JPS5978178A - Preparation of polyepoxy compound - Google Patents

Abstract

PURPOSE:To prepare the titled substance by the addition reaction of epichlorohydrin with diaminodiphenylmethane compound in the presence of a water-soluble alcohol, followed by the dehydrochlorination of the reaction product with an alkali metal hydroxide in a solvent such as DMF. CONSTITUTION:The titled substance is prepared by (1) carrying out the addition reaction of epichlorohydrin (A) with diaminodiphenylmethane, its alkyl-substituted compound or halogen-substituted compound (B) in 50-500pts.wt., based on 100pts.wt. of the component B, of a water-soluble alcohol (e.g. ethylene glycol) having a boiling point of >=120 deg.C, (2) removing the unreacted component A and the above alcohol from the system, and (3) dehydrochlorinating the reaction product with an alkali metal hydroxide in 2-50pts.wt., based on 100pts.wt. of the component B, of a solvent such as DMF, N-methyl-2-pyrrolidone, hexamethylphosphoramide, etc. EFFECT:A polymer having excellent impact resistance can be prepared from the above product.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a liquid tetraglycidyl compound of diaminodiphenylmethane in a short time, which provides a cured product with excellent heat resistance in the presence of a curing agent. The polyepoxy compound obtained by carrying out the present invention has a low content of saponifiable chlorine and provides a cured product with excellent heat resistance, so it is used as a carbon fiber reinforcing resin (hereinafter referred to as rcF'RPj) and as an encapsulating material for electrical parts. It is useful as a molding material.

Some resins, collectively known as epoxy resins, have excellent physical, chemical and electrical properties and are used in various coating materials, electrical insulation materials, laminated materials, structural materials and civil engineering and construction materials. It is widely used in

Currently, the cured epoxy resins that are widely used are mainly polyepoxy compounds obtained by addition condensation reaction of active hydrogen-containing compounds and epichlorohydrin, and are cured using amine-based or acid anhydride-based curing agents. It is cured by hardening. As such active hydrogen-containing compounds, phenolic compounds, aromatic amines, etc. are famous, and bisphenol A is most commonly used.

Bisphenol A type polyepoxy compounds are generally obtained by reacting bisphenol A and shrimp chlorhydritrin in the presence of caustic soda.

This bisphenol A type polyepoxy compound itself has a viscosity as high as 100 to 140 poise (at 25 DEG C.), and is actually used after being diluted with a reactive diluent such as butyl glycidyl ether or nonylphenyl glycidyl ether.

The heat distortion temperature of the cured product obtained by curing this bisphenol A type polyepoxy compound with an acid anhydride
It is low at ~120℃, '#f, and the elastic modulus is low, so CFR
Improvements are required for resin materials for P.

N,N,MSN'-tetraglycidyl bis(
Aminophenyl) methane from Ciba ``MY-720''
It is sold under the trade name "Y)T-434" by Tobu Kasei.

This tetrafunctional epoxy compound, when used as a curing agent, provides a cured product with excellent heat regeneration and mechanical strength.

This tetrafunctional epoxy compound can be obtained by subjecting diaminodiphenylmethane and epichlorohydrin to an addition reaction, and then adding IJum to the reaction product and carrying out a crude hydrochloric acid reaction.

However, this addition reaction takes a significantly long time (e.g. 24-3
0 hours), which has the disadvantage that the obtained tetrafunctional epoxy compound is colored due to oxidation of the amine group.

Unfortunately, the subsequent dehydrochlorination reaction also takes a long time, 15 to 20 hours, and the resulting polyepoxy compound is saponifiable in formula (■) in which some of the terminal 1,2-epoxy groups cannot be represented by the following formula. A large amount of epoxy compound replaced by a chlorine-containing group (5 to 8% by weight as saponifiable chlorine content)
Contains in.

Polyepoxy compounds whose products have a high saponifiable chlorine content are
Since the curing speed by the curing agent is slow and the electrical properties, heat resistance, and mechanical strength of the obtained cured product are reduced, after the dehydrochloric acid reaction is completed, the obtained polyepoxy compound is mixed with toluene, methyl isobutyl ketone, etc. Dissolve in the solvent and add sodium hydroxide again,
The saponifiable chlorine content is reduced to less than 1 part by heating and carrying out a hydrochloric acid reaction.

