Curable epoxy resin composition, cured product, and method for producing the cured product

Abstract

To provide a curable epoxy resin composition that utilizes biomass and gives a cured product excellent in heat resistance and electrical characteristics, a cured product, and a method for producing the cured product.SOLUTION: A curable epoxy resin composition comprises a biomass-derived non-aromatic epoxy compound and a biomass-derived curing agent, wherein the curing agent is at least one selected from the group consisting of acid anhydrides, thiols, and phenolic compounds.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a curable epoxy resin composition, a cured product, and a method for producing the cured product.

Background Art

[0002] In recent years, in order to promote a recycling-based society, the utilization of biomass has been attracting attention in the field of materials.

[0003] As a curable epoxy resin composition using a biomass material, it is known to use a diamine compound as a curing agent. (For example, see Patent Document 1)

Prior Art Documents

Patent Documents

[0004] [[ID=!]]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present disclosure is to provide a curable epoxy resin composition, a cured product, and a method for producing the cured product, which utilize biomass and provide a cured product excellent in heat resistance and electrical properties.

Means for Solving the Problems

[0006] The present disclosure (1) includes a non-aromatic epoxy compound derived from biomass and a curing agent derived from biomass, where the curing agent is at least one selected from the group consisting of an acid anhydride, a thiol, and a phenolic compound, and is a curable epoxy resin composition.

[0007] The present disclosure (2) is the curable epoxy resin composition according to the present disclosure (1), in which the biomass content of the non-aromatic epoxy compound and the curing agent is 50% or more.

[0008] Disclosure (3) is a curable epoxy resin composition according to Disclosure (1) or (2), wherein the biomass content of the non-aromatic epoxy compound and the curing agent is 100%.

[0009] Disclosure (4) is a curable epoxy resin composition according to any one of Disclosures (1) to (3), wherein the non-aromatic epoxy compound has a ring structure other than an epoxy group.

[0010] Disclosure (5) is a curable epoxy resin composition according to any one of Disclosures (1) to (4), wherein the non-aromatic epoxy compound contains two or more epoxy groups.

[0011] Disclosure (6) is a curable epoxy resin composition according to any one of Disclosures (1) to (5), wherein the non-aromatic epoxy compound is a non-aromatic diepoxy compound.

[0012] Disclosure (7) is a curable epoxy resin composition according to any one of Disclosures (1) to (6), wherein the non-aromatic epoxy compound has an isosorbide structure.

[0013] Disclosure (8) is a curable epoxy resin composition according to any one of Disclosures (1) to (7), wherein the non-aromatic epoxy compound is at least one selected from the group consisting of isosorbide diglycidyl ether, ethylene glycol diglycidyl ether, and poly(propylene glycol) diglycidyl ether.

[0014] Disclosure (9) is a curable epoxy resin composition according to any one of Disclosures (1) to (8), wherein the non-aromatic epoxy compound is isosorbide diglycidyl ether.

[0015] Disclosure (10) is a curable epoxy resin composition according to any one of Disclosures (1) to (9), wherein the curing agent is at least one selected from the group consisting of thiols and phenolic compounds.

[0016] The present disclosure (11) is a curable epoxy resin composition according to any one of the present disclosures (1) to (10) in which the acid anhydride has a ring structure other than the acid anhydride ring.

[0017] The present disclosure (12) is a curable epoxy resin composition according to any one of the present disclosures (1) to (11) in which the acid anhydride is at least one selected from the group consisting of maleic anhydride, phthalic anhydride, and 1,2,3,4-cyclobutanetetracarboxylic dianhydride.

[0018] The present disclosure (13) is a curable epoxy resin composition according to any one of the present disclosures (1) to (12) in which the thiol is an aliphatic thiol.

[0019] The present disclosure (14) is a curable epoxy resin composition according to any one of the present disclosures (1) to (13) in which the thiol is at least one selected from the group consisting of pentaerythritol tetrakis(3-mercaptobutyrate) and L-cysteine.

[0020] The present disclosure (15) is a curable epoxy resin composition according to any one of the present disclosures (1) to (14) in which the phenolic compound contains two or more hydroxy groups.

[0021] The present disclosure (16) is a curable epoxy resin composition according to any one of the present disclosures (1) to (15) in which the phenolic compound is (+)-catechin hydrate.

[0022] The present disclosure (17) is a cured product obtained by curing the curable epoxy resin composition according to any one of the present disclosures (1) to (16).

[0023] The present disclosure (18) is a cured product according to the present disclosure (17) having a relative permittivity of 6.0 or less at 10 GHz.

[0024] The present disclosure (19) is an insulating material using the curable epoxy resin composition according to any one of the present disclosures (1) to (16).

