JP2023023241A - Epoxy resin mixture, epoxy resin composition and cured product thereof - Google Patents

Abstract

To provide an epoxy resin mixture that shows excellent mechanical strength and toughness at room temperature and in a high-temperature region, an epoxy resin composition and a cured product thereof.SOLUTION: An epoxy resin mixture comprises an epoxy resin represented by the formula (1), with a sulfur content of 15 ppm-400 ppm by a combustion method. (In formula (1), n is a repeating number to denote a real number of 1-20).SELECTED DRAWING: None

Description

The present invention includes insulating materials for electric and electronic parts (such as highly reliable semiconductor sealing materials), laminates (printed wiring boards, build-up boards, etc.) and various composite materials such as FRP (fiber reinforced plastic), adhesives, The present invention relates to epoxy resin mixtures and epoxy resin compositions which are useful for applications such as paints, especially laminates, and are useful for metal foil-clad laminates, insulating materials for build-up substrates, flexible substrate materials, and the like.

Epoxy resins are widely used in fields such as electrical and electronic parts, structural materials, adhesives, and coatings due to their workability and the excellent electrical properties, heat resistance, adhesiveness, and water absorption resistance of their cured products.

Carbon fiber reinforced composite materials (CFRP), which are made by impregnating reinforcing fibers with epoxy resin and a curing agent as a matrix resin and curing, can provide properties such as light weight and high strength. , automobile outer panels, IC trays, and computer applications such as notebook computer housings, and the demand for them is increasing.

Cured products of thermosetting resins such as epoxy resins, which are used as resins for matrix resins such as CFRP, are generally brittle. Mechanical strength is required. In order to compensate for the low bending strength, toughness, adhesiveness, etc. of thermosetting resins, methods of adding thermoplastic resins with high toughness to thermosetting resin matrices are widely known (Patent Documents 1 to 3). Specifically, particles of a thermoplastic resin such as polyethersulfone, polyetherimide, or polyamide are combined with a thermosetting resin matrix resin to improve the bending strength and toughness of the prepreg.

However, thermoplastic resins such as polyethersulfone, polyetherimide, and polyamide are highly polar, and may undergo phase separation when mixed with epoxy resin or after prepreg production. may not be obtained.

Moreover, in the semiconductor-related field, in addition to high functionality and high performance, package substrates necessary for mounting chips are being developed, and thinning is progressing. Along with the thinning of package substrates, toughness is considered important in addition to properties such as heat resistance and dielectric properties. Various materials with different coefficients of linear expansion are used in laminates that are laminated with many layers. In recent years, the number of substrates has been increasing, and problems such as cracks in the substrate when subjected to heat or mechanical shock due to the inability to withstand the forces in various directions applied to the interlayer material have arisen. It's happening.

JP-A-60-243113 JP-A-09-100358 JP 2013-155330 A JP 2017-008177 A

Biphenyl aralkyl type epoxy resins are generally known to be excellent in flame retardancy and toughness, and are particularly used as sealing materials for semiconductors. However, in applications to various uses, it is particularly desired to respond to the recent sophistication of the demand for toughness as described above.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an epoxy resin mixture, an epoxy resin composition, and a cured product thereof that exhibit excellent mechanical strength and toughness at room temperature and high temperature ranges. .

That is, the present invention provides the following [1] to [4]. In the present application, "(numerical value 1) to (numerical value 2)" indicate that upper and lower limits are included.
[1]
An epoxy resin mixture containing an epoxy resin represented by the following formula (1) and having a sulfur content of 15 ppm to 400 ppm by a combustion method.

(In formula (1), n is the number of repetitions and represents a real number from 1 to 20.)
[2]
An epoxy resin mixture obtained by reacting a phenol resin represented by the following formula (2), epichlorohydrin, and a sulfur-containing compound.

(In formula (2), n is the number of repetitions and represents a real number from 1 to 20.)
[3]
An epoxy resin composition containing the epoxy resin mixture according to [1] or [2] above and a curing agent.
[4]
A cured product obtained by curing the epoxy resin composition described in [3] above.

According to the present invention, it is possible to provide an epoxy resin mixture, an epoxy resin composition, and a cured product using the same, the cured product of which exhibits excellent mechanical strength and toughness at room temperature and in a high temperature range. Therefore, it is useful for circuit boards such as package boards and FRP.

Figure 2 shows the stress-strain diagram of a 3-point bending test at 30°C. Figure 2 shows the stress-strain diagram of a 3-point bending test at 120°C.

The epoxy resin mixture of the present invention contains an epoxy resin represented by the following formula (1), and has a sulfur content of 15 ppm to 400 ppm as measured by a combustion method.

(In formula (1), n is the number of repetitions and represents a real number from 1 to 20.)

In the present invention, the value of n in the formula (1) can be determined by gel permeation chromatography (GPC, detector: RI). n is usually a real number of 1-20, preferably 1-10, more preferably 1-5. When n is larger than 20, the molecular weight increases and the viscosity becomes high, resulting in poor workability.
Also, the average value of n can be calculated from the number average molecular weight determined by gel permeation chromatography (GPC, detector: RI) or from the area ratio of each separated peak.
If the average n is less than 1, it indicates that there is a large amount of monofunctional epoxy resin, which not only affects the curability and the heat resistance of the cured product, but also causes a decrease in toughness because the crosslinked structure cannot be formed well. . On the other hand, when n exceeds 20, the solvent solubility of the epoxy resin deteriorates, the viscosity increases, and the softening point also rises significantly, making handling difficult.
In the present invention, the average n is preferably in the range of 1.3 to 3.5, which is also preferable in terms of fluidity, heat resistance and curability. In this case, the area ratio of n=1 is 15 to 50 area %, preferably 17 to 45 area %. If the area of n=1 is too small, fluidity will be a problem, and the solubility in a solvent will deteriorate, resulting in a problem of handling. When the area ratio is 50 area % or more, the crystallinity becomes high and handling may become a problem.

A preferred range of the epoxy equivalent weight of the epoxy resin mixture of the present invention is 260 g/eq. 400 g/eq. less than, more preferably 265 g/eq. 350 g/eq. less than, particularly preferably 270 g/eq. above 320 g/eq. less than, most preferably 280 g/eq. 300 g/eq. is less than Epoxy equivalent is 260 g/eq. If it is less than 100%, epichlorohydrin-derived impurities that excessively introduce or replicate epoxy groups remain, so crosslinking during curing does not proceed well, resulting in a decrease in heat resistance and toughness. Moreover, the epoxy equivalent is 400 g/eq. In the above cases, the epoxy groups are not perfectly ring-closed and the amount of chlorine increases, which adversely affects corrosion, or the raw materials and refined epoxy resin react unnecessarily in the epoxidation process, leading to a large molecular weight. This is not preferable because it causes a decrease in heat resistance. When the epoxy equivalent is appropriate, the heat resistance of the cured product can be improved without causing a decrease in mechanical strength.

In the present invention, the epoxy equivalent is measured by the method described in JIS K-7236.

The softening point of the epoxy resin mixture of the present invention preferably ranges from 60 to 100°C, more preferably from 47 to 90°C. When the softening point is within the above range, the resins do not block each other at room temperature, resulting in excellent handleability.

The epoxy resin mixture of the present invention has a sulfur content of 15 ppm to 400 ppm, preferably 20 to 250 ppm, particularly preferably 30 to 225 ppm, most preferably 40 to 200 ppm, according to the combustion method. Sulfur is introduced in the form of an aromatic ring or addition to epoxy. If the sulfur content is less than 15 ppm, high strength and toughness cannot be achieved, and if it exceeds 400 ppm, when used as a sealing material for semiconductors, etc., it causes corrosion of metal joints (wire bonding parts). I don't like it because it's possible. JP 2017-008177 describes that it is preferably 0.1% (1000 ppm) or less in terms of SO ₃ , and when applied to electronic material applications, it is about 400 ppm or less in terms of sulfur. It is also known from the known literature that this is preferable.
That is, when the sulfur content is within the above range, the cured product of the epoxy resin mixture of the present invention can exhibit excellent mechanical strength and toughness at room temperature and high temperature range, and can be used for electronic materials without problems. cannot occur.

In addition, in the present invention, the sulfur content is obtained by the combustion method, and in detail, it was carried out under the following conditions.
[Thermal decomposition process]
Equipment Manufacturer: Thermo SCIENTIFIC Combustion ion chromatography system (thermal decomposition conditions)
Combustion temperature 1000°C, 15 minutes keep Gas flow rate Ar 200ml/min O ₂ 400ml/min
0.05 g of sample
(decomposition gas absorption liquid)
Phosphate ion standard solution 1000ppm 1mL
_{H2O2 30} % 0.05 mL
Dilute with water and adjust to 500 mL [Ion chromatography process of absorption liquid]
Equipment: Dionex Integration HPLC
Guard column Dinonex Ionpac AS12A (4 x 50mm)
Column: Dionex Ion Pac AS12A (4 x 200mm)
Suppressor Dionex ADRS 600 (4mm)
Eluent: sodium carbonate/sodium hydrogen carbonate mixed solution Detector: CD (conductivity detector)

The epoxy resin mixture of the present invention preferably has an inorganic sulfur component (sulfide ion) content of 10 ppm or less. If it remains as ions rather than as an organic sulfur content as described above, there is a risk of corrosion and poor reliability in electrical devices obtained using the epoxy resin mixture. It is more preferably 5 ppm or less, most preferably 2 ppm or less.
The ion content can be confirmed by placing the resin in pure water, extracting the resin at a temperature above the softening point for 20 hours, and measuring the resulting extract by ion chromatography.

A cured product obtained by curing the epoxy resin mixture of the present invention has excellent mechanical strength and toughness at room temperature and high temperature. An index representing mechanical strength is stress (MPa) in a three-point bending test, and an index representing toughness is strain (%) in a three-point bending test. The stress in a three-point bending test at room temperature of 30° C. is preferably 90 MPa or more, more preferably 95 MPa or more, and particularly preferably 100 MPa or more. The strain in a three-point bending test at 30°C is preferably 4.0% or more, more preferably 6.0% or more. The stress in a three-point bending test at a high temperature of 120° C. is preferably 60 MPa or more, more preferably 65 MPa or more. Also, the strain in a three-point bending test at 120° C. is preferably 5.0% or more, more preferably 6.0% or more, and particularly preferably 8.0% or more. When applying cured thermosetting resins used for matrix resins such as CFRP to structural materials for aerospace applications and vehicles, high mechanical strength is required both at room temperature and in high temperature ranges, and mechanical strength is low. It may be damaged when a strong force is applied. Therefore, it is preferable that the mechanical strength is as high as possible. Moreover, when a thin substrate such as a package substrate is subjected to a mechanical shock, the substrate may be damaged because it cannot withstand the shock. Therefore, it is preferable that the toughness is as high as possible.

The epoxy resin mixture of the present invention can be obtained by epoxidizing a phenol resin represented by the following formula (2) with epichlorohydrin. At this time, by epoxidizing simultaneously with a sulfur-containing compound described later, a compound containing a sulfur atom in the molecule is obtained.

(In formula (2), n is the number of repetitions and represents a real number from 1 to 20.)

In formula (2), the preferred range of n is the same as in formula (1).

The method for synthesizing the phenolic resin represented by the formula (2) is not limited. In particular, the use of 4,4'-bischloromethylbiphenyl and 4,4'-bismethoxymethylbiphenyl with a purity of 90% or more is industrially preferable. In this case, the biphenyl compound is used in an amount of generally 1 to 9 mol, preferably 1 to 6 mol, per 10 mol of phenol. Specific synthesis methods include, but are not limited to, the methods described in Japanese Patent No. 3122834, Japanese Patent Application Laid-Open No. 2003-301031, Japanese Patent No. 3122834, Japanese Patent No. 5686770, and Japanese Patent No. 3934829. not something

Next, the reaction for obtaining the epoxy resin mixture of the present invention will be explained. The epoxy resin mixture of the present invention is obtained by reacting the phenol resin represented by the formula (2), epichlorohydrin, and a sulfur-containing compound.

Epichlorohydrin is readily available commercially. The amount of epichlorohydrin to be used is usually 3.0 to 10 mol, preferably 3.5 to 8.0 mol, more preferably 4.0 to 7.0 mol, per 1 mol of hydroxyl group of the raw material phenolic resin. .

In the above reaction, it is preferable to carry out the reaction by adding an alcohol such as methanol, ethanol or isopropyl alcohol, or an aprotic polar solvent such as dimethylsulfone, dimethylsulfoxide, tetrahydrofuran or dioxane.
When alcohols are used, the amount used is generally 2-50% by weight, preferably 4-20% by weight, based on the amount of epihalohydrin used. When an aprotic polar solvent is used, it is usually 5-100% by weight, preferably 10-80% by weight, based on the amount of epihalohydrin used.

In the above reaction, an alkali metal hydroxide can be used as a catalyst to accelerate the epoxidation process. Alkali metal hydroxides that can be used include sodium hydroxide, potassium hydroxide, and the like. From the point of view of handling, it is preferable to use solids molded into flakes. The amount of the alkali metal hydroxide to be used is usually 0.90 to 1.50 mol per 1 mol of the hydroxyl group of the raw material phenol resin. Especially preferred is 1.01 to 1.35. If it is less than 0.90, the number of compounds for which epoxidation is not completed increases, and the increased amount of chlorine tends to cause corrosion. In addition, when the ratio exceeds 1.5, hydroxide ions react with epoxy groups formed to easily form an α-glycol structure, which causes a decrease in crosslink density. Therefore, the above range is preferable.

Moreover, in order to promote the reaction, a quaternary ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide, trimethylbenzylammonium chloride, etc. may be added as a catalyst. The amount of the quaternary ammonium salt to be used is preferably 0.0009 to 0.15 mol per 1 mol of the hydroxyl group of the raw material phenol resin.

In the present invention, a sulfur-containing compound is simultaneously reacted during the epoxidation reaction to introduce sulfur into the molecule. The sulfur-containing compound is not particularly limited as long as it contains sulfur in its structure, and examples thereof include thioether compounds and disulfide compounds. Specifically, thioether compounds having 1 to 10 carbon atoms such as dimethyl sulfide, diallyl sulfide, diethyl sulfide and methylphenyl sulfide; disulfide compounds having 1 to 10 carbon atoms such as dimethyl disulfide, allyl disulfide, dibutyl disulfide and diphenyl disulfide; By adding a sulfur-containing compound such as trisulfide having 1 to 10 carbon atoms such as dimethyltrisulfide and dipropyltrisulfide, an epoxy resin mixture containing a sulfur-containing compound can be obtained. The sulfur-containing compound preferably has 2 to 4 carbon atoms, and particularly preferably dimethylsulfide and dimethyldisulfide. This is because an unreacted sulfide compound can be easily removed in a later step due to its low molecular weight. The amount of these sulfur compounds to be added is preferably 0.1 to 50 parts by weight, more preferably 0.5 to 40 parts by weight, particularly preferably 1 to 30 parts by weight, per 1,000 parts by weight of the starting phenolic resin. If the amount of the sulfur-containing compound added is less than the above range, the content of the sulfur-containing compound in the epoxy resin mixture after completion of the reaction process will be too small to obtain excellent mechanical strength and toughness. On the other hand, if the content of the sulfur-containing compound is more than the above range, the content of the sulfur-containing compound in the epoxy resin mixture after the completion of the reaction process becomes too large, and as described above, corrosion of metal wiring occurs in the high temperature range. It becomes the cause. If the amount of the sulfur compound added is within the above range, the corrosion of the metal wiring is less affected, and excellent mechanical strength and toughness can be obtained.

The reaction temperature for epoxidation is usually 30 to 90°C, preferably 35 to 80°C. The reaction time is usually 0.5 to 10 hours, preferably 1 to 8 hours.
After completion of the reaction, the epoxy resin represented by the formula (2) can be obtained by removing the epihalohydrin, solvent, etc. from the reactant under heating and reduced pressure after washing with water or without washing with water. Also, in order to obtain an epoxy resin with less hydrolyzable halogen, the recovered epoxy resin 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 added. can also be used to ensure ring closure. In this case, the amount of alkali metal hydroxide to be used is usually 0.01 to 0.3 mol, preferably 0.05 to 0.2 mol, per 1 mol of the hydroxyl group of the phenol compound used for glycidylation. The reaction temperature is usually 50-120° C., and the reaction time is usually 0.5-2 hours.

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

The epoxy resin composition of the present invention contains a curing agent. Examples of usable curing agents include phenol-based curing agents, acid anhydride-based curing agents, amide-based curing agents, and amine-based curing agents.

Especially in the epoxy resin composition of the present invention, a phenolic resin having a repeating unit is preferable as a phenolic curing agent because the cured product can have both heat resistance and thermal stability in a well-balanced manner. Examples of phenol-based curing agents include phenol novolac resins, cresol novolac resins, phenol aralkyl resins; biphenyl, 2,2'-dihydroxybiphenyl, 3,3',5,5'-tetramethyl-(1,1'-biphenyl)-4,4'-diol, hydroquinone, resorcinol, naphthalenediol, tris-(4 -hydroxyphenyl)methane and 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, etc.); , aldehydes (formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, o-hydroxybenzaldehyde, furfural, etc.), ketones (p-hydroxyacetophenone and o-hydroxyacetophenone, etc.), or dienes (dicyclopentadiene and tricyclopentadiene etc.); the phenols and substituted biphenyls (4,4′-bis(chloromethyl)-1,1′-biphenyl and 4,4′-bis(methoxymethyl)-1, 1'-biphenyl, etc.), or substituted phenyls (1,4-bis(chloromethyl)benzene, 1,4-bis(methoxymethyl)benzene, 1,4-bis(hydroxymethyl)benzene, etc.), etc. Phenol resins obtained by condensation; modified phenols and/or modified phenol resins; and halogenated phenols such as tetrabromobisphenol A and brominated phenol resins.

Acid anhydride curing agents include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride and methylhexahydrophthalic anhydride. Examples include phthalic anhydride and the like.

Examples of the amide-based curing agent include dicyandiamide, or a polyamide resin synthesized from a dimer of linolenic acid and ethylenediamine.

Amine curing agents include 3,3′-diaminodiphenylsulfone (3,3′-DDS), 4,4′-diaminodiphenylsulfone (4,4′-DDS), diaminodiphenylmethane (DDM), 3,3 '-diisopropyl-4,4'-diaminodiphenylmethane, 3,3'-di-t-butyl-4,4'-diaminodiphenylmethane, 3,3'-diethyl-5,5'-dimethyl-4,4'- Diaminodiphenylmethane, 3,3'-diisopropyl-5,5'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-di-t-butyl-5,5'-dimethyl-4,4'-diaminodiphenylmethane , 3,3′,5,5′-tetraethyl-4,4′-diaminodiphenylmethane, 3,3′-diisopropyl-5,5′-diethyl-4,4′-diaminodiphenylmethane, 3,3′-di- t-butyl-5,5'-diethyl-4,4'-diaminodiphenylmethane, 3,3',5,5'-tetraisopropyl-4,4'-diaminodiphenylmethane, 3,3'-di-t-butyl -5,5'-diisopropyl-4,4'-diaminodiphenylmethane, 3,3',5,5'-tetra-t-butyl-4,4'-diaminodiphenylmethane, diaminodiphenyl ether (DADPE), bisaniline, benzyldimethyl Aniline, 2-(dimethylaminomethyl)phenol (DMP-10), 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30), 2 of 2,4,6-tris(dimethylaminomethyl)phenol - ethyl hexanoic acid ester and the like can be used. Also, aniline novolak, orthoethylaniline novolak, aniline resin obtained by reacting aniline with xylylene chloride, aniline and substituted biphenyls (4,4'-bis(chloromethyl)-1,1'-biphenyl and 4,4 '-bis(methoxymethyl)-1,1'-biphenyl, etc.), or substituted phenyls (1,4-bis(chloromethyl)benzene, 1,4-bis(methoxymethyl)benzene and 1,4-bis( hydroxymethyl)benzene, etc.), and aniline resins obtained by polycondensation.

In the epoxy resin composition of the present invention, the amount of the curing agent used is preferably 0.7 to 1.2 equivalents per equivalent of the epoxy group of the epoxy resin. If the amount is less than 0.7 equivalents or if the amount exceeds 1.2 equivalents with respect to 1 equivalent of epoxy groups, curing may be incomplete and good cured physical properties may not be obtained.

Moreover, in the epoxy resin composition of the present invention, if necessary, a curing accelerator may be blended. The gelation time can also be adjusted by using curing accelerators. Examples of curing accelerators that can be used include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-(dimethylaminomethyl)phenol, triethylenediamine, tri Tertiary amines such as ethanolamine, 1,8-diasazabicyclo(5,4,0)undecene-7, triphenylphosphine, tri(toluyl)phosphine, tetraphenylphosphonium bromide, tetraphenylphosphonium tetraphenylborate, etc. phosphines and phosphonium compounds, metal compounds such as tin octylate, tetra-substituted phosphonium/tetra-substituted borate such as traphenylphosphonium/tetraphenylborate, tetraphenylphosphonium/ethyltriphenylborate, 2-ethyl-4-methylimidazole Tetraphenylboron salts such as tetraphenylborate and N-methylmorpholine-tetraphenylborate. 0.01 to 5.0 parts by weight of the curing accelerator is used as needed with respect to 100 parts by weight of the epoxy resin.

The epoxy resin composition of the present invention may contain other epoxy resins. Specific examples include phenols (phenol, alkyl-substituted phenol, aromatic-substituted phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, alkyl polycondensates of various aldehydes (formaldehyde, acetaldehyde, alkylaldehyde, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthaldehyde, glutaraldehyde, phthalaldehyde, crotonaldehyde, cinnamaldehyde, etc.), Polymers of phenols and various diene compounds (dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisopropenylbiphenyl, butadiene, isoprene, etc.), phenols and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, etc.), phenols and substituted biphenyls (4,4'-bis(chloromethyl)-1,1'-biphenyl and 4,4'- bis(methoxymethyl)-1,1'-biphenyl, etc.) or substituted phenyls (1,4-bis(chloromethyl)benzene, 1,4-bis(methoxymethyl)benzene and 1,4-bis(hydroxymethyl ) phenol resins obtained by polycondensation with benzene, etc.), polycondensates of bisphenols and various aldehydes, glycidyl ether epoxy resins obtained by glycidylating alcohols, 4-vinyl-1-cyclohexene diepoxide and 3, Alicyclic epoxy resins such as 4-epoxycyclohexylmethyl-3,4'-epoxycyclohexanecarboxylate, glycidylamine-based epoxies such as tetraglycidyldiaminodiphenylmethane (TGDDM) and triglycidyl-p-aminophenol. Resins, glycidyl ester-based epoxy resins, and the like can be mentioned, but the epoxy resins are not limited to these as long as they are commonly used epoxy resins.

Furthermore, an inorganic filler can be added to the epoxy resin composition of the present invention, if necessary. Inorganic fillers include powders of crystalline silica, fused silica, alumina, zircon, calcium silicate, calcium carbonate, silicon carbide, silicon nitride, boron nitride, zirconia, fosterite, steatite, schipinel, titania, talc, etc. Beads formed by spheroidizing are included, but are not limited to these. These may be used independently and may use 2 or more types. The amount of these inorganic fillers used varies depending on the application. It is preferably used in a proportion of 20% by weight or more in the epoxy resin composition, more preferably 30% by weight or more, and in particular 70 to 95% by weight in order to improve the coefficient of linear expansion with the lead frame. It is more preferred to use proportions.

The epoxy resin composition of the present invention may contain a mold release agent to improve release from the mold during molding. As the mold release agent, any conventionally known ones can be used. system waxes and the like. These may be used alone or in combination of two or more. The blending amount of these release agents is preferably 0.5 to 3% by weight based on the total organic components. If the amount is too small, the release from the mold will be poor, and if the amount is too large, adhesion to the lead frame or the like will be poor.

A coupling agent can be added to the epoxy resin composition of the present invention in order to increase the adhesion between the inorganic filler and the resin component. Any known coupling agent can be used, for example vinylalkoxysilane, epoxyalkoxysilane, styrylalkoxysilane, methacryloxyalkoxysilane, acryloxyalkoxysilane, aminoalkoxysilane, mercaptoalkoxysilane, isocyanatoalkoxy. 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 first treating the surface of the inorganic filler with the coupling agent and then kneading it with the resin, or by mixing the coupling agent with the resin and then kneading the inorganic filler. .

Further, the epoxy resin composition of the present invention may contain known additives as required. Specific examples of additives that can be used include polybutadiene and modified polybutadiene, modified acrylonitrile copolymer, polyphenylene ether, polystyrene, polyethylene, polyimide, fluorine resin, maleimide compound, cyanate ester compound, silicone gel, and silicone oil. , and coloring agents such as carbon black, phthalocyanine blue and phthalocyanine green.

The epoxy resin composition of the present invention may optionally contain a known maleimide compound. Specific examples of usable maleimide compounds include 4,4′-diphenylmethanebismaleimide, polyphenylmethanemaleimide, m-phenylenebismaleimide, 2,2′-bis[4-(4-maleimidophenoxy)phenyl]propane, 3 ,3′-dimethyl-5,5′-diethyl-4,4′-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, 4,4′-diphenyletherbismaleimide, 4,4′-diphenylsulfone Examples include, but are not limited to, bismaleimide, 1,3-bis(3-maleimidophenoxy)benzene, 1,3-bis(4-maleimidophenoxy)benzene, and the like. These may be used alone or in combination of two or more. When blending the maleimide-based compound, a curing accelerator is blended as necessary, and the above-mentioned curing accelerators, organic peroxides, radical polymerization initiators such as azo compounds, and the like can be used.

The epoxy resin composition of the present invention is obtained by uniformly mixing the above components. The epoxy resin composition of the present invention can be easily cured by a method similar to the conventionally known method. For example, an epoxy resin and a curing agent, and if necessary, a curing accelerator, an inorganic filler, a release agent, a silane coupling agent, and an additive are mixed until uniform using an extruder, a kneader, a roll, etc. The epoxy resin composition of the present invention is obtained by thorough mixing, which is molded by a melt casting method, transfer molding method, injection molding method, compression molding method, or the like, and further at 80 to 200° C. for 2 to 10 hours. A cured product can be obtained by heating to .

Moreover, the epoxy resin composition of the present invention may contain a solvent, if necessary. Epoxy resin composition containing a solvent (epoxy resin varnish) Prepreg obtained by impregnating fibrous substances (base material) such as steel fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, paper, etc., and heating and drying. A cured product of the epoxy resin composition of the present invention can be obtained by hot press molding. The solvent content of this epoxy resin composition is usually 10 to 70% by weight, preferably about 15 to 70% by weight. Examples of the solvent include amide solvents such as γ-butyrolactones, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide and N,N-dimethylimidazolidinone; sulfones such as tetramethylenesulfone; Ether solvents such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether monoacetate, propylene glycol monobutyl ether, preferably lower (1 to 3 carbon atoms) alkylene glycol mono- or di-lower (1 carbon atom) ~3) Alkyl ethers; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, preferably di-lower (C1-3) alkyl ketones in which two alkyl groups may be the same or different; aromatic solvents such as toluene and xylene A solvent etc. are mentioned. These may be used alone or as a mixed solvent of two or more.

Further, a sheet-like adhesive (sheet of the present invention) can be obtained by applying the epoxy resin varnish on a release film, removing the solvent under heating, and performing B-stage. This sheet-like adhesive can be used as an interlayer insulating layer in multilayer substrates and the like.

The prepreg of the present invention can also be obtained by heating and melting the epoxy resin composition and/or the resin sheet of the present invention to lower the viscosity and impregnating the fiber base material.

Alternatively, the prepreg of the present invention can be obtained by impregnating a fiber base material with a varnish-like epoxy resin composition and drying it by heating. After cutting the prepreg into a desired shape and laminating, the FRP of the present invention is obtained by heating and curing the epoxy resin composition while applying pressure to the laminate by a press molding method, an autoclave molding method, a sheet winding molding method, or the like. be able to. Also, a copper foil or an organic film can be laminated when laminating the prepreg.

Furthermore, the molding method of the FRP of the present invention can also be obtained by molding by a known method in addition to the above method. For example, a carbon fiber base material (usually carbon fiber fabric is used) is cut, laminated, and shaped to produce a preform (a preform before being impregnated with resin), and the preform is placed in a mold. A resin transfer molding technique (RTM method) can also be used in which the mold is closed, resin is injected to impregnate the preform, and the preform is cured, and then the mold is opened to take out the molded product.
In addition, a kind of RTM method, for example, VaRTM method, SCRIMP (Seeman's Composite Resin Infusion Molding Process) method, the resin supply tank described in Japanese translation of PCT publication No. 2005-527410 is evacuated to a pressure lower than atmospheric pressure, and circulating compression is performed. and control the net molding pressure to better control the resin infusion process, especially the VaRTM method, such as the CAPRI (Controlled Atmospheric Pressure Resin Infusion) method.

Furthermore, a film stacking method in which a fiber base material is sandwiched between resin sheets (films), a method in which powdered resin is attached to a reinforcing fiber base material to improve impregnation, a fluidized bed or a fluid slurry in the process of mixing resin with a fiber base material. A molding method using a method (Powder Impregnated Yarn) and a method of mixing resin fibers with a fiber base material can also be used.

Examples of carbon fibers include acrylic, pitch, and rayon carbon fibers, among which acrylic carbon fibers having high tensile strength are preferably used. Twisted yarn, untwisted yarn, untwisted yarn, and the like can be used as the form of the carbon fibers, but untwisted yarn or untwisted yarn is preferably used because the moldability and strength characteristics of the fiber-reinforced composite material are well balanced.

The cured product obtained by the present invention can be used for various uses other than the above-mentioned uses such as substrates and CFRP. More specifically, general applications where thermosetting resins such as epoxy resins are used include adhesives, paints, coating agents, molding materials (including sheets, films, FRP, etc.), insulating materials (wire coating, etc.). ), sealing agents, additives to other resins, and the like.

Adhesives include adhesives for civil engineering, construction, automobiles, general office and medical use, as well as adhesives for electronic materials. Among them, adhesives for electronic materials include interlayer adhesives for multilayer substrates such as build-up substrates, die bonding agents, adhesives for semiconductors such as underfill, underfill for BGA reinforcement, and anisotropic conductive films. (ACF), anisotropic conductive paste (ACP) and other mounting adhesives.

As the encapsulant, potting, dipping, transfer mold encapsulation for capacitors, transistors, diodes, light emitting diodes, ICs, LSIs, etc., potting encapsulation for COB, COF, TAB of ICs, LSIs, etc. Examples include underfill for flip chips, and sealing (including reinforcing underfill) when IC packages such as QFP, BGA, and CSP are mounted.

EXAMPLES The present invention will be described more specifically with reference to examples below. The materials, processing details, processing procedures, etc. described below can be changed as appropriate without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed to be limited by the specific examples shown below.

Various analysis methods were performed under the following conditions.
· Epoxy equivalent Measured by the method described in JIS K-7236, the unit is g / eq. is.
・Softening point Measured by a method conforming to JIS K-7234, and the unit is °C.
- Melt viscosity ICI melt viscosity (150°C) is measured by the cone plate method, and the unit is Pa·s.

・GPC (Gel Per Emission Chromatography) Analysis Manufacturer: Waters
Equipment: Alliance Waters e2695
Column: Guard column SHODEX GPC KF-601 (2), KF-602 KF-602.5, KF-603
Flow rate: 1.23 ml/min.
Column temperature: 25°C
Solvent used: THF (tetrahydrofuran)
Detector: RI (differential refraction detector)

・Sulfur content analysis (combustion method)
[Thermal decomposition process]
Equipment Manufacturer: Thermo SCIENTIFIC Combustion ion chromatography system (thermal decomposition conditions)
Combustion temperature 1000°C, 15 minutes keep Gas flow rate Ar 200ml/min O ₂ 400ml/min
0.05 g of sample
(decomposition gas absorption liquid)
Phosphate ion standard solution 1000ppm 1mL
_{H2O2 30} % 0.05 mL
Dilute with water and adjust to 500 mL [Ion chromatography process of absorption liquid]
Equipment: Dionex Integration HPLC
Guard column Dinonex Ionpac AS12A (4 x 50 mm)
Column: Dionex Ion Pac AS12A (4 x 200mm)
Suppressor Dionex ADRS 600 (4mm)
Eluent: sodium carbonate/sodium hydrogen carbonate mixed solution Detector: CD (conductivity detector)

・Ion chromatography of extracted water 8 g of a sample was immersed in pure water and extracted for 20 hours at 95°C, and the extracted water was measured by ion chromatography.
Equipment: Dionex Integration HPLC
Guard column Dinonex Ionpac AS12A (4 x 50 mm)
Column: Dionex Ion Pac AS12A (4 x 200mm)
Suppressor Dionex ADRS 600 (4mm)
Eluent: sodium carbonate/sodium hydrogen carbonate mixed solution Detector: CD (conductivity detector)

[Synthesis Example 1]
333 parts by weight of phenol and 0.5 part of concentrated hydrochloric acid were placed in a flask equipped with a stirrer, a reflux condenser, and a stirring device, stirred and dissolved, and then heated while blowing nitrogen to keep the temperature at 70°C. 240 parts by weight of 4'-bischloromethylbiphenyl was continuously added over 4 hours. After the addition was completed, the reaction was carried out at the same temperature for an additional 2 hours and at 80° C. for an additional 2 hours. After completion of the reaction, excess phenol was distilled off under heating and reduced pressure to obtain 304 parts by weight of phenol resin (P1). The resulting phenol resin had a residual phenol content of 0.15%, a softening point of 133° C., and an ICI melt viscosity at 150° C. of 0.12 Pa·s. Analysis by gel permeation chromatography confirmed that n = 1 was 40.5 area% (UV-254 nm)

[Synthesis Example 2]
693 parts by weight of phenol, 0.006 parts by weight of p-toluenesulfonic acid, and 75 parts by weight of sodium carbonate were charged into a flask equipped with a stirrer, a reflux condenser, and a stirring device, stirred and dissolved, and then heated while blowing nitrogen. While maintaining the temperature at 105° C., 799 parts by weight of 4,4′-bischloromethylbiphenyl was continuously added over 4 hours. After the addition was completed, the reaction was further carried out at the same temperature for 1.5 hours. After completion of the reaction, 11.7 parts by weight of sodium tripolyphosphate was added and stirred for 30 minutes. Excess phenol was distilled off under heating and reduced pressure to obtain 1080 parts by weight of phenol resin (P2). The resulting phenol resin had a residual phenol content of 0.01%, a softening point of 86.2°C, and an ICI melt viscosity at 150°C of 0.53 Pa·s. Analysis by gel permeation chromatography confirmed that n = 1 was 24.5 area% (UV-254 nm)

[Example 1]
475 parts by weight of epichlorohydrin, 143 parts by weight of dimethyl sulfoxide, 0.76 parts by weight of dimethyl sulfide, and 0.06 parts by weight of dimethyl disulfide are added to 200 parts by weight of the phenolic resin (P1) obtained in Synthesis Example 1 in a reaction vessel. After charging, stirring and dissolution in a nitrogen atmosphere, 42 parts by weight of flaky sodium hydroxide was continuously added over 2 hours while maintaining the temperature at 45°C. After the addition of sodium hydroxide was completed, the reaction was further carried out at 45° C. for 2 hours and at 70° C. for 1 hour. After repeated washing with water to remove by-product salts and the like, excess epichlorohydrin and the like were distilled off from the oil layer under heating and reduced pressure, and 512 parts by weight of methyl isobutyl ketone was added to the residue to dissolve it. This methyl isobutyl ketone solution was heated to 70° C., 20 parts by weight of a 30% aqueous sodium hydroxide solution was added, reacted for 1 hour, and then the reaction solution was washed with water repeatedly until the washing solution became neutral. Then, methyl isobutyl ketone was distilled off from the oil layer under heating and reduced pressure to obtain 220 parts by weight of an epoxy resin mixture (EP1). The epoxy equivalent of the resulting epoxy resin mixture was 276 g/eq. , a softening point of 57.9° C., and an ICI melt viscosity of 0.09 Pa·s (150° C.). It was confirmed that the sulfur content in the epoxy resin (EP1) was 24 ppm by quantification by the combustion method. Analysis by gel permeation chromatography confirmed that n=1 was 32.93 area % (UV-254 nm). Furthermore, as a result of ion chromatography of extracted water (extracted at 95° C.), it was confirmed that the quantitative value of sulfide ions was <1 ppm.

[Example 2]
381 parts by weight of epichlorohydrin, 95.3 parts by weight of dimethyl sulfoxide, 0.65 parts by weight of dimethyl sulfide, and 0.78 parts by weight of dimethyl disulfide are added to 200 parts by weight of the phenolic resin (P2) obtained in Synthesis Example 2. After charging into a reaction vessel and stirring and dissolving in a nitrogen atmosphere, 34.6 parts by weight of flaky sodium hydroxide was continuously added over 2 hours while maintaining the temperature at 45°C. After the addition of sodium hydroxide was completed, the reaction was further carried out at 45° C. for 2 hours and at 70° C. for 1 hour. After repeated washing with water to remove by-product salts and the like, excess epichlorohydrin and the like were distilled off from the oil layer under heating and reduced pressure, and 444 parts by weight of methyl isobutyl ketone was added to the residue to dissolve it. This methyl isobutyl ketone solution was heated to 70° C., 8.2 parts by weight of a 30% aqueous sodium hydroxide solution was added, reacted for 1 hour, and then the reaction solution was washed with water repeatedly until the washing solution became neutral. Then, methyl isobutyl ketone was distilled off from the oil layer under heating and reduced pressure to obtain 222 parts by weight of an epoxy resin mixture (EP2). The epoxy equivalent of the resulting epoxy resin mixture was 292 g/eq. , a softening point of 69° C., and an ICI melt viscosity of 0.31 Pa·s (150° C.). The sulfur content in the epoxy resin (EP2) was 52 ppm as determined by combustion method. Analysis by gel permeation chromatography confirmed that n=1 was 22.1 area % (UV-254 nm). Furthermore, as a result of ion chromatography of extracted water (extracted at 95° C.), it was confirmed that the quantitative value of sulfide ions was <1 ppm.

[Example 3]
381 parts by weight of epichlorohydrin, 95.3 parts by weight of dimethyl sulfoxide, 0.59 parts by weight of dimethyl sulfide, and 0.04 parts by weight of dimethyl disulfide are added to 200 parts by weight of the phenolic resin (P2) obtained in Synthesis Example 2. After charging into a reaction vessel and stirring and dissolving in a nitrogen atmosphere, 34.6 parts by weight of flaky sodium hydroxide was continuously added over 2 hours while maintaining the temperature at 45°C. After the addition of sodium hydroxide was completed, the reaction was further carried out at 45° C. for 2 hours and at 70° C. for 1 hour. After repeated washing with water to remove by-product salts and the like, excess epichlorohydrin and the like were distilled off from the oil layer under heating and reduced pressure, and 444 parts by weight of methyl isobutyl ketone was added to the residue to dissolve it. This methyl isobutyl ketone solution was heated to 70° C., 8.2 parts by weight of a 30% aqueous sodium hydroxide solution was added, reacted for 1 hour, and then the reaction solution was washed with water repeatedly until the washing solution became neutral. Then, methyl isobutyl ketone was distilled off from the oil layer under heating and reduced pressure to obtain 215 parts by weight of epoxy resin (EP3). The epoxy equivalent of the obtained epoxy resin was 296 g/eq. , a softening point of 69.8° C., and an ICI melt viscosity of 0.33 Pa·s (150° C.). The sulfur content in the epoxy resin (EP3) was 19 ppm as determined by combustion method. Analysis by gel permeation chromatography confirmed that n=1 was 20.2 area % (UV-254 nm). Furthermore, as a result of ion chromatography of extracted water (extracted at 95° C.), it was confirmed that the quantitative value of sulfide ions was <1 ppm.

[Comparative Example 1]
218 parts by weight of epoxy resin (EP4) was obtained by synthesizing in the same manner as in Example 2 except that dimethylsulfide and dimethyldisulfide were changed to 0 parts by weight. The epoxy equivalent of the resulting epoxy resin mixture was 289 g/eq. , a softening point of 67.1° C. and an ICI melt viscosity of 0.24 Pa·s (150° C.). The sulfur content in the epoxy resin (EP4) was less than 5 ppm as determined by combustion method. Analysis by gel permeation chromatography confirmed that n=1 was 21.5 area % (UV-254 nm). Furthermore, as a result of ion chromatography of extracted water (extracted at 95° C.), it was confirmed that the quantitative value of sulfide ions was <1 ppm.

[Comparative Example 2]
381 parts by weight of epichlorohydrin, 45 parts by weight of dimethyl sulfoxide, and 5 parts by weight of butanol are added to 200 parts by weight of the phenolic resin (P2) obtained in Synthesis Example 2 in a reaction vessel. While maintaining the temperature at 45° C., 39 parts by weight of flaky sodium hydroxide was continuously added over 2 hours. After the addition of sodium hydroxide was completed, the reaction was further carried out at 45° C. for 2 hours and at 70° C. for 1 hour. After repeated washing with water to remove by-product salts and the like, excess epichlorohydrin and the like were distilled off from the oil layer under heating and reduced pressure, and 444 parts by weight of methyl isobutyl ketone was added to the residue to dissolve it. This methyl isobutyl ketone solution was heated to 70° C., 10 parts by weight of a 30% aqueous sodium hydroxide solution was added, and the mixture was allowed to react for 1 hour. After that, the reaction solution was washed with water repeatedly until the washing solution became neutral. Then, methyl isobutyl ketone was distilled off from the oil layer under heating and reduced pressure to obtain 211 parts by weight of epoxy resin (EP5). The epoxy equivalent of the obtained epoxy resin was 312 g/eq. , a softening point of 66.9° C., and an ICI melt viscosity of 0.25 Pa·s (150° C.). The sulfur content in the epoxy resin (EP5) was less than 5 ppm as determined by combustion method. Analysis by gel permeation chromatography confirmed that n=1 was 21.4 area % (UV-254 nm). Furthermore, as a result of ion chromatography of extracted water (extracted at 95° C.), it was confirmed that the quantitative value of sulfide ions was <1 ppm.

[Examples 4, 5, 6 Comparative Example 3]
Epoxy resins (EP1, EP2, EP3) and a comparative epoxy resin (EP5) are used as main agents, respectively, phenol novolak (abbreviation; PN, hydroxyl equivalent 106 g / eq.) as a curing agent, and triphenylphosphine (abbreviation; TPP) was used to blend at the weight ratio shown in Table 1, kneaded with two rolls, tableted, prepared a resin molded body by transfer molding, and cured at 160 ° C. for 2 hours and further at 180 ° C. for 6 hours. Cured under conditions.

The physical properties were measured under the following conditions.
・3-point bending test manufacturer: A&D Co., Ltd. Equipment: RTG-1310
Test speed: 3mm/min
Distance between fulcrums: 64 mm
Measurement temperature 30℃
FIG. 1 shows the stress-strain diagram when the three-point bending test was performed.

[Examples 7, 8, 9 Comparative Example 4]
Epoxy resins (EP1, EP2, EP3) and comparative epoxy resin (EP5) are used as main agents, respectively, phenol novolak (abbreviation; PN, hydroxyl equivalent 103 g / eq.) as a curing agent, and triphenylphosphine (abbreviation; TPP) was used to blend at the weight ratio shown in Table 2, kneaded with two rolls, tableted, and a resin molded body was prepared by transfer molding, and cured at 160 ° C. for 2 hours and further at 180 ° C. for 6 hours. Cured under conditions.

The physical properties were measured under the following conditions.
・3-point bending test manufacturer: A&D Co., Ltd. Equipment: RTG-1310
Test speed: 3mm/min
Distance between fulcrums: 64 mm
Measurement temperature 120℃
FIG. 2 shows the stress-strain diagram when the three-point bending test was performed.

From the results in Table 1 and Figure 1, it was confirmed that Examples 4-6 had excellent maximum point stress and strain at 30°C. Furthermore, it was confirmed from the results in Table 2 and FIG. 2 that Examples 7 and 8 had excellent maximum point stress and strain at 120.degree. In particular, it was confirmed that Examples 5 and 7, which contained a large amount of sulfur, had particularly excellent maximum point stress and strain at both 30°C and 120°C.

That is, it was confirmed that the epoxy resin mixture of the present invention can give a cured product exhibiting excellent mechanical strength and toughness at room temperature and high temperature.

The present invention provides insulating materials for electric and electronic parts (such as highly reliable semiconductor sealing materials), laminates (printed wiring boards, build-up boards, etc.), various composite materials such as FRP, adhesives, paints, etc., among others. It is useful for applications such as laminates, metal foil-clad laminates, insulating materials for build-up substrates, flexible substrate materials, and the like.

Claims (4)

An epoxy resin mixture containing an epoxy resin represented by the following formula (1) and having a sulfur content of 15 ppm to 400 ppm by a combustion method.

(In formula (1), n is the number of repetitions and represents a real number from 1 to 20.) An epoxy resin mixture obtained by reacting a phenol resin represented by the following formula (2), epichlorohydrin, and a sulfur-containing compound.

(In formula (2), n is the number of repetitions and represents a real number from 1 to 20.) An epoxy resin composition comprising the epoxy resin mixture according to claim 1 or 2 and a curing agent. A cured product obtained by curing the epoxy resin composition according to claim 3 .

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