Novel organosilicon compound, novel crosslinking agent, curable composition, prepreg, laminate, metal-clad laminate, and wiring board

Abstract

The present application provides a novel organosilicon compound suitable for use as a crosslinking agent or the like, a novel crosslinking agent, a curable composition, a prepreg, a laminate, a metal-clad laminate, and a wiring board. An organosilicon compound represented by the following formula (1TQ). (In the above formula, M is a single bond or an alkylene group having 1 to 20 carbon atoms which can have a substituent. The benzene ring can have a substituent. The substitution position of the vinyl group on the benzene ring is arbitrary. n is an integer of 3 or 4. R is a hydrogen atom, a hydroxyl group, or an organic group, and when R is an organic group, the atom bonded to Si is C.)

Description

Technical Field

[0001] This invention relates to novel organosilicon compounds, novel crosslinking agents, curable compositions, prepregs, laminates, metal-clad laminates, and wiring substrates. Background Technology

[0002] Wiring boards (also known as printed wiring boards) are used in electrical equipment and electronic instruments. Wiring boards can be manufactured, for example, as follows: A prepreg is prepared by impregnating a curable composition into a fiber substrate and (semi-)curing the curable composition. 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. A conductor pattern (also known as a circuit pattern) is formed using the metal foil located on the outermost surface of the metal-clad laminate. The outermost metal foil may be disposed only on one side of the first temporary laminate.

[0003] The obtained wiring board is further overlapped with one or more prepregs, sandwiched between a pair of metal foils, and the resulting second temporary laminate is heated and pressurized. Conductor patterns such as wiring are formed using the outermost metal foil, thus manufacturing a multilayer wiring board (also known as a multilayer printed wiring board). The outermost metal foil can be disposed only on one side of the second temporary laminate.

[0004] The heated and pressurized prepreg contains a fiber matrix, resin, and inorganic filler materials (also known as fillers), and is therefore called a composite matrix. In wiring boards, the composite matrix functions as an insulating layer.

[0005] The resin contained in the prepreg is a (semi) cured product of the curing composition, and the resin contained in the composite substrate is a cured product of the curing composition.

[0006] In recent years, the demand for high-speed and high-capacity communication in applications such as portable electronic devices has been increasing, leading to a continuous development in high-frequency signals. This necessitates reduced transmission loss in the high-frequency range for wiring boards used in these applications. Transmission loss primarily consists of conductor loss caused by the surface resistance of the metal foil and dielectric loss factor (D) of the composite substrate. f The dielectric loss is caused by the dielectric loss in the high-frequency region. Therefore, the resin contained in the composite substrate of the wiring board used for the above-mentioned applications is required to reduce the dielectric loss in the high-frequency region. Generally, the dielectric loss factor (D) is... f The dielectric loss factor (D) depends on the frequency; for the same material, there is a higher dielectric loss factor (D) at higher frequencies. f The trend is towards a larger dielectric loss factor (D) in the composite substrate. The resin contained in the composite substrate preferably exhibits a dielectric loss factor (D) under high-frequency conditions. f )Low.

[0007] If the difference in coefficients of thermal expansion (CTE) between the prepreg or composite substrate and the metal foil is large, misalignment or peeling of the metal foil may occur when heating and pressurizing the first temporary laminate containing the prepreg and metal foil, or the second temporary laminate containing the composite substrate, prepreg, and metal foil. A smaller difference in CTE between the prepreg or composite substrate and the metal foil is preferable. Generally, the CTE of the resin is greater than that of the metal foil; therefore, a smaller CTE for the prepreg and composite substrate is preferred.

[0008] Wiring boards are sometimes used in high-temperature environments. To ensure the reliability of the wiring board under these conditions, it is preferable that the resin contained in the prepreg and composite substrate has a sufficiently high glass transition temperature (Tg).

[0009] In wiring boards, the adhesion between the composite substrate and the metal foil is crucial. Previously, techniques have been used to improve this adhesion by roughening the surface of the composite substrate side of the metal foil. However, this technique is prone to causing high-frequency current losses and is therefore not preferred.

[0010] As a technique to improve the adhesion between the composite substrate and the metal foil without roughening the surface of the composite substrate side of the metal foil, Patent Document 1 discloses a resin composition for wiring boards comprising a polyphenylene ether resin composed of polyphenylene ether and triallenyl isocyanurate, and vinyl silanes such as trimethoxyvinylsilane (TMVS) and triethoxyvinylsilane (TEVS), and a wiring board obtained using the composition.

[0011] Existing technical documents

[0012] Patent documents

[0013] Patent Document 1: Japanese Patent Application Publication No. 2004-259899

[0014] Patent Document 2: Specification of Korean Patent No. 10-1481417

[0015] Non-patent literature

[0016] Non-patent literature 1: JOURNAL OF POLYMER SCIENCE, PART A: POLYMER CHEMISTRY 2015, 53, 1707-1718.

[0017] Non-patent literature 2: J. Org. Chem. 2013, 78, 3329-3335. Summary of the Invention

[0018] The vinyl silanes such as trimethoxyvinylsilane (TMVS) and triethoxyvinylsilane (TEVS) used in Patent Document 1 are silane coupling agents containing bonds between Si and oxygen atoms (O), which are polar atoms.

[0019] The inventors conducted research and found that when a silane coupling agent containing a bond between Si and oxygen (O) as a polar atom is added to the curable composition, the dielectric loss factor (D) of the resulting composite substrate is improved. f The trend is increasing.

[0020] The inventors have discovered that organosilicon compounds having a specific chemical structure containing two or more reactive vinyl groups and not containing bonds between Si and polar atoms can be used as crosslinking agents in curable compositions. The dielectric loss factor (D) of composite substrates obtained using curable compositions containing this crosslinking agent under high-frequency conditions is [not specified]. f It effectively reduces the coefficient of thermal expansion (CTE) to a sufficiently low level and has a sufficiently high glass transition temperature (Tg), making it suitable for use as a wiring substrate in high-frequency regions.

[0021] It should be noted that in Patent Document 1, the use of silane coupling agents to improve the adhesion between the composite substrate and the metal foil is described and not suggested for the use of organosilicon compounds as crosslinking agents.

[0022] Other related technologies of this invention can be cited in non-patent documents 1 and 2 and patent document 2.

[0023] In Non-Patent Literature 1, a material with two 4-vinylphenyl groups and two alkyl groups (specifically -C8H) bonded to Si was synthesized. 17 The reaction scheme is as follows. In Non-Patent Literature 1, the synthesized organosilicon compound is polymerized, and the fluorescence properties of the resulting linear polymer are evaluated. In Non-Patent Literature 1, the organosilicon compound is used as a monomer, but its use as a crosslinking agent is not described or suggested, nor are its dielectric properties described.

[0024]

[0025] Non-Patent Literature 2 synthesizes an organosilicon compound having two 2-vinylphenyl groups and two alkyl groups (specifically -Me, -Et, or -Ph) bonded to Si. In Non-Patent Literature 2, the synthesized organosilicon compound is subjected to ring-closing metathesis to synthesize dibenzoheteropines. The reaction scheme is as follows. Non-Patent Literature 2 does not describe the use of the organosilicon compound, nor does it describe or suggest its use as a crosslinking agent, nor does it describe its dielectric properties.

[0026]

[0027] Patent Document 2 describes the synthesis of several organosilicon compounds in which two 2-, 3-, or 4-vinylphenyl groups and two alkyl groups are substituted on Si. Examples of the organosilicon compounds synthesized in Patent Document 2 are shown in [Chemical 3] below. In Patent Document 2, the organosilicon compounds are intended for gas barrier applications; their use as crosslinking agents is not described or suggested, nor are their dielectric properties described.

[0028]

[0029] In addition to the above, some organosilicon compounds with four Si atoms, all of which are nonpolar, and which have two or more reactive vinyl groups have also been reported. However, the use of organosilicon compounds with four Si atoms, all of which are nonpolar, and which have two or more reactive vinyl groups as crosslinking agents has not been reported in the past. The use of organosilicon compounds with four Si atoms, all of which are nonpolar, and which have two or more reactive vinyl groups as crosslinking agents is novel.

[0030] Furthermore, some organosilicon compounds with specific structures that have four nonpolar atoms bonded to Si and have more than two reactive vinyl groups are novel compounds.

[0031] Specifically, a polyfunctional organosilicon compound containing three or four reactive functional groups with vinylphenyl groups, all of which are nonpolar atoms bonded to Si, is novel as a compound.

[0032] The present invention was made in view of the above circumstances, and its object is to provide a novel organosilicon compound suitable for use as a crosslinking agent, etc.

[0033] Another object of the present invention is to provide a dielectric loss factor (D) suitable for use in curable compositions and capable of effectively reducing dielectric loss under high-frequency conditions. fNovel crosslinking agents for (semi)cured products with sufficiently low coefficient of thermal expansion (CTE) and sufficiently high glass transition temperature (Tg), and curable compositions using the crosslinking agents.

