TW202012484A - Epoxy resin composition, prepreg, laminate, and printed wiring substrate - Google Patents

Abstract

The invention provides an epoxy resin composition that exhibits excellent heat resistance and flame retardation even at a low phosphorus content and provides excellent cured product properties especially in printed wiring board application, and also provides a prepreg, a laminate and a printed wiring board. The epoxy resin composition comprises an epoxy resin and a curing agent as essential components, characterized in that the epoxy resin contains a biphenyl aralkyl-type epoxy resin represented by the following general formula (1) and a phosphorus-containing epoxy resin, where n is a number of repetition representing a number of 0 or more and having an average value of 1.3 to 20, and R1, R2 and R3 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms.

Description

Epoxy resin composition, prepreg, laminate and printed wiring board

The present invention relates to an epoxy resin composition used in the manufacture of a printed wiring board or a multilayer printed wiring board with high heat resistance and excellent flame retardancy, and a prepreg obtained from the epoxy resin composition, Laminated board or printed wiring board.

The epoxy resin composition is excellent in adhesiveness, flexibility, heat resistance, chemical resistance, insulation, and hardening reactivity, so it is used in many aspects such as coatings, civil bonding, injection molding, electrical and electronic materials, and film materials. In particular, in printed wiring board applications as one of electrical and electronic materials, flame retardancy is given to epoxy resins widely.

In recent years, the flame-retardation of electronic equipment has been considered in response to the impact on the environment, with the aim of suppressing the toxic gas generated during its combustion. The existing flame retardant use of halogen-containing compounds represented by brominated epoxy resins realizes the flame retardant use of organic phosphorus compounds, that is, halogen-free flame retardant. These correspondences are not limited to electronic circuit boards, but are generally widely used and recognized with phosphorus flame retardancy, and the same is true in the field of epoxy resins related to circuit boards.

As a specific representative example of such an epoxy resin imparting such flame retardancy, it is proposed to apply an organic phosphorus compound as disclosed in Patent Document 1 to Patent Document 4. Patent Literature 1 discloses a thermosetting resin obtained by reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide with an epoxy resin at a predetermined molar ratio.

In Patent Document 1 and Patent Document 2, since a phosphorus compound exhibiting flame retardancy is reacted with a multifunctional epoxy resin, the heat resistance after curing using a curing agent can obtain a glass transition equivalent to that of an FR-4 substrate Transition temperature (Tg), but in recent years, the development of high-density mounting of substrates or the mounting from the car cockpit to the periphery of the hood drive unit requires heat resistance equivalent to FR-5 as a further high-temperature response Tg is the actual state.

Patent Document 3 describes the following specific example: a phosphorus-containing epoxy resin that synthesizes and uses a trifunctional epoxy resin that can obtain a Tg higher than that of the existing novolak-type epoxy resin, and the Tg of the cured product is about 180 ℃. In addition, Patent Document 4 discloses a specific example of a phosphorus-containing epoxy resin with high heat resistance obtained by reacting a phosphorus compound with hydroxybenzaldehyde and reacting the obtained phosphorus-containing oligomer with a multifunctional epoxy resin The Tg of the hardened product is 185°C. As these substrates having heat resistance equivalent to FR-5, many technologies have been disclosed and are being widely used.

In any of the above documents, in order to ensure flame retardancy, it is necessary to have a high phosphorus content rate, and it is required to establish a method that can exhibit high flame retardancy even if the phosphorus content rate is low. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 11-166035 [Patent Document 2] Japanese Patent Laid-Open No. 11-279258 [Patent Document 3] Japanese Patent Laid-Open No. 2002-206019 [Patent Document 4] Japanese Patent Laid-Open No. 2013-35921

[Problems to be solved by the invention] The problem to be solved by the present invention is to provide an epoxy resin composition that exhibits excellent heat resistance and flame retardancy in a cured product even when the phosphorus content is low, and in particular, provides excellent cured product characteristics in printed wiring board applications Thing. [Technical means to solve the problem]

In order to solve the above-mentioned problems, the present inventors have made intensive research on epoxy resins and found that when a phosphorus-containing epoxy resin is blended with an epoxy resin having a structure obtained from a biphenol compound and a biphenyl-based condensing agent, The heat resistance and flame retardancy of the obtained cured product are excellent even when the phosphorus content rate is low, and the present invention has been completed.

此處，n為重複數，表示0以上的數，其平均值為1.3～20的數，R¹ 、R² 及R³ 分別獨立地表示氫原子或碳數1～8的烴基。That is, the present invention is an epoxy resin composition comprising an epoxy resin and a hardener as essential components, characterized in that the epoxy resin contains the following general formula (1) Biphenyl aralkyl type epoxy resin, and phosphorus-containing epoxy resin. [Chemical 1]

Here, n is the number of repetitions and represents a number of 0 or more, and the average value thereof is a number of 1.3 to 20, and R ¹ , R ² and R ³ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms.

The epoxy equivalent of the phosphorus-containing epoxy resin is preferably 200 g/eq. (gram/equivalent) to 1000 g/eq., and the phosphorus content is preferably 1.0 to 6.0% by mass.

In addition, the present invention is a prepreg, a laminate, or a printed wiring board characterized by using the epoxy resin composition. [Effect of invention]

The epoxy resin composition of the present invention exhibits excellent heat resistance and flame retardancy in its hardened material even when the phosphorus content is low, so it is useful in printed wiring board applications, especially where high reliability is required Useful for automotive substrates.

Hereinafter, embodiments of the present invention will be described in detail. The epoxy resin composition of the present invention is characterized in that the epoxy resin (A) and the hardener (B) are essential components, and the epoxy resin (A) contains the biphenyl arane represented by the general formula (1) Basic epoxy resin (a1) and phosphorus-containing epoxy resin (a2) as essential components.

The epoxy resin (A) contains biphenyl aralkyl type epoxy resin (a1) and phosphorus-containing epoxy resin (a2) as essential components, and may include various other epoxy resins (a3). In order to exhibit heat resistance and flame retardancy at a low phosphorus content, the biphenyl aralkyl type epoxy resin (a1) is preferably 5% by mass or more and 30% by mass or less in all epoxy resins (A) , More preferably, it is 7 mass% or more and 25 mass% or less.

In the general formula (1), R ¹ , R ² and R ³ each independently represent a hydrogen atom or a C 1-8 hydrocarbon group. Examples of the hydrocarbon group having 1 to 8 carbon atoms include alkyl groups having 1 to 8 carbon atoms such as methyl, ethyl, propyl, isopropyl, n-butyl, third butyl, and hexyl groups, and cyclohexyl groups. Cycloalkyl having 5 to 8 carbons, or aryl having 6 to 8 carbons such as phenyl, tolyl, and xylyl, or having 7 to 8 carbons such as benzyl, phenethyl, and 1-phenylethyl The aralkyl group is not limited to these, and each may be the same or different. From the viewpoints of ease of acquisition and physical properties such as heat resistance when made into a cured product, R ¹ , R ² and R ³ are preferably a hydrogen atom, 1-phenylethyl or methyl.

n is the number of repetitions and represents a number of 0 or more, and its average value (number average) is 1.3 to 20, preferably 1.5 to 15, more preferably 1.7 to 10, and still more preferably 2 to 6.

In addition, the weight average molecular weight (Mw) of the biphenyl aralkyl type epoxy resin (a1) measured by gel permeation chromatography (GPC) is preferably 1,000 to 8,000, more preferably 2000 to 7000 , It is further preferably 3000 to 6000.

From the viewpoint of solvent solubility, the content of the n=0 component where n is 0 is based on the area% measured by GPC, preferably less than 15%, more preferably 10% or less, and still more preferably 6% or less . In particular, when it is dissolved in an organic solvent for use in laminates and the like, it is preferably 2% to 5%. In addition, from the viewpoint of improving heat resistance, the content of n=5 components or more is preferably 20% or more, more preferably 25% or more, and still more preferably 27% or more. In addition, the measurement conditions of GPC follow the method described in the Examples.

The epoxy equivalent (g/eq.) of the biphenyl aralkyl type epoxy resin (a1) is preferably 200 to 240, more preferably 205 to 235, and still more preferably 210 to 230. In addition, the softening point is preferably 70°C to 130°C, more preferably 80°C to 120°C, and still more preferably 90°C to 110°C.

The biphenyl aralkyl type epoxy resin (a1) can be produced by the method disclosed in WO2011/074517 and the like. Specifically, the biphenyl compound and the biphenyl-based condensing agent are reacted with less than 1 mole of the biphenyl-based condensing agent with respect to 1 mole of the biphenol compound to make the resulting biphenyl aralkyl type phenol resin ring Oxidation method.

Examples of the biphenol compound include 4,4'-biphenol, 2,4'-biphenol, or 2,2'-biphenol. From the viewpoint of reactivity, 4,4'- is preferred Biphenol. In addition, these biphenol compounds may have one hydrocarbon group having 1 to 8 carbon atoms as a substituent on each aromatic ring.

Examples of the biphenyl-based condensing agent include biphenyl-4,4'-dimethanol, 4,4'-bis(chloromethyl)biphenyl, and 4,4'-bis(bromomethyl)biphenyl. , 4,4'-bis(methoxymethyl)biphenyl, 4,4'-bis(ethoxymethyl)biphenyl, biphenyl-2,4'-dimethanol, 2,4'-bis (Chloromethyl) biphenyl, 2,4'-bis (bromomethyl) biphenyl, 2,4'-bis (methoxymethyl) biphenyl, 2,4'-bis (ethoxymethyl ) Biphenyl, biphenyl-2,2'-dimethanol, 2,2'-bis(chloromethyl)biphenyl, 2,2'-bis(bromomethyl)biphenyl, 2,2'-bis( Methoxymethyl) biphenyl, 2,2'-bis(ethoxymethyl) biphenyl, etc. From the viewpoint of reactivity, biphenyl-4,4'-dimethanol and 4,4'-bis(chloromethyl)biphenyl are preferred, and from the viewpoint of reducing ionic impurities, biphenyl is preferred -4,4'-dimethanol, 4,4'-bis(methoxymethyl)biphenyl. In addition, these biphenyl-based condensing agents may have one or two hydrocarbon groups having 1 to 8 carbon atoms as substituents on each aromatic ring.

In the reaction of the biphenol compound and the biphenyl-based condensing agent, an excess of the biphenol compound is used relative to the biphenyl-based condensing agent. The use amount of the biphenyl-based condensing agent is preferably 0.1 mol to 0.55 mol, more preferably 0.3 mol to 0.5 mol relative to 1 mol of the biphenol compound. If the use amount of the biphenyl-based condensing agent is too large, the unreacted raw material biphenol compound becomes small, but the molecular weight itself becomes high, and the softening point or melt viscosity of the resin becomes high, which may cause an obstacle to moldability or workability. On the other hand, if the amount of the biphenyl-based condensing agent used is too small, the amount of unreacted raw material biphenol compound removed after the reaction is increased, which is industrially unfavorable.

Generally, the reaction is carried out in the presence of well-known acid catalysts such as inorganic acids and organic acids. Examples of such acid catalysts include mineral acids such as hydrochloric acid, sulfuric acid, and phosphoric acid, organic acids such as formic acid, oxalic acid, trifluoroacetic acid, and p-toluenesulfonic acid, and zinc chloride, aluminum chloride, and chlorine. Lewis acids such as iron oxide and boron trifluoride, or solid acids such as activated clay, silica-alumina, and zeolite.

Generally, the reaction is carried out at 10°C to 250°C for 1 hour to 20 hours. Furthermore, during the reaction, as the solvent, for example, alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol, methyl cellosolve, ethyl cellosolve, or diethylene glycol can be preferably used. Ethers such as dimethyl ether and triglyme, or halogenated aromatic compounds such as chlorobenzene and dichlorobenzene, etc. Among these, ethyl cellosolve and diethylene glycol dimethyl are particularly preferred Ether, triethylene glycol dimethyl ether, etc.

The biphenyl aralkyl type phenol resin obtained by the above method sometimes contains a large amount of unreacted raw material biphenol compound. Therefore, it is preferable to increase the step of removing the unreacted raw material biphenol compound as necessary after the reaction. From the viewpoint of solvent solubility, the content of the unreacted raw material biphenol compound is preferably less than 15% (area% measured by GPC), more preferably 10% or less, and still more preferably 6% or less, particularly preferably It is 3%～5%.

In the step of removing the unreacted raw material biphenol compound of the biphenyl aralkyl type phenol resin, for example, in order to dissolve the generated high molecular weight component without dissolving the raw material biphenol compound, it is preferable to use a mixed poor solvent The unreacted raw material biphenol compound is removed by a method such as filtration with a good solvent. The poor solvent is not particularly limited as long as it hardly dissolves the raw material biphenol compound, and examples thereof include aromatic solvents such as benzene, toluene, and xylene. Examples of good solvents include the alcohols, ethers, halogenated aromatic compounds, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

The softening point of the biphenyl aralkyl phenol resin can be easily adjusted by changing the molar ratio of the biphenol compound and the biphenyl-based condensing agent, but if the biphenol compound and the biphenyl-based condensing agent are changed in order to reduce the high molecular weight body component In the mole ratio of the agent, the content of the unreacted raw material biphenol compound that needs to be removed increases, the workability deteriorates, and the yield greatly decreases, so there is a limit.

The biphenyl aralkyl type epoxy resin (a1) used in the present invention can be produced by reacting the biphenyl aralkyl type phenol resin with epichlorohydrin. The reaction can be carried out in the same manner as a normal epoxidation reaction. For example, after dissolving biphenyl aralkyl phenol resin in excess epichlorohydrin, in the presence of alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, it is preferably 50°C to 150°C, preferably It is a method of reacting at 60°C to 120°C for 1 hour to 10 hours. At this time, the amount of the alkali metal hydroxide used is 0.8 to 1.2 moles, preferably 0.9 to 1.0 moles, relative to 1 mole of hydroxyl groups in the biphenyl aralkyl type phenol resin. In addition, epichlorohydrin is used excessively with respect to the hydroxyl group in the biphenyl aralkyl type phenol resin, and is usually 1.5 mol to 15 mol relative to 1 mol of the hydroxyl group in the biphenyl aralkyl type phenol resin. It is preferably from 2 mol to 8 mol. After the reaction, the excess epichlorohydrin is distilled off, the residue is dissolved in solvents such as toluene and methyl isobutyl ketone, and filtered and washed with water to remove inorganic salts, and then the solvent is distilled off to obtain biphenyl aryl Alkyl epoxy resin. In addition, in the case of epoxidation, there may be a small amount of by-produced epoxy compounds in which the epoxy groups of the produced epoxy compounds are ring-opened, condensed, and oligomerized, but such epoxy compounds may be present.

The phosphorus-containing epoxy resin (a2) used in the present invention is preferably used alone or in combination of two or more. In addition, a phosphorus-free epoxy resin (a3) may be used in combination. As the phosphorus-containing epoxy resin (a2), particularly preferred are Japanese Patent Laid-Open No. 04-11662, Japanese Patent Laid-Open No. 05-214070, Japanese Patent Laid-Open No. 2000-309624, and Japanese Patent Laid-Open 2002 -265562 and the like, by combining 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide or diphenylphosphine oxide and other reactive phosphorus compounds with 1 An epoxy resin obtained by reacting a quinone compound such as 4-benzoquinone or 1,4-naphthoquinone with an epoxy resin.

The epoxy equivalent (g/eq.) of these phosphorus-containing epoxy resins (a2) is preferably 200 to 1,000, more preferably 250 to 800, and still more preferably 270 to 700. The phosphorus content is preferably 1.0% by mass to 6.0% by mass, more preferably 1.5% by mass to 5.5% by mass, and still more preferably 1.7% by mass to 5.0% by mass.

When the phosphorus-free epoxy resin (a3) is used together, the phosphorus content of the phosphorus-containing epoxy resin (a23), which is a mixture of the phosphorus-containing epoxy resin (a2) and the phosphorus-free epoxy resin (a3) The rate is to adjust the phosphorus content rate of the phosphorus-containing epoxy resin (a2) or the phosphorus-containing epoxy resin (a2) and not to be within the range of the preferable phosphorus content of the phosphorus-containing epoxy resin (a2) The mixing amount of phosphorus epoxy resin (a3).

The phosphorus content rate in the epoxy resin composition for achieving V-0 of the flame retardancy test UL-94 is preferably 1.0% by mass to 5.0% by mass, and more preferably 1.3% by mass to 4.5% by mass. Particularly good is 1.5% by mass to 2.3% by mass. When the phosphorus content in the epoxy resin composition is small, the flame retardancy may be insufficient, and when the phosphorus content is large, the heat resistance or adhesion may be impaired.

Specific examples of the phosphorus-containing epoxy resin (a2) include, for example, Epotohto FX-305, Albert FX-289B, Albert FX-1225, YDFR-1320, TX-1328 (above Made for Nippon Steel & Sumitomo Chemical Co., Ltd.), etc., but not limited to these.

As the phosphorus-free epoxy resin (a3) that can be used in combination, a general epoxy resin having two or more epoxy groups in the molecule can be used without particular limitation, and a trifunctional or more epoxy resin is preferable. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, tetramethyl bisphenol F type epoxy resin, hydroquinone type epoxy resin, biphenyl type epoxy resin, bisphenol fluorene Type epoxy resin, bisphenol S type epoxy resin, disulfide type epoxy resin, resorcinol type epoxy resin, biphenyl aralkyl type ring other than the structure represented by the general formula (1) Oxygen resin, naphthalene type epoxy resin, phenol novolak type epoxy resin, aromatic modified phenol novolak type epoxy resin, cresol novolak type epoxy resin, alkyl novolak type epoxy resin, double Phenol novolac epoxy resin, naphthol novolac epoxy resin, β-naphthol aralkyl epoxy resin, dinaphthol aralkyl epoxy resin, α-naphthol aralkyl epoxy resin Resin, triphenylmethane type epoxy resin, alkanediol type epoxy resin, aliphatic cyclic epoxy resin, diaminodiphenylmethane tetraglycidylamine, aminophenol type epoxy resin, aminomethyl Ester-modified epoxy resin, epoxy resin containing oxazolidone ring, etc., but not limited to these. From the viewpoint of easy availability, naphthalene type epoxy resin, phenol novolak type epoxy resin, aromatic modified phenol novolak type epoxy resin, cresol novolak type epoxy resin, α-naphthalene are preferred Phenol aralkyl type epoxy resin, dicyclopentadiene type epoxy resin, epoxy resin containing oxazolidone ring, etc.

As the hardener (B) in the epoxy resin composition of the present invention, a conventionally known hardener can be used without particular limitation. For example, a commonly used curing agent such as a phenol resin-based curing agent, an acid anhydride-based curing agent, an amine-based curing agent, or other curing agents may be mentioned. These curing agents may be used alone or in combination of two or more.

In the epoxy resin composition of the present invention, the use amount of the hardener (B) is based on 1 mole of epoxy groups of the entire epoxy resin (A), and the active hydrogen group of the hardener (B) is The range of 0.2 moles or more and 1.5 moles or less. When the active hydrogen group is less than 0.2 moles or more than 1.5 moles with respect to 1 mole of epoxy groups, there is a fear that the hardening becomes incomplete and good hardening physical properties cannot be obtained. The preferable range is 0.3 moles or more and 1.5 moles or less, the more preferable range is 0.5 moles or more and 1.5 moles or less, and the more preferable range is 0.8 moles or more and 1.2 moles or less. For example, when a phenol resin-based hardener or an amine-based hardener is used, a molar equivalent of active hydrogen groups is blended with the epoxy group, and when an acid anhydride-based hardener is used, with respect to the epoxy group 1 An acid anhydride group of 0.5 mol to 1.2 mol, preferably 0.6 mol to 1.0 mol is prepared.

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

Specific examples of the phenol resin-based hardener include bisphenol A, bisphenol F, bisphenol C, bisphenol K, bisphenol Z, bisphenol S, tetramethyl bisphenol A, and tetramethyl bisphenol F. Bisphenols such as tetramethyl bisphenol S, tetramethyl bisphenol Z, dihydroxy diphenyl sulfide, 4,4'-thiobis (3-methyl-6-third butyl phenol), or all The biphenol compound, or catechol, resorcinol, methylresorcinol, hydroquinone, monomethylhydroquinone, dimethylhydroquinone, trimethylhydroquinone Dihydroxybenzenes such as phenol, mono-tert-butylhydroquinone, di-tert-butylhydroquinone, or hydroxynaphthalenes such as dihydroxynaphthalene, dihydroxymethylnaphthalene, trihydroxynaphthalene, or LC-950PM60 (Made by Shin-AT & C) and other phosphorus-containing phenolic hardeners, or Shono BRG-555 (made by Aica Kogyo Co., Ltd.) and other phenol novolak resins, DC-5 (Manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.) and other cresol novolak resins, aromatic modified phenol novolak resins, bisphenol A novolak resins, Resitop TPM-100 (Qunrong Chemical Industry Co., Ltd. Manufactured by the company) and other condensates of phenols, naphthols and/or bisphenols and aldehydes such as trihydroxyphenylmethane novolak resins and naphthol novolak resins, SN-160, SN-395, SN-485 (Manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.) Condensates of phenols, naphthols and/or bisphenols with xylylene glycol, phenols and/or naphthols with isopropenylacetophenone Condensates of phenols, naphthols and/or bisphenols and dicyclopentadiene, condensates of phenols, naphthols and/or bisphenols and biphenyl crosslinkers, etc. The phenol compound called "phenolic novolac type phenol resin" and so on. From the viewpoint of easy availability, phenol novolak resin, dicyclopentadiene type phenol resin, trihydroxyphenylmethane type novolak resin, aromatic modified phenol novolak resin, etc. are preferable.

In the case of novolak type phenol resins, examples of phenols include phenol, cresol, xylenol, butylphenol, amylphenol, nonylphenol, butylmethylphenol, trimethylphenol, phenylphenol, etc. Examples of naphthols include 1-naphthol and 2-naphthol, and the above-mentioned biphenol compounds and bisphenols can also be mentioned. Examples of aldehydes include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, hexanal, benzaldehyde, chloroaldehyde, bromoaldehyde, glyoxal, malondialdehyde, succinaldehyde, glutaraldehyde, and hexanedialdehyde. Aldehyde, pimelic aldehyde, sebacaldehyde, acrolein, crotonaldehyde, salicylaldehyde, o-phthalaldehyde, hydroxybenzaldehyde, etc. Examples of the biphenyl-based crosslinking agent include bis(hydroxymethyl)biphenyl, bis(methoxymethyl)biphenyl, bis(ethoxymethyl)biphenyl, and bis(chloromethyl)biphenyl. .

