WO2013035808A1

WO2013035808A1 - Epoxy resin, epoxy resin composition, and cured product thereof

Info

Publication number: WO2013035808A1
Application number: PCT/JP2012/072800
Authority: WO
Inventors: 政隆中西; 清二江原; 一真井上
Original assignee: 日本化薬株式会社
Priority date: 2011-09-08
Filing date: 2012-09-06
Publication date: 2013-03-14
Also published as: CN103906782A; TW201313769A; KR20140071357A; KR101882720B1; JP2013056987A; TWI522385B; CN103906782B; JP5832016B2

Abstract

Provided are an epoxy resin that produces a cured product having high heat resistance and an excellent coefficient of water absorption and electrical properties, as well as an epoxy resin composition. The epoxy resin is obtained by glycidylization of a naphthol-cresol novolak-type phenol resin, which is characterized in being obtained by reacting a naphthol and a cresol with an aldehyde such that when the naphthol and cresol are reacted with the aldehyde, the percentage of α-naphthol in the naphthol is 1 to 10 wt%. Preferably the ratio of naphthol:cresol when the naphthol and cresol are reacted with the aldehyde is 65:35 to 85:15 and the softening point of the resulting naphthol-cresol novolak-type phenol resin is 100 to 150ºC.

Description

Epoxy resin, epoxy resin composition, and cured product thereof

The present invention relates to an epoxy resin, an epoxy resin composition, and a cured product thereof that give a cured product excellent in heat resistance and water resistance.

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

However, in recent years, with the development in the electric / electronic field, moisture resistance, adhesion, dielectric properties, low viscosity for high filling of filler (inorganic or organic filler) as well as high purity of resin composition, There is a need for further improvements in various properties such as increased reactivity to shorten the molding cycle. Further, as a structural material, there is a demand for a material that is lightweight and has excellent mechanical properties in applications such as aerospace materials and leisure / sports equipment. Particularly in the field of semiconductor encapsulation and substrates (substrate itself or its peripheral materials), the required characteristics are becoming higher year by year. For example, there is a demand for higher Tg of peripheral materials due to an increase in semiconductor driving temperature. Yes.

Epoxy resins generally increase in water absorption when the Tg is increased (Non-patent Document 1). This is due to an increase in crosslink density. However, while high Tg is required for semiconductor peripheral materials that require low moisture absorption, there is an urgent need to develop a resin having these contradictory characteristics.
Similarly, generally, when the Tg is increased, the electrical reliability tends to decrease. That is, the dielectric constant and dielectric loss tangent deteriorate. In the development of electrical and electronic materials, it is necessary to reduce the dielectric constant and dielectric loss tangent while maintaining a high Tg in terms of improving electrical reliability.

The present invention has been made as a result of studies to solve such problems, and provides an epoxy resin whose cured product has high heat resistance, water absorption and low dielectric constant.

As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.
That is, the present invention is (1) obtained by reacting naphthol and cresol with an aldehyde, wherein the ratio of α-naphthol in the naphthol when reacting naphthol and cresol with aldehyde is 1 to 10% by weight. Epoxy resin obtained by glycidylating naphthol-cresol novolac type phenolic resin
(2) In the naphthol-cresol novolak type phenol resin described in (1), the weight ratio of naphthol and cresol when naphthol and cresol are reacted with an aldehyde is 65:35 to 85:15, and the obtained naphthol The epoxy resin according to (1), wherein the softening point of the cresol novolac-type phenol resin is 100 ° C. to 150 ° C.,
(3) The total amount of 74-76 ppm peak area and the total area of 68-71 ppm peak in ¹³ C-NMR is 60: 40-80: 20, and the softening point is 85 ° C.-100 ° C. (1) or the epoxy resin according to (2),
(4) The epoxy resin according to any one of (1) to (3), wherein (weight average molecular weight Mw) / (number average molecular weight Mn) is 1.4 to 2.5,
(5) An epoxy resin composition containing the epoxy resin according to any one of (1) to (4) and a curing accelerator,
(6) A cured product obtained by curing the epoxy resin composition according to (5),
Is to provide.

The epoxy resin composition using the epoxy resin of the present invention gives a cured product that can simultaneously achieve heat resistance and water resistance, and is used for insulating materials for electrical and electronic parts and laminated boards (printed wiring boards, build-up boards, etc.) It is useful for various composite materials such as CFRP, adhesives and paints. In particular, it is extremely useful for a semiconductor sealing material and a laminated plate material for protecting a semiconductor element.

