JP3871236B2 - Production method of epoxy resin - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing an epoxy resin of an allylated polyphenol compound. Specifically, for insulating materials for electrical and electronic parts including high-reliability semiconductor encapsulating materials, for various composite materials including laminated boards (printed wiring boards) and CFRP (carbon fiber reinforced plastic), various adhesives The present invention relates to a method for producing an epoxy resin useful for coatings, various paints, structural members and the like.
[0002]
[Prior art]
Conventionally, the process until obtaining an allylated product in the production of an epoxy resin of an allylated product of a polyhydric phenol compound has been performed by the following method.
That is, first, a polyhydric phenol compound is dissolved in a solvent such as alcohols such as methanol, isopropanol or n-propanol, or ketones such as acetone or methyl ethyl ketone, and then allyl chloride or sodium chloride using a base such as sodium hydroxide or potassium hydroxide. By reacting with an allyl halide such as allyl bromide, an allyl ether of a polyhydric phenol compound is obtained. However, alcohols may react with allyl halides, and a slight amount of impurities are generated. Ketones are hardly stable to bases.
Next, the by-product inorganic salt is removed by filtration or washing with water, and the resulting allyl ether is obtained in the presence or absence of a high-boiling solvent such as carbitol, paraffin oil, N, N′-dimethylaniline, etc. An allylated polyphenol compound is obtained by Claisen rearrangement by heating at 150 to 230 ° C. for 0.1 to 100 hours. In this case, there is a problem that allyl ether is removed without rearrangement to the o-position.
[0003]
[Problems to be solved by the invention]
The inventors of the present invention have reached the present invention when they have studied to produce an epoxy resin having a low viscosity and a low crystallinity and a cured product having low water absorption and high adhesion, which is a method free from the above problems.
An object of the present invention is to shorten the process and increase the efficiency of the allylation reaction in the production of an epoxy resin using an allylated polyphenol compound as a raw material.
[0004]
[Means for Solving the Problems]
That is, the present invention
(1) A method for producing an epoxy resin using a polyhydric phenol compound,
First step: Allyl etherification reaction of polyhydric phenol compound,
Second step: Claisen rearrangement reaction of allyl ether obtained in the first step,
3rd process: It consists of the glycidylation reaction of the allylated polyphenol compound obtained at the 2nd process, and includes any one or more processes selected from the following processes (a) to (d) (A) The second step is performed without removing the by-product salt in the first step, and the by-product salt is removed at the same time as the by-product salt in the third step. (B) a step of using an aprotic polar solvent as a reaction solvent in the first step (c) a step of performing the second step in an inert gas atmosphere or in a vacuum (d) a phenolic antioxidant It is related with the process of adding and performing a 2nd process.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The starting materials used in the production method of the present invention are, for example, bisphenol A, bisphenol F, bisphenol AD, biphenol, 4,4 ′-(1-methyl-ethylidene) bis [2-methylphenol], 4,4′- (1,3-dimethylbutylidene) bisphenol, 4,4 ′-(2-phenylethylidene) bisphenol, 4,4 ′-(2-ethylhexylidene) bisphenol, cyclohexylidene bisphenol, bis (4-hydroxyphenyl) ) Bisphenols such as sulfide, bis (4-hydroxyphenyl) methanone, 4,4 ′-(dimethylsilylene) bisphenol, 4,4′-oxybisphenol, phenols / aldehyde polycondensates, phenols / ketones heavy Condensate, hydroquinone, resorcin, catechol, phloroglici Polyhydric hydroxybenzenes such as alcohol, dihydroxynaphthalene, tris (4-hydroxyphenyl) methane, bis (3-methyl-4hydroxyphenyl) 4-hydroxyphenylmethane, and other phenols and hydroxybenzaldehydes polycondensates, phenols -Diene compound polymer, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, 1,1,2,2-tetraxy (3-methyl-4-hydroxyphenylethane), α, α, α ' , Α'-tetrakis (p-hydroxyphenyl) -p-xylene and other phenols / dialdehyde compounds polycondensates, phenols / aromatic dimethanols polycondensates, phenols / olefin aldehydes polycondensates, etc. A polyhydric phenol compound, including at least one o-hydroxyl group in the molecule; It is preferred that at least one place of a compound having no substituent.
[0006]
In the production method of the present invention, first, as a first step, an allyl halide such as allyl chloride, allyl bromide or methylallyl chloride is reacted with the polyhydric phenol compound as described above using a base such as an alkali metal hydroxide. To obtain allyl ether. At this time, an organic solvent having a high affinity with water, such as methanol, isopropanol, acetone, methyl ethyl ketone, etc., can be used, but the allyl halide reacts with the alcohol to a slight extent, and the base is hydroxylated. Since sodium or potassium hydroxide is usually used, a ketone solvent that is weak against strong alkali may not be preferable. Therefore, it is preferable to use an aprotic polar solvent such as dimethylsulfone, dimethylsulfoxide, dimethylformamide, 1,3-dimethyl-2-imidazolidinone as the solvent. Since these are solvents having a dehalogenation action, they also act as reaction catalysts, and the reaction proceeds at a lower temperature and in a shorter time than alcohol and ketone solvents, and the consumption efficiency of bases and allyl halides is high. The amount of the aprotic polar solvent used is usually 50 to 400 parts by weight, preferably 70 to 300 parts by weight, based on 100 parts by weight of the raw material, and these may be used alone or with other solvents such as alcohol and ketone. You may use together. In that case, the usage-amount of another solvent is 10-100 weight part normally with respect to 100 weight part of aprotic polar solvents. The usage-amount of an allyl halide and a base is 0.1-1.5 mol normally with respect to 1 equivalent of phenolic hydroxyl groups, Preferably it is 0.5-1.2 mol.
[0007]
Moreover, sodium chloride, potassium chloride, sodium bromide, potassium bromide, and the like are produced as by-products of allyl etherification, but conventionally, they are removed by filtration or washing with water after dissolving allyl ether in a water-insoluble organic solvent. It was. However, the inorganic salt as described above is also produced as a by-product in the glycidylation reaction and must be removed. Therefore, if these are removed at the same time, the step of removing the by-product salt at the time of allyl etherification can be omitted. In the present invention, the step of removing the by-product salt during the allyl etherification reaction is omitted, and after completion of the reaction, the organic solvent is distilled off as it is without filtering or washing with water, and then the inorganic solvent is removed. It is found that allylation proceeds normally even when the Claisen rearrangement reaction (second step) is carried out in the presence of a salt, and further, a glycidylation reaction is carried out in the presence of an inorganic salt, and an inorganic salt produced as a by-product at this time Was removed at the same time as the inorganic salt produced in the first step, thereby realizing a shortening of the target step.
[0008]
The Claisen rearrangement reaction, which is the second step, may be carried out according to a conventional method. For example, allyl ether obtained in the first step (which may contain a by-product salt) is converted into carbitol, paraffin oil, N, N′-dimethylaniline. The mixture is heated at 150 to 230 ° C. for 0.1 to 100 hours in the presence of a high boiling point solvent such as The solvent is used as required in an amount of 10 to 200 parts by weight per 100 parts by weight of allyl ether. After completion of the reaction, the used solvent can be removed if necessary to obtain an allylated polyphenol.
[0009]
Furthermore, in the Claisen rearrangement reaction, it was found that oxygen and water had an adverse effect on the reaction. Therefore, the reaction is preferably performed in a vacuum or in an inert gas atmosphere such as nitrogen or argon, and coloring of the product can be prevented. However, it is difficult to maintain a complete vacuum or inert gas atmosphere, and it is inevitable that a trace amount of oxygen is mixed into the system. For this reason, it is preferable to carry out the Claisen rearrangement by adding an antioxidant. However, since the product is later used in the glycidylation step (third step), the remaining oxidation is performed using a phenol-based antioxidant. If the inhibitor is glycidylated together with the allylated compound, it is not necessary to remove the inhibitor. However, the antioxidant is preferably used in an amount of about 10 parts by weight based on 100 parts by weight of allyl ether so as not to impair the physical properties of the target product. Phenol antioxidants include methylhydroquinone, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, tert-butylated bisphenol A, 2,2′-methylenebis (4-methyl- 6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 4,4′-ethylidenebis (3-methyl-6-tert-butylphenol), 4,4′-methylenebis (2,6-di-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 4,4′-thiobis (3-methyl-6-tert-butylphenol), 1, 1,3-tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) buta 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 1,1-bis (4-hydroxyphenyl) -cyclohexane, etc. However, it is not limited to these. These may be used alone or in combination of two or more, but it is preferable to use a compound having two or more phenolic hydroxyl groups per molecule.
[0010]
Next, the third step (glycidylation reaction) in the present invention will be described.
In the third step, the allylated polyphenol compound obtained as described above (which may contain by-product inorganic salts) is reacted with epihalohydrins.
Specific examples of epihalohydrins that can be used in the glycidylation reaction include epichlorohydrin, β-methylepichlorohydrin, epibromhydrin, β-methylepibromhydrin, epiiodohydrin, β-ethylepichlorohydrin, and the like. However, industrially available and inexpensive epichlorohydrin or epibromohydrin is preferable.