Specific examples of the acid anhydride hardener include methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, pyromellitic anhydride, phthalic anhydride, trimellitic anhydride, and methyl nadic Anhydride etc.

Specific examples of the amine-based hardener include diethylenetriamine, triethylenetetramine, m-xylylenediamine, isophoronediamine, diaminodiphenylmethane, diaminodiphenyl sulfone, Condensation of diaminodiphenyl ether, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, dicyandiamine, dimer acid and other acids with polyamines Amine compounds such as polyamidoamine.

As other hardeners, specific examples include phosphine compounds such as triphenylphosphine, phosphonium salts such as tetraphenylphosphonium bromide, 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole , 2-undecyl imidazole, 1-cyanoethyl-2-methylimidazole and other imidazoles, as imidazoles, salts of trimellitic acid, isocyanuric acid or boric acid, etc. Quaternary ammonium salts such as ammonium chloride, diazabicyclic compounds, salts of diazabicyclic compounds with phenols or phenol novolak resins, complex compounds of boron trifluoride with amines or ether compounds , Aromatic phosphonium salts, or iodonium salts.

A hardening accelerator may be used in the epoxy resin composition as needed. Examples of usable hardening accelerators include imidazoles such as 2-methylimidazole, 2-ethylimidazole, and 2-ethyl-4-methylimidazole, and 2-(dimethylaminomethyl)phenol , 1,8-diaza-bicyclic (5,4,0) undecene-7 and other tertiary amines, triphenylphosphine, tricyclohexylphosphine, triphenylphosphine triphenylborane and other phosphines , Tin octoate and other metal compounds. A hardening accelerator of 0.02 to 5 parts by mass may be used as needed with respect to 100 parts by mass of the epoxy resin component in the epoxy resin composition of the present invention. By using a hardening accelerator, the hardening temperature can be reduced, or the hardening time can be shortened.

In the epoxy resin composition, an organic solvent or a reactive diluent can be used to adjust the viscosity.

Examples of the organic solvent include: amides such as N,N-dimethylformamide, N,N-dimethylacetamide, or ethylene glycol monomethyl ether and dimethoxy diethylene glycol , Glycol diethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether and other ethers, or acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and other ketones, or methanol , Ethanol, 1-methoxy-2-propanol, 2-ethyl-1-hexanol, benzyl alcohol, ethylene glycol, propylene glycol, butyl diethylene glycol, pine oil and other alcohols, or butyl acetate , Methoxybutyl acetate, methyl cellosolve acetate, cellosolve acetate, ethyl diethylene glycol acetate, propylene glycol monomethyl ether acetate, carbitol acetate, benzyl alcohol ethyl Acetates such as acid esters, or benzoates such as methyl benzoate and ethyl benzoate, or cellosolves such as methyl cellosolve, cellosolve, butyl cellosolve, or methyl carbitol, Carbitols such as carbitol and butyl carbitol, or aromatic hydrocarbons such as benzene, toluene, xylene, or dimethyl sulfoxide, acetonitrile, N-methylpyrrolidone, etc., but not limited to these .

Examples of the reactive diluent include monofunctional glycidyl ethers such as allyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, and tolyl glycidyl ether. , Or resorcinol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, cyclohexane dimethanol Difunctional glycidyl ethers such as glycidyl ether and propylene glycol diglycidyl ether, or glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, trimethylolethane polyglycidyl ether, pentaerythritol polyglycidyl ether Such as polyfunctional glycidyl ethers, glycidyl esters such as neodecanoic acid glycidyl ester, or glycidylamines such as phenyl diglycidylamine and tolyl diglycidylamine, but not limited to these.

These organic solvents or reactive diluents are preferably used alone or as a mixture of a plurality of types with a non-volatile content of 90% by mass or less, and the appropriate type or usage amount can be appropriately selected according to the application. For example, in the use of printed wiring boards, polar solvents such as methyl ethyl ketone, acetone, 1-methoxy-2-propanol, etc., having a boiling point of 160° C. or less are preferred, and the amount used is preferably 40 in terms of non-volatile components. Mass% ~ 80 mass%. In addition, for adhesive film applications, for example, ketones, acetates, carbitols, aromatic hydrocarbons, dimethylformamide, dimethylacetamide, N-methylpyrrolidone are preferably used Etc., and the usage amount thereof is preferably 30% by mass to 60% by mass in terms of nonvolatile components.

The epoxy resin composition can be blended with other thermosetting resins and thermoplastic resins within a range that does not impair the characteristics. For example, phenol resin, acrylic resin, petroleum resin, indene resin, benzofuran-indene (coumarone-indene) resin, phenoxy resin, polyurethane resin, polyester resin, polyamide resin , Polyimide resin, Polyamide imide resin, Polyether imide resin, Polyphenylene ether resin, Modified polyphenylene ether resin, Polyether resin, Polyester resin, Polyether ether ketone resin, Poly Phenyl sulfide resin, polyvinyl formal resin, etc., but not limited to these.

In the epoxy resin composition, in order to improve the flame retardancy of the obtained cured product, various known flame retardants may be used in combination. Examples of the flame retardants that can be used in combination include phosphorus-based flame retardants, nitrogen-based flame retardants, silicone-based flame retardants, and inorganic-based flame retardants. Particularly preferred are phosphorus-based flame retardants. These flame retardants may be used alone or in combination of two or more.

As the phosphorus-based flame retardant, any of inorganic phosphorus-based compounds and organic phosphorus-based compounds can be used. Examples of the inorganic phosphorus-based compounds include ammonium phosphates such as red phosphorus, monoammonium phosphate, diammonium phosphate, triammonium phosphate, and ammonium polyphosphate, and inorganic nitrogen-containing phosphorus compounds such as phosphamide. Examples of the organic phosphorus-based compound include aliphatic phosphate esters, phosphate ester compounds, and condensed phosphate esters such as PX-200 (manufactured by Daiba Chemical Industry Co., Ltd.), phosphonic acid compounds, phosphinic acid compounds, and phosphine oxide compounds. , Such as PPQ (manufactured by Beiyou Chemical Industry Co., Ltd.), organic nitrogen-containing phosphorus compounds such as phosphorane compounds, phosphazene (phosphazene) and other general organic phosphorus compounds, or metal salts of phosphinic acid, except Other examples include 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10 -Phosphaphenanthrene-10-oxide, 10-(2,7-dihydroxynaphthyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide and other cyclic organic phosphorus compounds, or as Phosphorus-containing hardeners of derivatives obtained by reacting these compounds with compounds such as phenol resin.

The blending amount of the flame retardant can be appropriately selected according to the type of the phosphorus-based flame retardant, the components of the epoxy resin composition, and the degree of desired flame retardancy. The same applies to the formulation of phosphorus-based flame retardants. For example, regarding the phosphorus content of the organic components (excluding organic solvents) in the epoxy resin composition, all phosphorus compounds (phosphorus-containing epoxy resins and phosphorus-based The total amount of the fuel agent) is preferably 0.2% by mass or more and 4% by mass or less, more preferably 0.4% by mass or more and 3.5% by mass or less, and still more preferably 0.6% by mass or more and 3% by mass or less. If the phosphorus content is small, it may be difficult to ensure flame retardancy, and if it is too large, the heat resistance may be adversely affected, and the problem of the present invention cannot be achieved. In addition, flame retardant additives such as magnesium hydroxide may be used in combination.

Filling materials can be used in epoxy resin compositions as needed. Specific examples include: fused silica, crystalline silica, alumina, silicon nitride, aluminum hydroxide, boehmite, magnesium hydroxide, talc, mica, calcium carbonate, calcium silicate, calcium hydroxide , Magnesium carbonate, barium carbonate, barium sulfate, boron nitride, carbon, carbon fiber, glass fiber, alumina fiber, silica alumina fiber, silicon carbide fiber, polyester fiber, cellulose fiber, aromatic polyamide fiber , Ceramic fibers, fine particle rubber, thermoplastic elastomers, pigments, etc. As a reason for using a filler, the effect of improving impact resistance is generally cited. In addition, when metal hydroxides such as aluminum hydroxide, boehmite, and magnesium hydroxide are used, they have an effect of functioning as a flame retardant aid to improve flame retardancy. The blending amount of these fillers is preferably 1 part by mass to 150 parts by mass, and more preferably 10 parts by mass to 70 parts by mass relative to 100 parts by mass of the epoxy resin composition. If the compounding amount is large, there is a fear that the adhesiveness required for the application of the laminate is lowered, and further that the cured product becomes brittle and sufficient mechanical properties cannot be obtained. In addition, if the blending amount is small, the impact resistance of the cured product is improved, and there is a fear that the blending effect of the filler cannot be exerted.

When the epoxy resin composition is made into a plate-shaped substrate, etc., in terms of dimensional stability, bending strength, etc., a fibrous filler is cited as a suitable filler. More preferably, a glass fiber substrate in which glass fibers are knitted into a net shape is cited.

The epoxy resin composition may further contain various additives such as silane coupling agent, antioxidant, mold release agent, defoamer, emulsifier, thixotropy-imparting agent, smoothing agent, flame retardant, and pigment. These additives are preferably in the range of 0.01 to 20 parts by mass relative to 100 parts by mass of the epoxy resin composition.

The epoxy resin composition can be made into a prepreg used in a printed wiring board or the like by impregnating a fibrous base material. As the fibrous substrate, woven or nonwoven fabrics of organic fibers such as inorganic fibers such as glass, polyester resins, polyamine resins, polyacrylic resins, polyimide resins, and aromatic polyamide resins can be used , But not limited to this. The method for producing the prepreg from the epoxy resin composition is not particularly limited. For example, after immersing the fibrous base material in a resin varnish prepared by adjusting the viscosity of the epoxy resin composition with a solvent, it is heated The resin component is semi-hardened by drying to obtain a prepreg, which can be heated and dried at, for example, 100°C to 200°C for 1 to 40 minutes. Here, the amount of resin in the prepreg is preferably 30% by mass to 80% by mass.

In order to harden the prepreg, a method of hardening a laminate used for manufacturing a printed wiring board may be used, but it is not limited thereto. For example, in the case of using a prepreg to form a laminate, one or more prepregs are laminated, a metal foil is disposed on one side or both sides to form a laminate, and the laminate is heated and pressurized to make it Layered integration. Here, as the metal foil, copper, aluminum, brass, nickel, or the like can be used alone, and alloy or composite metal foil can be used. In addition, the laminate can be obtained by hardening the prepreg by heating the produced laminate. At this time, it is preferable to set the heating temperature to 160°C to 220°C, the pressurizing pressure to 50 N/cm ² to 500 N/cm ² , and the heat and pressurizing time to 40 minutes to 240 minutes. The target hardened object can be obtained. If the heating temperature is low, the curing reaction may not proceed sufficiently, and if the heating temperature is high, the epoxy resin composition may start to decompose. In addition, if the pressurization pressure is low, bubbles may remain inside the resulting laminate to lower the electrical characteristics. If the pressurization pressure is high, the resin may flow before curing, and a cured product of a desired thickness may not be obtained. Furthermore, if the heating and pressurizing time is short, the curing reaction may not proceed sufficiently. If the heating and pressurizing time is long, the epoxy resin composition in the prepreg may be thermally decomposed, which is not preferable. In addition, a printed wiring board can be obtained by performing circuit formation on the laminate board using an additive method, a subtractive method, or the like.

