Epoxy resin and curable composition containing the epoxy resin

Abstract

To provide an epoxy resin that can give a cured product having low moisture absorptivity, low thermal elasticity and high close adhesion in balanced manner, without impairing low viscosity during its melting, and a curable composition containing the epoxy resin.SOLUTION: An epoxy resin is a glycidyl etherified product of a polyhydric hydroxy resin made from a reaction material (1) comprising an aromatic compound (A) having a phenolic hydroxy group-bound aromatic ring and at least one monovalent hydrocarbon group at a meta position of the aromatic ring, and an aromatic divinyl compound (B1).SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to epoxy resins and curable compositions containing such epoxy resins. [Background technology]

[0002] Thermosetting resins, which have epoxy resins and their curing agents as essential components, are widely used in semiconductor encapsulants, printed circuit boards and other electronic components, conductive adhesives such as conductive pastes, other adhesives, matrices for composite materials, paints, photoresist materials, and color developing materials due to their excellent physical properties such as high heat resistance and moisture resistance. Among these various applications, in the field of semiconductor encapsulants, there is a growing demand for miniaturization and high integration of electronic devices, leading to a shift towards surface mount packages such as BGA and CSP, and the adoption of copper wires, which have high bonding reliability in high-temperature environments.

[0003] However, copper wires are more susceptible to corrosion than conventional gold. When interfacial degradation such as delamination occurs at the interface between the encapsulating resin and the lead frame, moisture concentrates at the delamination site due to capillary action, corroding the tip and wire bonding joint. Furthermore, during the high-temperature reflow process, moisture expands rapidly, becoming a cause of crack formation. Therefore, it is essential that the encapsulating resin properties reduce delamination at the lead frame interface during reflow, specifically requiring reduced moisture absorption, reduced elastic modulus, and improved adhesion to the lead frame.

[0004] In addition to the aforementioned performance characteristics, it is desirable that semiconductor encapsulating materials be made by highly filling the resin material with fillers such as silica in order to suppress thermal expansion. To increase the filling rate, it is important that the resin material has low viscosity and excellent fluidity.

[0005] Patent Document 1 discloses an epoxy resin, which is a derivative of a polyvalent hydroxy resin obtained by reacting a phenolic compound with an aromatic vinyl compound, as a resin that provides a cured product with excellent fluidity, moisture resistance, low elasticity at high temperatures, flame retardancy, and low dielectric properties. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2017-066268 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, the technology described in Patent Document 1 does not consider how to achieve a high-level simultaneous relationship between excellent moldability due to low viscosity during resin melting and excellent reflow resistance due to low moisture absorption rate, low elasticity at heat, and high adhesion to substrates such as copper foil of the cured product. Furthermore, the properties of the disclosed epoxy resin are insufficient, leaving room for improvement. Therefore, the problem that the present invention aims to solve is to provide an epoxy resin and a curable composition containing the epoxy resin that can achieve a high degree of simultaneous low moisture absorption, low thermal elasticity, and high adhesion of the cured product without impairing its low viscosity during melting. [Means for solving the problem]

[0008] As a result of diligent research to solve the above-mentioned problems, the present inventors have found that by using an epoxy resin which is a glycidyl ether of a polyvalent hydroxy resin, with an aromatic compound (A) having an aromatic ring to which a phenolic hydroxyl group is bonded and at least one monovalent hydrocarbon group at the meta position of the aromatic ring, and an aromatic divinyl compound (B1) as reaction raw materials (1), it is possible to obtain an epoxy resin and a curable composition containing said epoxy resin that can achieve a high degree of simultaneous low moisture absorption, low elasticity, and high adhesion of the cured product without impairing the low viscosity during melting, and have completed the present invention. [Effects of the Invention]

[0009] According to this disclosure, an epoxy resin can be obtained that maintains low viscosity during melting while simultaneously achieving a high degree of compatibility between low moisture absorption, low elasticity, and high adhesion in the cured product. Such a polyvalent hydroxy resin is particularly useful in applications such as electronic component encapsulation materials. [Modes for carrying out the invention]

[0010] The embodiments of the present invention (hereinafter referred to as "these embodiments") will be described in detail below, but this disclosure is not limited to the following description and can be implemented in various ways within the scope of its gist. <Epoxy resin> This disclosure relates to an epoxy resin, which is a glycidyl ether of a polyvalent hydroxy resin, wherein the reaction raw material (1) is an aromatic compound (A) having an aromatic ring to which a phenolic hydroxyl group is bonded and at least one monovalent hydrocarbon group at the meta position of the aromatic ring, and an aromatic divinyl compound (B1). The epoxy resin of this disclosure may also be an epoxy resin in which the reaction raw material (2) is the polyvalent hydroxy resin and an epihalohydrin (C). Furthermore, in this embodiment, the reaction raw material (1) may further contain an aromatic monovinyl compound (B2). The epoxy resin of this disclosure is obtained in which the aromatic compound (A), which is the reaction raw material (1), has an aromatic ring having at least one phenolic hydroxyl group and one monovalent hydrocarbon group at the meta position, thereby achieving a high degree of simultaneous low moisture absorption rate, low thermal elasticity, and high adhesion of the cured product without impairing low viscosity during melting.

[0011] -term- In this specification, "reaction raw material" refers to a compound used to obtain a target compound through a chemical reaction such as combination or decomposition, and which partially constitutes the chemical structure of the target compound. Substances that act as aids to chemical reactions, such as solvents and catalysts, are excluded. In particular, in this specification, "reaction raw material" refers to a precursor compound used to obtain a target polymer compound, epoxy resin, or its precursor compound (e.g., polyvalent hydroxyl resin) through a chemical reaction (e.g., polymerization reaction, etherification reaction). In this specification, "monovalent hydrocarbon group" is an alkyl group (for example, the alkyl groups listed below) or an aryl group, and one or more -CH2- in the alkyl group may be substituted with -O- or -S- so as not to be adjacent to each other, or one or more -CH2-CH2- in the alkyl group may be substituted with -CH=CH- so as not to be adjacent to each other. Furthermore, the hydrocarbon group may be linear, branched, or cyclic, and may be an alkyl group having 1 to 20 carbon atoms. In this specification, "alkyl group" refers to, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a tert-pentyl group, a neopentyl group, a 1,2-dimethylpropyl group, an n-hexyl group, an isohexyl group, an (n-)heptyl group, an (n-)octyl group, an (n-)nonyl group, an (n-)decyl group, an (n-)undecyl group, an (n-)dodecyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, or a cyclononyl group. In this specification, "alkenyl group" refers to groups such as ethynyl, 1-propynyl, 2-propynyl, 2-butynyl, pentynyl, hexynyl, vinyl, allyl, and isopropenyl. In this specification, "alkoxy group" refers to, for example, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a 2-ethylhexyloxy group, an octyloxy group, a nonyloxy group, and the like. In this specification, "aryl group" refers to a phenyl group, a 1-naphthyl group, or a 2-naphthyl group, among others. In this specification, "halogen atoms" include, for example, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, and the like. In this specification, the "monovalent organic group" is preferably an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 1 to 10 carbon atoms. Furthermore, one or more non-adjacent -CH2- groups in the alkyl group, alkenyl group, or alkoxy group may be substituted with -O-, -COO-, or -OCO-.

[0012] <Polyvalent hydroxy resin> In this embodiment, the "polyvalent hydroxy resin" and the "epoxy resin," which is a glycidyl ether of the "polyvalent hydroxy resin," are polymer compounds that differ only in that the phenolic hydroxyl group bonded to the aromatic ring is replaced by a glycidyl ether group. The "polyvalent hydroxy resin" in this embodiment is a polyvalent hydroxy resin in which an aromatic compound (A) having an aromatic ring to which a phenolic hydroxyl group is bonded and at least one monovalent hydrocarbon group at the meta position of the aromatic ring, and an aromatic divinyl compound (B1) are used as reaction raw materials (1). In this embodiment, an aromatic monovinyl compound (B2) may also be further contained in the reaction raw materials (1). In other words, the polyvalent hydroxy resin in this embodiment has a structure in which a structural unit of an aromatic compound (A) having an aromatic ring to which a phenolic hydroxyl group is bonded and at least one monovalent hydrocarbon group at the meta position of the aromatic ring is chemically bonded to a structural unit of an aromatic divinyl compound (B1), and optionally an aromatic monovinyl compound (B2) unit is chemically bonded to the aromatic ring in the structural unit of the aromatic compound (A). In this specification, "structural unit" refers to a (repeating) unit of chemical structure formed during a reaction or polymerization. In other words, it refers to a substructure other than the chemical bond structure involved in the reaction or polymerization of a compound formed during such reaction or polymerization, and is commonly known as a residue. In this embodiment, since an aromatic compound (A) having a specific aromatic ring structure is used as a reaction raw material, it becomes easier to control the reaction site with the aromatic divinyl compound (B1) described later, making it easier to obtain a polyvalent hydroxy resin with a uniform chemical structure or chain length. As a result, an epoxy resin exhibiting excellent adhesion to metal materials and a low thermal modulus can be provided during curing. The following describes the aromatic compound (A), aromatic divinyl compound (B1), and an optional aromatic monovinyl compound (B2), which are components of the reaction raw materials for the polyvalent hydroxy resin. Then, the preferred form of the polyvalent hydroxy resin and the epoxy resin of this disclosure, which is a glycidyl ether of the polyvalent hydroxy resin, will be described.

