JPH04270720A - Epoxy resin, its production and cured product - Google Patents

Abstract

PURPOSE:To provide an epoxy resin capable of providing cured products excellent in heat and moisture resistances. CONSTITUTION:An epoxy resin is obtained by reacting a dimethylol compound with naphthol and further reacting the resultant novolak type resin with an epihalohydrin in the presence of dimethyl sulfoxide. The aforementioned epoxy resin has a low content of total halogens and is especially useful for applications such as sealing media.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention provides a high-purity epoxy resin that provides a cured product with excellent moisture resistance and heat resistance, and is superior in terms of reliability with a reduced amount of halogens such as hydrolyzable chlorine.
The present invention relates to its manufacturing method and cured product.

0002

[Prior Art] In general, epoxy resins provide cured products with excellent adhesiveness, chemical resistance, electrical properties, mechanical properties, and heat resistance, so they can be used as adhesives, paints, electrically insulating materials, sealants, etc.
It is widely used as a material for electrical and electronic components such as various composite materials.

Among them, cresol novolac type epoxy resins are widely used, especially as materials for electrical and electronic parts such as sealants, because of their well-balanced properties such as heat resistance of the cured products.

On the other hand, various measures have been taken to ensure the reliability of these electrical and electronic components. As one of these efforts, attempts have been made to increase the purity of epoxy resins, and in particular efforts have been made to reduce the amount of halogens such as hydrolyzable chlorine in the resins. This is because hydrolyzable chlorine and the like cause deterioration of electrical insulation and corrosion of lead wires.

[0005]

[Problems to be Solved by the Invention] However, at present, no epoxy resin has been proposed that provides a cured product with excellent heat resistance and moisture resistance, has low viscosity and excellent workability, and has a low total halogen content. For example, JP-A-3-717 proposes an epoxy resin made from a condensate of naphthol and phenols, but the method disclosed in this publication does not yield an epoxy resin with a low total halogen content.

[0006]

[Means for solving the problem] Therefore, the present inventors
In order to solve the above problems, we conducted a detailed study on the structure of epoxy resin and its manufacturing conditions.We found that by manufacturing a specific epoxy resin under specific conditions, we can create a new product that has a low total halogen content and satisfies various required properties. The present invention was completed based on the discovery that an epoxy resin having the following properties can be obtained.

That is, the present invention provides formula (1) (A)

000
8]

An epoxy resin obtained by reacting a trinuclear compound represented by the formula (wherein R represents an alkyl group having 1 to 4 carbon atoms) with epihalohydrin and having a total halogen content of 800 ppm or less.

(2) Formula (B)

[0011]

The trinuclear compound described in (1) above, obtained by reacting the dimethylol compound represented by the formula (wherein R represents an alkyl group having 1 to 4 carbon atoms) with naphthol (
An epoxy resin obtained by reacting a novolac type resin containing A) with epihalohydrin and having a total halogen content of 800 ppm or less.

(3) Formula (C)

[0014]

Contains 30% by weight or more of a trinuclear epoxy compound represented by the formula (wherein R represents an alkyl group having 1 to 4 carbon atoms), and contains a compound having a lower molecular weight than the trinuclear epoxy compound. 10% by weight or less, and the total content of polynuclear compounds of heptanucleates or more is 40% by weight or less (1) above.
Or the epoxy resin described in (2).

(4) The trinuclear compound (A
) or the method for producing an epoxy resin as described in (1), (2) or (3) above, which comprises reacting the novolac type resin described in (2) above with epihalohydrin in the presence of dimethyl sulfoxide.

(5) 10 parts by weight of dimethyl sulfoxide per 100 parts by weight of the trinuclear compound (A) or novolac type resin.
The method for producing an epoxy resin as described in (4) above using 300 parts by weight. (6) A cured product of the epoxy resin described in (1), (2) or (3) above. Regarding.

In the compound of formula (A), (B) or (C), R is a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s
Examples include ec-butyl group and t-butyl group.

The trinuclear compound represented by formula (A) has the formula (
The dimethylol compound represented by B) and naphthol,
Generally, it can be produced by reaction (dehydration condensation) in the presence of an acid catalyst.

Examples of the dimethylol compound (B) include 2,6-dimethylol-4-methylphenol, 2
,6-dimethylol-4-t-butylphenol, 4,
Examples include 6-dimethylol-2-methylphenol and 4,6-dimethylol-2-t-butylphenol. Naphthols include α-naphthol and β-naphthol.

[0021] A preferred method for increasing the yield of the trinuclear compound (A) and obtaining a novolac type resin suitable for producing the epoxy resin described in (3) above, for example, is to combine the dimethylol compound (B) with naphthol. and in the presence of an acid catalyst 40
This is a method in which the reaction is carried out at a temperature of ~85°C, and excess naphthol in the reaction mixture is removed by heating and distillation at a temperature of 200°C or less under reduced pressure. can be suppressed.

Here, it is preferable to use naphthol in an amount of 2 to 10 times the mole, especially 3 to 6 times the mole of the dimethylol compound (B), and as the acid catalyst, hydrochloric acid, sulfuric acid, phosphoric acid, p-toluenesulfonic acid is used. Although p-toluenesulfonic acid can be used, it is particularly preferable to use p-toluenesulfonic acid. The amount of acid catalyst used is 0.1 to 0.1 to dimethylol compound (B).
It is sufficient to use 1% by weight.

The reaction can be carried out without a solvent using methanol, ethanol, propanol, butanol, benzene, toluene,
It can also be carried out in a solvent such as methyl isobutyl ketone. The reaction time is preferably 4 to 10 hours.

The novolak resin thus obtained contains the trinuclear compound (A) at a high content of 30% by weight or more, particularly 35% by weight or more, while the content of the trinuclear compound (A) is The amount is 10% by weight or less, especially 7% by weight or less, and furthermore, the total content of polynuclear compounds of heptanucleates or higher is 25% by weight or less, especially 20% by weight or less.

[0025] The term "X-nuclear compound" refers to a compound in which the sum of the numbers of benzene nuclei and naphthalene nuclei in one molecule is X. The novolac type resin thus obtained has a low viscosity, is easy to handle, and has excellent workability.

The reaction (epoxidation reaction) between the trinuclear compound (A) or the novolak resin containing it and epihalohydrin can be carried out according to a known method. Examples of epihalohydrin include epichlorohydrin,
Examples include epibromohydrin and epiiodohydrin.

To illustrate an example of the above epoxidation reaction, for example, the trinuclear compound (A) or a novolak type resin containing the same and an excess molar amount of epihalohydrin relative to the hydroxyl equivalent thereof are reacted with tetramethylammonium chloride, The reaction is carried out in the presence of a quaternary ammonium salt such as tetramethylammonium bromide or triethylammonium chloride or an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide. Since the reaction stops at the stage of the cycloaddition reaction, the alkali metal hydroxide is then added to carry out the ring-closing reaction.

When the alkali metal hydroxide is added from the beginning and the reaction is carried out, the ring-opening addition reaction and the ring-closing reaction are carried out at once. The usage ratio of epihalohydrin is usually 1 to 50 mol, preferably 2 to 15 mol per hydroxyl equivalent of the trinuclear compound (A) or the novolac type resin containing the same.
mol, particularly preferably in the range from 3 to 6 mol.

The amount of the alkali metal hydroxide used is preferably in the range of 0.9 to 1.3 mol per hydroxyl equivalent of the trinuclear compound (A) or the novolac type resin containing the same. When a quaternary ammonium salt is used, the amount used is usually 0.001 to 1 mol, preferably 0.005 to 0.1 mol, per 1 hydroxyl equivalent of the trinuclear compound (A) or the novolac type resin containing it. It is in the range of 5 moles.

The reaction temperature is usually 20 to 130°C, preferably 30 to 80°C. The reaction time may be generally 2 to 10 hours, although it depends on the reaction temperature.

The epoxy resin of the present invention has a total halogen content of 800 ppm or less, but by carrying out the above reaction in the presence of dimethyl sulfoxide, the total halogen content in the resulting epoxy resin can be reduced to 800 ppm or less. . The amount of dimethyl sulfoxide used is preferably 10 to 300 parts by weight, particularly preferably 50 to 250 parts by weight, based on 100 parts by weight of the trinuclear compound (A) or the novolac type resin containing the same.

Note that when the alkali metal hydroxide is added to the reaction system in the form of an aqueous solution, the trinuclear compound (A
) or 100 parts by weight of a novolak type resin containing this, it is preferable to use 100 to 300 parts by weight of dimethyl sulfoxide.

