JP2007277278A - Semiconductive composition for electrophotographic apparatus, and semiconductive member for electrophotographic apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductive composition for electrophotographic apparatuses exhibiting excellent controllability of electric resistance. <P>SOLUTION: The semiconductive composition for electrophotographic apparatuses comprises (A) below as an essential ingredient: (A) an electroconductive polypyrrole obtained by allowing a polypyrrole, having a structural unit represented by general formula (1), wherein R<SP>1</SP>is a 1-50C alkyl group; R<SP>2</SP>is a 1-50C alkyl group; and n is a positive number, to have electroconductivity using a dopant having a sulfonic group or a sulfonic acid salt structure. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductive composition for an electrophotographic apparatus and a semiconductive member for an electrophotographic apparatus using the same, and more particularly, to an electrophotographic composition such as a semiconductive composition and a developing roll using the same. The present invention relates to a semiconductive member for equipment.

  In general, in a semiconductive composition used for a semiconductive member for an electrophotographic apparatus such as a developing roll, the controllability of electric resistance is a very important characteristic because it greatly affects the image quality of an output image. Conventionally, electric resistance is controlled by mixing an electronic conductive agent such as carbon black and an ionic conductive agent such as a quaternary ammonium salt into a polymer such as resin or rubber.

  However, since the electronic conductive agent has a discontinuous aggregation structure, there is a problem in that variation in electric resistance is large and voltage fluctuation of electric resistance is large. On the other hand, the ionic conductive agent is susceptible to environmental influences such as humidity and heat, and has a drawback in that the electrical resistance is highly dependent on the environment.

On the other hand, the proposal which controls an electrical resistance using a polypyrrole-type conductive polymer is made | formed. That is, in a transfer belt formed by forming a conductive layer on the inner periphery of a semiconductive belt base material, a resin material obtained by blending a polypyrrole-based conductive polymer with at least one of a polyurea-based resin and a polyurethane-based resin There has been proposed a transfer belt in which the belt base material is formed using a polypyrrole conductive polymer and the conductive layer is formed using a polypyrrole conductive polymer (see Patent Document 1).
JP 2004-177601 A

  By the way, in a semiconductive member for an electrophotographic apparatus such as a developing roll or a charging roll, the coating layer must have flexibility and surface properties (not cracked, not scraped, not contaminated with toner, etc.). When the polypyrrole-based conductive polymer described in Patent Document 1 is used, there is a problem that flexibility and surface properties cannot be satisfied. In order to solve this problem, conjugation with a binder polymer that satisfies these physical properties can be considered, but the polypyrrole conductive polymer described in Patent Document 1 has poor compatibility with the binder polymer, As a result, agglomerates are generated, the voltage dependency and the environment dependency of the electrical resistance are large, and the controllability of the electrical resistance is significantly deteriorated.

  The present invention has been made in view of such circumstances, and provides a semiconductive composition for electrophotographic equipment having excellent controllability of electrical resistance and a semiconductive member for electrophotographic equipment using the same. Objective.

In order to achieve the above object, the present invention provides a semiconductive composition for electrophotographic equipment (hereinafter abbreviated as “semiconductive composition”) having the following (A) as an essential component as a first gist. To do.
(A) Conductive polypyrrole obtained by conducting polypyrrole having a structural unit represented by the following general formula (1) with a dopant having a sulfonic acid group or sulfonate structure.

  Moreover, this invention makes the 2nd summary the semiconductive member for electrophotographic apparatuses which used the said semiconductive composition for at least one part of the semiconductive member.

That is, as a result of further research on the polypyrrole conductive polymer described in Patent Document 1, the present inventors have found that 2,3,6,7-tetracyano-1,4,5,8-tetra Since azanaphthalene (TCNA) is used as a dopant, the obtained polypyrrole-based conductive polymer has poor compatibility with the binder polymer. Therefore, when this is used for a coating layer of a semiconductive member for an electrophotographic apparatus such as a developing roll or a charging roll, aggregates are generated, and the voltage dependence and environmental dependence of electrical resistance increase. I found out that the controllability of the electrical resistance deteriorates. Accordingly, the present inventors have conducted research on a combination of polypyrrole and a dopant having excellent compatibility with a binder polymer, and as a result, have found that a dopant (α ), Or a dopant having a sulfonic acid group or a sulfonate structure, such as a dopant (β) made of a non-conjugated polymer having a sulfonic acid group or a sulfonate structure, and represented by the above general formula (1) A special conductive polypyrrole obtained by conducting a polypyrrole having a structural unit was identified. That is, this special conductive polypyrrole is composed of an alkyl group (R ¹ ) and an ester group (COOR ² ) in the general formula (1), and an alkyl group in the dopant or a non-conjugated polymer structure (non-conjugated elastomer). As a result of improving the compatibility with the binder polymer due to the structure etc.), it has been found that the variation in electrical resistance is reduced, stable against voltage fluctuations and stable against environmental fluctuations. Reached.

