JPH1036593A - Semiconductive rubber composition and member for electrophotographic apparatus - Google Patents

Abstract

(57) [Problem] To provide a semiconductive rubber composition having a stable electric resistance and an electrophotographic apparatus member comprising the same. SOLUTION: An ethylene / α-olefin / non-conjugated diene copolymer rubber 10 having the following characteristics (a) to (e):
A semiconductive rubber composition comprising 0 parts by weight and 5 to 50 parts by weight of a conductive filler. (A) carbon number of α-olefin: 4 or more and 20 or less;
(B) α-olefin content: 20 mol% to 90 mol%, (c) Mooney viscosity at 100 ° C .: 30 to less than 200, (d) iodine value: 3 to 50,
(E) Molecular weight distribution: 3 or less

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductive rubber composition having a stable electric resistance and an electrophotographic apparatus member comprising the same.

[0002]

2. Description of the Related Art In an electrophotographic apparatus, various methods are known as a transfer method for transferring a toner image formed on an image carrier such as a photosensitive drum onto a transfer material such as paper. Among them, contact-type rolls are effective because they are effective for downsizing the device, require low applied voltage for transfer, have low corona products such as ozone, and have excellent transfer material transfer stability. Has attracted attention. Contact type rolls (charging rolls) using this method include:
Excellent ozone resistance and electric resistance of 1 to 10 ¹⁰ Ω · cm
There is a demand for a material exhibiting semiconductivity. At present, ethylene-propylene-diene copolymer rubber (EP
A material obtained by adding a conductive filler to DM) is often used. However, a material obtained by adding a conductive filler to EPDM has a large fluctuation in electric resistance depending on molding processing conditions, and it is extremely difficult to control the electric resistance. Furthermore, even if the molding conditions are controlled to be constant, the electric resistance value is not stable, and the yield is inevitable due to the variation between products. In order to avoid this problem, examples have been reported in which a liquid rubber such as silicone rubber or urethane rubber is used instead of EPDM (JP-A-1-126370, JP-A-6-248174, etc.).
(1) Since the rubber component before crosslinking is in a liquid state, handling is difficult and the manufacturing process becomes complicated. (2) In the case of urethane rubber, raw materials are often toxic, and there are also problems in use. There were many.

[0003]

SUMMARY OF THE INVENTION The present invention provides a semiconductive rubber composition having a stable electric resistance and an electrophotographic apparatus member comprising the same.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, completed the present invention. That is, the present invention provides a semiconductive material comprising 100 parts by weight of an ethylene / α-olefin / non-conjugated diene copolymer rubber having the following characteristics (a) to (e) and 5 to 50 parts by weight of a conductive filler. The present invention relates to a rubber composition and an electrophotographic apparatus member made of the same.

(A) carbon number of α-olefin: 4 or more 2
0 or less (b) α-olefin content: 20 to 90 mol% (c) Mooney viscosity (ML _{1 + 4} ) at 100 ° C .: 3
0 to less than 200 (d) Iodine value: 3 to 50 (e) Molecular weight distribution (weight average molecular weight / number average molecular weight) determined by gel permeation chromatography: 3 or less The details will be described below.

The α-olefin used in the ethylene / α-olefin / non-conjugated diene copolymer rubber used in the present invention has 4 to 20 carbon atoms.
-Butene, 1-pentene, 1-hexene, 4-methyl-
1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-
Tridecene, 1-tetradecene, 1-pentadecene, 1
-Hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene and the like, and one or more of these are used. Above all, 1
The use of -hexene or 1-octene is preferred because the semiconductive rubber of the present invention has more excellent electrical resistance stability.

The content of α-olefin is at least 20 mol% 9
0 mol% or less, preferably 25 mol% or more and 50 mol% or less. If the content of the α-olefin is less than 20 mol%, the flexibility of the semiconductive rubber composition of the present invention may be impaired, and if it exceeds 90 mol%, the productivity of the polymer is reduced and the production becomes difficult. Become. In addition, 25 mol% or more 50
When the content is not more than mol%, the semiconductive rubber of the present invention is more preferable because the stability of electric resistance is further improved.

The non-conjugated diene used in the ethylene / α-olefin / non-conjugated diene copolymer rubber used in the present invention includes 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 4-methyl-1,
4-hexadiene, 5-methyl-1,4-hexadiene, 4-methyl-1,5-heptadiene, 1,6-octadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 5- Methylene-2-norbornene, 5-ethylidene-2-norbornene, 5-isopropenyl-2-norbornene, 2,5-norbonadiene, 1,6-cyclooctadiene, 2-ethylene-2,
5-norbonadiene, 2-isopropenyl-2,5-norbonadiene, dicyclopentadiene, tricyclopentadiene and dihydrodicyclopentadienyloxyethylene with acrylic acid, methacrylic acid, itaconic acid,
Examples thereof include esters with unsaturated carboxylic acids such as maleic acid and fumaric acid, and one or more of these are used.

The content of the non-conjugated diene can be represented by an iodine value, and the iodine value is 3 to 50, preferably 5 to 40. If the iodine value is less than 3, a sufficient vulcanizing effect is not recognized, and the iodine value is 5
If it exceeds 0, gelation tends to occur during polymerization. The iodine value can be measured by a known method (for example, "Rubber Test Method", p. 657, edited by The Japan Rubber Association, (1)
963)).

The ethylene / α- used in the present invention
The Mooney viscosity (ML _{1 + 4} ) at 100 ° C. of the olefin / non-conjugated diene copolymer rubber is 30 or more and less than 200,
Preferably it is 50 or more and 150 or less. If the Mooney viscosity is less than 30 or more than 200, molding failure may occur. Further, when the ratio is 50 or more and 150 or less, the stability of the electric resistance of the semiconductive rubber of the present invention is more excellent, which is preferable.

The ethylene / α- used in the present invention
The molecular weight distribution (weight average molecular weight / number average molecular weight) of the olefin / non-conjugated diene copolymer rubber measured by gel permeation chromatography is 3 or less, preferably 2.5 or less. If the molecular weight distribution exceeds 3, the composition of the present invention obtained may be too sticky.

The method for producing the above-mentioned ethylene / α-olefin / non-conjugated diene copolymer rubber is not particularly limited, and it can be produced using various catalysts such as a titanium catalyst, a vanadium catalyst and a metallocene catalyst. . Especially, it is preferable to manufacture using a metallocene type catalyst excellent in copolymerizability. By this method, it is possible to obtain a copolymer having a high activity and a narrow molecular weight distribution and composition distribution.

As the metallocene-based catalyst, a combination of a metallocene-based compound and an aluminoxane compound (Japanese Patent Application Laid-Open No. 58-1983)
JP-A-19-19309, JP-A-60-35006, JP-A-6-30
Or a combination of a metallocene compound and an ionized ionic compound which reacts with the metallocene compound to form a stable anion (Japanese Patent Application Laid-Open No. 1-5020206, WO91). / 1
No. 4713, WO92 / 01723, and JP-A-5-310829). However, it is generally known that, in ethylene / α-olefin copolymerization, the molecular weight decreases as the content of α-olefin increases. Therefore, in order to efficiently produce the high molecular weight ethylene / α-olefin / non-conjugated diene copolymer rubber used in the present invention, it is preferable to use a catalyst comprising the following compound.

A) a transition metal compound represented by the following general formula (1) b) a cationic transition compound represented by the following general formulas (2), (3), (4) and (5) Components that can be metal compounds c) Organoaluminum compounds represented by the following general formula (6) a) Transition metal compounds are represented by the following general formula (1)

[0015]

Embedded image

[Cp ¹ is a cyclopentadienyl group, an indenyl group, a fluorenyl group or a substituted product thereof, and Cp ² is an unsubstituted or substituted group (—R, —BR ₂ , —S
_{iR 3, -NR 2, -PR 2} , -OR, -SR, -F, -
Cl, -Br, -I: where R is hydrogen or carbon number 1
And R ¹ and R ² are each independently hydrogen, halogen or a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group or an aryloxy group; At least one is an aryl group or a substituted aryl group, M is titanium, zirconium or hafnium, and R ³ and R ⁴ are each independently hydrogen, halogen or a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group or an aryloxy group. Group. ].

