JPS6335162B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for producing chlorosulfonated polyethylene using chlorine and furfuryl chloride.

Chlorosulfonation of polyethylene is carried out using chlorine and sulfur dioxide, chlorine and sulfuryl chloride, or sulfuryl chloride alone. The first two methods can be called a two-step method, in which polyethylene is dissolved in a solvent at high temperature (100 to 160°C), first chlorinated with chlorine at that high temperature, and then sulfur dioxide and chlorine or sulfuryl chloride are added. The reaction is carried out at a lower temperature (20 to 80°C). (JP-A-57-147) It is known that the introduction of sulfonyl chloride groups (--SO ₂ Cl), which serve as the vulcanization point in chlorosulfonated polyethylene, is more efficient when carried out at low temperatures. In other words, the efficiency of chlorosulfonation using sulfuryl chloride is only a few percent when the reaction temperature is 80°C or higher, and most of it exits the system as sulfur dioxide and hydrogen chloride. However, this does not change significantly even when the reaction temperature is lower than 80°C, and the reaction efficiency is only about 15% at most.

In other words, in the production of chlorosulfonated polyethylene, how to efficiently add sulfonyl chloride groups (-SO ₂ Cl) that serve as vulcanization points, or how to efficiently recover sulfur dioxide generated as an unreacted product. was one of the basic problems.

In order to solve these process difficulties,
Attempts have been made to carry out chlorosulfonation using sulfuryl chloride alone at a temperature of 100°C or higher, to lead the decomposed sulfur dioxide together with chlorine to an activated carbon layer, and to recover it as sulfuryl chloride. (Tokuko Akira
39-12113) However, in this method, in order to increase the recovery efficiency of sulfur dioxide, it is necessary to carry out the chlorosulfonation reaction at high temperature and high pressure. The sulfur component becomes sulfur dioxide and does not participate in the reaction, resulting in a significantly large amount of sulfur dioxide to be recovered.In addition, in this recovery process, recovery is affected by hydrogen chloride, chlorine, solvent, etc. that are discharged together with sulfur dioxide. There are drawbacks such as reduced yield and purity.

On the other hand, in the method of chlorinating polyethylene to some extent at a high temperature and then chlorosulfonating it at a low temperature using sulfuryl chloride, the efficiency of chlorosulfonation using sulfuryl chloride reaches about 15%, but the carbon dioxide produced by decomposition and not being used for the reaction is Treating sulfur without recovering it is disadvantageous in terms of cost, and if you try to recover the by-product sulfur dioxide in the same way as above, the reaction conditions for sulfuryl chloride are low temperature and low pressure, so it will take more time to recover. Equipment is required. Furthermore, as with the above, there are many difficulties, such as the need to take into account impurities that are entrained.

Furthermore, the sulfuryl chloride recovered in this way is easily decomposed by moisture in the air, and the decomposition products are corrosive and toxic, causing damage to equipment, piping, etc. It is easy to apply and requires a lot of effort to maintain and inspect. Therefore, in the production of chlorosulfonated polyethylene, one of the most important process factors is to increase the efficiency of chlorosulfonation as much as possible in the reaction using sulfuryl chloride.

The present invention aims to solve such problems in the production of chlorosulfonated polyethylene, and relates to a method for significantly improving the efficiency of chlorosulfonation with sulfuryl chloride at a temperature of 50 to 100°C.

According to the present invention, there is no need to recover sulfur dioxide, which is produced as a by-product when sulfuryl chloride is reacted.
It is sufficient to carry out a conventional neutralization process, making it more economical.

Generally, in the production of chlorosulfonated polyethylene using chlorine and sulfuryl chloride, polyethylene is melted at a temperature of 110 to 150°C, then chlorinated with chlorine at a temperature of 100°C or higher, and then 50 to 80°C.
The reaction is carried out with sulfuryl chloride at a temperature of Among these, chlorination with sulfuryl chloride reacts almost quantitatively, but the reaction rate of chlorosulfonation only reaches about 15%. For this reason, for example, chlorine content 36
When attempting to produce chlorosulfonated polyethylene with a sulfur content of 1.0% by weight, chlorination with chlorine is performed to approximately 30% by weight, and then the remaining 6% by weight is chlorinated with chlorine.
The reaction will be carried out using enough sulfuryl chloride to contain 1.0% by weight of chlorine and 1.0% by weight of sulfur. Strictly specify the degree of chlorination with chlorine. However, the reaction with sulfuryl chloride has extremely poor reproducibility, and even in the above case, at a reaction temperature of 60°C, the rate of chlorination is slow and the sulfur content tends to increase, and at 80°C, only chlorination takes precedence. Therefore, it is difficult to obtain the desired chlorine and sulfur content with good reproducibility.
The reaction with sulfuryl chloride could only be carried out under extremely limited conditions.

In the present invention, in the production of chlorosulfonated polyethylene using chlorine and sulfuryl chloride, if sulfuryl chloride is reacted with polyethylene and then a small amount of chlorine is introduced, chlorosulfonation proceeds further, and in particular, the sulfonyl chloride group This is based on the discovery that addition of sulfur (indicated by sulfur content) significantly improves the addition of sulfur.

That is, the present invention dissolves polyethylene in a solvent, then chlorinates it with chlorine, then substantially completes the chlorosulfonation reaction with sulfuryl chloride,
This method of producing chlorosulfonated polyethylene is characterized by further introducing chlorine and causing a reaction.

According to the present invention, the efficiency of chlorosulfonation is improved by passing chlorine after the addition reaction of sulfuryl chloride is substantially completed, so that there are fewer restrictions on the reaction temperature as described above. Further, since the reaction is carried out until completion by introducing chlorine, it is easy to obtain a target value for the chlorine content.

In the present invention, the amount of sulfuryl chloride added may be less than the amount used in the method in which only sulfuryl chloride is reacted, and since the unreacted by-product sulfur dioxide described above is not recovered, the amount of sulfuryl chloride added is calculated from the sulfur content in the polymer. It can be said that it is more economical if the reaction rate of chlorosulfonation is 30% or more.

In the present invention, the polyethylene includes low-density or high-density polyethylene having a melt index of 0.1 to 200 g/10 min, and monomers copolymerizable with ethylene, such as propylene,
The definition includes ethylene copolymers obtained by copolymerizing with butene-1, vinyl acetate, acrylic acid, etc. The polyethylene is dissolved in a halogenated solvent at a concentration of 2 to 20% by weight.

Examples of halogenated solvents include carbon tetrachloride, chloroform, chlorobenzene, 1,1,
2,2-tetrachloroethane and the like are used.

The reaction is carried out by using the above polyethylene in a halogenated solvent.
After melting at a temperature of 90-150°C, chlorine is introduced to chlorinate. At this time, as an initiator, 2,2'azobisisobutyronitrile or 2,2'azobis(2,2'
An azo initiator such as 4dimethylvaleronitrile) or a peroxide initiator such as benzoyl peroxide or di2ethylhexyl peroxydicarbonate is used. These processes are carried out by continuously adding a solution of 0.01 to 2.0% by weight of polyethylene dissolved in a solvent into the reaction system.

After the chlorination reaches a predetermined value, a predetermined amount of sulfuryl chloride is added and reacted at 50-100°C. At this time, a tertiary amine such as pyridine, quinoline, or tributylamine is added to the system as a cocatalyst. Next, chlorine is passed into the system again to start the reaction, and the chlorine is finally chlorinated to the target value. When the reaction is completed, the acid components (hydrogen chloride, sulfur dioxide, chlorine) remaining in the system are removed from the system while flowing a small amount of nitrogen. After adding an epoxy compound such as a condensate of 2,2' propane bisphenol and epichlorohydrin, the reaction product is separated and dried using a drum dryer or the like.

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but these are examples for helping understanding of the present invention, and the present invention is not limited thereto.

Example 1 Density with melt index 7.0 g/10 min in a glass-lined reactor with internal volume 30 and a stirrer
0.961g/cc polyethylene 3.0Kg carbon tetrachloride 30
Kg under pressure at a temperature of 110°C for 1 hour. Next, an initiator solution in which 7.0 kg of pyridine and 8.0 g of 2,2' azobisisobutyronitrile were dissolved in 3 kg of carbon tetrachloride was added to the reaction system using a pump, while chlorine was added at a flow rate of 3/min. Blow gas 110
The reaction was started at °C.

The reaction was carried out for 271 minutes at 110°C and approximately 2.5 kg gauge pressure. Then, the temperature of the system was lowered to 70°C and the pressure was lowered to normal pressure. When the temperature reached 70℃, a small amount of the reaction solution was sampled, the polymer was separated using a conventional method, and the chlorine content was measured.The chlorine content was 29.68.
It was in weight%. The reaction rate of chlorination was 93.2%.

Then, 0.429 kg of sulfuryl chloride was added into the system using a pump. At this time, the above initiator liquid was also added. After the addition of sulfuryl chloride was completed, the reaction was continued for about 20 minutes without reducing the pressure. Next, in order to measure the sulfur content and chlorine content in the polymer, a small amount of the reaction solution was sampled and analyzed, and the chlorine content was 31.27% by weight and the sulfur content was 0.26% by weight. The reaction rate of chlorine is
99.9%, and that of sulfur was 14.5%.

Next, chlorine was introduced into the reactor again at a rate of 1.45/min, and while an initiator was added at a temperature of 70°C, the pressure was adjusted to about 2.5 kg, and the reaction was carried out for 286 minutes. After the reaction was completed, nitrogen gas was introduced from the bottom of the reactor at a rate of 1.0/min, and the acid content in the system was removed over about 2 hours under reflux of carbon tetrachloride.

Next, 40 g of a condensate of 2,2' propane bisphenol and epichlorohydrin was added, and the chlorosulfonated polyethylene was separated and dried using a heated drum dryer. The obtained chlorosulfonated polyethylene contained 35.46% by weight of chlorine,
It contained 0.96% by weight of sulfur. The reaction rate of chlorine was 98%, and the reaction rate of chlorosulfonation was 44.4% based on the amount of sulfuryl chloride and sulfur used.

Example 2 In Example 1, chlorination at 110°C was
The mixture was chlorinated to a chlorine content of 26.06% by weight.
Next, 0.537 kg of sulfuryl chloride was added and reacted. Next, the chlorine and sulfur contents were analyzed in the same manner as in Example 1, and the chlorine content was 28.50% (reaction rate 99.4%), and the sulfur content was 0.22% by weight (reaction rate 0.71%).
It was hot. Next, a reaction treatment was carried out in the same manner as in Example 1 except that chlorination with chlorine was carried out for 240 minutes to obtain chlorosulfonated polyethylene. The obtained chlorosulfonated polyethylene contained 37.59% by weight of chlorine and 1.56% by weight of sulfur.

The reaction rate of chlorosulfonation was 60.5%.

Example 3 Instead of polyethylene in Example 1, it had a melt index of 3.5 g/10 min and a density of 0.922
Using 3.0Kg of low density polyethylene with g/cc,
After reacting at 110°C for 110 minutes at a chlorine flow rate of 4.28/min to make the chlorine content 19.12% by weight, 0.694 kg of sulfuryl chloride was added and reacted at 70°C. At the end of the reaction, the chlorine content was 22.37% by weight (chlorine reaction rate 93.0%) and the sulfur content was 0.74% by weight. (The reaction rate of the latter
(17.6%) Next, chlorine was introduced into the reaction system at a rate of 4.28/min, and the reaction was carried out for 60 minutes. It was then treated in the same manner as in Example 1 to obtain a chlorine content of 29.08% by weight and a sulfur content of 1.68%.
% by weight of chlorosulfonated polyethylene was obtained.
The reaction rate of chlorosulfonation calculated from the sulfur content was 44.2%.

Example 4 Chlorination with chlorine at 110°C as in Example 1 was carried out in the same manner as in Example 1 until the chlorine content reached 29.81% by weight, followed by reaction with sulfuryl chloride at a reaction temperature of 90°C in the same manner as in Example 1. The chlorine content after addition is 31.55
Weight% (chlorine reaction rate 100%) Sulfur content is 0.18
It was in weight%. (The latter reaction rate was 7.6%) Next, a reaction using chlorine was carried out in the same manner as in Example 1. The resulting chlorosulfonated polyethylene contained 37.11% by weight of chlorine and 0.77% by weight of sulfur. The reaction rate of chlorosulfonation was 36.6%.

Comparative Example 1 After chlorination at 110°C in Example 1 was carried out for 286 minutes at a flow rate of 3.0/min, 1.074 kg of sulfuryl chloride was added at 70°C over 30 minutes, and then the catalyst solution was added for 30 minutes. The reaction treatment was carried out in the same manner as in Example 1, except that the chlorination was not carried out again.
When the sampled polymers were analyzed,
The chlorine content in chlorination at 110°C was 30.27% by weight and the reaction rate was 95.8%, and after the addition reaction of sulfuryl chloride, chlorine
It contained 34.87% by weight and 0.96% by weight of sulfur.
The effectiveness rate of chlorine was 95.5%, and the effectiveness rate of chlorosulfonation was 14.3%.

Comparative Example 2 Chlorination at 110°C in Example 1 was carried out at a rate of 3.0/min for 270 minutes to reach a chlorine content of 29.83% by weight, then the temperature was lowered to 80°C, 1.364 kg of sulfuryl chloride was added and reacted, and then Nitrogen was introduced to remove the acid content, and the mixture was treated in the same manner as in Example 1 to obtain chlorosulfonated polyethylene.

The obtained chlorosulfonated polyethylene contained 37.20% by weight of chlorine and 0.18% by weight of sulfur.
The effectiveness rate of chlorine was 99.2%, and the effectiveness rate of chlorosulfonation was 2.6%.

Comparative Example 3 A reaction treatment was carried out in the same manner as in Comparative Example 2, except that the addition reaction temperature of sulfuryl chloride was changed to 50°C. The obtained chlorosulfonated polyethylene had a chlorine content of 33.29% by weight and a sulfur content of 0.60% by weight, and the respective reaction rates were 92.0% and 8.4%.

Comparative Example 4 After carrying out chlorination at 110°C for 140 minutes in Example 3 to a chlorine content of 23.40% by weight,
Chlorosulfonation was carried out in the same manner as in Example 3, except that the amount of chlorinated sulfurylation added at 70°C was 1.074 kg, and the reaction was carried out without reintroducing chlorine. The obtained chlorosulfonated polyethylene contained 27.96% by weight of chlorine and 1.19% by weight of sulfur, from which the reaction rate of chlorine was calculated to be 94.4% and the reaction rate of chlorosulfonation was calculated to be 19.8%.

As is clear from the above Examples and Comparative Examples, the chlorosulfonated polyethylene obtained by the present invention can contain a predetermined amount of sulfuryl chloride with a small sulfur content, and the efficiency of chlorosulfonation is significantly improved. That is clear.

Claims (1)

[Claims] 1. After dissolving polyethylene in a halogenated solvent, it is chlorinated with chlorine, then the chlorosulfonation reaction with sulfuryl chloride is substantially completed at a temperature of 50 to 100°C, and then chlorine is further introduced to cause the reaction. A method for producing chlorosulfonated polyethylene.