[0025] The sealing material according to the present disclosure (20) uses the curable epoxy resin composition described in any one of the present disclosures (1) to (16).

[0026] The optical material according to the present disclosure (21) uses the curable epoxy resin composition described in any one of the present disclosures (1) to (16).

[0027] The printed circuit board material according to the present disclosure (22) uses the curable epoxy resin composition described in any one of the present disclosures (1) to (16).

[0028] The method for producing a cured product according to the present disclosure (23) includes a step of curing the curable epoxy resin composition described in any one of the present disclosures (1) to (16).

Effect of the Invention

[0029] According to the present disclosure, it is possible to provide a curable epoxy resin composition, a cured product, and a method for producing a cured product that give a cured product excellent in heat resistance and electrical properties utilizing biomass.

Mode for Carrying Out the Invention

[0030] Hereinafter, the present disclosure will be specifically described.

[0031] The curable epoxy resin composition of the present disclosure contains a biomass-derived non-aromatic epoxy compound and a biomass-derived curing agent, and the curing agent is at least one selected from the group consisting of an acid anhydride, a thiol, and a phenolic compound.

[0032] The curable epoxy resin composition of the present disclosure contains a biomass-derived non-aromatic epoxy compound and a biomass-derived curing agent, and by the curing agent being at least one selected from the group consisting of an acid anhydride, a thiol, and a phenolic compound, it is possible to give a cured product excellent in heat resistance and electrical properties. Further, sustainability is improved and the environmental load can be reduced.

[0033] The curable epoxy resin composition of this disclosure can also provide a cured product with excellent transparency and weather resistance.

[0034] The above non-aromatic epoxy compounds are biomass-derived. Note that "non-aromatic epoxy compounds are biomass-derived" means that the biomass content of the non-aromatic epoxy compound is 10% or more. The above non-aromatic epoxy compound preferably has a biomass content of 50% or more, more preferably 70% or more, more preferably 90% or more, and particularly preferably 100%. The above biomass content is measured in accordance with ASTM D 6866. By using biomass-derived non-aromatic epoxy compounds, the concept of carbon neutrality can be applied to reduce net carbon dioxide emissions during combustion, thereby improving sustainability and reducing environmental impact.

[0035] Examples of the non-aromatic epoxy compounds mentioned above include aliphatic epoxy compounds. Aliphatic epoxy compounds may or may not have ring structures other than epoxy groups. The above-mentioned non-aromatic epoxy compounds may have at least one structure selected from the group consisting of ether bonds, ester bonds, and amide bonds in their structure.

[0036] Examples of non-aromatic epoxy compounds that do not have ring structures other than epoxy groups include glycidyl ether type epoxy compounds such as ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, glycerin triglycidyl ether, and poly(propylene glycol) diglycidyl ether; glycidyl ester type epoxy compounds derived from polycarboxylic acids such as dimer acids and their anhydrides; and glycidylamine type epoxy compounds derived from aliphatic amines.

[0037] Non-aromatic epoxy compounds having ring structures other than epoxy groups include hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, hydrogenated bisphenol AD ​​type epoxy resin, hydrogenated bisphenol S type epoxy resin, hydrogenated phenol novolac type epoxy resin, hydrogenated cresol novolac type epoxy resin, tetrakis(glycidyloxycyclohexyl)ethane, 1,2-diglycidyloxycyclohexane, 1,3-diglycidyloxycyclohexane, 1,4-diglycidyloxycyclohexane, isosorbide diglycidyl ether and other glycidyl ether type epoxy compounds; diglycidyl tetrahydrophthalate, diglycidyl hexahydrophthalate, dimethylglycidyl hexahydrophthalate Examples include glycidyl ester type epoxy compounds such as tetraphosphate; glycidylamine type epoxy compounds such as N,N-diglycidylaminocyclohexane, 2-methyl-N,N-diglycidylaminocyclohexane, N,N-diglycidyl-4-glycidyloxycyclohexane, 1,1-bis(4-N,N-diglycidylaminocyclohexyl)methane, 1,2-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, and 1,4-bis(N,N-diglycidylaminomethyl)cyclohexane; and alicyclic epoxy compounds in which the double bond of the cyclohexene ring is oxidized, such as alicyclic diepoxyacetals and alicyclic diepoxyadipates.

[0038] The above non-aromatic epoxy compounds preferably have a ring structure other than an epoxy group. The ring structure other than the epoxy group is preferably a non-aromatic ring, and more preferably a saturated non-aromatic ring. The ring structure other than the epoxy group described above may contain heteroatoms. Examples of heteroatoms include oxygen atoms, nitrogen atoms, sulfur atoms, etc., with oxygen atoms being preferred. The ring structure other than the epoxy group may be monocyclic or polycyclic, but is preferably polycyclic, and more preferably bicyclic.

[0039] The above-mentioned non-aromatic epoxy compound may also preferably have a structure that can form a ring structure upon curing. The ring structure that can be formed upon curing may be a non-aromatic ring, and is preferably a saturated non-aromatic ring. The ring structure formed by the above curing may contain heteroatoms. Examples of heteroatoms include oxygen atoms, nitrogen atoms, sulfur atoms, etc., with oxygen atoms being preferred. The ring structure that can be formed by the above curing may be monocyclic or polycyclic.

[0040] The above non-aromatic epoxy compound preferably contains two or more epoxy groups in its molecule, more preferably six or fewer epoxy groups, and even more preferably three or fewer epoxy groups. The above non-aromatic epoxy compound is more preferably a non-aromatic diepoxy compound, that is, it contains two epoxy groups.

[0041] As the above non-aromatic epoxy compound, glycidyl ether type epoxy resins are preferred, at least one selected from the group consisting of isosorbide diglycidyl ether, ethylene glycol diglycidyl ether, and poly(propylene glycol) diglycidyl ether is more preferred, and isosorbide diglycidyl ether is even more preferred. As the above non-aromatic epoxy compound, a glycidyl ether type epoxy resin having an antiparasitic ring other than an epoxy group is preferred, and isosorbide diglycidyl ether is more preferred.

[0042] The above non-aromatic epoxy compound preferably has an isosorbide structure.

[0043] The above-mentioned non-aromatic epoxy compounds are preferably plant-derived. Using plant-derived non-aromatic epoxy compounds improves sustainability and reduces environmental impact. Examples of plant-derived non-aromatic epoxy compounds include isosorbide diglycidyl ether, ethylene glycol diglycidyl ether, and poly(propylene glycol) diglycidyl ether.

[0044] The above-mentioned hardening agent is biomass-derived. Note that "the hardening agent is biomass-derived" means that the biomass content of the hardening agent is 10% or more. The above-mentioned curing agent preferably has a biomass content of 50% or more, more preferably 70% or more, even more preferably 90% or more, and particularly preferably 100%. The above biomass content is measured in accordance with ASTM D 6866. By using biomass-derived hardening agents, the concept of carbon neutrality can be applied to reduce net carbon dioxide emissions during combustion, thereby improving sustainability and reducing the environmental impact.

[0045] The curing agent described above is at least one selected from the group consisting of acid anhydrides, thiols, and phenolic compounds. The curing agent may be used alone or in combination of two or more types.

[0046] Examples of acid anhydrides include maleic anhydride, dodecenyl succinic anhydride, chlorendicic anhydride, sebacic anhydride, phthalic anhydride, succinic anhydride, pyromellitic anhydride, trimellitic anhydride, cyclopentane tetracarboxylic dihydrate, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, tetramethylene maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, endomethylene tetrahydrophthalic anhydride, methylendomethylene tetrahydrophthalic anhydride, oxabicyclodicarboxylic anhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, merophanic acid dianhydride, 5-(2,5-dioxotetrahydroxyfuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, and methylnadic anhydride.

[0047] The above acid anhydride preferably has a ring structure other than the acid anhydride ring in its molecule.

[0048] The above acid anhydride is preferably at least one selected from the group consisting of maleic anhydride, phthalic anhydride, succinic anhydride, oxabicyclodicarboxylic acid anhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, and merophanic acid dianhydride, and more preferably at least one selected from the group consisting of maleic anhydride, phthalic anhydride, and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride.

[0049] Examples of thiols include mercaptoacetic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 3-mercaptobutanoic acid, 4-mercaptobutanoic acid, mercaptosuccinic acid, mercaptostearic acid, mercaptooctanoic acid, 4-mercaptobenzoic acid, 2,3,5,6-tetrafluoro-4-mercaptobenzoic acid, L-cysteine, N-acetyl-L-cysteine, 3-methoxybutyl 3-mercaptopropionate, and 3-mercapto-2-methylpropyl Pionic acid, hexanedithiol, decanedithiol, 1,4-butanediol bisthiopropionate, 1,4-butanediol bisthioglycolate, ethylene glycol bisthioglycolate, ethylene glycol bisthiopropionate, trimethylolpropane tristhioglycolate, trimethylolpropane tristhiopropionate, trimethylolpropane tris(3-mercaptobutyrate), pentaerythritol tetraxthioglycolate Pentaerythritol tetraxthiopropionate, tris(2-hydroxyethyl) isocyanurate trimercaptopropionate, 1,4-dimethylmercaptobenzene, 2,4,6-trimercapto-s-triazine, 2-(N,N-dibutylamino)-4,6-dimercapto-s-triazine, tetraethylene glycol bis-3-mercaptopropionate, trimethylolpropane tris-3-mercaptopropionate, tris(3-mercapto Examples include tetrapropynyloxyethyl isocyanurate, pentaerythritol tetrakiss 3-mercaptopropionate, dipentaerythritol tetrakiss 3-mercaptopropionate, 1,4-bis(3-mercaptobutyryloxy)butane, 1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and pentaerythritol tetrakiss(3-mercaptobutyrate).

[0050] The thiol mentioned above may be an aliphatic thiol or an aromatic thiol, but it is preferably an aliphatic thiol.

[0051] The thiol described above may be a compound obtained by converting the OH group or COOH group of a biomass-derived compound to an SH group.

[0052] The thiol is preferably at least one selected from the group consisting of pentaerythritol tetrakis(3-mercaptobutyrate) and L-cysteine.

[0053] Examples of phenolic compounds include polyhydric phenols such as bisphenol A, bisphenol F, bisphenol S, bisphenol AD, hydroquinone, resorcinol, methylresorcinol, biphenol, tetramethylbiphenol, dihydroxynaphthalene, dihydroxydiphenyl ether, thiodiphenols, catechin hydrate, phenol novolac resin, cresol novolac resin, phenol aralkyl resin, biphenyl aralkyl resin, naphthol aralkyl resin, terpene phenol resin, dicyclopentadiene phenol resin, bisphenol A novolac resin, trisphenolmethane type resin, naphthol novolac resin, brominated bisphenol A, and brominated phenol novolac resin; lignin-modified phenol resins; and lignin decomposition products such as catechol, cresol, and creosol. Examples include cashew nut shell liquids such as anacardic acid, cardanol, cardol, and 2-methylcardol; resins obtained by adding biomass-derived active groups to bisphenols; polyhydric phenolic resins obtained by condensation reactions of phenols with aldehydes such as benzaldehyde, hydroxybenzaldehyde, crotonaldehyde, and glyoxal; polyhydric phenolic resins obtained by condensation reactions of xylene resins with phenols; co-condensation resins of heavy oils or pitches with phenols and formaldehydes; and phenolic resins such as phenol-benzaldehyde-xylylenedimethoxide polycondensate, phenol-benzaldehyde-xylylenedihalide polycondensate, phenol-benzaldehyde-4,4'-dimethoxide biphenyl polycondensate, and phenol-benzaldehyde-4,4'-dihalide biphenyl polycondensate.

[0054] The above-mentioned phenolic compounds preferably contain two or more hydroxyl groups, and more preferably each of the one or more aromatic rings contains two or more hydroxyl groups.

[0055] The phenolic compound mentioned above is preferably at least one selected from the group consisting of catechin hydrate, lignin-modified phenolic resin, catechol, cadol, 2-methylcadol, and bisphenol with biomass-derived active groups added, with catechin hydrate being more preferred, and (+)-catechin hydrate being even more preferred.

[0056] The curing agent may be at least one selected from the group consisting of thiols and phenolic compounds.

[0057] The curing agent described above is preferably plant-derived. Using a plant-derived curing agent improves sustainability and reduces environmental impact. Examples of plant-derived curing agents include phthalic anhydride, maleic anhydride, pentaerythritol tetrakis(3-mercaptobutyrate), and catechin hydrate (preferably (+)-catechin hydrate).

[0058] In the curable epoxy resin composition of this disclosure, the equivalent ratio (epoxy group / functional group) of the epoxy group of the non-aromatic epoxy compound to the functional group of the curing agent may be 0.75 or more, preferably 0.85 or more, and may be 1.50 or less, preferably 1.25 or less.

[0059] The curable epoxy resin composition of this disclosure may contain an organic solvent. The content of the organic solvent may be 75% by mass or less, preferably 65% ​​by mass or less, and may be 10% by mass or more, based on the curable epoxy resin composition. Examples of the above-mentioned organic solvents include toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, dimethylformamide, and N-methylpyrrolidone, which can be used individually or in combination of two or more.

[0060] The curable epoxy resin composition of this disclosure may contain a curing accelerator. The content of the curing accelerator may be 20% by mass or less, preferably 15% by mass or less, and may be 0.5% by mass or more, based on the curable epoxy resin composition. Examples of the curing accelerators mentioned above include 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo[5,4,0]-7-undecene, triphenylphosphine, methyldiphenylphosphine, etc., which can be used individually or in combination of two or more.

[0061] The curable epoxy resin composition of this disclosure may optionally contain additives commonly used in this art. Examples of such additives include flame retardants, storage stability enhancers, fillers, diluents, pigments, flexibility enhancers, coupling agents, antioxidants, sedimentation inhibitors, and dispersants. The content of the additives may be 0.01 to 10% by mass relative to the curable epoxy resin composition.

[0062] This disclosure also provides cured products obtained by curing the curable epoxy resin composition of this disclosure described above. Since the cured products of this disclosure are obtained by curing the above curable epoxy resin composition, they have excellent heat resistance and electrical properties, as well as excellent transparency and weather resistance. Furthermore, sustainability is improved and environmental impact can be reduced. Methods for curing a curable epoxy resin composition include those described later.

[0063] The glass transition temperature (Tg) of the cured product of this disclosure is preferably 22°C or higher, more preferably 50°C or higher, even more preferably 80°C or higher, even more preferably 100°C or higher, and may be 400°C or lower. The glass transition temperature can be determined by measuring it using a differential scanning calorimeter (TA Instruments Q1000) with a temperature-modulated DSC measurement method, in which a 5 mg sample is heated and cooled repeatedly at a constant period and amplitude to average the temperature. A DSC curve is obtained, and the temperature can be determined as the midpoint of the intersection of the baseline extension line before and after the second-order transition of the DSC curve and the tangent line at the inflection point of the DSC curve.

[0064] The thermal decomposition temperature (Td) of the cured product of this disclosure is preferably 125°C or higher, more preferably 150°C or higher, even more preferably 200°C or higher, and may be 450°C or lower. The thermal decomposition temperature was measured using a Bruker AXS TG-DTA 2000SA thermal analyzer. The measurement was performed under a nitrogen purge atmosphere of 150 mL / min. 10 mg of the sample was placed in a Pt pan, held at 25°C for 10 minutes, and then heated to 600°C at a heating rate of 10°C / min. The thermal decomposition temperature was evaluated as the temperature at which the initial mass decreased by 1% (Td1).

[0065] The cured product of this disclosure preferably has a relative permittivity of 6.0 or less, more preferably 4.0 or less, even more preferably 3.0 or less, particularly preferably 2.5 or less, and may also be 2.0 or more at 10 GHz. Furthermore, the cured product of this disclosure preferably has a dielectric loss tangent of 0.1 or less at 10 GHz, more preferably 0.05 or less, even more preferably 0.025 or less, even more preferably 0.02 or less, particularly preferably 0.01 or less, and may also be 0.0001 or more. The relative permittivity and dielectric loss tangent mentioned above are measured using a cavity resonator permittivity measuring device (manufactured by AET Co., Ltd.) at a frequency of 10 GHz for the cured material.

[0066] The relative permittivity and dielectric loss tangent described above are measured using a cavity resonator dielectric constant measuring device (manufactured by AET Co., Ltd.) with a powdered sample, at a frequency of 10 GHz. The specific gravity of the sample is measured using a specific gravity measuring device AUW120D manufactured by Shimadzu Corporation. Materials with low relative permittivity and dielectric loss tangent are useful as materials for electronic and electrical devices that have low transmission loss in the high-frequency range. Here, the transmission loss αd satisfies the following relationship (Equation (1)) with respect to frequency f, relative permittivity εr of the dielectric layer, and dielectric loss tangent tanδ. Since the transmission loss is proportional to the square root of the relative permittivity and the dielectric loss tangent, a small dielectric loss tangent is more important in order to reduce the transmission loss.

number

[0067] The cured product of this disclosure has a thickness of 100 μm and preferably has a transmittance of 70% or more at a wavelength of 550 nm, more preferably 80% or more. Alternatively, the transmittance may be 100%. The above transmittance values ​​were measured using an ultraviolet spectrophotometer. The above-mentioned materials with high transmittance are useful as encapsulants for UV-LEDs. High transmittance is observed when the cured product does not contain compounds with aromatic rings.

[0068] The cured product of this disclosure preferably has a refractive index of 1.35 to 1.60. More preferably it is 1.57 or less, even more preferably 1.55 or less, and may also be 1.40 or more, or 1.42 or more. The above refractive index is a value measured by an Abbe refractometer.

[0069] The cured product of this disclosure also exhibits excellent weather resistance. Weather resistance refers to the changes in appearance and mechanical strength when exposed to certain conditions, and can be measured, for example, with a Q-Lab UV fluorescent lamp accelerated weathering tester.

[0070] By using the cured product of this disclosure instead of conventional cured products, sustainability can be improved and the environmental impact can be reduced. One indicator of environmental impact is the amount of carbon dioxide emitted when the hardened material is incinerated. The above carbon dioxide emission figure for incineration is calculated assuming that all of the biomass-derived carbon contained in the hardened material is converted into carbon dioxide during combustion. In the case of carbon derived from biomass raw materials, carbon neutrality is achieved, so the carbon dioxide emission during combustion is considered to be 0. The amount of carbon dioxide emitted per kilogram of hardened material disposed of by combustion is preferably 1 kg or less, more preferably 0.8 kg or less, even more preferably 0.6 kg or less, even more preferably 0.4 kg or less, and particularly preferably 0.2 kg or less.

[0071] The curable epoxy resin composition and cured product of this disclosure are excellent in heat resistance and electrical properties, as well as in transparency and weather resistance, and can therefore be suitably used as insulating materials; encapsulating materials for LEDs, solar cells, and electronic components; optical materials such as optical lenses, optical elements, optical connectors, optical waveguides, and resins for optical molding; printed circuit board materials; semiconductor package substrate materials; communication cover antennas; drone housings; transparent heater substrates, etc. In particular, they can be suitably used as insulating materials, encapsulating materials, optical materials, and printed circuit board materials, and are especially suitable for use as insulating materials.

[0072] This disclosure also provides insulating materials, sealing materials, optical materials, and printed circuit board materials using the curable epoxy resin composition of this disclosure. The insulating materials, sealing materials, optical materials, and printed circuit board materials of this disclosure have excellent heat resistance and electrical properties, as well as excellent transparency and weather resistance. Furthermore, they offer improved sustainability and reduced environmental impact. The insulating materials, sealing materials, optical materials, and printed circuit board materials of this disclosure may include the curable epoxy resin compositions of this disclosure, or may include the cured products of this disclosure.

[0073] This disclosure also provides a method for producing a cured product, which includes a step of curing the curable epoxy resin composition of this disclosure.

[0074] There are no particular restrictions on the method for curing the curable epoxy resin composition; heating in an oven or other means, or blowing hot air, may be used. The temperature may be constant, or a temperature gradient may be applied. Furthermore, the temperature range may be below 100°C, but since the curable epoxy resin composition of this disclosure has excellent heat resistance, it can also be applied to processing in high-temperature ranges such as 120 to 200°C. There are no particular restrictions on the curing time, but for example, it is 1 to 15 hours. The curing temperature is preferably 200°C or lower, and the drying time in the high-temperature range of 160-200°C is preferably 5 hours or less, and more preferably 3 hours or less.

[0075] Although embodiments have been described above, it should be understood that various modifications to the form and details are possible without departing from the spirit and scope of the claims. [Examples]

[0076] The present disclosure will now be further described with reference to examples, but the present disclosure is not limited to these examples.

[0077] The various properties described herein were measured by the following method.

[0078] (Glass transition temperature) The glass transition temperature was measured using a differential scanning calorimeter (TA Instruments Q1000) by temperature-modulated DSC measurement, which involves heating and cooling a 5 mg sample repeatedly at a constant period and amplitude to average the temperature. A DSC curve was obtained, and the peak top temperature of the differential curve specified in JIS K6240 was defined as the glass transition temperature and evaluated.

[0079] (pyrolysis temperature) Measurements were performed using a Bruker AXS TG-DTA 2000SA thermal analyzer. Measurements were carried out under a nitrogen purge atmosphere of 150 mL / min. 10 mg of the sample was placed in a Pt pan, held at 25°C for 10 minutes, and then heated to 600°C at a rate of 10°C / min. The temperature at which the sample lost 1% of its initial mass (Td1) was used as the thermal decomposition temperature for evaluation.

[0080] (Method for measuring relative permittivity and dielectric loss tangent) The relative permittivity and dielectric loss tangent of the cured material at a frequency of 10 GHz were measured and evaluated using a powder cavity resonator dielectric constant measuring device (manufactured by AET Corporation). The specific gravity of the sample was measured using a specific gravity measuring device AUW120D manufactured by Shimadzu Corporation.

[0081] The following materials were used in the examples and comparative examples. Isosorbide diglycidyl ether (A: 100% biomass content, B: 50% biomass content) [ka] Ethylene glycol diglycidyl ether (100% biomass content) [ka] Poly(propylene glycol) diglycidyl ether (100% biomass content, Mn 380 or less) [ka] Phthalic anhydride (100% biomass content) [ka] Maleic anhydride (100% biomass content) [ka] Pentaerythritol tetrakis (3-mercaptobutyrate) (100% biomass content) [ka] (+)-Catechin hydrate (100% biomass content) [ka] Pentamethylenediamine (100% biomass content) [ka]

[0082] Example 1 In a 20 mL glass container, phthalic anhydride (2.06 g) and ethyl acetate (5.0 mL) were placed and heated and stirred on a hot plate heated to 70°C. The phthalic anhydride gradually dissolved, resulting in a colorless, transparent solution. Next, isosorbide diglycidyl ether A (2.0 g) was gradually added dropwise. After removing the hot plate and stirring at room temperature for about 5 minutes, 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30) (20 mg) was added. After stirring for 5 minutes, the mixture was cast onto a Teflon® sheet. The mixture was then cured in a constant-temperature drying oven (120°C for 5 hours → 150°C for 10 hours) to obtain 3.7 g of cured material. Various tests were performed on the resulting cured material, and the obtained properties are shown in Table 1.

[0083] Example 2 In a 20 mL glass container, maleic anhydride (2.1 g) and ethyl acetate (10 mL) were placed and heated and stirred on a hot plate heated to 70°C. The maleic anhydride gradually dissolved, resulting in a colorless, transparent solution. Next, isosorbide diglycidyl ether A (3.0 g) was gradually added dropwise. After removing the hot plate and stirring at room temperature for about 5 minutes, DMP-30 (24 mg) was added. After stirring for 5 minutes, the mixture was cast onto a Teflon® sheet. The mixture was then cured in a constant-temperature drying oven (120°C for 5 hours → 150°C for 10 hours) to obtain 4.5 g of cured material. Various tests were performed on the resulting cured material, and the obtained properties are shown in Table 2.

[0084] Example 3 Isosorbide diglycidyl ether A (1.9 g) and pentaerythritol tetrakis (3-mercaptobutyrate) (2.0 g) were placed in a 10 mL glass container and stirred at room temperature for about 10 minutes. Then, 2-ethyl-4-methylimidazole (2E4MZ) (19.5 mg) was added. After stirring for 10 minutes, the mixture was cast onto a Teflon® sheet. The mixture was then cured (100°C for 1 hour) to obtain 3.5 g of cured material. Various tests were performed on the resulting cured material, and the obtained properties are shown in Table 2.

[0085] Example 4 In a 20 mL glass container, (+)-catechin hydrate (2.1 g) and ethyl acetate (8.0 mL) were placed and heated and stirred on a hot plate heated to 70°C. The (+)-catechin hydrate gradually dissolved, forming an orange solution. Next, isosorbide diglycidyl ether A (3.5 g) was gradually added dropwise. After removing the hot plate and stirring at room temperature for about 5 minutes, 2E4MZ (28 mg) was added. After stirring for 5 minutes, the mixture was cast onto a Teflon® sheet. The mixture was then cured in a constant-temperature drying oven (160°C for 1.5 hours → 200°C for 1.5 hours) to obtain 5.5 g of cured product. Various tests were performed on the resulting cured material, and the obtained properties are shown in Table 2.

[0086] Example 5 In a 20 mL glass container, phthalic anhydride (3.06 g) and ethyl acetate (8.0 mL) were placed and heated and stirred on a hot plate heated to 70°C. The phthalic anhydride gradually dissolved, resulting in a colorless, transparent solution. Next, ethylene glycol diglycidyl ether (2.0 g) was gradually added dropwise. After removing the hot plate and stirring at room temperature for about 5 minutes, DMP-30 (20 mg) was added. After stirring for 5 minutes, the mixture was cast onto a Teflon® sheet. The mixture was then cured in a constant-temperature drying oven (120°C for 5 hours → 150°C for 10 hours) to obtain 4.6 g of cured material. Various tests were performed on the resulting cured material, and the obtained properties are shown in Table 2.

[0087] Example 6 In a 20 mL glass container, phthalic anhydride (1.89 g) and ethyl acetate (8.0 mL) were placed and heated and stirred on a hot plate heated to 70°C. The phthalic anhydride gradually dissolved, resulting in a colorless, transparent solution. Next, poly(propylene glycol) diglycidyl ether (2.7 g) was gradually added dropwise. After removing the hot plate and stirring at room temperature for about 5 minutes, DMP-30 (20 mg) was added. After stirring for 5 minutes, the mixture was cast onto a Teflon® sheet. The mixture was then cured in a constant-temperature drying oven (120°C for 5 hours → 150°C for 10 hours) to obtain 4.2 g of cured material. Various tests were performed on the resulting cured material, and the obtained properties are shown in Table 2.

[0088] Example 7 A 3.7 g cured product was obtained in the same manner as in Example 1, except that isosorbide diglycidyl ether B was used instead of isosorbide diglycidyl ether A. Various tests were performed on the resulting cured material, and the obtained properties are shown in Table 3.

[0089] Comparative Example 1 Isosorbide diglycidyl ether A (5.0 g) was placed in a 10 mL glass container and stirred at room temperature. Then, pentamethylenediamine (1.98 g) was gradually added dropwise. The isosorbide diglycidyl ether gradually dissolved, resulting in a colorless, transparent solution. After stirring at room temperature for about 15 minutes, the solution was cast into aluminum cups and Kapton film. The solution was then cured in a constant-temperature drying oven (120°C for 5 hours → 150°C for 10 hours) to obtain 3.7 g of cured material. Various tests were performed on the resulting cured material, and the obtained properties are shown in Table 1.

[0090] [Table 1]

[0091] [Table 2]

[0092] [Table 3]

[0093] (carbon dioxide emissions) The carbon dioxide emissions from the cured products obtained in the examples were calculated. The carbon dioxide emissions were calculated as follows: For each example, the amount of non-biomass-derived carbon (kg / 1kg (amount of non-biomass-derived carbon contained in 1kg of cured product)) in the epoxy compound, curing agent, and catalyst is calculated. Since carbon dioxide derived from biomass is excluded from carbon dioxide emissions under the concept of carbon neutrality, the carbon dioxide emissions generated when 1 kg of hardened material is burned refer to the amount of carbon dioxide derived from non-biomass carbon, and can be calculated using the following formula. Carbon dioxide emissions (kg / kg) = Non-biomass-derived carbon (kg / kg) × 44 / 12

[0094] We will calculate the carbon dioxide emissions for Example 1. The materials used in Example 1 are as follows: Isosorbide diglycidyl ether A (biomass-derived, molecular weight: 258.2, carbon content: 55.81% by mass): 2.0 g (49.02% by mass of the total cured product) Phthalic anhydride (biomass-derived, molecular weight: 148.12, carbon content: 64.82% by mass): 2.06 g (50.49% by mass of the total cured product) 2,4,6-Tris(dimethylaminomethyl)phenol (DMP-30) (non-biomass derived, molecular weight: 265.4, carbon content: 67.88% by mass): 0.02 g (0.49% by mass of the total cured product) Therefore, the amount of non-biomass-derived carbon in 1 kg of the cured product of Example 1 (kg / 1 kg) is: 67.83 / 100×0.49 / 100=0.00332(kg / 1kg) Therefore, the carbon dioxide emissions from the cured product of Example 1 are 0.00332 × 44 / 12 = 0.012 (kg / 1kg) This can be calculated.

[0095] When calculating the carbon dioxide emissions for Example 7 in the same manner as in Example 1, the carbon dioxide emissions were found to be 1.0 kg / kg. For reference, when using non-biomass derived isosorbide diglycidyl ether, non-biomass derived phthalic anhydride, and non-biomass derived DMP-30, the carbon dioxide emissions were calculated in the same manner as in Example 1, resulting in 2.2 kg / kg. From the above, it can be seen that the cured product of this disclosure has a very low environmental impact.

Claims

1. It contains a biomass-derived non-aromatic epoxy compound and a biomass-derived curing agent, The non-aromatic epoxy compound has a ring structure other than an epoxy group, The curing agent is an acid anhydride having a ring structure other than an acid anhydride ring in its molecule. The acid anhydride is at least one selected from the group consisting of phthalic anhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride. A curable epoxy resin composition used for at least one selected from the group consisting of insulating materials, sealing materials, optical materials, and printed circuit board materials.

2. The curable epoxy resin composition according to claim 1, wherein the biomass content of the non-aromatic epoxy compound and the curing agent is 50% or more.

3. The curable epoxy resin composition according to claim 1 or 2, wherein the biomass content of the non-aromatic epoxy compound and the curing agent is 100%.

4. The curable epoxy resin composition according to claim 1 or 2, wherein the non-aromatic epoxy compound comprises two or more epoxy groups.

5. The curable epoxy resin composition according to claim 1 or 2, wherein the non-aromatic epoxy compound is a non-aromatic diepoxy compound.

6. The curable epoxy resin composition according to claim 1 or 2, wherein the non-aromatic epoxy compound has an isosorbide structure.

7. The curable epoxy resin composition according to claim 1 or 2, wherein the non-aromatic epoxy compound is isosorbide diglycidyl ether.

8. A cured product obtained by curing the curable epoxy resin composition according to claim 1 or 2.

9. The cured product according to claim 8, wherein the relative permittivity at 10 GHz is 6.0 or less.

10. An insulating material using the curable epoxy resin composition according to claim 1 or 2.

11. A sealing material using the curable epoxy resin composition according to claim 1 or 2.

12. An optical material using the curable epoxy resin composition according to claim 1 or 2.

13. A printed circuit board material using the curable epoxy resin composition according to claim 1 or 2.

14. A method for producing a cured product, comprising the step of curing the curable epoxy resin composition according to claim 1 or 2.

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