TWI696659B - Flame retardant epoxy resin composition, prepreg, insulation sheet, adhesion sheet, laminate, sealing material, casting material and cured product - Google Patents

Abstract

A flame-retardant epoxy resin composition, which is a flame-retardant epoxy resin composition containing an epoxy resin (A), a hardener (B), and a phosphorus compound (C) as a flame retardant, characterized by: The phosphorus content rate is 0.2% by mass to 6% by mass relative to the total of the epoxy resin (A), the hardener (B), and the phosphorus compound (C); the epoxy resin (A) contains 5% by mass or more Novolac epoxy resin (A1) with oxazolidinone ring in the molecule; and epoxy equivalent of epoxy resin (A1) is 170 g/eq.～450 g/eq., oxazolidinone ring The content is 0.02 eq./kg～3.0 eq./kg.

Description

Flame retardant epoxy resin composition, prepreg, insulation sheet, adhesive sheet, laminated board, sealing material, casting material and hardened material

The present invention relates to a flame-retardant epoxy resin composition that can provide a hardened product excellent in flame retardancy, low dielectric properties, high heat resistance, low moisture absorption, high adhesion, etc., and The obtained epoxy resin hardened material, prepreg, insulating sheet, adhesive sheet, laminated board, sealing material, casting material.

Epoxy resins are excellent in adhesiveness, flexibility, heat resistance, chemical resistance, insulation, and hardening reactivity, so they are used in paints, civil adhesives, casting, electrical and electronic materials, and film materials. In particular, in printed wiring board applications as one of electrical and electronic materials, it is widely used by imparting flame retardancy to epoxy resins.

Infrastructure devices such as portable devices or base stations that maintain them as one of the uses of printed wiring boards have been required to increase functionality in recent years as the amount of leaps of information has increased dramatically. In portable devices, the purpose of miniaturization is to achieve high multilayers or fine wiring, and to make the substrate thinner, materials with lower dielectric constants are required. Because of the fine wiring, the adhesive surface is reduced, so adhesiveness is required. Higher material. In order to suppress the attenuation of high-frequency signals in substrates used in base stations, materials with a lower dielectric loss tangent are required.

Although characteristics such as low dielectric constant, low dielectric loss tangent, and high adhesion are derived from the structure of the epoxy resin that is the base resin of the printed wiring board, new epoxy resin or its modification technology is required to a large extent.

Regarding the lowering of the dielectric constant of epoxy resins, Patent Document 1 discloses 4,4'-[1,3-phenylenebis(1-methylethylene)]bis[2,6-dimethyl ] Diglycidyl ether of phenol. Furthermore, Patent Document 2 discloses an epoxy resin obtained by reacting an epoxy resin having an alcoholic hydroxyl equivalent of 1.0 meq/g or less with an isocyanate compound having two or more isocyanate groups in the molecule, and discloses that oxazolidine The ketone ring polymerized epoxy resin has a low dielectric constant, a low dielectric loss tangent, and a high glass transition temperature. However, regarding flame retardancy, the use of brominated epoxy resins in the raw materials is not applicable to halogen-free flame retardant applications.

Regarding an epoxy resin containing an oxazolidinone ring obtained by reacting an epoxy resin with an isocyanate, Patent Document 3 discloses a hardener such as an epoxy resin containing a oxazolidinone ring and a halogen group, dicyandiamide, etc. The epoxy resin composition for laminates as a raw material epoxy resin includes compounds obtained by glycidylation of divalent phenols such as bisphenol A, tris(glycidoxyphenyl)alkanes or p-amines Compounds obtained by glycidylation of phenol and the like, or compounds obtained by glycidylation of novolacs such as phenol novolak. However, the epoxy resin composition disclosed in any of the documents does not sufficiently satisfy the requirements of the dielectric properties based on the high functionalization in recent years, and the adhesiveness is also insufficient.

Furthermore, there is a problem that the cured product containing the flame-retardant epoxy resin composition deteriorates in proportion to the phosphorus content of the cured product after moisture absorption. The flame-retardant epoxy resin composition is formulated to provide Phosphorus-containing epoxy resin, phosphorus-containing hardener and phosphorus-based flame retardant modified by 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide for flame retardancy. In addition, in order to improve the hygroscopicity, studies have also been conducted on the preparation of fillers such as alumina, but there is a problem that the adhesion deteriorates. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 5-293929 [Patent Document 2] Japanese Patent Laid-Open No. 9-278867 [Patent Document 3] Japanese Patent Laid-Open No. 5-43655

[Problem to be solved by the invention] Therefore, the problem to be solved by the present invention is to provide excellent performance with flame retardancy, low dielectric properties, high heat resistance, and high adhesion in applications such as lamination, molding, casting, and adhesion Useful flame retardant epoxy resin composition and its hardened product. [Technical means to solve the problem]

In order to solve the above-mentioned problems, the present inventors have made intensive studies on materials with low dielectric constant and low dielectric loss tangent. As a result, it has been found that the epoxy resins containing novolak-type epoxy resins and isocyanate compounds contain Novolac epoxy resin with oxazolidinone ring can take into account the low dielectric constant, low dielectric loss tangent and high glass transition temperature and good adhesion that were not previously available, and it is further combined with phosphorus flame retardants Furthermore, it exhibits excellent flame retardancy, and the present invention has been completed.

That is, the present invention is a flame-retardant epoxy resin composition, which is a flame-retardant epoxy resin composition containing an epoxy resin (A), a hardener (B), and a phosphorus compound (C) as a flame retardant It is characterized in that the phosphorus content is 0.2% by mass to 6% by mass relative to the total (A+B+C) of the epoxy resin (A), the hardener (B) and the phosphorus compound (C), The epoxy resin (A) contains more than 5 wt% of a novolac epoxy resin (A1) having an oxazolidinone ring in the molecule, and the epoxy equivalent of the epoxy resin (A1) is 170 g/eq .～450 g/eq., the oxazolidinone ring content is 0.02 eq./kg～3.0 eq./kg.

The epoxy equivalent of the epoxy resin (A1) is preferably 175 g/eq. to 400 g/eq., its softening point is preferably 50°C to 150°C, and its oxazolidone ring content is preferably 0.05 eq./kg～2.5 eq./kg.

The epoxy resin (A1) is more preferably a compound represented by the following formula (1).

In the formula, A ₁ represents an aromatic ring group selected from a benzene ring, a naphthalene ring or a biphenyl ring, and these aromatic ring groups may have an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms or carbon Any group of 7 to 10 aralkyl groups is a substituent of the aromatic ring, X represents a divalent aliphatic cyclic hydrocarbon group or a crosslinking group represented by the following formula (2) or the following formula (3) Any of the groups, Z is independently a glycidyl group (Z1) represented by the following formula (4) or an oxazolidone ring-containing group (Z2) represented by the following formula (5), and Z1 in Z The molar ratio with Z2 (Z2/Z1) is 0.005 to 0.45. m represents 1 or 2, n is the number of repeating units, represents an integer of 1 or more, and its average value is 1.5 or more.

（式中，R₁ 、R₂ 、R₃ 及R₄ 分別獨立地表示氫原子或碳數1～6的烴基。A₂ 表示選自苯環、萘環或聯苯環的芳香族環基，這些芳香族環基也可以具有碳數1～6的烷基、碳數6～10的芳基或碳數7～10的芳烷基的任一基作為芳香族環的取代基。）

(In the formula, R ₁ , R ₂ , R ₃ and R ₄ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. A ₂ represents an aromatic ring group selected from a benzene ring, a naphthalene ring or a biphenyl ring, These aromatic ring groups may have a C 1-6 alkyl group, a C 6-10 aryl group or a C 7-10 aralkyl group as a substituent of the aromatic ring.)

（式中，Y表示也可以具有取代基的二價基，T表示自式（1）除去一個Z的結構、或下述式（6）所表示的基。）

(In the formula, Y represents a divalent group which may have a substituent, and T represents a structure in which one Z is removed from the formula (1), or a group represented by the following formula (6).)

（式中，A₁ 、X、Z、及m與式1同義。n₁ 、n₂ 是重複單元數，表示0以上的整數，n₁ ＋n₂ 變得與式1的n相同。）

(In the formula, A ₁ , X, Z, and m are synonymous with Formula 1. n ₁ and n ₂ are the number of repeating units and represent an integer of 0 or more, and n ₁ + n ₂ becomes the same as n in Formula 1.)

The epoxy resin (A1) is preferably 0.005 mol to 0.45 mol relative to the component 1 represented by formula (4), and the component represented by formula (5) is more preferably the following formula ( 7) It is obtained by reacting the novolak type epoxy resin (d) and the isocyanate compound (e).

(Wherein, A _1, X, m and n are respectively of formula (1), A _1, X, m and n are synonymous .G represents a glycidyl group.)

The novolac-type epoxy resin (d) is preferably determined by gel permeation chromatography (Gel Permeation Chromatography, GPC), the content of the dinuclear body is 20% by area or less, and the content of the trinuclear body is 15 A novolac-type epoxy resin (d1) having a specific molecular weight distribution of an area% or more and 60 area% or less, a content of pentads or more of 45 area% or less, and a number average molecular weight of 350 or more and 700 or less.

Here, the GPC measurement conditions are as follows. A GPC measuring device HLC-8220GPC manufactured by Tosoh Corporation was used. Using an apparatus including series columns TSKgelG4000HXL, TSKgelG3000HXL, and TSKgelG2000HXL manufactured by Tosoh Corporation, the column temperature was set to 40°C. Furthermore, tetrahydrofuran (THF) was used in the dissolution liquid, and the flow rate was set to 1 mL/min, and the detector used an RI (differential refractometer) detector. The data processing is using GPC-8020 model II version 4.10 manufactured by Tosoh Corporation. The measurement sample is obtained by dissolving 100 μL of 0.1 g sample in 10 mL of THF and filtering with a microfilter. Based on the obtained chromatogram, the dinuclear content rate, trinuclear content rate, tetranuclear content rate, and pentanuclear content rate or higher are calculated. Based on the use standard, monodisperse polystyrene (manufactured by Tosoh Corporation) A-500, A-1000, A-2500, A-5000, F-1, F-2, F-4, F-10, F-20, F-40, F-80, F-128) and Determine the calibration curve to determine the number average molecular weight. In addition, all areas are the sum of the areas of 2 cores or more.

The novolac epoxy resin (A1) containing an oxazolidinone ring is preferably an isocyanate group of the isocyanate compound (e) relative to the epoxy group of 1 mole of the novolac epoxy resin (d). It is obtained by reacting in a range of 0.01 moles or more and 0.5 moles or less, especially 0.02 moles or more and 0.35 moles or less.

The isocyanate compound (e) preferably has an average of 1.8 or more isocyanate groups in one molecule, and is more preferably selected from 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, and 3,5-toluene diisocyanate. Isocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, m-xylene diisocyanate, p-xylene diisocyanate, Tetramethylxylene diisocyanate, 1,4-naphthalenediyl diisocyanate, 1,5-naphthalenediyl diisocyanate, 2,6-naphthalenediyl diisocyanate, 2,7-naphthalenediyl diisocyanate, 3, 3'-dimethylbiphenyl-4,4'-diisocyanate, isophthalic diisocyanate, p-phenylene diisocyanate, cyclohexane-1,4-diyl diisocyanate, cyclohexane-1,3-diyl Dimethylene diisocyanate, cyclohexane-1,4-diyl bismethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4 At least one of the group consisting of 4,4-trimethylhexamethylene diisocyanate, 4,4'-methylenebiscyclohexyl diisocyanate, and isophorone diisocyanate.

The phosphorus compound (C) preferably includes a phosphorus-containing epoxy resin (CA) and/or a phosphorus-containing hardener (CB).

The epoxy equivalent of the phosphorus-containing epoxy resin (CA) is more preferably 200 g/eq. to 800 g/eq., and the phosphorus content rate thereof is more preferably 0.5% by mass to 6% by mass.

The phosphorus content of the phosphorus-containing hardener (CB) is more preferably 0.5% by mass to 12% by mass.

The phosphorus compound (C) is preferably a compound having a unit structure represented by the following formula (8).

With respect to all epoxy resins of the flame-retardant epoxy resin composition (including novolak epoxy resins containing an oxazolidinone ring (A1), phosphorus-containing epoxy resins (CA) and other rings For the epoxy resin 1 mole, it is preferable to formulate the active hydrogen group of the hardener (B) (including the phosphorus-containing hardener (CB)) within the range of 0.2 mole or more and 1.5 mole or less.

In a specific embodiment, the flame-retardant epoxy resin composition of the present invention further contains a filler (F).

In a specific embodiment, the flame-retardant epoxy resin composition of the present invention further includes a thermoplastic resin (G).

Furthermore, the present invention is a laminate obtained by using the prepreg, insulating sheet, and adhesive sheet characterized by using the flame-retardant epoxy resin composition. Furthermore, the present invention is a laminate, a sealing material, a casting material, and a cured product characterized by using the flame-retardant epoxy resin composition. [Effect of invention]

Regarding the flame-retardant epoxy resin composition of the present invention, the cured product maintains good adhesion and exhibits physical properties of the cured product with a high glass transition temperature and good flame retardancy. In addition, it has excellent dielectric properties and requires low dielectric properties. Laminated plates and electronic circuit boards exhibiting excellent characteristics in electrical constant and low dielectric loss tangent.

Hereinafter, embodiments of the present invention will be described in detail. The flame-retardant epoxy resin composition of the present invention contains epoxy resin (A), hardener (B), and phosphorus compound (C) as essential components. Furthermore, the epoxy resin (A) contains a novolak epoxy resin (A1) having an oxazolidinone ring as an essential component. Hereinafter, the novolak epoxy resin (A1) having an oxazolidinone ring is referred to as "epoxy resin (A1)". In addition, in this specification, when it is called "oxazolidone ring-containing epoxy resin", it means all epoxy resins containing an oxazolidone ring obtained from an epoxy resin and an isocyanate compound, among which Contains epoxy resin (A1). Therefore, when the epoxy resin (A1) is not included, it means an epoxy resin containing an oxazolidinone ring other than the epoxy resin (A1).

Hereinafter, each component contained in the flame-retardant epoxy resin composition of the present invention will be described.

