JPS604805B2 - Production method of clathrate compounds - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a encapsulated compound in which metacyclophane represented by the following formula is encapsulated with p-xylene.

Conventionally, regarding p-xylene cladding compounds, for example (
i) Encapsulation with tri-timotide; see American Chemical Society (Am, Chem. Soc.) 3747 (1952) and Am. 2339 (1958) (i;) Encapsulation with Q-cyclodextrin; United States See Japanese Patent No. 3,450-028 (iii) Encapsulation with natural or synthetic zeolite; see Japanese Patent Publication No. 37-5155. The present invention was arrived at as a result of various research into methods for producing flea bodies.

That is, the present invention is an inclusion compound in which p-xylene is enclosed in a metacyclophane represented by the following formula (1).

In the present invention, it has not been previously known that p-xylene is included in the metacyclophane to form an inclusion compound, and this compound can be used to remove p-xylene from a p-xylene-containing mixture with high selectivity. , can be separated with high recovery.

The present invention will be explained in detail below.

The metacyclophane of the present invention may be a cyclic compound represented by the above formula (1), and it can be obtained by various production methods.

For example, the manufacturing methods include 'a} Helvetica, Chimica Ac
) Volume 50 F2scicul Female 7 (1967) No.
204(b} Synthesis (Shm-esis) 424
(1974) and others.

In the present invention, various methods can be applied to obtain the encapsulated compound of metacyclophane and p-xylene represented by the general formula (1).

For example, the metacyclophane may be added to the p-xylene-containing mixture, or the mixture obtained by adding metacyclophane as described above may be overflowed to completely encapsulate the mixture. It can also be obtained by preparing a solution dissolved in water, cooling the solution, and separating the resulting crystals.

Either method can easily convert P- into metacyclophane.
A compound containing xylene can be obtained. The amount of metacyclophane of formula (1) used is o. ol~
100 mol, preferably 0.1 to 10 mol, especially 0.2
Proportions of ˜2 mol are advantageous. When p-xylene is included in metacyclophane as described above, generally -5
0 to 35,000, preferably 0 to 200 o'clock, especially 20
It is carried out at temperatures in the range of ~15,000 °C.

In order to separate the encapsulated acid compound thus formed from the mixture containing it, it is usually preferable to use solid-liquid separation (e.g., filtration, centrifugation, sedimentation, etc.) or to remove the solvent component by evaporation by distillation. I can do it. In either method, the operating temperature is -50 to 120 oo, preferably 0.
A range of ~90°C is desirable. Using the method of the invention, p
- The "p-xylene-containing mixture" from which xylene is separated may be any mixture containing p-xylene;
Any component other than p-xylene may be used as long as it does not inhibit encapsulation or easily desorb p-xylene from the generated encapsulation compound, and in particular, it does not easily dissolve the encapsulation compound. is suitable.

The content of p-xylene in the p-xylene-containing mixture is
Since an encapsulated acid compound can be obtained even when the content of p-xylene is extremely low, a wide range may be used. For example, when C8 aromatic hydrocarbons are used as the p-xylene-containing mixture, the p-xylene inclusion compound can be easily separated from the C8 aromatic hydrocarbons by adding metacyclophane to make it encapsulated. be able to. “C
"8 aromatic hydrocarbons" means ethylbenzene of three types of xylenes, o-xylene, m-xylene, and p-xylene, and these four types of C8 aromatic hydrocarbons have very close boiling points. It is very difficult to carry out distillation separation industrially.

In particular, the difference in boiling point between m-xylene and p-xylene is 4.5 mm, making it extremely difficult to isolate them even with ordinary laboratory precision distillation. Furthermore, the difference in boiling points between ethylbenzene and p-xylene is small, making it difficult to separate them by distillation. Currently, industrially known methods include a crystallization separation method that utilizes the abnormally high melting point of p-xylene, and a separation method that utilizes the formation of a compound of HF-BF3 and m-xylene, but both of these methods use raw material oil. There were problems such as deep cooling, handling of crystals, and corrosion of equipment.

In recent years, adsorption separation methods using zeolites have been industrialized. Since this method does not have the problems of eutectic point and solubility in crystallization separation methods, it is expected to improve the recovery rate of p-xylene, improve utility, and downsize the equipment.
However, on the other hand, the use of expensive adsorbents and the adsorption capacity over time (
It is not necessarily an advantageous process because of problems such as a decrease in equipment capacity, a complicated desorption mechanism, and separation of the desorbent and xylene. However, the metacyclophane used in the present invention has advantages such as not only its performance but also the fact that it can be synthesized at a low cost and that an economical process can be freely selected. Further, from the enveloping composition of metacyclophane and p-xylene, p-xylene can be easily desorbed by various methods, and pure p-xylene can be obtained. In the present invention, when p-xylene is separated from a packaged compound of metacyclophane and p-xylene, various methods are employed.
) The compound is heated at 90 to 350°C, preferably 120 to 2
A method of separating p-xylene by flooding the b-clathrate with a solvent such as n-hexane, benzene, cyclohexane, acetone, etc. Advantageously applied.

The encapsulated compound of the present invention will be explained below. The separated crystals (encapsulated acid compound) were vacuum dried to remove deposits, and then analyzed. The results were as follows.

m infrared analysis; metacyclophane, 3050-2850, 1610, 1590, 1490,
1455,1 female 0,890,790,700,460 ka-lp-xylene 3050-2850,1515,79
0,485 fox-1 envelope compound, 3050-2850,1
610,1590,1515,1490,1453,1
080,890''790,700,485,460C, no absorption other than that due to metacyclophane and p-xylene (1515,485) was observed.

■ Gas chromatography analysis: Gas chromatography analysis of the crystals (clathral compounds) revealed that the concentration of p-xylene clathrated in the crystals relative to other components was approximately 95% or more, and the majority was found to be p-xylene. It was done.

{3' Differential thermal analysis: Differential thermal analysis of the crystal (encyclopedia compound) revealed that it was 90-1
A weight decrease was observed at 15qo, and from the amount of decrease, the inclusion ratio [p-xylene/metacyclophane = 0.99 (
molar ratio)].

This result shows that p-xylene:metacyclophane is included at a molar ratio of ≠1:1. As shown in the examples, the above results indicate that p-xylene mixture
- Even if one or more components other than xylene are contained in any proportion, the clathrate compound of the present invention can be obtained,
This shows that p-xylene can be selectively included and separated from a p-xylene-containing mixture by using metacyclophane.

The present invention will be described in detail below with reference to Examples.

In the examples, mc means metacyclophane, px means p-xylene, m means m-xylene,
EB indicates ethylbenzene.

In addition, the selectivity (B trick) in the example is a value calculated based on the following formula.

(However, C and /C2 represent the molar ratio of component 1.2.

) Example 1mco. 05 parts by 0.5 parts px, m
K and EB respectively at room temperature.

At this time, only px becomes cloudy, but px and EB are completely dissolved. When the temperature of each solution is raised to 8,000 and held for about 2 minutes to completely dissolve each solution, the temperature is lowered to room temperature, and a large amount of needle-shaped crystals are generated from the px solution alone. The other mx and EB solutions were in a dissolved state and no crystals were formed even if they were left for a long time. Example 2mco. 2 parts of px, m were added to 3 parts of a mixed solution of 1 part of EB each, and the temperature was raised to 100°C.
When completely dissolved and cooled to room temperature, needle-shaped crystals will form.

This mixture was filtered, and the obtained crystals were collected at room temperature at 100 feet Hg.
Dry for 1 hour in an oven to remove attached xylene.
22 parts of white, needle-shaped crystals were obtained. When a part of this crystal was analyzed by gas chromatography, the selectivity was 8 px/mK = 2 mu
6px/EB=68, and the px concentration in the crystal is px/
(px+m is 10EB): 0.95, so in the crystal there is m
It was found that K and EB were hardly included. Furthermore, the infrared spectroscopy data of this crystal is 3050-285
0,1610,1590,1515,1490,145
31080,890,790,700,485,460
Skin-1, absorption by mc and absorption by px (1
515 485) (mK, EB) was not observed.

From these results, this crystal is considered to be an almost pure px enclosing body with no xylenes deposits.

Next, when 0.0083 part of this white needle-like crystal was analyzed using an indicative heat exchanger, it was found that 0.001 part at 90-115°C.
A weight loss of 2 parts was observed, and the inclusion rate (p
A value of x+m (10 EB)/mc (molar ratio) = 0.99 was obtained.

Example 3 mco. 2 parts px, m each 1 part mixed solution 2
The same procedure as in Example 2 was carried out to obtain 0.21 part of white needle-like crystals.

When this crystal was analyzed by gas chromatography, 8px/mx=
A value of 1.9 was obtained. Examples 4-9 mco. One part was added to the following solvent 1. Ikari county and pxl. After adding it to Etsuro's mixed solution and dissolving it by heating at 70 to 130 qo,
Cool slowly to room temperature to form crystals.

The resultant was separated from the solution by filtration in a suction oven at room temperature, and then dried for 1 hour under a reduced pressure of 0.3 skin Hg at room temperature. The thus obtained white crystals were dissolved in another solvent and subjected to gas chromatography analysis, and the results shown in the table below were obtained with a separation factor of 8 px/solv. Example 10 0.1 part of the white needle-like crystals obtained in Example 2 was added to 2 parts of methanol, and the mixture was separated in an oven at 10° C. for 10 minutes to obtain 0.0 part of white needle-like crystals.

When a part of this crystal was subjected to gas chromatography analysis, px
/(px+m is 10 EB) = 0.94, which was the same as before contact with methanol. Example 11 White needle-like crystals obtained in the same manner as in Example 2 (composition: (px+mx
+EB)/mc=0.99 (mol/mol), px/
(px 10 mx + EB) = 0.95 (mol/mol))
0.2 Oriko Benzene 1. Add Ikarito, prepare for transfer, 1
After heating until 1:30 AM to completely dissolve the crystals, the mixture was cooled to room temperature to form needle-like crystals again.

The total amount of the residual liquid obtained by separating the cake from the mixture by furnace filtration and the washing liquid obtained by washing the cake with 0.5 part of benzene (hereinafter referred to as furnace liquid) was 1.1 parts. When this furnace liquid was analyzed by gas chromatography, (px + mx + EB)/benzene = 2.1 (M%), px no (px 10 mK + EB) = 0
．． It was 95 (mol/mol).

Claims (1)

[Claims] 1. A metacyclophane represented by the following formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ and a p-xylene-containing mixture are brought into contact with each other. Method for producing clathrate compounds.