[0011]
For example, the reaction is carried out at 20 to 120 ° C. at 20 to 120 ° C. while adding or gradually adding a solid of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide as a catalyst to a mixture of an allylated polyphenol compound and an epihalohydrin. React for 5-10 hours. In this case, the alkali metal hydroxide may be used in the form of an aqueous solution. In this case, the alkali metal hydroxide is continuously added and water and epihalohydrin are continuously added from the reaction mixture under reduced pressure or normal pressure. It is also possible to distill off the liquid and separate it further to remove the water and to continuously return the epihalohydrin to the reaction mixture.
[0012]
In said method, the usage-amount of epihalohydrins is 0.5-20 mol normally with respect to 1 equivalent of hydroxyl groups of the compound of a formula, Preferably it is 0.7-10 mol. The usage-amount of an alkali metal hydroxide is 0.5-1.5 mol normally with respect to 1 equivalent of hydroxyl groups of an allylated polyhydric phenol compound, Preferably it is 0.7-1.2 mol. In addition, an epoxy resin having a low hydrolyzable halogen concentration can be obtained by adding an aprotic polar solvent such as dimethyl sulfone, dimethyl sulfoxide, dimethylformamide, 1,3-dimethyl-2-imidazolidinone in the above reaction, Suitable for use as an electronic material sealing material. The amount of the aprotic polar solvent used is usually 5 to 200% by weight, preferably 10 to 100% by weight, based on the weight of the epihalohydrin. In addition to the above solvents, the reaction can easily proceed by adding alcohols such as methanol and ethanol. In addition, toluene, xylene, dioxane and the like can also be used. As the aprotic polar solvent and alcohols, the solvent recovered after use in the allyl etherification reaction can be reused.
[0013]
Further, a quaternary ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide, trimethylbenzylammonium chloride or the like is used as a catalyst in a mixture of an allylated product of polyhydric phenol and an excess of epihalohydrin. A solid or aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is added to the halohydrin ether of an allylated product of polyhydric phenol obtained by reacting for -20 hours, and 1-20 at 20-120 ° C. The epoxy resin of the present invention can also be obtained by reacting for a period of time to cyclize the halohydrin ether. The amount of the quaternary ammonium salt used in this case is usually 0.001 to 0.2 mol, preferably 0.05 to 0.1 mol, relative to 1 equivalent of the hydroxyl group of the allylated polyphenol compound.
[0014]
Usually, these reaction products are filtered or washed with by-produced salts (including inorganic salts by-produced in the first step), and after removing excess epihalohydrins under reduced pressure, toluene, xylene, methyl isobutyl ketone, etc. In the solvent, an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is added to react again. In this case, the amount of alkali metal hydroxide used is usually 0.01 to 0.2 mol, preferably 0.05 to 0.1 mol, relative to 1 equivalent of the hydroxyl group of the allylated polyphenol compound. The reaction temperature is usually 50 to 120 ° C., and the reaction time is usually 0.5 to 2 hours. Further, it is possible to remove excess epihalohydrins under heating and reduced pressure without filtering or washing with water, and to perform the same operation as described above. You may wash with water.
[0015]
After completion of the reaction, an epoxy resin with less hydrolyzable halogen can be obtained by distilling off a solvent such as toluene, xylene, methyl isobutyl ketone, etc. under heating and reduced pressure. If the salt is not removed before the above reaction, the desired epoxy resin can be obtained by removing the by-produced salt by filtration, washing with water, etc. after completion of the reaction, and then distilling off the solvent. .
In the present invention, it is preferable to perform all the operations (a) to (d).
The epoxy resin thus obtained can be cured with a curing agent or the like in the same manner as a normal epoxy resin, and can be used in various fields such as the electric / electronic field, the building field, the paint, the adhesive, and the civil engineering field. it can.
[0016]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to these examples.
The physical property values were measured by the following methods.
・ Epoxy equivalent Value measured by a method according to JIS K-7236 ・ Viscosity E type rotational viscometer (25 ° C.)
[0017]
Example 1
A reaction vessel was charged with 114 parts by weight of bisphenol A and 200 parts by weight of dimethyl sulfoxide (DMSO, hereinafter the same), and after stirring and dissolving, 41 parts by weight of sodium hydroxide was added and stirring was continued. Next, 80 parts by weight of allyl chloride was dropped over 1 hour while maintaining the system at 40 ° C., and then reacted at 40 ° C. for 3 hours and at 70 ° C. for 30 minutes. After completion of the reaction, dimethyl sulfoxide was distilled off from the reaction solution under heating and reduced pressure to obtain a mixture of bisphenol A diallyl ether and sodium chloride.
This mixture of diallyl ether of bisphenol A and sodium chloride is charged into a reaction vessel, and after repeating depressurization and nitrogen substitution, a nitrogen atmosphere is created by flowing nitrogen into the system, and a Claisen rearrangement reaction is performed at 190 ° C. for 6 hours. As a result, a light yellow liquid mixture of allylated bisphenol A and sodium chloride was obtained. When this allylated bisphenol was analyzed by gas chromatography, monoallyl bisphenol A was 1% or less and diallyl bisphenol A was 93%.
Subsequently, a mixture of the allylated bisphenol A and sodium chloride, 555 parts by weight of epichlorohydrin (ECH, the same applies hereinafter) and 280 parts by weight of DMSO were charged into a reaction vessel, heated, stirred, dissolved, and maintained at 45 ° C. While maintaining the system at 45 Torr, 63 parts by weight of 40% aqueous sodium hydroxide solution was continuously added dropwise over 4 hours. At this time, ECH and water distilled off by azeotropic distillation were cooled and separated, and then the reaction was carried out while returning only the organic layer ECH into the reaction system. After completion of the dropwise addition of the aqueous sodium hydroxide solution, the reaction was further continued under reduced pressure at 45 ° C. for 2 hours and at 70 ° C. for 60 minutes. Next, after repeated washing with water to remove by-product sodium chloride and DMSO, excess ECH was distilled off from the oil layer under heating and reduced pressure, and 300 parts by weight of methyl isobutyl ketone (MIBK, hereinafter the same) was added to the residue. Dissolved.
Further, this MIBK solution was heated to 70 ° C., 10 parts by weight of a 30% aqueous sodium hydroxide solution was added and reacted for 2 hours, and then washing with water was repeated until the solution washing solution became neutral. Subsequently, MIBK was distilled off from the oil layer under reduced pressure under heating, and the residue was subjected to molecular distillation under reduced pressure under heating to obtain 198 parts by weight of a light yellow liquid epoxy resin (E1). The epoxy resin (E1) obtained had an epoxy equivalent of 225 g / eq and a viscosity of 1900 centipoise.
[0018]
Example 2
In Example 1, when the Claisen rearrangement reaction was performed, the same operation was performed except that 2.0 parts by weight of 4,4′-isopropylidenebis (2,6-di-tert-butylphenol) was added. 200 parts by weight of Resin (E2) was obtained. Epoxy resin (E2) had an epoxy equivalent of 227 g / eq and a viscosity of 2000 centipoise.
[0019]
Comparative Example 1
The reaction vessel was charged with 114 parts by weight of bisphenol A and 330 parts by weight of isopropanol (IPA, hereinafter the same), and after stirring and dissolving, 45 parts by weight of sodium hydroxide was added and stirring was continued. Next, 100 parts by weight of allyl chloride was dropped over 1 hour while maintaining the inside of the system at 40 ° C., and then reacted at 70 ° C. for 4 hours. After completion of the reaction, 300 parts by weight of methyl isobutyl ketone (MIBK, hereinafter the same) was added, and washing with water was repeated to remove IPA and sodium chloride by-produced. Subsequently, MIBK was distilled off under heating and reduced pressure to obtain diallyl ether of bisphenol A.
This diallyl ether of bisphenol A and 300 parts by weight of carbitol are charged into a reaction vessel, subjected to a Claisen rearrangement reaction at 190 ° C. for 6 hours, and then carbitol is distilled off under heating and reduced pressure to allylate a reddish brown liquid. Bisphenol A was obtained. When this allylated bisphenol was analyzed by high performance liquid chromatography, monoallyl bisphenol A was 5% and diallyl bisphenol A was 88%.
Subsequently, the same operation as in Example 1 was performed as a glycidylation step, and 190 parts by weight of a reddish brown liquid epoxy resin (R1) was obtained. The epoxy resin (R1) obtained had an epoxy equivalent of 221 g / eq and a viscosity of 1800 centipoise.
[0020]
【The invention's effect】
The method for producing an epoxy resin of the present invention can realize a shortening of the process and a reduction in energy required for the reaction as compared with a conventional production method. In addition, it is possible to obtain an epoxy resin with less coloration by suppressing elimination of allyl groups.

Claims (2)

A process for producing an epoxy resin using bisphenols , the first step: allyl etherification reaction of bisphenols , the second step: Claisen rearrangement reaction of allyl ether obtained in the first step, the third step: second step The manufacturing method of the epoxy resin which consists of the glycidylation reaction of the allylated bisphenol obtained by 1 and uses the process of following (a)- (c) as an essential process .
(A) performing the second step without removing the by-product salt in the first step, and removing the by-product salt after completion of the third step simultaneously with the salt by-produced in the third step (b) first Step (c) using an aprotic polar solvent as a reaction solvent for the step The second step is performed in an inert gas atmosphere or in a vacuum. The manufacturing method of the epoxy resin of Claim 1 which makes the following process (d) an essential process.
Step (d) Step of performing the second step by adding a phenolic antioxidant