JP2002338562A - Method for producing epoxy compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an epoxy compound with slight epoxy group decomposition by selectively and efficiently hydrogenating the carbon-carbon double bond(s) in a compound having the double bond(s) and epoxy group(s). SOLUTION: This method for producing the objective epoxy compound involves a hydrogenation in the presence of a catalyst which is prepared by bearing active carbon with a mineral acid salt of a noble metal except its chloride followed by reducing the salt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing an epoxy compound. More specifically, the present invention relates to a method for selectively hydrogenating an unsaturated bond of a compound having an epoxy group and a carbon-carbon unsaturated bond using a specific catalyst. The epoxy resin obtained by the present invention is expected to be used for paints, coating materials, binder resins and the like.

[0002]

2. Description of the Related Art Epichlorohydrin and bisphenol A
The bisphenol A type epoxy resin obtained by reacting the above is widely used as a general-purpose type epoxy resin in coating materials, electric insulating materials, laminates, structural materials and the like. However, bisphenol-type epoxy resins have difficulty in weather resistance due to having an aromatic ring.In particular, for applications requiring weather resistance, cyclohexene-based alicyclic olefins epoxidized with peracetic acid are used as weather-resistant epoxy resins. It is commercially available.

On the other hand, various attempts have been made to produce a corresponding alicyclic epoxy resin by hydrogenating an aromatic ring of a bisphenol-type epoxy resin instead of an epoxy resin using a peracid. In this case, it is necessary to suppress the decomposition of the epoxy group as much as possible during nuclear hydrogenation. As the prior art, for example, US Pat.
Japanese Patent No. 6241 discloses a method using a catalyst in which rhodium or ruthenium is supported on an inert carrier.
676 and JP-A-8-53370 disclose a method using a homogeneous ruthenium catalyst, and JP-A-10-20400.
No. 2 discloses a method using a catalyst in which ruthenium and sodium are supported on activated carbon, and Japanese Patent Application Laid-Open No.
Japanese Patent Application Laid-Open No. 2000-226 discloses a method using a catalyst in which rhodium or ruthenium is supported on a carbonaceous carrier having a specific surface area in the range of 5 to 600 m ² / g.
No. 380 describes a method in which a reaction is carried out in an ether solvent using a ruthenium-supported catalyst in the presence of a fatty acid ester.

[0004]

However, the catalyst using ruthenium in the conventional method has a very low activity per metal as compared with rhodium. To obtain sufficient activity, it is necessary to increase the amount of the catalyst or increase the reaction pressure. was there. The activity of the rhodium-supported catalyst was higher than that of the ruthenium catalyst, but the level was not sufficiently satisfactory.

[0005] It is an object of the present invention to provide a hydrogenation catalyst which has a low activity and a high activity in the reaction for selectively hydrogenating carbon-carbon unsaturated bonds of an epoxy group-containing compound.

[0006]

Means for Solving the Problems The present inventors have intensively studied a catalyst preparation method for solving the above-mentioned problems, and as a result, when preparing a catalyst in which a mineral salt is supported on activated carbon as a noble metal raw material, an epoxy group having an epoxy group The inventors have found that a catalyst with little decomposition and high hydrogenation activity can be obtained, and the present invention has been completed.

That is, the present invention provides a method for producing an epoxy compound by selectively hydrogenating a carbon-carbon unsaturated bond of a compound having at least one carbon-carbon unsaturated bond and at least one epoxy group. A gist of the present invention is a method for producing an epoxy compound, which comprises using a catalyst obtained by supporting a mineral acid salt excluding a noble metal chloride on activated carbon and reducing the same.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The starting material used in the present invention is a compound having at least one carbon-carbon unsaturated bond and at least one epoxy group. It may be a monomer, oligomer or polymer. Specific examples include an aromatic ring compound having an epoxy group, an unsaturated aliphatic compound, an unsaturated cyclic aliphatic compound, and an unsaturated polycyclic compound. Among them, a compound in which a carbon-carbon unsaturated bond forms an aromatic ring is preferable.

Specific examples of the aromatic ring compound include styrene oxide, phenylglycidyl ether, diglycidyl ether of hydroquinone, diglycidyl ether of resorcinol, bisphenol A or bisphenol F represented by the general formula (I) and epichlorohydrin. And a glyceryl ether of a phenol novolak resin or a cresol novolak resin represented by the general formula (II).

[0010]

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(Wherein, R ¹ represents a hydrogen atom or a methyl group, and n is 0 to 40) wherein the bisphenol A type epoxy resin represented by the formula (I) and the formula (II) Orthocresol novolak polyglycidyl ether is preferred, wherein
Diglycidyl ethers of bisphenol A (n = 1 in formula (I)) and oligomers thereof are particularly preferred.

The diglycidyl ether of bisphenol A is, for example, as Epikote 827 or 828, and its oligomer is as Epikote 834.
For I), Epicoat 152, 154, 180S65
Commercially available from Japan Epoxy Resin Co., Ltd. The hydrogenation catalyst used in the present invention is a catalyst in which a noble metal, particularly rhodium, is supported on activated carbon. The catalyst used in the present invention supports a noble metal compound on activated carbon,
It is prepared by performing a reduction treatment.

The noble metal compound used in the present invention, for example,
The rhodium compound is not particularly limited as long as it can be thermally decomposed, and examples thereof include mineral salts other than chlorides such as rhodium nitrate, rhodium sulfate, and rhodium phosphate. Is more preferred because of its low activity and high activity. In general, when a catalyst is prepared by liquid phase reduction, when a nitrate is used, a nitrate group tends to remain in the preparation process, and the hydrogenation activity of the aromatic ring is reduced due to the influence. For example, in the case of a graphite carrier, the activity using chloride is higher than that using nitrate. However, when activated carbon was used as the carrier, the opposite tendency was surprisingly shown.

There is no particular limitation on the method of supporting a noble metal, for example, rhodium on activated carbon, but in general, an immersion method is used. For example, the catalyst component is dissolved in a solvent capable of dissolving a metal compound such as a nitrate, for example, water to form a solution, and activated carbon is immersed in the solution to be impregnated and supported. Thereafter, the solvent is distilled off under reduced pressure to carry out a reduction treatment. The reduction treatment can be performed by either a gas phase reduction method or a liquid phase reduction method. However, it is more preferable to prepare by liquid phase reduction because the metal can be supported in a highly dispersed state because it is processed at a low temperature.

For example, when reducing in the gas phase using hydrogen gas, 100 to 600 ° C., preferably 150 to 500 ° C.,
It is more preferably performed at a temperature of 200 to 400 ° C. Examples of the reducing agent used here include carbon monoxide in addition to hydrogen. Further, it may be used after being diluted with an inert gas such as nitrogen or argon. In the case of reduction in the liquid phase, first, a noble metal compound, for example, a rhodium compound is supported, and then treated with an alkaline aqueous solution to insolubilize the noble metal as a hydroxide, fixed, and then reduced. preferable.

As the kind of alkali of the alkaline aqueous solution used for insolubilization and immobilization, aqueous ammonia and aqueous solutions of alkali metal hydroxides such as sodium hydroxide, sodium carbonate and potassium hydroxide can be preferably used. It is most preferable to use ammonia water in consideration of the easiness of washing with water later and the influence of remaining alkali metal cations.

The amount of alkali used is 3 per noble metal.
-100 equivalents are preferred, and 6-50 equivalents are more preferred. The treatment temperature with the alkaline aqueous solution is preferably from 20 ° C to 90 ° C, and particularly when using aqueous ammonia, if the temperature is higher than 50 ° C, the desorption of ammonia becomes remarkable, so it is preferably from 20 to 50 ° C. The catalyst which is insoluble and fixed in the alkaline aqueous solution is sufficiently washed with ion-exchanged water or the like. In particular, when an aqueous solution of an alkali metal hydroxide is used, if the alkali metal cations such as Na ⁺ and K ⁺ remain, the hydrogenation activity decreases, so that sufficient washing is required.

The insoluble and immobilized catalyst is preferably reduced in a liquid phase using formalin, formic acid, methanol or the like. The amount of the reducing agent used is 3 to 100 molar equivalents, preferably 6 to 50 molar equivalents with respect to the noble metal. The reduction temperature is from 20 to 120C, preferably from 50 to 100C.
The catalyst reduced in the liquid phase can be filtered, sufficiently washed with ion-exchanged water and the like, and then dried and used for the hydrogenation reaction.

The use of the liquid phase reduction is more preferable because the particle diameter of the metal particles supported on the carrier is reduced and the metal is uniformly supported, so that the epoxy loss rate is kept low. The amount of the catalyst used in the hydrogenation reaction is preferably 0.05 to 100 parts by weight, and more preferably 0.1 to 50 parts by weight based on 100 parts by weight of the reaction raw material.
It can be arbitrarily selected within a range where a practical reaction rate can be obtained according to various conditions such as a reaction temperature and a reaction pressure.

The reaction temperature in the hydrogenation reaction of the present invention is 30
To 150 ° C, preferably 70 to 120 ° C. Also,
The reaction pressure is usually 1 to 30 MPa, preferably 3 to 10 M
Pa. As a reaction method, either a liquid phase suspension reaction or a fixed bed reaction can be adopted. As the reaction solvent, ethers such as THF and dioxane and esters such as methyl acetate, ethyl acetate and methyl propionate are preferably used in view of the solubility of the starting materials.

After the hydrogenation reaction is carried out according to the method of the present invention, the catalyst is filtered off and then the volatile components are removed by distillation to obtain the desired product.

[0022]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the invention. Example 1 Rhodium nitrate aqueous solution containing 5.1 wt% Rh metal 4.9
4.75 g of commercially available powdered activated carbon in 1 g of water added to 0 g
Was added to carry out impregnation. Thereafter, the solvent was removed by an evaporator. This was added to an aqueous solution obtained by dissolving 0.78 g of 28% by weight aqueous ammonia in 6 ml of water, and immobilization treatment was performed at room temperature. After filtration, the precipitate was washed with ion-exchanged water. This immobilized catalyst was added to a mixed solution of 2 g of formic acid and 20 ml of water, and the mixture was heated under reflux to perform a reduction treatment for 5 hours. After filtration, the obtained catalyst was washed with ion-exchanged water and dried at 50 ° C. to obtain a 5% by weight rhodium / activated carbon catalyst.

Using 0.5 g of this catalyst, 50 ml of tetrahydrofuran was introduced into an induction-stirring autoclave having a capacity of 200 ml.
g, 50 g of 2,2-di- (p-glycidoxy-phenyl) -propane (Epicoat 828, epoxy equivalent 186, manufactured by Japan Epoxy Resin Co., Ltd.) was added, hydrogen was injected at 2 MPa, and the temperature was raised to 75 ° C. The pressure of hydrogen was increased to 7 MPa at 75 ° C., and the temperature was increased to 85 ° C., and the reaction was performed for 2.5 hours. After the reaction, the catalyst was filtered off, and volatile components were distilled off under reduced pressure. The hydrogenation rate of the aromatic ring was determined from the integrated value of the ¹ H-NMR spectrum, and the epoxy equivalent was determined by a perchloric acid titration method (JIS K7236). Here, the epoxy equivalent indicates the number of grams of an epoxy resin containing 1 mol of an epoxy group. The reaction results are shown in Table 1. Comparative Example 1 A catalyst was prepared and reacted in the same manner as in Example 1, except that rhodium chloride was used instead of rhodium nitrate. The results are shown in Table 1. Comparative Example 2 Graphite (TIMREX HSAG100 manufactured by TIMCAL, surface area 130 m ^{2) was} used instead of powdered activated carbon.
A catalyst was prepared and reacted in the same manner as in Example 1 except that / g) was used. Table 1 shows the results.

[0024]

Table 1 Carrier Rh raw material Aromatic ring hydrogenation rate Epoxy equivalent%% Example 1 Activated carbon rhodium nitrate 100 198 Comparative Example 1 Activated carbon rhodium chloride 70 197 Comparative Example 2 Graphite Rhodium nitrate 82 198

[0025]

According to the present invention, a carbon-carbon unsaturated bond of a compound having a carbon-carbon unsaturated bond and an epoxy group can be prepared by using a noble metal catalyst supported on activated carbon using a noble metal salt, particularly rhodium nitrate as a raw material. By selectively hydrogenating the bond, an epoxy compound can be produced with less decomposition of the epoxy group and at a higher hydrogenation rate.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) // C07B 61/00 300 C07B 61/00 300 F term (reference) 4C048 AA01 BB10 CC02 UU05 XX02 XX05 4G069 AA03 AA08 BA08A BA08B BB02A BB02B BB10C BB12C BB14C BC69A BC69C BC71A BC71B CB02 CB62 FA02 FB20 FB43 FB44 FB45 FC02 4H039 CA60 CB20

Claims (8)

[Claims] 1. A method for producing an epoxy compound by selectively hydrogenating a carbon-carbon unsaturated bond of a compound having at least one carbon-carbon unsaturated bond and at least one epoxy group, the method comprising: A method for producing an epoxy compound, comprising using a catalyst obtained by supporting a mineral acid salt excluding a substance on activated carbon and reducing the same. 2. The method according to claim 1, wherein the noble metal is rhodium. 3. The precious metal mineral salt is a nitrate.
Or the method for producing an epoxy compound according to 2. 4. The catalyst according to any one of claims 1 to 3, wherein a catalyst obtained by supporting a mineral acid salt excluding noble metal chloride on activated carbon, treating with an alkaline aqueous solution, and then reducing in a liquid phase is used. A method for producing an epoxy compound. 5. The method for producing an epoxy compound according to claim 1, wherein at least one carbon-carbon unsaturated bond forms an aromatic ring. 6. The method for producing an epoxy compound according to claim 1, wherein an ether or an ester is used as a reaction solvent. 7. The hydrogenation reaction is carried out at a reaction temperature of 30 to 150 ° C.
The method for producing an epoxy compound according to any one of claims 1 to 6, wherein the method is performed at a hydrogen pressure of 1 to 30 MPa. 8. The compound according to claim 1, wherein the compound is obtained by reacting epichlorohydrin with a polyhydric phenol.
8. The method for producing an epoxy compound according to any one of 7.