[0034] The novel organosilicon compounds and novel crosslinking agents of the present invention are suitable for use in curable compositions for applications such as prepregs, metal-coated laminates and wiring boards, and can also be used for any other purpose.

[0035] The present invention provides the following novel organosilicon compounds, novel crosslinking agents, curable compositions, prepregs, laminates, metal-clad laminates, and wiring substrates.

[0036] [1] Organosilicon compounds represented by the following formula (1TQ).

[0037] [2] The crosslinking agent represented by the following formula (1TQ).

[0038]

[0039] (In the above formula, M is a single bond or an alkylene group with 1 to 20 carbon atoms that may have substituents. The benzene ring may have substituents. The substitution positions of vinyl groups on the benzene ring are arbitrary. n is an integer of 3 or 4. R is a hydrogen atom, a hydroxyl group, or an organic group. When R is an organic group, the atom bonded to Si is C.)

[0040] [3] A curable composition comprising: [2] a crosslinking agent, and a curable compound having two or more crosslinking functional groups capable of crosslinking with the crosslinking agent.

[0041] [4] A prepreg comprising: a fiber substrate, and a semi-cured or cured product of the curable composition of [3].

[0042] [5] A laminate comprising: a substrate and a curable composition layer comprising the curable composition of [3].

[0043] [6] A laminate comprising: a substrate, and a layer of (semi)cured material containing a curable composition of [3].

[0044] [7] The laminate according to [5] or [6], wherein the substrate is a resin film or a metal foil.

[0045] [8] A metal-clad laminate comprising: an insulating layer of a cured material containing [3] of a curable composition, and a metal foil.

[0046] [9] A wiring substrate comprising: an insulating layer of a cured material containing a curable composition of [3], and wiring.

[0047] According to the present invention, a novel organosilicon compound suitable for use as a crosslinking agent, etc., can be provided. According to the present invention, a dielectric loss factor (D) suitable for use in curable compositions and effectively reducing dielectric loss under high-frequency conditions can be provided. f Novel crosslinking agents for (semi)cured products with sufficiently low coefficient of thermal expansion (CTE) and sufficiently high glass transition temperature (Tg), and curable compositions using the crosslinking agents. Attached Figure Description

[0048] Figure 1 This is a cross-sectional schematic diagram of the metal-clad laminate according to the first embodiment of the invention.

[0049] Figure 2 This is a cross-sectional schematic diagram of the metal-clad laminate according to the second embodiment of the present invention.

[0050] Figure 3 This is a cross-sectional schematic diagram of a wiring board according to one embodiment of the present invention. Detailed Implementation

[0051] In this instruction manual, (semi)cured refers to both semi-cured and cured products.

[0052] Unless otherwise specified in this specification, "wiring board" includes multilayer wiring boards.

[0053] In this specification, "high-frequency region" is defined as the region with a frequency above 1 GHz.

[0054] Unless otherwise specified in this specification, "number-average molecular weight (Mn)" is the number-average molecular weight of polystyrene calculated by gel permeation chromatography (GPC).

[0055] In this manual, unless otherwise specified, the "~" sign indicating a numerical range is used to encompass the values ​​listed before and after it as the lower and upper limits.

[0056] The embodiments of the present invention will be described below.

[0057] [Novel organosilicon compounds, novel crosslinking agents]

[0058] The organosilicon compounds of the present invention are represented by the following formula (1TQ).

[0059] The organosilicon compounds of the present invention are suitable for use as crosslinking agents, etc.

[0060] The crosslinking agent of the present invention is represented by the following formula (1TQ).

[0061]

[0062] (In the above formula, M is a single bond or an alkylene group with 1 to 20 carbon atoms that may have substituents. The benzene ring may have substituents. The substitution positions of vinyl groups on the benzene ring are arbitrary. n is an integer of 3 or 4. R is a hydrogen atom, a hydroxyl group, or an organic group. When R is an organic group, the atom bonded to Si is C.)

[0063] The organosilicon compounds and crosslinking agents of the present invention can be used for any purpose and are suitable for curable compositions, prepregs, laminates, metal-clad laminates and wiring boards, etc.

[0064] [Curing composition]

[0065] The curable composition of the present invention comprises: the crosslinking agent of the present invention, and a curable compound having two or more crosslinking functional groups capable of crosslinking with the crosslinking agent.

[0066] The curable composition can be thermosetting or radioactively heated. Radioactively heated compositions are those cured by irradiation with radioactive rays such as ultraviolet light and electron beams. For applications such as metal-clad laminates and wiring boards, thermosetting compositions are preferred.

[0067] Examples of curable compounds include monomers, oligomers, and prepolymers. More than one of these can be used.

[0068] Examples of cured products of curable compounds include polyphenylene oxide (PPE) resin, bismaleimide resin, epoxy resin, fluoropolymer, polyimide resin, olefin resin, polyester resin, polystyrene resin, hydrocarbon elastomer, and benzo[a]benzene resin. Azide resins, reactive ester resins, cyanate ester resins, butadiene resins, hydrogenated or non-hydrogenated styrene-butadiene resins, vinyl resins, cycloolefin polymers, aromatic polymers, divinyl aromatic polymers, and combinations thereof.

[0069] In applications such as metal-clad laminates and wiring boards, the cured product of the curable compound preferably includes polyphenylene ether resin (PPE).

[0070] In this specification, "polyphenylene ether resin (PPE)" includes both unmodified and modified polyphenylene ether resins unless otherwise specified.

[0071] In the above applications, polyphenylene ether oligomers represented by the following formula (P) are preferred as curable compounds.

[0072]

[0073] The X at both ends of formula (P) are independently represented by formula (x1) or formula (x2). In these formulas, "*" indicates a bonding site with an oxygen atom.

[0074]

[0075] m is preferably 1 to 20, and more preferably 3 to 15.

[0076] n is preferably 1 to 20, and more preferably 3 to 15.

[0077] The (semi)cured product of the curing composition comprises the reaction product of the curing compound and the crosslinking agent of the present invention.

[0078] The number average molecular weight (Mn) of the oligomer is not particularly limited, but is preferably 1,000 to 5,000, and more preferably 1,000 to 4,000.

[0079] The curable composition preferably contains one or more polymerization initiators. Organic peroxides, azo compounds, other known polymerization initiators, and combinations thereof can be used as polymerization initiators. Specific examples include dicumyl peroxide, benzoyl peroxide, cumyl hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)-3-hexyne, di-tert-butyl peroxide, tert-butyl cumyl peroxide, α,α'-di(tert-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, di-tert-butyl peroxide, tert-butyl peroxide, 2,2-bis(tert-butylperoxy)butane, 2,2-bis(tert-butylperoxy)octane, 2,5-dimethyl-2,5-bis(benzoyl peroxide)hexane, di(trimethylsilyl)peroxide, trimethylsilyltriphenylsilyl peroxide, and azobisisobutyronitrile, etc.

[0080] Curing compositions may contain one or more additives as needed. Examples of additives include inorganic fillers (also known as fillers), compatibilizers (compatible agents), and flame retardants.

[0081] Examples of inorganic filler materials include, for example, spherical silica, metal oxides such as silica, alumina, titanium dioxide, and mica; metal hydroxides such as aluminum hydroxide and magnesium hydroxide; talc; aluminum borate; barium sulfate; and calcium carbonate. One or more of these can be used. From the viewpoint of low thermal expansion, silica, mica, and talc are preferred, and spherical silica is more preferred.

[0082] Inorganic fillers can be surface-treated with epoxy silane, vinyl silane, methacrylic silane, or amino silane silane coupling agents. There are no particular restrictions on the timing of surface treatment with silane coupling agents. Inorganic fillers that have been surface-treated with silane coupling agents can be prepared in advance, or silane coupling agents can be added during the preparation of curable compositions using a monolithic blending method.

[0083] Examples of flame retardants include, for example, halogenated flame retardants and phosphorus-based flame retardants. More than one of these can be used. Examples of halogenated flame retardants include, for example, bromine-based flame retardants such as pentabromodiphenyl ether, octabromodiphenyl ether, decabromodiphenyl ether, tetrabromobisphenol A, and hexabromocyclododecane; and chlorinated flame retardants such as chlorinated paraffin. Examples of phosphorus-based flame retardants include, for example, phosphate esters such as condensed phosphate esters and cyclic phosphate esters; phosphazene compounds such as cyclic phosphazene compounds; phosphatate-based flame retardants such as aluminum dialkylphosphonates; melamine-based flame retardants such as melamine phosphate and polymelamine polyphosphate; and phosphine oxide compounds having a diphenylphosphine oxide group.

[0084] The curable composition may contain one or more organic solvents as needed. There are no particular limitations on the organic solvents, and examples 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.

