Curable polymer, curable composition, prepreg, multilayer body, metal-clad laminate and wiring board

Abstract

The present disclosure provides a curable polymer which enables the achievement of a resin that is effectively reduced in the dielectric loss tangent (Df) under high frequency conditions, while having a sufficiently high glass transition temperature (Tg). The present disclosure provides a curable polymer which is a copolymer that has one or more structural units (UX) represented by the formula and one or more other structural units. The present disclosure also provides a curable polymer which is a copolymer or a homopolymer that only contains one or more structural units (UX) represented by the formula, the curable polymer being used for the production of a prepreg, a metal-clad laminate or a wiring board. (In the formula, each of R1 and R2 independently represents a hydrogen atom, a hydroxyl group of an organic group; a benzene ring may have a substituent other than the above-described groups; and n represents an integer of 0 or more.)

Description

Curable polymer, curable composition, prepreg, laminate, metal-clad laminate, and wiring board

[0001] The present disclosure relates to a curable polymer, a curable composition, a prepreg, a laminate, a metal-clad laminate, and a wiring board.

[0002] Wiring boards (also called printed wiring boards) are used for applications such as electrical and electronic devices. Wiring boards can be manufactured, for example, as follows. A fiber substrate is impregnated with a curable composition containing a curable polymer and, if necessary, additives such as a flame retardant and an inorganic filler (also called a filler), and the curable composition is (semi-)cured to produce a prepreg. One or more prepregs are sandwiched between a pair of metal foils, and the resulting first temporary laminate is heated and pressurized to produce a metal-clad laminate. The metal foil on the outermost surface of this metal-clad laminate is used to form a conductor pattern (also called a circuit pattern) such as wiring. The outermost metal foil may be placed on only one side of the first temporary laminate.

[0003] One or more prepregs are then laminated on the resulting wiring board, sandwiched between a pair of metal foils, and the resulting second temporary laminate is heated and pressurized to form a conductor pattern such as wiring using the metal foil on the outermost surface, thereby producing a multilayer wiring board (also called a multilayer printed wiring board). The outermost metal foil may be disposed on only one side of the second temporary laminate.

[0004] The heated and pressurized prepreg contains a fiber substrate, a resin, an inorganic filler, and the like, and is also called a composite substrate. In a wiring board, the composite substrate functions as an insulating layer. The resin contained in the prepreg is a (semi-)cured product of a curable composition, and the resin contained in the composite substrate is a cured product of the curable composition.

[0005] Japanese Patent Application Publication No. 60-90205

[0006] Conventionally, modified polyphenylene ether (modified PPE) oligomers (see formula (PPE-o) below) having polymerizable functional groups at both ends have been widely used as curable polymers for prepregs used in the manufacture of wiring boards.

[0007] In recent years, in applications such as portable electronic devices, communication speeds and capacity have increased, and signals are becoming increasingly high frequency. Wiring boards used in these applications are required to reduce transmission loss in the high frequency range. Transmission loss mainly consists of conductor loss caused by the surface resistance of metal foil and dielectric loss tangent (D ｆ ) and dielectric loss due to the dielectric loss. Therefore, the resin contained in the composite base material of the wiring board used for the above-mentioned applications is required to reduce the dielectric loss in the high frequency range. Generally, the dielectric loss tangent (D ｆ ) depends on frequency, and for the same material, the higher the frequency, the greater the dielectric loss tangent (D ｆ The resin contained in the composite substrate tends to have a large dielectric loss tangent (D ｆ ) is preferably low.

[0008] The dielectric loss tangent (D) at 10 GHz of the polyphenylene ether (PPE) resin, which is the cured product of the modified polyphenylene ether (modified PPE) oligomer, ｆ ) is about 0.002 to 0.003. It is expected that communication speeds and capacities will continue to increase in the future, and the dielectric loss tangent (D ｆ It is thought that materials that can further reduce

[0009] Wiring boards are sometimes used in relatively high-temperature environments, and even in such cases, the resins contained in the prepreg and composite base material preferably have a sufficiently high glass transition temperature (Tg) to ensure the reliability of the wiring board.

[0010] The present inventors have found that a resin that does not contain polar atoms in the main chain has a higher dielectric loss tangent (D ｆ As a result, we have developed a material that is suitable for prepreg used in the manufacture of wiring boards and has a low dielectric loss tangent (D ｆ The inventors have invented a curable polymer that can produce a resin with a lower dielectric loss tangent (D) under high frequency conditions. ｆ) was effectively reduced, the glass transition temperature (Tg) was sufficiently high, and it was found that the resulting material has good properties for use in wiring boards used in high frequency regions.

[0011] A related art of the present disclosure is exemplified by Patent Document 1. Patent Document 1 discloses a method for producing a homopolymer of a vinylsilyl group-containing styrene compound represented by the following formula (I) (claim 1). (In the formula, R １ , R ２ is an alkyl group having 1 to 4 carbon atoms or a phenyl group, and n is a number from 0 to 3.

[0012] Patent Document 1 does not describe the applications of prepregs, metal-clad laminates, and wiring boards, nor does it describe dielectric properties. Patent Document 1 does not describe the copolymer of a vinylsilyl group-containing styrene compound represented by formula (I).

[0013] The present disclosure has been made in consideration of the above circumstances, and ｆ The present invention aims to provide a curable polymer that can effectively reduce the glass transition temperature (Tg) and produce a resin having a sufficiently high glass transition temperature (Tg), and a curable composition containing the same.

[0014] The present disclosure provides the following curable polymer, curable composition, prepreg, laminate, metal-clad laminate, and wiring board.

[0015] [1] A curable polymer which is a copolymer containing one or more structural units (UX) represented by the following formula and one or more other structural units: (In the above formula, R １ and R ２ are each independently a hydrogen atom, a hydroxyl group, or an organic group. The benzene ring may have a substituent other than those mentioned above. n is an integer of 0 or more.

[0016] [2] The curable polymer of [1], which is a copolymer containing one or more structural units (UX) and one or more structural units (UY) derived from a monovinyl aromatic compound. [3] The curable polymer of [1] or [2], wherein the content of the one or more structural units (UX) is 1 to 90 mol % relative to 100 mol % of the total amount of all structural units.

[0017] [4] A curable polymer which is a homopolymer or copolymer containing only one or more structural units (UX) represented by the following formula as structural units, and is used for producing a prepreg, a metal-clad laminate, or a wiring board. (In the above formula, R １ and R ２ are each independently a hydrogen atom, a hydroxyl group, or an organic group. The benzene ring may have a substituent other than those mentioned above. n is an integer of 0 or more.

[0018] [5] R １ and R ２ are each independently an alkyl group having 1 to 18 carbon atoms or a phenyl group which may have a substituent. [6] The curable polymer of [1] or [4], wherein n is 1 to 18.

[0019] [7] A curable composition comprising the curable polymer of [1] or [4]. [8] The curable composition of [7], further comprising another curable compound having one or more polymerizable functional groups.

[0020] [9] A prepreg comprising a fiber substrate and a semi-cured or cured product of the curable composition of [7].

[10] A laminate comprising a substrate and a curable composition layer comprising the curable composition of [7].

[11] A laminate comprising a substrate and a (semi-)cured product-containing layer containing a semi-cured or cured product of the curable composition of [7].

[12] A metal-clad laminate comprising an insulating layer containing a cured product of the curable composition of [7] and a metal foil.

[13] A wiring board comprising an insulating layer containing a cured product of the curable composition of [7] and wiring.

[0021] According to the present disclosure, the dielectric loss tangent (D ｆ The present invention provides a curable polymer and a curable composition containing the same, which can effectively reduce the glass transition temperature (Tg) and produce a resin having a sufficiently high glass transition temperature (Tg).

[0022] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments and is not to be construed as limiting the invention.

[0023] In this specification, (semi-)cured is a general term for semi-cured and cured. In this specification, unless otherwise specified, "wiring board" includes multilayer wiring boards. In this specification, unless otherwise specified, "polymer" includes homopolymers and copolymers. In this specification, unless otherwise specified, "alkyl groups having 3 or more carbon atoms" may be linear or branched. In this specification, unless otherwise specified, compounds with isomers include all isomers. In this specification, unless otherwise specified, "weight average molecular weight (Mw)" refers to the weight average molecular weight calculated in terms of standard polystyrene determined by gel permeation chromatography (GPC), and "number average molecular weight (Mn)" refers to the number average molecular weight calculated in terms of polystyrene determined by gel permeation chromatography (GPC). In this specification, in chemical formulas, Me refers to a methyl group, Et refers to an ethyl group, and Ph refers to a phenyl group. In this specification, the "high frequency region" is defined as a frequency region of 1 GHz or higher. In this specification, unless otherwise specified, the term "to" indicating a range of values ​​is used to mean that the values ​​before and after it are included as the lower and upper limits. Hereinafter, embodiments of the present invention will be described.