Thus, the semiconductive composition of the present invention is a non-conjugated polymer having a dopant (α) comprising an alkylbenzenesulfonic acid having at least one alkyl substituent or a salt thereof, or a sulfonic acid group or sulfonate structure. A special conductive polypyrrole formed by conducting a polypyrrole having a structural unit represented by the general formula (1) using a dopant having a sulfonic acid group or a sulfonate structure, such as a dopant (β) consisting of It is what is used. Therefore, the binder polymer is composed of the alkyl group (R ¹ ) and the ester group (COOR ² ) in the general formula (1), the alkyl group in the dopant, or a non-conjugated polymer structure (such as a non-conjugated elastomer structure). As a result, the variation in electrical resistance is reduced, and it is stable against voltage fluctuations and stable against environmental fluctuations.

In addition, since the polypyrrole-based conductive polymer described in Patent Document 1 has poor solubility in a general-purpose solvent, in order to dissolve this polypyrrole-based conductive polymer, it is necessary to use 2-methyl-2-pyrrolidone (NMP). It was necessary to use a special organic solvent. Moreover, when this polypyrrole-based conductive polymer is dissolved in NMP and used in a coating layer such as a developing roll, the NMP has a boiling point of 200 ° C. or higher, and if this NMP solvent is used, The film was unsuitable for mass production due to reasons such as repelling and uneven coating and poor coatability. On the other hand, the special conductive polypyrrole has an alkyl group (R ¹ ) and an ester group (COOR ² ) in the general formula (1), and an alkyl group or non-conjugated polymer structure (non-conjugated) in the dopant. It has excellent solubility in general-purpose solvents due to its conjugated elastomer structure and the like. Therefore, when the semiconductive composition of the present invention is used, for example, in the coat layer (surface layer) of the developing roll, the toner scatters compared to the case where a conventional electronic conductive agent such as carbon black is used. Less clear image quality can be obtained. The reason is that, as described above, carbon black has a discontinuous agglomerated structure, and thus there is a variation in electric resistance on the roll surface, and the toner cannot be uniformly charged. It is considered that this is because a very fine molecular-level conductive path is formed in the binder polymer, so that the electric resistance is uniform and each toner can be uniformly charged.

  A semiconductive member for an electrophotographic apparatus using the semiconductive composition as at least a part of the semiconductive member has a constant concentration and is uniform and durable regardless of temperature and humidity. There is an effect that an excellent image can be obtained.

  Next, embodiments of the present invention will be described in detail.

  The semiconductive composition of the present invention can be obtained using a special conductive polypyrrole (component A) obtained by conducting a specific polypyrrole with a specific dopant.

  The specific polypyrrole is not particularly limited as long as it has a structural unit represented by the following general formula (1).

In the above formula (1), as the alkyl group represented by R ¹ , an alkyl group having 1 to 50 carbon atoms is used, and an alkyl group having 1 to 20 carbon atoms is preferably used. Moreover, as an alkyl group represented by R < ² >, although a C1-C50 thing is used, Preferably a C1-C20 alkyl group is used.

  Preferred specific examples of the specific polypyrrole are, for example, structural units represented by the following general formula (1a) [ethyl 3-methyl-4-pyrrolecarboxylate] and the following general formula (1b). And a copolymer with a structural unit [butyl 3-methyl-4-pyrrolecarboxylate].

  The number average molecular weight (Mn) of the specific polypyrrole is preferably in the range of 2,000 to 500,000, particularly preferably in the range of 5,000 to 100,000.

  Next, as a specific dopant used with the said specific polypyrrole, a number average molecular weight (Mn) has a preferable thing of 300 or more, Most preferably, it exists in the range of 300-1000. That is, when the number average molecular weight (Mn) of the dopant is less than 300, the solubility with respect to the binder polymer or the general-purpose solvent tends to be deteriorated.

Although it will not specifically limit as said specific dopant if it has a sulfonic acid group or a sulfonate structure, For example, the following dopant ((alpha)) or dopant ((beta)) is mention | raise | lifted.
(Α) benzenesulfonic acid or a salt thereof having at least one selected from the group consisting of an alkyl group, an alkoxy group and a phenyl ether group in the molecular structure.
(Β) A non-conjugated polymer having a sulfonic acid group or sulfonate structure.

  Examples of the dopant (α) include those represented by the following general formula (2) or general formula (3).

  Examples of the sulfonate represented by the general formula (3) include sulfonate metal salts such as sodium sulfonate, potassium sulfonate, and barium sulfonate, ammonium sulfonate, pyridium sulfonate, and the like. Is given. Among these, sulfonic acid metal salts are preferably used.

  Specific examples of the dopant (α) include sodium dodecylbenzenesulfonate, sodium pentadecylbenzenesulfonate, sodium octadecylbenzenesulfonate, sodium trihexylbenzenesulfonate, sodium dihexylpentadecylbenzenesulfonate, hexyl dipentadecylbenzene. Examples include sodium sulfonate, sodium methyldioctadecylbenzenesulfonate, sodium dodecylphenylbutadecylphenylethersulfonate, sodium pentadecyldiphenylethersulfonate, sodium polyphenylethersulfonate, and the like. These may be used alone or in combination of two or more. Among these, in terms of imparting high conductivity, sodium dodecylbenzenesulfonate, sodium pentadecylbenzenesulfonate, sodium trihexylbenzenesulfonate, sodium dihexylpentadecylbenzenesulfonate, sodium hexyldipentadecylbenzenesulfonate, Sodium dodecylphenyl butadecyl phenyl ether sulfonate is preferably used.

  The pH of the dopant (α) is preferably in the range of 1 to 7, particularly preferably in the range of pH 1 to 3. That is, when the pH of the specific dopant exceeds 7, the dopant has no electron withdrawing property, and it tends to be difficult to extract electrons from the polypyrrole and impart conductivity.

  The specific conductive polypyrrole (component A) can be produced, for example, as follows. That is, pyrrole (monomer) having the structural unit represented by the general formula (1) and the dopant (α) are oxidatively polymerized in a solvent such as chloroform or ether in the presence of an oxidizing agent. In addition to the chemical oxidative polymerization method, it can also be obtained by an electrolytic polymerization method. In addition, the specific conductive polypyrrole (component A) can be obtained by polymerizing the pyrrole (monomer) having the structural unit represented by the general formula (1) and then doping, In a mixed solution with water, pyrrole (monomer) having the structural unit represented by the general formula (1) and the dopant (α) are emulsified, the dopant is introduced into the monomer, and then the monomer is polymerized. Can also be obtained. Moreover, after making a polypyrrole into a dedope state, it can obtain also by doping with the said dopant ((alpha)).

  Here, the mixing ratio of the specific polypyrrole (a) and the specific dopant (α) is a molar mixing ratio of (a) / (α) = 0.20 / 0.80-0.95 / 0. The range of 05 is preferable, and the range of (a) / (α) = 0.40 / 0.60 to 0.80 / 0.20 is particularly preferable. That is, when the molar mixing ratio of (a) is less than 0.20, excessive dopant functions as an ionic conductive agent, and there is a tendency that the electrical characteristics such as the environmental dependency of electrical resistance increase are deteriorated. On the other hand, if the molar mixing ratio of (a) exceeds 0.95, the amount of doping into polypyrrole is insufficient and the conductivity tends to decrease.

  In addition, as the dopant (β), a non-conjugated polymer having a sulfonic acid group or a sulfonate structure is used.

  Examples of the sulfonate include sulfonic acid metal salts such as sodium sulfonate, potassium sulfonate, and barium sulfonate, ammonium sulfonate, pyridium sulfonate, and the like. Among these, sulfonic acid metal salts are preferably used.

  The amount of the sulfonic acid functional group in the dopant (β) is preferably in the range of 0.2 to 0.75 mmol / g, particularly preferably in the range of 0.25 to 0.5 mmol / g, from the viewpoint of solubility. It is.

  The amount of the sulfonic acid functional group is determined, for example, by burning the dopant (β) in a flask, obtaining the amount of sulfur element by ion chromatography, and converting this as the amount of sulfonic acid functional group. Can do.

  Examples of the dopant (β) include acrylic polymers having a sulfonic acid functional group, urethane polymers, thermoplastic polymers, thermosetting polymers, rubber polymers, and thermoplastic elastomers. These may be used alone or in combination of two or more. Among these, an acrylic polymer having a sulfonic acid functional group and a urethane polymer having a sulfonic acid functional group are preferably used in terms of physical properties (wearability and strength).

  Examples of the acrylic polymer having a sulfonic acid functional group include polymethyl methacrylate (PMMA), polyethyl methacrylate, polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, polyhydroxy methacrylate, acrylic silicone resin, and acrylic fluorine-based polymer. Examples thereof include resins, copolymers of known acrylic monomers, and the like, in which at least one of a sulfonic acid group and a sulfonate structure is introduced into the molecular structure. A method of introducing a sulfonic acid group into an acrylic resin is a method in which a vinyl monomer having a sulfonic acid group or a sulfonate group such as 2-acrylamido-2-methylpropanesulfonic acid (AMPS) is copolymerized with a radical, an anion, and a cation Alternatively, there is a method of introducing a diol monomer having a sulfonic acid group by urethane reaction or transesterification reaction.

  The urethane polymer having a sulfonic acid functional group is not particularly limited as long as it is a polymer having a urethane bond in the molecular structure, for example, ether, ester, carbonate, acrylic, aliphatic, etc. And those obtained by copolymerizing a silicone polyol or a fluorine-based polyol, and having at least one of a sulfonic acid group and a sulfonate structure in the molecular structure. The urethane polymer may have a urea bond or an imide bond in the molecular structure.

  Examples of the thermoplastic polymer having a sulfonic acid functional group include polyester, polycarbonate, polyvinyl chloride (PVC), vinyl acetate, polyimide, polyethersulfone, polyvinylidene fluoride (PVDF), and vinylidene fluoride-tetrafluoride. An ethylene copolymer, a vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene copolymer, etc., in which at least one of a sulfonic acid group or a sulfonate structure is introduced into the molecular structure It is done.

  Examples of the thermosetting polymer having a sulfonic acid functional group include an epoxy resin, a urethane resin, a urea resin, a polyimide resin, and the like, and at least one of a sulfonic acid group and a sulfonate structure is included in the molecular structure. What has been introduced.

  Examples of the rubber-based polymer having a sulfonic acid functional group include natural rubber (NR), butadiene rubber (BR), acrylonitrile butadiene rubber (NBR), hydrogenated NBR (H-NBR), styrene butadiene rubber (SBR), Isoprene rubber (IR), urethane rubber, chloroprene rubber (CR), chlorinated polyethylene (Cl-PE), epichlorohydrin rubber (ECO, CO), butyl rubber (IIR), ethylene propylene diene polymer (EPDM), fluorine rubber, etc. In the molecular structure, at least one of a sulfonic acid group and a sulfonate structure is introduced.

  Examples of the thermoplastic elastomer having a sulfonic acid functional group include styrene-based thermoplastic elastomers such as styrene-butadiene block copolymer (SBS) and styrene-ethylene-butylene-styrene block copolymer (SEBS), and urethane-based elastomers. Thermoplastic elastomer (TPU), olefin thermoplastic elastomer (TPO), polyester thermoplastic elastomer (TPEE), polyamide thermoplastic elastomer, fluorine thermoplastic elastomer, PVC thermoplastic elastomer, etc. And those having at least one of a sulfonic acid group and a sulfonate structure introduced therein. These may be used alone or in combination of two or more.

  Among the above dopants (β), TPU having a sulfonic acid functional group and acrylic polymer having a sulfonic acid functional group are available in terms of simplicity of the synthesis process, solubility in a solvent, and physical properties (wearability, strength). Preferably used.

  The TPU can be obtained, for example, by reacting a polyester polyol obtained by reacting an acid component and a glycol component with an organic polyisocyanate.

  Examples of the acid component of the polyester polyol include aliphatic dibasic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, dodecynylsuccinic acid, 1,2-cyclohexanedicarboxylic acid, 1,3- Cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, 1,2-bis (4-carboxycyclohexyl) methane, 2,2-bis (4-carboxycyclohexyl) propane, etc. And aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, and naphthalenedicarboxylic acid. These may be used alone or in combination of two or more. Among these, adipic acid, sebacic acid, dodecinyl succinic acid, and 1,2-cyclohexanedicarboxylic acid are preferably used in terms of dispersibility. Further, in a predetermined range (preferably in the range of 20 to 50 mol%) in the total acid component, aromatic metal containing a sulfonic acid metal salt such as 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid, sodium sulfoterephthalic acid, etc. It is preferable to copolymerize dicarboxylic acid.