It is a graph which shows the result of an Example.

The epoxy resin of the present invention is obtained by reacting naphthol and cresol with an aldehyde, and the ratio of α-naphthol in the naphthol when reacting naphthol and cresol with aldehyde is 1 to 10% by weight. It can be obtained by glycidylating a phenolic resin.

A naphthol-cresol novolac type phenol resin (NCN) obtained by reacting naphthol and cresol with an aldehyde, wherein the ratio of α-naphthol in the naphthol when reacting naphthol and cresol with an aldehyde is 1 to 10% by weight. Is not particularly limited. For example, the following formula (1)

(In the formula, n represents an average number of repetitions. Further, a plurality of Ar and R are independently present, R is a methyl group or a hydrogen atom, and Ar is 1-naphthol, -Indicates naphthol and cresol.)
It is represented by

NCN is usually obtained by reacting naphthol, cresol and formaldehyde (or an equivalent thereof) under acidic or basic conditions.
Specifically, it can be obtained by adding naphthol, cresol, formaldehyde (or an equivalent thereof) and a catalyst simultaneously or sequentially and performing the reaction usually at 0 to 150 ° C., preferably 10 to 130 ° C. Here, it is possible to preferentially proceed the reaction with naphthol by performing the reaction at a low temperature.
At this time, if the temperature is 0 ° C. or higher, the progress of the reaction does not slow down, it does not take much time, and is excellent in productivity. Moreover, if it is 150 degrees C or less, reaction does not advance at a stretch, and the naphthol which does not participate in reaction does not increase, and it is preferable. By reacting within the aforementioned range, naphthol is relatively prioritized, whereby a compound having a small amount of residual naphthol can be obtained.
The reaction time is usually 5 to 150 hours.

The NCN obtained in this way can be used without purification depending on the use, but usually the reaction mixture is neutralized after completion of the reaction, and then unreacted raw materials and solvents are removed under heating and reduced pressure. Use it after purification. In this neutralization step, various bases, salts such as phosphates, buffers, and the like may be added, or washing with water is possible. However, using both together is more convenient and effective. When the reaction does not sufficiently consume naphthol, the amount of residual naphthol is preferably reduced to 1% or less by thin film distillation, bubbling of an inert gas such as nitrogen.

Solvents that can be used in the synthesis of NCN include, but are not limited to, methanol, ethanol, propanol, isopropanol, toluene, xylene, methyl isobutyl ketone, cyclopentanone, cyclohexanone, alone or in combination of two or more. You may use together. When a solvent is used, the amount used is usually in the range of 5 to 500 parts by weight, preferably 10 to 300 parts by weight, based on 100 parts by weight of the total amount of naphthol and cresol.

As the catalyst, either acidic or basic catalysts can be used.
Specific examples of acidic catalysts that can be used include mineral acids such as hydrochloric acid, sulfuric acid and phosphoric acid; organic acids such as oxalic acid, toluenesulfonic acid and acetic acid; heteropolyacids such as tungstic acid, activated clays, inorganic acids, stannic chloride , Zinc chloride, ferric chloride, and other acidic catalysts such as organic and inorganic acid salts that are usually used for producing novolak resins.
Specific examples of basic catalysts that can be used include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, alkaline earth metal hydroxides such as magnesium hydroxide and calcium hydroxide, sodium methoxide. Alkali metal alkoxides such as sodium ethoxide, potassium methoxide, potassium ethoxide and potassium tert-butoxide, and alkaline earth metal alkoxides such as magnesium methoxide and magnesium ethoxide.
An amine-based catalyst can also be used, and examples thereof include triethylamine, ethanolamine, pyridine, piperidine, morpholine and the like. In particular, when an amine-based catalyst is used, it can also be used as a solvent.
These catalysts are not limited to those mentioned above, and may be used alone or in combination of two or more. The amount of the catalyst used is usually in the range of 0.005 to 2.0 times mol, preferably 0.01 to 1.1 times mol, based on the total amount of naphthol and cresol. When the catalyst is used as a solvent, it is preferable to add about 30 to 200% by weight based on the total amount of naphthol and cresol.

Thus, since the naphthol-cresol novolak type phenol resin obtained by reacting naphthol, cresol and formaldehyde is obtained by random polymerization, the naphthalene skeleton and the phenol skeleton are randomly arranged.

