JP2000313807A - Electrically conductive composition, electrically conductive roller prepared therefrom and its preparation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition excellent in moldability and compression strain characteristics and giving less scatter and variability of electrical resistance by incorporating therein a liquid polymer derived from butadiene or isoprene and comprising structural units each having an alkenyl group in the side chain, a hydrosilyl crosslinking agent and a hydrosilylating catalyst. SOLUTION: The composition comprises 100 pts.wt. of a liquid polymer derived from butadiene and/or isoprene and comprising structural units each having an alkenyl group in the side chain, 1-15 pts.wt. of a hydrosilyl crosslinking agent of formula I, and the like, and a hydrosilylating catalyst such as chloroplatinic acid, and it further comprises 1-30 pts.wt. of an electrically conductive agent such as electrically conductive carbon black, a filler, a plasticizer, an antioxidant, and the like. The liquid polymer has a number average molecular weight of 700-200,000, and comprises structural units of formula II, and gives a three dimensional network by crosslinking to show a rubber elasticity. In formula I, R1 is a 2-20C hydrocarbon; R2 is a 1-20C hydrocarbon; R3 is hydrogen or methyl; (m) and (n) are each one or more; (p) is 0 or a positive number: and 2<=m+n+p<=200.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive composition used for a conductive roll and a blade member of an electrophotographic apparatus, a conductive roll using the same, and a method for producing the same.

[0002]

2. Description of the Related Art Generally, copying and printing by an electrophotographic apparatus such as a copying machine, a printer, and a facsimile are performed as follows. That is, a document image is formed as an electrostatic latent image on a photosensitive drum rotating about an axis, and toner is adhered to the image to form a toner image. Next, copying is performed by transferring the toner image to copy paper. in this case,
In order to form an electrostatic latent image on the surface of the photosensitive drum, the surface of the photosensitive drum is charged in advance, and an original image is projected on the charged portion via an optical system, and the charged portion is charged. Is to create an electrostatic latent image by canceling out. As a method for charging the surface of the photosensitive drum prior to the formation of the electrostatic latent image, recently, a roll charging method for charging the surface of the photosensitive drum by directly contacting a charging roll with the surface of the photosensitive drum has been adopted. . Further, as a method of forming a toner image on the electrostatic latent image formed on the surface of the photosensitive drum in this manner, a method using a developing roll (contact developing method) is employed. That is, the toner is frictionally charged between the layer forming blade or the toner replenishing roll and the developing roll to adhere the toner to the developing roll surface, and the toner is transferred from the developing roll to the electrostatic latent image on the photosensitive drum surface. Thus, a toner image is formed on the surface of the photosensitive drum. This toner image is transferred onto the copy paper by a transfer roll, and the toner is melted by heat by a fixing roll and pressed against the paper to perform copying.

[0003] A developing roll, a charging roll, a transfer roll, a toner supply roll,
As a conductive roll such as a static elimination roll, for example, a roll in which a base rubber layer is formed on the outer peripheral surface of a shaft body, an intermediate layer is formed on the outer peripheral surface, and a surface layer is further formed on the outer peripheral surface is used. I have. As a material for forming the base rubber layer, a liquid material is used from the viewpoint of moldability.
Among them, it is known that a liquid composition containing silicone rubber as a main component is optimal.

[0004]

However, since silicone rubber is very expensive, it is difficult to use it on a commercial basis. For this reason, inexpensive ethylene-propylene-diene copolymer (EPDM) has been awarded. But E
Since the composition containing PDM as a main component has a high molecular weight and low fluidity, there is a high possibility that the moldability will be affected. For this reason, although a large amount of oil is added and the viscosity is low, the base rubber layer formed has a poor compression set characteristic, so that a good copied image cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a low-cost, excellent moldability and compression set characteristic, a small variation and variation in electric resistance, and a good copied image. It is an object of the present invention to provide a conductive composition which can be used, a conductive roll using the same, and a method for producing the same.

[0006]

In order to achieve the above object, the present invention provides a conductive composition comprising the following component (A) as a main component and the following components (B) and (C): Is the first gist. (A) a structural unit (α) derived from at least one of butadiene and isoprene and having an alkenyl group in a side chain
A liquid polymer having: (B) a hydrosilyl crosslinking agent. (C) a hydrosilylation catalyst.

Further, the present invention is a conductive roll comprising a shaft and a base rubber layer formed on the outer peripheral surface of the shaft, wherein the base rubber layer comprises the specific conductive composition. The conductive roll formed by using the above is a second gist.

Further, the present invention relates to a method for producing the above-mentioned conductive roll, which comprises a liquid base containing the following components (A) and (C) and a liquid cross-linking agent containing the following component (B). A third aspect of the present invention is a method for preparing a conductive roll in which a mixed solution is prepared, introduced into a mold provided with a shaft body, molded and crosslinked, and then removed from the mold. (A) a structural unit (α) derived from at least one of butadiene and isoprene and having an alkenyl group in a side chain
A liquid polymer having: (B) a hydrosilyl crosslinking agent. (C) a hydrosilylation catalyst.

