JP3476027B2 - Manufacturing method of epoxy resin - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin and an epoxy resin composition which give a cured product having excellent heat resistance, water resistance and mechanical strength, and a cured product thereof. The epoxy resin and epoxy resin composition of the present invention are extremely useful for a wide range of applications such as molding materials, casting materials, laminated materials, composite materials, paints, adhesives, and resists. 2. Description of the Related Art Epoxy resins are generally cured with various curing agents to give cured products having excellent mechanical properties, water resistance, chemical resistance, heat resistance and electrical properties. It is used in a wide range of fields such as agents, paints, laminates, molding materials, and casting materials. Conventionally, there is a liquid and solid bisphenol A type epoxy resin obtained by reacting bisphenol A with epichlorohydrin as the epoxy resin most used industrially. Other liquid bisphenol A type epoxy resin is added to tetrabromobisphenol
A flame-retardant solid epoxy resin obtained by reacting the resin A is used industrially as a general-purpose epoxy resin. However, as the molecular weight of the above-mentioned general-purpose epoxy resin increases, the toughness of a cured product obtained by curing the resin increases, but the heat resistance decreases. There are drawbacks. In addition, although a cured product obtained when a polyfunctional epoxy resin such as cresol novolak epoxy resin is mixed to compensate for a decrease in heat resistance, heat resistance is increased, but there is a disadvantage that toughness is reduced and water absorption is increased. . On the other hand, with recent remarkable developments in the electronics industry, etc., the heat resistance, water resistance and mechanical strength required for electrical insulating materials used in these materials have become increasingly strict, and epoxy resins excellent in these properties have been developed. It is expected to appear. [0004] In view of these circumstances, the present inventors have conducted intensive studies for an epoxy resin which gives a cured product having excellent heat resistance, water resistance and mechanical strength. It has been found that an epoxy resin having the following formula (1) imparts excellent heat resistance, water resistance and mechanical strength to a cured product thereof, thereby completing the present invention. That is, the present invention provides (1) Formula (1) (Wherein, n represents an average value and takes a value of 0 to 10. R and Q represent a hydrogen atom, a halogen atom, and a carbon number of 1 to 8).
Represents either an alkyl group or an aryl group,
Q may be the same or different from each other. G represents a glycidyl group. (2) an epoxy resin composition containing the epoxy resin and the curing agent according to the above (1) and, if necessary, a curing accelerator; and (3) the epoxy resin according to the above (2). A cured product obtained by curing the composition. The compound represented by the formula (1) is, for example, a compound represented by the formula (2): (Wherein n, R, and Q have the same meanings as in formula (1)). The reaction of the compound represented by the formula with epihalohydrin is carried out in the presence of an alkali metal hydroxide. Can be obtained. The compound represented by the formula (2) is, for example, a compound represented by the formula (3): (Wherein X represents a halogen atom, a hydroxyl group or a lower alkoxy group; Q has the same meaning as in formula (1)) and a dihydroxybenzene compound in the presence of an acid catalyst It can be obtained by performing a condensation reaction below. In the formula (3), a chlorine atom, a bromine atom or the like is used as a halogen atom, a methyl group, an ethyl group or a t-butyl group is used as a lower alkyl group, and a methoxy group or an ethoxy group is used as a lower alkoxy group. Each is mentioned as a preferable group. Here, the dihydroxybenzenes correspond to compounds having two phenolic hydroxyl groups in one molecule, and include, for example, hydroquinone, resorcin, catechol, methylhydroquinone and the like. These dihydroxybenzenes may be used alone or in combination of two or more. When the above condensation reaction is carried out, the amount of the dihydroxybenzene used is preferably 0.5 to 20 mol, particularly preferably 2 to 2 mol per mol of the compound represented by the formula (3).
It is in the range of 10 moles. In the above condensation reaction, it is preferable to use an acid catalyst. Various acid catalysts can be used, but hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, oxalic acid, boron trifluoride, anhydrous aluminum chloride, chloride Zinc and the like are preferred, and p-toluenesulfonic acid, sulfuric acid and hydrochloric acid are particularly preferred. The use amount of these acid catalysts is not particularly limited, but it is preferable to use 0.1 to 30% by weight of the compound represented by the formula (3). The above condensation reaction can be carried out without a solvent or in the presence of an organic solvent. Specific examples of using an organic solvent include toluene, xylene, methyl isobutyl ketone, and the like. The amount of the organic solvent used is preferably 50 to 300% by weight, more preferably 100 to 250% by weight, based on the total weight of the charged raw materials. The reaction temperature is preferably in the range of 40 to 180 ° C, and the reaction time is 1 to 8
Time is preferred. After completion of the reaction, the pH value is adjusted to 3 to 7, preferably 5 to 7, by performing a neutralization treatment or a water washing treatment. When performing a water washing treatment, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkaline earth metal hydroxides such as calcium hydroxide and magnesium hydroxide, ammonia, sodium dihydrogen phosphate, diethylene triamine, triethylene The treatment may be performed using various basic substances such as organic amines such as ethylenetetramine, aniline, and phenylenediamine as neutralizing agents. In the case of a water washing treatment, it may be performed according to a conventional method. For example, water in which the neutralizing agent is dissolved is added to the reaction mixture, and the separation and extraction operation is repeated. After the neutralization treatment, the unreacted dihydroxybenzenes and the solvent are distilled off under reduced pressure and the product is concentrated to obtain the compound represented by the formula (2). As a method for obtaining the epoxy resin of the present invention from the compound represented by the formula (2), a known method can be adopted. For example, an alkali metal hydroxide such as sodium hydroxide, potassium hydroxide or the like is added to a dissolved mixture of the compound represented by the formula (2) obtained above and an epihalohydrin such as an excess epichlorohydrin or epibromohydrin, or The epoxy resin of the present invention can be obtained by reacting at a temperature of 20 to 120 ° C. for 1 to 10 hours while adding. In the reaction for obtaining the epoxy resin of the present invention, an aqueous solution of the alkali metal hydroxide may be used. In this case, the aqueous solution of the alkali metal hydroxide is continuously added to the reaction system. A method may be employed in which water and epihalohydrin are continuously distilled off under reduced pressure or normal pressure, liquids are separated, water is removed, and epihalohydrin is continuously returned into the reaction system. A quaternary ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide or trimethylbenzylammonium chloride is added as a catalyst to a dissolved mixture of the compound represented by the formula (2) and epihalohydrin at 50 to 150 ° C. 1-5
A solid or aqueous solution of an alkali metal hydroxide is added to the halohydrin etherified compound of the compound of the formula (2) obtained by reacting for 2 hours, and the mixture is reacted again at a temperature of 20 to 120 ° C. for 1 to 10 hours to remove hydrogen halide ( (Ring closure). The amount of epihalohydrin used in these reactions is usually 1 to 20 mol, preferably 2 to 10 mol, per equivalent of the hydroxyl group of the compound represented by the formula (2). The amount of the alkali metal hydroxide to be used is 0.8 to 15 mol, preferably 0.9 to 11 mol, per 1 equivalent of the hydroxyl group of the compound represented by the formula (2). Further, in order to make the reaction proceed smoothly, it is preferable to carry out the reaction by adding an aprotic polar solvent such as dimethyl sulfone or dimethyl sulfoxide in addition to alcohols such as methanol and ethanol. When alcohols are used, they are used in an amount of 2 to 20% by weight, more preferably 4 to 15% by weight, based on the amount of epihalohydrin. When an aprotic polar solvent is used, the amount is 5 to 1 with respect to the amount of epihalohydrin.
00% by weight, more preferably 10 to 90% by weight. After washing the reaction product of these epoxidation reactions with or without washing with water, at 110 to 250 ° C.
Epihalohydrin and other additional solvents are removed at a pressure of 10 mmHg or less. In order to further reduce the amount of hydrolyzable halogenated epoxy resin, the obtained epoxy resin is dissolved again in a solvent such as toluene and methyl isobutyl ketone, and an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is used. May be further reacted to ensure ring closure. In this case, the amount of the alkali metal hydroxide to be used is preferably 0.0 to 1 equivalent of the hydroxyl group of the compound represented by the formula (2) used for the epoxidation.
