Thermosetting composition, resin film, prepreg, metal-clad laminate, and printed wiring board

Abstract

The present invention provides a thermosetting composition containing an alkylsilyl peroxide and a radically polymerizable compound, the alkylsilyl peroxide being one or more compounds selected from the group consisting of compounds represented by general formula (1) and compounds represented by general formula (2). This thermosetting composition is capable of obtaining a cured product having excellent dielectric properties and excellent heat resistance. # imgabs0 # imgabs1 #

Description

Technical Field

[0001] The invention relates to a thermosetting composition, a resin film, a prepreg, a metal-clad laminate and a printed circuit board. Background Art

[0002] In recent years, with the remarkable progress of information network technology and the expansion of services that make full use of information networks, electronic devices that can increase the capacity of information and increase the processing speed are required. The increase in the capacity of information and the increase in the processing speed are further accelerated by the popularization of 5G, etc., and electronic circuit substrate materials such as printed wiring boards used in electronic equipment are required to have low dielectric constant and low dielectric loss tangent performance.

[0003] As a resin of a thermosetting composition, polyphenylene ether having excellent dielectric properties (low dielectric constant and low dielectric loss tangent) is suitable as an electronic circuit substrate material that can meet the above requirements, and thus has attracted attention. As a curing agent for polyphenylene ether, dialkyl peroxides having a tert-butyl group that decomposes at high temperatures and has high hydrogen abstraction ability are widely used (Patent Documents 1, 2).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2008 / 033612

[0007] Patent Document 2: Japanese Patent Application Publication No. 2019-172725 Summary of the invention

[0008] 1. Technical issues to be resolved

[0009] Organic peroxides having a tert-butyl group, such as di-tert-butyl peroxide isopropylbenzene, are generally used in fields requiring high crosslink density due to their high hydrogen abstraction ability. However, although the above-mentioned organic peroxide is a substance that decomposes at high temperatures among organic peroxides, it decomposes too quickly in the curing process at a high temperature of 190° C. or above, so that the curing reaction cannot be fully carried out, resulting in the inability to fully ensure the heat resistance of the cured product, and thus improvement is required.

[0010] Therefore, the technical problem to be solved by the present invention is to provide a thermosetting composition that can produce a cured product having excellent dielectric properties and excellent heat resistance.

[0011] (II) Technical solution

[0012] That is, the present invention relates to a thermosetting composition comprising an alkylsilyl peroxide and a radical polymerizable compound, wherein:

[0013] The alkylsilyl peroxide is one or more selected from the group consisting of compounds represented by the general formula (1) and compounds represented by the general formula (2),

[0014] [Chemical formula 1]

[0015]

[0016] In formula (1), R 1 , R 2 are independently an alkyl group having 1 to 6 carbon atoms or a phenyl group, R 3 is an alkyl group or a phenyl group having 4 to 6 carbon atoms,

[0017] [Chemical formula 2]

[0018]

[0019] In formula (2), R 4 It is ethylene or ethynylene.

[0020] Furthermore, the present invention relates to a resin film formed of the thermosetting composition.

[0021] Furthermore, the present invention relates to a prepreg obtained by impregnating or coating a fibrous base material with the thermosetting composition.

[0022] Furthermore, the present invention relates to a metal-clad laminate including the resin film or the prepreg and a metal foil laminated together.

[0023] Furthermore, the present invention relates to a printed wiring board obtained by removing a portion of the metal foil from the metal clad laminate.

[0024] (III) Beneficial effects

[0025] The thermosetting composition of the present invention contains an alkylsilyl peroxide having a silyl group to which a tert-butyl group and a specific substituent are bonded, and has a higher decomposition temperature and a higher hydrogen abstraction ability than a dialkyl peroxide, so that the curing process of the thermosetting composition at a high temperature can be carried out efficiently, thereby improving the heat resistance of the obtained cured product. In addition, the carbon radicals, which are low-polarity decomposition products generated by the decomposition of the alkylsilyl peroxide to which a specific substituent is bonded, can be introduced into the terminal of the resin formed by the radical polymerizable compound when the thermosetting composition is cured, thereby improving the dielectric properties of the cured product. DETAILED DESCRIPTION

[0026] <Thermosetting composition>

[0027] The thermosetting composition of the present invention contains an alkylsilyl peroxide having a silyl group to which a tert-butyl group and a specific substituent are bonded, and a radical polymerizable compound.

