JP2000044651A - Highly pure epoxy resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin capable of being used as an electric and electronic material such as an adhesive, an insulating material or a laminate material in high reliability by controlling the content of hydrolyzable chlorine as an impurity at a specific value or less. SOLUTION: This epoxy resin has a hydrolyzable chlorine content of <=1,000 ppm as an impurity. The epoxy resin is preferably obtained, for example, by dissolving a glycidylamino group-containing epoxy resin (preferably an aminophenol type epoxy resin, especially 4-amino-m-cresol type epoxy resin) having a hydrolyzable chlorine content of >1,000 ppm in an aprotic polar solvent such as dimethyl sulfoxide and subsequently dropwisely adding an alkaline substance such as sodium hydroxide to the solution with stirring, thus subjecting the resin to the chlorine-removing reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin having a glycidylamino group having a low content of hydrolyzable chlorine, which is useful as an electric or electronic material such as an adhesive, a paint, an insulating material or a laminate.

[0002]

2. Description of the Related Art It is essential that epoxy resins used as electric and electronic materials have a low content of hydrolyzable chlorine. Representative epoxy resins such as bisphenol A type, bisphenol F type and orthocresol novolak type have been highly purified, and the content of hydrolyzable chlorine is 500 ppm or less, and particularly about 200 ppm for high purity. Things are also being developed. However, epoxy resins having glycidylamino groups, especially
In aminophenol type epoxy resins such as 4-amino-m-cresol type and 4-aminophenol type, conventionally,
Since they are rarely used for electric and electronic applications and are difficult in production reaction, no high-purity ones have been developed, and those having a hydrolyzable chlorine content of 1000 ppm or less are not known.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a useful and low-hydrolyzable chlorine content which can obtain high reliability when used as an electric or electronic material such as an adhesive, an insulating material or a laminate. The purpose is to provide an epoxy resin.

[0004]

Means for Solving the Problems In view of such circumstances, the present inventors have conducted intensive studies, and as a result, have found that a specific epoxy resin meets the above-mentioned object, and have completed the present invention. That is, the present invention is as follows. (1) The content of hydrolyzable chlorine as an impurity is 1000
An epoxy resin having a glycidylamino group, which is at most ppm. (2) The epoxy resin according to the above (1), wherein the epoxy resin having a glycidylamino group is an aminophenol type epoxy resin. (3) The aminophenol type epoxy resin is 4-amino-
The epoxy resin according to the above (2), which is an m-cresol type epoxy resin. (4) The aminophenol type epoxy resin is 4-amino-
The epoxy resin according to the above (2), which is a phenol type epoxy resin.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The epoxy resin having a glycidylamino group in the present invention is an epoxy resin obtained by epoxidizing various amines with epihalohydrin, and specific examples thereof include an aminophenol type epoxy resin and Examples include, but are not limited to, glycidyl isocyanurate, tetraglycidyl diaminodiphenylmethane, tetraglycidyl metaxylene diamine, hexaglycidyl triaminobenzene, and the like.

In the present invention, the aminophenol type epoxy resin is obtained by epoxidizing various aminophenols by a known method. Examples of aminophenols include 2-aminophenol, 3-aminophenol, 4-aminophenol, 2-amino-m-cresol, 2-amino-p-cresol, 3-amino-o-cresol, 4-amino -M-cresol, 6-amino-
Examples thereof include, but are not limited to, aminophenols such as m-cresol, aminocresols, and the like. The viscosity of the epoxy resin having a glycidylamino group obtained in the present invention is not particularly limited, but generally it is desirable that the viscosity is low. In other words, if the viscosity after combination with the curing agent and the additive is too high, the coating properties, impregnation properties, etc. are inferior, and a problem occurs in workability. From such a viewpoint, the viscosity of the epoxy resin having a glycidylamino group is 2,000 Pa · s
The following is desirable. In the present invention, the hydrolyzable chlorine is
Formula 1 called 1,2-chlorohydrin compound

[0007]

Embedded image In addition to those included in the group represented by (Formula 1), 1,3
Formula 2 called chlorohydrin form

[0008]

Embedded image What is included in the group represented by (Formula 2) and Formula 3 called a chloromethyl form

[0009]

Embedded image It includes those included in the group represented by (Formula 3) and the like, and does not indicate only those included in the above 1,2-chlorohydrin compound.

In the present invention, the content of hydrolyzable chlorine is analyzed by the following method. That is, about 1 g of a sample is
Transfer to a 0 mL Erlenmeyer flask and accurately weigh to the nearest 1 mg. Add 30 mL of dioxane and dissolve completely using an ultrasonic cleaner. After correctly adding 5 mL of 1N potassium hydroxide / ethanol solution and shaking well, add boiling stone and attach a cooling tube. Reflux on a sand bath heated to about 180 ° C. The reflux time is 30 minutes after the start of boiling. After cooling to room temperature, the cooling tube is washed with 5 mL of methanol, and the washing solution is added to the sample solution. Remove the Erlenmeyer flask from the cooling tube and transfer the sample solution to a 200 mL beaker. The inside of the flask is washed three times with 50 mL of 80% acetone water, and the washing solution is added to the sample solution.
Add 5 mL of N / 400 sodium chloride solution correctly and turn on the rotor. After adding 3 mL of acetic acid and stirring for 2 minutes,
Potentiometric titration is performed using the N / 100 silver nitrate solution under the conditions shown in Table 1 below. Perform a blank test by the same operation as above.

[0011]

[Table 1] The hydrolyzable chlorine content is determined by the following equation. Hydrolysable chlorine (ppm) = F × (V−B) × 355 /
S where F: Factor of N / 100 silver nitrate solution V; Amount of N / 100 silver nitrate solution required for titration of sample (m
l) B: Amount of N / 100 silver nitrate solution required for titration in blank test (ml) S: Sample amount (g)

The content of hydrolyzable chlorine as an impurity is 1
The method for producing an epoxy resin having a glycidylamino group of 000 ppm or less is not particularly limited. For example, it can be obtained by subjecting an epoxy resin having a glycidylamino group having a hydrolyzable chlorine content exceeding 1000 ppm, produced by a known method, to a Cl removal reaction and a ring closure reaction. The Cl removal reaction is usually performed by dissolving an epoxy resin having a glycidylamino group in an aprotic polar solvent, dropping an alkaline substance, and keeping the mixture stirred. Examples of the alkaline substance used in this reaction include sodium hydroxide, potassium hydroxide, calcium hydroxide and the like, and these are used in the form of an aqueous solution or an alcohol solution. The amount of the alkaline substance to be used is preferably 0.1 mol to 10 mol, more preferably 0.5 mol to 5 mol, per 1 mol of the hydrolyzable chlorine content of the epoxy resin. If the amount of the alkaline substance used is too large, the molecular weight increases, and if the amount is too small, the effect of reducing the hydrolyzable chlorine decreases. As the aprotic polar solvent, dimethyl sulfoxide, dimethyl sulfone,
Examples include, but are not limited to, dimethylacetamide, tetramethylurea, hexamethylphosphoramide, and the like. The amount of the aprotic polar solvent may be any amount with respect to the amount of the epoxy resin, but is preferably 1.0 to 20 times by weight.

In the ring closure reaction, the aprotic polar solvent contained in the reaction solution obtained above is usually removed by washing or distilling off the water, and the residue is dissolved in an organic solvent other than the aprotic polar solvent. In this method, an alkaline substance is added dropwise to the solvent-substituted solution, the mixture is stirred, and neutralized after completion of the reaction. Thereafter, purification is performed by a method of washing liquid separation or purification filtration. Examples of the alkaline substance used in the ring closure reaction include the same substances as those used in the Cl removal reaction. Organic solvents other than the aprotic polar solvent used in the ring closure reaction include:
Various hydrocarbon solvents, ketones and the like,
It is not limited to these. Preferred are ketones such as methyl isobutyl ketone.

The epoxy resin of the present invention can be used in combination with a curing agent, a curing accelerator and the like. As the curing agent, any one may be used as long as it is usually used as a curing agent for an epoxy resin.Examples include dicyandiamide, tetramethylguanidine, a polyhydric alcoholic compound, an acid anhydride, an acid hydrazide compound, an aromatic amine, Aliphatic amines and alicyclic amines. Further, the epoxy resin of the present invention may be used by adding a filler such as silica or alumina, if necessary.

The epoxy resin having a glycidylamino group having a low hydrolyzable chlorine content according to the present invention is useful as an adhesive, an insulating material, or an electric / electronic material such as a laminate.

[0016]

The present invention will be described below with reference to specific examples, but the present invention is not limited to these examples. The viscosity was measured using a commercially available parallel plate type rheometer (CVO Rheometer manufactured by Bohlin). Examples 1, 2 and Comparative Example 1 (Production of 4-amino-m-cresol type epoxy resin having low content of hydrolyzable chlorine) 4-amino-m having 1450 ppm of hydrolyzable chlorine
-Cresol type epoxy resin (trade name Sumi Epoxy EL)
After dissolving 60 g of M-100 (manufactured by Sumitomo Chemical Co., Ltd.) in 440 g of dimethyl sulfoxide and purging the system with nitrogen, a 48% aqueous solution of sodium hydroxide in the amount shown in Table 2 was added dropwise to the mixture at 32 ° C. / 2 hours. After the reaction, 0.21 g of phosphoric acid and 2.4 g of sodium chloride were added for neutralization. (Cl removal reaction) Next, dimethyl sulfoxide contained in the above reaction solution was distilled off under reduced pressure, and methyl isobutyl ketone 18 was added to the residue.
0 g and 80 g of 20% warm brine were added and the mixture was separated, filtered, and the filtrate was washed with warm brine. (Replacement of solvent) Next, 17.2 g of a 48% aqueous sodium hydroxide solution was added to the reaction solution in which the solvent was replaced, and the reaction was performed at 80 ° C for 5 hours. (Ring-closure reaction) After completion of the reaction, carbon dioxide was added for neutralization, then water was removed by azeotropic dehydration, and inorganic matter was removed by filtration. A decrease in hydrolyzable chlorine was confirmed with an increase in the charged amount of sodium hydroxide in the Cl removal reaction.

[0017]

[Table 2]

[0018]

According to the present invention, it is possible to provide a useful epoxy resin having a glycidylamino group having a low content of hydrolyzable chlorine and capable of obtaining high reliability when used mainly as an electric / electronic material. .

Claims (4)

[Claims] (1) The content of a hydrolyzable chlorine as an impurity is 1
An epoxy resin having a glycidylamino group having a concentration of 000 ppm or less. 2. The epoxy resin according to claim 1, wherein the epoxy resin having a glycidylamino group is an aminophenol type epoxy resin. 3. The epoxy resin according to claim 2, wherein the aminophenol type epoxy resin is a 4-amino-m-cresol type epoxy resin. 4. The epoxy resin according to claim 2, wherein the aminophenol type epoxy resin is a 4-amino-phenol type epoxy resin.