JP6643900B2 - Phenol resin, epoxy resin, epoxy resin composition and cured product thereof - Google Patents

Description

  The present invention relates to an epoxy resin composition suitable for use in electric and electronic materials requiring heat resistance, and a cured product thereof.

  Epoxy resin compositions are widely used in the fields of electrical and electronic parts, structural materials, adhesives, paints, etc. due to workability and excellent electrical properties, heat resistance, adhesiveness, moisture resistance (water resistance), etc. of the cured product. Have been.

  However, in recent years, in the field of electricity and electronics, with the development of the resin composition, high purity of the resin composition, moisture resistance, adhesion, dielectric properties, low viscosity for highly filling a filler (inorganic or organic filler), Further improvements in various properties such as increased reactivity for shortening the molding cycle are required. As structural materials, lightweight materials having excellent mechanical properties are required for aerospace materials, leisure and sports equipment applications, and the like. In particular, in the field of semiconductor encapsulation and substrates (substrate itself or its peripheral materials), with the transition of semiconductors, the complexity of thinning, stacking, systematization, and three-dimensionalization has increased, resulting in a very high level. Required characteristics such as heat resistance and high fluidity are required (Non-Patent Document 1). In particular, with the expansion of plastic packages to in-vehicle applications, the demand for improved heat resistance has become more severe (Non-Patent Document 2). Specifically, heat resistance of 150 ° C. or higher has been required due to an increase in driving temperature of a semiconductor. In general, an epoxy resin having a high softening point tends to have high heat resistance, but on the other hand, there is a problem of lowering the thermal decomposition temperature and lowering the flame retardancy.

  Therefore, there has been a demand for an epoxy resin having high performance in both flame retardancy and heat resistance. A reaction between acetone and resorcinol has been attempted as an epoxy resin having good heat resistance, and an epoxy resin having a diflavan structure as described in Patent Document 1 and Non-Patent Document 3 has been developed. However, the flavan structure is unlikely to have high flame retardancy. In addition, since the structure obtained from the reaction product of the above two types of compounds was obtained from Patent Document 1 and Non-patent Document 3 as a flavan structure, a phenol resin having flame retardancy and heat resistance was obtained. Development was entrusted to a different skeleton phenolic resin. Under such circumstances, the demand for a phenol resin satisfying both excellent properties in both flame retardancy and heat resistance has been increasing.

JP 2010-275221 A

"2008 STRJ Report Semiconductor Roadmap Technical Committee 2008 Report", Chapter 8, p1-1, [online], March 2009, JEITA Japan Electronics and Information Technology Industries Association Semiconductor Technology Roadmap Technical Committee Member Kai, [May 30, 2012 search], Internet <URL: http: // strj-jeita. elisasp. net / strj / nenjihoukoku-2008. cfm> Nobuyuki Takakura et al., Matsushita Electric Works Technical Report Car-related Device Technology High-temperature Operation IC for Vehicle, No. 74, Japan, May 31, 2001, pp. 35-40 P. Livant et al. Org. Chem. , 1997, Vol. 62, 737-742

  In general, the higher the Tg of an epoxy resin, the lower the flame retardancy. This is due to the effect of increased crosslink density. However, as high Tg is required for semiconductor peripheral materials that are required to have flame retardancy, it is expected that resins having these contradictory characteristics will be developed promptly. Therefore, it was urgently necessary to find an epoxy resin that can be expected to have such properties.

The present inventors have conducted intensive studies to solve the above problems, and as a result, have completed the present invention.
That is, the present invention relates to the following (1) to (7).
(1) A phenol resin represented by the following formula (1).

(Wherein, R ₁ each independently represents an alkyl group having 1 to 6 carbon atoms, R ₂ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and k is an integer of 1 to 4 And n represents an integer of 0 to 10.)

(2) The phenolic resin according to the above (1), wherein the average value of n in the formula (1) of the molecules constituting the resin is 0.05 or more and 4.0 or less.
(3) Assuming that the peak area of CH ₃ carbon derived from a ketone is 1 in the ¹³ C-NMR spectrum chart, the phenol resin according to (1), wherein the peak area of CH ₂ carbon is 0 or more and 0.2 or less. .
(4) An epoxy resin obtained by reacting epihalohydrin with the phenolic resin according to any one of the above items (1) to (3).
(5) An epoxy resin composition containing the phenolic resin according to any one of the above items (1) to (3) and an epoxy resin.
(6) An epoxy resin composition containing the epoxy resin described in (4) above, a curing agent, and optionally a curing accelerator.
(7) A cured product obtained by curing the epoxy resin composition according to (5) or (6).

  The phenol resin and the epoxy resin of the present invention are phenol resins or epoxy resins having a benzopyran structure. When the phenol resin or the epoxy resin has the benzopyran structure, it is possible to obtain a resin having both excellent heat resistance and flame retardancy.

The phenolic resin of the present invention can be obtained by reacting dihydroxybenzenes (a) with ketones (b).
First, the dihydroxybenzenes (a) will be described. Dihydroxybenzenes (a) are compounds represented by the following formula (2).

