JP3377241B2 - Method for producing epoxy resin, epoxy resin composition and cured product thereof - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an epoxy resin which gives a cured product having excellent heat resistance and water resistance, an epoxy resin composition and a cured product thereof. The compositions of the present invention are extremely useful in a wide range of applications such as molding materials, casting materials, laminate materials, composite materials, paints, adhesives, resists, and the like. Further, by reacting the allyl group of the epoxy resin obtained in the present invention with the SiH group of silicone oil, application to a polymer alloy is also possible. 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, electrical properties, and the like. 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 frequently used industrially. In addition, a flame-retardant solid epoxy resin obtained by reacting liquid bisphenol A with a liquid bisphenol A epoxy resin is industrially used as a general-purpose epoxy resin. [0003] However, the above-mentioned general-purpose epoxy resin has a disadvantage that as the molecular weight increases, the cured product obtained by using the resin has higher water absorption and lower heat resistance. There is. On the other hand, with recent remarkable developments in the electronics industry, etc., the water resistance and heat resistance required for electrical insulating materials used for these are becoming increasingly severe, and the emergence of epoxy resins having excellent water resistance and heat resistance. Is eagerly awaited. [0004] In view of such circumstances, the present inventors have conducted intensive studies for an epoxy resin having excellent water resistance and heat resistance. As a result, an epoxy resin represented by the following formula (1) was obtained. Have been found to impart water resistance and heat resistance to the cured product, and have completed the present invention. That is, the present invention provides (1) the following formula (2) (In the formula, n represents an average value and represents a positive number. R represents a residue in which the hydroxyl group of a compound having two phenolic hydroxyl groups has been removed, and each R is different from each other even if they are the same. Wherein the alcoholic hydroxyl group of the compound represented by formula (1) is reacted with allyl halide (and, if necessary, epihalohydrin). Wherein n and R have the same meanings as in formula (1), and each X represents a hydrogen atom, an allyl group (CH ₂ ＣＨCHCH ₂ —) or a glycidyl group;
Each X may be the same or different from each other,
5% or more of X is an allyl group. (2) In an epoxy resin composition containing an epoxy resin, a curing agent and, if necessary, a curing accelerator, an epoxy resin of the formula (1) is used as the epoxy resin component. Epoxy resin composition characterized by containing,
(3) An epoxy resin composition for a laminate comprising the epoxy resin composition according to (2), and (4) a cured product of the epoxy resin composition according to (2) or (3). According to the present invention, a cured product having excellent heat resistance and water resistance can be obtained. In the production method of the present invention,
Formula (2) (Wherein n and R have the same meanings as described above). The alcoholic hydroxyl group of the compound represented by the formula (1) is reacted with allyl halide (further, if necessary, epihalohydrin). More specifically, the reaction between the alcoholic hydroxyl group of the compound represented by the formula (2) and allyl halide (furthermore, epihalohydrin if necessary) is carried out by using dimethyl sulfoxide or a quaternary ammonium salt or 1,3-dimethyl-2. −
The epoxy resin of the formula (1) can be obtained by performing the reaction in the presence of imidazolidinone and an alkali metal hydroxide and adjusting the amount of the alkali metal hydroxide used. According to the study of the present inventors, the alcoholic hydroxyl group of the compound of the formula (2) is more reactive than common alcohols, for example, dimethyl sulfoxide or quaternary ammonium salt or 1-hydroxyl. Surprisingly, by allowing coexistence of 2,3-dimethyl-2-imidazolidinone and an alkali metal hydroxide, the reaction between an alcoholic hydroxyl group and an allyl halide (and epihalohydrin if necessary) can be selectively carried out. Further, by adjusting the amount of the alkali metal hydroxide, the alcohol of the compound represented by the formula (2)
The hydroxyl group can be allylated (and, if necessary, further epoxidized) at a desired ratio. The reaction between the alcoholic hydroxyl group of the compound represented by the formula (2) and allyl halide (furthermore, epihalohydrin if necessary) is carried out by using dimethyl sulfoxide or a quaternary ammonium salt or 1,3-dimethyl-2-imidazolidinone. When the reaction is carried out in the co-presence of a solvent and an alkali metal hydroxide, alcohols, aromatic hydrocarbons, ketones, cyclic or chain ether compounds, etc. may be used in combination as a solvent. Dimethyl sulfoxide, quaternary ammonium salt, 1,3
-Dimethyl-2-imidazolidinone may be used alone or in combination. The use amount of dimethyl sulfoxide or 1,3-dimethyl-2-imidazolidinone is preferably 5% by weight to 300% by weight based on the compound represented by the formula (2). If the amount is less than 5% by weight based on the compound represented by the formula (2), the reaction between the hydroxyl group of the compound represented by the formula (2) and allyl halide or epihalohydrin becomes slow, so that a long-time reaction is required, which is preferable. Absent. If the amount exceeds 300% by weight based on the compound represented by the formula (2), the effect of increasing the amount is almost negligible, but the volumetric efficiency becomes poor, which is not preferable. Examples of the quaternary ammonium salt include tetramethylammonium chloride, tetramethylammonium bromide, trimethylbenzylammonium chloride, and the like. 0.3 to 50 g is preferable per equivalent. If the amount is less than 0.3 g, the reaction between the hydroxyl group of the compound represented by the formula (2) and allyl halide or epihalohydrin becomes slow, and a long reaction is required, which is not preferable. While it almost disappears, the cost increases, which is not preferable. The allyl halide and epihalohydrin include, for example, allyl chloride, allyl bromide,
Epichlorohydrin, epibromohydrin and the like can be mentioned, and these may be used in an amount of at least one equivalent to one equivalent of the hydroxyl group to be allylated or epoxidized of the compound represented by the formula (2). However, if the equivalent is more than 20 times equivalent to 1 equivalent of the hydroxyl group to be allylated or epoxidized, the effect of increasing the amount is hardly obtained, but the volumetric efficiency is deteriorated, which is not preferable. As the alkali metal hydroxide, caustic sodium
, Caustic potash, lithium hydroxide, calcium hydroxide and the like can be used, but caustic soda is preferred. The amount of the alkali metal hydroxide to be used is from 1 to 2 with respect to 1 equivalent of the hydroxyl group to be allylated or epoxidized of the compound represented by the formula (2).
What is necessary is just to use 5 times equivalent. The alkali metal hydroxide may be a solid or an aqueous solution. When an aqueous solution is used, the reaction can be carried out while distilling water out of the reaction system under normal pressure and reduced pressure during the reaction. The reaction temperature is preferably from 20 to 100 ° C. When the reaction temperature is lower than 20 ° C., the reaction becomes slow and a long-time reaction is required. If the reaction temperature exceeds 100 ° C., many side reactions occur, which is not preferable. In the epoxy resin of the formula (1) obtained in the present invention (hereinafter referred to as the epoxy resin of the present invention), n represents an average value and represents a positive number.
1 to 15, particularly preferred values are 1 to 10. Further, 5% or more of X is an allyl group, but it is preferable that 10% or more of X is an allyl group. Further, as R, for example, And the like. R may be the same or different for each contained molecule in the epoxy resin represented by the formula (1), and even in the same molecule, a plurality of Rs are the same as each other. Or different. Hereinafter, the epoxy resin composition of the present invention will be described. The epoxy resin of the present invention may be used alone or in combination with another epoxy resin. When used in combination with another epoxy resin, the epoxy resin of the present invention is preferably used in an amount of at least 10% by weight, more preferably at least 20% by weight of the total epoxy resin. Examples of other epoxy resins include bisphenol A epoxy resin, brominated bisphenol A epoxy resin, triphenylmethane epoxy resin, tetramethyl biphenol epoxy resin, phenol novolak epoxy resin, and cresol novolak epoxy resin. No. Examples of the curing agent include amine compounds, acid anhydride compounds, amide compounds, and phenol compounds. Specific examples thereof include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, and the like.