[0013] -Aromatic compound (A)- In this embodiment, aromatic compound (A) has an aromatic ring to which a phenolic hydroxyl group is bonded, and at least one monovalent hydrocarbon group is bonded to the meta position of the aromatic ring. Therefore, aromatic compound (A) can be a phenolic compound. Furthermore, the aromatic ring that forms the central structure of aromatic compound (A) is monocyclic and includes an aromatic hydrocarbon ring and an aromatic heterocycle. The aromatic hydrocarbon ring is preferably a benzene ring. Examples of aromatic heterocycles include heterosix-membered rings such as a pyran ring or a pyridine ring.

[0014] In the aromatic compound (A) of this embodiment, the monovalent hydrocarbon group bonded to the meta position of the aromatic ring having a phenolic hydroxyl group is a hydrocarbon group having 1 to 6 carbon atoms, and an aliphatic hydrocarbon group or phenyl group having 1 to 4 carbon atoms is preferred. The aliphatic hydrocarbon group may be either linear or branched. The aliphatic hydrocarbon group is preferably a saturated aliphatic hydrocarbon group in order to prevent addition reactions with other compounds. Examples of saturated aliphatic hydrocarbon groups include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, s-butyl group, t-butyl group, etc. The higher the molecular weight of the hydrocarbon group, the more pronounced the effects of the present invention (low hygroscopicity, low elasticity at high temperatures) become.

[0015] The number of monovalent hydrocarbon groups bonded to the aromatic ring in the aromatic compound (A) of this embodiment (i.e., the number of substitutions) is not particularly limited as long as at least one monovalent hydrocarbon group is bonded to the meta position of the aromatic ring having a phenolic hydroxyl group. For example, by having a total number of hydrocarbon groups bonded to the aromatic ring of 2 or more, excellent peel strength to metallic materials and a low thermal modulus can be achieved.

[0016] A preferred form of aromatic compound (A) will be described, using the case where the aromatic ring of aromatic compound (A) in this embodiment is a benzene ring as an example. In this embodiment, it is preferable that one or more carbon atoms in the benzene ring constituting the aromatic compound (A) that have the highest HOMO electron density are unsubstituted (or have hydrogen atoms as substituents). This allows for the formation of ArS by cationoid reagents from aromatic divinyl compounds (B1) as described later. E This makes it easier to control the reaction and molecular design. More specifically, if the carbon atom with the highest HOMO electron density among the carbon atoms in the benzene ring constituting aromatic compound (A) is unsubstituted, the carbocation of the aromatic divinyl compound (B1), which is a cationoid reagent, readily reacts with the carbon atom with the highest HOMO electron density. Therefore, by controlling the number and position of monovalent hydrocarbon groups or phenolic hydroxyl groups bonded to the carbon atoms of the benzene ring, the bonding site or number of bonds with the aromatic divinyl compound can be adjusted. As a result, it is hypothesized that it will be easier to design the chemical structure or molecular chain length of the resulting polyvalent hydroxy resin. For example, if the aromatic compound (A) is a phenol skeleton having one benzene ring and one hydroxyl group, it is preferable that at least one carbon atom among the 2nd, 4th, and 6th positions of the phenol nucleus is substituted with a hydrogen atom. This makes it easier for the cationoid reagent formed from the aromatic divinyl compound (B1) described later to react with at least one carbon atom among the 2nd, 4th, and 6th positions, which are the ortho and para positions of the phenol nucleus where the electron density is high.

[0017] Specific examples of the aromatic compound (A) in the present embodiment include, for example, not only alkylphenol compounds such as m-cresol, dimethylphenol (2,3-dimethylphenol, 2,5-dimethylphenol, 3,4-dimethylphenol, 3,5-dimethylphenol), trimethylphenol (2,3,4-trimethylphenol, 2,3,5-trimethylphenol, 2,3,6-trimethylphenol, 2,4,5-trimethylphenol, 3,4,5-trimethylphenol), but also compounds in which the hydrogen atom of one or more CH groups in the benzene ring of the compound selected from the group consisting of the alkylphenol compounds is substituted with the above hydrocarbon group. In the present embodiment, the aromatic compound (A) may be used alone or in combination of two or more.

[0018] The aromatic compound (A) which is the reaction raw material (1) of the polyhydric hydroxy resin in the present embodiment can be represented, for example, by the following general formula (A1). [[ID=I0]] ​​​​​​​​​​​​​​​​​​​​​​​​​​​​If multiple exist, they may be the same hydrocarbon group or different hydrocarbon groups. Also, R a3 It is preferable that it is a hydrocarbon group having 1 to 3 carbon atoms. In this embodiment, the aromatic compound (A) represented by the general formula (A1) may be used alone or in combination of two or more types.

[0020] -Aromatic divinyl compound (B1)- In this embodiment, the aromatic divinyl compound (B1) can be used without particular limitations as long as it can react with the aromatic compound (A). Examples of aromatic divinyl compound (B1) include divinylbenzene, divinylbiphenyl, divinylnaphthalene, and various compounds in which one or more alkyl or alkoxy groups, halogen atoms, etc., are substituted on the aromatic rings thereof. The alkyl group may be either linear or branched. In particular, from the viewpoint of exhibiting excellent peel strength to metal materials and a low thermal modulus, the number of carbon atoms in the alkyl group or alkoxy group is preferably 1 to 4. Specific examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, t-butyl group, isobutyl group, etc. Examples of the alkoxy group include methoxy group, ethoxy group, propyloxy group, butoxy group, etc. Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, etc. As described above, ArS E The reaction allows for the introduction of an aromatic divinyl compound (B1) to a specific position on the aromatic ring of the aromatic compound (A). This makes it easier to obtain a polyvalent hydroxy resin with a uniform chemical structure or chain length, and as a result, an epoxy resin composition exhibiting excellent adhesion to metal materials and a low thermal modulus can be provided.

[0021] The aromatic divinyl compound (B1), which is the reaction raw material (1) of the polyvalent hydroxy resin of this disclosure, can be represented by the following formula (B1). [ka] (In the above general formula (B1), R b1 Each of these independently represents a monovalent organic group, R b2 , R b3 , R b4 , R b5 , R b6 and R b7 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and p b1 represents an integer from 0 to 4. Note that p b1 If R is an integer greater than or equal to 2, there are multiple R's. b1 They may be the same or different from each other.

[0022] In the above general formula (B1), the monovalent organic group is preferably a halogen atom or an alkyl or alkoxy group having 1 to 4 carbon atoms. The alkyl or alkoxy group having 1 to 4 carbon atoms is the same as the alkyl or alkoxy group described above. Also, R b1 It is preferable that it is an alkyl group having 1 to 3 carbon atoms. In the above general formula (B1), R b3 , R b4 , R b6 and R b7 R is a hydrogen atom, b2 and R b5 Each of these is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. In the above general formula (B1), p b1 It is preferable that p is 0. b1 If the number is 2 or more, there are multiple R b1 These may be the same group or different groups.

[0023] Specific examples of the aromatic divinyl compound (B1) of this embodiment include, for example, 1,2-divinylbenzene, 1,3-divinylbenzene, 1,4-divinylbenzene, 2,5-dimethyl-1,4-divinylbenzene, 2,5-diethyl-1,4-divinylbenzene, cis,cis,β,β'-diethoxy-mm-divinylbenzene, 1,4-divinyl-2,5-dibutylbenzene, 1,4-divinyl-2,5-dihexylbenzene, 1,4-divinyl-2,5-dimethoxybenzene, and derivatives thereof. Examples include, but are not limited to, divinylbenzene compounds such as compounds of the same type, and divinylnaphthalene compounds such as 1,3-divinylnaphthalene, 1,4-divinylnaphthalene, 1,5-divinylnaphthalene, 1,6-divinylnaphthalene, 1,7-divinylnaphthalene, 2,3-divinylnaphthalene, 2,6-divinylnaphthalene, 2,7-divinylnaphthalene, 3,4-divinylnaphthalene, 1,8-divinylnaphthalene, 1,5-dimethoxy-4,8-divinylnaphthalene and compounds comprising these derivatives. In this embodiment, the aromatic divinyl compound (B1) may be used alone or in combination of two or more types. In particular, from the viewpoint of fluidity, divinylbenzene and compounds having substituents on its aromatic ring are preferred as the aromatic divinyl compound (B1), and divinylbenzene is more preferred. In addition, in this embodiment, the substitution position of the vinyl group of divinylbenzene is not particularly limited, but it is preferable that the meta isomer is the main component. The content of the meta isomer in divinylbenzene is preferably 40% by mass or more, and more preferably 50% by mass or more, relative to the total amount of divinylbenzene.

[0024] -Aromatic monovinyl compound (B2)- In this embodiment, the polyvalent hydroxy resin may use other compounds as reaction raw materials in addition to the aromatic compound (A) and the aromatic divinyl compound (B1). Examples of such other compounds include the aromatic monovinyl compound (B2). That is, in this embodiment, it is preferable to use the aromatic compound (A), the aromatic divinyl compound (B1), and the aromatic monovinyl compound (B2) as reaction raw materials (1). When the polyvalent hydroxy resin of this embodiment uses the aromatic monovinyl compound (B2) in addition to the aromatic compound (A) and the aromatic divinyl compound (B1) as reaction raw materials, the final polyvalent hydroxy resin obtained is preferable because it has excellent low hygroscopicity and low elasticity at high temperatures, resulting in good solder reflow resistance. Furthermore, since aromatic monovinyl compounds (B2) also generate carbocations, similar to aromatic divinyl compounds (B1), they readily react with the carbon atom in the aromatic hydrocarbon ring constituting aromatic compound (A) that has the highest HOMO electron density.

[0025] The aromatic monovinyl compound (B2) in this embodiment includes, for example, vinylbenzene, vinylbiphenyl, vinylnaphthalene, and various compounds in which one or more substituents such as alkyl or alkoxy groups or halogen atoms are substituted on the aromatic rings thereof. The alkyl group may be linear or branched and may have unsaturated bonds in its structure. In particular, when low hygroscopicity is important, the alkyl group or alkoxy group is preferably having 1 to 4 carbon atoms. Specific examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, t-butyl group, isobutyl group, etc. Examples of the alkoxy group include methoxy group, ethoxy group, propyloxy group, butoxy group, etc. Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, etc.

