JPH05170815A - Production of chlorosulfonated polyolefin - Google Patents

Abstract

PURPOSE:To provide a chlorosulfonated polyolefin of commercial value in the presence of a solvent outside the legal regulation. CONSTITUTION:The title process comprises reacting a polyolefin dissolved or suspended in a solvent with a combination of chlorine with sulfur dioxide, a combination of chlorine with sulfuryl chloride, sulfuryl chloride chloride alone, a combination of chlorine, sulfur dioxide and sulfuryl chloride, or a combination of sulfuryl chloride with sulfur dioxide in the presence of a free-radical generator as a catalyst, wherein the solvent used is 1,4-difluorobenzene.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a process for producing chlorosulfonated polyolefin. More specifically, it relates to a production method for producing a chlorosulfonated polyolefin by dissolving or suspending a polyolefin in 1,4-difluorobenzene and carrying out a chlorination and a chlorosulfonation reaction.

[0002]

BACKGROUND OF THE INVENTION It is known to dissolve or suspend a polyolefin in a solvent to produce a chlorosulfonated polyolefin. Carbon tetrachloride has also been used as the solvent. However, as a result of the revision of the “Montreal Protocol on Substances that Deplete the Ozone Layer” (hereinafter referred to as the “Protocol”) conducted in June 1990, carbon tetrachloride became a regulated substance, and as a result, chlorosulfonation from 1995 onwards. The use of carbon tetrachloride for commercial production of polyolefins has been difficult. Therefore, a new method for producing a chlorosulfonated polyolefin that does not use carbon tetrachloride has been desired.

[0003]

The present invention, from the viewpoint of global environment protection, is a substance that is not subject to the regulations of the Protocol 1,4-
An object of the present invention is to provide a method for producing a chlorosulfonated polyolefin having commercial value by using difluorobenzene as a solvent.

[0004]

That is, the present invention is a polyolefin dissolved or suspended in a solvent, with a radical generator as a catalyst, chlorine and sulfurous acid gas, chlorine and sulfuryl chloride,
Characterized by using 1,4-difluorobenzene as a solvent in the reaction of chlorination or chlorination and chlorosulfonation using sulfuryl chloride alone, three reagents of chlorine, sulfurous acid gas and sulfuryl chloride, or sulfuryl chloride and sulfurous acid gas And a method for producing a chlorosulfonated polyolefin. The details will be described below.

[0005]

The solvent used in the present invention is 1,4-difluorobenzene, which is a non-regulated substance in the Protocol.

The reaction for carrying out chlorination and chlorosulfonation uses three radical reagents as catalysts: chlorine and sulfurous acid gas, chlorine and sulfuryl chloride, sulfuryl chloride alone, chlorine and sulfurous acid gas and sulfuryl chloride, or sulfuryl chloride and sulfurous acid. The gas is reacted with a polyolefin dissolved or suspended in 1,4-difluorobenzene. When sulfuryl chloride is added, an amine compound such as pyridine or quinoline as a cocatalyst is added if necessary. The reaction temperature is 40 to 150 ° C., preferably 60 to 13
It is 0 ° C., and the reaction pressure is 0 to 10 kg / cm ² , preferably 0 to 7 kg / cm ² .

As the radical generator, an azo compound or an organic peroxide is used. Examples of the azo compound include α, α′-azobisisobutyronitrile, azobiscyclohexanecarbonitrile, and 2,2′-azobis (2,4-dimethylvaleronitrile), and the organic peroxide is a peroxide. Examples thereof include benzoyl oxide, acetyl peroxide, t-butyl peroxide, t-butyl perbenzoate and the like. An azo compound is preferable, and α, α′-azobisisobutyronitrile is particularly preferable.

Examples of the raw material polyolefin include high-density polyethylene (HDPE), low-density polyethylene (LDPE), and linear low-density polyethylene (LLDP).
E), ethylene homopolymers and copolymers such as ultra low density polyethylene (VLDPE), ethylene vinyl acetate copolymer (EVA) and ethylene / propylene copolymer (EPM).

After completion of the reaction, hydrogen chloride and sulfurous acid gas remaining in the reaction solution are removed by introducing nitrogen, and a stabilizer is added if necessary. The stabilizer is preferably an epoxy compound such as 2,2'-bis (4-glycidyloxyphenyl) propane.

Known methods for separating the product polymer from the solvent include steam distillation, a drum dryer, and a vented extruder, and these methods are used to separate the two.

However, the recovered 1,4-difluorobenzene contains chlorodifluorobenzene, which is a byproduct of chlorination of a part of 1,4-difluorobenzene during the reaction. By using this again in the reaction, the concentration of chlorodifluorobenzene in the recovered 1,4-difluorobenzene gradually increases. Since this chlorodifluorobenzene has a higher boiling point than 1,4-difluorobenzene, chlorodifluorobenzene remains in the chlorosulfonated polyolefin obtained by separating it from the solvent, which has various adverse effects on the physical properties of the elastomer. .. Therefore, it is important to remove chlorodifluorobenzene from the recovered 1,4-difluorobenzene and to suppress the chlorodifluorobenzene by-product itself.

The method of removing chlorodifluorobenzene from the recovered 1,4-difluorobenzene is conveniently performed by distillation. The 1,4-difluorobenzene thus purified is recycled again to the reactor.

On the other hand, as a method for suppressing the formation of chlorodifluorobenzene during the reaction, first, the process of avoiding the use of chlorine as a chlorinating agent and using sulfuryl chloride alone is effective. In particular, the reaction temperature at this time is 60 to 13
It is desirable to carry out at a relatively low temperature of 0 ° C.

The chlorosulphonated polyolefin referred to in the present invention includes, for example, chlorosulphonated polyethylene, chlorosulphonated ethylene / propylene copolymer, chlorosulphonated ethylene / butene copolymer according to the kind of the raw material polyolefin as described above. Examples thereof include chlorosulfonated ethylene / hexene copolymers and chlorosulfonated ethylene / vinyl acetate copolymers.

The obtained product is compounded and kneaded in the same manner as a conventional rubber or resin to be used as a vulcanized product or an unvulcanized product. Compounding agents include vulcanizing agents such as magnesia and calcium hydroxide, reinforcing agents such as carbon black and white carbon, fillers such as calcium carbonate and talc,
Compounding agents for rubber or resin such as plasticizers, processing aids, anti-aging agents or vulcanization accelerators such as TRA and TT can be mentioned. Vulcanization methods include steam vulcanization, UHF vulcanization, hot air vulcanization,
A general method such as injection, molding, or rotocure may be used.

For the end use, like the existing chlorosulfonated polyolefin, automobile hoses, gas hoses, industrial hoses, escalator handrails, electric wires, leisure boats, roofing, pond liners, rolls, belts,
Boots, packings, sheets, pull cloths, adhesives, paints, sealants and the like can be mentioned.

[0017]

The present invention will be described in more detail based on the following examples, but these are examples for assisting the present invention and the present invention is not limited to these examples.

The values used in these examples are obtained according to the following measuring methods. Chlorine and sulfur content: Combustion flask method Unvulcanized rubber Physical properties: JIS K 6300 Vulcanized rubber properties: JIS K 6301 Product hue: Visually. Stability of product hue due to accelerated degradation: 70 ° C. gear oven method, visually. Content of chlorodifluorobenzene in 1,4-difluorobenzene: By gas chromatography.

Example 1 A 30-liter glass-lined autoclave was charged with 28 kg of 1,4-difluorobenzene, 2.8 kg of high-density polyethylene having a melt index of 6.2 g / 10 minutes and a density of 0.95 g / cc.

After adding 0.3 g of pyridine as a cocatalyst for the chlorosulfonation reaction, steam was passed through the jacket of the reactor and the mixture was maintained at 120 ° C. for 2 hours to uniformly dissolve polyethylene. Also, during this period, nitrogen gas was introduced into the reactor at a flow rate of 15 liters / minute to eliminate air mixed in the reactor.

14 g of α, α'-as a radical initiator
Azobisisobutyronitrile was dissolved in 2.9 kg of 1,4-difluorobenzene. While continuously adding this solution to the reactor, the reaction was carried out by adding 5.9 kg of sulfuryl chloride to the reactor from another charging port. It took 3 hours during this period, but the reactor pressure was 3.0 kg / c.
I kept it at m2.

After the reaction was completed, the pressure was returned to normal pressure and the temperature of the reactor was lowered to 70 ° C. Nitrogen was introduced while maintaining the temperature at 70 ° C. to remove the sulfurous acid gas and hydrogen chloride gas remaining in the reaction solution. .

43 g of 2,2'-bis (4
-Glycidyloxyphenyl) propane,
This solution was fed to a drum dryer heated to 155 ° C. to separate chlorosulfonated polyethylene as a product from the solvent.

The product had a pure white hue and analysis showed that the chlorosulfonated polyethylene contained 35.0% chlorine and 1.2% sulfur. The Mooney viscosity (ML1 + 4, 100 ° C.) of the raw rubber was 50.

The stability of the hue of the product was tested by a heat acceleration test, but no change in hue was observed even after 10 days at 70 ° C.

Further, the product was kneaded according to the composition shown in Table 1, and the physical properties of an unvulcanized product represented by scorch time and vulcanized physical properties such as tensile strength were measured.

The values obtained are summarized in Table 2 below.

On the other hand, 1, separated by a drum dryer
As a result of analysis, 0.1% of 4-difluorobenzene was chlorinated to produce chlorodifluorobenzene. This 1,4-difluorobenzene was removed by distillation to remove chlorodifluorobenzene and used in the next reaction.

Example 2 A raw material polyolefin was melt-indexed 0.85 g.
/ Min, the reaction was performed in the same manner as in Example 1 except that high density polyethylene having a density of 0.965 g / cc was used, and then the product was separated.

The product had a pure white hue and analysis showed that the chlorosulfonated polyethylene contained 33.7% chlorine and 1.2% sulfur. The Mooney viscosity (ML1 + 4,100 ° C.) of the raw rubber was 111.

The hue stability of the product was tested by an accelerated test by heat, but no change in hue was observed even after 10 days at 70 ° C.

Further, the product was kneaded according to the composition shown in Table 1, and the physical properties and vulcanized physical properties of the unvulcanized product were measured.

This is summarized in Table 2.

On the other hand, 1, separated by a drum dryer
As a result of analysis, 0.1% of 4-difluorobenzene was chlorinated to produce chlorodifluorobenzene. This 1,4-difluorobenzene was removed by distillation to remove chlorodifluorobenzene and used in the next reaction.

Example 3 Polyolefin as a raw material had a melt index of 4.8 g /
Min, a high density polyethylene having a density of 0.963 g / cc was used, and the reaction was performed in the same manner as in Example 1 except that the amount of sulfuryl chloride added was changed to 3.4 kg, and then the product was separated.

The product had a pure white hue and analysis showed that the chlorosulfonated polyethylene contained 23.1% chlorine and 1.1% sulfur. The Mooney viscosity (ML1 + 4, 100 ° C.) of the raw rubber was 33.

The stability of the hue of the product was tested by a heat accelerated test, but no change in hue was observed even after 10 days at 70 ° C.

Further, the product was kneaded according to the composition shown in Table 1, and the physical properties and vulcanized physical properties of the unvulcanized product were measured.

This is summarized in Table 2.

On the other hand, 1, separated by a drum dryer
As a result of analysis, 0.1% of 4-difluorobenzene was chlorinated to produce chlorodifluorobenzene. This 1,4-difluorobenzene was removed by distillation to remove chlorodifluorobenzene and used in the next reaction.

