JP3041379B2 - Method for producing high purity sulfur monochloride - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing high-purity sulfur monochloride, and more particularly, to a method for converting sulfur and chlorine in the presence of a catalytic amount of Lewis acid and / or metal using sulfur monochloride as a solvent. The present invention relates to a method for producing sulfur monochloride in high yield and high purity by reacting substantially quantitatively.

[0002]

2. Description of the Related Art Sulfur monochloride is a useful compound used as a raw material for producing sulfur dichloride, thionyl chloride, aromatic thiols, thiobisphenols and the like, and as a rubber vulcanizing agent. Conventionally, as a general production method of sulfur monochloride,
A method of reacting chlorine with carbon disulfide or using sulfur chloride such as sulfur monochloride or sulfur dichloride as a solvent, dissolving solid sulfur in this, and then blowing chlorine to directly convert sulfur and chlorine. A reaction method is known (Encycl
opedia of Chemical Technology, Vol. 13, p. 402-403,
The Interscience Encyclopedia, Inc., NY, 195
Four).

Conventionally, the former method is industrially adopted, but according to the former method, carbon tetrachloride is simultaneously produced as a by-product in addition to sulfur monochloride. Since this carbon tetrachloride is a kind of halogenated hydrocarbon whose use is restricted as a substance causing ozone layer depletion, it is difficult to continue the above production method in the future.

On the other hand, the latter method is disclosed in Japanese Unexamined Patent Publication No.
Although the improvement is proposed in No. 01, in general, in a method of directly reacting sulfur with chlorine using sulfur monochloride as a solvent, a method in which excess chlorine is blown into a reaction vessel and reacted is adopted. Therefore, a facility for collecting or treating chlorine blown through the reaction vessel is required.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in a method of directly reacting sulfur with chlorine using sulfur monochloride as a reaction solvent, In general, high-purity sulfur monochloride having a purity of 99% or more can be obtained in a high yield without producing by-product sulfur dichloride and remaining unreacted sulfur, and without requiring a special purification operation after the completion of the reaction. To provide a method for producing sulfur monochloride obtainable by the method described above.

[0006]

The process for producing high-purity sulfur monochloride according to the present invention comprises dissolving sulfur in sulfur monochloride as a reaction solvent, and adding 5 to 300 ppm of Lewis to sulfur. Chlorine in the above solvent in the presence of acid and / or metal
While reacting this chlorine with sulfur,
The end of the reaction is determined by measuring the specific gravity or permeability of the compound.
The point is detected, at which point the reaction is terminated and the sulfur
It is characterized in that substantially stoichiometrically added chlorine and sulfur are reacted substantially quantitatively.

That is, according to the present invention, sulfur monochloride is used as a reaction solvent, sulfur is dissolved in the solvent, and chlorine is blown into the solvent in the presence of a Lewis acid and / or a metal.
While reacting chlorine with sulfur, the specific gravity or permeability of the reaction mixture
The end point of the reaction is detected by measuring the
At that point, stop blowing chlorine and terminate the reaction.
Thus, the injected chlorine is substantially stoichiometric with respect to sulfur.
And convert this theoretical amount of chlorine to virtually all sulfur
Reaction, and thus a substantially stoichiometric amount of salt relative to sulfur
Approximately 99% or more high purity sulfur monochloride is determined using hydrogen
It can be obtained quantitatively.

In the method of the present invention, sulfur monochloride is used as a reaction solvent. Here, this sulfur monochloride
Normal commercial products can be used, but high-purity sulfur monochloride produced according to the present invention may also be used. In the present invention, the purity of the sulfur monochloride used as the reaction solvent is not particularly limited, but usually, it is preferable to use a purity of 90% or more. Also, the amount of sulfur monochloride used as the reaction solvent is not particularly limited, but is usually in the range of 1 to 50 times the weight of sulfur used as a raw material. In particular, the range of 2 to 10 times by weight is preferable from the economical viewpoints such as effective utilization of chlorine and volumetric efficiency.

In the method of the present invention, the sulfur may be charged into the reaction vessel together with the reaction solvent in advance. It may be added intermittently to the solvent.

In the method of the present invention, a Lewis acid or metal is used as a catalyst. As Lewis acids, iron,
Nickel, chromium, copper or aluminum halides, especially chloride or bromide, are preferred, such as Lewis acids such as ferric chloride, nickel chloride, aluminum chloride, chromic ferric chloride, ferric bromide , Nickel bromide, aluminum bromide, chromium bromide, ferrous chloride,
Examples thereof include chromous chloride, ferrous bromide, and cupric bromide. As the metal, iron, nickel, chromium, or the like is used. In the present invention, among these, iron, nickel or chromium is preferably used as a catalyst when a metal is used, and a secondary chloride is used when a Lewis acid is used, from the viewpoint of economy and ease of handling. Iron, ferrous chloride, chromic chloride or chromic chloride are particularly preferably used.

The amount of the catalyst used varies depending on the reaction conditions and the like, and cannot be unconditionally limited. However, it is usually in the range of 5 to 300 ppm, preferably 20 to 100 ppm, based on the charged sulfur. . When the amount of the catalyst used is less than 5 ppm, the catalytic effect is not sufficiently exhibited, and therefore, the amount of residual sulfur and sulfur dichloride by-products may increase. It is not preferable because it is necessary to remove

In the method of the present invention, sulfur monochloride is used as a solvent, and sulfur is dissolved in the solvent.
The chlorine is blown to react the sulfur with the chlorine. At this time, in a temperature range of 10 to 80 ° C., the chlorine is added to the sulfur in a substantially theoretical amount, and the sulfur and the chlorine are substantially determined. It is important to make it react. Therefore, in the present invention, the blowing amount of chlorine is 0.4 per mol of sulfur.
A range from 9 to 0.51 mol is preferred.

When the chlorine blowing temperature is higher than 80 ° C., the activity of the catalyst decreases, so that the amount of residual unreacted sulfur and sulfur dichloride by-products increases. On the other hand, when the chlorine blowing temperature is lower than 10 ° C. However, since the reaction speed is slow, it takes a long time to blow chlorine, and the reaction is not efficiently performed. Particularly preferably, the blowing temperature of chlorine is in the range of 20 to 50 ° C.

In particular, according to the present invention, chlorine is blown into a reaction solvent in which sulfur is dissolved in the presence of a catalytic amount of a Lewis acid or a metal, and the end point of the reaction is detected while monitoring the reaction mixture. By reacting chlorine substantially quantitatively with sulfur, by-product sulfur dichloride and unreacted sulfur can be substantially eliminated in the reaction system, and thus,
High-purity sulfur monochloride substantially free of the impurities can be easily obtained in high yield.

In the method of the present invention, the reaction between sulfur and chlorine is preferably monitored by measuring the specific gravity or the permeability of the reaction mixture. When the reaction is monitored by the specific gravity of the reaction mixture, the specific gravity of the reaction mixture on the higher specific gravity side due to the effect of sulfur having a higher specific gravity (specific gravity of 2.06) increases with the progress of the reaction. The blowing of chlorine may be stopped when the specific gravity approaches 1.690, that is, when the specific gravity reaches a range of 1.688 to 1.692. The above specific gravity is a value sufficiently corresponding to a purity of 99% or more of sulfur monochloride.

On the other hand, when monitoring the reaction by the transmittance of the reaction mixture, it is performed by measuring a wavelength specific to by-produced sulfur dichloride, that is, 525 nm. Specifically, a cell having an optical path length of 1 cm has a light transmittance of 42 to 58%.
, Preferably 50 to 58%, when the chlorine blowing is stopped, sulfur monochloride substantially free of by-produced sulfur dichloride can be obtained.

[0017]

According to the method of the present invention, as described above,
By substantially quantitatively reacting sulfur with chlorine in the presence of a catalytic amount of a Lewis acid or metal, substantially no by-product of sulfur dichloride and residual unreacted sulfur remain, and Without the need for special purification operations after the end of
High-purity sulfur monochloride having a purity of 99% or more can be obtained in a high yield.

[0018]

EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited by these examples. In order to monitor the reaction mixture, the reaction mixture was externally circulated by a pump, and its specific gravity or permeability was continuously measured. The specific gravity was measured with a Coriolis mass flowmeter, and the transmittance was measured with a spectrophotometer using a quartz cell having an optical path length of 1 cm.

EXAMPLE 1 A glass four-necked flask having a capacity of 1000 ml was charged with 400.0 g of 99.2% sulfur monochloride as a solvent, and 160.0 g (5.00 mol) of sulfur and 160.0 g of sulfur as a catalyst were added thereto. About 10 mg of iron powder was added. The liquid temperature is 25 ° C, chlorine is blown in,
Thereafter, when the specific gravity of the reaction mixture reached 1.690, the blowing of chlorine was stopped. As a result, the chlorine blowing time was 3.2 hours, and the blowing amount was 0.497 per mole of sulfur.
Mole. When the obtained reaction mixture was analyzed,
The purity of sulfur monochloride was 99.8% and the yield was 99.8%.

EXAMPLE 2 A four-necked glass flask having a capacity of 1000 ml was charged with 400.0 g of 99.5% sulfur monochloride as a solvent, and 160.0 g (5.00 mol) of sulfur and 160.0 g of sulfur as a catalyst were added thereto. About 10 mg of iron powder was added. The liquid temperature is 30 ° C, chlorine is blown in,
Thereafter, when the transmittance of the reaction mixture reached 57%, the blowing of chlorine was stopped. As a result, the chlorine blowing time was 3.0 hours, and the blowing amount was 0.498 per mole of sulfur.
Mole. When the obtained reaction mixture was analyzed,
The purity of sulfur monochloride was 99.9% and the yield was 99.6%

Example 3 Example 1 was repeated except that 30 mg of nickel powder was used as the catalyst.
When the specific gravity of the reaction solution reached 1.688, the blowing of chlorine was stopped. As a result, the chlorine blowing time was 3.1 hours, and the chlorine blowing amount was 0.503 mol with respect to 1 mol of sulfur. When the obtained reaction mixture was analyzed, the purity of sulfur monochloride was 99.2%,
The yield was 99.6%.

Example 4 The same operation as in Example 1 was carried out except that 4 mg of ferric chloride powder was used as a catalyst. As a result, the chlorine blowing time was 2.9 hours, and the chlorine blowing amount was
0.500 mol. Analysis of the resulting reaction mixture showed that the purity of sulfur monochloride was 99.8% and the yield was 9
It was 9.7%.

Example 5 The same operation as in Example 2 was carried out except that 20 mg of ferric chloride powder was used as a catalyst.
%, The blowing of chlorine was stopped. As a result, the chlorine blowing time was 3.1 hours, and the chlorine blowing amount was 0.502 mol with respect to 1 mol of sulfur. When the obtained reaction mixture was analyzed, the purity of sulfur monochloride was 99.8.
%, And the yield was 99.6%.

Example 6 The same operation as in Example 2 was performed except that the chlorine blowing temperature was 40 ° C. As a result, the chlorine blowing time is 3.
One hour, the amount of chlorine blown was 0.49 with respect to 1 mole of sulfur.
8 moles. Analysis of the resulting reaction mixture showed that the purity of sulfur monochloride was 99.7% and the yield was 99.5.
%Met.

Example 7 A reaction was carried out in the same manner as in Example 1 except that sulfur monochloride having a purity of 90.2% was used. As a result, the chlorine blowing time was 3.2 hours, and the chlorine blowing amount was 0.502 mol with respect to 1 mol of sulfur. Analysis of the resulting reaction mixture showed that the purity of sulfur monochloride was 99.6% and the yield was 99.7%.

Comparative Example 1 A glass four-necked flask having a capacity of 1,000 ml was charged with 400.0 g of 99.5% sulfur monochloride as a solvent, and 160.0 g (5.00 mol) of sulfur was added thereto. Liquid temperature 25
° C, no catalyst added and 2.60 chlorine in the absence of catalyst.
Mole was bubbled in for 4.0 hours. When the obtained reaction mixture was analyzed, the purity of sulfur monochloride was 98.0%.
The yield was 97.5%.

COMPARATIVE EXAMPLE 2 A glass four-necked flask having a capacity of 1000 ml was charged with 400.0 g of 99.2% pure sulfur monochloride as a solvent, and 160.0 g (5.00 mol) of sulfur and 160.0 g of sulfur as a catalyst were added thereto. About 10 mg of iron powder was added. The liquid temperature is 30 ° C, chlorine is blown in,
Then, instead of measuring the specific gravity and permeability of the reaction solution, the weight loss of the chlorine cylinder was measured, and the weight loss of the cylinder was 177.5 g (2.
(50 mol), the blowing of chlorine was stopped.

As a result, the chlorine blowing time was 3.0 hours. According to this method, a theoretical amount of chlorine is added to sulfur, but the end point of the reaction is not monitored, so that at the end of the reaction, the reaction between sulfur and chlorine is not quantitatively completed. When the thus obtained reaction mixture was analyzed, the purity of sulfur monochloride was 98.5%. Also,
The yield was 98.3%.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-4-317401 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C01B 17/45 CA (STN)

Claims (5)

(57) [Claims] 1. Sulfur is dissolved in sulfur monochloride as a reaction solvent, and chlorine is blown into said solvent in the presence of 5-300 ppm of Lewis acid and / or metal relative to sulfur.
While reacting the chlorine with sulfur, the ratio of the reaction mixture
Detect end point of reaction by measuring weight or permeability
At which point the reaction is terminated and substantially reduced to sulfur.
A method for producing high-purity sulfur monochloride, comprising substantially quantitatively reacting stoichiometric chlorine and sulfur . 2. The metal is iron, nickel or chromium.
Item 7. The method according to Item 1. 3. The Lewis acid is iron, nickel, chromium, copper or
2. The method according to claim 1, which is a halide of aluminum.
Law. 4. The method according to claim 1, wherein chlorine is blown into the sulfur at a temperature of 10 to 80 ° C. to cause a reaction. 5. The amount of chlorine blown into one mole of sulfur is
2. The method according to claim 1, wherein the amount is 0.49 to 0.51 mol.