Hardening resin

Abstract

The object of the present invention is to provide a curable resin, a curable resin composition, a cured product, a varnish, a prepreg, a laminate and a circuit board having a specific structure. By using a curable resin composition containing the curable resin, a radical polymerization initiator and a flame retardant, a cured product having excellent flame retardancy, heat resistance (high glass transition temperature) and dielectric properties (low dielectric properties) is provided. Specifically, a curable resin represented by the following general formula (1) and a curable resin composition characterized by containing the curable resin, a radical polymerization initiator (B) and a flame retardant (C) are provided. (In the formula, Ra and Rb each independently represent an alkyl group, an aryl group, an arylalkyl group or a cycloalkyl group having 1 to 12 carbon atoms. k represents an integer from 0 to 3. X represents a hydrocarbon group. Y represents the following general formula (2) or general formula (3)) (In the formula, Z represents an alicyclic group, an aromatic group or a heterocyclic group)

Description

Technical Field

[0001] The present invention relates to a curable resin having a specific structure, and a cured product, a varnish, a prepreg, a laminate, and a circuit board obtained from a curable resin composition containing the curable resin, a radical polymerization initiator, and a flame retardant. Background Art

[0002] With the recent increase in the volume of information communication, information communication in high frequency bands has been actively carried out. In order to achieve better electrical properties, especially to reduce transmission loss in high frequency bands, electrical insulating materials having a low dielectric constant and a low dielectric loss tangent are required.

[0003] Furthermore, printed circuit boards or electronic components using these electrical insulating materials are exposed to high-temperature reflow soldering during assembly, and therefore require materials with excellent heat resistance and a high glass transition temperature. In particular, the recent use of lead-free solders with high melting points from the perspective of environmental issues has led to an increasing demand for electrical insulating materials with even higher heat resistance.

[0004] In response to these demands, vinyl-containing curable resins with various chemical structures have been proposed. Examples of such curable resins include divinylbenzyl ether of bisphenol, polyvinylbenzyl ether of novolac, and aliphatic-containing polyphenylene ether resins (see, for example, Patent Documents 1 to 3).

[0005] However, these vinylbenzyl ethers cannot provide cured products with sufficiently low dielectric properties, and the obtained cured products have problems in stable use in high-frequency bands. Furthermore, divinylbenzyl ether of bisphenol cannot be said to have sufficiently high heat resistance.

[0006] Thus, conventional vinyl group-containing curable resins including polyvinyl benzyl ether cannot provide cured products having both the low dielectric loss tangent required for use as electrical insulating materials, particularly for use in high-frequency electrical insulating materials, and the heat resistance required to withstand lead-free soldering.

[0007] Furthermore, flame retardancy is also required for electrical insulating materials such as printed circuit boards. However, if a large amount of flame retardant is added to achieve flame retardancy, dielectric properties deteriorate, making it impossible to simultaneously achieve both flame retardancy and dielectric properties.

[0008] [Prior art literature]

[0009] [Patent Document]

[0010] Patent Document 1: Japanese Patent Application Laid-Open No. 63-68537

[0011] Patent Document 2: Japanese Patent Application Laid-Open No. 64-65110

[0012] Patent Document 3: Japanese Patent No. 4320171 Summary of the Invention

[0013] [Problems to be solved by the invention]

[0014] Therefore, the problem to be solved by the present invention is to provide a curable resin having a specific structure, a cured product having excellent flame retardancy, heat resistance (high glass transition temperature), and dielectric properties (low dielectric properties) by using a curable resin composition containing the curable resin, a radical polymerization initiator, and a flame retardant, and a varnish, prepreg, laminate, and circuit board that contribute to or have these properties.

[0015] [Technical means to solve the problem]

[0016] Therefore, the present inventors have conducted intensive research to solve the above-mentioned problems. As a result, they have discovered a curable resin that can contribute to heat resistance and low dielectric properties, and a curable resin composition containing the curable resin, a radical polymerization initiator, and a flame retardant, which has excellent flame retardancy, heat resistance, and low dielectric properties. This has led to the completion of the present invention.

[0017] Specifically, the present invention relates to a curable resin and a resin composition containing the curable resin, a radical polymerization initiator (B), and a flame retardant (C), wherein the curable resin is characterized by having a repeating unit represented by the following general formula (1) and at least one reactive group selected from the group consisting of a (meth)acryloyloxy group, a vinylbenzyl ether group, and an allyl ether group as a terminal structure.

[0018] [Chemistry 1]

[0019]

[0020] (wherein, Ra and Rb each independently represent an alkyl group, aryl group, aralkyl group or cycloalkyl group having 1 to 12 carbon atoms. k represents an integer from 0 to 3. X represents a hydrocarbon group. Y represents the following general formula (2) or (3))

[0021] [Chemistry 2]

[0022]

[0023] (wherein Z represents an alicyclic group, an aromatic group or a heterocyclic group)

[0024] The curable resin of the present invention is preferably represented by the following general formula (1A) in the general formula (1).

[0025] [Chemistry 3]

[0026]

[0027] In the curable resin of the present invention, it is preferred that Z is a benzene ring.

[0028] In the curable resin of the present invention, it is preferable that the reactive group is a methacryloyloxy group.

[0029] The curable resin of the present invention preferably has a weight average molecular weight of 500 to 50,000.

[0030] The curable resin composition of the present invention preferably further contains a curable resin (D) other than the curable resin described above.

[0031] In the curable resin composition of the present invention, it is preferred that the component (B) is a dialkyl peroxide-based organic peroxide.

[0032] The curable resin composition of the present invention preferably contains a phosphorus-based flame retardant represented by any one of the following general formulas (P-1) to (P-5) as the component (C).

[0033] [Chemistry 4]

[0034]

[0035] (In the general formula (P-1), R 11 Each independently represents an alkyl group, an aryl group, an aralkyl group or a cycloalkyl group having 1 to 12 carbon atoms, and R 12 represents an alkylene group or an arylene group, and a represents an integer of 0 to 3)

[0036] [Chemistry 5]

[0037]

[0038] (In the general formula (P-2), R 13 Each independently represents an alkyl group, an aryl group, an aralkyl group or a cycloalkyl group having 1 to 12 carbon atoms, and M b+ represents a metal ion with a valence of b, where b represents an integer from 1 to 3)

[0039] [Chemistry 6]

[0040]

[0041] (In the general formula (P-3), R 14 Each independently represents an alkyl group, an aryl group, an aralkyl group or a cycloalkyl group having 1 to 12 carbon atoms, and R 15 represents an alkylene group or an arylene group, M c+ represents a metal ion with a valence of c, wherein c, d and e each independently represent an integer of 1 to 3, satisfying c×d=2×e)

[0042] [Chemistry 7]

[0043]

[0044] (In the general formula (P-4), R 16 Each independently represents an alkyl group, an aryl group, an aralkyl group or a cycloalkyl group having 1 to 12 carbon atoms, and may form a ring structure together with the phosphorus atom. 17 represents vinyl, vinylbenzyl or (meth)acryloyloxy, and f and g each independently represent 0 or 1)

[0045] [Chemistry 8]

[0046]

[0047] (In the general formula (P-5), R 18 Each independently represents an alkyl group, an aryl group, an aralkyl group or a cycloalkyl group having 1 to 12 carbon atoms, and may form a ring structure together with the phosphorus atom. 19 represents a divalent group having an arylene structure, R 20 represents a (meth)acryloyloxy group, a vinylbenzyl ether group or an allyl ether group, and h represents 0 or 1)

[0048] In the curable resin composition of the present invention, the component (D) is preferably at least one curable resin selected from the group consisting of epoxy resins, phenol resins, active ester resins, cyanate resins, maleimide resins, benzoxazine resins, polyphenylene ether resins, and vinyl resins.

[0049] The present invention relates to a cured product obtained by subjecting the curable resin composition to a curing reaction.

[0050] The present invention relates to a varnish obtained by diluting the curable resin composition with an organic solvent.

[0051] The present invention relates to a prepreg including a reinforcing base material and a semi-cured material of the varnish impregnated in the reinforcing base material.

[0052] The present invention relates to a laminate comprising a substrate and a layer containing the cured product.

[0053] The present invention relates to a circuit substrate, which is obtained by laminating the prepreg and copper foil and performing heat compression molding.

[0054] [Effects of the Invention]

[0055] The curable resin of the present invention has excellent heat resistance and low dielectric properties. A cured product obtained from a curable resin composition containing the curable resin, a radical polymerization initiator, and a flame retardant has excellent flame retardancy, heat resistance, and low dielectric properties and is useful. DETAILED DESCRIPTION

[0056] The present invention is described in detail below.

[0057] Curing resin

[0058] The curable resin of the present invention relates to a curable resin having, as a terminal structure, a repeating unit represented by the following general formula (1) and at least one reactive group (crosslinking group) selected from the group consisting of a (meth)acryloyloxy group, a vinylbenzyl ether group, and an allyl ether group. Hereinafter, the curable resin having, as a terminal structure, a repeating unit represented by the following general formula (1) and at least one reactive group (crosslinking group) selected from the group consisting of a (meth)acryloyloxy group, a vinylbenzyl ether group, and an allyl ether group is referred to as a curable resin (A) (also referred to as "component (A)").

[0059] [Chemistry 9]

[0060]

[0061] In the general formula (1), Ra and Rb each independently represent an alkyl group, an aryl group, an aralkyl group, or a cycloalkyl group having 1 to 12 carbon atoms. k represents an integer from 0 to 3. X represents a hydrocarbon group. Y represents the following general formula (2) or (3).

[0062] [Chemistry 10]

[0063]

[0064] In the general formula (3), Z represents an alicyclic group, an aromatic group or a heterocyclic group.

