JP7387413B2 - Epoxy resin composition, laminates and printed circuit boards using the same - Google Patents

Description

The present invention relates to epoxy resin compositions for manufacturing copper-clad laminates, film materials, resin-coated copper foils, etc. used in electronic circuit boards, encapsulants, molding materials, casting materials, adhesives, etc. used in electronic components, The present invention relates to a flame-retardant epoxy resin composition using a phosphorus-containing epoxy resin having flame-retardant properties such as electrical insulation materials and coating materials, and a copper-clad laminate and printed circuit board using the same.

In recent years, efforts have been made to make electronic equipment flame retardant, with the aim of suppressing toxic gases generated during combustion, with consideration given to the impact on the environment. This is a halogen-free flame retardant that has been changed from the conventional flame retardant using a halogen-containing compound, as typified by brominated epoxy resin, to an organic phosphorus compound. These measures are widely used and recognized as phosphorus flame retardant not only in electronic circuit boards but also in general, and the same is true in the field of epoxy resins related to circuit boards.

As specific representative examples of epoxy resins imparted with such phosphorus flame retardancy, proposals have been made to apply organic phosphorus compounds as disclosed in Patent Documents 1 to 4.
Patent Document 1 discloses a thermosetting resin obtained by reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and epoxy resins at a predetermined molar ratio. ing.
Patent Document 2 discloses that an organic phosphorus compound having an active hydrogen obtained by reacting a quinone compound with an organic phosphorus compound having one active hydrogen bonded to a phosphorus atom, such as DOPO, is further added to a novolak type epoxy. A phosphorus-containing epoxy resin composition obtained by reacting with an epoxy resin containing resin is disclosed.
Patent Document 3 discloses a phosphorus-containing epoxy resin obtained by reacting an organic phosphorus compound, a trifunctional epoxy resin, a bifunctional epoxy resin, and a bifunctional phenol compound at a predetermined mixing ratio.
Patent Document 4 discloses that a phosphorus atom-containing epoxy resin obtained by reacting a phosphorus atom-containing oligomer obtained by reacting and oligomerizing a phosphorus atom-containing compound with an o-hydroxybenzaldehyde compound and a polyfunctional epoxy resin is used as a main ingredient. A curable resin composition is disclosed.

In Patent Documents 1 to 4 mentioned above, the cured product can obtain flame retardancy and glass transition temperature (Tg) equivalent to that of FR-4 substrates, but in recent years, high-density mounting of substrates has been achieved, and As more and more devices are being installed in automobiles, glass transition temperatures (Tg), which are flame retardant and heat resistant, are required to be higher than FR-5.

In the curing technology of these phosphorus-containing epoxy resins, nitrogen-containing dicyandiamide (DICY) is effective in supplementing flame retardancy and is commonly used as a curing agent. However, it is known that cured products using this material are inferior in water absorption and heat resistance reliability than those made using phenol curing agents, especially after the pressure cooker test (PCT) moisture absorption test in laminate applications. Issues such as deterioration of solder heat resistance were considered to be problems.

Conventional phosphorus-containing epoxy resins generally have poor curability with polyfunctional phenol curing agents such as phenol novolak, and tend to have low heat resistance (glass transition temperature: Tg).

The use of oxazine resin as a curing agent was thought to be effective as one method for obtaining higher heat resistance. For example, Patent Document 5 discloses a resin composition containing an epoxy resin, a benzoxazine resin, a dicyclopentadiene phenol resin, and an amine curing agent in a predetermined mixing ratio.
However, in the resin composition of Patent Document 5, the flame retardance of the cured product is insufficient, and therefore it is necessary to use flame retardant additives in order to compensate for this. Addition of a flame retardant unavoidably causes a significant drop in heat resistance in resin formulations for substrates that require extremely high heat resistance of FR-5 or higher.
Therefore, there has been a need to propose a new epoxy resin composition that can simultaneously ensure heat resistance, dielectric properties, and flame retardancy.

Japanese Patent Application Publication No. 11-166035 Japanese Patent Application Publication No. 11-279258 Japanese Patent Application Publication No. 2002-206019 JP2013-035921A JP 2017-20011 Publication

The present invention is directed to a non-halogen flame-retardant epoxy resin composition that maintains high heat resistance with a Tg of 200°C or more while also having low water absorption and low dielectric constant properties, as well as prepregs, copper-clad laminates, etc. using the same. Its purpose is to provide printed circuit boards.

As a result of intensive research to overcome these problems, the present inventors found that in novolac type epoxy resin, which is a raw material for phosphorus-containing epoxy resin, the ratio of the polymer component of heptadons or more to the trinuclide, and the average number of functional groups. By focusing on these and identifying them, we discovered that they are highly effective in improving heat resistance and flame retardancy, and we also combined a specific oxazine resin and alicyclic structure-containing phenol resin as a curing agent for this epoxy resin. It has been discovered that this material can have low dielectric properties, water resistance (low water absorption), and flame retardancy while maintaining extremely high heat resistance.

That is, the present invention is an epoxy resin composition comprising (A) a phosphorus-containing epoxy resin, (B) an oxazine resin, and (C) an alicyclic structure-containing phenol resin,
(B) The oxazine equivalent of the oxazine resin is 230 g/eq. As described above, (A) the phosphorus-containing epoxy resin has a ratio (L /H) is in the range of 0.6 to 4.0, and the average number of functional groups (Mn/E) obtained by dividing the number average molecular weight (Mn) by the epoxy equivalent (E) in terms of standard polystyrene is 3.8 to 4.0. It is a product obtained from a novolac type epoxy resin having a phosphorus content in the range of 4.8 and a phosphorus compound represented by the following general formula (1) and/or general formula (2), and the phosphorus content of the epoxy resin composition is This is an epoxy resin composition characterized in that the ratio is in the range of 0.5 to 1.8% by mass.

In the above general formulas (1) and (2), R ¹ and R ² are each independently a hydrocarbon group having 1 to 20 carbon atoms which may have a hetero atom, and may be different or the same, It may be linear, branched, or cyclic, or may have a cyclic structure in which R ¹ and R ² are bonded. k1 and k2 are each independently 0 or 1. A is an arenetriyl group having 6 to 20 carbon atoms.

The measurement conditions for GPC are as follows: A main body (manufactured by Tosoh Corporation, HLC-8220GPC) equipped with a column (manufactured by Tosoh Corporation, TSKgelG4000H _XL , TSKgelG3000H _XL , TSKgelG2000H _XL ) is used, and the column temperature is 40°C. It was set to ℃. Moreover, tetrahydrofuran (THF) was used as an eluent at a flow rate of 1 mL/min, and a differential refractometer (RI) detector was used as a detector. As a measurement sample, 0.05 g of the sample was dissolved in 10 mL of THF, and 50 μL of the solution was filtered through a microfilter. The number average molecular weight (Mn) of the novolac type epoxy resin and the content rate (area %) of each nucleus were measured using a standard polystyrene calibration curve.

The above (B) oxazine resin can be selected from compounds having a structural formula as shown in the following general formula (3).

In the above general formula (3), R ³ is each independently an aromatic ring group, R ⁴ is each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and two R 3s in the same benzene ring ⁴ may be connected to form a cyclic structure. Each R ⁵ is independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. Y is -O- or -N(R ⁶ )-, and R ⁶ is a hydrocarbon group having 1 to 20 carbon atoms. Z is -CO- or -SO ₂ -.

Further, the (C) alicyclic structure-containing phenol resin used in the epoxy resin composition can be selected from compounds having a structural formula as shown by the following general formula (4).

In the above formula (4), T is an aliphatic cyclic hydrocarbon group, and X is an aromatic ring group selected from a benzene ring, a naphthalene ring, a biphenyl ring, or a bisphenyl structure, and these aromatic ring groups are , as a substituent, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, Alternatively, it may have an aralkyloxy group having 7 to 12 carbon atoms. i is an integer from 1 to 3. n is a number from 1 to 10 as an average value.

Further, the present invention is a cured product obtained by curing the above-mentioned epoxy resin composition, and a prepreg, a laminate, or a printed wiring board using the above-mentioned epoxy resin composition.

The epoxy resin composition of the present invention has both extremely high heat resistance and flame retardancy that cannot be obtained with conventional epoxy resin compositions, and can also provide a cured product with good low dielectric properties and low water absorption. It has become possible.

A GPC chart of the novolac type epoxy resin obtained in Synthesis Example 3 is shown. A GPC chart of a general-purpose phenol novolak type epoxy resin is shown.

Embodiments of the present invention will be described in detail below.
The epoxy resin composition of the present invention is a non-halogen flame-retardant epoxy resin composition containing (A) a phosphorus-containing epoxy resin, (B) an oxazine resin, and (C) an alicyclic structure-containing phenol resin as essential components, The phosphorus content ranges from 0.5 to 1.8% by weight. In this specification, the phosphorus content in an epoxy resin composition refers to the proportion in the organic component excluding the solvent and inorganic filler from the epoxy resin composition. If the phosphorus content is less than 0.5% by mass, flame retardancy may be insufficient, and if the phosphorus content exceeds 1.8% by mass, heat resistance above Tg = 200°C may not be ensured. be. A preferred range is a phosphorus content of 0.6 to 1.6% by mass, and a more preferred range is a phosphorus content of 0.8 to 1.3% by mass.

(A) The phosphorus-containing epoxy resin is a novolak-type epoxy resin having a specific molecular weight distribution and a specific average number of functional groups, and a phosphorus compound represented by the above general formula (1) and/or the general formula (2). It is obtained by reaction with a phosphorus compound. However, if only the phosphorus compound of general formula (2) is used alone, the heat resistance of the composition will be lowered, so it is preferable to increase the ratio of the phosphorus compound of general formula (1). Specifically, the molar ratio of the phosphorus compound of general formula (1) to the phosphorus compound of general formula (2) is preferably 99:1 to 75:25, more preferably 95:5 to 85:15. This range is preferable from the viewpoint of handling, such as viscosity, which affects the impregnability of glass cloth as a phosphorus-containing epoxy resin composition.
In addition, in terms of raw material molar ratio, for example, when the phosphorus compound of general formula (2) is DOPO and the phosphorus compound of general formula (1) is a reaction product of DOPO and naphthoquinone (NQ), NQ/DOPO (molar ratio) 0.50, the molar ratio of the phosphorus compound of general formula (1) to the phosphorus compound of general formula (2) corresponds to 50:50, and NQ/DOPO (molar ratio) 0.99. , it corresponds to 99:1.

As the phosphorus compound, it is necessary to use a phosphorus compound represented by the above general formula (1) or general formula (2), which may be used alone or in combination.
In general formula (1) or general formula (2), R ¹ and R ² represent a hydrocarbon group having 1 to 20 carbon atoms which may have a hetero atom, and each may be different or the same, or may be directly It may be chain, branched, or cyclic. Furthermore, R ¹ and R ² may be combined to form a cyclic structure. In particular, aromatic ring groups such as a benzene ring are preferred. When R ¹ and R ² are aromatic ring groups, the substituents include an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, and a cycloalkyl group having 6 to 10 carbon atoms. may have an aryl group having 7 to 11 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, or an aralkyloxy group having 7 to 11 carbon atoms. Examples of the heteroatom include an oxygen atom, which can be included between carbon atoms constituting a hydrocarbon chain or a hydrocarbon ring.
k1 and k2 are each independently 0 or 1.
A is a trivalent aromatic hydrocarbon group having 6 to 20 carbon atoms (arenetriyl group). Preferred are benzene ring groups and naphthalene ring groups. The aromatic hydrocarbon group includes, as a substituent, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms. It may have an aralkyl group having 7 to 12 carbon atoms or an aralkyloxy group having 7 to 12 carbon atoms.

First, examples of phosphorus compounds represented by the above general formula (2) used as raw materials include dimethylphosphine oxide, diethylphosphine oxide, dibutylphosphine oxide, diphenylphosphine oxide, dibenzylphosphine oxide, cyclooctylenephosphine oxide, tolyl Phosphine oxide, bis(methoxyphenyl)phosphine oxide, etc., phenyl phenylphosphinate, ethyl phenylphosphinate, tolyl tolylphosphinate, benzyl benzylphosphinate, etc., DOPO, 8-methyl-9,10-dihydro-9-oxa -10-phosphaphenanthrene-10-oxide, 8-benzyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 8-phenyl-9,10-dihydro-9-oxa-10 -Phosphaphenanthrene-10-oxide, 2,6,8-tri-butyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6,8-dicyclohexyl-9,10-dihydro Examples include -9-oxa-10-phosphaphenanthrene-10-oxide, diphenyl phosphonate, ditolyl phosphonate, dibenzyl phosphonate, 5,5-dimethyl-1,3,2-dioxaphosphorinane, etc. , but not limited to these. These phosphorus compounds may be used alone or in combination of two or more.

Further, examples of phosphorus compounds represented by the above general formula (1) used as raw materials include 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO -HQ), 10-[2-(dihydroxynaphthyl)]-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-NQ), diphenylphosphinylhydroquinone, diphenylphosphenyl- Examples include 1,4-dioxynaphthalene, 1,4-cyclooctylenephosphinyl-1,4-phenyldiol, and 1,5-cyclooctylenephosphinyl-1,4-phenyldiol. These phosphorus compounds may be used alone or in combination of two or more types, and are not limited to these.

(A) The novolak type epoxy resin used together with the above phosphorus compound as a raw material for the phosphorus-containing epoxy resin is generally made by reacting a novolak type phenol resin, which is a condensation reaction product of phenols and aldehydes, with an epihalohydrin such as epichlorohydrin. This is a polyfunctional novolak type epoxy resin obtained by the following formula (5).
Phenols used include phenol, cresol, ethylphenol, butylphenol, styrenated phenol, cumylphenol, naphthol, catechol, resorcinol, naphthalene diol, bisphenol A, etc., and aldehydes include formalin, formaldehyde, and hydroxybenzaldehyde. , salicylaldehyde and the like. Furthermore, aralkyl-type phenolic resins using xylylene dimethanol, xylylene dichloride, bischloromethylnaphthalene, bischloromethylbiphenyl, etc. instead of aldehydes also fall under the novolac-type phenolic resin in the present invention.

In the above general formula (5), W is an aromatic ring group selected from a benzene ring, a naphthalene ring, a biphenyl ring, or a bisphenyl structure, and these aromatic ring groups are an alkyl group having 1 to 6 carbon atoms, Having an alkoxy group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an aralkyloxy group having 7 to 12 carbon atoms. You can.
U is a crosslinking group represented by the following formula (5a) or formula (5b). It may also be a divalent aliphatic cyclic hydrocarbon group.
j is each independently an integer of 1 to 3 and represents the number of hydroxyl groups in each aromatic ring, and is preferably 1 or 2.
m is a number from 1 to 10 on average, preferably from 1 to 5.

In the above formulas (5a) and (5b), R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ are each independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. B is an aromatic ring group selected from a benzene ring, a naphthalene ring, or a biphenyl ring, and these aromatic ring groups include an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a carbon It may have an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an aralkyloxy group having 7 to 12 carbon atoms.

When U is a divalent aliphatic cyclic hydrocarbon group, the number of carbon atoms is preferably 5 to 15, more preferably 5 to 10. Here, the divalent aliphatic cyclic hydrocarbon group refers to unsaturated cyclic aliphatic groups such as dicyclopentadiene, tetrahydroindene, 4-vinylcyclohexene, 5-vinylnorbon-2-ene, α-pinene, β-pinene, and limonene. Examples include divalent aliphatic cyclic hydrocarbon groups derived from group hydrocarbon compounds, and cycloalkylene groups such as trimethylcyclohexylene, tetramethylcyclohexylene, and cyclododecylene groups.

Specific examples of common novolac type epoxy resins include phenol novolac type epoxy resins (e.g., Epototo YDPN-638 (manufactured by Nippon Steel Chemical & Materials Co., Ltd.), jER152, jER154 (all manufactured by Mitsubishi Chemical Corporation), Epiclon N-740, N-770, N-775 (manufactured by DIC Corporation, etc.), cresol novolac type epoxy resin (for example, Epototo YDCN-700 series (manufactured by Nippon Steel Chemical & Materials Corporation), Epiclon N-660 , N-665, N-670, N-673, N-695 (manufactured by DIC Corporation), EOCN-1020, EOCN-102S, EOCN-104S (manufactured by Nippon Kayaku Co., Ltd.), etc.), alkyl Novolak-type epoxy resins (e.g., Epototo ZX-1071T, ZX-1270, ZX-1342 (manufactured by Nippon Steel Chemical & Materials Co., Ltd.), etc.), aromatic modified phenol novolac-type epoxy resins (e.g., Epototo ZX-1247, GK-5855, TX-1210, YDAN-1000 (manufactured by Nippon Steel Chemical & Materials Co., Ltd.), etc.), bisphenol novolac type epoxy resin, naphthol novolac type epoxy resin (e.g. Epotote ZX-1142L (made by Nippon Steel Chemical & Materials Co., Ltd.) Co., Ltd.), β-naphthol aralkyl epoxy resins (for example, ESN-155, ESN-185V, ESN-175 (manufactured by Nippon Steel Chemical & Materials Co., Ltd.), etc.), naphthalene diol aralkyl epoxy resins ( For example, ESN-355, ESN-375 (all manufactured by Nippon Steel Chemical & Material Co., Ltd.), α-naphthol aralkyl type epoxy resin (such as ESN-475V, ESN-485 (all manufactured by Nippon Steel Chemical & Material Co., Ltd.) ), biphenylaralkylphenol type epoxy resins (e.g., NC-3000, NC-3000H (manufactured by Nippon Kayaku Co., Ltd.), etc.), trihydroxyphenylmethane type epoxy resins (e.g., EPPN-501, EPPN -502 (manufactured by Nippon Kayaku Co., Ltd.), dicyclopentadiene type epoxy resins (such as Epiclon HP7200, HP-7200H (manufactured by DIC Corporation), etc.). However, these commercially available novolac-type epoxy resins usually do not have the specific molecular weight distribution that is characteristic of the novolac-type epoxy resin used in the present invention, and the average number of functional groups is also outside the range.

In order to obtain a novolak type epoxy resin having a specific molecular weight distribution and a specific average number of functional groups used in the present invention, a novolak type phenol resin obtained by reacting phenols and aldehydes in the presence of an acid catalyst is used as a starting point. Use as raw material. These reaction methods may be, for example, known methods obtained by production methods as shown in JP-A No. 2002-194041, JP-A No. 2007-126683, and JP-A No. 2013-107980, and are not particularly limited. .
The obtained starting material novolac-type phenolic resin is subjected to various methods such as distillation to remove low molecular weight, mainly dinuclear bodies, or to reduce the content to 10% by area or less, and then further treated with aldehydes in the presence of an acid catalyst. Adjustments are made to reduce the number of dinuclear bodies and increase the ratio of heptanuclear bodies or more by performing condensation with. Since the novolac type epoxy resin is epoxidized to reflect the molecular weight distribution of the novolac type phenol resin, the content of each nucleus can be similarly adjusted in the obtained novolac type epoxy resin.
In this specification, the "content rate" of each core of the novolak-type epoxy resin refers to "area %" measured by GPC, and may be expressed as content rate or area %. Further, the content of heptadons or more and the content of trinuclear bodies may be simply expressed as "H" and "L", respectively. Here, in the novolac type epoxy resin represented by the above general formula (6), a trinuclear body is a case where m is 2, and a heptanuclear body is a case where m is 6 or more.

In the production of novolak type phenolic resin, the molar ratio of phenols to aldehydes is adjusted to adjust the molar ratio of phenols to 1 mole of aldehydes. Generally, when the molar ratio of phenols used is large, more dinuclear bodies are produced, followed by trinuclear bodies, and as the molar ratio of phenols used becomes smaller, more high molecular weight polynuclear bodies are produced. On the contrary, the number of binuclear bodies and trinuclear bodies decreases.

In general novolak-type phenolic resins that do not remove low molecules, when increasing the number of functional groups, it is common to increase the degree of condensation by decreasing the molar ratio of phenol to 1 mole of aldehyde. In the case of this production method, the dispersion (Mw/Mn) of the molecular weight distribution of the obtained novolac type phenol resin becomes wide, and the value of the number average molecular weight (Mn) becomes low due to the influence of the amount of remaining binuclear bodies. On the other hand, the increase in the content (area %) of hepta-nuclear bodies or more as determined by GPC measurement becomes significantly large. In addition, when this novolak type phenol resin is epoxidized, the epoxy equivalent (E) also increases, so the average number of functional groups (Mn/E) tends to decrease, making it suitable for epoxy resins aiming for high heat resistance. It wasn't.

In terms of flame retardancy, the binuclear substance of novolac type epoxy resin is a difunctional substance, so it has a weak contribution to the crosslinking structure in the cured product, and its high thermal decomposition upon ignition may have an adverse effect on flame retardancy. There are concerns. Therefore, as one of the systems for promoting flame retardancy, it is effective to remove low molecules, mainly binuclear bodies, and further condense them again.

On the other hand, as another method of promoting flame retardancy, a method of suppressing the generation of flammable decomposition gas to the outside is also known. For this purpose, it is considered preferable to keep the elastic modulus of the rubbery region of the cured product low at high temperatures. However, high-temperature cured products tend to have a high high-temperature elastic modulus due to their high crosslinking density, and there are known cases where the area around the non-flammable char formed after combustion becomes hard and brittle, worsening flame retardancy. Ta.

Therefore, we carefully considered the mechanism that promotes these flame retardant properties, and as a result of intensive study on how to achieve multifunctionalization by reducing the number of binuclear bodies while not increasing the number of high-nuclear bodies too much, we succeeded in reducing the number of binuclear bodies. Later, it was discovered that a method of re-condensing a raw material mainly consisting of trinuclear bodies as a starting material to achieve polyfunctionalization was effective for flame retardancy. In other words, a novolac type epoxy resin having a ratio (L/H) of the trinuclear content (L) to the content (H) of heptadonuclides or more is in the range of 0.6 to 4.0 is used as a phosphorus-containing epoxy resin. By using it as a raw material, even if the amount of phosphorus compound used is reduced, the flame retardant effect can be fully extracted from the resin itself.

When the phosphorus-containing epoxy resin obtained by the above method is used, the elastic modulus of the cured product of the phosphorus-containing epoxy resin composition in a high temperature range can be kept low, and the flame retardance is also improved. Specifically, in actual measurement using a dynamic viscoelasticity measuring device (DMA: measurement conditions of heating rate 2°C/min, frequency 1Hz), the value of the storage modulus stabilized at 220°C or higher decreases, and the combustion test is confirmed. The burning part of the piece foams and extinguishes the fire. The value of the elastic modulus is preferably adjusted to 150 MPa or less, more preferably 50 MPa or less. If the content of heptadons or more increases too much, the crosslinking density of the cured product will increase, and the char around the combustion part will become hard and brittle, resulting in poor flame retardancy.

In the novolac type epoxy resin, which is the raw material for the phosphorus-containing epoxy resin used in the present invention, a method for mainly removing or reducing dinuclear bodies from the novolac type phenol resin, which is the raw material, is to utilize the difference in solubility of various solvents. There are several known separation methods, such as a method of removing by dissolving in an alkaline aqueous solution, and a method of removing by thin film distillation, and any of these separation methods may be used.

The novolac type phenol resin whose binuclear bodies have been removed or reduced by the above method is again condensed with aldehydes to adjust its molecular weight distribution. The recondensation method may be a method in which the product is dissolved in an organic solvent such as toluene or isobutyl ketone and then reacted with an aldehyde using an acid catalyst, or a similar reaction is performed in a molten state without a solvent. Acid catalysts include inorganic acids such as hydrochloric acid, sulfuric acid, and boric acid, and organic acids such as oxalic acid, acetic acid, benzenesulfonic acid, p-toluenesulfonic acid, xylene sulfonic acid, p-phenolsulfonic acid, methanesulfonic acid, and ethanesulfonic acid. may be used alone or in combination. Moreover, generally known aldehydes can be used. Examples include formaldehyde, paraformaldehyde, chloroacetaldehyde, dichloroacetaldehyde, bromoacetaldehyde, trioxane, acetaldehyde, glyoxal, acrolein, methacrolein, etc., and formaldehyde and paraformaldehyde are preferred in the production of phenol novolak. In this case, one kind or a mixture of two or more kinds of aldehydes may be used. Aldehydes, etc. can be added in one go along with the raw materials in the presence of an acid catalyst with sufficient cooling equipment, or in portions while checking the heat generation as the reaction progresses. , it can be implemented using a method that suits the equipment.

The amount of aldehyde used in the recondensation is 0.06 to 0.30 times the number of moles obtained by dividing the amount of novolac type phenol resin charged by the actual average molecular weight of the novolak type phenol resin. It is preferable that the reaction is carried out at a rate of 0.08 to 0.15 times, more preferably 0.10 to 0.12 times, which allows the most suitable core to be prepared as a novolac type epoxy resin. Note that the "actual average molecular weight" here refers to the integrated average molecular weight obtained by multiplying the area % of each nucleus obtained from GPC measurement by each theoretical molecular weight. If this is less than 0.06 times, the average number of functional groups in the phosphorus-containing epoxy resin will be insufficient, making it impossible to obtain heat resistance of 200° C. or higher. If it is more than 0.30 times, the average number of functional groups increases excessively, and the cured product becomes highly elastic, making it impossible to obtain sufficient flame retardancy.

Epoxidation of the novolac type phenolic resin thus obtained can be carried out by a known method. For example, using 3 to 5 times the mole of epihalohydrin based on the number of moles of hydroxyl groups in the novolac type phenolic resin, the process is carried out at 60 to 70°C for 2 hours under reduced pressure of 100 to 200 torr (13.3 to 26.7 kPa). The reaction can be carried out while dropping the caustic soda aqueous solution.

The novolac type epoxy resin obtained by these methods has a ratio (L/H) of the area % (L) of trinuclear bodies to the area % (H) of heptadonucleons or more when measured using GPC (L/H). 4.0, and the average number of functional groups (Mn/E) obtained by dividing the number average molecular weight (Mn) by the epoxy equivalent (E) is in the range of 3.8 to 4.8.
If (L/H) exceeds 4.0, the number of trinuclear bodies increases, the average number of functional groups becomes less than 3.8, and the heat resistance of the cured product using the phosphorus-containing epoxy resin decreases. can't get it. On the other hand, when (L/H) is less than 0.6, the number of heptanuclear bodies or more increases and the number of dinuclear bodies decreases, so that the cured product becomes hard and brittle, and the flame retardance is greatly impaired. More preferably, it is a novolac type epoxy resin with L/H in the range of 1.0 to 3.0.

The reaction for obtaining a phosphorus-containing epoxy resin from the phosphorus compound represented by the general formula (1) and/or the general formula (2) and the above-mentioned novolac type epoxy resin is carried out by a known method. For example, as described in Patent Document 2, after synthesizing general formula (1) and general formula (2), adding a novolak type epoxy resin etc. to homogenize it, and then adding triphenylphosphine etc. as a catalyst. Alternatively, the reaction may be carried out at 150°C.

Further, a catalyst may be used in this reaction in order to shorten the time and lower the reaction temperature. The catalyst used is not particularly limited, and those commonly used in the synthesis of epoxy resins can be used. For example, tertiary amines such as benzyldimethylamine, quaternary ammonium salts such as tetramethylammonium chloride, phosphines such as triphenylphosphine, tris(2,6-dimethoxyphenyl)phosphine, ethyltriphenylphosphonium bromide, etc. Various catalysts such as phosphonium salts, imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole can be used, and they may be used alone or in combination of two or more types, and are limited to these. It's not a thing. Alternatively, it may be divided and used several times.

The amount of catalyst here is not particularly limited, but is preferably 5% by mass or less, more preferably 1% by mass or less, and 0.5% by mass or less, more preferably 1% by mass or less, based on the phosphorus-containing epoxy resin (the total amount of the raw material novolak epoxy resin and phosphorus compound). More preferably, it is 5% by mass or less. If the amount of the catalyst is too large, the self-polymerization reaction of the epoxy group may proceed in some cases, which increases the viscosity of the resin, which is not preferable. Further, in the case of using a pre-reacted epoxy resin in which the reaction here is stopped midway, the reaction rate can be easily adjusted to 60 to 90% by controlling the catalyst amount to 0.1% by mass or less.

When reacting the phosphorus compound represented by the general formula (1) or the general formula (2) with the novolac type epoxy resin, various epoxy resin modifiers may be used in combination as necessary within a range that does not impair the characteristics of the present invention. Good too. Modifiers include bisphenol A, bisphenol F, bisphenol AD, tetrabutylbisphenol A, hydroquinone, methylhydroquinone, dimethylhydroquinone, dibutylhydroquinone, resorcinol, methylresorcinol, biphenol, tetramethylbiphenol, 4,4'-(9-fluorenylidene) Diphenol, dihydroxynaphthalene, dihydroxydiphenyl ether, dihydroxystilbenes, phenol novolak resin, cresol novolak resin, bisphenol A novolak resin, dicyclopentadiene phenol resin, phenol aralkyl resin, naphthol novolac resin, terpene phenol resin, heavy oil-modified phenol resin , various phenols such as brominated phenol novolac resins, polyhydric phenol resins obtained by condensation reactions of various phenols with various aldehydes such as hydroxybenzaldehyde, crotonaldehyde, and glyoxal, aniline, and phenylenediamine. , toluidine, xylidine, diethyltoluenediamine, diaminodiphenylmethane, diaminodiphenylethane, diaminodiphenylpropane, diaminodiphenyl ketone, diaminodiphenylsulfide, diaminodiphenylsulfone, bis(aminophenyl)fluorene, diaminodiethyldimethyldiphenylmethane, diaminodiphenyl ether, diaminobenzanilide , diaminobiphenyl, dimethyldiaminobiphenyl, biphenyltetraamine, bisaminophenylanthracene, bisaminophenoxybenzene, bisaminophenoxyphenyl ether, bisaminophenoxybiphenyl, bisaminophenoxyphenyl sulfone, bisaminophenoxyphenylpropane, diaminonaphthalene, etc. Examples include, but are not limited to, compounds. These epoxy resin modifiers may be used alone or in combination of two or more.

Furthermore, an inert solvent may be used in the reaction. Specifically, various hydrocarbons such as hexane, heptane, octane, decane, dimethylbutane, pentene, cyclohexane, methylcyclohexane, benzene, toluene, xylene, ethylbenzene, isopropyl alcohol, isobutyl alcohol, isoamyl alcohol, methoxypropanol, etc. Various alcohols, ethers such as ethyl ether, isopropyl ether, butyl ether, diisoamyl ether, methyl phenyl ether, ethyl phenyl ether, amyl phenyl ether, ethyl benzyl ether, dioxane, methylfuran, tetrahydrofuran, methyl cellosolve, methyl cellosolve acetate , ethyl cellosolve, cellosolve acetate, ethylene glycol isopropyl ether, diethylene glycol dimethyl ether, methyl ethyl carbitol, propylene glycol monomethyl ether, dimethyl formamide, dimethyl sulfoxide, etc. can be used, but are not limited to these, and two or more types can be mixed. You may also use it.

(B) Various oxazine resins can be used as long as the oxazine equivalent is 230 g/eq or more. The preferred range of oxazine equivalent is 230 to 500 g/eq. and more preferably 240 to 400 g/eq. and more preferably 250 to 380 g/eq. and particularly preferably 260 to 350 g/eq. It is. In addition to the oxazine resin having the structure of the general formula (3) above, oxazine resins having the structure of the following general formula (6) or (7) are preferable. In order to further improve the heat resistance and flame retardance of the cured product, an oxazine resin having the structure of the above general formula (3) is more preferable.
Specifically, the oxazine resins include bisphenol A type benzoxazine compounds (for example, XU3560CH (manufactured by Huntsman), etc.), bisphenol S type benzoxazine compounds (for example, BS-BXZ (manufactured by Konishi Chemical Industry Co., Ltd.), etc.) , phenolphthalein-type benzoxazine compounds (for example, LMB6490 (manufactured by Huntsman), etc.), diaminodiphenylsulfone-type oxazine resins, phenol novolak-type benzoxazine compounds (for example, YBZ-2213 (manufactured by Nippon Steel Chemical & Materials Co., Ltd.), etc.) Examples include, but are not limited to.

In general formulas (3), (6) and (7), R ³ represents an aromatic ring group, preferably a phenyl group or a naphthyl group, and these aromatic ring groups have 1 to 1 carbon atoms as a substituent. 6 alkyl group, an alkoxy group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an aralkyl group having 7 to 12 carbon atoms. It may have an oxy group.
R ⁴ is each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, which may be linear, branched, or cyclic, and forms a cyclic structure in which two R ^4s in the same benzene ring are connected. You may do so. When R ⁴ is an aromatic ring group, the substituent may be an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, or an aryl group having 6 to 10 carbon atoms. , an aralkyl group having 7 to 11 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, or an aralkyloxy group having 7 to 11 carbon atoms.
Each R ⁵ is independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms.
R ⁷ is each independently -O-, -SO ₂ -, -C(CH ₃ ) ₂ -, -CH(CH ₃ )-, -CH ₂ -, and a substituted or unsubstituted tetrahydrodicyclopentadienediyl group It is.
V represents an aromatic ring group, preferably a phenylene group or a naphthylene group, and these aromatic ring groups may be substituted with an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. It may have an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an aralkyloxy group having 7 to 12 carbon atoms.
Y is -O- or -N(R ⁶ )-, and R ⁶ is a hydrocarbon group having 1 to 20 carbon atoms.
Z is -CO- or -SO ₂ -.

