JPH01135850A - Rubber composition and production thereof - Google Patents

Abstract

PURPOSE:To obtain a rubber composition for side wall of tire, etc., having excellent crack propagation resistance, abrasion resistance, etc., as well as weatherability and heat-resistance, by compounding a rubber component with a specific ethylene-propylene-diolefin copolymer rubber and an inorganic filler at specific ratios. CONSTITUTION:The objective rubber composition having improved breaking strength, elongation at break and adhesivity to a diene rubber is produced by compounding (A) 100pts.wt. of a rubber component with (B) >=20pts.wt. of an ethylene-propylene-diolefin copolymer rubber having a glass transition temperature Tg of <=-40 deg.C (determined by CDSC), an iodine value of 10-34, a weight-average molecular weight of >=220,000 and an ethylene content of 68-85mol.% and satisfying the formulas 2.0 <= molecular weight distribution (Mw/Mn) < 3.0, 95 <= 1.5 X (iodine value) + (ethylene content) <= 120 and 90 <= (weight-average molecular weight) X 10<-4> + (ethylene content) <= 160 and (C) 20-200pts.wt. of an inorganic filler.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention has an ethylene-propylene-diolefin copolymer rubber (hereinafter referred to as EPDM rubber) as a main component, and #
The present invention relates to a rubber composition that is excellent in weather resistance, heat resistance, crack growth resistance, abrasion resistance, etc., and a method for producing the rubber composition.

[Prior art] Since EPDM:f has almost no double bonds in its main chain, it inherently has excellent weather resistance and heat resistance.
Various studies have been conducted to utilize this characteristic in tires. For example, when this rubber is used for tire sidewalls, due to its excellent weather resistance, the amount of amine anti-aging agents and paraffin wax that have been used to ensure weather resistance can be reduced, or in some cases become unnecessary. It's sexual. However, this EPDM rubber is certainly
It has excellent weather resistance and heat resistance, but on the other hand, its breaking strength and bending durability are several steps lower than that of diene rubber, so it may be more effective to use diene rubber in combination with an amine anti-aging agent. It was considered.

Japanese Patent Application Laid-Open No. 12-148543 discloses, for the purpose of improving the vulcanization adhesion of EPDM rubber to adjacent rubber,
As the sole polymeric elastomer component, a polymer having a nonconjugated diene content of from about 6 to about 15% by weight (based on EPDM) combined with at least one highly unsaturated rubbery polymer, lEP
The EPDM polymer comprises from about 25 to about 50 parts by weight per 100 parts by weight of total elastomer, and the EPDM polymer has a Mooney viscosity (ML, .100°) greater than about 150. C) and about 50,150 to about 75
A rubber composition is disclosed that accommodates an ethylene/propylene weight ratio of /25.

However, there is still room for improvement in terms of breaking strength and bending resistance.

[Problems to be Solved by the Invention] By controlling the microstructure of EPDM rubber, which is a non-diene rubber, the present invention improves the durability compared to conventional EPDM rubber compositions without dramatically increasing the D and iodine value. To provide a rubber composition with significantly improved crack growth properties and abrasion resistance.Furthermore, in producing this rubber composition, a filler used in blending with the rubber, particularly carbon black or The present invention provides a technology that prevents silicon dioxide from being unevenly distributed in diene rubber and causing a significant deterioration in physical properties.

[Means for Solving the Problems] The present invention provides an ethylene-propylene-diolefin copolymer rubber (EPDM rubber), and A, a glass transition temperature Tg (DSC-r!M constant)≦-40°C B, iodine value=
10-34 C8 weight average molecular weight ≧220,000 D, ethylene content = 68-85 mol%E, 2.0≦molecular weight distribution (Mw/Mn)<3.0F, 95≦1.5
(iodine value) + (ethylene content) ≦120 G, 90≦ (weight average molecular weight) × 10-' + (ethylene content) ≦160 At least 20 to 20 parts by weight of inorganic filler
A vulcanizable rubber composition characterized in that it contains 0 parts by weight, and the rubber composition further comprises 0 parts by weight of E.
When producing a blend rubber composition of PDM rubber and diene rubber, D, 1
This is a method for producing a rubber composition, characterized in that 0 to 100 parts by weight of an inorganic filler, particularly carbon black or silicon dioxide, is blended.

