JPH0377876A - Purification of epoxy compound - Google Patents

Abstract

PURPOSE:To purify an epoxy compound by reducing organic chlorine compounds contained in the epoxy compound by reacting the epoxy compound with a metal amide compound in an inert solvent. CONSTITUTION:When organic chlorine compound in an epoxy compound is removed to purify the epoxy compound, the purification is carried out by reacting the epoxy compound with a metal amide compound in an inert solvent. The metal amide compound used includes a compound [e.g. KN[Si(CH3)3]2] expressed by formula I or formula II (M is Li, Na or K; R<1> to R<5> are H, alkyl, alkenyl, aralkyl or aryl). According to the method, a non-hydrolyzable chlorine which has been difficult to be removed can readily be eliminated. Therefore, when it is used for electrical or electronic component, an epoxy resin having low chlorine content and free from troubles such as lowering of electrical insulating properties or corrosion of lead line can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for purifying an epoxy compound, and particularly to a method for removing organic chlorine compounds from an epoxy compound.

(Prior Art and Problems to be Solved) When an epoxy compound such as an epoxy resin is crosslinked with a curing agent, it becomes a cured product having a large crosslink density and exhibits excellent properties. However, when this epoxy resin is used as a material for electronic or electrical equipment or as a coating for steel plates,
Chlorine, an organic chlorine compound that is an impurity contained in resins, often causes problems such as reduced electrical insulation, corrosion of lead wires, and corrosion of steel plates, and these industries are waiting for the emergence of epoxy resins with lower chlorine content. It was.

Generally, epoxy compounds are manufactured by reacting shrimp chlorohydrin with phenols or alcohols in the presence of alkali metal hydroxide, but the types of organic chlorine compounds that are produced as by-products during this manufacturing process are as follows: For example, in the case of epoxy compounds obtained from phenol and shrimp chlorohydrin, there are organic chlorine compounds represented by (C), (D) and (E) below.

Conventionally, methods for removing these organic chlorine compounds generally involve using an epoxy compound with 1-helene, an aromatic hydrocarbon such as xylene, or methyl ethyl ketone.

A known method is to dissolve 1 t in a ketone such as methyl isobutyl ketone, a cyclic or linear ether, or an aprotic polar solvent such as dimethyl sulfoxide, and heat it with an aqueous alkali metal hydroxide solution. . However, in the case of this method, although it is possible to reduce hydrolyzable chlorine such as the above formula (C), it has a small effect on non-hydrolyzable chlorine such as the formula (D> and formula (E)), and This side reaction of the epoxy compound has the disadvantage of increasing the epoxy equivalent, and if this method uses an aprotic polar solvent such as dimethyl sulfoxide, it requires a large amount of energy to recover the solvent. There is also.

(Means for Solving the Problems) The present invention provides a method for purifying an epoxy compound that reduces organic chlorine compounds in the epoxy compound. This is a method for purifying an epoxy compound, which is characterized by allowing a compound to act on the epoxy compound.

Specific examples of epoxy compounds targeted in the present invention include phenol, resorcinol, hyde quinone,
O-cresol, m-cresol, p-cresol, 2
, 2-bis(4-hydroxyphenyl)propane, bis(4-hydroxyphenyl)methane, 1,1-bis(4
-hydroxyphenyl)ethane, bis(4-hydroxyphenyl)sulfone, 1,1-bis(4-hydroxyphenyl)-1-ethane, 1,1,2.2-telherakis(4-hydroxyphenyl)ethane, 2,2-bis(3
, 5-dibromo-4-hydroxyphenyl)propane,
Phenol novolac, cresol novolac, brominated phenol novolac, brominated cresol novolac,
Epoxy compounds manufactured from phenols such as resorcinol novolac and brominated resorcinol novolac and shrimp chlorohydrin, allyl alcohol, methyl alcohol, ethyl alcohol, hexyl alcohol, cyclohexyl alcohol, heptyl alcohol, octyl alcohol, butanediol, polypropylene glycol , epoxy compounds produced from alcohols such as polyethylene glycol and shrimp chlorohydrin, and the like.

As the metal amide compound in the present invention, a metal amide compound represented by the following general formula (A> or (B)) is particularly preferable.

MN(SiR1R2R3>(A>MNR4R5
(B) In the above general formula (A>, (B)), M is Li.

represents an alkali metal selected from Na and )(R1
, R2, R3, R4 or R5 represents a group selected from hydrogen, alkyl, alkenyl, aralkyl and aryl; These may be the same. Alkyl is a straight chain bibranched or cyclic one with 1=10 carbon atoms, alkenyl is one with 2 to 10 carbon atoms, aralkyl is one with 7 to 15 carbon atoms, and aryl is one with carbon number G
-15 are preferable, respectively, and these general formulas (A>
Specific examples of the metal amide compound represented by (B) include unsubstituted metal amides such as lithium amide, sodium amide, potassium amide, and the following substituted metal amides. That is, as the amide moiety of the metal amide compound, diisopropylamide, diethylamide, dicyclohexylamide, isopropylcyclohexylamide,
t-octyl-1-butylamide, 2,2,6.6
-Te! - Dialkylamide such as methylpiperide, silylamide such as bis(trimethylsilyl)amide, bis(triethylsilyl)amide, his(dimethylphenylsilyl)amide, bis(tripropylsilyl)amide, bis(triphenylsilyl)amide, Examples of the metal portion include metals such as lithium, sodium, and potassium.

The use of the metal amide compound is 1 to 20 times the molar amount, preferably 1 to 20 times the amount of chlorine contained in the epoxy compound.
．． The amount ranges from 5 to 10 times the molar amount.

Inert solvents used in the present invention include aromatic hydrocarbons such as benzene, toluene, and xylene, aliphatic hydrocarbons such as pentane, hexane, heptane, octane, and cyclohexane, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, and ethylene glycol diethyl. Examples include ethers such as ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol dibutyl ether, and these can be used alone or as a mixture.

The purification method of the present invention involves mixing an epoxy compound with a metal amide compound in an inert solvent, heating the mixture to 20 to 150°C, preferably 80 to 140°C, for 0.5 to 50 hours, usually for 1 hour.
This is done by stirring for ~6 hours.

The metal amide compound may be used in its solid state, or as a solution in the above-mentioned inert solvent, or as a slurry.

Through the above purification treatment, the chlorine in the hydrolyzable and non-hydrolyzable organic chlorine compounds in the epoxy compound reacts with the metal amide compound to become metal chloride, and this metal chloride can be removed by appropriate treatment. can. That is,
The reaction solution is neutralized with phosphoric acid, a phosphate, an organic acid, carbonic acid, etc., and the salt produced by the neutralization and the excess acid are removed by washing with water or filtration to obtain an epoxy compound with a low chlorine content.

A filter aid such as silica gravel can also be used during the above filtration. Further, by performing the above purification treatment multiple times, an epoxy compound with even lower chlorine content can be obtained. In general, by combining the purification method of the present invention with other purification methods, it is possible to effectively obtain an epoxy compound with a low chlorine content. For example, an epoxy compound is dissolved in an aromatic hydrocarbon such as toluene or xylene, a ketone such as methyl isobutyl ketone or methyl ethyl ketone, an aprotic polar solvent such as dimethyl sulfoxide, or a cyclic or linear ether, and then dissolved in alkali metal water. After heat treatment with an oxide to reduce hydrolyzable chlorine, the purification treatment of the present invention can be performed. Furthermore, before or after the present invention, a method of reacting an epoxy compound with a phosphine or a silver compound can be used in combination. Generally, after the purification process of the present invention, the epoxy compound can be extracted with a solvent to obtain an epoxy compound with a further low chlorine content and low epoxy equivalent.

(Example) Synthesis of epoxy compound> 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) and shrimp chlorohydrin are reacted in the presence of sodium hydroxide, and excess shrimp chlorohydrin is removed under reduced pressure. After evaporation, the produced sodium chloride was removed by filtration and washed with water to obtain epoxy compound X shown in Table 1.

The same procedure was carried out using phenol novolak or cresol novolak instead of bisphenol A to obtain epoxy compound Y or Z as shown in Table 1.

Table 1 Examples 1 to 8 1 each of the above-obtained I poxy compounds X, Y, and Z
009 in a solvent, a metal amide compound was added thereto, and the treatment was carried out under the purification conditions shown in Table 2. In Examples 1 to 6, the solid material precipitated after the reaction was filtered off, and the filtrate was After neutralization with phosphoric acid, washing with water and drying was performed to obtain a purified epoxy compound. In Example 7, the reaction solution after purification was cooled and neutralized by adding excess dry ice, and then filtered using diatomaceous earth as a filter aid to obtain a purified epoxy compound. Example 8
After cooling the reaction solution after purification treatment, T:n-hexadi 300i
Add and dissolve insoluble materials, filter out the insoluble matter, concentrate the prepared solution, and
A manufactured epoxy compound was obtained. The physical properties of the purified epoxy compound are not shown in Table 2.

Comparative Example 1 Table 2 does not show the results of treating epoxy compound X100a with a conventional alkali metal hydroxide aqueous solution in place of the metal amide compound.

(Effects of the Invention) According to the method of the present invention, non-hydrolyzable chlorine, which was difficult to remove with conventional methods, can be easily removed, and even when used in electrical or electronic parts, there is no problem with deterioration of electrical insulation or lead wires. It is possible to obtain an epoxy compound with a low chlorine content without problems such as corrosion.

Claims (2)

[Claims] (1) A method for purifying an epoxy compound, which comprises reacting an epoxy compound with a metal amide compound in an inert solvent. (2) The metal amide compound has the following general formula (A) or (B)
The purification method according to claim 1, which is a compound represented by: MN (SiR^1R^2R^3) (A) MNR^4R^5 (B) In the above general formulas (A) and (B), M represents an alkali metal selected from Li, Na, and ^1, R^2, R
^3, R^4 or R^5 represents a group selected from hydrogen, alkyl, alkenyl, aralkyl and aryl, and these may be the same.