[0085] In curable compositions, the concentration of solid components and the formulation can be designed according to the intended use, etc.

[0086] In applications such as prepregs, the concentration of solid components is preferably 50-90% by mass.

[0087] [Prepreg]

[0088] The prepreg of the present invention comprises: a fiber substrate, and a (semi)cured product of the curable composition of the present invention. The (semi)cured product may contain additives such as inorganic fillers (fillers) as needed.

[0089] Prepregs can be manufactured by impregnating a curable composition into a fiber substrate and then (semi-)curing it using heat curing or the like.

[0090] There are no particular limitations on the materials used as fiber substrates, and examples include inorganic fibers such as glass fiber, silica fiber, and carbon fiber; organic fibers such as aramid fiber and polyester fiber; and combinations thereof. Glass fiber is preferred for applications such as metal-clad laminates and wiring boards. Examples of forms of glass fiber substrates include glass cloth, glass paper, and glass mats.

[0091] The curing conditions of the curing composition can be set according to the composition of the curing composition, with semi-curing conditions (conditions for incomplete curing) being preferred.

[0092] When using a curable composition containing a polyphenylene ether oligomer represented by the above formula (P), it is preferable to heat-cure by heating at 80 to 180°C for 1 to 10 minutes.

[0093] In applications such as metal-clad laminates and wiring boards, it is preferable to adjust the composition and curing conditions of the curable composition so that the resin content in the obtained prepreg is in the range of 40 to 80% by mass.

[0094] [Layered structure]

[0095] The first laminate of the present invention comprises: a substrate and a curable composition layer composed of the curable composition of the present invention described above.

[0096] The second laminate of the present invention comprises: a substrate, and a layer containing a (semi)cured product of the curable composition of the present invention described above.

[0097] In the first and second laminates of the present invention, there are no particular limitations on the substrate, and examples include resin films, metal foils and combinations thereof.

[0098] The layer containing the (semi)cured material can be a layer containing a fibrous substrate and the curable composition of the present invention.

[0099] There are no particular restrictions on the resin film used; any known resin film can be used. Examples of resins that constitute the resin film include polyimide, polyethylene terephthalate (PET), polyethylene naphthalate, cyclic olefin polymers, and polyether sulfides.

[0100] Because of its low resistance, copper foil, silver foil, gold foil, aluminum foil, and combinations thereof are preferred as metal foils, with copper foil being more preferred.

[0101] [Metal-clad laminate]

[0102] The metal-clad laminate of the present invention comprises: an insulating layer containing a cured product of the curable composition of the present invention, and a metal foil.

[0103] The insulating layer can be a cured layer containing a fibrous substrate and the curable composition of the present invention.

[0104] Due to their low resistance, copper foil, silver foil, gold foil, aluminum foil, and combinations thereof are preferred as metal foils, with copper foil being more preferred. The metal foil can be a metal foil with a metal plating on its surface. The metal foil can also be a carrier-supported metal foil comprising an extremely thin metal foil and a carrier metal foil supporting the extremely thin metal foil. The metal foil can be a metal foil for which at least one surface has undergone surface treatments such as rust prevention treatment, silane treatment, surface roughening treatment, and barrier formation treatment.

[0105] There is no particular limitation on the thickness of the metal foil, but it is preferably 0.1 to 100 μm, more preferably 0.2 to 50 μm, and particularly preferably 1.0 to 40 μm, in order to be suitable for forming conductor patterns such as wiring (also known as circuit patterns).

[0106] The metal-clad laminate can be a single-sided metal-clad laminate with metal foil on one side, or a double-sided metal-clad laminate with metal foil on both sides, preferably a double-sided metal-clad laminate.

[0107] Single-sided metal-clad laminates can be manufactured by overlapping one or more of the aforementioned prepregs with metal foils and heating and pressurizing the resulting first temporary laminate.

[0108] The double-sided metal-coated laminate can be manufactured by holding one or more of the above-mentioned prepregs with a pair of metal foils and heating and pressurizing the resulting first temporary laminate.

[0109] Metal-clad laminates that use copper foil as the metal foil are called copper clad laminates (CCL).

[0110] The insulation layer is preferably composed of a prepreg heated and pressurized form. The prepreg heated and pressurized form may contain a fiber matrix and resin, and may contain one or more additives such as inorganic fillers and flame retardants, as needed. The prepreg heated and pressurized form is also referred to as a composite matrix.

[0111] There are no particular restrictions on the heating and pressurization conditions of the first temporary laminate. For example, the preferred conditions are a temperature of 170–250°C, a pressure of 0.3–30 MPa, and a time of 3–240 minutes.

[0112] Figure 1 and Figure 2 The diagram shows cross-sectional schematics of the metal-clad laminates according to the first and second embodiments of the present invention.

[0113] Figure 1 The metal-clad laminate 1 shown is made of a prepreg heated and pressurized material, and is a single-sided metal-clad laminate (laminate) on one side of a composite substrate (layer containing cured material) 11 containing a cured material of the curable composition of the present invention, on which a metal foil (metal layer) 12 is laminated.

[0114] Figure 2 The metal-clad laminate 2 shown is made of a prepreg heated and pressurized material and is a double-sided metal-clad laminate in which metal foil (metal layer) 12 is laminated on both sides of a composite substrate (layer containing cured material) 11 containing the curable composition of the present invention.

[0115] The metal-clad laminates 1 and 2 may have layers other than those mentioned above.

[0116] The metal-clad laminates 1 and 2 may have an adhesive layer between the composite substrate (a layer containing a cured material) 11 and the metal foil (metal layer) 12 to improve their adhesion. Known materials can be used as the adhesive layer material, including epoxy resin, cyanate ester resin, acrylic resin, polyimide resin, maleimide resin, adhesive fluoropolymers, and combinations thereof. Commercially available adhesive fluoropolymers include "Fluon LM-ETFE LH-8000", "AH-5000", "AH-2000", and "EA-2000" manufactured by AGC.

[0117] The thickness of the composite substrate can be appropriately designed according to the application. From the viewpoint of preventing wire breakage on the wiring board, it is preferably 50 μm or more, more preferably 70 μm or more, and particularly preferably 100 μm or more. From the viewpoint of the flexibility, miniaturization, and lightweight of the wiring board, it is preferably 300 μm or less, more preferably 250 μm or less, and particularly preferably 200 μm or less.

[0118] [Wireline board]

[0119] The wiring substrate of the present invention comprises: an insulating layer containing a cured product of the curable composition of the present invention, and wiring.

[0120] The wiring substrate can be manufactured by forming conductor patterns (circuit patterns) such as wirings using a metal foil located on the outermost surface of the metal-clad laminate of the present invention described above. Examples of methods for forming conductor patterns such as wirings include subtractive etching methods that form wirings by etching a metal foil, and MSAP (Modified Semi-Additive Process) methods that form wirings by plating a metal foil.

[0121] Figure 3 The diagram shows a cross-sectional schematic of a wiring board according to one embodiment of the present invention. Figure 3 The wiring board 3 shown is used Figure 2 The wiring substrate shown is formed by forming a conductor pattern (circuit pattern) 22 such as wiring 22W on at least one outermost surface of the metal foil 12 of the metal-clad laminate 2 in the second embodiment.

[0122] The wiring substrate 3 is made of a prepreg heated and pressurized material, and at least one side of the composite substrate (layer containing the cured material, insulating layer) 11 containing the curable composition of the present invention has a conductor pattern (circuit pattern) 22 such as wiring 22W.

[0123] Alternatively, one or more prepregs can be overlapped on the obtained wiring board, sandwiched between a pair of metal foils, and the resulting second temporary laminate can be heated and pressurized. The outermost metal foil is used to form conductor patterns such as wiring, thereby manufacturing a multilayer wiring board (also known as a multilayer printed wiring board). The outermost metal foil can be disposed only on one side of the second temporary laminate.

[0124] The wiring board of the present invention is suitable for use in high-frequency regions (regions with frequencies above 1 GHz).

[0125] In recent years, communication speeds and capacities have been increasing in applications such as portable electronic devices, leading to a continuous development in high-frequency signals. For wiring boards used in these applications, there is a requirement to reduce transmission loss in the high-frequency region. Therefore, the resin contained in the composite substrate of wiring boards used in these applications needs to have reduced dielectric loss in the high-frequency region. Generally, the dielectric loss factor (D) is... f The dielectric loss factor (D) depends on the frequency; for the same material, there is a higher dielectric loss factor (D) at higher frequencies. f The trend is towards a larger dielectric loss factor (D) in the composite substrate. The preferred composite substrate contains resins with a dielectric loss factor (D) under high-frequency conditions. f () is relatively low.