However, re-doing the hydrochloric acid reaction increases the cost of the product and also causes the product to become discolored.

It's not nice.

A method using a water-soluble solvent with a low boiling point such as ethanol or isopropyl alcohol has been proposed as a method to improve the drawbacks of the addition reaction requiring a long time and the drawback that only a polyepoxy compound with a high content of saponifiable chlorine can be obtained.
The reality is that the addition reaction takes a long time, 12 to 18 hours, and it is desired to shorten this time. Furthermore, in this method of using low-boiling alcohol as a solvent, the unreacted epichlorohydrin recovered after the reaction contains low-boiling alcohol, so in order to reuse it, it is necessary to separate the alcohol from the recovered epichlorohydrin. 1. If the recovered epichlorohydrin is to be used as is, it is necessary to measure the alcohol content in the recovered epichlorohydrin and newly determine the blending ratio of fresh epichlorohydrin and alcohol for aminophenol. , it is not a good idea from the industrial/Qin perspective.

As a method to solve the problem of epichlorohydrin recovery using a low boiling point alcohol, we previously proposed a method in which an alcohol with a boiling point of 120°C or higher, such as ethylene glycol, is used in place of ethanol (Patent application No. 57). -1.23648).

Although this method is effective in recovering epichlorohydrin and shortening the addition reaction time, it is not as effective as ethyl alcohol in reducing the saponifiable chlorine content and shortening the dehydrochlorination reaction.

The present invention solves the problem that only a polyepoxy compound having a high content of saponifiable chlorine can be obtained in the method of the previous application in which an alcohol having a boiling point of 120° C. or more is used as a solvent during the addition reaction, and The purpose is to remove unreacted epichlorohydrin and the high-boiling alcohol used from the reaction system before the dehydrochlorination reaction, and to use a solvent for certain amines when performing the dehydrochlorination reaction using an alkali metal hydroxide. This is achieved by bringing into existence.

That is, Akira Kito conducted an addition reaction between epichlorohydrin, diaminodiphenylmethane, and its abakyl-substituted product, as well as its halogen-substituted product, in the presence of a water-soluble alcohol with a boiling point (measured under dog's sweat) of 120°C or higher. After that, unreacted epichlorohydrin was recovered (12), and then the resulting addition reaction product was subjected to a dehydrochlorination reaction with an alkali metal hydroxide in the presence of N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl The present invention provides a method for producing a polyepoxy compound, characterized in that the method is carried out in the presence of a solvent selected from -2-pyrrolidone and hegisamethylphosphoramide.

The aminophenol or its alkyl-substituted product or halogen-substituted product is represented by the general formula (TI), λ1, where X is H, Br, I, or an alkyl group having 1 to 4 carbon atoms. ] Specifically, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane,
2.3'-diaminodiphenylmethane, 2.4'-diaminodiphenylmethane, 2.2'-diaminodiphenylmethane, 2,4'-diamino-3,3'-short-diphenylmethane, 2.2'-diamino-5,5 ′−
Dibromo-diphenylmethane, 4,4'-diamino-3
, 3'-dichloro-diphenylmethane and the like.

Among these, 4,4'-diaminodiphenylmethane is preferred because it provides a cured product with better heat resistance.

The addition reaction between diaminodiphenylmethane or its alkyl-substituted product or its halogen-substituted product (represented by diaminodiphenylmethane) and epichlorohydrin is carried out in the presence of a water-soluble alcohol with a boiling point of 1.20°C or higher. Mix 8 to 40 moles of epichlorohydrin per mole, preferably 9 to 12 moles of epichlorohydrin, and heat at 40 to 100°C for 1 to 10 hours. be exposed.

The water-soluble alcohol used in this addition reaction has a boiling point of 120°C or higher, preferably 150°C.
- Monoalcohols such as ethylhexanol, diethylene glycol monoalkyl ether, triethylene glycol monoalkyl ether; ethylene glycol, diethylene glycol, triethylene glycol, phlopylene glycol, dipropylene glycol, tripropylene glycol, glycerol, Examples include polyalcohols such as 1,4-bis(hydroxymethyl)benzene. Among these, ethylene glycol is suitable in quantity because it can be easily separated from excess epichlorohydrin and also dissolves the raw materials epichlorohydrin, diaminodiphenylmethane, and polyepoxide produced.

These alcohols have a boiling point (120° C. or higher) higher than the boiling point (115° C.) of the raw material epichlorohydrin, and after the completion of the addition reaction, unreacted epichlorohydrin is distilled under reduced pressure (20 to 30 + mHg).

It is a water-soluble monoalcohol or polyalcohol that cannot be recovered together with epichlorohydrin because it has a higher boiling point than epichlorohydrin even under reduced pressure.

Moreover, since this high-boiling alcohol is a good solvent for the addition reaction product, it is not necessary to remove it from the reaction system.

When using a water-soluble alcohol with a boiling point lower than epichlorohydrin as a solvent, such as ethanol, n-glopanol, or impropanol, water is added to the reactor after the dehydrochlorination reaction to remove the alkali metal salt produced as a by-product. In the step of transferring to and separating the aqueous layer, the aqueous layer and the oil layer containing the polyepoxy compound are not separated, or the oil layer becomes emulsified, making it difficult to separate the product. Furthermore, after recovering the unreacted epichlorohydrin, separation of these alcohols is required before it can be reused.

However, alcohols with a boiling point higher than epichlorohydrin, such as n-octatool and n-hexanol, which are water-insoluble or slightly soluble in water, are used in the process of removing the by-product alkali metal salts. Since it is difficult to transfer to the aqueous layer, after recovering unreacted epichlorohydrin, it is necessary to heat the product to a higher temperature and remove these water-insoluble alcohols by distillation, which may cause coloration of the product. It has the disadvantage of thickening.

In the present invention, the water-soluble alcohol such as ethylene glycol is used in an amount of 50 to 500 parts by weight, preferably L<K75 to 10, per 100 parts by weight of diaminodiphenylmethane as a raw material.
Use in a proportion of 0 parts by weight.

The completion of the addition reaction is determined by gel permeation column analysis,
This is confirmed by liquid chromatography analysis by the absence (disappearance) of adducts of 1 to 3 moles of epichlorohydrin per 1 mole of diaminodiphenylmethane (see the specification of Japanese Patent Application No. 57-+23FI48).

After the addition reaction is completed, unreacted epichlorohydrin is removed from the reaction system and recovered. As mentioned above, removal is generally carried out by distillation under reduced pressure.

Next, to the reaction product from which unreacted epichlorohydrin was removed, the amine solvent having a boiling point of 100°C or higher was added, and furthermore, an alkali metal hydroxide was gradually added to the reaction product.
The tetrafunctional epoxy compound represented by the above formula (1) is produced by carrying out the dehydrochlorination reaction at a temperature of 0.degree. C. or lower for 2 to 10 hours.

Solvent H1N added before this second stage dehydrochlorination reaction,
A water-soluble amine with a boiling point exceeding 100°C selected from N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and hexamethylphosphoramide, which is a product of the general formula It is also a good solvent for polyepoxy compounds indicated by (+). These amines may be used alone or in combination of two or more.

These solvents contain 100% of the raw material diaminodiphenylmethane.
It is used in a ratio of 2 to 50 parts by weight, preferably 3 to 20 parts by weight. If it is less than 2 parts by weight, the effect of shortening the reaction time and reducing the saponifiable chlorine content of the resulting polyepoxy compound is small. On the other hand, if it exceeds 50 parts by weight, the organic layer containing the polyepoxy compound of the product and the aqueous layer will not be separated easily, making water washing and purification difficult, and the yield will decrease.

Further, as the alkali metal hydroxide to be used in the second step of the dehydrochloric acid reaction, sodium hydroxide 8 and potassium hydroxide are suitable, and although these can be used in solid form, it is preferable to add them to the reaction system as an aqueous solution. It is preferable to do so.

After the dehydrochlorination reaction is completed, the reaction product is washed several times with water11.
1. The by-product 1-7 alkali metal salt and the water-soluble solvent amines and alcohol are combined with water in 11? leave,
, the Q residue portion is dissolved in a solvent having poor compatibility with water, such as toluene, xylene, methyl isobutyl ketone, etc. The mixture is washed several times with water, and then the solvent having poor compatibility with water is distilled off to obtain the desired tetrafunctional epoxy compound.

The tetrafunctional epoxy compound thus obtained is a pale yellow to yellow viscous substance with a viscosity of 2,000 at 25°C.
0-5,0110 poise, viscosity at 50℃ 50-150
Boies, saponifiable chlorine content is below 0.1 weight 14- amount = IJJ.

This tetrafunctional epoxy compound mixed with a curing agent and cured by heating is a cured product that has excellent heat resistance, is tough, and is insoluble in organic solvents.

Such curing agents include, for example, amine compounds having at least one hydrogen atom directly bonded to a nitrogen atom, such as diethylenetriamine, triethylenetetramine, xylenediamine, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, aniline formaldehyde resins; Adducts of amino compounds with other compounds such as epoxy group-containing compounds, acrylonitrile and acrylic esters, such as polyamide amines derived from aliphatic polyamines and dimer acids of unsaturated fatty acids; polycarboxylic acids or their anhydrides ,
For example, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, maleic anhydride, dodecenylsuccinic anhydride, etc.; polythiols, such as bis-(2-hydrothionityloxy)methane, etc. and tertiary to tertiary amines, such as benzyldimethylamine, tris-(dimethylaminomethyl)phenol, imidazole, pyridine, piperidine, and triethanolamine; and dicyandiamide, BF3.amine salt, and the like.

The present invention will be explained in more detail with reference to Examples below. Note that parts in the examples represent parts by weight.

Example 1 30 parts (0.15 mol) of diaminodiphenylmethane, 224 parts (2.40 mol) of epichlorohydrin, and 3 parts of ethylene glycol were placed in a 40 glass flask with an internal volume of 1 t.
After charging 0 parts and reacting at 60° C. for 1 hour, a portion of the reaction solution was sampled.

Next, the reaction was continued for another 2 hours at the same temperature, and then sampling was performed again, and completion of the addition reaction was confirmed by gel permeation column analysis.

Next, while keeping the temperature of the flask at 60°C, the pressure was reduced (
Unreacted epichlorohydrin was distilled out of the flask under 20 to 30 tWMHg), and 160 parts of epichlorohydrin was recovered.

150 parts of toluene and 5 parts of N,N-dimethylformamide were added to the flask to dissolve the addition reaction product, and then 60 parts of a 48% sodium hydroxide aqueous solution was added to the flask.
(1 mol) was added dropwise over about 1 hour while keeping the temperature of the reaction solution at 50° C. or lower, and the reaction was further carried out at the same temperature for 2 hours.

After the reaction was completed, 300 parts of water at 70°C was added, and after stirring for about 15 minutes, the aqueous layer was removed. After washing the organic layer twice using 250 parts of water in the same manner (the pH of the aqueous layer at this time is about 7), the organic layer was washed at 125°C and about 20 to 30 mmHg.
Distillation under reduced pressure is carried out to remove toluene, and the tetrafunctional epoxy compound 6 represented by the general formula (I) is obtained as a residue.
I got 0 copies.

The obtained product was a pale yellow viscous liquid, and its physical properties were as follows.

Epoxy equivalent weight 119 Viscosity (50°C) 50 poise Gardner color number 5 Saponifiable chlorine content 0.02% 17- Production example of cured product 100 parts of the tetrafunctional epoxy compound obtained in Example 1 and diaminodiphenyl curing agent Mix 52 parts of sulfone, 14 parts
After degassing at 0°C, it is poured into a mold and heated at 180°C for 1 hour and 190°C for 3 hours to perform a curing reaction.
After cooling to 40℃, release the toiletries from the mold [2, W12 Dragon, Width 120
Finally, a product with a wall thickness of 6 deafness was obtained.

The heat distortion temperature (kSTM D-648) of this product is 24
2°C, tensile modulus (JTS R-6911) Jd
It was 39,000 K9/cl.

In addition, the electrical properties were as follows.

Comparative Example 1 30 parts (0.15 mol) of diaminodiphenylmethane, 224 parts (2.40 mol) of epichlorohydrin, and 30 parts of ethyl 18-17 glycol were placed in a 4-day glass flask with an internal volume of 1 mm, and heated at 50°C. After reacting for 1 hour, a portion of the reaction solution was sampled.

Next, the reaction was continued for another 2 hours at the same temperature, and then sampling was carried out again to complete the addition reaction.

Then, 60 parts (1 mole) of aqueous sodium hydroxide solution of 48 was added dropwise into the flask over about 1 hour while keeping the temperature of the reaction solution below 60° C., and maintained at the same temperature for 2 hours.

Thereafter, the pressure in the reaction system was reduced (20 to 30 τHg), and unreacted raw materials, water, etc. were distilled off at about 60° C., and the epichlorohydrin layer and water layer were separated to yield 160 parts of epichlorohydrin. This epichlorohydrin contained approximately 0.15 parts by weight of ethylene glycol.

Next, 200 parts of methyl isobutyl ketone, 7
After adding 300 parts of water at 0°C and stirring for about 15 minutes, the aqueous layer was removed. After washing the organic layer twice using 250 parts of water in the same manner (the pH of the aqueous layer at this time is about 7), the organic layer was subjected to vacuum distillation at 125°C and about 20 to 30 WanHg, and methyl Isobutyl ketone is distilled off and the residue and 1
60 parts of a tetrafunctional epoxy compound represented by the general formula (■) was obtained.

The obtained product was a pale yellow viscous liquid, and its physical properties were as follows.

Epoxy equivalent: 5 Viscosity (50°C): 60 Boise Gardner hue: 2-3 Saponifiable chlorine content: 5.0 30 parts of glycol was charged and an addition reaction was carried out at 60°C for 3 hours.

Next, 5 parts of N,N-dimethylformamide was added to the flask (after addition, 60 parts of a 48 mulberry sodium hydroxide aqueous solution was added to the flask for about 1 hour while keeping the temperature of the reaction solution below 50°C.
It dripped over time.

After that, the pressure inside the reaction system was reduced (20 to 30 mm Hg).
The unreacted raw materials, water, etc. were distilled off at about 60° C., and the epichlorohydrin layer and the water layer were separated from each other, and 132 parts of epichlorohydrin was recovered.

Next, 15.0 parts of toluene and 30 parts of water at 70°C were added to the distillation residue.
After adding 0 parts and stirring for about 15 minutes, the aqueous layer was removed.

After washing the organic layer twice using 250 parts of water in the same manner (the pH of the aqueous layer at this time is approximately 7), the organic layer was washed with 125 parts of water.
Distillation was carried out under reduced pressure at about 20 to 30 W+lHg at a temperature of about 20 to 30 W+lHg to remove toluene and obtain 58 parts of a tetrafunctional epoxy compound represented by the above general formula as a residue.

The obtained product was a pale yellow viscous liquid, and its physical properties were as follows.

Epoxy equivalent weight 128 Viscosity (50°C) 64 Boise donor hue 5 Saponifiable chlorine content 1.6% Examples 2 to 4, Comparative Examples 3 to 4 In Example 1, in place of the ethylene glycol used during the addition reaction, Table 1 The same procedure was followed except that the solvent shown in Table 1 was used in place of the N,N-dimethylformamide used in the dehydrochlorination reaction, and the period between 21 and 21 during the reaction was changed as shown in Table 1. A tetrafunctional epoxy compound having the physical properties shown in the same table was obtained.

The abbreviations of solvents in the table are as follows.

DMF: N,N-dimethylformamide NMI
):'N-Methyl-2-pyrrolidoneDMAA:
N,N-dimethylacetamide HMPA:
Hexamethylphosphoramide MTBK: Methyl isobutyl ketone EG: Ethylene glycol DEG: Diethylene glycol GC: Criserol BN: Butanol IPN: Isopropanol 2EHN: 2 Ethylhexanol (blank below) = 22-

Claims (1)

[Scope of Claims]), after an addition reaction of epichlorohydrin and diaminodiphenylmethane or its alkyl-substituted product or its halogen-substituted product in the presence of a water-soluble alcohol with a boiling point of 120°C or higher, unreacted epichlorohydrin Recovery 1-1 Then, a dehydrochloric acid reaction between the obtained reaction product and an alkali metal hydroxide is carried out using N,N-dimethylformamide, N
, N-dimethylacetamide, N-methyl-2-pyrrolidone, and hexamethylphosphoramide. 2) The manufacturing method according to claim 1, wherein the alkali metal hydroxide is sodium hydroxide. 3) The manufacturing method according to claim 1, wherein the alcohol is used in a proportion of 50 to 500 parts by weight based on 100 parts by weight of diaminodiphenylmethane or its alkyl substituted product. 4) The manufacturing method according to claim 1, wherein the alcohol is ethylene glycol. 5), per 100 parts by weight of diaminodiphenylmethane or its alkyl-substituted product or its halogen-substituted product,
2. The method according to claim 1, wherein the solvent is used in an amount of 2 to 50 parts by weight.