[0024] [Curable Polymer] The first curable polymer of the present disclosure is a copolymer containing one or more structural units (UX) represented by the following formula and one or more other structural units. (UX) The above equation is also called equation (UX).

[0025] In formula (UX), R １ and R ２ are each independently a hydrogen atom, a hydroxyl group, or an organic group. The organic group preferably does not contain a polar atom such as an oxygen atom. The benzene ring may have a substituent other than the substituent (SX) represented by the following formula. n is an integer of 0 or more.

[0026] (SX)

[0027] From the viewpoint of improving the glass transition temperature (Tg) of the cured product of the first curable polymer of the present disclosure, the other structural unit is preferably a structural unit (UY) derived from a monovinyl aromatic compound. The monovinyl aromatic compound is a compound containing a structure in which one polymerizable vinyl group is linked to an aromatic ring. The polymerizable vinyl group may be a substituent on the aromatic ring, or a vinyl group contained in a cyclopentadiene ring fused to the aromatic ring. Examples include styrene and vinylnaphthalene; nuclear alkyl-substituted styrenes such as methylstyrene, ethylstyrene, and t-butylstyrene; nuclear alkyl-substituted vinylnaphthalene; other nuclear alkyl-substituted aromatic vinyl compounds; nuclear dialkyl-substituted styrenes such as dimethylstyrene; other nuclear dialkyl-substituted aromatic vinyl compounds; α-alkyl-substituted styrenes such as α-methylstyrene; other α-alkyl-substituted aromatic vinyl compounds; β-alkyl-substituted styrenes such as β-methylstyrene; other β-alkyl-substituted aromatic vinyl compounds; indene, acenaphthylene; derivatives such as substituted and modified versions of these; and the like. When the monovinyl aromatic compound has structural isomers, any of the ortho-, meta-, and para-isomers may be used.

[0028] Examples of the structural unit (UY) include structural units represented by the following formulae (UY-1) to (UY-5).

[0029] (UY-1)

[0030] (UY-2)

[0031] (UY-3)

[0032] (UY-4)

[0033] (UY-5)

[0034] The first curable polymer of the present disclosure is a novel compound that can be used for any application, and is suitable for curable compositions, prepregs, laminates, metal-clad laminates, wiring boards, and the like.

[0035] The inventors have conducted studies and found that by using the first curable polymer of the present disclosure, the dielectric loss tangent (D ｆ ) can be effectively reduced.

[0036] In the first curable polymer of the present disclosure, the content of one or more structural units (UX) relative to 100 mol % of the total amount of all structural units is not particularly limited. The inventors have found that, when compared under common conditions other than the content of the structural unit (UX), the dielectric loss tangent (D ｆ It has been found that a copolymer containing one or more structural units (UX) and one or more other structural units (preferably, a structural unit (UY) derived from a monovinyl aromatic compound) tends to have a higher dielectric loss tangent (D) under high frequency conditions of a (semi-)cured product of the curable composition than a homopolymer or copolymer containing only one or more structural units (UX). ｆ ) tends to be effectively reduced.

[0037] The dielectric loss tangent (D ｆ ) can be effectively reduced, the curable polymer of the present disclosure is preferably a copolymer containing one or more structural units (UX) and one or more structural units (UY) derived from a monovinyl aromatic compound. ｆ ) can be effectively reduced, and therefore, in the first curable polymer of the present disclosure, the content of one or more structural units (UX) relative to the total amount of all structural units (100 mol %) is preferably 1 to 90 mol %, more preferably 5 to 80 mol %, particularly preferably 5 to 70 mol %, and most preferably 10 to 50 mol %.

[0038] The second curable polymer of the present disclosure is a homopolymer or copolymer containing only one or more structural units (UX) represented by the following formula as structural units, and is used for producing a prepreg, a metal-clad laminate, or a wiring board. (UX) As with the first curable polymer of the present disclosure, the above formula is also referred to as formula (UX).

[0039] In formula (UX), R １ and R ２ are each independently a hydrogen atom, a hydroxyl group, or an organic group. The organic group preferably does not contain a polar atom such as an oxygen atom. The benzene ring may have a substituent other than the substituent (SX) represented by the following formula. n is an integer of 0 or more.

[0040] (SX)

[0041] The inventors have conducted studies and found that by using the second curable polymer of the present disclosure, the dielectric loss tangent (D ｆ ) can be effectively reduced.

[0042] In the structural unit (UX) contained in the first and second curable polymers of the present disclosure, R １ and R ２ are each independently an alkyl group which may have a substituent, or a phenyl group which may have a substituent. ｆ ) can be reduced more effectively, １ and R ２ It is preferable that the group does not contain polar atoms such as oxygen atoms.

[0043] R １ and / or R ２ When R is an alkyl group, the alkyl group may be linear or branched, and is preferably linear. １ and / or R ２ When is an alkyl group, the number of carbon atoms in the alkyl group is preferably 1 to 18, more preferably 1 to 12, and particularly preferably 1 to 8, from the viewpoint of ease of synthesis of the raw material monomer.

[0044] R １ and / or R ２ is a phenyl group which may have a substituent, the dielectric loss tangent (D ｆ ) tends to be reduced more effectively. １ and / or R２ This is thought to be because, when R is a phenyl group which may have a substituent, the molecular motion of the polymer obtained by (semi-) curing the curable polymer is effectively suppressed even when a potential is applied. １ and / or R ２ is a phenyl group which may have a substituent, the resin obtained when the curable polymer is cured alone may be hard and brittle and may not be practical for use in prepregs, metal-clad laminates, or wiring boards. In this case, by using an appropriate other curable compound in combination, the brittleness of the resulting resin can be improved to a level practical for use in prepregs, metal-clad laminates, or wiring boards.

[0045] In the structural unit (UX) contained in the first and second curable polymers of the present disclosure, the substitution position of the substituent (SX) on the benzene ring may be any of the ortho, meta, and para positions. From the viewpoint of ease of synthesis of the raw material monomers and ease of synthesis of the first and second curable polymers of the present disclosure, the substitution position is preferably the para position. The benzene ring in the structural unit (UX) may have a substituent other than the substituent (SX). Examples of other substituents that the benzene ring may have include alkyl groups and aryl groups having 1 to 18 carbon atoms. From the viewpoint of raw material availability, methyl, ethyl, propyl, butyl, hexyl, octyl, phenyl, and tolyl groups are preferred. The benzene ring in formula (UX) preferably has no substituent other than the substituent (SX). In the structural unit (UX), n is an integer of 0 or greater, preferably 1 to 18, more preferably 1 to 12, particularly preferably 1 to 8, and most preferably 1 to 3.

[0046] The first and second curable polymers of the present disclosure may be thermosetting or active energy ray-curable. The active energy ray-curable polymer is a polymer that is cured by irradiation with active energy rays such as ultraviolet rays and electron beams. For applications such as metal-clad laminates and wiring boards, thermosetting polymers are preferred.

[0047] The first curable polymer of the present disclosure comprising one or more structural units (UX) and one or more other structural units can be produced by copolymerizing one or more monomers (MX) represented by the following formula with one or more other monomers copolymerizable therewith (preferably one or more monovinyl aromatic compounds). In other words, the first curable polymer of the present disclosure is a copolymer of one or more monomers (MX) with one or more other monomers copolymerizable therewith (preferably one or more other monomers including one or more monovinyl aromatic compounds). The second curable polymer of the present disclosure comprising only one or more structural units (UX) as a structural unit can be produced by homopolymerizing or copolymerizing one or more monomers (MX) represented by the following formula. In other words, the second curable polymer of the present disclosure is a homopolymer or copolymer of one or more monomers (MX).

[0048] (MX) The above equation is also called equation (MX).

[0049] In formula (MX), R １ and R ２ are each independently a hydrogen atom, a hydroxyl group, or an organic group. The organic group preferably does not contain a polar atom such as an oxygen atom. The benzene ring may have a substituent other than those mentioned above. n is an integer of 0 or more. Preferred R １ , preferred R ２ and preferred n is the same as in formula (UX).

[0050] The polymerization method is preferably chain polymerization, etc. Examples of chain polymerization include cationic polymerization, anionic polymerization, and radical polymerization, and cationic polymerization is preferred.