The epoxy resin (A) is not particularly limited except for the essential epoxy resin (A1). Other epoxy resins (A2) may be used together with the epoxy resin (A1), and as the other epoxy resin (A2), conventionally known epoxy resins may be used. In addition, the "epoxy resin" refers to an epoxy resin having at least one epoxy group, preferably an epoxy resin having two or more epoxy groups. By using an epoxy resin (A2) other than the epoxy resin (A1) together, the properties of the cured product can be further improved or other properties can be imparted. For example, a phosphorus-containing epoxy resin (CA) for imparting flame resistance or a naphthalene-type epoxy resin for low linear expansion is used. These epoxy resins that can be used in combination can be used within a range that does not hinder the effect of the epoxy resin (A1). The use amount of the epoxy resin (A1) needs to be 5 mass% or more in the epoxy resin (A), and it is preferably 10 mass% to 100 mass%, more preferably 10 mass% to 80 mass%, further It is more preferably 15% by mass to 70% by mass. Even if it is a small amount, the effect of using epoxy resin (A1) can be exerted, so if it is within this range, the physical properties of the hardened material obtained by use, such as low dielectric properties, high heat resistance, low absorption Enhancement effects such as wettability and high adhesion.

The epoxy equivalent (g/eq.) of the epoxy resin (A1) needs to be 170 to 450, preferably 175 to 400, more preferably 180 to 350, and still more preferably 185 to 300. If the epoxy equivalent is low, there is a concern that the content of the oxazolidinone ring becomes smaller and the hydroxyl group concentration in the hardened product becomes higher, so the dielectric constant becomes higher. In addition, if the epoxy equivalent is high, there is a concern that the content of the oxazolidinone ring needs to be more than necessary, and due to the effect of improving the dielectric properties, adverse effects such as deterioration in solvent solubility and increase in resin viscosity increase. Moreover, there is a concern that the cross-link density of the hardened product becomes low, and therefore the elastic modulus decreases at the temperature of reflow soldering, etc., which becomes a problem in use.

The softening point of the epoxy resin (A1) is preferably 50°C to 150°C, more preferably 55°C to 130°C, even more preferably 58°C to 100°C, and particularly preferably 60°C to 85°C. If the softening point is low, there is a concern that when the resin varnish is impregnated in the glass cloth and then heated and dried in an oven, the adhesion amount of the resin decreases due to the low viscosity. Moreover, if the softening point is high, there is a concern that the viscosity of the resin becomes high, impregnation in the prepreg deteriorates, or the solubility of the solvent deteriorates, and the diluted solvent does not remain volatile in the resin during heating and drying, so When a laminated board is produced, voids or the like are generated, which becomes a problem in use. Therefore, regarding the softening point of the entire epoxy resin (A), it is desirable to satisfy the softening point.

The oxazolidone ring content of the epoxy resin (A1) is 0.02 eq./kg to 3.0 eq./kg, preferably 0.05 eq./kg to 2.5 eq./kg, and more preferably 0.08 eq./kg to 2.0 eq./kg, further preferably 0.1 eq./kg to 1.8 eq./kg. If the content of the oxazolidinone ring is high, there is a concern that although the dielectric characteristics are improved (the dielectric constant is further lowered), the adverse effects such as the deterioration of the solvent solubility and the increase of the resin viscosity increase.

The presence of the oxazolidinone ring can be confirmed by IR measurement. In the analysis by total reflectometry (ATR method), the peak value of the stretching vibration of the carbonyl group derived from the oxazolidinone ring appears in 1745 cm ^-1 to 1760 cm ^-1 . The oxazolidinone ring content can be determined based on the magnitude of this peak. In addition to this, the oxazolidinone ring content can be determined by the chemical method described in the examples described later.

The epoxy resin (A1) is preferably the resin represented by the formula (1).

In formula (1), A ₁ is an aromatic ring group selected from any group including a benzene ring, naphthalene ring, or biphenyl ring which may have a substituent. The aromatic ring of these aromatic ring groups may have a substituent, and the substituent may be any of an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms. base. When there are multiple substituents, they may be the same or different.

The alkyl group means a linear, branched or cyclic alkyl group, and examples thereof include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secondary butyl, and tertiary butyl. Base, pentyl, hexyl, cyclohexyl, etc. Among these groups, there is a tendency that a branched or cyclic alkyl group can provide high heat resistance as compared with a linear alkyl group. In the case of a chain alkyl group, the carbon number is preferably 1 to 4, and in the case of a cyclic alkyl group, the carbon number is preferably 6. Preferred are isopropyl, isobutyl, tertiary butyl, and cyclohexyl, and more preferred are tertiary butyl and cyclohexyl. Furthermore, in order to increase the flame retardancy, methyl is also preferred.

Examples of the aryl group include phenyl and naphthyl, and phenyl is preferred. Examples of the aralkyl group include benzyl, phenethyl, 1-phenylethyl and the like, preferably benzyl and 1-phenylethyl.

X is any group of a divalent aliphatic cyclic hydrocarbon group or a crosslinking group represented by formula (2) or formula (3). The carbon number of the divalent aliphatic cyclic hydrocarbon group is preferably 5-15, more preferably 5-10. In Formula (2) and Formula (3), R ₁ , R ₂ , R ₃ and R ₄ independently represent a hydrogen atom or a C 1-6 hydrocarbon group. A ₂ has the same meaning as A ₁ in the above formula (1) except that the valence is divalent.

Z is independently a glycidyl group (Z1) represented by formula (4) or an oxazolidone ring-containing group (Z2) represented by formula (5). The molar ratio (Z2/Z1) of Z1 and Z2 in Z is preferably 0.005 to 0.45, more preferably 0.008 to 0.40, and even more preferably 0.01 to 0.35.

Moreover, the molar ratio (Z2/Z1) is the epoxy equivalent [Ep (g/eq.)] and oxazolidone ring content [Ox (eq./kg)] using the epoxy resin (A1), according to the following It is calculated by calculation. Z2/Z1=(Ox÷2)/(1000÷Ep)

The oxazolidone ring-containing epoxy resin is obtained from an epoxy compound having a glycidyl group and an isocyanate compound having an isocyanate group. The glycidyl group (Z1) is a part of the glycidyl group of the epoxy compound that remains unreacted, and the group containing the oxazolidinone ring (Z2) contains an oxazolidinone ring produced by the reaction of an epoxy group and an isocyanate group Structure, methylene which is the residue of the glycidyl group of the epoxy compound, and Y which is the residue of the isocyanate compound. Y represents a divalent functional group which may have a substituent, and is a residue from which the isocyanate group is removed from the isocyanate compound.

T is a terminal group, which is a residue produced by removing one glycidyl group from the raw material epoxy compound. In the case where the epoxy compound has two or more glycidyl groups, the other glycidyl groups may be left as they are, or they may be isocyanate groups. Reaction to form an oxazolidinone ring. The terminal group T is a structure in which one Z is removed from formula (1). Or expressed by formula (6).

m is 1 or 2, which corresponds to the number of glycidyl groups of the raw material epoxy compound. n is a repeating unit and represents an integer of 1 or more. The average value (number average) is preferably in the range of 1.5 to 5, more preferably 2 to 4.5, and even more preferably 2.5 to 4. In formula (6), n ₁ represents an integer of 0 or more, n ₂ represents an integer of 1 or more, and n ₁ + n ₂ corresponds to n.

The epoxy resin (A1) can be obtained by reacting a novolac epoxy resin (d) as a raw material epoxy compound and an isocyanate compound (e).

A suitable novolak-type epoxy resin (d) is obtained by reacting a novolak resin with epihalohydrin. The novolak resin is represented by formula (7). In the presence of an acid catalyst, phenols and aldehydes are used. Obtained by condensation of crosslinking agents. As the novolak-type epoxy resin (d), a novolak-type epoxy resin (d1) having a specific molecular weight distribution is preferable. The novolac epoxy resin (d1) is GPC measurement, the content of dinuclear body is 20 area% or less, the content of trinuclear body is 15 area% or more, 60 area% or less, and the content rate of pentasome is more than It is an epoxy resin with an area average of 45% or less and a number average molecular weight of 350 or more and 700 or less. Here, the so-called "i nucleus" in dinuclear bodies, trinuclear bodies, etc. refers to the A ₁ number (i) existing in the molecule. That is, the number obtained by adding 1 to n in equation (7) is i.

Phenols used to obtain the novolak resin may include phenol, cresol, ethylphenol, butylphenol, octylphenol, styrenated phenol, cumylphenol, naphthol, catechol, resorcinol Phenol, naphthol, etc., but not limited to these compounds, these phenols may be used alone or in combination of two or more. Among these phenols, monophenols such as phenol and alkylphenol are preferred. As the alkyl group in the case of an alkylphenol, an alkyl group having 1 to 8 carbon atoms is suitable.

Examples of the crosslinking agent such as aldehydes include aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, and benzaldehyde, or acetone, methyl ethyl ketone, methyl isobutyl ketone, and benzene. Ketones such as ethyl ketone, or p-xylylene glycol, p-xylylene glycol dimethyl ether, p-dichlorobenzyl, 4,4'-dimethoxymethylbiphenyl, 4, 4'-Dichloromethylbiphenyl, dimethoxymethylnaphthalenes, dichloromethylnaphthalenes and other crosslinking agents, or divinylbenzenes and divinylbiphenyls represented by the following formula (13) Crosslinking agents such as benzene and divinylnaphthalene, or cycloalkyldienes such as cyclopentadiene or dicyclopentadiene, but not limited to these compounds, these crosslinking agents can be used alone, Two or more types can be used in combination.

（式中，R₃ 、R₄ 及A₂ 分別與式（3）的R₃ 、R₄ 及A₂ 同義。L獨立地表示羥基、烷氧基、或鹵素原子。）

(Wherein, R R _3, R ₄ and A ₂ respectively of formula (3) _3, R ₄ and A ₂ independently represent synonymous .L hydroxy, alkoxy, or a halogen atom.)

In Formula (1), Formula (6), and Formula (7), X is a group derived from a crosslinking agent or a crosslinking group. When cycloalkyl dienes are used, they become divalent aliphatic cyclic hydrocarbon groups, and when aldehydes or ketones are used as cross-linking agents, they become cross-linking groups represented by formula (2), When the crosslinking agent of Formula (12) or Formula (13) is used, it becomes a crosslinking group represented by Formula (3). Among these crosslinking agents, formaldehyde, acetaldehyde, benzaldehyde, acetone, p-dichlorobenzyl, 4,4'-dichloromethylbiphenyl are preferred, and formaldehyde is particularly preferred. Preferred forms when using formaldehyde in the reaction include formalin aqueous solution, paraformaldehyde, trioxane, and the like.

The novolak resin obtained by condensing phenols and a crosslinking agent in the presence of an acidic catalyst may include the following epoxy resins. Phenol novolac-type epoxy resins exist: Epotohto YDPN-638 (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), jER152, jER154 (manufactured by Mitsubishi Chemical Co., Ltd.), and Epiclon N-740, Epicuron N-770, Epicuron N-775 (manufactured by DIC), etc. Cresol novolac-type epoxy resins exist: Ai Tao Tao Tao YDCN-700 series (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), Api Coulomb N-660, Api Coulomb N-665, Api Coulomb N- 670, Epicuron N-673, Epicuron N-695 (manufactured by Di Aisheng Co., Ltd.), EOCN-1020, EOCN-102S, EOCN-104S (manufactured by Nippon Kayaku Co., Ltd.), etc. Alkyl novolac epoxy resins exist: Ai Tao Tao Tao ZX-1071T, Ai Tao Tao Tao ZX-1270, Ai Tao Tao Tao ZX-1342, etc.; Styrenated phenol novolac epoxy resins exist: Ai Toss Taotao ZX-1247, toss Taotao GK-5855, toss Taotao TX-1210, toss Taotao YDAN-1000, etc.; naphthol novolac epoxy resins exist: toss Taotao ZX-1142L Etc.; β-naphthol aralkyl type epoxy resins exist: ESN-155, ESN-185V, ESN-175, etc.; dinaphthol aralkyl type epoxy resins exist: ESN-300 series of ESN-355 , ESN-375, etc.; α-naphthol aralkyl type epoxy resins exist: ESN-475V, ESN-485 of ESN-400 series (all manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.). Biphenyl aralkyl phenol type epoxy resins exist: NC-3000, NC-3000H (manufactured by Nippon Kayaku Co., Ltd.), etc.

As the raw material epoxy compound, the novolak-type epoxy resin (d) is preferably the novolak-type epoxy resin (d1) having a specific molecular weight distribution, but the commercially available novolak-type epoxy resin is not With this molecular weight distribution. It is preferable to use a novolak resin having a specific molecular weight distribution as the novolak resin of the novolac type epoxy resin (d1) as a raw material. Such a novolak resin can be adjusted by adjusting the molar ratio of phenols and aldehydes, and The obtained novolak resin is obtained by removing low molecular weight components. Moreover, such a novolak resin can also be obtained by the manufacturing method shown in Japanese Patent Laid-Open No. 2002-194041 or Japanese Patent Laid-Open No. 2007-126683.

In order to obtain a suitable novolak resin, it is manufactured under the condition that the molar ratio of phenols and crosslinking agent (phenolic/crosslinking agent) is 1 or more. When the molar ratio is large, the dinuclear is generated in many cases On the contrary, when the molar ratio is small, on the contrary, when the molar ratio is small, high-molecular bodies with more than five nucleosomes are generated, and there are fewer dinuclear bodies and trinuclear bodies. Moreover, the ratio of dinuclear bodies, trinuclear bodies, etc. is also related to the ratio in the novolak resins before epoxidation, but it also varies according to the conditions of epoxidation, so in order to obtain a novolak type ring with a specific molecular weight distribution The oxygen resin (d1) needs to undergo a reaction within the above range. Therefore, the molar ratio is preferably 3 or more and 6 or less, and more preferably 4 or more and 5 or less.

Regarding the novolak resins obtained by adjusting the molar ratio of phenols and crosslinking agents as described above, novolak resins having a specific molecular weight distribution can be obtained by reducing or removing low molecular weight components. In this case, examples of methods for reducing or removing low-molecular-weight components, especially dinuclear bodies, include poor solubility using various solvents, methods for dissolving in alkaline aqueous solutions, and other known separation methods.

By using a well-known epoxidation method for a novolak resin having a specific molecular weight distribution, a novolak-type epoxy resin (d1) having a specific molecular weight distribution that is advantageously used in the present invention can be obtained. Alternatively, various methods can be used to reduce or remove low molecular weight components, especially dinuclear components, from commercially available novolak epoxy resins, thereby obtaining novolak epoxy resins (d1) having a specific molecular weight distribution.

