JPS63196636A - Chlorosulfonated polymer composition - Google Patents

Abstract

PURPOSE:To suppress foaming during vulcanization, to reduce the amount of an acid acceptor required and to improve the oil resistance etc. of a vulcanizate, by using a polymer having a limited sulfur content and a limited chlorine content in vulcanizing a chlorosulfonated polymer with an organic peroxide. CONSTITUTION:A polymer such as polyethylene or an ethylene/butene-1 copolymer is chlorinated and chlorosulfonated with both of chlorine and sulfur dioxide gas or both of chlorine and sulfuryl chloride or the like to produce a chlorosulfonated polymer of a sulfur content of 0.25-0.7wt.% and a chlorine content of 20-50wt.%. 100pts.wt. this chlorosulfonated polymer is mixed with 0.1-20pts.wt. organic peroxide (e.g., Percumyl, trademark), 0.1-15pts.wt. crosslinking aid (e.g., triallyl isocyanurate) and 1-30pts.wt. acid acceptor (e.g., calcium hydroxide). A vulcanizate of the obtained composition is excellent in compression set etc. and can be suitably used for hoses, gaskets, etc.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the vulcanization of chlorosulfonated polymers, such as chlorosulfonated polyethylene and chlorosulfonated ethylene/butene-1 copolymer, with an organic peroxide. The present invention relates to a composition for carrying out. More specifically, when vulcanizing a chlorosulfonated polymer with peroxide, a vulcanizate is obtained that does not require the addition of a large amount of acid acceptor and has excellent compression set and oil resistance at high temperatures. The present invention relates to a chlorosulfonated polymer composition.

[Conventional technology]

In recent years, there has been a succession of technological innovations in the automobile industry, and rubber materials for automobiles such as chlorosulfonated polymers are required to exhibit even higher performance so that they can adapt to even harsher conditions.

The major challenges required of chlorosulfonated polymers are improvement in compression set at high temperatures and oil resistance.

On the other hand, peroxide vulcanization using an organic peroxide is known to be effective in improving the compression set of chlorosulfonated polymers at high temperatures.

However, when a chlorosulfonated polymer is vulcanized with an organic peroxide, it is necessary to incorporate a large amount of an acid acceptor such as magnesia, calcium hydroxide, or litharge. (about 20
Parts by weight (phr) or more. ) If the amount of acid acceptor is small,
The vulcanized density is low, and therefore not only the desired compression set and oil resistance cannot be obtained, but also the vulcanizate may foam during vulcanization and the surface texture may become rough.

However, adding a large amount of acid acceptor in order to prevent the above problems causes disadvantages such as increased hardness and deterioration of water resistance.

For this reason, various formulation restrictions pose a major obstacle to practical application.

The present inventors recognized that this problem was caused by the molecular structure of the chlorosulfonated polymer, and conducted extensive studies.

[Problem that the invention seeks to solve]

That is, the object of the present invention is to provide a method which does not require the addition of a large amount of acid acceptor when vulcanizing a chlorosulfonated polymer with a peroxide, and which has excellent compression set and oil resistance at high temperatures. An object of the present invention is to provide a chlorosulfonated polymer composition which provides a vulcanizate having the following properties.

[Means to solve the problem]

The sulfur content of a chlorosulfonated polymer is a measure of the amount of chlorosulfone groups (-so, at) contained in the molecule.

On the other hand, the chlorosulfone groups contained in conventional chlorosulfonated polyethylene act as crosslinking points during vulcanization, and the ideal sulfur content is approximately 1.0%, considering vulcanization density, vulcanization speed, and vulcanization physical properties. It has been said that it is a target.

Currently, commercial products of chlorosulfonated polymers include TO8O-CBM manufactured by Toyo Soda Kogyo ■, Hypalon manufactured by DuPont in the United States, and Denka-C8M manufactured by Denki Kagaku Kogyo ■ as chlorosulfonated polyethylene. Based on the ideal value of sulfur content, the sulfur content of these commercially available products is approximately 1.0% except for some paint grades of 1.1% and t4%.

The present inventors differ from this established theory, and found that when chlorosulfonated polymers are vulcanized with organic peroxides, sulfur t[1
It has been found that an ideal vulcanizate can be created with L25 to α70 wt%.

That is, the present invention has a) sulfur content α25 to α70 wt, chlorine t20 to 5
1) organic peroxide [11 to 20 parts by weight c) crosslinking aid (L1 to 15 parts by weight 2) acid acceptor 1 to 30 parts by weight per 100 parts by weight of chlorosulfone specific polymer which is 0 wt% In the composition.

However, the symbol ~ is written as A-B and represents that it is greater than or equal to A and less than or equal to B.

[Effect]

In this specification, sulfur t[L25~(L70 wt%
.

A chlorosulfonated polymer having 1120 to 150% sulfur chlorine means that the polymer contains a predetermined amount of sulfur (i.e.
t amount) and chlorine and sulfur dioxide gas to include the amount of chlorine.