As a specific example of the general formula (1), diphenylmethylene (cyclopentadienyl) (fluorenyl)
Zirconium dichloride, methylphenylmethylene (cyclopentadienyl) (fluorenyl) zirconium dichloride, diphenylmethylene (cyclopentadienyl) (2,7-di-t-butylfluorenyl) zirconium dichloride, methylphenylmethylene (cyclopentadiene) Enyl) (2,7-di-t-butylfluorenyl) zirconium dichloride, diphenylmethylene (cyclopentadienyl) (2,7-dimethylfluorenyl) zirconium dichloride, methylphenylmethylene (cyclopentadienyl) ( 2,7-dimethylfluorenyl) zirconium dichloride, diphenylmethylene (cyclopentadienyl) (2,7-diphenylfluorenyl) zirconium dichloride, methylphenylmethylene (cyclo Ntajieniru) (2,7-diphenyl fluorenyl) zirconium dichloride, diphenylmethylene (cyclopentadienyl) (a, i-dibenzo fluorenyl) zirconium dichloride, methylphenylmethylene (cyclopentadienyl) (a, i-
Dibenzofluorenyl) zirconium dichloride, diphenylmethylene (cyclopentadienyl) (b, h-
Dibenzofluorenyl) zirconium dichloride, methylphenylmethylene (cyclopentadienyl) (b,
h-dibenzofluorenyl) zirconium dichloride, di (4-tolyl) methylene (cyclopentadienyl) (fluorenyl) zirconium dichloride, di (4-biphenyl) methylene (cyclopentadienyl)
(Fluorenyl) zirconium dichloride, diphenylmethylene (cyclopentadienyl) (2-dimethylaminofluorenyl) zirconium dichloride, methylphenylmethylene (cyclopentadienyl) (2-dimethylaminofluorenyl) zirconium dichloride,
Diphenylmethylene (cyclopentadienyl) (2-methoxyfluorenyl) zirconium dichloride, methylphenylmethylene (cyclopentadienyl) (2-methoxyfluorenyl) zirconium dichloride, diphenylmethylene (3-methylcyclopentadienyl)
(Fluorenyl) zirconium dichloride, methylphenylmethylene (3-methylcyclopentadienyl)
(Fluorenyl) zirconium dichloride, diphenylmethylene (3,4-dimethylcyclopentadienyl)
(Fluorenyl) zirconium dichloride, methylphenylmethylene (3,4-dimethylcyclopentadienyl) (fluorenyl) zirconium dichloride, and compounds in which zirconium of the above compound is substituted with titanium or hafnium, but are not limited thereto. is not. Among them, a compound having a substituted fluorenyl group as a ligand and having hafnium as a central metal is preferable because it has excellent copolymerizability and can further increase the molecular weight.

B) Components which can convert the above transition metal compound into a cationic transition metal compound include protonic acid (2), Lewis acid (3), ionized ionic compound (4) and Lewis acidic compound (5).

The protonic acid represented by the following formula _{^{(2) [HL 1 l]}} [M 1 R 5 4] (2) [ wherein, H is a proton, L ¹ is a Lewis base each independently, l is 0 <l ≦ 2, M ¹ is a boron atom, aluminum atom or gallium atom, R ⁵
Are each independently a halogen-substituted aryl group having 6 to 20 carbon atoms. ] It is a compound represented by these.

[0020] Lewis _{^{acid, [5 4 M 1 R]}} (3) [ wherein following general formula (3) [C], C is a carbonium cation or tropylium cation, M ¹ is a boron atom, an aluminum atom Or a gallium atom, and each R ⁵ is independently a halogen-substituted aryl group having 6 to 20 carbon atoms. ] It is a compound represented by these.

The ionizing ionic compound is represented by the following general formula ^{(4) [M 2 L 2} m] [M 1 R 5 4] (4) [ wherein, M ² of the Periodic Table Group 2, Group 8, Group 9, 10 groups, 11
A cation of a metal selected from the group consisting of
² is a Lewis base or cyclopentadienyl group,
m is 0 ≦ m ≦ 2, M ¹ is a boron atom, an aluminum atom or a gallium atom, and R ⁵ is each independently a halogen-substituted aryl group having 6 to 20 carbon atoms. ] It is a compound represented by these.

The Lewis acidic compound is represented by the following general formula ^{(5) [M 1 R 5} 3] (5) [ wherein, M ¹ is a boron atom, aluminum atom or gallium atom, R ⁵ are each independently carbon Number 6-20
Is a halogen-substituted aryl group. ] It is a compound represented by these.

The protonic acid (2), Lewis acid (3), ionized ionic compound (4) and Lewis acidic compound (5) used as components of the catalyst react with the above-mentioned transition metal compound to form a cationic transition compound. A compound capable of forming a metal compound and providing a counter anion to the generated cationic transition metal compound.

Specific examples of the protonic acid represented by the general formula (2) include diethyloxonium tetrakis (pentafluorophenyl) borate, dimethyloxonium tetrakis (pentafluorophenyl) borate, tetramethyleneoxonium tetrakis (pentafluorophenyl) ) Borate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, tri-n-butylammonium tetrakis (pentafluorophenyl) borate, diethyloxonium tetrakis (pentafluorophenyl) aluminate, dimethyloxonium tetrakis (pentane) Fluorophenyl) aluminate, tetramethyleneoxoniumtetrakis (pentafluorophenyl) aluminate, N, N-dimethylaniliniumtetrakis Pentafluorophenyl) aluminate, but it can be exemplified tri -n- butylammonium tetrakis (pentafluorophenyl) aluminate, but are not limited thereto.

As the Lewis acid represented by the general formula (3), specifically, trityltetrakis (pentafluorophenyl) borate, trityltetrakis (pentafluorophenyl) aluminate, tropylium tetrakis (pentafluorophenyl) borate, Examples include, but are not limited to, tropylium tetrakis (pentafluorophenyl) aluminate.

Specific examples of the ionized ionic compound represented by the general formula (4) include lithium salts such as lithium tetrakis (pentafluorophenyl) borate and lithium tetrakis (pentafluorophenyl) aluminate, and ether complexes thereof. , Ferrocenium salts such as ferrocenium tetrakis (pentafluorophenyl) borate and ferrocenium tetrakis (pentafluorophenyl) aluminate, and silver salts such as silver tetrakis (pentafluorophenyl) borate and silver tetrakis (pentafluorophenyl) aluminate And the like, but are not limited thereto.

Specific examples of the Lewis acidic compound represented by the general formula (5) include tris (pentafluorophenyl) borane, tris (2,3,5,6-tetrafluorophenyl) borane, tris (2 3,4,5-tetraphenylphenyl) borane, tris (3,4,5-trifluorophenyl) borane, phenylbis (pentafluorophenyl) borane, tris (3,4,5-trifluorophenyl) aluminum, etc. But are not limited to these.

C) As the organometallic compound, Periodic Table 1
Group, Group 2, Group 3, Sn or Zn can be given an organometallic compound containing the following formula in particular ^{(6) [M 3 R 6} n] (6) [ wherein, M ³ is the period Table 1 group, 2 group, 3 group, Sn or Z
n. R ⁶ is each independently hydrogen, carbon number 1 to
24 alkyl groups or alkoxy groups, or an aryl group having 6 to 24 carbon atoms, an aryloxy group, an arylalkyl group, an arylalkoxy group, an alkylaryl group or an alkylaryloxy group, wherein at least one R ⁶ is a hydrogen atom, It is an alkyl group having 1 to 24 carbon atoms or an aryl group, an arylalkyl group or an alkylaryl group having 6 to 24 carbon atoms. n is equal to the oxidation number of M ^3. ] Is an organometallic compound represented by the formula:

The compound represented by the general formula (6) includes, for example, trimethylaluminum, triethylaluminum, triisopropylaluminum, tri-n-
Propyl aluminum, triisobutyl aluminum,
Tri-n-butylaluminum, triamylaluminum, dimethylaluminum ethoxide, diethylaluminum ethoxide, diisopropylaluminum ethoxide, di-n-propylaluminum ethoxide, diisobutylaluminum ethoxide, di-n-
Butyl aluminum ethoxide, dimethyl aluminum hydride, diethyl aluminum hydride,
Examples thereof include diisopropylaluminum hydride, di-n-propylaluminum hydride, diisobutylaluminum hydride, and di-n-butylaluminum hydride, but are not limited thereto.

Examples of the conductive filler used in the present invention include conductive carbon black, titanium oxide, ruthenium oxide, triiron tetroxide, tin oxide, conductive whiskers, alkali metal salts, carbon fibers, and double oxides. Species or two or more species are used. Among them, conductive carbon black is preferably used because of its availability. The type and amount of the conductive carbon black can be controlled according to the intended electric resistance.
It is preferable to use carbon black of 0 m ² / g or more. Carbon black having a specific surface area of less than 500 m ² / g may impair the semiconductive property. The specific surface area is evaluated by a known low-temperature nitrogen adsorption method.

The amount of the conductive filler is ethylene / α
5 parts by weight or more and 50 parts by weight or less based on 100 parts by weight of the olefin / non-conjugated diene copolymer rubber. If the amount is less than 5 parts by weight, the electric resistance of the semiconductive rubber composition of the present invention may be too large, and if it exceeds 50 parts by weight, the stability of the electric resistance may be impaired.

In addition, ionic and nonionic surfactants can be added to the semiconductive rubber composition of the present invention for the purpose of stabilizing electric resistance.

Further, the semiconductive rubber composition of the present invention includes:
It is also possible to add reinforcing carbon black.
As the reinforcing carbon black, those having a specific resistance of 1 Ω · cm or more can be suitably used. Examples of the reinforcing carbon black include HAF, FEF, and ISA.
F, SAF, SRF, FT, EPC, MPC and the like can be used.

Further, a softener may be added to the semiconductive rubber of the present invention for the purpose of adjusting the hardness or stabilizing the electric resistance value. Examples of the softener include paraffin softener, naphthene softener, aroma softener, asphalt, petrolatum, ozokerite, tall oil, low polymerization degree phenol formaldehyde resin, and low melting point styrene resin.

The method for crosslinking the semiconductive rubber of the present invention is not limited, and a known vulcanizing agent is used. It is also possible to use a vulcanization accelerator, a co-crosslinking agent, a vulcanization retarder, a dispersant, an anti-scorch agent, stearic acid, zinc white and the like together with the vulcanizing agent. Furthermore, to the extent that the performance of the semiconductive rubber of the present invention is not deteriorated, talc, clay, silica, a tackifier, an antioxidant, a heat stabilizer, a flame retardant, a flame retardant auxiliary, an ultraviolet absorber, a foaming agent, An antifoaming agent, a rust inhibitor, a fungicide and the like may be added as necessary.

It is also possible to add another rubber or resin to such an extent that the performance of the semiconductive rubber of the present invention is not impaired. Rubbers that can be added include EPDM, butyl rubber, natural rubber, acrylonitrile butadiene rubber, butadiene rubber, isoprene rubber, styrene butadiene rubber, silicone rubber, polynorbornene rubber, polyhexene rubber, and chloroprene rubber. Also,
Examples of resins that can be added include low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, polybutene, polypropylene, poly (4-methyl-1-pentene), styrene-isoprene-styrene block copolymer, and styrene-ethylene butene. -Styrene block copolymer, styrene-ethylene propylene-styrene block copolymer and olefin-based thermoplastic elastomer.

The method for producing the semiconductive rubber composition of the present invention is not particularly limited, and an ethylene / α-olefin / non-conjugated diene copolymer rubber and a conductive filler are prepared by a known method.
If desired, the vulcanizing agent or other auxiliary materials can be blended and then shaped and crosslinked.

The semiconductive rubber composition of the present invention comprises a roll,
After shaping into an arbitrary shape such as a plate, it is subjected to surface processing such as polishing and coating as necessary, and further laminated with other resin and rubber, etc., and it is used for electrophotographic equipment members such as charging rolls Used favorably.

[0039]

The present invention will now be described by way of examples, which are illustrative and not restrictive. Various measurements in the examples were performed by the following methods.

(Measurement of 1-hexene content of ethylene / 1-hexene / 5-ethylidene-2-norbornene copolymer rubber) o-dichlorobenzene / d ₆ -benzene (90
/ 10% by volume) as a solvent at 100 MHz, ¹³ C-NMR.
Spectrum (JNM GX400 manufactured by JEOL Ltd.)
The measurement was performed and Macromolecules, 15, 1
402 (1982).

(Measurement of Mooney Viscosity) The Mooney viscosity at 100 ° C. of the raw rubber was measured using a Mooney viscometer manufactured by Shimadzu Corporation. The rotor was L-shaped, the preheating time was 1 minute, and the operation time of the rotor was 4 minutes.

(Measurement of molecular weight distribution) Gel permeation chromatography at 140 ° C. using o-dichlorobenzene as a solvent (150C manufactured by Millipore Co., Ltd.)
Molecular weight distribution (weight-average molecular weight / number-average molecular weight) was determined by using GPC).

(Measurement of Volume Resistance) Four-terminal electrode type electric resistance measuring device (Loresta AP MCP-T40 manufactured by Mitsubishi Chemical Corporation)
Using 0), the volume resistance was measured.

