JPH0517243B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a chlorosulfonated copolymer obtained by chlorinating and chlorosulfonating a copolymer of ethylene and other α-olefins. Chlorosulfonated polyethylene, which is obtained by chlorinating and chlorosulfonating polyethylene as a raw material, has been known. Chlorosulfonated polyethylene is a special elastomer with excellent ozone resistance, weather resistance, heat resistance, oil resistance, chemical resistance, and bright color. Taking advantage of these properties, it can be used for extruded products such as electric wires and hoses, and for extruded products such as electric wires and hoses. Calendar products such as cloth or paint,
Used in adhesives, etc. However, it is hardly used as molded products such as automobile boots, gaskets, and gaskets. One of the reasons for this is poor compression set resistance, and this improvement has been desired for use as molded products. The chlorosulfonated copolymer according to the invention comprises:
In response to such demands, this product has improved compression resistance and makes it possible to manufacture molded products using chlorosulfonated copolymers. Furthermore, the chlorosulfonated copolymer of the present invention has better cold resistance than conventional chlorosulfonated polyethylene. That is, an object of the present invention is to provide a chlorosulfonated copolymer that has excellent compression set resistance and also excellent cold resistance. Chlorosulfonated copolymers obtained by chlorinating and chlorosulfonating copolymers of ethylene and other α-olefins are known techniques, as seen, for example, in US Pat. No. 3,206,444. However, in these prior art techniques, it is not possible to produce a chlorosulfonated copolymer having excellent compression set resistance and cold resistance, which are the objects of the present invention. Only the chlorosulfonated copolymer having the chemical composition, molecular structure, and molecular weight distribution specified by the present invention has excellent compression set resistance and cold resistance. That is, the present invention provides α-
Ethylene α containing 4.0 to 20.0 mol% olefin
- Olefin copolymer with a density of 0.88 g/cm ³ or more
less than 0.90, and the melt flow rate is from 0.1 to
300g/10 minutes (temperature 190℃, load 2160g),
And the amount of chlorine obtained by chlorination and chlorosulfonation of those whose M _W /M _N is less than 3.5 is
10-50% by weight, sulfur content is 0.3-3.0% by weight, Mooney viscosity (ML ₁₊₄ , 100℃) is 20-130, M _W /
A method for producing a chlorosulfonated copolymer having M _N of less than 3.5. However, the symbols A to B in the text mean greater than or equal to A and less than or equal to B. As an α-olefin having 3 to 8 carbon atoms,
Examples include butene-1, propylene, pentene-1, hexene-1, octene-1,4-methyl-pentene-1, and butene-1 is preferred in terms of strength and heat resistance. The content of α-olefin contained in the ethylene/α-olefin copolymer must be in the range of 4.0 to 20.0 mol%. If it is outside this range, it will not be possible to obtain a chlorosulfonated copolymer with excellent compression set resistance, which is a feature of the present invention. The density of ethylene/α-olefin copolymer is
A value of 0.88 g/cm ³ or more and less than 0.90 g/cm ³ is suitable. This density range corresponds to polyolefin elastomers such as ethylene-propylene rubber. The melt flow rate of ethylene/α-olefin copolymer is 0.1 to 300 g/10 min (ASTM D1238,
temperature 190℃, load 2160g). Outside this range, the processability and vulcanization properties of the chlorosulfonated copolymer will be poor, making it impractical. Preferably the melt flow rate is 1 to 30g/10
It's a minute. It is known that such ethylene/α-olefin copolymers can be produced by coordination ion polymerization using a transition metal catalyst. The chlorosulfonated copolymer obtained by chlorinating and chlorosulfonating an ethylene/α-olefin copolymer suitably has a chlorine content of 10 to 50% by weight and a sulfur content of 0.3 to 3.0% by weight. The amount of chlorine
If the amount is less than 10% by weight, the chlorination effect will be small and oil resistance, chemical resistance, etc. will be poor. On the other hand, those containing more than 50% chlorine become hard and cold resistant.
Repulsion elasticity etc. are significantly inferior. Preferably the amount of chlorine
It is 25-43% by weight. The amount of sulfur affects the vulcanization rate, vulcanization density, stability, etc. of the chlorosulfonated copolymer, but if it is less than 0.3% by weight, vulcanization will not be carried out sufficiently. On the other hand, if the sulfur content exceeds 3.0% by weight, the vulcanization is too fast, causing scorch, discoloration, etc., and also having an adverse effect on the storage stability of the unvulcanized product. Preferably, the sulfur content is 0.7 to 1.5% by weight. The Mooney viscosity (ML ₁₊₄ , 100℃) of the chlorosulfonated copolymer is 20-130, preferably 30-100
However, those within this range have an excellent balance of workability and physical properties. M _W /M _N means weight average molecular weight/number average molecular weight, and is a measure representing the molecular weight distribution of the obtained chlorosulfonated copolymer. The M _W /M _N of the chlorosulfonated copolymers according to the invention should be less than 3.5. Preferably, M _W /M _N is less than 2.5, but the improvement in compression set resistance, which is a feature of the present invention,
This is important for improving cold resistance. M _W /M _N is the linear low density polyethylene used.
By M _W /M _N. Therefore, M _W /M _N of the linear low density polyethylene needs to be less than 3.5. Preferably it is less than 2.5. The reaction of chlorinating and chlorosulfonating the ethylene/α-olefin copolymer to obtain a chlorosulfonated copolymer may be the same as the known method for producing chlorosulfonated polyethylene, and does not impair the intent of the present invention. There are no particular restrictions. For example, there is a method (solution method) in which the reaction is carried out by uniformly dissolving the ethylene/α-olefin copolymer in a solvent. A general method for synthesizing chlorosulfonated copolymers by a solution method is shown. After dissolving the ethylene/α-olefin copolymer in a solvent to make a homogeneous solution, using a radical generator as a catalyst, add 1. chlorine and sulfur dioxide gas, 2. chlorine and sulfuryl chloride, or 3. sulfuryl chloride alone to the reaction solution. Perform the reaction from The reaction temperature is 50 to 180°C, and the reaction pressure is suitably normal pressure to 8 Kg/cm ² (gauge pressure). During the reaction, gases such as hydrogen chloride generated are continuously purged out of the system. The solvent used for the reaction is one that is inert to the chlorination reaction, such as carbon tetrachloride, chloroform, dichloroethane, trichloroethane, tetrachloroethane, monochlorobenzene, cyclolbenzene, fluorobenzene, dichlorodifluoromethane, and trichlorofluoromethane. A halogenated hydrocarbon solvent is used. Carbon tetrachloride is preferred. As radical generators that act as catalysts, α, α′-
Azobisisobutyronitrile, Azobiscyclohexanecarbonitrile, 2,2'-azobis(2,
Examples include azo radical initiators such as 4-dimethylvaleronitrile) and organic peroxide radical initiators such as benzoyl peroxide, t-butyl peroxide, and acetyl peroxide. Preferred is α,α'-azobisisobutyronitrile. Instead of using a radical initiator, ultraviolet rays may be irradiated. As mentioned above, the reaction reagents for chlorination and chlorosulfonation are: 1. Chlorine and sulfur dioxide gas (for example, Japanese Patent Publication No. 33-7838
). 2. Chlorine and sulfuryl chloride (e.g., JP-A-56-
76406). 3 Sulfuryl chloride (e.g., Japanese Patent Publication No. 39-12113
). Three types are known, but 2) or 3) is industrially preferred. 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 copolymer to be dissolved may be arbitrary, but it is preferably from 5 to 20% by weight since the viscosity of the reaction becomes high. After the reaction is completed, hydrogen chloride and sulfur dioxide gas remaining in the solution are removed from the system by blowing inert gas such as nitrogen while the solvent is refluxed. Add an epoxy compound as a stabilizer if necessary. 2,2'-bis(4-glycidyloxyphenyl)propane is preferred. The obtained chlorosulfonated copolymer solution 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 in which a polymer solution is fed onto the surface of a heated rotating drum and the polymer is taken out as a film (see US Pat. No. 2,923,979). 3) is a method in which the reaction solution is preconcentrated and then separated by feeding it into an extrusion dryer equipped with a vent (see JP-A-57-47303). In the present invention, separation and drying can be performed by any of the above processes. The chlorosulfonated copolymer referred to in the present invention is used as a vulcanized product by being vulcanized with a vulcanizing agent, vulcanization accelerator, filler, stabilizer, etc., like chlorosulfonated polyethylene. As the vulcanizing agent, vulcanization accelerator, filler, stabilizer, etc., those currently used for chlorosulfonated polyethylene are used. As the vulcanizing agent, metal oxides such as magnesia and litharge, small amounts of sulfur, and organic peroxides are known. As a vulcanization accelerator, dipentamethylenethiuram hexasulfide (TRA), 2-mercaptoimidazoline (#22)
and so on. Examples of fillers include charcoal, clay, silica, and carbon rack. Stabilizers include Laobo NBC and the like. Like chlorosulfonated polyethylene, these are blended and kneaded using rolls or Banbury mixers, and then press vulcanized, steam vulcanized,
UHF vulcanization or electron beam vulcanization is performed. As mentioned above, vulcanizates have excellent compression set resistance,
Furthermore, it has excellent cold resistance. The cold resistance of amorphous elastomers is generally determined by the glass transition temperature, and those with lower glass transition temperatures have better cold resistance. Although the glass transition temperature essentially changes depending on the amount of chlorine and sulfur contained, the chlorosulfonated copolymer according to the present invention has a lower glass transition temperature than that of chlorosulfonated polyethylene with the same amount of chlorine and sulfur. It has a glass transition temperature. Next, the present invention will be described in more detail based on Examples, but these are examples to help understand the present invention, and the present invention is not limited in any way by these Examples. Note that the numerical values used in the present invention were obtained based on the following measurement method. Density: ASTM D1505 Melt flow rate: ASTM D1238 Temperature 190℃, load 2160g Mooney viscosity (ML ₁₊₄ , 100℃): JIS K6300 M _W /M _N : Gel vermi- cation chromatography Vulcanized rubber physical properties : JIS K 6301 Glass transition temperature: Based on dynamic dispersion measurement using Vibron-DDV-B (manufactured by Toyo Ballwin Co., Ltd.). Frequency: 3.5Hz, amplitude: 25μ Example 1 700g of ethylene-butene-1 copolymer having the properties shown in Table 1 and 7200g of carbon tetrachloride as a solvent were placed in 10 autoclaves, and heated at 100°C under pressure.
The ethylene-butene-1 copolymer was dissolved at a temperature of . 0.086 g of pyridine was added as a co-catalyst. 800 g of carbon tetrachloride dissolved in 2.0 g of α, α′-azobisisobutyronitrile as a radical generator
The reaction was carried out by adding 1100 g of sulfuryl chloride while adding . It took 3 hours to add sulfuryl chloride, during which time the reaction temperature was kept at 100°C.
℃ and the reaction pressure was maintained at 2.8 Kg/cm ² (gauge pressure). After lowering the internal temperature of the polymer solution to 75°C, hydrogen chloride and sulfur dioxide gas remaining in the solution were discharged from the system by blowing nitrogen into the refluxing solvent under normal pressure. After adding 10 g of 2,2'bis(4-glycidyloxyphenyl)propane as a stabilizer, the product was separated by feeding into a drum dryer. As a result of analysis, this chlorosulfonated copolymer has a
It was found to contain 1.1% chlorine and 1.1% sulfur by weight. In addition, bell permeation
M _W /M _N by chromatography (GPC)
I asked for Measurement was carried out using HCL- manufactured by Toyo Soda Kogyo Co., Ltd.
802UR, data processing device HLC-CP8MODEL
was determined at 23°C using tetrahydrofuran as the eluent. As a result, M _W is 19200 and M _N is 10300
, and M _W /M _N was 1.9. The Mooney viscosity (ML ₁₊₄ , 100°C) of the chlorosulfonated copolymer was 85. 50 to vulcanize chlorosulfonated copolymers
The following formulations were made on a 10 inch open roll heated to <0>C. (Composition) Chlorosulfonated copolymer 100 parts by weight Magnesium oxide 10 Vulcanization accelerator Sunceller 22C (manufactured by Sanshin Chemical Industry)
0.8 〃 The compound was press cured at 150℃ for 40 minutes,
The physical properties of the vulcanizate were measured. These results are summarized in Table-1. Example 2 An ethylene-butene-1 copolymer having the properties shown in Table 1 was chlorinated and chlorosulfonated in the same manner as in Example 1 to obtain a chlorosulfonated copolymer. This chlorosulfonated copolymer contains 29.5% chlorine and 1.0% sulfur by weight;
Mooney viscosity (ML ₁₊₄ , 100°C) was 31.
When analyzed by gel vermi- cation chromatography in the same manner as in Example 1, _MW was 116,000.
In this case, M _N was 53000, and M _W /M _N was 2.2. Furthermore, the mixture was blended and cured in the same manner as in Example 1, and the physical properties of the vulcanized product were measured. The results are summarized in Table 1. Comparative Example 1 Commercially available medium-low pressure polyethylene (melt flow rate 11.0 g/
10 minutes, density 0.96) 700g and solvent carbon tetrachloride 7200g
g was charged and the polyethylene was dissolved under pressure at a temperature of 110°C. 0.090g of pyridine as cocatalyst
was added to lower the internal temperature of the polymer solution to 100°C. 800 g of carbon tetrachloride dissolved in 2.0 g of α, α′-azobisisobutyronitrile as a radical generator
The reaction was carried out by adding 1,470 g of sulfuryl chloride while adding 1,470 g of sulfuryl chloride. It took three and a half hours to add surifuryl chloride, during which time the reaction temperature was kept constant.
The temperature was maintained at 100° C. and the reaction pressure was maintained at 2.8 Kg/cm ² (gauge pressure). After lowering the internal temperature of the polymer solution to 75°C, hydrogen chloride and sulfur dioxide gas remaining in the solution were discharged from the system by blowing nitrogen into the reflux of the solvent under normal pressure. After adding 12 g of 2,2'-bis(4-glycidyloxyphenyl)propane as a stabilizer, the mixture was fed to a drum dryer in the same manner as in Example 1 to separate the product. Analysis was conducted in the same manner as in Example 1, and after blending and vulcanization, the physical properties of the vulcanizate were measured. These results are summarized in Table-1. Comparative Example 2 Commercially available high-pressure polyethylene (melt flow rate 4g/10
minute, density 0.92) 700g and solvent carbon tetrachloride 7200g
was charged and the polyethylene was dissolved under pressure at a temperature of 110°C. 0,092g of pyridine as cocatalyst
was added to lower the internal temperature of the polymer solution to 100°C. 800 g of carbon tetrachloride dissolved in 2.0 g of α, α′-azobisizoptilonitrile as a radical generator
The reaction was carried out by adding 110 g of sulfuryl chloride while adding 110 g of sulfuryl chloride. It took 3 hours to add sulfuryl chloride, but the reaction temperature was kept constant during this time.
The temperature was maintained at 100° C. and the reaction pressure was maintained at 2.8 Kg/cm ² (gauge pressure). After lowering the internal temperature of the polymer solution to 75°C, hydrogen chloride and sulfur dioxide gas remaining in the solution were discharged from the system by blowing nitrogen into the reflux of the solvent under normal pressure. After adding 10 g of 2,2'-bis(4-glycidyloxyphenyl)propane as a stabilizer, the mixture was fed to a drum dryer in the same manner as in Example 1 to separate the product. Analysis was conducted in the same manner as in Example 1, and after blending and vulcanization, the physical properties of the vulcanizate were measured. These results are summarized in Table-1.

[Table] From the above Examples and Comparative Examples, it is clear that the present invention provides a chlorosulfonated copolymer that has better compression set resistance and also has better cold resistance.

Claims (1)

[Claims] 1 α-olefin having 3 to 8 carbon atoms
An ethylene/α-olefin copolymer containing 4.0 to 20.0 mol% with a density of 0.88 g/cm ³ or more and 0.90 g/cm ³
The melt flow rate is 0.1 to 300 g/10 minutes (temperature 190°C, load 2160 g), and M _W /
M _N is less than 3.5, characterized by chlorination and chlorosulfonation.
~50% by weight, sulfur content is 0.3-3.0% by weight, Mooney viscosity (ML ₁₊₄ , 100℃) is 20-130, M _W /
A method for producing a chlorosulfonated copolymer having M _N of less than 3.5. 2. The method for producing a chlorosulfonated copolymer according to claim 1), wherein the α-olefin is butene-1.