Example 4 The melt index of the raw material polyolefin was 4.3 g /
The reaction was performed in the same manner as in Example 1 except that linear low-density polyethylene (ethylene / butene 1 copolymer) having a density of 0.922 g / cc was used and the amount of sulfuryl chloride added was changed to 4.0 kg. The product was then separated.

The product had a pure white hue and analysis showed that this chlorosulfonated ethylene-butene 1 copolymer contained 27.2% chlorine and 1.1% sulfur. Mooney viscosity of raw rubber (ML1 + 4,100 ℃)
Was 40.

The stability of the hue of the product was tested by a heat accelerated test, but no change was observed in the hue even after 10 days at 70 ° C.

Further, the product was kneaded according to the composition shown in Table 1, and the physical properties and vulcanized physical properties of the unvulcanized product were measured.

This is summarized in Table 2.

On the other hand, 1, separated by a drum dryer
As a result of analysis, 0.1% of 4-difluorobenzene was chlorinated to produce chlorodifluorobenzene. This 1,4-difluorobenzene was removed by distillation to remove chlorodifluorobenzene and used in the next reaction.

Reference Example 1 The reaction was carried out in the same manner as in Example 1 except that carbon tetrachloride was used as the solvent, and then the product was separated.

The product had a pure white hue and analysis showed that the chlorosulfonated polyethylene contained 35.4% chlorine and 1.2% sulfur. The Mooney viscosity (ML1 + 4,100 ° C.) of the raw rubber was 52.

The stability of the hue of the product was tested by an accelerated test by heat, but no change was observed in the hue even after 10 days at 70 ° C.

Further, the product was kneaded according to the formulation shown in Table 1, and the physical properties and vulcanized physical properties of the unvulcanized product were measured.

This is summarized in Table 2.

Reference Example 2 The reaction was carried out in the same manner as in Example 4 except that carbon tetrachloride was used as the solvent, and then the product was separated.

The product had a pure white hue and analysis showed that this chlorosulfonated ethylene-butene 1 copolymer contained 27.0% chlorine and 1.1% sulfur. Mooney viscosity of raw rubber (ML1 + 4,100 ℃)
Was 40.

The hue stability of the product was tested by a heat acceleration test, but no change in hue was observed after 10 days at 70 ° C.

Further, the product was kneaded according to the composition shown in Table 1 and the physical properties and vulcanized physical properties of the unvulcanized product were measured.

This is summarized in Table 2.

As is clear from the above examples and reference examples, the chlorosulfonated polyolefin obtained in the present invention is no different from the chlorosulfonated polyolefin using carbon tetrachloride as a solvent and is commercially available. It turns out that it is of high value.

[0058]

Industrial Applicability According to the present invention, from the viewpoint of protecting the global environment, 1,4-difluorobenzene, which is a non-regulated substance of the Protocol, is used as a solvent to provide a method of producing a commercially valuable chlorosulfonated polyolefin. It becomes possible to do.

[Table 1]

[Table 2]

Claims (2)

[Claims] 1. A polyolefin dissolved or suspended in a solvent, using a radical generator as a catalyst, chlorine and sulfurous acid gas, chlorine and sulfuryl chloride, sulfuryl chloride alone, chlorine, sulfurous acid gas and sulfuryl chloride, or chlorine. A method for producing a chlorosulfonated polyolefin, which comprises using 1,4-difluorobenzene as a solvent in the reaction of chlorination or chlorination and chlorosulfonation using sulfuryl and sulfurous acid gas. 2. The chlorosulfonated polyolefin produced by the reaction is separated from the solvent, and the chlorine adduct of the solvent, which is a by-product of the solvent, is removed to the outside of the system to obtain 1,4-difluorobenzene. The production method according to claim 1, which is used again in the reaction.