[0126] If the difference in coefficients of thermal expansion (CTE) between the prepreg or composite substrate and the metal foil is large, heating and pressurizing the first temporary laminate containing the prepreg and metal foil, or the second temporary laminate containing the composite substrate, prepreg, and metal foil, may cause misalignment or peeling of the metal foil. Preferably, the difference in CTE between the prepreg or composite substrate and the metal foil is small. Generally, the CTE of the resin is greater than that of the metal foil; therefore, it is preferable that the prepreg and composite substrate have smaller CTEs.

[0127] Wiring boards are sometimes used in high-temperature environments. To ensure the reliability of the wiring board under these conditions, it is preferable that the resin contained in the prepreg and composite substrate has a sufficiently high glass transition temperature (Tg).

[0128] The organosilicon compound and crosslinking agent of the present invention are different from the silane coupling agent used in Patent Document 1 listed in the [Background Art] section. All four atoms bonded to Si are nonpolar atoms (specifically hydrogen atoms or carbon atoms).

[0129] The inventors conducted research and found that when the organosilicon compound of the present invention is added to a curable composition, the organosilicon compound functions as a crosslinking agent for crosslinking curable compounds having two or more crosslinking functional groups, and can effectively reduce the dielectric loss factor (D) of the (semi-)cured product of the curable composition. f ).

[0130] It has also been found that the (semi)cured products of curable compositions containing the organosilicon compounds of the present invention have sufficiently low coefficients of thermal expansion (CTE) and sufficiently high glass transition temperatures (Tg).

[0131] It has also been found that the (semi)cured products of curable compositions containing the organosilicon compounds of the present invention exhibit good practical adhesion to metals such as copper foil.

[0132] By adding the organosilicon compound of the present invention as a crosslinking agent to the curable composition, a dielectric loss factor (D) under high frequency conditions can be obtained. f This is a semi-cured material that effectively reduces thermal expansion, has a sufficiently low coefficient of thermal expansion (CTE), and a sufficiently high glass transition temperature (Tg). This semi-cured material is suitable for use as a composite substrate and insulating layer in wiring boards for high-frequency applications.

[0133] The dielectric loss factor (D) under high-frequency conditions of the (semi)cured product of the curable composition of the present invention and the composite substrate containing the (semi)cured product is preferred. f For example, within the following range.

[0134] Preferred dielectric loss factor (D) at 10 GHz f The value is relatively small, preferably 0.01 or less, more preferably 0.005 or less, and particularly preferably 0.003 or less. There is no particular limitation on the lower limit value, for example, it is 0.0001.

[0135] The coefficient of thermal expansion (CTE) of the (semi)cured product of the curable composition of the present invention and the composite substrate containing the (semi)cured product is preferably within the following range, for example.

[0136] The coefficient of thermal expansion (CTE) is preferably low, preferably below 70 ppm / ℃, and more preferably below 60 ppm / ℃. There is no particular limitation on the lower limit, for example, 1 ppm / ℃.

[0137] The glass transition temperature (Tg) of the (semi)cured product of the curable composition of the present invention is preferably 150°C or higher, more preferably 180°C or higher, and particularly preferably 200°C or higher. There is no particular upper limit, for example, 300°C.

[0138] Dielectric loss factor (D) f The coefficient of thermal expansion (CTE) and glass transition temperature (Tg) can be determined using the methods described in the [Examples] section below.

[0139] In the organosilicon compound of the present invention represented by formula (1TQ), the benzene ring may have substituents. Examples of substituents that may be present on the benzene ring include alkyl and aryl groups having 1 to 18 carbon atoms; from the viewpoint of availability of raw materials, methyl, ethyl, propyl, butyl, hexyl, octyl, phenyl, and tolyl are preferred. The benzene ring preferably does not have substituents.

[0140] In the organosilicon compound of the present invention represented by formula (1TQ), the substitution positions for the vinyl group on the benzene ring can be ortho, meta, or para, any of which may be used. The substitution positions can be ortho or para. From the viewpoint of less steric hindrance during crosslinking reactions, easier availability of starting materials, and easier synthesis, the substitution position can be para.

[0141] In the organosilicon compound of the present invention represented by formula (1TQ), the number of reactive functional groups (also simply referred to as the number of functional groups) n is 3 or 4.

[0142] It is believed that the more functional groups n there are, the higher the crosslinking density of the curable composition and the faster the curing speed.

[0143] The inventors conducted research and found that when the number of functional groups n is 3 or 4, compared with the number of functional groups n is 2, the dielectric loss factor (D) of the (semi-)cured product of the curable composition can be effectively reduced. f ).

[0144] If the number of functional groups (n) is large, the curing speed may be too fast, leaving unreacted reactive functional groups in the cured composition. Enabling the crosslinking reaction of the cured composition to proceed effectively before curing can suppress the residual unreacted reactive functional groups after curing, thus preventing the dielectric loss factor (D) from being affected. f Considering the added perspective, the number of functional groups n is more preferably 3.

[0145] It should be noted that when the number of functional groups n is 3 or 4, preferably 3, the dielectric loss factor (D) of the (semi-)cured product of the curable composition can be reduced more effectively under high-frequency conditions. f The reasons for this are not yet clear, and the above description includes the conjectures of the inventors.

[0146] In the organosilicon compound of the present invention represented by formula (1TQ), R is a hydrogen atom, a hydroxyl group, or an organic group, preferably an alkyl group with 1 to 18 carbon atoms that may have substituents. This allows for a more effective reduction of the dielectric loss factor (D) of the (semi-)cured product of the curable composition under high-frequency conditions. f Therefore, it is preferable that R does not contain polar atoms such as oxygen (O). R is preferably an alkyl group with 1 to 18 carbon atoms without substituents. More preferably, it is a straight-chain alkyl group with 1 to 18 carbon atoms.

[0147] When R has a high number of carbon atoms, the polarity of the cross-linking structure decreases, which can more effectively reduce the dielectric loss factor (D) of the (semi-)cured product of the curable composition under high-frequency conditions. f Therefore, it is preferred. From the viewpoint of ease of synthesis, the upper limit for the number of carbon atoms is 18. The dielectric loss factor (D) of the (semi-)cured product of the curable composition under high-frequency conditions is... f From the perspective of reducing the carbon content and ease of synthesis, the number of carbon atoms in R is more preferably 3 to 18, and particularly preferably 8 to 18.

[0148] In the organosilicon compounds of the present invention represented by formula (1TQ), M is a single bond or an alkylene group having 1 to 20 carbon atoms that may have substituents. From the viewpoint of ease of synthesis, the upper limit for the number of carbon atoms is 20. From the viewpoint of ease of synthesis of organosilicon compounds, M is preferably a single bond or an alkylene group having 1 to 4 carbon atoms, more preferably a single bond or a methylene group.

[0149] The organosilicon compound of the present invention, represented by formula (1TQ), can be synthesized using known synthetic methods. For specific synthetic examples, please refer to the section on [Examples].

[0150] As explained above, according to the present invention, a novel organosilicon compound suitable for use as a crosslinking agent, etc., can be provided. According to the present invention, a dielectric loss factor (D) suitable for use in curable compositions and capable of obtaining high-frequency conditions can be provided. f Novel crosslinking agents that effectively reduce (semi)cured materials with sufficiently low coefficient of thermal expansion (CTE) and sufficiently high glass transition temperature (Tg), and curable compositions using the crosslinking agent.

[0151] The novel organosilicon compounds and novel crosslinking agents of the present invention are suitable for use in curable compositions for applications such as prepregs, metal-coated laminates and wiring boards, and can be used for any purpose.

[0152] [use]

[0153] The novel organosilicon compounds of this invention are suitable for use as crosslinking agents, etc.

[0154] The crosslinking agent of the present invention is suitable for curable compositions containing curable compounds such as monomers, oligomers and prepolymers.

[0155] The novel organosilicon compounds and novel crosslinking agents of the present invention are suitable for use in curable compositions in applications such as prepregs, metal-clad laminates and wiring boards.

[0156] Curable compositions containing the crosslinking agent of the present invention are suitable for use in applications such as prepregs, metal-clad laminates, and wiring boards.

[0157] The metal-clad laminate of the present invention is suitable for wiring boards used in various electrical equipment and electronic instruments.

[0158] The wiring board of the present invention is suitable for portable electronic devices such as mobile phones, smartphones, portable information terminals and laptops; antennas for mobile phone base stations and automobiles; electronic devices such as servers, routers and baseboards; wireless infrastructure; radar for collision avoidance; and various sensors (such as automotive sensors such as engine management sensors).

[0159] The wiring board of the present invention is particularly suitable for applications using high-frequency signals for communication, and is suitable for various applications requiring reduced transmission loss in the high-frequency region.

[0160] Example

[0161] The following examples illustrate the invention in detail, but the invention is not limited thereto. Examples 1-6 and 101 are embodiments, and Examples 21, 31, and 32 are comparative examples. Unless otherwise specified, the room temperature is approximately 25°C.

