JPH06145222A - Production of chlorinated polyolefin - Google Patents

Abstract

PURPOSE:To establish an industrial process for producing a chlorinated polyolefin without manifesting adverse effects on the ozonosphere present in the stratosphere of the earth by using a specific solvent. CONSTITUTION:This method comprises using a 1-4C fluorinated hydrocarbon carbon containing >=2 hydrogen atoms in the molecule in carrying out the chlorinating reaction of a polyolefin dissolved or suspended in the solvent with chlorine gas or sulfuryl chloride using a radical former as a catalyst.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a chlorinated polyolefin. More specifically, a method for producing a chlorinated polyolefin by dissolving or suspending a polyolefin in a fluorohydrocarbon containing 1 to 4 carbon atoms and containing 2 or more hydrogen atoms in the molecule to carry out a chlorination reaction. It is about.

[0002]

It is known to dissolve or suspend a polyolefin in a solvent to produce a chlorinated 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. The use of carbon tetrachloride for commercial production has been difficult. Therefore, a new method for producing a chlorinated polyolefin that does not use carbon tetrachloride has been desired.

[0003]

SUMMARY OF THE INVENTION From the viewpoint of protecting the global environment, the present invention is a fluorocarbon containing 1 to 4 carbon atoms having a low ozone depletion potential (ODP) and containing 2 or more hydrogen atoms in the molecule. An object of the present invention is to provide a method for producing a chlorinated polyolefin having commercial value by using hydrogen as a solvent.

[0004]

Means for Solving the Problems That is, according to the present invention, when a polyolefin dissolved or suspended in a solvent is chlorinated using chlorine gas or sulfuryl chloride with a radical generator as a catalyst, the number of carbon atoms as a solvent is increased. A method for producing a chlorinated polyolefin characterized by using a fluorinated hydrocarbon containing 1 to 4 and 2 or more hydrogen atoms.

The details will be described below.

[0006]

The solvent used in the present invention has an ozone depletion potential (OD).
A fluorinated hydrocarbon having a small P) of 1 to 4 carbon atoms and containing 2 or more hydrogen atoms is used. Fluorinated hydrocarbons are generally chlorofluorocarbons (CFC: a compound that does not contain hydrogen and consists only of chlorine atoms, fluorine atoms and carbon elements), hydrofluorocarbons (HFC: does not contain chlorine atoms, hydrogen atoms, fluorine atoms and carbon elements). And a hydrochlorofluorocarbon (HCFC: compound consisting only of hydrogen atom, chlorine atom, fluorine atom and carbon element).

CFC has a high ozone depletion potential (ODP), and there is a movement to abolish it in this century. On the other hand, HF
It is known that C and HCFC are easily decomposed because they contain hydrogen atoms in the molecule, and most of them are decomposed before reaching the ozone layer. Therefore, HCFC and HF
C has an ozone depletion potential (ODP) of 1 compared to CFC
It is as low as / 10 or less and is considered to be an alternative to CFC.

The boiling point of the fluorinated hydrocarbon used in the present invention is preferably 30 to 200 ° C.

When a fluorinated hydrocarbon having a boiling point of less than 30 ° C. is used as a solvent for producing a chlorinated polyolefin, the vapor pressure at a normal chlorination reaction temperature becomes extremely high, which makes industrial production difficult. .

On the other hand, when a fluorinated hydrocarbon having a boiling point of more than 200 ° C. is used as a solvent for producing a chlorinated polyolefin, it becomes difficult to separate the chlorinated polyolefin from the solvent after the completion of the chlorination reaction.

Fluorinated hydrocarbons having 1 to 4 carbon atoms and 2 or more hydrogen atoms in the molecule include, for example, 1,
2-dichlorofluoroethane, 1,2-dibromo-1,
1-difluoroethane, 1,1,2-trichloro-1-
Fluoroethane, 2-bromo-1,1-difluoroethane, 2,3-dibromo-1,1,1-trifluoropropane, 2,3-dichloro-1,1,1-trifluoropropane, 3-chloro-1 , 1,1, -trifluoropropane, 1,1,2-trichloro-2,3,3-trifluorocyclobutane and the like.

The reaction for chlorination uses a radical generator as a catalyst, chlorine gas or sulfuryl chloride, a fluorinated hydrocarbon containing 1 to 4 carbon atoms and 2 or more hydrogen atoms in its molecule (hereinafter, simply Fluorinated hydrocarbon)
React with a polyolefin dissolved or suspended in.
The reaction temperature is 40 to 150 ° C, preferably 60 to 130 ° 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, and t-butyl perbenzoate. An azo compound is preferable, and α, α′-azobisisobutyronitrile is particularly preferable.

The polyolefin as a raw material is, for example, high density polyethylene (HDPE), low density polyethylene (LDPE), 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 remaining in the reaction solution is 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.

The method of separating the produced polymer from the solvent includes:
Steam distillation, a drum dryer, and an extruder with a vent are known, and these are separated by these methods.