In the present invention, the EPDM rubber of the present invention is limited to 20 parts by weight or more because if it is less than 20 parts by weight, sufficient weather resistance and heat deterioration resistance cannot be obtained. E of the present invention
The reason for PDM rubber is not clear, but as the amount of blending increases, the weather resistance suddenly increases from around 26 to 30 parts by weight.
A characteristic that improves heat deterioration resistance, preferably,
30 parts by weight or more is preferable. If the amount of the inorganic filler is less than 20 parts by weight, the breaking strength (strength at break, elongation at break) of the rubber composition after vulcanization will not be sufficient, and if it is more than 200 parts by weight, the rubber composition will not have sufficient strength when unvulcanized. It becomes impossible to obtain sufficient workability.

The reason for limiting the glass transition temperature of the EPDM rubber to -40°C or less when measured by DSC at a heating rate of 10°C/min is that if it is higher than -40°C, sufficient crack growth resistance and bending durability will be achieved. This is because the iodine value cannot be obtained from 1O to 34.
If it is smaller than IO, it will have sufficient co-vulcanization with diene rubber and crack growth resistance.

This is because strength at break and elongation at break cannot be obtained D, 34
If it is larger than 1, the synergistic effect of significantly improving crack growth resistance, strength at break, and elongation at break cannot be expected.D, and wear resistance after thermal deterioration also decreases, which is not preferable. In addition, the third component copolymerized to increase the iodine value is generally expensive and is used in rubber products. ! This is because, as a product, it is also a wood-related issue for EPDM rubber to suppress the amount of diolefin components as much as possible and produce a rubber with the best performance among them.

The reason why the weight average molecular weight of the EPDM rubber is limited to 220,000 or more is that a molecular weight of 220,000 or more significantly improves crack growth resistance and abrasion resistance, and surprisingly, the adhesive strength with diene rubber also improves. This is because it is a significant improvement. However, as the molecular weight is increased, the viscosity increases rapidly, which also has the drawback of significantly reducing processability when unvulcanized. Therefore, it is preferable to oil-extend the region where the weight average molecular weight exceeds 240,000. However, if the weight average molecular weight exceeds 600,000, the amount of oil necessary for processability will increase too much, and physical properties such as abrasion resistance after vulcanization will be significantly reduced, which is not preferable. As the oil type for oil extension, balaphinic oil is preferred.

The reason why the ethylene content of the patent featuring ethylene-propylene was limited to 68 to 85 mol% is that sufficient crack growth resistance, strength at break, and elongation at break can be obtained without the ethylene content within this range. That's because there isn't. To be more specific, if the ethylene content is lower than 68 mol%, even if the iodine value is set to 10 or more, the improvement effect on crack growth resistance, strength at break, and elongation at break is very small;
If it is higher than that, D is close to that of polyethylene resin, D has a small elongation at break, and the modulus of elasticity is high, making it difficult to use it industrially as a rubber.

In the present invention, the molecular weight distribution (Mw/Mn
) is limited to 2.0 or more because the molecular weight distribution (M w/
This is because if Mn) is lower than 2.0, roll workability is poor and industrial use is difficult.

The molecular weight distribution (Mw/Mn) is preferably less than 3.0 in order to reduce the low molecular weight components of EPDM and improve physical properties.

Also, fl, 5x (iodine value) + (ethylene content)
If it is less than 9.5, sufficient crack growth resistance, strength at break, and elongation at break cannot be obtained, and if it exceeds 120, heat deterioration resistance (including wear resistance after heat deterioration) decreases. .

If r (weight average molecule l) This is because not only the properties (dispersion of carbon black (C/B), roll workability) deteriorate, but also the elastic modulus of the rubber composition becomes too high, making it difficult to use it industrially.

As mentioned above, the reasons for each of the limiting conditions can be explained, but all of these reasons are valid within the scope of the EPDM rubber characteristics and the scope of the claims. In other words, it means that the effects of the present invention cannot be obtained unless all conditions A to G are satisfied at the same time. This is because there are some previously unknown synergistic effects between the respective conditions.

Several EPDM rubbers are used to obtain the EPDM rubber in the present invention.
There is also a method of making rubber by polymerizing it, but it does show quite good physical properties and naturally belongs to the scope of the present invention, but it is also possible to make it by polymerization from the beginning and satisfy the conditions shown in the claims at once. Rubber compositions using the rubber shown in Table 1 show superior physical properties (crack growth resistance, abrasion resistance, strength at break, elongation at break, etc.).

Ethylidenenorbornene is preferred as the diolefin component of the EPDM of the present invention, but it may be used in combination with other commonly used diolefin components such as dicyclopentadiene, 1,4-hexadiene, D, This is because superior improvement effects can be expected in crack growth resistance, breaking sowing strength, and elongation at break.

In the present invention, the oil-extended amount of the rubber containing ethylene-propylene as a main component of the present invention is preferably 40 parts by weight or more, but this is because the weight average molecular weight is preferably set to 40 parts by weight or more in order to fully obtain the effects of the present invention. , 250,000 or more, unless the oil extension amount is 40 parts by weight or more, processability will be poor and it will be difficult to use industrially.

The rubber component other than EPDM is at least one rubber member D selected from the group of diene rubbers, specific examples of which include natural rubber, cis-polybutadiene rubber, emulsion polymerization type or solution polymerization type SBR, etc. .

The rubber composition of the present invention preferably contains 10 parts by weight or more of isoprene rubber, and more preferably 20 parts by weight or more.

This is because if it is less than 10 parts by weight, kneading workability decreases, and depending on the formulation, it becomes difficult to obtain sufficient physical properties as a vulcanized rubber. Also, from the viewpoint of ensuring strength at break, it is industrially more efficient to use isoprene rubber than to use other diene rubbers. Here, isoprene rubber refers to natural rubber or synthetic polyisoprene rubber.

Inorganic fillers used in the rubber composition of the present invention include:
Carbon black is most suitable, but other materials such as silicon dioxide (silica), calcium carbonate, titanium dioxide, and white oxide can also be used.

In the method for producing a rubber composition of the present invention, EPDM
Adding 10 to 100 parts by weight of the inorganic filler per 100 parts by weight of rubber means that after EPDM polymerization.

It is also possible to use a so-called wet master hatch, in which the inorganic photonic agent is added, the solvent is removed, and then dried.
It is preferable to mix the inorganic brightening agent into the M rubber using a mixer such as a Banbury mixer.

The amount of inorganic photonic agent, especially carbon black, is 10%
It is preferably 20 to 200 parts by weight per 0 parts by weight.

If it is less than 20 parts by weight, the breaking strength of the rubber vulcanizate, that is, the strength at break, will be insufficient, and if it is more than 200 parts by weight, the processability when unvulcanized will be poor. This is because you won't be able to get enough.

Regarding the method of adding carbon black, for rubber compositions where weather resistance and flex durability are important, such as tire sidewalls, the concentration of carbon black mixed into the EPDM rubber in advance determines the final concentration of the rubber composition. It is preferable that the concentration is lower than that of carbon black in the carbon black.

In addition, for rubber compositions that emphasize wear resistance, such as tire treads, it is important that the concentration of carbon black that is mixed into the EPDM rubber in advance is higher than the final concentration of carbon black in the rubber composition. preferable.

In addition, in terms of the structure of carbon black, for rubber compositions where wear resistance is important, such as tire treads, the amount of iodine adsorbed by the carbon black that is kneaded into the EPDM rubber in advance is determined by the amount of iodine adsorbed by the carbon black added later. Preferably, it is larger than that.

On the other hand, for rubber compositions that place emphasis on weather resistance and flex durability, such as tire sidewalls, the amount of iodine adsorbed by carbon black that is mixed into EPDM rubber in advance is smaller than that of carbon black that is added later. That's preferable.

The carbon black for the rubber composition constituting the sidewall portion of the present invention has iodine adsorption l: I5 to
100mg/g, DBP oil absorption 70-140m
17,100 g is preferable, but this is because if the iodine adsorption amount is lower than 35 mg/g, it will be difficult to obtain the desired strength at break, whereas if it exceeds 100 mg/g, the flexural durability will decrease. It is. DBP oil absorption is 7
If the weight is less than 0 m 17,100 g, the carbon black will not be sufficiently dispersed, whereas if it is larger than 140 m 17,100 g, the hardness after vulcanization will become too large, reducing the bending durability.

The carbon black of the rubber composition constituting the tread portion of the present invention has an iodine adsorption amount of 85 to 200 mg.
/ g, DBP oil absorption 100-180m17100
g is preferable. To ensure wear resistance, the iodine adsorption amount is 85 mg/g or more, and the DBP oil absorption amount is 1001.
Ill/100 g or more is preferable, and in order to ensure the dispersion of carbon black in the rubber composition, the iodine adsorption amount is 200 mg/g or less and the DBP oil absorption amount is 180 mg/g or less.
It is preferable that the amount is less than m1/100 g.

The rubber composition of the present invention has overwhelmingly superior weather resistance and heat resistance compared to the diene rubber composition used in the shell, so it does not require amine anti-aging agents or paraffin wax. When the amount of the EPDM rubber of the invention used is small, for example, 20 parts by weight, a small amount may be added. Even so, if it is an amine-based anti-aging agent, it is G, 3 parts by weight or less, and if it is a paraffin-based wax, it is G.
, preferably 5 parts by weight or less. Of course, both may be used together.

When the rubber composition of the present invention is used for the sidewall part of a tire, if the hardness of the rubber composition (JIS spring type hardness [Type A]) is set to 30 to 60, the sidewall part will not undergo constant strain deformation. It is more preferable in terms of bending durability and crack growth resistance. Further, when the rubber composition of the present invention is used for the tread portion of a tire, the hardness of the rubber composition (
It is more preferable to set the JIS spring type hardness [A type] to 55 to 70. If it is less than 55, the steering stability of the tire is
Crack growth resistance decreases, and if it exceeds 70, not only will the rib tear resistance and bending durability of the tire tread decrease, but also the grip performance will decrease, making it difficult to ensure sufficient braking performance. Because it will be.

Next, a method for producing EPDM'':Im used in the present invention will be explained.

The EPDM rubber in the present invention can be prepared, for example, in a hydrocarbon solvent (
a) Soluble vanadium compound [VO(OR)nX3-,
:R is hydrocarbon, X is halogen, 0≦n≦3] or v
Vanadium compound represented by X4, (b) R', AI
X'z--[R' is hydrocarbon, X' is halogen, 0≦
m≦3], ethylene, propylene, and a third component such as ethylidene norbornene may be adjusted to a desired composition and randomly copolymerized.

Specific examples of vanadium compounds represented by the above general formula include the following.

VO(OCH3)CI2, VO(OCHz)tel
, VO(OCHz)+, VO(OCJs)CI□,
VO(OC2H5)2CI, VO(OCal(s)
:+, VO (OC2115) 1.5Br1. S,
VO(OCJ7)C12, VO(OCJy)+, aC
I+, s, VO(OC3H7)zcl, VO(O
C:I)I? ) :l, VO(0-n7C4H9)C1
2, VO(0-n-CJs) 2(:I , VO(0-i
so-C+119) CI2゜VO(0-sec-CJe
)= , VO(OC5H++)+, sC1+, s
, VOC1+, VCI-, or a mixture thereof. In cholerano, VO(OC,H5)CI2,
VOC+* is particularly preferred.

Further, specific examples of organoaluminum compounds include the following.

(Cllz) JICI, (CIl:l) l, Altl
:l+, 9, (C1lz)AICI□, (C21
1s) 2Alcl, (CJs)+, 5AIcl+
, s, (C2tls)AlCl2. (CJt)JI
CI, (C:IO2) 15AIcI+5, ((:
:+I+,)A Ic l□, (CsH+i)+5A
I(:l+5, (CaH+3)AlzCl, (CJI+
:+)AICI□ or a mixture thereof.

The usage ratio of organic aluminum and vanadium compound is A
The I/V (atomic ratio) is preferably in the range of 2 to 50, particularly 5 to 30.

Copolymerization can be carried out in a hydrocarbon solvent. For example, aliphatic hydrocarbons such as hexane, heptane, octane, and kerosene, and aromatic hydrocarbons such as benzene, toluene, and xylene can be used alone or in combination as a solvent.

