JPH03275637A - Production of biscyclohexanol - Google Patents

Abstract

PURPOSE:To obtain the subject substance useful as a raw material or resins and raw material or intermediate for plasticizers, antistatic agents, medicines, liquid crystals, etc., by hydrogenating bisphenol using a glycol monoether as a solvent. CONSTITUTION:A compound expressed by formula I is hydrogenated to provide a compound expressed by formula II. In the process, a compound expressed by formula III (R is 1-5C alkyl; R' is 2-4C alkylene; the total number of carbon atoms in R and R' is <=7) is used as a solvent. Since the compound expressed by formula III has a low vapor pressure, the solvent can be repeatedly used with hardy any loss in distilling away of the solvent without requiring high level of pressure resistance in a reactor. Since the boiling point difference from the objective substance is large, separation and purification by distillation, etc., are readily carried out. The aforementioned solvent can be sufficiently used in an amount of 100-300ml based on 50g raw material at ordinary tempera ture to 80 deg.C. Since the vapor pressure is low at the hydrogenation temperature of about 170 deg.C, partial pressure of H2 gas can be increased to shorten the reac tion time.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides an alkyd resin with excellent heat resistance and water resistance,
Resin raw materials such as epoxy resins, polyester resins, polycarbonate resins, and polyurethane resins; additives for various polymeric materials such as plasticizers, lubricants, and antistatic agents; raw materials and intermediates for pharmaceuticals, liquid crystals, surfactants, industrial chemicals, etc. [Prior Art] The hydrogenation reaction of biphenol can be carried out in a solvent or without a solvent. However, the melting point of the raw material is biphenyl-2
,2゛-diol at 109°C, biphenyl-3,3°-
Diol has a high temperature of 126°C, and biphenyl-4,4°-diol has a high temperature of 160°C, so when the hydrogenation reaction is carried out in an S-free medium,
In order to prevent the raw material from solidifying, it is necessary to heat the raw material transfer pipe and the raw material charging pump. Therefore, the heat resistance of transfer pipes, charging pumps, etc. becomes a problem.

In addition, the melting point of biscyclohexanol produced by hydrogenation is high, and the melting point of bicyclohexyl-4,4 diol is 216°C for the trans-trans form and 19°C for the cis-cis form.
7°C, the cis-trans form is 179°C to 181°C, and the melting point of bicyclohexyl-1°1°-diol is 130°C. Therefore, when the hydrogenation reaction is carried out without a solvent, it is necessary to heat the product extraction pump, the product transfer pipe, etc. to prevent the product from solidifying. Further, there are problems such as the tendency for products to adhere to an R-filter etc. during catalyst filtration, so hydrogenation in a solvent system is often used.

As a method for producing biscyclohexanol by hydrogenating biphenol, the following methods (I) to (2) and the like are conventionally known.

(I) 500 ml of ethyl acetate containing up to 2% water by volume was added to 40 g of biphenol as a raw material, and the mixture was hydrogenated at 140°C for 12 hours under hydrogen gas at 100 atm in the presence of a palladium catalyst to produce 4,4°-dihydroxy A method for obtaining dicyclohexane with a yield of 99.5% (Japanese Unexamined Patent Publication No. 1-34935).

(2) Dissolve 100 g of biphenyl-4,4°-diol in 1 liter of Improper Tool, add 5 g of anhydrous sodium carbonate and 5 g of carbon-supported palladium catalyst, and heat at a hydrogen pressure of 5 kg/cm'' for 25 to 30 hours. A method for obtaining bicyclohexyl-4,4-diol by hydrogenation (JP-A-1-156935).

In JP-A-1-34935, ethyl acetate, methyl-t-butyl ether, ethanol, and cyclohexane containing up to 2% by volume of water are used as solvents; however, when a solvent containing up to 2% by volume of water is used, Controlling the amount of water in the reaction solvent is complicated in terms of process and lacks productivity. Furthermore, since the amount of solvent is large relative to the raw material, and ethyl acetate and ethanol have low boiling points, there are safety problems due to losses during recovery of molten tIX and high vapor pressure.

