JP2898383B2 - Manufacturing method of epoxy resin - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing an epoxy resin having excellent heat resistance and water resistance. The epoxy resin obtained by the method of the present invention comprises a molding material, a casting material, and the like. Materials, laminated materials,
It is extremely useful for a wide range of applications such as composite materials, paints, adhesives, and resists.

[Conventional technology]

Epoxy resins are generally cured with various curing agents to provide mechanical properties, water resistance, chemical resistance, heat resistance,
It becomes a cured product with excellent electrical properties and is used for adhesives, paints,
It is used in a wide range of fields, such as laminates, molding materials, and casting materials. Conventionally, liquid and solid bisphenol A type epoxy resins obtained by reacting bisphenol A with epichlorohydrin are the most widely used epoxy resins in the industry. Bisphenol F obtained by reacting epichlorohydrin with dihydric phenol
Epoxy resins, tetrabromobisphenol A type epoxy resins and the like are used industrially.

[Problems to be solved by the invention]

However, the above-mentioned conventional epoxy resin has a low crosslinking density at the time of curing because there are no more than two glycidyl groups per molecule, and the heat resistance of the cured product is relatively low.
On the other hand, with recent remarkable developments in the electronics industry and the like, the heat resistance required for electrical insulating materials and the like used in these industries has become increasingly severe, and the appearance of epoxy resins having excellent heat resistance has been awaited.

[Means for Solving the Problems] In view of these circumstances, the present inventors have intensively studied for an epoxy resin having excellent heat resistance. As a result, the general formula (1), (2) or (3) (Wherein R is -H or And Y ₁ and Y ₂ are each independently an aromatic residue, and n is an integer of 1 or more. The present inventors have found a production method for epoxidizing the alcoholic hydroxyl group represented by the formula (1), and have further found that the epoxy resin has the above-mentioned properties, thereby completing the present invention. That is, the present invention relates to: 1. General formula (1), (2) or (3) Wherein R, Y ₁ , Y ₂ and n have the same meanings as described above. The reaction between the alcoholic hydroxyl group of the compound represented by the formula and epichlorohydrin is carried out in the presence of dimethyl sulfoxide. .

General formula (4), (5) or (6) corresponding to general formula (1), (2) or (3) (Wherein, Y ₁ , Y ₂ and n represent the same meaning as described above. M represents —H or It is. However, if n is 1, M must be And when n is 2 or more, M is at least one It is. A method for producing an epoxy resin represented by

2. Compound represented by general formula (2) is represented by general formula (7) (In the formula, Y ₁ , Y ₂ and n have the same meanings as described above.) The method for producing an epoxy resin according to claim 1, which is a compound represented by the following formula:

3. The compound represented by the general formula (3) is represented by the general formula (8) (In the formula, Y ₁ , Y ₂ and n have the same meanings as described above.) The method for producing an epoxy resin according to claim 1, which is a compound represented by the following formula:

It is about.

The epoxy resin obtained by the production method of the present invention provides a novel compound represented by the general formula (4), (5) or (6).

A feature of the method for producing an epoxy resin of the present invention is that the reaction between the alcoholic hydroxyl group of the compound represented by the general formula (1), (2) or (3) and epichlorohydrin is carried out in the presence of dimethyl sulfoxide. I do. The reaction between the alcoholic hydroxyl group of the compound represented by the general formula (1), (2) or (3) and epichlorohydrin, as in the reaction between general alcohols and epichlorohydrin, in the presence of a Lewis acid catalyst When the reaction is carried out below, a large amount of epichlorohydrin reacting with the hydroxyl group of chlorohydrin as an intermediate product is produced in large quantities, and only those having a high hydrolyzable chlorine content and a low epoxy content can be produced. Further, when an alcoholic hydroxyl group and an epoxy group are simultaneously contained in the molecule as in the general formulas (2) and (3), it is not preferable because the reaction between the terminal epoxy group and the alcoholic hydroxyl group occurs simultaneously. On the other hand, when the Lewis acid catalyst is not used, the reaction between the alcoholic hydroxyl group and epichlorohydrin cannot be performed only in the presence of a strong alkali, even if an excessive amount of epichlorohydrin is used. As a result of intensive studies, the present inventors have found that the alcoholic hydroxyl group in the general formula (1), (2) or (3) is more reactive than general alcohols, and surprisingly, The present inventors have found that the reaction between a hydrophilic hydroxyl group and epichlorohydrin can be selectively performed, and completed the present invention.

According to the production method of the present invention, the alcoholic hydroxyl group in the general formula (1), (2) or (3) can be epoxidized to a desired ratio by adjusting the amount of the alkali metal hydroxide.

 Hereinafter, the present invention will be described in more detail.

In the general formulas (1), (2) and (3), Y ₁ and Y ₂ are aromatic residues. And A is alkylene; cycloalkylene; halogen;
Alkylene substituted with cycloalkyl or aryl;-
O-; -S-; -SS-; And X _{1 to} X ₂₆ are each independently hydrogen, an alkyl group or halogen.

For example, For example, For example, For example, It is.

In the production method of the present invention, epichlorohydrin may be used in an amount equal to or more than 1 equivalent of the alcoholic hydroxyl group in the general formula (1), (2) or (3).
However, if the equivalent is more than 15 equivalents to 1 equivalent of hydroxyl group, the effect of increasing the amount is almost negligible, but the volumetric efficiency deteriorates, which is not preferable.

The amount of dimethyl sulfoxide used is represented by the general formula (1),
5% by weight to the compound represented by (2) or (3)
300% by weight is preferred. When the content is 5% by weight or less based on the compound represented by the general formula (1), (2) or (3), the reaction between the alcoholic hydroxyl group in the general formula (1), (2) or (3) and epichlorohydrin , And a long reaction time is required, which is not preferable. General formula (1),
300% by weight based on the compound represented by (2) or (3)
If it exceeds, the effect of increasing the amount is almost negligible, but the volumetric efficiency is undesirably deteriorated.

As the alkali metal hydroxide, caustic soda, caustic potash, lithium hydroxide, calcium hydroxide and the like can be used, but caustic soda is preferable. The amount of the alkali metal hydroxide used may be approximately equivalent to 1 equivalent of the alcoholic hydroxyl group to be epoxidized of the compound represented by the general formula (1), (2) or (3). When the entire amount of the alcoholic hydroxyl group of the compound represented by the general formula (1), (2) or (3) is epoxidized, the alcoholic hydroxyl group may be used in excess, but it is twice equivalent to 1 equivalent of the alcoholic hydroxyl group. If it exceeds, the polymer tends to be slightly polymerized.

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 30 to 100 ° C. When the reaction temperature is lower than 30 ° C., the reaction becomes slow and a long reaction time is required.
If the reaction temperature exceeds 100 ° C., many side reactions occur, which is not preferable.

After completion of the reaction, excess epichlorohydrin and dimethyl sulfoxide are distilled off under reduced pressure, and then the resin is dissolved in an organic solvent and a dehydrohalogenation reaction can be performed with an alkali metal hydroxide. On the other hand, after the completion of the reaction, the product was washed with water to separate by-product salts and dimethyl sulfoxide.Excess epichlorohydrin was distilled off from the oil layer under reduced pressure, and then the resin was dissolved in an organic solvent and dehalogenated with an alkali metal hydroxide. A reaction may be performed. As the organic solvent, methyl isobutyl ketone, benzene, toluene, xylene and the like can be used, but methyl isobutyl ketone is preferably used. These can be used alone or in a mixed system.

The epoxy resin obtained by the production method of the present invention can be cured alone or in combination with other epoxy resins by adding a curing agent, and if necessary, a curing accelerator as in the case of ordinary epoxy resins. .

As the curing agent, amine compounds, acid anhydride compounds,
Examples include amide compounds and phenol compounds. Specific examples include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, dicyandiamide,
A polyamide resin synthesized from a dimer of linolenic acid 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. These curing agents may be used alone or in combination of two or more.

The amount of these curing agents used is 0.7
~ 1.2 equivalents are preferred. 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 in any case, and a good cured product may not be obtained. Also, curing may be performed using a curing accelerator. Examples of the curing accelerator include imidazoles, tertiary amines, phenols, and Lewis acid salts such as boron trifluoride-monoethylamine complex.
Various additives such as an inorganic or organic filler can be added as needed.

The use amount of these curing accelerators is preferably 0.1 to 5.0 parts by weight based on 100 parts by weight of the epoxy resin.

The epoxy resin obtained by the production method of the present invention can easily obtain a cured epoxy resin by a method similar to a conventionally known method. For example, the epoxy resin obtained by the production method of the present invention is thoroughly mixed with a curing agent, a filler and other additives using an extruder, a kneader, a roll, or the like, if necessary, until the mixture becomes uniform. After melting, the mixture is molded using a casting or transfer molding machine, and further heated to 80 to 200 ° C. to obtain a cured product. Further, the epoxy resin obtained by the production method of the present invention and a curing agent, a filler and other additives are dissolved in a solvent to form a base material such as glass fiber, polyester resin, polyamide fiber, alumina fiber, carbon fiber, and paper. The prepreg obtained by impregnating the prepreg with heat and drying is subjected to hot press molding to obtain a cured product.

[Examples] Next, the present invention will be specifically described with reference to Examples, Application Examples, and Comparative Examples. In the following, all parts are by weight unless otherwise specified. The hydrolyzable chlorine content is determined by dissolving an epoxy resin in dioxane, adding an alcohol solution of 1N-potassium hydroxide, and titrating chloride ions released when heated at reflux for 30 minutes with a silver nitrate solution. , The weight of chlorine atoms in the compound expressed as a percentage by weight.

Example 1 Y ₁ and Y ₂ in the general formula (8) are In the bisphenol A type epoxy resin, the average n is 3.3, the epoxy equivalent is 650, and the hydrolyzable chlorine content is 0.039.
%, A softening point of 81.1 ° C and a dissolution viscosity (150 ° C) of 12.5 poise 371 g of epoxy resin (epoxy resin (f)) are dissolved in 925 g of epichlorohydrin and 462.5 g of dimethyl sulfoxide, and 52.8 g of 98.5% NaOH at 70 ° C under stirring. Was added over 100 minutes. After the addition, the reaction was further performed at 70 ° C. for 3 hours. Then, most of the unreacted epichlorohydrin and dimethyl sulfoxide were distilled off under reduced pressure, and the reaction product containing by-product salt and dimethyl sulfoxide was 750 g of methyl isobutyl ketone.
, And 10 g of 30% NaOH was further added thereto and reacted at 70 ° C. for 1 hour. After the completion of the reaction, the resultant was washed twice with 200 g of water. After oil-water separation, methyl isobutyl ketone is distilled and recovered from the oil layer, and has an epoxy equivalent of 287, a hydrolyzable chlorine content of 0.07%,
340 g of an epoxy resin (a) having a softening point of 64.2 ° C. and a melt viscosity (150 ° C.) of 7.1 poise was obtained. When the obtained epoxy resin (a) is calculated from the epoxy equivalent, about 3.1 of 3.3 alcoholic hydroxyl groups in the general formula (8) are epoxidized.

Example 2 In the same manner as in Example 1 except that the amount of 98.5% NaOH was changed to 24.3 g, an epoxy equivalent of 379 and a hydrolyzable chlorine content of 0.3 were used.
365 g of an epoxy resin (b) having 067%, a softening point of 76.8 ° C. and a melt viscosity (150 ° C.) of 11.0 poise was obtained. When the obtained epoxy resin (b) is calculated from the epoxy equivalent, about 1.7 of 3.3 alcoholic hydroxyl groups in the general formula (8) are epoxidized.

Example 3 In the same manner as in Example 1 except that the amount of 98.5% NaOH used was changed to 13.3 g, an epoxy equivalent of 444 and a hydrolyzable chlorine content of 0.1 were used.
350 g of an epoxy resin (c) having 054%, a softening point of 79.5 ° C. and a melt viscosity (150 ° C.) of 11.5 poise was obtained. When the obtained epoxy resin (c) is calculated from the epoxy equivalent, about 1.0 of 3.3 alcoholic hydroxyl groups in the general formula (8) are epoxidized.

Example 4 Instead of the epoxy resin (f), the compound represented by the general formula (8) was used.
Y ₁ and Y ₂ The average n is 2.2, epoxy equivalent 483, hydrolyzable chlorine content 0.097%, softening point 67.0 ° C, melt viscosity (150 ° C) 3.
An epoxy equivalent of 27 was obtained in the same manner as in Example 1 except that 442 g of a 4-poise epoxy resin (epoxy resin (g)) was used.
4, 450 g of epoxy resin (d) having a hydrolyzable chlorine content of 0.03%, a softening point of 56.1 ° C. and a melt viscosity (150 ° C.) of 2.7 poise was obtained. When the obtained epoxy resin (d) was calculated from the epoxy equivalent, the alcoholic hydroxyl group 2.2 in formula (8) was obtained.
About 1.9 of them are epoxidized.

Example 5 Instead of the epoxy resin (f), the compound represented by the general formula (8) was used.
Y ₁ and Y ₂ In the low-type epoxy resin that is a mixture,
Average n is 1.5, epoxy equivalent 493, hydrolyzable chlorine content
0.106%, softening point 70.7 ℃, melt viscosity 4.1ps, bromine content 21.1
% Epoxy resin (epoxy resin (h)) in the same manner as in Example 1 except that 641 g of epoxy resin (h) was used. Epoxy equivalent 304, hydrolyzable chlorine content 0.052%, softening point 57.8 ° C, melt viscosity (150
C.) 1.9 poise, 631 g of an epoxy resin (e) having a bromine content of 19.4%. When the obtained epoxy resin (e) is calculated from the epoxy equivalent, almost 1.5 of the alcoholic hydroxyl groups in the general formula (8) are epoxidized.

Epoxy resins (a) obtained in Examples 1 to 5
Table 1 shows the resin properties of (e) and the epoxy resins (f) to (h) for comparison.

Application Examples 1 to 5 and Comparative Examples 1 to 3 Epoxy resins (a) to (e) obtained in Examples 1 to 5 as epoxy resins, and epoxy resins (f) to
(H) One epoxy group of epoxy resin using Kayahard MCD (methylendmethylene tetrahydrophthalic anhydride, manufactured by Nippon Kayaku) as curing agent and 2E4MCZ (2-ethyl-4-methylimidazole) as curing accelerator The composition is as shown in Table 1 so that the number of acid anhydride groups becomes 0.9, and these are cured at 100 ° C for 2 hours, then at 120 ° C for 2 hours, and then at 200 ° C for 5 hours. At least, the test piece was used, and the heat deformation temperature, flexural strength, flexural modulus and water absorption were measured in accordance with JIS K-6911. The results are shown in Table 1.

As is clear from Table 1, the epoxy resin obtained by the method for producing an epoxy resin of the present invention is compared with a conventional bisphenol A type epoxy resin, and the cured product obtained by using them is heat resistant and water resistant. It turns out that it is excellent.

[Effect of the Invention] The epoxy resin obtained by the production method of the present invention can give a cured product having excellent heat resistance and water resistance, and can be used as a molding material, a casting material, a laminated material, a composite material, a paint, an adhesive. It is extremely useful for a wide range of uses such as resists.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C07D 301/28

Claims (3)

(57) [Claims] 1. A compound of the general formula (1), (2) or (3) (Wherein R is -H or Is an aromatic residue independently of each of Y ₁ and Y ₂ , and n is an integer of 1 or more. A) reacting the alcoholic hydroxyl group of the compound represented by the formula (1) with epichlorohydrin in the presence of dimethyl sulfoxide; (5) or (6) (Wherein, Y ₁ , Y ₂ and n represent the same meaning as described above. M represents —H or It is. However, if n is 1, M must be And when n is 2 or more, M is at least one It is. A method for producing an epoxy resin represented by 2. A compound represented by the general formula (2): (Wherein, Y ₁ , Y ₂ and n represent the same meaning as described above). The method for producing an epoxy resin according to claim 1, wherein the compound is represented by the following formula: 3. A compound represented by the general formula (3): (Wherein, Y ₁ , Y ₂ and n represent the same meaning as described above). The method for producing an epoxy resin according to claim 1, wherein the compound is represented by the following formula: