Epoxy resin composition

Abstract

The invention relates to an epoxy resin composition. The purpose of the present invention is to provide an epoxy resin composition capable of achieving low viscosity, improving low-temperature curability, shortening curing time, and ensuring a sufficient curing region when heat conduction is insufficient. The epoxy resin composition comprises the following component (A), the following component (B) and the following component (C). (A) an epoxy resin; (B) a curing agent; (C) A compound represented by formula (1).

Description

[0001] This application is a divisional application of the application with an application date of August 31, 2021, application number 202111009390.5, and invention name “Epoxy resin composition”. Technical Field

[0002] The present invention relates to epoxy resin compositions. Background Art

[0003] Epoxy resins are widely used in a wide range of applications, including insulating materials for electrical and electronic components, sealing materials, adhesives, conductive materials, and matrix resins for fiber-reinforced plastics.

[0004] In recent years, demands for electronic devices have broadened to include miniaturization, enhanced functionality, lightweighting, and multifunctionality. Semiconductor chip mounting technology is also progressing towards further miniaturization, miniaturization, and higher density through narrowing the pitch between electrode pads. Underfill material, a thermosetting resin using epoxy resin as an adhesive, is used in the gap between the chip and the substrate to protect the bump connections and the chip's circuit surface.

[0005] Fiber-reinforced plastics are manufactured using reinforcing fibers and a matrix resin. Most matrix resins use thermosetting epoxy resins. For example, Patent Document 1 discloses an epoxy resin composition that, by containing hydrolyzable chlorine and a component having two or more alcoholic hydroxyl groups, achieves sufficient storage stability, curing speed, mechanical strength, and heat resistance. Furthermore, Patent Document 2 discloses an epoxy resin composition that, by containing an acid anhydride and a polyol compound having an aromatic ring, can cure in a short time at low temperatures below 70°C.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-301029

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 2010-163573 Summary of the Invention

[0010] Problems to be solved by the invention

[0011] In recent years, in order to be able to penetrate into the narrow gaps accompanying the narrowing of pitches, the viscosity of the above-mentioned underfill materials has been required to be low. In addition, in order to improve productivity, the underfill materials are also strongly required to have a low curing temperature and a shortened curing time.

[0012] However, the epoxy resin compositions described in Patent Documents 1 and 2 have room for improvement in terms of lower viscosity, low-temperature curability, shortened curing time, and securing a sufficient curing region when heat conduction is uneven.

[0013] The present invention has been made in view of the above-mentioned current situation. Specifically, an object of the present invention is to provide an epoxy resin composition that can achieve low viscosity, improved low-temperature curing properties, shortened curing time, and secure a sufficient curing region when heat conduction is insufficient.

[0014] Solutions for solving problems

[0015] The present inventors have conducted in-depth research and found that the above-mentioned objects can be achieved by the following technical means, thereby completing the present invention.

[0016] It should be noted that the component having two or more alcoholic hydroxyl groups described in Patent Document 1 does not have the structure represented by the following formula (1).

[0017] The present invention is as follows. [1]

[0019] An epoxy resin composition comprises the following component (A), the following component (B), and the following component (C).

[0020] (A) Epoxy resin

[0021] (B) Curing agent

[0022] (C) Compound represented by the following formula (1)

[0023]

[0024] {In formula (1), R1 to R9 are each selected from the group consisting of hydrogen, an alkyl group, an aromatic group, a heteroatom-containing substituent, and a halogen-containing substituent. R1 to R9 are optionally the same as or different from each other. In addition, the compound represented by formula (1) is optionally a fused ring compound in which any of R5 to R9 are present in the same ring.} [2]

[0026] The epoxy resin composition according to [1], wherein the component (B) contains a solid curing agent. [3]

[0028] The epoxy resin composition according to [1] or [2], wherein R1 in the formula (1) is a hydroxyl group. [4]

[0030] The epoxy resin composition according to any one of [1] to [3], wherein R2, R3, and R4 in the formula (1) are hydrogen. [5]

[0032] The epoxy resin composition according to any one of [1] to [4], comprising a compound containing 4 or more active hydrogen atoms as the component (B). [6]

[0034] The epoxy resin composition according to any one of [1] to [4], wherein the component (B) contains an imidazole-based curing agent. [7]

[0036] The epoxy resin composition according to any one of [1] to [4], wherein the component (B) contains a microcapsule-type curing agent. [8]

[0038] The epoxy resin composition according to any one of [1] to [7], further comprising a curing accelerator as component (D). [9]

[0040] A method for producing an epoxy resin composition comprising the following components (A), (B), and (C), the method comprising adding the component (C) to a compound or composition comprising at least one selected from the group consisting of the components (A) and (B).

[0041] (A) Epoxy resin

[0042] (B) Curing agent

[0043] (C) Compound represented by the following formula (1)

[0044]

[0045] {In formula (1), R1 to R9 are each selected from the group consisting of hydrogen, an alkyl group, an aromatic group, a heteroatom-containing substituent, and a halogen-containing substituent. R1 to R9 are optionally the same as or different from each other. In addition, the compound represented by formula (1) is optionally a fused ring compound in which any of R5 to R9 are present in the same ring.}

[10]

[0047] The method for producing an epoxy resin composition according to [9], wherein the epoxy resin composition further comprises the following component (D):

[0048] (D) a curing accelerator,

[0049] The production method includes the step of adding component (C) to a compound or composition containing at least one selected from the group consisting of component (A), component (B), and component (D).

[11]

[0051] The method for producing an epoxy resin composition according to [9] or

[10] , wherein the epoxy resin composition further comprises the following component (E):

[0052] (E) filler,

[0053] The production method includes the step of adding component (C) to a compound or composition containing at least one selected from the group consisting of component (A), component (B), and component (E).

[0054] Effects of the Invention

[0055] According to the present invention, there is provided an epoxy resin composition capable of achieving low viscosity, improved low-temperature curability, shortened curing time, and securing a sufficient curing region when heat conduction is insufficient. DETAILED DESCRIPTION

[0056] The following describes in detail the mode for implementing the present invention (hereinafter referred to as "this embodiment"). The following embodiment is an example for illustrating the present invention and is not intended to limit the present invention to the following. The present invention can be implemented by appropriately deforming within the scope of its purpose.

[0057] <Epoxy resin composition>

[0058] The epoxy resin composition of the present embodiment contains (A) an epoxy resin (hereinafter also referred to as "component (A)"), (B) a curing agent (hereinafter also referred to as "component (B)"), and (C) a compound represented by the following formula (1) (hereinafter also referred to as "component (C)").

[0059]

[0060] {In formula (1), R1 to R9 are each selected from the group consisting of hydrogen, an alkyl group, an aromatic group, a heteroatom-containing substituent, and a halogen-containing substituent. R1 to R9 are optionally the same as or different from each other. In addition, the compound represented by formula (1) is optionally a fused ring compound in which any of R5 to R9 are present in the same ring.}

[0061] The epoxy resin composition of the present embodiment can achieve low viscosity, improved low-temperature curability, shortened curing time, and secure a sufficient curing region when heat conduction is insufficient, by containing components (A) to (C).

[0062] <Component (A) Epoxy resin>

[0063] Examples of the epoxy resin as component (A) include, but are not limited to, bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol AD ​​epoxy resin, bisphenol M epoxy resin, bisphenol P epoxy resin, tetrabromobisphenol A epoxy resin, biphenyl epoxy resin, tetramethylbiphenyl epoxy resin, tetrabromobiphenyl epoxy resin, diphenyl ether epoxy resin, benzophenone epoxy resin, phenyl benzoate epoxy resin, diphenyl sulfide epoxy resin, diphenyl sulfoxide epoxy resin, diphenyl sulfone epoxy resin, diphenyl disulfide epoxy resin, naphthalene epoxy resin, anthracene epoxy resin, hydroquinone epoxy resin, methylhydroquinone epoxy resin, dibutylhydroquinone epoxy resin, resorcinol epoxy resin, methylisophenyl epoxy resin, Bifunctional epoxy resins such as diphenol epoxy resins, catechol epoxy resins, and N,N-diglycidylaniline epoxy resins; trifunctional epoxy resins such as N,N-diglycidylaminobenzene epoxy resins, o-(N,N-diglycidylamino)toluene epoxy resins, and triazine epoxy resins; quadrifunctional epoxy resins such as tetraglycidyldiaminodiphenylmethane epoxy resins and diaminobenzene epoxy resins; polyfunctional epoxy resins such as phenol novolac epoxy resins, cresol novolac epoxy resins, triphenylmethane epoxy resins, tetraphenylethane epoxy resins, dicyclopentadiene epoxy resins, naphthol aralkyl epoxy resins, and brominated phenol novolac epoxy resins; and alicyclic epoxy resins. These may be used alone or in combination of two or more. Furthermore, these can also be used in combination with epoxy resins modified with isocyanate etc. From the viewpoint of handling properties and heat resistance, the epoxy resin composition of the present embodiment preferably contains a bisphenol-type epoxy resin.

[0064] From the perspective of imparting sufficient strength to the cured product, the content of the epoxy resin (A) is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and even more preferably 20% by mass or more, relative to the total mass of the epoxy resin composition. Furthermore, from the perspective of imparting sufficient curability by adding components (B) and (C), the content of the epoxy resin (A) is preferably 98% by mass or less, more preferably 95% by mass or less, and even more preferably 92% by mass or less, relative to the total mass of the epoxy resin composition.

[0065] <Component (B) Curing Agent>

[0066] The curing agent as component (B) contained in the epoxy resin composition of this embodiment is not limited to the following, and examples thereof include amine curing agents, amide curing agents, phenol curing agents, acid anhydride curing agents, latent curing agents, catalyst-type curing agents, etc. The curing agent is not limited to these.

[0067] Examples of the amine-based curing agent include, but are not limited to, aliphatic amines and aromatic amines.

[0068] Examples of the aliphatic amine include, but are not limited to, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, m-xylylenediamine, trimethylhexamethylenediamine, 2-methylpentamethylenediamine, isophoronediamine, 1,3-bisaminomethylcyclohexane, bis(4-aminocyclohexyl)methane, norbornene diamine, and 1,2-diaminocyclohexane.

[0069] Examples of the aromatic amine include, but are not limited to, diaminodiphenylmethane, m-phenylenediamine, diaminodiphenylsulfone, diethyltoluenediamine, trimethylenebis(4-aminobenzoate), poly-1,4-butylene glycol bis(p-aminobenzoate), KAYAHARD AA (manufactured by Nippon Kayaku Co., Ltd.), and ETHACURE 100 (manufactured by Mitsuui Fine Chemicals, Inc.).

[0070] Examples of the amide curing agent include, but are not limited to, dicyandiamide having four active hydrogen atoms and guanidine compounds as derivatives thereof, compounds obtained by adding an acid anhydride to an amine curing agent, and hydrazide compounds.

[0071] Examples of the hydrazide curing agent containing a hydrazide compound include, but are not limited to, succinic acid dihydrazide, adipic acid dihydrazide, phthalic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, p-hydroxybenzoic acid hydrazide, salicylic acid hydrazide, phenylaminopropionic acid hydrazide, and maleic acid dihydrazide.

[0072] Examples of the guanidine-based curing agent containing a guanidine compound include, but are not limited to, dicyandiamide, methylguanidine, ethylguanidine, propylguanidine, butylguanidine, dimethylguanidine, trimethylguanidine, phenylguanidine, diphenylguanidine, and toluylguanidine.

[0073] Examples of the acid anhydride curing agent include, but are not limited to, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride.

[0074] Examples of phenolic curing agents include, but are not limited to, phenol novolac resins, cresol novolac resins, phenol aralkyl resins, cresol aralkyl resins, naphthol aralkyl resins, biphenyl-modified phenolic resins, biphenyl-modified phenolic aralkyl resins, dicyclopentadiene-modified phenolic resins, aminotriazine-modified phenolic resins, naphthol novolac resins, naphthol-phenol co-condensation novolac resins, naphthol-cresol co-condensation novolac resins, and allyl acrylic phenolic resins.

[0075] As latent curing agents, for example, imidazole compounds, polyamine compounds, amine-epoxy adducts, amine-urea adducts, or microcapsule-type curing agents coated with these, or curing agents formed by adsorbing these on porous bodies, etc. Specific examples thereof, without limitation, include Novacure HX-3721, HX-3722, HX-3613, HX-3921HP, and HXA9322HP (manufactured by Asahi Kasei Corporation), Ajicure PN-23J, PN-40J, PN-H, and MY-24 (manufactured by Ajinomoto Fine-Techno Co., Inc.), and Fujicure FXR-1020 and FXR-1030 (manufactured by Fuji Chemical Industry Co., Ltd.). These may be used alone or in combination of two or more.

[0076] From the viewpoint of good curing property at low temperature, resin curing can be achieved by adding a small amount, and a cured product with a high glass transition temperature can be obtained by curing in a short time, as a curing agent, it is preferred to include an imidazole curing agent. As the imidazole compound contained in the imidazole curing agent, there is no particular limitation, and examples thereof include 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole, 2,4-diamino-6-[2-methylimidazolyl-(1)]ethyl-s-triazine, 2-phenylimidazoline, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole. In addition, as the imidazole curing agent, there is no particular limitation, and examples thereof include Novacure HX-3721, HX-3722, HX-3613, HX-3921HP, and HXA9322HP (made by Asahi Kasei Corporation).

[0077] Examples of the catalyst-type curing agent include, but are not limited to, cationic thermosetting catalysts and BF 3 -amine complexes.

[0078] From the perspective of storage stability, the curing agent of component (B) preferably comprises a solid curing agent, that is, a curing agent that is solid at 25°C and 1013 hPa. By dispersing the solid curing agent in the epoxy resin composition and initiating the curing reaction at a predetermined temperature after a predetermined time has passed since the start of heating, the epoxy resin composition can be made to have both reactivity and storage stability. Preferred examples of such solid curing agents include dicyandiamide, solid imidazole compounds, solid polyamine compounds, and masterbatch-type latent curing agents containing these. Masterbatch-type latent curing agents containing solid imidazole microcapsule-type curing agents more preferably include Novacure HX-3721, HX-3722, HX-3613, HX-3921HP, and HXA9322HP.

[0079] The curing agent (B) preferably contains a microcapsule-type curing agent from the viewpoints of storage stability at room temperature and control of thickening when applying the epoxy resin composition using a dispenser, etc. As the microcapsule-type curing agent, Novacure HX-3721, HX-3722, HX-3613, HX-3921HP, and HXA9322HP can be used.

[0080] In addition, from the perspective of increasing the number of crosslinking points to complicate the crosslinking structure and improve the strength of the cured product, component (B) preferably contains a compound containing four or more active hydrogen atoms. Furthermore, from the perspective of improving adhesion to the substrate, it is more preferably a compound containing a heteroatom and four or more active hydrogen atoms. Such a compound is not particularly limited, and an example thereof is dicyandiamide.

[0081] These curing agents may be used alone or in combination of two or more.

[0082] The content of component (B) is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more relative to the total epoxy resin composition. In addition, the content of component (B) is preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less relative to the total epoxy resin composition.

[0083] <Component (C): Compound represented by formula (1)>

[0084] The epoxy resin composition of the present embodiment includes a compound represented by the following formula (1) (component (C)). The epoxy resin composition of the present embodiment includes a compound represented by the following formula (1) (component (C)), thereby achieving excellent low-temperature curing properties, low viscosity, shortened curing time, and ensuring a sufficient curing region.

[0085]

[0086] In formula (1), R1 to R9 are each selected from the group consisting of hydrogen, an alkyl group (preferably an alkyl group having 1 to 50 carbon atoms), an aromatic group, a heteroatom-containing substituent, and a halogen-containing substituent. R1 to R9 are optionally the same or different from each other. In addition, the compound represented by the formula (1) is optionally a fused ring compound in which any one of R5 to R9 is present in the same ring. From the viewpoint of having both excellent coordination with the (B) curing agent and compatibility with the (A) epoxy resin obtained by having an aromatic ring, thereby improving curability, the compound represented by the above formula (1) is included as component (C).

[0087] Furthermore, from the viewpoint of improving coordination with the curing agent (B) and further improving curability, it is preferred that R1 in the above formula (1) is a hydroxyl group.

[0088] Furthermore, from the viewpoint of not inhibiting the coordination of the hydroxyl group due to steric hindrance, it is preferred that R2, R3, and R4 in the above formula (1) are hydrogen.

[0089] The compound represented by the above formula (1) is not particularly limited, and examples thereof include 3-phenoxy-1-propanol, 3-phenoxy-1,2-propanediol, 3-phenoxy-1,3-propanediol, cresol glycerol ether (3-(2-methylphenoxy)-1,2-propanediol), guaiacol glycerol ether (3-(2-methoxyphenoxy)propane-1,2-diol), bisphenol A (3-hydroxypropyl) glycidyl ether, bisphenol A (2,3-hydroxypropyl) glycidyl ether,

[0090] The compound represented by the following formula (1-1) (hereinafter also referred to as "Compound 1"),

[0091]

[0092] The compound represented by the following formula (1-2) (hereinafter also referred to as "Compound 2"),

[0093]

[0094] The compound represented by the following formula (1-3) (hereinafter also referred to as "Compound 3"),

[0095]

[0096] Compounds having a 1-propanol structure formed by ring-opening a terminal epoxy group of a bisphenol F-type epoxy resin, compounds having a 1,2-propylene glycol structure formed by ring-opening a terminal epoxy group of a bisphenol F-type epoxy resin (for example, bisphenol F glycidyl 2,3-dihydroxypropyl ether), compounds having a 1-propanol structure formed by ring-opening a terminal epoxy group of a naphthalene-type epoxy resin, compounds having a 1,2-propylene glycol structure formed by ring-opening a terminal epoxy group of a naphthalene-type epoxy resin, compounds having a 1-propanol structure formed by ring-opening a terminal epoxy group of a phenol novolac-type epoxy resin, compounds having a 1,2-propylene glycol structure formed by ring-opening a terminal epoxy group of a phenol novolac-type epoxy resin, compounds having a 1-propanol structure formed by ring-opening a terminal epoxy group of a cresol novolac-type epoxy resin, compounds having a 1,2-propylene glycol structure formed by ring-opening a terminal epoxy group of a cresol novolac-type epoxy resin, and the like. Among them, 3-phenoxy-1-propanol, 3-phenoxy-1,2-propanediol, bisphenol A (3-hydroxypropyl) glycidyl ether, bisphenol A (2,3-hydroxypropyl) glycidyl ether, Compound 1, Compound 2, and Compound 3 are preferred because they have a high effect of lowering the thickening starting temperature of the epoxy resin composition and have good compatibility with the epoxy resin (A), thereby obtaining a uniform epoxy resin composition. These components (C) represented by formula (1) can be used alone or in combination of two or more.

[0097] The content of component (C) is preferably 0.00001 mass % or more relative to the epoxy resin composition as a whole, more preferably 0.0001 mass % or more, further preferably 0.001 mass % or more. In addition, the content of component (C) is preferably less than 20 mass % relative to the epoxy resin composition as a whole, more preferably less than 15 mass %, further preferably less than 10 mass %, further preferably less than 8 mass %, further more preferably less than 7 mass %, extremely preferably less than 6 mass %, more extremely preferably less than 5 mass %, further extremely preferably less than 3 mass %, particularly extremely preferably less than 2 mass %. The epoxy resin composition of the present embodiment, by comprising the component (C) of more than 0.00001 mass %, can further achieve the reduction of thickening starting temperature, low viscosity, shortening of curing time, the curing of sufficient curing region. In addition, from the viewpoint of storage stability, the content of component (C) is preferably less than 20 mass % relative to the epoxy resin composition as a whole.

[0098] As a mechanism by which component (C) shows effects in terms of low viscosity, modified low temperature curing, shortened curing time, and improved curing region, it is believed that the mechanism is as follows but not limited to the following. The aromatic group and hydroxyl group of component (C) act on the interaction between the epoxy resins (A), thereby eliminating the interaction between the epoxy resins (A). As a result, the molecular movement of the epoxy resin composition as a whole becomes easy, thereby reducing viscosity. In addition, a coordination bond is formed between the hydroxyl group of component (C) and the curing agent (B), thereby improving the compatibility of the curing agent (B) with the epoxy resin (A), and improving the diffusibility of the curing agent (B) in the epoxy resin composition, thereby achieving sufficient diffusion of the curing agent (B) in the epoxy resin component (A) at a lower temperature and the accompanying curing reaction. It should be noted that, from the viewpoint of improving the coordination with the curing agent (B), as component (C), a 1,2-diol structure is more preferred. The improved compatibility and diffusivity of the curing agent (B) after coordination with the above-mentioned component (C) with the epoxy resin (A) also contribute to shortening the curing time and improving the curing range. The effects on interaction, coordination, and compatibility are greatly affected by the molecular structure. Therefore, the component (C) of the epoxy resin composition of this embodiment includes the compound represented by the above-mentioned formula (1).

[0099] As an indicator of compatibility, there is the sp value (δ), and it is known that when the difference in the sp values ​​of the compounds is small, good compatibility is exhibited. From the perspective of the excellent compatibility of component (C) with the epoxy resin of component (A), and the excellent compatibility with component (A) after component (C) is coordinated to the curing agent of component (B), thereby further exerting the effects of lowering viscosity, improving low-temperature curing properties, shortening curing time, and improving the curing range, it is preferred that the sp value of component (C) has a value close to that of the epoxy resin of component (A). The following are the sp values ​​of each compound at 25°C calculated by the Fedors calculation method (mathematical formula (i)) using the values ​​described in POLYMER ENGINEERING AND SCIENCE, FEBRUARY, 1974, Vol. 14, No. 2 by ROBERT F. FEDORS.