[0051] The monomer (MX) can be synthesized by a known method using a chloroalkylstyrene such as chloromethylstyrene (CMS) as a starting material. The monomer (MX) is preferably a CMS modified product obtained using chloromethylstyrene (CMS) as a starting material.

[0052] Below are shown an example of a reaction scheme for synthesizing a monomer (MX) using chloromethylstyrene (CMS) as a starting material, and a reaction scheme for polymerization using the obtained monomer (MX). In this example, in the monomer (MX), the substitution position of the substituent (SX) on the benzene ring is the para position, and n=1. This example shows copolymerization of the obtained monomer with styrene, a monovinyl aromatic compound.

[0053]

[0054] The first curable polymer of the present disclosure includes copolymers represented by the following formulas (MC-11) to (MC-20). The arrangement of structural units in the copolymer may be any of an alternating arrangement, a block arrangement, and a random arrangement.

[0055] (MC-11)

[0056] (MC-12)

[0057] (MC-13)

[0058] (MC-14)

[0059] (MC-15)

[0060] (MC-16)

[0061] (MC-17)

[0062] (MC-18)

[0063] (MC-19)

[0064] (MC-20)

[0065] In formulas (MC-11) to (MC-20), m and n represent the number of moles of each structural unit, with m > 0 and n > 0. n in these formulas is unrelated to n in formulas (MX) and (SX). When the total number of moles of m and n is taken as 100 mol%, the molar fraction of m is preferably 1 to 90 mol%, more preferably 5 to 80 mol%, and the molar fraction of n is preferably 99 to 10 mol%, more preferably 95 to 20 mol%.

[0066] In the copolymers represented by formulas (MC-11) to (MC-20), the number of carbon atoms n in the alkylene group that is the bonding group between Si and the benzene ring is 1. The first curable polymer of the present disclosure also includes copolymers represented by formulas (MC-11) to (MC-20) in which the number of carbon atoms n in the alkylene group that is the bonding group between Si and the benzene ring is changed to an integer of 0 or more other than 1 (for example, 0, 2, 3, etc.). Specific examples of copolymers in which the number of carbon atoms n in the alkylene group that is the bonding group between Si and the benzene ring is an integer of 0 or more other than 1 include copolymers (P24) and (P25) in the section [Examples] below.

[0067] The second curable polymer of the present disclosure includes homopolymers represented by the following formulas (MC-21) and (MC-22).

[0068] (MC-21)

[0069] (MC-22)

[0070] In formulas (MC-21) and (MC-22), m represents the number of moles of the structural unit, and m > 0. m is preferably 5 to 250, more preferably 10 to 200. Note that m in these formulas is unrelated to m in formulas (MX) and (SX).

[0071] In the copolymers represented by formulae (MC-21) and (MC-22), the number of carbon atoms n in the alkylene group that is the bonding group between Si and the benzene ring is 1. The second curable polymer of the present disclosure also includes homopolymers in which the number of carbon atoms n in the alkylene group that is the bonding group between Si and the benzene ring in the copolymers represented by formulae (MC-21) and (MC-22) is changed to an integer of 0 or more other than 1 (for example, 0, 2, 3, etc.).

[0072] Other examples of the second curable polymer of the present disclosure include copolymers having a structure combining the above formula (MC-21) and formula (MC-22). In these copolymers, too, the number of carbon atoms n in the alkylene group that is the bonding group between Si and the benzene ring can be changed to an integer of 0 or more other than 1 (e.g., 0, 2, 3, etc.).

[0073] The molecular weights of the first and second curable polymers of the present disclosure are not particularly limited. The number average molecular weight (Mn) is preferably 1,000 to 30,000, more preferably 5,000 to 17,000. The weight average molecular weight (Mw) is preferably 5,000 to 100,000, more preferably 10,000 to 90,000.

[0074] The first and second curable polymers of the present disclosure can have a structure in which the main chain does not contain polar atoms, unlike modified polyphenylene ether (modified PPE) oligomers and the like having polymerizable functional groups at both ends. The first and second curable polymers of the present disclosure can have a structure in which the main chain does not contain polar atoms or has a small number of polar atoms. It is preferable that the first and second curable polymers of the present disclosure do not contain polar atoms. By using the first curable polymer or the second curable polymer of the present disclosure that does not contain polar atoms or has a small number of polar atoms, the dielectric loss tangent (D ｆ ) can be effectively reduced.

[0075] [Curable Composition] Hereinafter, the first curable polymer and the second curable polymer of the present disclosure will be collectively referred to simply as the "curable polymer of the present disclosure." The curable composition of the present disclosure includes one or more curable polymers of the present disclosure. The curable composition of the present disclosure may optionally include one or more other curable compounds having one or more polymerizable functional groups. Depending on the molecular structure, the curable polymer of the present disclosure, when cured alone, may produce a hard and brittle resin that is impractical for use in prepregs, metal-clad laminates, or wiring boards. In this case, the use of an appropriate other curable compound in combination can improve the brittleness of the resulting resin to a level practical for use in prepregs, metal-clad laminates, or wiring boards. The use of the curable polymer of the present disclosure in combination with an appropriate other curable compound may improve the glass transition temperature (Tg) of the (semi-)cured product of the curable composition. The curable composition of the present disclosure may further include one or more optional components as necessary. The curable composition of the present disclosure may be heat-curable or active energy ray-curable. For applications such as metal-clad laminates and wiring boards, thermosetting is preferred.

[0076] The other curable compounds may be monofunctional compounds having one or more polymerizable functional groups, or polyfunctional compounds having two or more polymerizable functional groups. Examples of the polymerizable functional groups include groups having a polymerizable carbon-carbon unsaturated bond, epoxy groups, isocyanate groups, hydroxy groups, mercapto groups, amino groups, ureido groups, carboxy groups, sulfonic acid groups, acid chloride groups, and chlorine atoms. Examples of the groups having a polymerizable carbon-carbon unsaturated bond include vinyl groups, allyl groups, dienyl groups, (meth)acryloyloxy groups, and (meth)acrylamino groups.

[0077] Examples of other curable compounds include those which, when cured alone, become resins such as polyphenylene ether resin (PPE), bismaleimide resin, epoxy resin, fluororesin, polyimide resin, olefin resin, polyester resin, polystyrene resin, hydrocarbon elastomer, benzoxazine resin, active ester resin, cyanate ester resin, butadiene resin, hydrogenated or non-hydrogenated styrene butadiene resin, vinyl resin, cycloolefin polymer, aromatic polymer, and divinyl aromatic polymer. Examples of the form of other curable compounds include monomers, oligomers, prepolymers, and the like.

[0078] Other curable compounds include, for example, modified polyphenylene ether (modified PPE) oligomers having polymerizable functional groups at both ends, which are represented by the following formula (PPE-o):

[0079]

[0080] The m and n in formula (PPE-o) are unrelated to the m and n in formulae (MX), (SX), and (MC-11) to (MC-22). X at both ends of formula (PPE-o) are each independently a group represented by the following formula (x1) or (x2). In these formulas, "*" indicates a bond to the oxygen atom.

[0081]

[0082] In formula (PPE-o), m is preferably 1 to 20, more preferably 3 to 15, and n is preferably 1 to 20, more preferably 3 to 15.

[0083] The number average molecular weight (Mn) of the modified polyphenylene ether (modified PPE) oligomer is not particularly limited, but is preferably 1,000 to 5,000, more preferably 1,000 to 4,000.

[0084] When the curable polymer of the present disclosure is used in combination with another curable compound whose main chain contains polar atoms, such as a modified polyphenylene ether (modified PPE) oligomer, as the curable compound, the amount of polar atoms contained in the (semi-)cured product of the curable composition can be reduced compared to when only a curable compound containing many polar atoms, such as a modified PPE oligomer, is used as the curable compound. As a result, the dielectric loss tangent (D ｆ ) can be effectively reduced.

[0085] The dielectric loss tangent (D ｆ ) can be effectively reduced, and therefore, in the curable composition of the present disclosure, the content of the one or more curable polymers of the present disclosure is preferably 20 to 100 parts by mass, more preferably 30 to 100 parts by mass, particularly preferably 50 to 100 parts by mass, and most preferably 70 to 100 parts by mass, relative to 100 parts by mass of the total amount of the one or more curable polymers of the present disclosure and one or more other curable compounds.