However, in the recovered fluorinated hydrocarbon solvent, a compound in which a part of the solvent is chlorinated during the reaction is contained as a by-product. By using this again in the reaction, the concentration of the by-product in the recovered fluorinated hydrocarbon solvent is gradually increased. Since this by-product has a high boiling point, it remains in the chlorinated polyolefin obtained by being separated from the solvent, and gives various adverse effects on the physical properties of the elastomer. Therefore, it is important to remove by-products from the recovered fluorinated hydrocarbons and to suppress the production of by-products due to chlorination of the fluorinated hydrocarbons.

As a method for removing the by-products from the recovered fluorinated hydrocarbon, it is convenient and convenient to use distillation. The fluorinated hydrocarbon thus purified is recycled to the reactor again.

On the other hand, as a method for suppressing the chlorination of fluorinated hydrocarbons 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
A relatively low temperature of 0 ° C. is desirable.

The chlorinated polyolefin referred to in the present invention includes, for example, chlorinated polyethylene, chlorinated ethylene / propylene copolymer, chlorinated ethylene / butene copolymer, chlorinated ethylene. Examples include hexene copolymers and chlorinated ethylene / vinyl acetate copolymers.

The obtained product is compounded and kneaded in the same manner as a conventional rubber or resin, and is 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,
Examples thereof include compounding agents for rubber or resin such as plasticizers, processing aids, antioxidants and vulcanization accelerators. Examples of the vulcanizing method include general methods such as steam vulcanization, UHF vulcanization, hot air vulcanization, injection, mold and rotocure.

For the end use, like the existing chlorinated polyolefin, wire covering materials, vinyl chloride, PE, PP, PS and AB
Resin modification of S, rubber magnets, light electric parts, automobile parts,
Examples include waterproof sheets and sponges.

[0023]

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 content: Combustion flask method Physical properties of unvulcanized rubber: JIS K 6300 Physical properties of vulcanized rubber: JIS K 6301 Color of product: Visual stability of product due to accelerated deterioration: 70 ° C gear oven method, Visual content of chlorinated by-products in fluorinated hydrocarbons: gas chromatography.

Example 1 28 k of 1,2-dibromo-1,1-difluoroethane was added to a 30-liter glass-lined autoclave.
g, melt index 3.8 g / 10 min, density
0.963g / cc high density polyethylene 1.96k
g prepared.

Pass steam through the jacket of the reactor and
The polyethylene was uniformly dissolved by holding it at 2 ° C for 2 hours. 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.

2.65 g of α, α as a radical initiator
′ -Azobisisobutyronitrile was added to 1,2-dibromo-
It was dissolved in 2.9 kg of 1,1-difluoroethane. While continuously adding this solution to the reactor, chlorine gas was introduced into the reactor from another inlet at a flow rate of 6 liters / minute for 130 minutes to carry out the reaction. Reaction temperature is 115 ℃
In addition, the reactor pressure was kept at 3.5 kg / cm ² .

After the reaction was completed, the pressure was returned to normal pressure, the temperature of the reactor was lowered to 70 ° C., and nitrogen was introduced while maintaining the temperature at 70 ° C. to remove the hydrogen chloride gas remaining in the reaction solution. After adding 43 g of 2,2'-bis (4-glycidyloxyphenyl) propane as a stabilizer,
The product was fed to a drum dryer heated to 0 ° C. to separate the product chlorinated polyethylene from the solvent.

The product had a pure white hue and analysis showed that the chlorinated polyethylene contained 35.3% chlorine. Mooney viscosity of raw rubber (ML _{1 + 4} , 10
(0 ° C.) was 62.

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 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, 0.4% of 2-dibromo-1,1-difluoroethane was chlorinated, and a chlorinated by-product was produced. This 1,2-dibromo-1,1-difluoroethane was used for the next reaction after removing the chlorinated by-product by distillation.

Example 2 The reaction was carried out in the same manner as in Example 1 except that the solvent was changed to 1,1,2-trichloro-1-fluoroethane, and the product was separated.

The product had a pure white hue and analysis showed that the chlorinated polyethylene contained 35.1% chlorine. Mooney viscosity of raw rubber (ML _{1 + 4} , 10
0 ° C.) was 61.

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, 0.5% of 1,2-trichloro-1-fluoroethane was chlorinated and a chlorinated by-product was produced. This 1,1,2-trichloro-1-fluoroethane was used for the next reaction after removing the chlorinated by-product by distillation.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

As is apparent from the above description, the present invention establishes an industrial manufacturing process that does not have an adverse effect on the ozone layer existing in the stratosphere of the earth.

Claims (2)

[Claims] 1. When carrying out a chlorination reaction of a polyolefin dissolved or suspended in a solvent using a radical generator as a catalyst and chlorine gas or sulfuryl chloride, the solvent has 1 to 4 carbon atoms and a molecule. A process for producing a chlorinated polyolefin, characterized in that a fluorohydrocarbon containing two or more hydrogen atoms is used. 2. After separating the chlorinated polyolefin produced in the reaction from the solvent, the chlorine adduct of the solvent by-produced in the solvent is removed to the outside of the system, and the obtained solvent is used again in the reaction. The manufacturing method according to claim 1, wherein: