JPH0616716A - Production of chlorosulfonated polyolefin - Google Patents

Abstract

PURPOSE:To obtain a useful polyolefin according to a method suitable for environmental protection without using carbon tetrachloride by chlorosulfonating a polyolefin dissolved in a specific solvent with chlorine and sulfurous acid gas, etc., using a free radical former as a catalyst. CONSTITUTION:A polyolefin dissolved or suspended in 1,2-dibromo-1,1 difluoroethane as a solvent is chlorosulfonated with chlorine and sulfurous acid or the chlorine and sulfuryl chloride, etc., in combination using a free radical former as a catalyst. After the reaction, the resultant reactional product is separated from the solvent and a chlorine adduct of the solvent formed as a by-product therein is removed to the outside of the system. The obtained 1,2-dibromo-1,1-difluoroethane is reused for the reaction.

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 1,2-dibromo-1,1-difluoroethane and carrying out a chlorination and 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 has a commercial value by using 1,2-dibromo-1,1-difluoroethane, which is a non-regulated substance of the Protocol, as a solvent from the viewpoint of protecting the global environment. An object is to provide a method for producing a chlorosulfonated polyolefin.

[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,
In the reaction of chlorination or chlorination and chlorosulfonation using sulfuryl chloride alone or chlorine, sulfurous acid gas and sulfuryl chloride, sulfuryl chloride and sulfurous acid gas, 1,2-dibromo-1,1-difluoroethane as a solvent Is a method for producing a chlorosulfonated polyolefin. The details will be described below.

[0005]

FUNCTION As the solvent in the present invention, 1,2-dibromo-1,1-difluoroethane, which is a non-regulated substance of the Protocol, is used.

The reaction of chlorination and chlorosulfonation uses a radical generator as a catalyst, chlorine and sulfurous acid gas, chlorine and sulfuryl chloride, sulfuryl chloride alone, or three reagents of chlorine, sulfurous acid gas and sulfuryl chloride, sulfuryl chloride and sulfurous acid. The gas is reacted with a polyolefin dissolved or suspended in 1,2-dibromo-1,1-difluoroethane. 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
˜130 ° C., reaction pressure 0˜10 kg / cm ² ,
It is 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′-azobisisobutyronitylyl, azobiscyclohexanecarbonitrile, and 2,2′-azobis (2,4-dimethylvaleronitrile). Examples of the organic peroxide include Examples thereof include benzoyl peroxide, 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 1,2-dibromo-1,1
-Difluoroethane contains, for example, dibromodifluorochloroethane, which is a byproduct of chlorination of a part of 1,2-dibromo-1,1-difluoroethane during the reaction. By using this again in the reaction, the recovered 1,2-dibromo
The concentration of dibromodifluorochloroethane etc. in -1,1-difluoroloethane gradually increases. Since the boiling point of this dibromodifluorochloroethane etc. is higher than that of 1,2-dibromo-1,1-difluoroethane, dibrodifluorochloroethane etc. remains in the chlorosulfonated polyolefin obtained by separation from the solvent, and the elastomer It has various adverse effects on the physical properties of. Therefore, it is important to remove dibromodifluorochloroethane and the like from the recovered 1,2-dibromo-1,1-difluoroethane and to suppress by-products such as dibromodifluorochloroethane and the like.

The method for removing dibromodifluorochloroethane and the like from the recovered 1,2-dibromo-1,1-difluoroethane is conveniently by distillation. The 1,2-dibromo-1,1-difluoroethane thus purified is recycled to the reactor.

On the other hand, as a method for suppressing the formation of dibromodifluorochloroethane or the like during the reaction, first, the process of avoiding the use of chlorine as a chlorinating agent and using sulfuryl chloride alone is effective. Especially the reaction temperature at this time is 6
It is desirable to carry out at a relatively low temperature of 0 to 130 ° 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. Stabilization of product hue due to accelerated deterioration: 70 ° C. gear oven method, content of dibromodifluorochloroethane and the like in 1,2-dibromo-1,1-difluoroethane by visual inspection: by gas chromatography.

Example 1 In a 30-liter glass-lined autoclave 1,
28 kg of 2-dibromo-1,1-difluoroethane, melt index 6.2 g / 10 minutes, density 0.95 g / c
2.8 kg of high-density polyethylene (c) was charged.

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
Azobisisobutyronitylyl was dissolved in 2.9 kg of 1,2-dibromo-1,1-dichloroethane. 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 k
It was kept at g / cm ² .

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 the product chlorosulfonated polyethylene from the solvent.

Analysis revealed that this chlorosulfonated polyethylene contained 35.6% chlorine and 1.1% sulfur. Muni-viscosity of raw rubber (ML1 + 4,100
C.) was 53.

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 in the following formulation, and the physical properties of unvulcanized products represented by scorch time and vulcanized physical properties such as tensile strength were measured.

Chlorosulfonated polyethylene 100 parts by weight Magnesia 10 pentaerythritol 3 accelerator TRA * 2 (*: dipentamethylene thiuram tetrasulfide) The obtained values are summarized in Table 1.

On the other hand, 1,2-separated by a drum dryer
As a result of analysis, dibromo-1,1-difluoroethane was 0.
2% was chlorinated and produced dibromodifluorochloroethane and the like. The 1,2-dibromo-1,1-difluoroethane was used for the next reaction after removing dibromodifluorochloroethane and the like by distillation.

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.

Analysis revealed that this chlorosulfonated polyethylene contained 34.5% chlorine and 1.2% sulfur. Mooney viscosity of raw rubber (ML1 + 4,100
C.) was 119.

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 by the above-mentioned composition, and the physical properties and vulcanized physical properties of the unvulcanized product were measured.

This is summarized in Table 1.

On the other hand, 1,2-separated by a drum dryer
As a result of analysis, dibromo-1,1-difluoroethane was 0.
2% was chlorinated to produce dibromodifluorochloroethane and the like. The 1,2-dibromo-1,1-difluoroethane was used for the next reaction after removing dibromodifluorochloroethane and the like by distillation.

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.

Analysis revealed that the chlorosulfonated polyethylene contained 22.8% chlorine and 1.0% sulfur. Mooney viscosity of raw rubber (ML1 + 4,100
C.) was 32.

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 by the above-mentioned composition, and the physical properties and vulcanized physical properties of the unvulcanized product were measured.

This is summarized in Table 1.

On the other hand, 1,2-separated by a drum dryer
As a result of analysis, dibromo-1,1-difluoroethane was 0.
1% was chlorinated and produced dibromodifluorochloroethane and the like. The 1,2-dibromo-1,1-difluoroethane was used for the next reaction after removing dibromodifluorochloroethane and the like by distillation.

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.

As a result of analysis, it was found that this chlorosulfonated ethylene / butene 1 copolymer contained 27.3% chlorine and 1.1% sulfur. Mooney viscosity of raw rubber (ML
1 + 4,100 ° C.) was 44.

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 by the above-mentioned composition, and the physical properties and vulcanized physical properties of the unvulcanized product were measured.

This is summarized in Table 1.

On the other hand, 1,2-separated by a drum dryer
As a result of analysis, dibromo-1,1-difluoroethane was 0.
1% was chlorinated and produced dibromodifluorochloroethane and the like. The 1,2-dibromo-1,1-difluoroethane was used for the next reaction after removing dibromodifluorochloroethane and the like by distillation.

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.

Analysis revealed that this chlorosulfonated polyethylene contained 35.4% chlorine and 1.2% sulfur. Mooney viscosity of raw rubber (ML1 + 4,100
C.) was 52.

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 by the above-mentioned composition, and the physical properties and vulcanized physical properties of the unvulcanized product were measured.

This is summarized in Table 1.

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

As a result of the analysis, it was found that the chlorosulfonated ethylene / butene 1 copolymer contained 27.0% chlorine and 1.1% sulfur. Mooney viscosity of raw rubber (ML
1 + 4,100 ° C.) was 40.

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 composition shown in Table 1 and the physical properties and vulcanized physical properties of the unvulcanized product were measured.

This is summarized in Table 1.

[0055]

[Table 1] As is clear from the above examples and reference examples, the chlorosulfonated polyolefin obtained in the present invention has no difference from the chlorosulfonated polyolefin using carbon tetrachloride as a solvent and has a high commercial value. I know that it is a thing.

[0056]

As is apparent from the above description, according to the present invention, from the viewpoint of protecting the global environment, 1,2-dibromo-1,1-difluoroethane, which is a non-regulated substance of the Protocol, is used as a solvent and commercialized. It is possible to provide a method for producing a chlorosulfonated polyolefin that is of significant value.

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, or chlorine, sulfurous acid gas and sulfuryl chloride, three reagents, and chlorine. In the reaction of chlorination or chlorination and chlorosulfonation using sulfuryl and sulfurous acid gas, 1,2-dibromo
A method for producing a chlorosulfonated polyolefin, which comprises using 1, -1,1-difluoroethane. 2. A chlorosulfonated polyolefin produced by the reaction is separated from a solvent, and then a chlorine adduct of the solvent, which is a by-product of the solvent, is removed to the outside of the system to obtain 1,2-dibromo-
Process according to claim 1, characterized in that 1,1-difluoroethane is used again in the reaction.