The copolymerization is carried out using a vanadium compound or G, 01~ in the reaction medium.
5 mmol/l, preferably G, 1-2 mmol/l.

Regarding the ethylene content, it can be changed by controlling the amount supplied during copolymerization, but it is 85 mol%.
It is industrially difficult to achieve the above. (In the laboratory, it is possible although the yield is lower.) The polymerization temperature is 0 to 100°C, preferably 20 to 80°C.
C1 polymerization pressure is maintained at 0-50 kg/c112. Hydrogen is used to control the molecular weight of the EPDM rubber produced.

[Examples] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the wooden examples as long as the gist of the present invention is not exceeded.

The rubber containing ethylene-propylene as a main component in the present invention was produced as follows.

Ethylene, propylene, and ethylidene norbornene were continuously copolymerized using a 15-liter stainless steel polymerization vessel equipped with a stirring device.

Hexane was continuously supplied as a polymerization solvent from the top of the polymerization vessel at a rate of 5 liters per hour. On the other hand, the polymerization liquid in the polymerization vessel was drawn out from the lower part of the polymerization vessel so that the volume of the polymerization liquid remained at 5 liters at all times. As a catalyst (a) VO(OC211s)CI
□ so that the vanadium atom concentration in the polymerization vessel is G, 22 mmol/liter.

(b) ((:ztls)+, 5AICI+, and s were each continuously fed into the polymerization vessel from the top of the polymerization vessel so that the aluminum atom concentration in the polymerization vessel was 1.70 mmol/liter. A mixed gas of ethylene and propylene (ethylene 45 mol%, propylene 55 mol%) was fed from the top at a rate of 450 liters per hour, and ethylidene norbornene was fed from the top of the polymerization reactor at a rate of 28 g per hour.Hydrogen gas was also supplied as a molecular weight regulator. was fed at a rate of 2.5 liters per hour.

The polymerization temperature was controlled at 4560°C by a jacket attached to the outside of the polymerization vessel. The pressure inside the polymerization vessel is 4
．． 8 kg/cm”.

The polymerization solution taken out from the lower part of the polymerization vessel was subjected to steam stripping, and then dried at 80° C. for a day and night, and finally vacuum-dried. EPDM rubber was obtained at a rate of 285 g/hr.

Weight average molecular weight Mw and molecular distribution Mw/Mn are determined by GPC
It was measured by the method. The weight average molecular weight was determined in terms of polystyrene. The obtained sample was designated as Prototype-1, and Prototypes 2 to 8 were also produced by changing the amount of ethylene, the amount of the third component, the catalyst amount ratio, the polymerization temperature, the polymerization time, etc. as appropriate.

For prototypes 1 to 3.5 to 8, a predetermined amount of paraffinic oil manufactured by Idemitsu Petrochemical Co., Ltd. was mixed in after the polymerization reaction was completed and before steam stripping.

It was made of oil-extended rubber.

Details of the EPDM rubber sample obtained in Table 1 and amount of oil extension oil (parts by weight of oil extension oil per 100 parts by weight of rubber)
shows.

EXAMPLES The present invention will be explained in more detail with reference to Examples below.

First, the test method and EPDM rubber used will be explained.

<Test method> (1) Crack growth resistance test piece 60mmX 100m+sX 1.0 +11
G, :] 11m scratch in the center of 1, frequency 300
Elongation strain was applied at cycles/minute under conditions of 50% strain, and the time required for the scratch to grow to 20 mm was measured and evaluated using the following formula.

The larger this value is, the better the crack growth resistance is.

(2) Abrasion resistance (after heat treatment) The ratio of the amount of wear between the original sample and the sample left in a constant temperature bath at 120°C for 24 hours (heat treatment) was determined, and based on this, evaluation was made using the following formula. .

The wear test was performed using Akron wear (Br1tishSta).
ndard 903 Part A9 (1957)
, load 61bs, angle 15° single shear 1000 times).

Tatashi, The larger the abrasion resistance value, the better the abrasion resistance.

(3) Heat deterioration resistance test piece: 150 mm x 150 t++ x 2. O
AM's original sample of vulcanized rubber sheet and 120
The strength at break ratio of the sample that had been left in a constant temperature bath at .degree. C. for 24 hours (heat treated) was determined, and based on this, evaluation was made using the following formula.

however, The larger this value is, the better the heat deterioration resistance is.

