Curable resin composition and cured matter thereof

Abstract

To provide: a curable resin composition that has a high biomass degree and is excellent in high thermostability, low dielectric properties, and mechanical characteristics; and a cured matter of the curable resin composition.SOLUTION: A curable resin composition includes an epoxy resin represented by the following formula (1), and a lignin modified phenol resin or a cashew modified phenol resin. (In formula (1), n is an average value of repeating numbers and indicates a real number of 1<n<15.)SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a curable resin composition containing a specific epoxy resin and a lignin-modified phenolic resin or a cashew-modified phenolic resin, and a cured product thereof, and is suitably used in the fields of encapsulants for semiconductor elements, printed wiring boards, build-up multilayer boards and other electrical and electronic components, lightweight high-strength materials such as carbon fiber reinforced plastics and glass fiber reinforced plastics, 3D printing applications, and adhesives.

Background Art

[0002] Epoxy resins are widely used in the fields of electrical and electronic components, structural materials, adhesives, paints, etc. due to their workability and the excellent electrical properties, heat resistance, adhesiveness, moisture resistance (water resistance), etc. of their cured products. In recent years, especially in the electrical and electronic fields, with the development, further improvement of various resin properties such as heat resistance, low dielectric constant, and low dielectric tangent has been demanded. Also, as structural materials, materials that are lightweight and have excellent mechanical properties are demanded in aerospace materials, leisure and sports equipment applications, etc.

[0003] In recent years, biomass resources have attracted attention as carbon-neutral resources from the perspective of environmental issues. Furfural is known as a compound derived from biomass, and Patent Document 1 discloses an epoxy resin using furfural as a raw material.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, since Patent Document 1 uses furfural as a raw material and mixes it with an epoxy resin and a phenol novolak resin, which is a curing agent derived from petrochemicals, to form an epoxy resin composition, the biomass content of the composition is low.

[0006] Generally, when trying to increase the biomass content, it becomes difficult to maintain the performance required for the curable resin composition. Therefore, there has been a demand for a curable resin composition that has a high biomass content and satisfies the required characteristics.

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to provide a curable resin composition having a high biomass content, excellent high heat resistance, low dielectric properties, and mechanical properties, and a cured product thereof.

Means for Solving the Problems

[0008] That is, the present invention relates to the following [1] to [9]. In the present invention, “(numerical value 1) to (numerical value 2)” indicates that the upper and lower limit values are included. [1] A curable resin composition containing an epoxy resin represented by the following formula (1) and a lignin-modified phenol resin or a cashew-modified phenol resin.

[0009]

Chemical formula

[0010] (In formula (1), n is the average value of the number of repetitions and represents a real number of 1 < n < 15.) [2] The curable resin composition according to the above item [1], wherein the biomass content of the lignin-modified phenol resin or the cashew-modified phenol resin is 20% or more. [3] The curable resin composition according to the above item [1] or [2], wherein the ICI viscosity (150 ° C) of the epoxy resin is 0.01 to 0.20 Pa·s. [4] The curable resin composition according to any one of [1] to [3] above, having a biomass content of 20% or more. [5] The curable resin composition according to any one of [1] to [4] above, which is for carbon fiber reinforced plastics. [6] The curable resin composition according to any one of [1] to [4] above, which is for semiconductor element encapsulants. [7] The curable resin composition according to any one of [1] to [4] above, which is for printed wiring boards. [8] A cured product obtained by curing the curable resin composition according to any one of [1] to [7] above.

Advantages of the Invention

[0011] The present invention relates to a curable resin composition having a high biomass content and excellent high heat resistance, low dielectric properties, and mechanical properties. Therefore, the present invention is useful for insulating materials for electric and electronic parts (such as high-reliability semiconductor encapsulation materials), laminates (such as printed wiring boards and build-up substrates), various composite materials such as CFRP, adhesives, and the like.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0013] The curable resin composition of the present embodiment contains an epoxy resin represented by the following formula (1) and a lignin-modified phenol resin or a cashew-modified phenol resin.

[0014]

Chemical Formula

[0015] (In formula (1), n is the average value of the number of repetitions, indicating a real number where 1 < n < 15.)

[0016] In the above formula (1), the value of n can be determined from the number average molecular weight obtained by measuring the epoxy resin by gel permeation chromatography (GPC, detector: RI), or from the area ratio of each separated peak. It is preferable that n is a real number where 1 < n < 15, more preferably 1 < n < 10, and particularly preferably 1 < n < 5.)

[0017] The epoxy resin represented by the above formula (1) can be obtained by reacting a phenol resin represented by the following formula (2) with epihalohydrin.)

[0018] [Chemical formula]

[0019] (In formula (2), n is the average value of the number of repetitions, indicating a real number where 1 < n < 15.)

[0020] The preferable range of n in the above formula (2) is the same as that in formula (1).

[0021] The epihalohydrin can be easily obtained from the market. The amount of epihalohydrin used is preferably 2.0 to 10 moles, more preferably 3.0 to 8.0 moles, and even more preferably 3.5 to 6.0 moles per mole of the hydroxyl group of the raw material phenol mixture.)

[0022] In the above reaction, an alkali metal hydroxide can be used as a catalyst to promote the epoxidation process. Examples of the alkali metal hydroxide that can be used include sodium hydroxide, potassium hydroxide, etc. A solid can be used, or an aqueous solution thereof can be used. In this embodiment, in particular, it is preferable to use a solid molded into flakes from the viewpoints of solubility and handling.) The amount of alkali metal hydroxide used is preferably 0.90 to 1.5 moles, more preferably 0.95 to 1.25 moles, and even more preferably 0.99 to 1.15 moles per mole of hydroxyl group in the raw material phenol mixture.

[0023] In addition, in order to promote the reaction, quaternary ammonium salts such as tetramethylammonium chloride, tetramethylammonium bromide, and trimethylbenzylammonium chloride may be added as a catalyst. The amount of the quaternary ammonium salt used is preferably 0.1 to 15 g, more preferably 0.2 to 10 g, per mole of hydroxyl group in the raw material phenol mixture.

[0024] The reaction temperature is preferably 30 to 90 °C, more preferably 35 to 80 °C. Particularly in this embodiment, for higher purity epoxidation, 50 °C or higher is preferred, and particularly 60 °C or higher is preferred. The reaction time is preferably 0.5 to 10 hours, more preferably 1 to 8 hours, and particularly preferably 1 to 3 hours. If the reaction time is short, the reaction cannot proceed completely, and if the reaction time is long, by-products are formed, which is not preferred. After washing the reactants of these epoxidation reactions with water or without washing, epihalohydrin, solvent, etc. are removed under heating and reduced pressure. Further, in order to obtain an epoxy resin with less hydrolyzable halogen, the recovered epoxy resin is dissolved using a ketone compound having 4 to 7 carbon atoms (for example, methyl isobutyl ketone, methyl ethyl ketone, cyclopentanone, cyclohexanone, etc.) as a solvent, and an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is added to carry out the reaction to ensure ring closure. In this case, the amount of the alkali metal hydroxide used is preferably 0.01 to 0.3 moles, more preferably 0.05 to 0.2 moles, per mole of hydroxyl group in the raw material phenol mixture used for epoxidation. The reaction temperature is preferably 50 to 120 °C, and the reaction time is preferably 0.5 to 2 hours.

[0025] After the reaction is completed, the generated salt is removed by filtration, washing with water, etc., and the solvent is distilled off under heating and reduced pressure to obtain the epoxy resin represented by the formula (1).

[0026] As a method for synthesizing the phenol resin represented by the formula (2), when the reaction (condensation) between furfural and phenols is carried out, the amount of phenols is preferably in the range of 1.5 to 20 moles, particularly preferably 3 to 10 moles, per 1 mole of furfural.

[0027] Examples of phenols include catechol, resorcinol, hydroquinone as disubstituted phenols, and phenol as monosubstituted phenols, and they may be used alone or in combination of two or more.

[0028] Examples of the solvent include, but are not limited to, methanol, ethanol, propanol, isopropanol, toluene, xylene, etc., and they may be used alone or in combination of two or more. When using a solvent, its amount is preferably 5 to 500 parts by weight, more preferably 10 to 300 parts by weight, per 100 parts by weight of phenol.

[0029] In the above condensation reaction, it is preferable to use a base catalyst. Although polycondensation is possible with an acid catalyst, the reaction between furfurals also occurs and the amount of by-products increases. There is also a method using an organometallic compound, but it is disadvantageous in terms of cost. Specific examples of the basic catalyst include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, alkaline earth metal hydroxides such as magnesium hydroxide, calcium hydroxide, alkali metal alkoxides such as sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide, potassium tert-butoxide, alkaline earth metal alkoxides such as magnesium methoxide, magnesium ethoxide, etc., but are not limited to these, and they may be used alone or in combination of two or more. The amount of the catalyst used is preferably 0.005 to 2.0 times the molar amount, more preferably 0.01 to 1.1 times the molar amount, per 1 mole of phenol.

[0030] The condensation reaction in the presence of these base catalysts is preferably carried out in the range of 40 to 180 °C, particularly preferably in the range of 80 to 165 °C, and the reaction time is preferably selected in the range of 0.5 to 10 hours. The reaction product thus obtained is neutralized so that the system becomes neutral or washed with water repeatedly in the presence of a solvent, and after separating and draining the water, the solvent and unreacted substances are removed under heating and reduced pressure to obtain the phenolic resin represented by the above formula (2).

[0031] The curable resin composition of the present embodiment contains a lignin-modified phenolic resin or a cashew-modified phenolic resin together with the epoxy resin represented by the above formula (1). The lignin-modified phenolic resin is a phenolic resin modified with lignin, and those described in JP-A-2021-138806 are known. In addition, PLN-0051LP, which is a lignin-modified phenolic resin, can be obtained from Aica Kogyo Co., Ltd. The cashew-modified phenolic resin is a phenolic resin modified with cashew oil, and those described in JP-A-2007-2032 are known. The amount of the lignin-modified phenolic resin or the cashew-modified phenolic resin is preferably 0.7 to 1.2 equivalents per equivalent of the epoxy groups of the epoxy resin represented by the above formula (1). If it is less than 0.7 equivalent or exceeds 1.2 equivalents per equivalent of the epoxy groups, curing may be incomplete in both cases, and good cured physical properties may not be obtained.

[0032] From the viewpoint of environmental problems, the biomass content of the epoxy resin represented by the above formula (1) is preferably 20% or more. The biomass content of the lignin-modified phenolic resin or the cashew-modified phenolic resin is preferably 20% or more. The biomass content of the curable resin composition of the present embodiment is preferably 20% or more, more preferably 25% or more. The upper limit of the biomass content is not particularly limited and may be 100%, but from the balance with the cured physical properties, it is preferably 60%, more preferably 40%. A high biomass content can also mean reducing the amount of fossil resource-based materials typified by petroleum, etc., and is also significant in terms of sustainable use of resources.

[0033] The biomass content of each material and the curable resin composition can be determined by an accelerator mass spectrometry method in accordance with ASTM D6866-21.

[0034] In the curable resin composition of the present embodiment, the epoxy resin represented by the formula (1) can be used alone or in combination with other epoxy resins. When used in combination, the proportion of the epoxy resin represented by the formula (1) in all the epoxy resins is preferably 5 to 95% by weight, more preferably 10 to 95% by weight, and still more preferably 15 to 95% by weight. When the addition amount is small, sufficient heat resistance may not be exhibited.

[0035] Specific examples of epoxy resins that can be used in combination with the epoxy resin represented by the formula (1) include condensates of bisphenols (bisphenol A, bisphenol F, bisphenol S, biphenol, bisphenol AD, etc.) or phenols (phenol, alkyl-substituted phenols, aromatic-substituted phenols, naphthol, alkyl-substituted naphthol, dihydroxybenzene, alkyl-substituted dihydroxybenzene, dihydroxynaphthalene, etc.) with various aldehydes (formaldehyde, acetaldehyde, alkyl aldehydes, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthaldehyde, glutaraldehyde, phthalaldehyde, crotonaldehyde, cinnamaldehyde, etc.); polymers of the above phenols with various diene compounds (dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisopropenylbiphenyl, butadiene, isoprene, etc.); condensates of the above phenols with ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, etc.); condensates of the above phenols with aromatic dimethanols (benzenedimethanol, biphenyldimethanol, etc.); condensates of the above phenols with aromatic dichloromethyls (α,α'-dichloroxylene, bischloromethylbiphenyl, etc.); condensates of the above phenols with aromatic bisalkoxymethyls (bismethoxymethylbenzene, bis-methoxymethylbiphenyl, bisphenoxymethylbiphenyl, etc.); condensates of the above bisphenols with various aldehydes or glycidyl ethers obtained by glycidylating alcohols, etc., alicyclic epoxy resins, glycidylamine epoxy resins, glycidyl ester epoxy resins, etc. Specific examples of epoxy resins containing plant-derived components include compounds obtained by epoxidizing condensates of cardanol derived from cashew nut oil with various aldehydes using the above phenols, and compounds obtained by epoxidizing linseed oil or soybean oil. It is not limited to these as long as it is a commonly used epoxy resin. These may be used alone or in combination of two or more kinds.It is particularly preferable to use it in combination with an epoxy resin containing a plant-derived component, as it can increase the biomass content.

[0036] The curable resin composition of this embodiment may also be used in combination with a curing agent other than a guanine-modified phenol resin or a cashew-modified phenol resin. For example, acid anhydride compounds, amine compounds, amide-based compounds, phenol-based compounds, active ester compounds, etc. may be mentioned. Specific examples of the curing agent that can be used in combination include acid anhydride-based compounds such as phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride; amide-based compounds such as dicyandiamide and polyamide resins synthesized from dimers of linolenic acid and ethylenediamine;o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 2,2'-diaminodiphenyl sulfone, diethyltoluenediamine, dimethylthiotoluenediamine, diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-diethyl-4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane, 4,4'-diamino-3,3',5,5'-tetramethyldiphenylmethane, 4,4'-diamino-3,3',5,5'-tetraethyldiphenylmethane, 4,4'-diamino-3,3',5,5'-tetraisopropyldiphenylmethane, 4,4'-methylenebis(N-methylaniline), bis(aminophenyl)fluorene, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, bis[4-(4-aminophenoxy)phenyl]sulfone, 1,3'-bis(4-aminophenoxy)benzene, 1,4'-bis(4-aminophenoxy)benzene, 1,4'-bis(4-aminophenoxy)biphenyl, 4,4'-(1,3-phenylenediisopropylidene)bisaniline, 4,4'-(1,4-phenylenediisopropylidene)bisaniline, naphthalenediamine, benzidine, dimethylbenzidine and other aromatic amine compounds; 1,3-bis(aminomethyl)cyclohexane, isophoronediamine, 4,4'-methylenebis(cyclohexylamine), norbornanediamine, ethylenediamine, propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, dimer diamine, triethylenetetramine and other aliphatic amine compounds;A polycondensate of bisphenols (such as bisphenol A, bisphenol F, bisphenol S, biphenol, bisphenol AD, etc.) or phenols (such as phenol, alkyl-substituted phenol, aromatic-substituted phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, alkyl-substituted dihydroxybenzene, dihydroxynaphthalene, etc.) and various aldehydes (such as formaldehyde, acetaldehyde, alkyl aldehyde, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthaldehyde, glutaraldehyde, phthalaldehyde, crotonaldehyde, cinnamaldehyde, etc.), or a polymer of the above phenols and various diene compounds (such as dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisopropenylbiphenyl, butadiene, isoprene, etc.), or a polycondensate of the above phenols and ketones (such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, etc.), or a polycondensate of the above phenols and aromatic dimethanols (such as benzenedimethanol, biphenyldimethanol, etc.), or a polycondensate of the above phenols and aromatic dichloromethyls (such as α,α'-dichloroxylene, bischloromethylbiphenyl, etc.), or a polycondensate of the above phenols and aromatic bisalkoxymethyls (such as bismethoxymethylbenzene, bismethoxymethylbiphenyl, bisphenoxymethylbiphenyl, etc.), or a polycondensate of the above bisphenols and various aldehydes, and phenolic compounds such as modified products thereof; active ester compounds such as phenol esters, thiophenol esters, N-hydroxyamine esters, esters of heterocyclic hydroxy compounds, etc.; and the like, but are not limited thereto.;

[0037] The curable resin composition of this embodiment may be used in combination with a curing accelerator. Examples of the usable curing accelerators include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole; tertiary amines such as 2-(dimethylaminomethyl)phenol, triethylenediamine, triethanolamine, 1,8-diazabicyclo[5.4.0]undecene-7; organic phosphines such as triphenylphosphine, diphenylphosphine, tributylphosphine; metal compounds such as tin octylate; tetra-substituted phosphonium tetra-substituted borates such as tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium ethyltriphenylborate; tetraphenylboron salts such as 2-ethyl-4-methylimidazole tetraphenylborate, N-methylmorpholine tetraphenylborate; carboxylic acid-based compounds such as benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthoic acid, salicylic acid. The curing accelerator is used in an amount of 0.01 to 15 parts by weight as needed with respect to 100 parts by weight of the epoxy resin.

[0038] The curable resin composition of this embodiment may be added with an inorganic filler as needed. Examples of the inorganic filler include powders such as crystalline silica, fused silica, alumina, zircon, calcium silicate, calcium carbonate, silicon carbide, silicon nitride, boron nitride, zirconia, forsterite, steatite, spinel, titania, talc, or beads obtained by spheroidizing these, but are not limited thereto. These may be used alone or in combination of two or more. The amount of use of these inorganic fillers varies depending on the application. For example, when used for encapsulating semiconductor elements, it is preferably used in a proportion of 20% by weight or more in the curable resin composition from the viewpoints of heat resistance, moisture resistance, mechanical properties, flame retardancy, etc. of the cured product of the curable resin composition, more preferably 30% by weight or more, and particularly preferably 70 to 95% by weight to improve the linear expansion rate with the lead frame.

[0039] The curable resin composition of this embodiment can be blended with a mold release agent in order to improve the mold release property with the mold during molding. Any conventionally known mold release agent can be used. Examples thereof include ester waxes such as carnauba wax and montan wax, fatty acids such as stearic acid and palmitic acid and metal salts thereof, polyolefin waxes such as polyethylene oxide and non-oxidized polyethylene. These may be used alone or in combination of two or more. The blending amount of these mold release agents is preferably 0.5 to 3% by weight based on all the organic components. If it is too less than this, the mold release from the mold is poor, and if it is too much, the adhesion to the lead frame or the like deteriorates.

[0040] The curable resin composition of this embodiment can be blended with a coupling agent in order to enhance the adhesiveness between the inorganic filler and the resin component. Any conventionally known coupling agent can be used. Examples thereof include various alkoxysilane compounds such as vinylalkoxysilane, epoxyalkoxysilane, styrylalkoxysilane, methacryloxyalkoxysilane, acryloxyalkoxysilane, aminoalkoxysilane, mercaptoalkoxysilane, and isocyanatealkoxysilane, alkoxytitanium compounds, and aluminum chelates. These may be used alone or in combination of two or more. As for the addition method of the coupling agent, the surface of the inorganic filler may be treated with the coupling agent in advance and then kneaded with the resin, or the coupling agent may be mixed with the resin and then the inorganic filler may be kneaded.

[0041] Known additives can be blended into the curable resin composition of this embodiment as necessary. Specific examples of the additives that can be used include polybutadiene and its modified products, modified products of acrylonitrile copolymers, polyphenylene ether, polystyrene, polyethylene, polyimide, fluororesin, maleimide-based compounds, cyanate ester-based compounds, silicone gel, silicone oil, and colorants such as carbon black, phthalocyanine blue, and phthalocyanine green.

[0042] The curable resin composition of the present embodiment is obtained by uniformly mixing the above components. The production method of the curable resin composition of the present embodiment is not particularly limited. For example, a curing agent, a curing accelerator, an inorganic filler, a release agent, a silane coupling agent, an additive, etc. can be added to an epoxy resin and uniformly mixed using an extruder, a kneader, a roll, a planetary mixer, etc. until it becomes uniform.

[0043] The obtained curable resin composition can take various forms such as a resin sheet and a prepreg depending on its molding method. The form of the prepreg can be obtained, for example, by heating and melting the curable resin composition and / or the resin sheet of the present embodiment to reduce its viscosity and impregnating a fiber substrate therewith.

[0044] The curable resin composition of the present embodiment can be dissolved in a solvent such as toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. as needed to form a varnish-like composition (hereinafter also simply referred to as varnish), and impregnated into a substrate such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, paper, etc., and then dried by heating to prepare a prepreg. The solvent used at this time accounts for 10 to 70% by weight, preferably 15 to 70% by weight, in the mixture of the curable resin composition of the present embodiment and the solvent.

[0045] After cutting and laminating the above prepreg into a desired shape, a carbon fiber reinforced plastic (CFRP) can be obtained by heating and curing the epoxy resin composition while applying pressure to the laminate by a press molding method, an autoclave molding method, a sheet winding molding method, etc. Also, a copper foil or an organic film can be laminated during the lamination of the prepreg.

[0046] In addition to the above method, the CFRP forming method can also be obtained by forming with a known method. For example, a carbon fiber base material (usually a carbon fiber fabric is used) is cut, laminated, and shaped to produce a preform (a preform before impregnation with resin). The preform is placed in a mold, the mold is closed, resin is injected to impregnate the preform, and after curing, the mold is opened to take out the molded product. It is also possible to use a resin transfer molding technique (RTM method). Also, as a kind of RTM method, for example, in the VaRTM method, the SCRIMP (Seeman’s Composite Resin Infusion Molding Process) method, the resin supply tank described in JP-T-2005-527410 is evacuated to a pressure lower than atmospheric pressure, circulation compression is used, and by controlling the net molding pressure, the resin injection process, especially the CAPRI (Controlled Atmospheric Pressure Resin Infusion) method for more appropriately controlling the VaRTM method, etc. can also be used. Furthermore, a film stacking method in which a fiber base material is sandwiched between resin sheets (films), a method of attaching powdery resin to a reinforcing fiber base material to improve impregnation, a forming method (Powder Impregnated Yarn) using a fluidized bed or a fluid slurry method in the process of mixing resin with a fiber base material, and a method of mixing resin fibers with a fiber base material can also be used.

[0047] Examples of the carbon fiber include carbon fibers such as acrylic-based, pitch-based, and rayon-based carbon fibers. Among them, acrylic-based carbon fibers with high tensile strength are preferably used. As the form of the carbon fiber, twisted yarns, untwisted yarns, and non-twisted yarns can be used. However, untwisted yarns or non-twisted yarns are preferably used because of the good balance between the moldability and strength characteristics of the fiber-reinforced composite material.

[0048] The cured product of the curable resin composition of the present embodiment can be used in various applications other than the above-mentioned applications such as CFRP, for example, adhesives, paints, coating agents, molding materials (including sheets, films, CFRP, rotor fixing members, etc.), encapsulants for semiconductor elements, encapsulants for liquid crystal display elements, encapsulants for organic EL elements, printed wiring boards (substrates for BGA, build-up substrates, etc.), etc. for electrical and electronic components, 3D printing, etc., and additives to other resins, etc.

[0049] Examples of the adhesive include adhesives for civil engineering, construction, automobiles, general office use, medical use, and adhesives for electronic materials. Among these, adhesives for electronic materials include interlayer adhesives for multilayer substrates such as build-up substrates, die bonding agents, adhesives for semiconductors such as underfills, underfills for BGA reinforcement, anisotropic conductive films (ACF), anisotropic conductive pastes (ACP), etc. for mounting, etc., and can be applied to various applications.

[0050] When applying the curable resin composition of the present embodiment to an encapsulant for semiconductor elements, the curable resin composition of the present embodiment is placed in a mold on a lead frame or a semiconductor package substrate equipped with semiconductor elements, and molded by a melt casting method, a transfer molding method, an injection molding method, a compression molding method, etc., and then heated at 80 to 200 °C for 2 to 10 hours to obtain a cured product. Examples of semiconductor devices manufactured using this encapsulant include potting, dipping, transfer mold encapsulation for capacitors, transistors, diodes, light-emitting diodes, ICs, LSIs, etc., potting encapsulation for COB, COF, TAB, etc. of ICs, LSIs, etc., underfills for flip chips, encapsulation (including underfills for reinforcement) during mounting of IC packages such as QFP, BGA, CSP, etc.

[0051] When applying the curable resin composition of this embodiment to printed wiring boards, it can also be heated and melted to reduce its viscosity, and then impregnated into reinforcing fibers such as glass fibers and polyamide fibers to obtain a prepreg. Specific examples include, for example, glass fibers such as E-glass cloth, D-glass cloth, S-glass cloth, Q-glass cloth, spherical glass cloth, NE-glass cloth, and T-glass cloth, and / or organic fibers, but are not particularly limited thereto. The shape of the base material is not particularly limited, and examples include woven fabric, non-woven fabric, roving, and chopped strand mat. Also, as the weaving method of the woven fabric, plain weave, nanako weave, twill weave, etc. are known, and these known ones can be appropriately selected and used according to the intended application and performance. Also, a glass woven fabric obtained by opening the woven fabric or surface-treated with a silane coupling agent or the like is preferably used. The thickness of the base material is not particularly limited, but is preferably about 0.01 to 0.4 mm. Also, the varnish can be impregnated into the reinforcing fibers and then heated and dried to obtain a prepreg, and based on this, a copper-clad laminate (CCL) can be created. By thermally pressing and molding the obtained prepreg and CCL, a laminate using the curable resin composition of this embodiment can also be created. The laminate is not particularly limited as long as it includes one or more prepregs, and it may have any other layers. Also, by applying the varnish on a release film, removing the solvent under heating, and performing B-staging, a sheet-like adhesive can be obtained. This sheet-like adhesive can be used as an interlayer insulating layer in a multilayer substrate or an adhesive sheet when mounting a semiconductor. Also, the curable resin composition of this embodiment can be suitably used for special substrate materials such as package substrates (substrates) and HDI (high density interconnect).

[0052] When the curable resin composition of the present embodiment is used for the rotor fixing member, the curable resin composition of the present embodiment is placed in the mold of the rotor fixing member and molded by a melt casting method, a transfer molding method, an injection molding method, a compression molding method, etc., and further heated at 80 to 200 ° C for 2 to 10 hours to obtain a cured product.

Example

[0053] The present invention will be described in more detail below with reference to synthesis examples and examples. The materials, treatment contents, treatment procedures, etc. shown below can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below. Hereinafter, unless otherwise specified, parts are parts by weight.

[0054] The following conditions were used for various analysis methods. ·Epoxy equivalent Measured by the method described in JIS K-7236, and the unit is g / eq. ·Softening point Measured by a method conforming to JIS K-7234, and the unit is °C. ·Melt viscosity Measured by the ICI melt viscosity (150 °C) cone plate method, and the unit is Pa·s. ·Biomass degree analysis (accelerator gravimetry) Measured and calculated in accordance with ASTM D6866-21. The unit is %.

[0055] [Synthesis Example 1] Into a flask equipped with a stirrer, a reflux condenser, and a stirring device, 254 parts by weight of phenol, 63 parts by weight of water, and 27 parts by weight of sodium hydroxide were charged. After stirring and dissolving, when heated to 110°C, 44 parts by weight of furfural was added dropwise over 2 hours. Then, after reacting at 110°C for 3 hours, the temperature was raised to 145°C. During the temperature rise, the water that distilled out was removed from the system. After reaching 145°C, the reaction was carried out for 4 hours. Then, it was cooled to 80°C, 63 parts by weight of water was charged, and 4 parts by weight of phosphoric acid and 63 parts by weight of 35% hydrochloric acid were added for neutralization. After repeating the water washing, under heating and reduced pressure, unreacted phenol was distilled off to obtain 109 parts by weight of a phenol resin. To 78 parts by weight of the obtained phenol resin, 254 parts by weight of epichlorohydrin (ECH, the same hereinafter), 64 parts by weight of dimethyl sulfoxide (DMSO, the same hereinafter), and 13 parts by weight of water were charged into a reaction vessel. After heating, stirring, and dissolving, while maintaining the temperature at 45°C, 23 parts by weight of flaky sodium hydroxide was charged in portions over 2 hours. Then, the reaction was further carried out at 45°C for 2 hours and at 70°C for 60 minutes. Then, after repeating the water washing to remove the by-product salts and dimethyl sulfoxide, excess epichlorohydrin was distilled off from the oil layer under heating and reduced pressure, and 218 parts by weight of methyl isobutyl ketone was added to and dissolved in the residue. This methyl isobutyl ketone solution was heated to 70°C, 7 parts by weight of a 30% aqueous sodium hydroxide solution was added, and after reacting for 1 hour, the washing of the reaction solution was repeated until the washing liquid became neutral. Then, methyl isobutyl ketone was distilled off from the oil layer under heating and reduced pressure to obtain 97 parts by weight of the epoxy resin A represented by the formula (1). The epoxy equivalent was 214 g / eq., the softening point was 49°C, the ICI melt viscosity was 0.04 Pa·s, the average value n of the repeating number from GPC was 2.1, and the biomass degree was 25%. The GPC chart of the epoxy resin A is shown in Figure 1.

[0056] [Synthesis Example 2] According to JP-A-2007-2032, a cashew-modified phenol resin was synthesized. 250 parts by weight of phenol, 138 parts by weight of 37% formalin, 110 parts by weight of cashew oil, and 2 parts by weight of sulfuric acid were charged into a flask equipped with a stirrer, a reflux condenser, and a stirring device, and reacted at 100 °C under reflux for 1 hour. Subsequently, the temperature was raised to 190 °C while performing vacuum distillation to obtain 254 parts by weight of a cashew-modified phenol resin. The softening point of this resin was 80 °C, and the biomass content was 31%.

[0057] [Example 1] Using the epoxy resin A obtained in Synthesis Example 1 as the main component, a lignin-modified phenol resin (PLN-0051LP, manufactured by Aica Kogyo Co., Ltd., softening point: 106 °C, GPC chart shown in Figure 2) as the curing agent, and TPP (triphenylphosphine) as the curing accelerator, they were compounded and kneaded at the weight ratios shown in the compounding composition of Table 1, and cured under the curing conditions of 180 °C for 6 hours to prepare a cured product.

[0058] [Example 2] Using the epoxy resin A obtained in Synthesis Example 1 as the main component, the cashew-modified phenol resin obtained in Synthesis Example 2 as the curing agent, and TPP (triphenylphosphine) as the curing accelerator, they were compounded and kneaded at the weight ratios shown in the compounding composition of Table 1, and cured under the curing conditions of 180 °C for 6 hours to prepare a cured product.

[0059] [Comparative Example 1] Using the epoxy resin A obtained in Synthesis Example 1 as the main component, PN (phenol novolak resin, manufactured by Meiwafosis Co., Ltd., hydroxyl equivalent: 103 g / eq.) as the curing agent, and TPP (triphenylphosphine) as the curing accelerator, they were compounded and kneaded at the weight ratios shown in the compounding composition of Table 1, and cured under the curing conditions of 180 °C for 6 hours to prepare a cured product.

[0060] The physical property values were measured under the following conditions. <Measurement Conditions for Heat Resistance (Tg)>[[]] Dynamic viscoelasticity measuring instrument: TA-instruments, DMA-Q800 Measurement temperature range: 25 to 300 °C Heating rate: 2 °C / min ​Tg: The peak point of Tanδ was defined as Tg. <Dielectric Constant, Dielectric Loss Tangent Test> Using a 10 GHz cavity resonator manufactured by AET Co., Ltd., tests were conducted at 25 °C by the cavity resonator perturbation method. The sample size was 2.5 mm in width × 50 mm in length, and the thickness was 0.3 mm for the test. <Tensile Elastic Modulus, Maximum Tensile Stress Point> Using an autograph AGS-X from Shimadzu Corporation, the sample was clamped so that the tensile speed was 0.5 mm / min and the length of the test piece was 5 cm, and tensile measurement was performed at the above test speed in the 180° direction.

[0061]

Table 1

[0062] From the results in Table 1, it was confirmed that Examples 1 and 2 had a high biomass content and were excellent in high heat resistance, low dielectric properties, and mechanical strength.

Claims

1. A curable resin composition containing an epoxy resin represented by the following formula (1) and a lignin-modified phenol resin or a cashew-modified phenol resin. 【Chemical 1】 (In formula (1), n is the average value of the repeating number, and represents a real number of 1 < n < 15.)

2. The curable resin composition according to claim 1, wherein the biomass degree of the lignin-modified phenol resin or the cashew-modified phenol resin is 20% or more.

3. The curable resin composition according to claim 1, wherein the ICI viscosity (150 ° C) of the epoxy resin is 0.01 to 0.20 Pa·s.

4. The curable resin composition according to claim 1, wherein the biomass degree is 20% or more.

5. The curable resin composition according to any one of claims 1 to 4, which is for carbon fiber reinforced plastic.

6. The curable resin composition according to any one of claims 1 to 4, which is for a semiconductor element encapsulant.

7. The curable resin composition according to any one of claims 1 to 4, which is for a printed wiring board.

8. A cured product obtained by curing the curable resin composition according to any one of claims 1 to 4.

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