That is, the present inventors have developed a base rubber layer forming material in order to obtain a conductive roll which is low in cost, is excellent in both moldability and compression set characteristics, and can obtain good copied images. Focused on research. The liquid polymer (component A) derived from at least one of butadiene and isoprene and having a structural unit (α) having an alkenyl group in the side chain has excellent moldability equivalent to that of a liquid silicone rubber, and has a liquid silicone composition. I found that it was cheaper than rubber. Further, since the alkenyl group in the structural unit (α) in the liquid polymer (component A) serves as a crosslinking site and exists in the molecule in a so-called pendant type, the hydrosilyl crosslinking agent (component B) and the hydrosilylation catalyst (component C) It was found that by the effect of the above (2), the base rubber layer as a molded cross-linked body had a dense network structure, and excellent compression set characteristics were obtained. As a result, the conductive roll obtained by forming the base rubber layer using the composition containing the specific liquid polymer (component A), the hydrosilyl crosslinking agent (component B), and the hydrosilylation catalyst (component C) is excellent. The present inventors have found that an excellent copy image can be obtained, and have reached the present invention.

When a specific one represented by the above general formulas (1) to (3) is used as the hydrosilyl crosslinking agent (component B), the compatibility with the liquid polymer becomes good, and the compression set and the compression set are reduced. The storage stability (hardness) of the liquid rubber is improved.

The above specific liquid polymer (component A)
Has the structural unit (α) and the structural unit (β) derived from styrene, the dispersibility of carbon black is improved, the variation in electric resistance is reduced, and the liquid silicone Corona discharge treatment, primer treatment, and the like on the surface of the shaft, which are required when rubber is used as the base rubber layer forming material, are not required.

Further, when a specific conductive carbon black is used together with the above-mentioned components A to C, a crosslinking reaction can be favorably performed.

When an ionic conductive agent is used together with the components A to C, variations in electric resistance can be suppressed.

[0014]

Next, an embodiment of the present invention will be described.

FIG. 1 shows an example of the conductive roll of the present invention. In this conductive roll, a base rubber layer 2 is formed along an outer peripheral surface of a shaft body 1, an intermediate layer 3 is formed on an outer peripheral surface of the base rubber layer 2, and a surface layer 4 is formed on an outer peripheral surface of the intermediate layer 3. Is formed. The most important feature of the conductive roll of the present invention is that the base rubber layer 2 is formed using a special composition (liquid polymer composition).

The shaft 1 is not particularly limited.
For example, a metal core made of a solid metal body, a metal cylindrical body whose inside is hollowed out, and the like are used. Examples of the material include stainless steel, aluminum, and iron plated. If necessary,
An adhesive, a primer, or the like may be applied on the shaft 1, and the adhesive, the primer, or the like may be made conductive as necessary.

The base rubber layer 2 formed on the outer peripheral surface of the shaft 1 has a special composition containing a specific liquid polymer (component A), a hydrosilyl crosslinking agent (component B), and a hydrosilylation catalyst (component C). It is formed using a product (liquid polymer composition).

The specific liquid polymer (component A) is derived from at least one of butadiene and isoprene and has a structural unit (α) having an alkenyl group in a side chain. The specific structural unit (α) is not particularly limited, and includes, for example, structural units represented by the following structural formulas (I) to (III). Then, the alkenyl group (vinyl group, isopropenyl group), which is a side chain in the structural unit, is subjected to a crosslinking reaction to form a three-dimensional network structure, and exhibits rubber-like elasticity.

[0019]

Embedded image

Examples of the liquid polymer (component A) having the specific structural unit (α) include isoprene rubber (IR), butadiene rubber (BR), and IR-
BR copolymer rubber and the like. These may be used alone or in combination of two or more.

The above specific liquid polymer (component A)
May have a structural unit (β) derived from styrene together with the specific structural unit (α). The styrene may have a substituent, and the substituent is preferably an alkyl group, particularly preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, and a sec-butyl group. Group, te
An alkyl group having 1 to 5 carbon atoms such as an rt-butyl group.

The above structural unit (α) and structural unit (β)
Among the liquid polymers having the formula (A), isoprene-styrene copolymer rubber represented by the following general formula (IV) is preferably used.

[0023]

Embedded image

In the above specific liquid polymer (component A), the content ratio of the structural unit (α) is preferably set in the range of 0.5 to 80% by weight of the whole liquid polymer (component A), and particularly preferably. Is 1.5 to 20% by weight.
That is, when the content ratio of the structural unit (α) is less than 0.5% by weight, the crosslinking reaction becomes insufficient, and the stability of the obtained molded crosslinked product (base rubber layer) may be deteriorated, Conversely, if it exceeds 80% by weight, the network structure due to crosslinking becomes too dense, and the molded crosslinked product (base rubber layer) may become hard or brittle.

When the liquid polymer (component A) has a structural unit (α) and a structural unit (β), the content of the structural unit (β) is 5 to 30% of the whole liquid polymer (component A). It is preferably set in the range of 10% by weight, particularly preferably 10 to 25% by weight. That is, when the content of the structural unit (β) is less than 5% by weight,
This is because the effect of styrene may not be sufficiently obtained. Conversely, if it exceeds 30% by weight, the viscosity of the liquid polymer may be increased, and the moldability may be deteriorated, or the compression set characteristics may be deteriorated.

The specific liquid polymer (component A) can be prepared, for example, as follows. That is, first, at least one of butadiene and isoprene and, if necessary, styrene are prepared as monomer components. Then, the monomer component can be obtained by homopolymerization or copolymerization by various methods such as anionic polymerization in the presence of an appropriate catalyst (for example, a lithium catalyst or a Ziegler catalyst).

