JP2017039842A - Flame-retardant epoxy resin composition and cured product thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flame-retardant epoxy resin composition which has excellent performance of low dielectric properties, high heat resistance and high adhesiveness together with flame retardancy, and is useful in applications such as lamination, molding, casting and bonding; and a cured product thereof.SOLUTION: There is provided a flame-retardant epoxy resin composition which contains an epoxy resin (A), a curing agent (B) and a phosphorus compound (C) as a flame retardant, where a content of phosphorus with respect to the total of the epoxy resin (A), the curing agent (B) and the phosphorus compound (C) is 0.2-6 mass%, 5 mass% or more of a novolak type epoxy resin (A1) having an oxazolidone ring in the molecule is contained in the epoxy resin (A), an epoxy equivalent of the epoxy resin (A1) is 170-450 g/eq., and a content of the oxazolidone ring is 0.02-3.0 eq./kg.SELECTED DRAWING: None

Description

  The present invention relates to a flame retardant epoxy resin composition that gives a cured product excellent in flame retardancy, low dielectric properties, high heat resistance, low moisture absorption, high adhesion, and the like, and an epoxy resin cured product obtained from the composition , Prepreg, insulating sheet, adhesive sheet, laminate, sealing material, casting material.

  Epoxy resins have excellent adhesiveness, flexibility, heat resistance, chemical resistance, insulation, and curing reactivity, and are therefore used in a wide variety of fields such as paints, civil engineering adhesion, casting, electrical and electronic materials, and film materials. In particular, it is widely used in printed wiring board applications, which is one of electric and electronic materials, by imparting flame retardancy to epoxy resins.

  With respect to portable devices, which are one of the uses of printed wiring boards, and infrastructure devices such as base stations that connect them, demands for higher functionality are constantly demanded as the amount of information has increased dramatically in recent years. Mobile devices are becoming increasingly multi-layered and finely wired for the purpose of miniaturization, and a material with a low dielectric constant is required to make the substrate thinner. There is a need for adhesive materials. Substrates for base stations are required to have lower dielectric loss tangent materials in order to suppress signal attenuation due to high frequencies.

  The characteristics such as low dielectric constant, low dielectric loss tangent and high adhesive force are largely derived from the structure of the epoxy resin which is the matrix resin of the printed wiring board, and a new epoxy resin or its modification technology is required.

  Regarding lowering the dielectric constant of an epoxy resin, Patent Document 1 discloses a diglycidyl etherified product of 4,4 ′-[1,3-phenylenebis (1-methylethylidene)] bis [2,6-dimethyl] phenol. ing. Patent Document 2 discloses an epoxy resin obtained by reacting an epoxy resin having an alcoholic hydroxyl group equivalent of 1.0 meq / g or less with an isocyanate compound having two or more isocyanate groups in the molecule, It is disclosed that an epoxy resin polymerized by an oxazolidone ring has a low dielectric constant, a low dielectric loss tangent, and a high glass transition temperature. However, regarding flame retardancy, brominated epoxy resin is used as a raw material, which cannot be used for halogen-free flame retardant applications.

Regarding an oxazolidone ring-containing epoxy resin obtained by a reaction between an epoxy resin and an isocyanate, Patent Document 3 discloses an epoxy resin composition for a laminate comprising an oxazolidone ring, an epoxy resin containing a halogen group, and a curing agent such as dicyandiamide. As raw material epoxy resins, glycidyl is a compound obtained by glycidylating dihydric phenols such as bisphenol A, a compound obtained by glycidylating tris (glycidyloxyphenyl) alkanes or aminophenol, or a novolak such as phenol novolac. There is an example of the compound.
However, the epoxy resin compositions disclosed in any of the documents do not sufficiently satisfy the requirements for dielectric properties based on recent high functionality, and the adhesiveness is insufficient.

  Further, a phosphorus-containing epoxy resin modified with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, a phosphorus-containing curing agent, and a phosphorus-based flame retardant used for imparting flame retardancy The cured product composed of the flame retardant epoxy resin composition containing the above has a problem that the dielectric constant after moisture absorption deteriorates in proportion to the phosphorus content of the cured product. In addition, in order to improve hygroscopicity, studies have been made on blending a filler such as alumina, but there is a problem that the adhesiveness deteriorates.

JP-A-5-293929 JP-A-9-278867 JP-A-5-43655

  Therefore, the problem to be solved by the present invention is that it has excellent performance in flame retardancy, low dielectric property, high heat resistance and high adhesiveness, and is useful for applications such as lamination, molding, casting and adhesion. A flame retardant epoxy resin composition and a cured product thereof are provided.

  In order to solve the above problems, the present inventor has intensively studied a low dielectric constant and low dielectric loss tangent material, and as a result, among the epoxy resins, an oxazolidone ring-containing novolak type epoxy obtained by using a novolak type epoxy resin and an isocyanate compound. It has been found that the resin has both low dielectric constant, low dielectric loss tangent, high glass transition temperature and good adhesive strength, and also exhibits excellent flame retardancy when used in combination with phosphorus flame retardants. Completed the invention.

  That is, this invention is a flame retardant epoxy resin composition containing an epoxy resin (A), a curing agent (B), and a phosphorus compound (C) as a flame retardant, the epoxy resin (A) and a curing agent ( B) and the phosphorus compound (C) in total (A + B + C) have a phosphorus content of 0.2 to 6% by mass and a novolak-type epoxy resin (A1) having an oxazolidone ring in the molecule as the epoxy resin (A) Among them, the content of 5 wt% or more, and the epoxy equivalent of the epoxy resin (A1) is 170 to 450 g / eq. And the oxazolidone ring content is 0.02 to 3.0 eq. It is a flame retardant epoxy resin composition characterized by being / kg.

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

  As for the said epoxy resin (A1), what is represented by following formula (1) is more preferable.

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 are an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or Any of the aralkyl groups having 7 to 10 carbon atoms may be used as a substituent of the aromatic ring, and X is a divalent aliphatic cyclic hydrocarbon group or a group represented by the following formula (2) or the following formula (3). Each of Z is a glycidyl group (Z1) represented by the following formula (4) or an oxazolidone ring-containing group (Z2) represented by the following formula (5), The molar ratio (Z2 / Z1) between Z1 and Z2 in Z is 0.005 to 0.45. m represents 1 or 2, n represents the number of repeating units and represents an integer of 1 or more, and the average value thereof is 1.5 or more.

（式中、Ｒ_１、Ｒ_２、Ｒ_３及びＲ_４はそれぞれ独立に、水素原子又は炭素数１〜６の炭化水素基を示す。Ａ_２はベンゼン環、ナフタレン環又はビフェニル環から選ばれる芳香族環基を示し、これらの芳香族環基は、炭素数１〜６のアルキル基、炭素数６〜１０のアリール基又は炭素数７〜１０のアラルキル基のいずれかを芳香族環の置換基として有してもよい。）

(In the formula, R ₁ , R ₂ , R ₃ and R ₄ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. A ₂ is an aromatic selected from a benzene ring, a naphthalene ring or a biphenyl ring. An aromatic ring group, and these aromatic ring groups are 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, which is a substituent of an aromatic ring. You may have as.)

（式中、Ｙは置換基を有していてもよい２価の基を示し、Ｔは式（１）からＺを１つ除いた構造、あるいは、下記式（６）で表される基を示す。）

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

（式中、Ａ_１、Ｘ、Ｚ、及びｍは式１と同意である。ｎ_１、ｎ_２は繰り返し単位の数であって０以上の整数を示し、ｎ_１＋ｎ_２は式１のｎと同じとなる。）

(In the formula, A ₁ , X, Z, and m are the same as those in 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 is n in Formula 1. Is the same.)

  As for the said epoxy resin (A1), it is preferable that the component represented by Formula (5) is 0.005-0.45 mol with respect to 1 mol of components represented by Formula (4), and following formula (7) It is more preferable that it is obtained by reacting a novolac type epoxy resin (d) represented by ()) with an isocyanate compound (e).

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

  The novolac type epoxy resin (d) has a dinuclear content of 20 area% or less and a trinuclear content of 15 area% or more and 60 area% or less as measured by gel permeation chromatography (GPC). The novolac type epoxy resin (d1) having a specific molecular weight distribution in which the content of pentanuclear or higher is 45 area% or less and the number average molecular weight is 350 or more and 700 or less is preferable.

Here, the GPC measurement conditions are as follows.
A GPC measuring device manufactured by Tosoh Corporation, HLC-8220 GPC was used. A column equipped with a column manufactured by Tosoh Corporation, TSKgel G4000HXL, TSKgel G3000HXL, and TSKgel G2000HXL was used, and the column temperature was set to 40 ° C. Tetrahydrofuran (THF) was used as the eluent, the flow rate was 1 mL / min, and an RI (differential refractometer) detector was used as the detector. For data processing, GPC-8020 model II version 4.10 manufactured by Tosoh Corporation was used. As a measurement sample, 100 μL of 0.1 g of sample dissolved in 10 mL of THF and filtered through a microfilter was used. From the obtained chromatogram, the binuclear content rate, the trinuclear content rate, the tetranuclear content rate, and the pentanuclear content or more are calculated, and standard monodisperse polystyrene (A-500, manufactured by Tosoh Corporation). , A-1000, A-2500, A-5000, F-1, F-2, F-4, F-10, F-20, F-40, F-80, F-128) Was used to measure the number average molecular weight. The total area is the sum of the areas of two or more nuclei.

  The oxazolidone ring-containing novolak type epoxy resin (A1) has a range of 0.01 mol to 0.5 mol of the isocyanate group of the isocyanate compound (e) with respect to 1 mol of the epoxy group of the novolak type epoxy resin (d). In particular, it is preferably obtained by reacting at 0.02 mol or more and 0.35 mol or less.

  The isocyanate compound (e) preferably has an average of 1.8 or more isocyanate groups in one molecule. 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 3,5-tolylene diene Isocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, tetramethylxylylene diisocyanate, 1,4-naphthalenediyl Diisocyanate, 1,5-naphthalenediyl diisocyanate, 2,6-naphthalenediyl diisocyanate, 2,7-naphthalenediyl diisocyanate, 3,3′-dimethylbisphenyl-4,4′-diisocyanate , M-phenylene diisocyanate, p-phenylene diisocyanate, cyclohexane-1,4-diyl diisocyanate, cyclohexane-1,3-diyl bismethylene diisocyanate, cyclohexane-1,4-diyl bismethylene diisocyanate, hexamethylene One or more selected from the group consisting of diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 4,4′-methylenebiscyclohexyl diisocyanate, and isophorone diisocyanate. More preferred.

  The phosphorus compound (C) preferably contains a phosphorus-containing epoxy resin (CA) and / or a phosphorus-containing curing agent (CB).

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

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

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

  1 mol of epoxy group of all epoxy resins of the above flame-retardant epoxy resin composition (including oxazolidon ring-containing novolac type epoxy resin (A1), phosphorus-containing epoxy resin (CA) and other epoxy resins) On the other hand, it is preferable to mix | blend the active hydrogen group of a hardening | curing agent (B) (a phosphorus containing hardening | curing agent (CB) is included) in 0.2 mol or more and 1.5 mol or less.

  The flame-retardant epoxy resin composition of the present invention further includes a filler (F) in a specific aspect.

  The flame-retardant epoxy resin composition of the present invention further includes a thermoplastic resin (G) in a specific aspect.

  Moreover, this invention is a prepreg characterized by using the said flame-retardant epoxy resin composition, an insulating sheet, and an adhesive sheet, and is a laminated board obtained from it. Moreover, this invention is a laminated board, a sealing material, a casting material, and hardened | cured material characterized by using the said flame-retardant epoxy resin composition.

  The flame retardant epoxy resin composition of the present invention exhibits a cured product property with a high glass transition temperature and a good flame retardancy while maintaining a good adhesive strength of the cured product, and further has excellent dielectric properties, low It exhibits excellent characteristics in laminates and electronic circuit boards that require dielectric constant and low dielectric loss tangent.

The GPC chart of the novolak-type epoxy resin (d1) of the synthesis example 1 is shown. The GPC chart of the novolak-type epoxy resin (d) used in the synthesis example 7 is shown. The GPC chart of resin 1 [epoxy resin (A1)] of the synthesis example 1 is shown. The IR chart of the resin 1 [epoxy resin (A1)] of the synthesis example 1 is shown.

Hereinafter, embodiments of the present invention will be described in detail.
The flame-retardant epoxy resin composition of the present invention comprises an epoxy resin (A), a curing agent (B), and a phosphorus compound (C) as essential components. The epoxy resin (A) contains a novolac type epoxy resin (A1) having an oxazolidone ring as an essential component. Hereinafter, the novolac type epoxy resin (A1) having an oxazolidone ring is referred to as an epoxy resin (A1). In the present specification, the oxazolidone ring-containing epoxy resin refers to all epoxy resins containing an oxazolidone ring obtained from an epoxy resin and an isocyanate compound, and includes an epoxy resin (A1). Therefore, when the epoxy resin (A1) is not included, it is referred to as an oxazolidone ring-containing epoxy resin 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 that the epoxy resin (A1) is essential. Other epoxy resins (A2) may be used together with the epoxy resin (A1), and conventionally known epoxy resins can be used as the other epoxy resins (A2). The epoxy resin refers to an epoxy resin having at least one epoxy group, and an epoxy resin having two or more epoxy groups is preferable. By using together the epoxy resin (A2) other than the epoxy resin (A1), it is possible to impart further improvements in cured product characteristics and other characteristics. For example, phosphorus-containing epoxy resin (CA) for imparting flame retardancy, naphthalene type epoxy resin for reducing linear expansion, or the like is used. These epoxy resins that can be used in combination can be used as long as the effects of the epoxy resin (A1) are not hindered. The amount of the epoxy resin (A1) used must be 5% by mass or more in the epoxy resin (A), preferably 10% by mass to 100% by mass, more preferably 10% by mass to 80% by mass, 15 mass%-70 mass% is further more preferable. Since the effect of using the epoxy resin (A1) is exhibited even in a small amount, if it is within this range, the cured product properties obtained by use, for example, low dielectric properties, high heat resistance, low moisture absorption, high adhesiveness The improvement effect of etc. is not impaired.

  The epoxy equivalent (g / eq.) Of the epoxy resin (A1) needs to be 170 to 450, is preferably 175 to 400, more preferably 180 to 350, and further preferably 185 to 300. When the epoxy equivalent is low, the content of the oxazolidone ring is low, and the hydroxyl group concentration in the cured product is high, which may increase the dielectric constant. In addition, when the epoxy equivalent is high, the content of the oxazolidone ring is more than necessary, and there is a risk that adverse effects such as deterioration of solvent solubility and increase of resin viscosity may increase due to the improvement of dielectric properties. In addition, since the crosslink density of the cured product is low, there is a risk of problems in use such as a decrease in elastic modulus at the solder reflow temperature.

  The softening point of the epoxy resin (A1) is preferably 50 to 150 ° C, more preferably 55 to 130 ° C, further preferably 58 to 100 ° C, and particularly preferably 60 to 85 ° C. If the softening point is low, the resin varnish is impregnated with glass cloth and then heated and dried in an oven, the viscosity is low, which may reduce the amount of resin adhered. Also, if the softening point is high, the resin viscosity becomes high, the deterioration of impregnation into prepreg, the deterioration of solvent solubility, and the diluting solvent does not volatilize when heated and dried, so it remains in the resin. There may be a problem in use, for example, voids are generated when creating a film. Therefore, it is desirable that the softening point of the epoxy resin (A) as a whole also satisfies the softening point.

  The oxazolidone ring content of the epoxy resin (A1) is 0.02 to 3.0 eq. / Kg, 0.05 to 2.5 eq. / Kg, preferably 0.08 to 2.0 eq. / Kg is more preferable, and 0.1 to 1.8 eq. / Kg is more preferable. When the oxazolidone ring content is high, the dielectric properties are improved (lower dielectric constant), but adverse effects such as poor solvent solubility and increased resin viscosity are likely to increase.

The presence of the oxazolidone ring can be confirmed by IR measurement. When analyzed by the total reflection measurement method (ATR method), a peak derived from the stretching vibration of the carbonyl group of the oxazolidone ring appears at 1745 to 1760 cm ⁻¹ . The oxazolidone ring content can be measured by the size of this peak. In addition, the oxazolidone ring content can be determined by a chemical method described in Examples described later.

  It is preferable that an epoxy resin (A1) is what is represented by the said Formula (1).

In Formula (1), A ₁ is an aromatic ring group selected from any of a group consisting of a benzene ring, a naphthalene ring, or a biphenyl ring which may have a substituent. The aromatic ring of these aromatic ring groups can have a substituent, such as an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl having 7 to 10 carbon atoms. One of the groups.
When there are a plurality of substituents, they may be the same or different.

  The alkyl group represents a linear, branched or cyclic alkyl group, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, A pentyl group, a hexyl group, a cyclohexyl group, etc. are mentioned. Among these, a branched or cyclic alkyl group tends to give higher heat resistance than a straight chain. 1-4 are preferable in the case of a chain alkyl group, and 6 carbon atoms are preferable in the case of a cyclic alkyl group. Preferably they are an isopropyl group, an isobutyl group, a tert-butyl group, and a cyclohexyl group, More preferably, they are a tert-butyl group and a cyclohexyl group. Moreover, since a flame retardancy tends to improve, a methyl group is also preferable.

  As an aryl group, a phenyl group, a naphthyl group, etc. are mentioned, for example, Preferably it is a phenyl group. Examples of the aralkyl group include a benzyl group, a phenethyl group, and a 1-phenylethyl group, and a benzyl group and a 1-phenylethyl group are preferable.

X is either a divalent aliphatic cyclic hydrocarbon group or a bridging group represented by formula (2) or formula (3). 5-15 are preferable and, as for carbon number of a bivalent aliphatic cyclic hydrocarbon group, 5-10 are more preferable. In Formula (2) and Formula (3), R ₁ , R ₂ , R ₃ and R ₄ independently represent a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. A ₂ has the same meaning as A ₁ in the above formula (1) except that the valence is divalent.

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

The molar ratio (Z2 / Z1) is determined by the following formula using the epoxy equivalent [Ep (g / eq.)] Of the epoxy resin (A1) and the oxazolidone ring content [Ox (eq./kg)]]. Calculated.
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 left unreacted, and the oxazolidone ring-containing group (Z2) is an oxazolidone ring structure formed by the reaction of the epoxy group and the isocyanate group, and the epoxy compound It consists of a methylene group which is a residue of a glycidyl group and Y which is a residue of an isocyanate compound.
Y represents a divalent functional group which may have a substituent, and is a residue obtained by removing an isocyanate group from an isocyanate compound.

T is a terminal group, which is a residue generated by excluding one glycidyl group from the raw material epoxy compound, and when the epoxy compound has two or more glycidyl groups, the other glycidyl groups may be as they are, It may react with an isocyanate group to form an oxazolidone ring.
This terminal group T has a structure obtained by removing one Z from the formula (1). Or it represents with Formula (6).

m is 1 or 2, and 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, and the average value (number average) thereof is preferably in a 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) is obtained by a reaction between a novolac type epoxy resin (d) as a raw material epoxy compound and an isocyanate compound (e).

A suitable novolak-type epoxy resin (d) is represented by the formula (7), and a novolak resin obtained by condensing a phenol and an aldehyde or the like in the presence of an acidic catalyst is reacted with an epihalohydrin. can get.
As the novolak type epoxy resin (d), a novolak type epoxy resin (d1) having a specific molecular weight distribution is preferable. This novolak-type epoxy resin (d1) has a dinuclear content of 20 area% or less, a trinuclear content of 15 area% or more and 60 area% or less in GPC measurement, and a content ratio of pentanuclear or more. Is an epoxy resin having a number average molecular weight of 350 or more and 700 or less. Here, i nuclei in a dinuclear body, a trinuclear body, etc. mean the number (i) of A ₁ present in the molecule. That is, the number obtained by adding 1 to n in the formula (7) is i.

  Examples of phenols used to obtain the novolak resin include, but are not limited to, phenol, cresol, ethylphenol, butylphenol, octylphenol, styrenated phenol, cumylphenol, naphthol, catechol, resorcinol, naphthalenediol, and the like. However, these phenols may be used alone or in combination of two or more. Among these phenols, monophenols such as phenol and alkylphenol are preferable. As the alkyl group in the case of 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, propyl aldehyde, butyraldehyde, amyl aldehyde, benzaldehyde, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, and the following formula (12) P-xylylene glycol, p-xylylene glycol dimethyl ether, p-xylylene dichloride, 4,4′-dimethoxymethylbiphenyl, 4,4′-dichloromethylbiphenyl, dimethoxymethylnaphthalene, dichloromethylnaphthalene Crosslinkers such as divinylbenzenes, divinylbiphenyls and divinylnaphthalenes represented by the following formula (13), and cycloals such as cyclopentadiene and dicyclopentadiene Although Rujien acids are exemplified, but is not limited to, these crosslinking agents may be used alone or in combination of two or more.

（式中、Ｒ_３、Ｒ_４及びＡ_２は、式（３）のＲ_３、Ｒ_４及びＡ_２とそれぞれ同義である。Ｌは独立に水酸基、アルコキシ基、又はハロゲン原子を示す。）

_(Wherein, R 3, _{R 4} and _{A 2} represents _R 3, _{R 4} and _{A 2} and are each synonymous .L hydroxyl group independently of the formula (3), an alkoxy group, or halogen atom.)

In Formula (1), Formula (6), and Formula (7), X is a group derived from a crosslinking agent or a crosslinking group.
When a cycloalkyl diene is used, it becomes a divalent aliphatic cyclic hydrocarbon group,
When an aldehyde or ketone is used as a crosslinking agent, the crosslinking group is represented by the formula (2). When a crosslinking agent of the formula (12) or the formula (13) is used, the crosslinking group is represented by the formula (3). It becomes a crosslinking group. Among these crosslinking agents, formaldehyde, acetaldehyde, benzaldehyde, acetone, p-xylylene dichloride, and 4,4′-dichloromethylbiphenyl are preferable, and formaldehyde is particularly preferable. Preferable forms when using formaldehyde for the reaction include a formalin aqueous solution, paraformaldehyde, trioxane and the like.

Examples of the novolak resin obtained by condensing phenols and a crosslinking agent in the presence of an acidic catalyst include the following epoxy resins.
Examples of phenol novolac epoxy resins include Epototo YDPN-638 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), jER152, jER154 (manufactured by Mitsubishi Chemical Corporation), Epicron N-740, Epicron N-770, Epicron N-775 (DIC Corporation). Etc.).
As cresol novolac type epoxy resins, Epototo YDCN-700 series (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), Epicron N-660, Epicron N-665, Epicron N-670, Epicron N-673, Epicron N-695 (DIC Corporation) Manufactured), EOCN-1020, EOCN-102S, EOCN-104S (manufactured by Nippon Kayaku Co., Ltd.), and the like.
Examples of the alkyl novolac type epoxy resins include Epototo ZX-1071T, ZX-1270, ZX-1342, and the like, and examples of the styrenated phenol novolak type epoxy resins include Epototo ZX-1247, GK-5855, TX-1210, YDAN-1000. As naphthol novolac type epoxy resins, there are Epototo ZX-1142L and the like, and β-naphthol aralkyl type epoxy resins as ESN-155, ESN-185V, ESN-175 and the like, and dinaphthol aralkyl type epoxy. Examples of the resin include ESN-300 series ESN-355 and ESN-375, and α-naphthol aralkyl type epoxy resins include ESN-400 series ESN-475V and ESN-485 (both are Manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.). Examples of the biphenyl aralkylphenol type epoxy resin include NC-3000 and NC-3000H (manufactured by Nippon Kayaku Co., Ltd.).

  As the raw material epoxy compound, among the novolak type epoxy resins (d), the novolak type epoxy resin (d1) having the specific molecular weight distribution is preferable, but the commercially available novolak type epoxy resin does not have such a molecular weight distribution. As this novolak type epoxy resin (d1), it is preferable to use what has a specific molecular weight distribution as the novolak resin that is the raw material, and such novolak resin adjusts the molar ratio of phenols and aldehydes, It can be obtained by a method of removing low molecular weight components from the obtained novolak resin. Further, such a novolak resin may be obtained by using a production method as shown in JP-A No. 2002-194041 or JP-A No. 2007-126683.

  In order to obtain a suitable novolak resin, the molar ratio of phenols to crosslinking agent (phenols / crosslinking agent) is produced under a condition of 1 or more. On the contrary, when the molar ratio is small, a high molecular weight product of pentanuclear or higher is generated, and dinuclear and trinuclear are reduced. The proportion of dinuclear, trinuclear, etc. is related to the proportion in the novolak resin before epoxidation, but also changes depending on the epoxidation conditions, so that the novolac type epoxy having a specific molecular weight distribution. In order to obtain the resin (d1), it is necessary to carry out the reaction within the above range. Therefore, the molar ratio is preferably 3 or more and 6 or less, more preferably 4 or more and 5 or less.

  As described above, novolak resins having a specific molecular weight distribution can be obtained by reducing or removing low molecular weight components of the novolak resins obtained by adjusting the molar ratio of the phenols and the crosslinking agent. In this case, examples of a method for reducing or removing low molecular weight components, particularly dinuclear bodies, include a method using a difference in solubility between various solvents, a method of dissolving in an alkaline aqueous solution, and other known separation methods.

  By using a known epoxidation technique for a novolak resin having a specific molecular weight distribution, a novolak type epoxy resin (d1) having a specific molecular weight distribution which is advantageously used in the present invention can be obtained. Alternatively, a novolak epoxy resin (d1) having a specific molecular weight distribution can also be obtained by reducing or removing low molecular weight components, particularly dinuclear components, from commercially available novolak epoxy resins by various methods.

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

  The novolac epoxy resin (d1) has a binuclear content of 20 area% or less, preferably 15 area% or less, and more preferably 5 area% or more and 12 area% or less. When the binuclear content exceeds 20 area%, the heat resistance gradually decreases. When there are too few binuclear bodies, there exists a possibility that the resin viscosity as an epoxy resin (A1) may become high. The trinuclear content is 15 area% or more and 60 area% or less, more preferably 15 area% or more and 50 area% or less, and further preferably 15 area% or more and 35 area% or less. If the trinuclear content is less than 15% by area, the oxazolidone ring content cannot be increased, and heat resistance may be inferior. If it exceeds 60% by area, adhesion may be inferior. The content of pentanuclear or higher is 45 area% or less, more preferably 40 area% or less, and further preferably 30 area% or less. If the content of pentanuclear or more is 45 area% or less, a cured product having higher heat resistance can be obtained without lowering the adhesiveness. When the pentanuclear content is too high, the content of the oxazolidone ring cannot be increased, and not only the effect of improving the dielectric properties is not exhibited, but also gelation at the time of production proceeds and the desired epoxy resin (A1) is obtained. There is no fear. The content of the tetranuclear body is not particularly specified, but the total content of the trinuclear body and the tetranuclear body is preferably 15 area% or more and 85 area% or less, and preferably 30 area% or more and 70. More preferably, it is not more than area%, more preferably not less than 40 area% and not more than 60 area%. By setting it as this range, since the molecular weight increase at the time of carrying out an isocyanate modification can be suppressed, it becomes possible to improve an oxazolidone ring content rate. Comparing the effects of trinuclear body and tetranuclear body, trinuclear body improves adhesion more, and tetranuclear body improves heat resistance more. Thereby, resin physical properties, such as a dielectric property, heat resistance, adhesiveness, etc. of a flame-retardant epoxy resin composition containing the epoxy resin (A1) obtained using a novolak-type epoxy resin (d1) improve more.

  The number average molecular weight is 350 or more and 700 or less, and more preferably 380 or more and 600 or less. When the number average molecular weight exceeds 700, the resulting epoxy resin (A1) has a high viscosity, which may adversely affect workability and substrate impregnation. On the other hand, when the number average molecular weight is less than 350, the heat resistance may be deteriorated.

  In order to obtain the epoxy resin (A1), the isocyanate compound (e) is used together with the 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). This isocyanate compound (e) may be 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 substantially having two or more functions. Known and conventional isocyanate compounds can be used. The monofunctional isocyanate compound may be contained in a small amount, but this is an end group and is effective for the purpose of lowering the degree of polymerization, but does not increase the degree of polymerization.

  Specifically, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 3,5-tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'- Diphenylmethane diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, tetramethylxylylene diisocyanate, 1,4-naphthalenediyl diisocyanate, 1,5-naphthalenediyl diisocyanate, 2,6-naphthalenediyl diisocyanate, 2,7-naphthalene Diyl diisocyanate, naphthalene-1,4-diylbis (methylene) diisocyanate, naphthalene-1,5-diylbis (methylene) diisocyanate, m-phenylene diisocyanate P-phenylene diisocyanate, biphenyl-4,4′-diisocyanate, 3,3′-dimethylbisphenyl-4,4′-diisocyanate, 2,3′-dimethoxybisphenyl-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′-methylenebiscyclohexyl diisocyanate, lysine diisocyanate, 1,1-bis (isocyanatomethyl) cyclohexane, 1,2-bis (isocyanate L) cyclohexane, 1,3-bis (isocyanate methyl) cyclohexane, 1,4-bis (isocyanate methyl) cyclohexane, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, 4-methyl-1,3- Cyclohexylene diisocyanate, 2-methyl-1,3-cyclohexylene 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, Tan-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 Bifunctional isocyanate compounds such as -1,7-diisocyanate, octane-1,8-diisocyanate, nonane-1,9-diisocyanate, decane-1,10-diisocyanate, dimethylsilane diisocyanate, diphenylsilane diisocyanate, Nylmethane triisocyanate, 1,3,6-hexamethylene triisocyanate, 1,8-diisocyanato-4-isocyanenatomethyloctane, bicyclohebutane triisocyanate, tris (isocyanatephenyl) thiophosphate, lysine ester triisocyanate, undecane tri Polyfunctional isocyanate compounds such as isocyanate, tris (4-phenylisocyanate thiophosphate) -3,3 ′, 4,4′-diphenylmethanetetraisocyanate, polymethylenepolyphenylisocyanate, and dimers and trimers of the above isocyanate compounds And the like, and block isocyanates masked with blocking agents such as alcohol and phenol, and bisurethane compounds, but are not limited thereto. No. These isocyanate compounds may be used alone or in combination of two or more.

  Among these isocyanate compounds, a bifunctional isocyanate compound or a trifunctional isocyanate compound is preferable, and a bifunctional isocyanate compound is more preferable. When the number of functional groups of the isocyanate compound is large, the storage stability may be lowered, and when it is small, the heat resistance and adhesion when the resin composition is obtained may not be improved.

  The reaction of the novolac type epoxy resin (d) and the isocyanate compound (e) can be performed by a known method. As a specific reaction method, (1) after melting the novolac type epoxy resin and removing moisture in the epoxy resin by a method such as dry gas purging or reducing the pressure in the system, an isocyanate compound and a catalyst are added. (2) After mixing the novolac type epoxy resin and the catalyst in advance and removing moisture in the epoxy resin by a method such as dry gas purging or reducing the pressure in the system, an isocyanate compound is added. There is a method of performing the reaction. In either method, if the resin viscosity is high and stirring is difficult, a non-reactive solvent can be used if necessary.

  The reaction mechanism for forming the oxazolidone ring is represented by the following reaction formula (14). The novolac type epoxy resin (d) and the isocyanate compound (e) are added with a catalyst, whereby the epoxy group of the novolak type epoxy resin (d) and the isocyanate group of the isocyanate compound (e) react to form an oxazolidone ring.

The amount of the novolak-type epoxy resin (d) and the isocyanate compound (e) used is 0.01 equivalent or more of the isocyanate group of the isocyanate compound (e) with respect to 1 equivalent of the epoxy group of the novolak-type epoxy resin (d). A range of 5 equivalents or less is preferable, and a range of 0.1 equivalents or more and 0.45 equivalents or less is more preferable. The range of 0.15 equivalents or more and 0.4 equivalents or less is more preferred, and the range of 0.2 equivalents or more and 0.35 equivalents or less is particularly preferred. Here, 1 equivalent of epoxy group and 1 equivalent of isocyanate group are the same as 1 mol of epoxy group and 1 mol of isocyanate group.
If the ratio of isocyanate groups is low, the amount of oxazolidone ring produced may be reduced, and the effect of improving the dielectric properties and heat resistance of the cured product may not be obtained. Moreover, when there are many ratios of an isocyanate group, not only the residual amount of an epoxy group will fall, but the viscosity will increase at the time of reaction, and reaction will become difficult. Even if it is obtained, solvent solubility and impregnation into glass cloth are deteriorated, making it difficult to use in laminated plate applications.

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

  The reaction temperature is preferably in the range of 100 ° C to 250 ° C, more preferably in the range of 100 ° C to 200 ° C, and still more preferably in the range of 120 ° C to 160 ° C. When the reaction temperature is low, the oxazolidone ring is not sufficiently formed, and an isocyanurate ring is formed by a trimerization reaction of an isocyanate group. Further, when the reaction temperature is high, local high molecular weight occurs, and the generation of insoluble gel components increases. Therefore, it is preferable to adjust the addition rate of the isocyanate compound to maintain the reaction temperature at an appropriate temperature. By appropriately controlling the reaction conditions, the oxazolidone ring can be produced almost quantitatively from the epoxy group of the novolak-type epoxy resin and the isocyanate group of the isocyanate compound.

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

  Specific examples of the catalyst used in the above reaction include lithium compounds such as lithium chloride and butoxylithium, complex salts of boron trifluoride, tetramethylammonium chloride, tetramethylammonium bromide, tetrabutylammonium bromide, and tetramethyl. Quaternary ammonium salts such as ammonium iodide and tetraethylammonium iodide, tertiary amines such as dimethylamino ether, triethylamine, tributylamine, benzyldimethylamine and N-methylmorpholine, triphenylphosphine, tris (2,6-dimethoxy) Phosphines such as phenyl) phosphine, amyltriphenylphosphonium bromide, diallyldiphenylphosphonium bromide, ethyltriphenylphosphonium chloride, ethyltriphenylphosphine Nitrobromide, ethyltriphenylphosphonium iodide, tetrabutylphosphonium acetate / acetic acid complex, tetrabutylphosphonium acetate, tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, tetrabutyliodoid and other phosphonium salts, a combination of triphenylantimony and iodine, Examples thereof include, but are not limited to, imidazoles such as 2-phenylimidazole, 2-methylimidazole, and 2-ethyl-4-methylimidazole. These catalysts may be used alone or in combination of two or more. . Further, it may be divided and used in several times.

  The amount of the catalyst is not particularly limited, but may be 0.0001% by mass or more and 5% by mass or less based on the total mass of the novolak type epoxy resin (d) and the isocyanate compound (e). The content is preferably 1% by mass or less, more preferably 0.001% by mass or more and 0.5% by mass or less, and further preferably 0.002% by mass or more and 0.2% by mass or less. When the amount of the catalyst is large, the epoxy group self-polymerization reaction proceeds in some cases, and the resin viscosity becomes high. In addition, the self-polymerization reaction of isocyanate is promoted, and the formation of the oxazolidone ring is suppressed. Furthermore, it remains as an impurity in the generated resin, and when used for various purposes, particularly as a material for a laminated board or a sealing material, there is a risk of causing a decrease in insulation and a decrease in moisture resistance.

  When the reaction between the novolac-type epoxy resin (d) and the isocyanate compound (e) is performed, other various epoxy resins can be used in combination as long as the effects of the present invention are not affected. Examples of the epoxy resin that can be used in combination include the above-described commercially available epoxy resins and the following epoxy resins.

  Bisphenol A type epoxy resin [for example, Epototo YD-127, Epotot YD-128, Epototo YD-8125, Epotot YD-825GS (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)], Bisphenol F type epoxy resin [For example, Epotot YDF-170, Epotot YDF-1500, Epototo YDF-8170, Epototo YDF-870GS, YSLV-80XY, YSLV-70XY (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)], biphenol type epoxy resin [for example, YX-4000 (manufactured by Mitsubishi Chemical Corporation), ZX -1251 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)], hydroquinone type epoxy resins [for example, Epototo YDC-1312, ZX-1027 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)], bisphenolfluorene type epoxy resins [example ZX-1201 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)], naphthalenediol type epoxy resin [for example, ZX-1355 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), Epicron HP-4032D (manufactured by DIC Corporation, etc.]], bisphenol S type Epoxy resins [e.g. TX-0710 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), Epiklone EXA-1515 (manufactured by Dainippon Chemical Co., Ltd.), etc.], diphenyl sulfide type epoxy resins [e.g. Etc.], diphenyl ether type epoxy resin [for example, YSLV-80DE (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)], resorcinol type epoxy resin [for example, Epototo ZX-1684 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), Denacol EX-201 (Nagase Chemte Etc.], alkylene glycol type epoxy resins [Epototo PG-207, Epototo PG-207GS (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), SR-16H, SR-16HL, SR-PG, SR-4PG, SR- SBA, SR-EGM, SR-8EGS (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), etc.], aliphatic cyclic epoxy resins [Santoto ST-3000, Epototo ZX-1658, Epototo ZX-1658GS, FX-318 (Nippon Steel & Sumikin Chemical Co., Ltd.) Polyglycidyl ether compounds such as HBPA-DGE (manufactured by Maruzen Petrochemical Co., Ltd.) and the like, and diaminodiphenylmethane type epoxy resins [eg, Epototo YH-434, Epototo YH-434GS (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), ELM434 (Sumitomo Chemical Co., Ltd.), Aralda Ito MY720, Araldite MY721, Araldite MY9512, Araldite MY9663 (manufactured by Huntsman Advanced Chemicals), etc.], metaxylenediamine type epoxy resin [for example, TETRAD-X (manufactured by Mitsubishi Gas Chemical Co., Ltd.)], 1,3-bis Aminomethylcyclohexane type epoxy resin [eg TETRAD-C (Mitsubishi Gas Chemical Co., Ltd.)], isocyanurate type epoxy resin [eg TEPIC-P (Nissan Chemical Industry Co., Ltd.)], aniline type epoxy resin [eg GAN , GOT (manufactured by Nippon Kayaku Co., Ltd.), etc.], hydantoin type epoxy resins [eg Y238 (manufactured by Huntsman Advanced Materials), etc.], aminophenol type epoxy resins [eg ELM120, ELM100 (Sumitomo Chemical Co., Ltd.) ), JER630 (manufactured by Mitsubishi Chemical Corporation), Araldite MY0510, Araldite MY0600, Araldite MY0610 (manufactured by Huntsman Advanced Materials), etc.] and dimer acid type epoxy resins [for example, YD- 171 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), jER871 (manufactured by Mitsubishi Chemical Co., Ltd.), etc.], hexahydrophthalic acid type epoxy resin [for example, SR-HHPA (manufactured by Sakamoto Pharmaceutical Co., Ltd.), etc.] Alicyclic epoxy compounds [for example, Celoxide 2021, Celoxide 2021A, Celoxide 2021P, Celoxide 3000 (manufactured by Daicel Chemical Industries, Ltd.), DCPD-EP, MCPD-EP, TCPD-EP (manufactured by Maruzen Petrochemical Co., Ltd.), etc. Although and the like is not limited thereto, to these epoxy resins may be used alone or in combination of two or more.

  Among these epoxy resins that can be used in combination, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenol type epoxy resin, hydroquinone type epoxy resin, bisphenol fluorene type epoxy resin, naphthalenediol type epoxy resin, bisphenol S type epoxy resin, Bifunctional epoxy resins such as diphenyl sulfide type epoxy resin, poxy resin, diphenyl ether type epoxy resin, and resorcinol type epoxy resin are preferred. By using a small amount of these bifunctional epoxy resins, the tendency to increase the viscosity during the reaction can be suppressed without inhibiting the effects of the present invention, so that the amount of isocyanate compound (e) used is increased. It becomes possible, and the dielectric properties of the cured product can be further improved. The amount that can be used is preferably 50 parts by mass or less, more preferably 25 parts by mass or less, and still more preferably 10 parts by mass or less with respect to 100 parts by mass of the novolac type epoxy resin (d).

  Further, when the reaction between the novolac-type epoxy resin (d) and the isocyanate compound (e) is performed, the molecular weight (epoxy) can be further increased by using various epoxy resin modifiers within the range where the effects of the present invention are not affected. Equivalent) etc. can also be adjusted. The amount that can be used is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and still more preferably 10 parts by mass or less with respect to 100 parts by mass of the novolac type epoxy resin (d).

  Specific examples of epoxy resin modifiers that can be used include bisphenol A, bisphenol F, bisphenol AD, tetrabutyl bisphenol A, bisphenol Z, bisphenol TMC, hydroquinone, methyl hydroquinone, dimethyl hydroquinone, dibutyl hydroquinone, resorcin, methyl resorcin, Biphenol, tetramethylbiphenol, dihydroxynaphthalene, dihydroxydiphenyl ether, dihydroxystilbenes, phenol novolac resin, cresol novolac resin, bisphenol A novolac resin, dicyclopentadiene phenol resin, phenol aralkyl resin, naphthol novolac resin, styrenated phenol novolac resin, terpene Phenolic resin, heavy oil modified phenol Various phenolic compounds such as fats, polyhydric phenol resins obtained by condensation reactions of various phenols with various aldehydes such as hydroxybenzaldehyde, crotonaldehyde, glyoxal, aniline, phenylenediamine, toluidine, xylidine, Diethyltoluenediamine, diaminodiphenylmethane, diaminodiphenylethane, diaminodiphenylpropane, diaminodiphenyl ketone, diaminodiphenyl sulfide, diaminodiphenyl sulfone, bis (aminophenyl) fluorene, diaminodiethyldimethyldiphenylmethane, diaminodiphenyl ether, diaminobenzanilide, diaminobiphenyl, dimethyl Diaminobiphenyl, biphenyltetraamine, bisaminophenylanthracene, bisua Examples of amine compounds such as nophenoxybenzene, bisaminophenoxyphenyl ether, bisaminophenoxybiphenyl, bisaminophenoxyphenylsulfone, bisaminophenoxyphenylpropane, and diaminonaphthalene include, but are not limited to, these epoxy resin modified An agent may be used independently and may use 2 or more types together.

  Moreover, you may use a non-reactive solvent as needed. Specifically, hexane, heptane, octane, decane, dimethylbutane, pentene, cyclohexane, methylcyclohexane, benzene, toluene, xylene, ethylbenzene and other hydrocarbons, ethyl ether, isopropyl ether, butyl ether, diisoamyl ether, methyl Ethers such as phenyl ether, ethyl phenyl ether, amyl phenyl ether, ethyl benzyl ether, dioxane, methyl furan, tetrahydrofuran, methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, cellosolve acetate, ethylene glycol isopropyl ether, diethylene glycol dimethyl ether, methyl ethyl carb Tall, propylene glycol monomethyl ether, dimethylformamide, dimethyl Not intended sulfoxide, and the like are limited to, to these non-reactive solvent may be used alone or may be used in combination of two or more.

As described above, the flame retardant epoxy resin composition of the present invention can contain an epoxy resin (A2) other than the oxazolidone ring-containing epoxy resin (A1).
A conventionally well-known epoxy resin can be used as an epoxy resin (A2). The epoxy resin (A2) that can be used in combination can be used within a range that does not interfere with the effect of the epoxy resin (A1). Since the effect of using the epoxy resin (A1) is exhibited even in a small amount, the amount of the epoxy resin (A2) used is preferably 0% by mass to 95% by mass in the epoxy resin (A). % By mass is more preferable, and 30% by mass to 85% by mass is more preferable.

  As the epoxy resin (A), the epoxy resin (A2) that can be used in combination with the epoxy resin (A1) is preferably a bifunctional or higher polyfunctional epoxy resin, and can be selected according to the purpose. For example, it is preferable to use a phosphorus-containing epoxy resin (CA), which will be described later, for imparting flame retardancy, and a trifunctional or higher functional epoxy resin for further improving heat resistance.

  As the epoxy resin (A2), the above-described phenol novolac type epoxy resin, cresol novolak type epoxy resin, alkyl novolak type epoxy resin, styrenated phenol novolac type epoxy resin, naphthol novolak type epoxy resin, β-naphthol aralkyl type epoxy resin, Novolac epoxy resins such as dinaphthol aralkyl type epoxy resin, α-naphthol aralkyl type epoxy resin, biphenyl aralkyl phenol type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenol type epoxy resin, hydroquinone type epoxy resin , Bisphenol fluorene type epoxy resin, naphthalene diol type epoxy resin, bisphenol S type epoxy resin, diphenyl sulfide type Polyglycidyl ether compounds such as epoxy resins, diphenyl ether type epoxy resins, resorcinol type epoxy resins, alkylene glycol type epoxy resins, aliphatic cyclic epoxy resins, diaminodiphenylmethane type epoxy resins, metaxylenediamine type epoxy resins, 1,3-bis Polyglycidylamine compounds such as aminomethylcyclohexane type epoxy resin, isocyanurate type epoxy resin, aniline type epoxy resin, hydantoin type epoxy resin, aminophenol type epoxy resin, dimer acid type epoxy resin, hexahydrophthalic acid type epoxy resin, etc. There are polyglycidyl ester compounds and alicyclic epoxy compounds. In addition, trihydroxyphenylmethane type epoxy resin (for example, EPPN-501, EPPN-502 (manufactured by Nippon Kayaku Co., Ltd.)), tetrahydroxyphenylethane type epoxy resin (for example, YDG-414 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) ), Etc.], dicyclopentadiene type epoxy resins (for example, Epicron HP7200, HP-7200H (manufactured by DIC Corporation), etc.), urethane-modified epoxy resins (for example, AER4152 (manufactured by Asahi Kasei E-Materials Corporation), etc.), epoxy resins Oxazolidone ring-containing epoxy resins other than (A1), epoxy-modified polybutadiene rubber derivatives (for example, PB-3600 (manufactured by Daicel Chemical Industries, Ltd.)), CTBN-modified epoxy resins (for example, YR-102, YR-450 (Nippon Steel & Sumitomo Metal) Made by Chemical Co., Ltd. Etc.), but the present invention may be mentioned phosphorus containing epoxy resin (CA) to be described later is not limited to, those epoxy resins may be used alone or in combination of two or more.

  Next, the curing agent (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 cures an epoxy resin, and includes a phenolic curing agent, an acid anhydride curing agent, an amine curing agent, a hydrazide curing agent, an active ester curing agent, and a phosphorous content described later. A curing agent for epoxy resin such as a curing agent (CB) can be used. These curing agents may be used alone or in combination of two or more. Of these, dicyandiamide, a phenolic curing agent or an active ester curing agent is preferable, and a phenolic curing agent or an active ester curing agent is more preferable.

The usage-amount of a hardening | curing agent (B) is the range of 0.2 mol or more and 1.5 mol or less of active hydrogen groups of a hardening | curing agent (B) with respect to 1 mol of epoxy groups of an epoxy resin (A). When the active hydrogen group is less than 0.2 mol or exceeds 1.5 mol with respect to 1 mol of the epoxy group, curing may be incomplete and good cured properties may not be obtained. A preferred range is 0.3 mol or more and 1.5 mol or less, a more preferred range is 0.5 mol or more and 1.5 mol or less, and a further preferred range is 0.8 mol or more and 1.2 mol or less. For example, when a phenolic curing agent, an amine curing agent or an active ester curing agent is used, an active hydrogen group is mixed in an approximately equimolar amount with respect to the epoxy group, and when an acid anhydride curing agent is used, an epoxy group is used. An acid anhydride group is added in an amount of 0.5 to 1.2 mol, preferably 0.6 to 1.0 mol, per mol.
Here, the epoxy resin (A) includes a compound having an epoxy group such as an epoxy resin (A1), an epoxy resin (A2), and a phosphorus-containing epoxy resin (CA). Moreover, a hardening | curing agent (B) contains a phosphorus containing hardening | curing agent (CB).

The active hydrogen group in the present invention includes a functional group having an active hydrogen reactive with an epoxy group (a functional group having a latent active hydrogen that generates active hydrogen by hydrolysis or the like, or a functional group having an equivalent curing action) Specifically, an acid anhydride group, a carboxyl group, an amino group, a phenolic hydroxyl group, and the like can be given. In addition, regarding an active hydrogen group, 1 mol of carboxyl groups (—COOH) and phenolic hydroxyl groups (—OH) are calculated as 1 mol, and amino groups (—NH ₂ ) are calculated as 2 mol. If the active hydrogen group is not clear, the active hydrogen equivalent can be determined by measurement. For example, by reacting a monoepoxy resin with known epoxy equivalent such as phenylglycidyl ether with a curing agent with unknown active hydrogen equivalent, and measuring the amount of monoepoxy resin consumed, the active hydrogen equivalent of the used curing agent Can be requested.

  Specific examples of phenolic curing agents include bisphenol A, bisphenol F, bisphenol C, bisphenol K, bisphenol Z, bisphenol S, tetramethyl bisphenol A, tetramethyl bisphenol F, tetramethyl bisphenol S, tetramethyl bisphenol Z, Bisphenols such as dihydroxydiphenyl sulfide, 4,4′-thiobis (3-methyl-6-tert-butylphenol), catechol, resorcin, methylresorcin, hydroquinone, monomethylhydroquinone, dimethylhydroquinone, trimethylhydroquinone, mono-tert- Dihydroxybenzenes such as butylhydroquinone and di-tert-butylhydroquinone, dihydroxynaphthalene, dihydroxymethy Hydroxynaphthalenes such as naphthalene, dihydroxymethylnaphthalene and trihydroxynaphthalene, phenol novolac resins (for example, Shonor BRG-555 (manufactured by Showa Denko KK), etc.), cresol novolac resins (for example, DC-5 (Nippon Steel & Sumikin Chemical) Etc.), trishydroxyphenylmethane type novolak resin (for example, Resitop TPM-100 (manufactured by Gunei Chemical Industry Co., Ltd.)), phenols such as naphthol novolak resin and / or naphthols and aldehydes Condensation of phenols and / or naphthols with xylylene glycol and / or xylylene dihalide such as condensates and naphthol aralkyl resins (SN-160, SN-395, SN-485 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)) Things, Condensates of enols and / or naphthols with isopropenyl acetophenone, reaction products of phenols and / or naphthols with dicyclopentadiene, condensates of phenols and / or naphthols with biphenyl crosslinking agents Such as phenolic compounds, aminotriazine-modified phenolic resins (polyhydric phenolic compounds in which phenolic nuclei are linked with melamine, benzoguanamine, etc.) and these phenolic compounds have been substituted with substituents such as alkyl, alkoxy or aryl groups Although a phenol compound etc. are mentioned, it is not limited to these.

  Examples of raw materials for these phenol compounds include phenols such as phenol, cresol, xylenol, butylphenol, amylphenol, nonylphenol, butylmethylphenol, trimethylphenol, and phenylphenol, and naphthols include 1-naphthol and 2-naphthol. Etc. Aldehydes are formaldehyde, acetaldehyde, propyl aldehyde, butyraldehyde, valeraldehyde, capronaldehyde, benzaldehyde, chloraldehyde, bromaldehyde, glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipine aldehyde, pimelin aldehyde, sebacin aldehyde, Examples include acrolein, crotonaldehyde, salicylaldehyde, phthalaldehyde, and hydroxybenzaldehyde. Examples of the biphenyl crosslinking agent include bis (methylol) biphenyl, bis (methoxymethyl) biphenyl, bis (ethoxymethyl) biphenyl, and bis (chloromethyl) biphenyl.

  Further, a benzoxazine compound that is ring-opened upon heating to become a phenol compound is also useful as a curing agent. Specific examples include bisphenol F-type or bisphenol S-type benzoxazine (for example, BF-BXZ or BS-BXZ (manufactured by Konishi Chemical Co., Ltd.)).

  Specific examples of the acid anhydride curing agent include methyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, pyromellitic anhydride, phthalic anhydride, trimellitic anhydride , Methyl nadic acid anhydride, maleic anhydride and the like, but are not limited thereto.

  Specific examples of the amine-based curing agent include diethylenetriamine, triethylenetetramine, metaxylenediamine, isophoronediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiphenyl ether, benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl). ) Examples include, but are not limited to, amine compounds such as polyamidoamine which is a condensate of acids such as phenol, dicyandiamide and dimer acid and polyamines.

  Examples of the active ester curing agent include a reaction product of a polyfunctional phenol compound and an aromatic carboxylic acid as described in Japanese Patent No. 5152445, and commercially available products include Epicron HPC-8000-65T (DIC Corporation). However, it is not limited to these.

  Specific examples of other curing agents 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 and 1-cyanoethyl-2-methylimidazole, imidazoles which are salts of imidazoles with trimellitic acid, isocyanuric acid, boric acid and the like, quaternary ammonium salts such as trimethylammonium chloride, diazabicyclo Compounds, salts of diazabicyclo compounds with phenols or phenol novolac resins, etc., complex compounds of boron trifluoride with amines or ether compounds, aromatic phosphonium, or iodonium salts. The invention is not, may be used these epoxy resins alone or in combination of two or more.

Next, the phosphorus compound (C) mix | blended with the flame-retardant epoxy resin composition of this invention is demonstrated.
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 divided into phosphorus-containing epoxy resins (CA) and phosphorus-containing curing agents (CB). It is divided into. When the additive type phosphorus flame retardant is compared with the reactive phosphorus compound, the reactive phosphorus compound is larger in the flame retardant effect, and therefore it is preferable to use the reactive phosphorus compound.

  As the additive-based phosphorus flame retardant, either an inorganic phosphorus compound or an organic phosphorus compound can be used. Examples of inorganic phosphorus compounds include red phosphorus, monoammonium phosphate, diammonium phosphate, triammonium phosphate, ammonium phosphates such as ammonium polyphosphate, and inorganic nitrogen-containing phosphorus compounds such as phosphate amides. It is done. Examples of organic phosphorus compounds include general use of aliphatic phosphate esters, phosphate ester compounds, condensed phosphate esters, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphorane compounds, organic nitrogen-containing phosphorus compounds, etc. In addition to organophosphorus compounds and metal salts of phosphinic acid, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10- (2,5-dihydroxyphenyl) -10H-9- Although cyclic organic phosphorus compounds, such as oxa-10-phosphaphenanthrene-10-oxide, 10- (2,7-dihydrooxynaphthyl) -10H-9-oxa-10-phosphaphenanthrene-10-oxide, are mentioned. However, it is not limited to these.

  Specific examples include methyl acid phosphate, ethyl acid phosphate, isopropyl acid phosphate, dibutyl phosphate, monobutyl phosphate, butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, bis (2-ethylhexyl) phosphate, monoisodecyl acid phosphate, Phosphoric acids such as lauryl acid phosphate, tridecyl acid phosphate, stearyl acid phosphate, isostearyl acid phosphate, oleyl acid phosphate, butyl pyrophosphate, tetracosyl acid phosphate, ethylene glycol acid phosphate, (2-hydroxyethyl) methacrylate acid phosphate Esters and 9,10-dihydro 9-oxa-10-phosphaphenanthrene-10-oxide, phosphorus compounds such as diphenylphosphine oxide, phosphorus compounds having an active hydrogen group directly bonded to a phosphorus atom such as diphenylphosphine, and 10- (2,5-dihydroxyphenyl) -10H-9 -Oxa-10-phosphaphenanthrene-10-oxide, 10- (1,4-dioxynaphthalene) -10H-9-oxa-10-phosphaphenanthrene-10-oxide, diphenylphosphinylhydroquinone, diphenylphosphenyl Phosphorus-containing phenols such as 1,4-dioxynaphthalene, 1,4-cyclooctylenephosphinyl-1,4-phenyldiol, 1,5-cyclooctylenephosphinyl-1,4-phenyldiol But are not limited to those illustrated. .

  As the phosphorus compound used in the phosphorus-containing epoxy resin (CA) and the phosphorus-containing curing agent (CB), phosphorus compounds and phosphorus-containing phenols having an active hydrogen group directly connected to the phosphorus atom are preferable, and are easily available. To 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-phosphaphenanthrene-10-oxide and the like are more preferable.

  The phosphorus-containing epoxy resin (CA) can be obtained by reacting a phosphorus compound having a unit structure represented by the formula (8) with an epoxy resin. Specific examples include Epototo FX-305, Epototo FX-289B, TX-1320A, Epototo TX-1328 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) and the like, but are not limited thereto.

  As a phosphorus containing hardening | curing agent (CB), in addition to said phosphorus containing phenols, it is a unit represented by Formula (8) by a manufacturing method as shown to a special table 2008-501063 gazette and patent 4548547 gazette. A phosphorus-containing phenol compound can be obtained by reacting a phosphorus compound having a structure, an aldehyde, and a phenol compound. Further, a phosphorus-containing active ester compound can be obtained by further reacting an aromatic carboxylic acid with a production method as shown in JP2013-185002A.

The epoxy equivalent of phosphorus containing epoxy resin (CA) is 200-800 g / eq. And preferably 300 to 780 g / eq. And more preferably 400 to 760 g / eq. It is. Moreover, it is good that the phosphorus content rate of a phosphorus containing epoxy resin (CA) is 0.5-6 mass%, Preferably it is 2-5.5 mass%, More preferably, it is 3-5 mass%. .
The phosphorus content of the phosphorus-containing curing agent (CB) is preferably 0.5 to 12% by mass, preferably 2 to 11% by mass, and more preferably 4 to 10% by mass.

The amount of the phosphorus compound (C) is appropriately selected depending on the type of the phosphorus compound (C), the components of the flame retardant epoxy resin composition, and the desired degree of flame retardancy. The phosphorus content is preferably 0.2% by mass or more and 6% by mass or less, and preferably 0.4% by mass or more and 4% by mass or more with respect to the total (A + B + C) of the epoxy resin (a), the curing agent (B), and the phosphorus compound (C). % By mass or less is more preferable, 0.5% by mass or more and 3.5% by mass or less is more preferable, and 0.6% by mass or more and 3% by mass or less is particularly preferable. If the phosphorus content is low, it may be difficult to ensure flame retardancy, and if it is too high, the heat resistance may be adversely affected.
Here, the phosphorus-containing epoxy resin (CA) is treated as both a phosphorus compound (C) and an epoxy resin (A). Similarly, phosphorus containing hardening | curing agent (CB) is also a phosphorus compound (C), and treats it as applicable to both hardening | curing agents (B). Therefore, when using a phosphorus containing hardening | curing agent (CB), use of another hardening | curing agent or a phosphorus compound may become unnecessary. Similarly, when using a phosphorus containing epoxy resin (CA), use of another epoxy resin or a phosphorus compound may become unnecessary.

  Moreover, a well-known various flame retardant adjuvant can be used for a flame-retardant epoxy resin composition for the purpose of the improvement of the flame retardance of the hardened | cured material obtained as needed. Examples of flame retardant aids that can be used include nitrogen flame retardants, silicone flame retardants, inorganic flame retardants, and organic metal salt flame retardants. These flame retardants may be used alone or in combination of two or more.

  In general, in the case of a cured product using a phosphate ester flame retardant or a phosphorus compound having a structure represented by the formula (8) as a flame retardant, the dielectric properties after moisture absorption often deteriorate, In the case of a flame retardant epoxy resin composition, since high phosphatization is not necessary to obtain flame retardancy, there is little adverse effect due to phosphorus atoms after moisture absorption.

  A filler (F) can be used for the flame-retardant epoxy resin composition of the present invention as necessary. Specifically, fused silica, crystalline silica, alumina, silicon nitride, aluminum hydroxide, boehmite, magnesium hydroxide, talc, mica, calcium carbonate, calcium silicate, calcium hydroxide, magnesium carbonate, barium carbonate, barium sulfate, Examples thereof include boron nitride, carbon, carbon fiber, glass fiber, alumina fiber, silica alumina fiber, silicon carbide fiber, polyester fiber, cellulose fiber, aramid fiber, ceramic fiber, fine particle rubber, thermoplastic elastomer, and pigment. In general, the reason for using a filler is the effect of improving impact resistance. Moreover, when metal hydroxides, such as aluminum hydroxide, boehmite, and magnesium hydroxide, are used, there exists an effect which acts as a flame retardant adjuvant and improves a flame retardance. 1 mass%-150 mass% is preferable with respect to the whole flame-retardant epoxy resin composition, and, as for the compounding quantity of these fillers (F), 10 mass%-70 mass% are more preferable. If the blending amount is large, the adhesiveness required for the laminate application may be lowered, and further, the cured product may be brittle so that sufficient mechanical properties may not be obtained. Moreover, when there are few compounding quantities, there exists a possibility that the compounding effect of a filler (F), such as an improvement of the impact resistance of hardened | cured material, may not exist.

  The flame retardant epoxy resin composition of the present invention may be blended with a thermoplastic resin (G) as necessary. In particular, it is effective when the flame retardant epoxy resin composition is molded into a sheet or film. Examples of the thermoplastic resin (G) include phenol resin, acrylic resin, petroleum resin, indene resin, coumarone indene resin, phenoxy resin, polyurethane resin, polyester resin, polyamide resin, polyimide resin, polyamideimide resin, and polyetherimide resin. , Polyphenylene ether resin, modified polyphenylene ether resin, polyether sulfone resin, polysulfone resin, polyether ether ketone resin, polyphenylene sulfide resin, polyvinyl formal resin, and the like, but are not limited thereto. Phenoxy resins are preferable from the viewpoint of compatibility with epoxy resins, and polyphenylene ether resins and modified polyphenylene ether resins are preferable from the viewpoint of low dielectric properties.

If necessary, the flame retardant epoxy resin composition of the present invention includes a curing accelerator, a silane coupling agent, an antioxidant, a release agent, an antifoaming agent, an emulsifier, a thixotropic agent, a smoothing agent, and a flame retardant. In addition, other additives such as pigments can be blended. These additives are preferably in the range of 0.01 to 20% by mass with respect to the flame retardant epoxy resin composition.
Furthermore, an organic solvent, a diluent, etc. can be mix | blended.

  Examples of curing accelerators include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2- (dimethylaminomethyl) phenol, 1,8-diaza-bicyclo (5,4 , 0) Tertiary amines such as undecene-7, phosphines such as triphenylphosphine, tricyclohexylphosphine and triphenylphosphine triphenylborane, and metal compounds such as tin octylate. The curing accelerator is used in an amount of 0.02 parts by mass to 5 parts by mass as necessary 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 curing accelerator, the curing temperature can be lowered or the curing time can be shortened.

An organic solvent or a reactive diluent can also be used for viscosity adjustment.
The organic solvent is not particularly specified, but amides such as N, N-dimethylformamide, ethers such as ethylene glycol monomethyl ether, ketones such as acetone and methyl ethyl ketone, methanol, ethanol, benzyl alcohol, and butyldiethanol. Examples thereof include alcohols such as glycol and pine oil, and aromatic hydrocarbons such as benzene and toluene.
The reactive diluent is monofunctional such as allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, bifunctional such as resorcinol glycidyl ether, neopentyl glycol glycidyl ether, 1,6-hexanediol diglycidyl ether, etc. And polyfunctional glycidyl ethers such as glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, and pentaerythritol polyglycidyl ether.
These solvents or reactive diluents can be blended in an amount of 90% by mass or less, alone or in combination of a plurality of types.

  When the flame-retardant epoxy resin composition is used as a plate-like substrate or the like, a fibrous material is preferable as a filler in terms of dimensional stability, bending strength, and the like. More preferred is a glass fiber substrate in which glass fibers are knitted in a mesh shape.

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

Moreover, in order to harden a prepreg, although the hardening method of the laminated board generally used when manufacturing a printed wiring board can be used, it is not limited to this. For example, when a prepreg is used to form a laminate, one or more prepregs are laminated, a metal foil is placed on one or both sides to form a laminate, and this laminate is heated and pressed to form a laminate. Turn into. Here, as the metal foil, a single, alloy, or composite metal foil of copper, aluminum, brass, nickel or the like can be used. And the prepreg can be hardened by pressurizing and heating the produced laminated body, and a laminated board can be obtained. At that time, the heating temperature is preferably 160 to 220 ° C., the pressing pressure is preferably 50 to 500 N / cm ² , and the heating and pressing time is preferably 40 to 240 minutes, and a desired cured product can be obtained. If the heating temperature is low, the curing reaction does not proceed sufficiently, and if it is high, the flame-retardant epoxy resin composition may start to decompose. Also, if the pressure is low, bubbles may remain inside the resulting laminate and the electrical characteristics may deteriorate. If it is high, the resin will flow before curing, and a cured product with the desired thickness will be obtained. There is a fear that it is not possible. Furthermore, if the heating and pressing time is short, the curing reaction may not proceed sufficiently, and if it is long, the flame-retardant epoxy resin composition in the prepreg may be thermally decomposed, which is not preferable.

  The flame retardant epoxy resin composition can be cured in the same manner as known epoxy resin compositions to obtain a cured epoxy resin. As a method for obtaining a cured product, a method similar to that of a known epoxy resin composition can be employed, such as casting, pouring, potting, dipping, drip coating, transfer molding, compression molding, resin sheets, resins, and the like. A method of forming a laminated board by laminating the laminated copper foil, a prepreg, or the like and curing by heating and pressing is suitably used. The curing temperature at that 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 used after being formed into a sheet or film. In this case, it is possible to form a sheet or a film using a conventionally known method. As an example of a suitable molding method, the resin obtained by dissolving the flame retardant epoxy resin composition in a solvent. The solution is coated on a base material such as a metal foil, polyester film, polyimide film or the like whose surface is peeled by a conventionally known method, and then dried and peeled off from the base material, thereby insulating sheet, insulating film, and adhesive. There is a method of using a sheet or an adhesive film.

  Although it does not specifically limit as a method to manufacture an adhesive sheet, For example, on the carrier film which does not melt | dissolve in epoxy resin compositions, such as a polyester film and a polyimide film, Preferably the epoxy resin composition of this invention is 5-100 micrometers. After being applied to the thickness of the film, it is dried by heating at 100 to 200 ° C. for 1 to 40 minutes to form a sheet. A resin sheet is generally formed by a method called a casting method. Under the present circumstances, if the sheet | seat which apply | coats an epoxy resin composition is surface-treated beforehand with a mold release agent, the shape | molded adhesive sheet can be peeled easily. Here, the thickness of the adhesive sheet is preferably 5 to 80 μm. The adhesive sheet thus obtained usually becomes an insulating adhesive sheet having insulation, but a conductive adhesive sheet is obtained by mixing conductive metal or metal-coated fine particles with the epoxy resin composition. be able to.

Next, a method for producing a laminate using the prepreg or insulating adhesive sheet of the present invention will be described. When forming a laminated board using prepreg, one or more prepregs are laminated, a metal foil is placed on one or both sides to form a laminate, and this laminate is heated and pressed to integrate the laminate. To do. Here, as the metal foil, a single, alloy, or composite metal foil of copper, aluminum, brass, nickel or the like can be used. Conditions for heating and pressurizing the laminate may be adjusted as appropriate under the conditions for curing the epoxy resin composition, and heating and pressurizing. However, if the amount of pressurization is too low, bubbles are generated inside the resulting laminate. Since it may remain and electrical characteristics may deteriorate, it is desirable to apply pressure under conditions that satisfy moldability. For example, the temperature can be set to 160 to 220 ° C., the pressure can be set to 49.0 to 490.3 N / cm ² (5 to 50 kgf / cm ² ), and the heating time can be set to 40 to 240 minutes. Furthermore, a multilayer board can be produced using the single-layer laminated board thus obtained as an inner layer material. In this case, first, a circuit is formed on the laminate by an additive method, a subtractive method, or the like, and the formed circuit surface is treated with an acid solution to perform a blackening process to obtain an inner layer material. The inner layer material is formed with a prepreg or an insulating adhesive sheet on one or both sides of the circuit forming surface, and a conductor layer is formed on the surface of the insulating layer to form a multilayer board.

  When forming an insulating layer with an insulating adhesive sheet, the insulating adhesive sheet is arranged on the serial number circuit forming surface of a plurality of inner layer materials to form a laminate. Alternatively, an insulating adhesive sheet is disposed between the circuit forming surface of the inner layer material and the metal foil to form a laminate. Then, the laminate is heated and pressed to be integrally molded, thereby forming a cured product of the insulating adhesive sheet as an insulating layer, and forming a multilayered inner layer material. Alternatively, the inner layer material and the metal foil as the conductor layer are formed by using the cured product of the insulating adhesive sheet as the insulating layer. Here, as a metal foil, the thing similar to what was used for the laminated board used as an inner layer material can be used. Further, the heat and pressure molding can be performed under the same conditions as the molding of the inner layer material. In the case where an insulating layer is formed by applying an epoxy resin composition to a laminate, the outermost circuit-forming surface resin of the inner layer material is preferably applied to the thickness of 5 to 100 μm, and then 100 It is dried by heating at ~ 200 ° C for 1 to 90 minutes to form a sheet. It is generally formed by a method called a casting method. The thickness after drying is preferably 5 to 80 μm. A printed wiring board can be formed by further forming a via hole or a circuit by the additive method or the subtractive method on the surface of the multilayer laminate thus formed. Further, by repeating the above-mentioned construction method using this printed wiring board as an inner layer material, a multilayer laminate board can be formed.

  When an insulating layer is formed with a prepreg, a laminate is formed by placing one or a plurality of laminated prepregs on the circuit forming surface of the inner layer material, and further placing a metal foil on the outside thereof. To do. Then, this laminate is heated and pressed to be integrally formed, whereby a cured product of the prepreg is formed as an insulating layer, and the outer metal foil is formed as a conductor layer. Here, as a metal foil, the thing similar to what was used for the laminated board used as an inner layer board can also be used. Further, the heat and pressure molding can be performed under the same conditions as the molding of the inner layer material. A printed wiring board can be molded by further forming via holes or circuits by the additive method or the subtractive method on the surface of the multilayer laminate thus formed. Further, by repeating the above-described construction method using this printed wiring board as an inner layer material, a multilayer board can be formed.

  The sealing material obtained using the flame retardant epoxy resin composition includes a semiconductor chip tape-like sealing material, a potting liquid sealing agent, an underfill resin, and a semiconductor interlayer insulating film. It can be used suitably.

  In order to adjust the flame-retardant epoxy resin composition for semiconductor sealing materials, other coupling agents, additives such as mold release agents, etc., blended into the flame-retardant epoxy resin composition as necessary, An example is a method in which an inorganic filler or the like is premixed and then sufficiently mixed until uniform using an extruder, kneader, roll, or the like. When used as a tape-like sealant, the resin composition obtained by the above-described method is heated to produce a semi-cured sheet, which is used as a sealant tape, and then this sealant tape is applied to a semiconductor chip. And a method of softening by heating to 100 to 150 ° C. and completely curing at 170 to 250 ° C. can be mentioned. Further, when used as a potting type liquid sealant, the resin composition obtained by the above-described method is dissolved in a solvent as necessary, and then applied onto a semiconductor chip or an electronic component and directly cured. That's fine.

  As a result of preparing a flame retardant epoxy resin composition and evaluating the epoxy resin cured product of the laminate by heat curing, the epoxy resin (A1) obtained from the novolac type epoxy resin (d) and the isocyanate compound (e) is an epoxy resin. Compared to oxazolidone ring-containing epoxy resins other than the resin (A1), not only has low viscosity and good workability, but also has high heat resistance and high adhesiveness, and can further improve low dielectric properties.

  EXAMPLES The present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited to these. Unless otherwise specified, “parts” represents parts by mass, and “%” represents mass%. Moreover, the measuring method was measured with the following method, respectively.

  Epoxy equivalent: Conforms to JIS K7236 standard.

  Softening point: Measured according to JIS K7234 standard, ring and ball method. Specifically, an automatic softening point apparatus (manufactured by Meitec Co., Ltd., ASP-MG4) was used.

Oxazolidone ring content (Ox, eq./kg): In the oxazolidone ring formation reaction of this example, the epoxy group was not substantially used except for the reaction forming an oxazolidone ring, and thus the following formula was used.
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 the epoxy equivalent (g / eq.) Of the oxazolidone ring-containing epoxy resin.
Wt0 is the mass (g) of the raw material epoxy resin used, and Wt is the mass (g) of the oxazolidone ring-containing epoxy resin.

  Dinuclear content, trinuclear content, tetranuclear content, pentanuclear content or more, number average molecular weight (Mn), mass average molecular weight (Mw), and dispersity (Mw / Mn): GPC The molecular weight distribution is measured using the dinuclear content, trinuclear content, tetranuclear content, pentanuclear content and more content from the peak area%, the number average molecular weight, weight average molecular weight, dispersity are Standard monodispersed polystyrene (A-500, A-1000, A-2500, A-5000, F-1, F-2, F-4, F-10, F-20, F-40, manufactured by Tosoh Corporation) , F-80, F-128). Specifically, a main body (manufactured by Tosoh Corporation, HLC-8220GPC) and a column (manufactured by Tosoh Corporation, TSKgelG4000HXL, TSKgelG3000HXL, TSKgelG2000HXL) were used in series, and the column temperature was 40 ° C. Further, THF was used as the eluent, the flow rate was 1 mL / min, and an RI (differential refractometer) detector was used as the detector. For data processing, GPC-8020 model II version 4.10 manufactured by Tosoh Corporation was used. As a measurement sample, 100 μL of 0.1 g of sample dissolved in 10 mL of THF and filtered through a microfilter was used.

  Phosphorus content: Sulfuric acid, hydrochloric acid and perchloric acid were added to the sample and heated to wet ash to convert all phosphorus atoms to orthophosphoric acid. Metavanadate and molybdate were reacted in a sulfuric acid acidic solution, and the absorbance at 420 nm of the resulting phosphomadomolybdate complex was measured. The phosphorus atom content determined by a previously prepared calibration curve was expressed in wt%. The phosphorus content of the laminate was expressed as the content relative to the resin content of the laminate. 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 blended in the composition.

  Copper foil peel strength and interlayer adhesion: measured according to JIS C6481, and interlayer adhesion was measured by peeling between the fifth and sixth layers.

  Glass transition temperature (Tg): IPC-TM-650 2.4.25. DSC / Tgm (with respect to the tangent of the glass state and the rubber state) when measured under a temperature rising condition of 20 ° C./min with a differential scanning calorimeter (EXSTA16000 DSC6200, manufactured by Hitachi High-Tech Science Co., Ltd.) according to c. And expressed as the temperature of the intermediate temperature of the mutation curve.

  Dielectric constant and dielectric loss tangent: Evaluated by obtaining the dielectric constant and dielectric loss tangent at a frequency of 1 GHz by a capacitance method using a material analyzer (manufactured by AGILENT Technologies) according to IPC-TM-650 2.5.5.9. did.

  Flame retardancy: Evaluated by vertical method according to UL94.

Synthesis example 1
Synthesis example 1a
While adding 2500 parts of phenol and 7.5 parts of oxalic acid dihydrate to a glass separable flask equipped with a stirrer, thermometer, nitrogen gas introduction device, cooling pipe and dropping device, while injecting nitrogen gas The mixture was stirred and heated to raise the temperature. Next, while stirring at 80 ° C., 474.1 parts of 37.4% formalin was added dropwise over 30 minutes to react. Further, the reaction was carried out for 3 hours while maintaining the reaction temperature at 92 ° C. The temperature was raised and the temperature was raised to 110 ° C. while removing the reaction product water out of the system. The residual phenol was recovered under reduced pressure at 160 ° C., and the temperature was further raised to 250 ° C. to recover a part of the binuclear body, thereby obtaining a phenol novolac resin (1a) in which the binuclear body was reduced. The obtained phenol novolac resin had a dinuclear content and a trinuclear content of 10 area% and 38 area%, respectively.

Synthesis example 1b
Subsequently, to a glass separable flask equipped with a stirrer, a thermometer, a nitrogen gas introducing device, a cooling pipe and a dropping device, 666 parts of the obtained phenol novolac resin (1a), 2110 parts of epichlorohydrin, 17 parts of ion-exchanged water was charged, and the temperature was raised to 50 ° C. with stirring. After uniformly dissolving, 14.2 parts of 49% aqueous sodium hydroxide solution was added and reacted for 3 hours. Next, after the temperature was raised to 64 ° C., the pressure was reduced to such an extent that water was refluxed, and 457.7 parts of a 49% aqueous sodium hydroxide solution was added dropwise over 3 hours. Epichlorohydrin was separated in a separation tank, epichlorohydrin was returned to the reaction vessel, and water was removed from the system to react. After completion of the reaction, the temperature was raised to 70 ° C. to perform dehydration, and the remaining epichlorohydrin was recovered at a temperature of 135 ° C. The pressure was returned to normal pressure, and 1232 parts of methyl isobutyl ketone (MIBK) was added and dissolved. 1200 parts of ion-exchanged water was added, and the mixture was left to stand with stirring. The salt produced as a by-product was dissolved in water and removed. Next, 37.4 parts of a 49% aqueous sodium hydroxide solution was added, and the mixture was stirred at 80 ° C. for 90 minutes to carry out a purification reaction. MIBK was added and washed with water several times to remove ionic impurities. The solvent was recovered to obtain a phenol novolac type epoxy resin (1b). The resulting phenol novolac epoxy resin has a dinuclear content of 10 area%, a trinuclear content of 35 area%, a total of trinuclear and tetranuclear contents of 52 area%, and a pentanuclear content of 38 or more. Area%, number average molecular weight 635, weight average molecular weight 884, dispersity 1.39, epoxy equivalent 174 g / eq. Met.
A GPC measurement chart is shown in FIG. In the figure, the peak indicated by A indicates a dinuclear body, the peak indicated by B indicates a trinuclear body, and the peak group indicated by C indicates pentanuclear or higher. The horizontal axis indicates the elution time, the left vertical axis indicates the signal intensity, and the right vertical axis indicates the number average molecular weight M in common logarithm (log). The measured value of the number average molecular weight of the standard substance used was plotted with a black circle, which was used as a calibration curve.

Synthesis Example 1c
Subsequently, a phenol novolac type epoxy resin (1b) obtained above as a novolak type epoxy resin (d) was added to a glass separable flask equipped with a stirrer, a thermometer, a nitrogen gas introduction device, a cooling pipe and a dropping device. ) As a catalyst, 0.17 part of tetramethylammonium iodide (manufactured by Tokyo Chemical Industry Co., Ltd., reagent) is charged, and the temperature is raised while nitrogen gas is being introduced, and the temperature is maintained at 120 ° C. for 30 minutes. The water in the system was removed. Next, while maintaining a temperature of 130 ° C. to 140 ° C., 14.4 parts (isocyanate group e / epoxy) as the isocyanate compound (e), diphenylmethane diisocyanate (Mitsui Chemicals, Cosmonate PH, NCO concentration 34%) The equivalent ratio of group d (e / d) = 0.20) was added dropwise as a 50% toluene solution over 3 hours. After completion of the dropping, stirring was continued for another 60 minutes while maintaining the same temperature. After completion of the reaction, the solvent was removed under the recovery conditions of 150 ° C. and 1.33 kPa for 30 minutes to obtain an oxazolidone ring-containing novolac type epoxy resin (Resin 1). The number average molecular weight (Mn) of the obtained resin 1 was 1139, the weight average molecular weight (Mw) was 5846, and the dispersity (Mw / Mn) was 5.13. FIG. 3 shows a GPC chart, and FIG. 4 shows an IR chart. In addition, IR measured the light absorbency of wave number 650-4000cm < ^-1 > by the total reflection measurement method (ATR method) of the Fourier-transform type infrared spectrophotometer (PerkinEller Precisiony, Spectrum One FT-IR Spectrometer 1760X).

Synthesis example 2
Except for changing diphenylmethane diisocyanate to 7.5 parts (equivalent ratio (e / d) = 0.10) of polymethylene polyphenyl polyisocyanate (Mitsui Chemicals, Cosmonate M-50, NCO concentration 34%), The synthesis was performed using the same apparatus and procedure as in Synthesis Example 1c to obtain an oxazolidone ring-containing novolac type epoxy resin (Resin 2).

Synthesis example 3
Tetramethylammonium iodide is added to 0.12 part of n-butyltriphenylphosphonium bromide (manufactured by Nippon Chemical Industry Co., Ltd., Hishicolin BTPPBr), diphenylmethane diisocyanate is added to 2,4-tolylene diisocyanate (80%) and 2,6- Addition of isocyanate compound to 22.5 parts (equivalent ratio (e / d) = 0.45) of a mixture of tolylene diisocyanate (20%) (manufactured by Mitsui Chemicals, Cosmonate T-80, NCO concentration 48%) The synthesis was performed using the same apparatus and procedure as in Synthesis Example 1c except that the time was changed from 3 hours to 6 hours to obtain an oxazolidone ring-containing novolak type epoxy resin (Resin 3).

Synthesis example 4
Except for changing diphenylmethane diisocyanate to 11.3 parts (equivalent ratio (e / d) = 0.20) of cyclohexane-1,3-diylbismethylene diisocyanate (Mitsui Chemicals, Takenate 600, NCO concentration 43%). The synthesis was carried out using the same apparatus and procedure as in Synthesis Example 1c to obtain an oxazolidone ring-containing novolac type epoxy resin (Resin 4).

Synthesis example 5
Phenol novolac type epoxy resin, 90 parts of the above phenol novolac type epoxy resin (1b) and bisphenol F type liquid epoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., Epototo YDF-1500, epoxy equivalent 168 g / eq., Viscosity 2500 mPa · s) Is 10 parts, diphenylmethane diisocyanate is 21.7 parts (equivalent ratio (e / d) = 0.30), and the dropping time of the isocyanate compound is changed from 3 hours to 6 hours. Synthesis was performed using the apparatus and procedure to obtain an oxazolidone ring-containing novolac type epoxy resin (resin 5).

Synthesis Example 6
Phenol novolac type epoxy resin, phenol novolak type epoxy resin (1b) 90 parts and bisphenol A type liquid epoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., Epototo YD-8125, epoxy equivalent 174 g / eq., Viscosity 4100 mPa · s) 10 Except that the amount of diphenylmethane diisocyanate was 21.6 parts (equivalent ratio of isocyanate group e / epoxy group d (e / d) = 0.30) and the dropping time of the isocyanate compound was changed from 3 hours to 6 hours. The synthesis was performed using the same apparatus and procedure as in Synthesis Example 1c to obtain an oxazolidone ring-containing novolac type epoxy resin (resin 6).

Synthesis example 7
A phenol novolac type epoxy resin was replaced with a commercially available phenol novolac type epoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., Epototo YDPN-638, dinuclear content 22 area%, trinuclear content 15 area%, trinuclear and four The total nucleus content is 25 area%, pentanuclear content is 53 area%, number average molecular weight 528, weight average molecular weight 1127, dispersity 2.13, epoxy equivalent 176 g / eq. A, B and C are the same as those in FIG. 1) 100 parts, tetramethylammonium iodide 0.11 parts n-butyltriphenylphosphonium bromide, 9.2 parts diphenylmethane diisocyanate ( Except for changing the equivalent ratio (e / d) = 0.13), the synthesis was performed using the same apparatus and procedure as in Synthesis Example 1c, and the oxazolidone ring was contained. To obtain a novolak type epoxy resin (resin 7).

Synthesis Example 8
The phenol novolac type epoxy resin was converted into an ortho cresol novolak type epoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., Epototo YDCN-700-7, epoxy equivalent 204 g / eq., Dinuclear content 5.9 area%, trinuclear containing. 6.8 area%, trinuclear and tetranuclear content is 15.3 area%, pentanuclear and higher content is 72.0 area%) 100 parts, tetramethylammonium iodide is n-butyl The same as Synthesis Example 1c except that 0.1 part of triphenylphosphonium bromide was changed to 4.3 parts of diphenylmethane diisocyanate (equivalent ratio of isocyanate group e / epoxy group d (e / d) = 0.07). The synthesis was carried out using various devices and procedures to obtain an oxazolidone ring-containing novolac type epoxy resin (resin 8).

Synthesis Example 9
Phenol novolac type epoxy resin, α-naphthol aralkyl type epoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., Epototo ESN-475V, epoxy equivalent 330 g / eq., Softening point 80 ° C., binuclear content 48.2 area%, The trinuclear content is 24.8 area%, the total of the trinuclear and tetranuclear contents is 13.7 area%, and the pentanuclear content is 13.3 area%). Except for changing to 3 parts of -1,3-diyl bismethylene diisocyanate (equivalent ratio (e / d) = 0.10), synthesis was carried out in the same apparatus and procedure as in Synthesis Example 1c, and an oxazolidone ring-containing novolak epoxy Resin (Resin 9) was obtained.

Comparative Synthesis Example 1
Phenol novolac type epoxy resin, 100 parts of bisphenol A type liquid epoxy resin, diphenylmethane diisocyanate 20.1 parts of a mixture of 2,4-tolylene diisocyanate (80%) and 2,6-tolylene diisocyanate (20%) ( Except that the equivalent ratio (e / d) = 0.40) and the dropping time of the isocyanate compound was changed from 3 hours to 6 hours, the synthesis was performed by the same apparatus and procedure as in Synthesis Example 1c, and the oxazolidone ring-containing epoxy resin (Comparative resin 1) was obtained.

Comparative Synthesis Example 2
The same apparatus as in Synthesis Example 1c except that the phenol novolac type epoxy resin was changed to 100 parts of bisphenol A type liquid epoxy resin and 14.4 parts of diphenylmethane diisocyanate (equivalent ratio (e / d) = 0.20). And an oxazolidone ring-containing epoxy resin (Comparative Resin 2).

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

  The abbreviations used in Examples and Comparative Examples are as follows.

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

Epoxy resin (A2): Comparative resin 1 to comparative resin 2 obtained in Comparative Synthesis Examples 1 and 2, and the following epoxy resin a to epoxy resin d
Epoxy resin a: dicyclopentadiene / phenol co-condensed epoxy resin (Kunito Chemical Co., Ltd., KDCP-130, epoxy equivalent 254 g / eq.)
Epoxy resin b: aromatic modified novolak type epoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., Epototo YDAN-1000-9C, epoxy equivalent 276 g / eq.)
Epoxy resin c: Cresol novolak type epoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., Epototo YDCN-700-7, epoxy equivalent 204 g / eq.)
Epoxy resin d: tetrafunctional epoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., Epototo YDG-414, epoxy equivalent 187 g / eq.)

[Curing agent (B)]
Curing agent a: Phenol novolac resin (Showa Denko KK, Shoenol BRG-557, softening point 80 ° C., phenolic hydroxyl group equivalent 105 g / eq.)
Curing agent b: aromatic modified novolak resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., GK-5855P, phenolic hydroxyl group equivalent 230 g / eq.)
Curing agent c: dicyclopentadiene / phenol co-condensation resin (manufactured by Gunei Chemical Co., Ltd., GDP 9140, phenolic hydroxyl group equivalent 196 g / eq.)
Curing agent d: Dicyandiamide (Nippon Carbite Corporation, DIHARD, active hydrogen equivalent 21 g / eq)
Curing agent e: Phenol-terminated PPO resin (Sabic, SA90, phenolic hydroxyl group equivalent 803 g / eq.)
Curing agent f: benzoxazine resin (manufactured by Shikoku Kasei Kogyo Co., Ltd., Fa type benzoxazine resin)
Curing agent g: active ester resin (DIC Corporation, Epicron HPC-8000-65T, active ester equivalent 223 g / eq.)
Curing agent h: Styrene / maleic acid co-condensation resin (manufactured by Cray Valley, SMA2000, acid anhydride equivalent 316 g / eq.)

[Phosphorus Compound (C)]
Phosphorus compound a: Phosphorus-containing epoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., Epototo TX-1320A, epoxy equivalent 763 g / eq., Phosphorus content 5.0%)
Phosphorus compound b: Phosphorus-containing epoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., Epototo TX-1328, epoxy equivalent 307 g / eq., Phosphorus content 3.4%)
Phosphorus compound c: Phosphorus-containing phenoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., phenototo ERF-001M30, phosphorus content 4.2%, weight average molecular weight = 40000)
Phosphorus compound d: phosphorus-containing epoxy resin flame retardant (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., Epototo FX-289FA, phosphorus content 7.0%)
Phosphorus compound e: Phosphorus-containing phenol curing agent (Shin-AT & C, LC-950PM60, phosphorus content 9.2%)
Phosphorus compound f: Phosphorus-containing phenol curing agent (manufactured by DIC Corporation, Epicron EXB9000, phenolic hydroxyl group equivalent 207 g / eq, phosphorus content 5.0%)
Phosphorus compound g: aromatic condensed phosphate ester (Daihachi Chemical Industry Co., Ltd., PX-200, phosphorus content: 9.0%)
Phosphorus compound h: organophosphorus flame retardant (manufactured by Clariant, Exolit OP935, phosphorus content 23%)
Phosphorus compound i: Phosphazene flame retardant (Otsuka Chemical Co., Ltd., SPE-100, phosphorus content 13%)

[Filler (F)]
Silica filler: crystalline silica (manufactured by Tatsumori Co., Ltd., crystallite CMC-12, crystalline silica, average particle size 5 μm)
Boehmite: Alumina monohydrate (manufactured by Kawai Lime Industry Co., Ltd., BMB, average particle size 1.5 μm)

[Thermoplastic resin (G)]
YP-50S: bisphenol A type phenoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., phenototo YP-50S, weight average molecular weight = 40000)

[Curing accelerator]
2E4MZ: 2-ethyl-4-methylimidazole (manufactured by Shikoku Kasei Kogyo Co., Ltd., Curesol 2E4MZ)

[Other]
Glass cloth a: E glass cloth (manufactured by Nitto Boseki Co., Ltd., WEA2116, 0.1 mm thickness)
Glass cloth b: Low dielectric glass cloth (Nitto Boseki Co., Ltd., NEA2116, 0.1 mm thickness)

Example 1
100 parts of resin 1 as epoxy resin (A), 64 parts of curing agent a as curing agent (B), 165 parts of phosphorus compound a as phosphorus compound (C), and 0.01 part of 2E4MZ as curing accelerator Then, it was dissolved in methyl ethyl ketone (MEK) to obtain a flame retardant epoxy resin composition varnish.

  The obtained flame-retardant epoxy resin composition varnish was impregnated into 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 prepregs obtained and copper foil (Mitsui Metal Mining Co., Ltd., 3EC-III, thickness 35 μm) are stacked on top and bottom, and a 2 MPa vacuum press is performed at a temperature of 130 ° C. × 15 minutes + 190 ° C. × 80 minutes. A laminated plate having a thickness of 0.8 mm was obtained. Moreover, the both surfaces of the obtained laminated board were etched, and the test piece for a flame retardance measurement was obtained. Table 2 shows the results of measuring the flame retardancy, glass transition temperature, relative dielectric constant, dielectric loss tangent, copper foil peel strength, and interlayer adhesion of the laminate.

Examples 2-11
Resin 1, epoxy resins a to d, curing agent a, phosphorus compounds a to b, phosphorus compounds d to g, phosphorus compound i, and 2E4MZ were blended in the blending amounts (parts) of the formulations shown in Table 2, and Example 1 Using the same apparatus, the flame retardant epoxy resin composition varnish was obtained by the same operation, and further a laminate and a test piece were obtained. The same test as in Example 1 was performed, and the results are shown in Table 2. In addition, "-" in a table | surface represents non-use.

Comparative Examples 1-6
Resin 1, Comparative Resin 1-2, Epoxy Resin d, Curing Agent a, Phosphorus Compound a, Phosphorus Compound g, and 2E4MZ were blended in the blending amounts (parts) of the formulation in Table 3, and the same apparatus as in Example 1 was used. Using the same operation, a flame retardant epoxy resin composition varnish was obtained, and a laminate and a test piece were further obtained. The same test as in Example 1 was performed, and the results are shown in Table 3.

Examples 12-19
Resin 2-9, curing agent a, phosphorus compound a, and 2E4MZ were blended in the blending amounts (parts) of the formulation shown in Table 4, and using the same apparatus as in Example 1, flame retardant in the same operation An epoxy resin composition varnish was obtained, and a laminate and a test piece were further obtained. The same test as in Example 1 was performed, and the results are shown in Table 4.

Examples 20-27
Resin 1, curing agents a to c, curing agents e to h, phosphorus compound a, phosphorus compound i, and 2E4MZ were blended in the blending amounts (parts) of the prescription in Table 5, and the same apparatus as in Example 1 was used. In the same manner, a flame retardant epoxy resin composition varnish was obtained, and a laminate and a test piece were further obtained. The same test as in Example 1 was performed and the results are shown in Table 5. In Example 27, the glass cloth a was changed to the glass cloth b.

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

  The obtained flame-retardant epoxy resin composition varnish was applied onto 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 having 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. It cut out to the magnitude | size of 4 mm x 20 mm from the cured film, and was set as the test piece for glass transition temperature measurement. On the other hand, a glass epoxy copper clad double-sided laminate with 100 μm pitch between lines was used as the simulated inner layer circuit board, and the resin film and copper foil obtained on both sides of this simulated inner layer circuit board were used with a dry laminator. After laminating, it was heated and cured at 180 ° C. for 2 hours to obtain a four-layer printed wiring board. Table 6 shows the results of measurement of flame retardancy, glass transition temperature, relative dielectric constant, dielectric loss tangent of the cured film, and copper foil peeling strength of the printed wiring board.

Example 29 and Comparative Example 7
Resin 1, Comparative resin 1, Curing agents de, Phosphorus compound c, Phosphorus compound g, Boehmite, YP-50S and 2E4MZ were blended in the blending amounts (parts) of the formulation shown in Table 5, and the same apparatus as Example 28 Were used to obtain a flame-retardant epoxy resin composition varnish by the same operation, and a resin film, a cured film, a printed wiring board, and a test piece were obtained. The same test as in Example 28 was performed, and the result is shown in Table 6.

Example 30 and Comparative Examples 8-9
In the blending amount (parts) of the formulation in Table 7, resin 1, comparative resin 1-2, curing agent a, phosphorus compound a, and silica filler are blended, and stirred and homogenized while heating to 130 ° C. to make flame retardant An epoxy resin composition was obtained. The obtained flame-retardant epoxy resin composition was degassed under reduced pressure at the same temperature, and then charged with a curing accelerator and carefully casted into a mold so as not to entrain air bubbles. And then cured at 150 ° C. for 2 hours and then at 180 ° C. for 6 hours to obtain a cast cured product.
Table 7 shows the results of measuring the flame retardancy, glass transition temperature, relative dielectric constant, and dielectric loss tangent of the cast cured product. However, the cast cured product of Comparative Example 8 could not be measured because of insufficient molding. In addition, "-" in a table | surface represents non-use and "x" represents a measurement impossibility.

  In the case of a conventionally used low dielectric epoxy resin, a composition using a phosphorus-based flame retardant has insufficient flame retardancy. Getting worse. Moreover, in the case of an oxazolidone ring-containing epoxy resin other than the epoxy resin (A1), the heat resistance deteriorates (the glass transition temperature decreases), and the adhesiveness also deteriorates. On the other hand, the flame retardant epoxy resin compositions of the examples were able to have both high heat resistance and high adhesiveness while maintaining flame retardancy, and further improved dielectric properties. In particular, by using an epoxy resin (A1) made from a novolac type epoxy resin (d1) having a specific molecular weight distribution as a raw material, the dielectric properties and heat resistance could be further improved.

  The flame-retardant epoxy resin composition using the epoxy resin (A1) used in the present invention and its cured product are excellent in flame retardancy, heat resistance, adhesiveness, and dielectric properties, and meet the recent demand for higher functionality. It can be used as a flame retardant epoxy resin composition for various high performance materials such as electronic circuit board materials.

Claims (25)

  A flame retardant epoxy resin composition containing an epoxy resin (A), a curing agent (B), and a phosphorus compound (C) as a flame retardant, the epoxy resin (A), the curing agent (B) and the phosphorus compound ( The phosphorus content is 0.2 to 6% by mass with respect to the total of C), and novolac type epoxy resin (A1) having an oxazolidone ring in the molecule is contained in 5% by mass or more in the epoxy resin (A). And the epoxy equivalent of the epoxy resin (A1) is 170 to 450 g / eq. And the oxazolidone ring content is 0.02 to 3.0 eq. / Kg of a flame-retardant epoxy resin composition.   The epoxy equivalent of the epoxy resin (A1) is 175 to 400 g / eq. The flame retardant epoxy resin composition according to claim 1.   The flame retardant epoxy resin composition according to claim 1 or 2, wherein the softening point of the epoxy resin (A1) is 50 to 150 ° C.   The oxazolidone ring content of the epoxy resin (A1) is 0.05 to 2.5 eq. It is / kg, The flame-retardant epoxy resin composition of any one of Claims 1-3. Epoxy resin (A1) is represented by following formula (1), The flame-retardant epoxy resin composition of any one of Claims 1-4 characterized by the above-mentioned.

(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 are an alkyl group having 1 to 6 carbon atoms and an aryl group having 6 to 10 carbon atoms. Or any of aralkyl groups having 7 to 10 carbon atoms as an aromatic ring substituent, and X is a divalent aliphatic cyclic hydrocarbon group or the following formula (2) or the following formula (3): Any one of the crosslinking groups represented, Z is each independently a glycidyl group (Z1) represented by the following formula (4) or an oxazolidone ring-containing group (Z2) represented by the following formula (5). The molar ratio (Z2 / Z1) of Z1 and Z2 in Z is 0.005 to 0.45, m is 1 or 2, n is the number of repeating units and is an integer of 1 or more. The average value is 1.5 or more.)

(In the formula, each of R ₁ and R ₂ independently represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms.)

(Wherein R ₃ and R ₄ each independently represents 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 any one of an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms as a substituent for the aromatic ring. .)

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

(In the formula, A ₁ , X, Z, and m are the same as those in 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 is n in Formula 1. Is the same.) The flame retardant according to claim 5 or 6, wherein the epoxy resin (A1) is obtained from a novolac type epoxy resin (d) represented by the following formula (7) and an isocyanate compound (e). Epoxy resin composition.

(In the formula, A ₁ , X, m and n are the same as those in Formula 1. G is a glycidyl group.)   The novolac type epoxy resin (d) has a binuclear content of 20 area% or less, a trinuclear content of 15 area% or more and 60 area% or less, as measured by gel permeation chromatography, and a pentanuclear body. The flame retardant epoxy resin composition according to claim 7, wherein the content is 45 area% or less and the number average molecular weight is 350 or more and 700 or less.   The epoxy resin (A1) is obtained by reacting the isocyanate group of the isocyanate compound (e) within a range of 0.01 mol to 0.5 mol with respect to 1 mol of the epoxy group of the novolak type epoxy resin (d). The flame-retardant epoxy resin composition according to claim 7 or 8, wherein   The flame retardant epoxy resin composition according to any one of claims 7 to 9, wherein the isocyanate compound (e) has an average of 1.8 or more isocyanate groups in one molecule.   Isocyanate compound (e) is 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 3,5-tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4 '-Diphenylmethane diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, tetramethylxylylene diisocyanate, 1,4-naphthalenediyl diisocyanate, 1,5-naphthalenediyl diisocyanate, 2,6-naphthalenediyl diisocyanate, 2,7 -Naphthalenediyl diisocyanate, 3,3'-dimethylbisphenyl-4,4'-diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, cyclo Xan-1,4-diyl diisocyanate, cyclohexane-1,3-diyl bismethylene diisocyanate, cyclohexane-1,4-diyl bismethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene The one or more selected from the group consisting of diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 4,4'-methylenebiscyclohexyl diisocyanate, and isophorone diisocyanate. Flame retardant epoxy resin composition.   The flame-retardant epoxy resin composition according to claim 1, wherein the phosphorus compound (C) includes a phosphorus-containing epoxy resin (CA) and / or a phosphorus-containing curing agent (CB).   The epoxy equivalent of phosphorus containing epoxy resin (CA) is 200-800 g / eq. The flame-retardant epoxy resin composition according to claim 12.   The flame-retardant epoxy resin composition according to claim 12 or 13, wherein the phosphorus content of the phosphorus-containing epoxy resin (CA) is 0.5 to 6% by mass.   The flame-retardant epoxy resin composition according to claim 12, wherein the phosphorus content of the phosphorus-containing curing agent (CB) is 0.5 to 12% by mass. The flame retardant epoxy resin composition according to any one of claims 1 to 15, wherein the phosphorus compound (C) is a compound having a unit structure represented by the following formula (8).

  The blending ratio of the epoxy resin (A) and the curing agent (B) is such that the active hydrogen group of the curing agent (B) is 0.2 mol or more and 1.5 mol or less with respect to 1 mol of the epoxy group of the epoxy resin (A). The flame-retardant epoxy resin composition according to any one of claims 1 to 16, which is blended within a range.   The compounding ratio of the phosphorus compound (C) is 1 to 60 wt% with respect to the total of the epoxy resin (A), the curing agent (B), and the phosphorus compound (C). Flame retardant epoxy resin composition.   The flame-retardant epoxy resin composition according to any one of claims 1 to 17, further comprising a filler (F), a thermoplastic resin (G), or both.   A prepreg comprising the flame-retardant epoxy resin composition according to any one of claims 1 to 18.   An insulating sheet using the flame retardant epoxy resin composition according to any one of claims 1 to 18.   The adhesive sheet using the flame-retardant epoxy resin composition of any one of Claims 1-18.   A laminate comprising the flame retardant epoxy resin composition according to any one of claims 1 to 18.   The sealing material characterized by using the flame-retardant epoxy resin composition of any one of Claims 1-18.   A casting material comprising the flame retardant epoxy resin composition according to any one of claims 1 to 18.   Hardened | cured material which hardened the flame-retardant epoxy resin composition of any one of Claims 1-18.

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