[0086] The curable composition preferably contains one or more polymerization initiators, such as organic peroxides, azo compounds, other known polymerization initiators, and combinations thereof. Specific examples include dicumyl peroxide, benzoyl peroxide, cumene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, di-t-butyl peroxide, t-butylcumyl peroxide, α,α'-di(t-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, di-t-butylperoxyisophthalate, t-butylperoxybenzoate, 2,2-bis(t-butylperoxy)butane, 2,2-bis(t-butylperoxy)octane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, di(trimethylsilyl)peroxide, trimethylsilyltriphenylsilyl peroxide, and azobisisobutyronitrile.

[0087] The curable composition may contain one or more additives as needed. Examples of additives include inorganic fillers (also referred to as fillers), compatibilizers, and flame retardants. Examples of inorganic fillers include silica such as spherical silica, metal oxides such as alumina, titanium oxide, and mica; metal hydroxides such as aluminum hydroxide and magnesium hydroxide; talc; aluminum borate; barium sulfate; calcium carbonate; and the like. One or more of these may be used. Among these, silica, mica, and talc are preferred from the viewpoint of low thermal expansion, and spherical silica is more preferred.

[0088] The inorganic filler may be surface-treated with an epoxy silane type, vinyl silane type, methacryl silane type, or amino silane type silane coupling agent. The timing of the surface treatment with the silane coupling agent is not particularly limited. An inorganic filler surface-treated with a silane coupling agent may be prepared in advance, or the silane coupling agent may be added by integral blending during the preparation of the curable composition.

[0089] Examples of flame retardants include halogen-based flame retardants and phosphorus-based flame retardants. One or more of these may be used. Examples of halogen-based flame retardants include bromine-based flame retardants such as pentabromodiphenyl ether, octabromodiphenyl ether, decabromodiphenyl ether, tetrabromobisphenol A, and hexabromocyclododecane; and chlorine-based flame retardants such as chlorinated paraffin. Examples of phosphorus-based flame retardants include phosphate esters such as condensed phosphate esters and cyclic phosphate esters; phosphazene compounds such as cyclic phosphazene compounds; phosphinate-based flame retardants such as aluminum dialkylphosphinate; melamine-based flame retardants such as melamine phosphate and melamine polyphosphate; and phosphine oxide compounds having a diphenylphosphine oxide group.

[0090] The curable composition may contain one or more organic solvents as needed. The organic solvents are not particularly limited, and examples thereof include ketones such as methyl ethyl ketone, ethers such as dibutyl ether, esters such as ethyl acetate, amides such as dimethylformamide, aromatic hydrocarbons such as benzene, toluene, and xylene, and chlorinated hydrocarbons such as trichloroethylene.

[0091] The blending composition and solids concentration of the curable composition can be designed as appropriate. The blending composition of the curable composition can be designed so that the resulting (semi-)cured product is not brittle and has suitable properties such as dielectric loss tangent (Df) and glass transition temperature (Tg). In applications such as prepregs, the solids concentration of the curable composition can be designed to facilitate impregnation into a fiber substrate, and is preferably 50 to 90 mass%.

[0092] [Prepreg] The prepreg of the present disclosure comprises a fibrous substrate and a (semi-)cured product of the curable composition of the present disclosure. The prepreg can be produced by impregnating a fibrous substrate with the curable composition and (semi-)curing it by thermal curing or the like. The (semi-)cured product can comprise a single cured product of one type of curable polymer of the present disclosure, a reaction product of multiple types of curable polymers of the present disclosure, or a reaction product of one or more types of curable polymers of the present disclosure with one or more other curable compounds. The (semi-)cured product can contain additives such as inorganic fillers as needed.

[0093] The material of the fiber substrate is not particularly limited, and examples thereof include inorganic fibers such as glass fiber, silica fiber, and carbon fiber; organic fibers such as aramid fiber and polyester fiber; and combinations thereof. For applications such as metal-clad laminates and wiring boards, glass fiber is preferred. Examples of the form of the glass fiber substrate include glass cloth, glass paper, and glass mat.

[0094] The curing conditions for the curable composition can be set depending on the composition of the curable composition, and semi-curing conditions (conditions that do not completely cure) are preferred. For example, thermal curing by heating at 80 to 180°C for 1 to 10 minutes is preferred. For applications such as metal-clad laminates and wiring boards, it is preferable to adjust the composition of the curable composition and the curing conditions so that the resin content in the resulting prepreg is within the range of 40 to 80 mass%.

[0095] [Laminate] The first laminate of the present disclosure includes a substrate and a curable composition layer made of the curable composition of the present disclosure. The second laminate of the present disclosure includes a substrate and a (semi-)cured-product-containing layer containing a (semi-)cured product of the curable composition of the present disclosure. In the first and second laminates of the present disclosure, the substrate is not particularly limited, and examples thereof include a resin film, a metal foil, and combinations thereof. The (semi-)cured-product-containing layer may be a layer containing a fiber substrate and a (semi-)cured product of the curable composition of the present disclosure. The resin film is not particularly limited, and known resins can be used. Examples of resins constituting the resin film include polyimide, polyethylene terephthalate (PET), polyethylene naphthalate, cycloolefin polymer, and polyether sulfide. Due to their low electrical resistance, the metal foil is preferably copper foil, silver foil, gold foil, aluminum foil, or a combination thereof, with copper foil being more preferred.

[0096] [Metal-Clad Laminate] The metal-clad laminate of the present disclosure includes an insulating layer containing a cured product of the curable composition of the present disclosure and a metal foil. The insulating layer may be a layer containing a fiber substrate and a cured product of the curable composition of the present disclosure. Due to their low electrical resistance, the metal foil is preferably copper foil, silver foil, gold foil, aluminum foil, or a combination thereof, with copper foil being more preferred. The metal foil may have a metal plating layer on its surface. The metal foil may be a carrier-attached metal foil containing an ultrathin metal foil and a carrier metal foil supporting it. At least one surface of the metal foil may be subjected to a surface treatment such as an anti-rust treatment, a silane treatment, a surface roughening treatment, or a barrier-forming treatment. The thickness of the metal foil is not particularly limited, and is preferably 0.1 to 100 μm, more preferably 0.2 to 50 μm, and particularly preferably 1.0 to 40 μm, because it is suitable for forming conductor patterns (also referred to as circuit patterns) such as wiring.

[0097] The metal-clad laminate may be a single-sided metal-clad laminate having a metal foil on one side, or a double-sided metal-clad laminate having metal foil on both sides, with a double-sided metal-clad laminate being preferred. The single-sided metal-clad laminate can be produced by stacking one or more of the above prepregs and metal foil and heating and pressurizing the resulting first temporary laminate. The double-sided metal-clad laminate can be produced by sandwiching one or more of the above prepregs between a pair of metal foils and heating and pressurizing the resulting first temporary laminate. A metal-clad laminate using copper foil as the metal foil is called a copper clad laminate (CCL).

[0098] The insulating layer is preferably made of a heated and pressed prepreg. The heated and pressed prepreg contains a fiber substrate and a resin, and may contain one or more additives such as an inorganic filler and a flame retardant as needed. The heated and pressed prepreg is also called a composite substrate. The heating and pressing conditions for the first temporary laminate are not particularly limited, and are preferably, for example, a temperature of 170 to 250°C, a pressure of 0.3 to 30 MPa, and a time of 3 to 240 minutes.

[0099]

[0023] Figures 1 and 2 show schematic cross-sectional views of metal-clad laminates according to first and second embodiments of the present disclosure. The metal-clad laminate 1 shown in Figure 1 is a single-sided metal-clad laminate (laminate) in which a metal foil (metal layer) 12 is laminated on one side of a composite substrate (cured-product-containing layer) 11 made of a heated and pressurized prepreg and containing a cured product of the curable composition of the present disclosure. The metal-clad laminate 2 shown in Figure 2 is a double-sided metal-clad laminate in which a metal foil (metal layer) 12 is laminated on both sides of a composite substrate (cured-product-containing layer) 11 made of a heated and pressurized prepreg and containing a cured product of the curable composition of the present disclosure.

[0100] The metal-clad laminates 1 and 2 may have layers other than those described above. The metal-clad laminates 1 and 2 may have an adhesive layer between the composite substrate (cured product-containing layer) 11 and the metal foil (metal layer) 12 to enhance adhesion therebetween. Known materials can be used for the adhesive layer, including epoxy resins, cyanate ester resins, acrylic resins, polyimide resins, maleimide resins, adhesive fluororesins, and combinations thereof. Commercially available adhesive fluororesins include "Fluon LM-ETFE LH-8000," "AH-5000," "AH-2000," and "EA-2000" manufactured by AGC.

[0101] The thickness of the composite substrate can be appropriately designed depending on the application. From the viewpoint of preventing disconnection of the wiring substrate, it is preferably 50 μm or more, more preferably 70 μm or more, and particularly preferably 100 μm or more. From the viewpoint of flexibility, miniaturization, and weight reduction of the wiring substrate, it is preferably 300 μm or less, more preferably 250 μm or less, and particularly preferably 200 μm or less.

[0102] [Wiring Board] The wiring board of the present disclosure includes an insulating layer containing a cured product of the curable composition of the present disclosure, and wiring. The wiring board can be produced by forming a conductor pattern (circuit pattern) such as wiring using the metal foil on the outermost surface of the metal-clad laminate of the present disclosure. Methods for forming conductor patterns such as wiring include the subtractive method, in which metal foil is etched to form wiring, and the MSAP (Modified Semi-Additive Process) method, in which wiring is formed on metal foil by plating.

[0103] Fig. 3 shows a schematic cross-sectional view of a wiring board according to one embodiment of the present disclosure. The wiring board 3 shown in Fig. 3 is formed by using the metal foil 12 on at least one outermost surface of the metal-clad laminate 2 of the second embodiment shown in Fig. 2 to form a conductor pattern (circuit pattern) 22 such as wiring 22W. The wiring board 3 is made of a heated and pressurized prepreg, and has a conductor pattern (circuit pattern) 22 such as wiring 22W formed on at least one surface of a composite substrate (cured-product-containing layer, insulating layer) 11 containing a cured product of the curable composition of the present disclosure.

[0104] One or more prepregs may be further stacked on the obtained wiring board, sandwiched between a pair of metal foils, and the obtained second temporary laminate may be heated and pressed to form a conductor pattern such as wiring using the metal foil on the outermost surface, thereby producing a multilayer wiring board (also called a multilayer printed wiring board). The outermost metal foil may be disposed on only one side of the second temporary laminate. The wiring board of the present disclosure is suitable for use in the high frequency range (frequency range of 1 GHz or more).

[0105] In recent years, in applications such as portable electronic devices, communication speeds and capacities have increased, and signals are becoming increasingly frequent. Wiring boards used in these applications are required to have reduced transmission loss in the high-frequency range. For this reason, resins contained in composite substrates for wiring boards used in the above applications are required to have reduced dielectric loss in the high-frequency range. Generally, the dielectric loss tangent (D ｆ ) depends on frequency, and for the same material, the higher the frequency, the greater the dielectric loss tangent (D ｆ The resin contained in the composite substrate tends to have a large dielectric loss tangent (Dｆ ) is preferably low.

[0106] Wiring boards are sometimes used in relatively high-temperature environments, and even in such cases, the resins contained in the prepreg and composite base material preferably have a sufficiently high glass transition temperature (Tg) to ensure the reliability of the wiring board.

[0107] If the difference in the coefficient of thermal expansion (CTE) between the prepreg or composite substrate and the metal foil is large, there is a risk that the metal foil will shift or peel when a first temporary laminate including the prepreg and the metal foil, or a second temporary laminate including the composite substrate, the prepreg, and the metal foil, is heated and pressurized. It is preferable that the difference in the coefficient of thermal expansion (CTE) between the prepreg or composite substrate and the metal foil is small. Generally, resins have a larger coefficient of thermal expansion (CTE) than metal foil, so it is preferable that the coefficient of thermal expansion (CTE) of the prepreg and composite substrate is small.

[0108] The inventors have conducted studies and found that by using the curable polymer of the present disclosure which does not contain polar atoms or has a small number of polar atoms, the dielectric loss tangent (D ｆ ) can be effectively reduced. It has also been found that a (semi-)cured product of a curable composition containing the curable polymer of the present disclosure has a sufficiently high glass transition temperature (Tg). It has also been found that a (semi-)cured product of a curable composition containing the curable polymer of the present disclosure has a sufficiently low coefficient of thermal expansion (CTE). It has also been found that a (semi-)cured product of a curable composition containing the curable polymer of the present disclosure has practically good adhesion to metals such as copper foil.

[0109] By using the curable polymer of the present disclosure, the dielectric loss tangent (D ｆ The (semi-)cured product is suitable for composite substrates and insulating layers suitable for wiring boards used in high frequency regions.

[0110] The dielectric loss tangent (D) of the (semi-)cured product of the curable composition of the present disclosure and the composite substrate containing the same under high frequency conditions ｆ) is preferably within the following range, for example: ｆ The dielectric loss tangent (D) at a frequency of 10 GHz is preferably small, and is preferably 0.010 or less, more preferably 0.005 or less, even more preferably 0.003 or less, particularly preferably 0.002 or less, and most preferably less than 0.002. ｆ The dielectric loss tangent (D) at a frequency of 10 GHz can be 0.0018 or less, 0.0016 or less, 0.0014 or less, 0.0012 or less, or 0.0010 or less. ｆ The lower limit of ) is not particularly limited, and is, for example, 0.0001.

[0111] The glass transition temperature (Tg) of a (semi-)cured product of the curable composition of the present disclosure is preferably 130° C. or higher, more preferably 150° C. or higher, and particularly preferably 180° C. or higher. The upper limit is not particularly limited, and is, for example, 300° C.

[0112] The coefficient of thermal expansion (CTE) of the (semi-)cured product of the curable composition of the present disclosure and the composite substrate containing the same is preferably within the following range, for example. The smaller the coefficient of thermal expansion (CTE), the better, and it is preferably 70 ppm / °C or less, and more preferably 60 ppm / °C or less. The lower limit is not particularly limited, and is, for example, 1 ppm / °C.

[0113] Dielectric loss tangent (D ｆ The viscosity (Tg) and glass transition temperature (Tg) can be measured by the method described in the Examples section below. The coefficient of thermal expansion (CTE) can be measured by a known method using a commercially available thermomechanical analyzer.

[0114] As described above, according to the present disclosure, the dielectric loss tangent (D ｆ The present disclosure provides a curable polymer and a curable composition containing the same, which can effectively reduce the glass transition temperature (Tg) and produce a resin having a sufficiently high glass transition temperature (Tg). The curable polymer and the curable composition containing the same according to the present disclosure are suitable for applications such as prepregs, metal-clad laminates, and wiring boards, but can also be used for any application.

[0115] [Applications] The curable polymers of the present disclosure and curable compositions containing the same are suitable for applications such as prepregs, metal-clad laminates, and wiring boards. The metal-clad laminates of the present disclosure are suitable for wiring boards used in various electrical devices and electronic devices. The wiring boards of the present disclosure are suitable for portable electronic devices such as mobile phones, smartphones, personal digital assistants, and laptop computers; antennas for mobile phone base stations and automobiles; electronic devices such as servers, routers, and backplanes; wireless infrastructure; radar for collision prevention; and various sensors (e.g., automotive sensors such as engine management sensors). The wiring boards of the present disclosure are particularly suitable for applications in which communication is performed using high-frequency signals, and are suitable for various applications requiring reduced transmission loss in the high-frequency range.

[0116] The present invention will be described in detail below using examples, but the present invention is not limited to these. Examples 11, 12, 21 to 25, 31, 41, 51, 61, 71, 81, 91, 101 to 115, 121, and 301 are working examples, and Example 201 is a comparative example. Unless otherwise specified, room temperature is about 25°C.

[0117] [Commercially Available Reagents] In the section [Examples], unless otherwise specified, commercially available catalysts and reagents were used as they were in the reactions. Dehydrated and deoxygenated commercially available solvents were used.

[0118] [Evaluation Items and Evaluation Methods for Curable Polymers] (Monomer Structure) The structure of the synthesized monomer was determined using a nuclear magnetic resonance apparatus ("AVANCE NEO400" manufactured by Bruker). １ It was identified by H-NMR measurement.

[0119] (Number Average Molecular Weight (Mn) and Weight Average Molecular Weight (Mw)) The number average molecular weight (Mn) and weight average molecular weight (Mw) of the synthesized curable polymer were determined by gel permeation chromatography (GPC). The GPC apparatus used was a Tosoh Corporation "HLC-8320GPC" equipped with a differential refractive index detector (RI detector). Tetrahydrofuran was used as the eluent. Four columns, "TSKgel Super HZ2000," "TSKgel Super HZ2500," "TSKgel Super HZ3000," and "TSKgel Super HZ4000" (all manufactured by Tosoh Corporation), connected in series, were used. A sample solution was prepared by dissolving 20 mg of resin in 2 mL of tetrahydrofuran. 10 μL of the sample solution was injected, and the chromatogram was measured. GPC measurement was performed using 10 standard polystyrenes with molecular weights ranging from 400 to 5,000,000, and a calibration curve showing the relationship between retention time and molecular weight was prepared. Based on this calibration curve, the Mn and Mw of the curable polymer were determined.

[0120] [Evaluation Items and Evaluation Methods for Film-Like Cured Products] (Dielectric Constant (D ｋ ) and dielectric loss tangent (D ｆ )) The relative dielectric constant (D) of the evaluation sample (cured film) at 10 GHz ｋ ) and dielectric loss tangent (D ｆ ) was measured at room temperature by the SPDR method using a vector network analyzer ("E8361C" manufactured by Agilent Technologies).

[0121] (Glass Transition Temperature Tg) Using a dynamic viscoelasticity measuring device ("DVA-200" manufactured by IT Measurement & Control Co., Ltd.), the evaluation sample (film-like cured product) was subjected to dynamic viscoelasticity measurement (DMA) to measure the glass transition temperature (Tg) (°C). The measurement was performed under conditions of a frequency of 10 Hz, a heating rate of 2°C / min, and a temperature range of 25 to 300°C.

[0122] Synthesis Example 1 Synthesis of Dimethylvinylsilane A (Dimethyl(vinyl)(4-vinylbenzyl)silane) Under a nitrogen atmosphere, a 1 L four-neck flask was charged with magnesium (cuttings, 7.96 g, 328 mmol) and diethyl ether (327 mL) and cooled in an ice bath. Iodine (250 mg, 0.985 mmol) was added to this suspension, and then 4-(chloromethyl)styrene (50.0 g, 328 mmol) was added dropwise over 1 hour, followed by stirring for an additional 1 hour. Chlorodimethylvinylsilane (51.9 mL, 377 mmol) was added dropwise to the reaction mixture over 30 minutes, after which the flask was warmed to room temperature and stirred for 20 hours. The flask was cooled to 0°C, and saturated aqueous ammonium chloride solution (328 mL) was added to quench the reaction, after which insoluble matter was removed by filtration. The filtrate was allowed to stand, and then extraction was performed to separate the organic phase. Furthermore, ethyl acetate (328 mL) was added to the aqueous phase, and extraction was performed to separate the organic phase. The organic phases obtained by these extractions were combined, dried over magnesium sulfate, filtered, and the filtrate was concentrated under vacuum to obtain a crude product. The crude product was purified using silica gel column chromatography (mobile phase: n-hexane) to obtain 59.0 g of colorless liquid dimethylvinylsilane A (dimethyl(vinyl)(4-vinylbenzyl)silane) (yield: 86%). The obtained compound was one of the monomers (MX) (R １ = methyl group, R ２ = methyl group, n = 1).

[0123] The reaction scheme and NMR analysis results are as follows:

[0124] １ H-NMR (CDCl ３ ): δ (ppm) 7.26 (d, 2H, J = 8.34Hz, Ar-H), 6.96 (d, 2H, J = 8.34Hz, Ar-H), 6.67 (dd, 1H, J = 10.85, 17.52Hz), 6.12 (dd, J = 14.66, 2 0.03Hz, 1H), 5.96 (dd, 1H, J = 3.93, 14.66Hz), 5.69-5.63 (m, 2H), 5.14 (dd, 1H, J = 0.83, 10.85Hz), 2.13 (s, 2H), 0.05 (s, 6H).

[0125] Synthesis Example 2 Synthesis of Dimethylvinylsilane B (Dimethyl(vinyl)(4-vinylphenyl)silane) Under a nitrogen atmosphere, a 500 mL four-neck flask was charged with magnesium (cuttings, 1.50 g, 61.7 mmol) and tetrahydrofuran (65 mL) and cooled in an ice bath. Iodine (53.9 mg, 0.212 mmol) was added to this suspension, and then 4-bromostyrene (9.67 g, 52.8 mmol) was added dropwise. The mixture was stirred at room temperature for 15 minutes and then heated to 70°C for 1 hour. The reaction mixture was cooled to room temperature, and magnesium (cuttings, 0.40 g, 16.3 mmol) was added, followed by heating to reflux for 1 hour. The reaction mixture was again cooled to room temperature, and chlorodimethylvinylsilane (8.04 g, 66.6 mmol) was added dropwise, followed by stirring at room temperature for 1 hour. The flask was cooled to 0°C, saturated aqueous ammonium chloride solution (100 mL) was added, and the mixture was stirred overnight at room temperature to quench the reaction. Ethyl acetate was then added, and the organic phase was separated and extracted. The organic phase obtained by extraction was dried over magnesium sulfate, filtered, and the filtrate was concentrated under vacuum to obtain a crude product. The crude product was purified using silica gel column chromatography (mobile phase: n-hexane), yielding 6.58 g of colorless liquid dimethylvinylsilane B (dimethyl(vinyl)(4-vinylphenyl)silane) (yield: 54%). The obtained compound was one of the monomers (MX) (R １ = methyl group, R ２ = methyl group, n = 0).

[0126] The reaction scheme and NMR analysis results are as follows:

[0127] １ H-NMR (CDCl ３ ): δ (ppm) 7.57-7.45 (m, 2H), 7.46-7.36 (m, 2H), 6.71 (dd, 1H, J = 10.9, 17.6Hz), 6.28 (dd, 1H, J = 14.6, 20.2Hz), 6.05 (dd, 1H, J = 3.8, 14.6Hz), 5.82-5.70 (m, 2H), 5.26 (dd, 1H, J = 1.0, 10.9Hz), 0.34 (s, 6H).

[0128] Synthesis Example 3 Synthesis of dimethylvinylsilane C (dimethyl(vinyl)(2-(4-vinylphenyl)ethyl)silane) Under a nitrogen atmosphere, a 500 mL four-neck flask was charged with a hexane solution of N-butyllithium (28.8 mL, 46 mmol) and diisopropylamine (6.5 mL, 46 mmol) and stirred at −78°C. 4-Methylstyrene (5.0 g, 42 mmol) and tetrahydrofuran (40 mL) were charged to this solution and stirred again at −78°C. After returning this solution to room temperature, vinyl(chloromethyl)dimethylsilane (7.5 mL, 50 mmol) was added and the mixture was stirred at 50°C for 12 hours. The flask was cooled to room temperature and quenched by the addition of an aqueous ammonium chloride solution, and the crude liquid was concentrated under vacuum. This concentrate was purified using silica gel column chromatography (mobile phase: n-hexane) and gel permeation chromatography (GPC) to obtain 3.2 g of dimethylvinylsilane C (dimethyl(vinyl)(2-(4-vinylphenyl)ethyl)silane) (yield: 35%). The compound obtained was one of the monomers (MX) (R １ = methyl group, R ２ = methyl group, n = 2).

[0129] The reaction scheme and NMR analysis results are as follows:

[0130] １ H-NMR (CDCl ３ ): δ (ppm) 7.33 (d, 2H, J = 8.0Hz), 7.20-7.08 (m, 2H), 6.70 (dd, 1H, J = 17.6, 10.9Hz), 6.16 (dd, 1H, J = 20.2, 14.7Hz,), 5.99 (d d.

[0131] Synthesis Example 4 Synthesis of methyl(phenyl)(vinyl)(4-vinylbenzyl)silane Under a nitrogen atmosphere, a 500 mL four-neck flask was charged with magnesium (cuttings, 1.59 g, 65.4 mmol) and diethyl ether (65.4 mL) and cooled in an ice bath. After adding a small amount of iodine to this suspension, a solution of 4-(chloromethyl)styrene (10.0 g, 65.5 mmol) in diethyl ether (65.4 mL) was added dropwise over 1.5 hours and stirred for an additional 1 hour. Chloro(methyl)(phenyl)(vinyl)silane (13.9 mL, 78.4 mmol) was added dropwise to the reaction mixture over 10 minutes, and the flask was warmed to room temperature and stirred for 22 hours. The flask was cooled to 0°C and quenched by adding saturated aqueous ammonium chloride (131 mL), followed by extraction to separate the organic phase. Furthermore, diethyl ether (100 mL) was added to the aqueous phase, and extraction to separate the organic phase was performed twice. The organic phases obtained by these extractions were combined, dried over magnesium sulfate, filtered, and the filtrate was concentrated under vacuum to obtain a crude product. The crude product was purified using silica gel column chromatography (mobile phase: n-hexane) to obtain 15.0 g of colorless liquid methyl(phenyl)(vinyl)(4-vinylbenzyl)silane (yield: 86%). The obtained compound was one of the monomers (MX) (R １ = methyl group, R ２ = phenyl group, n = 1).

[0132] The reaction scheme and NMR analysis results are as follows:

[0133] １ H-NMR (CDCl ３): δ (ppm) 7.46 (dm, 2H, J = 7.75Hz, Ar-H), 7.39-7.32 (m, 3H, Ar-H), 7.22 (d, 2H, J = 7.99Hz, Ar-H), 6.90 ( d, 2H, J = 7.87Hz, Ar-H), 6.65 (dd, 1H, J = 10.85, 17.52Hz), 6.27 (ddd, 1H, J = 1.19, 14.66, 20.15Hz), 6.09 (ddd, 1H, J=1.19, 3.82, 14.78Hz), 5.72 (ddd, 1H, J=1.19, 3.70, 20.15Hz), 5.66 (dd, 1H, J=0.95, 17.64H z), 5.14 (d, 1H, J = 10.85Hz), 2.42 (d, 1H, J = 13.71Hz), 2.37 (d, 1H, J = 13.71Hz), 0.30 (d, 3H, J = 1.19Hz).

[0134] Example 11 Synthesis of Copolymer (P11) Dimethylvinylsilane A (dimethyl(vinyl)(4-vinylbenzyl)silane) (6.7 g, 32.9 mmol) obtained in Synthesis Example 1, styrene (13.3 g, 128.2 mmol), toluene (20 g, 21.7 mmol), and boron trifluoride diethyl ether complex (0.36 g, 2.6 mmol) were placed in a 100 mL pressure-resistant reactor under a nitrogen atmosphere, and the mixture was allowed to react at 50°C for 5 hours. After completion of the reaction, a saturated sodium bicarbonate solution was added to the polymerization solution to terminate the reaction. The polymerization solution was added dropwise to a large amount of methanol to precipitate the polymer. The precipitate was collected, washed, and dried to obtain 12.0 g of copolymer (P11) (yield: 59.8%).

[0135] Example 12 Synthesis of Copolymer (P12) The same procedure as in Example 11 was repeated, except that the amount of dimethylvinylsilane A (dimethyl(vinyl)(4-vinylbenzyl)silane) was changed to 9.0 g, 44.5 mmol, and the amount of styrene was changed to 11.0 g, 105.8 mmol, to obtain 11.9 g of copolymer (P12) (yield: 59.4%).

[0136] The reaction schemes for Examples 11 and 12 are as follows:

[0137] Example 21 Synthesis of Copolymer (P21) Dimethylvinylsilane A (dimethyl(vinyl)(4-vinylbenzyl)silane) (4.6 g, 22.7 mmol), 4-methylstyrene (15.4 g, 130.4 mmol), toluene (20 g, 21.7 mmol), and boron trifluoride diethyl ether complex (0.36 g, 2.6 mmol) were placed in a 100 mL pressure-resistant reactor under a nitrogen atmosphere, and the mixture was allowed to react at 50°C for 5 hours. After completion of the reaction, saturated aqueous sodium bicarbonate solution was added to the polymerization solution to terminate the reaction. This polymerization solution was added dropwise to a large amount of methanol to precipitate the polymer. The precipitate was collected, washed, and dried to obtain 19.4 g of copolymer (P21) (yield: 97.2%).

[0138] Example 22 Synthesis of Copolymer (P22) The same procedure as in Example 21 was repeated, except that the amount of dimethylvinylsilane A (dimethyl(vinyl)(4-vinylbenzyl)silane) was changed to 6.0 g, 29.6 mmol, and the amount of 4-methylstyrene was changed to 14.0 g, 118.5 mmol, to obtain 19.3 g of copolymer (P22) (yield: 96.3%).

[0139] Example 23 Synthesis of Copolymer (P23) The same procedure as in Example 21 was repeated, except that the amount of dimethylvinylsilane A (dimethyl(vinyl)(4-vinylbenzyl)silane) was changed to 8.4 g, 41.5 mmol, and the amount of 4-methylstyrene was changed to 11.6 g, 98.2 mmol, to obtain 18.9 g of copolymer (P23) (yield: 94.6%).

[0140] The reaction schemes for Examples 21-23 are as follows:

[0141] Example 24 Synthesis of Copolymer (P24) The same procedure as in Example 21 was repeated, except that dimethylvinylsilane A (dimethyl(vinyl)(4-vinylbenzyl)silane) was replaced with dimethylvinylsilane B (dimethyl(vinyl)(4-vinylphenyl)silane) (6.8 g, 29.8 mmol) obtained in Synthesis Example 2, and the amount of 4-methylstyrene was changed to 14.0 g, 118.8 mmol, to obtain 17.6 g of copolymer (P24) (yield: 84.7%).

[0142] The reaction scheme for Example 24 is as follows:

[0143] Example 25 Synthesis of Copolymer (P25) The same procedure as in Example 21 was repeated, except that dimethylvinylsilane A (dimethyl(vinyl)(4-vinylbenzyl)silane) was replaced with dimethylvinylsilane C (dimethyl(vinyl)(2-(4-vinylphenyl)ethyl)silane) (6.4 g, 29.7 mmol) obtained in Synthesis Example 3, and the amount of 4-methylstyrene was changed to 14.0 g, 118.4 mmol, to obtain 18.5 g of copolymer (P25) (yield: 91.0%).

[0144] The reaction scheme for Example 25 is as follows:

[0145] Example 31 Synthesis of Copolymer (P31) Dimethylvinylsilane A (dimethyl(vinyl)(4-vinylbenzyl)silane) (4.8 g, 23.7 mmol) obtained in Synthesis Example 1, 4-tert-butylstyrene (15.2 g, 94.8 mmol), toluene (20 g, 21.7 mmol), and boron trifluoride diethyl ether complex (0.36 g, 2.6 mmol) were placed in a 100 mL pressure-resistant reactor under a nitrogen atmosphere, and the mixture was allowed to react at 50°C for 5 hours. After completion of the reaction, a saturated aqueous solution of sodium bicarbonate was added to the polymerization solution to terminate the reaction. This polymerization solution was added dropwise to a large amount of methanol to precipitate the polymer. The precipitate was collected, washed, and dried to obtain 19.0 g of Copolymer (P31) (yield: 95%).

[0146] The reaction scheme is as follows:

[0147] Example 41 Synthesis of Copolymer (P41) Dimethylvinylsilane A (dimethyl(vinyl)(4-vinylbenzyl)silane) (6.0 g, 29.6 mmol) obtained in Synthesis Example 1, indene (14.0 g, 120.5 mmol), toluene (20 g, 21.7 mmol), and boron trifluoride diethyl ether complex (0.36 g, 2.6 mmol) were placed in a 100 mL pressure-resistant reactor under a nitrogen atmosphere, and the mixture was allowed to react at 50°C for 5 hours. After completion of the reaction, a saturated aqueous solution of sodium bicarbonate was added to the polymerization solution to terminate the reaction. The polymerization solution was added dropwise to a large amount of methanol to precipitate the polymer. The precipitate was collected, washed, and dried to obtain 18.9 g of copolymer (P41) (yield: 94.7%).

[0148] The reaction scheme is as follows:

[0149] [Example 51] Synthesis of Copolymer (P51) Under a nitrogen atmosphere, methyl(phenyl)(vinyl)(4-vinylbenzyl)silane (7.6 g, 29.1 mmol) obtained in Synthesis Example 4, styrene (12.4 g, 119.2 mmol), toluene (20 g, 21.7 mmol), and boron trifluoride diethyl ether complex (0.36 g, 2.6 mmol) were placed in a 100 mL pressure-resistant reactor, and the mixture was allowed to react at 50°C for 5 hours. After completion of the reaction, saturated aqueous sodium bicarbonate solution was added to the polymerization solution to terminate the reaction. This polymerization solution was added dropwise to a large amount of methanol to precipitate the polymer. The precipitate was collected, washed, and dried to obtain 17.8 g of copolymer (P51) (yield: 89.2%).

[0150] The reaction scheme is as follows:

[0151] Example 61 Synthesis of Copolymer (P61) Under a nitrogen atmosphere, methyl(phenyl)(vinyl)(4-vinylbenzyl)silane (5.8 g, 22.2 mmol) obtained in Synthesis Example 4, 4-tert-butylstyrene (14.2 g, 88.6 mmol), toluene (20 g, 21.7 mmol), and boron trifluoride diethyl ether complex (0.36 g, 2.6 mmol) were placed in a 100 mL pressure-resistant reactor and reacted at 50°C for 5 hours. After completion of the reaction, saturated aqueous sodium bicarbonate solution was added to the polymerization solution to terminate the reaction. This polymerization solution was added dropwise to a large amount of methanol to precipitate the polymer. The precipitate was collected, washed, and dried to obtain 18.6 g of copolymer (P61) (yield: 93.2%).

