JPH1160681A - Biphenol epoxy resin and its composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin which gives a cured item having a high glass transition temp., excellent strengths, and a low water absorption by subjecting a specific alkylated 4,4'-biphenol obtd. by the oxidation of a substance in the presence of a biocatalyst to the addition reaction with an epihalohydrin followed by cyclization. SOLUTION: An alkylated 4,4'-biphenol of formula I obtd. by the oxidation of a substance in the presence of a biocatalyst (e.g. hexamethyl-4,4'-biphenol obtd. by the oxidation of 2,3,5-trimethylphenol with a peroxide in the presence of peroxidase as the oxidation catalyst) is subjected to the addition reaction with an epihalohydrin e.g. in the presence of a basic catalyst and then to cyclization e. g. in the presence of an alkali metal compd. to give an epoxy resin of formula II. In those formulas, R<1> to R<8> are each H or a 1-4C alkyl provided at least two of R<1> to R<3> and at least two of R<6> to R<8> are respectively a 1-4C alkyl; (m) is 1-4; and (n) is 0-6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid biphenol type epoxy resin which is excellent in heat resistance, has a low heat-melt viscosity, is soluble in a solvent, and is easy to handle during production, and a composition thereof.

[0002]

2. Description of the Related Art With the recent development of the electronics industry, the market for epoxy resins as insulating materials has been expanding. Above all, in a sealing material application for the purpose of protecting a semiconductor element, a biphenol-type epoxy resin having a low melt viscosity and excellent heat resistance is often used. In particular, 3,3 ', 5
Glycidyl ether of 5'-tetramethyl-4,4'-biphenol is widely used because of its good solubility in solvents. However, the demands in the field of electronic materials are becoming severer every day, and there is a demand for materials having higher strength of cured products and higher heat resistance for the purpose of reducing the weight and weight of parts.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cured product having a higher glass transition temperature, a higher strength, and a lower water absorption than conventional epoxy resins containing a biphenyl skeleton which are commercially available. And to provide a solid biphenol type epoxy resin.

[0004]

SUMMARY OF THE INVENTION The present invention relates to an addition reaction of an alkyl-substituted 4,4'-biphenol represented by the following general formula (I) obtained by a method for oxidizing a substance using a biocatalyst with epihalohydrin and a ring closure. An object of the present invention is to provide an epoxy resin represented by the general formula (II) obtained by the reaction.

[0005]

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In the general formulas (I) to (II), R ¹ to
R ^3, R ⁶ ~R ⁸ are the same or different each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ¹ ~
At least two of R ³ and R ^{6 to} R ⁸ are the above-mentioned alkyl groups, and R ^{4 to} R ⁵ are the same or different and represent an alkyl group having 1 to 4 carbon atoms or a hydrogen atom;
And n is an integer of 0 to 6. The present invention also provides an epoxy resin composition comprising the epoxy resin and at least one curing agent selected from the group consisting of an acid anhydride, an organic amine, and a phenol resin.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for oxidizing a substance using a biocatalyst according to the present invention is specifically described in JP-A-4-262785. That is, a phenol resin can be obtained by using peroxidase obtained from legumes such as soybeans, rice, or other plants as an oxidation catalyst and oxidizing phenol using peroxide in the presence of peroxidase. This makes it possible to synthesize the polyphenol compound at low cost and efficiently. In particular, according to this method, it is possible to easily produce a polysubstituted polyphenol compound, which has been relatively difficult with conventional organic synthesis techniques. Of course, if the polysubstituted polyphenol obtained by this method is not sufficiently purified, fibrous components containing peroxidase are mixed. However, in the synthesis of an epoxy resin using a general phenolic compound and epihalohydrin such as epichlorohydrin, surprisingly, the mixed fibrous components and the like do not adversely affect the epoxidation reaction and can be used with high yield. It has been found that an epoxy resin can be obtained, which has led to the present invention.

There is no particular limitation on the phenolic compound applicable to the oxidation reaction by peroxidase in the present invention. For example, 2,3-xylenol, 2,4-
Xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, 3,6-xylenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, etc. Is mentioned. By subjecting these to an oxidation reaction using a biocatalyst, polyphenols of about 2 to pentamer [m = 1 to 4 in the above general formula (I)] can be obtained in good yield regardless of the number of substituents. it can. Among these, the two that have excellent cured product properties as epoxy resin are
It is a coupling product of a trisubstituted phenol such as 3,5-trimethylphenol.