[0065] Since the component (A) has a repeating unit represented by the general formula (1) and at least one reactive group (crosslinking group) selected from the group consisting of a (meth)acryloyloxy group, a vinylbenzyl ether group, and an allyl ether group as a terminal structure, the ester bond or carbonate bond contained in the component (A) has lower molecular mobility than ether groups, etc., resulting in low dielectric properties (especially low dielectric loss tangent). Furthermore, since Ra or Rb (especially Ra) is present as a substituent at a site adjacent to the reactive group (crosslinking group), the polarity of the reactive group (crosslinking group) is constrained by the steric hindrance of Ra, and a cured product with an even lower dielectric loss tangent can be obtained, which is preferred. In addition, since the component (A) has a reactive group (crosslinking group), the obtained cured product has excellent heat resistance. Furthermore, since the ester bond or carbonate bond with low molecular mobility has low dielectric properties, a cured product with a high glass transition temperature can be obtained.

[0066] In the general formula (1), Ra and Rb each independently represent an alkyl group, an aryl group, an aralkyl group, or a cycloalkyl group having 1 to 12 carbon atoms, preferably an alkyl group, an aryl group, or a cycloalkyl group having 1 to 4 carbon atoms. When Ra and Rb are alkyl groups having 1 to 12 carbon atoms, the planarity near the benzene ring in the general formula (1) is reduced, and due to the reduced crystallinity, the solvent solubility is improved, and the melting point is lowered, thereby becoming a preferred form. In addition, by having Ra or Rb (especially Ra) as a substituent at a position adjacent to the reactive group (crosslinking group), the polarity of the reactive group (crosslinking group) is constrained by the steric hindrance of Ra, and a cured product with a lower dielectric loss tangent can be obtained, which is preferred.

[0067] In the general formula (1), k represents an integer of 0 to 3, preferably an integer of 0 to 1. When k is within the above range, the planarity near the benzene ring in the general formula (1) is reduced, and due to the reduced crystallinity, the solvent solubility is improved, and the melting point is lowered, thereby becoming a preferred form. In addition, when k is not 0, that is, when Rb is present as a substituent and is present near the reactive group (crosslinking group), the polarity derived from the reactive group (crosslinking group) is constrained by the steric hindrance of Rb, and a cured product with a low dielectric loss tangent can be obtained, which is preferred.

[0068] In the general formula (1), X only needs to be a hydrocarbon group. In terms of ease of obtaining industrial raw materials, it is preferably represented by the structures of the following general formulas (4) to (6). In particular, in terms of a good balance between heat resistance and low dielectric properties, the structure of the following general formula (4) is more preferred.

[0069] [Chemistry 11]

[0070]

[0071] In the general formulas (4) to (6), R1 and R2 each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl group, or a cycloalkyl group. Alternatively, R1 and R2 may be bonded together to form a cyclic skeleton. n represents an integer from 0 to 2, preferably an integer from 0 to 1. When n is within the above range, high heat resistance is achieved, which is a preferred embodiment.

[0072] In the general formula (1), Y represents the general formula (2) or the general formula (3), and is preferably the general formula (2) from the viewpoint of heat resistance.

[0073] In the general formula (3), in order to obtain a highly heat-resistant cured product, Z represents an alicyclic group, an aromatic group or a heterocyclic group, and is preferably a structure represented by the following general formulas (7) to (11). From the perspective of cost and heat resistance, the structure (benzene ring) of the following general formula (7) is particularly preferred.

[0074] [Chemistry 12]

[0075]

[0076] Component (A) has at least one reactive group (crosslinking group) selected from the group consisting of a (meth)acryloyloxy group, a vinylbenzyl ether group, and an allyl ether group as a terminal structure. A methacryloyloxy group is more preferred as the terminal structure because the resulting cured product has a low dielectric loss tangent. While the methacryloyloxy group forms an ester bond, vinylbenzyl ether and allyl ether groups form an ether bond, which tends to increase molecular mobility and thus the dielectric loss tangent.

[0077] The curable resin of the present invention preferably has a repeating unit represented by the general formula (1) as shown below (1A), and the reactive group is a methacryloyloxy group. The presence of a methacryloyloxy group as the terminal structure preferably results in a cured product having a low dielectric loss tangent.

[0078] [Chemistry 13]

[0079]

[0080] In the general formula (1A), Rc preferably represents a hydrogen atom or a methyl group, more preferably a hydrogen atom. A preferred embodiment is achieved when Rc is a hydrogen atom or the like, resulting in low polarity. Furthermore, in the general formula (3), Ra, Rb, and Y are the same as those in the general formula (1).

[0081] The component (A) is characterized by having a repeating unit represented by the general formula (1) (or a repeating unit represented by the general formula (1A)) and the reactive group (crosslinking group) as a terminal structure, and may contain other repeating units (structures) as long as the characteristics of the component (A) are not impaired.

[0082] The weight average molecular weight (Mw) of the component (A) is preferably 500 to 50,000, more preferably 1,000 to 10,000, and even more preferably 1,500 to 5000. Within the above range, solvent solubility is improved and workability is good, which is preferred.

[0083] <Method for producing curable resin (A)>

[0084] The method for producing the component (A) will be described below.

[0085] Examples of the production method include methods of reacting in an organic solvent such as interfacial polymerization and methods of reacting in a molten state such as melt polymerization.

[0086] <Interfacial polymerization method>

[0087] As the interfacial polymerization method, the following method can be cited: a solution (organic phase) obtained by dissolving a dicarboxylic acid halide and a cross-linking group introducing agent used for introducing a reactive group (cross-linking group) as a terminal structure in a water-incompatible organic solvent is mixed with an alkaline aqueous solution (aqueous phase) containing a dihydric phenol, a polymerization catalyst and an antioxidant, and a polymerization reaction is carried out at a temperature of 50° C. or less while stirring for 1 to 8 hours.

[0088] In addition, as other interfacial polymerization methods, the following methods can be cited: in the process of mixing a solution (organic phase) obtained by dissolving a cross-linking group introducing agent used for introducing a reactive group (cross-linking group) as a terminal structure in an organic solvent incompatible with water with an alkaline aqueous solution (aqueous phase) containing a dihydric phenol, a polymerization catalyst and an antioxidant, phosgene is blown into the mixture, and a polymerization reaction is carried out at a temperature below 50°C while stirring for 1 to 8 hours.

[0089] The organic solvent used in the organic phase is preferably a solvent that is incompatible with water and dissolves the polyarylate. Examples of such solvents include chlorine-based solvents such as dichloromethane, 1,2-dichloroethane, chloroform, carbon tetrachloride, chlorobenzene, 1,1,2,2-tetrachloroethane, 1,1,1-trichloroethane, o-dichlorobenzene, m-dichlorobenzene, and p-dichlorobenzene; aromatic hydrocarbons such as toluene, benzene, and xylene; and tetrahydrofuran. Dichloromethane is preferred due to its ease of use in production.

[0090] Examples of the aqueous alkali solution used in the aqueous phase include an aqueous sodium hydroxide solution and an aqueous potassium hydroxide solution.

[0091] Antioxidants are used to prevent oxidation of the dihydric phenol component. Examples of antioxidants include sodium bisulfite, L-ascorbic acid, isoascorbic acid, catechol, tocopherol, and butylated hydroxyanisole. Among these, sodium bisulfite is preferred due to its excellent water solubility.

[0092] Examples of the polymerization catalyst include quaternary ammonium salts such as tri-n-butylbenzylammonium halide, tetra-n-butylammonium halide, trimethylbenzylammonium halide, and triethylbenzylammonium halide; and quaternary phosphonium salts such as tri-n-butylbenzylammonium halide, tetra-n-butylphosphonium halide, trimethylbenzylammonium halide, and triethylbenzylammonium halide. Among these, tri-n-butylbenzylammonium halide, trimethylbenzylammonium halide, tetra-n-butylammonium halide, tri-n-butylbenzylammonium halide, and tetra-n-butylphosphonium halide are preferred because they can produce polymers having high molecular weight and low acid value.

[0093] The amount of the polymerization catalyst added is preferably 0.01 mol% to 5.0 mol%, more preferably 0.1 mol% to 1.0 mol%, relative to the molar number of the dihydric phenol used in the polymerization. Furthermore, an amount of 0.01 mol% or more of the polymerization catalyst is preferred because the polymerization catalyst effect is achieved and the molecular weight of the polyarylate resin increases. On the other hand, an amount of 5.0 mol% or less is preferred because the hydrolysis reaction of the divalent aromatic carboxylic acid halide is suppressed, and the molecular weight of the polyarylate resin increases.

[0094] Examples of the dihydric phenol include 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3,6-dimethylphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3,5,6-trimethylphenyl)propane, 2,2-bis(4-hydroxy-2,3,6-trimethylphenyl)propane, bis(4-hydroxy-3,5-dimethylphenyl)methane, bis(4-hydroxy-3,6-dimethylphenyl)methane, bis(4-hydroxy-3-methylphenyl)methane, bis(4-hydroxy-3,5,6-trimethylphenyl)methane, bis(4-hydroxy-2,3,6-trimethylphenyl)methane, 1,1-bis(4-hydroxy-3,5-dimethylphenyl)-1-phenylethane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)-1-phenylethane, 2,2-bis(4-hydroxy-2,3,6-trimethylphenyl)methane, bis(4-hydroxy-3,6-dimethylphenyl)methane, bis(4-hydroxy-3,6-dimethylphenyl)methane, bis(4-hydroxy-3,6-dimethylphenyl)methane, bis(4-hydroxy-3,6-trimethylphenyl)methane, bis(4-hydroxy-2,3,6-trimethylphenyl)methane, 1,1-bis(4-hydroxy-3,5-dimethylphenyl)-1-phenylethane, 2,2 ...2,3,6-trimethylphenyl)methane, bis(4-hydroxy-3,6-dimethylphenyl)methane, bis(4-hydroxy-3,6-dimethylphenyl)methane ,2-bis(4-hydroxy-3,5-dimethylphenyl)butane, bis(4-hydroxy-3,5-dimethylphenyl)diphenylmethane, 2,2-bis(4-hydroxy-3-isopropylphenyl)propane, 1,1-bis(4-hydroxy-3,5-dimethylphenyl)ethane, 1,3-bis(2-(4-hydroxy-3,5-dimethylphenyl)-2-propyl)benzene, 1,4-bis(2-(4-hydroxy-3,5-dimethylphenyl)-2-propyl)benzene, 1,1-bis(4-hydroxy-3,5-dimethylphenyl)-3,3,5-trimethylcyclohexane, 1,1-bis(4-hydroxy-3,5-dimethylphenyl)cyclohexane, 2,2-bis(2-hydroxy-5-biphenyl)propane, 2,2-bis(4-hydroxy-3-cyclohexyl-6-methylphenyl)propane, etc.

[0095] Examples of the dicarboxylic acid halide include terephthalic acid halide, isophthalic acid halide, phthalic acid halide, biphenylcarboxylic acid halide, biphenyl-4,4′-dicarboxylic acid halide, 1,4-naphthalene dicarboxylic acid halide, 2,3-naphthalene dicarboxylic acid halide, 2,6-naphthalene dicarboxylic acid halide, 2,7-naphthalene dicarboxylic acid halide, 1,8-naphthalene dicarboxylic acid halide, 1,5-naphthalene dicarboxylic acid halide, diphenyl ether-2,2′-dicarboxylic acid halide, diphenyl ether-2,3′-dicarboxylic acid halide, diphenyl ether-2,4′-dicarboxylic acid halide, diphenyl ether-3,3′-dicarboxylic acid halide, diphenyl ether-3,4′-dicarboxylic acid halide, diphenyl ether-4,4′-dicarboxylic acid halide, 1,4-cyclohexane dicarboxylic acid halide, and 1,3-cyclohexane dicarboxylic acid halide.

[0096] The terminal structure of component (A) has at least one reactive group selected from the group consisting of a (meth)acryloyloxy group, a vinylbenzyl ether group, and an allyl ether group. A crosslinking group-introducing agent can be used to introduce these reactive groups (crosslinking groups). Examples of crosslinking group-introducing agents include (meth)acrylic anhydride, (meth)acrylic acid chloride, chloromethylstyrene, chlorostyrene, allyl chloride, and allyl bromide. In particular, (meth)acrylic anhydride or (meth)acrylic acid chloride is more preferred because it allows the cured product obtained from a curable resin composition containing a curable resin having a methacryloyloxy group introduced as the terminal structure to have a low dielectric loss tangent. By reacting these, reactive groups can be introduced into the curable resin, resulting in a low dielectric constant and a low dielectric loss tangent, which is a preferred embodiment.

[0097] Examples of the (meth)acrylic anhydride include acrylic anhydride and methacrylic anhydride. Examples of the (meth)acrylic acid chloride include methacrylic acid chloride and acrylic acid chloride. Examples of chloromethylstyrene include p-chloromethylstyrene and m-chloromethylstyrene, and examples of chlorostyrene include p-chlorostyrene and m-chlorostyrene. Examples of allyl chloride include 3-chloro-1-propene, and examples of allyl bromide include 3-bromo-1-propene. These may be used alone or in combination. Among these, it is particularly preferred to use methacrylic anhydride or methacrylic acid chloride, which can produce a cured product with a lower dielectric loss tangent.

[0098] <Melt polymerization method>

[0099] Examples of the melt polymerization method include a method in which a dihydric phenol as a raw material is acetylated and then the acetylated dihydric phenol is subjected to deacetoxypolymerization with a dicarboxylic acid; or a method in which a dihydric phenol is subjected to an ester exchange reaction with a carbonate ester.

[0100] In the acetylation reaction, an aromatic dicarboxylic acid component, a dihydric phenol component, and acetic anhydride are placed in a reaction vessel. The reaction vessel is then purged with nitrogen and stirred under an inert atmosphere at a temperature of 100°C to 240°C, preferably 120°C to 180°C, at normal pressure or under pressure for 5 minutes to 8 hours, preferably 30 minutes to 5 hours. The molar ratio of acetic anhydride to the hydroxyl group of the dihydric phenol component is preferably 1.00 to 1.20.

[0101] The so-called deacetylating polymerization reaction refers to a polycondensation reaction in which an acetylated dihydric phenol reacts with a dicarboxylic acid. During the deacetylating polymerization reaction, the mixture is stirred at a temperature of 240°C or higher, preferably 260°C or higher, and more preferably 280°C or higher, and a reduced pressure of 500 Pa or lower, preferably 260 Pa or lower, and more preferably 130 Pa or lower, for 30 minutes or longer. When the temperature is 240°C or higher, the reduced pressure is 500 Pa or lower, or the holding time is 30 minutes or longer, the deacetylating reaction proceeds sufficiently, which not only reduces the amount of acetic acid in the resulting polyarylate resin, but also shortens the overall polymerization time and suppresses deterioration in the polymer's color tone.

[0102] In the acetylation reaction and deacetylation polymerization reaction, a catalyst is preferably used as needed. Examples of the catalyst include organic titanate compounds such as tetrabutyl titanate; alkali metal salts such as zinc acetate and potassium acetate; alkaline earth metal salts such as magnesium acetate; organic tin compounds such as antimony trioxide, hydroxybutyltin oxide, and tin octoate; and heterocyclic compounds such as N-methylimidazole. The amount of catalyst added is generally 1.0 mol% or less, more preferably 0.5 mol% or less, and even more preferably 0.2 mol% or less, relative to the total monomer components of the resulting polyarylate resin.

[0103] The transesterification reaction is carried out at a temperature of 120° C. to 260° C., preferably 160° C. to 200° C., and a pressure of normal pressure to 1 Torr for 0.1 to 5 hours, preferably 0.5 to 6 hours.

[0104] As catalysts for the transesterification reaction, for example, salts of zinc, tin, zirconium, and lead can be preferably used, and these can be used alone or in combination. Specifically, zinc acetate, zinc benzoate, zinc 2-ethylhexanoate, tin (II) chloride, tin (IV) chloride, tin (II) acetate, tin (IV) acetate, dibutyltin dilaurate, dibutyltin oxide, dibutyltin dimethanol, zirconium acetylacetonate, zirconium glycolate, zirconium tetrabutoxide, lead (II) acetate, lead (IV) acetate, etc. can be used. These catalysts are used at a ratio of 0.000001 mol% to 0.1 mol%, preferably 0.00001 mol% to 0.01 mol%, relative to 1 mol of the total dihydric phenol.

[0105] As the dihydric phenol, the dihydric phenol used in the above-mentioned interfacial polymerization method can be used in the same manner.

[0106] Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, biphenylcarboxylic acid, biphenyl-4,4'-dicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, diphenyl ether-2,2'-dicarboxylic acid, diphenyl ether-2,3'-dicarboxylic acid, diphenyl ether-2,4'-dicarboxylic acid, diphenyl ether-3,3'-dicarboxylic acid, diphenyl ether-3,4'-dicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and 1,3-cyclohexanedicarboxylic acid.

[0107] Examples of the carbonate ester include diphenyl carbonate, ditolyl carbonate, bis(chlorophenyl) carbonate, m-hydroxycresyl carbonate, dinaphthyl carbonate, bis(diphenyl) carbonate, diethyl carbonate, dimethyl carbonate, dibutyl carbonate, and dicyclohexyl carbonate.

[0108] The terminal structure of the component (A) has at least one reactive group selected from the group consisting of a (meth)acryloyloxy group, a vinylbenzyl ether group, and an allyl ether group. In order to introduce these reactive groups (crosslinking groups), a crosslinking group introducing agent can be used. As the crosslinking group introducing agent, the crosslinking group introducing agent used in the interfacial polymerization method can also be used.

[0109] The present invention relates to a curable resin composition comprising the curable resin (A), a radical polymerization initiator (B), and a flame retardant (C), as described below. The curable resin has excellent solvent solubility, making the curable resin composition easy to prepare and easy to handle. The curable resin composition is useful for enhancing flame retardancy, heat resistance, and low dielectric properties.

[0110] Curing resin (D)

[0111] The curable resin composition of the present invention preferably further contains a curable resin (D) (also referred to as "component (D)") in addition to the component (A). Using a curable resin composition containing the component (D) provides a preferred embodiment in which a cured product imparting the properties of each curable resin can be obtained.

[0112] From the viewpoints of high heat resistance, high adhesion, low thermal expansion, and miscibility, the component (D) is preferably at least one curable resin selected from the group consisting of epoxy resins, phenol resins, active ester resins, cyanate resins, maleimide resins, benzoxazine resins, polyphenylene ether resins, and vinyl resins.

[0113] Examples of the epoxy resin include dicyclopentadiene epoxy resins, bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, bisphenol A novolac epoxy resins, salicylaldehyde novolac epoxy resins, bisphenol F novolac epoxy resins, alicyclic epoxy resins, glycidyl ester epoxy resins, glycidylamine epoxy resins, hydantoin epoxy resins, isocyanurate epoxy resins, aliphatic cyclic epoxy resins, halides thereof, hydrogenated products thereof, and mixtures of the above resins, or a mixture of two or more thereof.

[0114] Examples of the phenol resin include phenol novolac, o-cresol novolac, p-cresol novolac, tert-butylphenol novolac, dicyclopentadiene cresol, poly(p-vinylphenol), bisphenol A novolac, phenol aralkyl resin, naphthol aralkyl resin, biphenyl-type phenol novolac resin, biphenyl-type naphthol novolac resin, decalin-modified novolac, poly(di-o-hydroxyphenyl)methane, poly(di-m-hydroxyphenyl)methane, and poly(di-p-hydroxyphenyl)methane.

[0115] Examples of the active ester resin include active ester compounds obtained by reacting a carboxylic acid compound and / or a thiocarboxylic acid compound with a hydroxy compound and / or a thiol compound.

[0116] Examples of the cyanate resin include bis(4-cyanatephenyl)ethane, 2,2-bis(4-cyanatephenyl)propane, 2,2-bis(3,5-dimethyl-4-cyanatephenyl)methane, 2,2-bis(4-cyanatephenyl)-1,1,1,3,3,3-hexafluoropropane, α,α′-bis(4-cyanatephenyl)-m-diisopropylbenzene, and cyanate esters of phenol-added dicyclopentadiene polymers.

[0117] Examples of the maleimide resin include 4,4′-diphenylmethanebismaleimide, m-phenylenebismaleimide, bisphenol A diphenyl ether bismaleimide, 3,3′-dimethyl-5,5′-diethyl-4,4′-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, and 1,6′-bismaleimide-(2,2,4-trimethyl)hexane.

[0118] Examples of the benzoxazine resin include Fa-type benzoxazine compounds obtained by reacting a bisphenol compound with an amine compound (e.g., aniline) such as bisphenol A-type benzoxazine compounds and bisphenol F-type benzoxazine compounds; and Pd-type benzoxazine compounds obtained by reacting a phenyldiamine compound with a phenol compound such as diaminodiphenylmethane-type benzoxazine compounds.

[0119] Examples of the polyphenylene ether resin include poly(2,6-dimethyl-1,4-phenylene) ether, a polymer alloy of poly(2,6-dimethyl-1,4-phenylene) ether and polystyrene, and a polymer alloy of poly(2,6-dimethyl-1,4-phenylene) ether and a styrene-butadiene copolymer.

[0120] Examples of the vinyl resin include triallyl isocyanurate compounds such as triallyl isocyanurate, polybutadiene resins having repeating units of 1,2-butadiene, cis-1,4-butadiene, and trans-1,4-butadiene, and vinylbenzyl compounds such as styrene and divinylbenzene having a vinylbenzyl group in the molecule.

[0121] As the component (D), maleimide resins, cyanate resins, polyphenylene ether resins, and vinyl resins are particularly preferred from the viewpoint of reducing the dielectric loss tangent.

[0122] The curable resin composition of the present invention preferably contains 0 to 80 parts by mass of the component (D), more preferably 0 to 60 parts by mass, relative to 100 parts by mass of the component (A). The component (D) can be added within a range that does not impair the characteristics of the present invention, and can be suitably used when it is desired to impart characteristics attributable to the component (D), within a range that does not exceed the amount of the component (A).

[0123] <Radical polymerization initiator (B)>

[0124] The curable resin composition of the present invention is characterized by containing a radical polymerization initiator (B) (also referred to as "component (B)"). Using a curable resin composition containing component (B) improves reactivity, reduces residual low-molecular-weight components, and thereby produces a cured product with excellent heat resistance, which is a preferred embodiment.

[0125] Examples of the component (B) include isobutyl peroxide, α,α'-bis(neodecanoylperoxy)diisopropylbenzene, cumyl peroxyneodecanoate, di-n-propyl peroxydicarbonate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, diisopropyl peroxydicarbonate, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, di-2-ethoxyethyl peroxydicarbonate, di(2-ethylhexylperoxy)dicarbonate, tert-hexyl peroxyneodecanoate, dimethoxybutyl peroxydidecanoate, di(3-methyl-3-methoxybutylperoxy)dicarbonate, tert-butyl peroxyneodecanoate, tert-hexyl peroxytrimethylacetate, tert-butyl peroxytrimethylacetate, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, 1,1,3 ,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, tert-hexylperoxy-2-ethylhexanoate, tert-butylperoxy-2-ethylhexanoate, m-toluoyl peroxide, tert-butylperoxyisobutyrate, 1,1-bis(tert-butylperoxy)cyclohexane, α,α'-bis(tert-butylperoxy)diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butylcumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, tert-butyltrimethylsilyl peroxide 2,3-dimethyl-2,3-diphenylbutane, etc. In particular, from the perspective of increasing the crosslinking density, dialkyl peroxide-based organic peroxides are preferred, and among them, α,α'-bis(tert-butylperoxy)diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butylcumyl peroxide, di-tert-butyl peroxide, and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3 are more preferred.

[0126] The curable resin composition of the present invention preferably contains 0.05 to 30 parts by mass of the component (B) per 100 parts by mass of the component (A), more preferably 0.1 to 20 parts by mass, and even more preferably 0.5 to 10 parts by mass. A content of 0.05 parts by mass or greater of the component (B) allows for a sufficiently cured product to be obtained, while a content of 30 parts by mass or less is preferred because deterioration of dielectric properties can be suppressed.

[0127] Flame retardant (C)

[0128] The curable resin composition of the present invention is characterized by containing a flame retardant (C) (also referred to as "component (C)"). A cured product obtained using the curable resin composition containing the component (C) has excellent flame retardancy and is a preferred embodiment.

[0129] As the (C) component, there can be used without particular limitation, and examples thereof include phosphorus flame retardants, nitrogen compounds, silicone flame retardants, metal hydroxides, polysilanes, etc. As the phosphorus flame retardant, organic phosphorus flame retardants, reactive organic phosphorus flame retardants, and organic nitrogen-containing phosphorus compounds are preferred.

[0130] Examples of the organic phosphorus flame retardant include phenanthrene-type phosphorus compounds such as HCA, HCA-HQ, and HCA-NQ manufactured by Sanko Co., Ltd., phosphorus-containing benzoxazine compounds such as HFB-2006M manufactured by Showa High Polymer Co., Ltd., and Ajinomoto Fine Chemicals. Phosphate ester compounds such as Reofos 30, 50, 65, 90, 110, TPP, RPD, BAPP, CPD, TCP, TXP, TBP, TOP, KP140, and TIBP manufactured by Fine-Techno Co., Ltd., FP-800 and FP-600 manufactured by ADEKA Co., Ltd., PPQ manufactured by Hokusei Chemical Industry Co., Ltd., and PX-200 manufactured by Daihachi Chemical Co., Ltd., organic phosphinates such as OP930, OP935, and OP945 manufactured by Clariant Co., Ltd., phosphorus-containing epoxy resins such as FX289 and FX305 manufactured by Tohto Kasei Co., Ltd., phosphorus-containing phenoxy resins such as ERF001 manufactured by Tohto Kasei Co., Ltd., and phosphorus-containing epoxy resins such as YL7613 manufactured by Japan Epoxy Resin Co., Ltd., etc.

[0131] Examples of the reactive organophosphorus flame retardant include MC-2, MC-4, S-2, S-4, V1, V2, V3, V4, V5, W-1o, W-2h, W-2o, W-3o, and W-4o manufactured by Katayama Chemical Industry Co., Ltd.

[0132] Examples of the organic nitrogen-containing phosphorus compound include phosphate ester amide compounds such as SP670 and SP703 manufactured by Shikoku Chemical Industries, Ltd., SPB100 and SP100 manufactured by Otsuka Chemical Co., Ltd., and phosphazene compounds such as the FP-series manufactured by Fushimi Seisakusho Co., Ltd.

[0133] Examples of the metal hydroxide include magnesium hydroxides such as UD65, UD650, and UD653 manufactured by Ube Materials Co., Ltd., and aluminum hydroxides such as B-30, B-325, B-315, B-308, B-303, and UFH-20 manufactured by Basak Industries Co., Ltd. Examples of the polysilane include SI-10, SI-20, and SI-30 manufactured by Osaka Gas Chemical Co., Ltd.

[0134] Generally, flame retardants tend to increase the dielectric loss tangent when used. However, as the component (C), from the viewpoint of reducing the dielectric loss tangent, it is preferred to use a phosphate ester compound such as PX-200 manufactured by Daihachi Chemical Co., Ltd., an organic phosphinate such as OP930, OP935, and OP945 manufactured by Clariant Co., Ltd., or a reactive organophosphorus flame retardant such as MC-2, MC-4, S-2, S-4, V1, V2, V3, V4, V5, W-1o, W-2h, W-2o, W-3o, and W-4o manufactured by Katayama Chemical Industry Co., Ltd.

[0135] Furthermore, as the component (C), it is preferred that a phosphorus-based flame retardant represented by any one of the following general formulas (P-1) to (P-5) be contained.

[0136] [Chemistry 14]

[0137]

[0138] In the general formula (P-1), R 11 Each independently represents an alkyl group, aryl group, aralkyl group or cycloalkyl group having 1 to 12 carbon atoms, and is preferably a phenyl group having substituents at the 2 and 6 positions, and particularly preferably a 2,6-dimethylphenyl group, from the viewpoint of low dielectric loss tangent. 12 represents an alkylene group or an arylene group, and is preferably a phenylene group from the viewpoint of heat resistance. a represents an integer of 0 to 3, and is preferably 0 or 1 from the viewpoint of flame retardancy.

[0139] [Chemistry 15]

[0140]

[0141] In the general formula (P-2), R 13 Each independently represents an alkyl group, aryl group, aralkyl group or cycloalkyl group having 1 to 12 carbon atoms, and is preferably a methyl group, an ethyl group, a propyl group, a butyl group, a cyclohexyl group, a benzyl group or a phenyl group in view of low dielectric constant. b+ represents a metal ion with a valence of b. Examples of the metal include aluminum, magnesium, sodium, potassium, and calcium. Aluminum is preferred from the perspective of flame retardancy. b represents an integer of 1 to 3. From the perspective of flame retardancy, 3 is preferred.

[0142] [Chemistry 16]

[0143]

[0144] In the general formula (P-3), R 14 Each independently represents an alkyl group, aryl group, aralkyl group or cycloalkyl group having 1 to 12 carbon atoms, and is preferably a methyl group, an ethyl group, a propyl group, a butyl group, a cyclohexyl group, a benzyl group or a phenyl group in view of low dielectric constant. 15 M represents an alkylene group or an arylene group, and is preferably a phenylene group in terms of heat resistance. c+ The metal ion represents a valence of c. Examples of the metal include aluminum, magnesium, sodium, potassium, and calcium. Aluminum is preferred from the perspective of flame retardancy. c, d, and e each independently represent an integer from 1 to 3. From the perspective of flame retardancy, c is preferably 3, d is 2, and e is preferably 3. The relationship c×d=2×e is preferably satisfied.