[0028] <Alkylsilyl peroxide>

[0029] The alkylsilyl peroxide of the present invention is one or more selected from the group consisting of compounds represented by the general formula (1) and compounds represented by the general formula (2).

[0030] [Chemical formula 3]

[0031]

[0032] In formula (1), R 1 , R 2 are independently an alkyl group having 1 to 6 carbon atoms or a phenyl group, R 3 is an alkyl group or a phenyl group having 4 to 6 carbon atoms,

[0033] [Chemical formula 4]

[0034]

[0035] In formula (2), R 4 It is ethylene or ethynylene.

[0036] In the formula (1), R 1 and R 2 Examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, neopentyl, n-hexyl, tert-hexyl (t-hexyl group), tert-hexyl (thexyl group), and phenyl.

[0037] In the formula (1), R 3 , for example, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, neopentyl, n-hexyl, tert-hexyl, tert-hexyl, phenyl and the like can be cited.

[0038] Specific examples of the alkylsilyl peroxide of the present invention are shown below, but the present invention is not limited thereto.

[0039] [Chemical formula 5]

[0040]

[0041]

[0042]

[0043] Preferred examples of the dialkyl peroxide include Compounds 1 to 12, and more preferred examples include Compounds 1, 2, 5, 6, 9, 10, 11, and 12 in view of the availability of raw materials and ease of synthesis of the alkylsilyl peroxide.

[0044] The method for producing the alkylsilyl peroxide represented by the general formula (1) is not limited in any way, and examples thereof include a method comprising a step (hereinafter also referred to as step (X)) of reacting a hydroperoxide compound represented by the general formula (3) with a chlorosilane compound represented by the general formula (4).

[0045] [Chemical formula 6]

[0046]

[0047] [Chemical formula 7]

[0048]

[0049] The method for producing the alkylsilyl peroxide represented by the general formula (2) is not limited in any way, and examples thereof include a method comprising a step (hereinafter also referred to as step (Y)) of reacting a hydroperoxide compound represented by the general formula (5) with a chlorosilane compound represented by the following general formula (6).

[0050] [Chemical formula 8]

[0051]

[0052] [Chemical formula 9]

[0053]

[0054] In the step (X) or the step (Y), the hydroperoxide compound represented by the general formula (3) or (5) and the chlorosilane compound represented by the general formula (4) or (6) may be commercially available products.

[0055] In the step (X), from the perspective of improving the yield of the target product, the hydroperoxide compound represented by the general formula (3) is preferably used in an amount of 0.8 to 5.0 mol, more preferably 1.0 to 3.0 mol, relative to 1.0 mol of the chlorosilane compound represented by the general formula (4). In addition, in the step (Y), from the perspective of improving the yield of the target product, the hydroperoxide compound represented by the general formula (5) is preferably used in an amount of 0.4 to 10.0 mol, more preferably 0.5 to 6.0 mol, relative to 1.0 mol of the chlorosilane compound represented by the general formula (6).

[0056] In the step (X) or the step (Y), it is preferred to use a base catalyst. The base catalyst is not particularly limited, and examples thereof include pyridine, dimethylaminopyridine, triethylamine, sodium hydroxide, potassium hydroxide, sodium carbonate, etc. The base catalyst may be used alone or in combination of two or more.

[0057] In the step (X) or the step (Y), the amount of the base catalyst used is not particularly limited, but from the perspective of improving the yield of the target product, it is preferably 0.1 mol to 5.0 mol, more preferably 1.0 mol to 3.0 mol, relative to 1.0 mol of the chlorosilane compound represented by the general formula (4).

[0058] In the step (X) or the step (Y), an organic solvent is preferably used. The organic solvent is not particularly limited, but is preferably an organic solvent that is inactive in the reaction system. Examples of the organic solvent include non-polar compounds such as pentane, hexane, and toluene; polar compounds such as acetone, acetonitrile, tetrahydrofuran, and ethyl acetate. The organic solvent may be used alone or in combination of two or more.

[0059] In the step (X) or the step (Y), the amount of the organic solvent used is not particularly limited, but is generally about 0.1 to 100 parts by mass relative to 1 part by mass of the chloride compound represented by the general formula (4) or the general formula (6).

[0060] From the perspective of improving the yield of the target product, the reaction temperature of the step (X) or the step (Y) is preferably above -10°C, more preferably above 0°C, and from the perspective of safety, is preferably below 60°C, more preferably below 50°C.

[0061] The reaction time of the step (X) or the step (Y) varies depending on the raw materials, reaction temperature, etc. and cannot be generalized, but from the perspective of improving the yield of the target product, it is usually preferably 0.1 hours or more, more preferably 0.5 hours or more, and preferably 5 hours or less.

[0062] The step (X) or the step (Y) may be performed in an air atmosphere at normal pressure, or may be performed in a nitrogen atmosphere or a nitrogen gas stream.

[0063] In order to remove excess raw materials or by-products, the alkylsilyl peroxide may be purified by washing with an aqueous electrolyte solution such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium sulfite, hydrogen chloride, sulfuric acid, sodium chloride, or ion exchange water after the step (X) or the step (Y).

[0064] The obtained alkylsilyl peroxide can be identified by gas chromatography (GC), liquid chromatography (LC), nuclear magnetic resonance spectroscopy (NMR), infrared spectroscopy (IR), mass spectrometry (MS) or the like.

[0065] <Radical polymerizable compounds>

[0066] There are no particular limitations on the free radical polymerizable compound as long as it can be polymerized by a heat-induced free radical polymerization reaction. Examples thereof include compounds having ethylenically unsaturated groups such as a vinyl group, an allyl group, a methacryloyl group, a styryl group, a meth(acryloyl) group, and a maleimide group. From the perspective of being able to use the above-mentioned alkylsilyl peroxide to improve the dielectric properties and heat resistance of the cured product, examples thereof include polyphenylene ether.

[0067] The polyphenylene ether is not particularly limited as long as it has a radical polymerizable double bond at a molecular terminal. The polyphenylene ether having a radical polymerizable double bond may be used alone or in combination of two or more.

[0068] Specific examples of the structural unit of the polyphenylene ether include poly(2,6-dimethyl-1,4-phenylene ether), poly(2-methyl-6-ethyl-1,4-phenylene ether), poly(2-methyl-6-phenyl-1,4-phenylene ether), poly(2,6-dichloro-1,4-phenylene ether), etc. From the perspective of excellent dielectric properties and heat resistance, poly(2,6-dimethyl-1,4-phenylene ether) is preferred. Further, as specific examples of the structural unit of the polyphenylene ether, for example, copolymers of 2,6-dimethylphenol and other phenols (e.g., 2,3,6-trimethylphenol, 2-methyl-6-butylphenol, 2-allylphenol, etc.) can be cited; polyphenylene ether copolymers obtained by coupling 2,6-dimethylphenol with biphenols or bisphenols; and polyphenylene ether having a linear or branched structure obtained by heating poly(2,6-dimethyl-1,4-phenylene ether) and a phenol compound such as bisphenols or triphenols in a toluene solvent and in the presence of an organic peroxide to perform a redistribution reaction. The phenyl group in the phenylene ether unit may have a substituent, and the polyphenylene ether may contain other structural units other than the phenylene ether unit within the range that does not hinder the technical effect of the present invention.

[0069] Examples of the radical polymerizable double bond at the molecular end include (meth)acryloyl, styryl, vinylbenzyl, vinyl, allyl, 1,3-butadienyl, etc. Among them, (meth)acryloyl and vinylbenzyl are preferred from the viewpoint of high reactivity during thermal curing and excellent dielectric constant and dielectric loss tangent of the cured product.

[0070] The number of radically polymerizable double bonds in one molecule of the polyphenylene ether having radically polymerizable double bonds at the molecular terminals is preferably 1.5 to 6 on average, more preferably 1.6 to 4 on average, and even more preferably 1.7 to 3 on average.

[0071] The number of ethylenically unsaturated double bonds in one molecule of the polyphenylene ether having a free radical polymerizable double bond at the molecular end can be measured, for example, by measuring the number of hydroxyl groups remaining in the polyphenylene ether and calculating the portion reduced from the number of hydroxyl groups of the polyphenylene ether before modification with the compound having ethylenically unsaturated double bonds. In addition, the method for measuring the number of hydroxyl groups remaining in the polyphenylene ether can be obtained by adding tetraethylammonium hydroxide to a dichloromethane solution of the polyphenylene ether based on the method described in Polymer Thesis, Vol. 51, No. 7, 480 (1994) and measuring the absorbance of the mixed solution at a wavelength of 318 nm.

[0072] Furthermore, the polyphenylene ether having a radical polymerizable double bond at a molecular terminal preferably has a structure represented by the following general formula (7).

[0073] [Chemical formula 10]

[0074]

[0075] In formula (7), X is an arbitrary linking group with a valence of a, Y is a radical polymerizable double bond at the molecular terminal, and a is 1 to 6.

[0076] In the formula (7), specific examples of X include divalent phenols such as bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4'-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, 4,4'-dihydroxy-3,3'5,5'-tetramethylbiphenyl, 4,4'-dihydroxy-2,2',3,3'5,5'-hexamethylbiphenyl, hydroquinone, and resorcinol; and trivalent or higher phenols such as tris-(4-hydroxyphenyl)methane, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, phenol novolac, o-cresol novolac, and naphthol novolac.

[0077] From the viewpoint of dielectric properties and permeability into fibrous substrates, the number average molecular weight of the polyphenylene ether having a radically polymerizable double bond at a molecular terminal is preferably 800 to 5000, more preferably 900 to 4500, and even more preferably 1000 to 3000.

[0078] The number average molecular weight may be a value measured by a conventional molecular weight determination method, and examples thereof include a polystyrene conversion value measured by gel permeation chromatography (GPC), etc. Specifically, after preparing a measurement sample having a sample concentration of 0.2 w / vol% (solvent: chloroform), HLC-8220GPC (manufactured by TOSOH CORPORATION) can be used as a measurement device, and the measurement can be performed under the following conditions, i.e., chromatographic column: Shodex GPC KF-405L HQ×3 (manufactured by Showa Denko KK); eluent: chloroform; injection volume: 20 μL; flow rate: 0.3 mL / min; chromatographic column temperature: 40° C.; detector: RI.

[0079] The synthetic method of the polyphenylene ether having a free radical polymerizable double bond at the molecular end is not particularly limited as long as it is capable of synthesizing a modified polyphenylene ether modified by a free radical polymerizable double bond. Specifically, a method of reacting a compound having an ethylenically unsaturated double bond and a chlorine atom with a polyphenylene ether before modification, etc., can be cited. As a compound having an ethylenically unsaturated double bond and a chlorine atom, for example, (meth) acryloyl chloride or vinyl benzyl chloride, etc., can be cited. In addition, the polyphenylene ether having a free radical polymerizable double bond at the molecular end can use a commercially available product, for example, product names "OPE-2St" (Mitsubishi Gas Chemical Company, Inc. manufacture), "Noryl SA9000" (SABIC Innovative Plastics manufacture), etc. can be cited.

[0080] The dialkyl peroxide may be used in any amount relative to the radical polymerizable compound. Generally, the dialkyl peroxide is preferably used in an amount of 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and most preferably 0.5 to 3 parts by mass, relative to 100 parts by mass of the radical polymerizable compound.

[0081] <Other ingredients>

[0082] The thermosetting composition of the present invention can further contain other components in appropriate combination. Other components include multifunctional monomers, solvents, organic peroxides, azo compounds, bismaleimide, polyisoprene, polybutadiene, styrene butadiene rubber, butyl rubber, ethylene propylene rubber, ethylene propylene diene rubber, styrene-butadiene-styrene block copolymers, styrene-ethylene-butylene-styrene block copolymers, ethylene-styrene-divinylbenzene copolymers, ethylene-hexene-styrene-divinylbenzene copolymers, fluororubber, silicone rubber and other elastomers, natural silica, Inorganic fillers such as fused silica, synthetic silica, amorphous silica, hollow silica, alumina, boron nitride, aluminum nitride, clay, talc and glass staple fibers, silane coupling agents such as γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-(meth)acryloxypropyltrimethoxysilane, flame retardants, polymerization inhibitors, ultraviolet absorbers, light stabilizers, metal passivators, surfactants, lubricants, thickeners, defoamers, antistatic agents, pigments, dyes, etc.

[0083] From the perspective of adjusting the viscosity of the thermosetting composition, improving the heat resistance of the cured product, etc., the multifunctional monomer can be blended. As the multifunctional monomer, for example, multifunctional (meth) acrylates such as ethylene glycol di(meth) acrylate, hexanediol di(meth) acrylate, trimethylolpropane tri(meth) acrylate, pentaerythritol tetra(meth) acrylate, dipentaerythritol hexa(meth) acrylate, 1,4-divinylbenzene, vinylbenzene derivatives such as 4-vinylbenzoic acid-2-acryloylethyl ester, alkenyl isocyanurate derivatives such as triallyl isocyanurate (TAIC), and alkenyl cyanurate derivatives such as triallyl cyanurate (TAC) can be listed. Among them, triallyl isocyanurate and triallyl cyanurate are preferred due to their excellent heat resistance. The multifunctional monomer can be used alone or in combination of two or more.

[0084] The amount of the polyfunctional monomer is preferably 5 to 50 parts by mass, more preferably 7 to 40 parts by mass, and even more preferably 10 to 30 parts by mass, relative to 100 parts by mass of the radical polymerizable compound.

[0085] The solvent may be added from the viewpoint of improving the viscosity of the thermosetting composition, the permeability to glass cloth, the smoothness of the cured film, etc. The solvent is not particularly limited as long as it can dissolve or disperse the above components and volatilize during drying.

[0086] As the solvent, from the perspective of solubility, aromatic solvents such as toluene and xylene are preferred; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone; amide solvents such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. are preferred. These solvents can be used alone or in combination of two or more. From the perspective of the solubility of the thermosetting composition in the solvent and the ease of the volatilization process, the amount of the solvent used is preferably 10 to 1000 parts by mass, and more preferably 20 to 500 parts by mass, relative to 100 parts by mass of the solid content of the thermosetting composition.

[0087] <Method for preparing thermosetting composition>

[0088] When preparing the thermosetting composition, the alkylsilyl peroxide, the radical polymerizable compound, and other components added as needed are added into a storage container, and a ball mill, a bead mill, a planetary mixer, a roller mill, etc. are used to dissolve or disperse them according to a conventional method. At this time, heating can be performed as needed. When the radical polymerizable compound is dissolved in a solvent by heating, the alkylsilyl peroxide can be added after cooling to 50° C. or less after dissolution to suppress unnecessary gelation. In addition, it can be filtered through a sieve or a membrane filter as needed.

[0089] <Resin film>

[0090] The resin film of the present invention is formed by the thermosetting composition. The resin film contains the thermosetting composition before curing, and a part of the thermosetting composition may be cured. The resin film can be obtained, for example, by drying a resin varnish which is a mixture of the thermosetting composition and the solvent alone, or by drying the resin varnish after coating it on a support such as a support film. The solvent can be dried and removed, for example, using a hot air dryer at 20°C to 180°C. The drying temperature is preferably 20°C to 150°C, and more preferably 50°C to 130°C.

[0091] Examples of the support of the resin film include polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polycarbonate, polyimide, ethylene tetrafluoroethylene copolymer, metal foils such as copper foil and aluminum foil, and release paper. The material obtained by coating the thermosetting composition on the metal foil and then drying and removing the solvent using a hot air dryer is also called a metal foil with resin. In addition, the support may be subjected to chemical or physical treatments such as matte treatment, corona treatment, and release treatment.

[0092] The resin film is suitable for use as an interlayer insulating sheet, an adhesive film, or the like of a laminate such as a multilayer printed wiring board.

[0093] <Prepreg>

[0094] The prepreg of the present invention is a composite of a fibrous substrate and the thermosetting composition. The prepreg contains a thermosetting composition before curing, but a part of the thermosetting composition may be cured. The prepreg is preferably a composite of a fibrous substrate and a thermosetting composition impregnated or coated on the fibrous substrate. Even when the thermosetting composition is coated on the surface of the fibrous substrate to form a layer, a structure in which a cured product of the thermosetting composition is impregnated in the substrate can be obtained by press molding for curing the prepreg. The prepreg can be obtained, for example, by the following method: after impregnating or coating a resin varnish which is a mixture of the thermosetting composition of the present invention and a solvent on a substrate such as glass cloth, the solvent is dried and removed. In addition, the impregnation or coating can be repeated several times. Furthermore, it is also possible to adjust to the final required impregnation amount by repeatedly impregnating or coating with a plurality of thermosetting compositions with different concentrations or compositions. The drying and removal of the solvent uses a hot air dryer, for example, at 20°C to 180°C. The drying temperature is preferably 20°C to 150°C, more preferably 50°C to 130°C.

[0095] As the fibrous substrate, for example, glass cloth, aramid cloth, polyester cloth, glass nonwoven fabric, aramid nonwoven fabric, pulp paper and cotton linter paper can be cited. Among them, in order to make the mechanical strength of the printed circuit board excellent, glass cloth is preferred, and glass cloth processed by flattening is more preferred. These fibrous substrates can be used alone or in combination of two or more. In addition, as the thickness of the fibrous substrate, for example, a fibrous substrate of 1 to 300 μm can be used.

[0096] In the solid content of the prepreg, the ratio of the solid content of the thermosetting composition is preferably 30 to 80% by mass, more preferably 40 to 70% by mass. When the above ratio is less than 30% by mass, when the prepreg is used for electronic substrates, there is a tendency for poor insulation reliability. In addition, when the above ratio is greater than 80% by mass, when used for electronic substrates, there is a tendency for poor mechanical properties such as bending elastic modulus.

[0097] <Metal-clad laminate>

[0098] The metal-clad laminate of the present invention is a laminated body in which the resin film or the prepreg and the metal foil are laminated. The laminated body can be prepared by overlapping one or more sheets of the resin film and / or the prepreg with a substrate such as a metal foil, and then curing the thermosetting composition by compression molding to form an insulating layer. The metal foil with the resin can also be used instead of the metal foil. The heat molding can be performed, for example, at a temperature of 180°C to 240°C, a heating time of 30 minutes to 300 minutes, and a pressure of 20 kgf / cm 2 ~40kgf / cm 2 The surface pressure is carried out.

[0099] The metal foil is not particularly limited, and examples thereof include aluminum foil and copper foil, and among them, copper foil is preferred because of its low electrical resistance. As the thickness of the metal foil, for example, a metal foil of 1 to 50 μm can be used.

[0100] The resin film and prepreg combined with the metal foil may be one sheet or multiple sheets, and the metal foil may be stacked on one or both sides to form a laminated board according to the application. The metal-clad laminate is particularly suitable for use as a printed wiring board.

[0101] <Printed circuit board>

[0102] The printed wiring board of the present invention can be obtained by removing part of the metal foil on the surface of the metal-clad laminate by etching or the like to form a circuit, thereby forming a circuit on the surface of a resin film or a prepreg. By containing the thermosetting composition, the printed wiring board has excellent dielectric properties such as dielectric constant and dielectric loss tangent, formability, and heat resistance.

[0103] In addition, the thermosetting composition can be used for molding, lamination, adhesives, composite materials such as copper-clad laminates, etc. In particular, when isocyanate or epoxy is used alone or in combination, representative examples of applications include prepregs formed by semi-curing the resin and laminates formed by curing the prepreg. In addition, when epoxy is used, representative examples of applications in semiconductor sealing materials can be cited.

[0104] Example

[0105] The present invention will be described in further detail below with reference to examples, but the present invention is not limited to these examples.

[0106] <Synthesis of alkylsilyl peroxide>

[0107] <Preparation Example 1, Synthesis of Compound 1>

[0108] Triphenylsilane (purity of 99%, 56.03 g, 0.19 mol), toluene (146.62 g), and a toluene solution of tert-butyl hydroperoxide (purity of 50.0%, 37.59 g, 0.21 mol) were added to a 500 mL round-bottom flask and stirred. The above solution was heated to 30°C, and pyridine (purity of 99%, 18.03 g, 0.23 mol) was added dropwise. After the addition was completed, the mixture was stirred for 2 hours, and the obtained solution was washed with 1% hydrochloric acid and then with water. Then, sodium sulfate and magnesium sulfate were used for dehydration to obtain R in the above general formula (1): 1 and R 2 and R 3 A toluene solution of triphenyl(tert-butylperoxy)silane representing a phenyl group (190.2 g, purity: 22.2%, yield: 63.7% by mass).

[0109] In addition, the NMR spectrometer was used with an AVANCEN NMR spectrometer (manufactured by BRUCKER Scientific Technology Co. Ltd.). 1 H-NMR measurement, 13 The structure of the alkylsilyl peroxide was identified by C-NMR measurement and TOFMS (manufactured by JEOL LTD.). In addition, the purity was calculated by the simple area method in GC (GC-2014 series manufactured by Shimadzu Corporation). The EI-MS and 1 The analysis results obtained by H-NMR are shown in Table 1.

[0110] <Preparation Example 2, Synthesis of Compound 2>

[0111] The same procedures were followed except that the triphenylsilyl chloride in Preparation Example 1 was replaced with methyldiphenylsilyl chloride. A toluene solution of methyldiphenyl(tert-butylperoxy)silane (163.3 g, purity 21.5%, yield 64.5% by mass) was obtained. The EI-MS and 1 The analysis results obtained by H-NMR are shown in Table 1.

[0112] <Preparation Example 3, Synthesis of Compound 5>

[0113] The same procedures were followed except that the triphenylsilyl chloride in Preparation Example 1 was replaced with dimethylphenylsilyl chloride. A toluene solution of dimethylphenyl(tert-butylperoxy)silane (149.4 g, purity 19.8%, yield 69.4% by mass) was obtained. The EI-MS and 1 The analysis results obtained by H-NMR are shown in Table 1.

[0114] <Preparation Example 4, Synthesis of Compound 9>

[0115] The same procedures were followed except that the triphenylsilyl chloride in Preparation Example 1 was replaced with tert-butyldimethylsilyl chloride. A toluene solution of tert-butyldimethyl (tert-butylperoxy)silane (120.0 g, purity 57.3%, yield 67.3% by mass) was obtained. The EI-MS and 1 The analysis results obtained by H-NMR are shown in Table 1.

[0116] <Preparation Example 5, Synthesis of Compound 11>

[0117] Add dimethylaminopyridine (purity of 99%, 68.42g, 0.56mol), tetrahydrofuran (15.41g), and a tetrahydrofuran solution of 2,5-dimethyl-2,5-di-tert-butyl hydroperoxide (purity of 19.0%, 139.41g, 0.15mol) to a 500mL round-bottom flask and stir. Cool the above solution to 15°C, and dropwise add a tetrahydrofuran (30.0g) solution of trimethylsilyl chloride (purity of 99%, 30.42g, 0.28mol). After the addition is completed, stir for 3 hours, and perform reduction washing on the resulting solution with an aqueous sodium sulfite solution, and then wash with water. Then, dehydrate with sodium sulfate and magnesium sulfate to obtain R in the above general formula (2): 5 and R 6 and R 7 Represents methyl, R 8 A toluene solution of 2,2,5,5,8,8,11,11-octamethyl-3,4,9,10-tetraoxo-2,11-disiladodecane representing ethylene. Then, separation was performed by silica gel column chromatography to obtain 2,2,5,5,8,8,11,11-octamethyl-3,4,9,10-tetraoxo-2,11-disiladodecane (45.4 g, purity 99.9%, yield 50.2% by mass). The EI-MS and 1 The analysis results obtained by H-NMR are shown in Table 1.

[0118] <Reference Example 4>

[0119] The same procedures were followed except that the triphenylsilyl chloride in Preparation Example 1 was replaced with trimethylsilyl chloride. A toluene solution of trimethylbutyl peroxysilane (132.2 g, purity 53.0%, yield 43.2% by mass) was obtained. The EI-MS and 1 The analysis results obtained by H-NMR are shown in Table 1.

[0120] <Evaluation of decomposition starting temperature>

[0121] "DSC-7000X" manufactured by Hitachi High-Tech Science Corporation was used as DSC (differential scanning calorimeter). During the measurement, about 8 mg of the synthetic sample was placed in a SUS box, and the temperature was raised from 50°C to 300°C at a heating rate of 10°C per minute under a nitrogen atmosphere. In addition, the decomposition starting temperature was set to the intersection of the initial baseline of DSC and the tangent at the inflection point of the curve. The measurement results of the decomposition starting temperature (°C) of the dialkyl peroxide synthesized in Preparation Examples 1 to 5 are shown in Table 1. In addition, as a reference example for comparison of Preparation Examples 1 to 5, the results of di-tert-butyl peroxide, di-tert-butyl peroxide isopropylbenzene, 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane, and trimethylbutyl peroxysilane are shown.

[0122] [Table 1]

[0123]

[0124] <Examples 1 to 8, Comparative Examples 1 to 6>

[0125] <Preparation of cured products and evaluation of dielectric properties>

[0126] Each component (parts by mass) shown in Table 2 and Table 3 was diluted with toluene and blended in a concentration of 50% by mass, and 6 g of the solvent solution of the composition thus obtained was added to an aluminum pan, and a vacuum dryer (EYELA VACUUMOVEN VOS-3LSD) was used to dry at 400 Pa and 60°C for 2 hours, and then the solvent was further dried at 80°C for 2 hours. The obtained powder was molded at 130°C using a hand press (Hand Press) (manufactured by TOYOSEIKI Co., Ltd.) and cured at 200°C to obtain a cured product (film, 16 cm round, 60 μm thick). The dielectric constant and dielectric loss tangent of the obtained cured product at 1 GHz were determined by a method based on IPC-TM-650-2.5.5.9, and evaluated according to the following benchmarks.

[0127] ◎: Dielectric constant (Dk) is less than 2.90, and dielectric loss tangent (Df) is less than 0.0040.

[0128] ○: The dielectric constant (Dk) is 2.90 or more and 3.00 or less, and the dielectric loss tangent (Df) is 0.0040 or more and 0.0050 or less.

[0129] ×: The dielectric constant (Dk) and the dielectric loss tangent (Df) are other than the above ◎ or ○.

[0130] <Evaluation of heat resistance>

[0131] The glass transition temperature of the above-mentioned cured product is measured by using "DSC-7000X" manufactured by Hitachi High-Tech Science Corporation as DSC (differential scanning calorimeter). During the measurement, about 2 mg of the synthetic sample is placed in an Al box, and the temperature is raised from 50°C to 350°C at a heating rate of 10°C per minute under a nitrogen atmosphere. In addition, the glass transition temperature is set to the temperature at the point where the straight line at which the distance from the straight line extending from the low temperature side baseline and the distance from the straight line extending from the high temperature side baseline in the longitudinal direction are equidistant and intersect with the curve of the step-shaped change part of the glass transition. The following benchmarks are used for evaluation, and the results are shown in Table 2.

[0132] ◎: Glass transition temperature (°C) is 180 or higher.

[0133] ○: Glass transition temperature (°C) is 175 or higher.

[0134] ×: Glass transition temperature (°C) is less than 175.

[0135] [Table 2]

[0136]

[0137] [Table 3]

[0138]

[0139] In Tables 2 and 3, OPE-2St 2200 represents a polyphenylene ether having an average of 2 ethylenically unsaturated double bonds at the molecular terminals ((number average molecular weight: 2200), manufactured by MITSUBISHI GAS CHEMICAL COMPANY, INC.);

[0140] OPE-2St 1200 is a polyphenylene ether having an average of 2 ethylenically unsaturated double bonds at the molecular terminal ((number average molecular weight: 1200), manufactured by MITSUBISHI GAS CHEMICAL COMPANY, INC.);

[0141] SA900 is a polyphenylene ether having an average of 2 ethylenically unsaturated double bonds at the molecular terminal ((number average molecular weight 2756), manufactured by SABIC Innovative Plastics);

[0142] Compound 1 represents triphenyl(tert-butylperoxy)silane of Preparation Example 1 (purity: 22.2%);

[0143] Compound 2 represents methyldiphenyl(tert-butylperoxy)silane of Preparation Example 2 (purity: 21.5%);

[0144] Compound 5 represents dimethylphenyl(tert-butylperoxy)silane of Preparation Example 3 (purity: 19.8%);

[0145] Compound 9 represents tert-butyldimethyl(tert-butylperoxy)silane of Preparation Example 4 (purity: 57.3%);

[0146] Compound 11 represents 2,2,5,5,8,8,11,11-octamethyl-3,4,9,10-tetraoxo-2,11-disiladodecane (purity: 99.9%) of Preparation Example 5;

[0147] Di-tert-butyl peroxide was manufactured by NOF Corporation (purity 98%);

[0148] Di-tert-butyl peroxide isopropylbenzene manufactured by NOF Corporation (purity: 99%);

[0149] 2,5-Dimethyl-2,5-(di-tert-butylperoxy)hexane was manufactured by NOF Corporation (purity: 94%);

[0150] Trimethylbutyl peroxysilane represents Reference Example 4 (purity 53.0%);

[0151] TAIC (Triallyl Isocyanurate) was manufactured by Tokyo Chemical Industry Co., Ltd. (purity: 96.0%).

[0152] Compared with Comparative Examples 1 to 6, Examples 1 to 8 were able to obtain cured products exhibiting excellent physical properties.

Claims

1. A thermosetting composition comprising an alkylsilyl peroxide and a free radical polymerizable compound, wherein: The alkylsilyl peroxide is one or more selected from the group consisting of compounds represented by the general formula (1) and compounds represented by the general formula (2), [Chemical formula 1] In formula (1), R 1 , R 2 are independently an alkyl group having 1 to 6 carbon atoms or a phenyl group, R 3 is an alkyl group or a phenyl group having 4 to 6 carbon atoms, [Chemical formula 2] In formula (2), R 4 It is ethylene or ethynylene.

2. The thermosetting composition according to claim 1, characterized in that The free radical polymerizable compound is polyphenylene ether.

3. A resin film, characterized in that: It is formed from the thermosetting composition according to claim 2.

4. A prepreg, characterized in that: The thermosetting composition according to claim 2 is impregnated or coated on a fibrous substrate.

5. A metal-clad laminate, characterized in that: The resin film according to claim 3 or the prepreg according to claim 4 is laminated with a metal foil.

6. A printed circuit board, characterized in that: It is obtained by removing part of the metal foil from the metal-clad laminate according to claim 5.

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