(4) Strength at break and elongation at break: The sample shape uses JIS No. 3 and JIS K6:1.
Measured according to 01.

(5) Weather resistance test piece 20m+sX 100mmX 1. Oam rubber plate stretched 50% in the length direction, 40℃, ozone concentration 5O
The sample was left in a constant temperature bath at pph■, and the time required until cracks could be confirmed was determined and evaluated using the following formula.

The larger this value, the better the weather resistance.

[Examples 1-2. Comparative Examples 1 to 3] These Examples and Comparative Examples compare the EPDM rubber with a specific structure of the present invention and a conventional diene-based EPDM rubber that does not satisfy the structure, and the results are shown in Table 2. From the results in Table 2, it can be seen that the EPDM rubber of the present invention has extremely excellent properties not only in weather resistance and heat resistance but also in crack growth resistance.

Table 2 Evaluation results (Part 1) (Note) (1) BRO1: Nippon Gosei Rubber Co., Ltd. Sisu 1,4-Polytutadiene (2) HAF carbon black: Adsorption amount of Isao (90■/g) DBP adsorption amount (120
■ / 100 g) (3) Aromatic oil: manufactured by Fuji Kosan Co., Ltd. (4) Sandflex 13; N (1,
3-diIIIethylbutyl)-N-pheny
l-p-phenylendiamine (5) CZ; N-Cyclohexyl-2-b
enzothiazyl-1-3ufenamide (
6) T S ; Tetrasetyl thiu
(7) No cracks even after 168 hours 8) RT, room temperature (20-25℃),
HT: High temperature (100°C) [Examples 1.3 to 4. Comparative example 1
] These Examples and Comparative Examples compare a method of using EPDM rubber kneaded with carbon black in advance (masterbatch method) and a conventional method when preparing an EPDM rubber composition. It is shown in Table 3. From the results shown in Table 3, it can be seen that this master hatch method has a dramatic improvement effect on crack growth resistance, heat deterioration resistance, strength at break, elongation at break, and abrasion resistance.

Table 3 Evaluation results (Part 2) (Note) (1) Prototype-IMB, Prototype-1 (Table 1) 130
Prototype carbon masterbatch of 30 parts by weight and HAF carbon black - 6MB, Prototype - 6 (Table 1) 1
Carbon master hatch of 50 parts by weight and 30 parts by weight of HAF carbon black (2)*; same as Table 2 (3) Aromatic oil, Sandflex 13.
CZ and TS: Same as Table 2 [Examples 5-8. Comparative Examples 4 to 7] These Examples and Comparative Examples examine the effects of the manufacturing method of the present invention in the rubber composition manufacturing method of the present invention (masterbatch method) in which carbon black is kneaded into EPDM rubber in advance. It is.

The results are shown in Table 4. From Table 4, it can be seen that even in this masterbatch method, it is necessary for the EPDM rubber used to satisfy all the structural conditions A to G in order to obtain excellent physical properties.

[Examples 9-11. Comparative Examples 8 to 9] In these Examples and Comparative Examples, the amount of EPDM rubber was investigated, and the results are shown in Table 5. From Table 5, the amount of EPDM was 20 parts by weight in order to exhibit the characteristics. I see if anything more is needed.

[Examples 12-13. Comparative Examples 10 to 12] This example,
In the comparative example, the amount of carbon black was examined and the results are shown in Table 6. From the results of Table 6, the amount was 20~
It can be seen that the amount is limited to 200 parts by weight.

[Effects of the invention] As shown in the examples above, requirements A to EPDM rubber
The rubber composition of the present invention, which satisfies all of G, has better crack growth resistance, abrasion resistance, strength at break, elongation at break, and adhesion to diene rubber compared to rubber compositions using conventional EPDM rubber. It is clear that this has been dramatically improved.

Further, by a method of preparing an EPDM rubber composition by a method (masterbatch method) in which EPDM rubber that simultaneously satisfies structural requirements A to G described in the claims is kneaded with carbon fluff in advance, D. In addition to the weather resistance and heat resistance of this EPDM rubber, the breaking strength, flexural durability, crack growth resistance, and abrasion resistance, which had been considered disadvantageous in the past, were also dramatically improved.

By using the rubber composition of the present invention in tire sidewalls, the appearance is dramatically improved, and by using it in tire treads, the appearance and group crack resistance are significantly improved, and the retread life of large tires is also significantly improved. The rubber composition of the present invention can be used not only for tires but also for general rubber products such as tires, industrial belts, hoses, anti-vibration rubber,
Can be used for fenders.

Claims (1)

[Scope of Claims] 1. Ethylene-propylene-diolefin copolymer rubber, and A. Glass transition temperature Tg (measured by DSC) ≦-40°C B
, iodine value = 10-34 C, weight average molecular weight ≧220,000 D, ethylene content = 68-85 mol% E, 2.0≦molecular weight distribution (Mw/Mn)<3.0F, 9
5≦1.5×(iodine value)+(ethylene content)≦12
0 G, 90≦(weight average molecular weight)×10^-^4+(ethylene content)≦160 20 parts by weight or more of rubber satisfying all the conditions, based on 100 parts by weight of the rubber component, and 20 to 200 parts of inorganic filler. A vulcanizable rubber composition characterized in that it contains parts by weight. 2. The rubber composition according to claim 1, wherein the ethylene-propylene-diolefin copolymer rubber is 30 parts by weight or more. 3. The rubber composition according to claim 1, wherein the rubber component other than the ethylene-propylene-diolefin copolymer rubber is at least one rubber selected from the group of diene rubbers. 4. The rubber composition according to claim 1, wherein the diolefin component of the ethylene-propylene-diolefin copolymer rubber is ethylidene norbornene. 5. The rubber composition according to claim 1, wherein the ethylene-propylene-diolefin copolymer rubber is an oil-extended rubber. 6. The rubber composition according to claim 3, which contains 10 parts by weight or more of isoprene rubber. 7. The rubber composition according to claim 4, which contains 20 parts by weight or more of isoprene rubber. 8. The rubber composition according to claim 5, wherein the oil used for oil extension is a paraffinic oil. 9. Claim 5 in which the amount of oil extended is 20 parts by weight or more
The rubber composition described in . 10. The inorganic filler is carbon black, silicon dioxide,
The rubber composition according to claim 1, which is calcium carbonate, titanium dioxide, etc. 11. Carbon black has an iodine adsorption amount of 35 to 200 m
11. The rubber composition according to claim 10, which is carbon black with a DBP oil absorption of 70 to 180 ml/100 g. 12. The rubber composition according to claim 1, which does not substantially contain an amine-based antiaging agent. 13. Ethylene-propylene-diolefin copolymer rubber, and A, glass transition temperature Tg (measured by DSC) ≦ -40°C B
, iodine value = 10-34 C, weight average molecular weight ≧220,000 D, ethylene content = 68-85 mol% E, 2.0≦molecular weight distribution (Mw/Mn)<3.0F, 9
5≦1.5×(iodine value)+(ethylene content)≦12
0 G, 90≦(weight average molecular weight)×10^-^4+(ethylene content)≦160 20 parts by weight or more of rubber satisfying all the conditions, based on 100 parts by weight of the rubber component, and 20 to 200 parts of inorganic filler. When producing a vulcanizable rubber composition containing part by weight of ethylene-propylene-diolefin copolymer rubber 1
A method for producing a rubber composition, characterized in that 10 to 100 parts by weight of the inorganic filler is blended per 00 parts by weight. 14. The rubber composition according to claim 13, wherein the rubber component other than the ethylene-propylene-diolefin copolymer rubber is at least one rubber selected from the group of diene rubbers. 15. The method for producing a rubber composition according to claim 13, wherein the diolefin component of the ethylene-propylene-diolefin copolymer rubber is ethylidene norbornene. 16. The method for producing a rubber composition according to claim 13, wherein the inorganic filler is carbon black. 17. The method for producing a rubber composition according to claim 13, wherein an ethylene-propylene-diolefin copolymer rubber is used as the oil-extended rubber. 18. Claim 13, characterized in that the rubber composition does not substantially contain an amine-based antiaging agent.
A method for producing a rubber composition as described in Section 1.