[0145] [Chemistry 17]

[0146]

[0147] In the general formula (P-4), R 16 Each independently represents an alkyl group, aryl group, aralkyl group or cycloalkyl group having 1 to 12 carbon atoms, and is preferably a phenyl group in terms of heat resistance. It can form a ring structure together with the phosphorus atom, and R 17 represents a vinyl group, a vinylbenzyl group, or a (meth)acryloyloxy group. In terms of low dielectric loss tangent, vinyl group or vinylbenzyl group is preferred. f and g each independently represent 0 or 1. Furthermore, examples of phosphorus-based flame retardants that form a cyclic structure together with the phosphorus atom include the following general formula (P1).

[0148] [Chemistry 18]

[0149]

[0150] [Chemistry 19]

[0151]

[0152] In the general formula (P-5), R 18 Each independently represents an alkyl group, aryl group, aralkyl group or cycloalkyl group having 1 to 12 carbon atoms, and is preferably a phenyl group in terms of heat resistance. It can form a ring structure together with the phosphorus atom, and R 19 R represents a divalent group having an arylene structure, and is preferably a phenyl group in terms of heat resistance. 20represents a (meth)acryloyloxy group, a vinylbenzyl ether group, or an allyl ether group. In view of low dielectric loss tangent, a vinylbenzyl ether group is preferred. h represents 0 or 1. Examples of phosphorus-based flame retardants that form a cyclic structure together with the phosphorus atom include the following general formula (P2).

[0153] [Chemistry 20]

[0154]

[0155] The curable resin composition of the present invention preferably contains 0.05 to 300 parts by mass of the component (C) per 100 parts by mass of the component (A), more preferably 0.1 to 200 parts by mass, even more preferably 1 to 100 parts by mass, and even more preferably 5 to 50 parts by mass. When the content of the component (C) is 0.05 parts by mass or greater, the resulting cured product exhibits excellent flame retardancy, while when it is 300 parts by mass or less, deterioration of dielectric properties is suppressed, which is preferred.

[0156] <Other resins, etc.>

[0157] In the curable resin composition of the present invention, in addition to the components (A), (B), (C), and (D), other resins, curing agents, and curing accelerators may be used without particular limitation, as long as the objectives of the present invention are not impaired. The curable resin composition can be cured by heating or the like without adding a curing agent or a curing accelerator. For example, when the component (D) is added simultaneously, a curing agent or a curing accelerator may be added separately.

[0158] <Other resins>

[0159] Not only can the (A) component or the (D) component be mixed, but a thermoplastic resin can also be mixed as needed. Examples of the thermoplastic resin include styrene-butadiene resin, styrene-butadiene-styrene block resin, styrene-isoprene-styrene resin, styrene-maleic anhydride resin, acrylonitrile-butadiene resin, polybutadiene resin, or hydrogenated resins thereof, acrylic resins, and silicone resins. The use of the thermoplastic resin can impart properties derived from the resin to the cured product, resulting in a preferred form. For example, the properties that can be imparted include improved formability, high-frequency characteristics, conductor adhesion, solder heat resistance, adjustment of the glass transition temperature, thermal expansion coefficient, and the imparting of tail removal properties.

[0160] <Hardener>

[0161] Examples of the curing agent include amine compounds, amide compounds, acid anhydride compounds, phenol compounds, and cyanate compounds. These curing agents may be used alone or in combination of two or more.

[0162] <Hardening accelerator>

[0163] As the hardening accelerator, various substances can be used, for example, phosphorus compounds, tertiary amines, imidazoles, organic acid metal salts, Lewis acids, amine complex salts, etc. In particular, when used as a semiconductor sealing material, phosphorus compounds such as triphenylphosphine or imidazoles are preferred in terms of excellent hardening properties, heat resistance, electrical properties, moisture resistance, and reliability. These hardening accelerators can be used alone or in combination of two or more.

[0164] In addition, as the curing accelerator, when an epoxy resin is used as the component (D) in the curable resin composition, for example, organic phosphine compounds such as TPP, TPP-K, TPP-S, and TPTP-S (Hokuko Chemical Industry Co., Ltd.), amines such as dicyandiamide, diaminodiphenylethane, guanylurea, Novacure (Asahi Kasei Industries Co., Ltd.), and Fujikyu (Fuji Kasei Industries Co., Ltd.) amine adduct compounds, 1,8-diazabicyclo[5,4,0]undecene-7, 4-dimethylaminopyridine (Dimethylaminopyridine) and the like can be used. Pyridine, DMAP), benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, etc., imidazoles: 2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, benzimidazole, Curezol 2MZ, 2E4MZ, C11Z, C11Z-CN, C11Z-CNS, C11Z-A, 2MZ-OK, 2MA-OK, 2PHZ (Shikoku Chemicals Co., Ltd.), when a maleimide resin is used as the component (D), for example, an acidic Catalysts: p-toluenesulfonic acid, amine compounds: triethylamine, pyridine, tributylamine, tertiary amine compounds; quaternary ammonium compounds, imidazole compounds, phosphorus compounds, organic peroxides: dicumyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 3,2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butylperoxyisopropyl monocarbonate, α,α'-bis(tert-butylperoxy)diisopropylbenzene, carboxylates: manganese, cobalt, zinc. When a cyanate resin is used as the component (D), imidazole compounds and their derivatives, carboxylates of manganese, cobalt, zinc, etc.; organic metal compounds such as acetylacetone complexes of transition metals such as manganese, cobalt, and zinc, etc. can be used.

[0165] <Inorganic fillers>

[0166] The curable resin composition of the present invention may optionally contain an inorganic filler. Examples of such inorganic fillers include silica (fused silica, crystalline silica), aluminum oxide, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum borate, barium titanate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, and calcium zirconate. Surface treatment with a silane coupling agent is also possible. When the amount of the inorganic filler is particularly increased, it is preferred to use fused silica. Fused silica can be used in either crushed or spherical form, but to increase the amount of fused silica and suppress an increase in the melt viscosity of the molding material, it is preferred to primarily use spherical silica. To further increase the amount of spherical silica, it is preferred to appropriately adjust the particle size distribution of the spherical silica.

[0167] <Other ingredients>

[0168] The curable resin composition of the present invention may contain various additives such as a silane coupling agent, a release agent, a pigment, and an emulsifier, as needed.

[0169] <Hardened material>

[0170] The present invention relates to a cured product obtained by subjecting the curable resin composition to a curing reaction. The curable resin composition is obtained by uniformly mixing various components, such as the component (D) or a curing agent, in addition to the components (A), (B), and (C), depending on the intended purpose. The cured product can be easily formed using methods similar to conventional methods. Examples of the cured product include laminates, casts, adhesive layers, coatings, and films.

[0171] Examples of the curing reaction include heat curing and ultraviolet curing. Heat curing is easy to perform even without a catalyst, and the use of component (B) allows for a faster reaction. In addition to component (B), a polymerization initiator or catalyst may also be used.

[0172] Varnish

[0173] The present invention relates to a varnish obtained by diluting a curable resin composition with an organic solvent. The varnish can be prepared by using a known method, and the curable resin composition can be dissolved (diluted) in an organic solvent to form a resin varnish.

[0174] <Prepreg>

[0175] The present invention relates to a prepreg comprising a reinforcing base material and a semi-cured product of a varnish impregnated in the reinforcing base material. The prepreg can be produced by impregnating the reinforcing base material with the varnish (resin varnish) and then heat-treating the reinforcing base material impregnated with the varnish (resin varnish) to semi-cure (or uncure) the curable resin composition.

[0176] As the organic solvent, for example, toluene, xylene, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, methyl ethyl ketone (MEK), methyl isobutyl ketone, dioxane, tetrahydrofuran, etc. can be used alone or as a mixed solvent of two or more.

[0177] The reinforcing substrate impregnated with the varnish (resin varnish) is a woven or non-woven fabric containing inorganic fibers such as glass fibers, polyester fibers, and polyamide fibers, organic fibers, or felt, paper, etc. These materials can be used alone or in combination.

[0178] The mass ratio of the curable resin composition to the reinforcing substrate in the prepreg is not particularly limited, but is preferably prepared so that the curable resin composition (resin component therein) in the prepreg is 20% to 60% by mass.

[0179] The heat treatment conditions for the prepreg can be appropriately selected depending on the types and amounts of the organic solvent, catalyst, and various additives used, and are generally performed at a temperature of 80° C. to 220° C. for 3 to 30 minutes.

[0180] <Laminated body>

[0181] The present invention relates to a laminate comprising a substrate and a layer containing a cured product. The laminate formed by the layer containing the cured product (cured product layer) has a low dielectric constant, a low dielectric loss tangent, and high heat resistance, and is therefore preferably used for high-frequency printed circuit boards and the like.

[0182] The substrate used in the laminate is an inorganic material such as metal or glass, or an organic material such as plastic or wood, and can be used appropriately depending on the application. Examples thereof include glass fibers such as E glass, D glass, S glass, Q glass, spherical glass, NE glass, L glass, and T glass; inorganic fibers such as quartz; wholly aromatic polyamides such as polyparaphenylene terephthalamide (Kevlar (registered trademark), manufactured by DuPont), copolymerized p-phenylene / 3,4'-oxydiphenylene / p-phenylene diformamide (Technora (registered trademark), manufactured by Teijin Techno Products Co., Ltd.); polyesters such as 2,6-hydroxynaphthoic acid / parahydroxybenzoic acid (Vectran (registered trademark), manufactured by Kuraray Co., Ltd.); Zexion (registered trademark, manufactured by KB Xilinx). Seiren), organic fibers: polyparaphenylenebenzoxazole (Zylon (registered trademark), manufactured by Toyobo Co., Ltd.), polyimide, etc.

[0183] The laminate may be in the form of a flat plate, a sheet, or a three-dimensional structure. Any shape suitable for the purpose, such as a shape having curvature over the entire surface or in a portion, may be used. Furthermore, the hardness and thickness of the substrate are not limited. Furthermore, the cured product of the present invention may be used as a substrate upon which the cured product of the present invention may be laminated.

[0184] When the laminate is used for a circuit board or a semiconductor package board, it is preferable to laminate metal foil. Examples of the metal foil include copper foil, aluminum foil, gold foil, and silver foil. Copper foil is preferably used because of its good workability.