Specifically, peroxidase is added to a solution of the above-mentioned phenolic compound, and peroxides such as hydrogen peroxide, methyl peroxide, and ethyl peroxide are gradually reacted dropwise at room temperature with stirring. An oxidative addition reactant can be easily obtained. That is, for example, hexamethylbiphenol can be easily obtained from 2,3,5-trimethylphenol.

The thus obtained general formula (I)
In the alkyl-substituted 4,4'-biphenol represented by R ^{1 to} R ³ , R ^{6 to} R ⁸ , or R ^{4 to} R ⁵ , the alkyl group having 1 to 4 carbon atoms may be a methyl group,
Examples include an ethyl group, a propyl group, and a butyl group. In addition, all of R ^{1 to} R ³ or R ^{6 to} R ⁸ may be substituted with an alkyl group (trisubstituted) or two may be substituted (disubstituted). . The alkyl-substituted 4, represented by the general formula (I),
A specific example of 4′-biphenol is “ENZOH” supplied by ENZYMOL, USA.
MBP ”(hexamethyl 4,4′-biphenol) and“ ENZO TTBBP ”(tetra-t-butyl 4,4 ′)
-Biphenol) and the like.

The epoxy resin of the present invention represented by the general formula (II) can be obtained by subjecting an alkyl-substituted 4,4'-biphenol represented by the general formula (I) to an addition reaction and a ring closing reaction with epihalohydrin. . Here, the epihalohydrin includes epichlorohydrin, epibromohydrin and the like, and preferably epichlorohydrin.

The above addition reaction and ring closure reaction are carried out, for example, in 4,4'-bishydroxy-2,2 ', 3,3', 5,
An alkyl-substituted 4,4'-biphenol represented by the above general formula (I) such as 5'-hexamethyl-biphenyl is mixed with an excess of epihalohydrin such as epichlorohydrin, and subjected to an addition reaction in the presence of a basic catalyst, and then to an alkali. A ring closure reaction may be performed by adding a metal hydroxide.
Here, as the basic catalyst, quaternary ammonium salts such as tetramethylammonium chloride, tetramethylammonium bromide, triethylmethylammonium chloride, tetraethylammonium iodide, and cetyltriethylammonium bromide are used. As the alkali metal hydroxide, potassium hydroxide,
Sodium hydroxide and the like can be used, and these can be added as a solid or as a 40 to 50% by weight aqueous alkali solution.

The above addition reaction is carried out at 70 to 130 ° C., preferably 80 to 120 ° C., for 1 to 10 hours, preferably 2 to 10 hours.
Perform for 6 hours. The amount of epihalohydrin used is 1 to 30 moles, preferably 3 to 25 moles per mole of the alkyl-substituted 4,4 'biphenol represented by the above general formula (I), and excess epihalohydrin is recovered by distillation. By doing so, reuse is possible. The basic catalyst is used in an amount of about 5 to 30 mol% based on the phenolic hydroxyl group of the alkyl-substituted 4,4'-biphenol.
Further, the ring closure reaction is preferably performed using an inert organic solvent. Examples of the organic solvent used include ethanol, isopropanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, benzene, toluene, xylene, dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether,
Examples include various aprotic polar organic solvents such as various glycol monoethers, dimethyl sulfoxide, dimethylformamide, and diacetone alcohol. The amount of the alkali metal compound used for the ring closure reaction is 1.0 to 1.0 mol per mol of the saponified halogen.
10.0 moles.

After the completion of the above addition reaction and ring closure reaction, the reaction product is washed with warm water, and then purified by removing water.
Alternatively, the reaction product is dissolved in an organic solvent that is insoluble or hardly soluble in water, such as methyl isobutyl ketone, methyl ethyl ketone, and toluene, and this solution is contacted with water or warm water to dissolve inorganic impurities such as salt in the aqueous phase. Then, the organic solvent is distilled off to purify. The epoxy resin represented by the above general formula (II) thus obtained has n
Is not occupied only by the compound of 0, and also includes the case where the polyepoxy compound having n of 1 to 6 is contained in a proportion of 20% by weight or less. In the general formula (II) of the present invention, n is an integer of 0 to 6, and when n is 7 or more, the softening point is high and disadvantageous in terms of workability, which is not preferable. n is
Preferably it is 0-3, more preferably 0.