Synthesis Example of Ethylene / 1-hexene / 5-ethylidene-2-norbornene copolymer rubber In a 5-liter autoclave, 2200 ml of toluene and 5-
50 ml of ethylidene-2-norbornene and 750 ml of 1-hexene were added, and the internal temperature was raised to 80 ° C. while stirring. Further, ethylene was introduced so that the total pressure became 8 kg / cm ² . Next, toluene 1 was placed in another reaction vessel.
0 ml, 3 μmol of diphenylmethylene (cyclopentadienyl) (fluorenyl) hafnium dichloride, 3 mmol of triisobutylaluminum, 3.6 μmol of dimethylanilinium pentafluorophenylborate synthesized by a known method, and the mixed solution was added. After stirring for 20 minutes, the mixture was introduced into an autoclave and polymerization was started. In this polymerization, the total pressure was maintained at 8 kg / cm ² by continuously introducing ethylene, and 80 ° C.
For 10 minutes.

After completion of the polymerization, the polymer was washed with a large amount of ethanol and dried at 80 ° C. under reduced pressure for 12 hours. As a result, the 1-hexene content was 45 mol% and the iodine value was 15
Of ethylene / 1-hexene / 5-ethylidene-2-norbornene copolymer rubber (107 g). The Mooney viscosity of this copolymer at 100 ° C. (ML _{1 + 4} (100
C)) was 65 and the molecular weight distribution was 1.8.

Example 1 A 6-inch roll kneader having a surface temperature of 50 ° C. (Kansai roll)
In addition, 100 parts by weight of the ethylene / 1-hexene / 5-ethylidene-2-norbornene copolymer rubber obtained in the synthesis example,
One part by weight of stearic acid was charged and kneaded. Then, 10 parts by weight of conductive carbon black (Printer XE2, manufactured by Degussa, specific surface area: 950 m ² / g), 5 parts by weight of zinc white, tetramethylthiuram disulfide (TMT)
D) 1 part by weight of 2-mercaptobenzothiazole (MB
T) 0.5 parts by weight and 1.5 parts by weight of sulfur were added in this order to obtain a rubber compound.

The obtained rubber compound was extruded into a roll shape and cured by a Labo Plastomill single screw extruder (manufactured by Toyo Seiki Seisaku-sho, Ltd.) set at 50 ° C. 150 ℃
Was left in a vulcanization tube set for 30 minutes to perform secondary vulcanization. Volume resistance was measured at arbitrary 12 places of the obtained rubber roll. Table 1 shows the results.

Comparative Example 1 Instead of the ethylene / 1-hexene / 5-ethylidene-2-norbornene copolymer rubber, an ethylene / propylene / 5-ethylidene-2-norbornene copolymer rubber (J
SREP24, iodine value 15, ML _{1 + 4} (100 ° C) 6
A rubber roll was obtained and tested in the same manner as in Example 1, except that 5) was used. Table 1 shows the results.

Comparative Example 2 In place of conductive carbon black, HAF carbon (Diablack H, manufactured by Mitsubishi Chemical Corporation, specific surface area: 86 m ² /
A rubber roll was obtained and tested in the same manner as in Example 1 except that g) was used. Table 1 shows the results.

[0050]

[Table 1]

[0051]

As described above, the semiconductive rubber composition of the present invention exhibits a stable electric resistance and can be preferably used for a member of an electrophotographic apparatus.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location C08L 23/08 KEC C08L 23/08 KEC 47/00 LKC 47/00 LKC

Claims (2)

[Claims] 1. An ethylene / α-olefin / non-conjugated diene copolymer rubber 100 having the following characteristics (a) to (e):
A semiconductive rubber composition comprising parts by weight and 5 to 50 parts by weight of a conductive filler. (A) Number of carbon atoms of α-olefin: 4 or more and 20 or less (b) Content of α-olefin: 20 mol% or more and 90 mol% or less (c) Mooney viscosity (ML _{1 + 4} ) at 100 ° C .: 3
0 to less than 200 (d) Iodine value: 3 to 50 (e) Molecular weight distribution (weight average molecular weight / number average molecular weight) determined by gel permeation chromatography: 3 or less 2. An electrophotographic apparatus member comprising the semiconductive rubber composition according to claim 1.