[0162] [Commercially available reagents]

[0163] In the [Examples] section, unless otherwise specified, commercially available products are used directly in the reaction for catalysts and reagents. Commercially available products that have been dehydrated and deoxygenated are used as solvents.

[0164] [Evaluation Items and Methods for Organosilicon Compounds]

[0165] (structure)

[0166] The structures of the synthesized organosilicon compounds were determined using a nuclear magnetic resonance (NMR) apparatus (JNM-AL300, manufactured by Nippon Electron Ltd.). 1 Identification was performed using H-NMR spectroscopy.

[0167] (Molecular weight)

[0168] The molecular weights of the synthesized organosilicon compounds were determined using an electron impaction method with a gas chromatograph (GC-HRMS) (Agilent "7890A" / JEOL "JMS-T200 AccuTOF GCx-plus").

[0169] [Method for preparing evaluation samples (film-like cured products)]

[0170] As curable compounds, the following two types of polyphenylene ether oligomers are prepared.

[0171] (SA9000) 2-functional methacrylic acid modified PPE (SABIC Corporation "SA9000"), (OPE-2st) 2-functional chloromethyl styrene modified PPE (Mitsubishi Gas Chemical Co., Ltd. "OPE-2st").

[0172] SA9000 and OPE-2st are represented by the following formula.

[0173]

[0174] A toluene solution (curing composition) was prepared by mixing the above-mentioned difunctional methacrylic acid modified PPE (SA9000) or difunctional chloromethyl styrene modified PPE (OPE-2st), the organosilicon compounds synthesized or prepared in each example, dicumyl peroxide as a free radical polymerization initiator, and toluene in a mass ratio of 7:3:0.1:7 and stirring at room temperature.

[0175] Next, the toluene solution was applied to a 125 μm thick polyimide film using a coating applicator (manufactured by YOSHIMITSU SEIKI) to form a 250 μm thick coating film.

[0176] In an oven, under air atmosphere, the coating was heated and dried at 80°C for 30 minutes, followed by heating at 200°C for 2 hours under nitrogen atmosphere, thereby thermally curing the coating film (thermal crosslinking reaction) to obtain an evaluation sample (cured film) with a thickness of approximately 100 μm. The obtained evaluation sample was evaluated as follows.

[0177] [Evaluation Items and Methods for Film-like Cured Materials]

[0178] (relative permittivity (D) k ) and dielectric loss factor (D f ))

[0179] At room temperature, the relative permittivity (Di) of the evaluation sample (film-like cured material) at 10 GHz was determined using a vector network analyzer (Agilent Technologies E8361C) and the SPDR method. k ) and dielectric loss factor (D f ) to be measured.

[0180] (Glass transition temperature Tg)

[0181] The dynamic viscoelasticity (DMA) of the evaluation samples (film-like cured material) was measured using a dynamic viscoelasticity measuring apparatus (IT Measurement Control Co., Ltd. "DVA-200"), and the glass transition temperature (Tg) (°C) was determined. The measurement was performed at a frequency of 10 Hz, a heating rate of 2°C / min, and a temperature range of 25–300°C.

[0182] (Coefficient of thermal expansion (CTE))

[0183] The coefficient of thermal expansion (CTE) of evaluation samples (cured film) below the glass transition temperature (Tg) was determined using a thermomechanical analysis apparatus (TMA / SS7100, manufactured by Seiko Electronics Nanotechnology Co., Ltd.). The determination was performed at a heating rate of 5°C / min and a temperature range of -50 to 340°C.

[0184] [Example 1] Synthesis of methyltris(4-vinylphenyl)silane (C1-T-p-St-Si)

[0185] <Synthesis of Tris(4-formylphenyl)methylsilane>

[0186] Under a nitrogen atmosphere, 24.0 g (102 mmol) of 4-bromobenzaldehyde dimethyl acetal and 300 mL of tetrahydrofuran were added to a 500 mL four-necked flask. The solution was cooled to below -70 °C, and an n-BuLi / n-hexane solution (2.6 mol / L, 39 mL, 100 mmol) was added dropwise over 1 hour, while the reaction solution was stirred at below -70 °C for 2 hours. Trichloro(methyl)silane (3.17 mL, 27.1 mmol) was added dropwise to the resulting suspension over 40 minutes, and the mixture was stirred at the same temperature for 2 hours. The flask was then heated to room temperature and stirred for at least 12 hours. The reaction mixture was quenched with hydrochloric acid (2 mol / L, 120 mL), and 100 mL of diethyl ether was added for extraction to separate the organic phase. Further extraction of the organic phase was performed by adding 100 mL of diethyl ether to the aqueous phase. The organic phases obtained from these extractions were combined. The combined organic phases were washed with saturated brine (100 mL), dried over magnesium sulfate, filtered, and the filtrate was concentrated under vacuum to obtain a crude mixture of acetal / aldehyde. Tetrahydrofuran (100 mL) and hydrochloric acid (2 mol / L, 100 mL) were added to the crude mixture, and the mixture was heated under reflux for 2 hours. After cooling to room temperature, a saturated sodium bicarbonate aqueous solution (400 mL) was added dropwise to the reaction solution. Diethyl ether (100 mL) was added to the reaction solution, and the organic phases were extracted three times. The organic phases obtained from these extractions were combined. The combined organic phases were washed with saturated brine (100 mL), dried over magnesium sulfate, filtered, and the filtrate was concentrated under vacuum to obtain a crude product (yellow oil). The crude product was purified by silica gel column chromatography (mobile phase: ethyl acetate / n-hexane = 1:4 (v / v)) to obtain 9.95 g of tris(4-formylphenyl)methylsilane as a colorless liquid (yield: 98%, purity: 96%).

[0187] The reaction scheme and NMR analysis results are as follows.

[0188]

[0189] 1 H-NMR (CDCl3): δ (ppm) 10.06 (s, 3H, CHO), 7.89 (d, 6H, J=7.68Hz, Ar-H), 7.67 (d, 6H, J=7.68Hz, Ar-H), 0.97 (s, 3H, Si-CH3).

[0190] <Synthesis of Methyltris(4-vinylphenyl)silane>

[0191] Methyltriphenyl bromide was added to a 500 mL four-necked flask under a nitrogen atmosphere. (27.5 g, 77.0 mmol) and tetrahydrofuran (128 mL). The flask was cooled to 0 °C, and potassium tert-butoxide (9.74 g, 86.8 mmol) was added to the suspension. The reaction mixture was stirred at the same temperature as above for at least 5 minutes. A solution of tris(4-formylphenyl)methylsilane (8.00 g, 21.4 mmol) in tetrahydrofuran (128 mL) was added dropwise to the reaction mixture over 20 minutes. The flask was heated to room temperature and stirred for 2 hours. After adding 4-tert-butylcatechol (0.60 mg) to the reaction mixture, it was concentrated under reduced pressure at 30 °C. Water (200 mL) and diethyl ether (200 mL) were added to the resulting mixture for extraction to separate the organic phase. Diethyl ether (200 mL) was added to the aqueous phase for further extraction to separate the organic phase. The organic phases obtained from these extractions were combined. The combined organic phases were dried over magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure to give a crude mixture. Add n-hexane (160 mL) and diethyl ether (40 mL) to the crude mixture and stir for 30 minutes. Filter the mixture using filter paper and concentrate the filtrate under reduced pressure to obtain a crude product (yellow oil). Purify the crude product by silica gel column chromatography (mobile phase: n-hexane) to give 6.41 g of methyltris(4-vinylphenyl)silane (C1-T-p-St-Si) as a colorless liquid (yield: 85%).

[0192] The reaction scheme, NMR analysis results, and HRMS analysis results are as follows.

[0193]

[0194] 1H-NMR (CDCl3): δ (ppm) 7.47 (d, 6H, J=7.68Hz, Ar-H), 7.39 (d, 6H, J=7.68 Hz, Ar-H), 6.72 (dd, 3H, J=11.1, 17.9Hz, -CH=CH2), 5.78 (d, 3H, J=17.9Hz, -CH=CH2), 5.27 (d, 3H, J=11.1Hz, -CH=CH2), 0.81 (s, 3H, Si-CH3).

[0195] HRMS (EI): m / z Calcd for C 25 H 24 Si:(M ＋ ) 352.165, found 352.162.

[0196] [Example 2] Synthesis of dodecyltris(4-vinylphenyl)silane (C12-T-p-St-Si)

[0197] <Synthesis of dodecyltris(4-formylphenyl)silane>

[0198] 24.0 g (102 mmol) of 4-bromobenzaldehyde dimethyl acetal and 300 mL of tetrahydrofuran were added to a 500 mL four-necked flask under a nitrogen atmosphere. The solution was cooled to below -66 °C, and an n-BuLi / n-hexane solution (2.6 mol / L, 39 mL, 100 mmol) was added dropwise over 1 hour. The reaction solution was stirred at below -70 °C for 2 hours. Dodecyltrichlorosilane (8.08 mL, 27.2 mmol) was added dropwise over 40 minutes, and the mixture was stirred at the same temperature for 2 hours. The flask was heated to room temperature and stirred for at least 12 hours. The reaction mixture was quenched with hydrochloric acid (2 mol / L, 120 mL), and ether (100 mL) was added for extraction to separate the organic phase. Further extraction of the organic phase was performed by adding ether (100 mL) to the aqueous phase. The organic phases obtained from these extractions were combined. The combined organic phases were washed with saturated brine (100 mL), dried over magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography (mobile phase: chloroform / n-hexane = 1:1 (volume ratio)) to obtain 9.53 g of dodecyltris(4-formylphenyl)silane as a colorless liquid (yield: 68%).

[0199] The reaction scheme and NMR analysis results are as follows.

[0200]

[0201] 1H-NMR (CDCl3): δ (ppm) 10.06 (s, 3H, CHO), 7.89 (d, 6H, J=8.54Hz, Ar-H), 7.67 (d, 6H, J=8.54Hz, Ar-H), 1.47~1.39 (m, 6H, -CH2-), 1.23 (brs, 16H, -CH2-), 0.87 (t, 3H, J=6.83 Hz, Si-CH3).

[0202] <Synthesis of dodecyltris(4-vinylphenyl)silane>

[0203] Methyltriphenyl bromide was added to a 500 mL four-necked flask under a nitrogen atmosphere. (21.3 g, 59.6 mmol) and tetrahydrofuran (136 mL). The flask was cooled to 0 °C, and potassium tert-butoxide (7.53 g, 67.1 mmol) was added to the suspension. The reaction mixture was stirred at the same temperature as above for at least 5 minutes. A solution of tetrahydrofuran (136 mL) of dodecyltris(4-formylphenyl)silane (8.50 g, 16.6 mmol) was added dropwise to the reaction mixture over 20 minutes. The flask was heated to room temperature and stirred for 1 hour. After adding 4-tert-butylcatechol (2.55 mg) to the reaction mixture, it was concentrated under reduced pressure at 30 °C. Water (200 mL) and diethyl ether (200 mL) were added to the resulting mixture for extraction to separate the organic phase. Diethyl ether (200 mL) was added to the aqueous phase for further extraction to separate the organic phase. The organic phases obtained from these extractions were combined. The combined organic phases were dried over magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure to give a crude mixture. Add n-hexane (160 mL) and diethyl ether (40 mL) to the crude mixture and stir for 30 minutes. Filter the mixture using filter paper and concentrate the filtrate under reduced pressure to obtain a crude product (yellow oil). Purify the crude product by silica gel column chromatography (mobile phase: n-hexane) to obtain 4.73 g of dodecyltris(4-vinylphenyl)silane (C12-T-p-St-Si) as a pale yellow liquid (yield: 56%).

[0204] The reaction scheme, NMR analysis results, and HRMS analysis results are as follows.

[0205]

[0206] 1H-NMR (CDCl3): δ (ppm) 7.47 (d, 6H, J=7.68Hz, Ar-H), 7.39 (d, 6H, J=8.54Hz, Ar-H), 6.72 (dd, 3H, J=10.7, 17.5Hz, -CH=CH2), 5.79 (d, 3H, J=17.9Hz, -CH=CH2), 5.27 (d, 3H, J=11.1Hz, -CH=CH2), 1.49~1.22 (m, 22H, -CH2-), 0.86 (t, 3H, J=6.40Hz, CH3).

[0207] HRMS (EI): m / z Calcd for C 36 H 46 Si:(M ＋ 506.337, found 506.331.

[0208] [Example 3] Synthesis of dodecyltris(3-vinylphenyl)silane (C12-T-m-St-Si)

[0209] <Synthesis of dodecyltris(3-formylphenyl)silane>

[0210] 3-Bromobenzaldehyde diethyl acetal (24.0 g, 90.8 mmol) and tetrahydrofuran (300 mL) were added to a 500 mL four-necked flask under a nitrogen atmosphere. The solution was cooled to below -65 °C, and an n-BuLi / n-hexane solution (2.6 mol / L, 35 mL, 91 mmol) was added dropwise over 1 hour. The reaction solution was stirred at below -70 °C for 2 hours. Dodecyltrichlorosilane (7.20 mL, 24.2 mmol) was added dropwise over 40 minutes, and the mixture was stirred at the same temperature for 2 hours. The flask was heated to room temperature and stirred for at least 12 hours. The reaction mixture was quenched with hydrochloric acid (2 mol / L, 120 mL), stirred at room temperature for 1 hour, and the organic phase was separated. The organic phase was further extracted twice by adding ethyl acetate (100 mL) to the aqueous phase. The organic phases obtained from these extractions were combined. The combined organic phases were washed with saturated brine (100 mL), dried over magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography (mobile phase: chloroform / n-hexane = 1:1 (volume ratio)) to obtain 10.5 g of dodecyltris(3-formylphenyl)silane as a colorless liquid (yield: 85%).

[0211] The reaction scheme and NMR analysis results are as follows.

[0212]

[0213] 1 H-NMR (CDCl3): δ (ppm) 10.01 (s, 3H, CHO), 8.00 (brs, 3H, s, Ar-H), 7.97 (td, 3H, J=7.68, 1.71 Hz, Ar-H), 7.76 (d, 3H, J=7.68Hz, Ar-H), 7.58 (t, 3H, J=7.68Hz, Ar-H), 1.56~1.33 (m, 6H, -CH2-), 1.22 (brs, 16H, -CH2-), 0.87 (t, 3H, J=6.83 Hz, CH3).

[0214] <Synthesis of dodecyltris(3-vinylphenyl)silane>

[0215] Methyltriphenyl bromide was added to a 500 mL four-necked flask under a nitrogen atmosphere. (22.6 g, 63.3 mmol) and tetrahydrofuran (144 mL). The flask was cooled to 0 °C, and potassium tert-butoxide (7.98 g, 71.1 mmol) was added to the suspension. The reaction mixture was stirred at the same temperature as above for at least 5 minutes. A solution of tetrahydrofuran (144 mL) of dodecyltris(3-formylphenyl)silane (9.00 g, 17.6 mmol) was added dropwise to the reaction mixture over 20 minutes. The flask was heated to room temperature and stirred for 1 hour. 4-tert-butylcatechol (2.55 mg) was added to the reaction mixture, and the mixture was concentrated under reduced pressure at 30 °C. Water (200 mL) and diethyl ether (200 mL) were added to the resulting mixture for extraction to separate the organic phase. Further, diethyl ether (200 mL) was added to the aqueous phase for extraction to separate the organic phase. The organic phases obtained from these extractions were combined. The combined organic phases were dried over magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure to give a crude mixture. Add n-hexane (160 mL) and diethyl ether (40 mL) to the crude mixture and stir for 30 minutes. Filter the mixture using filter paper and concentrate the filtrate under reduced pressure to obtain a crude product (red oil). Purify the crude product by silica gel column chromatography (mobile phase: n-hexane) to give 6.32 g of dodecyltris(3-vinylphenyl)silane (C12-T-m-St-Si) as a pale yellow liquid (yield: 71%).

[0216] The reaction scheme, NMR analysis results, and HRMS analysis results are as follows.

[0217]

[0218] 1H-NMR (CDCl3): δ (ppm) 7.54 (brs, 3H, Ar-H), 7.48 (d, 3H, J=6.83Hz, Ar-H), 7.40 (d, 3H, J= 6.83Hz, Ar-H), 7.32 (t, 3H, J=6.83Hz, Ar-H), 6.69 (dd, 3H, J=11.10, 17.93Hz, -CH=CH2), 5.69 (d, 3H, J = 17.93Hz, -CH = CH2), 5.21 (d, 3H, J = 11.10Hz, -CH = CH2), 1.52-1.42 (m, 2H, - CH2-), 1.42-1.32 (m, 4H, -CH2-), 1.32-1.11 (m, 16H, -CH2-), 0.87 (t, 3H, J=6.83Hz, CH3).

[0219] HRMS (EI): m / z Calcd for C 36 H 46 Si:(M ＋ 506.337, found 506.329.

[0220] [Example 4] Synthesis of dodecyltris(4-vinylbenzyl)silane (C12-T-p-Bn-Si)

[0221] Magnesium (cut flakes, 0.898 g, 36.9 mmol) and diethyl ether (21.1 mL) were added to a 50 mL four-necked flask under a nitrogen atmosphere and cooled in an ice bath. A solution of 4-(chloromethyl)styrene (5.12 g, 33.5 mmol) in diethyl ether (10.5 mL) was added dropwise over 1 hour. After stirring for 1 hour at the same temperature as above, dodecyltrichlorosilane (3.33 mL, 11.2 mmol) was added dropwise over 20 minutes. The flask was heated to room temperature and stirred for at least 12 hours. Water (15 mL) was added to the reaction mixture and stirred for at least 10 minutes to separate the organic phase. Diethyl ether (30 mL) was added to the aqueous phase for two more extractions to separate the organic phase. The organic phases obtained from these extractions were combined. The combined organic phases were dried over magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography (mobile phase: n-hexane) to obtain 1.09 g of dodecyltris(4-vinylbenzyl)silane (C12-T-p-Bn-Si) as a pale yellow liquid (yield: 18%).

[0222] The reaction scheme, NMR analysis results, and HRMS analysis results are as follows.

[0223]

[0224] 1H-NMR (CDCl3): δ (ppm) 7.26 (d, 6H, J=7.68Hz, Ar-H), 6.91 (d, 6H, J=8.54Hz, Ar-H), 6.68 (dd, 3H, J=11.1, 17.9Hz, -CH=CH2), 5.68 (d, 3H, J=17.9Hz, -C H=CH2), 5.17 (d, 3H, J=10.2Hz, -CH=CH2), 2.09 (s, 6H, Si-CH2-Ar), 1.38-1.08 (m, 20H, -CH2-), 0.88 (t, 3H, J=6.40Hz, CH3), 0.53-0.38 (m, 2H, -CH2-).

[0225] HRMS (EI): m / z Calcd for C 39 H 52 Si:(M ＋ 548.384, found 548.374.

[0226] [Example 5] Synthesis of a mixture of dodecyltris(vinylbenzyl)silane isomers (C12-T-mp-Bn-Si)

[0227] Magnesium (cut flakes, 0.898 g, 36.9 mmol) and diethyl ether (21.1 mL) were added to a 50 mL four-necked flask under a nitrogen atmosphere and cooled in an ice bath. A solution of 4-(chloromethyl)styrene / 3-(chloromethyl)styrene mixture (1:1 molar ratio, 5.12 g, 33.5 mmol) in diethyl ether (10.5 mL) was added dropwise over 1 hour. After stirring for 1 hour at the same temperature as above, dodecyltrichlorosilane (3.33 mL, 11.2 mmol) was added dropwise over 20 minutes. The flask was heated to room temperature and stirred for at least 12 hours. Water (15 mL) was added to the reaction mixture and stirred for at least 10 minutes to separate the organic phase. Diethyl ether (30 mL) was added to the aqueous phase for two further extractions of the separated organic phases. The organic phases obtained from these extractions were combined. The combined organic phases were dried over magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography (mobile phase: n-hexane) to obtain 0.319 g of a mixture of dodecyltris(vinylbenzyl)silane isomers (C12-T-mp-Bn-Si) as a colorless liquid (yield: 5.2%). Based on NMR analysis, the molar ratio of 3-vinylbenzyl to 4-vinylbenzyl groups in the isomer mixture was calculated to be 1.4:1.6.

[0228] The reaction scheme, NMR analysis results, and HRMS analysis results are as follows.

[0229]

[0230] 1 H-NMR (CDCl3): δ (ppm) 7.35~6.81 (m, 12H, Ar-H), 6.74~6.55 (m, 3H, H-5, -CH=CH2), 5.68 (d, 3H, J=17.1Hz, -CH=CH2), 5.20 (d, 1.36H, J=10.2Hz, -CH=CH 2， m-body), 5.17 (d, 1.64H, J = 11.1Hz, -CH = CH 2， o-body), 2.10 (s, 6H, Si-CH2-Ar), 1.38-1.06 (m, 20H, -CH2-), 0.88 (t, 3H, J=6.83Hz, CH3), 0.56-0.39 (m, 2H, -CH2-).

[0231] HRMS (EI): m / z Calcd for C 39 H 52 Si:(M ＋ 548.384, found 548.376.

[0232] [Example 6] Synthesis of tetra(4-vinylphenyl)silane (C1-Q-p-St-Si)

[0233] <Synthesis of tetra(4-formylphenyl)silane>

[0234] 12.0 g (50.9 mmol) of 4-bromobenzaldehyde dimethyl acetal and 150 mL of tetrahydrofuran were added to a 300 mL four-necked flask under a nitrogen atmosphere. The solution was cooled to below -65 °C, and an n-BuLi / n-hexane solution (2.6 mol / L, 20 mL, 52 mmol) was added dropwise over 1 hour. The reaction solution was stirred at below -68 °C for 2 hours. Tetrachlorosilane (1.14 mL, 9.81 mmol) was added dropwise to the resulting suspension over 30 minutes, and the mixture was stirred at the same temperature for 2 hours. The flask was then heated to room temperature and stirred for at least 12 hours. The reaction mixture was quenched with hydrochloric acid (2 mol / L, 60 mL), and ether (50 mL) was added for extraction to separate the organic phase. Ether (50 mL) was added to the aqueous phase for two more extractions to separate the organic phase. The organic phases obtained from these extractions were combined. The combined organic phases were washed with saturated brine (50 mL), dried over magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain a crude mixture of acetal / aldehyde. Tetrahydrofuran (50 mL) and hydrochloric acid (2 mol / L, 50 mL) were added to the crude mixture, and the mixture was heated under reflux for 2 hours. After cooling to room temperature, a saturated sodium bicarbonate aqueous solution (100 mL) was added dropwise to the reaction solution. Diethyl ether (50 mL) was added to the reaction solution, and the organic phases were extracted three times. The organic phases obtained from these extractions were combined. The combined organic phases were washed with saturated brine (50 mL), dried over magnesium sulfate, filtered, and the filtrate was concentrated under vacuum to obtain a crude product (pale yellow oil). An ethyl acetate / n-hexane mixture (1:3, v / v, 40 mL) was added to the crude product, and the mixture was heated under reflux and slowly cooled to 0°C. The suspension was filtered, and the resulting solid was dried under reduced pressure to obtain 2.25 g of tetra(4-formylphenyl)silane (yield: 51%).

[0235] The reaction scheme and NMR analysis results are as follows.

[0236]

[0237] 1 H-NMR (CDCl3): δ (ppm) 10.09 (s, 4H, CHO), 7.94 (d, 8H, J=7.68Hz, Ar-H), 7.73 (d, 8H, J=8.54Hz, Ar-H).

[0238] <Synthesis of tetra(4-vinylphenyl)silane>

[0239] Methyltriphenyl bromide was added to a 100 mL four-necked flask under a nitrogen atmosphere. (8.03 g, 22.5 mmol), potassium tert-butoxide (3.03 g, 27.0 mmol), and tetrahydrofuran (34 mL). The flask was cooled to 0 °C, and the reaction mixture was stirred for at least 5 minutes. A solution of tetra(4-formylphenyl)silane (2.10 g, 4.68 mmol) in tetrahydrofuran (34 mL) was added dropwise to the reaction mixture over 10 minutes. The flask was heated to room temperature and stirred for 2 hours. The reaction mixture was concentrated under reduced pressure at 30 °C, and water (50 mL) and diethyl ether (50 mL) were added to the resulting mixture for extraction to separate the organic phase. Further extraction of the organic phase was performed by adding diethyl ether (50 mL) to the aqueous phase. The organic phases obtained from these extractions were combined. The combined organic phases were dried over magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain a crude mixture. Hexane (40 mL) and diethyl ether (10 mL) were added to the crude mixture, and the mixture was stirred for 30 minutes. The mixture was filtered using filter paper, and the filtrate was concentrated under reduced pressure to obtain a crude product. Methanol (10 mL) and 4-tert-butylcatechol (0.6 mg) were added to the crude product, and the mixture was stirred at room temperature for 30 minutes. The suspension was filtered, and the resulting solid was dried under reduced pressure to give 0.747 g of tetrakis(4-vinylphenyl)silane (C1-Q-p-St-Si) (yield: 36%).

[0240] The reaction scheme and NMR analysis results are as follows.

[0241]

[0242] 1 H-NMR (CDCl3): δ (ppm) 7.53 (d, 8H, J=7.68Hz, Ar-H), 7.41 (d, 8H, J=8.54Hz, Ar-H), 6.73 (dd, 4H , J=10.7, 17.5Hz, -CH=CH2), 5.80 (d, 4H, J=17.9Hz, -CH=CH2), 5.29 (d, 4H, J=11.1Hz, -CH=CH2).

[0243] [Example 21] Synthesis of dimethylbis(4-vinylphenyl)silane (C1-D-p-St-Si)

[0244] <Synthesis of bis(4-formylphenyl)dimethylsilane>

[0245] 24.0 g (102 mmol) of 4-bromobenzaldehyde dimethyl acetal and 300 mL of tetrahydrofuran were added to a 500 mL four-necked flask under a nitrogen atmosphere. The solution was cooled to below -65 °C, and an n-BuLi / n-hexane solution (2.6 mol / L, 39 mL, 100 mmol) was added dropwise over 1 hour. The reaction solution was stirred at below -70 °C for 2 hours. Dichlorodimethylsilane (4.93 mL, 40.7 mmol) was added dropwise over 40 minutes, and the mixture was stirred at the same temperature for 2 hours. The flask was heated to room temperature and stirred for at least 12 hours. The reaction mixture was quenched with hydrochloric acid (2 mol / L, 120 mL), and 100 mL of diethyl ether was added for extraction to separate the organic phase. The organic phases obtained from these extractions were combined. The combined organic phases were washed with saturated brine (100 mL), dried over magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain a crude mixture of acetal / aldehyde. Tetrahydrofuran (100 mL) and hydrochloric acid (2 mol / L, 100 mL) were added to the crude mixture, and the mixture was heated under reflux for 2 hours. After cooling to room temperature, saturated sodium bicarbonate aqueous solution (240 mL) was added dropwise to the reaction solution. Diethyl ether (100 mL) was added to the reaction solution, and the organic phases were extracted three times. The organic phases obtained from these extractions were combined. The combined organic phases were washed with saturated brine (100 mL), dried over magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain a crude product (pale yellow oil). An ethyl acetate / n-hexane mixture (1:7, v / v, 120 mL) was added to the crude product, and the mixture was heated under reflux and then slowly cooled to 0°C. The suspension was filtered, and the resulting solid was dried under reduced pressure to give 8.40 g of bis(4-formylphenyl)dimethylsilane (yield: 77%).

[0246] The reaction scheme and NMR analysis results are as follows.

[0247]

[0248] 1 H-NMR (CDCl3): δ (ppm) 10.03 (s, 2H, CHO), 7.86 (d, 4H, J=7.68Hz, Ar-H), 7.68 (d, 4H, J=8.54Hz, Ar-H), 0.64 (s, 6H, Si-CH3).

[0249] <Synthesis of dimethylbis(4-vinylphenyl)silane>

[0250] Methyltriphenyl bromide was added to a 500 mL four-necked flask under a nitrogen atmosphere. (25.6 g, 71.7 mmol) and tetrahydrofuran (128 mL). The flask was cooled to 0 °C, and potassium tert-butoxide (9.03 g, 80.5 mmol) was added to the suspension. The reaction mixture was stirred at the same temperature as above for at least 5 minutes. A solution of bis(4-formylphenyl)dimethylsilane (8.00 g, 29.8 mmol) in tetrahydrofuran (128 mL) was added dropwise to the reaction mixture over 20 minutes. The flask was heated to room temperature and stirred for 2 hours. After adding 4-tert-butylcatechol (0.60 mg) to the reaction mixture, it was concentrated under reduced pressure at 30 °C. Water (200 mL) and diethyl ether (200 mL) were added to the resulting mixture for extraction to separate the organic phase. Diethyl ether (200 mL) was added to the aqueous phase for further extraction to separate the organic phase. The organic phases obtained from these extractions were combined. The combined organic phases were dried over magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure to give a crude mixture. Add n-hexane (160 mL) and diethyl ether (40 mL) to the crude mixture and stir for 30 minutes. Filter the mixture using filter paper and concentrate the filtrate under reduced pressure to obtain the crude product. Purify the crude product by silica gel column chromatography (mobile phase: n-hexane) to obtain 7.27 g of dimethylbis(4-vinylphenyl)silane (C1-D-p-St-Si) as a colorless liquid (yield: 92%).

[0251] The reaction scheme, NMR analysis results, and HRMS analysis results are as follows.

[0252]

[0253] 1 H-NMR (CDCl3): δ (ppm) 7.48 (d, 4H, J = 8.54Hz, Ar-H), 7.38 (d, 4H, J = 7.68Hz, Ar-H), 6.71 (dd, 2H, J = 11.1, 1 7.9Hz, -CH=CH2), 5.77 (d, 2H, J=17.1Hz, -CH=CH2), 5.25 (d, 2H, J=10.2Hz, -CH=CH2), 0.54 (s, 6H, Si-CH3).

[0254] HRMS (EI): m / z Calcd for C 18 H 20 Si:(M ＋ )264.133, found 264.131.

[0255] [Example 31]

[0256] As a comparative organosilicon compound, we will prepare a commercially available silane coupling agent, trimethoxyvinylsilane (TMVS, a product of TCI).

[0257] [Example 32]

[0258] As a comparative organosilicon compound, we will prepare a commercially available silane coupling agent, triethoxyvinylsilane (TEVS, TCI).

[0259] [Evaluation and Results]

[0260] In Examples 1-3, 21, 31, and 32, the obtained or prepared organosilicon compounds were used to prepare evaluation samples according to the above-described method for preparing evaluation samples (film-like cured products), and the evaluations were performed. The evaluation results are shown in Tables 1-3.

[0261]

[0262] [Summary of Results]

[0263] In Examples 1 to 3, a film-like cured product was obtained by using organosilicon compounds with three or more functions (organosilicon compounds represented by formula (1TQ)).

[0264] In Example 21, a film-like cured product was obtained using a dual-functional organosilicon compound for comparison.

[0265] In Examples 31 and 32, silane coupling agents of organosilicon compounds used as comparisons were used to obtain film-like cured products.

[0266] In Examples 1-3 and 21, compared to Examples 31 and 32 which use silane coupling agents, the dielectric loss factor (D) under high-frequency conditions can be effectively reduced. f ).

[0267] Based on the comparison between Example 1 and Example 21, it can be seen that by using organosilicon compounds with more than three functionalities as crosslinking agents, the dielectric loss factor (D) under high-frequency conditions can be reduced more effectively. f ).

[0268] In Examples 1-3, the dielectric loss factor (D) under high-frequency conditions can be obtained. f Effectively reduces the coefficient of thermal expansion (CTE) of the cured film, which is sufficiently low and has a sufficiently high glass transition temperature (Tg).

[0269] [Example 101]

[0270] A curable composition (varnish) was prepared by mixing difunctional methacrylic acid modified PPE (SA9000), the organosilicon compound synthesized in Example 1, dicumyl peroxide as a free radical polymerization initiator, spherical silica as an inorganic filler, and toluene in a mass ratio of 7:3:0.1:10:10 and stirring at room temperature.

[0271] After impregnating the obtained curable composition (varnish) with glass cloth (E glass, #2116) as a fiber substrate, the mixture is heated at 130°C for 5 minutes to partially cure the curable composition, thus obtaining a prepreg.

[0272] Two pieces of prepreg are overlapped and sandwiched between a pair of copper foils. The resulting temporary laminate is heated and pressurized at 200°C for 1.5 hours and 3 MPa to produce a metal-clad laminate.

[0273] This invention is not limited to the above-described embodiments and examples. As long as the spirit of this invention is not departed, appropriate design changes can be made.

[0274] The application claims priority based on Japanese Patent Application No. 2021-094354, filed on June 4, 2021, and all its disclosures are incorporated herein by reference.

[0275] Symbol Explanation

[0276] 1, 2: Metal-clad laminate, 3: Wiring substrate, 11: Composite substrate, 12: Metal foil, 22: Conductor pattern (circuit pattern), 22W: Wiring.

Claims

1. A crosslinking agent represented by the following formula (1TQ), In the above formula (1TQ), M is a single bond or an alkylene group with 1 carbon atom. The vinyl group on the benzene ring is either unsubstituted or has methyl, ethyl, propyl, butyl or hexyl as substituents. The substitution position of the vinyl group on the benzene ring is arbitrary, n is 3, and R is an alkyl group with 1 to 18 carbon atoms.

2. The crosslinking agent according to claim 1, wherein, M stands for a single bond.

3. The crosslinking agent according to claim 1 or 2, used in a curable composition for use in the manufacture of prepregs, metal-coated laminates or wiring boards.

4. A curable composition comprising the crosslinking agent of claim 1 and a curable compound having two or more crosslinking functional groups capable of crosslinking with the crosslinking agent.

5. A prepreg comprising: a fiber substrate, and a semi-cured or cured product of the curable composition of claim 4.

6. A laminate comprising: a substrate, and a curable composition layer comprising the curable composition of claim 4.

7. A laminate comprising: a substrate, and a semi-cured layer or a cured layer, wherein the semi-cured layer contains a semi-cured product of the curable composition of claim 4, and the cured layer contains a cured product of the curable composition of claim 4.

8. The laminate according to claim 6 or 7, wherein, The substrate is a resin film or a metal foil.

9. A metal-clad laminate comprising: an insulating layer containing a cured product of the curable composition of claim 4, and a metal foil.

10. A wiring substrate comprising: an insulating layer containing a cured product of the curable composition of claim 4, and wiring.

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