JP5293997B2 - Semiconductive vulcanized rubber composition, semiconductive vulcanized rubber molded product, and semiconductive rubber roll - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductive vulcanized rubber molded product and a semiconductive rubber roll using it having excellent (1) semiconductivity, (2) environment dependency, (3) compression set property, (4) low hardness, (5) storage stability, (6) photoreceptor anti-stain properties (inhibition of blooming onto the semiconductive vulcanized rubber molded product surface), and (7) polishing workability of the semiconductive vulcanized rubber, without containing N-cyclohexylthio phthalimide. <P>SOLUTION: The semiconductive vulcanized rubber composition comprises (a) 100 pts.wt. of an epihalohydrin rubber, (b) 0.1-5 pts.wt. of an organozinc compound, (c) 0.1-5 pts.wt. of 1,8-diazabicyclo(5,4,0)undecene-7 and/or its salt, (d) 0.1-10 pts.wt. of a quinoxaline vulcanizing agent, and (e) 1-10 pts.wt. of an acid acceptor, which is at least one kind selected from the group consisting of a metal oxide, a metal hydroxide, and microporous inorganic crystals. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a composition for a semiconductive vulcanized rubber, a semiconductive vulcanized rubber molded article, and a semiconductive rubber roll used in an electrophotographic copying machine, a printer or the like provided with a photoreceptor using these.

  In recent years, in rolls that are in direct contact with a photoreceptor such as charging rolls and transfer rolls used in contact-type charging systems, there has been a demand for further improvements in the physical properties of rubber materials at the base material due to demands for high image quality and high speed. Yes.

In particular, a semiconductive rubber material (semiconductive vulcanized rubber) such as a rubber charging roll and a rubber transfer roll of an electrophotographic copying machine is required to satisfy the following conditions (1) to (7).
(1) It has conductivity of about 10 ⁶ to 10 ¹⁰ Ω · cm in volume resistivity.
(2) Since it is preferable that the printing characteristics do not change even under low temperature and low humidity and high temperature and high humidity, the environmental dependency of volume resistivity is small.
(3) When a roll is used for the above-mentioned use, since both ends of the roll are loaded and used, load deformation is often repeated over a long period of time. Be excellent.
(4) A soft rubber material for reducing the driving torque of the roll and for uniformly charging the surface of the photoreceptor.
(5) Premature vulcanization is difficult to occur during processing and molding.
(6) The component used to prevent early vulcanization during processing and molding should bloom from the rubber material (vulcanized rubber) and not adhere to the surface of the photoreceptor.
(7) The rubber material (vulcanized rubber) has good polishing processability.

  As a method for obtaining a semiconductive rubber material having excellent compression set, a method using a 2,3-dimercaptoquinoxaline derivative is disclosed (see Patent Document 1). When using the 2,3-dimercaptoquinoxaline derivative, in order to obtain a good vulcanization rate, 1,8-diazabicyclo (5,4,0) undecene-7 or a weak acid salt thereof is used as a vulcanization accelerator. However, by adding 1,8-diazabicyclo (5,4,0) undecene-7 or the like, the composition for vulcanized rubber using them can be used during storage or before the vulcanization step. In order to obtain a vulcanization retarding effect, N-cyclohexylthiophthalimide, which is a known vulcanization retarder, is usually used during the kneading process.

  When N-cyclohexylthiophthalimide is used as a vulcanization retarder, N-cyclohexylthiophthalimide exhibits a very good vulcanization retarding effect. As a result of sublimation, there were problems such as odor and sublimated N-cyclohexylthiophthalimide crystallized on the surface of the process equipment, increasing the maintenance frequency of the equipment.

  Furthermore, N-cyclohexylthiophthalimide is prone to a so-called Bloom phenomenon in which it migrates to the rubber surface and crystallizes due to the incompatibility with epihalohydrin rubber. Therefore, there is a problem that the surface of the photoreceptor is contaminated particularly when the rubber is used for a charging roller or the like.

  Moreover, in order to prevent premature vulcanization, a method using an organic zinc salt in combination with the N-cyclohexylthiophthalimide is disclosed (see Patent Document 2).

  However, in this case as well, as described above, the addition of the N-cyclohexylthiophthalimide could not solve the bloom problem in the charging roller used for the semiconductive material.

JP 2000-191900 A JP 2003-253112 A

  Therefore, the present inventors have used (1) semiconductivity, (2) environment dependency, and (2) environment dependence by using a composition for semiconductive vulcanized rubber containing a specific amount of the above (a) to (e). 3) compression set, (4) low hardness, (5) storage stability, (6) non-contamination of photoreceptor (inhibition of bloom on the surface of semiconductive vulcanized rubber), and (7) semi It is an object of the present invention to provide a semiconductive vulcanized rubber molded article excellent in polishing processability of a conductive vulcanized rubber molded article and a semiconductive rubber roll using the same. In particular, the present invention provides a composition for semiconductive vulcanized rubber that can suppress bloom on the surface of a semiconductive vulcanized rubber molded article without containing N-cyclohexylthiophthalimide that is usually used as a vulcanization retarder. For the purpose.

That is, the composition for semiconductive vulcanized rubber of the present invention is based on (a) 100 parts by weight of epihalohydrin rubber.
(B) 0.1 to 5 parts by weight of an organic zinc compound,
(C) 0.1 to 5 parts by weight of 1,8-diazabicyclo (5,4,0) undecene-7 and / or its weak acid salt,
(D) 0.1 to 10 parts by weight of a quinoxaline vulcanizing agent,
(E) It contains 1 to 10 parts by weight of an acid acceptor which is at least one selected from the group consisting of metal oxides, metal hydroxides, and inorganic microporous crystals.

  In the composition for semiconductive vulcanized rubber of the present invention, (b) at least one organic zinc compound is selected from the group consisting of benzimidazoles, thiophenols, dithiocarbamic acids, and zinc salts of carboxylic acids. It is preferable that

  In the composition for semiconductive vulcanized rubber of the present invention, the weight ratio of (c) 1,8-diazabicyclo (5,4,0) undecene-7 and / or a salt thereof and (b) an organic zinc compound is 0.15 ≦ (c) / (b) ≦ 0.7.

  In the composition for semiconductive vulcanized rubber of the present invention, it is preferable that (d) the quinoxaline vulcanizing agent is 6-methylquinoxaline-2,3-dithiocarbonate.

  In the composition for semiconductive vulcanized rubber of the present invention, the inorganic microporous crystal is at least one selected from the group consisting of synthetic hydrotalcite, Li-Al inclusion compound, and synthetic zeolite. Is preferred.

  The semiconductive vulcanized rubber composition of the present invention preferably further contains (f) sulfur and / or active sulfur releasing organic vulcanization accelerator.

  In the composition for semiconductive vulcanized rubber of the present invention, the active sulfur releasing organic vulcanization accelerator is preferably a thiuram compound.

  In the semiconductive vulcanized rubber composition of the present invention, the thiuram compound is preferably dipentamethylene thiuram tetrasulfide.

  The semiconductive vulcanized rubber molded article of the present invention is preferably formed by vulcanizing the composition for semiconductive vulcanized rubber.

  The semiconductive rubber roll of the present invention is preferably made of the semiconductive vulcanized rubber molded body and used in an electrophotographic process including a photoreceptor.

  The composition for a semiconductive vulcanized rubber of the present invention contains a specific amount of the above (a) to (e) and does not contain N-cyclohexylthiophthalimide which is usually used as a vulcanization retarder. (1) Semiconductivity is required for semiconductive vulcanized rubber moldings used, and semiconductive rubber rolls that are in direct contact with a photoreceptor such as a charging roll or transfer roll used in an electrophotographic copying machine using the same. , (2) environmental dependence, (3) compression set, (4) low hardness, (5) storage stability, (6) suppression of bloom on the surface of the semiconductive vulcanized rubber molding, and (7 ) It is very useful because it satisfies the requirements for polishing processability of the semiconductive vulcanized rubber molding.

  Furthermore, when at least one selected from the group consisting of zinc salts of benzimidazoles, thiophenols, dithiocarbamic acids, and carboxylic acids is used as the specific organic zinc compound, the half of the present invention is used. It is very useful as a semiconductive rubber molding (material) used in electrophotographic copying machines because it can suppress bloom in the conductive vulcanized rubber molding and prevent contamination of the photoreceptor surface. It is. Moreover, this invention has confirmed that when a quinoxaline type | system | group vulcanizing agent and the said specific organozinc compound were combined, a vulcanization delay effect can be exhibited and a bloom can be suppressed.

  Hereinafter, the configuration of the present invention will be described in detail.

  The (a) epihalohydrin rubber used in the present invention refers to an epihalohydrin homopolymer or other epoxide copolymerizable with epihalohydrin, such as ethylene oxide, propylene oxide, allyl glycidyl ether, and the like. Examples of these are epichlorohydrin homopolymer, epibromohydrin homopolymer, epichlorohydrin-ethylene oxide copolymer, epibromohydrin-ethylene oxide copolymer, epichlorohydrin-propylene oxide copolymer, epibromohydrin- Propylene oxide copolymer, epichlorohydrin-ethylene oxide-allyl glycidyl ether ternary copolymer, epibromohydrin-ethylene oxide-allyl glycidyl ether terpolymer, epichlorohydrin-ethylene oxide-propylene oxide-allyl glycidyl ether quaternary Examples thereof include a copolymer and an epibromohydrin-ethylene oxide-propylene oxide-allyl glycidyl ether quaternary copolymer. These homopolymers or copolymers can be used alone or in combination of two or more.

  The (a) epihalohydrin rubber is preferably an epichlorohydrin homopolymer, epichlorohydrin-ethylene oxide copolymer, epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer, and more preferably epichlorohydrin-ethylene oxide-allyl. It is a glycidyl ether terpolymer.

As for the molecular weight of these homopolymers or copolymers, those having a Mooney viscosity display of about ML _{1 + 4} (100 ° C.) = 30 to 150 are usually used as they are.

  The (b) organozinc compound in the present invention is used as a vulcanization retarder in order to improve the early vulcanization property of the semiconductive vulcanized rubber composition, and is added in order to further improve the photoreceptor non-contamination property. It has been. Usually, N-cyclohexylthiophthalimide, which is a known vulcanization retarder, is used to improve early vulcanizability. However, the incorporation of N-cyclohexylthiophthalimide causes a bloom problem. By using together with the component (d) a quinoxaline-based vulcanizing agent, which will be described in detail below, it is possible to improve early vulcanization and non-contamination of the photoreceptor.

  The amount of component (b) is 0.1 to 5 parts by weight, preferably 0.5 to 2 parts by weight, based on 100 parts by weight of (a) epihalohydrin rubber. If the blending amount is less than 0.1 parts by weight, the effect of delaying vulcanization cannot be sufficiently exhibited, and if it exceeds 5 parts by weight, it is not economical and not preferred.

  Examples of the component (b) include benzimidazoles, thiazoles, dithiocarbamic acids, xanthogenic acids, dithiophosphoric acids, carboxylic acids, thiols, and zinc salts of thiophenols. Benzimidazoles, thiophenols, dithiocarbamic acids, and zinc salts of carboxylic acids are preferable, and benzimidazoles and zinc salts of carboxylic acids are particularly preferable in terms of non-contamination of the photoreceptor.

  Specific examples of the component (b) include 2-mercaptobenzimidazole zinc salt, 2-mercaptobenzothiazole salt, zinc dibenzyldithiocarbamate, zinc dibutyldithiocarbamate, zinc pentamethylenedithiocarbamate, diamyldithiocarbamine. Zinc acid, zinc butylxanthate, zinc isopropylxanthate, zinc o, o'-diisopropyldithiophosphate, zinc o, o'-dibutyldithiophosphate, zinc salt of 2-benzamidothiophenol, zinc stearate and the like. These zinc compounds may be used alone or in combination of two or more, as long as the effects of the present invention are not impaired.

  As the vulcanization accelerator (c) used in the present invention, 1,8-diazabicyclo (5,4,0) undecene-7 (DBU) and / or its weak acid salt is used. , Carboxylate, phenol salt, thiol salt and other weak acid salts can be used. Representative examples of these DBU salts include, for example, DBU-carbonate, DBU-stearate, DBU-2-ethylhexylate, DBU-benzoate, DBU-salicylate, DBU-3-hydroxy- Examples thereof include 2-naphthoate, DBU-phenol resin salt, DBU-2-mercaptobenzothiazole salt, DBU-2-mercaptobenzimidazole salt and the like.

  The amount of component (c) is 0.1 to 5 parts by weight, preferably 0.25 to 2 parts by weight, based on 100 parts by weight of (a) epihalohydrin rubber. When the blending amount is less than 0.1 parts by weight, vulcanization does not proceed sufficiently and excellent compression set cannot be obtained. On the other hand, if the blending amount exceeds 5 parts by weight, the vulcanization rate of the epihalohydrin rubber becomes too fast, which may cause a processing problem.

  Further, regarding the effect of preventing early vulcanization, the weight ratio of the component (c) and the component (b) is preferably set to 0.15 ≦ (c) / (b) ≦ 0.7, and further 0.30 It is particularly preferable to set ≦ (c) / (b) ≦ 0.7.

  In the present invention, (d) the quinoxaline-based vulcanizing agent is used for vulcanizing the semiconductive vulcanized rubber composition of the present invention, and the blending amount thereof is (a) 100 parts by weight of epihalohydrin-based rubber. On the other hand, it is 0.1-10 weight part, Preferably, it is 0.5-5 weight part. When the blending amount is less than 0.1 parts by weight, vulcanization is insufficient, and when it exceeds 10 parts by weight, the progress of vulcanization becomes excessive, and the resulting rubber material (vulcanized rubber) becomes too rigid. In general, the physical properties expected as an epihalohydrin rubber (vulcanized rubber) cannot be obtained.

  Examples of the component (d) include quinoxaline-2,3-dithiocarbonate, 6-methylquinoxaline-2,3-dithiocarbonate, 6-isopropylquinoxaline-2,3-dithiocarbonate, 5,8-dimethylquinoxaline- 2,3-dithiocarbonate and the like can be mentioned. In particular, it is preferable to use 6-methylquinoxaline-2,3-dithiocarbonate, and it is more preferable that the blending amount is 0.5 to 5 parts by weight.

  As the (e) acid acceptor used in the present invention, at least one selected from the group consisting of metal oxides, metal hydroxides, and inorganic microporous crystals is used depending on the vulcanizing agent. Inorganic microporous crystals or inorganic microporous crystals and metal compounds are preferable, and inorganic microporous crystals are particularly preferable.

  The inorganic microporous crystal refers to a crystalline porous body, and can be clearly distinguished from an amorphous porous body such as silica gel and alumina. Examples of such inorganic microporous crystals include zeolites, aluminophosphate type molecular sieves, layered silicates, synthetic hydrotalcites, alkali metal titanates and the like. More preferred acid-accepting agents include zeolites and synthetic hydrotalcite, and particularly preferred is synthetic hydrotalcite.

  The zeolites are natural zeolites, A type, X type, Y type synthetic zeolites, sodalites, natural or synthetic mordenites, various zeolites such as ZSM-5, and metal substitutes thereof. It may be used in combination of two or more. Further, the metal of the metal substitution product is often sodium. As the zeolite, those having a large acid-accepting ability are preferable, and A-type zeolite is preferable.

The synthetic hydrotalcite is represented by the following general formula (1).
_{Mg X Zn Y Al Z (OH} ) 2 (X + Y) + 3Z-2 CO 3 · wH 2 O (1)
[Wherein x and y are real numbers of 0 to 10, where x + y is 1 to 10, z is a real number of 1 to 5, and w is a real number of 0 to 10, respectively]. Examples of hydrotalcites represented by the general formula (1) include Mg _4.5 Al ₂ (OH) ₁₃ CO ₃ .3.5H ₂ O, Mg _4.5 Al ₂ (OH) ₁₃ CO ₃ , Mg ₄ Al ₂ (OH) ₁₂ CO ₃ .3.5H ₂ O, Mg ₆ Al ₂ (OH) ₁₆ CO ₃ .4H ₂ O, Mg ₅ Al ₂ (OH) ₁₄ CO ₃ .4H ₂ O, Mg ₃ Al _{2 (OH) 10 CO 3 · 1.7H} 2 O, Mg 3 ZnAl 2 (OH) 12 CO 3 · wH 2 O, Mg 3 ZnAl 2 (OH) 12 CO 3, and the like.

  Among the inorganic microporous crystals, the acid acceptor capable of obtaining particularly good compression set is preferably synthetic hydrotalcite, Li-Al inclusion compound, synthetic zeolite, or a metal oxide thereof. In particular, a synthetic hydrotalcite or a combination of a synthetic hydrotalcite and a metal oxide is particularly preferable.

  As the acid acceptor other than the inorganic microporous crystals, metal oxides and metal hydroxides are used, but other metal compounds can be used as long as the effects of the present invention are not impaired. Examples include Periodic Table Group II (Group 2 and Group 12) metal oxides, hydroxides, carbonates, carboxylates, silicates, borates, phosphites, Periodic Table Group III ( Group 3 and Group 13) Metal oxides, hydroxides, carboxylates, silicates, sulfates, nitrates, phosphates, Group IV (Groups 4 and 14) metal oxides, bases Metal compounds such as basic carbonate, basic carboxylate, basic phosphite, basic sulfite, and tribasic sulfate. In particular, it is preferable to use a metal oxide and a metal hydroxide.

  Further, specific examples of the metal oxide, metal hydroxide and other metal compounds include magnesia, magnesium hydroxide, aluminum hydroxide, barium hydroxide, magnesium carbonate, barium carbonate, quicklime, slaked lime, calcium carbonate, silicic acid. Calcium, calcium stearate, calcium phthalate, calcium phosphite, zinc white, tin oxide, lisage, red lead, lead white, dibasic lead phthalate, dibasic lead carbonate, tin stearate, basic lead phosphite, Examples thereof include basic tin phosphite, basic lead sulfite, and tribasic lead sulfate.

  The amount of the component (e) is preferably 1 to 10 parts by weight, more preferably 1.5 to 5 parts by weight with respect to 100 parts by weight of the (a) epihalohydrin rubber. When the blending amount is less than 1 part by weight, crosslinking is insufficient. On the other hand, when the blending amount exceeds 10 parts by weight, the vulcanizate (vulcanized rubber) becomes too rigid, and usually an epihalohydrin rubber ( The physical properties expected as vulcanized rubber) cannot be obtained.

  The (f) sulfur and / or active sulfur releasing type organic vulcanization accelerator used in the present invention is added to improve the polishing processability of a rubber material (vulcanized rubber) obtained by vulcanizing the composition of the present invention. The blending amount is preferably 0.05 to 10 parts by weight, and more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of (a) epihalohydrin rubber. If the blending amount is less than 0.05 parts by weight, the effect of improving the polishing processability cannot be expected, and if it exceeds 10 parts by weight, the rubber material (vulcanized rubber) becomes rigid, which is not preferable.

  Specific examples of the component (f) include sulfur, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram monosulfide, tetrabutylthiuram disulfide, N, N′-dimethyl-N, N ′. -Active sulfur-releasing organic vulcanization accelerator compounds such as diphenylthiuram disulfide, dipentamethylene thiuram monosulfide, dipentamethylene thiuram disulfide, dipentamethylene thiuram tetrasulfide, dipentamethylene thiuram hexasulfide. In particular, it is preferable to use dipentamethylene thiuram tetrasulfide, and it is more preferable that the blending amount is 0.1 to 0.5 parts by weight.

  In addition to the above, the composition for a semiconductive vulcanized rubber of the present invention includes various anti-aging agents, fillers, reinforcing agents, plasticizers, processing aids, pigments, flame retardants, additives, which are used in the technical field. Sulfur accelerators, vulcanization retarders, and the like can be arbitrarily blended. Furthermore, a rubber or resin usually used in the art can be blended in a small amount as long as the characteristics of the present invention are not lost.

  As a method of blending the composition for semiconductive vulcanized rubber of the present invention, any means conventionally used in the field of polymer processing can be used, for example, using a mixing roll, a Banbury mixer, various kneaders, etc. I can do it. The semiconductive vulcanized rubber molded product of the present invention can be obtained by heating the semiconductive vulcanized rubber composition of the present invention to 100 to 200 ° C., and the vulcanization time varies depending on the temperature. Usually between 5 and 300 minutes. As a method of vulcanization molding, any method such as compression molding using a mold, injection molding, a steam can, an air bath, infrared rays, or heating by microwaves can be used.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. In addition, this invention is not limited to a following example, unless it deviates from the summary.

<Examples 1-11, Comparative Examples 1-3>
First, each compounding agent shown in Tables 1 and 2 was kneaded with a pressure kneader at 120 ° C. to prepare an A-kneaded compound. This A kneaded compound was kneaded with an open roll to prepare a B kneaded compound. In addition, A in a table | surface is a raw material of A kneading compound, B shows the raw material further mix | blended with A kneading compound, when producing B kneading compound.

The compounding agents used in Examples and Comparative Examples are shown below.
* 1 Epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer made by Daiso Corporation, "Epichromer DG"
* 2 DHT-4A (synthetic hydrotalcite) manufactured by Kyowa Chemical Industry Co., Ltd.
* 3 P-152 manufactured by Daiso Corporation (1,8-diazabicyclo (5,4,0) undecene-7 phenol resin salt: DBU salt)
* 4 Light calcium carbonate akadama made by Shiraishi Calcium Co., Ltd.

<Mooney scorch test>
Measurement was performed based on JIS K6300 using an L-shaped rotor (diameter 38.1 mm). In each table, Vm is the minimum viscosity, and t5 is the Mooney scorch time defined in the Mooney scorch test of JIS K6300.

<Storage stability test>
A compound in which all additives were kneaded was allowed to stand for 4 days in a constant temperature and humidity chamber set at 35 ° C. and a relative humidity of 75%, and then the Mooney scorch test was carried out based on JIS K6300-1, and storage stability Was measured. The initial stability and storage stability of the unvulcanized semiconductive vulcanized rubber composition were measured by measuring Vm and t5 at the initial stage and after storage for 4 days with moist heat (35 ° C. × 75% relative humidity). Was evaluated. In addition, (DELTA) Vm in each table | surface is a difference of Vm after an initial stage and the said 4-day wet heat storage (35 degreeC, relative humidity 75%), and shows the value which evaluates storage (preservation) stability.

<Tensile properties>
The B-kneaded compound prepared as described above was made into a sheet immediately after kneading and was press-vulcanized at 170 ° C. for 15 minutes to form a vulcanized rubber molded product (150 mm × 150 mm × 2 mm). Further, secondary vulcanization was performed in an air oven at 150 ° C. for 1 hour. From the obtained secondary vulcanized rubber molding, a dumbbell-shaped No. 3 test piece shown in JIS K6251 is punched out using a punching die, and tensile stress, tensile strength, and elongation at break are measured according to JIS K6251. did. In the tables, M100 is the tensile stress at 100% elongation defined in the tensile test of JIS K6251, M300 is the tensile stress at 300% elongation defined in the tensile test of JIS K6251, and TB is defined in the tensile test of JIS K6251. Tensile strength, EB, indicates elongation at break as defined in JIS K6251 tensile test.

<Hardness>
The vulcanizate hardness was measured according to JIS K6253. If the A hardness was 50 or less, it was judged to be low hardness (soft) and suitable for the purpose of the present invention. Hs in each table means the hardness specified in the hardness test of JIS K6253.

<Compression set test>
It measured based on JIS K6262. That is, the B kneaded sheet was press vulcanized at 170 ° C. for 20 minutes using a test piece preparation mold to obtain a cylindrical vulcanized rubber test piece (thickness: about 12.5 mm × diameter: about 29 mm). Further, secondary vulcanization was performed in an air oven at 150 ° C. for 1 hour. It measured using the obtained secondary vulcanized rubber test piece.

<Volume specific resistivity>
It measured based on JIS K6271. That is, after leaving a vulcanized sheet and an insulation resistance meter (insulation resistance meter Hiresta HP, manufactured by Mitsubishi Yuka Co., Ltd.) in a constant temperature and humidity chamber set at 23 ° C. and a relative humidity of 50% for 24 hours or more. 10V was applied and the value after 1 minute was read.

<Broom test>
The vulcanized sheet was allowed to stand in a constant temperature and humidity chamber set at 35 ° C. and 75% relative humidity for 10 days, and then the surface of the vulcanized sheet was visually confirmed.
○: No change on the surface of the vulcanized sheet △: Dirt is confirmed on the surface of the vulcanized sheet ×: Dirt is confirmed on the surface of the vulcanized sheet

  Tables 3 and 4 show the test results of Examples and Comparative Examples obtained from each test method.

  As shown in Examples 1 to 11 in Tables 3 and 4, a vulcanization delay effect was obtained with an organic zinc compound without using N-cyclohexylthiophthalimide, which is a known vulcanization retarder. Moreover, compared with Comparative Example 1 using N-cyclohexylthiophthalimide, Bloom was suppressed in Examples using organozinc compounds, and in Examples 1 and 4 to 11 in particular, no bloom was observed. Further, in Comparative Example 2 in which a large amount of the vulcanization accelerator was added, the obtained vulcanized rubber could not be molded, and in Comparative Example 3 in which no vulcanization accelerator was added, the vulcanization itself did not proceed and evaluation was performed. I couldn't.

  The semiconductive vulcanized rubber molded product obtained by vulcanizing the composition for semiconductive vulcanized rubber of the present invention has (1) semiconductivity, (2) environment dependency, and (3) compression set. , (4) low hardness, (5) storage stability, (6) photoreceptor non-contaminating (inhibition of bloom on the surface of the semiconductive vulcanized rubber molding), and (7) semiconductive vulcanized rubber molding It has excellent body grindability and is extremely effective for applications such as semiconductive rubber rolls used in electrophotographic copying machines and printers.

Claims (9)

(A) For 100 parts by weight of epihalohydrin rubber,
(B) 0.1 to 5 parts by weight of an organic zinc compound that is at least one selected from the group consisting of zinc salts of benzimidazoles and zinc salts of carboxylic acids ;
(C) 0.1 to 2 parts by weight of 1,8-diazabicyclo (5,4,0) undecene-7 and / or its weak acid salt,
(D) 0.1 to 10 parts by weight of a quinoxaline vulcanizing agent,
(E) containing 1 to 10 parts by weight of an acid acceptor which is at least one selected from the group consisting of metal oxides, metal hydroxides, and inorganic microporous crystals, and N-cyclohexylthiophthalimide A composition for a semiconductive vulcanized rubber for an electrophotographic process, which is not contained . The weight ratio of (c) 1,8-diazabicyclo (5,4,0) undecene-7 and / or its weak acid salt to (b) the organic zinc compound is 0.15 ≦ (c) / (b) ≦ 0 The composition for a semiconductive vulcanized rubber for an electrophotographic process according to claim 1 , wherein the composition is .7. 3. The semiconductive vulcanized rubber composition for electrophotographic processes according to claim 1 or 2, wherein (d) the quinoxaline vulcanizing agent is 6-methylquinoxaline-2,3-dithiocarbonate. . The inorganic microporous crystal compound is synthesized hydrotalcite, according to claim 1, characterized in that at least one member selected from the group consisting of Li-Al clathrate compound and synthetic zeolite A semiconductive vulcanized rubber composition for electrophotographic process . The composition for a semiconductive vulcanized rubber for an electrophotographic process according to any one of claims 1 to 4 , further comprising (f) sulfur and / or an active sulfur releasing type organic vulcanization accelerator. object. 6. The composition for a semiconductive vulcanized rubber for an electrophotographic process according to claim 5, wherein the active sulfur releasing organic vulcanization accelerator is a thiuram compound. The composition for a semiconductive vulcanized rubber for an electrophotographic process according to claim 6 , wherein the thiuram compound is dipentamethylene thiuram tetrasulfide. A semiconductive vulcanized rubber molded article for an electrophotographic process obtained by vulcanizing the composition for a semiconductive vulcanized rubber for an electrophotographic process according to any one of claims 1 to 7 . A semiconductive rubber roll comprising the semiconductive vulcanized rubber molded product for an electrophotographic process according to claim 8 and used for an electrophotographic process provided with a photoreceptor.