JP2684431B2 - Method for purifying 4,4'-isopropylidenedicyclohexanol - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention provides 4,4'-isopropylidenedicyclohexanol, which is useful as a raw material for polymers such as unsaturated polyester resins and epoxy resins, in high purity and efficiently. It relates to a method for purifying 4,4'-isopropylidenedicyclohexanol which can be recovered.

[Problems to be solved by conventional technology and invention]

Conventionally, as a method for purifying 4,4′-isopropylidenedicyclohexanol, for example, a method of distilling a solvent by vacuum distillation and recovering a product (Japanese Patent Publication No. 42-1423,
Japanese Patent Publication No. 61-260034) and a method of recovering a product by a recrystallization method (Japanese Patent Publication No. 43859/43859, US Pat. No. 4,487,979) are known.

According to the above method, the product 4,4′-isopropylidenedicyclohexanol can be almost completely recovered, but it requires considerably severe distillation conditions, and the product is excessively purified so that it is excessive. Since it is heated to a high temperature, there is a drawback that the product tends to be colored. Also,
If the distillation conditions are mild, the solvent remains in the product,
Only low melting points may be obtained.

On the other hand, according to the above method, it is possible to remove the split by-products during the hydrogenation reaction, and as a result, the product purity can be expected to improve, but since a good solvent is used as the solvent, it is a product. There are disadvantages that the distribution of isomers of 4,4'-isopropylidenedicyclohexanol is extremely changed and the recovery rate is remarkably low. That is, since a good solvent is used in the above method, some components (cis-cis form, cis-trans form) in the product which are relatively soluble in the solvent are partially transferred to the solvent, and as a result, trans-trans form is obtained. There is a risk that the body content will increase and the isomer distribution will change.

[Means for solving the problem]

The present invention solves the conventional problems as described above, and
-High purity isopropylidene dicyclohexanol,
Moreover, it is an object of the present invention to provide a method for purifying 4,4'-isopropylidenedicyclohexanol that can be efficiently recovered.

That is, the present invention includes a reaction solvent in purifying 4,4′-isopropylidenedicyclohexanol obtained by catalytic hydrogenation of 4,4′-isopropylidenediphenol using a catalyst in the presence of a solvent. The catalyst is removed from the reaction product solution, and then a part of the reaction solvent is removed.
4,4'-characterized in that it is washed with a poor solvent for 4,4'-isopropylidenedicyclohexanol and dried.
The present invention provides a method for purifying isopropylidenedicyclohexanol.

In the present invention, 4,4′-isopropylidenedicyclohexanol to be purified is the raw material 4,4′-
Isopropylidene diphenol (bisphenol A)
Can be easily obtained by catalytic hydrogenation in the presence of a solvent using a general nuclear hydrogenation catalyst.

In this case, as the catalyst, a general nuclear hydrogenation catalyst, for example, a ruthenium catalyst having alumina or carbon as a carrier, a rhodium catalyst having alumina or carbon as a carrier, Raney nickel, a nickel catalyst supported on alumina, etc. may be used. it can.

The reaction solvent used in the catalytic hydrogenation is preferably an alcohol solvent, more specifically an aliphatic alcohol or an alicyclic alcohol.

Furthermore, the reaction conditions in the catalytic hydrogenation are as follows. First, the reaction temperature has a final temperature depending on the type of catalyst used, but is usually in the range of 50 to 250 ° C.

The reaction pressure is preferably as high pressure from the viewpoint of reaction rate and product purity usually is in the range of ^{30kg / cm 2 G~70kg / cm 2} G.

In the purification method of the present invention, the reaction product liquid containing the reaction solvent (that is, the catalyst,
First, the catalyst is removed from the reaction solvent, the reaction product solution containing the product 4,4′-isopropylidenedicyclohexanol).

Removal of the catalyst is usually carried out by filtration, whereby a colorless and transparent liquid is obtained.

Next, a part of the reaction solvent is removed from the reaction product liquid (colorless transparent liquid) from which the catalyst has been removed as described above.

Partial removal of the reaction solvent is carried out by, for example, evaporating it using an evaporator. The reaction solvent is concentrated by this evaporation.

Here, the amount of solvent removed is preferably 60 to 95%. If the removal amount of the solvent is small, the recovery rate is lowered, while if the removal amount of the solvent is large, the solvent is solidified and the cleaning efficiency is lowered, which is not preferable.

Further, in the present invention, the concentrated liquid thus obtained is washed with a poor solvent for 4,4'-isopropylidenedicyclohexanol and dried. That is, the concentrated liquid was washed by adding a poor solvent for 4,4′-isopropylidenedicyclohexanol, and then the poor solvent was removed by evaporation by drying to obtain 4,4′-the purified product of interest. Isopropylidene dicyclohexanol can be obtained.

Here, the poor solvent has a function of selectively dissolving the light component of the decomposition product which is a reaction by-product, whereby the light component of the decomposition product is transferred to the poor solvent. On the other hand, the main product, 4,4'-isopropylidenedicyclohexanol, is hardly dissolved in a poor solvent. Therefore, it is possible to increase the purity of the product 4,4′-isopropylidenedicyclohexanol while maintaining a high recovery rate.

The poor solvent used in the present invention is preferably an aliphatic hydrocarbon or an alicyclic hydrocarbon such as cyclopentane or cyclohexane. In the present invention, aliphatic hydrocarbons, particularly straight-chain aliphatic hydrocarbons, are preferred from the viewpoints of improving product purity and product recovery rate. This is because these linear aliphatic hydrocarbons more selectively dissolve the light components of the decomposition products that are reaction by-products. Examples of such linear aliphatic hydrocarbons include n-hexane, n-pentane, n-octane, n-heptane and the like.

The amount of the poor solvent used is the volume of the concentrated solution,
The amount is preferably 0.5 to 5 times, particularly preferably 1 to 2 times.

〔Example〕

 Next, the present invention will be described in more detail with reference to examples.

Example 1 (1) Production of 4,4′-isopropylidenedicyclohexanol 4,4′-isopropylidenediphenol (bisphenol A) 20 g, isopropyl alcohol 80 g and carbon supported in a nitrogen-sealed 250 cc autoclave equipped with a stirrer. Ruthenium catalyst (Ruthenium loading 5wt%) 0.2
First, 50 g / cm ² G was pressurized with hydrogen, and the temperature was raised to 165 ° C. over 20 minutes. Then, the pressure was further increased to 60 kg / cm ² G with hydrogen, and the reaction was carried out with stirring. During the reaction,
Hydrogen was introduced into the autoclave through a regulator to keep the autoclave pressure constant.

 After 60 minutes, the hydrogen absorption disappeared and the reaction was completed.

(2) Purification of 4,4'-isopropylidenedicyclohexanol After the reaction of the above (1) was completed, depressurization and cooling were performed. Then
The reaction product was taken out and the catalyst was removed to obtain a reaction product liquid from which the catalyst was removed.

The purity and isomer distribution of the obtained reaction product liquid (4,4'-isopropylidenedicyclohexanol) were determined by gas chromatography. As a result, the purity was 95.0%, the cis-cis body was 7%, and the cis-trans body was 40%. %, And the trans-trans form was 53%.

Next, 200 cc of the above reaction product liquid (containing 80% by weight of solvent isopropyl alcohol) was concentrated by removing the solvent isopropyl alcohol by evaporation with an evaporator under the conditions of 50 ° C. and 20 Torr to obtain a viscous 4,4′- A liquid (60 cc) containing isopropylidenedicyclohexanol was obtained.

To this, as a poor solvent, double the amount of n-hexane 12
After adding 0 cc and washing, the crystals were separated by filtration. 120 ° C of this crystal
After drying for 4 hours at 40 ° C., the solvent was removed to obtain the desired purified product of 4,4′-isopropylidenedicyclohexanol (hereinafter referred to as “product”).

Table 1 shows the recovery rate, product purity, isomer distribution, crystal melting point and OH number of this product crystal. The product purity and isomer distribution were determined by gas chromatography after dissolving the crystals in methanol.

Example 2 In Example 1, n-hexane as a poor solvent was replaced with n.
-The same procedure as in Example 1 was repeated except that octane was used instead. The results are shown in Table 1.

Comparative Example 1 In Example 1, the reaction product liquid from which the catalyst was removed was
Distillation under reduced pressure (200 ° C., 4 Torr) was performed to remove isopropyl alcohol as a reaction solvent.

The obtained distillation residue product was poured into a vat to obtain a colorless transparent solid. The results are shown in Table 1.

Comparative Example 2 In Example 1, the reaction product liquid from which the catalyst was removed was concentrated, and crystals were precipitated by a recrystallization method. The results are shown in Table 1.

Example 3 In Example 1, 3 parts of n-hexane was used as a poor solvent.
-A procedure similar to that of Example 1 was performed except that methylpentane was used instead. The results are shown in Table 1.

[Effect of the Invention] According to the purification method of the present invention, the light component of the decomposition product, which is a reaction by-product, can be selectively dissolved in a poor solvent and selectively transferred into the poor solvent. On the other hand, the main product 4,4'-isopropylidenedicyclohexanol is
It hardly dissolves in a poor solvent.

Therefore, according to the purification method of the present invention, the target 4,
The product purity of 4'-isopropylidene dicyclohexanol can be improved.

Moreover, according to the refining method of the present invention, the high recovery rate of the product is sufficiently maintained, and there is no problem of lowering the recovery rate.

Furthermore, according to the purification method of the present invention, a product having a high melting point can be obtained without changing the isomer distribution.

Claims (1)

(57) [Claims] 1. A reaction solvent is used for purifying 4,4′-isopropylidenedicyclohexanol obtained by catalytic hydrogenation of 4,4′-isopropylidenediphenol in the presence of a solvent using a catalyst. The catalyst was removed from the reaction product solution, and then a part of the reaction solvent was removed, followed by 4,4 '.
-A method for purifying 4,4'-isopropylidenedicyclohexanol, which comprises washing with a poor solvent for isopropylidenedicyclohexanol and drying.