

[0016] Based on the above problems, the present inventors conducted research and found that in a resin composition using a maleimide compound having a specific structure, by combining it with a polyfunctional vinyl aromatic polymer, the above problems can be solved, and thus the present invention was completed. Specifically, the above problems are preferably solved by the following scheme <1>, and more preferably by <2> to <10>.

[0017] <1> A resin composition comprising a polyfunctional vinyl aromatic polymer (A) and a maleimide compound (B), and as the maleimide compound (B), at least one compound represented by any of the following formulas (1) to (4) is contained.

[0018]

[0019] (In formula (1), R 1 , R 2 , R 3 and R 4 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, and n1 represents a number of 1 or more and 10 or less.)

[0020]

[0021] (In formula (2), R 6 each independently represent a methyl group or an ethyl group, and R 7 each independently represent a hydrogen atom or a methyl group.)

[0022]

[0023] (In formula (3), R 8 each independently represents a hydrogen atom, a methyl group, or an ethyl group.)

[0024]

[0025] (In formula (4), R 9 each independently represents a hydrogen atom, a methyl group, or an ethyl group.)

[0026] <2>The resin composition according to <1>, wherein the polyfunctional vinyl aromatic polymer (A) is a polymer having a structural unit represented by formula (V).

[0027]

[0028] (In formula (V), Ar represents an aromatic hydrocarbon linking group. * represents the bonding position.)

[0029] <3>The resin composition according to <1> or <2>, wherein, based on 100 parts by mass of the total amount of the resin components in the resin composition, the content of the maleimide compound (B) is 5 to 95 parts by mass.

[0030] <4>The resin composition according to any one of <1> to <3>, wherein, based on 100 parts by mass of the total amount of the resin components in the resin composition, the content of the polyfunctional vinyl aromatic polymer (A) is 5 to 95 parts by mass.

[0031] <5>The resin composition according to any one of <1> to <4>, further comprising a filler (C).

[0032] <6>The resin composition according to <5>, wherein, based on 100 parts by mass of the total amount of the resin components in the resin composition, the content of the filler (C) is 10 to 500 parts by mass.

[0033] <7>A prepreg formed from a base material and the resin composition according to any one of <1> to <6>.

[0034] <8>A metal foil-clad laminate comprising: at least one layer formed from the prepreg according to <7>, and a metal foil disposed on one or both sides of the layer formed from the prepreg.

[0035] <9>A resin composite sheet comprising: a support, and a layer formed from the resin composition according to any one of <1> to <6> disposed on the surface of the support.

[0036] <10>A printed circuit board includes an insulating layer and a conductor layer disposed on the surface of the aforementioned insulating layer. The aforementioned insulating layer includes at least one of a layer formed of the resin composition according to any one of <1> to <6> and a layer formed of the prepreg according to <7>.

[0037] Effects of the Invention

[0038] According to the present invention, in a resin composition containing a specific maleimide compound, a resin composition having a novel composition is provided, whereby the range of materials that can be suitably used for prepregs can be expanded. In addition, a resin composition that sufficiently suppresses the dielectric constant and the tangent of the dielectric loss angle to a low level, and also sufficiently suppresses the change amounts of the dielectric constant and the tangent of the dielectric loss angle after long-term heating to a low level, has excellent peel resistance with respect to a conductor layer (metal foil) when formed into a film or sheet, and has sufficient heat resistance (high glass transition temperature) in practice, a prepreg using the same, a metal-clad laminate, a resin composite sheet, and a printed circuit board can be provided. Detailed Embodiments

[0039] Hereinafter, the content of the present invention will be described in detail. It should be noted that in this specification, "~" is used in the meaning of the lower limit value and the upper limit value of the numerical values described before and after it.

[0040] The resin composition of the present embodiment is characterized by containing a polyfunctional vinyl aromatic polymer (A) and a maleimide compound (B), and as the aforementioned maleimide compound (B), at least one compound represented by any one of the following formulas (1) to (4) is contained. By adopting such a configuration, a resin composition that sufficiently suppresses the dielectric constant and the tangent of the dielectric loss angle to a low level, and in addition sufficiently suppresses the change amounts of the dielectric constant and the tangent of the dielectric loss angle after long-term heating to a low level, has excellent peel resistance when formed into a film or sheet, and has sufficient heat resistance in practice can be provided.

[0041]

[0042] (In formula (1), R 1 , R 2 , R 3 and R 4 each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, and n1 represents a number of 1 or more and 10 or less.)

[0043]

[0044] (In formula (2), R 6 each independently represents a methyl group or an ethyl group, and R 7 each independently represents a hydrogen atom or a methyl group.)

[0045]

[0046] (In formula (3), R 8 independently represents a hydrogen atom, a methyl group or an ethyl group respectively.)

[0047]

[0048] (In formula (4), R 9 independently represents a hydrogen atom, a methyl group or an ethyl group respectively.)

[0049] It should be noted that the resin composition of the present embodiment is not cured by light, and is preferably a non-photosensitive thermosetting resin composition mainly cured by heat.

[0050] <Polyfunctional vinyl aromatic polymer (A)>

[0051] The resin composition of the present embodiment contains a polyfunctional vinyl aromatic polymer (A).

[0052] The polyfunctional vinyl aromatic polymer (A) is preferably a polymer obtained by polymerizing an aromatic compound having two or more vinyl groups in the molecule. For an aromatic compound having two or more vinyl groups in the molecule, for example, regarding the vinyl group, each stereoisomer is acceptable, and it may also be a mixture of such stereoisomers. More specifically, when the polyfunctional vinyl aromatic polymer (A) is an aromatic compound having two vinyl groups in the molecule, the m-form, p-form, o-form or a mixture of these stereoisomers is acceptable, and any of the m-form, p-form or a mixture of these stereoisomers is preferred.

[0053] As the monomer constituting the polyfunctional vinyl aromatic polymer (A), an aromatic compound having one or two or more vinyl groups (hereinafter, an aromatic compound having two or more vinyl groups is also referred to as a polyfunctional vinyl aromatic compound) can be cited, and an aromatic compound having one or two vinyl groups is preferred. For example, as the polyfunctional vinyl aromatic polymer (A), a polymer containing a structural unit (a) derived from an aromatic compound having two vinyl groups (also referred to as a divinyl aromatic compound) and a structural unit (b) derived from an aromatic compound having one vinyl group can be exemplified.

[0054] The divinyl aromatic compound forming the structural unit (a) is preferably a compound having a hydrocarbon aromatic ring, and examples thereof include divinylbenzene, diallylbenzene, bis(vinyl oxy)benzene, bis(1-methylethenyl)benzene, divinylnaphthalene, divinylanthracene, divinylbiphenyl, divinylphenanthrene, bis(4-allyloxyphenyl)fluorene, etc. Among them, divinylbenzene is particularly preferred. The mode of the structural unit derived from the divinyl aromatic compound in the polymer can be: (a-1) a mode in which only one vinyl group undergoes a polymerization reaction and the other vinyl group remains unreacted and directly remains; and (a-2) a mode in which both undergo a polymerization reaction. In the present embodiment, the mode (a-1) in which one vinyl group remains unreacted and remains is preferably included. It should be noted that the polyfunctional vinyl aromatic compound (preferably divinyl aromatic compound) may have any substituent Z (such as an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a hydroxyl group, an amino group, a carboxyl group, a halogen atom, etc.) within the range of exerting the effects of the present invention.

[0055] The structural unit (a) derived from the above polyfunctional vinyl aromatic compound (preferably divinyl aromatic compound) preferably contains a structural unit represented by the following formula (V).

[0056]

[0057] In formula (V), Ar represents an aromatic hydrocarbon linking group. As a specific example, the following L 1 can be cited. The * in the formula represents the bonding position.

[0058] The aromatic hydrocarbon linking group may be a group formed only by an aromatic hydrocarbon optionally having a substituent, or a group formed by a combination of an aromatic hydrocarbon optionally having a substituent and other linking groups, and is preferably a group formed only by an aromatic hydrocarbon optionally having a substituent. It should be noted that among the substituents optionally possessed by the aromatic hydrocarbon, the above-mentioned substituent Z can be cited. In addition, the above aromatic hydrocarbon preferably does not have a substituent.

[0059] The aromatic hydrocarbon linking group is usually a divalent linking group.

[0060] Specifically, among the aromatic hydrocarbon linking groups, a phenylene group, a naphthalenediyl group, an anthracenediyl group, a phenanthrenediyl group, a biphenyldiyl group, a fluorenediyl group optionally having a substituent can be cited, and a phenylene group optionally having a substituent is preferred. Among the substituents, the above-mentioned substituent Z can be exemplified, but the above-mentioned groups such as phenylene group preferably do not have a substituent.

[0061] The structural unit (a) derived from a polyfunctional vinyl aromatic compound (preferably a divinyl aromatic compound) more preferably contains at least one of the structural unit represented by the following formula (V1), the structural unit represented by the following formula (V2), and the structural unit represented by the following formula (V3). It should be noted that * in the following formula represents the bonding position.

[0062]

[0063] In formulas (V1) to (V3), L 1 is an aromatic hydrocarbon linking group (preferably having 6 to 22 carbon atoms, more preferably 6 to 18 carbon atoms, and further preferably 6 to 10 carbon atoms). Specifically, examples include a phenylene group, a naphthalenediyl group, an anthracenediyl group, a phenanthrenediyl group, a biphenyldiyl group, and a fluorenediyl group, each optionally having a substituent, and among them, a phenylene group optionally having a substituent is preferred. Among the substituents, the above-mentioned substituent Z can be exemplified, but the above-mentioned groups such as the phenylene group preferably do not have a substituent.

[0064] As described above, the polyfunctional vinyl aromatic polymer (A) can be a homopolymer of the structural unit (a) or a copolymer with the structural unit (b) or the like. When the polyfunctional vinyl aromatic polymer (A) is a copolymer, the copolymerization ratio is preferably 5 mol% or more, more preferably 10 mol% or more, and further preferably 15 mol% or more for the structural unit (a). As the upper limit value, it is practical to be 90 mol% or less.

[0065] When the polyfunctional vinyl aromatic polymer (A) is a copolymer containing the structural unit (b) derived from a monovinyl aromatic compound, examples of the monovinyl aromatic compound include vinyl aromatic compounds such as styrene, vinylnaphthalene, and vinylbiphenyl; nuclear alkyl-substituted vinyl aromatic compounds such as o-methylstyrene, m-methylstyrene, p-methylstyrene, o,p-dimethylstyrene, o-ethylvinylbenzene, m-ethylvinylbenzene, p-ethylvinylbenzene, methylvinylbiphenyl, and ethylvinylbiphenyl. The monovinyl aromatic compounds exemplified here may also appropriately have the above-mentioned substituent Z. In addition, one of these monovinyl aromatic compounds can be used, or two or more can be used.

[0066] The structural unit (b) derived from a monovinyl aromatic compound preferably has the structural unit represented by the following formula (V4).

[0067]

[0068] In formula (V4), L 2 is an aromatic hydrocarbon linking group, and as a preferred specific example, the above-mentioned L 1 can be exemplified.

[0069] R V1is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms (preferably an alkyl group). R V1 When R is a hydrocarbon group, the number of carbon atoms thereof is preferably 1 to 6, more preferably 1 to 3. R V1 and L 2 may also have the above-mentioned substituent Z.

[0070] When the polyfunctional vinyl aromatic polymer (A) is a copolymer containing the structural unit (b), the copolymerization ratio of the structural unit (b) is preferably 10 mol% or more, more preferably 15 mol% or more. As the upper limit value, it is preferably 98 mol% or less, more preferably 90 mol% or less, and further preferably 85 mol% or less.

[0071] The polyfunctional vinyl aromatic polymer (A) may also have other structural units. As other structural units, for example, a structural unit (c) derived from a cycloolefin compound, etc. can be cited. As the cycloolefin compound, hydrocarbons having a double bond in the ring structure can be cited. Specifically, in addition to monocyclic cyclic olefins such as cyclobutene, cyclopentene, cyclohexene, and cyclooctene, compounds having a norbornene ring structure such as norbornene and dicyclopentadiene, and cycloolefin compounds formed by condensation of aromatic rings such as indene and acenaphthylene can also be cited. As an example of the norbornene compound, those described in paragraphs 0037 to 0043 of JP-A-2018-39995 can be cited, and the content thereof is incorporated into this specification. It should be noted that the cycloolefin compounds exemplified here may also have the above-mentioned substituent Z.

[0072] When the polyfunctional vinyl aromatic polymer (A) is a copolymer containing the structural unit (c), the copolymerization ratio of the structural unit (c) is preferably 10 mol% or more, more preferably 20 mol% or more, and further preferably 30 mol% or more. As the upper limit value, it is preferably 90 mol% or less, more preferably 80 mol% or less, further preferably 70 mol% or less, may be 50 mol% or less, or may be 30 mol% or less.

[0073] The polyfunctional vinyl aromatic polymer (A) may further incorporate a structural unit (d) derived from a different polymerizable compound (hereinafter also referred to as other polymerizable compounds). As other polymerizable compounds (monomers), for example, compounds containing 3 vinyl groups can be cited. Specifically, 1,3,5-trivinylbenzene, 1,3,5-trivinylnaphthalene, 1,2,4-trivinylcyclohexane can be cited. Or, ethylene glycol diacrylate, butadiene, etc. can be cited. The copolymerization ratio of the structural unit (d) derived from other polymerizable compounds is preferably 30 mol% or less, more preferably 20 mol% or less, and further preferably 10 mol% or less.

[0074] As one embodiment of the polyfunctional vinyl aromatic polymer (A), a polymer which necessarily has the structural unit (a) and contains at least one of the structural units (b) to (d) can be exemplified. Further, a form in which the total of the structural units (a) to (d) accounts for 95 mol% or more, and further 98 mol% or more of all the structural units can be exemplified.

[0075] As another embodiment of the polyfunctional vinyl aromatic polymer (A), it necessarily has the structural unit (a), and among all the structural units except the terminals, the structural units containing an aromatic ring are preferably 90 mol% or more, more preferably 95 mol% or more, and may be 100 mol%.

[0076] When calculating the mol% in all the structural units, one structural unit is assumed to be derived from one molecule of the monomer constituting the polyfunctional vinyl aromatic polymer (A).

[0077] The method for producing the polyfunctional vinyl aromatic polymer (A) is not particularly limited, and a usual method can be adopted. For example, in the presence of a Lewis acid catalyst, a monomer containing a divinyl aromatic compound (optionally coexisting with a monovinyl aromatic compound, a cycloolefin compound, etc.) is polymerized. As the Lewis acid catalyst, a metal fluoride or its complex can be used.

[0078] The structure of the chain terminal of the polyfunctional vinyl aromatic polymer (A) is not particularly limited. For the group derived from the above divinyl aromatic compound, a structure represented by the following formula (E1) can be exemplified. It should be noted that L in the formula (E1) 1 is the same as defined in the above formula (V1). * represents the bonding position.

[0079] *-CH=CH-L 1 -CH=CH2 (E1)

[0080] When the group derived from the monovinyl aromatic compound is the chain terminal, a structure represented by the following formula (E2) can be exemplified. L and R in the formula 2 and V1 have the same meanings as defined in the above formula (V4), respectively. * represents the bonding position.

[0081] *-CH=CH-L 2 -R V1 (E2)

[0082] The molecular weight of the polyfunctional vinyl aromatic polymer (A) is preferably 300 or more, more preferably 500 or more, and still more preferably 1000 or more in terms of the number average molecular weight Mn. As the upper limit, it is preferably 100,000 or less, more preferably 10,000 or less, still more preferably 5000 or less, and still more preferably 4000 or less. The monodispersity (Mw / Mn) represented by the ratio of the weight average molecular weight Mw to the number average molecular weight Mn is preferably 100 or less, more preferably 50 or less, and still more preferably 20 or less. As the lower limit value, it is practical to be 1.1 or more. The polyfunctional vinyl aromatic polymer (A) is preferably soluble in toluene, xylene, tetrahydrofuran, dichloroethane, or chloroform.

[0083] Regarding the polyfunctional vinyl aromatic polymer (A) in this specification, reference can be made to the compounds and their synthesis reaction conditions described in paragraphs 0029 to 0058 of International Publication No. 2017 / 115813, the compounds and their synthesis reaction conditions described in paragraphs 0013 to 0058 of Japanese Patent Application Laid-Open No. 2018-039995, the compounds and their synthesis reaction conditions described in paragraphs 0008 to 0043 of Japanese Patent Application Laid-Open No. 2018-168347, the compounds and their synthesis reaction conditions described in paragraphs 0014 to 0042 of Japanese Patent Application Laid-Open No. 2006-070136, the compounds and their synthesis reaction conditions described in paragraphs 0014 to 0061 of Japanese Patent Application Laid-Open No. 2006-089683, and the compounds and their synthesis reaction conditions described in paragraphs 0008 to 0036 of Japanese Patent Application Laid-Open No. 2008-248001, which are incorporated into this specification.

[0084] When the total amount of the resin components in the resin composition is set to 100 parts by mass, the content of the polyfunctional vinyl aromatic polymer (A) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, still more preferably 15 parts by mass or more, still more preferably 20 parts by mass or more, and further can be 30 parts by mass or more, 40 parts by mass or more, 50 parts by mass or more, 60 parts by mass or more. By setting the content of the polyfunctional vinyl aromatic polymer (A) to the above lower limit value or more, low dielectric constant and low dissipation factor (especially low dielectric constant) can be effectively achieved. On the other hand, when the total amount of the resin components in the resin composition is set to 100 parts by mass, the upper limit value of the content of the polyfunctional vinyl aromatic polymer (A) is preferably 95 parts by mass or less, more preferably 90 parts by mass or less, still more preferably 85 parts by mass or less, still more preferably 80 parts by mass or less, and can also be 70 parts by mass or less.

[0085] The polyfunctional vinyl aromatic polymer (A) in the resin composition may contain only one kind or two or more kinds. When two or more kinds are contained, the total amount is preferably in the above range.

[0086] It should be noted that the resin component includes a polyfunctional vinyl aromatic polymer (A) and a maleimide compound (B), and also includes other resin components described later.

[0087] <Maleimide compound (B)>

[0088] The maleimide compound (B) used in the resin composition of the present embodiment contains a compound represented by any of the following formulas (1) to (4).

[0089]

[0090] (In formula (1), R 1 , R 2 , R 3 and R 4 each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, and n1 represents a number of 1 or more and 10 or less.)

[0091] In formula (1), R 1 , R 2 , R 3 and R 4 are each independently preferably a methyl group, an ethyl group, a phenyl group, or a hydrogen atom, and more preferably a hydrogen atom.

[0092] n1 represents a number of 1 to 10, more preferably a number of 1 to 4. Compounds having different n1 values may also include two or more kinds.

[0093]

[0094] (In formula (2), R 6 each independently represents a methyl group or an ethyl group, and R 7 each independently represents a hydrogen atom or a methyl group.)

[0095] Preferably, among the four R 6 , 1 to 3 are methyl groups, and the remaining 3 to 1 are ethyl groups; more preferably, among the four R 6 , 2 are methyl groups, and the remaining 2 are ethyl groups. Further preferably, for the two aromatic rings, more preferably, the two substituted R 6 are a methyl group and an ethyl group, respectively.

[0096]

[0097] (In formula (3), R 8 each independently represents a hydrogen atom, a methyl group, or an ethyl group.)

[0098] R 8 is preferably a methyl group or an ethyl group, and more preferably a methyl group.

[0099]

[0100] (In formula (4), R 9 each independently represents a hydrogen atom, a methyl group or an ethyl group.)

[0101] R 9 is preferably a methyl group or an ethyl group, more preferably a methyl group.)

[0102] The equivalent weight of the unsaturated imide group of the maleimide compound (B) is preferably 200 g / eq or more, and preferably 400 g / eq or less. When two or more maleimide compounds (B) are included, the equivalent weight of the unsaturated imide group of the weighted average is set in consideration of the mass of each maleimide compound (B) contained in the resin composition.)

[0103] When the total amount of the resin components in the resin composition is 100 parts by mass, the content of the maleimide compound (B) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, further preferably 15 parts by mass or more, still more preferably 20 parts by mass or more, and may also be 30 parts by mass or more. By setting the content of the maleimide compound (B) to the above lower limit value or more, the peel strength and heat resistance tend to increase. On the other hand, when the total amount of the resin components in the resin composition is 100 parts by mass, the upper limit value of the content of the maleimide compound (B) is preferably 95 parts by mass or less, more preferably 90 parts by mass or less, further preferably 85 parts by mass or less, still more preferably 80 parts by mass or less, and further may also be 70 parts by mass or less, 60 parts by mass or less, 50 parts by mass or less, 40 parts by mass or less.)

[0104] One kind or two or more kinds of the maleimide compound (B) can be used. When two or more kinds are used, the total amount is in the above range.)

[0105] In the present invention, particularly by setting the amount of the maleimide compound (B) relative to the polyfunctional vinyl aromatic polymer (A) appropriately, the effects of the present invention can be exhibited at a high level, which is preferred. Specifically, the dielectric constant and the tangent of the dielectric loss angle can be maintained at a low level, and on the other hand, high heat resistance and peel strength can be achieved. In view of this effect, relative to 100 parts by mass of the content of the polyfunctional vinyl aromatic polymer (A), the content of the maleimide compound (B) is preferably 6 parts by mass or more, more preferably 11 parts by mass or more, further preferably 25 parts by mass or more. As the upper limit value, it is preferably 1900 parts by mass or less, more preferably 900 parts by mass or less, further preferably 400 parts by mass or less.)

[0106] When the resin composition of the present embodiment does not contain the following filler (C), the resin component preferably accounts for 90% by mass or more of the resin composition, more preferably 95% by mass or more, and further preferably 98% by mass or more.

[0107] When the resin composition of the present embodiment contains the filler (C), the resin component preferably accounts for 15% by mass or more of the resin composition, more preferably 20% by mass or more, and further preferably 30% by mass or more. In addition, as the upper limit value, the resin component preferably accounts for 90% by mass or less of the resin composition, more preferably 85% by mass or less, and further preferably 80% by mass or less.

[0108] <Filler (C)>

[0109] For the improvement of low dielectric constant, low dielectric loss tangent, flame retardancy and low thermal expansion, the resin composition of the present embodiment preferably contains the filler (C), preferably an inorganic filler. As the filler (C) to be used, those known in the art can be appropriately used, and the types thereof are not particularly limited, and those commonly used in the art can be suitably used. Specifically, silica-based materials such as natural silica, fused silica, synthetic silica, amorphous silica, AEROSIL, hollow silica, etc., white carbon, titanium white, zinc oxide, magnesium oxide, zirconium oxide, boron nitride, aggregated boron nitride, silicon nitride, aluminum nitride, barium sulfate, aluminum hydroxide, heat-treated aluminum hydroxide (obtained by heat-treating aluminum hydroxide to reduce a part of the crystal water), boehmite, magnesium hydroxide and other metal hydrates, molybdenum compounds such as molybdenum oxide and zinc molybdate, zinc borate, zinc stannate, alumina, clay, kaolin, talc, calcined clay, calcined kaolin, calcined talc, mica, E-glass, A-glass, NE-glass, C-glass, L-glass, D-glass, S-glass, M-glass G20, glass short fibers (including glass micro powders such as E glass, T glass, D glass, S glass, Q glass, etc.), hollow glass, spherical glass and other inorganic fillers, and rubber powders such as styrene type, butadiene type, acrylic type, core-shell type rubber powders, silicone resin powders, silicone rubber powders, silicone composite powders and other organic fillers.

[0110] Among these, it is desirable to select one or more from the group consisting of silica, aluminum hydroxide, boehmite, magnesium oxide and magnesium hydroxide, and silica is more preferred. The silica is preferably spherical silica. The spherical silica may also be hollow silica.

[0111] By using these fillers, the properties such as thermal expansion characteristics, dimensional stability, and flame retardancy of the resin composition are improved.

[0112] The content of the filler (C) in the resin composition of the present embodiment can be appropriately set according to the desired properties and is not particularly limited. When the total amount of the resin components in the resin composition is 100 parts by mass, it is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, further preferably 30 parts by mass or more, and may also be 50 parts by mass or more. As the upper limit value, it is preferably 500 parts by mass or less, more preferably 400 parts by mass or less, further preferably 300 parts by mass or less, still more preferably 250 parts by mass or less, and may also be 200 parts by mass or less.

[0113] One type or two or more types of the filler (C) can be used. When two or more types are used, the total amount thereof is preferably within the above range.

[0114] <Other resin components>

[0115] The resin composition of the present embodiment may also contain other resin components in addition to the above-mentioned polyfunctional vinyl aromatic polymer (A) and maleimide compound (B). Examples of the other resin components include those selected from the group consisting of maleimide compounds other than the above-mentioned maleimide compound (B), epoxy resins, phenolic resins, cyanate ester compounds (such as phenol novolak type cyanate ester compounds, naphthol aralkyl type cyanate ester compounds, biphenyl aralkyl type cyanate ester compounds, naphthalene ether type cyanate ester compounds, xylene resin type cyanate ester compounds, adamantane skeleton type cyanate ester compounds, bisphenol A type cyanate ester compounds, diallyl bisphenol A type cyanate ester compounds, bisphenol M type cyanate ester compounds, etc.), nadic imide compounds, oxetane resins, benzoxazine compounds, compounds having polymerizable unsaturated groups, modified polyphenylene ethers end-modified with substituents containing carbon-carbon unsaturated double bonds, elastomers, and active ester compounds.

[0116] When the resin composition of the present embodiment contains other resin components, the content thereof is, for example, preferably 1 to 30 parts by mass relative to 100 parts by mass of the resin components.

[0117] In addition, the proportion of the total content of the polyfunctional vinyl aromatic polymer (A) and the maleimide compound (B) in the resin components contained in the resin composition of the present embodiment is preferably 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, and further preferably 80% by mass or more.

[0118] <Curing accelerator (catalyst)>

[0119] The resin composition of this embodiment may further contain a curing accelerator. There is no particular limitation on the curing accelerator, and examples thereof include organic metal salts (such as zinc octoate, zinc naphthenate, cobalt naphthenate, copper naphthenate, iron acetylacetonate, nickel octoate, manganese octoate, etc.), phenol compounds (such as phenol, xylenol, cresol, resorcinol, catechol, octylphenol, nonylphenol, etc.), alcohols (such as 1-butanol, 2-ethylhexanol, etc.), imidazoles (such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, etc.), and derivatives such as adducts of these imidazoles with carboxylic acids or their acid anhydrides, amines (such as dicyandiamide, benzyldimethylamine, 4-methyl-N,N-dimethylbenzylamine, etc.), phosphorus compounds (such as phosphine compounds, phosphine oxide compounds, phosphonium salt compounds, diphosphine compounds, etc.), and epoxy-imidazole adduct compounds.

[0120] Preferred curing accelerators are imidazoles and organic metal salts, and more preferably imidazoles.

[0121] Regarding the content of the curing accelerator, when contained, the lower limit is preferably 0.005 parts by mass or more, more preferably 0.01 parts by mass or more, and further preferably 0.1 parts by mass or more, relative to 100 parts by mass of the total amount of the resin components in the resin composition. In addition, the upper limit of the content of the curing accelerator is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and further preferably 2 parts by mass or less, relative to 100 parts by mass of the total amount of the resin components in the resin composition.

[0122] The curing accelerator can be used alone or in combination of two or more. When using two or more, the total amount is within the above range.

[0123] <Solvent>

[0124] The resin composition of the present embodiment may also contain a solvent, preferably an organic solvent. In this case, the resin composition of the present embodiment is in a form (solution or varnish) in which at least a part, preferably all, of the above various resin components are dissolved or miscible in the solvent. As the solvent, there is no particular limitation as long as it is a polar organic solvent or a non-polar organic solvent that can dissolve or miscible at least a part, preferably all, of the above various resin components. Examples of polar organic solvents include ketones (such as acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), cellosolves (such as propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, etc.), esters (such as ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, isopentyl acetate, ethyl lactate, methyl methoxypropionate, methyl hydroxyisobutyrate, etc.), amides (such as dimethoxyacetamide, dimethylformamide, etc.). Examples of non-polar organic solvents include aromatic hydrocarbons (such as toluene, xylene, etc.).

[0125] The solvent may be used alone or in combination of two or more.

[0126] <Other components>

[0127] In the range where the effects of the present invention are not inhibited, the resin composition of the present embodiment may further contain a flame retardant, an ultraviolet absorber, an antioxidant, a polymerization initiator (both a photoinitiator and a thermal initiator are acceptable, and it may also be a radical polymerization initiator or a cationic polymerization initiator), a fluorescent brightening agent, a photosensitizer, a dye, a pigment, a thickening agent, a flow regulator, a lubricant, an antifoaming agent, a dispersant, a leveling agent, a gloss agent, a polymerization inhibitor, a silane coupling agent, etc. These additives may be used alone or in combination of two or more.

[0128] <Physical properties of the resin composition>

[0129] When the resin composition of the present embodiment is formed into a cured product in the form of a plate with a thickness of 1.6 mm, the relative dielectric constant (Dk) at 10 GHz can be set to 2.7 or less, or can be set to 2.6 or less, or can be set to 2.5 or less. The lower limit value of the aforementioned dielectric constant is preferably 1.0, but is practically 2.1 or more.

[0130] In addition, when the resin composition of the present embodiment is formed into a cured product in the form of a plate with a thickness of 1.6 mm, the tangent of the dielectric loss angle (Df) at 10 GHz can be set to 0.0040 or less, or can be set to 0.0020 or less, or can be set to 0.0015 or less. The lower limit value of the aforementioned dielectric constant is preferably 0, but is practically 0.0005 or more.

[0131] The dielectric constant and the tangent of the dielectric loss angle are measured by the method described in the following examples.

[0132] When the resin composition of this embodiment is formed into a cured product in the form of a plate with a thickness of 1.6 mm, the glass transition temperature can be set to 200 °C or higher, can also be set to 220 °C or higher, and can further be set to 300 °C or higher. The upper limit value of the aforementioned glass transition temperature is not particularly limited, and it is 400 °C or lower, and more practically 350 °C or lower.

[0133] The glass transition temperature is measured by the method described in the examples below.

[0134] <Manufacturing method of resin composition>

[0135] The resin composition of this embodiment can be manufactured by a conventional method. For example, a method of mixing a polyfunctional vinyl aromatic polymer (A) and a maleimide compound (B) can be cited. The preferred content at this time is as described above. In addition, in the resin composition of this embodiment, a filler (C), other resin components, and other additives can also be appropriately coexisted and kneaded, etc. The appearance can also be improved and other properties can be optimized by compounding other resin components.

[0136] An example of the resin composition of this embodiment is a varnish containing a solvent. Another example of the resin composition of this embodiment is a plate-shaped cured product and a film. Furthermore, the resin composition of this embodiment is preferably used for the uses described below.

[0137] <Uses>

[0138] The resin composition of this embodiment can be used as a cured product. Specifically, for the resin composition of this embodiment, as a low dielectric constant material and / or a low dissipation factor material, it can be suitably used as an insulating layer of a printed circuit board and a material for a semiconductor package. The resin composition of this embodiment can be suitably used as a prepreg, a metal-clad laminate formed from the prepreg, a resin composite sheet, and a material constituting a printed circuit board.

[0139] For the resin composition of this embodiment, when a layered molded product is made using it, its thickness is preferably 5 μm or more, and more preferably 10 μm or more. As the upper limit value, it is preferably 2 mm or less, and more preferably 1 mm or less. It should be noted that, for example, when the resin composition of this embodiment is impregnated into a glass cloth, etc., the thickness of the above-mentioned layered molded product means including the thickness of the glass cloth.

[0140] Molded products such as films formed from the resin composition of this embodiment can be used for uses where a pattern is formed by exposure and development, and can also be used for uses where exposure and development are not performed. It is particularly suitable for uses where exposure and development are not performed.

[0141] <<Prepreg>>

[0142] The prepreg of the preferred embodiment is formed from a base material (prepreg base material) and the resin composition of the present embodiment. The prepreg of the present embodiment is obtained, for example, by applying the resin composition of the present embodiment to a base material (such as impregnation or coating), and then semi-curing it by heating (such as a method of drying it at 120 to 220 °C for 2 to 15 minutes). At this time, the amount of the resin composition adhered to the base material, that is, the amount of the resin composition (including the filler) relative to the total amount of the semi-cured prepreg, is preferably in the range of 20 to 99% by mass.

[0143] The base material is not particularly limited as long as it is a base material used in various printed circuit board materials. Examples of the material of the base material include glass fiber (such as E glass, D glass, L glass, S glass, T glass, Q glass, UN glass, NE glass, spherical glass, etc.), inorganic fiber other than glass (such as quartz, etc.), and organic fiber (such as polyimide, polyamide, polyester, liquid crystal polyester, etc.). The form of the base material is not particularly limited, and examples include base materials composed of layered fibers such as woven fabric, non-woven fabric, roving, short glass fiber mat, and surface mat. A base material composed of long fibers such as glass cloth is particularly preferred. Here, the long fiber means, for example, a fiber having a number average fiber length of 6 mm or more. These base materials can be used alone or in combination of two or more. Among these base materials, from the viewpoint of dimensional stability, a woven fabric subjected to an ultra-fibrillation treatment and a pore plugging treatment is preferred; from the viewpoint of moisture absorption and heat resistance, a glass woven fabric subjected to a surface treatment using a silane coupling agent such as an epoxy silane treatment or an amino silane treatment is preferred; from the viewpoint of electrical properties, a low dielectric glass cloth formed of glass fibers such as L-glass, NE-glass, and Q-glass that exhibit low dielectric constant and low dielectric loss tangent is preferred. The thickness of the base material is not particularly limited and can be, for example, about 0.01 to 0.19 mm.

[0144] <<Metal-clad laminate>>

[0145] The metal foil-clad laminate of the preferred embodiment includes: at least one layer formed of the prepreg of this embodiment, and a metal foil disposed on one or both sides of the layer formed of the aforementioned prepreg. The metal foil-clad laminate of this embodiment can be manufactured, for example, by the following method: disposing at least one sheet (preferably overlapping two or more sheets) of the prepreg of this embodiment, and laminating and forming by disposing a metal foil on one or both sides thereof. More specifically, it can be manufactured by laminating and forming by disposing a metal foil such as copper or aluminum on one or both sides of the prepreg. As the number of prepreg sheets, it is preferably 1 to 10 sheets, more preferably 2 to 10 sheets, and still more preferably 2 to 7 sheets. As the metal foil, there is no particular limitation as long as it can be used for materials for printed circuit boards, and examples thereof include copper foils such as rolled copper foil and electrolytic copper foil. The thickness of the copper foil is not particularly limited and can be about 1.5 to 70 μm. As the forming method, there are methods commonly used when forming laminates and multilayer boards for printed circuit boards. More specifically, there are examples such as using a multi-stage press, a multi-stage vacuum press, a continuous forming machine, an autoclave forming machine, etc., and laminating and forming at a temperature of about 180 to 350 °C, a heating time of about 100 to 300 minutes, and a surface pressure of 20 to 100 kg / cm 2 or so. In addition, the prepreg of this embodiment and a circuit board for the inner layer (also referred to as an inner layer circuit board) manufactured separately can be laminated and formed to produce a multilayer board. As a manufacturing method of the multilayer board, for example, copper foils of about 35 μm can be disposed on both sides of one sheet of the prepreg of this embodiment, and after laminating and forming by the above-mentioned forming method, an inner layer circuit is formed, and a blackening treatment is performed on the circuit to form an inner layer circuit board. Then, the inner layer circuit board and one sheet of the prepreg of this embodiment are alternately disposed, and further, a copper foil is disposed on the outermost layer, and preferably laminated and formed under vacuum under the above conditions to produce a multilayer board. The metal foil-clad laminate of this embodiment can be suitably used as a printed circuit board.

[0146] <<Printed Circuit Board>>

[0147] The printed circuit board of the preferred embodiment includes an insulating layer and a conductor layer disposed on the surface of the aforementioned insulating layer. The aforementioned insulating layer includes at least one of a layer formed of the resin composition of the present embodiment and a layer formed of the prepreg of the above embodiment. Such a printed circuit board can be manufactured by a conventional method, and its manufacturing method is not particularly limited. Hereinafter, an example of the manufacturing method of the printed circuit board is shown. First, a metal foil-clad laminate such as the above copper-clad laminate is prepared. Next, an etching process is performed on the surface of the metal foil-clad laminate to form an inner layer circuit, and an inner layer substrate is produced. If necessary, a surface treatment for improving the bonding strength is performed on the surface of the inner layer circuit of the inner layer substrate, and then the required number of the above prepregs are overlapped on the surface of the inner layer circuit. Furthermore, a metal foil for the outer layer circuit is laminated on the outside thereof, and heating and pressing are performed for integral molding. Thus, a multilayer laminate is manufactured in which an insulating layer formed of a cured product of a base material and a thermosetting resin composition is formed between the inner layer circuit and the metal foil for the outer layer circuit. Then, after performing drilling for through holes and via holes on the multilayer laminate, a plated metal coating film for electrically connecting the inner layer circuit and the metal foil for the outer layer circuit is formed on the wall surface of the holes, and then an etching process is performed on the metal foil for the outer layer circuit to form an outer layer circuit, thereby manufacturing a printed circuit board.

[0148] The printed circuit board obtained in the above manufacturing example has an insulating layer and a conductor layer formed on the surface of the insulating layer, and the insulating layer is configured to include the resin composition of the present embodiment. That is, the prepreg of the present embodiment (for example, a prepreg formed of a base material and the resin composition of the present embodiment impregnated or coated therein), and the layer formed of the resin composition of the metal foil-clad laminate of the present embodiment are the insulating layer of the present embodiment.

[0149] <<Resin composite sheet>>

[0150] The resin composite sheet of the preferred embodiment includes: a support, and a layer formed of the resin composition of the present embodiment disposed on the surface of the aforementioned support. The resin composite sheet can be used as a lamination film or a dry film solder resist. As the manufacturing method of the resin composite sheet, there is no particular limitation, and for example, a method of obtaining a resin composite sheet by coating (applying) a solution obtained by dissolving the resin composition of the present embodiment in a solvent on a support and drying it can be cited.

[0151] As the support used herein, for example, organic film substrates such as polyethylene film, polypropylene film, polycarbonate film, polyethylene terephthalate film, ethylene tetrafluoroethylene copolymer film, and release films coated with a release agent on the surface of these films, polyimide film, etc., conductor foils such as copper foil and aluminum foil, glass plates, SUS plates, plate-like substrates such as FRP, etc. are cited, and there is no particular limitation.

[0152] As a coating method, for example, a method of coating a solution obtained by dissolving a resin composition in a solvent on a support using a bar coater, a die coater, a doctor blade, a Baker applicator, etc. can be mentioned. Further, after drying, a single-layer sheet can also be produced by peeling the support from the resin composite sheet formed by laminating the support and the resin composition or by etching it. Note that a solution obtained by dissolving the resin composition of the present embodiment in a solvent may be supplied into a mold having a sheet-like cavity and dried, etc., to be formed into a sheet, and thus a single-layer sheet can be obtained without using a support.

[0153] In the production of the resin composite sheet of the present embodiment, the drying conditions for removing the solvent are not particularly limited. If the temperature is low, the solvent is likely to remain in the resin composition. If the temperature is high, the resin composition will be cured. Therefore, it is preferably 1 to 90 minutes at a temperature of 20°C to 200°C. Further, in the resin composite sheet, the resin composition may be used in an uncured state in which only the solvent is dried, and may also be used in a semi-cured (B-staged) state as needed. Furthermore, the thickness of the resin layer of the resin composite sheet of the present embodiment can be adjusted by the concentration and coating thickness of the solution of the resin composition of the present embodiment, and is not particularly limited. Generally, from the aspect that the solvent is likely to remain during drying when the coating thickness becomes thick, it is preferably 0.1 to 500 μm.

[0154] Examples

[0155] Hereinafter, the present invention will be further specifically described with reference to examples. The materials, amounts used, ratios, treatment contents, treatment steps, etc. shown in the following examples can be appropriately changed as long as they do not depart from the gist of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

[0156] In this example, unless otherwise specified, measurements were carried out at 23°C.

[0157] <Example 1>

[0158] 75 parts by mass of the following synthesized polyfunctional vinylbenzene polymer (ap), 25 parts by mass of a biphenyl aralkyl type maleimide (manufactured by Nippon Kayaku Co., Ltd., MIR-3000 (trade name)) (compound represented by formula (1)), and 0.5 part by mass of an imidazole catalyst (manufactured by Shikoku Chemicals Corporation, 2E4MZ (trade name)) were dissolved in methyl ethyl ketone and mixed to obtain a varnish.

[0159] (Synthesis of polyfunctional vinylbenzene polymer (ap))

[0160] 2.25 moles (292.9 g) of divinylbenzene, 1.32 moles (172.0 g) of ethyl vinylbenzene, 11.43 moles (1190.3 g) of styrene, and 15.0 moles (1532.0 g) of n-propyl acetate were charged into a reactor, and 600 mmol of boron trifluoride diethyl ether complex was added at 70 °C, followed by reacting for 4 hours. After terminating the polymerization solution with an aqueous sodium bicarbonate solution, the oil layer was washed 3 times with pure water, and volatile components were removed under reduced pressure at 60 °C to recover the polyfunctional vinylbenzene polymer (ap). The obtained polyfunctional vinylbenzene polymer (ap) was weighed, and it was confirmed that 860.8 g of the polyfunctional vinylbenzene polymer (ap) was obtained.

[0161] The Mn of the obtained polyfunctional vinylbenzene polymer (ap) was 2060, Mw was 30700, and Mw / Mn was 14.9. By performing 13 C-NMR and 1 H-NMR analysis, resonance lines derived from each monomer unit were observed in the polyfunctional vinylbenzene polymer (ap). Based on the NMR measurement results and GC analysis results, the proportions of the structural units of the polyfunctional vinylbenzene polymer (ap) were calculated as follows.

[0162] Structural unit derived from divinylbenzene: 20.9 mol% (24.3 mass%)

[0163] Structural unit derived from ethyl vinylbenzene: 9.1 mol% (10.7 mass%)

[0164] Structural unit derived from styrene: 70.0 mol% (65.0 mass%)

[0165] In addition, the structural unit having a residual vinyl group derived from divinylbenzene was 16.7 mol% (18.5 mass%).

[0166] <<Manufacture of test pieces of cured plates with a thickness of 1.6 mm>>

[0167] By evaporating and distilling off the solvent from the obtained varnish, a mixed resin powder was obtained. The mixed resin powder was filled in a mold with a side length of 100 mm and a thickness of 1.6 mm, and 12 μm copper foils (3EC-M3-VLP, manufactured by Mitsui Mining & Smelting Co., Ltd.) were arranged on both sides, and vacuum pressing was performed at a pressure of 30 kg / cm 2 and a temperature of 220 °C for 120 minutes to obtain a cured plate with a side length of 100 mm and a thickness of 1.6 mm.

[0168] For the obtained 1.6 mm-thick cured plate, physical properties etc. (dielectric properties (Dk, Df), peel strength, glass transition temperature, coefficient of thermal expansion (CTE)) were evaluated according to the method described below.

[0169] <Example 2>

[0170] The amount of the above-synthesized polyfunctional vinylbenzene polymer (ap) was changed to 50 parts by mass, and the amount of the biphenyl aralkyl type maleimide (MIR-3000) was changed to 50 parts by mass. Otherwise, a varnish was obtained in the same manner as in Example 1. Using this varnish, a cured plate with a thickness of 1.6 mm was obtained in the same manner as in Example 1. The obtained 1.6-mm-thick cured plate was evaluated for physical properties and the like according to the method described below.

[0171] <Example 3>

[0172] The amount of the above-synthesized polyfunctional vinylbenzene polymer (ap) was changed to 25 parts by mass, and the amount of the biphenyl aralkyl type maleimide (MIR-3000) was changed to 75 parts by mass. Otherwise, a varnish was obtained in the same manner as in Example 1. Using the obtained varnish, a cured plate with a thickness of 1.6 mm was obtained in the same manner as in Example 1. The obtained 1.6-mm-thick cured plate was evaluated for physical properties and the like according to the method described below.

[0173] <Example 4>

[0174] The amount of the above-synthesized polyfunctional vinylbenzene polymer (ap) was changed to 50 parts by mass, 25 parts by mass of the biphenyl aralkyl type maleimide (MIR-3000) was added, and 25 parts by mass of a phenyl ether type maleimide (manufactured by KI Kasei Co., Ltd., BMI-80 (trade name)) (the compound represented by formula (3)) was added. Otherwise, a varnish was obtained in the same manner as in Example 1. Using the obtained varnish, a cured plate with a thickness of 1.6 mm was obtained in the same manner as in Example 1. The obtained 1.6-mm-thick cured plate was evaluated for physical properties and the like according to the method described below.

[0175] <Example 5>

[0176] The amount of the above-synthesized polyfunctional vinylbenzene polymer (ap) was changed to 50 parts by mass, and 50 parts by mass of BisM type maleimide (manufactured by KI Kasei Co., Ltd., BMI-BisM (trade name)) (the compound represented by formula (4)) was used instead of 25 parts by mass of the biphenyl aralkyl type maleimide (MIR-3000). Otherwise, a varnish was obtained in the same manner as in Example 1. Using the obtained varnish, a cured plate with a thickness of 1.6 mm was obtained in the same manner as in Example 1. The obtained 1.6-mm-thick cured plate was evaluated for physical properties and the like according to the method described below.

[0177] <Example 6>

[0178] The amount of the above-synthesized polyfunctional vinylbenzene polymer (ap) was changed to 50 parts by mass, and 50 parts by mass of a phenyl-type maleimide (manufactured by KI Kasei Co., Ltd., BMI-70 (trade name)) (the compound corresponding to formula (2)) was used instead of 25 parts by mass of the biphenyl aralkyl-type maleimide (MIR-3000). Otherwise, a varnish was obtained in the same manner as in Example 1. Using the obtained varnish, a test piece of a cured plate with a thickness of 1.6 mm was obtained in the same manner as in Example 1. For the obtained cured plate with a thickness of 1.6 mm, evaluations of physical properties and the like were carried out according to the method described below.

[0179] <Reference Example 1>

[0180] The biphenyl aralkyl-type maleimide (MIR-3000) and the imidazole catalyst (2E4MZ) were not used, and otherwise, a varnish was obtained in the same manner as in Example 1. Using the obtained varnish, a cured plate with a thickness of 1.6 mm was obtained in the same manner as in Example 1. For the obtained cured plate with a thickness of 1.6 mm, evaluations of physical properties and the like were carried out according to the method described below.

[0181] <Reference Example 2>

[0182] The above-synthesized polyfunctional vinylbenzene polymer (ap) was not used, and the biphenyl aralkyl-type maleimide (MIR-3000) was set to 100 parts by mass. Otherwise, a varnish was obtained in the same manner as in Example 1. Using the obtained varnish, a cured plate with a thickness of 1.6 mm was obtained in the same manner as in Example 1. For the obtained cured plate with a thickness of 1.6 mm, evaluations of physical properties and the like were carried out according to the method described below.

[0183] <Reference Example 3>

[0184] The above-synthesized polyfunctional vinylbenzene polymer (ap) was not used, and 100 parts by mass of a BisM-type maleimide (manufactured by KI Kasei Co., Ltd., BMI-BisM (trade name)) was used instead of 25 parts by mass of the biphenyl aralkyl-type maleimide (MIR-3000). Otherwise, a varnish was obtained in the same manner as in Example 1. Using the obtained varnish, a cured plate with a thickness of 1.6 mm was obtained in the same manner as in Example 1. For the obtained cured plate with a thickness of 1.6 mm, evaluations of physical properties and the like were carried out according to the method described below.

[0185] <Reference Example 4>

[0186] The amount of the above-synthesized polyfunctional vinylbenzene polymer (ap) was set to 50 parts by mass, and 50 parts by mass of a novolak-type maleimide (manufactured by Daiwa Kasei Co., Ltd., BMI-2300 (trade name)) (a maleimide compound not corresponding to formulas (1) to (4)) was used instead of 25 parts by mass of the biphenyl aralkyl-type maleimide (MIR-3000). Otherwise, a varnish was obtained in the same manner as in Example 1. Using the obtained varnish, a cured plate with a thickness of 1.6 mm was obtained in the same manner as in Example 1. For the obtained cured plate with a thickness of 1.6 mm, evaluations of physical properties and the like were carried out according to the method described below.

[0187] <Reference Example 5>

[0188] The amount of the above-synthesized polyfunctional vinylbenzene polymer (ap) was set to 50 parts by mass, and 50 parts by mass of a terminal-modified polyphenylene ether (manufactured by Mitsubishi Gas Chemical Company, Inc., OPE-2St 1200 (trade name)) was used instead of 25 parts by mass of the biphenyl aralkyl-type maleimide (MIR-3000). Otherwise, a varnish was obtained in the same manner as in Example 1. Using the obtained varnish, a cured plate with a thickness of 1.6 mm was obtained in the same manner as in Example 1. For the obtained cured plate with a thickness of 1.6 mm, evaluations of physical properties and the like were carried out according to the method described below.

[0189] <Reference Example 6>

[0190] The amount of the above-synthesized polyfunctional vinylbenzene polymer (ap) was set to 50 parts by mass, and 36.5 parts by mass of a biphenyl aralkyl-type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., NC3000FH (trade name)) and 13.5 parts by mass of a cresol novolak (manufactured by DIC Corporation, KA-1163 (trade name)) were used instead of 25 parts by mass of the biphenyl aralkyl-type maleimide (MIR-3000), and the amount of the imidazole catalyst was changed to 0.2 parts by mass. Otherwise, a varnish was obtained in the same manner as in Example 1. Using the obtained varnish, a cured plate with a thickness of 1.6 mm was obtained in the same manner as in Example 1. For the obtained cured plate with a thickness of 1.6 mm, evaluations of physical properties and the like were carried out according to the method described below.

[0191] <Dielectric properties (Dk and Df)>

[0192] For a test piece obtained by removing the copper foil from the obtained cured plate with a thickness of 1.6 mm by etching, the relative dielectric constant (Dk) and the dielectric loss tangent (Df) at 10 GHz were measured using a perturbation method cavity resonator. The measurement temperature was set to 23°C.

[0193] The perturbation method cavity resonator used a product of Agilent technologies, inc., Agilent8722ES.

[0194] It should be noted that in Table 1 below, those with a Dk (relative permittivity) of 2.5 or less are denoted as "S", those greater than 2.5 and 2.6 or less are denoted as "A", those greater than 2.6 and 2.7 or less are denoted as "B", and those greater than 2.7 are denoted as "C". Regarding Df (tangent of dielectric loss angle), those of 0.0015 or less are set as "S", those greater than 0.0015 and 0.0020 or less are set as "A", those greater than 0.0020 and 0.0040 or less are set as "B", and those greater than 0.0040 are set as "C".

[0195] <Long-term heat-resistant dielectric properties>

[0196] At 125 °C in an air atmosphere, a test piece obtained by removing the copper foil of a 1.6-mm-thick cured plate obtained by etching was placed for 500 hours. Using the obtained test piece, Dk and Df at 10 GHz after thermal degradation were measured by a perturbation method cavity resonator, and the change amounts of Dk and Df before thermal degradation were obtained.

[0197] The perturbation method cavity resonator uses a product of Agilent technologies, inc., Agilent 8722ES.

[0198] It should be noted that in Table 1 below, regarding the change amount of Dk from before thermal degradation to after thermal degradation, those of 0.02 or less are set as "S", those greater than 0.02 and 0.04 or less are set as "A", those greater than 0.04 and 0.06 or less are set as "B", and those greater than 0.06 are set as "C". In addition, regarding the change amount of Df from before thermal degradation to after thermal degradation, those of 0.001 or less are set as "S", those greater than 0.001 and 0.002 or less are set as "A", those greater than 0.002 and 0.003 or less are set as "B", and those greater than 0.003 are set as "C".

[0199] <Peel strength>

[0200] Using the cured plate obtained as described above, in accordance with the provisions of "Peel strength" in 5.7 of JIS C6481, the copper foil peel strength (adhesive force) was measured 2 times, and the average value was obtained.

[0201] It should be noted that in Table 1 below, regarding the peel strength, those of 0.8 kN / m or more are set as "S", those less than 0.8 kN / m and 0.6 kN / m or more are set as "A", those less than 0.6 kN / m and 0.5 kN / m or more are set as "B", and those less than 0.5 kN / m are set as "C".

[0202] <Glass transition temperature>

[0203] For the glass transition temperature (Tg), a test piece obtained by removing the copper foil from a 1.6 mm thick cured board to be obtained by etching was measured by the DMA (Dynamic Mechanical Analysis) bending method using a dynamic viscoelasticity analyzer in accordance with JIS C6481 5.17.2. The glass transition temperature was evaluated based on the obtained tanδ graph.

[0204] The dynamic viscoelasticity analyzer used was a device manufactured by TA INSTRUMENTS.

[0205] It should be noted that in Table 1, regarding the glass transition temperature, those of 300 °C or higher were designated as "S", those less than 300 °C and 220 °C or higher were designated as "A", those less than 220 °C and 200 °C or higher were designated as "B", and those less than 200 °C were designated as "C".

[0206] <Coefficient of Thermal Expansion (CTE)>

[0207] (CTE: Coefficient of linear Thermal Expansion)

[0208] For a test piece obtained by removing the copper foil from a 1.6 mm thick cured board by etching, the coefficient of thermal expansion of the cured board was measured by the TMA method (Thermo-Mechanical Analysis) specified in JlS C6481 5.19, and its value was obtained. Specifically, after removing the copper foil on both sides of the above-obtained cured board by etching, the linear coefficient of thermal expansion (ppm / °C) was measured with a thermo-mechanical analyzer (manufactured by TA INSTRUMENTS) by heating from 40 °C to 340 °C at a rate of 10 °C per minute. ppm is the volume ratio. For other detailed contents, refer to the above JIS C 6481 5.19.

[0209] [Table 1]

[0210]

[0211] (Notes in the table)

[0212] Dk: Relative dielectric constant at 10 GHz

[0213] Df: Tangent of the dielectric loss angle at 10 GHz

[0214] Peel strength: Result of the copper foil peel test

[0215] Glass transition temperature: Glass transition temperature evaluated based on tanδ measured by the DMA method

[0216] CTE: Coefficient of thermal expansion measured by the TMA method

[0217] As can be seen from the results in Table 1 above, in a resin composition comprising a polyfunctional vinyl aromatic polymer (A) (a polyfunctional vinylbenzene polymer (ap)) of the present embodiment and a maleimide compound (B) having a specific structure (compounds represented by formulas (1) to (4)), with respect to the film formed using the same, its dielectric properties (low dielectric constant, low dielectric loss tangent) are excellent, it has a high peel strength and excellent heat resistance (a sufficiently high glass transition temperature), and furthermore, the dielectric properties (change amount) after long-term heating are also excellent.

[0218] In contrast, Reference Example 1 is an example in which the specific maleimide compound (B) is not contained and only the polyfunctional vinyl aromatic polymer (A) is used. The dielectric properties and peel strength after long-term heating are poor, and in addition, the glass transition temperature is also low.

[0219] Reference Examples 2 and 3 are examples in which the polyfunctional vinyl aromatic polymer (A) is not contained. In Reference Example 2, the relative dielectric constant (Dk) is poor. In Reference Example 3, the peel strength is poor, and the glass transition temperature is low and poor.

[0220] In Reference Example 4, a polyfunctional vinyl aromatic polymer (A) and a compound having a maleimide group are used. However, the compound having a maleimide group is a novolac-type maleimide (BMI-2300), which does not belong to the compounds represented by formulas (1) to (4). In Reference Example 4, the glass transition temperature is low and poor.

[0221] In Reference Example 5, a polyfunctional vinyl aromatic polymer (A) and a terminally modified polyphenylene ether resin are combined, but in this resin composition, the result is that the dielectric properties after long-term heating are poor.

[0222] In Reference Example 6, a biphenyl aralkyl-type epoxy resin and a cresol novolac resin are combined with the polyfunctional vinyl aromatic polymer (A). In this resin composition, the results are that Df, Dk after long-term heating, and the peel strength are poor, and the glass transition temperature is low and poor.

[0223] Furthermore, it was found that among the examples, by varying the amounts and types of the polyfunctional vinyl aromatic polymer (A) and the maleimide compound (B), the dielectric constant can be made particularly excellent (Example 1), and the dielectric properties, peel strength, and heat resistance (high glass transition temperature) after long-term heating can be made excellent (Examples 2 to 5, particularly Examples 2 and 3).

[0224] <Example 7>

[0225] Dissolve 50 parts by mass of the above-synthesized polyfunctional vinylbenzene polymer (ap), 50 parts by mass of a biphenyl aralkyl type maleimide (manufactured by Nippon Kayaku Co., Ltd., MIR-3000 (trade name)), 0.5 part by mass of an imidazole catalyst (manufactured by Shikoku Chemicals Corporation, 2E4MZ (trade name)), and 50 parts by mass of slurry silica (spherical silica) (manufactured by Admatechs Company Limited, SC2050-MNU (trade name)) and mix them to obtain a varnish.

[0226] The obtained varnish was impregnated and coated on a low-dielectric glass cloth with a thickness of 0.069 mm, and using a dryer (a pressure-resistant explosion-proof steam dryer, manufactured by Takasugi Seisakusho Co., Ltd.), it was heated and dried at 150 °C for 3 minutes to obtain a prepreg with an adhesion amount of 60% by mass of the resin composition to the substrate. On both sides of one piece of this prepreg, a 12 μm copper foil (3EC-M3-VLP, manufactured by Mitsui Mining & Smelting Co., Ltd.) was arranged, and under a pressure of 30 kg / cm 2 and at a temperature of 220 °C, vacuum pressing was performed for 120 minutes to obtain a copper-clad laminate with a thickness of 0.1 mm.

[0227] In addition, in a state where 4 pieces of the above prepregs were overlapped, 12 μm copper foils were arranged on both sides, and under a pressure of 30 kg / cm 2 and at a temperature of 220 °C, vacuum pressing was performed for 120 minutes to obtain a copper-clad laminate with a thickness of 0.4 mm.

[0228] For the obtained copper-clad laminates with thicknesses of 0.1 mm and 0.4 mm, evaluations of physical properties, etc. (dielectric properties (Dk, Df), dielectric properties after long-term heating, peel strength, glass transition temperature) were carried out according to the above method. However, the cured board is a copper-clad laminate with a board thickness of 1.6 mm to 0.1 mm and 0.4 mm. For the copper-clad laminate, in the measurement of dielectric properties and glass transition temperature, the copper foil was removed by etching.

[0229] For the coefficient of thermal expansion (CTE), the coefficient of thermal expansion in the warp direction of the glass cloth was measured. In addition, the moisture absorption heat resistance (expansion) described later was measured.

[0230] <Reference Example 7>

[0231] The above-synthesized polyfunctional vinylbenzene polymer (ap) was set to 100 parts by mass, and a copper-clad laminate was prepared in the same manner as in Example 7 except that the biphenyl aralkyl type maleimide (MIR-3000) and the imidazole catalyst (2E4MZ) were not used. The evaluation results of each item of the obtained copper-clad laminate are shown in Table 2.

[0232] <Reference Example 8>

[0233] Without using the above-synthesized polyfunctional vinylbenzene polymer (ap), 100 parts by mass of biphenyl aralkyl maleimide (MIR-3000) was used, and in other respects, a varnish was prepared in the same manner as in Example 7 to obtain a copper-clad laminate. The evaluation results of each item of the obtained copper-clad laminate are shown in Table 2.

[0234] <Moisture absorption heat resistance>

[0235] The copper-clad laminate (50 mm × 50 mm × insulation layer thickness 0.4 mm) was cut, and the copper foil on all but half of one side was etched away to obtain a test piece. According to JIS C648, using a high-accelerated life test machine (manufactured by Hirayama Seisakusho, PC-3 type), the obtained test piece was treated at 121 °C and 2 atmospheres for 5 hours, and then immersed in solder at 260 °C for 30 seconds. The presence or absence of swelling after immersion was visually observed, and the moisture absorption heat resistance was evaluated according to the following evaluation criteria.

[0236] <<Presence or absence of swelling>>

[0237] A: No abnormality

[0238] B: Swelling occurs

[0239] [Table 2]

[0240]

[0241] (Notes in the table)

[0242] Dk: Relative dielectric constant at 10 GHz

[0243] Df: Dielectric loss tangent at 10 GHz

[0244] Peel strength: Result of the copper foil peel test

[0245] Glass transition temperature: Glass transition temperature evaluated based on tanδ measured by the DMA method

[0246] CTE: Coefficient of thermal expansion measured by the TMA method

[0247] Based on the results in Table 2 above, it was confirmed that for the resin composition of this embodiment, when using a filler (spherical silica) and manufacturing a copper-clad laminate, it exhibits extremely high durability against heat (high glass transition temperature). In addition, the moisture absorption heat resistance is also good.

[0248] In contrast, the moisture absorption heat resistance of Reference Example 7 that does not contain a specific maleimide compound (B) is poor and swelling occurs.

[0249] In addition, in Reference Example 8 that does not contain a polyfunctional vinyl aromatic polymer (A), Dk is high.

Claims

1. A resin composition comprising a polyfunctional vinyl aromatic polymer (A) and a maleimide compound (B), wherein the polyfunctional vinyl aromatic polymer (A) is a polyfunctional vinyl aromatic polymer (A) having a structural unit derived from an aromatic compound having two or more vinyl groups in the molecule and a structural unit derived from ethyl vinylbenzene, and as the maleimide compound (B), at least one compound represented by any of the following formulas (1), (3), and (4) is contained. In formula (1), R 1 , R 2 , R 3 and R 4 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, and n1 represents a number of 1 or more and 10 or less; In formula (3), R 8 each independently represents a hydrogen atom, a methyl group or an ethyl group; In formula (4), R 9 each independently represents a hydrogen atom, a methyl group or an ethyl group.

2. The resin composition according to claim 1, wherein The maleimide compound (B) contains at least one compound represented by any of formula (1) and formula (4).

3. The resin composition according to claim 1 or 2, wherein The polyfunctional vinyl aromatic polymer (A) contains a structural unit (a) derived from a divinyl aromatic compound and a structural unit (b) derived from a monovinyl aromatic compound, the copolymerization ratio of the structural unit (a) is 10 mol% or more and 20.9 mol% or less, and the copolymerization ratio of the structural unit (b) is 79.1 mol% or more and 90 mol% or less.

4. The resin composition according to claim 1 or 2, wherein, The resin composition does not contain a modified polyphenylene ether modified at the terminal with a substituent containing a carbon-carbon unsaturated double bond.

5. The resin composition according to claim 1 or 2, wherein The maleimide compound (B) contains at least one compound represented by any of formula (1) and formula (4). The polyfunctional vinyl aromatic polymer (A) contains a structural unit (a) derived from a divinyl aromatic compound and a structural unit (b) derived from a monovinyl aromatic compound, the copolymerization ratio of the structural unit (a) is 10 mol% or more and 20.9 mol% or less, and the copolymerization ratio of the structural unit (b) is 79.1 mol% or more and 90 mol% or less. The resin composition does not contain a modified polyphenylene ether modified at the terminal with a substituent containing a carbon-carbon unsaturated double bond.

6. The resin composition according to claim 1, wherein, The polyfunctional vinyl aromatic polymer (A) is a polymer having a structural unit represented by formula (V). In formula (V), Ar represents an aromatic hydrocarbon linking group, and * represents a bonding position.

7. The resin composition according to claim 1 or 6, wherein, The structural unit derived from an aromatic compound having two or more vinyl groups in the molecule is a structural unit derived from divinylbenzene. It further contains a structural unit derived from styrene.

8. The resin composition according to claim 6, wherein, The polymer having the structural unit represented by formula (V) has a structural unit (a) derived from a divinyl aromatic compound and a structural unit (b) derived from a monovinyl aromatic compound. The structural unit (a) derived from a divinyl aromatic compound contains at least one of the structural unit represented by formula (V1), the structural unit represented by formula (V2), and the structural unit represented by formula (V3). The structural unit (b) derived from a monovinyl aromatic compound contains the structural unit represented by formula (V4). In formulas (V1) to (V3), L 1 is an aromatic hydrocarbon linking group, and * represents the bonding position; In formula (V4), L 2 is phenyl, R V1 is ethyl, and * indicates the bonding position.

9. The resin composition according to claim 6, wherein, The polymer having the structural unit represented by formula (V) contains the structural unit (a) derived from a divinyl aromatic compound in a proportion of 5 mol% or more and 90 mol% or less, and among all the structural units except the terminals, the structural units containing aromatic rings are 90 mol% or more.

10. The resin composition according to claim 6, wherein, The polymer having the structural unit represented by the formula (V) contains the structural unit (b) derived from a monovinyl aromatic compound in a proportion of 15 mol% or more and 85 mol% or less.

11. The resin composition according to claim 6, wherein, The number average molecular weight Mn of the polymer having the structural unit represented by the formula (V) is 1,000 or more and 10,000 or less.

12. The resin composition according to claim 6, wherein, The number average molecular weight Mn of the polymer having the structural unit represented by the formula (V) is 1,000 or more and 5,000 or less.

13. The resin composition according to claim 6, wherein, The polymer having the structural unit represented by the formula (V) has a structural unit (a) derived from a divinyl aromatic compound and a structural unit (b) derived from a monovinyl aromatic compound. The structural unit (a) derived from a divinyl aromatic compound contains at least one of the structural unit represented by the formula (V1), the structural unit represented by the formula (V2), and the structural unit represented by the formula (V3). The structural unit (b) derived from a monovinyl aromatic compound contains the structural unit represented by the formula (V4). The polymer having the structural unit represented by the formula (V) contains the structural unit (a) derived from a divinyl aromatic compound in a proportion of 5 mol% or more and 90 mol% or less, and among all the structural units except the terminals, the structural units containing an aromatic ring are 90 mol% or more, and the structural unit (b) derived from a monovinyl aromatic compound is contained in a proportion of 15 mol% or more and 85 mol% or less. The number average molecular weight Mn of the polymer having the structural unit represented by the formula (V) is 1,000 or more and 5,000 or less. In formulas (V1) to (V3), L 1 is an aromatic hydrocarbon linking group, and * indicates the bonding position; In formula (V4), L 2 is phenyl, R V1 is ethyl, and * represents the bonding position.

14. The resin composition according to any one of claims 1, 6, 8 to 13, wherein, The content of the maleimide compound (B) is 5 to 95 parts by mass with respect to 100 parts by mass of the total amount of the resin components in the resin composition.

15. The resin composition according to any one of claims 1, 6, 8 to 13, wherein The content of the polyfunctional vinyl aromatic polymer (A) is 5 to 95 parts by mass with respect to 100 parts by mass of the total amount of the resin components in the resin composition.

16. The resin composition according to any one of claims 1, 6, 8 to 13, further comprising a filler (C).

17. The resin composition according to claim 16, wherein, The content of the filler (C) is 10 to 500 parts by mass with respect to 100 parts by mass of the total amount of the resin components in the resin composition.

18. The resin composition according to any one of claims 1, 6, 8 to 13, wherein When the resin composition is formed into a cured product in the form of a plate having a thickness of 1.6 mm, the relative dielectric constant (Dk) at a frequency of 10 GHz is 2.1 or more and 2.7 or less.

19. The resin composition according to any one of claims 1, 6, 8 to 13, wherein, When the resin composition is formed into a cured product in the form of a plate having a thickness of 1.6 mm, the dielectric loss tangent (Df) at a frequency of 10 GHz is 0.0005 or more and 0.0040 or less.

20. A prepreg formed from a base material and the resin composition according to any one of claims 1 to 19.

21. A metal foil-clad laminate comprising: at least one layer formed from the prepreg according to claim 20, and a metal foil disposed on one or both sides of the layer formed from the prepreg.

22. A resin composite sheet comprising: a support, and a layer formed from the resin composition according to any one of claims 1 to 19 disposed on the surface of the support.

23. A printed circuit board comprising an insulating layer and a conductor layer disposed on a surface of the insulating layer, wherein the insulating layer includes at least one of a layer formed of the resin composition according to any one of claims 1 to 19 and a layer formed of the prepreg according to claim 20.

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