[0185] In the laminate, the layer containing the cured product (cured product layer) can be formed by direct coating or forming on a substrate, or by laminating already formed layers. In the case of direct coating, the coating method is not particularly limited, and examples thereof include spraying, spin coating, dipping, roller coating, blade coating, blade-on-roll coating, blade coating, curtain coating, slit coating, screen printing, and inkjet coating. In the case of direct forming, examples thereof include in-mold forming, insert forming, vacuum forming, extrusion lamination, and press forming.

[0186] Furthermore, the precursor that can serve as the substrate can be applied to the cured product of the present invention and cured to form a laminate. Alternatively, the precursor that can serve as the substrate or the curable resin composition of the present invention can be applied to the cured product of the present invention in an uncured or semi-cured state and then cured. The precursor that can serve as the substrate is not particularly limited, and various curable resin compositions can be used.

[0187] <Application>

[0188] The cured product obtained by the curable resin composition of the present invention has excellent flame retardancy, heat resistance and dielectric properties, and can therefore be preferably used for heat-resistant components or electronic components. In particular, it can be preferably used for varnishes, prepregs, circuit boards, semiconductor sealing materials, semiconductor devices, build-up films, build-up substrates, adhesives or resist materials used in the manufacture of prepregs. In addition, it can also be preferably used for the matrix resin of fiber-reinforced resins, and is particularly suitable as a prepreg that is flame retardant and highly heat-resistant. The heat-resistant components or electronic components thus obtained can be preferably used for various purposes, for example, industrial machinery parts, general machinery parts, automobile / railway / vehicle parts, aerospace / aviation-related parts, electronic / electrical parts, building materials, container / packaging components, daily necessities, sports / leisure products, wind power generation frame components, etc., but are not limited to these.

[0189] Hereinafter, representative products produced using the curable resin composition of the present invention will be described with examples.

[0190] <Circuit board>

[0191] The present invention relates to a circuit board obtained by laminating the above-mentioned prepreg and copper foil and subjecting them to heat and pressure molding. Specifically, a method for obtaining a circuit board from the curable resin composition of the present invention includes laminating the above-mentioned prepregs by a conventional method, appropriately overlapping the copper foils, and subjecting them to heat and pressure molding at 170°C to 300°C under a pressure of 1 MPa to 10 MPa for 10 minutes to 3 hours.

[0192] Semiconductor sealing materials

[0193] As a semiconductor sealing material, it is preferably containing the curable resin composition. Specifically, as a method for obtaining a semiconductor sealing material from the curable resin composition of the present invention, the following method can be cited: in the curable resin composition, an extruder, a kneader, a roller, etc. are used as needed to fully melt-mix a curing accelerator as an optional component and a blending agent such as an inorganic filler until uniform. At this time, as an inorganic filler, fused silica can usually be used. When used as a high thermal conductivity semiconductor sealing material for power transistors and power ICs, crystalline silica, aluminum oxide, silicon nitride, etc. with a thermal conductivity higher than that of fused silica can be used. Its filling rate is preferably to use an inorganic filler in the range of 30 to 95 parts by mass per 100 parts by mass of the curable resin composition. Among them, in order to achieve an improvement in flame retardancy, moisture resistance or solder crack resistance and a reduction in the linear expansion coefficient, it is more preferably 70 parts by mass or more, and further preferably 80 parts by mass or more.

[0194] Semiconductor devices

[0195] The semiconductor device preferably includes a cured product obtained by heat-curing the semiconductor encapsulating material. Specifically, a semiconductor package molding method for obtaining a semiconductor device from the curable resin composition of the present invention includes casting the semiconductor encapsulating material or molding it using a transfer molding machine, injection molding machine, or the like, and then heat-curing it at 50°C to 250°C for 2 to 10 hours.

[0196] <Build-up substrate>

[0197] Methods for obtaining a build-up substrate from the curable resin composition of the present invention include methods involving steps 1 to 3. In step 1, the curable resin composition, suitably formulated with rubber, fillers, and the like, is first applied to a circuit substrate having a circuit formed thereon using a spray coating method, curtain coating, or the like, and then cured. In step 2, after the circuit substrate coated with the curable resin composition is provided with predetermined through-holes and the like, it is treated with a roughening agent, washed with hot water, thereby forming irregularities on the substrate, and then plated with a metal such as copper. In step 3, steps 1 and 2 are repeated as needed, alternately building up resin insulating layers and conductor layers having predetermined circuit patterns to form a build-up substrate. Furthermore, in this step, the through-holes may be formed after the outermost resin insulating layer has been formed. In addition, the build-up substrate in the present invention can also be produced by forming a roughened surface by heating and pressing the resin-coated copper foil obtained by semi-curing the resin composition on the copper foil at 170°C to 300°C onto a wiring substrate formed with a circuit, thereby omitting the plating process and making a build-up substrate.

[0198] <Build-up film>

[0199] As a build-up film, it is preferred to contain the curable resin composition. As a method for obtaining a build-up film from the curable resin composition of the present invention, for example, the following method can be cited: after applying the curable resin composition on a support film, it is dried to form a resin composition layer on the support film. When the curable resin composition of the present invention is used for a build-up film, it is important that the film softens under the lamination temperature conditions (usually 70°C to 140°C) in the vacuum lamination method, and exhibits fluidity (resin flow) that allows the resin to be filled into the vias or through-holes present in the circuit substrate while laminating the circuit substrate. In order to exhibit such characteristics, it is preferred to formulate the above-mentioned components.

[0200] Here, the diameter of the through hole of the circuit board is usually 0.1mm to 0.5mm, and the depth is usually 0.1mm to 1.2mm. It is usually preferable to fill the through hole with resin within the above range. In the case of laminating both sides of the circuit board, it is ideal to fill about 1 / 2 of the through hole.

[0201] As a specific method for manufacturing the above-mentioned build-up film, the following method can be listed: after preparing a varnished resin composition by mixing an organic solvent, the varnished resin composition is coated on the surface of the support film (Y), and the organic solvent is dried by heating or hot air blowing, thereby forming a resin composition layer (X).

[0202] As the organic solvent used here, preferably used are ketones such as acetone, methyl ethyl ketone, and cyclohexanone; acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitols such as cellosolve and butyl carbitol; aromatic hydrocarbons such as toluene and xylene; dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. In addition, it is preferably used in a ratio of 30% by mass to 60% by mass of the non-volatile component.

[0203] Furthermore, the thickness of the formed resin composition layer (X) must generally be greater than the thickness of the conductor layer. The thickness of the conductor layer of the circuit board is generally within the range of 5 μm to 70 μm, so the thickness of the resin composition layer (X) is preferably 10 μm to 100 μm. Furthermore, the resin composition layer (X) in the present invention may also be protected by a protective film described later. By protecting with a protective film, it is possible to prevent dust and the like from adhering to or damaging the surface of the resin composition layer.

[0204] The support film and the protective film can be listed as follows: polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate, polycarbonate, polyimide, and release paper or metal foils such as copper foil and aluminum foil. Furthermore, in addition to matte treatment and corona treatment, the support film and the protective film can also be subjected to demolding treatment. The thickness of the support film is not particularly limited, and is generally 10 μm to 150 μm, preferably used in the range of 25 μm to 50 μm. In addition, the thickness of the protective film is preferably set to 1 μm to 40 μm.

[0205] The support film (Y) is removed after lamination onto the circuit board or heat-curing to form the insulating layer. Removing the support film (Y) after heat-curing the resin composition layer constituting the build-up film prevents the adhesion of dust and the like during the curing process. When removing the support film after curing, the support film is typically pre-treated with a mold release.

[0206] Furthermore, a multilayer printed circuit board can be manufactured from the build-up film obtained as described above. For example, when the resin composition layer (X) is protected by a protective film, after peeling them off, the resin composition layer (X) is directly contacted with the circuit substrate and laminated to one or both sides of the circuit substrate by, for example, vacuum lamination. The lamination method may be batch or continuous using a roller. In addition, the build-up film and the circuit substrate may be preheated (preheated) as needed before lamination. The lamination conditions are preferably set to a pressing temperature (lamination temperature) of 70°C to 140°C, and preferably a pressing pressure of 1kgf / cm 2 ~11kgf / cm 2 (9.8×10 4 N / m 2 ~107.9×10 4 N / m 2 ), preferably lamination is performed under reduced pressure such that the gas pressure is 20 mmHg (26.7 hPa) or less.

[0207] Conductive paste

[0208] The conductive paste can be obtained from the curable resin composition of the present invention by dispersing conductive particles in the composition. Depending on the type of conductive particles used, the conductive paste can be a circuit-connecting paste resin composition or an anisotropic conductive adhesive.

[0209] [Example]

[0210] The present invention is described in detail below using Examples and Comparative Examples. "Parts" and "%" are by mass unless otherwise specified. Furthermore, a curable resin (referred to simply as "resin" in Comparative Example 1) and a cured product obtained using the curable resin (or resin) were prepared under the following conditions, and the resulting cured product was measured and evaluated under the following conditions.

[0211] <Gel Permeation Chromatography (GPC) Measurement (Evaluation of the Weight Average Molecular Weight (Mw) of Curable Resin)>

[0212] The following measuring apparatus and measuring conditions were used to obtain a GPC chart of the curable resin obtained by the synthesis method shown below. The weight average molecular weight (Mw) of the curable resin was calculated based on the results of the GPC chart (GPC chart not shown).

[0213] Measuring device: HLC-8320GPC manufactured by Tosoh Corporation

[0214] Column: Protective column "HXL-L" manufactured by Tosoh Corporation + "TSK-GEL G2000HXL" manufactured by Tosoh Corporation + "TSK-GEL G2000HXL" manufactured by Tosoh Corporation + "TSK-GEL G3000HXL" manufactured by Tosoh Corporation + "TSK-GEL G4000HXL" manufactured by Tosoh Corporation

[0215] Detector: RI (differential refractometer)

[0216] Data processing: GPC WorkStation EcoSEC WorkStation manufactured by Tosoh Corporation

[0217] Measurement conditions: column temperature 40°C

[0218] Expanding solvent: tetrahydrofuran

[0219] Flow rate 1.0 ml / min

[0220] Standard: According to the measurement manual of the "GPC WorkStation EcoSEC WorkStation", the following monodisperse polystyrene having a known molecular weight was used.