(In the formula (2), R ₂ independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and k represents an integer of 1 to 4.)

  Examples of the dihydroxybenzenes (a) include catechol, 3-methylcatechol, 4-tert-butylcatechol, 3,5-di-tert-butylcatechol, resorcin, 2-methylresorcin, 5-methylresorcin, 2,5- Dimethyl resorcin, 4-butyl resorcin, 4-hexyl resorcin, hydroquinone, 2-methylhydroquinone, 2,6-dimethylhydroquinone, 2,3-dimethylhydroquinone, 2,3,5-trimethylhydroquinone, 2-tert-butylhydroquinone, Examples thereof include, but are not limited to, 2,5-di-tert-butylhydroquinone. Catechol, resorcin and hydroquinone are preferred, with resorcin being particularly preferred. Here, in order to obtain a compound of the formula (1) in which n is greater than 0 (for example, a compound in which n is 1 or more), resorcinol can be particularly preferably used.

  Next, the ketones (b) will be described. Ketones are compounds represented by the following formula (3).

(In the formula (3), R ₁ represents the same meaning as the formula (1).)
Examples of the ketone (b) include acetone, methyl ethyl ketone, methyl butyl ketone, 3-methyl-2-butanone, methyl isobutyl ketone, 3-pentanone, 2-methyl-3-pentanone, 2,4-dimethyl-3-pentanone, and the like. And acetone and methyl ethyl ketone are preferred, and acetone is particularly preferred.

The phenolic resin of the present invention is obtained by a condensation reaction between one or more compounds represented by the formula (2) and a compound represented by the formula (3) under acidic conditions. The reaction can be carried out under basic conditions, but preferably under acidic conditions.
The compound represented by the formula (3) is used in an amount of usually 0.25 to 5.0 mol, preferably 0.3 to 2.5 mol, per 1 mol of the compound represented by the formula (2).

When the condensation reaction is performed under acidic conditions, usable acidic catalysts are not particularly limited, and examples thereof include organic acid catalysts such as toluenesulfonic acid, xylenesulfonic acid, and oxalic acid, and inorganic acid catalysts such as hydrochloric acid and sulfuric acid. These may be used alone or in combination of a plurality of types. The amount of the acidic catalyst to be used is generally 0.001 to 15 mol, preferably 0.002 to 10 mol, per 1 mol of the compound represented by the formula (3).
When the condensation reaction is carried out under basic conditions, the reaction can be carried out in the same manner, and the basic catalyst used is not particularly limited as long as it is known.

In the reaction for obtaining the phenolic resin of the present invention, a solvent may be used as necessary. The solvent that can be used is not particularly limited as long as it does not have reactivity with the compound represented by the formula (2), for example, ketones. It is preferable to use alcohols as a solvent from the viewpoint of dissolving in water.
Specific examples of solvents that can be used include methanol, ethanol, alcohols such as isopropyl alcohol, dimethyl sulfone, dimethyl sulfoxide, tetrahydrofuran, dioxane, methyl ethyl ketone, aprotic polar solvents such as methyl isobutyl ketone, toluene, xylene and the like. And aromatic hydrocarbons.
The amount of the solvent used is not particularly limited, but for example, 100 to 500 parts by weight per 1 mol of the compound represented by the formula (2) can be used.

  The reaction temperature is usually from 10 to 150 ° C, preferably from 50 to 140 ° C, and particularly preferably from 85 to 140 ° C. The reaction time is usually 0.5 to 20 hours, but is not limited to this, since there is a difference in reactivity depending on the type of the starting compound.

In order to obtain the phenolic resin of the present invention, after completion of the reaction of the compounds of the above formulas (2) and (3), the reaction proceeds at a high temperature as a second step. The second-stage high-temperature reaction is preferably performed at 100 ° C. or higher. At this time, it is preferable to remove by-produced water by azeotropic distillation or the like in order to complete the reaction. By performing the second-stage reaction, the peak of CH ₂ carbon in the ¹³ C-NMR spectrum chart decreases, and a compound having a structure represented by the general formula (1) is generated.
After completion of the reaction, the acid catalyst is neutralized with a base. The base is not particularly limited, but examples include sodium hydroxide, sodium carbonate, pentasodium tripolyphosphate, ammonia and the like. At this time, in order to disperse the base uniformly, it is preferable to gradually drop the solution as an aqueous solution.

  When the product is taken out as a resin after the completion of the reaction, unreacted substances, solvents, and the like are removed from the reaction solution under heating and reduced pressure after or without washing the reaction product with water. In order to remove unreacted substances efficiently, washing may be performed under basic conditions. When the product is taken out as crystals, the crystals are precipitated by dropping the reaction solution into a large amount of water.

  The phenolic resin of the present invention thus obtained is a phenolic resin represented by the following formula (1).

(Wherein, R ₁ each independently represents an alkyl group having 1 to 6 carbon atoms, R ₂ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and k is an integer of 1 to 4 And n represents an integer of 0 to 10.)

In the phenolic resin of the present invention, the peak area of a molecule having a structure of n = 0 in a chromatogram by gel permeation chromatography (GPC) analysis is usually 20 to 95 area% with respect to the total area of all peaks, Preferably it is 30 to 80 area%.
^{In the 13} C-NMR spectrum chart, the peak area of CH ₂ carbon is usually 0 or more and 0.3 or less, preferably 0.2 or less when the peak area of acetone-derived CH ₃ carbon is 1, particularly preferably 0.2 or less. 0.1 or less, very preferably 0.05 or less. In particular, when the content is 0.2 or less, excellent flame retardancy is exhibited, which is preferable.
The average value of n in the formula (1) of the molecules constituting the resin is preferably 0.05 to 4, and particularly preferably a phenol resin of 0.1 to 3. This is because the dielectric constant can be reduced by increasing the number of repetitions. Here, the content ratio of the molecule (phenol compound) where n is not 0 in the obtained phenol resin is determined by the content ratio (total area of all peaks in the chromatogram) calculated by the measurement of gel permeation chromatography (GPC). Is preferably 5 to 80 area%, more preferably 20 to 70 area%.

Further, the hydroxyl equivalent is preferably from 125 to 250 g / eq, and particularly preferably from 140 to 200 g / eq. The softening point is preferably from 100 to 200 ° C, particularly preferably from 120 to 180 ° C.
The phenolic resin of the present invention is useful as a resin raw material such as a cyanate resin and an epoxy resin.

Next, the epoxy resin of the present invention will be described.
The epoxy resin of the present invention can be obtained by reacting the phenol resin of the present invention obtained by the above-mentioned method with epihalohydrin in a solvent, followed by epoxidation. Here, a phenol compound other than the phenol resin of the present invention may be used in combination with the phenol resin of the present invention.
As the phenol compound other than the phenol resin of the present invention that can be used in combination, any phenol compound that is generally used as a raw material for an epoxy resin can be used without any particular limitation.
According to the epoxy resin of the present invention, a cured product having excellent heat resistance due to a high melting point and high flame retardancy can be obtained.

  In the reaction for obtaining the epoxy resin of the present invention, epichlorohydrin, α-methylepichlorohydrin, β-methylepichlorohydrin, epibromohydrin and the like can be used as epihalohydrin, but epichlorohydrin which is easily available industrially is preferable. The amount of epihalohydrin to be used is generally 2 to 20 mol, preferably 2 to 15 mol, particularly preferably 2 to 8 mol, per 1 mol of the hydroxyl group of the phenolic resin of the present invention. The epoxy resin is obtained by a reaction of adding a phenol compound and epihalohydrin in the presence of an alkali metal oxide, and then opening the generated 1,2-halohydrin ether group to epoxidize. At this time, by using epihalohydrin in a significantly smaller amount than usual as described above, the molecular weight distribution and the molecular weight distribution of the epoxy resin can be extended. As a result, the obtained epoxy resin can be taken out of the system as a resin having a relatively low softening point, and exhibits excellent solvent solubility.

  In addition, at the time of epoxidation, it is preferable from the viewpoint of the reaction progress to carry out the reaction by adding an alcohol such as methanol, ethanol and isopropyl alcohol, and an aprotic polar solvent such as dimethyl sulfone, dimethyl sulfoxide, tetrahydrofuran and dioxane. Among them, alcohols are preferable, and the polarity of the alcohol solvent allows the ionic reaction at the time of epoxidation to proceed efficiently, and an epoxy resin with high purity can be obtained. As the alcohol solvent that can be used, methanol, ethanol, and isopropyl alcohol are preferable. Among them, it is particularly preferable to use methanol from the viewpoint of compatibility with the epoxy resin.

  When the alcohols are used, they are used in an amount of usually 2 to 50% by mass, preferably 4 to 35% by mass, based on the amount of epihalohydrin used. When an aprotic polar solvent is used, it is usually 5 to 100% by mass, preferably 10 to 80% by mass, based on the amount of epihalohydrin used.

Examples of the alkali metal hydroxide that can be used in the epoxidation reaction include sodium hydroxide, potassium hydroxide, and the like. These may be used as a solid or as an aqueous solution thereof. When an aqueous solution is used, the aqueous solution of the alkali metal hydroxide is continuously added to the reaction system, and separated from a mixed solution of water and epihalohydrin continuously distilled under reduced pressure or normal pressure. A method in which water is removed and only epihalohydrin is continuously returned into the reaction system may be used. The amount of the alkali metal hydroxide to be used is generally 0.9 to 3.0 mol, preferably 1.0 to 2.5 mol, more preferably 1.0 to 1.0 mol per 1 mol of the hydroxyl group of the phenolic resin of the present invention. It is 2.0 mol, particularly preferably 1.0 to 1.3 mol.
In addition, in the epoxidation reaction, in particular, by using flake-like sodium hydroxide, it becomes possible to remarkably reduce the amount of halogen contained in the obtained epoxy resin as compared with the use of aqueous solution of sodium hydroxide. Further, it is preferable that the flake-form sodium hydroxide is added in portions in the reaction system. By performing the divisional addition, it is possible to prevent a rapid decrease in the reaction temperature, thereby preventing the generation of impurities such as 1,3-halohydrin and halomethylene.

  In order to accelerate the epoxidation reaction, it is preferable to add a quaternary ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide or trimethylbenzylammonium chloride as a catalyst. The amount of the quaternary ammonium salt to be used is generally 0.1 to 15 g, preferably 0.2 to 10 g, per 1 mol of the hydroxyl group of the phenol compound of the present invention.

The reaction temperature is usually 30 to 90 ° C, preferably 35 to 80 ° C. The reaction time is generally 0.5 to 10 hours, preferably 1 to 8 hours. Among them, when an alcohol solvent is used, the temperature is preferably from 50C to 90C, more preferably from 60C to 85C, and particularly preferably from 70C to 80C.
After completion of the reaction, epihalohydrin, a solvent, and the like are removed from the reaction solution after the reaction is washed with water or without heating and under reduced pressure with heating. Further, in order to further reduce the amount of halogen contained in the obtained epoxy resin, the recovered epoxy resin of the present invention is dissolved in a solvent such as toluene, methyl isobutyl ketone, and an alkali metal such as sodium hydroxide or potassium hydroxide. The reaction can be carried out by adding an aqueous solution of a hydroxide to ensure ring closure. In this case, the amount of the alkali metal hydroxide to be used is generally 0.01 to 0.3 mol, preferably 0.05 to 0.2 mol, per 1 mol of the hydroxyl group of the phenol compound of the present invention. The reaction temperature is usually 50 to 120 ° C, and the reaction time is usually 0.5 to 2 hours.

After completion of the reaction, the formed salt is removed by filtration, washing with water, or the like, and the solvent is distilled off under reduced pressure while heating to obtain the epoxy resin of the present invention. When the epoxy resin of the present invention precipitates as crystals, the crystals of the epoxy resin of the present invention may be collected by filtration after dissolving the generated salt in a large amount of water.
As the epoxy resin thus obtained, a glycidylated product of the above formula (1) can be obtained, and when the phenol resin as a raw material contains the phenol compound represented by the above formula (2) In this case, a glycidylated product of the above formula (2) is also obtained. Therefore, a mixture of at least two types of epoxy resins is obtained. Here, in the obtained epoxy resin, the content ratio of the glycidylated compound of the formula (2) in the resin calculated by the measurement of gel permeation chromatography (GPC) (based on the total area of all peaks in the chromatogram) Ratio) is preferably 1 to 25 area%, more preferably 1 to 20 area%.

  As described above, the total halogen content of the epoxy resin of the present invention obtained by using flaky sodium hydroxide is usually 1800 ppm or less, preferably 1600 ppm or less, more preferably 1300 ppm or less. If the total halogen content is too high, the cured product will have a bad effect on the physical properties of the cured product and may remain as uncrosslinked terminals. There is a concern that physical properties may decrease.

  Hereinafter, the epoxy resin composition of the present invention will be described. The epoxy resin composition of the present invention contains at least one of the epoxy resin of the present invention and the phenol resin of the present invention as essential components.

  In the epoxy resin composition of the present invention, the epoxy resin of the present invention can be used alone or in combination with another epoxy resin.

  Specific examples of other epoxy resins include bisphenols (bisphenol A, bisphenol F, bisphenol S, biphenol, bisphenol AD and bisphenol I) and phenols (phenol, alkyl-substituted phenol, aromatic-substituted phenol, naphthol, alkyl-substituted). Naphthol, dihydroxybenzene, alkyl-substituted dihydroxybenzene, dihydroxynaphthalene, etc.) and various aldehydes (formaldehyde, acetaldehyde, alkylaldehyde, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthaldehyde, glutaraldehyde, phthalaldehyde, crotonaldehyde, cinnamaldehyde, etc.) Of polycondensation with an aromatic compound such as xylene and formaldehyde Polycondensates of compounds and phenols, phenols and various diene compounds (dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisopropenylbiphenyl, butadiene and isoprene Polycondensates with phenols and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, etc.), phenols and aromatic dimethanols (benzene dimethanol, biphenyl dimethanol, etc.) With phenols and aromatic dichloromethyls (such as α, α'-dichloroxylene and bischloromethylbiphenyl), phenols and aromatic bisalkoxymethyl (Bismethoxymethylbenzene, bismethoxymethylbiphenyl, bisphenoxymethylbiphenyl, etc.), polycondensates of bisphenols and various aldehydes, glycidyl ether epoxy resins obtained by glycidylation of alcohols, etc., alicyclic Examples include an epoxy resin, a glycidylamine-based epoxy resin, and a glycidyl ester-based epoxy resin, but are not limited to these as long as they are commonly used epoxy resins. These may be used alone or in combination of two or more.

  When another epoxy resin is used in combination, the proportion of the epoxy resin of the present invention in all epoxy resin components in the epoxy resin composition of the present invention is preferably 30% by mass or more, more preferably 40% by mass or more, and 70% by mass. The above is more preferably, and particularly preferably 100% by mass (when no other epoxy resin is used in combination). However, when the epoxy resin of the present invention is used as a modifier for an epoxy resin composition, it is added at a ratio of 1 to 30% by mass in all epoxy resins.

Examples of the curing agent that can be used in the epoxy resin composition of the present invention include amine compounds, acid anhydride compounds, amide compounds, and phenol compounds. Specific examples of these other curing agents are shown in (a) to (e) below.
(A) amine compounds diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, naphthalenediamine, etc. (b) acid anhydride compounds phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride , Tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, etc. (c) Amide compounds Dicyandiamide or dimer of linolenic acid is synthesized from ethylenediamine Polyamide resin, etc.

(D) Phenolic Compounds Polyhydric phenols (bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, terpene diphenol, 4,4′-dihydroxybiphenyl, 2,2′-dihydroxybiphenyl, 3,3 ′, 5 5'-tetramethyl- (1,1'-biphenyl) -4,4'-diol, hydroquinone, resorcinol, naphthalene diol, tris- (4-hydroxyphenyl) methane and 1,1,2,2-tetrakis (4 Phenols (eg, phenol, alkyl-substituted phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, dihydroxynaphthalene, etc.) and aldehydes (formaldehyde, acetaldehyde, benzaldehyde, p-hydro A phenolic resin obtained by condensation with sibenzaldehyde, o-hydroxybenzaldehyde, furfural, etc.), ketones (p-hydroxyacetophenone, o-hydroxyacetophenone, etc.), or dienes (dicyclopentadiene, tricyclopentadiene, etc.); Phenols and substituted biphenyls (such as 4,4'-bis (chloromethyl) -1,1'-biphenyl and 4,4'-bis (methoxymethyl) -1,1'-biphenyl) or substituted phenyls ( A phenol resin obtained by polycondensation with 1,4-bis (chloromethyl) benzene, 1,4-bis (methoxymethyl) benzene, 1,4-bis (hydroxymethyl) benzene, etc .; Or a modified product of the phenolic resin; Nord A and halogenated phenols such as brominated phenol resin (e) Other imidazoles, BF ₃ ^- amine complex, guanidine derivatives

Among these other curing agents, amine compounds such as diaminodiphenylmethane, diaminodiphenylsulfone and naphthalenediamine, and active hydrogens such as condensates of catechol with aldehydes, ketones, dienes, substituted biphenyls or substituted phenyls A curing agent having a structure in which groups are adjacent to each other is preferable because it contributes to the arrangement of epoxy resins.
Other curing agents may be used alone or in combination. When another curing agent is used in combination, the proportion of the phenol compound of the present invention in all the curing agent components in the epoxy resin composition of the present invention is preferably 20% by mass or more, more preferably 30% by mass or more, and 70% by mass. The above is more preferably, and particularly preferably 100% by mass (when no other curing agent is used together).
In the epoxy resin composition of the present invention, the amount of the total curing agent containing the phenolic resin of the present invention is preferably 0.5 to 2.0 equivalents, more preferably 0.6 to 2.0 equivalents to 1 equivalent of epoxy group of all epoxy resins. 1.5 equivalents are particularly preferred.

If necessary, a curing accelerator may be added to the epoxy resin composition of the present invention. Specific examples of the curing accelerator include phosphines such as triphenylphosphine and bis (methoxyphenyl) phenylphosphine, imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-ethylimidazole, and the like. Tertiary amines such as 2- (dimethylaminomethyl) phenol, trisdimethylaminomethylphenol, diazabicycloundecene, tetrabutylammonium salt, triisopropylmethylammonium salt, trimethyldecanylammonium salt, cetyltrimethylammonium salt and the like Quaternary ammonium salts such as quaternary ammonium salts, triphenylbenzylphosphonium salts, triphenylethylphosphonium salts, and tetrabutylphosphonium salts (the counter ion of quaternary salts is halogen , Organic acid ion, a hydroxide ion, etc., in particular specify no particular organic acid ion, a hydroxide ion.), Metal compounds such as tin octylate and the like.
The amount of the curing accelerator to be used is generally 0.2 to 5.0 parts by weight, preferably 0.2 to 4.0 parts by weight, per 100 parts by weight of the epoxy resin.

The epoxy resin composition of the present invention can contain an inorganic filler as needed.
The inorganic filler contained in the epoxy resin composition of the present invention is not particularly limited as long as it is a known one. Specific examples of the inorganic filler include inorganic powder fillers such as boron nitride, aluminum nitride, silicon nitride, silicon carbide, titanium nitride, zinc oxide, tungsten carbide, alumina, and magnesium oxide; and fibrous materials such as synthetic fibers and ceramic fibers. Fillers, coloring agents and the like can be mentioned. The shape of these inorganic fillers may be any of powder (lumpy, spherical), single fiber, long fiber and the like.
The amount of the inorganic filler used in the epoxy resin composition of the present invention is usually 2 to 1000 parts by mass based on 100 parts by mass of the resin component in the epoxy resin composition. These inorganic fillers may be used alone or in combination of two or more.

  Various compounding agents such as a silane coupling agent, a release agent and a pigment, various thermosetting resins, various thermoplastic resins, and the like can be added to the epoxy resin composition of the present invention as needed. Specific examples of the thermosetting resin and the thermoplastic resin include a vinyl ester resin, an unsaturated polyester resin, a maleimide resin, a cyanate resin, an isocyanate compound, a benzoxazine compound, a vinylbenzyl ether compound, polybutadiene and a modified product thereof, and acrylonitrile. Modified polymer, indene resin, fluororesin, silicone resin, polyetherimide, polyethersulfone, polyphenylene ether, polyacetal, polystyrene, polyethylene, dicyclopentadiene resin and the like can be mentioned. The thermosetting resin or the thermoplastic resin is usually used in an amount occupying 60% by mass or less in the epoxy resin composition of the present invention.

The epoxy resin composition of the present invention is obtained by uniformly mixing the above-mentioned components, and preferable applications thereof include a semiconductor encapsulant and a printed wiring board.
The epoxy resin composition of the present invention can be easily cured by a method similar to a conventionally known method. For example, an epoxy resin which is an essential component of the epoxy resin composition of the present invention, a curing agent, and a curing accelerator if necessary, a compounding agent, various thermosetting resins and various thermoplastic resins, and the like, an extruder as necessary, Epoxy resin composition of the present invention obtained by sufficiently mixing until uniform using a kneader or a roll, molded by a melt casting method or a transfer molding method or an injection molding method, a compression molding method, and the like. By heating at a temperature higher than the melting point for 2 to 10 hours, a cured product of the epoxy resin composition of the present invention can be obtained. The epoxy resin composition of the present invention can be used for semiconductor encapsulation by encapsulating a semiconductor element mounted on a lead frame or the like by the method described above.

  Further, the epoxy resin composition of the present invention may be a varnish containing a solvent. The varnish includes, for example, at least one of an epoxy resin and a curing agent containing at least one of the epoxy resin of the present invention and the phenol resin of the present invention, and has a thermal conductivity of 20 W / m · K or more as necessary. A mixture containing other components such as an inorganic filler is mixed with toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, N, N′-dimethylformamide, N, N′-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl Esters such as glycol ethers such as ether, ethyl acetate, butyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, carbitol acetate, propylene glycol monomethyl ether acetate, dialkyl glutarate, dialkyl succinate, dialkyl adipate, It can be obtained by mixing with cyclic esters such as γ-butyrolactone, and organic solvents such as petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha and solvent naphtha. The amount of the solvent is usually 10 to 95% by mass, preferably 15 to 85% by mass based on the whole varnish.

  The varnish obtained as described above is impregnated into a fiber base material such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber and paper, and then the solvent is removed by heating, and the epoxy resin composition of the present invention. In a semi-cured state, the prepreg of the present invention can be obtained. Here, the “semi-cured state” means a state in which an epoxy group which is a reactive functional group remains partially unreacted. The prepreg can be subjected to hot press molding to obtain a cured product.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. In the synthesis examples, examples, and comparative examples, “parts” means “parts by mass”.
The hydroxyl equivalent, epoxy equivalent, softening point, and ICI melt viscosity were measured under the following conditions.

-Hydroxy group equivalent Measured according to the method described in JIS K-7236, and the unit is g / eq. It is.
-Epoxy equivalent Measured by the method described in JIS K-7236, and the unit is g / eq. It is.
-Softening point Measured by a method according to JIS K-7234, and the unit is ° C.
-ICI melt viscosity Measured by a method according to JIS K 7117-2, and the unit is Pa · s.

Example 1 (Synthesis 1 of phenolic resin)
To a flask equipped with a stirrer, a reflux condenser and a stirrer, 330 parts of resorcinol and 174 parts of acetone were added while purging with nitrogen, dissolved under stirring, and heated to 100 ° C. When 88 parts of 98% sulfuric acid was added dropwise thereto, the reaction solution generated a violent heat and rose to 125 ° C. After cooling to 80 ° C. at room temperature, the reaction was continued for 10 hours. Subsequently, Dean-Stark was placed in the flask, the temperature was raised to 120 ° C. while dehydrating by azeotropic distillation, and the reaction was further performed for 10 hours. After completion of the reaction, the mixture was neutralized with 10% sodium hydroxide, and 1000 parts of methyl isobutyl ketone was added to dissolve the resin. Subsequently, water washing is performed until the washing water becomes neutral, and methylisobutyl ketone and the like are distilled off from the resulting solution under reduced pressure using a rotary evaporator to obtain 318 parts of the phenol resin (P1) of the present invention. Was. The hydroxyl equivalent of the obtained phenol resin P1 was 170 g / eq. The softening point is 146 ° C., the ICI melt viscosity is 5.4 Pa · s, and in GPC, the n = 0 component is 41 area%, the average value of n in the general formula (1) is 0.44, and the peak of CH ₂ carbon. Was not detected.

Comparative Example 1 (Synthesis 2 of phenolic resin)
To a flask equipped with a stirrer, a reflux condenser and a stirrer, 330 parts of resorcinol and 174 parts of acetone were added while purging with nitrogen, dissolved under stirring, and heated to 100 ° C. When 88 parts of 98% sulfuric acid was added dropwise thereto, the reaction solution generated a violent heat and rose to 125 ° C. After cooling to 80 ° C. at room temperature, the reaction was continued for 10 hours. After completion of the reaction, the mixture was neutralized with 10% sodium hydroxide, and 1000 parts of methyl isobutyl ketone was added to dissolve the resin. Subsequently, water washing was performed until the washing water became neutral, and methyl isobutyl ketone and the like were distilled off from the obtained solution under reduced pressure using a rotary evaporator to obtain 342 parts of a phenol resin (P2). The hydroxyl equivalent of the obtained phenol resin P2 was 215 g / eq. , The softening point is 127 ° C., the ICI melt viscosity is 8.0 Pa · s, the n = 0 component is 12 area% in GPC, and the peak area of acetone-derived CH ₃ carbon is 1 in ¹³ C-NMR. the peak area of CH ₂ carbon was 0.27.

Comparative Example 2 (Synthesis of phenolic resin 3)
A flask equipped with a stirrer, a reflux condenser, and a stirrer was charged with 300 parts of resorcin, 78 parts of acetone, and 0.3 part of paratoluenesulfonic acid, and reacted at 80 ° C. for 2 hours. Next, 78 parts of acetone was added and reacted at 80 ° C. for 2 hours. Next, washing was performed with pure water until the washing water became neutral, and a distillate was removed from the resulting solution under reduced pressure using a rotary evaporator to obtain 228 parts of a white crystalline phenol resin (P3). . The melting point of the obtained phenolic resin P3 was 200 ° C., and the hydroxyl equivalent was 118 g / eq. Met.

Example 2 (Synthesis 1 of epoxy resin)
A flask equipped with a stirrer, a reflux condenser, and a stirrer was charged with 210 parts of the phenol resin (P1) of the present invention, 462 parts of epichlorohydrin (4 molar equivalents per phenol resin), and 28 parts of methanol while performing a nitrogen purge. In addition, the mixture was dissolved under stirring, and the temperature was raised to 70 to 75 ° C. Next, 51.1 parts of sodium hydroxide in the form of flakes were added in portions over 90 minutes, and the reaction was further carried out at 75 ° C. for 75 minutes. After completion of the reaction, the reaction mixture was washed with water, and excess solvent such as epichlorohydrin was distilled off from the oil layer under reduced pressure using a rotary evaporator. 532 parts of methyl isobutyl ketone was added to and dissolved in the residue, and the temperature was raised to 75 ° C. Under stirring, 16.8 parts of a 30% by weight aqueous sodium hydroxide solution and 6.3 parts of methanol were added, and the mixture was reacted for 1 hour. Then, the resultant was washed with water until the washing water of the oil layer became neutral. Then, using a rotary evaporator, methyl isobutyl ketone and the like were distilled off under reduced pressure to obtain 35 parts of the epoxy resin (E1) of the present invention. The epoxy equivalent of the obtained epoxy resin E1 was 259 g / eq. The ICI melt viscosity at a softening point of 72 ° C. and 150 ° C. was 0.21 Pa · s.

Comparative Example 3 (Epoxy resin synthesis 2)
To a flask equipped with a stirrer, a reflux condenser, and a stirrer, 237 parts of phenol resin (P2), 953 parts of epichlorohydrin (9.2 molar equivalents to phenol resin), and 62 parts of methanol were added while purging with nitrogen. The mixture was dissolved under stirring, and the temperature was raised to 70 to 75 ° C. Next, 46.4 parts of sodium hydroxide in the form of flakes was added in portions over 90 minutes, and the reaction was further carried out at 75 ° C. for 75 minutes. After completion of the reaction, the reaction mixture was washed with water, and excess solvent such as epichlorohydrin was distilled off from the oil layer under reduced pressure using a rotary evaporator. 570 parts of methyl isobutyl ketone was added to and dissolved in the residue, and the temperature was raised to 75 ° C. Under stirring, 14.9 parts of a 30% by weight aqueous sodium hydroxide solution and 6.8 parts of methanol were added, and the mixture was reacted for 1 hour. Then, the resultant was washed with water until the washing water of the oil layer became neutral. Then, using a rotary evaporator, methyl isobutyl ketone and the like were distilled off under reduced pressure to obtain 296 parts of an epoxy resin (E2). The epoxy equivalent of the obtained epoxy resin E2 was 276 g / eq. The ICI melt viscosity at a softening point of 71 ° C. and 150 ° C. was 0.15 Pa · s.

Comparative Example 4 (Epoxy resin synthesis 3)
To a flask equipped with a stirrer, a reflux condenser, and a stirrer, 336 parts of phenol resin (P3), 1082 parts of epichlorohydrin (4 molar equivalents to phenol resin), and 70 parts of methanol were added while performing nitrogen purge, followed by stirring. Dissolved below and heated to 70-75 ° C. Next, 121.1 parts of sodium hydroxide in the form of flakes were added in portions over 90 minutes, and the reaction was further carried out at 75 ° C. for 75 minutes. After completion of the reaction, the reaction mixture was washed with water, and excess solvent such as epichlorohydrin was distilled off from the oil layer under reduced pressure using a rotary evaporator. 950 parts of methyl isobutyl ketone was added to and dissolved in the residue, and the temperature was raised to 75 ° C. Under stirring, 39.0 parts of a 30% by weight aqueous sodium hydroxide solution and 11.4 parts of methanol were added, and the mixture was allowed to react for 1 hour. From there, methyl isobutyl ketone and the like were distilled off under reduced pressure using a rotary evaporator to obtain 466 parts of an epoxy resin (E3). The epoxy equivalent of the obtained epoxy resin E3 was 207 g / eq. Its ICI melt viscosity at a softening point of 79 ° C. and 150 ° C. was 0.57 Pa · s.

Example 3, Comparative Examples 5 and 6
The compositions shown in the composition column of the composition in Table 1 were uniformly mixed with a mixing roll to obtain an epoxy resin composition. This composition was crushed and tablets were obtained on a tablet machine. The obtained tablet was molded by a transfer molding machine to form a test piece of 10 × 4 × 90 mm. The test piece was heated at 160 ° C. for 2 hours and further at 180 ° C. for 8 hours to perform post-curing.
The test piece was held vertically by a clamp, the flame of the burner was adjusted to a blue flame of 19 mm, and 9.5 mm of the flame was brought into contact with the center of the lower end of the test piece for 10 seconds. After the flame contact, the burner was released and the duration of combustion was measured. Immediately after the flame was extinguished, the flame was immediately contacted for 10 seconds, the burner was released, and the duration of combustion was measured. Table 1 shows the total combustion time of 10 samples.

The heat resistance (DMA) in Table 1 was measured under the following conditions.
・ Heat resistance (DMA)
Dynamic viscoelasticity meter: TA-instruments, DMA-2980
Measurement temperature range: -30 to 280 ° C
Temperature rate: 2 ° C./min Tg: The peak point of Tan-δ was defined as Tg.

XLC: phenylaralkyl-type phenolic resin (Mirex (trade name) XLC-3L manufactured by Mitsui Chemicals, Inc.)
TPP: Triphenylphosphine (manufactured by Junsei Chemical Co., Ltd.)
Filler: fused silica filler (MSR-2212 manufactured by Tatsumori Co., Ltd.)

Example 4, Comparative Example 7
The various components were mixed in the ratio (parts) shown in Table 2, kneaded with a mixing roll, tableted, and then a resin molded body was prepared by transfer molding. The resulting mixture was heated at 160 ° C for 2 hours and further heated at 180 ° C for 8 hours. Cured products of the epoxy resin composition of the present invention and the comparative resin composition were obtained. The physical properties of these cured products were measured under the following conditions, and the results are shown in Table 2.

・ TMA
TMA thermomechanical measuring device: TM-7000 manufactured by Vacuum Riko Co., Ltd.
Heating rate: 2 ° C / min.

・ Peel strength Conforms to JIS K-6911 ・ Water absorbency After boiling a disc-shaped test piece with a diameter of 5 cm and a thickness of 4 mm under conditions of 100 ° C.-immersion, 85 ° C.-85%, 121 ° C.-100% for 24 hours. Weight increase rate (%)

・ Measured at 1 GHz according to K6991

PN: phenol novolak (H-1 manufactured by Meiwa Kasei Kogyo Co., Ltd.)

  As is clear from the results in Table 1, the cured product of Example 3 had higher flame retardancy and heat resistance than Comparative Examples 5 and 6. Further, from the results in Table 2, the epoxy resin of the present invention has excellent heat resistance, low water absorption, and low dielectric properties as well as high heat resistance as compared with the heat resistant resin shown in Comparative Example 7. In particular, it can be suitably used for electronic materials.

Although the present invention has been described in detail with reference to particular embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
This application is a Japanese patent application filed on November 19, 2013 (Japanese Patent Application No. 2013-238463) and a Japanese patent application filed on June 18, 2014 (Japanese Patent Application No. 2014-125509). And is incorporated by reference in its entirety. Also, all references cited herein are incorporated in their entirety.

  The epoxy resin composition using the phenolic resin of the present invention has excellent heat resistance and flame retardancy, so that the insulating material for electric / electronic parts, particularly electric / electronic parts, structural material, adhesive It is useful for paints and the like.

Claims (6)

A phenol resin represented by the following formula (1).

(Wherein, R ₁ each independently represents an alkyl group having 1 to 6 carbon atoms, R ₂ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and k is an integer of 1 to 4 The average value of n is 0.05 or more and 4.0 or less .) _2. The phenol resin according to claim 1, wherein the peak area of CH ₂ carbon is 0 or more and 0.2 or less when the peak area of CH ₃ carbon derived from a ketone is 1 in the ¹³ C-NMR spectrum chart. Claim 1 or 2 epihalohydrin are reacted in the phenolic resin according to have obtained an epoxy resin. And the phenol resin according to claim 1 or 2, epoxy resin compositions containing an epoxy resin. An epoxy resin composition comprising the epoxy resin according to claim 3 , a curing agent, and optionally a curing accelerator. Cured product obtained by curing the epoxy resin composition according to claim 4 or 5.