JPH0618815B2 - Method for producing chlorosulfonated polyethylene - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for producing chlorosulfonated polyethylene.

More specifically, the present invention relates to a method for producing chlorosulfonated polyethylene using a high molecular weight polyethylene having a melt index of less than 0.5 g / 10 minutes as a raw material.

Chlorosulfonated polyethylene is a special elastomer with excellent ozone resistance, weather resistance, heat resistance, oil resistance, chemical resistance and bright color.By utilizing these characteristics, fuel hose, lubricating oil hose, It is widely used for automobile parts such as brake system hoses, radiator hoses, and cord coatings for wiring.

Conventionally, when producing chlorosulfonated polyethylene, the raw material polyethylene has a melt index of 0.5 g.
/ 10 minutes or more, preferably 1.0 g / 10 minutes or more.

This is because when chlorosulfonated polyethylene is produced from polyethylene having a melt index of less than 0.5 g / 10 minutes as a raw material, its Mooney viscosity becomes extremely high due to its large molecular weight, resulting in poor processability and not suitable for practical use. .

On the other hand, in recent years, there has been a demand for the development of a new elastomer that can be filled with a large amount of lightweight fillers such as oils and softeners for the purpose of weight reduction of automobiles. One of the means for developing this highly-fillable elastomer is to increase the molecular weight of the elastomer.

However, as described above, in chlorosulfonated polyethylene, this means an extreme increase in the Mooney viscosity, and a solution for this has been demanded.

The present invention ameliorates such drawbacks and has a melt index of 0.
The purpose of the present invention is to produce a highly-filled chlorosulfonated polyethylene with improved processability by using a high molecular weight polyethylene of less than 5 g / 10 minutes as a raw material.

That is, the present invention has a melt index of less than 0.5 g / 10 minutes and a melt flow ratio (MI21.6 / MI2.16).
Is a method for producing chlorosulfonated polyethylene, which comprises chlorinating and chlorosulfonating polyethylene having a ratio of 80 or more.

The melt index referred to in this specification is JIS K721.
Although described in detail in No. 0-1976, it was measured at 190 ° C. under a load of 2160 g. (Abbreviated as MI2.16.) This is shown in Table-1 in JIS K7210-1976.
Corresponding to test condition 4 of.

Melt flow ratio (MI21.6 / MI2.16) is the melt index (MI2.16) and melt flow index measured at 190 ° C and a load of 21.6 kg (this is JIS K721).
0-1976 corresponds to test condition 7 in Table-1. Abbreviated as MI21.6. ) Is the ratio.

The chlorosulfonated polyethylene produced according to the present invention has a Mooney viscosity (ML _{1 + 4} , 100 ° C.) of 150 or less even though it is made of high molecular weight polyethylene having a melt index of less than 0.5 g / 10 minutes. It is possible to The Mooney viscosity (ML _{1 + 4} , 100 ° C) is a typical index showing the processability as an elastomer,
It is practically preferable that the ratio is 100 or less.

For this reason, the workability during roll work during compounding or during Banbury kneading is improved.

The chlorosulfonated polyethylene produced according to the present invention is a chlorosulfonated polyethylene suitable for weight reduction of automobiles because it can contain a large amount of oil and a softening agent.

Further, the chlorosulfonated polyethylene produced by the present invention has a long 1) Mooney scorch time.

2) The hardness of the vulcanizate is low and the tensile stress at low elongation is low.

It has the feature.

A long Mooney scorch time means that the stability of the unvulcanized compound during storage is excellent, or that vulcanization proceeds at an appropriate vulcanization rate, which prevents problems such as burning. It is preferable.

In addition, the hardness of the vulcanizate is low and the tensile stress at low elongation is low, so it exhibits softer and rubber-like properties.

On the other hand, the ozone resistance, weather resistance, heat resistance, oil resistance, chemical resistance and bright color, which are the characteristics of chlorosulfonated polyethylene, are retained as they are.

Examples of polyethylene used in the present invention include high-density polyethylene, linear low-density polyethylene, high-pressure polyethylene or a copolymer of ethylene and less than 10 mol% of α-olefin.

High density polyethylene and linear low density polyethylene are preferred.

Polyethylene has a melt index of less than 0.5 g / 10 minutes and a melt flow ratio (MI21.6 / MI2.1
6) must be 80 or more. The effect is particularly remarkable when the melt index is less than 0.2 g / 10 minutes and the melt flow ratio (MI21.6 / MI2.16) is 100 or more.

Chlorosulfonated polyethylene is produced by chlorinating and chlorosulfonating this polyethylene, and the amount of chlorine contained in the chlorosulfonated polyethylene is 10 to 60% by weight, preferably 20 to 45% by weight.

Further, the chlorine content of 33 to 38% by weight is oil resistance,
Good balance of heat resistance and cold resistance.

The amount of sulfur is the vulcanization rate of chlorosulfonated polyethylene,
Although it affects vulcanization density, stability, etc.
If it is less than 3% by weight, vulcanization will not be carried out sufficiently. On the other hand, when the amount of sulfur exceeds 3.0% by weight, the vulcanization is too fast, which causes scorch, burns and the like, and adversely affects the storage stability of the unvulcanized product. Preferably sulfur amount 0.7-
It is 1.5% by weight.

However, the present invention is not limited to these amounts of chlorine and sulfur.

Polyethylene with a melt index of less than 0.5 g / 10 minutes and a melt flow ratio (MI21.6 / MI2.16) of 80 or more is chlorinated and chlorosulfonated to give chlorosulfonated polyethylene. The method may be the same as the known method for producing sulfonated polyethylene, and is not particularly limited as long as the intention of the present invention is not impaired.

For example, there is a method (solution method) in which polyethylene is uniformly dissolved in a solvent to carry out the reaction.

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

Dissolve polyethylene in a solvent to make a homogeneous solution, and then use 1) chlorine and sulfurous acid gas or 2) chlorine and sulfuryl chloride or 3) sulfuryl chloride alone with the radical generator as a catalyst to start the reaction. To do.

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 reaction of carbon tetrachloride, chloroform, dichloroethane, trichloroethane, tetrachloroethane, monochlorobenzene, dichlorobenzene, fluorobenzene, dichlorodifluoromethane, trichlorofluoromethane, etc. Halogenated hydrocarbon solvents are used. Carbon tetrachloride is preferred.

Examples of the radical generator that serves as a catalyst include azo radical initiators such as α, α′-azobisisobutyronitrile, azobiscyclohexanecarbonitrile, and 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, α'-
Azobisisobutyronitrile.

Ultraviolet rays may be irradiated instead of using the radical initiator.

As mentioned 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, amine compounds such as viridine, quinoline, dimethylaniline, nicotine and piperidine are used as co-catalysts in order to add sulfur.

The amount of polyethylene to be dissolved may be arbitrary, but it is preferably 3 to 15% by weight in terms of 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 refluxing the solvent and blowing an inert gas such as nitrogen. If necessary, an epoxy compound as a stabilizer is added.

2,2'-bis (4-glycidyloxyphenyl) propane is preferred.

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

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 to the surface of a heated rotating drum to take out the polymer as a film (see US Pat. No. 2,923,979).

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

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

The chlorosulfonated polyethylene referred to in the present invention is an unvulcanized product like the conventional chlorosulfonated polyethylene,
Alternatively, it is vulcanized with a vulcanizing agent, a vulcanization accelerator, a filler, a stabilizer and the like to be used as a vulcanized product. As the vulcanizing agent, vulcanization accelerator, filler, stabilizer and the like, those currently used for chlorosulfonated polyethylene are used.

Known vulcanizing agents are metal oxides such as magnesia and litharge, and small amounts of sulfur and organic peroxides. As the vulcanization accelerator, dipentamethylene thiuram
Hexasulfide (TRA), 2-mercapto imidazoline (# 22) and the like. Examples of the filler 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 blended and kneaded by a roll or a Banbury mixer, and then subjected to press vulcanization, steam vulcanization, UHF vulcanization or electron beam vulcanization.

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 obtained according to the following measuring methods.

Melt index and melt flow ratio (MI
21.6 / MI2.16): As described above: Density: JISK7112 Chlorine and sulfur content analysis: Combustion flask method Mooney viscosity (ML _{1 + 4} (100 ° C)) of raw rubber and compound: JISK6300 Mooney scorch: JISK6300 Vulcanization Rubber physical properties: JISK6301 Example-1 A glass lined autoclave of 30 with a melt index of 0.051 g / 10 minutes and a melt flow ratio (M
I21.6 / MI2.16) 261 1.12 kg of high-density polyethylene with a density of 0.953 g / cc and 28.0 kg of carbon tetrachloride as a solvent were charged.

The temperature was raised to 110 ° C under pressure to dissolve polyethylene.

After adding 0.28 g of pyridine as a co-catalyst and lowering the temperature to 100 ° C, a carbon tetrachloride solution in which 3.0 g of α, α'-azobisisobutyronitrile as a radical generator is dissolved
The reaction was carried out by adding 2433 g of sulfuryl chloride while adding 2.88 kg.

It took 75 minutes to add sulfuryl chloride, but during this time, the reaction temperature was kept at 100 ° C. and the reaction pressure was kept at 3.3 kg / cm ² (gauge pressure).

After the reaction was completed, the inner temperature of the polymer solution was lowered to 72 ° C., and nitrogen was blown into the polymer solution under normal pressure, so that hydrogen chloride and sulfurous acid gas remaining in the solution were discharged to the outside of the system.

After adding 21 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 analysis, this chlorosulfonated polyethylene was 35.4
It was found to contain weight percent chlorine and 1.0 weight percent sulfur.

The Mooney viscosity was 94.

The following formulation was carried out using a 10 inch open roll.

(Combination) 100 parts by weight of chlorosulfonated polyethylene 10 parts by weight of magnesium oxide (Kyowamag 150 from Kyowa Chemical Industry Co., Ltd.) 3 parts by weight of pentaerythritol 2 parts by weight of TRA Formulation of the compound is Mooney viscosity and Mooney Scorch 150 Press vulcanization was performed at 20 ° C. for 20 minutes and the physical properties of the vulcanized product were measured.

The results are summarized in Table-1.

Example-2 Melt index of polyethylene as a raw material used in the reaction
0.046 g / 10 minutes, melt flow ratio (MI21.6 / MI2.
16) 172, high density polyethylene 1.1 with a density of 0.952 g / cc
The reaction was carried out under the same conditions as in Example 1 except that the amount was changed to 2 kg to obtain chlorosulfonated polyethylene.

As a result of analysis, this chlorosulfonated polyethylene is 35.5.
It was found to contain weight percent chlorine and 1.0 weight percent sulfur.

The Mooney viscosity was 98.

Compounding and vulcanization were performed under the same conditions as in Example-1, and the physical properties thereof were measured. The results are summarized in Table-1.

Comparative Example-1 The autoclave used in Example-1 had a melt index of 1.01 g / 10 minutes and a melt flow ratio (MI21.6 / MI).
2.16) 36, high density polyethylene 1.7 with a density of 0.953 g / cc
0 kg and 28.0 kg of carbon tetrachloride as a solvent were charged.

The temperature was raised to 110 ° C under pressure to dissolve polyethylene.

After adding 0.24 g of pyridine as a co-catalyst and lowering the temperature to 100 ° C, a carbon tetrachloride solution in which 3.0 g of α, α'-azobisisobutyronitrile as a radical generator is dissolved
The reaction was carried out by adding 3560 g of sulfuryl chloride while adding 2.88 kg.

It took 110 minutes to add sulfuryl chloride, and the reaction temperature was kept at 100 ° C. and the reaction pressure was kept at 3.3 kg / cm ² (gauge pressure) during this period.

After the reaction was completed, the internal temperature of the polymer was lowered to 72 ° C., and nitrogen was blown into the polymer under atmospheric pressure, so that hydrogen chloride and sulfurous acid gas remaining in the solution were discharged to the outside of the system.

After adding 31 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 analysis, this chlorosulfonated polyethylene was 35.6.
It was found to contain weight percent chlorine and 1.0 weight percent sulfur.

The Mooney viscosity was 105.

Compounding and vulcanization were performed under the same conditions as in Example-1, and the physical properties thereof were measured. The results are summarized in Table-1.

Example-3 Polyethylene as a raw material used in the reaction was melted with a melt index of 0.47 g / 10 minutes and a melt flow ratio (MI2).
1.6 / MI216) 84 and 1.12 kg of high-density polyethylene having a density of 0.952 g / cc, and the reaction was carried out under the same conditions as in Example-1 to obtain a chlorosulfonated polyethylene.

As a result of analysis, this chlorosulfonated polyethylene is 3
It was found to contain 5.6% by weight chlorine and 1.0% by weight sulfur.

The Mooney viscosity was 142.

Compounding and vulcanization were performed under the same conditions as in Example-1, and the physical properties thereof were measured. The results are summarized in Table-1.

Comparative Example-2 Polyethylene as a raw material used in the reaction had a melt index of 0.48 g / 10 minutes and a melt flow ratio (MI2
1.6 / MI216) 76, and 1.70 kg of high-density polyethylene having a density of 0.953 g / cc. The reaction was carried out under the same conditions as in Comparative Example-1 to obtain chlorosulfonated polyethylene.

As a result of analysis, this chlorosulfonated polyethylene is 3
It was found to contain 5.3% by weight chlorine and 1.1% by weight sulfur.

The Mooney viscosity was 158.

Compounding and vulcanization were performed under the same conditions as in Example-1, and the physical properties thereof were measured. The results are summarized in Table-1.

It is shown that the chlorosulfonated polyethylenes of Examples 1, 2 and 3 have a low Mooney viscosity of the raw material rubber and have improved processability even though the melt index is small as less than 0.5 g / 10 min. .

Furthermore, since the difference from the Mooney viscosity of the blend is small, it shows the characteristics of the highly-filled chlorosulfonated polyethylene.

From the above examples, it is clear that the chlorosulfonated polyethylene produced according to the present invention has excellent processability and mechanical properties.

Claims (4)

[Claims] 1. A melt index of less than 0.5 g / 10 minutes and a melt flow ratio (MI21.6 / MI2.16).
A process for producing chlorosulfonated polyethylene, which comprises chlorinating and chlorosulfoning polyethylene having a ratio of 80 or more. 2. The method for producing chlorosulfonated polyethylene according to claim 1, wherein the polyethylene is high-density polyethylene. 3. The method for producing chlorosulfonated polyethylene according to claim 1, wherein the polyethylene is a linear low density polyethylene. 4. The melt index of polyethylene is 0.2.
g / 10 min and melt flow ratio (MI
21.6 / MI2.16) is 100 or more claims 1)
Item 2. A method for producing chlorosulfonated polyethylene according to Item 2) or 3).