Preferred oxazine resins having the structure of general formula (3) include, for example, compounds represented by the following formulas (3a) to (3l), but are not limited thereto. Among these, (3a), (3b), (3c), (3d), (3g), (3h), (3i), (3j), (3k), and (3l) are more preferable, and (3a) ), (3c), (3d), (3g), (3h), (3i), (3j), (3k), (3l) are more preferred, and (3a), (3c), (3h), ( 3i), (3k), and (3l) are more preferred.

In the epoxy resin composition of the present invention, the blending amount of (B) oxazine resin is preferably 10 to 80 parts by mass, more preferably 15 to 75 parts by mass, based on 100 parts by mass of (A) phosphorus-containing epoxy resin. More preferably 20 to 70 parts by weight, particularly preferably 30 to 65 parts by weight. If the content of the oxazine resin is within this range, the cured product obtained from the resin composition of the present invention can have the expected low dielectric loss value (Df). If the oxazine resin is less than 10 parts by mass, the expected low dielectric loss value may not be achieved, and if it exceeds 80 parts by mass, the heat resistance of the substrate manufactured with the resin composition may deteriorate.

(C) The alicyclic structure-containing phenol resin is represented by the above general formula (4).
In general formula (4), T is a divalent aliphatic cyclic hydrocarbon group. This is an essential structure.
W is an aromatic ring group selected from a benzene ring, a naphthalene ring, a biphenyl ring, or a bisphenyl structure, and these aromatic ring groups include an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms. , an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an aralkyloxy group having 7 to 12 carbon atoms.
i is each independently an integer of 1 to 3, represents the number of hydroxyl groups in each aromatic ring, and is preferably 1 or 2.
n is a number from 1 to 10 on average, preferably from 1 to 5.

The divalent aliphatic cyclic hydrocarbon group preferably has 5 to 20 carbon atoms, more preferably 5 to 12 carbon atoms. Here, the divalent aliphatic cyclic hydrocarbon group is a substituted or unsubstituted cycloalkyldiyl group or a condensed ring group thereof, preferably a condensed ring group in which two or more aliphatic rings are condensed, and has 1 or more carbon atoms. It may have ~10 substituents, and in the case of a monocyclic ring, a 1,1-cycloalkylidene group (cycloalkyl-1,1-diyl group) to which the same carbon atoms are bonded is preferable.
Examples of the substituent having 1 to 10 carbon atoms include an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms. The alkyl group having 1 to 10 carbon atoms may be linear, branched, or cyclic, such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, t-butyl group, etc. Examples include, but are not limited to, -butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, cyclohexyl group, methylcyclohexyl group, dimethylcyclohexyl group, cyclooctyl group, and the like. Examples of the aryl group having 6 to 10 carbon atoms include, but are not limited to, phenyl group, tolyl group, xylyl group, ethylphenyl group, and naphthyl group. Examples of the aralkyl group having 7 to 10 carbon atoms include, but are not limited to, benzyl group and α-methylbenzyl group.

Examples of the divalent aliphatic cyclic hydrocarbon group include cyclopentane-1,1-diyl group, cyclohexane-1,1-diyl group, cycloheptane-1,1-diyl group, and cyclooctane-1,1-diyl group. Diyl group, cyclononane-1,1-diyl group, cyclodecane-1,1-diyl group, cycloundecan-1,1-diyl group, cyclododecane-1,1-diyl group, 2-methylcyclohexane-1,1- Diyl group, 3-methylcyclohexane-1,1-diyl group, 4-methylcyclohexane-1,1-diyl group, 2-ethylcyclohexane-1,1-diyl group, 3-ethylcyclohexane-1,1-diyl group , 4-ethylcyclohexane-1,1-diyl group, 2-t-butylcyclohexane-1,1-diyl group, 3-t-butylcyclohexane-1,1-diyl group, 4-t-butylcyclohexane-1, 1-diyl group, 2-phenylcyclohexane-1,1-diyl group, 3-phenylcyclohexane-1,1-diyl group, 4-phenylcyclohexane-1,1-diyl group, 3,3,5-trimethylcyclohexane- 1,1-diyl group, 3,3,5,5-tetramethylcyclohexane-1,1-diyl group, 3-methylcyclohexane-1,1-diyl group, 2-isopropyl-5-methylcyclohexane-1,5 -diyl group, crosslinking groups represented by the following formulas (4a) to (4l), etc., but are not limited to these. Note that the crosslinking groups represented by the following formulas (4a) to (4l) may have a substituent having 1 to 6 carbon atoms.
Among these, 3,3,5-trimethylcyclohexane-1,1-diyl group, 3,3,5,5-tetramethylcyclohexane-1,1-diyl group, cyclododecane-1,1-diyl group, (4a), (4b), (4c), (4d), (4e), (4f), (4h), (4j), and (4l) are more preferred, and 3,3,5-trimethylcyclohexane-1, 1-diyl group, 3,3,5,5-tetramethylcyclohexane-1,1-diyl group, cyclododecane-1,1-diyl group, (4a), (4b), (4c), (4d), (4e) and (4f) are more preferred, and 3,3,5-trimethylcyclohexane-1,1-diyl group, cyclododecane-1,1-diyl group, and (4c) are particularly preferred.

In the epoxy resin composition of the present invention, the blending amount of (C) alicyclic structure-containing phenol resin is preferably 10 to 50 parts by mass, and 15 to 45 parts by mass, based on 100 parts by mass of (A) phosphorus-containing epoxy resin. is more preferable, and even more preferably 20 to 40 parts by mass. If the content of the alicyclic structure-containing phenolic resin is blended within this range, the cured product obtained from the resin composition can have the expected dielectric constant value (Dk). If the amount of the alicyclic structure-containing phenolic resin is less than 10 parts by mass, there is a possibility that the expected dielectric constant value will not be obtained, and furthermore, there is a possibility that the heat resistance of the substrate will deteriorate. If the amount exceeds 50 parts by mass, the heat resistance of the substrate manufactured with the resin composition may deteriorate.

The epoxy resin composition of the present invention may also contain epoxy resins other than the above-mentioned phosphorus-containing epoxy resins, if necessary. Examples of epoxy resins that can be used in combination include, but are not limited to, polyglycidyl ether compounds, polyglycidyl amine compounds, polyglycidyl ester compounds, alicyclic epoxy compounds, and other modified epoxy resins. These epoxy resins may be used alone or in combination of two or more. When an epoxy resin is used in combination, it is preferably 50% by mass or less, more preferably 30% by mass or less of the total epoxy resin. If too much epoxy resin is used in combination, there is a risk that it will not be possible to achieve both heat resistance and flame retardancy.

Examples of epoxy resins that can be used in combination include bisphenol A epoxy resin, bisphenol F epoxy resin, tetramethylbisphenol F epoxy resin, hydroquinone epoxy resin, biphenyl epoxy resin, bisphenol fluorene epoxy resin, and bisphenol S. type epoxy resin, bisthioether type epoxy resin, resorcinol type epoxy resin, biphenylaralkylphenol type epoxy resin, naphthalene diol type epoxy resin, phenol novolac type epoxy resin, aromatic modified phenol novolac type epoxy resin, cresol novolak type epoxy resin, alkyl Novolac type epoxy resin, bisphenol novolac type epoxy resin, naphthol novolak type epoxy resin, β-naphthol aralkyl type epoxy resin, dinaphthol aralkyl type epoxy resin, α-naphthol aralkyl type epoxy resin, trisphenylmethane type epoxy resin, dicyclopentadiene Examples include, but are not limited to, type epoxy resins, alkylene glycol type epoxy resins, aliphatic cyclic epoxy resins, diaminodiphenylmethane tetraglycidylamine, aminophenol type epoxy resins, urethane-modified epoxy resins, oxazolidone ring-containing epoxy resins, etc. isn't it.

The epoxy resin composition of the present invention may be used in combination with a conventional known curing agent as long as the effect is not impaired. Examples of curing agents that can be used in combination include commonly used curing agents such as phenolic resin curing agents other than the alicyclic structure-containing phenolic resin (C) above, acid anhydride curing agents, amine curing agents, and other curing agents. However, these curing agents may be used alone or in combination of two or more. Among these, dicyandiamide curing agents are preferred in terms of imparting heat resistance, and phenolic resin curing agents are preferred in terms of imparting water absorption and long-term thermal stability.

The amount of the curing agent that can be used in combination is preferably 50 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 10 parts by mass or less, based on 100 parts by mass of the (c) alicyclic structure-containing phenolic resin. Moreover, the blending amount can also be determined from another viewpoint. The active hydrogen group of the curing agent is in the range of 0.2 to 1.5 mole per mole of epoxy groups of all the epoxy resins in the epoxy resin composition. If the number of active hydrogen groups is less than 0.2 mole or more than 1.5 mole per mole of epoxy group, curing may be incomplete and good cured physical properties may not be obtained. The amount is preferably 0.3 to 1.5 mol, more preferably 0.5 to 1.5 mol, and even more preferably 0.8 to 1.2 mol.

In the present invention, the active hydrogen group refers to a functional group that has an active hydrogen that is reactive with an epoxy group (including a functional group that has a latent active hydrogen that generates active hydrogen through hydrolysis, etc., and a functional group that exhibits an equivalent curing effect). ), and specific examples include acid anhydride groups, carboxyl groups, amino groups, and phenolic hydroxyl groups. Regarding active hydrogen groups, 1 mole of carboxyl group or phenolic hydroxyl group is calculated as 1 mole, and 2 moles of amino group (NH ₂ ). Furthermore, when the active hydrogen group is not clear, the active hydrogen equivalent can be determined by measurement. For example, by reacting a monoepoxy resin such as phenyl glycidyl ether with a known epoxy equivalent with a curing agent with an unknown active hydrogen equivalent, and measuring the amount of monoepoxy resin consumed, the active hydrogen equivalent of the used curing agent can be determined. can be found.

Specific examples of phenolic resin curing agents that can be used in combination include bisphenol A, bisphenol F, bisphenol C, bisphenol K, bisphenol Z, bisphenol S, tetramethylbisphenol A, tetramethylbisphenol F, tetramethylbisphenol S, and tetramethyl. Bisphenols such as bisphenol Z, dihydroxydiphenyl sulfide, bisphenol TMC, 4,4'-(9-fluorenylidene) diphenol, 4,4'-thiobis(3-methyl-6-t-butylphenol), catechol, resorcinol, Dihydroxybenzenes such as methylresorcinol, hydroquinone, monomethylhydroquinone, dimethylhydroquinone, trimethylhydroquinone, mono-t-butylhydroquinone, di-t-butylhydroquinone, and hydroxynaphthalenes such as dihydroxynaphthalene, dihydroxymethylnaphthalene, dihydroxymethylnaphthalene, and trihydroxynaphthalene. phosphorus-containing phenol curing agents such as LC-950PM60 (manufactured by Shin-AT&C), phenol novolac resins such as Shonol BRG-555 (manufactured by Aica Kogyo Co., Ltd.), and DC-5 (manufactured by Nippon Steel Chemical & Materials Co., Ltd.). Phenols such as cresol novolak resins such as Aromatically modified phenol novolac resins, bisphenol A novolac resins, tris-hydroxyphenylmethane type novolac resins such as Resitop TPM-100 (manufactured by Gunei Chemical Industry Co., Ltd.), and naphthol novolac resins. Naphthols, biphenols and/or condensates of bisphenols and aldehydes, phenols such as SN-160, SN-395, SN-485 (manufactured by Nippon Steel Chemical & Materials Co., Ltd.), naphthols , biphenols and/or condensates of bisphenols and xylylene glycol, phenols, naphthols, condensates of biphenols and/or bisphenols and isopropenylacetophenone, phenols, naphthols, biphenols and/or Phenol compounds called so-called "novolak phenol resins" such as condensates of bisphenols and biphenyl condensing agents, compounds containing triazine rings and hydroxyphenyl groups such as PS-6313 (manufactured by Gunei Chemical Industry Co., Ltd.), etc. can be mentioned. From the viewpoint of easy availability, phenol novolak resins, trishydroxyphenylmethane type novolak resins, aromatic modified phenol novolak resins, and the like are preferred.

In the case of novolak type phenolic resin, phenols include phenol, cresol, xylenol, butylphenol, amylphenol, nonylphenol, butylmethylphenol, trimethylphenol, phenylphenol, etc., and naphthols include 1-naphthol, 2-naphthol, etc. Examples include naphthol, and in addition, the above-mentioned biphenols and bisphenols.
Examples of aldehydes include formaldehyde, acetaldehyde, propylaldehyde, butyraldehyde, valeraldehyde, capronaldehyde, benzaldehyde, chloraldehyde, bromaldehyde, glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipinealdehyde, pimelinaldehyde, and sebacinaldehyde. , acrolein, crotonaldehyde, salicylaldehyde, phthalaldehyde, hydroxybenzaldehyde and the like.
Examples of the biphenyl condensing agent include bis(methylol)biphenyl, bis(methoxymethyl)biphenyl, bis(ethoxymethyl)biphenyl, and bis(chloromethyl)biphenyl.

Specific examples of the acid anhydride curing agent include methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, pyromellitic anhydride, phthalic anhydride, trimellitic anhydride, methylnadic acid, and the like.

Specific examples of amine curing agents include diethylenetriamine, triethylenetetramine, metaxylene diamine, isophoronediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiphenyl ether, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl ) Phenol, dicyandiamide, and amine compounds such as polyamidoamine, which is a condensation product of acids such as dimer acid and polyamines.

Other curing agents include, specifically, phosphine compounds such as triphenylphosphine, phosphonium salts such as tetraphenylphosphonium bromide, 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4methylimidazole, 2- Imidazoles such as undecylimidazole and 1-cyanoethyl-2-methylimidazole, imidazole salts that are salts of imidazoles and trimellitic acid, isocyanuric acid, or boric acid, benzyldimethylamine, 2,4,6-tris Amines such as (dimethylaminomethyl)phenol, quaternary ammonium salts such as trimethylammonium chloride, diazabicyclo compounds, salts of diazabicyclo compounds with phenols and phenol novolac resins, boron trifluoride and amines, ether compounds, etc. Examples include complex compounds with, aromatic phosphonium or iodonium salts, hydrazides, and acidic polyesters.

Furthermore, the epoxy resin composition of the present invention may contain a known reaction retarder in order to adjust its curability. For example, boric acid, boric esters, phosphoric acid, alkyl phosphoric esters, p-toluenesulfonic acid, etc. can be used.
Examples of boric acid esters include tributylborate, trimethoxyboroxine, ethyl borate, and epoxy-phenol-boric acid ester combinations (for example, Cureduct L-07N (manufactured by Shikoku Kasei Kogyo Co., Ltd.)). Examples of the alkyl phosphate ester include trimethyl phosphate and tributyl phosphate.
The reaction retarder may be used alone or in combination, but it is preferable to use it alone from the viewpoint of ease of adjusting the amount used, and in particular, the effect is best when boric acid is used in a small amount. When used, it can be dissolved in an alcoholic solvent such as methanol, butanol, or 2-propanol, and used at a concentration of 5 to 20% by mass. Particularly when the curing agent is dicyandiamide, boric acid is preferably 0.1 to 0.5 mol per 1 mol of the curing agent, and more preferably 0.15 to 0.35 mol to obtain a retarding effect and heat resistance. . Further, when the curing agent is a phenolic curing agent, the amount is preferably 0.1 to 5 parts by mass based on the phosphorus-containing epoxy resin, and more preferably 0.1 to 1 part by mass in order to obtain heat resistance. In particular, when the amount of boric acid used increases to 5 parts by mass or more, it is necessary to increase the amount of a reaction accelerator such as imidazole to adjust the curability, which is undesirable because it significantly impairs the insulation reliability of the cured product. .

A curing accelerator can be used in the epoxy resin composition if necessary. For example, imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-(dimethylaminomethyl)phenol, 1,8-diaza-bicyclo(5,4,0)undecene, etc. Examples include tertiary amines such as -7, phosphines such as triphenylphosphine, tricyclohexylphosphine, triphenylphosphine triphenylborane, and metal compounds such as tin octylate. The curing accelerator is used in an amount of 0.02 to 5.0 parts by weight based on 100 parts by weight of the epoxy resin in the epoxy resin composition, if necessary. By using a curing accelerator, it is possible to lower the curing temperature and shorten the curing time.

The epoxy resin composition can also use an organic solvent or a reactive diluent for adjusting the viscosity.

Examples of organic solvents include amides such as N,N-dimethylformamide and N,N-dimethylacetamide, and ethers such as ethylene glycol monomethyl ether, dimethoxydiethylene glycol, ethylene glycol diethyl ether, diethylene glycol diethyl ether, and triethylene glycol dimethyl ether. Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methanol, ethanol, 1-methoxy-2-propanol, 2-ethyl-1-hexanol, benzyl alcohol, ethylene glycol, propylene glycol, butyl diglycol, Alcohols such as pine oil, acetate esters such as butyl acetate, methoxybutyl acetate, methyl cellosolve acetate, cellosolve acetate, ethyl diglycol acetate, propylene glycol monomethyl ether acetate, carbitol acetate, benzyl alcohol acetate, and methyl benzoate. , benzoic acid esters such as ethyl benzoate, cellosolves such as methyl cellosolve, cellosolve, and butyl cellosolve, carbitols such as methyl carbitol, carbitol, butyl carbitol, and aromatic compounds such as benzene, toluene, and xylene. Examples include, but are not limited to, hydrocarbons, dimethyl sulfoxide, acetonitrile, N-methylpyrrolidone, and the like.

Examples of the reactive diluent include monofunctional glycidyl ethers such as allyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, tolyl glycidyl ether, resorcinol diglycidyl ether, and neopentyl glycol diglycidyl ether. , 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, propylene glycol diglycidyl ether, etc., glycerol polyglycidyl ether, trimethylolpropane Polyfunctional glycidyl ethers such as polyglycidyl ether, trimethylolethane polyglycidyl ether, and pentaerythritol polyglycidyl ether, glycidyl esters such as neodecanoic acid glycidyl ester, and glycidyl amines such as phenyl diglycidyl amine and tolyl diglycidyl amine. Examples include, but are not limited to.

These organic solvents or reactive diluents are preferably used alone or as a mixture of multiple types in an amount of 90% by mass or less as a nonvolatile content, and the appropriate type and amount to be used are appropriately selected depending on the purpose. For example, for printed wiring board applications, it is preferable to use a polar solvent with a boiling point of 160° C. or lower, such as methyl ethyl ketone, acetone, or 1-methoxy-2-propanol, and the amount used is preferably 40 to 80% by mass in terms of nonvolatile content. In addition, for adhesive film applications, it is preferable to use, for example, ketones, acetic esters, carbitols, aromatic hydrocarbons, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. It is preferably 30 to 60% by mass.

The epoxy resin composition may contain an inorganic filler if necessary. Specifically, fused silica, crystalline silica, alumina, silicon nitride, aluminum hydroxide, magnesium hydroxide, talc, calcined talc, mica, clay, kaolin, boehmite, calcium carbonate, calcium silicate, calcium hydroxide, magnesium carbonate, Examples include inorganic fillers such as barium carbonate, barium sulfate, titanium oxide, boron nitride, carbon, glass powder, and silica balloons, but pigments and the like may also be blended. Inorganic fillers are generally used to improve impact resistance, but they also contribute to dimensional stability as a countermeasure against warpage of the substrate due to thermal expansion. Further, metal hydroxides such as aluminum hydroxide, boehmite, and magnesium hydroxide may be used not only to act as flame retardant aids but also to supplement tracking resistance. When the phosphorus content of the composition is reduced, it is effective in ensuring flame retardancy, but if a large amount is used, the moldability of the substrate is greatly reduced. In particular, if the blending amount is not 10% by mass or more, the impact resistance effect will be small, but if the blending amount exceeds 150% by mass, the adhesion required for laminates will decrease, and other forming properties such as drill workability will be affected. Processing characteristics may deteriorate. In addition, fibrous fillers such as glass fiber, carbon fiber, alumina fiber, silica alumina fiber, silicon carbide fiber, polyester fiber, cellulose fiber, and aramid fiber, and organic fillers such as fine particle rubber and thermoplastic elastomer are also available as needed. They can also be used together to the extent that the characteristics of the present invention are not impaired.

The epoxy resin composition may contain other thermosetting resins and thermoplastic resins as long as the properties are not impaired. For example, phenolic resin, acrylic resin, petroleum resin, indene resin, coumaron indene resin, phenoxy resin, polyurethane resin, polyester resin, polyamide resin, polyimide resin, polyamideimide resin, polyetherimide resin, polyphenylene ether resin, modified polyphenylene ether Examples include, but are not limited to, resins such as polyether sulfone resin, polysulfone resin, polyether ether ketone resin, polyphenylene sulfide resin, and polyvinyl formal resin.

Moreover, the epoxy resin composition can also be used in combination with various known flame retardants for the purpose of improving the flame retardancy of the resulting cured product. Examples of flame retardants that can be used in combination include phosphorus flame retardants, nitrogen flame retardants, silicone flame retardants, inorganic flame retardants, and organometallic salt flame retardants, with phosphorus flame retardants being particularly preferred. These flame retardants may be used alone or in combination of two or more.

As the phosphorus flame retardant, either an inorganic phosphorus compound or an organic phosphorus compound can be used. Examples of inorganic phosphorus compounds include red phosphorus, ammonium phosphates such as monoammonium phosphate, diammonium phosphate, triammonium phosphate, and ammonium polyphosphate, and inorganic nitrogen-containing phosphorus compounds such as phosphoric acid amide. It will be done. Examples of organic phosphorus compounds include aliphatic phosphoric esters, phosphoric ester compounds, condensed phosphoric esters such as PX-200 (manufactured by Daihachi Chemical Industry Co., Ltd.), phosphonic acid compounds, phosphinic acid compounds, In addition to general-purpose organic phosphorus compounds such as organic nitrogen-containing phosphorus compounds such as phosphine oxide compounds, phosphorane compounds, and phosphazenes, and metal salts of phosphinic acid, cyclic organic phosphorus compounds such as DOPO, DOPO-HQ, and DOPO-NQ, Examples include phosphorus-containing epoxy resins and phosphorus-containing curing agents, which are derivatives obtained by reacting these with compounds such as epoxy resins and phenol resins. Moreover, when using a phosphorus-based flame retardant, a flame retardant aid such as magnesium hydroxide may be used in combination.