Polyamide resin synthesized from diaminodiphenylsulfone, isophoronediamine, dicyandiamide, linolenic acid dimer and ethylenediamine, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydro Phthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, phenol
Lunovolac and modified products thereof, imidazole, B
F3-amine complexes, guanidine derivatives and the like. Each of these curing agents may be used alone,
Two or more kinds may be used in combination. The amount of the curing agent used is preferably 0.7 to 1.2 equivalents to 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 the 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. Furthermore, various compounding agents such as inorganic or organic fillers can be added as needed. When a curing accelerator is used, its amount is preferably 0.1 to 5.0 parts by weight based on 100 parts by weight of the epoxy resin. The epoxy resin composition of the present invention can be obtained by uniformly mixing an epoxy resin, a curing agent, and if necessary, a curing accelerator and other various compounding agents. A cured product of the epoxy resin composition can be easily obtained from the epoxy resin composition of the present invention by a method similar to a conventionally known method. For example, an epoxy resin and a curing agent, and if necessary, a curing accelerator, a filler, and other additives are sufficiently mixed using an extruder, a kneader, a roll, or the like, as needed, until the mixture becomes homogeneous. A cured product can be obtained by obtaining a resin composition, molding the epoxy resin composition after casting by using a casting or transfer molding machine, and further heating to 80 to 200 ° C. Further, a prepreg obtained by dissolving the resin composition of the present invention in a solvent, impregnating a base material such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber or paper and drying by heating is subjected to hot press molding. To obtain a cured product. The epoxy resin composition of the present invention has water resistance,
Gives a cured product with excellent heat resistance and can be used for various applications such as laminates, paints, adhesives, and sealing materials. 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. The measurement conditions of glass transition point, water absorption and NMR are as follows. Glass transition point thermomechanical analyzer (TMA): Vacuum Science and Technology TM-7000 Heating rate: 2 ° C./min Water absorption measurement conditions Test piece (cured product): diameter 50 mm thickness 3 mm disk 100 ° C. in water at 20 ° C. Weight increase after boiling for hours (% by weight) NMR measurement conditions NMR: Varian Gemini-300 Solvent: CDCl ₃ Temperature: 20 ° C. Frequency range: 4500.5 Hz Concentration: 150 mg / ml Pulse interval: 10.0 microsec integration Number of times: 16 Examples 1-3, Comparative Example 1 As a compound represented by the formula (2), bisphenol A wherein R is a residue represented by the formula (3) and n is 2.2 220 parts of epoxy resin (epoxy R-301, Mitsui Petrochemical Co., Ltd., epoxy equivalent: 479 g / eq) (alcohol hydroxyl group: 0.5 equivalent) is dimethyl Sulfoxide 4
After dissolving in 40 parts, allyl chloride 7
6.5 parts were added. Then, 30% NaOH aqueous solution 9
4.7 parts were added, the temperature was raised to 50 ° C. under reflux, and the reaction was carried out for 3 hours. After completion of the reaction, 880 parts of methyl isobutyl ketone and 440 parts of water were added, and the mixture was washed twice with water. After oil-water separation, methyl isobutyl ketone and dimethyl sulfoxide were distilled and recovered from the oil layer under reduced pressure to obtain 217 parts of an epoxy resin (1) having an epoxy equivalent of 511 g / eq. Using NMR, the total functional group equivalent of the obtained epoxy resin (1) including the allyl group and the glycidyl group was calculated to be 288 g / eq. In the obtained epoxy resin (1), n = 2.2 in the formula (1), R is a residue represented by the formula (3), X is a hydrogen atom and an allyl group, and 69% of X is an allyl group. It is an epoxy resin. In the same manner, the amount of the 30% aqueous NaOH solution was changed to 67.7 parts, and the epoxy equivalent was 504 g / eq.
Of epoxy resin (2) was obtained. The total functional group equivalent of the allyl group and the glycidyl group of the obtained epoxy resin (2) was calculated using NMR to be 319 g /
eq. In the obtained epoxy resin (2), n = 2.2 in the formula (1), R is a residue represented by the formula (3), X is a hydrogen atom and an allyl group, and 52% of X is an allyl group. It is an epoxy resin. Further, in the same manner, the amount of the 30% aqueous NaOH solution was changed to 40.6 parts and the epoxy equivalent was 496 g / eq.
206 parts of an epoxy resin (3) was obtained. Using NMR, the total functional group equivalent of the obtained epoxy resin (3), including allyl groups and glycidyl groups, was 372 g /
eq. In the obtained epoxy resin (3), n = 2.2 in the formula (1), R is a residue represented by the formula (3), X is a hydrogen atom and an allyl group, and 30% of X is an allyl group. It is an epoxy resin. The obtained epoxy resin (1)
(3) Epoxy resin epomic R-30 for comparison
1. Diaminodiphenylmethane (DDM) as curing agent
And kneaded with a roll at 70 ° C. for 15 minutes, and transfer-molded at 150 ° C. for 180 seconds, then at 160 ° C. for 2 hours, and further at 180 ° C. for 8 hours.
A test piece was prepared by curing for a time, and the glass transition point and the water absorption were measured. Table 1 shows the results. In the table, the numerical values in the columns of the respective components indicate parts by weight. Table 1 Example Comparative Example 1 2 3 1 Epoxy resin (1) 100 Epoxy resin (2) 100 Epoxy resin (3) 100 Epomic R-301 100 Epoxy equivalent (g / eq) 511 504 496 479 Total functionality Group equivalent (g / eq) 288 319 372 479 DDM 17 16 13 10 Glass transition point (° C) 155 147 144 140 Water absorption (%) 1.51 1.60 1.67 1.87 Examples 4 to 5, Comparative Example 2 Example 1 Raw material epomic R-301 similar to
In the same manner as in the synthesis of the epoxy resin (3) using two parts, the epoxy equivalent was 494 g / eq, and the total functional group equivalent of allyl groups and glycidyl groups calculated using NMR was 369 g / eq. 522 parts of a certain epoxy resin were obtained. After dissolving 219 parts of the obtained epoxy resin in 648 parts of epichlorohydrin, 2.5 parts of tetramethylammonium chloride was added, and then 13.13 parts of NaOH was added.
5 parts were added, and the reaction was further performed at 40 ° C. for 3 hours with stirring.
After the completion of the reaction, 324 parts of water was added and washed with water. After oil-water separation, excess unreacted epichlorohydrin was distilled and recovered from the oil layer under reduced pressure to obtain 221 parts of an epoxy resin (4) having an epoxy equivalent of 349 g / eq. When the total functional group equivalent of the allyl group and the glycidyl group was calculated using NMR, it was 2
It became 91 g / eq. Epoxy resin obtained (4)
In Formula (1), n = 2.2, R represents a residue represented by Formula (3), X represents a hydrogen atom, an allyl group, and a glycidyl group, 30% of X represents an allyl group, An epoxy resin in which 45% of X is a glycidyl group. In the same manner, 217 parts of an epoxy resin (5) having an epoxy equivalent of 371 g / eq was obtained, using 12.2 parts of 98.5% NaOH. Using NMR, the total functional group equivalent of the allyl group and the glycidyl group was calculated to be 300 g / eq. In the obtained epoxy resin (5), n = 2.2 and R in the formula (1) are the same as those in the formula (3).
X represents a hydrogen atom, an allyl group or a glycidyl group, and 30% of X is an allyl group;
5% is an epoxy resin having a glycidyl group. The obtained epoxy resin (4)
(5) Epoxy resin epomic R-30 for comparison
1. Diaminodiphenylmethane (DDM) as curing agent
And kneaded with a roll at 70 ° C. for 15 minutes, transfer-molded at 150 ° C. for 180 seconds, and then cured at 160 ° C. for 2 hours and further at 180 ° C. for 8 hours. A test piece was prepared, and the glass transition point and the water absorption were measured. Table 2 shows the results. In the table, the numerical values in the column of each component indicate parts by weight. [0039] Examples 6 and 7, Comparative Example 3 As a compound represented by the formula (2), R represents both a residue represented by the formula (3) and a residue represented by the formula (4); A bromine-containing bisphenol A type epoxy resin in which n is 2.6 (Epicoat 5049, Yuka Shell Epoxy Co., Ltd., epoxy equivalent 735 g / eq, bromine content 2)
After dissolving 281 parts (0.5 equivalent of alcoholic hydroxyl group) in 560 parts of dimethyl sulfoxide,
76.5 parts of allyl chloride and 30% NaO
The reaction was carried out in the same manner as in Example 1 except that 88.0 parts of an H aqueous solution was added to obtain 217 parts of an epoxy resin (6) having an epoxy equivalent of 782 g / eq. The total functional group equivalent of the allyl group and the glycidyl group of the obtained epoxy resin (6) was calculated to be 416 g / eq using NMR.
The obtained epoxy resin (6) is represented by the formula (1) where n =
2.6, R represents a residue represented by the formula (3) and a residue represented by the formula (4), the bromine content is 25% by weight, X represents a hydrogen atom and an allyl group, 65% of the epoxy resin is an allyl group. In the same manner, the amount of the 30% aqueous NaOH solution was changed to 60.9 parts, and the epoxy equivalent was 770 g / eq.
206 parts of an epoxy resin (7) was obtained. NMR was used to calculate the total functional group equivalent of the obtained epoxy resin (7) including allyl groups and glycidyl groups, which was 476 g /
eq. In the obtained epoxy resin (7), n = 2.6 in formula (1), R represents the residue represented by formula (3) and the residue represented by formula (4), and the bromine content is 2
The epoxy resin is 5.4% by weight, X represents a hydrogen atom and an allyl group, and 45% of X is an allyl group. The obtained epoxy resin (6)
(7), epoxy resin epicoat 5049 for comparison,
Using diaminodiphenylmethane (DDM) as a curing agent, compounded with the composition shown in Table 3, kneaded with a roll at 70 ° C. for 15 minutes, and transfer-molded at 150 ° C. for 180 seconds, and then at 160 ° C. for 2 hours, A test piece was prepared by curing at 180 ° C. for 8 hours, and the glass transition point and the water absorption were measured. Table 3 shows the results. In the table, the numerical values in the column of each component indicate parts by weight. [0043] Examples 8 to 10 and Comparative Example 4 As an epoxy resin represented by the formula (2), a bisphenol A type epoxy resin wherein R is a residue represented by the formula (3) and n is 3.2 After dissolving 389 parts (1.0 equivalent of alcoholic hydroxyl group) of epoxide R-302, Mitsui Petrochemical Co., Ltd., epoxy equivalent 629 g / eq) in 800 parts of dimethyl sulfoxide, allyl chloride 7 was stirred at 30 ° C.
6.5 parts were added. Then 30% NaOH aqueous solution 1
35 parts (1.0 mol) were added, and the temperature was raised to 50 ° C. under reflux to obtain 3
A time reaction was performed. After the completion of the reaction, 1600 parts of methyl isobutyl ketone and 800 parts of water were added, and the mixture was washed twice with water. After oil-water separation, methyl isobutyl ketone and dimethyl sulfoxide were distilled and recovered from the oil layer under reduced pressure, and the epoxy equivalent was 69%.
375 parts of 0 g / eq epoxy resin (8) were obtained. The obtained epoxy resin (8) has the formula (1) where n = 3.
2, an epoxy resin in which R is a residue represented by the formula (3), X is a hydrogen atom and an allyl group, 50% of X is an allyl group, and the total functional group equivalent by NMR is 381 g / eq. . In a similar manner, the amount of the 30% aqueous NaOH solution was changed to 94.7 parts (0.7 mol) to obtain 371 parts of an epoxy resin (9) having an epoxy equivalent of 682 g / eq.
The obtained epoxy resin (9) is represented by the formula (1) where n =
3.2, R is a residue represented by the formula (3), X is a hydrogen atom and an allyl group, 35% of X is an allyl group, and NMR
Is an epoxy resin having a total functional group equivalent of 432 g / eq. In the same manner, the amount of the 30% aqueous NaOH solution was changed to 54.1 parts (0.4 mol) to obtain 366 parts of an epoxy resin (10) having an epoxy equivalent of 671 g / eq.
The obtained epoxy resin (10) is represented by the formula (1)
= 3.2, R is a residue represented by the formula (3), X is a hydrogen atom and an allyl group, 20% of X is an allyl group,
It is an epoxy resin having a total functional group equivalent of 495 g / eq by MR. The obtained epoxy resins (8) to (1)
0), epoxy resin epomic R-302 as a comparison,
Using DDM as a curing agent, compounded with the composition shown in Table 4, roll-kneaded at 70 ° C for 15 minutes, transfer-molded at 150 ° C for 180 seconds, and then at 160 ° C for 2 hours.
Further, a test piece was prepared by curing at 180 ° C. for 8 hours, and the glass transition point and the water absorption were measured. Table 4 shows the results.
In the table, the numerical values in the column of each component indicate parts by weight. Table 4 Example Comparative Example 8 9 10 4 Epoxy resin (8) 100 Epoxy resin (9) 100 Epoxy resin (10) 100 Epomic R-302 100 Epoxy equivalent (g / eq) 690 682 671 629 Total functional groups Equivalent (g / eq) 381 432 495 629 DDM 13 11 10 8 Glass transition point (° C) 156 152 145 130 Water absorption (%) 1.33 1.67 1.84 2.04 [Effect of the Invention] The epoxy resin of the present invention has heat resistance. , Can give a cured product having excellent water resistance properties,
It is extremely useful for a wide range of applications such as molding materials, casting materials, laminate materials, paints, adhesives, and resists.

Continuation of the front page (56) References JP-A-1-168722 (JP, A) JP-A-1-230622 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 39 / 14 C08G 59/32

Claims (1)

(57) [Claims] [Claim 1] The following formula (2) (In the formula, n represents an average value and represents a positive number. R represents a residue in which the hydroxyl group of a compound having two phenolic hydroxyl groups has been removed, and each R is different even if it is the same as each other. Wherein the alcoholic hydroxyl group of the compound represented by the formula (1) is reacted with allyl halide (and, if necessary, epihalohydrin). (In the formula, n and R have the same meanings as in formula (1). Each X represents a hydrogen atom, an allyl group, or a glycidyl group, and even if each X is the same as each other, The method may be different, but 5% or more of X is an allyl group.)