[0221] (Using polystyrene)

[0222] "A-500" manufactured by Tosoh Co., Ltd.

[0223] "A-1000" manufactured by Tosoh Co., Ltd.

[0224] "A-2500" manufactured by Tosoh Co., Ltd.

[0225] "A-5000" manufactured by Tosoh Co., Ltd.

[0226] "F-1" manufactured by Tosoh Co., Ltd.

[0227] "F-2" manufactured by Tosoh Co., Ltd.

[0228] "F-4" manufactured by Tosoh Co., Ltd.

[0229] "F-10" manufactured by Tosoh Co., Ltd.

[0230] "F-20" manufactured by Tosoh Co., Ltd.

[0231] "F-40" manufactured by Tosoh Co., Ltd.

[0232] "F-80" manufactured by Tosoh Co., Ltd.

[0233] F-128 manufactured by Tosoh Co., Ltd.

[0234] Sample: A sample (50 μl) obtained by filtering a 1.0% by mass tetrahydrofuran solution of the curable resin obtained in Examples and Comparative Examples in terms of solid content using a microfilter.

[0235] (Example 1)

[0236] In a reaction vessel equipped with a stirrer, 113.8 parts by mass of 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 64.0 parts by mass of sodium hydroxide, 0.25 parts by mass of tri-n-butylbenzylammonium chloride, and 2000 parts by mass of pure water were placed and dissolved to prepare an aqueous phase. 30.5 parts by mass of terephthalic acid dichloride, 30.5 parts by mass of isophthalic acid dichloride, and 20.9 parts by mass of methacrylic acid chloride were dissolved in 1500 parts by mass of dichloromethane to prepare an organic phase.

[0237] The aqueous phase was pre-stirred, and the organic phase was added to the aqueous phase with vigorous stirring, and the reaction was carried out at 20°C for 5 hours. Stirring was then stopped, the aqueous and organic phases were separated, and the organic phase was washed 10 times with pure water. Dichloromethane was then distilled from the organic phase under reduced pressure using an evaporator to dry the resulting polymer. The resulting polymer was dried under reduced pressure to yield a curable resin having the following repeating units and a weight-average molecular weight of 3100 with terminal methacryloyloxy groups.

[0238] [Chemistry 21]

[0239]

[0240] (Example 2)

[0241] Synthesis was carried out in the same manner as in Example 1, except that 102.5 parts by mass of bis(4-hydroxy-3,5-dimethylphenyl)methane was used instead of 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane in Example 1, to obtain a curable resin having the following repeating units, a terminal methacryloyloxy group, and a weight average molecular weight of 2900.

[0242] [Chemistry 22]

[0243]

[0244] (Example 3)

[0245] Synthesis was carried out in the same manner as in Example 1, except that 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane in Example 1 was replaced with 141.0 parts by mass of 2,2-bis(2-hydroxy-5-biphenyl)propane, to obtain a curable resin having the following repeating units, a terminal methacryloyloxy group, and a weight average molecular weight of 3200.

[0246] [Chemistry 23]

[0247]

[0248] (Example 4)

[0249] Synthesis was carried out in the same manner as in Example 1, except that 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane in Example 1 was replaced with 157.0 parts by mass of 2,2-bis(4-hydroxy-3-cyclohexyl-6-methylphenyl)propane. A curable resin having the following repeating units and a weight-average molecular weight of 3200 and terminal methacryloyloxy groups was obtained.

[0250] [Chemistry 24]

[0251]

[0252] (Example 5)

[0253] Synthesis was carried out in the same manner as in Example 1, except that 113.8 parts by mass of 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane was used instead of 2,2-bis(4-hydroxy-3,5,6-trimethylphenyl)propane. A curable resin having the following repeating units and a weight-average molecular weight of 3100 and terminal methacryloyloxy groups was obtained.

[0254] [Chemistry 25]

[0255]

[0256] (Example 6)

[0257] Synthesis was carried out in the same manner as in Example 1, except that 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane in Example 1 was replaced with 129.8 parts by mass of 1,1-bis(4-hydroxy-3,5-dimethylphenyl)cyclohexane, to obtain a curable resin having the following repeating units, a terminal methacryloyloxy group, and a weight-average molecular weight of 3100.

[0258] [Chemistry 26]

[0259]

[0260] (Example 7)

[0261] Synthesis was carried out in the same manner as in Example 1, except that 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane in Example 1 was replaced with 161.0 parts by mass of 1,4-bis(2-(4-hydroxy-3,5-dimethylphenyl)-2-propyl)benzene, to obtain a curable resin having the following repeating units, a terminal methacryloyloxy group, and a weight average molecular weight of 3500.

[0262] [Chemistry 27]

[0263]

[0264] (Example 8)

[0265] A curable resin having a weight average molecular weight of 3100 and having the following repeating units and a terminal methacryloyloxy group was synthesized by the same method as in Example 1, except that terephthalic acid dichloride and isophthalic acid dichloride were replaced with 62.7 parts by mass of 1,4-cyclohexanedicarboxylic acid dichloride.

[0266] [Chemistry 28]

[0267]

[0268] (Example 9)

[0269] A curable resin having the following repeating units and a weight average molecular weight of 3500 and having a methacryloyloxy group at the terminal was synthesized by the same method as in Example 1 except that terephthalic acid dichloride and isophthalic acid dichloride were replaced with 88.5 parts by mass of diphenyl ether 4,4′-dicarboxylic acid dichloride.

[0270] [Chemistry 29]

[0271]

[0272] (Example 10)

[0273] A reaction vessel equipped with a stirrer, a distillation column, and a pressure-reducing device was charged with 113.8 parts by mass of 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 64.2 parts by mass of diphenyl carbonate, and 0.01 parts by mass of tetramethylammonium hydroxide. After nitrogen substitution, the mixture was dissolved at 140°C. After stirring for 30 minutes, the internal temperature was raised to 180°C, and the reaction was carried out at an internal pressure of 100 mmHg for 30 minutes to distill off the generated phenol. Subsequently, the internal temperature was raised to 200°C, the pressure was gradually reduced, and the phenol was distilled off at 50 mmHg and the reaction was continued for 30 minutes. The temperature was then gradually raised to 220°C, the pressure was reduced to 1 mmHg, and the reaction was continued at the same temperature and pressure for 30 minutes. The resulting solid was washed with methanol and then dried under reduced pressure to obtain an intermediate compound.

[0274] In a 200 mL flask equipped with a thermometer, cooling tube, and stirrer, 20 g of toluene and 22 g of the intermediate compound were mixed and heated to approximately 85°C. 0.19 g of dimethylaminopyridine was added. When the solids were considered completely dissolved, 30.6 g of methacrylic anhydride was slowly added. The resulting solution was maintained at 85°C for 3 hours while continuously mixing. The solution was then cooled to room temperature and added dropwise to methanol vigorously stirred in a 1 L beaker with a magnetic stirrer. The resulting precipitate was filtered under reduced pressure and dried to obtain a curable resin having the following repeating units and a weight-average molecular weight of 2700 with terminal methacryloyloxy groups.

[0275] [Chemistry 30]

[0276]

[0277] (Example 11)

[0278] A curable resin having the following repeating units and a terminal vinylbenzyl ether group and a weight average molecular weight of 3100 was synthesized by the same method as in Example 1 except that 30.5 parts by mass of chloromethylstyrene was used instead of methacrylic acid chloride.

[0279] [Chemistry 31]

[0280]

[0281] (Example 12)

[0282] A curable resin having the following repeating units and a weight average molecular weight of 3100 and having an allyl ether group at the end was synthesized by the same method as in Example 1 except that methacrylic acid chloride was replaced with 15.3 parts by mass of allyl chloride.

[0283] [Chemistry 32]

[0284]

[0285] (Comparative Example 1)

[0286] In a reaction vessel equipped with a stirrer, 113.8 parts by mass of 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 64.0 parts by mass of sodium hydroxide, 0.25 parts by mass of tri-n-butylbenzylammonium chloride, and 2000 parts by mass of pure water were placed and dissolved to prepare an aqueous phase. 30.5 parts by mass of terephthalic acid dichloride and 30.5 parts by mass of isophthalic acid dichloride were dissolved in 1500 parts by mass of dichloromethane to prepare an organic phase.

[0287] The aqueous phase was pre-stirred, and the organic phase was added to the aqueous phase with vigorous stirring. The reaction was allowed to proceed at 20°C for 5 hours. Stirring was then stopped, and the aqueous and organic phases were separated. The organic phase was washed with a 10% aqueous acetic acid solution and then washed ten times with pure water. Dichloromethane was then distilled from the organic phase under reduced pressure using an evaporator, and the polymer obtained by the reaction was dried to dryness. The resulting polymer was dried under reduced pressure to yield a resin having the following repeating units, a terminal phenyl group, and a weight-average molecular weight of 2800.

[0288] [Chemistry 33]

[0289]

[0290] (Comparative Example 2)

[0291] A curable resin having a weight average molecular weight of 3000 and having the following repeating units and a methacryloyloxy group at the terminal was synthesized by the same method as in Example 1, except that 91.3 parts by mass of 2,2-bis(4-hydroxyphenyl)propane was used instead of 2,2-bis(4-hydroxyphenyl)propane.

[0292] [Chemistry 34]

[0293]

[0294] <Production of Resin Film (Cured Product)>

[0295] The curable resins obtained in the Examples and Comparative Examples were placed in a 5 cm square mold, held between stainless steel plates, and placed in a vacuum press. Pressure was applied to 1.5 MPa at room temperature and pressure. The pressure was then reduced to 10 Torr and heated over 30 minutes to a temperature 50°C higher than the thermal curing temperature. After allowing the mold to stand for 2 hours, the mold was slowly cooled to room temperature, yielding a uniform resin film (cured product) with an average thickness of 100 μm.

[0296] Furthermore, the resin obtained in Comparative Example 1 is different from the other embodiments and comparative examples and does not self-harden. Therefore, an epoxy resin (jER828, manufactured by Mitsubishi Chemical Corporation, a bisphenol A-type epoxy resin) and the resin obtained in Comparative Example 1 (a phenolic resin containing terminal hydroxyl groups) were mixed in such a manner that the phenolic hydroxyl group equivalent / epoxy equivalent was 1, and 0.2 parts by mass of 2-ethyl-4-methylimidazole was mixed as a curing catalyst relative to 100 parts by mass of the resin (the total of the entire resin) to obtain a resin film (cured product).

[0297] <Evaluation of Dielectric Properties>

[0298] The dielectric properties of the obtained resin film (cured product) in the in-plane direction were measured by using a network analyzer N5247A from Keysight Technologies, Inc., using a split dielectric resonator method to measure the dielectric constant and dielectric loss tangent at a frequency of 10 GHz.

[0299] As the dielectric loss tangent, if it is 10.0×10 -3 Below, there is no problem in practical use, preferably 3.0×10 -3 Below, more preferably 2.5×10 -3 the following.

[0300] In addition, there is no practical problem as long as the dielectric constant is 3 or less, and it is preferably 2.7 or less, and more preferably 2.5 or less.

[0301] <Evaluation of heat resistance (glass transition temperature)>

[0302] The obtained resin film (cured product) was measured using a PerkinElmer differential scanning calorimeter (DSC) apparatus (PyrisDiamond). The peak exothermic temperature (thermal curing temperature) observed when measuring at a temperature increase of 20°C / minute from 30°C was measured, and then the sample was held at a temperature 50°C higher for 30 minutes. Subsequently, the sample was cooled to 30°C at a temperature decrease of 20°C / minute, and then the temperature was again increased at a temperature increase of 20°C / minute to measure the glass transition temperature (Tg) (°C) of the resin film (cured product).

[0303] The glass transition temperature (Tg) does not cause any practical problems if it is 100°C or higher, but is preferably 150°C or higher, and more preferably 190°C or higher.

[0304] [Table 1]

[0305]

[0306]

[0307] <Preparation of Curable Resin Composition>

[0308] Using the curable resins obtained in the Examples and Comparative Examples, curable resin compositions having the formulations (raw materials, formulation amounts) described in Tables 2 and 3 below, and the conditions (temperature, time, etc.) described below, evaluation samples (resin films (cured products)) were prepared and evaluated as Examples and Comparative Examples. Specifically, the curable resins shown in Tables 2 and 3 were designated as curable resin (A1), the curable resin obtained in Example 2 as curable resin (A2), the curable resin obtained in Example 11 as curable resin (A3), and the curable resin obtained in Comparative Example 2 as curable resin (A4).

[0309] <Production of Resin Film (Cured Product)>

[0310] The curable resin composition described in Tables 2 and 3 below was placed in a 10 cm square mold, clamped between stainless steel plates, and placed in a vacuum press. The mold was pressurized to 1.5 MPa at 30°C. The pressure was then reduced to 10 torr, heated to 100°C over 30 minutes, and allowed to stand for 1 hour. The mold was then heated to 220°C over 30 minutes and allowed to stand for 2 hours. The mold was then slowly cooled to 30°C. A uniform resin film (cured product) with an average thickness of 100 μm was produced.

[0311] <Evaluation of heat resistance (glass transition temperature)>

[0312] The obtained resin film (cured product) was measured using a PerkinElmer DSC apparatus (Pyris Diamond). The peak exothermic temperature (thermal curing temperature) observed when measuring at a temperature increase of 20°C / minute from 30°C was then maintained at a temperature 50°C higher for 30 minutes. The sample was then cooled to 30°C at a temperature decrease of 20°C / minute and then again heated at a temperature increase of 20°C / minute to measure the glass transition temperature (Tg) (°C) of the resin film (cured product). While the glass transition temperature (Tg) is practically acceptable if it is 100°C or higher, it is preferably 150°C or higher, and more preferably 200°C or higher.

[0313] <Evaluation of heat resistance (10% weight loss temperature)>

[0314] The obtained resin film (cured product) was measured using a TG-DTA apparatus (TG-8120) manufactured by Rigaku Co., Ltd. under a nitrogen flow of 20 mL / min at a temperature increase rate of 20°C / min to determine the 10% weight loss temperature (Td10). A 10% weight loss temperature of 400°C or higher is practically acceptable, preferably 410°C or higher, and more preferably 420°C or higher.

[0315] <Evaluation of Dielectric Properties>

[0316] The dielectric properties of the obtained resin film (cured product) in the in-plane direction were measured using a network analyzer N5247A from Keysight Technology using the separated dielectric resonator method to measure the dielectric constant and dielectric loss tangent at a frequency of 10 GHz. -3 Below, there is no problem in practical use, preferably 3.0×10 -3 Below, more preferably 2.5×10 -3In addition, as for the dielectric constant, there is no problem in practical use if it is 3.0 or less, and it is preferably 2.7 or less, and more preferably 2.5 or less.

[0317] <Evaluation of flame retardancy>

[0318] The resin film was cut into strips 13 mm wide and 100 mm long to prepare test pieces for flame retardancy evaluation. The UL94 20 mm vertical burning test was performed and evaluated according to the following standards. A flame retardancy rating of V-1 is considered practically acceptable, and V-0 is preferred.

[0319] ○: UL94 V-0

[0320] △: UL94 is V-1

[0321] ×: UL94 less than V-1

[0322] The details of the abbreviations in Tables 2 and 3 below are shown below.

[0323] V5: V5 (9,10-dihydro-9-oxa-10-vinyl-10-phosphaphenanthrene-10-oxide) manufactured by Katayama Chemical Industry Co., Ltd.

[0324] OP930: OP930 (aluminum tris(diethylphosphinate)) manufactured by Clariant Japan Co., Ltd.

[0325] PX-200: PX-200 (resorcinol bis(di-2,6-xylyl phosphate)) manufactured by Daba Chemical Industry Co., Ltd.

[0326] DT-4000: DT-4000 (dicyclopentadiene cyanate resin) manufactured by Lonza Japan Co., Ltd.

[0327] SA9000: SA9000 (terminal methacryloyl-modified polyphenylene ether resin) manufactured by SABIC Japan Joint Venture

[0328] BMI-5100: BMI-5100 (3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide) manufactured by Yamato Chemical Industry Co., Ltd.

[0329]

[0330]

[0331] The evaluation results in Table 1 above confirmed that in all examples, the cured products obtained by using the curable resin can achieve both heat resistance and low dielectric properties, and are at a level that poses no practical problem.

[0332] On the other hand, the evaluation results in Table 1 indicate that in Comparative Example 3 (using the resin of Comparative Example 1), the use of an epoxy resin and a phenolic resin containing terminal hydroxyl groups and their reaction resulted in the formation of hydroxyl groups, leading to improved dielectric properties. Furthermore, in Comparative Example 4 (using the curable resin of Comparative Example 2), the curable resin used did not contain a substituent corresponding to Ra in its structure, leading to improved dielectric properties compared to the examples.

[0333] The evaluation results in Tables 2 and 3 indicate that, in all Examples, the cured products obtained by using the curable resin can achieve improved flame retardancy, heat resistance, and low dielectric properties, reaching levels that pose no practical problems.

[0334] On the other hand, according to the evaluation results in Table 3, Comparative Example 5 used only component (A), Comparative Example 6 used components (A) and (B), Comparative Example 7 used only components (A) and (C), and Comparative Example 8 used a curable resin composition that used component (A) without the required structure (Ra and Rb). Therefore, it was not possible to obtain a cured product that simultaneously satisfied all of the requirements for flame retardancy, heat resistance, and low dielectric properties. In particular, in Comparative Examples 5 and 7, the absence of component (B), a free radical polymerization initiator, reduced reactivity, resulting in a large amount of residual low-molecular-weight components. This resulted in a weight loss during high-temperature heating, confirming poor heat resistance. Furthermore, in Comparative Examples 5 and 6, the absence of component (C), a flame retardant, confirmed poor flame retardancy. In Comparative Example 8, since component (A) that does not have the required structure (Ra and Rb) is used, Ra and Rb (especially Ra) as substituents are not present at positions adjacent to the reactive group (cross-linking group). The polarity of the reactive group (cross-linking group) is not easily constrained by steric hindrance such as Ra, which is presumably the result of deterioration in dielectric properties.

[0335] Industrial applicability

[0336] The cured product obtained using the curable resin composition of the present invention exhibits excellent flame retardancy, heat resistance, and low dielectric properties, making it suitable for use in heat-resistant components or electronic components, particularly prepregs, circuit boards, build-up films, build-up substrates, adhesives, and resist materials. Furthermore, it can be used as a matrix resin for fiber-reinforced resins, making it suitable for use as highly heat-resistant prepregs.

Claims

1. A hardening resin characterized by A terminal structure consisting of a repeating unit represented by the following general formula (1) and at least one reactive group selected from the group consisting of a (meth)acryloyloxy group, a vinylbenzyl ether group, and an allyl ether group; In the formula, Ra and Rb each independently represent an alkyl group, an aryl group, an aralkyl group or a cycloalkyl group having 1 to 12 carbon atoms; k represents an integer from 0 to 3; X represents a hydrocarbon group; and Y represents the following general formula (2) or (3). In the formula, Z represents an alicyclic group, an aromatic group or a heterocyclic group.

2. The curable resin according to claim 1, wherein the general formula (1) is a repeating unit represented by the following general formula (1A); In the formula, Rc represents a hydrogen atom or a methyl group. The curable resin according to claim 1 or 2, wherein Z is a benzene ring. The curable resin according to claim 1 or 2, wherein the reactive group is a methacryloyloxy group. 5 . The curable resin according to claim 1 , wherein the curable resin has a weight average molecular weight of 500 to 50,000.

Images