JPS59227872A - Preparation of epoxy compound - Google Patents

Abstract

PURPOSE:To obtain an epoxy compound useful as a raw material for an epoxy resin with a low halogen content, especially useful for high integration, by reacting a mono-, di-, or polyallyl ether compound with H2O2 in the presence of acetonitrile under specific conditions. CONSTITUTION:A mono-, di-, or polyallyl ether compound [e.g., compounds shown by the formula I and formula II (R, R1 and R2, are H, or CH3; n is 1-3)] is reacted with 30-80wt% aqueous solution of H2O2 in the presence of acetonitrile with adjusting the reaction system to >=7.5 (especially 8-9.5)pH, to give an epoxy compound. The reaction temperature is preferably 40-70 deg.C. NaOH, K2CO3, etc. are used as an alkali to adjust pH. EFFECT:This process has improved safety, has an extremely small amount of by- products of oxidation of aryl nucleus because epoxidation is advanced selectively, and it has an extremely small amount of by-products of ring opening of epoxy ring because of an alkali condition.

Description

[Detailed description of the invention] The present invention relates to a method for producing an epoxy compound.

Epoxy compounds are used in a variety of applications by utilizing the cleavage of the oxycyto ring of 1,2-epoxide, and novolak-type epoxy resins in particular are used as materials for electrical and electronic components, especially as semiconductor encapsulation materials. The demand for it is increasing not only from a cost perspective but also because of its excellent heat resistance and water resistance.

However, in recent years, the demands on the electrical properties of resins have increased all the time, and resins for high integration are particularly desired.

The conventionally known novola type epoxy resin is obtained by reacting a phenolic novolak resin with shrimp halohydrin, but although it contains almost no inorganic halogen, it contains organic halogens that decompose under high temperature and high humidity. Since it contains about 11,000 pp of sexual halogen, there was a problem that it could not be used for high-density applications.

The present inventors have conducted various studies focusing on epoxidation by oxidation of olefins as an epoxidation method that does not use ebihalohydrin, with the aim of improving the quality of various epoxy compounds in addition to the above-mentioned novola-tsuk type epoxy resin. As a result, they discovered that the object could be achieved by oxidizing an allyl ether compound with hydrogen peroxide under specific conditions, and completed the present invention.

That is, in the present invention, a mono-, di-, or polyallyl ether compound is mixed in the presence of acetonitrile, and the pH of the reaction system is adjusted to 7.
Provided is a method for producing an epoxy compound, which is characterized by reacting with hydrogen peroxide while adjusting the hydrogen peroxide concentration to 5 or more.

The method of the present invention is superior in safety to methods using peracids, which are well known as conventional methods for epoxidizing olefins, and since epoxidation proceeds selectively, oxidation by-products of aryl nuclei are eliminated. Furthermore, unlike the acidic conditions that are common in epoxidation reactions, the reaction is carried out under specific alkaline conditions, so that the ring-opening by-products of the epoxy ring are extremely small.

The present invention will be explained in detail below.

The monoallyl ether compound used in the present invention can be expressed, for example, by the following general formula (wherein R represents hydrogen or methyl, and n represents 1 to 8).

) Examples include allyl phenyl ether, allyl-methyl phenyl ether, allyl-dimethyl phenyl ether, allyl-trimethyl phenyl ether, and the like.

Further, the dimethylallyl ether compound is represented by, for example, the following general formula (in the formula, ■ and R2 each independently represent hydrogen or methyl), and examples include bisphenol F diallyl ether and bisphenol A diallyl ether.

Further, as the polyallyl ether compound used in the method of the present invention, an allyl ether compound of a novola-tsuk type phenolic resin is exemplified.
o, m, p-isomers) Resin having an average number of nuclei of usually 3 to 15 obtained by condensing aldehydes such as toformaldehyde, furfural, and acrolein in the presence of an acid or alkali catalyst by a known method. is preferred, and when producing these novolac type phenolic resins, it is also possible to use co-condensed novolac type resins in which other phenols are added in an amount of 50 mol% or less based on the total phenol.

Examples of other phenols include monohydric phenols such as ethylphenol, isopropylphenol, butylphenol, octylphenol, and xylenol, and dihydric phenols such as resorcinol, hydroquinone, and catechol.

Allyl etherified products of these novolac type phenolic resins are produced by combining novolac type phenolic resins and allyl halides in the presence of an alkaline compound, for example, as disclosed in the patent application filed in 1973.
It can be produced according to the method described in No. 7-147159.

Among these polyallyl ether compounds, allyl etherified phenol Novola Tsukugi [1! , allyl etherified resol novola, tsuk resin, and allyl etherified cresol/xylenol cocondensation novola tsuk resin are preferably used.

The hydrogen peroxide used in the present invention includes hydrogen peroxide containing 30
Used as a ~80% aqueous solution.

The amount of acetonitrile used in the present invention is preferably at least equimolar or more than the same mole as hydrogen peroxide.

Examples of the alkali for pH adjustment used in the present invention include alkali hydroxides such as sodium hydroxide, potassium hydroxide, and calcium hydroxide, alkali such as potassium carbonate and soda carbonate, and reaction system (7) that always maintains a pH of 7. It is preferable to supply the water so as to keep the pH between .5 and 10, and particularly preferably between 8 and 9.5. If the alkali supply stops here, p
If the pH drops below 7.5, the epoxidation reaction will slow down significantly, and too much alkali will be supplied, resulting in a decrease in pEI.
If it exceeds 10, the decomposition of hydrogen peroxide becomes intense, which is industrially disadvantageous because the amount of hydrogen peroxide used increases.

For the purpose of adjusting the viscosity of the reaction system, a solvent inert to the reaction,
For example, methanol, ethanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc. can be used. Moreover, acetonitrile can also be used as a solvent.

The epoxidation reaction of the present invention is usually carried out at a temperature of 30 to 80°C, preferably 40 to 70°C, and the reaction rate becomes significantly slow below 30°C.

Further, if the temperature is 80° C. or higher, hydrogen peroxide decomposes rapidly, which is not preferable.

Next, examples will be shown to explain the present invention in detail, but the present invention is not limited thereto.

Note that "Example Middle" indicates the weight unit.

Example 1 In a reactor equipped with a thermometer, a stirrer, a dropping funnel, a reflux condenser and a pH meter, 2-methylphenyl allyl ether 8
．． 4 parts of acetonitrile, 8.8 parts of methanol, 0.1 part of sodium hydrogen phosphate, and 6.5 parts of 85% hydrogen peroxide solution, and heated to 60°C with stirring. It was kept at temperature for 8 hours. During this time, a 5% aqueous sodium hydroxide solution was added dropwise to maintain the pH in the system at 8 to 9.5. When the reaction solution was analyzed by gas chromatography, it was found that it contained 2.4 parts of 2-methylphenylglycidyl ether and 1.1 parts of 2-methylphenyl allyl ether. material(
7) The conversion rate was 67.6%, and the selectivity to 2-methylphenylglycidyl ether was 95.0%.

Furthermore, from the analysis of hydrogen peroxide, the selectivity of hydrogen peroxide for oxidation was 62.5%. Allyl etherified 0-cresol novola, 3.7 parts of Tsuku type resin, 45 parts of acetonitrile, 20
0.1 part of dihydrogen phosphate, 2.4 parts of 70% hydrogen peroxide solution were added, and the temperature was raised to 60'C without stirring and maintained at the same temperature for 16 hours. During this time, a 5% aqueous sodium hydroxide solution was added dropwise to maintain the pH of the reaction system at 8 to 9.5. Further, 2.4 parts of 70% hydrogen peroxide solution was added to the reaction system at each of the 4th hour, 8th hour, and 122nd hour after the start of the reaction. After the reaction was completed, 50 d of water was added, and the resin was extracted and separated with 100 ml of $ toluene. The obtained toluene layer is 100? ? ! t
The mixture was washed with water and separated. Subsequently, the toluene layer was concentrated under reduced pressure, and 3.8 parts of the concentrate was analyzed. From the quantitative determination of olefin double bonds in the nuclear magnetic resonance spectrum, the epoxy equivalent was 274.
It was confirmed that the conversion rate of allyl groups was 65%. The selectivity to epoxy groups was 94.5%. Further, the epoxidation selectivity of hydrogen peroxide was 8%. Furthermore, the chlorine content was 80 ppm.

Reference Example: Into a reactor equipped with a thermometer, a stirrer, a dropping funnel, and a reflux condenser, 118 parts (1 equivalent) of an 0-cresol novolak resin with a softening point of t o 'c and 2 ooofrLL of acetone as a reaction solvent were charged. After completely dissolving 806 parts (1.58 mol) of a 20% aqueous sodium hydroxide solution, the mixture was stirred well. While maintaining the temperature of the reaction system at 40°C, 181 parts (1.5 mol) of allyl bromide was added dropwise.
After holding at 40°C for 2 hours, the temperature was raised to 60°C and held at the same temperature for 2 hours.

Next, the aqueous layer was removed by liquid separation, and diethyl ether was added to the oil layer to extract 11 fV of produced wood, which was then concentrated to obtain 1160 parts of pale yellow viscous liquid wood.

As a result of analyzing the obtained resin, the OH content was 0.1%.
, when the bromine content was 20 ppm or less, the infrared absorption spectrum showed that there was no absorption of the phenol hydroxyl group <8400 cm 1, and furthermore, the quantitative analysis of the olefin double bond in the nuclear magnetic resonance spectrum showed that the allyl etherification rate was 112%. - It was confirmed that it was a cresol novolak resin.

Claims (1)

[Claims] A method for producing an epoxy compound, which comprises reacting a mono-, di-, or polyallyl ether compound with hydrogen peroxide in the presence of acetonitrile while controlling the pH of the reaction system to 7.5 or higher.