JPH0649809B2 - Vulcanizable fluororubber composition - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention makes it possible to improve low temperature properties and reduce specific gravity without impairing the heat resistance and oil resistance of vulcanizable fluororubber compositions, and more particularly fluororubbers. It relates to a vulcanizable fluororubber composition.

Technical background Fluorine rubber is used for gaskets, rubber cloths, tire valves, steam seals, O-rings, etc. in the fields of space equipment, aviation equipment, automobiles, chemical industry, electric equipment, etc. due to its excellent heat resistance and oil resistance. Has been done. However, fluororubber has the drawback that it becomes brittle at low temperatures, and its use is limited because it is at higher temperatures.

SUMMARY OF THE INVENTION AND OBJECT The present inventors have made a blend of an ethylene / α-olefin copolymer rubber having a hot toluene insoluble amount of 30% by weight or more with a fluororubber in a fixed blending amount, and The average particle size of ethylene / α-olefin copolymer rubber is 0.2
It has been found that in a fluororubber composition having a range of μm to 40 μm, the low temperature properties of the fluororubber are remarkably improved without impairing the excellent properties such as heat resistance and oil resistance of the fluororubber. It was

That is, an object of the present invention is to provide a fluororubber composition having significantly improved low temperature properties while preserving other advantages.

According to the present invention, the fluororubber (A) has a fine-grain ethylene / α-olefin copolymer weight of 30% by weight or more insoluble in hot toluene and an average particle size of 0.2 μm to 40 μm. A vulcanizable fluororubber composition characterized by comprising the united rubber (B) in a ratio of A / B = 95/5 to 20/80 on a weight basis.

Preferred Embodiments of the Invention Fluororubber (A) As the fluororubber used in the present invention, various known fluororubbers such as vinylidene fluoride series, fluorine-containing silicon series, fluorine-containing vinyl ether series and the like can be used, From the standpoint of workability and workability, the fluorine content is 35 to 75% by weight, and the Mooney viscosity ML _{1 + 4} (121 ° C) is 20.
To 180 and specific gravity of 1.25 to 2.10 can be preferably used.

These fluororubbers have remarkably excellent properties in heat resistance, oil resistance, chemical resistance, etc., but they are not satisfactory in mechanical properties at low temperatures.

Therefore, in the present invention, ethylene / α-
This problem is solved by using an olefin copolymer rubber in combination.

Ethylene / α-olefin copolymer rubber (B) In the present invention, the ethylene / α-olefin copolymer rubber (B) used in combination with the fluororubber (A) includes ethylene and α-
Olefins such as propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-
It is a copolymer with one or more α-olefins having 3 to 10 carbon atoms such as octene and 1-decene.

The ethylene content is usually 50 to 95 mol%, preferably 60 to 92 mol%, and the intrinsic viscosity [η] measured in 135 ° C. decalin is 0.5 to 4.5 dl / g, preferably 0.8 to 3.0 dl / g. Is in the range.

Furthermore, this ethylene / α-olefin copolymer rubber has 1
One or more polyene components may be contained.

Specific examples of the polyene component include 1,4-hexadiene, 1,6-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, and 7-methyl-1,6-octadiene. Such chain non-conjugated dienes, cyclohexadiene, dicyclopentadiene, methyltetrahydroindene, 5-vinylnorbornene, 5
-Ethylidene-2-norbornene, 5-methylene-2-
Cyclic non-conjugated dienes such as norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene, 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-
Typical examples are trienes such as isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene, 1,3,7-octatriene and 1,4,9-decatriene. Suitable polyenes are cyclic non-conjugated dienes and 1,4-hexadiene, especially dicyclopentadiene or 5-ethylidene-2-norbornene.

These polyene components are copolymerized in the resulting copolymer so that the iodine value is at most 30, preferably 20 or less.

The ethylene / α-olefin copolymer rubber as described above is
For example, it can be produced by a method known per se, as described in Synthetic Rubber Processing Technology "Ethylene Propylene Rubber" (Taisei Co., Ltd.).

