JPH0651745B2 - Method for producing chlorosulfonated polymer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a chlorosulfonated polymer.

More specifically, it relates to a method for producing a chlorosulfonated polymer having improved oil resistance of chlorosulfonated polyethylene.

Conventionally, chlorosulfonated polyethylene has been used for automobile hoses or automobile wiring cord coatings by taking advantage of its excellent weather resistance, ozone resistance, heat resistance and oil resistance.

On the other hand, in recent years, further improvement in oil resistance, represented by sour oil resistance and sour gasoline resistance, has become an issue for elastomers used in automobiles. In chlorosulfonated polyethylene, the oil resistance, Improvement in gasoline resistance is strongly desired.

Since the oil resistance of chlorosulfonated polyethylene depends on its chlorine content, the chlorine content is increased, so that the oil resistance of chlorosulfonated polyethylene can be improved.

However, the rubber elasticity of chlorosulfonated polyethylene depends largely on its chlorine content, and the smallest chlorine content at which polyethylene crystals are destroyed by chlorination and becomes amorphous shows the most "rubber-like" properties. (This is called the optimum chlorine amount. Polymer processing, Vol 32, No. 6, P10 (198
3). Therefore, changing the amount of chlorine for the purpose of improving the oil resistance of chlorosulfonated polyethylene is not appropriate because it results in deterioration of rubber elasticity or "rubber-likeness".

From this, it is important to improve the oil resistance of chlorosulfonated polyethylene without impairing the original rubber elasticity or "rubberiness" of chlorosulfonated polyethylene.

The present invention aims to solve the above problems and to produce a chlorosulfonated polymer having improved oil resistance.

That is, in the present invention, polyethylene and the copolymerization component are represented by one of the following structural formulas. (However, R ₁ , R ₂ , R ₃ , and R ₄ are hydrogen or a substituent.) A chlorosulfone characterized by chlorinating and chlorosulfonating a polymer comprising an ethylene copolymer blend. It is a method for producing a polymerized polymer composition.

The polyethylene used in the present invention is an ethylene polymer having a density of 0.88 to 0.96, which contains a homopolymer of ethylene and a copolymer mainly composed of ethylene and α-olefin.

Here, as α-olefin which is copolymerized with ethylene, propylene, butene-1, pentene-1, hexene-1,
Octene-1, decene-1,4-methylpentene-1,
3-methylpentene-1 and the like can be mentioned.

Specific examples of polyethylene used in the present invention include medium- and low-pressure polyethylene, linear low-density polyethylene, and high-pressure polyethylene.

However, in order to expect better workability and rubber elasticity, it is desirable to select medium- and low-pressure polyethylene or linear low-density polyethylene as polyethylene.

In the ethylene copolymer that constitutes the raw material polymer together with this polyethylene, the copolymerization component must have one of the following constitutional formulas.

(However, R ₁ , R ₂ , R ₃ , and R ₄ are hydrogen or a substituent.

Examples of the kind of the substituent include an alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group, or a glycidyl group, but if the chemical structure is allowed,
There are no particular restrictions.

An ethylene-vinyl acetate copolymer is an ethylene copolymer having a copolymerization component represented by the structural formula on the left above.

The ethylene copolymer having the copolymerization component represented by the structural formula on the right above is an ethylene-ethyl acrylate copolymer,
There are ethylene-methyl acrylate copolymer, ethylene-isobutyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer and the like.

Particularly preferable ethylene copolymers are ethylene-vinyl acetate copolymers, ethylene-ethyl acrylate copolymers, and ethylene-methyl acrylate copolymers.

The content of the copolymerization component copolymerized with ethylene is 1 to 70 wt%
Is preferable, and particularly preferably 30 to 50 wt%
Is.

The chlorosulfonated ethylene copolymer obtained by chlorinating and chlorosulfonating this ethylene copolymer alone has excellent oil resistance of the vulcanized product, but it sticks to the roll surface during compounding by the roll and the rubber is The workability of the roll is poor because the so-called roll separation phenomenon occurs.

Furthermore, the rubber elasticity of the vulcanizate is inferior, so
It is not suitable for use as an industrial product such as a mold.

It is important to chlorinate and chlorosulfonate a polymer prepared by blending polyethylene and an ethylene copolymer.

The reason why the oil resistance of the chlorosulfonated polymer is improved by the present invention is not clear, but since a polar group such as an ester group or a carboxylic acid group is introduced into the chlorosulfonated polymer, the affinity with oil is improved. It is estimated that the oil resistance is lowered and the oil resistance is improved.

In the present invention, there is no particular restriction on the mixing ratio of the polymer blend comprising polyethylene and ethylene copolymer, and the mixing ratio of polyethylene: ethylene copolymer is from 99: 1 to 1: 9.
It is possible to take up to 9 arbitrarily.

However, the mixing ratio of polyethylene: ethylene copolymer is 9
9: 1 to 60:40, more preferably 95: 5 to 70:
A value of 30 is highly effective in improving oil resistance without impairing the original workability and rubber elasticity of chlorosulfonated polyethylene. The chlorine and sulfur contents of the chlorosulfonated polymer composition obtained by chlorinating and chlorosulfonating a polymer blend consisting of these polyethylenes and ethylene copolymers are the same as those of conventional chlorosulfonated polyethylene. %, Sulfur amount 0.3 to
A content of 3.0 wt% is preferable.

However, when more excellent rubber elasticity or "rubber-likeness" is required, the chlorine content is about 35 wt% when polyethylene of the medium and low pressure method is used as polyethylene, and about 30 wt% when linear low density polyethylene is used. It is desirable that the content is ˜33 wt%, and 30 wt% when high-pressure polyethylene is used.

This is because the optimum chlorine content of each polyethylene is about 35 wt% for medium and low pressure polyethylene and about 30 for linear low density polyethylene.
~ 33wt%, about 30wt% for high pressure polyethylene, while the optimum chlorine content of ethylene copolymer is about 27 ~ 30
Correlate with wt%.

That is, in the raw material polymer used in the present invention, the optimum chlorine content of the polymer blend consisting of the medium- and low-pressure polyethylene and the ethylene copolymer is about 35 wt%, and the optimum chlorine content of the polymer blend consisting of the linear low-density polyethylene and the ethylene copolymer is This is because the optimum chlorine amount is about 30 to 33 wt% and the optimum chlorine amount of the polymer blend composed of the high-pressure polyethylene and the ethylene copolymer is about 30 wt%.

These optimum chlorine contents can be obtained by measuring the decrease in crystallinity due to chlorination with a differential scanning calorimeter (DSC).

Here, in order to improve the workability or the rubber elasticity of the roll of the chlorosulfonated polymer composition, it is desirable to select medium- and low-pressure polyethylene or linear low-density polyethylene as the polyethylene, but the linear low-density polyethylene is preferable. The optimum chlorine amounts of the density polyethylene and the ethylene copolymer are about 30 to 33 wt% and about 27 to 30 wt%, respectively, which are close to each other.

For this reason, it is possible to obtain a chlorosulfonated polymer composition by chlorinating and chlorosulfonating a polymer blend consisting of linear low density polyethylene and an ethylene copolymer up to about 30 to 33 wt%. It is especially effective in obtaining a product.

Furthermore, chlorosulfonated polyethylene made from linear low-density polyethylene has a lower optimum chlorine content than that of chlorosulfonated polyethylene made from medium- and low-pressure method polyethylene, so it has excellent rubber elasticity but inferior oil resistance. This is a drawback, and the industrial value of improving this drawback is great.

However, the present invention is not limited to these chlorine amounts or polyethylene species.

The amount of sulfur affects the vulcanization rate, vulcanization density, stability, etc. of the chlorosulfonated polymer, but is 0.3 wt.
If it is less than%, the vulcanization is not performed sufficiently. On the other hand, when the amount of sulfur exceeds 3.0 wt%, the vulcanization is too fast, which causes scorch, burns, etc., and adversely affects the storage stability of the unvulcanized product. Preferably, the amount of sulfur is 0.7-1.
It is 5 wt%.

Mooney viscosity of chlorosulfonated polymers (ML _{1 +} 4,100
C.) is 10 to 150, preferably 20 to 130.

In practicing the present invention, the reaction of chlorinating and chlorosulphonating the polymer blend to a chlorosulphonated polymer composition may be the same as known methods for producing chlorosulphonated polyethylene.

There is no particular limitation as long as the intention of the present invention is not impaired, but a method of uniformly dissolving the polymer in a solvent to carry out the reaction (solution method) is a particularly preferable method for obtaining the effect of the present invention.

The general method for synthesizing a chlorosulfonated polymer by the solution method is shown below.

Dissolve polyethylene and ethylene copolymer in a solvent to make a homogeneous solution, then add 1) chlorine and sulfurous acid gas or 2) chlorine and sulfuryl chloride or 3) sulfuryl chloride alone to the reaction solution using the radical generator as a catalyst. The reaction starts from that.

The reaction temperature is 50 to 180 ° C., and the reaction pressure is atmospheric pressure to
8 kg / cm ² (gauge pressure) is suitable. During the reaction, the generated gas such as hydrogen chloride is continuously purged out of the system.

The solvent used in the reaction is inert to chlorination reactions of carbon tetrachloride, chloroform, dichloroethane, trichloroethane, tetrachloroethane, monochlorobenzene, dichlorobenzene, fluorobenzene, dichlorodifluoromethane, trichlorofluoromethane, etc. Halogenated hydrocarbon solvents are used. Carbon tetrachloride is preferred.

As the radical generator serving as a catalyst, an azo radical initiator such as α, α′-azobisisobutyronitrile, azobiscyclohexanecarbonitrile, 2,2′-azobis (2,4-dimethylvaleronitrile) There are organic peroxide-based radical initiators such as benzoyl peroxide, t-butyl peroxide, and acetyl peroxide. Preferably α,
It is α'-isobisisobutyronitrile.

Ultraviolet rays may be irradiated instead of using the radical disclosing agent.

As described above, the reaction reagents for chlorination and chlorosulfonation are 1) chlorine and sulfurous acid gas (for example, Japanese Patent Publication No. 33-7838).

2) Chlorine and sulfuryl chloride (for example, JP-A-56-764)
There is 06).

3) Sulfuryl chloride (for example, Japanese Patent Publication No. 39-12113).

Although 3 kinds of are known, 2) or 3) is industrially preferable.

When sulfuryl chloride is used, an amine compound such as pyridine, quinoline, dimethylaniline, nicotine or piperidine is used as a cocatalyst in order to add sulfur.

The amount of the polymer to be dissolved may be arbitrary, but it is preferably 5 to 20% by weight in terms of the reaction because the viscosity of the reaction increases.

After completion of the reaction, hydrogen chloride and sulfurous acid gas remaining in the solution are removed from the system by blowing an inert gas such as nitrogen under reflux of the solvent. If necessary, an epoxy compound is added as a stabilizer. 2,2'-bis (4-glycidyloxyphenyl) propane is preferred.

The solution of the obtained chlorosulfonated polymer composition is separated into rubber and solvent by 1) steam distillation 2) drum drying 3) extrusion drying and the like.

1) is a method of feeding a polymer solution into hot water (see US Pat. No. 2,592,814). 2) is a method of feeding a polymer solution onto the surface of a heated rotating drum to take out the polymer as a film (US Pat. No. 2,923,979).
See).

3) is a method in which the reaction solution is pre-concentrated and then fed to an extrusion dryer with a pent and separated.) JP-A-57-4730
See).

In the present invention, separation and drying can be performed by any of the above processes.

The chlorosulfonated polymer composition referred to in the present invention is, like the conventional chlorosulfonated polyethylene, vulcanized as an unvulcanized product or after being vulcanized with a vulcanizing agent, a vulcanization accelerator, a filler, a stabilizer and the like. Used as a sulphate. Vulcanizing agent,
As the vulcanization accelerator, filler, stabilizer, etc., those currently used for chlorosulfonated polyethylene are used.

Known vulcanizing agents include metal oxides such as magnesia and litharge, and small amounts of sulfur and organic peroxides. As the vulcanization accelerator, dipentamethylene thiuram
Hexasulfide (TRA), 2-mercaptoimidazoline (# 22) and the like. Fillers include calcium carbonate, clay, silica, oil softener, carbon black and the like. Stabilizers include anti-proliferation NBC and the like.

Similar to chlorosulfonated polyethylene, these are compounded and kneaded by a roll or a Banbury mixer, and then subjected to press vulcanization, steam vulcanization, UHF vulcanization or electron beam vulcanization.

The chlorosulfonated polymer obtained by the present invention has a characteristic of excellent oil resistance.

Therefore, it is suitable for automobile parts such as various fuel system hoses, lubricating oil system hoses, brake system hoses, radiator hoses, cooler hoses, ignition cables, cord coatings for various wirings, etc., because of its excellent oil resistance.

On the other hand, since an ester bond is introduced into the molecule of the chlorosulfonated polymer, the adhesiveness with fibers, metals, etc. is improved, so that it is used as a draw cloth, electric wire coating, escalator handrail, turboline, various gas hoses, roofing adhesives. It is also suitable for use as paint.

Next, the present invention will be described in more detail based on examples, but these are examples for helping the understanding of the present invention.
The present invention is not limited to these examples.

The numerical values used in the present invention are those obtained according to the following measuring methods.

Melt index: ASTM D 1238 Density: ASTM D 1505 Vinyl acetate content: JIS K 6730 Chlorine and sulfur content: Combustion flask method Mooney viscosity (ML _{1 + 4} , 100 ° C): JIS K 6300 Vulcanized rubber Physical properties: JIS K 6301 Oil resistance: According to JIS K 6301 immersion test. Condition JIS
The volume change rate (%) of No. 3 oil after 120 ° C x 70 hours is obtained.

Example 1 A glass lined autoclave with a stirrer of 30 had a melt index of 4.0 g / 10 min and a density of 0.921.
In g / cm ³ , the α-olefin as a copolymer component is butene-
1240 linear low-density polyethylene and Toyo Soda Kogyo Co., Ltd. ethylene-vinyl acetate copolymer UE634
(Melt index 4.0 g / 10 minutes, density 0.94
560 g of 9 g / cm ³ and a vinyl acetate content of 26 wt% were charged to obtain a raw material polymer.

28.0 kg of carbon tetrachloride as a solvent and 0.3 of pyridine as a cocatalyst
After charging 81 g, the temperature was raised to 110 ° C. under pressure to dissolve the polymer.

Then, the temperature was lowered to 100 ° C., and 7.5 g of 2,2′-azobisisobutyronitrile as a radical generator was added.
The reaction was carried out by adding 4,650 g of sulfuryl chloride while adding 2.86 kg of a carbon tetrachloride solution in which was dissolved.

It took 180 minutes to add sulfuryl chloride, during which time the reaction temperature was 100 ° C and the reaction pressure was 3.3 kg / cm 3.
Maintained at ³ (gauge pressure).

After the reaction was completed, the internal temperature of the polyer solution was lowered to 70 ° C., and nitrogen was blown into the solution under reflux of the solvent, so that hydrogen chloride and sulfurous acid gas remaining in the solution were discharged out of the system.

After adding 47 g of 2,2'-bis (4-glycidyloxyphenyl) propane as a stabilizer, it was fed to a drum dryer to separate the product from the solvent.

As a result of the analysis, this chlorosulfonated polymer composition was 3
It was found to contain 0.1 wt% chlorine and 1.0 wt% sulfur.

The Mooney viscosity was 49.

The following formulation was carried out using a 10 inch open roll heated to 50 ° C.

(Combination) Chlorosulfonated polymer composition 100 parts by weight Magnesium oxide 10 parts by weight (Kyowamag 150 from Kyowa Chemical Industry Co., Ltd.) Pentaerythritol 3 parts by weight Dipentamethylene thiuram hexahexasulfide 2 parts by weight (Ouchi Shinko Chemical Industry Co., Ltd. Noxcellor TRM Co., Ltd. Workability with rolls was good.

The compound was press-vulcanized at 150 ° C. for 40 minutes, and the physical properties of the vulcanized product were measured.

The results are summarized in Table-1.

Example-2 In the autoclave used in Example-1, a melt index of 6.0 g / 10 minutes, a density of 0.958 g / cm ³ of medium- and low-pressure polyethylene 2520 g and an ethylene-ethyl acrylate copolymer manufactured by Nippon Unicar Co., Ltd. DPDJ-6169
(Melt index 6g / 10min, density 0.931g / cm
³ ) 280 g was charged to obtain a raw material polymer.

28.0 kg of carbon tetrachloride as a solvent and 0.3 of pyridine as a cocatalyst
After charging 05 g, the temperature was raised to 110 ° C. under pressure to dissolve the polymer.

Then, the temperature was lowered to 100 ° C., and 2,2′-azobisisobutyronitrile 7.5 as a radical generator was added.
While adding 2.86 kg of carbon tetrachloride solution in which g was dissolved,
The reaction was carried out by adding 5955 g of sulfuryl chloride.

It took 230 minutes to add sulfuryl chloride, during which time the reaction temperature was 100 ° C and the reaction pressure was 3.3 kg / cm 3.
Maintained at ³ (gauge pressure).

After completion of the reaction, hydrogen chloride and sulfurous acid gas remaining in the solution were discharged to the outside of the system as in Example-1.

As a stabilizer, 53 g of 2,2'-bis (4-glycidyloxyphenyl) propane was added and then fed to a drum dryer to separate the product from the solvent.

As a result of the analysis, this chlorosulfonated polymer composition was 3
It was found to contain 5.7 wt% chlorine and 1.0 wt% sulfur.

The Mooney viscosity was 53.

Blending with a roll was performed in the same manner as in Example-1, but the workability was good.

It was vulcanized in the same manner as in Example-1, and its physical properties were measured.
The results are summarized in Table-1.

Autoclave melt index 11.0 g / 10 min was used in Example -3 Example -1, high-pressure polyethylene 1960g and Toyo Soda Manufacturing Co., Ltd. ethylene density 0.922 g / cm ³ - vinyl acetate copolymer 625 g of UE625 (melt index 14 g / 10 min, density 0.934 g / cm ³ , vinyl acetate content 15 wt%) was charged to obtain a raw material polymer.

The reaction was performed under the same conditions as in Example 1 except that the amount of pyridine used as a cocatalyst was 0.458 g, and the product was separated.

As a result of the analysis, this chlorosulfonated polymer composition was 3
It was found to contain 0.3 wt% chlorine and 1.4 wt% sulfur.

The Mooney viscosity was 27.

Blending with rolls was performed in the same manner as in Example-1.

The rubber adhered to the loom surface and the phenomenon was observed depending on the roll, and the workability of the roll was poor, but compounding was possible.

It was vulcanized in the same manner as in Example-1, and its physical properties were measured.
The results are summarized in Table-1.

Comparative Example-1 2800 g of the linear low density polyethylene used in Example-1
Example 1 except that polyethylene was used as a raw material by itself.
The reaction was carried out in the same manner as described above, and the product was obtained after separation and drying.

As a result of analysis, this chlorosulfonated polyethylene is 3
It was found to contain 0.0 wt% chlorine and 1.0 wt% sulfur.

The Mooney viscosity was 49.

The blending was performed in the same manner as in Example-1, but the workability with rolls was good.

The blend was vulcanized and its physical properties were measured in the same manner as in Example-1, and the results are summarized in Table-1.

Comparative Example-2 The reaction was carried out in the same manner as in Example-2 except that 2800 g of the medium- and low-pressure polyethylene used in Example-2 was solely used as the raw material polyethylene, and a product was obtained after separation and drying.

As a result of analysis, this chlorosulfonated polyethylene is 3
It was found to contain 5.8 wt% chlorine and 1.0 wt% sulfur.

The Mooney viscosity was 55.

Blending was carried out in the same manner as in Example-2, but workability with rolls was good.

The compound was vulcanized in the same manner as in Example-2, and its physical properties were measured. The results are summarized in Table-1.

Comparative Example-3 A reaction was conducted in the same manner as in Example-3 except that 2800 g of the high-pressure polyethylene used in Example-3 was used alone as the raw material polyethylene, and a product was obtained after separation and drying.

As a result of analysis, this chlorosulfonated polyethylene is 3
It was found to contain 0.5 wt% chlorine and 1.4 wt% sulfur.

The Mooney viscosity was 28.

Blending was carried out in the same manner as in Example-3, but a phenomenon was observed in which the rolls were separated due to adhesion to the rolls.

Although the workability of the roll was inferior, it could be compounded.

The compound was vulcanized in the same manner as in Example-3 and its physical properties were measured. The results are summarized in Table-1.

According to the above examples, the chlorosulfonated polymer composition obtained by the present invention has the property of improved oil resistance. It is obvious that the present invention provides a method for producing a chlorosulfonated polymer having characteristics of being excellent in oil resistance.

Claims (4)

[Claims] 1. A polyethylene and a copolymerization component are represented by one of the following structural formulas. (However, R ₁ , R ₂ , R ₃ , and R ₄ are hydrogen or a substituent.) The mixing ratio of the ethylene copolymer is 99: 1 to 1: 1.
A process for producing a chlorosulfonated polymer composition, which comprises chlorinating and chlorosulfonating a 99 (weight ratio) polymer blend. 2. The method for producing a chlorosulfonated polymer composition according to claim 1, wherein the polyethylene is a linear low density polyethylene. 3. The ethylene copolymer according to claim 1, which is an ethylene-vinyl acetate copolymer.
A method for producing the chlorosulfonated polymer composition according to the item 1. 4. The method for producing a chlorosulfonated polymer composition according to claim 1, wherein the ethylene copolymer is an ethylene-acrylate copolymer.