In this way, the trinuclear compound (A
) or a novolak-type resin containing the same and carrying out the reaction in the presence of dimethyl sulfoxide, the following advantages can be obtained. That is, although the reaction can be carried out under reduced pressure or normal pressure, it is particularly easy to carry out the reaction under normal pressure.

Further, it is not necessary to set the reaction temperature to 100 to 110°C, and a low reaction temperature of 30 to 80°C is sufficient. Furthermore, when carrying out the reaction, it is not particularly necessary to remove water within the system from the system by azeotropic dehydration. However, in order to reduce the influence of water in the system, it is preferable to use the alkali metal hydroxide in a solid state.

After the reaction is thus completed, the dimethyl sulfoxide is recovered under reduced pressure without washing with water or the like in order to enable reuse of the dimethyl sulfoxide in an industrial manner.

At this time, unreacted epihalohydrin and dimethyl sulfoxide are recovered all at once at a temperature of 130° C. or lower so as not to inhibit polymerization or high purity of the reactants. When the temperature exceeds 130°C, polymerization and an increase in the total amount of halogens such as hydrolyzable chlorine occur.

Furthermore, the epihalohydrin, dimethyl sulfoxide and water thus recovered can be easily separated by distillation and reused.

Furthermore, if necessary, the resin content of the obtained epoxy resin (including the produced salt) is redissolved in a solvent such as methyl isobutyl ketone, benzene, toluene, or xylene to remove the slight remaining hydrolyzable chlorine. In order to further remove halogens such as, the alkali metal hydroxide is converted into a trinuclear compound (A) or a novolak type resin containing the same with a hydroxyl equivalent of 1
Preferably 0.01 to 0.2 mol is added again to
It is desirable to further provide a step of reacting preferably at 50°C to 80°C for 0.5 to 2 hours.

After completion of the reaction, the reaction product is dissolved in a solvent such as methyl isobutyl ketone if it does not contain a solvent, and then washed repeatedly with water to remove the generated common salt and unreacted alkali metal hydroxide. The high purity epoxy resin of the present invention is obtained by removing the solvent such as , methyl isobutyl ketone, etc. under reduced pressure.

[0041] In the epoxy resin of the present invention, the total amount of halogen is 800 ppm or less, preferably 700 ppm.
pm or less, particularly preferably 600 ppm or less.

In the epoxy resin of the present invention, the content of the trinuclear epoxy compound (C) is preferably 30% by weight.
The content is more preferably 35% by weight or more, particularly preferably 40% by weight or more. In addition, trinuclear epoxy compounds (C
) The content of lower molecular weight compounds (by-products, etc.) is preferably 10% by weight or less, more preferably 7% by weight or less,
Particularly preferably, it is 5% by weight or less.

Furthermore, the total content of polynuclear compounds of hepta-nuclear or higher is preferably 40% by weight or less, more preferably 35% by weight or less, particularly preferably 30% by weight.
It is as follows. When the range of each component is as above, the epoxy resin has low viscosity and excellent workability,
The heat resistance and moisture resistance of the cured product are further improved.

Since the epoxy resin of the present invention has a small total amount of halogens such as hydrolyzable chlorine, it can be suitably used as a sealant for surface mounting, etc., and is a highly reliable cured product with excellent heat resistance and moisture resistance. can be provided.

The epoxy resin of the present invention can be cured according to known methods. That is, the epoxy resin of the present invention, a curing agent, a curing accelerator, and, if necessary, known additives are mixed uniformly, and the resulting composition is cured. This results in
A cured product of the present invention is obtained.

As the curing agent, the trinuclear compound (A
) or a novolac resin containing these can be used, but other known curing agents such as polyamine curing agents such as aliphatic polyamines, aromatic polyamines, polyamide polyamines, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, etc. Acid anhydride curing agents, phenolic curing agents such as phenol novolak and cresol novolak, Lewis acids such as boron trifluoride or their salts, and curing agents such as dicyandiamides can also be used, but are not limited to these. do not have. These may be used alone or in combination of two or more.

The amount of curing agent used is preferably 0.5 to 1.5 equivalents, particularly preferably 0.6 to 1.2 equivalents, per equivalent of epoxy groups in the epoxy resin.

Examples of the curing accelerator include imidazole compounds such as 2-methylimidazole and 2-ethylimidazole, and tertiary compounds such as 2-(dimethylaminomethyl)phenol.
Various known curing accelerators can be used, including amine compounds and phosphine compounds such as triphenylphosphine, and are not particularly limited.

[0049] The amount of curing accelerator used is epoxy resin 100%
The range is preferably from 0.01 to 15 parts by weight, particularly preferably from 0.1 to 10 parts by weight.

Examples of known additives include inorganic fillers such as silica, alumina, talc, and glass fibers, surface treatment agents for fillers such as silane coupling agents, mold release agents, and pigments.

[0051] The composition is usually heated at a temperature of 130 to 170°C.
Precure in the range of 0 to 300 seconds, and further cure for 150 to 20 seconds.
By post-curing at a temperature of 0° C. for 2 to 8 hours, a sufficient curing reaction proceeds and the cured product of the present invention is obtained. The cured product thus obtained has low water absorption (moisture resistance) while maintaining heat resistance.

In the present invention, the total amount of halogen means approximately 1 g of sample (epoxy resin) is accurately weighed into a 100 ml stoppered flask, 25 ml of n-butylcarbitol is added, and the mixture is heated and dissolved. After dissolving, 1N-
Add 25 ml of KOH propylene glycol solution and heat to reflux for 10 minutes, then completely reflux the solution.
This value was determined by transferring the mixture to a 00 ml beaker, adding 50 ml of glacial acetic acid, and performing potentiometric titration with an aqueous silver nitrate solution.

[0053]

[Examples] The present invention will be explained in more detail with reference to Examples below.

Synthesis Example 108 g (1 mol) of para-cresol, 60 g (2 mol) of paraformaldehyde, and 100 ml of water were placed in a 1-liter flask equipped with a thermometer, condenser, dropping funnel, and stirrer, and stirred while blowing nitrogen. did.

At room temperature, 80g of 15% caustic soda aqueous solution (
0.3 mol (as caustic soda) was slowly added dropwise to the solution while being careful not to generate heat so that the liquid temperature did not exceed 50°C.

[0056] Thereafter, it was heated to 50°C in a water bath and heated to 10°C.
Time reacted. After the reaction was completed, 200 ml of water was added, the mixture was cooled to room temperature, and while being careful not to generate heat, the mixture was gradually neutralized with a 10% aqueous hydrochloric acid solution, and the aqueous hydrochloric acid solution was further added until the pH reached 4.

Thereafter, the precipitated crystals were separated and further washed with water. The obtained crystals were dried under reduced pressure (10 m
mHg) and dried at 50°C to obtain white 2,6-dimethylol-4-methylphenol. The yield was 143g. (Yield from para-cresol is 85%)

Example 1. 168 g of 2,6-dimethylol-4-methylphenol obtained in the synthesis example was placed in a glass container equipped with a thermometer and a stirrer, and 576 g of α-naphthol and 1000 ml of methyl isobutyl ketone were added and stirred at room temperature under a nitrogen atmosphere. did.

Then, 1 g of p-toluenesulfonic acid (2
, 0 for 6-dimethylol-4-methylphenol
．． 6% by weight) was gradually added while paying attention to heat generation so that the liquid temperature did not exceed 50°C.

After the addition, the mixture was heated to 50°C on an oil bath and reacted for 2 hours, then further heated to 70°C and reacted for 7 hours, and then transferred to a separatory funnel and washed with water.

After washing with water until the washing water showed neutrality, in order to remove unreacted naphthol from the organic layer using an evaporator, vacuum distillation was carried out under reduced pressure (10 mmHg or less) at a bath temperature of 195°C. Distillation time required 2 hours. Through this operation, 372 g of novolac type resin (A-1) was obtained.

Product (A-1) had a softening temperature of 112°C and a hydroxyl equivalent (g/mol) of 137. Further, the amount of unreacted naphthol in the product (A-1) was found to be 1% by weight or less as a result of gas chromatography analysis.

[0063] Furthermore, by GPC analysis, product (A-1)
The content of the trinuclear compound (A) is 52% by weight, and the content of compounds with lower molecular weight than the trinuclear compound (A) is 3.5% by weight.
% by weight, and the total content of polynuclear compounds of heptanucleates or more was 15% by weight. The viscosity of the product (A-1) is 25
It was Poise.

137 g of the product (A-1) was charged into a reaction apparatus equipped with a thermometer, a stirrer, and a vacuum recovery device, and 374 g (3.5 mol) of epichlorohydrin and 68 g of dimethyl sulfoxide (50 g based on the novolak type resin) were charged.
% by weight) was added and dissolved. During this time, nitrogen is introduced into the system.

After dissolution, while keeping the reaction temperature at 40°C,
40 g (1 mole) of solid caustic soda was slowly added. The addition time required 1 hour. After the addition of caustic soda, the reaction was further carried out at 40°C for 1 hour, and then the reaction temperature was raised to 70°C, and the reaction was further carried out for 1 hour. As a result, the total reaction time was 3 hours.

Next, the bath temperature of the reactor was raised to 130° C., and the pressure was gradually reduced while paying attention to bumping to remove unreacted epichlorohydrin, dimethyl sulfoxide, and produced water all at once. The final degree of pressure reduction was 5 mmHg, and it took 2 hours.

Then, 500 m of methyl isobutyl ketone
1, dissolve the resin, and add 20% caustic soda aqueous solution 2.
0 g was added, and the reaction was carried out at a reaction temperature of 70° C. for 2 hours. After the reaction was completed, washing with water was repeated using a separatory funnel to return the aqueous phase to neutrality. The methyl isobutyl ketone phase was then heated under reduced pressure to remove the methyl isobutyl ketone.

As a result, 175 g of a pale yellow solid (B-1), which is an epoxy resin, was obtained. The softening temperature of the product (B-1) is 75°C, and the epoxy equivalent (g/mol) is 21
2. Viscosity 10 poise, free chlorine amount 1 ppm or less, hydrolyzable chlorine amount 230 ppm, total chlorine amount 510 ppm,
The chloride ion concentration in the extracted water by PCT was 3 ppm.

[0069] Furthermore, by GPC analysis, product (B-1)
The content of trinuclear epoxy compound (C) in it is 50% by weight.
The content of compounds having a lower molecular weight than the trinuclear epoxy compound (C) was 3.2% by weight, and the total content of polynuclear compounds of heptanuclear or higher was 25% by weight.

Example 2. In Example 1, the amount of α-naphthol used was 504g.
(3.5 mol), and in the same manner as in Example 1, 375 g of novolac type resin (A-2) was obtained. Using 139 g of this product (A-2), 172 g of an epoxy resin (B-2) was obtained in the same manner as in Example 1 except for the above.

[0071] Furthermore, by GPC analysis, product (B-2)
The content of trinuclear epoxy compound (C) in it is 45% by weight.
The content of compounds having a lower molecular weight than the trinuclear epoxy compound (C) was 3.2% by weight, and the total content of polynuclear compounds of heptanuclear or higher was 17% by weight.

Example 3. In Example 1, 509 g of epichlorohydrin (5.5
180 g of epoxy resin (B-3) was obtained in the same manner as in Example 1 except that 180 g of epoxy resin (B-3) was used.

[0073] Furthermore, by GPC analysis, product (B-3)
The content of trinuclear epoxy compound (C) in it is 51% by weight.
The content of compounds having a lower molecular weight than the trinuclear epoxy compound (C) was 3.1% by weight, and the total content of polynuclear compounds of heptanuclear or higher was 24% by weight.

Example 4. Epoxy resin (B-4) 1 was prepared in the same manner as in Example 1 except that 136 g of dimethyl sulfoxide (100% by weight based on the novolac type resin) was used in Example 1.
79g was obtained.

[0075] Furthermore, by GPC analysis, product (B-4)
The content of trinuclear epoxy compound (C) in it is 50% by weight.
The content of compounds having a lower molecular weight than the trinuclear epoxy compound (C) was 3.1% by weight, and the total content of polynuclear compounds of heptanuclear or higher was 23% by weight.

Example 5. The same procedure as in Example 1 was carried out, except that 274 g of dimethyl sulfoxide (200% by weight based on the novolak type resin) was used in Example 1, and 85 g of a 48% aqueous solution of caustic soda (1 mol as caustic soda) was used instead of solid caustic soda. Through the operation, 178 g of epoxy resin (B-5) was obtained.

[0077] Furthermore, by GPC analysis, product (B-5)
The content of trinuclear epoxy compound (C) in it is 49% by weight
The content of compounds having a lower molecular weight than the trinuclear epoxy compound (C) was 3.2% by weight, and the total content of polynuclear compounds of heptanuclear or higher was 30% by weight.

Comparative Example 1. In Example 1, in the process of producing a novolac resin, after washing with water in a separating funnel until the washing water shows neutrality, 1
Steam distillation was carried out using steam at 50° C. until the amount of unreacted naphthol was reduced to the same amount as in Example 1 (1% by weight or less). Steam distillation took 5 hours. (The amount of unreacted naphthol after 2 hours, which is the same operation time as in Example 1.
．． It was 5% by weight. )

[0079] Thus, novolac type resin (A-6) 3
65g was obtained. The resulting product (A-6) had a softening temperature of 135°C and a hydroxyl equivalent of 143. Also, the product (
Gas chromatography analysis showed that unreacted naphthol in A-6) was 1% by weight or less.

[0080] Furthermore, by GPC analysis, product (A-6)
The content of trinuclear compound (A) is 25% by weight, the content of compounds with lower molecular weight than trinuclear compound (A) is 15% by weight, and the total content of polynuclear compounds of heptanuclear or higher is 25% by weight. The content was 30% by weight.

Using 143 g of this product (A-6),
68g of methanol instead of 68g of dimethyl sulfoxide
The same operation as in Example 1 was carried out except that 150 g of epoxy resin (B-6) was obtained.

[0082] Furthermore, by GPC analysis, product (B-6)
The content of trinuclear epoxy compound (C) in it is 18% by weight
The content of compounds having a lower molecular weight than the trinuclear epoxy compound (C) was 16% by weight, and the total content of polynuclear compounds of heptanuclear or higher was 41% by weight.

Comparative example 2. 137 g of the product (A-1) of Example 1 was charged into a 1-liter reactor equipped with a thermometer, a stirrer, a dropping funnel, and a water separation device, and 509 g (5.5 g) of epichlorohydrin was charged.
mol) was added and dissolved while blowing with nitrogen.

After dissolution, reaction temperature: 60°C, pressure: 100~1
85g of 48% caustic soda aqueous solution under 50mmHg condition
was added dropwise over 5 hours. During this time, the produced water and the water in the caustic soda aqueous solution were continuously removed from the reaction system by azeotroping with epichlorohydrin, and epichlorohydrin was returned to the system.

[0085] After recovering excess unreacted epichlorohydrin under reduced pressure, 500 m of methyl isobutyl ketone was added.
1 was added and washed with water until the aqueous layer became neutral. Methyl isobutyl ketone was removed from the methyl isobutyl ketone phase under reduced pressure, and then 50% of methyl isobutyl ketone was removed again.
0ml was added and redissolved.

2 to the obtained methyl isobutyl ketone solution.
Add 20g of 0% sodium hydroxide solution and reaction temperature: 70℃
It reacted for 2 hours. After the reaction was completed, washing was repeated with water until the aqueous layer became neutral. Then, methyl isobutyl ketone was removed from the methyl isobutyl ketone phase under reduced pressure to obtain 170 g of epoxy resin (B-7).

[0087] Furthermore, by GPC analysis, product (B-7)
The content of trinuclear epoxy compound (C) in it is 43% by weight.
The content of compounds having a lower molecular weight than the trinuclear epoxy compound (C) was 3.3% by weight, and the total content of polynuclear compounds of heptanuclear or higher was 35% by weight.

The properties of the products (B-1) to (B-7) are shown in Table-1.

[0089]

[0090]

In the examples and comparative examples, free chlorine amount, hydrolyzable chlorine amount, viscosity, softening temperature, total chlorine amount, chlorine amount by PCT (pressure cooker test), and GPC analysis were as follows. It was measured.

(Amount of free chlorine) Approximately 10 g of sample (epoxy resin) was accurately weighed in a 200 ml beaker, and 1
Dissolve in 00 ml of acetone, and add 2 ml of distilled water.
ml and 1 ml of glacial acetic acid were added, and potentiometric titration was performed using an aqueous silver nitrate solution for quantitative determination.

(Amount of hydrolyzable chlorine) Approximately 0.5 g of sample (
Precisely weigh the epoxy resin into a 100 ml flask with a stopper, and dissolve it in 30 ml of dioxane. After dissolution, 5 ml of 1N-KOH ethanol solution is added, and the mixture is boiled and refluxed for 30 minutes. Thereafter, this solution was completely transferred to a 200 ml beaker, 100 ml of an 80% aqueous acetone solution was added thereto, 2 ml of concentrated nitric acid was further added, and the amount was determined by potentiometric titration with an aqueous silver nitrate solution.

The viscosity at 150° C. was measured using an ICI viscometer (cone plate type). (Softening temperature) Measured by JIS K2425 ring and ball method.

(Total chlorine amount) Approximately 1 g of sample (epoxy resin) was accurately weighed into a 100 ml flask with a stopper.
Add 25 ml of n-butyl carbitol and dissolve by heating. After dissolving, add 25 ml of 1N-KOH propylene glycol solution and heat under reflux for 10 minutes. Thereafter, this solution was completely transferred to a 200 ml beaker, 50 ml of glacial acetic acid was added, and the amount was determined by potentiometric titration with an aqueous silver nitrate solution.

(PCT) 50 g of ion-exchanged water was added to 5 g of epoxy resin, and the mixture was held at 180° C. for 20 hours. The chlorine ion concentration in the extracted water was determined by ion chromatography.

(GPC analysis) GPC device; Shimadzu Corporation (
Column; TSK-G-3000XL (1 piece) + TSK-
G-2000XL (2 bottles) Solvent: Tetrahydrofuran 1ml/min Detection: UV (254nm)

Application Examples 1 to 5, Application Comparative Examples 1 to 2 Phenol novolak (manufactured by Nippon Kayaku Co., Ltd.,
The products obtained in Examples 1 to 5 and Comparative Examples 1 to 2 (B-1) with a softening temperature of 85°C and a hydroxyl equivalent (g/mol) of 105
) to (B-7) and 2-methylimidazole were blended to obtain a composition.

This composition was roll-kneaded at 70 to 80°C for 15 minutes, cooled, crushed, and tableted. After molding using a transfer molding machine, it was precured at 160°C for 2 hours, and then at 180°C for 8 hours. Post-curing was performed to obtain a cured product (test piece). The glass transition temperature (Tg), heat distortion temperature (HDT), and water absorption of this cured product were measured under the following conditions.

Glass transition temperature thermomechanical measuring device (TMA): Shinku Riko Co., Ltd. TM-70
00 Heating rate: 2℃/min Heat distortion temperature Conditions specified in JIS K7207

[0101] Water absorption test Piece Diameter: 50 mm (cured product) Thickness: 3 mm Disc conditions Weight increase after boiling in water at 100°C for 50 hours (weight %)

[0102] PCT test piece crushed product 60-100 mesh (
(hardened product) Conditions: 5 g of crushed product mixed with 50 g of deionized water
After pressure extraction at 180° C. for 50 hours, the chlorine ion concentration in the extracted water was measured (ppm) using ion chromatography. The evaluation results of the cured product are shown in Table 2.

[0103]

[0104]

[0105]

[0106]

Effects of the Invention The epoxy resin of the present invention has a small total halogen content, and a cured product with high reliability and excellent heat resistance and moisture resistance can be obtained. Resin can be easily produced.

Claims (6)

[Claims] Claim 1: Obtained by reacting a trinuclear compound represented by formula (A) (wherein R represents an alkyl group having 1 to 4 carbon atoms) with epihalohydrin, the total amount of halogen is 800 ppm or less. Some epoxy resin. 2. The trinuclear compound according to claim 1, which is obtained by reacting a dimethylol compound represented by formula (B) (wherein R represents an alkyl group having 1 to 4 carbon atoms) with naphthol. An epoxy resin obtained by reacting a novolac type resin containing (A) with epihalohydrin, and having a total halogen content of 800 ppm or less. 3. Contains 30% by weight or more of a trinuclear epoxy compound represented by formula (C) (wherein R represents an alkyl group having 1 to 4 carbon atoms), and has a lower molecular weight than the trinuclear epoxy compound. The content of the compound is 1
The epoxy resin according to claim 1 or 2, wherein the total content of polynuclear compounds of hepta-nuclear or higher is 40% by weight or less. 4. The trinuclear compound (A) according to claim 1 or the novolac type resin according to claim 2 and epihalohydrin are reacted in the presence of dimethyl sulfoxide. 3. The method for producing the epoxy resin described in 3. 5. 10 to 30 parts by weight of dimethyl sulfoxide per 100 parts by weight of the trinuclear compound (A) or novolac type resin.
5. The method for producing an epoxy resin according to claim 4, wherein 0 parts by weight is used. 6. A cured product of the epoxy resin according to claim 1, 2 or 3.