Curing resin, curing resin composition, and curing agent

Abstract

To provide a curable resin that is superior in heat resistance (high glass transition temperature), and dielectric properties (low dielectric properties) and the resin composition, and a cured product thereof.SOLUTION: A curable resin comprises a repeat unit represented by the general formula (1) and at least one reactive group selected from the group consisting of (meth)acryloyloxy groups, vinylbenzyl ether groups, and allyl ether groups as a terminal structure. In the formula 1, substituents and their numbers are as defined in the specifications.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curable resin having a specific structure, a curable resin composition containing the curable resin, and a cured product obtained from the curable resin composition. [Background technology]

[0002] With the recent increase in the volume of information and communication, information and communication in the high frequency band has become more prevalent. This has created a demand for electrical insulating materials with better electrical properties, particularly low dielectric constants and low dielectric loss tangents, to reduce transmission loss in the high frequency band.

[0003] Furthermore, printed circuit boards or electronic components that use these electrical insulating materials are exposed to high-temperature solder reflow during mounting, so materials with excellent heat resistance and a high glass transition temperature are required. In particular, in recent years, lead-free solders with high melting points have been used from the perspective of environmental issues, so there has been an increasing demand for electrical insulating materials with even higher heat resistance.

[0004] To meet these demands, vinyl group-containing curable resins with various chemical structures have been proposed, including, for example, divinylbenzyl ether of bisphenol or polyvinylbenzyl ether of novolac, and polyphenylene ether resins containing aliphatic unsaturation (see, for example, Patent Documents 1 and 2).

[0005] However, these vinyl benzyl ethers are unable to give cured products with sufficiently small dielectric properties, and the resulting cured products have problems in being used stably in high frequency bands. Furthermore, divinyl benzyl ethers of bisphenols do not have sufficiently high heat resistance.

[0006] In order to improve the dielectric properties of vinylbenzyl ethers having the above-mentioned improved properties, several polyvinylbenzyl ethers having specific structures have been proposed (see, for example, Patent Documents 3 to 5). However, although attempts have been made to reduce the dielectric loss tangent or improve the heat resistance, the improvements in these properties are still insufficient, and further improvements in properties are desired.

[0007] As described above, conventional vinyl group-containing curable resins, including polyvinyl benzyl ether, have not been able to give cured products that have both a low dielectric dissipation factor required for electrical insulating material applications, particularly for high-frequency electrical insulating material applications, and heat resistance sufficient to withstand lead-free soldering. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 63-68537 [Patent Document 2] Japanese Patent Application Publication No. 64-65110 [Patent Document 3] Special Publication No. 1-503238 [Patent Document 4] Japanese Patent Application Publication No. 9-31006 [Patent Document 5] Japanese Patent Application Laid-Open No. 2005-314556 Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, the problem to be solved by the present invention is to provide a cured product having excellent heat resistance (high glass transition temperature) and dielectric properties (low dielectric properties) by using a curable resin having a specific structure. [Means for solving the problem]

[0010] Therefore, the present inventors conducted extensive research to solve the above problems, and as a result, found that a curable resin that can contribute to heat resistance and low dielectric properties, and a cured product obtained from a curable resin composition containing the curable resin, have excellent heat resistance and low dielectric properties, and have thus completed the present invention.

[0011] That is, the present invention relates to a curable resin 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: [ka] (In the formula, 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 of 0 to 3. X represents a hydrocarbon group. Y represents an alicyclic group, aromatic group, or heterocyclic group.)

[0012] In the curable resin of the present invention, the general formula (1) is preferably a repeating unit represented by the following general formula (1A). [ka]

[0013] In the curable resin of the present invention, the Y is preferably a benzene ring.

[0014] In the curable resin of the present invention, the reactive group is preferably a methacryloyloxy group.

[0015] The curable resin of the present invention preferably has a weight average molecular weight of 500 to 50,000.

[0016] The present invention relates to a curable resin composition containing the curable resin.

[0017] The present invention relates to a cured product obtained by subjecting the curable resin composition to a curing reaction. [Effects of the Invention]

[0018] The curable resin of the present invention can contribute to heat resistance and low dielectric properties, and therefore a cured product obtained from a curable resin composition containing the curable resin is useful because it has excellent heat resistance (high glass transition temperature) and low dielectric properties. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention will be described in detail below.

[0020] <Curing resin> The present invention relates to a curable resin 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: [ka]

[0021] In the general formula (1), 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 of 0 to 3. X represents a hydrocarbon group. Y represents an alicyclic group, aromatic group, or heterocyclic group.

[0022] The curable resin has a repeating unit represented by the 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, which results in lower molecular mobility compared to the ether bond contained in the curable resin, resulting in low dielectric properties. Furthermore, the presence of substituents Ra or Rb (particularly Ra) adjacent to the reactive group constrains the polarity derived from the reactive group by steric hindrance of Ra, resulting in a cured product with a lower dielectric loss tangent, which is preferable. Furthermore, the presence of reactive groups in the curable resin results in the cured product having excellent heat resistance, and the presence of ether bonds with low molecular mobility results in a cured product with not only low dielectric properties but also a high glass transition temperature.

[0023] In the general formula (1), Ra and Rb each independently represent an alkyl group, aryl group, aralkyl group, or cycloalkyl group having 1 to 12 carbon atoms, and are preferably an alkyl group, aryl group, or cycloalkyl group having 1 to 4 carbon atoms. When Ra and Rb are alkyl groups having 1 to 12 carbon atoms, the planarity in the vicinity of the benzene ring in the general formula (1) is reduced, and the reduced crystallinity improves solvent solubility and lowers the melting point, which is a preferred embodiment. Furthermore, when the substituent Ra or Rb (particularly Ra) is present adjacent to the reactive group, the polarity derived from the reactive group is restricted by the steric hindrance of Ra, and a cured product having a lower dielectric tangent can be obtained, which is preferred.

[0024] 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 in the vicinity of the benzene ring in the general formula (1) is reduced, and the reduced crystallinity improves solvent solubility and lowers the melting point, which is a preferred embodiment. Furthermore, when k is not 0, that is, when the substituent Rb is present and present in the vicinity of the reactive group, the polarity derived from the reactive group is restricted by the steric hindrance of Rb, and a cured product with a low dielectric loss tangent can be obtained, which is preferable.

[0025] In the above general formula (1), X may be any hydrocarbon group, but in view of ease of availability of industrial raw materials, it is preferable that X be represented by a structure of the following general formulas (2) to (4), and in particular, the structure of the following general formula (2) is more preferable because it has a good balance between heat resistance and low dielectric properties. [ka]

[0026] In the above general formulas (2) to (4), 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, or R1 and R2 may be bonded together to form a cyclic skeleton. n represents an integer of 0 to 2, preferably an integer of 0 to 1. When n is within the above range, high heat resistance is achieved, which is a preferred embodiment.

[0027] In the above general formula (1), Y represents an alicyclic group, an aromatic group, or a heterocyclic group in order to obtain a highly heat-resistant cured product, but is preferably a structure represented by the following general formulas (5) to (9), and in particular, the structure of the following general formula (5) (benzene ring) is more preferred from the viewpoints of cost, heat resistance, and low dielectric properties. [ka]

[0028] The curable resin 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 as a terminal structure, and preferably a methacryloyloxy group as the terminal structure, since the resulting cured product has a low dielectric loss tangent. The methacryloyloxy group forms an ester bond, whereas the vinylbenzyl ether group and the allyl ether group form an ether bond, which tend to have high molecular mobility and a high dielectric loss tangent.

[0029] In the curable resin of the present invention, the general formula (1) is preferably a repeating unit represented by the following general formula (1A). [ka]

[0030] In the general formula (1A), Rc preferably represents a hydrogen atom or a methyl group, and more preferably a hydrogen atom. When Rc is a hydrogen atom or the like, the polarity becomes low, which is a preferred embodiment. In the general formula (1A), Ra, Rb, and Y are the same as those in the general formula (1).

[0031] The curable resin is characterized by having a repeating unit represented by the above general formula (1) (or a repeating unit represented by the above general formula (1A)) and the above reactive group as a terminal structure, but may contain other repeating units (structures) as long as the properties of the curable resin are not impaired.

[0032] The weight average molecular weight (Mw) of the curable resin is preferably 500 to 50000, more preferably 1000 to 10000, and even more preferably 1500 to 5000. When it is within the above range, the solvent solubility is improved and the processability is good, which is preferable.

[0033] <Method for producing curable resin> The method for producing the curable resin is not particularly limited, but preferably includes condensing a dihydroxy aromatic compound or an alkali metal salt of a dihydroxy aromatic compound with an aryl halide in the presence of a copper catalyst at a temperature of 50 to 250°C for 1 to 20 hours while stirring.

[0034] Examples of the dihydroxy aromatic compound 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)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-biphenylyl)propane, 2,2-bis(4-hydroxy-3-cyclohexyl-6-methylphenyl)propane, and the like. Among these, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane and bis(4-hydroxy-3,5-dimethylphenyl)methane are preferred from the viewpoint of cost.

[0035] Examples of the alkali metal salts of the hydroxy aromatic compounds include sodium salts, potassium salts, lithium salts, etc. Among these, from the viewpoint of cost, sodium salts, potassium salts, and lithium salts of 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane and bis(4-hydroxy-3,5-dimethylphenyl)methane are preferred.

[0036] The alkali metal salt of the hydroxy aromatic compound may be prepared by mixing the dihydroxy aromatic compound with an aqueous alkali metal solution, and then heating the mixture to remove water. Examples of the aqueous alkali metal solution include sodium hydroxide, potassium hydroxide, and lithium hydroxide.

[0037] Examples of the aryl halide include dichlorobenzene, dibromobenzene, diiodobenzene, dichloronaphthalene, dibromonaphthalene, diiodonaphthalene, dichlorobiphenyl, dibromobiphenyl, diiodobiphenyl, dichlorodiphenyl ether, dibromodiphenyl ether, diiododiphenyl ether, etc. Among these, from the viewpoint of solvent solubility, chlorobenzene, dibromobenzene, diiodobenzene, dichloronaphthalene, dibromonaphthalene, and diiodonaphthalene are preferred.

[0038] Examples of the copper-containing catalyst include copper powder, copper(I) compounds (i.e., cuprous compounds), and copper(II) compounds (i.e., cupric compounds). These compounds may be oxides or salts. Specific examples of the copper-containing catalyst include copper(I) oxide, copper(II) oxide, cuprous chloride, cupric chloride, cuprous bromide, cupric bromide, cuprous iodide, cupric iodide, cupric acetate, cuprous sulfate, cupric sulfate, and copper acetylacetonate. Among these, copper(I) oxide, copper(II) oxide, cuprous chloride, and cupric chloride are preferred from the viewpoint of reactivity.

[0039] The amount of the copper-containing catalyst added is preferably 0.01 to 2 times the number of moles of the dihydroxy aromatic compound (which may be a protonated product or a salt), more preferably 0.1 to 1 time. It is preferable that the amount of the copper-containing catalyst added is 0.01 times or more, since the reactivity is increased and the reaction time can be shortened. On the other hand, it is preferable that the amount of the copper-containing catalyst added is 2 times or less, since the reaction cost can be reduced.

[0040] The copper-containing catalyst may be bound to a ligand, if necessary. Examples of the ligand include, but are not limited to, 1,10-phenanthroline, dimethylglycine, 1-butylimidazole, 1-methylimidazole, and DL-alanine. When the copper catalyst is bound to such a ligand, the molar ratio of the ligand to the copper-containing catalyst is preferably 1:10 to 10:1.

[0041] The curable resin 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 as its terminal structure. A reactive group-introducing agent can be used to introduce these reactive groups. Examples of reactive group-introducing agents include (meth)acrylic anhydride, (meth)acrylic acid chloride, chloromethylstyrene, chlorostyrene, allyl chloride, and allyl bromide. In particular, the cured product obtained from a curable resin composition containing a curable resin having a methacryloyloxy group introduced as its terminal structure has a low dielectric loss tangent. Reaction with these agents allows the introduction of reactive groups into the curable resin, resulting in a thermosetting resin with a low dielectric constant and a low dielectric loss tangent, which is a preferred embodiment.

[0042] 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 the chloromethylstyrene include p-chloromethylstyrene and m-chloromethylstyrene, and examples of the 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 preferable to use methacrylic anhydride or methacrylic acid chloride, which can provide a cured product with a lower dielectric loss tangent.

[0043] <Curable resin composition> The present invention relates to a curable resin composition containing the curable resin. The curable resin has excellent solvent solubility, making it easy to prepare the curable resin composition and easy to handle. A cured product obtained using the curable resin composition containing the curable resin has excellent heat resistance and low dielectric properties, which is a preferred embodiment.

[0044] [Other resins, etc.] In the curable resin composition of the present invention, in addition to the curable resin, other resins, curing agents, curing accelerators, etc. can be used without particular limitation as long as the object of the present invention is not impaired. As will be described later, the curable resin can be cured by heating or the like without blending a curing agent, but when blending other resins, etc., for example, a curing agent, a curing accelerator, etc. can be blended and used. The curable resin composition of the present invention contains the curable resin. However, when an allyl ether group is introduced as a reactive group in the terminal structure of the curable resin, the reactive group cannot homopolymerize (crosslink or self-cure) (a cured product cannot be obtained by itself) unlike a (meth)acryloyloxy group or a vinylbenzyl ether group, and therefore, in the case of the allyl ether group, it is necessary to use a curing agent, a curing accelerator, or the like.

[0045] [Other resins] Examples of the other resins that can be added include alkenyl group-containing compounds such as bismaleimides, allyl ether compounds, allylamine compounds, triallyl cyanurate, alkenylphenol compounds, and vinyl group-containing polyolefin compounds. Other thermosetting resins such as thermosetting polyimide resins, epoxy resins, phenolic resins, active ester resins, benzoxazine resins, and cyanurate resins can also be added depending on the purpose. Maleimide resins, cyanate ester resins, polyphenylene ether resins, and vinyl resins are particularly preferred because they reduce the dielectric loss tangent.

[0046] Examples of the cyanate ester resin include bis(4-cyanatophenyl)ethane, 2,2-bis(4-cyanatophenyl)propane, 2,2-bis(3,5-dimethyl-4-cyanatophenyl)methane, 2,2-bis(4-cyanatophenyl)-1,1,1,3,3,3-hexafluoropropane, α,α'-bis(4-cyanatophenyl)-m-diisopropylbenzene, and cyanate esters of phenol-added dicyclopentadiene polymers.

[0047] Examples of the maleimide resin include 4,4'-diphenylmethane bismaleimide, m-phenylene bismaleimide, bisphenol A diphenyl ether bismaleimide, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, and 1,6'-bismaleimide-(2,2,4-trimethyl)hexane.