The epoxy resin of the present invention represented by the general formula (II) contains at least one curing agent selected from the group consisting of an acid anhydride, an organic amine and a phenol resin,
It can be an epoxy resin composition. Here, examples of the acid anhydride-based curing agent include tetrahydrophthalic anhydride, pyromellitic anhydride, succinic anhydride, maleic anhydride, methylnadic anhydride, benzophenonetetracarboxylic acid, and derivatives thereof. Also,
As an organic amine-based curing agent, diethylene triamine,
Examples include triethylenetetramine, N-aminoethylpiperazine, diethylaminopropylamine, benzyldimethylamine, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, dicyandiamide, xylenediamineethylmethylimidazole, and the like. Furthermore, examples of the phenolic resin-based curing agent include novolak-type phenol resins, novolak-type cresol resins, and the like.

The amount of the curing agent used is 10 to 200 parts by weight, preferably 30 to 150 parts by weight, based on 100 parts by weight of the epoxy resin of the present invention. If less than 10 parts by weight,
The curing of the epoxy resin of the present invention becomes insufficient, and good mechanical strength and heat resistance cannot be obtained. On the other hand, if it exceeds 200 parts by weight, the toughness of the composition tends to decrease.

Further, the epoxy resin composition of the present invention may contain, if necessary, various known curing accelerators, fillers, release agents, flame retardants, coloring agents, plasticizers, coupling agents, and the like. Can be.

[0018]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In Examples, parts and% are based on weight unless otherwise specified. Example 1 (Synthesis of Epoxy Resin) US-based ENZYM was used as an alkyl-substituted 4,4'-biphenol obtained by a method of oxidizing a substance using a biocatalyst.
OL, ENZO-HMBP (hexamethyl 4,4 '
-Biphenol) to synthesize an epoxy resin. That is, 81.0 g of ENZO-HMBP (0.
3 mol) and 555 g (6.0 m) of epichlorohydrin.
ol), 2.5 g of water, 28.8 g (0.09 mol) of tetrabutylammonium bromide, and 200 ml of dimethyl sulfoxide (DMSO) were charged into a 2.0 L four-necked flask equipped with a cooling tube, and charged under a nitrogen atmosphere.
The reaction was carried out for 7 hours while stirring at 0 ° C. to synthesize a chlorohydrin adduct.

Next, a 50% aqueous solution of sodium hydroxide 1
20 g (1.5 mol) was slowly added dropwise while cooling so that the inside of the system became 10 ° C. or lower, and further reacted at 10 ° C. for 6 hours. After completion of the reaction, the mixture was washed with methanol / water (1: 1% by volume), dissolved in 1,4-dioxane (1,200 ml), and the filtrate was reprecipitated in water. The precipitate was filtered again, washed with distilled water, and dried under reduced pressure at 70 ° C. to obtain a pale yellow solid epoxy resin in a yield of 83%. The melting point of the obtained diglycidylated form of HMBP (DGEHMBP) was 113 to 116 ° C, and the epoxy equivalent was 198 to 206.

The infrared absorption (I
R) The spectrum and ¹ H-NMR were measured. In the IR spectrum, absorption at 915 cm ^-1 based on the glycidyl group was observed, and absorption at 3,500 cm ^-1 based on biphenol had disappeared. In the ¹ H-NMR spectrum, a signal of an epoxy group at 2.64 to 4.15 ppm was confirmed, and a signal of a biphenol hydroxyl group at 7.78 ppm disappeared. From these results, it was confirmed that the desired diglycidylated product of ENZO-HMBP could be synthesized. The infrared spectrum of ENZO-HMBP and
¹ H-NMR spectra are shown in FIGS. 1 and 3 as DGEHMBP.
2 and 4 show the infrared spectrum and ¹ H-NMR spectrum of
Are shown below. Further, G of the obtained DGEHMBP
FIG. 5 shows the PC chart. From this, it was confirmed that DGEHMBP starting from a biphenol compound obtained by an oxidation method using a biocatalyst was a high-purity diepoxylated product.

Example 2 (Curing and Hardening Physical Properties of Epoxy Resin Composition) DGEHMBP obtained in Example 1 was added to 63.9 g, and methylhexahydrophthalic anhydride (MeHHPA) was used.
After adding 1 g as a curing agent and further adding 0.64 g of benzyldimethylamine as a curing catalyst, the mixture was uniformly mixed, and then mixed at 85 ° C. for 5 hours, 150 ° C. for 15 hours, and further added at 18 ° C.
By heating at 0 ° C. for 3 hours, a completely cured product was obtained.
For the obtained cured product, the glass transition temperature (T
g), the fracture toughness value, and the fracture strength and elastic modulus by the bending test were measured. Table 1 shows the results.

Comparative Example 1 (Curing and Curing Physical Properties of Epoxy Resin Composition) As an epoxy resin, YX-4000 [manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent: 187 g / eq. Tetramethylbiphenol diglycidyl ether] 61.0 g,
Using 54.0 g of MeHHPA and 0.61 g of benzyldimethylamine, a cured product was obtained and evaluated in the same manner as in Example 2. Table 1 shows the results. It turns out that the cured product of the epoxy resin composition using the epoxy resin of the present invention has good heat resistance and mechanical strength.

Example 3 (Curing and Curing Physical Properties of Epoxy Resin Composition) As an epoxy resin, 120 g of DGEHMBP was used, and as a curing agent, a modified polycarbodiimide [methylenebis (4-phenyl) described in Japanese Patent Application No. 08-083085. Of polycarbodiimide, which is a 15-mer of isocyanate), with 10 mol% of trimellitic anhydride added to the carbodiimide group], and the mixture was homogenized. After heating this resin composition at 150 C for 30 minutes, it is 60 kgf / cm at 200 ° C. for 1 hour.
Perform compression molding at a pressure of ² and then 200 ° C
For 4 hours in an oven to prepare a cured product for evaluation. For the obtained cured product, heat deformation temperature, Vicat softening point temperature, bending strength test, Izod impact strength,
The surface / volume resistivity was measured by the following method. Table 2 shows the results.

Heat deformation temperature (according to ASTM D648) test condition; bending stress = 18.6 kgf / cm ² , heating rate = 120 ° C./hr Vicat softening point temperature (according to ASTM D1528) test condition; load = 1 kgf, heating Speed = 50 ° C./hr bending test (according to ASTM D790 ) Test conditions; bending speed = 1.5 mm / min: distance between supporting points = 50 mm, test temperature = 23 ° C. × 50% RH Izod impact strength (according to ASTM D256 ) Test Conditions: Notch, test temperature = 23 ° C x 50% RH

Surface resistivity (according to ASTM D257 ) Test conditions: applied voltage = 500 V × 1 min test environment = 23 ° C. × 50% RH test piece = 95 mm × 95 mm × 3 mm thickness test electrode main electrode = φ50 mm, counter electrode = φ83 mm Electrode material Silver paste coating volume resistivity (according to ASTM D257 ) Test conditions; same as surface resistivity measurement

Comparative Example 2 (Curing and Cured Physical Properties of Epoxy Resin Composition) YX-4000 used in Comparative Example 1 as an epoxy resin
A cured product was prepared and evaluated in the same manner as in Example 3 except that を was used. Table 2 shows the results.

From the results shown in Table 2, it can be seen that the epoxy resin composition using the novel epoxy resin of the present invention shows superior properties in heat resistance, strength and electric properties as compared with the conventional product.

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

The novel epoxy resin of the present invention has good heat resistance, physical strength, and electrical properties not found in conventional epoxy resins. Therefore, it can be widely used in the field of electronic and electric parts, such as sealing materials, paints, casting materials, adhesives, prepregs for printed circuit boards, and sealing materials.

[Brief description of the drawings]

FIG. 1 is an infrared absorption spectrum of hexamethylbiphenol.

FIG. 2 is an infrared absorption spectrum of an epoxy resin (DGEHMB).

FIG. 3 is a ¹ H-NMR spectrum of hexamethylbiphenol.

FIG. 4 ¹ H-NMR of epoxy resin (DGEHMB)
It is a spectrum.

FIG. 5 is a GPC elution curve of an epoxy resin (DGEHMB).

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hozumi Sato 2--11-24 Tsukiji, Chuo-ku, Tokyo Inside Nippon Gosei Rubber Co., Ltd.

Claims (2)

[Claims] An alkyl-substituted 4,4 compound represented by the following general formula (I) obtained by a method for oxidizing a substance using a biocatalyst.
An epoxy resin represented by the general formula (II) obtained by subjecting 4'-biphenol to an addition reaction and a ring closure reaction with epihalohydrin. Embedded image Embedded image [In the general formulas (I) to (II), R ^{1 to} R ³ , R ⁶ to
R ⁸ is the same or different and is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ^{1 to} R ³ , R ⁶ to
At least two of R ⁸ are the above-mentioned alkyl groups, R ^{4 to} R ⁵ are the same or different and represent an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, m is an integer of 1 to 4, n
Is an integer of 0 to 6. ] 2. An epoxy resin composition comprising the epoxy resin according to claim 1 and at least one curing agent selected from the group consisting of an acid anhydride, an organic amine and a phenol resin.