In the present invention, β-naphthol and α-naphthol can be used together as naphthol, and orthocresol, metacresol, paracresol, or a mixture of any two or more can be used as cresol.
Here, in the naphthol used in the reaction, the ratio of α-naphthol is 1 to 10% by weight.
The weight ratio of naphthol and cresol used in the reaction is preferably 65:35 to 85:15, more preferably 62:38 to 80:20, and particularly preferably 62:38 to 76:24. On the other hand, a preferable ratio for obtaining the characteristics of high heat resistance and low water absorption is 71:29 to 85:15. If the amount of naphthol is 62% by weight or more, the desired high heat resistance and low moisture absorption characteristics can be easily obtained, and if the amount of naphthol is 85% by weight or less, the reaction can be easily controlled and residual naphthol Is preferable. Residual naphthol is not preferable because of odor, toxicity, and heat resistance of the cured product.

Further, in the present invention, the ratio of β-naphthol and α-naphthol in naphthol when naphthol and cresol are reacted with aldehyde is 1 to 10% by weight of α-naphthol based on the total amount of naphthol. When α-naphthol is less than 1% by weight, the heat resistance does not increase. When α-naphthol exceeds 10% by weight, the reaction becomes difficult to control and the amount of residual naphthol increases. There is also a technique to control the molecular weight by condensing after methylolation of naphthol or cresol, and reducing the residual naphthol, but the production is cumbersome, the productivity is bad and not preferable, because the distribution is small Insufficient heat resistance.
In this case, the NCN preferably has a softening point of 100 to 150 ° C. The feature of this skeleton is the size of its molecular weight. If there is a chain of molecules having a softening point of 100 ° C. or higher, the desired heat resistance can be easily obtained. In addition, a softening point of 150 ° C. or lower is preferable because handling becomes easy and it is easy to reduce residual naphthol. It should be noted that naphthol residue is not preferable for the safety of the user. In the present invention, it is important that it is at least 1% or less.

The epoxy resin of the present invention is obtained by glycidylating the NCN.
In order to glycidylate the NCN, the NCN and epihalohydrin are preferably reacted.
Examples of the epihalohydrin used in the reaction of NCN and epihalohydrin include epichlorohydrin, α-methylepichlorohydrin, γ-methylepichlorohydrin, epibromohydrin, and the like. In the present invention, epichlorohydrin which is easily available industrially is preferable. The amount of epihalohydrin used is usually 3.0 to 10 moles, preferably 3.5 to 8 moles per mole of NCN hydroxyl group.

In the epoxidation reaction, it is preferable to use an alkali metal hydroxide. Examples of the alkali metal hydroxide include sodium hydroxide and potassium hydroxide. The alkali metal hydroxide may be used as a solid or an aqueous solution thereof. For example, when alkali metal hydroxide is used as an aqueous solution, an aqueous solution of alkali metal hydroxide is continuously added to the reaction system, and water and epihalohydrin are continuously distilled under reduced pressure or normal pressure. Then, liquid separation is performed to remove water, and the epoxidation reaction can be carried out by continuously returning the epihalohydrin to the reaction system. Moreover, when using solid, it is preferable to use a flaky thing from problems, such as the ease of handling and solubility. The amount of the alkali metal hydroxide used is usually 0.90 to 1.5 mol, preferably 0.95 to 1.25 mol, more preferably 0.99 to 1 mol with respect to 1 mol of the hydroxyl group of NCN. 1.15 moles.

In the epoxidation reaction, it is preferable to add a quaternary ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide, trimethylbenzylammonium chloride as a catalyst in order to accelerate the reaction. The amount of the quaternary ammonium salt used is usually 0.1 to 15 g, preferably 0.2 to 10 g, based on 1 mol of the hydroxyl group of NCN.

In the epoxidation reaction, it is preferable to carry out the reaction by adding an alcohol such as methanol, ethanol or isopropyl alcohol, an aprotic polar solvent such as dimethyl sulfone, dimethyl sulfoxide, tetrahydrofuran or dioxane.
When the above alcohols are used, the amount used is usually 2 to 50% by mass, preferably 4 to 20% by mass, based on the amount of epihalohydrin used. On the other hand, when the aprotic polar solvent is used, the amount used is usually 5 to 100% by mass, preferably 10 to 80% by mass, based on the amount of epihalohydrin used.

In the epoxidation reaction, the reaction temperature is usually 30 to 90 ° C., preferably 35 to 80 ° C. On the other hand, the reaction time is usually 0.5 to 10 hours, preferably 1 to 8 hours. The reaction product of these epoxidation reactions can be purified by removing epihalohydrin, a solvent, or the like under heating and reduced pressure after washing with water or without washing with water. In addition, in order to make an epoxy resin with less hydrolyzable halogen, the recovered reaction product is dissolved in a solvent such as toluene or methyl isobutyl ketone, and an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is prepared. In addition, a ring closure reaction of the by-product can be performed to ensure the ring closure of the by-product halohydrin.
In this case, the amount of the alkali metal hydroxide used is usually 0.01 to 0.3 mol, preferably 0.05 to 0.2 mol, relative to 1 mol of the hydroxyl group of NCN used for epoxidation. . The reaction temperature is usually 50 to 120 ° C., and the reaction time is usually 0.5 to 2 hours.

In the epoxidation reaction, after the completion of the reaction, the produced salt is removed by filtration, washing with water, and the like, and the solvent is distilled off under reduced pressure by heating to obtain the epoxy resin of the present invention.

The epoxy resin thus obtained preferably satisfies the following conditions. The softening point is preferably from 80 to 100 ° C, more preferably from 85 to 100 ° C, particularly preferably from 85 to 97 ° C. In order to obtain a preferable softening point, it can be adjusted by the weight ratio of naphthol, cresol, formalin (or a synthetic equivalent thereof) used in the reaction, and naphthol and cresol can be realized by applying the above preferred range. The amount can be obtained by adding 0.5 to 1.1 mol, more preferably 0.60 to 1.1 mol, per equivalent of phenolic hydroxyl group. Formalin may be added all at once or dividedly.
The epoxy equivalent is 200 to 300 g / eq. Is more preferable, and 210 g / eq. ~ 260 g / eq. It is. The epoxy equivalent is adjusted by the amount of epihalohydrin used in the reaction, the amount of raw material naphthol and cresol, and the molecular weight, and the epoxy resin of the present invention having a preferable epoxy equivalent has the same molecular weight as the method described in the adjustment of the softening point. Employing a technique, the amount of epihalohydrin can be obtained by applying the above preferred amount.
Further, in ¹³ C-NMR, the total amount of peak areas of 74 to 76 ppm and the total amount of peak areas of 68 to 71 ppm are preferably 60:40 to 80:20. The peaks at 74-76 ppm and 68-71 ppm correspond to the peaks at the methylene site where the oxirane structure of the glycidyl group bonded to the naphthol and cresol structures is bonded, respectively.

Furthermore, the average molecular weight of the epoxy resin of the present invention preferably satisfies the following conditions.
The number average molecular weight is preferably from 500 to 1,000, more preferably from 500 to 800. Further, the weight average molecular weight is preferably 600 to 2000, more preferably 600 to 1700. In order to obtain an epoxy resin of the present invention having a preferred average molecular weight, it can be adjusted by the weight ratio of naphthol, cresol, formalin (or a synthetic equivalent thereof) used in the reaction, and if the amount of formalin relative to naphthol, cresol is small, The molecular weight can be increased, and the molecular weight can be increased as the amount of epihalohydrin decreases.
If the molecular weight is too small, heat resistance will not be achieved, and if the molecular weight is too large, the viscosity will be too high and handling will be difficult, and the solubility in the solvent will be poor, which is not preferable.

In the present invention, the molecular weight distribution is important. If the molecular weight distribution is too narrow, sufficient heat resistance cannot be improved and water absorption cannot be reduced. This means that the improvement in heat resistance due to the crosslinking density at the time of crosslinking at the stage of thermosetting affects the increase in water absorption rate because a hydroxyl group is released at the time of crosslinking. In the present invention, not only heat resistance but also a reduction in water absorption can be achieved at the same time by increasing the number of bonds at the methylene chain in the mother skeleton.
As a specific molecular weight distribution, (weight average molecular weight Mw) / (number average molecular weight Mn) is preferably 1.4 or more. In addition, when the molecular weight distribution is too wide, problems such as an excessively high viscosity occur, so the maximum value is preferably 2.5.
The molecular weight distribution can be adjusted by the weight ratio of naphthol, cresol, formalin (or its synthetic equivalent) and the amount of epihalohydrin used in the reaction. Specifically, the molecular weight distribution is easily narrowed as the naphthol ratio increases, and can be narrowed by adding formalin in divided portions. Further, the molecular weight distribution can be widened by reducing the amount of epihalohydrin, and conversely, the molecular weight distribution can be narrowed by increasing the amount. Further, at the time of NCN production, the molecular weight distribution can be broadened by performing a rearrangement reaction in which methylene bonds are once broken and re-bonded at 80 to 150 ° C. In rearrangement, 0.005 to 0.1 equivalent of formalin (or a synthetic equivalent thereof) is preferably added per equivalent of phenolic hydroxyl group.

Next, the epoxy resin composition of the present invention will be described.
In the epoxy resin composition of the present invention, the proportion of the epoxy resin of the present invention is preferably 50% by weight or more, more preferably 70% by weight or more, and particularly preferably 80% by weight or more in the total epoxy resin.
Representative examples of the other epoxy resins include novolak type epoxy resins, biphenyl type epoxy resins, triphenylmethane type epoxy resins, and phenol aralkyl type epoxy resins.

Specific examples of other epoxy resins that can be used in combination with the epoxy resin of the present invention include bisphenols (bisphenol A, bisphenol F, bisphenol S, biphenol, bisphenol AD, etc.) or phenols (phenol, alkyl-substituted phenol, aromatic substitution). 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, croton Polycondensates with aldehydes, cinnamaldehyde, etc.]; phenols and various dieneizations Polymers of products (dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisopropenylbiphenyl, butadiene, isoprene, etc.); the phenols and ketones (acetone, Polycondensates of methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, etc .; polycondensates of the phenols with aromatic dimethanols (benzene dimethanol, biphenyl dimethanol, etc.); the phenols and aromatic dichloromethyl Polycondensates (α, α'-dichloroxylene, bischloromethylbiphenyl, etc.); phenols and aromatic bisalkoxymethyls (bismethoxymethylbenzene, bismethoxymethylbiphenyl) Glycidyl ether epoxy resin, alicyclic epoxy resin, glycidylamine epoxy resin obtained by glycidylation of polycondensates of the above bisphenols and various aldehydes or alcohols, etc., Examples thereof include glycidyl ester-based epoxy resins, but are not limited thereto as long as they are usually used epoxy resins. These may be used alone or in combination of two or more.

Examples of the curing agent contained in the epoxy resin composition of the present invention include amine compounds, acid anhydride compounds, amide compounds, phenol compounds, and carboxylic acid compounds. Specific examples of curing agents that can be used include amine compounds such as diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, and isophoronediamine; amides such as polyamide resins synthesized from dimers of dicyandiamide and linolenic acid and ethylenediamine Compounds: phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, etc. Acid anhydride compounds; bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, terpene diphenol, 4,4′-biphenol, 2,2′-biphenol, 3,3 ′, 5,5′-te Tramethyl- [1,1′-biphenyl] -4,4′-diol, hydroquinone, resorcin, naphthalenediol, tris- (4-hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) Ethane and phenols (phenol, alkyl-substituted phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, dihydroxynaphthalene, etc.) and formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, o-hydroxybenzaldehyde, p-hydroxyacetophenone, o-hydroxy Novolac resin that is a polycondensate of acetophenone and furfural, phenol or cresol and phenylene dimethylol, dimethoxymethyl, or methyl halide Or a reaction product of phenol or cresol with bischloromethylbiphenyl, bismethoxymethylbiphenyl or bishydroxymethylbiphenyl, or phenol with benzenediisopropanol, benzenediisopropanoldimethylether or benzenebis (chloroisopropane) Phenol-based aralkyl resins and their modified products, halogenated bisphenols such as tetrabromobisphenol A, phenolic compounds such as terpene and phenol condensates, imidazoles, trifluoroborane-amine complexes, guanidine derivatives However, it is not limited to these. These may be used alone or in combination of two or more.
In the present invention, from the viewpoint of heat resistance, chemical resistance, and electrical reliability, it is preferable to use a phenolic compound as a curing agent, and particularly from a flame retardancy, a novolak resin, particularly a phenol novolak resin or a cresol novolak resin, Phenol aralkyl resins are preferred. In the present invention, a curing agent having a softening point of 50 to 100 ° C. is preferably used. A lower softening point tends to improve fluidity and flame retardancy, but it is preferable to use a higher softening point in order to increase heat resistance.

In the epoxy resin composition of the present invention, the amount of curing agent used is preferably 0.8 to 1.1 equivalents relative to 1 equivalent of epoxy group of the epoxy resin. If it is 0.8 equivalent or more, or 1.1 equivalent or less with respect to 1 equivalent of epoxy groups, hardening will become perfect and favorable hardened | cured material property will be obtained, and it is preferable. In the present invention, a preferable combination of an epoxy resin and a curing agent is an epoxy resin having a softening point of 45 to 70 ° C. (more preferably 50 to 65 ° C.) and a curing agent having a softening point of 50 to 100 ° C. (preferably 55 to 85 ° C.). It is. A resin composition having balanced properties in terms of fluidity, flame retardancy, and heat resistance is obtained.

The epoxy resin composition of the present invention may contain a curing accelerator. Specific examples of curing accelerators that can be used include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2- (dimethylaminomethyl) phenol, 1,8-diaza- And tertiary amines such as bicyclo (5,4,0) undecene-7, phosphines such as triphenylphosphine, and metal compounds such as tin octylate. The curing accelerator is used as necessary in an amount of 0.1 to 5.0 parts by weight based on 100 parts by weight of the epoxy resin.

The epoxy resin composition of the present invention may contain a phosphorus-containing compound as a flame retardant component. The phosphorus-containing compound may be a reactive type or an additive type. Specific examples of phosphorus-containing compounds include trimethyl phosphate, triethyl phosphate, tricresyl phosphate, trixylylenyl phosphate, cresyl diphenyl phosphate, cresyl-2,6-dixylylenyl phosphate, 1,3-phenylenebis ( Phosphoric acid ester compounds such as dixylylenyl phosphate), 1,4-phenylenebis (dixylylenyl phosphate), 4,4′-biphenyl (dixylylenyl phosphate); 9,10-dihydro-9- Phosphanes such as oxa-10-phosphaphenanthrene-10-oxide, 10 (2,5-dihydroxyphenyl) -10H-9-oxa-10-phosphaphenanthrene-10-oxide; activity of epoxy resin and said phosphanes Phosphorus obtained by reacting with hydrogen -Containing epoxy compounds, red phosphorus, and the like. Phosphate esters, phosphanes or phosphorus-containing epoxy compounds are preferable, and 1,3-phenylenebis (dixylylenyl phosphate), 1,4-phenylenebis (dixylyl) is preferable. Renyl phosphate), 4,4′-biphenyl (dixylylenyl phosphate) or phosphorus-containing epoxy compounds are particularly preferred.
However, the amount of the phosphoric acid ester compound as described above is preferably phosphoric acid ester compound / epoxy resin ≦ 0.1 (weight ratio) due to environmental problems and concerns about electrical characteristics. More preferably, it is 0.05 or less. It is particularly preferable not to add a phosphorus compound except that it is added as a curing accelerator.

The epoxy resin composition of the present invention may contain an inorganic filler. Inorganic fillers include fused silica, crystalline silica, alumina, calcium carbonate, calcium silicate, barium sulfate, talc, clay, magnesium oxide, aluminum oxide, beryllium oxide, iron oxide, titanium oxide, aluminum nitride, silicon nitride, and nitride Examples thereof include boron, mica, glass, quartz, and mica. Further, it is also preferable to use a metal hydroxide such as magnesium hydroxide or aluminum hydroxide in order to impart a flame retardant effect. However, it is not limited to these. Two or more kinds may be mixed and used. Of these inorganic fillers, silicas such as fused silica and crystalline silica are preferred because of low cost and good electrical reliability. In the epoxy resin composition of the present invention, the amount of the inorganic filler used is usually 60% to 95% by weight, preferably 70% to 95% by weight, more preferably 75% to 90% by weight. It is. If it is 60% by weight or more, the flame retardant effect is surely obtained, and if it is 95% by weight or less, the linear expansion of the sealing resin and the frame occurs when the semiconductor element to be sealed is mounted on a copper-based lead frame. The rate is surely matched, and it is difficult for defects due to thermal stress such as heat shock to occur.

In the epoxy resin composition of the present invention, a release agent can be blended to improve the release from the mold during molding. Any conventionally known release agent can be used, for example, ester waxes such as carnauba wax and montan wax, fatty acids such as stearic acid and palmitic acid, and metal salts thereof, polyolefins such as polyethylene oxide and non-oxidized polyethylene And waxes. These may be used alone or in combination of two or more. The compounding amount of these release agents is preferably 0.5 to 3% by weight based on the total organic components. If it is 0.5% by weight or more, release from the mold does not deteriorate, and if it is 3% by weight or less, adhesion to a lead frame or the like does not deteriorate.

In the epoxy resin composition of the present invention, a coupling agent can be blended in order to enhance the adhesion between the inorganic filler and the resin component. Any conventionally known coupling agent can be used. For example, vinyl alkoxy silane, epoxy alkoxy silane, styryl alkoxy silane, methacryloxy alkoxy silane, acryloxy alkoxy silane, amino alkoxy silane, mercapto alkoxy silane, isocyanate alkoxy Examples include various alkoxysilane compounds such as silane, alkoxytitanium compounds, and aluminum chelates. These may be used alone or in combination of two or more. The coupling agent may be added by treating the surface of the inorganic filler with the coupling agent in advance and then kneading with the resin, or mixing the coupling agent with the resin and then kneading the inorganic filler. .

Furthermore, a known additive can be blended in the epoxy resin composition of the present invention as necessary. Specific examples of additives that can be used include polybutadiene and modified products thereof, modified products of acrylonitrile copolymer, polyphenylene ether, polystyrene, polyethylene, polyimide, fluororesin, maleimide compounds, cyanate ester compounds, silicone gel, and silicone oil. And colorants such as carbon black, phthalocyanine blue, and phthalocyanine green.

The epoxy resin composition of the present invention can be produced using any conventionally known technique capable of uniformly dispersing and mixing each component. For example, all the components are pulverized and pulverized, mixed with a Henschel mixer, etc., then melt kneaded with a heating roll, melt kneaded with a kneader, mixed with a special mixer, or an appropriate combination of these methods. Moreover, a semiconductor device can be manufactured by resin-sealing a semiconductor element mounted on a lead frame or the like by transfer molding or the like using the epoxy resin composition of the present invention.

The semiconductor device has a cured product of the epoxy resin composition of the present invention such as the one sealed with the epoxy resin composition of the present invention. As semiconductor devices, for example, DIP (Dual Inline Package), QFP (Quad Flat Package), BGA (Ball Grid Array), CSP (Chip Size Package), SOP (Small Outline Package), TSOP (Thin Small Outline Package), TQFP (Sink Quad Flat Package).

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.
Here, the measurement conditions of each physical property value are as follows.
・¹³ C-NMR
Measuring apparatus: VARian NMR system 400 MHz
Solvent: deuterated chloroform / epoxy equivalent Measured by the method described in JIS K-7236, the unit is g / eq. It is.
-Softening point Measured by a method according to JIS K-7234, the unit is ° C.
-Elastic modulus (DMA)
Dynamic viscoelasticity measuring instrument: TA-instruments, DMA-2980
Measurement temperature range: -30 to 280 ° C
Temperature rate: 2 ° C./min Test piece size: 5 mm × 50 mm cut out (thickness is about 800 μm)
Tg: Tan-δ peak point in DMA measurement was defined as Tg.
-Water absorption rate Weight increase rate (%) after boiling a disk-shaped test piece having a diameter of 5 cm and a thickness of 4 mm in water at 100 ° C for 72 hours

Example 1
A flask equipped with a stirrer, a reflux condenser, and a stirrer is charged with naphthol-cresol novolak resin while purging with nitrogen (when naphthol and cresol are reacted with aldehyde, naphthol content in naphthol and cresol is 70% by weight, total naphthol Resin obtained by reaction with 5% by weight of α-naphthol in the middle, 160 parts of softening point 110 ° C., 370 parts of epichlorohydrin (4 molar equivalents to phenol resin), 37 parts of dimethyl sulfoxide were added and dissolved under stirring. The temperature was raised to 40-45 ° C. Next, 41 parts of flaky sodium hydroxide was added in portions over 90 minutes, followed by further reaction at 40 ° C. for 2 hours and at 70 ° C. for 1 hour. After completion of the reaction, washing with 500 parts of water was performed, and excess solvents such as epichlorohydrin were distilled off from the oil layer under reduced pressure using a rotary evaporator. To the residue, 500 parts of methyl isobutyl ketone was added and dissolved, and the temperature was raised to 70 ° C. Under stirring, 10 parts of a 30% by weight aqueous sodium hydroxide solution was added and the reaction was performed for 1 hour, followed by washing with water until the washing water of the oil layer became neutral. From the resulting solution, the pressure was reduced using a rotary evaporator. Methyl isobutyl ketone and the like were distilled off below to obtain 196 parts of the epoxy resin (EP1) of the present invention.
The epoxy equivalent of the obtained epoxy resin was 233 g / eq. The melt viscosity (ICI melt viscosity cone # 1) at a softening point of 93 ° C. and 150 ° C. was 1.3 Pa · s. In ¹³ C-NMR, the ratio of the total 74-76 ppm peak area to the total 68-71 ppm peak area was 64:36.

Synthesis example 1
282 parts of β-naphthol was dissolved in 600 parts of methyl isobutyl ketone, and 53 parts of 30% by weight sodium hydroxide was added. 67 parts of paraformaldehyde was added to this solution and reacted at 20 ° C. for 3 hours. After completion of the reaction, 35% hydrochloric acid was added to neutralize (pH 6 to 7) to obtain a solution containing 1-methylol body of β-naphthol.
After 108 parts of orthocresol was added to the resulting solution, 2 parts of 35% hydrochloric acid was added and reacted at 30 ° C. for 1 hour and at 70 ° C. for 6 hours. Then, it washed with water until the reaction liquid became neutral, the solvent etc. were distilled off from the organic layer, and 420 parts of comparative NCN resins were obtained. The resulting resin had a softening point of 90 ° C. and a hydroxyl group equivalent of 140 g / eq. Met.

Synthesis example 2
An epoxy resin was synthesized in the same manner using 140 parts of the NCN resin obtained in Synthesis Example 1 instead of the naphthol-cresol novolak resin in Example 1.
The obtained epoxy resin had an epoxy equivalent of 210 g / eq. The melt viscosity at a softening point of 68 ° C. and 150 ° C. was 0.12 Pa · s (EP2). In ¹³ C-NMR, the ratio of the total 74-76 ppm peak area to the total 68-71 ppm peak area was 81:19.

Test examples 1-10
The epoxy resin obtained above and the various epoxy resins shown in Table 1 below are blended in equal equivalents of phenol novolac (softening point 83 ° C., hydroxyl group equivalent 106 g / eq) as a curing agent with respect to 1 molar equivalent of epoxy equivalent. Then, triphenylphosphine as a catalyst is blended at a ratio (parts by weight) of 1 part by weight with respect to 100 parts by weight of the epoxy resin, and uniformly mixed and kneaded using a mixing roll to obtain an epoxy resin composition for sealing. Obtained. This epoxy resin composition was pulverized with a mixer and further tableted with a tablet machine. The tableted epoxy resin composition was transfer-molded (175 ° C. × 60 seconds), and after demolding, cured under the conditions of 160 ° C. × 2 hours + 180 ° C. × 6 hours to obtain a test piece for evaluation.
Details of the epoxy resin used for the evaluation are shown in Table 2 below.

As is clear from FIG. 1, cured products using general epoxy resins (Test Examples 2 to 9) basically have a correlation that the water absorption increases as Tg increases. On the other hand, although the hardened | cured material using the epoxy resin of this invention has high heat resistance, it has confirmed that water absorption was low and it remove | deviated from said relationship significantly.

Although the invention has been described in detail with reference to specific 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 based on a Japanese patent application (Japanese Patent Application No. 2011-195585) filed on Sep. 8, 2011, which is incorporated by reference in its entirety. Also, all references cited herein are incorporated as a whole.

The epoxy resin of the present invention can be used in an epoxy resin composition that gives a cured product capable of simultaneously achieving heat resistance and water resistance. The composition comprises an insulating material for electrical and electronic parts and a laminate (printed wiring board, It is useful for various composite materials such as build-up substrates) and CFRP, adhesives, paints and the like. In particular, it is extremely useful for a semiconductor sealing material and a laminated plate material for protecting a semiconductor element.

Claims

It is obtained by reacting naphthol and cresol with an aldehyde, and naphthol-cresol novolak type phenol resin in which the ratio of α-naphthol is 1 to 10% by weight in the naphthol when reacting naphthol and cresol with aldehyde is glycidylated. An epoxy resin characterized by that.
In the naphthol-cresol novolac type phenol resin, the weight ratio of naphthol to cresol when reacting naphthol and cresol with an aldehyde is 65:35 to 85:15, and the obtained naphthol-cresol novolak type phenol resin is softened The epoxy resin according to claim 1, wherein the point is 100 ° C to 150 ° C.
The total amount of peak areas of 74-76 ppm and the total area of peaks of 68-71 ppm in 13 C-NMR is 60: 40-80: 20, and the softening point is 85 ° C.-100 ° C. The epoxy resin according to claim 1 or 2.
The epoxy resin according to any one of claims 1 to 3, wherein (weight average molecular weight Mw) / (number average molecular weight Mn) is 1.4 to 2.5.
An epoxy resin composition comprising the epoxy resin according to any one of claims 1 to 4 and a curing accelerator.
A cured product obtained by curing the epoxy resin composition according to claim 5.