[0100] δ=(∑⊿e / ∑⊿v) 1 / 2 Mathematical formula (i)

[0101] ⊿e represents the cohesive energy of each substituent, and ⊿v represents the molar volume.

[0102] [Ingredients (A)]

[0103] Bisphenol A epoxy resin (n=0)·····δ=10.9(cal / cm 3 ) 1 / 2 Bisphenol F epoxy resin (n=0)·····δ=12.1(cal / cm 3 ) 1 / 2 Epoxy cresol novolac ·····δ=11.0(cal / cm 3 ) 1 / 2 Tetraglycidyldiaminodiphenylmethane·····δ=11.9(cal / cm 3 ) 1 / 2

[0104] [Ingredient (B)]

[0105] Dicyandiamide·····δ=17.8(cal / cm 3 ) 1 / 2

[0106] [Ingredient (C)]

[0107] 3-Phenoxy-1-propanol·····δ=12.0(cal / cm 3 ) 1 / 2

[0108] 3-Phenoxy-1,2-propanediol·····δ=14.3(cal / cm 3 ) 1 / 2 Bisphenol A (3-hydroxypropyl) glycidyl ether·····δ=11.6(cal / cm 3 ) 1 / 2 Bisphenol A (2,3-hydroxypropyl) glycidyl ether·····δ=12.9(cal / cm 3 ) 1 / 2 Compound 1·····δ=12.0(cal / cm 3 ) 1 / 2 Compound 2·····δ=12.0(cal / cm 3 ) 1 / 2 Compound 3·····δ=12.6(cal / cm 3 ) 1 / 2

[0109] [Other ingredients]

[0110] Glycerol·····δ=20.0(cal / cm 3 ) 1 / 2

[0111] From the viewpoint of further exhibiting the effects of lowering viscosity, improving low-temperature curing properties, shortening curing time, and improving curing range by making the sp value of component (C) close to that of component (A), when component (A) contains a sp value of 10 to 13 (cal / cm 3 ) 1 / 2 When the epoxy resin is used, the lower limit of the sp value of component (C) is preferably 7 (cal / cm 3 ) 1 / 2 More than 8 (cal / cm 3 ) 1 / 2 More preferably, 9 (cal / cm 3 ) 1 / 2 More preferably, 10 (cal / cm 3 ) 1 / 2 More preferably, 11 (cal / cm 3 ) 1 / 2 The upper limit of the sp value of component (C) is preferably less than 20 (cal / cm 3 ) 1 / 2 , more preferably 18 (cal / cm 3 ) 1 / 2 Below, further more preferably 16 (cal / cm 3 ) 1 / 2 the following.

[0112] Component (C) may be added when mixing with other components, or may be generated in the system after mixing. Alternatively, it may be generated in the system when producing other components (A) and (B) and components (D) and (E) described later.

[0113] <Component (D) Curing Accelerator>

[0114] The epoxy resin composition of the present embodiment may further include a (D) curing accelerator (hereinafter also referred to as "component (D)") for the purpose of promoting the curing reaction. The curing accelerator (D) is not particularly limited, and examples thereof include amine compounds, imidazole compounds, boron salts of onium compounds, phosphorus compounds, Lewis acids, urea derivatives, and the like. The urea derivative is not particularly limited, and examples thereof include 3-(3,4-dichlorophenyl)-1,1-dimethylurea (also known as DCMU, diuron), 3-(4-chlorophenyl)-1,1-dimethylurea, and the like. These may be used alone or in combination of two or more.

[0115] When the imidazole compound that is the component (B) curing agent contains another component (B) curing agent, it corresponds to the component (D) curing accelerator depending on the combination. In this specification, the imidazole compound is the component (D) curing accelerator in the following cases.

[0116] When component (B) contains at least one of a guanidine compound, a hydrazide compound, an acid anhydride compound, a phenolic resin, a polythiol compound, an aromatic amine, a benzoxazine, and a cyanate ester, and the addition of an imidazole compound exhibits curability-enhancing effects such as shortened curing time, lowered curing temperature, and improved strength of the cured product, the imidazole compound serves as the component (D) curing accelerator.

[0117] When component (B) contains two or more imidazole compounds, the imidazole compound that contributes less per unit to curability-enhancing effects such as shortening the curing time, lowering the curing temperature, and improving the strength of the cured product is used as component (D) as a curing accelerator.

[0118] Specific examples of the curing agent as the component (B) described above when the imidazole compound is used as the curing accelerator as the component (D) include the compounds described in the section [Curing agent as the component (B)].

[0119] The imidazole compound used in combination to form the curing accelerator of component (D) is not particularly limited, and examples thereof include 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole, 2,4-diamino-6-[2-methylimidazolyl-(1)]ethyl-s-triazine, 2-phenylimidazoline, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, Novacure HX-3721, HX-3722, HX-3613, HX-3921HP, HXA9322HP (manufactured by Asahi Kasei), and AER Hardner D1207 and D1301 (manufactured by Asahi Kasei).

[0120] From the viewpoint of showing sufficient curability, the content of component (D) in the epoxy resin composition is preferably 2% by mass or more, more preferably 3% by mass or more, and even more preferably 4% by mass or more. In addition, from the viewpoint of showing sufficient storage stability, the content of component (D) in the epoxy resin composition is preferably 20% by mass or less, more preferably 17% by mass or less, and even more preferably 14% by mass or less.

[0121] <Component (E) Filler>

[0122] The epoxy resin composition of the present embodiment may contain (E) an organic filler and / or an inorganic filler (hereinafter also referred to as "component (E)") as needed.

[0123] Examples of organic fillers include, but are not limited to, thermoplastic resins and thermoplastic elastomers such as triblock copolymers, carbon fibers, cellulose, polyethylene powder, and polypropylene powder. These organic fillers may be used alone or in combination of two or more.

[0124] As the inorganic filler, not limited to the following, for example, fused silica, crystalline silica, alumina, talc, silicon nitride, aluminum nitride, zinc oxide (ZnO), coal tar, glass fiber, asbestos fiber, boron fiber, quartz powder, mineral silicate, mica, asbestos powder, slate powder, etc. can be listed. These inorganic fillers can be used alone one or two or more in combination.

[0125] These organic fillers and inorganic fillers have a function of changing the viscoelasticity of the epoxy resin composition, making the viscosity, storage modulus and thixotropy suitable, and also have a tendency to improve the breaking toughness of the cured product of the epoxy resin composition, reducing the reduction of the curing shrinkage.

[0126] From the viewpoint of sufficiently suitably making the thixotropy and improving the breaking toughness, the content of the component (E) in the epoxy resin composition is preferably 10% by mass or more, more preferably 20% by mass or more, and further preferably 25% by mass or more. In addition, from the viewpoint of sufficiently low viscosity and excellent handling properties, the content of the component (E) in the epoxy resin composition is preferably 85% by mass or less, more preferably 80% by mass or less, and further preferably 75% by mass or less.

[0127] In the epoxy resin composition of the present embodiment, a diluent, a reactive diluent, a pigment, a dye, a flow adjusting agent, a thickening agent, a reinforcing agent, a release agent, a wetting agent, a flame retardant, a surfactant, a resin, etc. can be further included as an additive, as needed, in addition to the above components.

[0128] <Method for producing the epoxy resin composition>

[0129] The epoxy resin composition of the present embodiment can be obtained by mixing the above components (A), (B) and (C). The mixing method of each component is not particularly limited, and a conventional mixing device and processing condition can be applied. Not particularly limited, and for example, the following method can be listed: the above components (A) to (C), and the above components (D) and (E) used as needed, and other additive components, etc. are sufficiently mixed to be uniform with a 3-roll mill or the like mixing roll, a dissolver, a planetary mixer, a kneader, an extruder, etc. to obtain the epoxy resin composition.

[0130] In the method for producing the epoxy resin composition of the present embodiment, from the viewpoint of obtaining a uniform epoxy resin composition by improving the dispersibility of the component (C), and the viewpoint of improving the productivity by suppressing the curing reaction during the production, it is preferable to include a step of adding the component (C) to a compound or composition having at least one selected from the group of the component (A) and the component (B) when mixing each component.

[0131] In the method for producing the epoxy resin composition of the present embodiment, when the epoxy resin composition further contains component (D), from the viewpoint of obtaining a uniform epoxy resin composition by improving the dispersibility of component (C) and from the viewpoint of improving productivity by suppressing the curing reaction during the production process, the step of adding component (C) to a compound or composition having at least one selected from the group consisting of component (A), component (B) and component (D) is preferably included when mixing the components.

[0132] In the method for producing the epoxy resin composition of the present embodiment, when the epoxy resin composition further contains component (E), from the viewpoint of obtaining a uniform epoxy resin composition by improving the dispersibility of component (C) and improving productivity by suppressing the curing reaction during the production process, it is preferred that the step of adding component (C) to a compound or composition containing at least one selected from the group consisting of component (A), component (B) and component (E) be included when mixing the components.

[0133] Example

[0134] The present invention will be further described in detail below by way of Examples and Comparative Examples, but the present invention is not limited in any way by these Examples. It should be noted that the following "parts" and "%" are by mass unless otherwise specified.

[0135] (Preparation of epoxy resin composition)

[0136] Components (A) to (C) and other components described below were weighed according to the blending ratios shown in Table 1 below, and then stirred and degassed for 3 minutes using a non-bubbling kneader to prepare an epoxy resin composition. The amounts of the individual components in Table 1 are expressed in parts by mass based on 100 parts by mass of the total amount of component (A).

[0137] (Determination of thickening onset temperature)

[0138] A dynamic viscosity η'-temperature curve was obtained using a rheometer (HAAKE MARS, manufactured by Thermo Scientific) when the epoxy resin composition was heated from 25°C to 200°C at a heating rate of 5°C / min in an oscillation mode (f = 1 Hz). In the obtained dynamic viscosity-temperature curve, the temperature T0°C at which the dynamic viscosity η' monotonically increases within the range of T0°C to T0+5°C and the dynamic viscosity η' at T0+5°C (T0+5°C) satisfies the equation (1) compared to the dynamic viscosity η' at T0°C (To°C) was defined as the thickening start temperature.

[0139] η'(T0+5℃)-η'(T0℃)≥500(mPa·s)······Mathematical formula (1)

[0140] (Measurement of Initial Viscosity of Epoxy Resin Composition)

[0141] The viscosity (initial viscosity) of the epoxy resin composition immediately after preparation was measured at room temperature (25° C.) using an E-type viscometer (TVE-35H, manufactured by Toki Sangyo Co., Ltd.).

[0142] (Gel time measurement)

[0143] The gel time of the epoxy resin composition was measured using a curelastometer (curelastometer V, manufactured by Teixeiniger Co., Ltd.) at a set temperature of 80°C to generate a torque-vulcanization time graph. For the graph obtained in this embodiment, the points where the torque reached 1 N·m and the point where the torque reached 0.5 N·m were determined, and the time at which a straight line passing through these two points intersected the vulcanization time axis was defined as the gel time.

[0144] (Storage stability ratio)

[0145] The initial viscosity of the epoxy resin composition immediately after preparation and the viscosity over time after standing at 40°C for 7 days were measured using an E-type viscometer at room temperature (25°C), and the storage stability ratio was calculated using the following mathematical formula (2).

[0146] Storage stability ratio = viscosity after 7 days at 40°C / initial viscosity ... Formula (2)

[0147] The storage stability ratio is preferably 2 or less, more preferably 1.5 or less, even more preferably 1.2 or less, even more preferably 1.1 or less, and particularly preferably 1.

[0148] (Curing area)

[0149] An epoxy resin composition was poured fully into a Teflon (registered trademark) mold measuring 550 mm long, 350 mm wide, and 2 mm thick, up to the opening, and then heated in a heating furnace at a set temperature of 100°C for 90 minutes. After heating, the volume of the cured product removed from the Teflon (registered trademark) mold was designated as Vc, and the volume of the poured epoxy resin composition was designated as V0. The cured area was calculated using the following mathematical formula (3).

[0150] Curing area (%) = 100 × Vc / V0······Mathematical formula (3)

[0151] The following judgment was made based on the ratio (%) of the cured region.

[0152] [Table 1]

[0153] ◎Curing area: 100% ○Curing area: 80% or more and less than 100% △Curing area: more than 50% and less than 80% ×Curing area: less than 50%

[0154] The larger the cured region when the epoxy resin composition is cured, the more excellent the property of ensuring a sufficient cured region when heat conduction in the cured region is insufficient.

[0155] The components described in Table 1 are as described below.

[0156] [(A) Epoxy Resin]

[0157] Component A-1: Bisphenol A-type epoxy resin (manufactured by Mitsubishi Chemical Corporation) (epoxy equivalent 182 g / eq.)

[0158] [(B) Curing Agent]

[0159] Component B-1: Dicyandiamide (manufactured by Wako Pure Chemical Industries, Ltd.)

[0160] Component B-2: Novacure HXA9322HP (manufactured by Asahi Kasei Corporation)

[0161] Component B-3: Ajicure PN-H (manufactured by Ajinomoto Fine-Techno Co., Inc.) solid amine compound

[0162] [(C) Compound represented by Formula (1)]

[0163] Component C-1: 3-phenoxy-1,2-propanediol (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0164] Component C-2: 3-phenoxy-1-propanol (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0165] [(D) Curing Accelerator]

[0166] Component D-1: AER Hardner D1301 (manufactured by Asahi Kasei Corporation)

[0167] Component D-2: 3-(3,4-dichlorophenyl)-1,1-dimethylurea (alias DCMU, monuron) (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0168] [Other Components]

[0169] Other Component-1: Glycerol (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0170] [Examples 1 to 8 and Comparative Examples 1 to 5]

[0171] Epoxy resin compositions were prepared by the aforementioned method by blending the components in the proportions shown in Tables 1-1 to 1-6. The properties of the prepared epoxy resin compositions were measured using the aforementioned methods. The results of rheometer measurements of the thickening onset temperature and initial viscosity of each epoxy resin composition are shown in Tables 1-1 to 1-6.

[0172] [Table 1-1]

[0173]

[0174] [Table 1-2]

[0175]

[0176] [Table 1-3]

[0177]

[0178] [Table 1-4]

[0179]

[0180] [Table 1-5]

[0181]

[0182] [Table 1-6]

[0183]

[0184] Comparing Examples 1 to 3 and Comparative Example 1, which have the same ratio of components (A) and (B), it can be seen that the epoxy resin compositions of Examples 1 to 3 have a lower thickening starting temperature and initial viscosity than Comparative Example 1 which does not contain component (C) (component C-1), and have lower viscosity and improved low-temperature curing properties.

[0185] In addition, by comparing Example 4 and Comparative Example 2, which have the same ratio of components (A), (B) and (D), it can be seen that the epoxy resin composition of Example 4 has a lower thickening starting temperature and initial viscosity than Comparative Example 2 which does not contain component (C) (component C-1), and has lower viscosity and improved low-temperature curing properties.

[0186] In addition, by comparing Example 5 and Comparative Example 3, which have the same ratio of components (A) and (B), it can be seen that the epoxy resin composition of Example 5 has a lower thickening starting temperature and initial viscosity than Comparative Example 3 which does not contain component (C) (component C-1), and has lower viscosity and improved low-temperature curing properties.

[0187] Furthermore, a comparison of Examples 6 to 8 and Comparative Example 4, which have the same ratio of components (A) and (B), reveals that the epoxy resin compositions of Examples 6 to 8 have lower thickening onset temperatures and initial viscosities, resulting in improved low viscosity and low-temperature curing properties, compared to Comparative Example 4, which does not contain component (C) (component C-1 or component C-2). It should be noted that the epoxy resin composition of Comparative Example 5, which uses "Other Component-1: Glycerol," a compound having a terminal hydroxyl group but not represented by formula (1), instead of component (C), has an initial viscosity that is the same as the initial viscosity (13 Pa·s) of Comparative Example 4, which is identical except for the absence of glycerol, indicating no viscosity-lowering effect.

[0188] In addition, by comparing Example 9 and Comparative Example 6, which have the same ratio of components (A) and (B), it can be seen that the epoxy resin composition of Example 9 has a lower thickening starting temperature and initial viscosity than Comparative Example 6 which does not contain component (C) (component C-1), and has lower viscosity and improved low-temperature curing properties.

[0189] In addition, by comparing Examples 10 and 11 and Comparative Example 7, which have the same ratio of components (A), (B) and (D), it can be seen that the epoxy resin compositions of Examples 10 and 11 have a lower thickening starting temperature and initial viscosity than Comparative Example 7 which does not contain component (C) (component C-1), and the viscosity is reduced and the low-temperature curing property is improved.

[0190] The gel time measurement results of the epoxy resin compositions of Example 6 and Comparative Example 4 are shown in Table 2. It is found that the epoxy resin composition of Example 6, which contains component (C) (component C-1) in addition to the epoxy resin composition of Comparative Example 4, has a significantly shorter gel time (curing time).

[0191] [Table 2]

[0192] Example 6 Comparative Example 4 Gel time 32 minutes More than 90 minutes

[0193] Table 3 shows the measurement results of the storage stability ratios of the epoxy resin compositions of Examples 1 to 3 and 6 to 8 and Comparative Example 5.

[0194] [Table 3]

[0195] Example 1 Example 2 Example 3 Example 6 Example 7 Example 8 Comparative Example 5 Storage stability ratio 1 1.1 1.6 1 More than 2 times 1 1.2

[0196] The evaluation results of the cured regions of the epoxy resin compositions of Examples 5 and 6 and Comparative Examples 3 and 4 are shown in Table 4. The epoxy resin compositions of Examples 5 and 6 showed a 100% cured region, whereas the epoxy resin compositions of Comparative Examples 3 and 4, which did not contain component (C) (component C-1), did not show a sufficient cured region.

[0197] [Table 4]

[0198] Example 5 Example 6 Comparative Example 3 Comparative Example 4 Determination of curing area ◎ ◎ × △

[0199] Although the present embodiment has been described above, the present invention is not limited thereto and can be appropriately modified within the scope of the gist of the invention.

[0200] Industrial applicability

[0201] According to the present invention, there is provided an epoxy resin composition capable of achieving low viscosity, improved low-temperature curability, shortened curing time, and securing a sufficient curing region when heat conduction is insufficient.

Claims

1. An epoxy resin composition comprising the following component (A), the following component (B), and the following component (C), (A) epoxy resin, (B) a curing agent, (C) a compound represented by the following formula (1), In formula (1), R1 to R9 are each one selected from the group consisting of hydrogen, an alkyl group, an aromatic group, a heteroatom-containing substituent, and a halogen-containing substituent, and R1 to R9 are optionally the same as or different from each other. Furthermore, the compound represented by formula (1) is optionally a fused ring compound in which any one selected from R5 to R9 is present in the same ring. in, Component (C) does not include bisphenol A (2,3-hydroxypropyl) glycidyl ether and bisphenol F glycidyl 2,3-dihydroxypropyl ether.

2. The epoxy resin composition according to claim 1, wherein The component (B) contains a solid curing agent.

3. The epoxy resin composition according to claim 1 or 2, wherein R1 in the formula (1) is a hydroxyl group.

4. The epoxy resin composition according to any one of claims 1 to 3, wherein R2, R3 and R4 in the formula (1) are hydrogen.

5. The epoxy resin composition according to any one of claims 1 to 4, wherein A compound containing 4 or more active hydrogen atoms is contained as the component (B).

6. The epoxy resin composition according to any one of claims 1 to 4, wherein The component (B) contains an imidazole-based curing agent.

7. The epoxy resin composition according to any one of claims 1 to 4, wherein The component (B) contains a microcapsule-type curing agent.

8. The epoxy resin composition according to any one of claims 1 to 7, wherein A curing accelerator is also contained as component (D).

9. A method for producing an epoxy resin composition comprising the following components (A), (B), and (C), the method comprising the steps of: adding component (C) to a compound or composition comprising at least one selected from the group consisting of component (A) and component (B); (A) epoxy resin, (B) a curing agent, (C) a compound represented by the following formula (1), In formula (1), R1 to R9 are each one selected from the group consisting of hydrogen, an alkyl group, an aromatic group, a heteroatom-containing substituent, and a halogen-containing substituent, and R1 to R9 are optionally the same as or different from each other. Furthermore, the compound represented by formula (1) is optionally a fused ring compound in which any one selected from R5 to R9 is present in the same ring. in, Component (C) does not include bisphenol A (2,3-hydroxypropyl) glycidyl ether and bisphenol F glycidyl 2,3-dihydroxypropyl ether.

10. The method for producing an epoxy resin composition according to claim 9, wherein The epoxy resin composition further comprises the following component (D): (D) a curing accelerator, The production method includes the step of adding component (C) to a compound or composition containing at least one selected from the group consisting of component (A), component (B), and component (D).

11. The method for producing an epoxy resin composition according to claim 9 or 10, wherein: The epoxy resin composition further comprises the following component (E): (E) filler, The production method includes the step of adding component (C) to a compound or composition containing at least one selected from the group consisting of component (A), component (B), and component (E).

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