It is obtained by chlorination and chlorosulfonation of chlorine and sulfuryl chloride or sulfuryl chloride alone.

The raw material polymer is polyethylene or ethylene butene.
Examples include ethylene copolymers such as 1 copolymer, ethylene/propylene copolymer, and ethylene/vinyl acetate copolymer.

If the polymer is polyethylene, the resulting product will be chlorosulfonated polyethylene, and if the polymer is an ethylene/butene-1 copolymer, the resulting product will be chlorosulfonated ethylene/butene-1 copolymer.
It becomes a butene-1 copolymer.

However, when considering the desired compression set properties, oil resistance, or mechanical properties, it is preferable that the polymer has a linear structure.

That is, using linear polyethylene and linear ethylene/butene-1 copolymer as raw materials, the sulfur content is α25 to α70wt,
Most desirable are chlorosulfonated polyethylene and chlorosulfonated ethylene/butene-1 copolymer obtained by chlorination and chlorosulfonation to a chlorine content of 20 to 50 wt.

In the present invention, it is extremely important that the sulfur content of the chlorosulfonated polymer is α25 to [1L70 wt%.

If the sulfur content is less than (L 25 wt%), foaming during vulcanization is small, but the rheometer torque during vulcanization is low and the vulcanization density is low, so that the desired compression set and oil resistance cannot be obtained.

If the sulfur content exceeds α70 wtl, it tends to foam during vulcanization, and furthermore, the rheometer torque for vulcanization is low, and the vulcanization density is low, so that the desired compression set and oil resistance cannot be obtained.

Only chlorosulfonated polymers with a sulfur content of α25 to 1170 wtl have the desired compression set and oil resistance due to less foaming during vulcanization, increased rheometer torque during vulcanization, and increased vulcanization density. It will be done.

The reason for this is not clear at present, but it is clearly a different phenomenon from the conventional ideal sulfur content of chlorosulfonated polyethylene of about 1.0-.

More preferably, the sulfur content is α40 to α65 wtl.

In the present invention, the amount of chlorine contained in the chlorosulfonated polymer is not particularly limited, and any conventionally used amount may be used.

It weighs between 20 and 50wt.

There are no particular limitations on the organic peroxide, and commercially available organic peroxides can be used. For example, percmil D, peroximon F,
Commercial products such as Perhexa 3M, Perbutyl I, I) or Perhexa 25B are used.

These organic peroxides are chlorosulfonated polymers 100
α1 to 20 parts by weight are used. Preferably it is 1 to 8 parts by weight.

The term "crosslinking aid" as used herein refers to a co-agent such as a polyfunctional ester having the function of increasing the crosslinking efficiency of peroxides. For example, triallyl cyanurate (TA
C),) Reallylisocyanurate (TAC), ethylene glycol dimethacrylate, trimethylpropane trimethacrylate L/-), 1:, Ruiha N, N'-m-phenylene bismaleimide are known. Preferably T
AC or '1' AIC.

These crosslinking aids are used in an amount of α1 to 15 parts by weight per 100 parts by weight of the chlorosulfonated polymer. Preferably 1~
It is 8 parts by weight.

The acid acceptor referred to in this specification has the effect of capturing by-product acid generated in the peroxide vulcanization step and promoting crosslinking.

Metal oxides, metal hydroxides, metal compounds, etc., such as magnesia, calcium hydroxide, calcium oxide, and tribasic lead maleate, are used.

As mentioned above, in the present invention, it is possible to increase the vulcanization density in peroxide vulcanization even if the amount of acid acceptor added is reduced to about 10 to 20 parts by weight K.

This improves water resistance, reduces viscosity and hardness, improves stability during storage, and prevents adhesion during processing.

That is, the acid acceptor is used in an amount of 1 to 50 parts by weight, more preferably 10 to 20 parts by weight, per 100 parts by weight of the chlorosulfonated polymer.

In addition to the essential components a) 1), c), and 2), the composition of the present invention includes carbon black, clay, silica, calcium carbonate as a filler, oil, esters, and chlorine as a plasticizer. Other conventional rubber compounding agents such as paraffin, low molecular weight polyethylene as a processing aid, and anti-aging agents can be added as required.

Vulcanization is usually carried out at 140 to 250° C. for 1 to 100 minutes using known methods such as steam vulcanization, press vulcanization, and UHF vulcanization.

〔Effect of the invention〕

As is clear from the above description, the present invention optimizes the amount of sulfur for peroxide vulcanization of chlorosulfonated polymers, thereby suppressing foaming during vulcanization and eliminating the need for large amounts of acid acceptor. To provide a chlorosulfonated polymer vulcanizate which also has excellent compression set and oil resistance.

The vulcanizate according to the present invention is used for automobile hoses, gaskets, gaskets, belts, electric wires and other industrial products.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples.
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.

Chlorine and sulfur content: Combustion flask method rheometer: Monsanto rheometer (160°C) Vulcanized rubber physical properties: JK SK 6501 Prior to the Examples and Comparative Examples, chlorosulfonated ethylene-butene-1 copolymer with different sulfur content was prepared. The combined and chlorosulfonated polyethylene was synthesized by the method shown below.

Linear ethylene butene-1 polymerized with transition metal catalyst
Copolymer (melt index 39/10 minutes, density α8
99/cc) 53609 as a solvent carbon tetrachloride 2
It was dissolved in 8 to 9. After adding pyridine 117f, which is a cocatalyst for the chlorosulfonation reaction, 5670 g of sulfuryl chloride was added while adding 9 g of azobisisobutyronitrile. The reaction was carried out under pressure at 100°C. After the addition was completed, nitrogen was blown into the reaction solution to remove any acid remaining in the solution.

After adding 48 g of U'-bis(4-glycidyloxyphenyl)propane as a stabilizer, the mixture was fed to a drum dryer to obtain a product.

As a result of analysis, this chlorosulfonated ethylene butene
1 copolymer contains 5α2wt% chlorine and lllL52wt sulfur and has a Mooney viscosity (ML, +4.100°C).
was 66. This is shown in Table 1 as product number ■. Furthermore, the chlorosulfonated ethylene/butene-1 copolymers shown in Table 1 were synthesized by changing the amount of the cocatalyst pyridine added.

Next, the raw material polymer was converted into linear high-density polyethylene (melt index 6 g/10 min, density α969/cc)
Five types of chlorosulfonated polyethylenes with different sulfur contents were obtained by performing the reaction with different amounts of sulfur, which are shown in Table 2.

On the other hand, as representative commercially available chlorosulfonated polyethylenes, those shown in Table 3 were analyzed and the results are described.

Table-2 [Examples 1 to 3 and Comparative Example 1.2] Chlorosulfonated ethylene/butene-1 shown in Table-1
Using the copolymer, an unvulcanized compound having the composition shown in Table 4 was prepared using a roll.

Figure shows the Monsanto rheometer curve for this compound.
Shown in 1.

Compared to the Examples, the reached torque of the rheometer in the Comparative Examples was lower, and vulcanization was not effective.

Next, this compound was press-vulcanized at 160°C for 40 minutes, and the physical properties of this vulcanized product are shown in Table 5.

In the comparative example, compression set and oil resistance volumetric swelling ratio are large, whereas in the example, each is small.

Furthermore, Table 5 shows the surface condition of the vulcanized product when the unvulcanized compound was placed in a vulcanizer at 160° C. for 40 minutes and subjected to steam vulcanization.

In Comparative Example 2, blisters due to foaming were observed on the surface, whereas the surface conditions of the other products were smooth and good.

Table-4 Chlorosulfonated ethylene butene-1 copolymer 10
0 parts by weight Magnesia 15
l Carbon black 50 I Dioctylsebacic acid 20 1 AC polyethylene 31 Suntite
21 Barkumi kD-407,5# TA engineering C4I umbrella For comparative example-1, chlorinated ethylene butene-1
Copolymer [Example 4 and Comparative Examples 5 to 7] Using the chlorocellphonated polyethylene shown in Tables 2 and 5, unvulcanized compounds having the formulations shown in Table 6 were prepared using a roll.

Table-6 Nechlorosulfonated polyethylene 100 parts by weight Magnesia 15 #
Dicumyl peroxide 5ITAI
C41 *Comparative Example-3 is chlorinated polyethylene.The figure shows the Monsand rheometer curve of this compound.
Shown in 2.

Compared to Example 4, in Comparative Examples 3 to 7, the reached torque of the rheometer was lower (and vulcanization was not effectively applied).

Next, this compound was press-vulcanized at 160°C for 20 minutes, and the physical properties of this vulcanized product are shown in Table 7.

Compared to the comparative example, Example 4 shows good results with a small compression set and a small volumetric swelling rate of oil resistance.

Referring to these Examples and Comparative Examples, it is clear that the present invention prevents foaming during peroxide vulcanization of chlorosulfoy specific polymers, does not require the addition of large amounts of acid acceptors, and has excellent compression set properties and oil resistance. It is clear that an excellent vulcanizate is obtained.

[Brief explanation of the drawing]

Figure-1 in 1! ,/Rorosulfonated ethylene butene-1
Figure 2 shows the vulcanization curve of the copolymer measured with a Monsanto rheometer, and Figure 2 shows the vulcanization curve of chlorosulfonated polyethylene with a Monsanto rheometer.

Claims (1)

[Claims] a) Sulfur content: 0.25 to 0.70 wt%, chlorine content: 20 to 20%
b) 0.1 to 20 parts by weight of organic peroxide, c) 0.1 to 15 parts by weight of crosslinking aid, and d) 1 to 30 parts by weight of acid acceptor, per 100 parts by weight of the chlorosulfonated polymer, which is 50 wt%. A chlorosulfonated polymer composition comprising: