JP2011207932A - Epoxy resin and epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-purity epoxy resin produced by using an epihalohydrin, and having the extremely reduced total halogen content.SOLUTION: The epoxy resin is obtained by the reaction of an active hydrogen compound with the epihalohydrin, and has ≤80 wt.ppm of the total halogen content. The epoxy resin obtained by the reaction of the active hydrogen compound with the epihalohydrin is purified by a sublimation method, a distillation method, a crystallization method or an alkali cleaning method. The epoxy resin can provide a high-reliability epoxy resin-cured product useful as an electric or electronic material such as various kinds of insulation materials and laminated sheets, and hardly having problems of elution of the halogen.

Description

  The present invention relates to an epoxy resin having a significantly reduced total halogen content and an epoxy resin composition using the epoxy resin.

  Epoxy resins are used in a wide range of fields such as adhesion, casting, sealing, lamination, molding, and painting because of their excellent cured properties and ease of handling.

  As an epoxy resin production method, an epoxy resin production method using epihalohydrin is widely used industrially as the most general epoxy resin production method. However, the epoxy resin produced by this method is a multi-component mixture containing various impurities. Most of these impurities are brought in from the raw material of the epoxy resin, or are generated by a side reaction in the manufacturing process and remain in the resin.

  However, it is desired that an epoxy resin used for sealing or bonding particularly electrical and electronic parts has few impurities. In other words, it is known that impurities in the epoxy resin have adverse effects such as lowering the electrical insulation and heat resistance of the cured product and corroding lead wires, etc. In particular, ionic impurities such as halogen compounds are In the past, efforts have been made to eliminate this as much as possible. In addition, in order to reduce the generation of harmful substances such as dioxins during incineration, the demand for low halogen has become stricter.

  As an epoxy resin with few ionic impurities, an epoxy resin obtained by reaction of 3,3 ′, 5,5′-tetramethylbiphenyl and epihalohydrin (referred to as “tetramethylbiphenyl type epoxy resin” in this specification) It has been known. Tetramethylbiphenyl type epoxy resin is widely used as a resin for semiconductor encapsulation due to its excellent characteristics such as high heat resistance, low melt viscosity, low stress, high adhesion, and low moisture absorption. Usually about 1000 ppm by weight.

  For this reason, attempts have been made to further reduce the ionic impurities of the tetramethylbiphenyl type epoxy resin, and the total halogen content is about 300 ppm by weight by including alkali cleaning in the manufacturing process (Patent Document 1). ) Has been developed and industrially produced.

JP 2006-257445 A

  However, in recent years, as the degree of integration of semiconductor integrated circuits has increased, the purity required for semiconductor sealing resins has been increasing, and epoxy resins having a total halogen content of about 300 ppm by weight cannot meet the requirements. It is.

  The present invention has been made in view of the above-described conventional situation, and provides a high-purity epoxy resin and an epoxy resin composition, which are epoxy resins manufactured using epihalohydrin, in which the total halogen content is remarkably reduced. The task is to do.

As a result of intensive studies to solve the above problems, the present inventors have found that an epoxy resin satisfying a specific condition can solve the above problems, and have completed the present invention.
That is, the gist of the present invention is as follows.

[1] An epoxy resin obtained by a reaction between an active hydrogen compound and epihalohydrin and having a total halogen content of 80 ppm by weight or less.

[2] The epoxy resin according to [1], which is produced through a step of sublimating an epoxy resin obtained by a reaction between an active hydrogen compound and an epihalohydrin.

[3] The epoxy resin according to [1] or [2], which is produced through a step of distilling an epoxy resin obtained by a reaction between an active hydrogen compound and an epihalohydrin.

[4] The epoxy resin according to any one of [1] to [3], which is produced through a step of crystallizing an epoxy resin obtained by a reaction between an active hydrogen compound and epihalohydrin.

[5] The epoxy resin according to any one of [1] to [4], which is produced through a step of alkali-washing an epoxy resin obtained by a reaction between an active hydrogen compound and epihalohydrin.

[6] An epoxy resin composition comprising the epoxy resin according to any one of [1] to [5] and a curing agent for epoxy resin, wherein the inorganic halogen concentration measured by the following dissolution test is 10 ppm by weight or less.

<Dissolution test>
To the cured powder obtained by pulverizing the cured epoxy resin composition into a 20 mesh pass, 10 times the amount of purified water is added and left at 180 ° C. for 20 hours, and then the inorganic halogen concentration in the water is adjusted. taking measurement.

ADVANTAGE OF THE INVENTION According to this invention, the highly purified epoxy resin and epoxy resin composition which are reliable as electrical and electronic materials, such as various insulating materials and a laminated board, are provided.
According to the epoxy resin of the present invention in which the total halogen content is remarkably reduced, an epoxy resin composition having extremely low halogen and excellent electrical performance can be obtained.

The epoxy resin of the present invention is also useful as a raw material for producing an epoxy resin by a two-stage method, and gives a polymer epoxy resin having extremely low halogen and excellent electrical performance.
The epoxy resin of the present invention is also useful as a material for semiconductor sealing devices, and can solve the problem of low electrical reliability caused by the halogen content of the sealing material in the semiconductor sealing field. .
The epoxy resin of the present invention can also be suitably used for solder resists for printed wiring boards or for interlayer insulation by combining with unsaturated group-containing polycarboxylic acids. Epoxy resins used in these fields The problem of low electrical reliability due to the halogen content of can be solved.
The epoxy resin of the present invention is also useful as a die bonding material, and can solve the problem of low electrical reliability caused by the halogen content of the epoxy resin used in this field.
The epoxy resin of the present invention is also useful as a material for printed wiring boards such as multilayer electrical laminates and build-up methods, and solves migration problems caused by halogen impurities contained in conventional epoxy resins. can do.

  The epoxy resin of the present invention is also useful in the fields of adhesives for metal core laminates, electrical / electronic parts such as underfill materials, adhesive films, optical films for display members, protective films, sealing films, etc. In any field, problems caused by halogen impurities in epoxy resins can be solved.

It is a schematic diagram explaining the buildup method.

  Hereinafter, embodiments of the present invention will be described in detail.

[Epoxy resin]
<Reaction of active hydrogen compound with epihalohydrin>
The epoxy resin of the present invention is an epoxy resin obtained by a reaction between an active hydrogen compound and epihalohydrin.

  As an epoxy resin included in the present invention, for example, the following reaction (1) to (5) such as phenolic compounds, alcoholic compounds, carboxylic acids, amine compounds, or thiols, which are active hydrogen compounds, and epihalohydrin However, the epoxy resin obtained by the above method is not limited thereto.

(1) Bisphenol A, bisphenol F, bisphenol E, bisphenol Z, bisphenol S, bisphenol AD, bisphenol acetophenone, bisphenol trimethylcyclohexane, bisphenol fluorene, tetramethyl bisphenol A, tetramethyl bisphenol F, tetra-t-butyl bisphenol A, tetra Methyl bisphenol S, biphenol, tetramethyl biphenol, tetra-t-butyl biphenol, hydroquinone, methyl hydroquinone, dibutyl hydroquinone, dihydroanthrahydroquinone, resorcin, methyl resorcin, dihydroxy diphenyl ether, thiodiphenols, dihydroxy naphthalene, dihydroxy stilbene, phenol Novolac resin, Kure Various phenols such as ur novolak resin, bisphenol A novolak resin, naphthol novolak resin, phenol aralkyl resin, terpene phenol resin, dicyclopentadiene phenol resin, phenol biphenylene resin, phenol modified xylene resin, various phenols, and hydroxybenzaldehyde Various phenolic compounds such as polyhydric phenol resins obtained by condensation reaction with various aldehydes such as crotonaldehyde and glyoxal, co-condensation resins of heavy oil or pitches with phenols and formaldehydes, Epoxy resins produced from epihalohydrin and epoxy resins in which hydrogen is added to the aromatic ring of these epoxy resins

(2) Methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, isobutanol, t-butanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol 1,8-octanediol, 1,10-decanediol, 2,2-dimethyl-1,3-propanediol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polypentamethylene glycol, polyhexamethylene glycol, 1 , 4-cyclohexanedimethanol, glycerin, diglycerin, trimethylolpropane, dextrose, sorbitol, mannitol, pentaerythritol, polyethylene glycol, polypropylene Glycol, polytetramethylene glycol, water-contained bisphenol A, and various alcohol compounds of such as water-contained bisphenol F, epoxy resins produced from an epihalohydrin

(3) Manufactured from various carboxylic acids such as adipic acid, succinic acid, phthalic acid, tetrahydrophthalic acid, methylhexahydrophthalic acid, terephthalic acid, isophthalic acid, orthophthalic acid, biphenyldicarboxylic acid, dimer acid, and epihalohydrin Epoxy resin

(4) Epoxy resins produced from various amine compounds such as diaminodiphenylmethane, aminophenol, xylenediamine, and epihalohydrin

(5) Various compounds such as 3-methoxybutyl-3 mercaptopropionate, methylthioglycosylate, 1-butanethiol, 1,4-butanethiol, benzenethiol, benzyl mercaptan, 1,3,5-trimercaptomethylbenzene Epoxy resin manufactured from thiols and epihalohydrin

  The reaction between the active hydrogen compound and epihalohydrin can be carried out by a known method, and typical embodiments are described in detail below.

  First, the active hydrogen compound is dissolved in an amount of epihalohydrin corresponding to 3 to 20 moles per mole of active hydrogen groups to obtain a uniform solution. Next, while stirring the solution, an alkali metal hydroxide in an amount of 0.9 to 2 mol per mol of active hydrogen groups is added to the solution as a solid or an aqueous solution and reacted. This reaction can be carried out under normal pressure or reduced pressure, and the reaction temperature is usually about 30 to 105 ° C. in the case of reaction under normal pressure and about 30 to 80 in the case of reaction under reduced pressure. ° C. During the reaction, the reaction liquid is azeotroped while maintaining a predetermined temperature as necessary, and the condensate obtained by cooling the vaporized vapor is separated into oil / water, and the oil component excluding moisture is added to the reaction system. The reaction system is dehydrated by the returning method. Addition of the alkali metal hydroxide is intermittently or continuously added little by little over 1 to 8 hours in order to suppress a rapid reaction. The total reaction time is usually about 1 to 10 hours.

  After completion of the reaction, the insoluble by-product salt is removed by filtration or removed by washing with water, and then the unreacted epihalohydrin is removed by distillation under reduced pressure to obtain the desired epoxy resin.

  Epichlorohydrin or epibromohydrin is usually used as the epihalohydrin in this reaction, and sodium hydroxide or potassium hydroxide is usually used as the alkali metal hydroxide.

  In this reaction, quaternary ammonium salts such as tetramethylammonium chloride and tetraethylammonium bromide; tertiary amines such as benzyldimethylamine and 2,4,6- (trisdimethylaminomethyl) phenol; 2-ethyl Catalysts such as imidazoles such as -4-methylimidazole and 2-phenylimidazole; phosphonium salts such as ethyltriphenylphosphonium iodide; phosphines such as triphenylphosphine may be used.

  Furthermore, in this reaction, alcohols such as methanol, ethanol, propanol, isopropanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol; acetone, methyl ethyl ketone, methyl isobutyl ketone, Ketones such as cyclopentanone, cyclohexanone, 2-pentanone; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether Aromatics such as benzene, xylene and toluene; aromatics such as benzyl alcohol Examples include alcohols; glycol ether acetates such as ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate; ethers such as 1,3-dioxane, 1,4-dioxane, diethyl ether and tetrahydrofuran; Alternatively, a plurality of types can be mixed and used.

<Total halogen content>
The epoxy resin of the present invention is obtained by the reaction of the active hydrogen compound and epihalohydrin as described above, and has a total halogen content of 80 ppm by weight or less.
If the total halogen content of the epoxy resin exceeds 80 ppm by weight, the object of the present invention of providing a high purity epoxy resin cannot be achieved. The total halogen content of the epoxy resin is preferably as low as possible, preferably 50 ppm by weight or less, more preferably 30 ppm by weight or less.

  However, as an epoxy resin obtained by reaction of an active hydrogen compound and epihalohydrin, the lower limit of the total halogen content is usually 1 ppm by weight.

  The total halogen content referred to in the present invention is represented by the following (formula 1) called 1,2-halohydrin which is known to be by-produced in the reaction step of the above-mentioned active hydrogen compound and epihalohydrin. A compound, a compound represented by the following (formula 2) referred to as a 1,3-halohydrin compound, a compound represented by the following (formula 3) referred to as a halomethyl body, and further generated by an unknown side reaction It means the total content of halogens contained in all forms in the epoxy resin, including organic halogens in the above compounds.

The total halogen content in the epoxy resin can be measured, for example, by the following method.
That is, in an epoxy resin produced using epichlorohydrin as an epihalohydrin, since halogen in the epoxy resin is chlorine derived from epichlorohydrin, it can be measured using a total chlorine analyzer. However, in the examples described later, the total chlorine content was determined based on a calibration curve prepared in advance by a total chlorine analyzer and fluorescent X-ray analysis.

  Further, when epibromohydrin is used as the epihalohydrin, the halogen in the epoxy resin is bromine derived from epibromohydrin, and therefore, it can be measured using a total halogen analyzer.

  Hereinafter, the epoxy resin of the present invention having a total halogen content of 80 ppm by weight or less may be referred to as a “low halogen epoxy resin”.

<Reduction of total halogen content>
Since the total halogen content of the epoxy resin obtained by the reaction of the active hydrogen compound and epihalohydrin is usually 1000 to 50000 ppm by weight or more, in the present invention, in order to achieve the total halogen content described above, The epoxy resin obtained by the reaction between the active hydrogen compound and epihalohydrin is subjected to a treatment for reducing the total halogen content. The treatment operation for reducing the total halogen content may be a general purification method as long as it is a method capable of reducing the total halogen content in the epoxy resin obtained by the reaction of the active hydrogen compound and epihalohydrin, Specific examples include, but are not limited to, a sublimation method, a distillation method, a crystallization method (synonymous with recrystallization in the present invention), and an alkali cleaning method.

A) Sublimation method The sublimation method is a method in which an epoxy resin is heated in vacuum and the sublimated components are cooled and recovered. The sublimation temperature in the sublimation tube is 120 to 180 ° C., and the degree of vacuum is 1.0 ×. The low halogen epoxy resin can be recovered as a sublimation component by setting the collection part to room temperature at about 10 ⁻² to 10 ⁻⁵ Pa.

B) Distillation method The distillation method is a method of obtaining a high-purity low-halogen epoxy resin by distilling an epoxy resin and removing a polymer compound, an inorganic compound, or the like. The specific operation is not particularly specified, but includes batch distillation using a distillation kettle, continuous distillation using a rotary evaporator, etc., thin film molecular distillation such as a disk type and a falling film type.
The distillation conditions are such that the total halogen content of the produced epoxy resin falls within a predetermined range. Actual conditions vary depending on the quality of the epoxy resin at the end of the reaction process, the boiling point of impurities to be removed, etc. The temperature is 120 ° C. to 240 ° C., preferably 140 ° C. to 200 ° C., the residence time is 30 minutes to 5 hours for batch distillation, 0.5 minutes to 10 minutes for continuous distillation, and the pressure is 0.01 to 2000 Pa. It is. If this temperature is too high or the pressure is too low, the purity of the final product will be reduced. Conversely, if the temperature is too low or the pressure is too high, the yield will be reduced.

C) Crystallization Method Crystallization is a method in which a crystalline epoxy resin is dissolved in a solvent and the temperature of the solution is slowly lowered to precipitate out pure crystals. In some cases, seed crystals are added during the temperature decrease. Thus, the yield can be improved.
The solvent that can be used in the crystallization method (hereinafter sometimes referred to as “crystallization solvent”) is not particularly limited as long as it dissolves the crystalline epoxy resin. Methanol, ethanol, propanol, isopropanol, n- Alcohols such as propanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol; hydrocarbons such as pentane, hexane, heptane; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, 2- Ketones such as pentanone; glycols such as ethylene glycol, diethylene glycol, propylene glycol and tripropylene glycol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol Glycol ethers such as ethylene monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether; aromatics such as benzene, xylene and toluene; aromatic alcohols such as benzyl alcohol; ethylene glycol monomethyl ether Glycol ether acetates such as acetate and propylene glycol monomethyl ether acetate; Lactones such as γ-butyrolactone; Ethers such as 1,3-dioxane, 1,4-dioxane, diethyl ether and tetrahydrofuran; Dimethylformamide, dimethyl sulfoxide, N -Aprotic polar solvents such as methylpyrrolidone and dimethylacetamide; Can be used as a mixture of plural kinds. Examples of mixed solvent combinations include glycols and alcohols, glycols and ketones, glycols and glycol ethers, glycols and ethers, hydrocarbons and aromatics, alcohols and aromatic alcohols, alcohol And ketones, ethers and cellosolves, ethers and glycol ether acetates, ethers and furans, ketones and glycol ethers, ketones and ethers, ketones and aprotic polar solvents, aprotic And a combination of aprotic polar solvents and glycols, aprotic polar solvents and alcohols, aprotic polar solvents and glycol ethers, aprotic polar solvents and ethers, and the like.

In the crystallization method, the concentration of the epoxy resin when dissolving the epoxy resin in the crystallization solvent, the heating temperature at that time, and the cooling temperature when precipitating the crystals are such that a high-purity epoxy resin can be obtained with high crystallization efficiency. Depending on the type and purity of the epoxy resin used for crystallization, the type of solvent used, etc., the concentration of the epoxy resin in dissolving the epoxy resin in the crystallization solvent is 10 to 80% by weight, particularly 20 It is preferable to set it to -60 weight%.
The heating temperature for dissolving the epoxy resin in the crystallization solvent is 30 ° C. to 180 ° C., particularly 50 ° C. to 150 ° C., and then the cooling temperature for crystal precipitation is −50 ° C. to 100 ° C. It is preferable that the temperature be about 10 to 100 ° C. lower than the heating temperature at which the epoxy resin is dissolved at -20 ° C. to 80 ° C., because it is excellent in crystallization efficiency and purity improvement effect by crystallization.

  Such a crystallization operation may be performed in an air atmosphere, but is preferably performed in an inert gas atmosphere such as nitrogen gas in order to suppress generation of impurities due to oxidation.

  Such a crystallization operation is not limited to one time, and may be performed a plurality of times. In a case where the crystallization operation is performed a plurality of times, it is preferably performed about 2 to 10 times in view of the balance between the number of operations and the purity improvement effect by crystallization.

D) Alkali cleaning method In the alkali cleaning method, first, an epoxy resin is dissolved in a solvent, an alkali (basic compound) is added to the resulting epoxy resin solution, then the substrate is washed with water, and then the solvent is removed. Thus, a purified epoxy resin is obtained.

  Examples of the solvent used for dissolving the epoxy resin by the alkali cleaning method include one or more of those exemplified as the crystallization solvent used in the crystallization method described above, and the same applies to examples of the mixed solvent. .

The concentration of the epoxy resin in the epoxy resin solution is preferably 10 to 80% by weight, more preferably 20 to 60% by weight.
The basic compound is diluted with a solid, an aqueous solution or an organic solvent and added to the epoxy resin solution. After adding the basic compound to the epoxy resin solution, it is treated at a temperature of about 30 to 120 ° C. for 0.5 to 8 hours.
As the basic compound, sodium hydroxide or potassium hydroxide is usually used. The amount of the basic compound used is 0.5 to 50 mol times, preferably 1.0 to 20.0 mol times, based on the total halogen content in the epoxy resin.

It is important for the stabilization of the quality of the resulting low halogen epoxy resin to stop the reaction immediately after the treatment with the basic compound. Examples of the method for stopping the reaction include rapidly decreasing the temperature; diluting the solution with an inert solvent; neutralizing the alkali with an acid; adding excess water; and the like. Since the reaction can be surely stopped by the simplest operation, a method of adding excess water is preferable.
The amount of water for stopping the reaction is preferably 0.1 times (weight) or more of the total reaction mixture.

  After the reaction is stopped, water-soluble impurities such as excess basic compounds and by-product salts are removed by washing with water. This water washing operation can be performed in the same manner as a washing operation generally used for removing water-soluble impurities. At the time of washing with water, the concentration of the epoxy resin in the solvent which is not mixed with water is preferably about 5 to 80% by weight, more preferably 10 to 50% by weight. In the washing operation, 0.1 to 10 times (by weight) of purified water is added to the total amount of the epoxy resin solution, and after sufficiently stirring and mixing, the mixture is allowed to stand and be separated to remove the aqueous layer. Is done. The temperature at this time is generally 30 to 120 ° C. By repeating this operation 2 to 10 times, the ion concentration in the epoxy resin can be reduced. At this time, in order to neutralize the excess basic compound, a weak acid such as phosphoric acid, sodium phosphate, oxalic acid, acetic acid or carbonic acid may be added to the washing water.

  After the washing with water, a low halogen epoxy resin can be obtained by evaporating and removing the solvent from the organic layer.

  In each of the purification methods (A) to (D), any one purification method may be performed once or a plurality of times, or a plurality of purification methods may be combined. In that case, one purification method may be performed only once or multiple times.

<Epoxy equivalent>
Although there is no restriction | limiting in particular in the epoxy equivalent of the epoxy resin of this invention, 80-1000 g / eq. It is preferable that it is a grade.

[Epoxy resin composition]
The epoxy resin composition of the present invention contains the above-described epoxy resin of the present invention and an epoxy resin curing agent.

<Curing agent for epoxy resin>
There is no restriction | limiting in particular in the hardening | curing agent for epoxy resins mix | blended as an essential component with the epoxy resin composition of this invention, The hardening | curing agent for general epoxy resins can be used.

  For example, polyfunctional phenols, amines, acid anhydrides, unsaturated group-containing polycarboxylic acids, thiols, and a curing agent that initiates polymerization of epoxy groups can be used.

  Examples of polyfunctional phenols include bisphenol A, bisphenol F, bisphenol AD, tetramethyl bisphenol A, tetramethyl bisphenol F, tetra-t-butyl bisphenol A, tetramethyl bisphenol S, biphenol, tetramethyl biphenol, tetra-t. -Butylbiphenol, hydroquinone, resorcin, methylresorcin, tetramethylbiphenol, dihydroxynaphthalene, dihydroxydiphenyl ether, thiodiphenols, phenol novolac resin, cresol novolac resin, phenol aralkyl resin, terpene phenol resin, dicyclopentadiene phenol resin, bisphenol A Various types such as novolak resin, naphthol novolak resin, phenol biphenylene resin Polyhydric phenols, polyhydric phenol resins obtained by condensation reaction of various phenols with various aldehydes such as benzaldehyde, hydroxybenzaldehyde, crotonaldehyde, glyoxal, heavy oil or pitches, phenols and formaldehyde Various phenol resins such as co-condensation resins with styrene.

  Examples of amines include aliphatic primary, secondary, tertiary amines, aromatic primary, secondary, tertiary amines, cyclic amines, guanidines, urea derivatives, etc., specifically, triethylene Tetramine, diaminodiphenylmethane, diaminodiphenyl ether, metaxylenediamine, dicyandiamide, 1,5-diazabicyclo (5.4.0) -7-undecene, 1,5-diazabicyclo (4.3.0) -5-nonene, dimethylurea And guanylurea.

  Examples of acid anhydrides include methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, pyromellitic anhydride, methyl nadic acid, and a condensation product of maleic anhydride and an unsaturated compound.

  Examples of unsaturated group-containing polycarboxylic acids include a reaction product of a polyfunctional epoxy resin and an unsaturated group-containing monocarboxylic acid and a reaction product of a polybasic carboxylic acid anhydride.

  Examples of thiols include aliphatic polythioether type, aliphatic polythioester type, aromatic ring-containing polythioether type and the like.

Examples of the curing agent that initiates polymerization of epoxy groups include phosphine compounds such as triphenylphosphine; phosphonium salts such as tetraphenylphosphonium tetraphenylborate; 2-methylimidazole, 2-phenylimidazole, and 2-ethyl. Imidazoles such as -4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-methylimidazole, 2,4-dicyano-6- [2-methylimidazolyl- (1)]-ethyl-S-triazine; 1-cyanoethyl-2-undecylimidazolium trimellitate, 2-methylimidazolium isocyanurate, 2-ethyl-4-methylimidazolium tetraphenylborate, 2-ethyl-1,4-dimethylimidazolium tetraphenylborate Any imidazolium salt; amines such as 2,4,6-tris (dimethylaminomethyl) phenol, benzyldimethylamine; ammonium salts such as triethylammonium tetraphenylborate; 1,8-diazabicyclo (5.4.0)- Diazabicyclo compounds such as 7-undecene and 1,5-diazabicyclo (4,3,0) -5-nonene; tetraphenylborate, phenol salt, phenol novolak salt, 2-ethylhexanoate and the like of these diazabicyclo compounds. .
Further, triflic acid salts, boron trifluoride ether complex compounds, metal fluoroboron complex salts, bis (perfluoroalkylsulfonyl) methane metal salts, aryldiazonium compounds, aromatic onium salts, periodic tables IIIa to Va dicarbonyl chelates of group elements, thiopyrylium salts, MF ₆ ^- anion (wherein M is phosphorus, are selected from antimony and arsenic) form of the periodic table group VIb element, arylsulfonium complex salts, aromatic iodonium complex salts, aromatic Group sulfonium complex salts, bis [4- (diphenylsulfonio) phenyl] sulfide-bis-hexafluorometal salts (for example, phosphates, arsenates, antimonates, etc.), arylsulfonium complex salts, halogen-containing complex ion aromatic sulfoniums or An iodonium salt or the like can be used.

  These epoxy resin curing agents may be used alone or in combination of two or more.

The amount of the epoxy resin curing agent used in the epoxy resin composition of the present invention is such that, in the case of a compound having a group that reacts with an epoxy group, the total epoxy is used with respect to 1 mol of the epoxy group in all epoxy resin components. The amount that the total of the groups that react with the epoxy group in the resin curing agent component is 0.5 to 2.0 mol is preferable, and the amount that is 0.7 to 1.5 mol is more preferable.
In the case of a curing agent of the type that initiates polymerization of epoxy groups, 0.1 to 10 parts by weight is preferable, more preferably 0.3 to 5 parts by weight with respect to 100 parts by weight of the total epoxy resin in the epoxy resin composition. Part.

<Curing accelerator for epoxy resin>
The epoxy resin composition of the present invention can contain an epoxy resin curing accelerator. There is no restriction | limiting in particular as a hardening accelerator for epoxy resins, A general hardening accelerator for epoxy resins can be used.

  For example, phosphine compounds such as tributylphosphine, triphenylphosphine, tris (dimethoxyphenyl) phosphine, tris (hydroxypropyl) phosphine, tris (cyanoethyl) phosphine; tetraphenylphosphonium tetraphenylborate, methyltributylphosphonium tetraphenylborate, methyltricyanoethyl Phosphonium salts such as phosphonium tetraphenylborate; 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-methylimidazole, 2,4-dicyano-6 -[2-Methylimidazolyl- (1)]-ethyl-S-triazine, 2,4-dicyano-6- [2-undecylimidazolyl- (1) -Imidazoles such as ethyl-S-triazine; 1-cyanoethyl-2-undecylimidazolium trimellitate, 2-methylimidazolium isocyanurate, 2-ethyl-4-methylimidazolium tetraphenylborate, 1,4 -Imidazolium salts such as dimethylimidazolium tetraphenylborate; 2,4,6-tris (dimethylaminomethyl) phenol, benzyldimethylamine, tetramethylbutylguanidine, N-methylpiperazine, 2-dimethylamino-1-pyrroline, etc. Amines; ammonium salts such as triethylammonium tetraphenylborate; 1,8-diazabicyclo (5.4.0) -7-undecene, 1,5-diazabicyclo (4.3.0) -5-nonene, 1, 4-diazabicyclo (2.2 2) - diazabicyclo compounds such as octane tetraphenylborate thereof diazabicyclo compounds, phenol salts, phenol novolak salts and 2-ethylhexanoic acid salts.

  These epoxy resin curing accelerators may be used alone or in combination of two or more.

  The curing accelerator for epoxy resin is preferably blended in an amount of 0.01 to 10.0 parts by weight with respect to 100 parts by weight of the total epoxy resin in the epoxy resin composition.

<Other epoxy resins>
An epoxy resin other than the epoxy resin of the present invention can be blended in the epoxy resin composition of the present invention. The epoxy resin that can be used in combination is not particularly specified, and any epoxy resin other than the epoxy resin of the present invention can be used.

  The other epoxy resins that can be mixed are the epoxy resins (1) to (5) mentioned above as examples of various epoxy resins in the description of the epoxy resin of the present invention, and the epoxy resin of the present invention. Those that do not correspond to the above can be mentioned, and these can be used alone or in combination.

  The amount of other epoxy resins used in combination is 80% by weight or less, preferably 60% by weight or less, more preferably 50% by weight or less, based on the total amount of epoxy resin. If the combined amount of other epoxy resins is too large, the effect of using the epoxy resin of the present invention will not be sufficiently exhibited.

<Additives>
Various additives can be mix | blended with the epoxy resin composition of this invention similarly to other general epoxy resin compositions. Examples of these various additives include inorganic fillers, colorants, pigments, coupling agents, flame retardants, plasticizers, ultraviolet absorbers, antioxidants, reactive diluents, and the like. Can be blended.

Among these additives, examples of the inorganic filler include aluminum hydroxide, alumina, calcium carbonate, silica, and carbon, and examples of the colorant or pigment include titanium dioxide and molybdenum red.
A silane coupling agent, a titanate coupling agent, etc. can be used as a coupling agent.
Further, as the flame retardant, non-halogen type phosphorus-based, nitrogen-based, silicon-based flame retardant, or the like can be used.
Any of the above additives may be used alone or in combination of two or more.

<Inorganic halogen concentration>
The epoxy resin composition of the present invention is characterized in that the inorganic halogen concentration measured by the following dissolution test is 10 ppm by weight or less.

<Dissolution test>
The cured product obtained by curing the epoxy resin composition under the curing conditions of the epoxy resin composition is pulverized into a 20 mesh pass using a mill or the like, and purified to 10 times the amount by weight. Water is added and the mixture is allowed to stand at 180 ° C. for 20 hours.
When this inorganic halogen concentration exceeds 10 ppm by weight, it is not possible to provide an epoxy resin composition having a low halogen content that is the object of the present invention.

  The inorganic halogen concentration is preferably as low as possible, and is preferably 5 ppm by weight or less. The lower limit of the inorganic halogen concentration is not particularly limited, but the lower limit of the inorganic halogen concentration of the epoxy resin composition using the epoxy resin of the present invention obtained by the reaction of an active hydrogen compound and epihalohydrin is usually 0.8. About 1 ppm by weight.

[Usage]
The epoxy resin of the present invention has an extremely low total halogen content which has not been conventionally used, and can be used for various applications. When this epoxy resin is used as a main component, it has extremely low halogen and electric performance. An excellent epoxy resin composition is provided.
The epoxy resin of the present invention is also useful as a raw material for producing an epoxy resin by a two-stage method as described in JP-A-2006-36801, and is a polymer having extremely low halogen and excellent electrical performance. Give epoxy resin.

  Therefore, these epoxy resins are useful in the field of electrical / electronic related members, and provide highly reliable materials.

<Semiconductor sealing material>
The epoxy resin of the present invention is useful as a sealing material for semiconductor sealing devices. The semiconductor chip to be sealed is not particularly limited, for example, an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, or the like, and the form of the semiconductor package is not particularly limited.
As a general method of sealing, a low-pressure transfer molding method can be mentioned, but sealing can also be performed by injection molding, compression molding, casting, potting, or the like. In this field, the low electrical reliability due to the halogen content of the epoxy resin used in the past has been a problem. The low halogen epoxy resin of the present invention can solve this problem. it can.

<Solder resist for printed wiring boards and materials for interlayer insulation layers>
The epoxy resin of the present invention is suitable for use as a solder resist for printed wiring boards or as an interlayer insulation material by combining with unsaturated group-containing polycarboxylic acids for uses as described in JP-A-2005-202023. Available to:
In order to use the epoxy resin of the present invention as a solder resist for a printed wiring board, first, a solution of an alkali developing type photosensitive resin composition containing the epoxy resin of the present invention is applied to the surface of the printed wiring board, or A film is formed by a method such as pasting as a dry film. Subsequently, a negative film is applied on the coating thus obtained, irradiated with actinic rays to cure the exposed portion, and further the end exposed portion is eluted using a weak alkaline aqueous solution. Examples of light suitable for photocuring the epoxy resin of the present invention include light from an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a metal halide lamp, a xenon lamp, and the like. Examples of the developer include an aqueous solution of an alkali metal or alkaline earth metal carbonate, an aqueous solution of an alkali metal hydroxide. For example, an aqueous solution of 1 to 3% by weight such as sodium carbonate, potassium carbonate, or lithium carbonate, A fine image can be developed precisely. After alkali development, it is desirable to perform heat treatment in order to improve heat resistance, corrosion resistance, adhesion, and the like. The heating and curing conditions are 80 to 200 ° C. and 10 minutes to 2 hours.
Conventionally, the low electrical reliability due to the halogen content of the epoxy resin used in this field has been a problem, and the low halogen epoxy resin of the present invention can be suitably used.

<Die bonding material>
The epoxy resin of the present invention is also useful as a die bonding material.
A die bonding material is a material used for bonding between a semiconductor chip and a support (substrate, lead frame, tape, etc.) in a semiconductor package. Conventionally, it is also used in this field. The low electrical reliability due to the halogen content of the epoxy resin has become a problem, and the low halogen epoxy resin of the present invention can be suitably used.

<Material for printed wiring boards>
The epoxy resin of the present invention is also useful as a printed wiring board material for multilayer electrical laminates and build-up methods.
Among them, the build-up method is highly expected as an excellent method for reducing the size and weight of electronic members.

  As shown in FIG. 1, the build-up method is a film (insulating layer) having a thickness of 40 to 90 μm on an inner circuit board (core substrate, 1A indicates a circuit) 1 in which glass prepregs are laminated, or This is a method of laminating a film 3 with a copper foil in which a copper foil 2A (copper foil thickness: 9 to 18 μm) is laminated on the film 2, and in general, this laminating press step, drilling (laser or drill) A circuit is formed through two types of processes, a desmear / plating process. The build-up method is an excellent method for reducing the size and weight, because the obtained laminated plate has the same performance as a conventional laminated plate, and the mounting area and weight are about 1/4.

  In such electronic member semiconductor package applications, epoxy resins are used for build-up layers and core substrates. However, conventional epoxy resins have a problem of migration due to halogen impurities contained therein. In recent years, the circuit line width is predicted to be further shortened for the purpose of reducing the size and weight, and the halogen content required for epoxy resins is expected to become increasingly severe. Therefore, in order to use the epoxy resin used in this field, it is essential to lower the halogen which could not be achieved conventionally, and the low halogen epoxy resin of the present invention is suitable.

<Others>
Not only in the above-mentioned fields, but also in electrical and electronic parts related to adhesives such as metal core laminates and underfill materials, low electrical reliability due to halogen impurities is an issue. The low halogen epoxy resin of the present invention provides a very useful material.
In addition, the epoxy resin of the present invention can be used effectively in the fields of adhesive films, optical films for display members, protective films, sealing films, and the like.

  The following are production examples and production comparative examples of the epoxy resin of the present invention, and further evaluation examples and comparative examples of the epoxy resin composition of the present invention. It is not limited to.

In the following, the epoxy equivalent was determined by a method described in JIS K 7236: 2001.
For the total chlorine content of the epoxy resin, obtain the total chlorine content of the epoxy resin sample in advance using a total chlorine analyzer “Mitsubishi Chemical Analytech Co., Ltd .: TOX2100H”, and prepare a calibration curve of fluorescent X-rays using the same sample. The actual total chlorine content was determined based on the result of fluorescent X-ray analysis and this calibration curve.
Moreover, the density | concentration of the inorganic halogen eluted in water by the elution test of inorganic halogen was calculated | required by the method of JISK7243-1: 2005.

[Manufacture of epoxy resin]
<Comparative Example 1>
Into a 1 L three-neck flask equipped with a thermometer, a stirrer, and a condenser tube, 121 g of 4,4′-dihydroxy-3,3 ′, 5,5′-tetramethylbiphenyl, 555 g of epichlorohydrin, and 200 g of isopropyl alcohol were added. After charging and dissolving at 50 ° C., 91 g of a 48.5 wt% aqueous sodium hydroxide solution was added dropwise over 1 hour. During that time, the temperature was gradually raised so that the temperature inside the system reached 70 ° C. at the end of dropping. Thereafter, the reaction was carried out by maintaining at 70 ° C. for 30 minutes. After the reaction was completed, the product was washed with water to remove by-product salts and excess sodium hydroxide. Subsequently, excess epichlorohydrin and isopropyl alcohol were distilled off from the product under reduced pressure to obtain a crude epoxy resin.

This crude epoxy resin was dissolved in 250 g of methyl isobutyl ketone, 2 g of 48.5 wt% aqueous sodium hydroxide solution was added, and the mixture was reacted at a temperature of 70 ° C. for 1 hour. After completion of the reaction, sodium phosphate monobasic was added to neutralize excess sodium hydroxide, and further washed with water to remove by-product salts. Next, methyl isobutyl ketone was completely removed under reduced pressure while heating to obtain the desired epoxy resin A.
This epoxy resin A had a total chlorine content of 1033 ppm by weight and an epoxy equivalent of 185 g / eq. Met.

<Comparative example 2>
A 3 L three-neck flask equipped with a thermometer, a stirrer, and a condenser is charged with 100 g of epoxy resin A and 160 g of methyl isobutyl ketone, uniformly dissolved and mixed, then 22 g of dimethyl sulfoxide is added and mixed to 60 ° C. The temperature rose. Under stirring, 2.6 g of a 15 wt% isopropyl alcohol solution of sodium hydroxide was added at once. After the reaction for 90 minutes, 200 g of purified water was added over 5 minutes to stop the reaction.
To this, 150 g of methyl isobutyl ketone was added and mixed uniformly, followed by stirring for 10 minutes. Then, it was made to stand still and the water layer was removed. To the organic layer, 500 ml of a 0.1% by weight aqueous solution of primary sodium phosphate was added and stirred at 70 ° C. for 10 minutes, followed by washing with neutralized water. Stirring was stopped, the mixture was allowed to stand and separated, and the aqueous layer was removed. Further, it was washed twice with 500 ml of warm water at 70 ° C. to remove by-product salts, excess sodium hydroxide, dimethyl sulfoxide, isopropyl alcohol, and the like. Subsequently, methyl isobutyl ketone was removed from the organic layer under reduced pressure. Finally, it was kept at 1.3 kPa and 160 ° C. for 30 minutes, and the volatile matter was removed almost completely to obtain an epoxy resin B.
This epoxy resin B has a total chlorine content of 321 ppm by weight and an epoxy equivalent of 193 g / eq. Met.

<Example 1>
A glass sublimation distillation apparatus comprising a sublimation part, a collection part I, and a collection part II is charged with 100 g of epoxy resin B, heated to 150 ° C. with a vacuum degree of 1.2 × 10 ⁻² Pa, and treated for 24 hours. did. Next, the temperature raising part was heated to 165 ° C. and treated for 12 hours. Epoxy resin C was recovered at the latter stage (low temperature side) of the collecting part I.
Epoxy resin C has a total chlorine content of 57 ppm by weight and an epoxy equivalent of 178 g / eq. Met.

<Example 2>
The same operation as in Production Comparative Example 1 was performed except that 121 g of 4,4′-dihydroxy-3,3 ′, 5,5′-tetramethylbiphenyl was changed to 222 g of 2,5-di-tert-butylhydroquinone. A crude epoxy resin D was obtained.
A glass sublimation distillation apparatus comprising a sublimation part, a collection part I, and a collection part II is charged with 100 g of crude epoxy resin D, heated to 150 ° C. with a vacuum degree of 1.2 × 10 ⁻² Pa, and treated for 24 hours. did. Next, the temperature raising part was heated to 165 ° C. and treated for 12 hours. Epoxy resin D was recovered at the latter stage (low temperature side) of the collection part I.
The total chlorine content in the epoxy resin D is 54 ppm by weight, and the epoxy equivalent is 172 g / eq. Met.

<Example 3>
A 1 L glass flask equipped with a stirrer, a dropping funnel and a thermometer was charged with 108 g of 1,4-butanediol and 3 g of tin tetrachloride previously heated to 30 ° C. and heated to 80 ° C. 244 g of epichlorohydrin was added dropwise over a period of time so that the temperature did not exceed 85 ° C. Thereafter, the mixture was aged for 1 hour while maintaining the temperature at 80 to 85 ° C, and then cooled to 45 ° C. To this was added 528 g of a 22% by weight aqueous sodium hydroxide solution, heated to 45 ° C. and stirred vigorously for 4 hours. After cooling to room temperature, the aqueous phase was separated and removed, and heated under reduced pressure to remove unreacted epichlorohydrin and water, whereby a crude epoxy resin E was obtained.
This crude epoxy resin E was purified by distillation using an Oldshaw distillation column (15 stages) to obtain an epoxy resin having a main fraction of a pressure of 1300 Pa and 140 to 160 ° C., and further to the obtained epoxy resin. Then, the same operation as the above distillation purification was repeated 5 times to obtain an epoxy resin E.
This epoxy resin E had a total chlorine content of 49 ppm by weight and an epoxy equivalent of 102 g / eq. Met.

<Example 4>
Crude epoxy resin F was obtained in the same manner as in Production Example 3, except that 108 g of 1,4-butanediol was changed to 142 g of 1,6-hexanediol.
This crude epoxy resin F was purified by distillation in an Oldshaw distillation column (15 stages) to obtain an epoxy resin having a main fraction of a pressure of 1300 Pa and 140 to 160 ° C., and further to the obtained epoxy resin. Then, the same operation as the above distillation purification was repeated 5 times to obtain an epoxy resin F.
This epoxy resin F has a total chlorine content of 51 ppm by weight and an epoxy equivalent of 116 g / eq. Met.

<Example 5>
A crude epoxy resin G was obtained in the same manner as in Production Comparative Example 1 except that 121 g of 4,4′-dihydroxy-3,3 ′, 5,5′-tetramethylbiphenyl was changed to 256 g of tetramethylbisphenol F. It was.
A 200 ml four-necked glass Kolben was charged with 40 g of crude epoxy resin G and 60 g of methyl isobutyl ketone, and heated and dissolved at 70 ° C. using an oil bath in a nitrogen atmosphere. After confirming that the epoxy resin was sufficiently dissolved, it was cooled to 25 ° C. The obtained crystals were filtered and rinsed with a small amount of methyl isobutyl ketone. 30 g of the obtained crystals were again charged into Kolben, and after adding 45 g of new methyl isobutyl ketone, the temperature was raised to 70 ° C. and dissolved. After confirming that the epoxy resin was sufficiently dissolved, it was cooled to 25 ° C. The obtained crystals were filtered and rinsed with a small amount of methyl isobutyl ketone. 20 g of the obtained crystal was charged into Kolben three times and charged with 30 g of new methyl isobutyl ketone. After confirming that the epoxy resin was sufficiently dissolved, it was cooled to 25 ° C. The obtained crystals were filtered and rinsed with a small amount of methyl isobutyl ketone to obtain the desired epoxy resin G.
This epoxy resin G has a total chlorine content of 49 ppm by weight and an epoxy equivalent of 185 g / eq. Met.

<Example 6>
200 g of four-necked glass Kolben was charged with 20 g of epoxy resin A and 80 g of isopropyl alcohol, and heated and dissolved at 80 ° C. using an oil bath in a nitrogen atmosphere. After confirming that the epoxy resin was sufficiently dissolved, it was cooled to 25 ° C. The obtained crystals were filtered and rinsed with a small amount of isopropyl alcohol. 20 g of the obtained crystals were again charged into Kolben, 65 g of new isopropyl alcohol was added, and the mixture was heated to 80 ° C. and dissolved. After confirming that the epoxy resin was sufficiently dissolved, it was cooled to 25 ° C. Further, the obtained crystals were filtered and rinsed with a small amount of isopropyl alcohol. 17 g of the obtained crystals were charged into Kolben three times, 55 g of new isopropyl alcohol was added and heated to 80 ° C., and after confirming that the epoxy resin was sufficiently dissolved, it was cooled to 25 ° C. The obtained crystals were filtered and rinsed with a small amount of isopropyl alcohol to obtain the desired epoxy resin H.
This epoxy resin H has a total chlorine content of 62 ppm by weight and an epoxy equivalent of 177 g / eq. Met.

<Example 7>
Crude epoxy resin I was obtained in the same manner as in Production Comparative Example 1 except that 121 g of 4,4′-dihydroxy-3,3 ′, 5,5′-tetramethylbiphenyl was changed to 228 g of bisphenol A.
200 g of four-necked glass Kolben was charged with 20 g of crude epoxy resin I and 80 g of ethanol, and heated and dissolved at 80 ° C. using an oil bath in a nitrogen atmosphere. After confirming that the epoxy resin was sufficiently dissolved, it was cooled to 0 ° C. The obtained crystals were filtered and rinsed with a small amount of ethanol. 15 g of the obtained crystal was again charged into Kolben, and after adding 60 g of new ethanol, the temperature was raised to 80 ° C. and dissolved. After confirming that the epoxy resin was sufficiently dissolved, it was cooled to 0 ° C. The obtained crystals were filtered and rinsed with a small amount of ethanol. 12 g of the obtained crystals were charged into Kolben three times, and 48 g of new ethanol was added and the temperature was raised. After confirming that the epoxy resin was sufficiently dissolved, it was cooled to 0 ° C. The obtained crystals were filtered and rinsed with a small amount of ethanol to obtain the desired epoxy resin I.
This epoxy resin I has a total chlorine content of 52 ppm by weight and an epoxy equivalent of 171 g / eq. Met.

<Example 8>
200 ml four-necked glass Kolben mixed with 20 g of epoxy resin D and 70:30 by weight of isopropyl alcohol / methyl isobutyl ketone (in this example, the mixing ratio of isopropyl alcohol / methyl isobutyl ketone mixed solvent is as follows) The same as above) was dissolved in a nitrogen atmosphere by heating at 75 ° C. using an oil bath. After confirming that the epoxy resin was sufficiently dissolved, it was cooled to 25 ° C. The obtained crystals were filtered and rinsed with a small amount of isopropyl alcohol / methyl isobutyl ketone mixed solvent. 17 g of the obtained crystals were again charged into Kolben, and after adding 50 g of a new isopropyl alcohol / methyl isobutyl ketone mixed solvent, the mixture was heated to 75 ° C. and dissolved. After confirming that the epoxy resin was sufficiently dissolved, it was cooled to 25 ° C. Further, the obtained crystals were filtered and rinsed with a small amount of isopropyl alcohol / methyl isobutyl ketone mixed solvent. 13 g of the obtained crystal was charged into Kolben three times, 37 g of a new mixed solvent of isopropyl alcohol / methylisobutylketone was added, the temperature was raised to 75 ° C., and after confirming that the epoxy resin was sufficiently dissolved, cooled to 25 ° C. did. The obtained crystals were filtered and rinsed with a small amount of isopropyl alcohol / methyl isobutyl ketone mixed solvent to obtain the desired epoxy resin J.
This epoxy resin J had a total chlorine content of 44 ppm by weight and an epoxy equivalent of 168 g / eq. Met.

<Example 9>
An epoxy resin G 100 g and methyl isobutyl ketone 160 g were charged into a 3 L three-necked flask equipped with a thermometer, a stirrer, and a cooling tube, and uniformly dissolved and mixed. Then, 22 g of dimethyl sulfoxide was added and mixed, and then 60 ° C. The temperature was raised to. Under stirring, 2.6 g of a 15 wt% isopropyl alcohol solution of sodium hydroxide was added at once. After the reaction for 90 minutes, 200 g of purified water was added over 5 minutes to stop the reaction.
To this, 150 g of methyl isobutyl ketone was added and mixed uniformly, followed by stirring for 10 minutes. Then, it was made to stand still and the water layer was removed. To the organic layer, 500 ml of a 0.1% by weight aqueous solution of primary sodium phosphate was added and stirred at 70 ° C. for 10 minutes, followed by washing with neutralized water. Stirring was stopped, the mixture was allowed to stand and separated, and the aqueous layer was removed. Further, it was washed twice with 500 ml of warm water at 70 ° C. to remove by-product salts, excess sodium hydroxide, dimethyl sulfoxide, isopropyl alcohol, and the like. Subsequently, methyl isobutyl ketone was removed from the organic layer under reduced pressure.
For the obtained epoxy resin, the same operations as in the alkali treatment and water washing steps were repeated 5 times. Finally, it was kept at 1.3 kPa and 160 ° C. for 30 minutes to remove volatile matter almost completely, thereby obtaining an epoxy resin K.
This epoxy resin K has a total chlorine content of 50 ppm by weight and an epoxy equivalent of 202 g / eq. Met.

<Example 10>
Except that 121 g of 4,4′-dihydroxy-3,3 ′, 5,5′-tetramethylbiphenyl was replaced with 166 g of 1,5-dihydroxynaphthalene, the same operation as in Production Comparative Example 1 was carried out to obtain a crude epoxy resin L was obtained.
Into a 3 L three-necked flask equipped with a thermometer, a stirrer, and a condenser tube, 100 g of the obtained crude epoxy resin L and 160 g of methyl isobutyl ketone were charged, uniformly dissolved and mixed, and then 22 g of dimethyl sulfoxide was added and mixed. The temperature was raised to 60 ° C. Under stirring, 2.6 g of a 15 wt% isopropyl alcohol solution of sodium hydroxide was added at once. After the reaction for 90 minutes, 200 g of purified water was added over 5 minutes to stop the reaction.
To this, 150 g of methyl isobutyl ketone was added and mixed uniformly, followed by stirring for 10 minutes. Then, it was made to stand still and the water layer was removed. To the organic layer, 500 ml of a 0.1% by weight aqueous solution of primary sodium phosphate was added and stirred at 70 ° C. for 10 minutes, followed by washing with neutralized water. Stirring was stopped, the mixture was allowed to stand and separated, and the aqueous layer was removed. Further, it was washed twice with 500 ml of warm water at 70 ° C. to remove by-product salts, excess sodium hydroxide, dimethyl sulfoxide, isopropyl alcohol, and the like. Subsequently, methyl isobutyl ketone was removed from the organic layer under reduced pressure.
For the obtained epoxy resin, the same operations as in the alkali treatment and water washing steps were repeated 5 times. Finally, it was kept at 1.3 kPa and 160 ° C. for 30 minutes to remove volatile matter almost completely, thereby obtaining an epoxy resin L.
This epoxy resin L has a total chlorine content of 45 ppm by weight and an epoxy equivalent of 101 g / eq. Met.

<Example 11>
Into a 3 L three-necked flask equipped with a thermometer, a stirrer, and a condenser tube, 100 g of epoxy resin A and 160 g of methyl isobutyl ketone were charged, uniformly dissolved and mixed, then 22 g of dimethyl sulfoxide was added and mixed, and 60 ° C. The temperature was raised to. Under stirring, 2.6 g of a 15 wt% isopropyl alcohol solution of sodium hydroxide was added at once. After the reaction for 90 minutes, 200 g of purified water was added over 5 minutes to stop the reaction.
To this, 150 g of methyl isobutyl ketone was added and mixed uniformly, followed by stirring for 10 minutes. Then, it was made to stand still and the water layer was removed. To the organic layer, 500 ml of a 0.1% by weight aqueous solution of primary sodium phosphate was added and stirred at 70 ° C. for 10 minutes, followed by washing with neutralized water. Stirring was stopped, the mixture was allowed to stand and separated, and the aqueous layer was removed. Further, it was washed twice with 500 ml of warm water at 70 ° C. to remove by-product salts, excess sodium hydroxide, dimethyl sulfoxide, isopropyl alcohol, and the like. Subsequently, methyl isobutyl ketone was removed from the organic layer under reduced pressure.
For the obtained epoxy resin, the same operations as in the alkali treatment and water washing steps were repeated 5 times. Finally, it was kept at 1.3 kPa and 160 ° C. for 30 minutes to remove volatile matter almost completely, thereby obtaining an epoxy resin M.
This epoxy resin M has a total chlorine content of 40 ppm by weight and an epoxy equivalent of 205 g / eq. Met.

<Example 12>
A 3-L four-necked flask equipped with a stirrer, a reflux condenser and a thermometer was charged with 109 g of paraaminophenol, 1400 g of epichlorohydrin and 700 g of isopropyl alcohol, the inside of the system was purged with nitrogen under reduced pressure, and stirred uniformly in a nitrogen atmosphere. Dissolved. In addition, since it heated up by heat_generation | fever, it adjusted so that it might be set to 60 degreeC. Then, it was made to react by stirring at 60 degreeC for 3 hours. Subsequently, 313 g of 48.5% by weight sodium hydroxide aqueous solution was added dropwise over 90 minutes, and after completion of the addition, the reaction was further maintained at 60 ° C. for 30 minutes. After removing by-product salts and excess sodium hydroxide by washing with water, excess epichlorohydrin and isopropyl alcohol were distilled off from the product under reduced pressure, and solid content was removed by filtration to obtain a crude epoxy resin N. .
200 g of crude epoxy resin N was dissolved in 400 g of methyl isobutyl ketone, and the system was purged with nitrogen under reduced pressure. Under a nitrogen atmosphere, 7 g of a 48.5% by weight aqueous sodium hydroxide solution was added and reacted at a temperature of 65 ° C. for 1 hour. Thereafter, an aqueous sodium hydrogen phosphate solution was added to the reaction solution to neutralize excess sodium hydroxide, followed by washing with water to remove by-product salts. Subsequently, methyl isobutyl ketone was completely removed under heating and reduced pressure. The obtained epoxy resin was distilled at 0.13 kPa and 180 to 200 ° C. using an internal condenser type film evaporator.
With respect to the obtained epoxy resin N, the above-described alkali washing and distillation operations were repeated 5 times to obtain an epoxy resin N.
This epoxy resin N has a total chlorine content of 45 ppm by weight and an epoxy equivalent of 105 g / eq. Met.

[Evaluation of epoxy resin composition]
<Examples 13 to 36, Comparative Examples 3 to 6>
Epoxy resin produced in Examples 1 to 12 or Comparative Examples 1 and 2 as an epoxy resin, phenol novolak resin (“PSM4261” hydroxyl group equivalent: 103 g / eq., Manufactured by Gunei Chemical Co., Ltd.) as a curing agent, and triphenyl as a curing accelerator Phosphine (manufactured by Tokyo Chemical Industry Co., Ltd., abbreviated as “TPP”) or 1,8-diazabicyclo (5.4.0) -7-undecene (manufactured by Tokyo Chemical Industry Co., Ltd., abbreviated as “DBU” in the table). Were compounded as shown in Tables 1-A and B, and were completely cured under the conditions of 175 ° C. and 8 hours to obtain each epoxy resin cured composition.
Next, these epoxy resin cured compositions were pulverized into 20 mesh passes by a mill. 50 g of purified water (distilled water for high performance liquid chromatograph manufactured by Wako Pure Chemical Industries, Ltd.) was added to 5 g of the cured powder, and the mixture was allowed to stand at 180 ° C. for 20 hours. The results of measuring the chlorine concentration in the elution water are shown in Tables 1-A and B.

  From Tables 1-A and B, according to the present invention, it is possible to provide a highly reliable cured epoxy resin that is useful as an electric or electronic material such as various insulating materials and laminated plates and has no problem of halogen elution. I understand.

DESCRIPTION OF SYMBOLS 1 Inner layer circuit board 1A Circuit 2 Film 2A Copper foil 3 Film with copper foil

Claims (6)

  An epoxy resin obtained by reacting an active hydrogen compound with epihalohydrin and having a total halogen content of 80 ppm by weight or less.   The epoxy resin of Claim 1 manufactured through the process of sublimating the epoxy resin obtained by reaction of an active hydrogen compound and epihalohydrin.   The epoxy resin of Claim 1 or 2 manufactured through the process of distilling the epoxy resin obtained by reaction of an active hydrogen compound and epihalohydrin.   The epoxy resin according to any one of claims 1 to 3, which is produced through a step of crystallizing an epoxy resin obtained by a reaction between an active hydrogen compound and epihalohydrin.   The epoxy resin according to any one of claims 1 to 4, which is produced through a step of alkali-cleaning an epoxy resin obtained by a reaction between an active hydrogen compound and epihalohydrin. An epoxy resin composition comprising the epoxy resin according to any one of claims 1 to 5 and a curing agent for an epoxy resin, wherein the inorganic halogen concentration measured by the following dissolution test is 10 ppm by weight or less.
<Dissolution test>
To the cured powder obtained by pulverizing the cured epoxy resin composition into a 20 mesh pass, 10 times the amount of purified water is added and left at 180 ° C. for 20 hours, and then the inorganic halogen concentration in the water is adjusted. taking measurement.

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