[0026] The aromatic monovinyl compound (B2) that can serve as a reaction raw material (1) for the polyvalent hydroxy resin of this disclosure can be represented by the following general formula (B2). [ka] (In the above general formula (B2), R b8 Each of these independently represents a monovalent organic group, R b9 , R b10 and R b11 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and p b2 represents an integer from 0 to 5. Note that p b2 If R is an integer greater than or equal to 2, there are multiple R's. b2 They may be the same or different from each other.

[0027] In the above general formula (B2), the monovalent organic group is preferably a halogen atom or an alkyl or alkoxy group having 1 to 4 carbon atoms. The alkyl or alkoxy group having 1 to 4 carbon atoms is the same as the alkyl or alkoxy group described above. Also, R b8 R is preferably an alkyl group having 1 to 3 carbon atoms. In the above general formula (B2), b10 and R b11 R is a hydrogen atom, b2 and R b5 It is preferable that this is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. In the above general formula (B2), p b2 It is preferable that p is between 0 and 1. b2 If the number is 2 or more, there are multiple R b2 These may be the same group or different groups.

[0028] Specific examples of the aromatic monovinyl compound (B2) of this embodiment include, but are not limited to, vinylbenzenes such as styrene, fluorostyrene, vinyl benzyl chloride, alkyl vinylbenzenes (o-,m-,p-methylstyrene, o-,m-,p-ethyl vinylbenzene), o-,m-,p-(chloromethyl)styrene and compounds thereof; biphenyl compounds such as 4-vinyl biphenyl, 4-vinyl-p-terphenyl and compounds thereof; and vinyl naphthalenes such as 1-vinyl naphthalene, 2-vinyl naphthalene and compounds thereof. Ethyl vinylbenzene is particularly preferred because it is contained in the raw materials for divinylbenzene. Furthermore, while the substitution positions of the vinyl and ethyl groups in ethylvinylbenzene are not particularly limited, it is preferable that the meta isomer be the main component. The content of the meta isomer in ethylvinylbenzene is more preferably 40% by mass or more, and even more preferably 50% by mass or more, relative to the total amount of ethylvinylbenzene.

[0029] In this embodiment, when an aromatic monovinyl compound (B2) is used as the reaction raw material for the polyvalent hydroxy resin, the aroma in the reaction raw material Tribe Monobi Nyl compounds ( B2) Aroma Gizoku Gibi Nyl compounds ( B1) The mass ratio ((B1) / (B2)) is preferably 99 / 1 to 50 / 50, and more preferably 98 / 2 to 70 / 30. Having the mass ratio of aromatic divinyl compound (B1) to aromatic monovinyl compound (B2) within this range is preferable because it allows for a balance in the handling properties of the resulting polyvalent hydroxy resin, as well as the moldability and curability of the epoxy resin obtained from the polyvalent hydroxy resin during manufacturing.

[0030] Furthermore, in the polyvalent hydroxy resin of this embodiment, the total proportion of the structural units of the aromatic compound (A), the aromatic divinyl compound (B1), and the structural units of the aromatic monovinyl compound (B2), which are added as needed, in the reaction raw material (1) is preferably 80% by mass or more, and more preferably 90% by mass or more, relative to the total amount of the polyvalent hydroxy resin (100% by mass).

[0031] <Preferred form of polyvalent hydroxy resin> In this embodiment, the structural units of aromatic compound (A) are preferably present in an amount of 10 to 90% by mass, and more preferably 20 to 80% by mass, relative to the total amount of polyvalent hydroxy resin. Furthermore, the structural units of aromatic divinyl compound (B1) are preferably present in an amount of 10 to 90% by mass, and more preferably 20 to 80% by mass, relative to the total amount of polyvalent hydroxy resin. Furthermore, the structural units of aromatic monovinyl compound (B2) are preferably present in an amount of 1 to 40% by mass, and more preferably 2 to 35% by mass, relative to the total amount of polyvalent hydroxy resin. Furthermore, in polyvalent hydroxy resins, the structural units of aromatic compound (A), aromatic divinyl compound (B1), and aromatic monovinyl compound (B2) are as follows: 13 The units of each component can be calculated from the integral values ​​of 1C-NMR (solvent: deuterated dimethyl sulfoxide CDCl3, etc., reference substance: TMS, etc.).

[0032] The following describes preferred embodiments of the polyvalent hydroxy resin of this disclosure, using the case where each aromatic ring is a benzene ring as an example. The following chemical structural formulas are for illustrative purposes only, and the scope of this disclosure is not limited to these chemical structural formulas.

[0033] In this embodiment, the polyvalent hydroxy resin preferably has repeating units represented by the following general formula (I). [ka] (In the above general formula (I), R 1 and R2 Each of these independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, however, R 1 and R 2 At least one of them is a monovalent hydrocarbon group having 1 to 6 carbon atoms, R 4 , R 5 , R 9 and R 10 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R 3 This refers to a hydrocarbon group having 1 to 6 carbon atoms or general formula (b2) [ka] (In general formula (b2), R 7 R represents a hydrocarbon group with 1 to 6 carbon atoms. 11 (where 'r' represents a hydrogen atom or an alkyl group with 1 to 3 carbon atoms, and 'r' represents an integer from 0 to 5.) This represents a substituent represented by R 6 This represents a monovalent organic group, p is the R per phenol ring in the entire polyvalent hydroxy resin. 3 This is the average number of substitutions, representing a number between 0 and 3. q is the R value per benzene ring in the entire polyvalent hydroxy resin. 6 This represents the average number of substitutions, expressed as a number between 0 and 4. Note that the asterisk (*) in the general formula (I) above represents a bond with another atom. In the above general formula (I), the monovalent hydrocarbon group having 1 to 6 carbon atoms is preferably the same as the monovalent hydrocarbon group described above.

[0034] In this embodiment, in the above general formula (I), R 1 and R 2 Each of these independently represents a hydrogen atom or an alkyl group or phenyl group having 1 to 4 carbon atoms, and R 1 and R 2 It is preferable that at least one of them is an alkyl group or phenyl group having 1 to 4 carbon atoms. In the above general formula (I), R 3is preferably a substituent represented by the above general formula (b2). In the above general formula (I), R 4 or R 5 is preferably a hydrogen atom, and R 9 or R 10 is preferably a hydrogen atom. In the above general formula (I), R 6 is preferably an alkyl group or an alkoxy group having 1 to 4 carbon atoms. In the above general formula (I), p is preferably a number from 0 to 2. In the above general formula (I), q is preferably a number from 0 to 2. In the above general formula (I), for example, when either R 1 or R 2 is a hydrogen atom and the phenol ring becomes a terminal group, all hydrogen atoms of the benzene ring constituting the phenol ring may be substituted with R 3 , and in that case, p can be 3. In the present embodiment, in the above general formula (b2), R 7 is preferably an alkyl group having 1 to 4 carbon atoms. R 11 is preferably a hydrogen atom. r is preferably from 0 to 2.

[0035] Also, in the above general formula (I), R 1 and R 2 [[ID=第30]]correspond to a monovalent hydrocarbon group bonded to the meta position and correspond to R a1 and R a2 in the above general formula (A1). Similarly, in the above general formula (I), R 3 may correspond to R a3 in the above general formula (A1) or a chemical structure represented by the above general formula (B2) which is an optional component. Also, R 4 , R 5 , R 9 and R 10 in the above general formula (I) respectively correspond to R<​​​​​​​​​​​​b1 It corresponds to. Furthermore, the chemical structure represented by the general formula (b2) corresponds to the chemical structure represented by the general formula (B2). In addition, the values of p and q in the general formula (I) and r in the general formula (b2) 13 can be calculated from the integral values of 13C-NMR (solvent: deuterated dimethyl sulfoxide, CDCl3, etc., reference substance: TMS, etc.).

[0036] The polyhydric hydroxy resin in this embodiment is preferably represented by the following general formula (II) and / or (III).

Chemical formula

Chemical formula

Chemical formula

[0037] The hydroxyl group equivalent of the polyvalent hydroxy resin in this embodiment is preferably 200 to 500 g / equivalent, and more preferably 200 to 400 g / equivalent. In this specification, the hydroxyl group equivalents of polyvalent hydroxy resins shall be measured using a method compliant with the neutralization titration method specified in JIS K 0070 (1992). The softening point of the polyvalent hydroxy resin in this embodiment is often 40 to 180°C, preferably in the range of 40 to 150°C. The softening point here is measured according to JIS K 7234 (ring-ball method) using the measurement conditions described in the Examples section below. The polyvalent hydroxy resin of this embodiment preferably has a melt viscosity at 150°C measured with an ICI viscometer of 0.01 to 50.0 dPa·s, more preferably 0.01 to 30.0 dPa·s, and even more preferably 0.01 to 10.0 dPa·s. When the melt viscosity of the polyvalent hydroxy resin is within the above range, it is preferable because it has low viscosity and excellent fluidity, resulting in excellent moldability of the cured product obtained from the polyvalent hydroxy resin. The polyvalent hydroxy resin of this embodiment has low viscosity and excellent fluidity, so its number average molecular weight (Mn) is preferably in the range of 430 to 1500, and more preferably in the range of 450 to 1200. Furthermore, the weight average molecular weight (Mw) of the polyvalent hydroxy resin is preferably in the range of 500 to 2000, and more preferably in the range of 600 to 1500. The molecular weight distribution (Mw / Mn), expressed as the ratio of the number average molecular weight (Mn) to the weight average molecular weight (Mw), is preferably in the range of 1.1 to 3.0, and more preferably in the range of 1.2 to 2.5.

[0038] <Preferred form of epoxy resin of this disclosure> <<Preferred Structure>> The epoxy resin of this disclosure is a compound obtained by glycidyl ethering the polyvalent hydroxy resin in the above embodiment, and more specifically, is a compound in which a hydrogen atom in one or more phenolic hydroxyl groups in the polyvalent hydroxy resin is substituted with a glycidyl group. In other words, the epoxy resin of this disclosure may have a chemical structure in which a structural unit of an aromatic compound (A), to which a phenolic hydroxyl group is bonded and at least one monovalent hydrocarbon group is bonded to the meta position of the aromatic ring, is chemically bonded to a structural unit of an aromatic divinyl compound (B1), and optionally a structural unit of an aromatic monovinyl compound (B2) is chemically bonded to the aromatic ring in the structural unit of the aromatic compound (A), and the hydrogen atom in the phenolic hydroxyl group is substituted with a glycidyl ether group. As will be explained later in the section on the method of producing the epoxy resin of this disclosure, the epoxy resin of this disclosure can be produced by reacting a polyvalent hydroxy resin with an epihalohydrin.

[0039] The epoxy resin of this disclosure preferably has repeating units represented by the following general formula (IV). [ka] (In the above general formula (IV), G represents a glycidyl group, R 1 and R 2 Each of these independently represents a hydrogen atom or a monovalent hydrocarbon group (for example, a monovalent hydrocarbon group having 1 to 6 carbon atoms), however, R 1 and R 2 At least one of them is a monovalent hydrocarbon group (for example, a monovalent hydrocarbon group having 1 to 6 carbon atoms), R 4 , R 5 , R 9 and R 10 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R 3 Each of these independently represents a monovalent group derived from the aromatic monovinyl compound (B2), preferably a hydrocarbon group having 1 to 6 carbon atoms or general formula (b2). [ka] (In general formula (b2), R 7 R represents a hydrocarbon group with 1 to 6 carbon atoms. 11 (where 'r' represents a hydrogen atom or an alkyl group with 1 to 3 carbon atoms, and 'r' represents an integer from 0 to 5.) This represents a substituent represented by R 6 This represents a monovalent organic group, p is the R per phenol ring in the entire polyvalent hydroxy resin. 3 This is the average number of substitutions, representing a number between 0 and 1. q is the R value per benzene ring in the entire polyvalent hydroxy resin. 6 This represents the average number of substitutions, and is expressed as a number between 0 and 4. Note that the asterisk (*) in the general formulas (IV) and (b2) above represents a bond with another atom. In the above general formula (IV), R 1 ~R7 , R 9 ~R 11 Furthermore, the preferred conditions for p, q, and r are the same as those for general formula (I) above, and are therefore omitted here.

[0040] The epoxy resin of this disclosure is preferably represented by the following general formula (V) and / or (VI). [ka] [ka] (In the above general formulas (V) and (VI), G represents a glycidyl group, and R 1 and R 2 Each of these independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, however, R 1 and R 2 At least one of them is a monovalent hydrocarbon group having 1 to 6 carbon atoms, R 4 , R 5 , R 9 and R 10 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R 3 This refers to a hydrocarbon group having 1 to 6 carbon atoms or general formula (b2) [ka] (In general formula (b2), R 7 R represents a hydrocarbon group with 1 to 6 carbon atoms. 11 represents a substituent represented by ), where is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and r is an integer from 0 to 5. R 8 This represents a hydrogen atom or a monovalent organic group, preferably a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. n is the number of repeating units, representing an integer between 0 and 20, preferably between 0 and 15. m is the number of repeating units, representing an integer between 0 and 20, preferably between 0 and 15. p 1 ~p6 Each of these independently represents the average R per phenol ring. 3 The number of substitutions is p 2 , p 4 , p 5 and p 6 Each of these independently represents a number between 0 and 2, preferably between 0 and 1. p 1 and p 3 Each of these independently represents a number between 0 and 3, preferably between 0 and 2. q 1 and q 2 Each of these independently has an R value per benzene ring. 6 This is the average value of the number of substitutions, representing a number between 0 and 4, preferably between 0 and 2. In the above general formulas (V) and (VI), R 1 ~R 7 , R 9 ~R 11 The preferred conditions for and r are the same as those for the general formula (I) above, so they are omitted here.

[0041] <<Desirable characteristics>> The epoxy equivalent of the epoxy resin disclosed herein is preferably 250 to 600 g / equivalent, more preferably 250 to 500 g / equivalent, and even more preferably 260 to 450 g / equivalent. Having the epoxy equivalent of the epoxy resin within this range is preferable because it suppresses the generation of secondary hydroxyl groups that occur when the epoxy resin reacts with the curing agent, resulting in a cured product with excellent low hygroscopicity and consequently superior reflow resistance. The epoxy equivalent in this specification is measured according to JIS K 7236, as described in the Examples section.

[0042] The epoxy resins of this disclosure preferably have a melt viscosity at 150°C measured by an ICI viscometer of 0.01 to 30.0 dPa·s, more preferably 0.01 to 10.0 dPa·s, and even more preferably 0.01 to 5.0 dPa·s. A melt viscosity within the above range of the epoxy resin is preferable because it has low viscosity and excellent fluidity, resulting in excellent moldability of the resulting cured product. The melt viscosity in this specification is measured by an ICI viscometer in accordance with ASTM D4287, as described in the Examples section.

[0043] The epoxy resin of this disclosure has low viscosity and excellent fluidity, so it is preferable that its number-average molecular weight (Mn) is in the range of 430 to 1500. Furthermore, it is preferable that its weight-average molecular weight (Mw) is in the range of 500 to 2000. The molecular weight distribution (Mw / Mn), expressed as the ratio of the number-average molecular weight (Mn) to the weight-average molecular weight (Mw), is preferably in the range of 1.2 to 3.0. In this invention, the molecular weight of the epoxy resin is measured using gel permeation chromatography (hereinafter abbreviated as "GPC") under the measurement conditions described in the examples below.

[0044] <The best mode for epoxy resin> The epoxy resin (or glycidyl ether of a polyvalent hydroxy resin) of this embodiment has the following general formula (1): [ka] (In the above general formula (1), G represents a glycidyl group, R 1 and R 2 Each of these independently represents a hydrogen atom or a monovalent hydrocarbon group, and R 1 or R 2 One of them is a monovalent hydrocarbon group, R 3 Each of the above general formulas (1) independently represents a monovalent group derived from the aromatic monovinyl compound (B2), p represents a number from 0 to 3, and k represents an integer from 0 to 21. It is preferable that it is represented as ( ). In the above general formula (1), R 1 or R 2 If either of them is a hydrogen atom, then that hydrogen atom is R3 It can be substituted for. Furthermore, the terminal hydrogen atom "H" in the above general formula (1) (more specifically, the hydrogen atom "H" directly bonded to the benzene ring to which the OG group within the repeating unit is bonded) can also be substituted for R 3 It can be replaced by ). It is preferable to represent it as ). In the above general formula (1), R 1 ~R 6 , R 9 and R 10 , and p are synonymous with the above general formula (I), and a preferred embodiment of general formula (I) can be used. Furthermore, k in the above general formula (1) represents the degree of polymerization, and k is preferably an integer from 0 to 16. In addition, in the above general formula (1), the monovalent group derived from the aromatic monovinyl compound (B2) refers to the same chemical structure as the so-called aromatic monovinyl compound (B2) carbocation, for example, the following general formula (b2-1): [ka] (In general formula (b2-1), R 7 ) represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, and * represents a bond to the carbon atom of the aromatic ring in general formula (1).

[0045] <Method for manufacturing epoxy resin> The method for producing the epoxy resin of this disclosure will be described below. The epoxy resin in this embodiment is not particularly limited in its manufacturing method, as long as it is a glycidyl ether of the polyvalent hydroxy resin in this embodiment; it may be manufactured in any way. Examples of such manufacturing methods for the epoxy resins of this disclosure include, for example, a manufacturing method comprising the following steps: Step (1): A step of reacting an aromatic compound (A), an aromatic divinyl compound (B1), and optionally another aromatic divinyl compound (B1) as reaction raw materials (1) to obtain the polyhydric hydroxy compound in this embodiment; Step (2): A step of reacting the polyvalent hydroxy compound obtained in step (1) with an epihalohydrin as a reaction raw material (2) to obtain the epoxy resin of the present disclosure. The following describes each step of the method for manufacturing the epoxy resin of this disclosure.

[0046] <<Process (1): Manufacturing process for polyvalent hydroxy resin>> The following describes the manufacturing process of the polyvalent hydroxy compound in this embodiment. The method for producing the polyvalent hydroxy resin in this embodiment is not particularly limited, but for example, the polyvalent hydroxy resin in this embodiment can be produced by reacting an aromatic compound (A) having an aromatic ring to which a phenolic hydroxyl group is bonded and at least one monovalent hydrocarbon group at the meta position of the aromatic ring with an aromatic divinyl compound (B1) (e.g., divinylbenzene), and optionally other compounds such as an aromatic monovinyl compound (B2) (e.g., ethylvinylbenzene), in the presence of an acid catalyst.

[0047] The polyvalent hydroxy resin obtained by the method for producing polyvalent hydroxy resin of this embodiment allows for control of the hydroxyl group equivalent and other properties depending on the blending ratio of aromatic divinyl compound (B1) and the aromatic monovinyl compound (B2) that can be used. Regarding the mixing ratio of the aromatic compound (A) and the aromatic divinyl compound (B1), considering the balance of moldability and curability properties during the production of the resulting cured product, it is preferable that the molar ratio of the aromatic divinyl compound (B1) to 1 mole of the aromatic compound (A) is 0.1 to 1.0 moles, and more preferably 0.1 to 0.9 moles. Furthermore, when the aromatic monovinyl compound (B2) is used in combination, it is preferable that the total molar ratio of the aromatic divinyl compound (B1) and the aromatic monovinyl compound (B2) to 1 mole of the aromatic compound (A) is 0.1 to 1.0 moles, and more preferably 0.1 to 0.9 moles.

[0048] In this embodiment, the reaction between the aromatic compound (A) and the aromatic divinyl compound (B1) and / or aromatic monovinyl compound (B2), etc., can be carried out in the presence of an acid catalyst. This acid catalyst can be appropriately selected from well-known inorganic acids and organic acids. For example, mineral acids such as hydrochloric acid, sulfuric acid, and phosphoric acid; organic acids such as formic acid, oxalic acid, trifluoroacetic acid, p-toluenesulfonic acid, p-toluenesulfonic acid hydrate, dimethyl sulfuric acid, and diethyl sulfuric acid; Lewis acids such as zinc chloride, aluminum chloride, iron chloride, and boron trifluoride; or solid acids such as ion exchange resins, activated clay, silica-alumina, and zeolites. The amount of the acid catalyst used is preferably 0.01 to 50 parts by mass, more preferably 0.01 to 10 parts by mass, and even more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the total raw materials of the polyvalent hydroxy resin. The above reaction is usually carried out at 10 to 250°C for 1 to 20 hours.

[0049] Examples of solvents that can be used in the above reaction include alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol, methyl cellosolve, and ethyl cellosolve; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ethers such as dimethyl ether, diethyl ether, diisopropyl ether, tetrahydrofuran, and dioxane; and aromatic compounds such as benzene, toluene, chlorobenzene, and dichlorobenzene.

[0050] Specific methods for carrying out the above reaction include charging all raw materials together and reacting them at a predetermined temperature, or charging aromatic compound (A) and acid catalyst and reacting them dropwise while maintaining a predetermined temperature, using aromatic divinyl compound (B1) and other compounds (e.g., aromatic monovinyl compound (B2)). In this case, the dropwise addition time is usually 1 to 10 hours, preferably 5 hours or less. After the reaction, if a solvent is used, the solvent and unreacted products can be removed by distillation as needed to obtain the polyhydric hydroxy resin. If no solvent is used, the target product, the polyhydric hydroxy resin, can be obtained by distilling off the unreacted products.

[0051] <<Process (2): Glycidylate conversion process>> In this process, the polyvalent hydroxy compound obtained in step (1) is subjected to an addition reaction and a ring-closing reaction with an epihalohydrin, thereby substituting the hydrogen atoms in the phenolic hydroxyl group of the polyvalent hydroxy compound with glycidyl groups, and the epoxy resin of this disclosure is obtained as a glycidyl ether of the polyvalent hydroxy compound.

[0052] The reaction between the polyvalent hydroxy resin and the epihalohydrin can be carried out, for example, by reacting them in the presence of a basic catalyst at a temperature of typically 20 to 150°C, preferably 30 to 100°C, for 0.5 to 10 hours.

[0053] In this embodiment, examples of epihalohydrins include epichlorohydrin, epibromohydrin, and β-methylepichlorohydrin. The amount of epihalohydrin added is in excess of 1 mole of the total hydroxyl groups in the polyhydric hydroxy resin, but is usually 1.5 to 30 moles, preferably in the range of 2 to 15 moles.

[0054] Examples of the basic catalyst include alkaline earth metal hydroxides, alkali metal carbonates, and alkali metal hydroxides. Among these, alkali metal hydroxides are preferred due to their excellent catalytic activity, and specifically, sodium hydroxide and potassium hydroxide are more preferred. These basic catalysts may be used in solid form or in aqueous solution form. The amount of basic catalyst added is preferably in the range of 0.9 to 2.0 moles per mole of total hydroxyl groups in the polyvalent hydroxy resin.

[0055] In this embodiment, the reaction between the polyvalent hydroxy resin and the epihalohydrin may be carried out in an organic solvent. Examples of organic solvents that can be used include ketones such as acetone and methyl ethyl ketone, alcohols such as methanol, ethanol, 1-propyl alcohol, isopropyl alcohol, 1-butanol, secondary butanol, and tertiary butanol, cellosolves such as methyl cellosolve and ethyl cellosolve, ethers such as tetrahydrofuran, 1,4-dioxane, 1,3-dioxane, and diethoxyethane, and aprotic polar solvents such as acetonitrile, dimethyl sulfoxide, and dimethylformamide. These organic solvents may be used individually, or two or more may be used in combination as appropriate to adjust the polarity.

[0056] After the reaction with the epihalohydrin is complete, the crude product can be obtained by distilling off the excess epihalohydrin. If necessary, the obtained crude product may be dissolved again in an organic solvent, and the reaction may be repeated with a basic catalyst to reduce the hydrolyzable halogen. The salts produced in the reaction can be removed by filtration or washing with water. If an organic solvent is used, the resin solids may be removed by distillation, or the solution may be used as is.

[0057] <Curable composition> The epoxy resin of this disclosure can be used to prepare a curable composition. The curable composition may contain the epoxy resin of this disclosure, a curing agent (e.g., a curing agent for epoxy resins), and optionally other components (inorganic fillers, silane coupling agents, curing aids, etc.). By using the epoxy resin of this disclosure in a curable composition, the curable composition exhibits excellent moldability due to its low viscosity during melting. Furthermore, the cured product obtained from the curable composition exhibits excellent reflow resistance because it achieves a high-level balance of low moisture absorption, low thermal elasticity, and high adhesion. Due to these properties, a curable composition using the epoxy resin of this disclosure exhibits excellent properties, for example, as a semiconductor encapsulating material.

[0058] <<Hardening agent>> The curable composition of this embodiment contains the epoxy resin of this embodiment and a curing agent. The curing agent can be any epoxy resin curing agent capable of crosslinking with the epoxy groups of the epoxy resin, without any particular limitations. Examples of curing agents include phenol curing agents, amine curing agents, acid anhydride curing agents, activated ester resins, cyanate ester resins, and the like. The curing agents may be used individually or in combination of two or more.

[0059] Examples of the phenol curing agents include phenol novolac resin, cresol novolac resin, aromatic hydrocarbon formaldehyde resin-modified phenol resin, dicyclopentadienephenol addition resin, phenol aralkyl resin (Zyloc resin), naphthol aralkyl resin, triphenylol methane resin, tetraphenylolethane resin, naphthol novolac resin, naphthol-phenol co-condensed novolac resin, naphthol-cresol co-condensed novolac resin, and biphenyl-modified phenol resin (with a bismethylene group). Examples of polyvalent phenolic hydroxyl group-containing compounds include polyvalent phenolic hydroxyl group-containing compounds with linked phenol nuclei, biphenyl-modified naphthol resins (polyvalent naphthol compounds with linked phenol nuclei via bismethylene groups), aminotriazine-modified phenol resins (polyvalent phenolic hydroxyl group-containing compounds with linked phenol nuclei via melamine, benzoguanamine, etc.), and alkoxy-group-containing aromatic ring-modified novolac resins (polyvalent phenolic hydroxyl group-containing compounds with linked phenol nuclei and alkoxy-group-containing aromatic rings via formaldehyde). Among these, phenol novolac resins are more preferred from the viewpoint of moldability. The compounds containing phenolic hydroxyl groups may be used individually or in combination of two or more.

[0060] Examples of the amine curing agents include aliphatic amines such as diethylenetriamine (DTA), triethylenetetramine (TTA), tetraethylenepentamine (TEPA), diproprendiamine (DPDA), diethylaminopropylamine (DEAPA), N-aminoethylpiperazine, mensendiamine (MDA), isophoronediamine (IPDA), 1,3-bisaminomethylcyclohexane (1,3-BAC), piperidine, N,N,-dimethylpiperazine, and triethylenediamine; and aromatic amines such as m-xylenediamine (XDA), methanephenylenediamine (MPDA), diaminodiphenylmethane (DDM), diaminodiphenylsulfone (DDS), benzylmethylamine, 2-(dimethylaminomethyl)phenol, and 2,4,6-tris(dimethylaminomethyl)phenol.

[0061] Examples of the acid anhydride curing agents include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, ethylene glycol bistrimellitate, glycerol trimellitate, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, methylbutenyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, succinic anhydride, and methylcyclohexendicarboxylic anhydride.

[0062] In the curable composition of this embodiment, the amount of curing agent used relative to the amount of epoxy resin used is not particularly limited, for example, as a functional group equivalent ratio (e.g., hydroxyl group equivalent of the phenol curing agent / epoxy equivalent of the epoxy resin). However, from the standpoint of obtaining a cured product with good mechanical properties, it is preferable that the amount of curing agent is such that the amount of active groups in the curing agent is 0.5 to 1.5 equivalents, and more preferably 0.8 to 1.2 equivalents, for a total of 1 equivalent of epoxy groups in the epoxy resin and other epoxy resins used in combination as needed.

[0063] In addition to the epoxy resin and curing agent described above, other resins may be used in the curable composition of this embodiment, provided that they do not impair the effects of the present disclosure. Examples include epoxy resins other than the epoxy resin described above, maleimide resins, bismaleimide resins, polymaleimide resins, polyphenylene ether resins, polyimide resins, benzoxazine resins, triazine-containing cresol novolac resins, styrene-maleic anhydride resins, allyl group-containing resins such as diallylbisphenol and triallyl isocyanurate, polyphosphate esters, phosphate ester-carbonate copolymers, and the like. These other resins may be used individually or in combination of two or more.

[0064] <<Solvent>> The curable composition of this embodiment may be prepared without a solvent, or it may contain a solvent. The solvent has a function such as adjusting the viscosity of the curable composition.

[0065] Specific examples of the aforementioned solvent are not particularly limited, but include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether solvents such as diethyl ether and tetrahydrofuran; ester solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitols such as cellosolve and butyl carbitol; aromatic hydrocarbons such as toluene, xylene, ethylbenzene, mesitylene, 1,2,3-trimethylbenzene, and 1,2,4-trimethylbenzene; and amide solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. These solvents may be used individually or in combination of two or more.

[0066] The amount of solvent used is preferably 10 to 90% by mass, and more preferably 20 to 80% by mass, relative to the total mass of the curable composition. A solvent usage of 10% by mass or more is preferable due to its excellent handling properties. On the other hand, a solvent usage of 90% by mass or less is preferable from an economic standpoint.

[0067] <<Additives>> The curable composition of this embodiment may contain various additives as needed, such as curing accelerators, flame retardants, inorganic fillers, silane coupling agents, mold release agents, pigments, colorants, and emulsifiers.

[0068] <<Curing accelerator>> The curing accelerator is not particularly limited, but examples include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, urea-based curing accelerators, etc. The curing accelerator may be used alone or in combination of two or more types.

[0069] Examples of the phosphorus-based curing accelerators include organophosphine compounds such as triphenylphosphine, tributylphosphine, triparathylphosphine, diphenylcyclohexylphosphine, and tricyclohexylphosphine; organophosphine compounds such as trimethylphosphine and triethylphosphine; and phosphonium salts such as ethyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, butylphosphonium tetraphenylborate, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, triphenylphosphinetriphenylborane, tetraphenylphosphonium thiocyanate, tetraphenylphosphonium dicyanamide, butylphenylphosphonium dicyanamide, and tetrabutylphosphonium decanoate.

[0070] Examples of the amine-based curing accelerators include triethylamine, tributylamine, N,N-dimethyl-4-aminopyridine (4-dimethylaminopyridine, DMAP), 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo[5.4.0]-undecene-7 (DBU), and 1,5-diazabicyclo[4.3.0]-nonene-5 (DBN).

[0071] The imidazole-based curing accelerators include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, and 1-cyanoethyl-2-ethyl-4-methylimidazole. Examples include ethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5 hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, and 2-methylimidazoline.

[0072] Examples of the guanidine-based curing accelerators include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]deca-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]deca-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-butylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, and 1-phenylbiguanide.

[0073] Examples of the urea-based curing accelerators include 3-phenyl-1,1-dimethylurea, 3-(4-methylphenyl)-1,1-dimethylurea, chlorophenylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, and 3-(3,4-dichlorophenyl)-1,1-dimethylurea.

[0074] Among the curing accelerators mentioned above, when used particularly in semiconductor encapsulation materials, it is preferable to use triphenylphosphine among phosphorus compounds and 1,8-diazabicyclo-[5.4.0]-undecene (DBU) among tertiary amines, due to their excellent curability, heat resistance, electrical properties, and moisture resistance reliability.

[0075] The amount of the curing accelerator used can be adjusted as appropriate to obtain the desired curability, but it is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the total amount of the epoxy resin and curing agent mixture. When the amount of the curing accelerator used is within the above range, the curability and insulation reliability are excellent, which is preferable.

[0076] <<Flame retardant>> The aforementioned flame retardant is not particularly limited, but examples include inorganic phosphorus-based flame retardants, organophosphorus-based flame retardants, halogen-based flame retardants, etc. The flame retardant may be used alone or in combination of two or more types.

[0077] The inorganic phosphorus-based flame retardant is not particularly limited, but examples include red phosphorus; ammonium phosphates such as monoammonium phosphate, diammonium phosphate, triammonium phosphate, and polyammonium phosphate; and phosphate amides.

[0078] The organophosphorus flame retardants mentioned above are not particularly limited, but include methyl acid phosphate, ethyl acid phosphate, isopropyl acid phosphate, dibutyl phosphate, monobutyl phosphate, butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, bis(2-ethylhexyl) phosphate, monoisodecyl acid phosphate, lauryl acid phosphate, tridecyl acid phosphate, and stearyl acid phosphate. Phosphate esters such as isostearyl acid phosphate, oleyl acid phosphate, butyl pyrophosphate, tetracosyl acid phosphate, ethylene glycol acid phosphate, and (2-hydroxyethyl) methacrylate acid phosphate; diphenylphosphine such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and diphenylphosphine oxide; and 10-(2,5-dihydroxyphenyl)-10H-9-oxa Phosphorus-containing phenols such as -10-phosphaphenanthrene-10-oxide, 10-(1,4-dioxynaphthalene)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, diphenylphosphinnylhydroquinone, diphenylphosphenyl-1,4-dioxynaphthalene, 1,4-cyclooctylenephosphinnyl-1,4-phenyldiol, and 1,5-cyclooctylenephosphinnyl-1,4-phenyldiol; 9,10-dihydro-9-oxa-10-phos Examples include cyclic phosphorus compounds such as phaphenanthrene-10-oxide, 10-(2,5-dihydrooxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-(2,7-dihydrooxynaphthyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide; and compounds obtained by reacting the aforementioned phosphate esters, diphenylphosphine, or phosphorus-containing phenols with epoxy resins, aldehyde compounds, or phenolic compounds.

[0079] The halogenated flame retardant is not particularly limited, but examples include brominated polystyrene, bis(pentabromophenyl)ethane, tetrabromobisphenol A bis(dibromopropyl ether), 1,2-bis(tetrabromophthalimide), 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine, and tetrabromophthalic acid.

[0080] The amount of the flame retardant used is preferably 0.1 to 20 parts by mass per 100 parts by mass of the epoxy resin of this disclosure.

[0081] <<Inorganic fillers>> The inorganic filler is not particularly limited, but examples include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, zirconium tungstate phosphate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, carbon black, etc. Of these, silica is preferred. In this case, amorphous silica, fused silica, crystalline silica, synthetic silica, hollow silica, etc. can be used as silica. Among these, fused silica is preferred because it allows for a larger amount of inorganic filler to be incorporated. The fused silica can be used in either crushed or spherical form, but it is preferable to mainly use spherical silica in order to increase the amount of fused silica and suppress the increase in the melt viscosity of the curable composition. Furthermore, in order to increase the amount of spherical silica, it is preferable to appropriately adjust the particle size distribution of the spherical silica. The inorganic filler may be used alone or in combination of two or more types.

[0082] Furthermore, the inorganic filler may be surface-treated as needed. In this case, there are no particular limitations on the surface treatment agents that can be used, but aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, organosilazane compounds, titanate coupling agents, etc. Specific examples of surface treatment agents include 3-glycidoxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, hexamethyldisilazane, etc.

[0083] The amount of the inorganic filler used is preferably 0.5 to 1200 parts by mass per 100 parts by mass of the total amount of the epoxy resin and curing agent mixture of the present disclosure. When the amount of the inorganic filler used is within this range, it is preferable because it exhibits excellent flame retardancy and insulation reliability. Furthermore, in addition to the inorganic filler, an organic filler may be added, provided that it does not impair the properties of the present disclosure. Examples of the organic filler include polyamide particles.

[0084] This disclosure relates to a cured product of the curable composition of this embodiment. By using the epoxy resin of this disclosure, the cured product obtained from the curable composition of this embodiment containing the epoxy resin of this disclosure can exhibit low hygroscopicity, low thermal modulus, or high adhesion to metal materials, which is a preferred embodiment. As for a method of obtaining a cured product by curing the curable composition of this embodiment, for example, the heating temperature during heat curing is not particularly limited, but is usually 100 to 300°C, and the heating time is 1 to 24 hours.

[0085] The cured product of this embodiment preferably has a moisture absorption rate of 1.3% or less. The method for measuring the moisture absorption rate is the same as the evaluation method described in the Examples section.

[0086] <Semiconductor encapsulation materials> This disclosure relates to a semiconductor encapsulation material containing the curable composition of this embodiment. The semiconductor encapsulation material obtained using the curable composition of this embodiment has low viscosity and excellent fluidity because it uses the epoxy resin of this disclosure, and further improves hygroscopicity, thermal modulus, and adhesion to metal materials, resulting in excellent processability, moldability, and reflow resistance in the manufacturing process, making it a desirable embodiment.

[0087] The curable composition of this embodiment used in the semiconductor encapsulating material may contain an inorganic filler. The filling ratio of the inorganic filler can be, for example, 0.5 to 1200 parts by mass of the inorganic filler per 100 parts by mass of the curable composition of this embodiment.

[0088] A method for obtaining the aforementioned semiconductor encapsulating material includes, as necessary, a method of thoroughly melting and mixing the curable composition of this embodiment with an optional additive until uniform, using an extruder, needle, roll, or the like.

[0089] [Semiconductor device] This disclosure relates to a semiconductor device comprising a cured product of the semiconductor encapsulating material. A semiconductor device obtained using the semiconductor encapsulating material obtained using the curable composition of this embodiment is preferable because, since it uses the epoxy resin of this disclosure, it has low viscosity and excellent fluidity, and furthermore, its hygroscopicity, thermal modulus, and adhesion to metal materials are improved, resulting in excellent processability, moldability, and reflow resistance in the manufacturing process.

[0090] Methods for obtaining the semiconductor device include casting the semiconductor encapsulating material, molding it using a transfer molding machine, injection molding machine, etc., and then heat-curing it in a temperature range of room temperature (20°C) to 250°C.

[0091] [Prepreg] This disclosure relates to a prepreg having a reinforcing substrate and a semi-cured product of the curable composition of this embodiment impregnated into the reinforcing substrate. A method for obtaining a prepreg from the curable composition includes impregnating a reinforcing substrate (paper, glass cloth, glass nonwoven fabric, aramid paper, aramid cloth, glass mat, glass roving cloth, etc.) with a varnished curable composition made by blending it with an organic solvent, as described later, and then heating it at a heating temperature corresponding to the type of solvent used, preferably 50 to 170°C, to semi-cure (or not cure) the curable composition and obtain a prepreg. The mass ratio of the curable composition to the reinforcing substrate used at this time is not particularly limited, but it is generally preferable to prepare it so that the resin content in the prepreg is 20 to 60% by mass. In this embodiment, a semi-cured product of the curable composition is obtained by adjusting the heating temperature and heating time to stop the curing reaction before it is completed. For example, the semi-cured product may have a degree of curing of 85% or less and 5% or more. On the other hand, the cured product in this embodiment may have a higher degree of curing than the semi-cured product. The degree of hardening of the semi-cured product can be calculated using the following formula by measuring the heat generated during the curing of the curable composition and the heat generated during the curing of the semi-cured product using DSC. Degree of curing (%) = [1 - (heat generated during curing of the semi-cured material / heat generated during curing of the curable composition)] × 100

[0092] Examples of organic solvents used here include methyl ethyl ketone, acetone, dimethylformamide, methyl isobutyl ketone, methoxypropanol, cyclohexanone, methyl cellosolve, ethyl diglycol acetate, and propylene glycol monomethyl ether acetate. The selection and appropriate amount can be appropriately chosen depending on the application. For example, when further manufacturing a printed circuit board from a prepreg as described below, it is preferable to use a polar solvent with a boiling point of 160°C or lower, such as methyl ethyl ketone, acetone, or dimethylformamide, and it is also preferable to use it in a proportion that results in a non-volatile content of 40 to 80% by mass.

[0093] [Circuit board] This disclosure relates to a circuit board which is a laminate of the prepreg and copper foil. A method for obtaining a printed circuit board from the curable composition of this embodiment is to laminate the prepreg by a conventional method, add copper foil as appropriate, and heat-press it at 170 to 300°C for 10 minutes to 3 hours under pressure of 1 to 10 MPa.

[0094] [Build-up film] This disclosure relates to a build-up film containing the curable composition of this embodiment. A method for manufacturing the build-up film of this embodiment is to apply the curable composition onto a support film to form a curable composition layer, thereby producing an adhesive film for multilayer printed circuit boards.

[0095] When manufacturing a build-up film from a curable composition, it is essential that the film softens under the lamination temperature conditions (usually 70-140°C) in the vacuum lamination method and exhibits fluidity (resin flow) that allows for simultaneous lamination of the circuit board and resin filling of via holes or through holes present in the circuit board. It is preferable to formulate the above-mentioned components in such a way as to exhibit these characteristics.

[0096] Here, the diameter of the through-holes in a multilayer printed circuit board is typically 0.1 to 0.5 mm, and the depth is typically 0.1 to 1.2 mm. It is generally preferable to be able to fill the holes with resin within this range. When laminating both sides of the circuit board, it is desirable to fill about half of the through-holes.

[0097] The adhesive film described above can be manufactured by first preparing a varnish-like curable composition, then applying this varnish-like composition to the surface of a support film (Y), and finally drying the organic solvent by heating or blowing hot air to form a composition layer (X) made of the curable composition.

[0098] The thickness of the formed composition layer (X) is usually preferably greater than or equal to the thickness of the conductor layer. Since the thickness of the conductor layer of a circuit board is usually in the range of 5 to 70 μm, the thickness of the resin composition layer is preferably 10 to 100 μm.

[0099] Furthermore, the composition layer (X) in this embodiment may be protected by a protective film, which will be described later. Protecting it with a protective film can prevent dirt and other debris from adhering to the surface of the resin composition layer and prevent scratches.

[0100] The support film (Y) and protective film mentioned above can be made of polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate, polycarbonate, polyimide, and also release paper and metal foils such as copper foil and aluminum foil. The support film and protective film may be treated with a mat treatment, corona treatment, or release treatment.

[0101] The thickness of the support film is not particularly limited, but is usually 10 to 150 μm, and preferably in the range of 25 to 50 μm. The thickness of the protective film is preferably 1 to 40 μm.

[0102] The support film (Y) described above is peeled off after lamination to the circuit board or after an insulating layer is formed by heat curing. Peeling off the support film (Y) after heat curing the adhesive film prevents the adhesion of dust and other debris during the curing process. When peeling off after curing, the support film is usually treated with a release agent beforehand.

[0103] [Other uses] The cured product obtained from the curable composition of the present embodiment is excellent in low moisture absorption, high toughness, etc., and can be suitably used not only for applications such as semiconductor encapsulation materials, semiconductor devices, prepregs, circuit boards, and build-up films, but also for various applications such as build-up substrates, adhesives, resist materials, and matrix resins of fiber-reinforced resins. In the applications, it is not limited to these.

Examples

[0104] The present invention will be specifically described with reference to Examples and Comparative Examples. Hereinafter, "parts" and "%" are based on mass unless otherwise specified. The physical properties of the synthesized epoxy resin were measured as follows and are shown in Tables 1 and 2. <Measurement of epoxy equivalent> Measured according to JIS K 7236.

[0105] <Method for measuring melt viscosity at 150°C> Measured with an ICI viscometer in accordance with ASTM D4287.

[0106] <Measurement of softening point> Measured according to JIS K7234.

[0107] [[ID=2​​​​​​​​​​​​​​​​​​​​ Flow rate 1.0ml / min Standard: In accordance with the measurement manual for the aforementioned "GPC Workstation EcoSEC-WorkStation," the following monodisperse polystyrenes with known molecular weights were used. (Uses polystyrene) "A-500" manufactured by Tosoh Corporation "A-1000" manufactured by Tosoh Corporation "A-2500" manufactured by Tosoh Corporation "A-5000" manufactured by Tosoh Corporation "F-1" manufactured by Tosoh Corporation "F-2" manufactured by Tosoh Corporation "F-4" manufactured by Tosoh Corporation Tosoh Corporation's "F-10" F-20 manufactured by Tosoh Corporation Tosoh Corporation's "F-40" Tosoh Corporation's "F-80" Tosoh Corporation's "F-128" Sample: A 1.0% by mass tetrahydrofuran solution of the polyvalent hydroxy resin or epoxy resin obtained in the examples shown below was filtered through a microfilter (50 μl). The synthesis of the obtained polyvalent hydroxy resin or glycidyl ether (epoxy resin) was confirmed from the GPC measurement results. The number-average molecular weight (Mn), weight-average molecular weight (Mw), and molecular weight distribution (Mw / Mn) of the obtained polyvalent hydroxy resin or glycidyl ether (epoxy resin) were also calculated.

[0108] <Manufacturing Example 1> Polyvalent hydroxy resin (A-1) In a flask equipped with a thermometer, condenser, fractionation column, nitrogen gas inlet tube, and stirrer, 540.7 g (5.0 mol) of m-cresol and 270.4 g of toluene were charged, and 5.4 g of p-toluenesulfonic acid was added. The temperature was then raised to 115°C. After confirming that the raw materials were completely dissolved, 390.6 g of a mixture of divinylbenzene and ethylvinylbenzene (DVB-810, manufactured by Nippon Steel Chemical Co., Ltd.) was added dropwise over 2 hours, and the reaction was continued at 115°C for 1 hour. After the reaction was complete, the temperature was lowered to 80°C, and the mixture was neutralized with an aqueous sodium hydroxide solution. After washing with water four times to remove the generated salt, the unreacted m-cresol and solvent were removed under reduced pressure and heating to obtain polyvalent hydroxy resin (A-1). The physical properties of the obtained polyvalent hydroxy resin (A-1) are shown in Table 1. The Mn of (A-1) was 565, Mw was 756, and Mw / Mn was 1.34.

[0109] <Manufacturing Example 2> Polyvalent Hydroxy Resin (A-2) The reaction was carried out under the same conditions as in Production Example 1, except that "m-cresol 540.7g (5.0 mol)" used in Production Example 1 was replaced with "3,5-dimethylphenol 610.9g (5.0 mol)" to obtain polyvalent hydroxy resin (A-2). The physical properties of the obtained polyvalent hydroxy resin (A-2) are shown in Table 1. The Mn of (A-2) was 612, Mw was 820, and Mw / Mn was 1.34.

[0110] <Comparative Manufacturing Example 1> DVB-modified phenolic resin (1) The reaction was carried out under the same conditions as in Production Example 1, except that "m-cresol 540.7 g (5.0 mol)" used in Production Example 1 was replaced with "phenol 470.6 g (5.0 mol)" to obtain phenol resin (1). The physical properties of the obtained phenol resin (1) are shown in Table 1.

[0111] <Comparative Manufacturing Example 2> DVB-modified phenolic resin (2) The reaction was carried out under the same conditions as in Production Example 1, except that "m-cresol" used in Production Example 1 was changed to "o-cresol," and phenolic resin (2) was obtained. The physical properties of the obtained phenolic resin (2) are shown in Table 1.

[0112] [Table 1]

[0113] <Synthesis Example 1> Synthesis of epoxy resin (E-1) In a flask equipped with a thermometer, dropping funnel, condenser, and stirrer, 210.0 g of the polyvalent hydroxy resin (A-1) obtained in Production Example 1, 463 g (5.0 equivalents) of epichlorohydrin, 238 g of n-butanol, and 40 g of water were charged and dissolved while purging with nitrogen gas. After raising the temperature to 60°C, 90 g (1.1 equivalents) of 49% sodium hydroxide aqueous solution was added dropwise over 5 hours. Then, stirring was continued under the same conditions for 0.5 hours. The unreacted epichlorohydrin was then removed by vacuum distillation. 532 g of methyl isobutyl ketone was added to the obtained crude epoxy resin and dissolved to prepare a crude epoxy resin solution. Furthermore, 15 g of 5% sodium hydroxide aqueous solution was added to the crude epoxy resin solution and reacted at 80°C for 2 hours, after which it was washed with 140 g of water three times. Next, the system was dehydrated by azeotropy, and after microfiltration, the solvent was removed under reduced pressure to obtain epoxy resin (E-1). The properties of the obtained epoxy resin (E-1) are shown in Table 2. The Mn of (E-1) was 592, Mw was 944, and Mw / Mn was 1.595.

[0114] <Synthesis Example 2> Synthesis of epoxy resin (E-2) The reaction was carried out under the same conditions as in Synthesis Example 1, except that "210.0 g of polyvalent hydroxy resin (A-1)" used in Synthesis Example 1 was replaced with "216.0 g of polyvalent hydroxy resin (A-2)" to obtain epoxy resin (E-2). The physical properties of the obtained epoxy resin (E-2) are shown in Table 2. The Mn of (E-2) was 642, Mw was 1010, and Mw / Mn was 1.600.

[0115] <Comparative Synthesis Example 1> Synthesis of epoxy resin (1) The reaction was carried out under the same conditions as in Synthesis Example 1, except that "210.0 g of polyvalent hydroxy resin (A-1)" used in Synthesis Example 1 was replaced with "208.0 g of DVB-modified phenolic resin (1)" to obtain epoxy resin (1). The physical properties of the obtained epoxy resin (1) are shown in Table 2.

[0116] <Comparative Synthesis Example 2> Synthesis of epoxy resin (2) The reaction was carried out under the same conditions as in Synthesis Example 1, except that "210.0 g of polyvalent hydroxy resin (A-1)" used in Synthesis Example 1 was replaced with "210.0 g of DVB-modified phenolic resin (2)" to obtain epoxy resin (2). The physical properties of the obtained epoxy resin (2) are shown in Table 2.

[0117] [Table 2]

[0118] <Curable composition and preparation of the composition> Using the resins produced in Synthesis Examples 1-2 and Comparative Synthesis Examples 1-2, the components were blended according to the compositions shown in Tables 3 and 4 below, and the curable compositions of Examples 1-8 and Comparative Examples 1-6 were prepared by melt-kneading at 90°C for 5 minutes using two rolls. -Raw materials- The details of each component used in Tables 3 and 4 described below are as follows. Epoxy resin (3): Biphenyl aralkyl type epoxy resin (Nippon Kayaku Co., Ltd. "NC-3000" epoxy equivalent 278g / equivalent) Hardener (1): Novolac-type phenolic resin (DIC Corporation "TD-2131", hydroxyl group equivalent 104g / equivalent) Hardener (2): Phenolic aralkyl type phenolic resin (HE100C-15 manufactured by Air Water Co., Ltd., hydroxyl group equivalent 174g / equivalent) Hardening agent (3): Biphenyl aralkyl type phenolic resin (MEHC-7851SS manufactured by Meiwa Kasei Co., Ltd., hydroxyl group equivalent 203 g / equivalent) Curing accelerator: Triphenylphosphine (manufactured by Hokko Chemical Industry Co., Ltd., "TPP") Inorganic filler: Fused silica (Denka Co., Ltd. "FB-5604", spherical silica) Coupling agent: γ-glycidoxyethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) Coloring agent: Carbon black (Mitsubishi Chemical Corporation "MA100")

[0119] <Preparation of hardened material> The curable compositions prepared as shown in Table 3 were poured into an 11cm × 9cm × 2.4mm mold, molded at 150°C for 10 minutes using a press, then the molded product was removed from the mold and cured at 175°C for 5 hours to obtain evaluation samples.

[0120] <Measurement of elastic modulus> The 2.4 mm thick cured material prepared as described above was cut into pieces measuring 5 mm in width and 54 mm in length, and these were designated as test specimen 1. Then, using a viscoelasticity analyzer (DMA: Rheometric RSAII solid viscoelasticity analyzer, rectangular tension method: frequency 1 Hz, heating rate 3 °C / min), test specimen 1 was measured to determine the glass transition temperature, which is the temperature at which the change in elastic modulus is maximum (the tanδ change rate is largest).

[0121] <Evaluation of hygroscopic properties> Test piece 2, cut from the above cured material to 75 mm x 25 mm x 2.4 mm thick, was left for 300 hours in an environment with a temperature / humidity of 85°C / 85%RH. The moisture absorption rate (%) was then calculated using the following formula to evaluate the hygroscopicity. Moisture absorption rate (%) = {(Weight of test specimen 2 after testing) - (Weight of test specimen 2 before testing)} ÷ (Weight of test specimen 2 before testing) × 100

[0122] <Adhesion> Adhesion was evaluated by die shear test. Using a transfer molding machine (KTS-15-1.5C, manufactured by Kotaki Seiki), under conditions of mold temperature of 150°C, molding pressure of 9.8 MPa, and curing time of 600 seconds, copper foil (EFTEC-64T, manufactured by Furukawa Electric Co., Ltd.) was placed in the mold, and the resin compositions of Examples 7-8 and Comparative Examples 4-6, prepared with the compositions shown in Table 4, were injected and molded to create test pieces 3 measuring 6 mm in length, 6 mm in width, and 2 mm in thickness on the copper foil. Test pieces 3 were then post-cured at 175°C for 5 hours. Adhesion was measured using a bonding tester (PTR-1102, manufactured by RHESCA) at a measurement temperature of 40°C. The test was performed at a height of 0.1 mm from the substrate, a shear speed of 0.1 mm / second, with N=5 for each test, and the average value (gf) of the peel strength from the copper foil was calculated. The peel strength was calculated by determining the relative strength of each resin composition, with the molded product of Comparative Example 6 set to 100.

[0123] [Table 3]

[0124] [Table 4] [Industrial applicability]

[0125] According to the present invention, it is possible to provide an epoxy resin and a curable composition containing the epoxy resin that can achieve a high degree of simultaneous low moisture absorption, low thermal elasticity, and high adhesion of the cured product without impairing its low viscosity during melting.

Claims

1. An aromatic compound (A) represented by the following general formula (A1) has an aromatic ring to which a phenolic hydroxyl group is bonded and at least one monovalent hydrocarbon group at the meta position of the aromatic ring, 【Chemistry 1】 (In the above general formula (A1), R ａ1 and R ａ2 Each of these independently represents a hydrogen atom or a monovalent hydrocarbon group, and R ａ1 and R ａ2 At least one of them is a monovalent hydrocarbon group, R ａ3 represents the number of carbon atoms from 1 to 12, p ａ This represents a number between 0 and 3. However, there are multiple R's. ａ3 They may be the same or different. Aromatic divinyl compound (B1) represented by the following general formula (B1), 【Chemistry 2】 (In the above general formula (B1), R ｂ１ each independently represents an alkyl group having 1 to 3 carbon atoms, and R ｂ２ , R ｂ３ , R ｂ４ , R ｂ５ , R ｂ６ and R ｂ７ each independently represents a hydrogen atom, and p ｂ１ represents the number 0.) Aromatic monovinyl compound (B2) represented by the following general formula (B2) 【Transformation 3】 (In the above general formula (B2), R ｂ８ Each of these independently represents an ethyl group, and R ｂ９ , R ｂ１０ and R ｂ１１ Each of these independently represents a hydrogen atom, and p ｂ２ (This represents 1.) An epoxy resin which is a glycidyl ether of a polyvalent hydroxy resin, with (1) as the reaction raw material, An epoxy resin in which the mass ratio ((B1) / (B2)) of divinylbenzene, an aromatic divinyl compound (B1), to ethylvinylbenzene, an aromatic monovinyl compound (B2), is 50 / 50 to 99 / 1.

2. The epoxy resin according to claim 1, wherein the polyvalent hydroxy resin and epihalohydrin (C) are used as reaction raw materials (2).

3. The epoxy resin according to claim 1, wherein the glycidyl ether of the polyvalent hydroxy resin has repeating units represented by the following general formula (IV). 【Chemistry 4】 (In the above general formula (IV), G represents a glycidyl group, and R １ and R ２ Each of these independently represents a hydrogen atom or the monovalent hydrocarbon group, except R １ and R ２ At least one of them is a monovalent hydrocarbon group having 1 to 6 carbon atoms, R ３ R represents a monovalent group derived from the aromatic monovinyl compound (B2), ４ , R ５ , R ９ and R １０ Each of these independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ６ (where 'p' represents a monovalent organic group, 'p' represents a number from 0 to 2, and 'q' represents a number from 0 to 4.)

4. The epoxy resin according to claim 3, wherein the monovalent group derived from the aromatic monovinyl compound (B2) is represented by the following general formula (b2-1). 【Transformation 5】 (In general formula (b2-1), R ７ (where * represents an ethyl group, and * represents a bond to the carbon atom of the aromatic ring in general formula (1).)

5. A curable composition comprising an epoxy resin according to any one of claims 1 to 4 and a curing agent.

6. A cured product of a curable composition according to claim 5.

7. A prepreg having a reinforcing substrate and a semi-cured product of the curable composition according to claim 5 impregnated into the reinforcing substrate.

8. A circuit board formed by laminating the prepreg and copper foil according to claim 7 and then heat-pressing them together.

9. A build-up film containing the curable composition described in claim 5.

10. A semiconductor encapsulant containing the curable composition described in claim 5.

11. A semiconductor device comprising a cured product of the semiconductor encapsulant according to claim 10.

Images