That is, in a medium, using a Ziegler catalyst such as a soluble vanadium compound and an organoaluminum compound, ethylene,
It is produced by supplying an α-olefin having 3 to 10 carbon atoms, polyene as the case requires, and hydrogen gas as a molecular weight modifier. Examples of the medium include aliphatic hydrocarbons such as pentane, hexane, heptane, octane and kerosene, alicyclic hydrocarbons such as cyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene, chlorobenzene and tetrachloride. Halogenated hydrocarbons such as carbon, tetrachloroethylene, trichloroethylene, ethyl chloride, methylene chloride and dichloroethane can be used alone or in combination. Examples of the soluble vanadium compound include vanadium tetrachloride, vanadyl trichloride, vanadium triacetylacetonate,
Vanadyl acetylacetonate, vanadyl trialkoxide VO (OR) ₃ (wherein R represents an aliphatic hydrocarbon group), halogenated vanadyl alkoxide VO (OR) _n X _3-n
(Wherein R represents an aliphatic hydrocarbon group, X represents a halogen atom, and 0 <n <3) and the like can be used alone or in combination. On the other hand, as the organoaluminum compound, a compound represented by the general formula R _m AlX _3-m (wherein R represents an aliphatic hydrocarbon group, X represents a halogen, and 1 ≦ m ≦ 3), for example, triethylaluminum, Diethyl aluminum chloride, ethyl aluminum sesquichloride, ethyl aluminum dichloride and the like can be used alone or in combination.

Further, the above ethylene / α-olefin copolymer rubber is
It may be modified with halogen. In this case, the halogen content is 40% by weight or less, preferably 30% by weight or less. When the halogen content exceeds the above range, it becomes difficult to achieve the initial purpose of improving the low temperature characteristics.

This halogenated ethylene / α-olefin copolymer rubber can be produced by halogenating the ethylene / α-olefin copolymer rubber, for example, as shown in Reference Example 4 described later.

The ethylene / α-olefin copolymer rubber (B) used in the present invention has a fine particle size such that the average particle size is 0.2 to 40 μm, and the hot toluene insoluble content is 30% by weight or more, particularly It is important that the resin is crosslinked so as to be 40% by weight or more.

When the average particle size is larger than the above range, the particle size of the copolymer rubber particles in the rubber composition becomes large, and the properties such as oil resistance and heat resistance of the composition are impaired.

If the hot toluene insoluble content is lower than the above range, it becomes difficult to atomize the ethylene / α-olefin copolymer rubber. For example, rubber particles aggregate and coarsen during the process of drying or kneading, and eventually the average particle size of the copolymer rubber particles in the rubber composition is made larger than 50 μm. As a result, oil resistance and heat resistance are the same as above. And other characteristics are impaired.

This hot toluene insoluble content is an index showing the degree of crosslinking of the rubber component and is quantified as follows.

That is, after cross-linking latex composition described below is salted out, the dried ethylene / α-olefin copolymer rubber is precisely weighed and placed in a basket of a 200-mesh wire net, and left in a large excess of boiling toluene. After 6 hours, the basket is taken out and the insoluble matter is precisely weighed to obtain hot toluene insoluble matter.

In the present invention, by blending the above-mentioned ethylene / α-olefin copolymer rubber having the above-mentioned physical properties with the fluororubber (A), the heat resistance of the fluororubber as shown in Examples described later. Thus, the low temperature characteristics can be remarkably improved without impairing the characteristics such as oil resistance.

The average particle size of the ethylene / α-olefin copolymer rubber and the amount of hot toluene-insoluble matter are adjusted by making the copolymer rubber into a latex, crosslinking in the latex state, and then drying the latex. .

(i) Latexing of ethylene / α-olefin copolymer rubberThe production of ethylene / α-olefin copolymer rubber latex is performed by using ethylene / α-olefin copolymer rubber in toluene,
It can be produced by a method of dissolving in a solvent such as hexane and emulsifying in water in which a surfactant is dispersed, and then removing the solvent.

For emulsification in water, a known method such as a method using a homomixer equipped with a high-speed stirring blade or a high-speed pipe emulsifier can be used.

As another method, a method of producing a latex by reacting an organic solvent, an emulsifier and at most 20 wt% of water in a multi-screw extruder can be used.

In any case, partially saponified polyvinyl alcohol, EVA (ethylene, vinyl acetate copolymer) as an emulsification aid
It is well known that a stable latex can be obtained by adding a modified polyethylene wax or the like.

(Ii) Crosslinking of ethylene / α-olefin copolymer rubber latex and drying The ethylene / α-olefin copolymer rubber latex prepared as described above is subjected to a crosslinking reaction in a latex state.

This crosslinking is effectively performed by, for example, crosslinking with an organic peroxide or crosslinking with an electron beam.

As the organic peroxide used, stability of latex particles,
From the standpoint of stability and economic efficiency of the crosslinking reaction operation, those having a 10-hour half-life temperature of 0 ° C. or more and 100 ° C. or less are preferable.

1,1-bis (t-butylperoxy) cyclohexane, t-butylperoxybiparate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisopropyl carbonate, 2,5-dimethyl-2 , 5-di (benzoylperoxy) hexane, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, isobutyl peroxide, diisopropylperoxy Dicarbonate, di (2-ethylhexyl) peroxycarbonate, acetylcyclohexylsulfonyl peroxide, 1,1-bis (t-butylperoxy) -3,3,5-
Trimethylcyclohexane.

The amount of the organic peroxide used varies depending on the required degree of crosslinking, but in the present invention, it is usually 3 × 10 ^{−4 to} 5 × per 100 parts by weight of the ethylene / α-olefin copolymer rubber.
The hot toluene insoluble content can be adjusted within the above-mentioned range by using it in the range of 10 ^-2 mol, particularly 10 ^{-3 to} 3 × 10 ^-2 mol.

Further, in crosslinking with an organic peroxide, it is preferable to use a crosslinking aid together.

Examples of the cross-linking aid include sulfur, quinone dioximes such as p-quinone dioxime, methacrylates such as polyethylene glycol dimethacrylate, allyls such as diallyl phthalate and triallyl cyanurate, other maleimides, and divinylbenzene. To be done. Such a vulcanization aid is based on 1 mol of the organic peroxide used.
1/2 to 2 mol, preferably about equimolar amount is used.

These organic peroxides and crosslinking aids may be blended in advance before latex production, or may be blended after latex production.

The heating time for crosslinking is usually 5 to 1 which is a half-life.
It is preferably 0 times, and it may be carried out under normal pressure or under pressure.

In electron beam crosslinking, the absorbed dose is selected according to the required degree of crosslinking, but in the case of the present invention, it is usually 1 to 10
It is controlled in the range of 0 Mrad, preferably 5 to 30 Mrad. Also in such electron beam crosslinking, the crosslinking efficiency can be improved by adding a crosslinking aid in advance.

In order to collect fine rubber powder from the thus obtained crosslinked ethylene / α-olefin copolymer rubber latex, salting out is carried out under stirring, water is allowed to pass through, and then dried by heating.

The ethylene / α-olefin copolymer rubber obtained as described above is fine particles having an average particle size of 0.2 μm to 40 μm, and the hot toluene insoluble content is 30% by weight or more. This ethylene / α-olefin copolymer rubber is extremely peculiar in that when heated and dried, the rubber particles hardly coagulate with each other and the fine particle size in the latex state is maintained as it is. It has various properties.

Therefore, the obtained rubber particles are extremely fine particles having an average particle diameter of 0.2 μm to 40 μm. This property is exhibited even when kneading with the fluororubber (A), and even in the rubber composition, the ethylene / α-olefin copolymer rubber (B) maintains the state that the average particle diameter is 40 μm or less. It is evenly dispersed.

Fluororubber composition The vulcanizable fluororubber composition of the present invention comprises the above-mentioned fluororubber (A) and ethylene / α-olefin copolymer rubber (B) on a weight basis, A / B = 95/5. ˜20 / 80, in particular 80/20 to 40/60.

When the blending amount of the ethylene / α-olefin copolymer rubber (B) is less than the above range, the low temperature characteristics, particularly the flexibility at low temperature is impaired, and when the amount is more than the above range, the composition may flow. As a result of deterioration of the property, there arises a problem that processing becomes difficult.

The fluororubber composition of the present invention is characterized in that the ethylene / α-olefin copolymer rubber (B) is dispersed in the fluororubber phase of the composition in an extremely fine state with an average particle size of 0.2 μm to 40 μm. Have

When the average particle size of the dispersed rubber particles is larger than 40 μm, the strength of the vulcanized product obtained from the rubber composition is lowered and it becomes difficult to put it into practical use.

The average particle size of the ethylene / α-olefin copolymer rubber particles in the rubber composition of the present invention is measured as follows.

That is, this composition was freeze-cut and the cut surface was immersed in cyclohexane at 60 ° C. for 1 hour to disperse ethylene.
After removing the α-olefin copolymer rubber, an electron microscope is used to arbitrarily select three areas where the number of dispersed rubber particles is from about 50 to about 100, and the major axis and the number of dispersed rubber particles are observed for each region to obtain a number average. The particle size was calculated and the average value of the three regions was used as the average particle size.

Example Area 1 Number average particle size A ₁ 〃 2 〃 A ₂ 〃 3 〃 A _{3 The} average particle size of ethylene / α-olefin copolymer rubber The rubber composition of the present invention contains a compounding agent known per se, such as a rubber filler, a plasticizer, a processing aid, an acid acceptor, a vulcanizing agent, and a vulcanizing agent, depending on the intended use of the vulcanized product. Sulfurization aids and the like can be added.

In this case, the total amount of the fluororubber (A) and the ethylene / α-olefin copolymer rubber (B) occupying in the composition is usually 40% by weight or more, particularly 50% by weight, although it varies depending on the use.
It is suitable to make it above.

As the rubber filler, for example, carbon black such as MT black, FT black and FEF black, talc, inorganic filler such as white carbon, calcium carbonate, barium sulfate and clay, and pigments such as red iron oxide and cyanine green are used. be able to.

These rubber fillers are fluororubber (A) and ethylene / α
The amount is usually 150 parts by weight or less, preferably 100 parts by weight or less, per 100 parts by weight of the total amount of the olefin copolymer rubber (B).

Fluorosilicone oil or the like is used as the plasticizer, and stearic acid, polyethylene wax or the like is used as the processing aid.

The blending amount of these plasticizers and processing aids is fluororubber.
It is usually 20 parts by weight or less, preferably 10 parts by weight or less, per 100 parts by weight of the total amount of (A) and the ethylene / α-olefin copolymer rubber (B).

Examples of the acid acceptor include magnesium oxide, litharge,
Calcium oxide etc. can be used, and the compounding amount is fluororubber
The amount is usually 30 parts by weight or less, preferably 15 parts by weight or less, per 100 parts by weight of the total amount of (A) and the ethylene / α-olefin copolymer rubber (B).

As the vulcanizing agent, polyamines such as hexamethylenediamine carbamate, N, N′-dicinnamylidene-1,6-hexadiamine, 4,4-bis (aminocyclohexyl) methane carbamate, dicumyl peroxide,
Organic peroxide such as 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, or Daier G601, F
Illustrative examples include polyol-based vulcanizing agents commercially available under the names luorel FC-2170, Viton E-60C, etc., and combinations of triazine compounds and various amine compounds.

These vulcanizing agents are usually used per 100 parts by weight of the total amount of the fluororubber (A) and the ethylene / α-olefin copolymer rubber.
The amount is 0.2 to 10 parts by weight, preferably 0.5 to 5 parts by weight.

When vulcanizing using an organic peroxide, a quinone oxime-based compound such as p-quinone dioxime, as a vulcanization aid,
It is preferable to use a methacrylate type such as polyethylene glycol dimethacrylate, an aryl type such as diallyl phthalate and triaryl cyanurate, a maleimide type, divinylbenzene and the like in combination.

These vulcanization aids are fluororubber (A) and ethylene / α-
It is usually used in an amount of 0.5 to 6 parts by weight, preferably 1 to 4 parts by weight, based on 100 parts by weight of the total amount of the olefin copolymer rubber (B).

The rubber composition of the present invention is usually prepared by the following method.

That is, a mixer such as a Banbury mixer is kneaded with a fluororubber, an ethylene / α-olefin copolymer rubber, a filler and a softening agent at a temperature of 80 ° C to 150 ° C for 3 to 10 minutes, and then a roll such as an oven roll. The vulcanizing agent is additionally mixed by using a class, and the roll temperature is 40 ° C to 80 ° C.
After kneading for 8 minutes, the mixture is dispensed to obtain a ribbon-shaped or sheet-shaped rubber composition.

Vulcanizate The rubber composition prepared as described above is molded into a desired shape by an extruder, a calender roll, a press or the like, and at the same time as molding or by introducing the molded product into a vulcanization tank, the temperature is usually 130 ° C. The vulcanized product can be obtained by heating at a temperature of to 230 ° C. for usually 1 to 30 minutes.

This vulcanization step may be carried out using a mold or may be carried out without using a mold.

Further post-vulcanization using an oven or the like will produce even better performance.

Uses The vulcanizates produced as described above are used for automobile parts such as O-rings, valves, pump seals, diaphragms, hoses, industrial machinery O-rings, oil seals,
It can be used for tank seals, oil seals, mechanical seals, etc. for the chemical plant industry such as gaskets, tubes and rolls.

The invention is illustrated by the following example.

Reference Example 1 Ethylene / propylene copolymer rubber (ethylene content: 60
Mol%, iodine value: 20, polyene component: ethylidene /
Lebornen, And modified polyethylene wax (Mitsui High Wax 110
10 g of 5A) was dissolved in 900 g of n-hexane and stirred until uniform. On the other hand, 5 g of potassium oleate as a surfactant was dispersed in 900 g of water and then mixed with the above solution using a homomixer at a rotation speed of 10,000 rpm for 30 minutes. The obtained emulsion is transferred to an evaporator,
N at a temperature of 60 to 80 ° C while slowly stirring at 0 rpm.
-Hexane was removed under reduced pressure.

Reference Example 2 Ethylene / propylene copolymer rubber (ethylene content: 60
Mol%, iodine value: 20, polyene component: ethylidene /
Lebornen, And modified polyethylene wax (Mitsui High Wax 110
5 g of 5A) was dissolved in 900 g of n-hexane and stirred until uniform. On the other hand, 5 g of potassium oleate as a surfactant was dispersed in 900 g of water, and then mixed with the above solution using a homomixer at a rotation speed of 2000 rpm for 30 minutes. The obtained emulsion was transferred to an evaporator and n-hexane was removed under reduced pressure at a temperature of 60 to 80 ° C. while slowly stirring at 60 rpm.

Reference Example 3 Ethylene / propylene copolymer rubber (ethylene content: 60
Mol%, iodine value: 20, polyene component: ethylidene /
Lebornen, And modified polyethylene wax (Mitsui High Wax 110
5A) 3g was melt | dissolved in n-hexane 900g, and it stirred until it became uniform. On the other hand, 5 g of potassium oleate as a surfactant was dispersed in 900 g of water, and then mixed with the above solution using a homomixer at a rotation speed of 500 rpm for 30 minutes. The obtained emulsion was transferred to an evaporator and n-hexane was removed under reduced pressure at a temperature of 60 to 80 ° C. while slowly stirring at 60 rpm.

Reference Example 4 Ethylene / 1-butene copolymer rubber [ethylene content 92 mol% Was dissolved in carbon tetrachloride (4), and the temperature was maintained at 60 ° C. in a glass reaction vessel of volume 6 equipped with a stirrer and a thermometer, while irradiating a 20 W daylight fluorescent lamp from the outside of the vessel. Chlorine gas was introduced therein at a rate of 2.0 g / min, and a chlorination reaction was carried out for 70 minutes. Then, nitrogen gas was passed through the reaction vessel to remove excess chlorine gas.

Next, a large excess of methanol was added to this solution to precipitate a chlorinated rubber. After filtration, this was dried under reduced pressure at room temperature.

The chlorine content of the chlorinated ethylene / 1-butene copolymer rubber thus obtained was 28 when measured by the cylinder combustion method.
It was wt%.

100 g of this chlorinated ethylene / 1-butene copolymer rubber was dissolved in 900 g of toluene and stirred until uniform. On the other hand, as surface active agent, 5 g of potassium oleate was added to 900 parts of water.
After being dispersed in g, the above solution was mixed with a homomixer at a rotation speed of 10,000 rpm for 30 minutes. The obtained emulsion was transferred to an evaporator, and toluene was removed under reduced pressure at a temperature of 80 to 100 ° C while slowly stirring at 60 rpm.

Example 1 The ethylene-propylene rubber latex obtained in Reference Example 1 was impregnated with a mixture of 2.0 parts by weight of 3M of Perhexa and 2.0 parts by weight of divinylbenzene with respect to 100 parts by weight of a rubber content, followed by stirring in a glass autoclave. 5 at 120 ° C
Heat treated for hours.

Excess hydrochloric acid water was added to this under stirring at 100 rpm to precipitate and filter a rubber component. This was washed 3 times with 200 m of water and dried under reduced pressure at 50 ° C., and this was designated as prototype A.

The hot toluene insoluble content of the prototype A was determined as follows. That is, a screen basket was made with a wire mesh of 200 mesh, and about 0.2 g of the prototype A was precisely weighed to the 0.1 mg unit and placed in 300 m of boiling toluene for 6 hours to remove the insoluble matter remaining in the screen basket. 50 ℃,
It was dried under reduced pressure for 3 hours, allowed to cool at room temperature, and precisely weighed to the 0.1 mg unit, and the proportion of the insoluble matter was taken as the hot toluene insoluble matter.

Trial product A and a commercially available fluororubber were mixed in the following formulation and used for the test.

The kneading was performed using an 8-inch open roll at 60 to 70 ° C. for 20 minutes.

The dispersion state of the prototype A in the kneaded material was investigated as follows.

That is, the kneaded material was frozen in methanol cooled to −70 ° C. with dry ice, and this was cut using a microtome. The cut surface was immersed in cyclohexane at 60 ° C. for 1 hour and subjected to ultrasonic treatment for 1 minute. This cut surface was observed with an electron microscope to determine the number average particle size of the prototype A.

Next, the kneaded material was press-vulcanized at 160 ° C. for 30 minutes to give a thickness of 2
A vulcanized rubber sheet of mm was prepared. This vulcanized rubber sheet was subjected to secondary vulcanization for 8 hours in an air oven at 200 ° C. and subjected to measurement. The following items were measured according to the method of JIS K 6301.

Normal physical properties Tensile strength (T _B ), Elongation (E _B ), Spring hardness (H _S ), Permanent elongation (PS) Heat aging resistance [Aging condition: 180 ° C-7 days in air oven] Tensile strength retention rate (A _R (T _B )), Elongation retention rate (A _R (E _B )) Oil resistance [Oil resistance condition: 50 ° C-7 days in JIS No. 3 oil] Swelling rate (ΔV) Low temperature characteristics Brittle temperature (Tb) result Is shown in Table 1 below.

Example 2 The formulation of Example 1 was as follows.

Except for this, the procedure was exactly the same as in Example 1.

The results are shown in Table 1 below.

Example 3 In Example 1, the formulation was as follows.

Except for this, the procedure was exactly the same as in Example 1.

The results are shown in Table 1 below.

Comparative Example 1 The following formulation was used in Example 1 without using the prototype A at all.

Except for this, the procedure was exactly the same as in Example 1.

The results are shown in Table 1 below.

Comparative Example 2 The following composition was used in Example 1 without using any fluororubber.

This composition could not be processed because it was not wrapped around an open roll.

Comparative Example 3 The ethylene-propylene rubber latex obtained in Reference Example 1 was impregnated with a mixture of 0.1 parts by weight of perhexa 3M and 0.1 parts by weight of divinylbenzene with respect to 100 parts by weight of a rubber content, and then stirred in a glass autoclave. 5 at 120 ° C
Heat treated for hours.

Excess hydrochloric acid water was added to this under stirring at 100 rpm to precipitate and filter a rubber component. This was washed three times with 200 m of water and dried under reduced pressure at 50 ° C., and this was designated as prototype B.

In the same manner as in Example 1, hot toluene insoluble matter was obtained. Further, the same test as in Example 1 was carried out except that Prototype B and a commercially available fluororubber were mixed in the following formulation.

The results are shown in Table 1 below.

Comparative Example 4 Ethylene / propylene copolymer rubber (ethylene content: 60
Mol%, iodine value: 20, polyene component: ethylidene /
Lebornene, Intrinsic viscosity ▲ [η] ^delican _{135 ℃} ▼: 1.
7) and commercially available fluororubber were compounded in the following formulation.

Except for this, the same test as in Example 1 was carried out.

The results are shown in Table 1 below.

Example 4 The ethylene / propylene rubber latex obtained in Reference Example 2 was impregnated with a mixture of 2.0 parts by weight of 3M Perhexa and 20 parts by weight of divinylbenzene per 100 parts by weight of the rubber content, and then stirred in a glass autoclave. Heat treatment was performed at 120 ° C. for 5 hours.

Excess hydrochloric acid water was added to this under stirring at 100 rpm to precipitate and filter a rubber component. This was washed three times with 200 m of water and dried under reduced pressure at 50 ° C., and this was designated as prototype C.

In the same manner as in Example 1, hot toluene insoluble matter was obtained. Further, the same test as in Example 1 was carried out except that Prototype C and a commercially available fluororubber were mixed in the following formulation.

The results are shown in Table 1 below.

Comparative Example 5 The ethylene / propylene rubber latex obtained in Reference Example 3 was impregnated with a mixture of 2.0 parts by weight of Perhexa 3M and 2.0 parts by weight of divinylbenzene per 100 parts by weight of the rubber content, and then stirred in a glass autoclave. Heat treatment was performed at 120 ° C. for 5 hours.

Excess hydrochloric acid water was added to this under stirring at 100 rpm to precipitate and filter a rubber component. This was washed three times with 200 m of water and dried under reduced pressure at 50 ° C., and this was designated as prototype D.

In the same manner as in Example 1, the hot toluene insoluble content was obtained. Further, the same test as in Example 1 was carried out except that Prototype D and a commercially available fluororubber were mixed in the following formulation.

The results are shown in Table 1 below.

Example 5 Divinylbenzene 2 was added to 100 parts by weight of the rubber component of the chlorinated ethylene / 1-butene copolymer rubber latex obtained in Reference Example 4.
Parts by weight were impregnated. This latex was irradiated with an electron beam. That is, this latex was put into a container so that the thickness was 1.5 mm, the upper part of the container was sealed with a polyethylene film of 30 μ, and 20 Mrad was irradiated at an accelerating voltage of 750 kV.

Excess hydrochloric acid water was added to this under stirring at 100 rpm to precipitate and filter a rubber component. This was washed three times with 200 m of water and dried under reduced pressure at 50 ° C., and this was named prototype E.

In the same manner as in Example 1, hot toluene insoluble matter was obtained. Further, a trial product E and a commercially available fluororubber were mixed in the following formulation and used for the test.

The kneading was performed using an 8-inch open roll at 60 to 70 ° C. for 20 minutes.

The dispersion state of the prototype D in the kneaded product was the same as in Example 1. Next, the kneaded product was press-vulcanized at 160 ° C. for 20 minutes to prepare a vulcanized rubber sheet having a thickness of 2 mm. This vulcanized rubber sheet was subjected to secondary vulcanization in an air oven at 180 ° C. for 4 hours for measurement. The measurement was performed in the same manner as in Example 1.

The results are shown in Table 1 below.

Example 6 In Example 5, the formulation was as follows.

Except for this, the procedure was exactly the same as in Example 1.

The results are shown in Table 1 below.

Example 7 In Example 5, the formulation was as follows.

Except for this, the procedure was exactly the same as in Example 1.

The results are shown in Table 1 below.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location C08L 29/10 LGZ 6904-4J 83/08 LRY 8319-4J (56) Reference JP-A-60- 65048 (JP, A) JP 59-193940 (JP, A) JP 47-30751 (JP, A) JP 52-121654 (JP, A) JP 61-12711 (JP, A) Japanese Patent Publication No. 4-49865 (JP, B2)

Claims (4)

[Claims] 1. A finely divided ethylene / α-olefin copolymer rubber (B) having a fluororubber (A) content of 30% by weight or more insoluble in hot toluene and an average particle size in the range of 0.2 μm to 40 μm. ), On a weight basis, in a ratio of A / B = 95/5 to 20/80. A vulcanizable fluororubber composition. 2. The vulcanizable fluororubber composition according to claim 1, wherein the α-olefin of the ethylene / α-olefin copolymer rubber contains 3 to 10 carbon atoms. . 3. The fluororubber composition according to claim 1, wherein the ethylene / α-olefin copolymer rubber contains a polyene component having a maximum iodine value of 30. 4. An ethylene / α-olefin copolymer rubber
The vulcanizable fluororubber composition according to claim 1, wherein (B) is modified with halogen and the halogen content is up to 40% by weight.