In order to improve productivity, it is necessary to use a solvent with good solubility, use a large amount of catalyst, or raise the reaction temperature to carry out the hydrogenation reaction in a short time.

However, using a large amount of catalyst is economically disadvantageous;
Moreover, it will also have an adverse effect on operations after the reaction is completed.

In addition, if the reaction temperature is raised above the limit, side reactions such as elimination of secondary hydroxyl groups will occur, which is not preferable.
Therefore, it is essential to select a solvent with good solubility.

In JP-A-1-156935, 1 liter of inpropanol is added to 100 g of biphenyl-4,4°-diol as a raw material to carry out the reaction, but the amount of solvent is large relative to the raw material, and isopropanol is low. Due to its boiling point, there are losses during solvent recovery and safety issues due to its high vapor pressure.

On the other hand, bisphenol A (4,4'-dihydroxydiphenyl-2,2-propane) was dissolved in decalin WI medium (A
nn, 472.68 (I929)), or in7
0 in panol or n-butanol solvent
-1423), in a solvent such as methanol or ethanol (Japanese Patent Publication No. 45-35300) discloses a method for producing hydrogenated bisphenol A, but since bisphenol A has an inpropylidene group, biphenol The solubility in solvents is lower than that of biscyclohexanol and biscyclohexanol, and it is difficult to directly apply the solvent used for the hydrogenation of bisphenol A to the hydrogenation of biphenol.

In the hydrogenation of biphenol, the raw material biphenol and the product biscyclohexanol have different solubility and affinity for solvents, and it has been extremely difficult to select a solvent that has a low vapor pressure and can dissolve both solvents well.

[Problem to be solved by the invention] When hydrogenating biphenol to produce biscyclohexanol, the reaction rate is improved by selecting a good solvent for both the raw material biphenol and the product biscyclohexanol. The aim is to improve the productivity of biscyclohexanol.

[Means for Solving the Problems] In order to solve the above problems, the present inventors have made efforts to improve the solubility of biphenol shown in general formula 1) and biscyclohexanol shown in general formula (II>) in a solvent. As a result of investigation, it was found that solubility, reaction rate, etc. are greatly affected by the type of solvent, and the present invention was completed by using a glycol monoalkyl ether represented by general formula (III).

RO-(RO)n (III) (R represents an alkyl group having 1 to 5 carbon atoms, and Ro represents an alkylene group having 2 to 4 carbon atoms.

The total number of carbon atoms in R and Ro is 7 or less. 〉Furthermore, since the glycol monoalkyl ether has a low vapor pressure, it does not require a high degree of pressure resistance in the reaction equipment.
It also has the advantage that there is little loss during solvent distillation, the solvent can be reused repeatedly, it has a large boiling point difference with the target product, and it is easy to separate and purify by distillation or the like.

When the solvent of the present invention is used, it is possible to melt t1100 per 50 g of raw material at the normal charging temperature of raw materials from room temperature to about 80°C.
ml to 300ml is sufficient, and 170℃
Since the vapor pressure is small at a hydrogenation temperature of about 100%, the partial pressure of hydrogen gas can be increased in the same pressure-resistant container, and the hydrogenation reaction time can be shortened.

Glycol monoalkyl ethers used as reaction solvents are methanol, ethanol, propatool, impropatol, butanol, -isobutanol, amyl alcohol, and isoamyl alcohol to which alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide are added. and the total number of carbon atoms is 7 or less.

Specifically, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether.

Ethylene glycol monoamyl ether, ethylene glycol monoisoamyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monoimpropyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, Propylene glycol monopropyl ether, propylene glycol monoisopropyl ether, propylene glycol monobutyl ether, propylene glycol monoin butyl ether, dipropylene glycol monomethyl ether, butylene glycol monomethyl ether, butylene glycol monoethyl ether, butylene glycol monopropyl ether,
Examples include butylene glycol monoisopropyl ether.

Among the above examples, propylene glycol monomethyl ether represented by formula (IV) is particularly preferred from the viewpoint of boiling point, solubility of raw materials, and solubility of products.

CH30-CH2-CH-CH3 0H(IV) Glycol monoalkyl ether having 8 or more carbon atoms is
It has a high boiling point, which is unfavorable for separation from the target product.

The amount of solvent is 50ml to 500ml per 50g of raw material. More preferably, it is 100 m1 to 300 m1. If the amount of solvent is less than 50ml, the raw materials and products cannot be dissolved in the temperature range from room temperature to 80℃, which is the normal preparation temperature, and conversely, if the amount is more than 500ml, the amount of raw materials charged will be reduced. This results in a decrease in productivity.

Examples of the hydrogenation catalyst used in the present invention include conventionally known hydrogenation catalysts, such as nickel-based catalysts, cobalt-based catalysts, and noble metal catalysts such as palladium catalysts, rhodium catalysts, ruthenium catalysts, and platinum catalysts. etc. can be used. Among the catalysts, stabilized di-y-Kel catalysts and palladium-based catalysts are preferred, but they are not limited to these.As the carrier for supporting the catalyst, any commonly used carrier can be used, such as diatomaceous earth or graphite. , silica, activated carbon, alumina, calcium carbonate, etc. can be used. The amount of catalyst supported is suitably 0.1 to 5% by weight on a carrier such as diatomaceous earth, alumina, or carbon.

The amount of catalyst is 0.1% to 30% by weight, preferably 0.5% to 15% by weight, based on the amount of raw materials charged.

The amount of catalyst varies depending on the type of catalyst used for hydrogenation, and in the case of a stabilized nickel catalyst, it is usually used in an amount of 1 to 3% by weight based on the raw material. In the case of a noble metal catalyst, it is usually used in an amount of 0.3 to 2% by weight. For nickel-based catalysts, the hydrogenation temperature is
The temperature is usually 100°C to 250°C. If the reaction temperature is lower than this, the hydrogenation reaction will be slow, and if it is higher than this, the elimination reaction of the secondary hydroxyl group of the biscyclohexanol produced will occur, resulting in the production of olefins. However, when a noble metal catalyst such as a palladium-based catalyst is used, the reaction can be carried out at even lower temperatures.

The reaction hydrogen pressure may be any pressure as long as it is a gauge pressure (hereinafter the same) 1 kg/cm" or higher, but generally it is 1 to 10
0 kg/cm2 is preferred, and for stabilized nickel catalysts 3
A range of 0 to 100 kg/cm2 is suitable. When using a precious metal catalyst, 10 kg/cm'
Hydrogenation can also be carried out below.

In the present invention, the reaction time is not particularly limited, but the time required for hydrogenation is 20 minutes to 15 hours. More preferably, it is 30 minutes to 4 hours.

If it is shorter than 20 minutes, the hydrogenation reaction will be insufficient, and if it is longer than 15 hours, secondary hydroxyl groups will be eliminated due to overreaction, which is not preferable in terms of productivity.

According to the present invention, productivity can be significantly improved compared to conventional methods, and it has the advantage that a product with extremely high purity can be obtained simply by passing the reaction mixture through filtration and evaporating the solvent. , is an industrially useful method. Furthermore, there is no deterioration of the catalyst due to repeated use.

The reaction method can be either a batch reaction or a continuous reaction method, and is appropriately selected depending on the production amount and the like.

[Examples] Hereinafter, the present invention will be explained in detail by giving Examples, but the present invention is not limited thereto.

Example 1 4.4゛-dihydroxydiphenyl (Honshu Chemical Co., Ltd.) was placed in a 5 liter autoclave equipped with an electromagnetic stirrer.
1,500 g of the same product manufactured by Nippon Nyukazai Co., Ltd. and 1,500 g of propylene glycol monomethyl ether (manufactured by Nippon Nyukazai Co., Ltd.)
000ml and 5N-300+ as hydrogenation catalyst.
Stabilized nickel catalyst, manufactured by Sakai Chemical Co., Ltd.
% by weight, replace the inside of the autoclave with hydrogen gas, charge the autoclave to a pressure of 30 kg/cm2, raise the temperature, and when it reaches 170°C, increase the hydrogen pressure to 50 kg/cm2.
It was adjusted to kg/'cm2. If hydrogen gas is absorbed, add hydrogen gas as needed to keep the reaction pressure at 50 k.
The pressure was adjusted to g/cm2, and the hydrogenation reaction was carried out for 120 minutes until absorption of hydrogen gas stopped.

Thereafter, the contents were cooled to 60° C. over 20 minutes, taken out from the autoclave, and the solvent was evaporated under reduced pressure to obtain the desired product, 4,4° dihydroxydicyclohexane. Purity analysis was performed by gas chromatography. The results obtained are shown in Table 1.

Example 2 Diethylene glycol 7-methyl ether (
The same procedure as in Example 1 was conducted except that Nippon Nyukazai Co., Ltd.) was used. The results obtained are shown in Table 1.

Example 3 The same procedure as in Example 1 was carried out except that ethylene glycol monobutyl ether (manufactured by Nippon Nyukazai Co., Ltd.) was used as the solvent. The results obtained are shown in Table 1.

Example 4 2,2゛-dihydroxydiphenyl (Wako Pure Chemical Industries, Ltd.) was used as a raw material.
The same procedure as in Example 1 was carried out except that a reagent (1st class reagent manufactured by Co., Ltd.) was used. The results obtained are shown in Table 1.

Example 5 As a catalyst, a palladium catalyst (manufactured by NT Cat Co., Ltd.) supported at 5% by weight on carbon was added to
．． 1 reaction using 5 wt% hydrogen pressure 10 kg/c
The procedure was carried out in the same manner as the actual IMI except that m' was replaced. The results obtained are shown in Table 1.

Example 6 500g of 4.4゛-dihydroxydiphenyl as raw material,
Propylene glycol monomethyl ether 10100O
The same procedure as in Example 1 was carried out except that . The results obtained are shown in Table 1.

Example 7゜Same as Example 1 except that the catalyst 5N-300 was used in an amount of 1% by weight based on the raw material 4,4-dihydroxydiphenyl.
The reaction was carried out in the same manner. The results obtained are shown in Table 1.

Comparative Example 1 500g of 4.4゛-dihydroxydiphenyl as raw material
,! The same procedure as in yMPs1 was carried out except that 2,500 ml of ethyl acetate (first grade reagent manufactured by Wako Pure Chemical Industries, Ltd.) was used as the medium. The results obtained are shown in Table 1.

Comparative Example 2 500g of 4,4゛-dihydroxydiphenyl as raw material
The same procedure as in Example 1 was carried out except that 12,500 ml of isopropanol (12,500 ml of a first-grade reagent manufactured by Wako Pure Chemical Industries, Ltd.) was used as the solvent. The obtained results are shown in Table 1.

The same procedure as in Example 1 was carried out, except that 250 g and 2500 ml of ethyl acetate (a first-class reagent manufactured by Wako Pure Chemical Industries, Ltd.) were used as the solvent. The results obtained are shown in Table 1.

[Effects of the invention] According to the present invention, productivity can be significantly improved compared to conventional methods, and products with extremely high purity can be obtained simply by treating the reaction mixture and evaporating the solvent. It has the following advantages.

Claims (1)

[Claims] When producing biscyclohexanol represented by general formula (II) by hydrogenating biphenol represented by general formula (I), one of the glycol monoethers represented by general formula (III) or A method for producing biscyclohexanol, which comprises using two or more types of solvents. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) RO-(R'O)n-H(III) (R is an alkyl group with 1 to 5 carbon atoms and R' represents an alkylene group having 2 to 4 carbon atoms. The total number of carbon atoms of R and R' is 7 or less.)