The number average molecular weight (Mn) of the specific liquid polymer (component (A)) is preferably set in the range of 700 to 200,000, particularly preferably 2,000.
00 to 100,000. That is, by setting the number average molecular weight (Mn) of the liquid polymer (A component) within the above range, the handleability is excellent and the crosslinking reaction can be performed satisfactorily. In particular, when the liquid polymer (component A) has only the structural unit (α), the number average molecular weight (Mn) is 700 to 60,000.
The range of 0 is preferable, and especially preferable is 2,000-5.
It is 0000. Further, the liquid polymer (A component)
Has a structural unit (α) and a structural unit (β), the number average molecular weight (Mn) is 1,000 to 10
It is preferably in the range of 10,000, particularly preferably 10,000.
00 to 80,000.

The viscosity of the liquid polymer (component A) is 1
The range of 100 to 3,000,000 (cps / 25 ° C) is preferable,
Particularly preferably, 1,000 to 500,000 (cps / 25 ° C.)
It is.

The hydrosilyl crosslinking agent (component B) used together with the above specific liquid polymer (component A) includes:
There is no particular limitation, and examples include those having a hydrosilyl group in the molecule. The above-mentioned hydrosilyl group means a group in which a hydrogen atom is bonded to at least one of the four bonds of a silicon atom.

Among the above-mentioned hydrosilyl cross-linking agents (component B), the following general formula (1) is preferred in that compatibility with liquid polymers is improved, and compression set and storage stability (hardness) of liquid rubber are improved. Hydrosilyl compounds represented by formulas (1) to (3) are preferably used. In addition, each repeating unit m, n,
The p and q portions may be in any polymerization form such as random polymerization and block polymerization.

[0031]

Embedded image

[0032]

Embedded image

[0033]

Embedded image

The hydrosilyl compounds represented by the above general formulas (1) to (3) can be produced, for example, by the following methods, and can be carried out relatively easily. Is particularly preferred.

In the molecular structure, a chlorosilyl group (SiC
l) is converted to a reducing agent (LiAlH
₄ , NaBH ₄ ) to reduce the chlorosilyl group to a hydrosilyl group.

A hydrocarbon compound having a functional group,
A method of producing by reacting a compound having both a functional group capable of reacting with the above functional group and a hydrosilyl group.

[0037] A method for producing a hydrocarbon-based compound having an alkenyl group and a polyhydrosilane compound by reacting a hydrosilyl group in a molecular structure of an obtained reactant.

A method for producing a compound by reacting a cyclic siloxane having a hydrosilyl group with a cyclic siloxane having a hydrocarbon group.

Among the hydrosilyl compounds thus obtained, those represented by the following structural formulas (4) to (8) are particularly preferred. In addition, each repeating unit may be in any polymerization form such as random polymerization and block polymerization.

[0040]

Embedded image

[0041]

Embedded image

[0042]

Embedded image

[0043]

Embedded image

[0044]

Embedded image

The hydrosilyl compound represented by the structural formula (4) can be produced, for example, by the following reaction.

[0046]

Embedded image

The mixing ratio of the hydrosilyl crosslinking agent (component B) is preferably set in the range of 1 to 15 parts, more preferably 2 to 8 parts, per 100 parts of the liquid polymer (component A). is there. That is, if the amount is less than 1 part, the crosslinking is not sufficiently performed, so that the strength and the compression set are deteriorated. If the amount exceeds 15 parts, the crosslinking proceeds too much,
This is because it becomes hard and brittle, and the pot life is shortened.

The hydrosilylation catalyst (component C) used together with the above-mentioned specific liquid polymer (component A) and hydrosilyl crosslinking agent (component B) is not particularly limited as long as it can exhibit a catalytic function for a crosslinking reaction. For example, chloroplatinic acid, complexes of chloroplatinic acid with alcohols, aldehydes, ketones, etc., platinum / vinylsiloxane complexes,
Platinum / olefin complexes, platinum / phosphite complexes, and those in which solid platinum is supported on a carrier such as platinum, alumina, silica, carbon black, and the like. Examples of the catalyst other than the platinum compound include a palladium compound, a rhodium compound, an iridium compound, and a ruthenium compound. These may be used alone or in combination of two or more.

The special composition (liquid polymer composition) for forming the base rubber layer 2 preferably contains a conductive agent as appropriate in addition to the components A to C. The conductive agent is not particularly limited, for example, conductive carbon black, potassium titanate, iron oxide,
c-TiO ₂ , c-ZnO, c-indium oxide (“c
− ”Means having conductivity), an ion conductive agent that does not inhibit crosslinking (quaternary ammonium salt, borate, surfactant, metal ion, polyethylene oxide (PE)
O) etc.]. These may be used alone or in combination of two or more. Among these, conductive carbon black is preferable from the viewpoint of crosslinking reactivity, and ionic conductive agents are preferably used from the viewpoint of suppressing variation in electric resistance. Then, the control of the electric resistance becomes easy, and the fluctuation of the electric resistance due to the applied voltage is reduced.
It is particularly preferred to use a combination of conductive carbon black and an ionic conductive agent.

The conductive carbon black preferably has an ash content of 0.3% by weight or less from the viewpoint of crosslinking reactivity.

The compounding ratio of the conductive agent is preferably in the range of 1 to 30 parts, more preferably 5 to 15 parts, based on 100 parts of the liquid polymer (component (A)).

The special composition (liquid polymer composition) for forming the base rubber layer 2 includes fillers such as calcium carbonate, mica, silica, and graphite, a plasticizer, and an oil in addition to the above-mentioned components. , A crosslinking accelerator, a crosslinking retarder, an antioxidant, and a coloring agent such as zinc oxide or titanium oxide.

The special composition (liquid polymer composition) for forming the base rubber layer 2 can be prepared, for example, as follows. That is, first, a liquid polymer (A component) and a hydrosilylation catalyst (C component) are blended at an appropriate ratio to prepare a liquid base material, and a liquid curing agent containing a hydrosilyl crosslinking agent (B component) is prepared. If necessary, other components are added to the liquid base material and the liquid hardener, respectively. And at the time of use, it can be prepared by mixing a liquid main agent and a liquid curing agent. Thus, from the viewpoint of storage stability, it is preferable that the liquid polymer composition is prepared by separately storing the liquid main agent and the liquid curing agent, and mixing the two liquids at the time of use.

The material for forming the intermediate layer 3 formed on the outer peripheral surface of the base rubber layer 2 is not particularly limited.
For example, acrylonitrile-butadiene rubber (nitrile rubber) (hereinafter abbreviated as “NBR”), polyurethane elastomer, chloroprene rubber (CR), natural rubber, butadiene rubber (BR), butyl rubber (IIR), hydrin rubber (ECO, CO), Nylon and the like. Above all, from the viewpoint of the adhesiveness and the stability of the coating solution,
NBR is preferably used.

The material for forming the intermediate layer 3 may include a conductive agent, a crosslinking agent, a crosslinking accelerator, stearic acid,
It is also possible to mix ZnO (zinc white), a softener and the like. Examples of the conductive agent include carbon black, graphite, potassium titanate, iron oxide, c-TiO ₂ , c-
ZnO, c-indium oxide, ionic conductive agents (quaternary ammonium salts, borates, surfactants, etc.) and the like. Note that the above “c−” means having conductivity.

The material for forming the surface layer 4 formed on the outer peripheral surface of the intermediate layer 3 is not particularly limited. For example, polyurethane elastomer, acrylic polymer,
Polyamide and the like can be mentioned. These can be used alone or 2
Used in combination of more than one species.

The material for forming the surface layer 4 may contain a conductive agent, a curing agent, and the like, if necessary.

The conductive roll of the present invention can be manufactured, for example, as follows. That is, first, a liquid polymer composition (a liquid base material and a liquid curing agent) to be the material for forming the base rubber layer 2 is prepared by the same method as described above. Further, the respective components for the intermediate layer 3 forming material are kneaded using a kneading machine such as a roll, and an organic solvent is added to this mixture, followed by mixing and stirring to prepare an intermediate layer 3 forming material (coating liquid). I do. Further, a material (coating liquid) for forming the surface layer 4 is prepared according to the above method.

Next, a liquid base material and a liquid curing agent as the above-mentioned base rubber layer forming material (liquid polymer composition) are filled in an injection molding die in which a core metal serving as a shaft is set, and under predetermined conditions. Heat crosslinking is performed. After that, remove the mold,
A base roll having a base rubber layer formed along the outer peripheral surface of the shaft body is manufactured. Next, the intermediate layer forming material (coating liquid) is applied to the outer peripheral surface of the base rubber layer to form an intermediate layer. Further, the surface layer forming material (coating liquid) is applied to the outer peripheral surface of the intermediate layer to form a surface layer. Thus, an intermediate layer is formed on the outer peripheral surface of the base rubber layer, an intermediate layer is formed on the outer peripheral surface, and a surface layer is formed on the outer peripheral surface of the conductive roll having a three-layer structure (see FIG. 1). Can be produced.

The method for forming the base rubber layer 2 is as follows.
It is not limited to the injection molding method, but may be produced by a casting method or a polishing method after press molding. The method for applying the coating liquid is not particularly limited, and examples thereof include a conventionally known dipping method, spray coating method, and roll coating method.

The conductive roll of the present invention is suitable for a developing roll, but is not necessarily limited to a developing roll, and may be applied to a transfer roll, a charging roll, a toner replenishing roll, a neutralizing roll, a fixing roll, and the like. Can be. The conductive roll of the present invention is not limited to the three-layer structure, and an appropriate number of layers are formed. However, the base rubber layer must necessarily be formed of the special liquid polymer composition.

In the conductive roll of the present invention, the thickness of each layer is appropriately determined according to the use of the conductive roll.
For example, when used as a developing roll, the thickness of the base rubber layer is preferably set in the range of 0.5 to 10 mm, particularly preferably 3 to 6 mm. The thickness of the intermediate layer is usually set in the range of 1 to 90 μm, preferably 3 to 30 μm, and the thickness of the surface layer is usually 3 to 1 μm.
It is set in the range of 00 μm, preferably 5 to 50 μm.

Next, examples will be described together with comparative examples.

[0064]

[Example 1] [Preparation of base rubber layer forming material] As component A, liquid isoprene rubber (Kuraray Co., Ltd., Kuraray LI)
R-30) [Mn: 29,000, content ratio of structural unit (α): 6.5% by weight] and 100 parts of a hydrosilyl crosslinking agent represented by the following structural formula (9) as B component (Toshiba Silicone) 5 parts of TSF484), 0.01 part of hydrosilylation catalyst (chloroplatinic acid) as a C component, and 12 parts of conductive carbon black (Denka Black, manufactured by Denki Kagaku Kogyo Co., Ltd., ash content: 0.01% by weight) And 75 parts of paraffin plasticizer (PW-150, manufactured by Idemitsu Kosan Co., Ltd.)
A liquid polymer composition was prepared according to the method described above.

[0065]

Embedded image

[Preparation of Intermediate Layer Forming Material] Carbon black and a vulcanizing agent were added to hydrogenated nitrile rubber, and this was dissolved in methyl ethyl ketone to prepare an intermediate layer forming material (coating solution).

[Preparation of Surface Layer Forming Material] Polyurethane elastomer (Nipporan 2 manufactured by Nippon Polyurethane Industry Co., Ltd.)
304) 100 parts, carbon black 20 parts, and a curing agent (manufactured by Dainippon Ink and Chemicals, Pernock D-75)
0) 25 parts were kneaded according to the method described above, and this was dispersed in an organic solvent to prepare a surface layer forming material (coating liquid).

[Preparation of Developing Roll] After filling the base rubber layer forming material (liquid polymer composition) into an injection mold having a core (diameter: 10 mm, made of SUS304) set as a shaft, Heat crosslinking was performed at 160 ° C. for 2 minutes. Thereafter, the base roll was released and a base roll having a base rubber layer formed along the outer peripheral surface of the shaft body was manufactured. Then, the intermediate layer forming material (coating liquid) was applied to the outer peripheral surface of the base rubber layer to form an intermediate layer. Further, the surface layer forming material (coating liquid) was applied to the outer peripheral surface of the intermediate layer to form a surface layer. Thus, a developing roll having a three-layer structure in which the intermediate layer was formed on the outer peripheral surface of the base rubber layer, the intermediate layer was formed on the outer peripheral surface, and the surface layer was formed on the outer peripheral surface. The thickness of the base rubber layer was 5 mm, the thickness of the intermediate layer was 25 μm, and the thickness of the surface layer was 10 μm.

[0069]

Example 2 Instead of the liquid isoprene rubber (Kuraray Co., Ltd., Kuraprene LIR-30) of Example 1, liquid isoprene rubber (Kuraray Co., Ltd., Kuraprene LIR-50) [M
n: 47,000, content ratio of structural unit (α): 6.8
% By weight], and a liquid polymer composition was prepared in the same manner as in Example 1. Example 1 was repeated except that a base rubber layer was formed using this liquid polymer composition.
A developing roll was prepared in the same manner as described above.

[0070]

Example 3 As the component A, isoprene: butadiene =
12.6: 87.4 (weight ratio) isoprene-butadiene copolymer rubber (Kuraray Co., Ltd., Kuraprene LIR-3)
90) [Mn: 43,000, content ratio of structural unit (α): 9.3% by weight] 100 parts and the above hydrosilyl crosslinking agent as component B (TSF484 manufactured by Toshiba Silicone Co., Ltd.)
5 parts, a hydrosilylation catalyst (chloroplatinic acid) 0.01 part as a C component, and conductive carbon black (Texa P
A liquid polymer composition was prepared according to the method described above using 18 parts of rintex V, ash content: 0.02% by weight) and 75 parts of a paraffin plasticizer (PW-150, manufactured by Idemitsu Kosan Co., Ltd.). Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this liquid polymer composition.

[0071]

Example 4 A liquid isoprene rubber (Kuraray LIR-30, manufactured by Kuraray Co., Ltd.) [Mn: 29,00
0, content ratio of structural unit (α): 6.5% by weight] 100
Part, 5 parts of the above hydrosilyl crosslinking agent (TSF484, manufactured by Toshiba Silicone Co., Ltd.) as the B component, 0.01 part of a hydrosilylation catalyst (chloroplatinic acid) as the C component, and conductive carbon black (Ketjen Black EC, ash content). : 0.
1 part by weight) and 30 parts of a paraffin-based plasticizer (PW-150, manufactured by Idemitsu Kosan Co., Ltd.) to prepare a liquid polymer composition according to the above-described method. Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this liquid polymer composition.

[0072]

Example 5 A liquid butadiene rubber (B-3000, manufactured by Nippon Oil Co., Ltd.) [Mn: 3,0] was used instead of the liquid isoprene rubber (manufactured by Kuraray Co., Ltd., Kuraprene LIR-30).
00, the content ratio of the structural unit (α): 65% by weight], and a liquid polymer composition was prepared in the same manner as in Example 1. Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this liquid polymer composition.

[0073]

Example 6 As component A, liquid butadiene rubber (Kuraray Co., Ltd., Kuraprene LIR-300) [Mn: 40,000
0, content ratio of structural unit (α): 9.4% by weight] 100
Part, 5 parts of the above hydrosilyl crosslinking agent (TSF484, manufactured by Toshiba Silicone Co., Ltd.) as the B component, 0.01 part of a hydrosilylation catalyst [platinum carbonyl complex (SIP 6829.0, manufactured by AZMAX)] as the C component, Carbon black (Denka Black, manufactured by Denki Kagaku Kogyo Co., Ltd.)
A liquid polymer composition was prepared using 10 parts of ash content (0.01% by weight) and 30 parts of a paraffin plasticizer (PW-150, manufactured by Idemitsu Kosan Co., Ltd.) according to the method described above. Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this liquid polymer composition.

[0074]

Example 7 100 parts of liquid butadiene rubber (Kuraray Co., Ltd., Kuraprene LIR-300) was used as the component A, and the above hydrosilyl crosslinking agent (manufactured by Toshiba Silicone Co., Ltd.) was used as the component B.
TSF484) and 5 parts of a hydrosilylation catalyst [platinum carbonyl complex (manufactured by Admax Corp., SIP
6829.0)] 0.01 part, 1 part of a quaternary ammonium salt (A-902, manufactured by Nippon Carlit Co., Ltd.) and 30 parts of a paraffin plasticizer (PW-150, manufactured by Idemitsu Kosan Co., Ltd.) A liquid polymer composition was prepared according to the method described above. Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this liquid polymer composition.

[0075]

Example 8 As the component A, isoprene: styrene = 8
1:19 (weight ratio) isoprene-styrene copolymer rubber (Kuraray Co., Ltd., Kuraprene LIR-310) [M
n: 30,000, content ratio of structural unit (α): 5.4
% By weight, content ratio of structural unit (β): 19% by weight] 10
0 parts, 6.2 parts of the above hydrosilyl crosslinking agent (TSF484, manufactured by Toshiba Silicone Co., Ltd.) as the B component, and 0.01 parts of a hydrosilylation catalyst [platinum carbonyl complex (SIP 6829.0, manufactured by AZMAX)] as the C component. And 1 part of a borate (LR147, manufactured by Nippon Carlit Co., Ltd.) and 30 of a paraffin plasticizer (PW-150, manufactured by Idemitsu Kosan Co., Ltd.)
The liquid polymer composition was prepared according to the above-mentioned method using the above-mentioned parts. Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this liquid polymer composition.

[0076]

Example 9 As the component A, isoprene: butadiene =
12.6: 87.4 (weight ratio) isoprene-butadiene copolymer rubber (Kuraray Co., Ltd., Kuraprene LIR-3)
90) [Mn: 43,000, content ratio of structural unit (α): 9.3% by weight] 100 parts and the above hydrosilyl crosslinking agent as component B (TSF484 manufactured by Toshiba Silicone Co., Ltd.)
6.2 parts and a hydrosilylation catalyst [platinum carbonyl complex (manufactured by Admax Co., SIP 6829.
0)] Using 0.01 part, 1 part of lithium ion (manufactured by Nippon Carlit Co., PEL20A), and 30 parts of a paraffin plasticizer (manufactured by Idemitsu Kosan Co., Ltd., PW-150) according to the method described above, A composition was prepared. Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this liquid polymer composition.

[0077]

Example 10 Instead of the liquid butadiene rubber (Kuraray Co., Ltd., Kuraprene LIR-300) of Example 6, an isoprene-butadiene copolymer rubber (Kuraray Co., Ltd., Kuraprene L)
A liquid polymer composition was prepared in the same manner as in Example 6, except that IR-390) was used. Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this liquid polymer composition.

[0078]

Example 11 Instead of the liquid butadiene rubber (Kuraray Co., Ltd., Kuraprene LIR-300) of Example 6, isoprene-styrene copolymer rubber (Kuraray Co., Ltd., Kuraprene LI)
A liquid polymer composition was prepared in the same manner as in Example 6, except that R-310) was used. Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this liquid polymer composition.

[0079]

EXAMPLE 12 100 parts of liquid butadiene rubber (Kuraray Co., Ltd., Kuraprene LIR-300) as component A, 5 parts of the above hydrosilyl crosslinking agent (TSF484, manufactured by Toshiba Silicone Co., Ltd.) as component B, and hydrosilylation catalyst as component C [Platinum carbonyl complex (Admax, SI
P 6829.0)] and 0.01 part of conductive carbon black (acetylene black, ash content: 0.01% by weight)
Using 10 parts, 1 part of a quaternary ammonium salt (A-902, manufactured by Nippon Carlit Co., Ltd.), and 30 parts of a paraffin plasticizer (PW-150, manufactured by Idemitsu Kosan Co., Ltd.), the liquid polymer was prepared according to the method described above. A composition was prepared. Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this liquid polymer composition.

[0080]

Example 13 In place of the liquid butadiene rubber (Kuraray Co., Ltd., Kuraprene LIR-300) of Example 12, isoprene-styrene copolymer rubber (Kuraray Co., Ltd., Kuraprene L)
A liquid polymer composition was prepared in the same manner as in Example 12, except that IR-310) was used. And except for forming a base rubber layer using this liquid polymer composition,
A developing roll was produced in the same manner as in Example 1.

[0081]

Example 14 In place of the liquid butadiene rubber of Example 6 (Kuraray Co., Ltd., Kuraprene LIR-300), styrene-isoprene = 5: 95 (weight ratio) was used.
Liquid in the same manner as in Example 6 except that isoprene copolymer rubber [Mn: 30,000, content of structural unit (α): 3% by weight, content of structural unit (β): 5% by weight] was used. A polymer composition was prepared. Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this liquid polymer composition.

[0082]

Example 15 Instead of the liquid butadiene rubber (Kuraray Co., Ltd., Kuraprene LIR-300) of Example 6, a styrene-isoprene copolymer rubber (Mn: 30, styrene: isoprene = 30: 70 (weight ratio)) was used. 000, the content ratio of the structural unit (α): 3% by weight and the content ratio of the structural unit (β): 30% by weight] to prepare a liquid polymer composition in the same manner as in Example 6. Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this liquid polymer composition.

[0083]

Example 16 A hydrosilyl crosslinking agent represented by the structural formula (5) was used in place of the hydrosilyl crosslinking agent (TSF484 manufactured by Toshiba Silicone Co., Ltd.) in Example 1.
A liquid polymer composition was prepared in the same manner as in Example 1.
Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this liquid polymer composition.

[0084]

Example 17 A hydrosilyl crosslinking agent represented by the structural formula (6) was used in place of the hydrosilyl crosslinking agent (TSF484, manufactured by Toshiba Silicone Co., Ltd.) of Example 1.
A liquid polymer composition was prepared in the same manner as in Example 1.
Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this liquid polymer composition.

[0085]

Example 18 The procedure of Example 1 was repeated, except that the hydrosilyl crosslinking agent represented by the structural formula (7) was used instead of the hydrosilyl crosslinking agent (TSF484, manufactured by Toshiba Silicone Co., Ltd.).
A liquid polymer composition was prepared in the same manner as in Example 1.
Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this liquid polymer composition.

[0086]

Example 19 A hydrosilyl crosslinking agent represented by the above structural formula (8) was used in place of the hydrosilyl crosslinking agent (TSF484, manufactured by Toshiba Silicone Co., Ltd.) of Example 1.
A liquid polymer composition was prepared in the same manner as in Example 1.
Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this liquid polymer composition.

[0087]

Example 20 A hydrosilyl crosslinking agent represented by the structural formula (5) was used in place of the hydrosilyl crosslinking agent (TSF484, manufactured by Toshiba Silicone Co., Ltd.) in Example 12.
A liquid polymer composition was prepared in the same manner as in Example 12. Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this liquid polymer composition.

[0088]

Example 21 A hydrosilyl crosslinking agent represented by the structural formula (5) was used instead of the hydrosilyl crosslinking agent (TSF484, manufactured by Toshiba Silicone Co., Ltd.) in Example 13.
A liquid polymer composition was prepared in the same manner as in Example 13. Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this liquid polymer composition.

[0089]

Comparative Example 1 100 parts of EPDM, 5 parts of a peroxide crosslinking agent, 80 parts of carbon black (Diablack # 3030 manufactured by Mitsubishi Chemical Corporation), and paraffin oil 75
And the composition was prepared according to the above-mentioned method using the above components.
Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this composition under vulcanization conditions of 160 ° C. × 45 minutes.

[0090]

Comparative Example 2 100 parts of EPDM, 5 parts of a peroxide crosslinking agent, 80 parts of carbon black (Diablack # 3030, manufactured by Mitsubishi Chemical Corporation), and 90 parts of paraffinic oil
And the composition was prepared according to the above-mentioned method using the above components.
Then, a developing roll was prepared in the same manner as in Example 1 except that a base rubber layer was formed using this composition under vulcanization conditions of 160 ° C. × 45 minutes.

Using the developing rolls of the example product and the comparative example product thus obtained, each characteristic was evaluated according to the following criteria. These results are shown in Tables 1 to 5 below.
Are also shown.

[Mold Transferability] Evaluation was made by visually observing the base rubber layer as the innermost layer. Then, a molding defect such as a dent or swelling does not occur on the surface of the base rubber layer, and a sample whose reproducibility of the outer diameter is good is evaluated as 、, and a molding defect such as a dent or swelling occurs on the surface of the base rubber layer. Poor reproducibility was indicated as x.

[Hardness] Hardness of base rubber layer (JIS
A) was measured according to JIS K6301.

[Compression Set] The compression set of the base rubber layer was measured according to JIS K6301. The measurement conditions were a temperature of 70 ° C., a test time of 22 hours, and a compression ratio of 25%. If this measured value is 5% or less, the compression set is very good, but if it is 8% or less, there is no problem in use.

[Electrical Resistance] The electrical resistance of the base rubber layer
It was measured according to JIS K 6911.

[Dispersion of electric resistance] 1 of base rubber layer
Measure the electrical resistance at 0 points and log (maximum / minimum)
Was evaluated.

[Rubber Storage Property] (Electrical Resistance) A liquid composed of a liquid polymer (component A) and a hydrosilyl crosslinking agent (component B), and a liquid polymer (component A)
In the case of mixing 1: 1 with the liquid comprising the hydrosilylation catalyst (component C), they were separately prepared so as to have a predetermined ratio, and were left at ordinary temperature (25 ° C.) for 3 months. afterwards,
10% of the supernatant and the lower bottom of each liquid were taken out, and a mixture thereof was formed into a sheet. Then, the electric resistance of the sheet was measured, and the rubber preservability was evaluated based on the electric resistance difference. In addition, the evaluation result was displayed as follows. ：: Electric resistance difference of one digit or less △: Electric resistance difference of less than one or two digits

(Hardness) The rubber hardness of this sheet (J
IS A) was measured, and the rubber preservability was evaluated based on the difference in hardness. In addition, the evaluation result was displayed as follows. ：: hardness difference of less than 3 △: hardness difference of 3 or more and less than 5 ×: hardness difference of 5 or more

[Image] (solid black image) The developing roll is incorporated in the printer,
After being left for 1 week in an environment of 5 ° C. and 85% RH, and printing a solid black image, the image was visually observed. Then, those with white spots were indicated by x, and those without white spots were indicated by 見.

(Fine Line Reproducibility) The developing roll was set in a printer, left for one week in an environment of 35 ° C. and 85% RH, and after a character image was printed, the image was visually observed. Then, those in which blurring of the image was observed due to breaks in the thin lines were displayed as x, and those in which the blurring of the image was not observed were displayed as ○.

[0101]

[Table 1]

[0102]

[Table 2]

[0103]

[Table 3]

[0104]

[Table 4]

[0105]

[Table 5]

From the results shown in Tables 1 to 5, since the developing roll of the example product has a low hardness and a base rubber layer having excellent mold transferability and compression set characteristics, it has a solid black image. Also, excellent reproducibility of fine lines can be obtained, and a good copied image can be obtained. Among them, the developing rolls of Examples 16 to 21 are particularly excellent in compression set characteristics and rubber preservability (hardness), so that a better copy image can be obtained.

On the other hand, the developing roll of Comparative Example 1 was
Poor mold transferability and poor moldability of base rubber layer
It can be seen that the solid black image and the fine line reproducibility are inferior and a good copied image cannot be obtained. Further, it can be seen that the developing roll of Comparative Example 2 had poor compression set characteristics of the base rubber layer, and thus was inferior in solid black image and fine line reproducibility and could not obtain a good copied image.

[0108]

As described above, the conductive roll of the present invention comprises a liquid polymer (component A) derived from at least one of butadiene and isoprene and having a structural unit (α) having an alkenyl group in a side chain; A base rubber layer is formed using a special composition (liquid polymer composition) containing a hydrosilyl crosslinking agent (component B) and a hydrosilylation catalyst (component C). Therefore, since the alkenyl group in the structural unit (α) in the liquid polymer (component A) serves as a crosslinking site and is present in the molecule in a so-called pendant type, the hydrosilyl crosslinking agent (component B) and the hydrosilylation catalyst (component C) Due to the effect of (1), the base rubber layer, which is a molded crosslinked product, has a dense network structure, and excellent compression set characteristics can be obtained. As a result, a good copied image can be obtained.

When the hydrosilyl cross-linking agent (component B) used is a specific one represented by any one of the above general formulas (1) to (3), the compatibility with the liquid polymer becomes good, and the compression set and the compression set are reduced. The storage stability (hardness) of the liquid rubber is improved.

When the liquid polymer (component A) has the structural unit (α) and the structural unit (β) derived from styrene, the dispersibility of carbon black is improved. In addition, variations in electric resistance are reduced, and corona discharge treatment, primer treatment, and the like on the shaft body surface, which are required when liquid silicone rubber is used as the base rubber layer forming material, become unnecessary.

Further, when a specific conductive carbon black is used together with the above-mentioned components A to C, a crosslinking reaction can be favorably performed.

When an ionic conductive agent is used together with the components A to C, variations in electric resistance can be suppressed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a conductive roll of the present invention.

[Explanation of symbols]

 1 Shaft 2 Base rubber layer 3 Intermediate layer 4 Surface layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16C 13/00 F16C 13/00 E 4F204 G03G 15/02 101 G03G 15/02 101 4J002 15/08 501 15 / 08 501D 15/16 103 15/16 103 H01B 1/12 H01B 1/12 Z // B29C 39/10 B29C 39/10 B29K 55:00 B29L 31:00 (72) Inventor Akihiko Kaji Komaki, Aichi Prefecture 3600 Togayama Gezu Tokai Rubber Industries Co., Ltd. (72) Inventor Kenichi Ohoe Komaki City, Aichi Prefecture Kokugaiyama 3600 Gezu Tokai Rubber Industries Co., Ltd. F-term (reference) 2H003 CC05 2H032 AA05 2H077 AD06 FA12 FA25 3J103 AA02 AA15 AA33 AA35 AA51 BA34 BA41 EA02 EA20 FA03 FA06 FA14 FA15 FA18 GA02 GA57 GA58 GA60 HA03 HA04 HA05 HA12 HA15 HA20 HA32 HA33 HA37 HA41 HA52 HA53 HA55 4F070 AA06 AA60 AC04 AC06 AC14 AC17 AC20 AC23 AC25 AC92 AE06 AE08 AE16 GA01 GA06 GC03 GC06 GC08 4F204 AA31 AA45 AA49 AB03 AB07 AB13 AB18 AD03 AD12 AD15 AG03 AG07 AH04 AH33 EB03 AC01 EB03 AC02 CP042 DA037 DA076 DA116 DE097 DE107 DE117 DE137 DE187 DK007 EN137 FD117 FD206 FD317 GQ02

Claims (7)

[Claims] 1. A conductive composition comprising the following component (A) as a main component and the following components (B) and (C): (A) a structural unit (α) derived from at least one of butadiene and isoprene and having an alkenyl group in a side chain
A liquid polymer having: (B) a hydrosilyl crosslinking agent. (C) a hydrosilylation catalyst. 2. The component (B) is represented by the following general formula (1):
The conductive composition according to claim 1, which is represented by at least one general formula selected from the group consisting of (3) to (3). Embedded image Embedded image Embedded image 3. The component (A) has a structural unit (α) and a structural unit (β) derived from styrene.
The conductive composition according to claim 1, which has: 4. The conductive composition according to claim 1, which contains a conductive carbon black having an ash content of 0.3% by weight or less. 5. The conductive composition according to claim 1, further comprising an ionic conductive agent. 6. A conductive roll comprising a shaft and a base rubber layer formed on an outer peripheral surface of the shaft, wherein the base rubber layer is any one of claims 1 to 5. A conductive roll formed by using the conductive composition of (1). 7. The method for producing a conductive roll according to claim 6, wherein a liquid main agent containing the following components (A) and (C) and a liquid crosslinking agent containing the following component (B) are provided. A method for producing a conductive roll, comprising preparing, introducing a mixed solution thereof into a mold provided with a shaft, forming and crosslinking, and then removing the mold. (A) a structural unit (α) derived from at least one of butadiene and isoprene and having an alkenyl group in a side chain
A liquid polymer having: (B) a hydrosilyl crosslinking agent. (C) a hydrosilylation catalyst.