JP2002338559A - 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 loss by selectively 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 is characterized by involving using a catalyst with a noble metal borne on a carbonaceous carrier and feeding hydrogen while bubbling it into a liquid phase.

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 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 have been conventionally proposed. In this reaction, it is necessary to minimize the decomposition of the epoxy group during nuclear hydrogenation.

As a prior art, for example, US Pat.
No. 3,336,241 discloses a method using a catalyst in which rhodium or ruthenium is supported on an inert carrier;
JP-A-48676 and JP-A-8-53370 disclose a method using a homogeneous ruthenium catalyst, and JP-A-10-204.
No. 002 discloses a method using a catalyst in which ruthenium and sodium are supported on activated carbon, and Japanese Patent Application Laid-Open No. 11-217379 proposed by the present inventors discloses that rhodium or ruthenium has a specific surface area of 5 to 600 m ² / g. Method using catalyst supported on a certain carbonaceous carrier and JP-A-2000-2
No. 26380 discloses 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]

The hydrogenation reaction of carbon-carbon unsaturated bonds and the decomposition reaction of the epoxy group are simultaneous reactions. Therefore, the longer the reaction time, the more the decomposition of the epoxy group proceeds. Therefore, in order to suppress the decomposition of the epoxy group and accelerate the hydrogenation reaction of carbon-carbon unsaturated bonds such as aromatic rings, it is effective to efficiently introduce hydrogen during the liquid phase reaction. Although it is conceivable, there is no description in the conventional known documents that only hydrogen was injected but only an effective method for introducing hydrogen.

An object of the present invention is to provide a method for hydrogenating carbon-carbon unsaturated bonds of an epoxy group-containing compound, in which hydrogen is supplied to a reactor having a small loss of epoxy groups.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems, and as a result, when hydrogen is introduced into the reactor, the reaction rate is improved by bubbling the liquid phase, The inventors have found that the loss of the epoxy group can be suppressed, and have completed the present invention. That is, the present invention provides at least one
The compound having at least one carbon-carbon unsaturated bond and at least one epoxy group is selectively hydrogenated with hydrogen using a catalyst in which a noble metal is supported on a carbonaceous carrier to form a liquid phase. In the method for producing an epoxy compound therein, a method for producing an epoxy compound is characterized in that hydrogen is supplied while bubbling to a liquid phase portion.

[0007]

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, for example, 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).

[0009]

Embedded image

(Wherein, R ¹ represents a hydrogen atom or a methyl group, and n is 0 to 40). Among them, a bisphenol A type epoxy resin represented by the formula (I) and a compound represented by 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 used, for example, as Epicoat 827 or 828, and its oligomer is used as Epicoat 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. As the carbonaceous carrier used in the present invention, carbon black, activated carbon and graphite are preferred.

The catalyst used in the present invention is prepared by dissolving a compound of a catalytic noble metal, supporting the solution on a carbonaceous carrier, and subjecting the solution to a reduction treatment if necessary. Among the noble metal compounds used, the rhodium compound is not particularly limited as long as it can be thermally decomposed, and inorganic salts such as rhodium chloride, rhodium nitrate, and rhodium sulfate, organic metal compounds such as rhodium acetylacetonate, and tetrarhodium dodeca. Coordination compounds such as carbonyl,
It is preferable to use rhodium chloride because the activity is reduced when the counter anion hetero element remains, and the organorhodium compound is expensive. Examples of the ruthenium compound include inorganic salts such as ruthenium chloride and ruthenium nitrosyl nitrate; organometallic compounds such as ruthenium acetylacetonate; and coordination compounds such as triruthenium dodecacarbonyl. The amount of the metal component supported is not particularly limited, but if the amount is small, the effect of the catalyst is reduced, and if the amount is large, the cost is disadvantageous. It is preferable that the metal of the present invention is contained.

The method of supporting a noble metal such as rhodium or ruthenium on a carbonaceous carrier is not particularly limited, but usually a dipping method is used. For example, the metal component of the catalyst component is dissolved in a solvent capable of dissolving, 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, and a reduction treatment is performed if necessary. 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 gaseous 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, after supporting a noble metal compound such as rhodium or ruthenium, the solution is treated with an alkaline aqueous solution to insolubilize the noble metal compound as a hydroxide, fixed, and reduced. Is preferred. As the kind of alkali of the alkaline aqueous solution used for insolubility and immobilization, aqueous ammonia or an aqueous solution of an alkali metal hydroxide such as sodium hydroxide, sodium carbonate and potassium hydroxide can be preferably used. It is most preferable to use aqueous ammonia in consideration of the easiness of the reaction and the influence of the residual alkali metal cation.

The amount of the alkali used is preferably 3 to 100 equivalents, more preferably 6 to 50 equivalents, based on a noble metal such as rhodium or ruthenium. 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 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 to be used is 3 to 100 molar equivalents, preferably 6 to 50 molar equivalents based on a noble metal such as rhodium or ruthenium. The reduction temperature is 2
The temperature is 0 to 120 ° C, preferably 50 to 100 ° C. The catalyst reduced in the liquid phase can be filtered, sufficiently washed with ion-exchanged water and the like, and then washed and used for the hydrogenation reaction.

If the reaction temperature in the hydrogenation reaction of the present invention is too low, the reaction rate is reduced, and if it is too high, hydrogenolysis of the epoxy group proceeds. ° C. The reaction pressure is usually 1 to 30 MPa, preferably 3 to 10 MPa.
As for the method of introducing hydrogen, a hydrogen introducing pipe is placed in a liquid phase portion and introduced while bubbling in the liquid. In the case of a compound in which a carbon-carbon unsaturated bond forms an aromatic ring, the hydrogenation of the aromatic ring consumes a very large amount of hydrogen. It can proceed, and decomposition of the epoxy group can be suppressed.

The supply amount of hydrogen is supplied according to the consumption amount of hydrogen. The amount of the catalyst used for the hydrogenation reaction is as follows:
The amount is preferably from 0.05 to 100 parts by weight, and more preferably from 0.1 to 50 parts by weight, per 100 parts by weight, but a practical reaction rate can be obtained depending on various conditions such as the reaction temperature or the reaction pressure. Can be arbitrarily selected within the range given. It is preferably 0.001 to 0.1% by weight, preferably 0.005 to 0.05% by weight of the metal based on the weight of the raw material.

As a reaction system, 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 carrying out the hydrogenation reaction 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.

[0020]

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 chloride hydrate 62 containing 40.0% by weight of Rh metal
5 mg was dissolved in 6 g of water while graphite (TIM
4.75 g of TIMLEX HSAG100 (manufactured by CAL, specific surface area: 130 m ^{2 /} g) was added and impregnated and supported. 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 / graphite catalyst. 200 m using 0.16 g of this catalyst
In an induction-stirring autoclave equipped with a hydrogen inlet tube for releasing hydrogen to the middle liquid phase in the height direction of the reactor in the vicinity of the 1-volume stirring blade, 20 g of THF and 2,2-di- (p-glycidyloxy) were added. 80 g of Seaphenyl) -propane (Epicoat 828 made by Japan Epoxy Resin Co., Ltd., epoxy equivalent 1
86) was added, hydrogen was injected at a pressure of 2 MPa, and the temperature was raised to 75 ° C. The pressure of hydrogen was increased to 7 MPa at 75 ° C., the temperature was increased to 85 ° C., and hydrogen was bubbled and supplied according to the amount of hydrogen consumed, and the reaction was performed for 1.5 hours. After the reaction, the catalyst is filtered off,
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 epoxy decomposition rate was calculated from the epoxy equivalent. Table 1 shows the results. Comparative Example 1 A reaction was carried out for 2.5 hours in the same manner as in Example 1 except that the reaction was performed without supplying a hydrogen introduction tube and supplying hydrogen to the gas phase. Table 1 shows the results.

[0022]

[Table 1] Table 1 Hydrogen introduction reaction time Aromatic ring hydrogenation rate Ethoxy decomposition rate h%% Example 1 Liquid phase binder 1.5 1.5 2 Comparative example 1 Gas phase 2.5 100 10

[0023]

According to the present invention, there is provided a method for hydrogenating a carbon-carbon unsaturated bond of an epoxy group-containing compound having at least one carbon-carbon unsaturated bond and at least one epoxy group. By introducing a method of bubbling hydrogen into the liquid phase, the reaction rate is improved and the loss of epoxy groups can be suppressed.

Claims (7)

[Claims] 1. A method comprising selecting a carbon-carbon unsaturated bond of a compound having at least one carbon-carbon unsaturated bond and at least one epoxy group with hydrogen using a catalyst in which a noble metal is supported on a carbonaceous carrier. A method for producing an epoxy compound in a liquid phase by hydrogenation, wherein hydrogen is supplied to the liquid phase while bubbling. 2. The method according to claim 1, wherein at least one carbon-carbon unsaturated bond forms an aromatic ring. 3. The method according to claim 1, wherein the carbonaceous carrier is carbon black, activated carbon or graphite. 4. The method for producing an epoxy compound according to claim 1, wherein the noble metal is rhodium. 5. The method for producing an epoxy compound according to claim 1, wherein an ether or an ester is used as a reaction solvent. 6. The hydrogenation reaction is carried out at a reaction temperature and a hydrogen pressure of 1 to 30.
The method for producing an epoxy compound according to any one of claims 1 to 5, which is performed at MPa. 7. The compound according to claim 1, wherein the compound is obtained by reacting epichlorohydrin with a polyhydric phenol.
7. The method for producing an epoxy compound according to any one of 6.