A cured product can be obtained by curing the epoxy resin composition of the present invention. At the time of curing, a laminate can be obtained by, for example, taking the form of a resin sheet, resin-coated copper foil, prepreg, etc., and stacking them and curing them under heat and pressure.

When the epoxy resin composition is used as a plate-like substrate, fibrous fillers are preferred from the viewpoint of dimensional stability, bending strength, etc. More preferably, a glass fiber substrate in which glass fibers are woven into a mesh shape is used.

The epoxy resin composition may further contain various additives such as a silane coupling agent, an antioxidant, a mold release agent, an antifoaming agent, an emulsifier, a thixotropy agent, and a smoothing agent, as required. The amount of these additives is preferably in the range of 0.01 to 20% by mass based on the epoxy resin composition.

By impregnating a fibrous base material with the epoxy resin composition, prepregs used in printed wiring boards and the like can be created. As the fibrous base material, inorganic fibers such as glass, and woven or nonwoven fabrics of organic fibers such as polyester resin, polyamine resin, polyacrylic resin, polyimide resin, aromatic polyamide resin, etc. can be used, but are not limited thereto. It's not something you can do. The method for producing prepreg from an epoxy resin composition is not particularly limited. For example, the epoxy resin composition is impregnated with a resin varnish made by adjusting the viscosity with a solvent, and then heated and dried to make a resin. It is obtained by semi-curing (B-staged) components, and can be dried by heating at 100 to 200° C. for 1 to 40 minutes, for example. Here, the amount of resin in the prepreg is preferably 30 to 80% by mass.

Furthermore, in order to cure the prepreg, a method for curing laminates that is generally used when manufacturing printed wiring boards can be used, but the method is not limited thereto. For example, when forming a laminate using prepreg, one or more sheets of prepreg are laminated, metal foil is placed on one or both sides to form a laminate, and this laminate is heated and pressurized to form a laminate. Unify. Here, as the metal foil, single, alloy, or composite metal foils such as copper, aluminum, brass, and nickel can be used. Then, the prepared laminate is heated under pressure to harden the prepreg, and a laminate can be obtained. At that time, it is preferable that the heating temperature is 160 to 220°C, the pressure is 50 to 500 N/cm ² , and the heating and pressing time is 40 to 240 minutes, so that the desired cured product can be obtained. If the heating temperature is low, the curing reaction will not proceed sufficiently, and if it is high, the epoxy resin composition may begin to decompose. In addition, if the pressure is too low, air bubbles may remain inside the resulting laminate and the electrical properties may deteriorate, while if it is too high, the resin will flow before curing, resulting in a cured product with the desired thickness. There is a possibility that it will not be possible. Furthermore, if the heating and pressurizing time is short, the curing reaction may not proceed sufficiently, and if it is long, the epoxy resin composition in the prepreg may be thermally decomposed, which is not preferable.

An epoxy resin cured product can be obtained by curing the epoxy resin composition in the same manner as known epoxy resin compositions. As a method for obtaining a cured product, methods similar to those for known epoxy resin compositions can be used, such as casting, injection, potting, dipping, drip coating, transfer molding, compression molding, resin sheets, etc. Preferred methods include forming a resin-coated copper foil, prepreg, or the like into a laminate by laminating them and curing them under heat and pressure. The curing temperature at that time is usually in the range of 100 to 300°C, and the curing time is usually about 1 to 5 hours.

As a result of producing an epoxy resin composition using a phosphorus-containing epoxy resin and evaluating a laminate by heat curing, it was found that a specific phosphorus compound reacted with a novolac-type epoxy resin having a specific molecular weight distribution and a specific average number of functional groups. The resulting phosphorus-containing epoxy resin exhibits higher heat resistance and flame retardancy than conventionally known phosphorus-containing epoxy resins, and also has improved dielectric properties, improving the physical properties of the cured product. We were able to provide an epoxy resin composition that can.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Unless otherwise specified, "parts" represent parts by mass, and "%" represent % by mass. The measurement methods were as follows. The unit of equivalent is "g/eq.".

Epoxy equivalent: Measured according to JIS K 7236. Specifically, using an automatic potentiometric titration device (manufactured by Hiranuma Sangyo Co., Ltd., COM-1600ST), using chloroform as a solvent, a brominated tetraethylammonium acetic acid solution was added, and 0.1 mol/L perchloric acid-acetic acid was added. Titrated with solution.

Phosphorus content: Add 3 mL of sulfuric acid to 150 mg of sample and heat for 30 minutes. The temperature was returned to room temperature, 3.5 mL of nitric acid and 0.5 mL of perchloric acid were added, and the mixture was thermally decomposed until the contents became transparent or yellow. This solution was diluted with water in a 100 mL volumetric flask. 10 mL of this sample solution was placed in a 50 mL volumetric flask, 1 drop of phenolphthalein indicator was added, 2 mol/L ammonia water was added until it turned slightly red, 2 mL of 50% sulfuric acid solution was added, and water was added. After adding 5 mL of a 2.5 g/L ammonium metavanadate aqueous solution and 5 mL of a 50 g/L ammonium molybdate aqueous solution, the volume was made constant with water. After being left at room temperature for 40 minutes, measurements were taken using a spectrophotometer at a wavelength of 440 nm using water as a control. A calibration curve was prepared in advance using an aqueous solution of potassium dihydrogen phosphate, and the phosphorus content was determined from the absorbance.

Glass transition temperature (Tg): DSC Tgm (glass state and rubber The temperature is expressed as the midpoint temperature of the mutation curve with respect to the tangent to the state.

Pressure Cooker Test (PCT) Soldering Heat Resistance/Water Resistance: A test piece prepared in accordance with JIS C 6481 was processed in an autoclave at 121°C and 0.2 MPa for 3 hours, and then immersed in a 260°C solder bath. did. Those in which no swelling or peeling occurred for more than 20 minutes were evaluated as ○, those in which swelling or peeling occurred within 10 minutes were evaluated as ×, and the others were evaluated as △.

Thermal peel test (TMA method) T-288: The test was conducted at 288°C in accordance with IPC TM-650 TM2.4.24.1.

Copper foil peel strength: Measured according to JIS C 6481, 5.7.

Flammability: Conforms to UL94 (safety certification standard of Underwriters Laboratories Inc.). The test was conducted on 5 specimens, and the total duration of flaming combustion after the first and second flame contact (2 times for each of the 5 specimens, 10 times in total) was determined based on the criteria of the same standard. Yes, it was judged as V-0, V-1, and V-2. Incidentally, those that were completely burnt out were judged as NG.

Relative permittivity and dielectric loss tangent: Using the cavity resonance method (vector network analyzer (VNA) E8363B (manufactured by Agilent Technologies), cavity resonator perturbation method dielectric constant measurement device (manufactured by Kanto Denshi Applied Development)) After being stored indoors at 50% humidity for 24 hours, the value at a frequency of 2 GHz was measured.

Trinuclear, 7-nuclear or more, number average molecular weight (Mn): determined by GPC measurement. Specifically, a main body (manufactured by Tosoh Corporation, HLC-8220GPC) equipped with a column (manufactured by Tosoh Corporation, TSKgelG4000H _XL , TSKgelG3000H _XL , TSKgelG2000H _XL ) in series was used, and the column temperature was set at 40°C. . Further, THF was used as the eluent at a flow rate of 1 mL/min, and an RI (differential refractometer) detector was used as the detector. As the measurement sample, 0.05 g of the sample was dissolved in 10 mL of THF, and 50 μL of the solution was filtered through a microfilter. For data processing, GPC-8020 Model II version 6.00 manufactured by Tosoh Corporation was used. For trinuclear bodies, heptadonucleans or more, Mn is determined from the area % of the peak. 2, F-4, F-10, F-20, F-40).

Synthesis example 1
Add 1,000 parts of phenol to a four-neck separable glass flask equipped with a stirrer, temperature controller, reflux condenser, total condenser, pressure reducer, etc., raise the temperature to 80°C, and then add 2.8 parts of phenol. of oxalic acid dihydrate was added and dissolved with stirring, and 142 parts of 37.5% formalin was added dropwise over 30 minutes. Thereafter, the reaction temperature was maintained at 92° C. and the reaction was carried out for 3 hours. After the reaction was completed, the temperature was raised to 110°C for dehydration, and approximately 90% of the remaining phenol was recovered under recovery conditions of 150°C and 60mmHg, then recovered under conditions of 5mmHg, and then further under conditions of 160°C and 80mmHg. After 10 parts of water was added dropwise over 90 minutes to remove the remaining phenol, nitrogen gas was bubbled into the melted phenol novolac resin for 60 minutes to obtain a phenol novolac resin (N0).
A part of the binuclear substance was further distilled off from the obtained N0 using a thin film distiller at 280° C. and 5 mmHg to obtain a phenol novolac resin (N1). The obtained N1 has a softening point of 65° C., and contains 10.8 area% of dinuclear bodies, 52.9 area% of trinuclear bodies, 21.8 area% of tetranuclear bodies, 8.5 area% of pentanuclear bodies, and 6 area% of hexanuclear bodies. The average molecular weight was 6.0 area % and 355.

Synthesis example 2
Using the N0 obtained in Synthesis Example 1, a part of the binuclear substance was more strongly distilled off using a thin film distiller at 300° C. and 5 mmHg to obtain a phenol novolac resin (N2). The obtained N2 has a softening point of 66°C, and contains 5.9 area% of dinuclear bodies, 58.4 area% of trinuclear bodies, 22.9 area% of tetranuclear bodies, 8.3 area% of pentanuclides, and 6 area% of hexanuclear bodies. The area was 4.6%, and the measured average molecular weight was 356.

Synthesis example 3
1000 parts of N1 obtained in Synthesis Example 1 was placed in a four-necked separable glass flask equipped with a stirrer, a temperature control device, a reflux condenser, a total condenser, a nitrogen gas introduction device, a pressure reduction device, and a dropping device. , 0.38 part of oxalic acid dihydrate was charged, and the mixture was stirred while introducing nitrogen gas and heated to raise the temperature. Dropwise addition of 13.5 parts of 37.5% formalin was started at 80°C and completed in 30 minutes. Thereafter, the reaction temperature was kept at 92°C and the reaction was carried out for 3 hours, and then the temperature was raised to 110°C to remove the water produced by the reaction from the system. Finally, heating was performed at 160° C. for 2 hours to obtain a phenol novolac resin (N3). The obtained N3 had a softening point of 63° C., 9.4 area % of dinuclear bodies, 48.1 area % of trinuclear bodies, 9.0 area % of seven or more nuclear bodies, and Mn 552. A GPC measurement chart of N3 is shown in FIG. The horizontal axis shows elution time (minutes), and the vertical axis shows detection intensity (mV). The peak indicated by A is trinuclear, and the peak group indicated by B is heptaduclide or more.

Then, in the same apparatus, 500 parts of N3, 2200 parts of epichlorohydrin, and 400 parts of diethylene glycol dimethyl ether were charged, dissolved at 60°C, and 332 parts of a 49% caustic soda aqueous solution was added under a reduced pressure of 130 mmHg while maintaining the temperature at 58 to 62°C. It was added dropwise over 2 hours. During this time, epichlorohydrin was azeotroped with water, and the distilled water was sequentially removed from the system. Thereafter, the reaction was continued for 2 hours under the same conditions. After the reaction was completed, epichlorohydrin was collected at 5 mmHg and 150°C, and 1200 parts of MIBK was added to dissolve the product. Then, 70 parts of a 10% aqueous sodium hydroxide solution was added, the reaction was carried out at 80 to 90°C for 2 hours, 1000 parts of water was added to dissolve the by-produced salt, and the lower layer of brine was separated and removed. did. After neutralization with an aqueous phosphoric acid solution, the resin solution was washed with water until the washing solution became neutral, dehydrated under reflux, and filtered to remove impurities. Then, MIBK was distilled off by heating to 150° C. under a reduced pressure of 5 mmHg to obtain a phenol novolac type epoxy resin (E1). The obtained E1 has an epoxy equivalent of 171, Mn 650, 40.6 area % of trinuclear bodies, 20.9 area % of heptanuclear bodies or more, and the ratio of trinuclear bodies to the content of heptanuclear bodies or more (area %, H). The ratio (L/H) of the content (area %, L) was 1.9, and the average number of functional groups (Mn/E) was 3.8.

Synthesis example 4
A phenol novolak resin (N4) was obtained in the same manner as in Synthesis Example 3, except that 1000 parts of N1, 0.63 parts of oxalic acid dihydrate, and 22.5 parts of 37.5% formalin were added. The obtained N4 had a softening point of 69° C., 8.0 area % of dinuclear bodies, 43.7 area % of trinuclear bodies, 14.2 area % of hepta-nuclear bodies, and Mn of 574. Thereafter, in the same manner as in Synthesis Example 3, N4 was epoxidized to obtain a phenol novolac type epoxy resin (E2). The obtained E2 had an epoxy equivalent of 172, Mn 682, 36.4 area % of trinuclear bodies, 26.7 area % of heptadonuclides or more, the content ratio (L/H) was 1.4, and the average number of functional groups ( Mn/E) was 4.0.

Synthesis example 5
A phenol novolak resin (N5) was obtained in the same manner as in Synthesis Example 3, except that 1000 parts of N1, 1.89 parts of oxalic acid dihydrate, and 67.6 parts of 37.5% formalin were added. The obtained N5 had a softening point of 78° C., 7.2 area % of di-nuclear bodies, 31.2 area % of tri-nuclear bodies, 30.9 area % of heptad-nuclear bodies, and Mn of 690. Thereafter, in the same manner as in Synthesis Example 3, N5 was epoxidized to obtain a phenol novolac type epoxy resin (E3). The obtained E3 had an epoxy equivalent of 173, an Mn of 824, a trinuclear body of 26.1 area%, a heptanuclear body or more of 42.2 area%, a content ratio (L/H) of 0.6, and an average number of functional groups ( Mn/E) was 4.8.

Synthesis example 6
A phenol novolac resin (N6) was obtained in the same manner as in Synthesis Example 3, except that 1000 parts of N2, 0.63 parts of oxalic acid dihydrate, and 22.5 parts of 37.5% formalin were added. The obtained N6 had a softening point of 70° C., 5.1 area % of di-nuclear bodies, 45.8 area % of tri-nuclear bodies, 14.4 area % of hepta-nuclear bodies, and Mn of 589. Thereafter, in the same manner as in Synthesis Example 3, N6 was epoxidized to obtain a phenol novolac type epoxy resin (E4). The obtained E4 had an epoxy equivalent of 174, an Mn of 693, 38.8 area% of trinuclear bodies, 26.0 area% of seven or more nuclear bodies, a content ratio (L/H) of 1.5, and an average number of functional groups ( Mn/E) was 4.0.

Synthesis example 7
LV-70S (phenol novolac resin manufactured by Gunei Chemical Industry Co., Ltd., softening point 65°C, dinuclear 1.0 area %, trinuclear 74.7 area %, tetranuclear 18.1 area %, pentanuclear 6. Phenol novolac was prepared in the same manner as in Synthesis Example 3, except that 1000 parts of 2 area%, measured number average molecular weight 337), 0.66 parts of oxalic acid dihydrate, and 23.7 parts of 37.5% formalin were added. Resin (N7) was obtained. The obtained N7 had a softening point of 67°C, 1.1 area% of dinuclear bodies, 57.3 area% of trinuclear bodies, and it was difficult to separate hexanuclear bodies and heptadonuclides, and the content of hexanuclear bodies or more was The Mn was 22.0 area% and 580. Thereafter, in the same manner as in Synthesis Example 3, N7 was epoxidized to obtain a phenol novolac type epoxy resin (E5). The obtained E5 had an epoxy equivalent of 173, an Mn of 669, 48.9 area% of trinuclear bodies, 14.6 area% of seven or more nuclear bodies, a content ratio (L/H) of 3.3, and an average number of functional groups ( Mn/E) was 3.9.

Synthesis example 8
A phenol novolak resin (N8) was obtained in the same manner as in Synthesis Example 3, except that 1000 parts of N1, 0.32 parts of oxalic acid dihydrate, and 11.3 parts of 37.5% formalin were added. The obtained N8 had a softening point of 62° C., 9.6 area % of di-nuclear bodies, 48.4 area % of tri-nuclear bodies, 7.7 area % of heptad-nuclear bodies or more, and Mn of 545. Thereafter, in the same manner as in Synthesis Example 3, N8 was epoxidized to obtain a phenol novolac type epoxy resin (E6). The obtained E6 had an epoxy equivalent of 171, an Mn of 623, 41.9 area% of trinuclear bodies, 19.9 area% of seven or more nuclear bodies, a content ratio (L/H) of 2.1, and an average number of functional groups ( Mn/E) was 3.6.

Synthesis example 9
A phenol novolac resin (N9) was obtained in the same manner as in Synthesis Example 3, except that 1000 parts of N1, 2.52 parts of oxalic acid dihydrate, and 90.1 parts of 37.4% formalin were added. The obtained N9 had a softening point of 84° C., 5.7 area % of di-nuclear bodies, 24.1 area % of tri-nuclear bodies, 41.5 area % of hepta-nuclear bodies, and Mn748. Thereafter, in the same manner as in Synthesis Example 3, N9 was epoxidized to obtain a phenol novolac type epoxy resin (E7). The obtained E7 had an epoxy equivalent of 175, Mn 858, trinuclear bodies 20.7 area%, heptanuclear bodies or more 48.5 area%, the content ratio (L/H) was 0.4, and the average number of functional groups ( Mn/E) was 4.9.

Synthesis example 10
YDPN-638 (phenol novolac type epoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd., epoxy equivalent: 178) and YDF-170 (bisphenol F type liquid epoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd., epoxy equivalent: 168) A phenol novolak type epoxy resin (E8) was obtained by melting and mixing at a ratio of /1 (mass ratio). The obtained E8 had an epoxy equivalent of 173, an Mn of 468, 12.1 area% of trinuclear bodies, 19.3 area% of seven or more nuclear bodies, a content ratio (L/H) of 0.6, and an average number of functional groups ( Mn/E) was 2.7.

Synthesis example 11
100 parts of HCA (manufactured by Sanko Co., Ltd., DOPO) and 185 parts of toluene were placed in a four-necked separable glass flask equipped with a stirrer, temperature control device, reflux condenser, total condenser, and nitrogen gas introduction device. , and dissolved by heating at 80°C. Thereafter, 62.2 parts of 1,4-naphthoquinone (NQ) was added in portions while being careful not to raise the temperature due to the heat of reaction. At this time, the molar ratio of NQ and DOPO (NQ/DOPO) was 0.85. After this reaction, 627 parts of epoxy resin E1 was charged, stirred while introducing nitrogen gas, and heated to 130° C. to dissolve it. After adding 0.08 parts of triphenylphosphine (TPP) and reacting at 150°C for 4 hours, 42 parts of methoxypropanol was added and the reaction was further carried out at 140°C for 2 hours to form a phosphorus-containing epoxy resin (PE1). Obtained. The obtained PE1 had an epoxy equivalent of 263 and a phosphorus content of 1.8%. Note that the reaction rate (consumption rate of the raw material phosphorus compound calculated from the measured epoxy equivalent) was 78%.

Synthesis example 12
A phosphorus-containing epoxy resin (PE2) was obtained in the same manner as in Synthesis Example 11 except that the epoxy resin was changed to 627 parts of E2. The obtained PE2 had an epoxy equivalent of 261 and a phosphorus content of 1.8%. Note that the reaction rate was 72%.

Synthesis example 13
A phosphorus-containing epoxy resin (PE3) was obtained in the same manner as in Synthesis Example 11 except that 627 parts of E3 was used as the epoxy resin. The obtained PE3 had an epoxy equivalent of 261 and a phosphorus content of 1.8%. Note that the reaction rate was 70%.

Synthesis example 14
A phosphorus-containing epoxy resin (PE4) was obtained in the same manner as Synthesis Example 11 except that 627 parts of E4 was used as the epoxy resin. The obtained PE4 had an epoxy equivalent of 264 and a phosphorus content of 1.8%. Note that the reaction rate was 72%.

Synthesis example 15
A phosphorus-containing epoxy resin (PE5) was obtained in the same manner as in Synthesis Example 11 except that 627 parts of E5 was used as the epoxy resin. The obtained PE5 had an epoxy equivalent of 262 and a phosphorus content of 1.8%. Note that the reaction rate was 72%.

Synthesis example 16
A phosphorus-containing epoxy resin (PE6) was prepared in the same manner as in Synthesis Example 11, except that NQ was changed to 72.4 parts (NQ/DOPO = 0.99), TPP was changed to 0.09 parts, and the epoxy resin was changed to 715 parts of E5. I got it. The obtained PE6 had an epoxy equivalent of 276 and a phosphorus content of 1.6%. Note that the reaction rate was 100%.

Synthesis example 17
A phosphorus-containing epoxy resin (PE7) was prepared in the same manner as in Synthesis Example 11, except that NQ was changed to 36.6 parts (NQ/DOPO = 0.50), TPP was changed to 0.07 parts, and the epoxy resin was changed to 431 parts of E2. I got it. The obtained PE7 had an epoxy equivalent of 313 and a phosphorus content of 2.5%. Note that the reaction rate was 100%.

Synthesis example 18
A phosphorus-containing epoxy resin (PE8) was obtained in the same manner as in Synthesis Example 11, except that NQ was changed to 68.0 parts (NQ/DOPO=0.93) and the epoxy resin was changed to 542 parts of E2. The obtained PE8 had an epoxy equivalent of 278 and a phosphorus content of 2.0%. Note that the reaction rate was 67%.

Synthesis example 19
A phosphorus-containing epoxy resin (PEH1) was obtained in the same manner as in Synthesis Example 11 except that 627 parts of E6 was used as the epoxy resin. The obtained PEH1 had an epoxy equivalent of 263 and a phosphorus content of 1.8%. Note that the reaction rate was 78%.

Synthesis example 20
A phosphorus-containing epoxy resin (PEH2) was obtained in the same manner as in Synthesis Example 11 except that the epoxy resin was changed to 627 parts of E7. The obtained PEH2 had an epoxy equivalent of 264 and a phosphorus content of 1.8%. Note that the reaction rate was 69%.

Synthesis example 21
Epoxy resin was mixed with 627 parts of phenol novolac type epoxy resin (manufactured by Nippon Steel Chemical & Materials Co., Ltd., YDPN-6300, epoxy equivalent: 175, Mn 653, 35.2 area % of trinuclear bodies, 21.8 area % of heptadonuclides or more, A phosphorus-containing epoxy resin (PEH3) was obtained in the same manner as in Synthesis Example 11, except that the content ratio (L/H) was 1.6 and the average number of functional groups (Mn/E) was 3.7. The obtained PEH3 had an epoxy equivalent of 266 and a phosphorus content of 1.8%. Note that the reaction rate was 72%.

Synthesis example 22
Epoxy resin was mixed with 627 parts of phenol novolak type epoxy resin (manufactured by Nippon Steel Chemical & Materials Co., Ltd., YDPN-638, epoxy equivalent: 178, Mn 662, 3-nucleus 14.7 area %, 7-nuclear or more 38.6 area %, A phosphorus-containing epoxy resin (PEH4) was obtained in the same manner as in Synthesis Example 11, except that the content ratio (L/H) was 0.4 and the average number of functional groups (Mn/E) was 3.7. The obtained PEH4 had an epoxy equivalent of 272 and a phosphorus content of 1.8%. Note that the reaction rate was 72%.

Synthesis example 23
Epoxy resin was mixed with 627 parts of phenol novolac type epoxy resin (manufactured by DIC Corporation, N775, epoxy equivalent: 187, Mn1308, trinuclear 6.7 area%, septanuclear or more 71.6 area%, content ratio (L/ A phosphorus-containing epoxy resin (PEH5) was obtained in the same manner as in Synthesis Example 11, except that H) was 0.1 and the average number of functional groups (Mn/E) was 7.0). The obtained PEH5 had an epoxy equivalent of 278 and a phosphorus content of 1.8%. Note that the reaction rate was 60%.

Synthesis example 24
A phosphorus-containing epoxy resin (PEH6) was prepared in the same manner as in Synthesis Example 11, except that NQ was changed to 68.0 parts (NQ/DOPO = 0.93), TPP was changed to 0.17 parts, and the epoxy resin was changed to 542 parts of E8. I got it. The obtained PEH6 had an epoxy equivalent of 317 and a phosphorus content of 2.0%. Note that the reaction rate was 100%.

The abbreviations of the epoxy resin, oxazine resin, phenol resin, and other materials used are shown below.

[Epoxy resin]
PE1: Phosphorus-containing epoxy resin obtained in Synthesis Example 11 PE2: Phosphorus-containing epoxy resin obtained in Synthesis Example 12 PE3: Phosphorus-containing epoxy resin obtained in Synthesis Example 13 PE4: Phosphorus-containing resin obtained in Synthesis Example 14 Epoxy resin PE5: Phosphorus-containing epoxy resin obtained in Synthesis Example 15 PE6: Phosphorus-containing epoxy resin obtained in Synthesis Example 16 PE7: Phosphorus-containing epoxy resin obtained in Synthesis Example 17 PE8: Phosphorus-containing epoxy resin obtained in Synthesis Example 18 Phosphorus-containing epoxy resin PEH1: Phosphorus-containing epoxy resin obtained in Synthesis Example 19 PEH2: Phosphorus-containing epoxy resin obtained in Synthesis Example 20 PEH3: Phosphorus-containing epoxy resin obtained in Synthesis Example 21 PEH4: Phosphorus-containing epoxy resin obtained in Synthesis Example 22 Phosphorus-containing epoxy resin obtained PEH5: Phosphorus-containing epoxy resin obtained in Synthesis Example 23 PEH6: Phosphorus-containing epoxy resin obtained in Synthesis Example 23 E9: Dicyclopentadiene type epoxy resin (manufactured by DIC Corporation, HP-7200H, Epoxy equivalent 273)
E10: Naphthol aralkyl type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., NC-3000H, epoxy equivalent 292)

[Phenol resin]
H1: Dicyclopentadiene type phenol resin (manufactured by Gunei Chemical Industry Co., Ltd., GDP-6140, active hydrogen equivalent 196)
H2: 4,4-(1,3-adamantanediyl) diphenol resin (active hydrogen equivalent: 191)
H3: Phenol novolac type resin (manufactured by Gunei Chemical Industry Co., Ltd., Resitop PSM-6358, softening point 118°C, active hydrogen equivalent 106)

[Oxazine resin]
B1: Phenolphthalein type benzoxazine resin (active hydrogen equivalent 276)
B2: Phenol red type benzoxazine resin (active hydrogen equivalent: 294)
B3: Phenolphthaleinanilide type benzoxazine resin (active hydrogen equivalent: 313)
B4: α-naphtholphthalene type benzoxazine resin (active hydrogen equivalent: 326)
B5: Bisphenol F type benzoxazine resin (active hydrogen equivalent 217)

[Additive flame retardant]
FR1: Cyclophosphazene (non-halogen flame retardant, manufactured by Fushimi Pharmaceutical Co., Ltd., Ravitol FP-100, phosphorus content 13%)
FR2: DOPO added BPA (non-halogen flame retardant, manufactured by SHIN-A T&C, LC-9501, phosphorus content 9.2%)

[others]
C1: 2-ethyl-4-methylimidazole (curing accelerator, manufactured by Shikoku Kasei Kogyo Co., Ltd., Curesol 2E4MZ)
C2: Boric acid (manufactured by Sigma-Aldrich Japan)
C3: Epoxysilane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-403)

[Filling material]
FL1: Fused silica (manufactured by Admatec Co., Ltd., SO-C2, average particle size: approximately 0.4 to 0.6 μm)

Example 1
100 parts of epoxy resin (PE1), 48.3 parts of phenolic resin (H1), 52.5 parts of oxazine resin (B1), and 0.5 part of C2 were blended as a 20% methanol solution. When blending these, the epoxy resin, phenol resin, and oxazine resin were prepared in the form of a varnish dissolved in methyl ethyl ketone, and the nonvolatile content was adjusted to 48 to 50% with methyl ethyl ketone and methoxypropanol. Thereafter, the gel time of this varnish was adjusted to 200 to 350 seconds at 170° C. using a methoxypropanol solution of C1 to obtain an epoxy resin composition varnish.

After adding 0.1 part of C3 to the obtained epoxy resin composition varnish, using a homodisper, 23 parts of FL1 was added in portions with shear stirring at 5000 rpm, and uniformly dispersed for about 10 minutes. Ta.

The obtained epoxy resin composition varnish was impregnated into a glass cloth (manufactured by Nitto Boseki Co., Ltd., WEA 7628XS13, 0.18 mm thick), and then the glass cloth was dried in a full exhaust drying oven at 150°C for 7 minutes to form a prepreg. Obtained. The obtained prepreg was stacked in 8 sheets, copper foil (manufactured by Mitsui Mining and Mining Co., Ltd., 3EC, 35 μm thick) was further layered on top and bottom, and after preheating at 130°C for 15 minutes using a vacuum press machine, it was heated at 240°C. Press molding was performed at 2 MPa under curing conditions for 80 minutes to obtain a laminate with a thickness of about 1.6 mm. Table 1 shows the results of tests on Tg, PCT solder heat resistance test, flame retardancy, copper foil peel strength, interlayer adhesion strength, and dielectric properties of the obtained laminate.

Examples 2 to 14
The ingredients were mixed in the amounts (parts) shown in Table 1, and the same operations as in Example 1 were performed to obtain a laminate. The same test as in Example 1 was conducted, and the results are shown in Table 1.

Comparative examples 1 to 11
The ingredients were blended in the amounts (parts) shown in Table 2, and the same operations as in Example 1 were performed to obtain a laminate. The same test as in Example 1 was conducted, and the results are shown in Table 2.

Compared to the epoxy resin composition of the comparative example, the epoxy resin composition of the example provides high heat resistance with a Tg of 220°C or higher, maintains flame retardancy of V-0, and has excellent dielectric properties and adhesion. superiority was seen. On the other hand, in the comparative examples, there was a tendency that compatibility in Tg, flame retardance, dielectric properties, and adhesiveness could not be maintained.

Claims (10)

An epoxy resin composition comprising a phosphorus-containing epoxy resin, an oxazine resin, and an alicyclic structure-containing phenol resin,
The oxazine equivalent of the oxazine resin is 230 to 500 g/eq . The above-mentioned phosphorus-containing epoxy resin uses a novolac phenol resin in which the content of binuclear bodies is reduced to 10 area% or less as a raw material for a novolac type epoxy resin, and has a content of hepta-nuclear bodies or more as determined by gel permeation chromatography. The ratio (L/H) of the trinuclear content (area %, L) to the content (area %, H) is in the range of 0.6 to 4.0, and the number average molecular weight is based on a standard polystyrene equivalent value. (Mn) divided by the epoxy equivalent (E) is a novolac type epoxy resin whose average number of functional groups (Mn/E) is in the range of 3.8 to 4.8, and the following general formula (1) and/or general formula ( 2) is a product obtained from a phosphorus compound represented by
10 to 80 parts by mass of oxazine resin and 10 to 50 parts by mass of alicyclic structure-containing phenol resin are blended with 100 parts by mass of phosphorus-containing epoxy resin, and the phosphorus content is 0.5 to 1.8 mass%. An epoxy resin composition characterized in that it is in the range of.

(In the formula, R ¹ and R ² are each independently a hydrocarbon group having 1 to 20 carbon atoms that may have a hetero atom, and may be different or the same , and R ¹ and R ² are bonded together. It may have a cyclic structure. k1 and k2 are each independently 0 or 1. A is an arenetriyl group having 6 to 20 carbon atoms.) The epoxy resin composition according to claim 1, wherein the oxazine resin has an oxazine resin represented by the following general formula (3).

(In the formula, R ³ is each independently an aromatic ring group, R ⁴ is each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and a cyclic group in which two R 4s in the same benzene ring are connected) structure. R ⁵ is each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. Y is -O- or -N(R ⁶ )-, and R ⁶ is a carbon number 1 to 20 hydrocarbon groups. Z is -CO- or -SO ₂ -.) The epoxy resin composition according to claim 1, wherein the alicyclic structure-containing phenol resin has an alicyclic structure-containing phenol resin represented by the following general formula (4).

(In the formula, T is a divalent aliphatic cyclic hydrocarbon group, and X is an aromatic ring group selected from a benzene ring, a naphthalene ring, a biphenyl ring, or a bisphenyl structure, and these aromatic ring groups are , as a substituent, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, Alternatively, it may have an aralkyloxy group having 7 to 12 carbon atoms.i is an integer of 1 to 3.n is a number of 1 to 10 on average. The epoxy resin composition according to any one of claims 1 to 3, further comprising one or a combination of an inorganic filler, a curing accelerator, a silane coupling agent , and a solvent. A prepreg characterized by using the epoxy resin composition according to any one of claims 1 to 4. A laminate using the epoxy resin composition according to any one of claims 1 to 4. A laminate using the prepreg according to claim 5. A printed circuit board characterized by using the epoxy resin composition according to any one of claims 1 to 4. A printed circuit board using the laminate according to claim 6 or 7. A cured product obtained by curing the epoxy resin composition according to any one of claims 1 to 4.

Images