In addition, the laminate can also be used as an inner layer material to obtain a multilayer laminate. For example, first, a circuit is formed on the laminated board by an addition method or a subtraction method, and the circuit surface is blackened with an acid solution to obtain an inner layer material. One or more pieces of the prepreg are arranged on the circuit forming surface of one or both sides of the obtained inner layer material, and a metal foil is arranged on the outside thereof to form a laminate. The multilayer body is formed by heating and pressing the laminate and integrally forming it. In the formation of the insulating layer, an insulating adhesive sheet, a metal foil with resin, etc. can also be used instead of the prepreg. In addition, as the metal foil, the same metal foil as that used in the laminate can be used. In addition, heat and pressure molding can be carried out in the same manner as described above. On the surface of the obtained multilayer build-up board, through-hole formation or circuit formation is performed by an addition method or a subtraction method to obtain a multilayer printed wiring board. In addition, by using the multilayer printed wiring board as an inner layer material and repeating the above-mentioned method, a multilayer printed wiring board can be further obtained.

The epoxy resin composition can be cured by a method similar to a known epoxy resin composition to obtain a cured epoxy resin. As a method for obtaining a hardened product, the same method as a known epoxy resin composition can be used, and injection molding, injection, potting, dipping, drip coating, transfer molding, and compression can be suitably used A method such as forming a laminate or the like by forming or forming a resin sheet, a copper foil with resin, a prepreg, etc., and performing lamination, heat and pressure curing. The curing temperature at this time is usually in the range of 100°C to 300°C, and the curing time is usually about 1 hour to 5 hours.

When an epoxy resin composition is produced, which is used as a laminate and cured by heating to form a laminate, the cured epoxy resin exhibits excellent heat resistance and flame retardancy. [Example]

The present invention will be specifically described with examples and comparative examples, but the present invention is not limited to these. Unless otherwise specified, "parts" means mass parts, and "%" means mass %. In addition, the measurement methods are measured by the following methods, respectively.

Epoxy equivalent: measured according to the Japanese Industrial Standard (JIS) K7236 standard, the unit is represented by "g/eq." Specifically, using an automatic potentiometric titration device (made by Hiranuma Industry Co., Ltd., COM-1600ST), chloroform was used as a solvent, tetraethylammonium bromide acetic acid solution was added, and a 0.1 mol/L perchloric acid-acetic acid solution was used. Titration.

Softening point: Measured according to JIS K 7234 standard and the ring and ball method. Specifically, an automatic softening point device (made by Meitech Co., Ltd., ASP-MG4) was used.

GPC measurement: An apparatus including a column (TSKgelG4000H _XL , TSKgelG3000H _XL , TSKgelG2000H _XL manufactured by Tosoh Corporation) connected in series in the main body (HLC-8220GPC manufactured by Tosoh Corporation) was used, and the column temperature was set to 40°C . In addition, tetrahydrofuran (THF) was used as the eluent, and the flow rate was set to 1 mL/min, and the detector used a differential refractive index detector. As a measurement sample, 50 μL of a sample obtained by dissolving 0.1 g of the sample in 10 mL of THF and filtering with a microfilter was used. For data processing, GPC-8020 model II version 6.00 manufactured by Tosoh Corporation was used. Calculate n=0 component amount and n=5 or more component amount from the obtained chromatogram, and use standard monodisperse polystyrene (A-500, A-1000, A-2500, A manufactured by Tosoh Corporation) -5000, F-1, F-2, F-4, F-10, F-20, F-40, F-80, F-128) to determine the number average molecular weight (Mn), weight Average molecular weight (Mw), degree of dispersion (Mw/Mn).

Glass transition temperature: Based on IPC-TM-650 2.4.25.c, a differential scanning calorimeter (EXSTAR) 6000 differential scanning calorimeter (differential scanning calorimeter, manufactured by Hitachi High-Tech Co., Ltd.) DSC) 6200) The temperature of DSC·Tgm (the middle temperature of the variation curve with respect to the tangent of the glass state and the rubber state) when measured under a temperature increase condition of 20°C/min.

Flame retardancy: According to UL94, the evaluation is performed by the vertical method. The evaluation is described by V-0, V-1, and V-2.

Copper foil peel strength and interlayer adhesion: measured according to the JIS C 6481 standard. The interlayer adhesion is measured by peeling between the 7th and 8th layers.

[Epoxy resin] A1: Biphenyl aralkyl type epoxy resin obtained in Synthesis Example 2 A2: Triphenol methane epoxy resin (manufactured by Nippon Kayaku Co., Ltd., EPPN-501H, epoxy equivalent 166) A3: Phosphorus-containing epoxy resin (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., FX-1225, epoxy equivalent 318, phosphorus content rate 2.5%) A4: Phosphorus-containing epoxy resin (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., YDFR-1320, epoxy equivalent 763, phosphorus content rate 5.0%)

[hardener] B1: Phenol novolak resin (manufactured by Aike Industrial Co., Ltd., Shonol BRG-557, phenolic hydroxyl equivalent 105, softening point 80°C) B2: Dicyandiamide (manufactured by Nippon Carbide Industries Co., Ltd., DICY, active hydrogen equivalent 21) B3: Phenol resin (made by Qunrong Chemical Industry Co., Ltd., Resitop TPM-100, phenolic hydroxyl equivalent of 98, softening point 108℃)

[Hardening accelerator] C1: 2-ethyl-4-methylimidazole (manufactured by Shikoku Chemical Industry Co., Ltd., solid azole (Curezol) 2E4MZ)

Synthesis Example 1 In a reaction device equipped with a stirrer, a thermometer, a nitrogen introduction tube, and a cooling tube, add 246 parts of 4,4'-biphenol, 380 parts of diethylene glycol dimethyl ether, and 4,4'-bischloromethylbiphenyl 133 Portions, the temperature was raised to 170°C while stirring under a nitrogen flow, and the reaction was carried out for 2 hours. After the reaction, all the diethylene glycol dimethyl ether was distilled off under reduced pressure, 311 parts of toluene and 104 parts of methyl isobutyl ketone were added and stirred and mixed, and after cooling to room temperature, the precipitated unreacted raw materials 4 After 4'-biphenol was separated by filtration and removed, toluene and methyl isobutyl ketone were distilled off to obtain 187 parts of biphenyl aralkyl phenol resin. The phenolic hydroxyl equivalent weight is 155 and the softening point is 130°C.

Synthesis Example 2 In a reaction device equipped with a stirrer, a thermometer, a nitrogen introduction tube, and a cooling tube, 127 parts of the biphenyl aralkyl type phenol resin obtained in Synthesis Example 1 were added, and 448 parts of epichlorohydrin and diethylene glycol dimethyl ether were added 67 parts, heated to 60 ℃. Under a reduced pressure of 110 mmHg, while maintaining a temperature of 58°C to 62°C, 64 parts of 49% sodium hydroxide aqueous solution was added dropwise over 4 hours. During this period, epichlorohydrin azeotroped with water, and the distilled water was sequentially removed to the outside of the system. After the reaction was completed, epichlorohydrin was recovered at 5 mmHg and 180°C, and 560 parts of toluene was added to dissolve the product. 180 parts of water was added to dissolve the by-produced salt, and the solution was allowed to stand to separate the lower salt water. After neutralization with phosphoric acid aqueous solution, the resin solution was washed with water until the washing liquid became neutral, and filtered. Under a reduced pressure of 5 mmHg, the temperature was raised to 180°C, and toluene was distilled off to obtain 95 parts of biphenyl aralkyl type epoxy resin (A1). Epoxy equivalent is 218, softening point is 97°C, n=0 component is 4.3 area%, n=5 component or more is 30.5 area%, Mn is 1440, Mw is 3200, Mw/Mn is 2.22.

Example 1 Mix 10 parts of A1, 90 parts of A3, 35 parts of B1, and 0.05 parts of C1, and dissolve them in methyl ethyl ketone (MEK), propylene glycol monomethyl ether, N,N-dimethyl In the mixed solvent in which the formamide was adjusted, the epoxy resin composition varnish was obtained. The obtained epoxy resin composition varnish was impregnated in glass cloth (manufactured by Nittobo Textile Co., Ltd., WEA 7628 XS13, 0.18 mm thick). The impregnated glass cloth was dried in a hot air circulating oven at 150°C for 9 minutes to obtain a prepreg. The obtained 8 prepregs were overlapped with copper foil (Mitsui Metal Mining Co., Ltd., 3EC-III, thickness 35 μm) up and down, and performed at a temperature of 130°C × 15 minutes + 190°C × 80 minutes. Vacuum pressing of MPa to obtain a 1.6 mm thick laminate. Table 1 shows the results of the glass transition temperature, copper foil peel strength, interlayer adhesion and flame retardancy of the laminate.

Example 2 to Example 7 A1 to A4 as the epoxy resin, B1 to B3 as the curing agent, and C1 as the curing accelerator were prepared at the blending amounts (parts) in Table 1, and the same operations as in Example 1 were performed to obtain a laminate and a test piece. At this time, the use amount of the hardening accelerator is an amount that can adjust the varnish gel time to about 300 seconds. The same test as in Example 1 was conducted, and the results are shown in Table 1. In addition, the phosphorus content rate in the table is a value calculated with an epoxy resin composition.

[Table 1]

Comparative Example 1 to Comparative Example 8 A2 to A4 as an epoxy resin, B1 to B3 as a curing agent, and C1 as a curing accelerator were prepared at the blending amounts (parts) in Table 2, and the same operations as in Example 1 were performed to obtain a laminate and a test piece. The same test as in Example 1 was conducted, and the results are shown in Table 2.

[Table 2]

From these results, it can be seen that an epoxy resin composition having both high heat resistance and flame retardancy can be obtained by using an epoxy resin composition of a biphenyl aralkyl type epoxy resin and a phosphorus-containing epoxy resin.

Claims (5)

An epoxy resin composition comprising an epoxy resin and a hardener as essential components, wherein the epoxy resin contains a biphenyl aralkyl type epoxy represented by the following general formula (1) Resin, and phosphorus-containing epoxy resin,

Here, n is the number of repetitions and represents a number of 0 or more, and the average value thereof is a number of 1.3 to 20, and R1, R2, and R3 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. The epoxy resin composition as described in item 1 of the patent application scope, in which The epoxy equivalent of the phosphorus-containing epoxy resin is 200 g/equivalent to 1000 g/equivalent, and the phosphorus content is 1.0% to 6.0% by mass. A prepreg that uses the epoxy resin composition described in the first or second patent application. A laminated board using the epoxy resin composition as described in the first or second patent application. A printed wiring board using the epoxy resin composition as described in the first or second patent application.