It is 1 to 0.3 mol, particularly preferably 0.05 to 0.2 mol. The reaction temperature is 50 to 120 ° C, and the reaction time is usually 0.5 to 2 hours. After completion of the reaction, the formed salt is removed by filtration, washing with water, and the like, and the solvent such as toluene and methyl isobutyl ketone is distilled off under reduced pressure under heating to obtain the epoxy resin of the present invention. The epoxy resin composition of the present invention can be obtained by uniformly mixing the epoxy resin of the present invention, a curing agent, and if necessary, a curing accelerator. In the epoxy resin composition of the present invention, an epoxy resin other than the epoxy resin of the present invention can be used in combination as the epoxy resin. In the epoxy resin composition of the present invention, as a curing agent, an amine compound, an acid anhydride compound, an amide compound, a phenol compound, or the like can be used. Specific examples of the curing agent that can be used include diaminodiphenylmethane,
Polyamide resin synthesized from diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, dicyandiamide, linolenic acid dimer and ethylenediamine, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride,
Tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, phenol novolak, and modified products thereof, imidazole, BF ₃
-Amine complexes, guanidine derivatives and the like. Further, the compound represented by the formula (2) used as a raw material of the epoxy resin of the present invention can also be used as a curing agent. These curing agents may be used alone or in combination of two or more. The amount of the curing agent used is preferably 0.7 to 1.2 equivalents per equivalent of the epoxy group of the epoxy resin. If the amount is less than 0.7 equivalents or more than 1.2 equivalents with respect to 1 equivalent of epoxy group, curing may be incomplete and good cured physical properties may not be obtained. When the above curing agent is used, a curing accelerator may be used in combination. Examples of the curing accelerator include imidazoles, tertiary amines, phenols, and metal compounds. When the curing accelerator is used, the amount used is 0.1 to 5.0 with respect to 100 parts by weight of the epoxy resin.
Parts by weight are preferred. Further, the epoxy resin composition of the present invention may contain various additives such as fillers such as silica, alumina and talc, silane coupling agents, release agents and pigments, if necessary. The epoxy resin composition of the present invention can be obtained by uniformly mixing the components. The epoxy resin composition of the present invention containing the epoxy resin of the present invention, the curing agent and, if necessary, a curing accelerator can be easily formed into a cured product by a method similar to a conventionally known method. For example, the epoxy resin composition of the present invention is thoroughly mixed with an epoxy resin of the present invention and a curing agent, a filler and other additives, if necessary, using an extruder, a kneader, a roll, or the like until uniform. The epoxy resin composition is melted and then molded using a casting or transfer molding machine.
A cured product can be obtained by heating at 00 ° C. for 2 to 10 hours. Further, the epoxy resin composition of the present invention is dissolved in a solvent such as toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone and the like, and is used to prepare glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, paper and the like. A prepreg obtained by impregnating a substrate and drying by heating may be subjected to hot press molding to obtain a cured product. As specific examples of the diluting solvent which can be used in this case, methyl ethyl ketone, acetone, methyl isobutyl ketone and the like are preferable, and the amount of the diluting solvent is usually 10 to 70% by weight in the mixture of the epoxy resin composition of the present invention and the diluting solvent. , Preferably 15 to 65% by weight. Since the cured product thus obtained is excellent in heat resistance, water resistance and mechanical strength, it can be used in a wide range of fields requiring heat resistance, water resistance and high mechanical strength.
Specifically, it is useful as any electric or electronic material such as a sealing material, a laminate, or an insulating material. Further, it can be used in the fields of molding materials, adhesives, composite materials, paints, and the like. EXAMPLES Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. Hereinafter, all parts are by weight unless otherwise specified. Example 1 A flask equipped with a thermometer, a dropping funnel, a condenser and a stirrer was charged with 4,4'-bis (chloromethyl) biphenyl 2
51 parts, 660 parts of resorcinol and 500 ml of methyl isobutyl ketone were charged and stirred at room temperature while blowing nitrogen. 2.8 p-toluenesulfonic acid (monohydrate)
The mixture was slowly added while keeping the liquid temperature from exceeding 50 ° C. while paying attention to heat generation. Thereafter, the mixture was heated to 110 ° C. in an oil bath and reacted for 2 hours. After completion of the reaction, 500 ml of methyl isobutyl ketone was further added, and the mixture was transferred to a separating funnel and washed with water. After washing with water until the washing water shows neutrality, the solvent and unreacted substances are removed from the organic layer by heating under reduced pressure, and the following formula (4) is obtained. 367 parts of the compound represented by the formula were obtained. The softening point of the product was 85.2 ° C. and the hydroxyl equivalent was 104 g / eq. When analyzed by a GPC analyzer using tetrahydrofuran as a solvent, the value of n in the formula (4) was 0.2. Then, 208 parts of the compound obtained by the above reaction and epichlorohydrin 740 were added to the flask equipped with a thermometer, a condenser and a stirrer while purging with nitrogen gas.
Parts and 185 parts of dimethyl sulfoxide were charged and dissolved. Further, the mixture was heated to 50 ° C., and 80.8 parts of flaky sodium hydroxide (99% pure) was added in portions over 90 minutes.
Thereafter, the reaction was further performed at 60 ° C. for 2 hours and at 70 ° C. for 1 hour. After completion of the reaction, dimethyl sulfoxide and epichlorohydrin were distilled off under heating and reduced pressure at 130 ° C., and 64
0 parts of methyl isobutyl ketone was added and dissolved. Further, the solution of methyl isobutyl ketone was heated to 70.degree.
After adding 0 parts and reacting for 1 hour, washing with water was repeated three times to make the pH neutral. Further, the aqueous layer was separated and removed, and methyl isobutyl ketone was distilled off from the oil layer under heating and reduced pressure by using a rotary evaporator to obtain the following formula (5). The epoxy resin (A) 3 of the present invention represented by the formula:
04 parts were obtained. The softening point of the obtained epoxy resin is 62.
At 4 ° C., the epoxy equivalent was 181 g / eq. Example 2 A reaction was carried out in the same manner as in Example 1 except that 330 parts of hydroquinone was used in place of resorcin, and the following formula (6) was used. 334 parts of the compound represented by the formula were obtained. The product has a softening point of 93.5 ° C. and a hydroxyl equivalent of 113 g / eq.
Met. GPC analysis revealed that the value of n in equation (6) was 0.9. Further, an epoxidation reaction was carried out in the same manner as in Example 1 except that 226 parts of the obtained compound represented by the formula (6) was used, and the following formula (7) was used. The epoxy resin (B) 3 of the present invention represented by the formula:
21 parts were obtained. The softening point of the obtained epoxy resin is 70.
At 3 ° C., the epoxy equivalent was 192 g / eq. Examples 3 to 4, Comparative Example 1 The obtained epoxy resins (A) and (B) were compared with o-
Cresol novolak epoxy resin (EOCN102
0, Nippon Kayaku Co., Ltd., softening point 65.1 ° C., epoxy equivalent 200 g / eq), phenol novolak as a curing agent (hydroxyl equivalent 106 g / eq, softening point 80.2 ° C.),
Triphenylphosphine (TPP) was used as a curing accelerator, blended with the composition shown in Table 1, kneaded with a roll at 70 ° C. for 15 minutes, and heated at 150 ° C. under a molding pressure of 50 kg / cm ² .
Transfer molding for 80 seconds, then 2 hours at 160 ° C
After curing at 180 ° C. for 8 hours, a test piece was prepared, and the glass transition point, water absorption and mechanical strength were measured. Table 1 shows the results. The measurement conditions of the glass transition point, the water absorption and the bending strength are as follows. In the table, the numerical value in the column of the formulation indicates parts by weight. Glass transition point thermomechanical analyzer (TMA): TM- manufactured by Vacuum Riko Co., Ltd.
7000 Temperature rise rate: 2 ° C./min Water absorption test piece (cured product): diameter 50 mm thickness 3 mm Weight increase after boiling in disc at 100 ° C. for 24 hours (% by weight) Flexural strength Complies with JIS K-6911 Table 1 Example 3 Example 4 Comparative Example 1 Epoxy resin (A) 100 Epoxy resin (B) 100 EOCN1020 100 Epoxy equivalent (g / eq) 181 192 202 Phenol novolak 58.6 55.2 52.5 TPP 1 1 1 Glass transition temperature (° C) 172 176 154 Water absorption (%) 0.89 0.93 1.28 Flexural strength (Kg / mm ² ) 11.8 12.3 9.1 From the above Table 1, the cured product of the epoxy resin of the present invention is known. As compared with the cured product of the epoxy resin of the above, it showed a high glass transition point, a low water absorption and a high mechanical strength. The epoxy resin of the present invention can give a cured product having properties excellent in heat resistance, water resistance and mechanical strength, and can be used as a molding material, a casting material, a laminate material, a paint,
It is extremely useful for a wide range of applications such as adhesives and resists.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-25370 (JP, A) JP-A-6-65472 (JP, A) JP-A-4-342719 (JP, A) JP-A-7- 238147 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08G 59/06-59/08

Claims (1)

(57) [Claims] [Claim 1] The following formula (3) (In Formula (3), X represents a halogen atom, a hydroxyl group, or a lower alkoxy group. Q represents a hydrogen atom, a halogen atom,
Represents any one of an alkyl group and an aryl group. ) And a dihydroxybenzene compound in the presence of an acid catalyst to react the resulting compound in the presence of epihalohydrin and an alkali metal hydroxide. ) (In the formula (1), Q represents the same meaning as in the formula (3). N is an average value and takes a value of 0 to 10. R is a hydrogen atom, a halogen atom, or an alkyl group having 1 to 8 carbon atoms.) , An aryl group, each R may be the same or different from each other, and G represents a glycidyl group.)
A method for producing an epoxy resin represented by