By using the novolak-type epoxy resin (d1) having a specific molecular weight distribution, an epoxy resin (A1) that becomes a hardened product having more excellent dielectric properties, heat resistance, and adhesiveness can be obtained.

The novolak type epoxy resin (d1) has a dinuclear content rate of 20 area% or less, preferably 15 area% or less, and more preferably 5 area% or more and 12 area% or less. If the content of the dinuclear body exceeds 20 area%, the heat resistance gradually decreases. If there are too few dinuclear bodies, the resin viscosity as an epoxy resin (A1) may become high. The trinuclear content rate is 15 area% or more and 60 area% or less, more preferably 15 area% or more and 50 area% or less, and even more preferably 15 area% or more and 35 area% or less. If the content of the trinuclear body is less than 15 area%, there is a concern that the content of the oxazolidinone ring cannot be increased and the heat resistance is poor; when the content of the trinuclear body exceeds 60 area%, there is a concern that the adhesion is poor . The content rate of the pentasome or more is 45 area% or less, more preferably 40 area% or less, and still more preferably 30 area% or less. If the content rate of the pentads or more is 45% by area or less, a hardened product with higher heat resistance can be obtained without lowering the adhesiveness. If the content of the pentad is too large, there is a concern that the content of the oxazolidinone ring cannot be increased, the effect of improving the dielectric properties cannot be exerted, or gelation occurs during production, and the target epoxy resin cannot be obtained (A1). In addition, the content of the tetranuclear body is not particularly limited, but the total content of the trinuclear body and the tetranuclear body is preferably 15 area% or more, 85% area or less, more preferably 30 area% or more, 70 The area% or less is more preferably 40 area% or more and 60 area% or less. By setting it as this range, the molecular weight increase at the time of isocyanate modification can be suppressed, and therefore the content ratio of oxazolidone ring can be improved. If the effect of the trinuclear body is compared with the tetranuclear body, the trinuclear body can further improve the adhesion, and the tetranuclear body can further improve the heat resistance. This can further improve resin properties such as dielectric properties, heat resistance, and adhesiveness of the flame-retardant epoxy resin composition containing epoxy resin (A1), which is a novolac-type epoxy resin Resin (d1).

Moreover, the number average molecular weight is 350 or more and 700 or less, more preferably 380 or more and 600 or less. When the number average molecular weight exceeds 700, there is a concern that the viscosity of the obtained epoxy resin (A1) becomes high, which adversely affects workability or substrate impregnation. On the other hand, if the number average molecular weight is less than 350, there is a concern that the heat resistance will deteriorate.

In order to obtain an epoxy resin (A1), an isocyanate compound (e) is used together with a novolac-type epoxy resin (d). The desired epoxy resin (A1) can be obtained by the reaction of the novolac-type epoxy resin (d) and the isocyanate compound (e). If the isocyanate compound (e) is an isocyanate compound having an average of 1.8 or more isocyanate groups (-N=C=O) in the molecule, that is, a polyfunctional isocyanate compound having substantially two or more functions, known and conventional ones can be used. Of isocyanate compounds. The monofunctional isocyanate compound may be contained in a small amount, but it becomes an end group, so it is effective for the purpose of reducing the degree of polymerization, but the degree of polymerization is not improved.

Specific examples include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 3,5-toluene diisocyanate, 2,2'-diphenylmethane diisocyanate, and 2,4'-diphenyl Methane diisocyanate, 4,4'-diphenylmethane diisocyanate, m-xylene diisocyanate, p-xylene diisocyanate, tetramethylxylene diisocyanate, 1,4-naphthalenediyl diisocyanate, 1,5- Naphthalene diyl diisocyanate, 2,6-naphthalene diyl diisocyanate, 2,7-naphthalene diyl diisocyanate, naphthalene-1,4-diyl bis(methylene) diisocyanate, naphthalene-1,5-di Bis(methylene) diisocyanate, isophthalic diisocyanate, p-phenylene diisocyanate, biphenyl-4,4'-diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, 2,3'-dimethoxybiphenyl-4,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, 3,3'-dimethoxydiphenylmethane-4,4 '-Diisocyanate, 4,4'-dimethoxydiphenylmethane-3,3'-diisocyanate, diphenylsulfite-4,4'-diisocyanate, diphenylsulfone-4,4 '-Diisocyanate, isophorone diisocyanate, 4,4'-methylene biscyclohexyl diisocyanate, lysine diisocyanate, 1,1-bis(isocyanatomethyl) cyclohexane, 1,2- Bis(isocyanatomethyl)cyclohexane, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, 4-methyl-1,3-cyclohexane diisocyanate, 2-methyl-1,3-cyclohexane diisocyanate, 1-methylbenzene-2,4-diisocyanate, 1-methylbenzene-2,5-diisocyanate, 1-methylbenzene-2,6-diisocyanate, 1-methylbenzene-3,5-diisocyanate, hexamethylene diisocyanate, 2,2, 4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, methane diisocyanate, ethane-1,2-diisocyanate, propane-1,3-diisocyanate , Butane-1,1-diisocyanate, butane-1,2-diisocyanate, butane-1,4-diisocyanate, 2-butene-1,4-diisocyanate, 2-methylbutene- 1,4-diisocyanate, 2-methylbutane-1,4-diisocyanate, pentane-1,5-diisocyanate, 2,2-dimethylpentane-1,5-diisocyanate, hexane -1,6-diisocyanate, heptane-1,7-diisocyanate, octane-1,8-diisocyanate, nonane-1,9-diisocyanate, decane-1,10-diisocyanate, dimethyl Silane diisocyanate, diphenylsilane diisocyanate and other bifunctional isocyanate compounds, or triphenylmethane triisocyanate, 1,3,6-hexamethylene triisocyanate, 1,8-diisocyanate-4- Isocyanatomethyloctane, dicycloheptene triisocyanate, tris(isocyanatophenyl) thiophosphorus Ester, lysine triisocyanate, undecane triisocyanate, tris(4-phenylisocyanate phosphorothioate)-3,3',4,4'-diphenylmethane tetraisocyanate, polymethylene Polyfunctional isocyanate compounds such as polyphenyl isocyanate, or multimers such as dimers or trimers of the isocyanate compounds, or blocked isocyanates that are blocked with a blocking agent such as alcohol or phenol , Or biscarbamate compounds, etc., but not limited to these compounds. These isocyanate compounds can be used alone or in combination of two or more.

Among these isocyanate compounds, a bifunctional isocyanate compound or a trifunctional isocyanate compound is preferred, and a bifunctional isocyanate compound is even more preferred. If the number of functional groups of the isocyanate compound is large, there is a possibility that the storage stability will be reduced; if the number of functional groups of the isocyanate compound is small, there is a concern that the heat resistance or adhesiveness in the case of forming a resin composition does not improve.

The reaction of the novolak-type epoxy resin (d) and the isocyanate compound (e) can be carried out by a known method. Specific reaction methods include: (1) Melting a novolac epoxy resin, flushing with dry gas, or depressurizing the system to remove moisture in the epoxy resin, and then adding an isocyanate compound and a catalyst to proceed The method of reaction; or (2) Premix the novolac epoxy resin with the catalyst, flush with dry gas or reduce the pressure in the system to remove the water in the epoxy resin, and then add the isocyanate compound to react Method etc. In either method, when the resin viscosity is high and it is difficult to stir, etc., a non-reactive solvent may be used as necessary.

The reaction mechanism for forming an oxazolidinone ring is represented by the following reaction formula (14). The epoxy resin of novolak type epoxy resin (d) and isocyanate compound (e) react with the isocyanate group of isocyanate compound (e) by adding a catalyst to form oxazolidine Ketone ring.

The use amount of the novolak epoxy resin (d) and the isocyanate compound (e) is 1 equivalent of the epoxy group of the novolak epoxy resin (d), and the isocyanate group of the isocyanate compound (e) is preferably The range of 0.01 equivalent or more and 0.5 equivalent or less is more preferably the range of 0.1 equivalent or more and 0.45 equivalent or less. Even more preferably, it is in the range of 0.15 equivalent or more and 0.4 equivalent or less, and particularly preferably in the range of 0.2 equivalent or more and 0.35 equivalent or less. Here, 1 equivalent of epoxy groups is equivalent to 1 equivalent of isocyanate groups, and 1 mole of earrings is the same as 1 mole of isocyanate groups. If the ratio of isocyanate groups is low, there is a concern that the amount of oxazolidone ring formation decreases, and the effect of improving the dielectric properties of the cured product or the heat resistance may not be obtained. Furthermore, if the ratio of isocyanate groups is large, not only the residual amount of epoxy groups decreases, but also thickening during the reaction is violent, making the reaction difficult. Moreover, even if it is obtained, the solubility of the solvent or the impregnability in the glass cloth deteriorates, and it becomes difficult to use it for laminated board applications.

The reaction of the novolac-type epoxy resin (d) and the isocyanate compound (e) is preferably carried out by adding a catalyst. The addition temperature of the catalyst is preferably in the range of room temperature to 150°C, and more preferably in the range of room temperature to 100°C.

The reaction temperature is preferably in the range of 100°C or more and 250°C or less, more preferably in the range of 100°C or more and 200°C or less, and even more preferably in the range of 120°C or more and 160°C or less. If the reaction temperature is low, the formation of the oxazolidinone ring cannot be sufficiently performed, and the isocyanurate ring is formed due to the trimerization reaction of the isocyanate group. Furthermore, if the reaction temperature is high, localized polymer quantification occurs, and the generation of insoluble gel components increases. Therefore, the rate of addition of the isocyanate compound can be adjusted to maintain the reaction temperature at an appropriate temperature. By appropriately controlling the reaction conditions, the oxazolidinone ring can be generated substantially quantitatively from the epoxy group of the novolac epoxy resin and the isocyanate group of the isocyanate compound.

The reaction time is preferably in the range of 15 minutes to 10 hours after the end of the addition of the isocyanate compound (e), more preferably 30 minutes to 8 hours, and still more preferably 1 hour to 5 hours.

Specific examples of the catalyst used in the reaction include lithium compounds such as lithium chloride and lithium butoxylate, miscellaneous salts of boron trifluoride, tetramethylammonium chloride, and tetramethylammonium bromide. Tetrabutylammonium bromide, tetramethylammonium iodide, tetraethylammonium iodide and other quaternary ammonium salts, dimethylaminoethanol, triethylamine, tributylamine, benzyldimethylamine, N- Tertiary amines such as methylmorpholine, phosphines such as triphenylphosphine, tris(2,6-dimethoxyphenyl)phosphine, pentyltriphenylphosphonium bromide, diallyldiphenyl bromide Phosphonium chloride, ethyltriphenylphosphonium chloride, ethyltriphenylphosphonium bromide, ethyltriphenylphosphonium iodide, tetrabutylphosphonium acetate acetate complex, tetrabutylphosphonium acetate, tetrabutyl Phosphonium salts such as phosphonium chloride, tetrabutylphosphonium bromide, tetrabutylphosphonium iodide, a combination of triphenylantimony and iodine, 2-phenylimidazole, 2-methylimidazole, 2-ethyl-4- Imidazoles such as methylimidazole are not limited to these catalysts, and these catalysts may be used alone or in combination of two or more. Moreover, it can be divided and used in fractions.

The amount of the catalyst is not particularly limited, and it may be used if it is 0.0001 mass% or more and 5 mass% or less relative to the total mass of the novolak epoxy resin (d) and the isocyanate compound (e), and is preferably 0.0005 The mass% or more and 1 mass% or less, more preferably 0.001 mass% or more and 0.5 mass% or less, still more preferably 0.002 mass% or more and 0.2 mass% or less. If the amount of the catalyst is large, the self-polymerization reaction of epoxy groups proceeds according to circumstances, so the resin viscosity becomes high. Furthermore, it promotes the self-polymerization of isocyanate and suppresses the formation of oxazolidinone rings. In addition, there is a concern that the resin may remain as impurities in the generated resin, and when used in various applications, particularly as a material for a laminate or a sealing material, the insulation properties or moisture resistance may be reduced.

In the reaction of the novolac-type epoxy resin (d) and the isocyanate compound (e), other various epoxy resins may be used in combination within a range that does not affect the effect of the present invention, if necessary. Epoxy resins that can be used in combination include the above-mentioned commercially available epoxy resins or the epoxy resins shown below.

Bisphenol A type epoxy resin [for example, Aipao Taotao YD-127, Aipao Taotao YD-128, Aipao Taotao YD-8125, Aipao Taotao YD-825GS (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd. ) Etc], bisphenol F type epoxy resin [such as Ai Tao Tao Tao YDF-170, Ai Tao Tao Tao YDF-1500, Ai Tao Tao Tao YDF-8170, Ai Tao Tao Tao YDF-870GS, Ai Tao Tao Tao YSLV -80XY, Aitao Taotao YSLV-70XY (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), etc.], biphenol epoxy resin [e.g. YX-4000 (manufactured by Mitsubishi Chemical Co., Ltd.), ZX-1251 (new day Tetsumitsu Chemical Co., Ltd.), etc.], hydroquinone type epoxy resin [such as Ai Tao Tao Tao YDC-1312, Ai Tao Tao Tao ZX-1027 (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), etc.], Bisphenol fluorene type epoxy resin [e.g. ZX-1201 (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), etc.], naphthalene type epoxy resin [e.g. ZX-1355 (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), Epicuron HP-4032D (manufactured by Dickson Co., Ltd.), etc.], bisphenol S-type epoxy resin [e.g. TX-0710 (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), and Epicuron EXA-1515 (Great Japan) Chemical Industry Co., Ltd.) etc.], diphenyl sulfide epoxy resin [e.g. YSLV-50TE, YSLV-120TE (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), etc.], diphenyl ether epoxy resin [e.g. YSLV-80DE (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), etc.], resorcinol type epoxy resin [e.g. Aipuo Taotao ZX-1684 (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), Denacol (DENACOL) EX-201 (manufactured by Nagase Chemical Co., Ltd.), etc., alkanediol type epoxy resin [Ai Tao Tao Tao PG-207, Ai Tao Tao Tao PG-207GS (Nippon Steel & Sumitomo Chemical Co., Ltd. Manufacturing), SR-16H, SR-16HL, SR-PG, SR-4PG, SR-SBA, SR-EGM, SR-8EGS (manufactured by Sakamoto Pharmaceutical Co., Ltd.), etc.], aliphatic cyclic epoxy resin [ Sun Tohto ST-3000, Aipao Taotao ZX-1658, Aipao Taotao ZX-1658GS, Aipao Taotao FX-318 (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), HBPA-DGE ( Maruzen Petrochemical Co., Ltd., etc.] and other polyglycidyl ether compounds, or diaminodiphenylmethane type epoxy resins [such as Ai Tao Tao Tao YH-434, Ai Tao Tao Tao YH-434GS (Nippon Steel Sumitomo Chemical Co., Ltd.), ELM434 (Sumitomo Chemical Co., Ltd.), Araldite MY720, Aralda MY721, Aralda MY9512, Ai Laoda MY9663 (manufactured by Huntsman Advanced Chemical Company), etc.], m-xylene diamine epoxy resin [such as TETRAD-X (manufactured by Mitsubishi Gas Chemical Co., Ltd.)], 1, 3-bisaminomethylcyclohexane type epoxy resin [such as Taitao Radao-C (made by Mitsubishi Gas Chemical Co., Ltd.), etc.], isocyanurate type epoxy resin [such as TEPIC )-P (manufactured by Nissan Chemical Industry Co., Ltd.), etc.], aniline-type epoxy resin [e.g. GAN, GOT (manufactured by Nippon Kayaku Co., Ltd.), etc.], hydantoin-type epoxy resin [e.g. Y238 (Heng SMI Advanced Materials Co., Ltd.], etc.], aminophenol-type epoxy resin [e.g. ELM120, ELM100 (made by Sumitomo Chemical Co., Ltd.), jER630 (made by Mitsubishi Chemical Co., Ltd.), Ai Laoda MY0510, Ai Laoda MY0600 , Ai Laoda MY0610 (manufactured by Huntsman Advanced Materials), etc.] and other polyglycidylamine compounds, or dimer acid epoxy resins [such as YD-171 (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), jER871 Mitsubishi Chemical Co., Ltd.), etc.], hexahydrophthalic acid type epoxy resin [for example, SR-HHPA (manufactured by Sakamoto Pharmaceutical Co., Ltd.), etc.] polyglycidyl ester compounds, or alicyclic epoxy compounds [E.g. Celloside 2021, Celloside 2021A, Celloside 2021P, Celloside 3000 (manufactured by Daicel Chemical Industry Co., Ltd.), DCPD-EP, MCPD-EP, TCPD-EP (Made by Maruzen Petrochemical Co., Ltd.) etc., but not limited to these compounds, these epoxy resins can be used alone or in combination of two or more.

Among these epoxy resins that can be used in combination, bisphenol A epoxy resin, bisphenol F epoxy resin, biphenol epoxy resin, hydroquinone epoxy resin, and bisphenol fluorene epoxy resin are preferred Resin, naphthalene type epoxy resin, bisphenol S type epoxy resin, diphenyl sulfide type epoxy resin, diphenyl ether type epoxy resin, resorcinol type epoxy resin and other bifunctional epoxy resins. By using a small amount of these bifunctional epoxy resins, the tendency of thickening during the reaction can be suppressed without hindering the effect of the present invention, so the amount of isocyanate compound (e) can be increased, and the dielectric of the cured product can be increased. The characteristics are further improved. The usable amount is preferably 50 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 10 parts by mass or less with respect to 100 parts by mass of the novolac epoxy resin (d).

In addition, when the reaction of the novolac epoxy resin (d) and the isocyanate compound (e) is performed, it can be adjusted by further using various epoxy resin modifiers within a range that does not affect the effect of the present invention. Molecular weight (epoxy equivalent), etc. The usable amount is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less with respect to 100 parts by mass of the novolac epoxy resin (d).

The epoxy resin modifiers that can be used specifically include bisphenol A, bisphenol F, bisphenol AD, tetrabutyl bisphenol A, bisphenol Z, bisphenol TMC, hydroquinone, and methyl parabenzene. Diphenol, dimethylhydroquinone, dibutylhydroquinone, resorcinol, methylresorcinol, biphenol, tetramethylbiphenol, dihydroxynaphthalene, dihydroxydiphenyl ether, Dihydroxystilbene, phenol novolak resin, cresol novolak resin, bisphenol A novolak resin, dicyclopentadiene phenol resin, phenol aralkyl resin, naphthol novolak resin, styrenated phenol novolak resin Variety of phenol compounds such as varnish resin, terpene phenol resin, heavy oil modified phenol resin, or polyphenol resin obtained by condensation reaction of various phenols with various aldehydes such as hydroxybenzaldehyde, crotonaldehyde, glyoxal, or Aniline, phenylenediamine, toluidine, xylidine, diethyltoluenediamine, diaminodiphenylmethane, diaminodiphenylethane, diaminodiphenylpropane, diaminodiphenyl Ketone, diaminodiphenylsulfide, diaminodiphenylsulfone, bis(aminophenyl)fluorene, diaminodiethyldimethyldiphenylmethane, diaminodiphenyl ether, Diaminobenzylaniline, diaminobiphenyl, dimethyldiaminobiphenyl, biphenyltetramine, diaminophenylanthracene, diaminophenoxybenzene, diaminophenoxybenzene Amine compounds such as ether, bisaminophenoxybiphenyl, bisaminophenoxyphenyl sulfone, bisaminophenoxyphenylpropane, diaminonaphthalene, etc., but not limited to these compounds, these epoxy The resin modifier can be used alone or in combination of two or more.

Furthermore, non-reactive solvents can also be used as necessary. Specific examples include various hydrocarbons such as hexane, heptane, octane, decane, dimethylbutane, pentene, cyclohexane, methylcyclohexane, benzene, toluene, xylene, ethylbenzene, etc. Diethyl ether, isopropyl ether, butyl ether, diisoamyl ether, methyl phenyl ether, ethyl phenyl ether, pentyl phenyl ether, ethyl benzyl ether, dioxane, methyl furan, tetrahydrofuran and other ethers, methyl Cellosolve, methyl cellosolve acetate, ethyl cellosolve, acetate cellosolve, ethylene glycol isopropyl ether, diethylene glycol dimethyl ether, methyl ethyl carbitol, propylene glycol monomethyl Ether, dimethylformamide, dimethylsulfoxide, etc., but not limited to these solvents, these non-reactive solvents may be used alone, or two or more kinds may be used in combination.

The flame-retardant epoxy resin composition of the present invention may contain an epoxy resin (A2) other than the epoxy resin (A1) containing an oxazolidinone ring as described above. As the epoxy resin (A2), a conventionally known epoxy resin can be used. These epoxy resins (A2) that can be used in combination can be used within a range that does not hinder the effects of the epoxy resin (A1). Even if it is a small amount, the effect of using the epoxy resin (A1) can be exerted, so the amount of the epoxy resin (A2) used in the epoxy resin (A) is preferably 0% by mass to 95% by mass, more preferably 10% by mass % To 90% by mass, further preferably 30% to 85% by mass.

As the epoxy resin (A), the epoxy resin (A2) that can be used in combination with the epoxy resin (A1) is preferably a multifunctional epoxy resin having two or more functions, and can be selected according to the purpose. For example, in order to impart flame retardancy, it is preferable to use a phosphorus-containing epoxy resin (CA) described later in combination, and to further improve heat resistance, it is preferable to use a trifunctional or more epoxy resin together.

The epoxy resin (A2) includes the phenol novolac epoxy resin, cresol novolac epoxy resin, alkyl novolac epoxy resin, styrenated phenol novolac epoxy resin, naphthol Novolac epoxy resin, β-naphthol aralkyl epoxy resin, dinaphthol aralkyl epoxy resin, α-naphthol aralkyl epoxy resin, biphenyl aralkyl phenol ring Novolac epoxy resin such as oxygen resin, or bisphenol A epoxy resin, bisphenol F epoxy resin, biphenol epoxy resin, hydroquinone epoxy resin, bisphenol fluorene epoxy resin , Naphthalene type epoxy resin, bisphenol S type epoxy resin, diphenyl sulfide type epoxy resin, diphenyl ether type epoxy resin, resorcinol type epoxy resin, alkanediol type epoxy resin , Polycyclic glycidyl ether compounds such as aliphatic cyclic epoxy resin, or diaminodiphenylmethane type epoxy resin, m-xylene diamine type epoxy resin, 1,3-bisaminomethylcyclohexane Epoxy resin, isocyanurate epoxy resin, aniline epoxy resin, hydantoin epoxy resin, aminophenol epoxy resin and other polyglycidylamine compounds, or dimer acid ring Oxygen resin, hexahydrophthalic acid type epoxy resin and other polyglycidyl ester compounds, or alicyclic epoxy compounds. In addition to this, trihydroxyphenylmethane type epoxy resins (for example, EPPN-501, EPPN-502 (manufactured by Nippon Kayaku Co., Ltd.)), and tetrahydroxyphenylethane type epoxy resins (for example, YDG- 414 (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), etc.), dicyclopentadiene-type epoxy resin (for example, Epicuron HP7200, Epicuron HP-7200H (manufactured by Di Aisheng Co., Ltd.), etc.), amine group Formate modified epoxy resin (for example, AER4152 (manufactured by Asahi Kasei Electronic Materials Co., Ltd.), etc.), epoxy resin (A1) containing oxazolidinone ring-containing epoxy resin, epoxy modified polybutadiene Rubber derivatives (such as PB-3600 (made by Daicel Chemical Industry Co., Ltd.), etc.), CTBN modified epoxy resins (such as YR-102, YR-450 (made by Nippon Steel & Sumitomo Chemical Co., Ltd.), etc.), The phosphorus-containing epoxy resin (CA) described later is not limited to these compounds, and these epoxy resins may be used alone or in combination of two or more.

Next, the hardener (B) contained in the flame-retardant epoxy resin composition of the present invention will be described. The curing agent is not particularly limited as long as it can cure the epoxy resin. Phenolic curing agents, anhydride curing agents, amine curing agents, hydrazine curing agents, active ester curing agents, and phosphorus-containing curing agents described below can be used. (CB) hardener for epoxy resin. Only one type of these hardeners may be used, or two or more types may be used in combination. Among these hardeners, dicyandiamide, phenol-based hardeners or active ester-based hardeners are preferred, and phenol-based hardeners or active ester-based hardeners are more preferred.

The usage amount of the hardener (B) is such that the active hydrogen group of the hardener (B) is in the range of 0.2 moles or more and 1.5 moles or less relative to 1 mole of epoxy groups of the epoxy resin (A). When the active hydrogen group is less than 0.2 moles or more than 1.5 moles relative to 1 mole of epoxy groups, there is a concern that the hardening becomes incomplete and good hardening physical properties cannot be obtained. The preferred range is 0.3 mol or more and 1.5 mol or less, the more preferable range is 0.5 mol or more and 1.5 mol or less, and the more preferable range is 0.8 mol or more and 1.2 mol or less. For example, when a phenol-based hardener, an amine-based hardener, or an active ester-based hardener is used, an active hydrogen group that is substantially equal to moles is blended with the epoxy group; when an anhydride-based hardener is used, the As for the oxygen 1 mole, an acid anhydride group of 0.5 mole to 1.2 mole, preferably 0.6 mole to 1.0 mole is blended. Here, the epoxy resin (A) includes an epoxy group-containing compound such as an epoxy resin (A1), an epoxy resin (A2), and a phosphorus-containing epoxy resin (CA). Moreover, the hardener (B) contains a phosphorus-containing hardener (CB).

In the present invention, the "active hydrogen group" is a functional group having active hydrogen reactive with an epoxy group (including a functional group having a potential active hydrogen that generates active hydrogen due to hydrolysis or the like, or exhibits an equivalent hardening effect Functional group), specifically, an acid anhydride group, a carboxyl group, an amine group, a phenolic hydroxyl group, or the like. In addition, regarding the active hydrogen group, 1 mol of carboxyl group (-COOH) or phenolic hydroxyl group (-OH) is calculated as 1 mol, and 1 mol of amine group (-NH ₂ ) is calculated as 2 mol. In addition, when the active hydrogen group is not clear, the active hydrogen equivalent can be determined by measurement. For example, a single epoxy resin having a known epoxy equivalent such as phenyl glycidyl ether can be reacted with a hardener whose active hydrogen equivalent is unknown, and the amount of single epoxy resin consumed can be measured to determine the hardener used. Equivalent of active hydrogen.

Specific examples of the phenolic hardener include bisphenol A, bisphenol F, bisphenol C, bisphenol K, bisphenol Z, bisphenol S, tetramethyl bisphenol A, tetramethyl bisphenol F, and tetramethyl Bisphenol S, tetramethyl bisphenol Z, dihydroxydiphenyl sulfide, 4,4'-thiobis (3-methyl-6-tertiary butylphenol) and other bisphenols, and can be listed Catechol, resorcinol, methylresorcinol, hydroquinone, monomethylhydroquinone, dimethylhydroquinone, trimethylhydroquinone, mono-tertiary butyl Dihydroxybenzenes such as hydroquinone, di-tertiary butyl hydroquinone, hydroxynaphthalenes such as dihydroxynaphthalene, dihydroxymethylnaphthalene, trihydroxynaphthalene, or phenol novolac resins (such as Shonolu ( Shonol) BRG-555 (manufactured by Showa Denko Co., Ltd.), etc.), cresol novolak resin (such as DC-5 (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), etc.), trihydroxyphenylmethane novolak resin ( For example, Resitop TPM-100 (manufactured by Qunrong Chemical Industry Co., Ltd.), naphthol novolak resin and other phenols and/or condensates of naphthols and aldehydes, or naphthol arane Condensation of base resins (SN-160, SN-395, SN-485 (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., etc.) and other phenols and/or naphthols with benzenedimethanol and/or dihalomethylbenzene Substances, or condensates of phenols and/or naphthols with isopropenylacetophenone, or reactants of phenols and/or naphthols with dicyclopentadiene, or phenols and/or naphthols Phenolic compounds such as condensates with biphenyl-based crosslinking agents; aminotriazine-modified phenol resins (polyphenol compounds with phenol nuclei linked by melamine, benzoguanamine, etc.) or these phenol compounds via alkyl, Phenolic compounds in which substituents such as alkoxy groups and aryl groups are substituted on the ring are not limited to these compounds.

As raw materials of these phenol compounds, phenols include phenol, cresol, xylenol, butylphenol, amylphenol, nonylphenol, butylmethylphenol, trimethylphenol, phenylphenol, etc. Naphthols may be Examples include 1-naphthol, 2-naphthol and the like. Examples of aldehydes include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, hexanal, benzaldehyde, chloroaldehyde, bromaldehyde, glyoxal, malondialdehyde, succinaldehyde, glutaraldehyde, adipic aldehyde, Pimelicaldehyde, sebacaldehyde, acrolein, crotonaldehyde, salicylaldehyde, o-phthalaldehyde, hydroxybenzaldehyde, etc. Examples of the biphenyl-based crosslinking agent include bis(hydroxymethyl)biphenyl, bis(methoxymethyl)biphenyl, bis(ethoxymethyl)biphenyl, and bis(chloromethyl)biphenyl.

Furthermore, a benzoxazine compound that becomes a phenol compound by ring opening upon heating can also be used as a hardener. Specifically, bisphenol F-type or bisphenol S-type benzoxazines (for example, BF-BXZ or BS-BXZ (manufactured by Xiaoxi Chemical Industry Co., Ltd.), etc.) may be mentioned.

The acid anhydride hardener specifically includes methyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, and pyromellitic acid diacid. Anhydrides, phthalic anhydride, trimellitic anhydride, methylnadic anhydride, maleic anhydride, etc. are not limited to these compounds.

Specific examples of the amine-based hardener include diethylenetriamine, triethylenetetramine, m-xylylenediamine, isophoronediamine, diaminodiphenylmethane, diaminodiphenylbenzene, Diaminodiphenyl ether, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, dicyandiamide, as a condensate of acids such as dimer acids and polyamines Amine compounds such as polyamidoamine are not limited to these compounds.

Examples of the active ester-based hardener include the reaction product of the polyfunctional phenol compound and aromatic carboxylic acids described in Japanese Patent No. 5152445, and the commercially available product is Epicuron HPC-8000-65T (manufactured by Dickson Co., Ltd.) Etc., but not limited to these compounds.

Other hardeners specifically include phosphine compounds such as triphenylphosphine, phosphonium salts such as tetraphenylphosphonium bromide, 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2 -Imidazoles such as undecylimidazole, 1-cyanoethyl-2-methylimidazole, and the like, imidazole salts of imidazoles with trimellitic acid, isocyanuric acid, boric acid, etc., trimethyl chloride Quaternary ammonium salts such as ammonium chloride, diazabicyclic compounds, salts of diazabicyclic compounds with phenols or phenol novolac resins, complex compounds of boron trifluoride with amines or ether compounds, Aromatic phosphonium, iodonium salts, etc., but not limited to these compounds, these epoxy resins may be used alone or in combination of two or more.

Next, the phosphorus compound (C) blended in the flame-retardant epoxy resin composition of the present invention will be described. The phosphorus compound (C) imparts a flame retardant effect to the flame-retardant epoxy resin composition. Phosphorus compounds (C) are divided into two types: additive-based phosphorus flame retardants and reactive phosphorus compounds. Reactive phosphorus compounds are further classified into phosphorus-containing epoxy resins (CA) and phosphorus-containing hardeners (CB). Regarding the flame retardant effect, when the additive-based phosphorus flame retardant is compared with the reactive phosphorus compound, the reactive phosphorus compound has a large flame retardant effect, so it is preferable to use a reactive phosphorus compound.

As the additive-based phosphorus flame retardant, any of inorganic phosphorus compounds and organic phosphorus compounds can be used. Examples of the inorganic phosphorus-based compound include ammonium phosphates such as red phosphorus, monoammonium phosphate, diammonium phosphate, triammonium phosphate, and ammonium polyphosphate, and inorganic nitrogen-containing phosphorus compounds such as phosphamide. Examples of the organic phosphorus-based compounds include general-purpose organic phosphorus-based compounds such as aliphatic phosphates, phosphate compounds, condensed phosphates, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, orthophosphine compounds, and organic nitrogen-containing phosphorus compounds. , Or a metal salt of phosphinic acid, other examples include 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(2,5-dihydroxyphenyl)- 10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(2,7-dihydroxynaphthyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide and other rings The organic phosphorus compound is not limited to these compounds.

Specific examples include methyl acid phosphate, ethyl phosphoric acid, isopropyl phosphoric acid, dibutyl phosphate, monobutyl phosphate, butoxyethyl phosphoric acid, 2-ethylhexyl phosphoric acid, Bis(2-ethylhexyl) phosphate, monoisodecyl phosphoric acid, lauryl phosphoric acid, tridecyl phosphoric acid, stearyl phosphoric acid, isostearyl phosphoric acid, oleyl phosphoric acid, butyl pyrophosphate, bis Phosphate esters such as tetraalkyl phosphoric acid, ethylene glycol phosphate, (2-hydroxyethyl) methacrylate phosphate, or 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- Phosphorus compounds such as oxides, diphenylphosphine oxide and other diphenylphosphines having an active hydrogen group directly bonded to a phosphorus atom, or 10-(2,5-dihydroxyphenyl)-10H-9-oxa -10-phosphaphenanthrene-10-oxide, 10-(1,4-dioxynaphthalene)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, diphenylphosphine oxide pair Hydroquinone, diphenylphosphinyl-1,4-dioxynaphthalene, 1,4-cyclooctylphosphinyl-1,4-phenyldiol, 1,5-cyclooctyloxy The phosphorus-containing phenols such as phosphino-1,4-phenyldiol are not limited to these exemplified compounds.

As the phosphorus compound used in the phosphorus-containing epoxy resin (CA) or the phosphorus-containing hardener (CB), the phosphorus compound or phosphorus-containing phenols having an active hydrogen group directly bonded to a phosphorus atom are preferred, From the viewpoint of availability, it is more preferably a compound having a structure represented by formula (8), for example, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(2 ,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(1,4-dioxynaphthalene)-10H-9-oxa-10-phosphorus Heterophenanthrene-10-oxide, etc.

The phosphorus-containing epoxy resin (CA) can be obtained by reacting a phosphorus-based compound having a unit structure represented by formula (8) with an epoxy resin. If it is specifically exemplified, it may include Ai Tao Tao Tao FX-305, Ai Tao Tao Tao FX-289B, Ai Tao Tao Tao TX-1320A, Ai Tao Tao Tao TX-1328 (Nippon Steel & Sumitomo Chemical Co., Ltd.) Etc., but not limited to these compounds.

As the phosphorus-containing hardener (CB), in addition to the phosphorus-containing phenols, the production method shown in Japanese Patent Publication No. 2008-501063 or Japanese Patent No. 4548547 can be used to obtain the formula (8) The phosphorus-based compound of the unit structure represented and aldehydes and phenol compounds react to obtain a phosphorus-containing phenol compound. Further, by using the production method shown in Japanese Patent Laid-Open No. 2013-185002, the reaction of aromatic carboxylic acids is further performed, thereby obtaining a phosphorus-containing active ester compound.

The epoxy equivalent of the phosphorus-containing epoxy resin (CA) may be 200 g/eq. to 800 g/eq., preferably 300 g/eq. to 780 g/eq., and more preferably 400 g/eq.~ 760 g/eq. Furthermore, the phosphorus content of the phosphorus-containing epoxy resin (CA) may be 0.5% by mass to 6% by mass, preferably 2% by mass to 5.5% by mass, and more preferably 3% by mass to 5% by mass. The phosphorus content of the phosphorus-containing hardener (CB) may be 0.5% by mass to 12% by mass, preferably 2% by mass to 11% by mass, and more preferably 4% by mass to 10% by mass.

The compounding amount of the phosphorus compound (C) can be appropriately selected according to the kind of the phosphorus compound (C), the components of the flame-retardant epoxy resin composition, and the degree of desired flame retardancy. The phosphorus content is preferably 0.2% by mass or more, 6% by mass or less, and more preferably 0.4% by mass relative to the total (A+B+C) of the epoxy resin (a), the hardener (B), and the phosphorus compound (C). Above, 4% by mass or less, further preferably 0.5% by mass or more and 3.5% by mass or less, still more preferably 0.6% by mass or more and 3% by mass or less. If the phosphorus content rate is small, there is a concern that it becomes difficult to ensure flame retardancy; if the phosphorus content rate is too high, there is a concern that the heat resistance may be adversely affected. Here, the phosphorus-containing epoxy resin (CA) may be regarded as a phosphorus compound (C) or an epoxy resin (A). Similarly, the phosphorus-containing hardener (CB) can be regarded as a phosphorus compound (C) or a compound equivalent to both of the hardener (B). Therefore, in the case of using a phosphorus-containing hardener (CB), it sometimes becomes unnecessary to use other hardeners or phosphorus compounds. Similarly, in the case of using a phosphorus-containing epoxy resin (CA), it sometimes becomes unnecessary to use other epoxy resins or phosphorus compounds.

In addition, in the flame-retardant epoxy resin composition, in order to improve the flame retardancy of the obtained cured product, various well-known flame-retardant additives may be used as necessary. Examples of flame retardants that can be used include nitrogen-based flame retardants, silicone-based flame retardants, inorganic-based flame retardants, and organic metal salt-based flame retardants. These flame retardants can be used alone or in combination of two or more.

In general, when a phosphate-based flame retardant or a phosphorus-based compound having the structure represented by formula (8) is used as the hardened product of the flame retardant, the dielectric properties after moisture absorption often deteriorate. However, in the case of the flame-retardant epoxy resin composition of the present invention, it is not necessary to increase the phosphorus in order to obtain flame retardancy, and therefore, the adverse effects caused by phosphorus atoms after moisture absorption are small.

The filler (F) may be used in the flame-retardant epoxy resin composition of the present invention as needed. Specific examples include fused silica, crystalline silica, alumina, silicon nitride, aluminum hydroxide, boehmite, magnesium hydroxide, talc, mica, calcium carbonate, calcium silicate, calcium hydroxide, and carbonic acid. Magnesium, barium carbonate, barium sulfate, boron nitride, carbon, carbon fiber, glass fiber, alumina fiber, aluminosilicate fiber, silicon carbide fiber, polyester fiber, cellulose fiber, aromatic polyamide fiber, ceramic fiber, Microparticle rubber, thermoplastic elastomer, pigment, etc. The reasons for using fillers in general include the effect of improving impact resistance. In addition, when metal hydroxides such as aluminum hydroxide, boehmite, and magnesium hydroxide are used, they have an effect of functioning as a flame retardant aid to improve flame retardancy. The blending amount of these fillers (F) is preferably 1% by mass to 150% by mass with respect to the entire flame-retardant epoxy resin composition, and more preferably 10% by mass to 70% by mass. If there are many compounding amounts, there exists a possibility that the adhesiveness required for laminated board use may fall, and a hardened material may become brittle, and a sufficient mechanical property may not be obtained. Furthermore, if the blending amount is small, there is a concern that there is no blending effect of the filler (F) such as improvement in impact resistance of the cured product.

The flame-retardant epoxy resin composition of the present invention may also contain a thermoplastic resin (G) as needed. In particular, it is effective when the flame-retardant epoxy resin composition is molded into a sheet shape or a film shape. Examples of the thermoplastic resin (G) include phenol resin, acrylic resin, petroleum resin, indene resin, benzofuran-indene resin, phenoxy resin, polyurethane resin, polyester resin, polyamide resin, poly Amidimide resin, polyimide amidimide resin, polyether amidimide resin, polyphenylene ether resin, modified polyphenylene ether resin, polyether alum resin, polyaluminum resin, polyether ether ketone resin, polyphenylene sulfide Ether resin, polyvinyl formaldehyde resin, etc., but not limited to these compounds. In terms of compatibility with epoxy resins, phenoxy resins are preferred, and in terms of low dielectric properties, polyphenylene ether resins or modified polyphenylene ether resins are preferred.

In the flame retardant epoxy resin composition of the present invention, a hardening accelerator, silane coupling agent, antioxidant, mold release agent, defoamer, emulsifier, thixotropy-imparting agent, lubricant, flame retardant Agent, pigment and other additives. These additives are preferably in the range of 0.01% by mass to 20% by mass relative to the flame-retardant epoxy resin composition. In addition, organic solvents, thinners, etc. can be blended.

Examples of the hardening accelerator include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-(dimethylaminomethyl)phenol, 1,8- Diaza-bicyclo[5.4.0] undecene-7 and other tertiary amines, triphenylphosphine, tricyclohexylphosphine, triphenylphosphine triphenylborane and other phosphines, tin octoate and other metal compounds. A hardening accelerator of 0.02 part by mass to 5 parts by mass may be used as needed with respect to 100 parts by mass of the epoxy resin component in the flame-retardant epoxy resin composition of the present invention. By using a hardening accelerator, the hardening temperature can be reduced and the hardening time can be shortened.

Organic solvents or reactive diluents can also be used for viscosity adjustment. The organic solvent is not particularly limited, and examples include amides such as N,N-dimethylformamide, ethers such as ethylene glycol monomethyl ether, ketones such as acetone and methyl ethyl ketone, methanol, ethanol, and benzyl. Alcohols such as alcohol, diethylene glycol butyl ether and pine oil; aromatic hydrocarbons such as benzene and toluene. Furthermore, the reactive diluent includes monofunctional glycidyl ethers such as allyl glycidyl ether, 2-ethylhexyl glycidyl ether, and phenyl glycidyl ether, resorcinol glycidyl ether, and neopentyl glycol glycidyl ether. Difunctional glycidyl ethers such as glyceryl ether, 1,6-hexanediol diglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, pentaerythritol polyglycidyl ether and other multifunctional glycidyl ethers . These solvents or reactive diluents can be blended with a single compound or a mixture of multiple types of 90% by mass or less.

When the flame-retardant epoxy resin composition is made into a plate-shaped substrate or the like, from the aspects of dimensional stability, bending strength, etc., a fibrous material can be cited as a suitable filler. More preferably, a glass fiber substrate in which glass fibers are knitted into a net shape is mentioned.

The prepreg used in printed wiring boards and the like can be made by impregnating a flame-retardant epoxy resin composition into a fibrous base material. For the fibrous base material, inorganic fibers such as glass, or polyester resins, polyamine resins, polyacrylic resins, polyimide resins, aromatic polyamide resins, or other organic fibers such as woven fabrics or nonwoven fabrics can be used. It is not limited to this. The method for manufacturing the prepreg from the flame-retardant epoxy resin composition is not particularly limited, for example, after being impregnated in a resin varnish prepared by adjusting the viscosity of the flame-retardant epoxy resin composition with a solvent, It is obtained by heat-drying to semi-harden the resin component (stage B), and it can be heat-dried at 100° C. to 200° C. for 1 to 40 minutes, for example. Here, the amount of the resin in the prepreg is preferably 30% to 80% by mass of the resin component.

In addition, when hardening the prepreg, a method of hardening a laminated board that is generally used when manufacturing a printed wiring board can be used, but it is not limited thereto. For example, in the case of using a prepreg to form a laminated plate, one or more prepregs are laminated, a metal foil is disposed on one side or both sides to form a laminate, and the laminate is heated and pressurized to perform Stacked integration. Here, as the metal foil, individual, alloy, or composite metal foils such as copper, aluminum, brass, and nickel can be used. Next, the laminate can be obtained by hardening the prepreg by heating the produced laminate. In this case, it is preferable to set the heating temperature to 160°C to 220°C, the pressurizing pressure to 50 N/cm ² to 500 N/cm ² , and the heat and pressurizing time to 40 minutes to 240 minutes. Obtain the target hardened object. If the heating temperature is low, there is a concern that the curing reaction does not sufficiently proceed; if the heating temperature is high, there is a concern that the flame-retardant epoxy resin composition starts to decompose. Moreover, if the pressurization pressure is low, bubbles may remain inside the resulting laminate, and electrical characteristics may be reduced; if the pressurization pressure is high, there is a concern that the resin flows before curing and the desired thickness cannot be obtained Hardened. In addition, if the heating and pressurizing time is short, there is a concern that the curing reaction may not proceed sufficiently; if the heating and pressurizing time is long, there is a concern that the flame-retardant epoxy resin composition in the prepreg may thermally decompose, and Not good.

A hardened epoxy resin can be obtained by hardening a flame-retardant epoxy resin composition by the same method as a well-known epoxy resin composition. The method for obtaining the hardened material can be the same as that of the known epoxy resin composition, and casting, injection, pouring, dipping, drip coating, transfer molding, compression molding, etc. or resin sheets and tapes can be suitably used. Methods such as resin-coated copper foil, prepreg, and the like are laminated and heated and pressure-cured to produce a laminated board. The curing temperature at this time is usually in the range of 100°C to 300°C, and the curing time is usually about 1 hour to 5 hours.

The cured epoxy resin of the present invention can take the form of a laminate, a molded product, an adhesive, a coating film, a film, and the like.

The flame-retardant epoxy resin composition of the present invention can be formed into a sheet or film and used. In this case, sheeting or filming can be performed using conventionally known methods. Examples of suitable forming methods include the following: dissolving the flame-retardant epoxy resin composition in a solvent, using existing A known method is to apply the obtained resin solution to a substrate such as a metal foil, polyester film, polyimide film, etc. whose surface has been subjected to peeling treatment, and then to dry it and peel it off from the substrate, thereby making insulation Sheet, insulating film, adhesive sheet or adhesive film.

The method of manufacturing the adhesive sheet is not particularly limited. For example, the epoxy resin composition of the present invention is applied to a carrier film that is not dissolved in an epoxy resin composition, such as a polyester film or a polyimide film. After coating to a thickness of preferably 5 μm to 100 μm, it is heated and dried at 100° C. to 200° C. for 1 to 40 minutes to form a sheet. The resin sheet is generally formed by a method called "casting method". At this time, if the epoxy resin composition-coated sheet is surface-treated with a release agent in advance, the formed adhesive sheet can be easily peeled off. Here, it is desirable that the thickness of the adhesive sheet is 5 μm to 80 μm. The adhesive sheet obtained as described above is generally an insulating adhesive sheet having insulation properties, but the conductive adhesive sheet can be obtained by mixing conductive metal or metal-coated fine particles in an epoxy resin composition.

Next, a method of manufacturing a laminated board using the prepreg or insulating adhesive sheet of the present invention will be described. In the case of using a prepreg to form a laminated plate, one or more prepregs are laminated, metal foils are arranged on one side or both sides to form a laminate, and the laminate is heated and pressurized to laminate together Change. Here, as the metal foil, individual, alloy, or composite metal foils of copper, aluminum, brass, nickel, and the like can be used. As the conditions for heating and pressurizing the laminate, if the epoxy resin composition is hardened, the heat and pressure may be appropriately adjusted, and if the amount of pressure is too low, it may be present in the obtained laminate. If air bubbles remain inside and the electrical characteristics are degraded, it is desirable to apply pressure under conditions satisfying moldability. For example, the temperature can be set to 160℃～220℃, the pressure can be set to 49.0 N/cm ² ～490.3 N/cm ² (5 kgf/cm ² ～50 kgf/cm ² ), and the heating time can be set to 40 minutes～ 240 minutes. In addition, a single-layer laminated board obtained as described above can be used as an inner layer material to form a multilayer board. In this case, first, circuit formation is performed on the laminated board by an addition method or a subtraction method, and the surface of the formed circuit is treated with an acid solution to perform blackening treatment to obtain an inner layer material. A prepreg or an insulating adhesive sheet is used to form an insulating layer on one or both sides of the inner layer material, and a conductor layer is formed on the surface of the insulating layer to form a multilayer board.

When an insulating adhesive sheet is used to form an insulating layer, the insulating adhesive sheet is arranged on the circuit forming surface of a plurality of inner layer materials to form a laminate. Alternatively, an insulating adhesive sheet is arranged between the circuit forming surface of the inner layer material and the metal foil to form a laminate. Next, the laminate is heated and pressed to be integrally formed, thereby forming a cured product of the insulating adhesive sheet as an insulating layer, and forming a multilayer of the inner layer material. Alternatively, the inner layer material and the metal foil as the conductor layer are formed as a hardened product of the insulating adhesive sheet as the insulating layer. Here, as the metal foil, the same metal foil as that used in the laminate used as the inner layer material can be used. Furthermore, the heat and pressure molding can be performed under the same conditions as the molding of the inner layer material. When an epoxy resin composition is coated on a laminated board to form an insulating layer, the epoxy resin composition is applied as the outermost layer of the circuit-forming surface resin of the inner layer material so as to be preferably 5 μm to 100 μm. The thickness is then heated and dried at 100°C to 200°C for 1 minute to 90 minutes to form a sheet. It is generally formed by a method called "casting method". Ideally, the thickness after drying should be 5 μm to 80 μm. On the surface of the multilayer laminated board formed as described above, the formation of via holes or the formation of circuits is further performed by an addition method or a subtraction method, and a printed wiring board can be formed. Furthermore, by repeating the above-described method by using the printed wiring board as an inner layer material repeatedly, a multilayer laminate can be further formed.

Furthermore, in the case of forming an insulating layer using a prepreg, if one prepreg is arranged on the circuit forming surface of the inner layer material or a plurality of prepregs are laminated, a metal foil is further arranged on the outside to form a laminate . Next, the laminate is heated and pressed to be integrally formed, thereby forming a cured product of the prepreg as an insulating layer, and forming a metal foil on the outside thereof as a conductor layer. Here, as the metal foil, the same metal foil used in the laminate used as the inner layer plate may be used. Furthermore, the heat and pressure molding can be performed under the same conditions as the molding of the inner layer material. The printed wiring board may be formed on the surface of the multilayer laminated board formed as described above by further adding or subtracting the formation of via holes or the formation of circuits. Furthermore, the printed wiring board is further used as an inner layer material, and the above-mentioned construction method is repeated, whereby a multilayer multilayer board can be further formed.

Sealing materials obtained using flame-retardant epoxy resin compositions include tape-like sealing materials for semiconductor wafers, pouring liquid sealants, underfill resins, and materials for semiconductor interlayer insulating films, which can be suitably used among these materials To use.

In order to adjust the flame-retardant epoxy resin composition to a semiconductor sealing material, the flame-retardant epoxy resin composition may be preliminarily mixed with additives such as other coupling agents, mold release agents, or inorganic fillers, etc., if necessary. Then, use an extruder, kneader, roller, etc. to mix thoroughly until it becomes uniform. When it is used as a tape-like sealant, the resin composition obtained by the above method is heated to produce a semi-hardened sheet, after the sealant tape is prepared, the sealant tape is placed on a semiconductor wafer , Heating to 100 ℃ ~ 150 ℃ to soften and form, and 170 ℃ ~ 250 ℃ completely hardened method. In addition, when used as an infusion type liquid sealant, the resin composition obtained by the above method may be dissolved in a solvent as needed, and then coated on a semiconductor wafer or an electronic component, and it may be cured directly. .

A flame-retardant epoxy resin composition was prepared, and the epoxy resin cured product of the laminate was evaluated by heating and curing. As a result, the epoxy resin was obtained from a novolac epoxy resin (d) and an isocyanate compound (e). (A1) Compared with epoxy resins containing oxazolidinone rings other than epoxy resins (A1), not only is the viscosity low, the workability is good, but also it has both high heat resistance and high adhesion. In addition, low dielectric properties have also been improved. [Example]

The present invention will be specifically described by giving examples and comparative examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" means mass parts, and "%" means mass %. Furthermore, the measurement method can be measured according to the following methods.

Epoxy equivalent: according to JIS K7236 specifications.

Softening point: Measured in accordance with JIS K7234 standard and ring and ball method. Specifically, an automatic softening point device (manufactured by Mindak Co., Ltd., ASP-MG4) is used.

Oxazolidone ring content (Ox, eq./kg): In the oxazolidone ring formation reaction of this example, the epoxy group is not substantially used except for the reaction to form an oxazolidone ring, so it can be It is calculated according to the following formula. Ox=((Wt0/Ep0)-(Wt/Ep))/Wt×1000 Here, Ep0 is the epoxy equivalent (g/eq.) of the raw material epoxy resin used, and Ep is an oxazolidone ring The epoxy equivalent of the epoxy resin (g/eq.). Wt0 is the mass (g) of the raw material epoxy resin used, and Wt is the mass (g) of the epoxy resin containing an oxazolidinone ring.

Dinuclear content, trinuclear content, tetranuclear content, pentanuclear content or higher, number average molecular weight (Mn), mass average molecular weight (Mw), and dispersion (Mw/Mn): use The molecular weight distribution is measured by GPC, and the dinuclear content rate, trinuclear content rate, tetranuclear content rate, pentanuclear content rate or more are calculated based on the area% of the peak. The number average molecular weight, weight average molecular weight, and degree of dispersion are According to the use standard, monodisperse polystyrene (A-500, A-1000, A-2500, A-5000, F-1, F-2, F-4, F-10, F manufactured by Tosoh Corporation) -20, F-40, F-80, F-128) and the calibration curve obtained by conversion. Specifically, an apparatus including a series column (TSKgelG4000HXL, TSKgelG3000HXL, TSKgelG2000HXL manufactured by Tosoh Corporation) in the main body (manufactured by Tosoh Corporation, HLC-8220GPC) was used, and the column temperature was set to 40°C. Furthermore, THF was used in the dissolution solution, and the flow rate was set to 1 mL/min, and the detector used an RI (differential refractometer) detector. The data processing is using GPC-8020 model II version 4.10 manufactured by Tosoh Corporation. The measurement sample is obtained by dissolving 100 μL of 0.1 g sample in 10 mL of THF and filtering with a microfilter.

Phosphorus content rate: Add sulfuric acid, hydrochloric acid, perchloric acid to the sample, heat it and perform wet incineration, so that all phosphorus atoms become orthophosphoric acid. The metavanadate and molybdate are reacted in a sulfuric acid solution to measure the absorbance of 420 nm of the resulting phosphovanadium molybdate complex, and the weight percentage is used to indicate the phosphorus atom calculated from the calibration curve prepared in advance. content. The phosphorus content rate of the laminated plate is expressed as the content relative to the resin component of the laminated plate. Here, the "resin component of the laminate" refers to a component corresponding to the epoxy resin (A), the curing agent (B), and the phosphorus compound (C) among the components formulated in the composition.

Copper foil peel strength and interlayer adhesion: Measured in accordance with JIS C6481. The interlayer adhesion is measured by peeling between the fifth layer and the sixth layer.

Glass transition temperature (Tg): measured according to IPC-TM-650 2.4.25.c using a differential scanning calorimeter (manufactured by Hitachi High-Technologies Co., Ltd., EXSTA16000 DSC6200) at a temperature rise of 20°C/min DSC·Tgm (the middle temperature of the variation curve with respect to the tangent of the glass state and the rubber state) at the time.

Relative permittivity and dielectric loss tangent: according to IPC-TM-650 2.5.5.9, using a material analyzer (manufactured by AGILENT Technologies), the relative permittivity and The electric loss tangent was evaluated accordingly.

Flame retardancy: Based on UL94, the vertical method was used for evaluation.

Synthesis Example 1 Synthesis Example 1a In a glass separable flask equipped with a stirring device, a thermometer, a nitrogen introduction device, a condenser, and a dropping device, 2500 parts of phenol and 7.5 parts of oxalic acid dihydrate were charged, while injecting nitrogen Stir, heat and raise the temperature. Next, 474.1 parts of 37.4% formalin was added dropwise while stirring at 80°C for 30 minutes to make it react. The reaction temperature was further maintained at 92°C to carry out the reaction for 3 hours. The temperature was raised to 110°C while removing the reaction water from the system. The remaining phenol was recovered under reduced pressure at 160°C, and the temperature was further increased to 250°C to recover a part of the dinuclear body to obtain a phenol novolak resin (1a) that reduced the dinuclear body. The dinuclear content and trinuclear content of the obtained phenol novolak resin were 10 area% and 38 area%, respectively.

Synthesis Example 1b Next, 666 parts of the obtained phenol novolak resin (1a) and 2110 parts of epichlorohydrin were placed in a glass separable flask equipped with a stirring device, thermometer, nitrogen introduction device, condenser, and dropping device , 17 parts of ion-exchanged water, while stirring to raise the temperature to 50 ℃. After uniformly dissolving, 14.2 parts of 49% sodium hydroxide aqueous solution was charged and reacted for 3 hours. Next, after the temperature was raised to 64°C, the pressure was reduced to the extent that water refluxed. 457.7 parts of 49% sodium hydroxide aqueous solution was added dropwise over 3 hours. During the dropwise addition, the water and reflux distilled off were separated by a separation tank Epichlorohydrin, which returns epichlorohydrin to the reaction vessel, removes water out of the system, and reacts. After the reaction was completed, the temperature was raised to 70°C to perform dehydration, and the temperature was set to 135°C to recover the remaining epichlorohydrin. After returning to normal pressure, 1232 parts of methyl isobutyl ketone (MIBK) was added and dissolved. 1200 parts of ion-exchanged water was added, and the mixture was allowed to stand and allowed to dissolve by-product salt in water to remove it. Next, 37.4 parts of 49% sodium hydroxide aqueous solution was charged, and the reaction was stirred at 80°C for 90 minutes to carry out a purification reaction. MIBK was added and washed several times to remove ionic impurities. The solvent is recovered to obtain a phenol novolac epoxy resin (1b). The obtained phenol novolac-type epoxy resin had a dinuclear content rate of 10 area%, a trinuclear content rate of 35 area%, and a total of the trinuclear and tetranuclear content rate of 52 area%, five-core The content ratio above the body is 38 area%, the number average molecular weight is 635, the weight average molecular weight is 884, the degree of dispersion is 1.39, and the epoxy equivalent is 174 g/eq. The GPC measurement chart is shown in FIG. 1. In the figure, the peak represented by A represents a dinuclear body, the peak represented by B represents a trinuclear body, and the peak group represented by C represents more than a five-nuclear body. The horizontal axis represents the dissociation time, the left vertical axis represents the signal intensity, and the right vertical axis represents the number average molecular weight M in common logarithm (log). The measurement value of the number average molecular weight of the standard substance used is plotted with black dots to prepare a calibration curve.

Synthesis Example 1c Next, 100 parts of the novolac-type epoxy resin (d) obtained as described above was placed in a glass separable flask equipped with a stirring device, thermometer, nitrogen introduction device, condenser, and dropping device. Phenol novolak-type epoxy resin (1b), 0.17 parts of tetramethylammonium iodide (produced by Tokyo Chemical Industry Co., Ltd., reagent) as a catalyst, heated up while putting in nitrogen, and maintaining the temperature at 120°C for 30 Remove water from the system in minutes. Next, while maintaining the temperature of 130°C to 140°C, diphenylmethane diisocyanate (Misoi Chemical Co., Ltd., Cosmonate PH, NCO concentration is 34%) 14.4 parts (isocyanate group e/epoxy d equivalent ratio (e/d)=0.20) of 50% toluene solution. After the dropwise addition was completed, the stirring was continued for 60 minutes while maintaining the same temperature. After the reaction was completed, the solvent was removed under a recovery condition of 150° C., 1.33 kPa, and 30 minutes to obtain a novolak epoxy resin (Resin 1) containing an oxazolidinone ring. The number average molecular weight (Mn) of the obtained resin 1 was 1139, the weight average molecular weight (Mw) was 5846, and the degree of dispersion (Mw/Mn) was 5.13. FIG. 3 shows a GPC chart, and FIG. 4 shows an IR chart. Further, IR is the use of a Fourier transform infrared spectrophotometer PerkinElmer precision instrument (PerkinElmer Precisely) producing, Spectrum One FT-IR Spectrometer 1760X ) Determination of total reflection (ATR method) is measured wave number 650 cm ^{- 1} ~ 4000 cm ^-1 absorbance.

Synthesis Example 2 Diphenylmethane diisocyanate was changed to polymethylene polyphenyl polyisocyanate (Mitsui Chemical Co., Ltd., Cosmo Knight M-50, NCO concentration 34%) 7.5 parts (equivalent ratio ( e/d) = 0.10), except that synthesis was carried out by the same equipment and procedure as in Synthesis Example 1c to obtain a novolak epoxy resin (Resin 2) containing an oxazolidinone ring.

Synthesis Example 3 Tetramethylammonium iodide was changed to 0.12 parts of n-butyltriphenylphosphonium bromide (manufactured by Nippon Chemical Industry Co., Ltd., HISHICOLIN BTPPBr), and diphenylmethane diisocyanate Becomes a mixture of 2,4-toluene diisocyanate (80%) and 2,6-toluene diisocyanate (20%) (Mitsui Chemical Co., Ltd., Cosmo Knight T-80, NCO concentration 48%) 22.5 parts (equivalent ratio (e/d) = 0.45), except that the dropping time of the isocyanate compound was changed from 3 hours to 6 hours, except that synthesis was carried out using the same equipment and procedure as in Synthesis Example 1c to obtain oxazolidine-containing Novolac epoxy resin (resin 3) with ketone ring.

Synthesis Example 4 Conversion of diphenylmethane diisocyanate to cyclohexane-1,3-diylbismethylene diisocyanate (Mitsui Chemical Co., Ltd., Takenate 600, NCO concentration 43% ) 11.3 parts (equivalent ratio (e/d)=0.20), except that synthesis was carried out using the same equipment and procedure as in Synthesis Example 1c to obtain a novolak epoxy resin (Resin 4) containing an oxazolidinone ring.

Synthesis Example 5 The phenol novolak-type epoxy resin was 90 parts of the phenol novolak-type epoxy resin (1b) and 10 parts of bisphenol F-type liquid epoxy resin (Nippon Steel & Sumitomo Chemical Co., Ltd.) Manufacturing, Aipao Taotao YDF-1500, epoxy equivalent of 168 g/eq., viscosity of 2500 mPa·s), set diphenylmethane diisocyanate to 21.7 parts (equivalent ratio (e/d) = 0.30) , The isocyanate compound dropping time was changed from 3 hours to 6 hours, except that the synthesis was performed using the same equipment and procedure as in Synthesis Example 1c to obtain a novolak epoxy resin (Resin 5) containing an oxazolidinone ring .

Synthesis Example 6 Phenol novolak epoxy resin (1b) with 90 parts of phenol novolak epoxy resin and 10 parts of bisphenol A liquid epoxy resin (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., Ai Taotao Tao YD-8125, epoxy equivalent of 174 g/eq., viscosity of 4100 mPa·s), set diphenylmethane diisocyanate to 21.6 parts (equivalent ratio of isocyanate group e/epoxy group d ( e/d) = 0.30), except that the dropping time of the isocyanate compound was changed from 3 hours to 6 hours, except that synthesis was carried out using the same equipment and procedure as in Synthesis Example 1c to obtain a novolak type containing an oxazolidinone ring Epoxy resin (Resin 6).

Synthesis Example 7 Commercially available phenol novolak-type epoxy resin was changed to 100 parts of phenol novolak-type epoxy resin (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., Ai Tao Tao Tao YDPN-638, dinuclear body content rate 22 area%, trinuclear content rate is 15 area%, the total content of trinuclear body and tetranuclear body is 25 area%, the content rate of pentuclear body or more is 53 area%, the number average molecular weight is 528, The weight average molecular weight is 1127, the degree of dispersion is 2.13, the epoxy equivalent is 176 g/eq., and the GPC measurement chart is shown in FIG. 2. A, B, and C are the same as in FIG. 1), and tetramethyl iodide Ammonium was changed to 0.11 parts of n-butyltriphenylphosphonium bromide, and diphenylmethane diisocyanate was changed to 9.2 parts (equivalent ratio (e/d) = 0.13), except that the same equipment as in Synthesis Example 1c was used Synthesis in order and to obtain a novolak epoxy resin (resin 7) containing an oxazolidinone ring.

Synthesis Example 8 An o-cresol novolak type epoxy resin was converted into 100 parts of o-cresol novolak type epoxy resin (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., Ai Tao Tao Tao YDCN-700-7, epoxy equivalent 204 g/eq., the content of dinuclear bodies is 5.9 area%, the content of trinuclear bodies is 6.8 area%, the total content of trinuclear bodies and tetranuclear bodies is 15.3 area%, and the content rate of pentanuclear bodies or more 72.0 area%), changing tetramethylammonium iodide to 0.1 parts of n-butyltriphenylphosphonium bromide and diphenylmethane diisocyanate to 4.3 parts (equivalent of isocyanate group e/epoxy d Ratio (e/d) = 0.07), except that synthesis was carried out using the same equipment and procedure as in Synthesis Example 1c to obtain a novolak epoxy resin (Resin 8) containing an oxazolidinone ring.

Synthesis Example 9 An α-naphthol aralkyl type epoxy resin (made by Nippon Steel & Sumitomo Chemical Co., Ltd., Aipao Taotao ESN-475V, epoxy equivalent 330 g/eq., softening point is 80℃, dinuclear content is 48.2 area%, trinuclear content is 24.8 area%, the total content of trinuclear and tetranuclear is 13.7 area%, five The content rate above the core is 13.3 area%), and diphenylmethane diisocyanate is changed to 3 parts of cyclohexane-1,3-diylbismethylene diisocyanate (equivalent ratio (e/d) = 0.10 ), except that synthesis was carried out using the same equipment and procedure as in Synthesis Example 1c to obtain a novolak epoxy resin (Resin 9) containing an oxazolidinone ring.

Comparative Synthesis Example 1 The phenol novolac epoxy resin was changed to 100 parts of bisphenol A liquid epoxy resin, and the diphenylmethane diisocyanate was changed to 2,4-toluene diisocyanate (80%) and 2, 20.1 parts of a mixture of 6-toluene diisocyanate (20%) (equivalent ratio (e/d) = 0.40), except that the dropping time of the isocyanate compound was changed from 3 hours to 6 hours, except that the same as in Synthesis Example 1c was used The apparatus and the sequence were synthesized to obtain an oxazolidone ring-containing epoxy resin (Comparative Resin 1).

Comparative Synthesis Example 2 The phenol novolac epoxy resin was changed to 100 parts of bisphenol A liquid epoxy resin, and the diphenylmethane diisocyanate was changed to 14.4 parts (equivalent ratio (e/d) = 0.20), Other than that, synthesis was carried out using the same equipment and procedure as in Synthesis Example 1c, and an epoxy resin containing oxazolidinone ring (Comparative Resin 2) was obtained.

Table 1 shows the epoxy equivalent, softening point, oxazolidone ring content of the obtained resin, and the molar ratio of the glycidyl group (Z1) to the oxazolidone ring-containing group (Z2) [Z2 /Z1].

[Table 1]

The abbreviations used in the examples and comparative examples are described below.

[Epoxy resin (A)] Epoxy resin (A1): Resin 1 to Resin 9 obtained in Synthesis Example 1 to Synthesis Example 9

Epoxy resin (A2): Comparative resin 1 to comparative resin 2 obtained in Comparative Synthesis Example 1 to Comparative Synthesis Example 2 and the following epoxy resin a to epoxy resin d Epoxy resin a: dicyclopentadiene/ Phenol copolycondensation epoxy resin (manufactured by Guodu Chemical Co., Ltd., KDCP-130, epoxy equivalent of 254 g/eq.) Epoxy resin b: Aromatic modified novolac epoxy resin (Nippon Steel & Sumitomo Chemical Co., Ltd., Ai Tao Tao Tao YDAN-1000-9C, epoxy equivalent of 276 g/eq.) Epoxy resin c: cresol novolac epoxy resin (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., Ai Taotao Tao YDCN-700-7, epoxy equivalent of 204 g/eq.) Epoxy resin d: 4-functional epoxy resin (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., Aitao Taotao YDG-414, ring Oxygen equivalent is 187 g/eq.)

[Hardener (B)] Hardener a: Phenol novolak resin (manufactured by Showa Denko Co., Ltd., Shonolu BRG-557, softening point 80°C, phenolic hydroxyl equivalent 105 g/eq.) Hardener b : Aromatic modified novolak resin (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., GK-5855P, phenolic hydroxyl equivalent 230 g/eq.) Hardener c: dicyclopentadiene/phenol copolycondensation resin (group Rong Chemical Co., Ltd., GDP9140, phenolic hydroxyl equivalent: 196 g/eq.) Hardener d: dicyandiamide (manufactured by Nippon Calcium Co., Ltd., DIHARD), active hydrogen equivalent: 21 g/ eq.) Hardener e: PPO phenol terminal resin (made by Sabic, SA90, phenolic hydroxyl equivalent of 803 g/eq.) Hardener f: benzoxazine resin (Shikoku Chemical Industry Co., Ltd. limited Manufactured by the company, Fa-type benzoxazine resin) Hardener g: Active ester resin (manufactured by Dickson Co., Ltd., Epicuron HPC-8000-65T, active ester equivalent of 223 g/eq.) Hardener h: Benzene Ethylene/maleic acid co-polycondensation resin (manufactured by Cray Valley, SMA2000, anhydride equivalent 316 g/eq.)

[Phosphorus compound (C)] Phosphorus compound a: Phosphorus-containing epoxy resin (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., Ai Tao Tao Tao TX-1320A, epoxy equivalent 763 g/eq., phosphorus content rate 5.0) %) Phosphorus compound b: Phosphorus-containing epoxy resin (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., Ai Tao Tao Tao TX-1328, epoxy equivalent of 307 g/eq., phosphorus content rate is 3.4%) Phosphorus compound c : Phosphorus-containing phenoxy resin (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., Phenotohto ERF-001M30, phosphorus content rate 4.2%, weight average molecular weight = 40000) Phosphorus compound d: phosphorus-containing epoxy Resin-based flame retardant (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., Alto Taotao FX-289FA, phosphorus content rate of 7.0%) Phosphorus compound e: phosphorus-containing phenol hardener (manufactured by Shin-AT&C Corporation, LC-950PM60 , Phosphorus content rate 9.2%) Phosphorus compound f: Phosphorus-containing phenol hardener (manufactured by Di Aisheng Co., Ltd., Epicuron EXB9000, phenolic hydroxyl equivalent 207 g/eq., phosphorus content rate 5.0%) Phosphorus compound g: Aromatic condensed phosphate ester (manufactured by Daba Chemical Industry Co., Ltd., PX-200, phosphorus content rate is 9.0%) Phosphorus compound h: Organic phosphorus flame retardant (manufactured by Clariant Co., Ltd. Exolit OP935, phosphorus content rate is 23%) Phosphorus compound i: phosphazene flame retardant (manufactured by Otsuka Chemical Co., Ltd., SPE-100, phosphorus content rate is 13%)

[Filler (F)] Silica filler: crystalline silica (manufactured by Longsen Co., Ltd., CRYSTALITE CMC-12, crystalline silica, average particle size 5 μm) Boehm Stone: Alumina monohydrate (manufactured by Hehe Lime Industry Co., Ltd., BMB, average particle size 1.5 μm)

[Thermoplastic resin (G)] YP-50S: Bisphenol A phenoxy resin (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., Feinuo Taotao YP-50S, weight average molecular weight=40,000)

[Hardening accelerator] 2E4MZ: 2-ethyl-4-methylimidazole (manufactured by Shikoku Chemical Industry Co., Ltd., Curezol 2E4MZ)

[Others] Glass cloth a: E glass cloth (made by Nittobo Textile Co., Ltd., WEA2116, 0.1 mm thick) Glass cloth b: low dielectric glass cloth (made by Nittobo Textile Co., Ltd., NEA2116, 0.1 mm thick)

Example 1 100 parts of resin as epoxy resin (A), 64 parts of hardener a as hardener (B), 165 parts of phosphorus compound a as phosphorus compound (C), 0.01 parts as 2E4MZ, a hardening accelerator, is dissolved in methyl ethyl ketone (MEK) to obtain a flame-retardant epoxy resin composition varnish.

The obtained flame-retardant epoxy resin composition varnish is impregnated into the glass cloth a. The impregnated glass cloth was dried in a hot air circulating oven at 150°C for 11 minutes to obtain a prepreg. Six obtained prepregs were stacked on top and bottom of copper foil (Mitsui Metal Mining Co., Ltd., 3EC-III, thickness 35 μm), under the temperature conditions of 130 ℃ × 15 minutes + 190 ℃ × 80 minutes 2 Vacuum pressing of MPa to obtain a 0.8 mm thick laminate. Then, both sides of the obtained laminated plate were etched to obtain a test piece for flame retardancy measurement. Table 2 shows the measurement results of the flame retardancy, glass transition temperature, relative dielectric constant, dielectric loss tangent, copper foil peel strength, and interlayer adhesion of the laminate.

Example 2 to Example 11 Resin 1, epoxy resin a to epoxy resin d, hardener a, phosphorus compound a to phosphorus compound b, phosphorus compound d to phosphorus compound were prepared with the formulation amount (parts) of the formulation of Table 2 g, the phosphorus compound i, and 2E4MZ, using the same apparatus as in Example 1, the flame retardant epoxy resin composition varnish was obtained by the same operation, and a laminate and a test piece were further obtained. The same test as in Example 1 was conducted, and the results are shown in Table 2. In addition, "-" in the table indicates that it is not used.

[Table 2]

Comparative Example 1 to Comparative Example 6 Resin 1, Comparative resin 1 to Comparative resin 2, Epoxy resin d, Hardener a, Phosphorus compound a, Phosphorus compound g, and 2E4MZ were prepared with the formulation amount (parts) of the formulation in Table 3. Using the same apparatus as in Example 1, a flame-retardant epoxy resin composition varnish was obtained by the same operation, and a laminate and a test piece were further obtained. The same test as in Example 1 was conducted, and the results are shown in Table 3.

[table 3]

Example 12 to Example 19 Resin 2 to Resin 9, hardener a, phosphorus compound a, and 2E4MZ were prepared with the formulation amount (parts) of the formulation in Table 4, and obtained by the same operation using the same apparatus as in Example 1. The flame-retardant epoxy resin composition varnish is further obtained as a laminate and a test piece. The same test as in Example 1 was conducted, and the results are shown in Table 4.

[Table 4]

Example 20 to Example 27 Resin 1, hardener a to hardener c, hardener e to hardener h, phosphorus compound a, phosphorus compound i, and 2E4MZ were compounded in the formulation amount (parts) of the formulation of Table 5. In the same apparatus as Example 1, the flame retardant epoxy resin composition varnish was obtained by the same operation, and the laminated board and the test piece were further obtained. The same test as in Example 1 was conducted, and the results are shown in Table 5. Furthermore, Example 27 was implemented by changing the glass cloth a to the glass cloth b.

[table 5]

Example 28 100 parts of resin 1, epoxy resin (A), 2.5 parts of hardener d as hardener (B), 120 parts of hardener e, 165 parts of phosphorus compound c as phosphorus compound (C), 30 parts of boehmite as a filler (F) and 0.01 parts of 2E4MZ as a hardening accelerator, dissolved in a mixed solvent prepared using MEK, propylene glycol monomethyl ether, N,N-dimethylformamide To obtain a varnish of flame retardant epoxy resin composition.

The obtained flame-retardant epoxy resin composition varnish was coated on a separator film (polyimide film) using a roll coater, and dried in an oven at 130° C. for 10 minutes to obtain a resin film with a thickness of 50 μm. The resin film was peeled off from the separator film, and the resin film was further cured in an oven at 200° C. for 60 minutes to obtain a cured film. A size of 4 mm×20 mm was cut out from the cured film and used as a test piece for measuring the glass transition temperature. On the other hand, as a simulated inner layer circuit board, a copper blackened epoxy double-sided laminated board with a copper blackening treatment of 100 μm between lines was used, and a dry laminator was used on both sides of the simulated inner layer circuit board. The obtained resin film and copper foil were laminated on each surface, and then heated and hardened at 180°C for 2 hours to obtain a 4-layer printed wiring board. Table 6 shows the measurement results of the flame retardancy, glass transition temperature, relative dielectric constant, and dielectric loss tangent of the cured film and the copper foil peel strength of the printed wiring board.

Example 29 and Comparative Example 7 Resin 1, comparative resin 1, hardener d to hardener e, phosphorus compound c, phosphorus compound g, boehmite, YP-50S and YP-50S 2E4MZ, using the same apparatus as in Example 28, the flame retardant epoxy resin composition varnish was obtained by the same operation, and a resin film, a cured film, a printed wiring board, and a test piece were further obtained. The same test as in Example 28 was conducted, and the results are shown in Table 6.

[Table 6]

Example 30 and Comparative Example 8 to Comparative Example 9 Resin 1, Compound 1 to Comparative Resin 2, Hardener a, Phosphorus Compound a, and Silicon Dioxide Filler were blended with the formulation amount (parts) of the formulation of Table 7 while heating At 130°C, the mixture was stirred and homogenized to obtain a flame-retardant epoxy resin composition. The obtained flame-retardant epoxy resin composition was defoamed under reduced pressure at the same temperature, and a hardening accelerator was put in to carefully homogenize without entrapment of air bubbles, cast in a mold, and placed in a hot air circulation oven 1. Curing at 150°C for 2 hours, followed by curing at 180°C for 6 hours to obtain a cast cured product. Table 7 shows the measurement results of the flame retardancy, glass transition temperature, relative dielectric constant, and dielectric loss tangent of the cast hardened product. Among them, the cast hardened product of Comparative Example 8 cannot be measured due to insufficient molding. In addition, "-" in the table indicates that it is not used, and "×" indicates that it cannot be measured.

[Table 7]

In the case of the epoxy resin for low dielectric used previously, the flame retardancy is not sufficient in the composition using the phosphorus flame retardant, if more phosphorus compounds are used in order to improve the flame retardancy, Then the adhesion deteriorates. In addition, in the case of an epoxy resin containing an oxazolidinone ring other than the epoxy resin (A1), heat resistance deteriorates (glass transition temperature decreases), and adhesiveness also deteriorates. On the other hand, the flame-retardant epoxy resin composition of the embodiment can maintain flame retardancy, and has both high heat resistance and high adhesion, and also improved dielectric properties. In particular, by using an epoxy resin (A1) using a novolak epoxy resin (d1) having a specific molecular weight distribution as a raw material, the dielectric properties and heat resistance can be further improved. [Industry availability]

The flame-retardant epoxy resin composition using the epoxy resin (A1) and its hardened product used in the present invention are excellent in flame retardancy, heat resistance, adhesiveness, and dielectric properties, and can be used as a high-performance Flame retardant epoxy resin compositions for various high-functional materials such as electronic circuit board materials are required.

no.

FIG. 1 shows a GPC chart of the novolac epoxy resin (d1) of Synthesis Example 1. FIG. 2 shows a GPC chart of the novolak-type epoxy resin (d) used in Synthesis Example 7. FIG. FIG. 3 shows a GPC chart of Resin 1 [Epoxy resin (A1)] of Synthesis Example 1. FIG. FIG. 4 shows an IR chart of Resin 1 [Epoxy resin (A1)] of Synthesis Example 1. FIG.

Claims (23)

A flame-retardant epoxy resin composition, which is a flame-retardant epoxy resin composition containing an epoxy resin (A), a hardener (B), and a phosphorus compound (C) as a flame retardant, characterized by: The phosphorus content rate is 0.2% by mass to 6% by mass relative to the total of the epoxy resin (A), the hardener (B), and the phosphorus compound (C), and the epoxy resin (A) contains 5% by mass or more The novolac epoxy resin (A1) having an oxazolidinone ring in the molecule, and the epoxy equivalent of the epoxy resin (A1) are 170g/eq. to 450g/eq., and the oxazolidinone ring content is 0.02eq./kg~3.0eq./kg, wherein the epoxy resin (A1) is a ring obtained from a novolac epoxy resin (d) and an isocyanate compound (e) represented by the following formula (7) Oxygen resin, and in the measurement by gel permeation chromatography, the novolac epoxy resin (d) has a dinuclear content rate of 20 area% or less and a trinuclear content rate of 15 area% or more and 60 area % Or less, the content rate of pentasome or more is 45 area% or less, and the number average molecular weight is 350 or more and 700 or less;

In the formula, A ₁ represents an aromatic ring group selected from a benzene ring, a naphthalene ring or a biphenyl ring, and these aromatic ring groups may have an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms or carbon Any group of 7 to 10 aralkyl groups as a substituent of the aromatic ring, X represents a divalent aliphatic cyclic hydrocarbon group or a crosslinking group represented by the following formula (2) or the following formula (3) Any group, G is a glycidyl group; m represents 1 or 2, n is the number of repeating units, represents an integer of 1 or more, and its average value is 1.5 or more;

In the formula, R ₁ and R ₂ independently represent a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms;

In the formula, R ₃ and R ₄ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, and A ₂ represents an aromatic ring group selected from a benzene ring, a naphthalene ring or a biphenyl ring, and these aromatic ring groups may also be Any group having an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms as a substituent for the aromatic ring. The flame-retardant epoxy resin composition as described in item 1 of the patent application range, wherein the epoxy resin (A1) has an epoxy equivalent of 175 g/eq. to 400 g/eq. The flame-retardant epoxy resin composition as described in item 1 or 2 of the patent application range, wherein the softening point of the epoxy resin (A1) is 50°C to 150°C. The flame-retardant epoxy resin composition as described in item 1 or item 2 of the patent application scope, wherein the oxazolidone ring content of the epoxy resin (A1) is 0.05eq./kg~2.5eq./kg . The flame-retardant epoxy resin composition as described in item 1 or item 2 of the patent application scope, wherein the epoxy resin (A1) is represented by the following formula (1):

In the formula, A ₁ , X, m, and n are synonymous with the above formula (7), and Z are each independently a glycidyl group (Z1) represented by the following formula (4) or a content represented by the following formula (5) The base (Z2) of the oxazolidinone ring, the molar ratio of Z2 and Z1 in Z is 0.005~0.45;

In the formula, Y represents a divalent group which may have a substituent, and T represents a residue produced by removing one glycidyl group from the formula (7). The flame-retardant epoxy resin composition according to item 1 or 2 of the patent application scope, wherein the epoxy resin (A1) is 1 mole of epoxy based on the novolac epoxy resin (d) Specifically, the resin obtained by reacting the isocyanate group of the isocyanate compound (e) in the range of 0.01 moles or more and 0.5 moles or less. The flame-retardant epoxy resin composition according to Item 1 or Item 2 of the patent application range, wherein the isocyanate compound (e) is a compound having an average of 1.8 or more isocyanate groups in one molecule. The flame-retardant epoxy resin composition according to item 1 or item 2 of the patent application scope, wherein the isocyanate compound (e) is selected from 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 3 ,5-Toluene diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, m-xylene diisocyanate, para Xylene diisocyanate, tetramethylxylene diisocyanate, 1,4-naphthalenediyl diisocyanate, 1,5-naphthalenediyl diisocyanate, 2,6-naphthalenediyl diisocyanate, 2,7-naphthalenediyl Diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, isophthalic diisocyanate, terephthalic diisocyanate, cyclohexane-1,4-diyl diisocyanate, cyclohexane-1 ,3-diylbismethylene diisocyanate, cyclohexane-1,4-diylbismethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate One or more of the group consisting of isocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 4,4'-methylenebiscyclohexyl diisocyanate, and isophorone diisocyanate. The flame-retardant epoxy resin composition according to item 1 or 2 of the patent application scope, wherein the phosphorus compound (C) contains a phosphorus-containing epoxy resin (CA) and/or a phosphorus-containing hardener (CB). The flame-retardant epoxy resin composition as described in item 9 of the patent application scope, wherein the epoxy equivalent of the phosphorus-containing epoxy resin (CA) is 200 g/eq. to 800 g/eq. The flame-retardant epoxy resin composition as described in item 9 of the patent application range, wherein the phosphorus content of the phosphorus-containing epoxy resin (CA) is 0.5% by mass to 6% by mass. The flame retardant epoxy resin composition as described in item 9 of the patent application range, wherein the phosphorus content of the phosphorus-containing hardener (CB) is 0.5% by mass to 12% by mass. The flame-retardant epoxy resin composition according to item 1 or item 2 of the patent application scope, wherein the phosphorus compound (C) is a compound having a unit structure represented by the following formula (8);

The flame-retardant epoxy resin composition as described in item 1 or 2 of the patent application scope, wherein the blending ratio of epoxy resin (A) and hardener (B) is relative to epoxy resin (A) In terms of 1 mole of epoxy group, the active hydrogen group of the hardener (B) is adjusted within a range of 0.2 mole or more and 1.5 mole or less. The flame-retardant epoxy resin composition as described in item 1 or item 2 of the scope of patent application, wherein, relative to the total of epoxy resin (A), hardener (B) and phosphorus compound (C), The compounding ratio of the phosphorus compound (C) is 1wt%~60wt%. The flame-retardant epoxy resin composition according to item 1 or 2 of the patent application scope, which further contains a filler (F), a thermoplastic resin (G), or both. A prepreg characterized by using the flame-retardant epoxy resin composition as described in any one of claims 1 to 16. An insulating sheet characterized by using the flame-retardant epoxy resin composition as described in any one of claims 1 to 16. An adhesive sheet characterized by using the flame-retardant epoxy resin composition as described in any one of claims 1 to 16. A laminated board characterized by using the flame-retardant epoxy resin composition as described in any one of claims 1 to 16. A sealing material characterized by using the flame-retardant epoxy resin composition as described in any one of claims 1 to 16. A casting material characterized by using the flame-retardant epoxy resin composition according to any one of items 1 to 16 of the patent application range. A hardened product obtained by hardening the flame-retardant epoxy resin composition as described in any one of claims 1 to 16.

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