[0152] The reaction scheme is as follows:

[0153] Example 71 Synthesis of Copolymer (P71) Under a nitrogen atmosphere, methyl(phenyl)(vinyl)(4-vinylbenzyl)silane (7.2 g, 27.5 mmol) obtained in Synthesis Example 4, indene (12.8 g, 110.2 mmol), toluene (20 g, 21.7 mmol), and boron trifluoride diethyl ether complex (0.36 g, 2.6 mmol) were placed in a 100 mL pressure-resistant reactor, and the mixture was allowed to react at 50°C for 5 hours. After completion of the reaction, saturated aqueous sodium bicarbonate solution was added to the polymerization solution to terminate the reaction. This polymerization solution was added dropwise to a large amount of methanol to precipitate the polymer. The precipitate was collected, washed, and dried to obtain 19.0 g of copolymer (P71) (yield: 95.1%).

[0154] The reaction scheme is as follows:

[0155] Example 81 Synthesis of Homopolymer (P81) Dimethylvinylsilane A (dimethyl(vinyl)(4-vinylbenzyl)silane) (20 g, 98.8 mmol) obtained in Synthesis Example 1, toluene (20 g, 21.7 mmol), and boron trifluoride diethyl ether complex (0.36 g, 2.6 mmol) were placed in a 100 mL pressure-resistant reactor under a nitrogen atmosphere, and the mixture was allowed to react at 50°C for 5 hours. After completion of the reaction, a saturated aqueous solution of sodium bicarbonate was added to the polymerization solution to terminate the reaction. This polymerization solution was added dropwise to a large amount of methanol to precipitate the polymer. The precipitate was collected, washed, and dried to obtain 16.8 g of homopolymer (P81) (yield: 83.8%).

[0156] The reaction scheme is as follows:

[0157] Example 91 Synthesis of Homopolymer (P91) Under a nitrogen atmosphere, methyl(phenyl)(vinyl)(4-vinylbenzyl)silane (20 g, 76.5 mmol) obtained in Synthesis Example 4, toluene (20 g, 21.7 mmol), and boron trifluoride diethyl ether complex (0.36 g, 2.6 mmol) were placed in a 100 mL pressure-resistant reactor and reacted at 50°C for 5 hours. After completion of the reaction, saturated aqueous sodium bicarbonate solution was added to the polymerization solution to terminate the reaction. This polymerization solution was added dropwise to a large amount of methanol to precipitate the polymer. The precipitate was collected, washed, and dried to obtain 17.9 g of homopolymer (P91) (yield: 89.3%).

[0158] The reaction scheme is as follows:

[0159] In Examples 11, 12, 21 to 25, 31, 41, 51, 61, 71, 81 and 91, the monomer compositions and the physical properties of the resulting polymers are shown in Table 1.

[0160] [Example 101] A curable polymer (P11), dicumyl peroxide (DCP) as a radical polymerization initiator, and toluene were mixed in a mass ratio of 100:1:100 and stirred at room temperature to prepare a curable composition. Next, using an applicator (manufactured by Yoshimitsu Seiki Co., Ltd.), the curable composition was applied to a 125 μm-thick polyimide film to form a 250 μm-thick coating film. The film was dried by heating in an oven under air at 80°C for 30 minutes, and then heated under a nitrogen atmosphere at 200°C for 2 hours to thermally cure the coating film, yielding a film-like cured product with a thickness of approximately 100 μm. The formulation of the curable composition excluding the solvent and the evaluation results of the resulting film-like cured product are shown in Table 2. The blend amounts in the table are in parts by mass.

[0161] [Example 102] A curable composition was prepared by mixing the curable polymer (P12), the following modified polyphenylene ether (PPE) oligomer (SA9000), dicumyl peroxide (DCP) as a radical polymerization initiator, and toluene in a mass ratio of 50:50:1:100 and stirring at room temperature. A film-like cured product was produced using the obtained curable composition in the same manner as in Example 101.

[0162] (SA9000) Bifunctional methacrylic-modified PPE oligomer represented by the following formula ("SA9000" manufactured by SABIC). Table 2 shows the formulation of the curable composition excluding the solvent, and the evaluation results of the obtained film-like cured product.

[0163] [Examples 103 to 115, 121, 201] Curable compositions were prepared and film-like cured products were produced in the same manner as in Example 101 or Example 102, except that the type and amount of one or more curable polymers were changed. The formulations of the curable compositions excluding the solvent and the evaluation results of the obtained film-like cured products are shown in Tables 2 and 3.

[0164]

[0165]

[0166] [Summary of Results] In Examples 101 to 115, a curable polymer that is a copolymer containing the structural unit (UX) and the structural unit (UY) derived from a monovinyl aromatic compound was used to obtain a film-like cured product. In Example 121, a curable polymer that is a homopolymer containing only the structural unit (UX) as a structural unit was used to obtain a film-like cured product. In Example 201, a cured film was obtained using only a modified PPE oligomer that does not contain the structural unit (UX). In Examples 101 to 115 and 121, the dielectric loss tangent (D ｆ In these examples, the dielectric loss tangent (D ｆ ) was effectively reduced, and a film-like cured product having a sufficiently high glass transition temperature (Tg) was obtained.

[0167] [Example 301] The curable polymer (P11) obtained in Example 11, dicumyl peroxide (DCP) as a radical polymerization initiator, spherical silica as an inorganic filler, and toluene were mixed in a mass ratio of 100:1:100:100 and stirred at room temperature to prepare a curable composition (varnish). The obtained curable composition (varnish) was impregnated into a glass cloth (E glass, #2116) as a fiber substrate, and then heated at 130 ° C. for 5 minutes to semi-cure the curable composition, thereby obtaining a prepreg. Two sheets of the obtained prepreg were stacked, sandwiched between a pair of copper foils, and the obtained temporary laminate was heated and pressed at 200 ° C., 1.5 hours, and 3 MPa to produce a metal-clad laminate.

[0168] The present invention is not limited to the above-described embodiments and examples, and various modifications can be made to the design as appropriate without departing from the spirit of the present invention.

[0169] This application claims priority based on Japanese Patent Application No. 2022-074066, filed April 28, 2022, the disclosure of which is incorporated herein by reference in its entirety.

[0170] 1, 2: metal-clad laminate, 3: wiring board, 11: composite substrate, 12: metal foil, 22: conductor pattern (circuit pattern), 22W: wiring.

Claims

1. A curable polymer, which is a copolymer containing one or more structural units (UX) represented by the following formula and one or more structural units other than the structural units (UX) that do not contain polar atoms. 【Chemistry 1】 (In the above formula, R １ and R ２ are each independently a hydrogen atom, a hydroxyl group, or an organic group. The benzene ring may have a substituent other than those mentioned above. n is an integer of 0 or more.

2. The curable polymer according to claim 1, which is a copolymer comprising one or more structural units (UX) and one or more structural units (UY) derived from a monovinyl aromatic compound not containing a polar atom.

3. The curable polymer according to claim 1 or 2, wherein the content of the one or more structural units (UX) is 1 to 90 mol % relative to 100 mol % of the total amount of all structural units.

4. A curable polymer which is a homopolymer or copolymer containing only one or more structural units (UX) represented by the following formula as structural units, and is used for producing a prepreg, a metal-clad laminate, or a wiring board. 【Chemistry 2】 (In the above formula, R １ and R ２ are each independently a hydrogen atom, a hydroxyl group, or an organic group. The benzene ring may have a substituent other than those mentioned above. n is an integer of 0 or more.

5. R １ and R ２ Each of independently represents an alkyl group having 1 to 18 carbon atoms or a phenyl group which may have a substituent.

6. The curable polymer according to claim 1 or 4, wherein n is 1 to 18.

7. A curable composition comprising the curable polymer according to claim 1 or 4.

8. 8. The hardenable composition of claim 7 further comprising another hardenable compound having one or more polymerizable functional groups.

9. A prepreg comprising a fiber substrate and a semi-cured or cured product of the curable composition according to claim 7.

10. A laminate comprising a substrate and a curable composition layer comprising the curable composition according to claim 7.

11. A laminate comprising a substrate and a (semi-)cured product-containing layer comprising a semi-cured product or a cured product of the curable composition according to claim 7.

12. A metal-clad laminate comprising an insulating layer comprising the cured product of the curable composition according to claim 7 and a metal foil.

13. A wiring board comprising an insulating layer comprising the cured product of the curable composition according to claim 7 and wiring.

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