[0048] Examples of the polyphenylene ether resin include poly(2,6-dimethyl-1,4-phenylene) ether, an alloy polymer of poly(2,6-dimethyl-1,4-phenylene) ether and polystyrene, and an alloy polymer of poly(2,6-dimethyl-1,4-phenylene) ether and styrene-butadiene copolymer.

[0049] Examples of the vinyl resin include trialkenyl isocyanurate compounds such as triallyl isocyanurate, polybutadiene resins whose repeating units are 1,2-butadiene, cis-1,4-butadiene, or trans-1,4-butadiene, and vinylbenzyl compounds such as styrene and divinylbenzene having a vinylbenzyl group in the molecule.

[0050] [Curing agent] Examples of the curing agent include amine compounds, amide compounds, acid anhydride compounds, phenol compounds, cyanate ester compounds, etc. These curing agents may be used alone or in combination of two or more.

[0051] [Curing accelerator] Various curing accelerators can be used, including, for example, phosphorus-based compounds, tertiary amines, imidazoles, organic acid metal salts, Lewis acids, and amine complex salts. Particularly when used as a semiconductor encapsulation material, phosphorus-based compounds such as triphenylphosphine or imidazoles are preferred because of their excellent curability, heat resistance, electrical properties, and moisture resistance reliability. These curing accelerators may be used alone or in combination of two or more.

[0052] Furthermore, when an epoxy resin is used as another resin in the curable resin composition, examples of the curing accelerator include organic phosphine compounds: TPP, TPP-K, TPP-S, and TPTP-S (Hokuko Chemical Industry Co., Ltd.), amines: dicyandiamide, diaminodiphenylethane, guanylurea, amine adduct compounds such as Novacure (Asahi Chemical Industry Co., Ltd.) and Fujicure (Fuji Chemical Industry Co., Ltd.), and 1,8-diazabicyclo[5,4,0]undecene-7,4-dimethylaminopyridine ( 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 α,α'-bis(t-butylperoxy)diisopropylbenzene; and carboxylates such as manganese, cobalt, and zinc. When a maleimide resin is used as the resin, examples of suitable catalysts include acidic catalysts such as p-toluenesulfonic acid, amine compounds such as triethylamine, pyridine, and tributylamine, and tertiary amine compounds; quaternary ammonium compounds, imidazole compounds, and phosphorus compounds. When a cyanate ester resin is used as the resin, examples of suitable catalysts include imidazole compounds and derivatives thereof, carboxylates of manganese, cobalt, zinc, and the like, and organometallic compounds such as acetylacetone complexes of transition metals such as manganese, cobalt, and zinc.

[0053] [Flame retardant] The curable resin composition of the present invention may contain a flame retardant, if necessary, to impart flame retardancy. Among these, it is preferable to use a non-halogen flame retardant that is substantially free of halogen atoms. Examples of the non-halogen flame retardant include phosphorus-based flame retardants, nitrogen-based flame retardants, silicone-based flame retardants, inorganic flame retardants, and organic metal salt-based flame retardants. These flame retardants may be used alone or in combination of two or more.

[0054] [Filler] The curable resin composition of the present invention can optionally contain an inorganic filler. Examples of such inorganic fillers include silica (fused silica, crystalline silica), alumina, barium sulfate, talc, Kleni, 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 may also be used. Fused silica is preferred when the amount of inorganic filler to be incorporated is particularly large. Fused silica can be used in either crushed or spherical form. However, in order to increase the amount of fused silica incorporated and suppress an increase in the melt viscosity of the molding material, it is preferable to primarily use spherical silica. Furthermore, in order to increase the amount of spherical silica incorporated, it is preferable to appropriately adjust the particle size distribution of the spherical silica. Furthermore, when the curable resin composition is used in applications such as conductive pastes, as described in detail below, conductive fillers such as silver powder and copper powder can be used.

[0055] [Other compounding agents] If necessary, various compounding agents such as a silane coupling agent, a release agent, a pigment, an emulsifier, etc. may be added to the curable resin composition of the present invention.

[0056] <Cured product> The present invention relates to a cured product obtained by curing the curable resin composition. The curable resin composition can be obtained by uniformly mixing the curable resin alone or the curable resin with various components such as the curing agent described above, and can be easily cured by a method similar to a conventional method. Examples of the cured product include molded cured products such as laminates, cast products, adhesive layers, coating films, and films.

[0057] The curing reaction can be exemplified by heat curing or ultraviolet curing, and heat curing can be easily carried out without a catalyst, but to accelerate the reaction, it is effective to add a polymerization initiator such as an organic peroxide or an azo compound, or a basic catalyst such as a phosphine compound or a tertiary amine. Examples of such a catalyst include benzoyl peroxide, dicumyl peroxide, azobisisobutyronitrile, triphenylphosphine, triethylamine, and imidazoles.

[0058] <Application> The cured products obtained from the curable resin composition of the present invention have excellent heat resistance and low dielectric properties, making them suitable for use in heat-resistant components and electronic components. They are particularly suitable for use in prepregs, circuit boards, semiconductor encapsulants, semiconductor devices, build-up films, build-up boards, adhesives, and resist materials. They are also suitable for use as matrix resins for fiber-reinforced resins, making them particularly suitable for highly heat-resistant prepregs. The curable resin contained in the curable resin composition exhibits excellent solubility in various solvents and can be used as a paint. The heat-resistant components and electronic components thus obtained can be used in a variety of applications, including, but not limited to, industrial machine parts, general machine parts, automobile, railway, and vehicle parts, aerospace and aviation-related parts, electronic and electrical components, building materials, containers and packaging materials, household goods, sports and leisure goods, and housing materials for wind power generation.

[0059] Representative products produced using the curable resin composition of the present invention will be described below with reference to examples.

[0060] <Prepreg> The prepreg preferably contains a varnish obtained by diluting the curable resin composition with an organic solvent. The varnish (resin varnish) is impregnated into a reinforcing substrate, and the reinforcing substrate is heat-treated to semi-cure (or uncure) the curable resin composition, thereby producing a prepreg. The heat treatment conditions are appropriately selected depending on the type and amount of the organic solvent, catalyst, and various additives used, but are typically performed at a temperature of 80 to 220°C for 3 to 30 minutes. The reinforcing substrate to be impregnated with the varnish (resin varnish) may be woven or nonwoven fabrics made of inorganic fibers such as glass fiber, polyester fiber, or polyamide fiber, or organic fibers, or mats, paper, etc., and these may be used alone or in combination. The mass ratio of the curable resin composition to the reinforcing substrate is not particularly limited, but it is typically preferable to prepare the prepreg so that the curable resin composition (resin content therein) is 20 to 60 mass%.

[0061] <Laminate> The laminate preferably contains a cured product obtained by curing the curable resin composition. The laminate has a substrate and a layer containing the cured product. The substrate may be an inorganic material such as metal or glass, or an organic material such as plastic or wood, and may be selected appropriately depending on the application. For example, glass fibers include E-glass, D-glass, S-glass, Q-glass, spherical glass, NE-glass, L-glass, and T-glass; inorganic fibers include quartz; wholly aromatic polyamides include polyparaphenylene terephthalamide (Kevlar®, manufactured by DuPont Co., Ltd.); and copolyparaphenylene-3,4'-oxydiphenylene terephthalamide (Technora®, manufactured by Teijin Techno Products Co., Ltd.). Examples include polyester: 2,6-hydroxynaphthoic acid / parahydroxybenzoic acid (Vectran (registered trademark), manufactured by Kuraray Co., Ltd.), Zexion (registered trademark, manufactured by KB Seiren), organic fiber: polyparaphenylene benzoxazole (Zylon (registered trademark), manufactured by Toyobo Co., Ltd.), and polyimide.

[0062] The laminate may have a flat plate or sheet shape, or may have a three-dimensional structure or a three-dimensional shape. It may have any shape depending on the purpose, such as a shape having curvature over the entire surface or a portion thereof. Furthermore, there are no limitations on the hardness, thickness, etc. of the substrate. Furthermore, the cured product may be used as a substrate, and another cured product may be laminated on top of it.

[0063] When the laminate is used as a circuit board or a semiconductor package substrate, it is preferable to laminate a metal foil. Examples of the metal foil include copper foil, aluminum foil, gold foil, and silver foil, and copper foil is preferably used because of its good processability.

[0064] In the laminate, the layer containing the cured product (cured product layer) may be formed by direct coating or molding on a substrate, or an already molded product may be laminated. When directly coating, the coating method is not particularly limited, and examples thereof include spraying, spin coating, dipping, roll coating, blade coating, doctor roll coating, doctor blade coating, curtain coating, slit coating, screen printing, and inkjet printing. When directly molding, examples thereof include in-mold molding, insert molding, vacuum molding, extrusion lamination molding, and press molding.

[0065] Alternatively, the cured product may be laminated by applying a precursor capable of serving as the substrate to the cured product and curing the applied precursor, or the precursor capable of serving as the substrate or the curable resin composition of the present invention may be adhered in an uncured or semi-cured state and then cured. The precursor capable of serving as the substrate is not particularly limited, and various curable resin compositions and the like may be used.

[0066] <Circuit board> The circuit board preferably contains the prepreg. Specifically, a method for obtaining a circuit board from the curable resin composition of the present invention includes laminating the prepreg by a conventional method, appropriately overlaying copper foil, and subjecting the laminate to thermocompression molding at 170 to 300°C under a pressure of 1 to 10 MPa for 10 minutes to 3 hours.

[0067] <Semiconductor encapsulation material> The semiconductor encapsulant preferably contains the curable resin composition. Specifically, a method for obtaining a semiconductor encapsulant from the curable resin composition of the present invention includes thoroughly melt-mixing the curable resin composition with optional additives such as a curing accelerator and an inorganic filler, using an extruder, kneader, roll, or the like, until the mixture is homogeneous. In this case, fused silica is typically used as the inorganic filler. However, when used as a high-thermal-conductivity semiconductor encapsulant for power transistors and power ICs, highly filled inorganic fillers such as crystalline silica, alumina, and silicon nitride, which have higher thermal conductivity than fused silica, or fused silica, crystalline silica, alumina, and silicon nitride may be used. The inorganic filler content is preferably in the range of 30 to 95 parts by weight per 100 parts by weight of the curable resin composition. In particular, a content of 70 parts by weight or more is more preferred, and 80 parts by weight or more is even more preferred, in order to improve flame retardancy, moisture resistance, and solder crack resistance and to reduce the linear expansion coefficient.

[0068] <Semiconductor device> The semiconductor device preferably includes a cured product obtained by heat-curing the semiconductor encapsulant. Specifically, a semiconductor package molding method for obtaining a semiconductor device from the curable resin composition of the present invention includes molding the semiconductor encapsulant using a casting machine, a transfer molding machine, an injection molding machine, or the like, and then heat-curing the molded product at 50 to 250°C for 2 to 10 hours.

[0069] <Build-up board> A method for obtaining a build-up substrate from the curable resin composition of the present invention includes a method via steps 1 to 3. In step 1, the curable resin composition, which is appropriately blended with rubber, filler, etc., is first applied to a circuit board on which a circuit has been formed using a spray coating method, curtain coating method, or the like, and then cured. In step 2, if necessary, the circuit board to which the curable resin composition has been applied is drilled with predetermined through-holes, etc., treated with a roughening agent, and the surface is washed with hot water to form a roughened surface on the board, followed by plating with a metal such as copper. In step 3, the operations of steps 1 and 2 are sequentially repeated as desired to alternately build up resin insulating layers and conductor layers with predetermined circuit patterns to form a build-up substrate. In the above steps, drilling of through-holes is preferably performed after forming the outermost resin insulating layer. Furthermore, the build-up substrate of the present invention can be produced by forming a roughened surface by semi-curing the resin composition on a copper foil, and then heat-pressing the copper foil onto a wiring board on which a circuit has been formed at 170 to 300°C, thereby eliminating the need for a plating process.

[0070] <Build-up film> The build-up film preferably contains the curable resin composition. A method for obtaining a build-up film from the curable resin composition of the present invention includes, for example, applying the curable resin composition to a support film, followed by drying 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 essential that the film softens under the lamination temperature conditions (usually 70 to 140°C) in a vacuum lamination method, and exhibits fluidity (resin flow) that allows resin to fill via holes or through holes present in the circuit board simultaneously with lamination of the circuit board. It is preferable to blend the components described above so as to exhibit such properties.

[0071] Here, the diameter of the through-holes in the circuit board is usually 0.1 to 0.5 mm, and the depth is usually 0.1 to 1.2 mm, and it is usually preferable to make it possible to fill the resin within this range. When laminating both sides of the circuit board, it is desirable to fill about half of the through-holes.

[0072] A specific method for producing the build-up film described above includes preparing a resin composition varnished by blending an organic solvent, applying the varnished resin composition to the surface of a support film (Y), and then drying the organic solvent by heating or blowing hot air or the like to form a resin composition layer (X).

[0073] The organic solvent used here is preferably, for example, a ketone such as acetone, methyl ethyl ketone, or cyclohexanone; an acetate ester such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, or carbitol acetate; a carbitol such as cellosolve or butyl carbitol; an aromatic hydrocarbon such as toluene or xylene; dimethylformamide, dimethylacetamide, or N-methylpyrrolidone; and it is preferably used in a proportion such that the nonvolatile content is 30 to 60% by mass.

[0074] The thickness of the resin composition layer (X) formed usually needs to be equal to or greater than the thickness of the conductor layer. Since the thickness of the conductor layer of a circuit board is usually in the range of 5 to 70 μm, the thickness of the resin composition layer (X) is preferably 10 to 100 μm. The resin composition layer (X) in the present invention may be protected with a protective film, which will be described later. Protection with a protective film can prevent the adhesion of dust and the like to the surface of the resin composition layer and scratches.

[0075] Examples of the support film and protective film include polyolefins such as polyethylene, polypropylene, and polyvinyl chloride; polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate; polycarbonate; polyimide; and release paper and metal foils such as copper foil and aluminum foil. The support film and protective film may be subjected to a mud treatment, a corona treatment, or a release treatment. The thickness of the support film is not particularly limited, but is typically 10 to 150 μm, preferably 25 to 50 μm. The thickness of the protective film is preferably 1 to 40 μm.

[0076] The support film (Y) is peeled off after laminating it onto a circuit board or after forming an insulating layer by heat curing. If the support film (Y) is peeled off after the resin composition layer constituting the build-up film is heat cured, adhesion of dust and the like during the curing process can be prevented. When peeling off after curing, the support film is usually subjected to a release treatment in advance.

[0077] A multilayer printed circuit board can be produced from the build-up film obtained as described above. For example, when the resin composition layer (X) is protected by a protective film, the protective film is peeled off, and then the resin composition layer (X) is laminated onto one or both sides of the circuit board so as to be in direct contact with the circuit board, for example, by a vacuum lamination method. The lamination method may be a batch method or a continuous method using a roll. If necessary, the build-up film and the circuit board may be heated (preheated) before lamination. The lamination conditions are preferably a pressure bonding temperature (lamination temperature) of 70 to 140°C and a pressure bonding pressure of 1 to 11 kgf / cm. 2 (9.8×10 4 ~107.9×10 4 N / m 2 ), and lamination is preferably carried out under reduced air pressure of 20 mmHg (26.7 hPa) or less.

[0078] <Conductive paste> As a method for obtaining a conductive paste from the curable resin composition of the present invention, for example, a method of dispersing conductive particles in the composition can be mentioned. The above conductive paste can be made into a circuit connection paste resin composition or an anisotropic conductive adhesive depending on the type of conductive particles used.

Examples

[0079] Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. Unless otherwise specified, "parts" and "%" are based on mass. Under the conditions shown below, a curable resin and a cured product obtained using the curable resin were prepared, and the obtained cured product was measured and evaluated under the following conditions.

[0080] <GPC measurement (evaluation of the weight average molecular weight (Mw) of the curable resin)> Measurement was carried out using the following measuring apparatus and measuring conditions, and a GPC chart of the curable resin obtained by the synthesis method shown below was obtained. From the results of the GPC chart, the weight average molecular weight (Mw) of the curable resin was calculated (the GPC chart is not shown). Measuring apparatus: "HLC-8320 GPC" manufactured by Tosoh Corporation Column: Guard 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 Detector: RI (differential refractometer) Data processing: "GPC Workstation EcoSEC-WorkStation" manufactured by Tosoh Corporation Measuring conditions: Column temperature 40°C Developing solvent: Tetrahydrofuran Flow rate: 1.0 ml / min Standard: In accordance with the measurement manual of the "GPC Workstation EcoSEC-WorkStation", the following monodisperse polystyrene with a known molecular weight was used. (Polystyrene used) "A-500" manufactured by Tosoh Corporation Tosoh Corporation "A-1000" Tosoh Corporation "A-2500" Tosoh Corporation "A-5000" "F-1" manufactured by Tosoh Corporation "F-2" manufactured by Tosoh Corporation "F-4" manufactured by Tosoh Corporation "F-10" manufactured by Tosoh Corporation "F-20" manufactured by Tosoh Corporation "F-40" manufactured by Tosoh Corporation "F-80" manufactured by Tosoh Corporation Tosoh Corporation "F-128" Sample: A tetrahydrofuran solution (50 μl) of 1.0% by mass (solid content equivalent) of the curable resin obtained in the examples and comparative examples was filtered through a microfilter.

[0081] Example 1 A reaction vessel equipped with a Dean-Stark trap, condenser, nitrogen inlet, stirrer, and thermometer was charged with 113.8 parts by weight of 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 66.7 parts by weight of 48% sodium hydroxide, and 200 parts by weight of xylene. The mixture was heated to 140 °C, and the azeotropic mixture of water and xylene was collected. After 4 hours, the reaction mixture was completely dehydrated. The temperature was then raised to 200 °C, and the xylene was removed by distillation. Next, 200 parts by weight of N-methyl-2-pyrrolidone, 70.8 parts by weight of 1,4-dibromobenzene, and 0.396 parts by weight of copper(I) chloride were added, and the mixture was stirred at 200 °C for 20 hours. The reaction mixture was cooled to 60 °C, and 100 parts by weight of N-methyl-2-pyrrolidone, 20.2 parts by weight of triethylamine, and 20.9 parts by weight of methacrylic acid chloride were added. The mixture was stirred at 60 °C for 10 hours. The reaction mixture was then poured little by little into a rapidly stirred mixture of 2 L of methanol and 100 mL of acetic acid to obtain a precipitate. The precipitate was washed twice with 1 L of methanol, then twice with 1 L of hot water, and then dried under reduced pressure at 80°C to obtain a curable resin with the following repeating unit and a terminal methacryloyloxy group and a weight-average molecular weight of 2700. [ka]

[0082] Example 2 Synthesis was carried out in the same manner as in Example 1, except that 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane was changed to 102.5 parts by mass of bis(4-hydroxy-3,5-dimethylphenyl)methane, to obtain a curable resin having the following repeating unit and a weight-average molecular weight of 2600, which has a methacryloyloxy group at the end. [ka]

[0083] Example 3 Synthesis was carried out in the same manner as in Example 1, except that 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane was changed to 157.0 parts by mass of 2,2-bis(4-hydroxy-3-cyclohexyl-6-methylphenyl)propane, to obtain a curable resin having the following repeating unit and a weight-average molecular weight of 2900, which has a methacryloyloxy group at its terminal. [ka]

[0084] Example 4 Synthesis was carried out in the same manner as in Example 1, except that 161.0 parts by mass of 1,4-bis(2-(4-hydroxy-3,5-dimethylphenyl)-2-propyl)benzene was used instead of 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, to obtain a curable resin having the following repeating unit and a weight average molecular weight of 3,000, which has a methacryloyloxy group at its terminal. [ka]

[0085] Example 5 Synthesis was carried out in the same manner as in Example 1, except that 98.4 parts by mass of 4,4'-dibromodiphenyl ether was used instead of 1,4-dibromobenzene, to obtain a curable resin having the following repeating unit, a methacryloyloxy group at the end, and a weight average molecular weight of 3,200. [ka]

[0086] Example 6 Synthesis was carried out in the same manner as in Example 1, except that methacrylic acid chloride was changed to 30.5 parts by mass of chloromethylstyrene, to obtain a curable resin having the following repeating unit and a terminal vinylbenzyl ether group and a weight average molecular weight of 2700. [ka]

[0087] Example 7 Synthesis was carried out in the same manner as in Example 1, except that 15.3 parts by mass of allyl chloride was used instead of methacrylic acid chloride, to obtain a curable resin having the following repeating unit, an allyl ether group at the end, and a weight average molecular weight of 2700. [ka]

[0088] (Comparative Example 1) Synthesis was carried out in the same manner as in Example 1, except that 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane was changed to 91.3 parts by mass of 2,2-bis(4-hydroxyphenyl)propane, to obtain a curable resin having the following repeating unit and a weight-average molecular weight of 2600, which has a methacryloyloxy group at its terminal. [ka]

[0089] <Preparation of resin film (cured product)> The curable resins obtained in the Examples and Comparative Examples were placed in a 5 cm square mold, sandwiched between stainless steel plates, and set in a vacuum press. A pressure of 1.5 MPa was applied at normal pressure and room temperature. The pressure was then reduced to 10 torr, and the resin was heated over 30 minutes to a temperature 50°C higher than the heat curing temperature. After allowing to stand for a further 2 hours, the resin was slowly cooled to room temperature, yielding a uniform resin film (cured product) with an average film thickness of 100 μm.

[0090] <Evaluation of dielectric properties> The dielectric properties of the obtained resin film (cured product) in the in-plane direction were measured using a Keysight Technologies Network Analyzer N5247A by the split post dielectric resonator method at a frequency of 10 GHz, including the dielectric constant and dielectric loss tangent. The dielectric loss tangent is 10.0 × 10 -3 If it is less than this, there is no practical problem, and preferably it is 3.0 × 10 -3 or less, more preferably 2.5 × 10 -3 The following is the result. Furthermore, there is no practical problem if the dielectric constant is 3 or less, preferably 2.7 or less, and more preferably 2.5 or less.

[0091] <Evaluation of heat resistance (glass transition temperature)> The resulting resin film (cured product) was measured using a PerkinElmer DSC device (Pyris Diamond) at a temperature increase rate of 20°C / min from 30°C to observe the exothermic peak temperature (thermosetting temperature), and then held at a temperature 50°C higher than that for 30 minutes. The sample was then cooled to 30°C at a temperature decrease rate of 20°C / min, and then heated again at a temperature increase rate of 20°C / min, and the glass transition temperature (Tg) (°C) of the resin film (cured product) was measured. The glass transition temperature (Tg) is 100° C. or higher without any practical problems, preferably 150° C. or higher, and more preferably 190° C. or higher.

[0092] <Heat resistance evaluation (10% weight loss temperature)> The obtained resin film (cured product) was measured using a TG-DTA device (TG-8120) manufactured by Rigaku Corporation under a nitrogen flow of 20 mL / min at a temperature increase rate of 20°C / min to measure the 5% weight loss temperature (Td5).

[0093] [Table 1]

[0094] From the evaluation results in Table 1 above, it was confirmed that in all examples, the cured products obtained by using the curable resin were able to achieve both heat resistance and low dielectric properties, and were at a level that would not pose any problems in practical use.

Claims

1. A repeating unit represented by the following general formula (1), a (meth)acryloyloxy group, a vinylbenzyl ether group, and having at least one reactive group selected from the group consisting of allyl ether groups as a terminal structure; A curable resin comprising a component having two or more of the repeating units. [Case 1] (In the formula, 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 of 0 to 3; X represents a hydrocarbon group; and Y represents an alicyclic group, aromatic group, or 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): [Case 2] (In the formula, Rc represents a hydrogen atom or a methyl group.)

3. The curable resin according to claim 1 or 2, wherein Y is a benzene ring.

4. The curable resin according to any one of claims 1 to 3, wherein the reactive group is a methacryloyloxy group.

5. The curable resin according to any one of claims 1 to 4, wherein the weight average molecular weight of the curable resin is 1,000 to 50,000.

6. A curable resin composition comprising the curable resin according to any one of claims 1 to 5.

7. A cured product obtained by curing the curable resin composition according to claim 6.

Images