  Examples of the glycol component of the polyester polyol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,2-propylene. Glycol, 1,3-propylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 2,2-dimethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2 -Aliphatic glycols such as dimethyl-3-hydroxypropyl, 2 ', 2'-dimethyl-3-hydroxypropanate, 2,2-diethyl-1,3-propanediol, and 1,3-bis (hydroxymethyl) ) Cyclohexane, 1,4-bis (hydroxymethyl) cyclohexane, 1,4- (Hydroxyethyl) cyclohexane, 1,4-bis (hydroxypropyl) cyclohexane, 1,4-bis (hydroxymethoxy) cyclohexane, 1,4-bis (hydroxyethoxy) cyclohexane, 2,2-bis (4-hydroxymethoxy) And cycloaliphatic glycols such as cyclohexyl) propane, 2,2-bis (4-hydroxyethoxycyclohexyl) propane, bis (4-hydroxycyclohexyl) methane, and 2,2-bis (4-hydroxycyclohexyl) propane. . These may be used alone or in combination of two or more. Among these, 2,2-dimethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2,2-dimethyl-3-hydroxypropyl, 2 ', 2'-dimethyl- 3-hydroxypropanate and 1,6-hexanediol are preferred. In addition, it is preferable to copolymerize sulfonic acid metal salt-containing glycols such as 2-sodium sulfo-1,4-butanediol and 2-sodium sulfo-1,6-hexanediol within a predetermined range in all glycol components.

  Examples of the organic polyisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, m-phenylene diisocyanate, 3,3'- Dimethoxy-4,4'-biphenylene diisocyanate, 2,6-naphthalene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 4,4'-diphenylene diisocyanate, 4,4'-diisocyanate diphenyl ether, 1 , 5-Naphthalene diisocyanate, m-xylene diisocyanate, 1,3-diisocyanate methylcyclohexane, 1,4-diisocyanate methylcyclohexane, 4,4'-diisocyanate cyclohexa , 4,4'-diisocyanate cyclohexylmethane, isophorone diisocyanate, and the like. These may be used alone or in combination of two or more. Among these, 4,4′-diphenylmethane diisocyanate is preferably used.

  As TPU which has the said sulfonic acid functional group, what was equipped with the structure represented by following Structural formula (4), for example is preferable.

  Moreover, as an acrylic polymer which has the above-mentioned sulfonic acid functional group, what was equipped with the structure represented by following Structural formula (5) is preferable, for example.

  Here, the conductive polymer can be prepared, for example, by the following simultaneous polymerization method or ion exchange method.

(Simultaneous polymerization method)
A predetermined amount of pyrrole (monomer) having the structural unit represented by the general formula (1), a dopant (β), and a mixed solvent of an organic solvent such as chloroform, toluene, ketone, ether, and the like are put in a flask. While controlling at a predetermined temperature (usually about 15 ° C.), an oxidizing agent such as ferric chloride is dropped over several hours (usually about 1 hour), and oxidative polymerization is conducted for several hours (usually about 20 hours). To obtain a polymer. Next, the target conductive polymer can be prepared by washing and purifying the polymer with water and methanol.

[Ion exchange method]
A predetermined amount of pyrrole (monomer) having the structural unit represented by the general formula (1) and an oxidizing agent such as anhydrous iron chloride (III) are mixed to obtain polypyrrole. This polypyrrole is dedoped in an alkaline environment and purified with water and methanol. Then, the sulfonic acid-containing polymer is ion-exchanged in an acidic environment to obtain sulfonic acid. Then, a desired conductive polymer can be prepared by mixing a predetermined amount of the dedoped polypyrrole and the ion-exchanged sulfonic acid functional group-containing dopant (β).

  Here, the molar ratio between the number of moles of the monomer unit of the specific polypyrrole (a) and the number of moles of the sulfonic acid functional group (b) of the dopant (β) is (a) / (b) = 1/0. The range of 0.05 to 1/3 is preferable, and the range of (a) / (b) = 1 / 0.05 to 1/2 is particularly preferable. That is, when (b) is too low, the compatibility with a specific polypyrrole tends to be reduced. Conversely, when (b) is too high, the reactivity is deteriorated or the ionic conductivity is contributed. This is because of a tendency to reduce the electronic conductivity of the conductive polymer.

  The specific conductive polypyrrole (component A) includes methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), ketone solvents such as acetone, ester solvents such as ethyl acetate and butyl acetate, aromatic solvents such as toluene, It is soluble in ether solvents such as tetrahydrofuran (THF).

  In addition, in the semiconductive composition of this invention, when using the electroconductive polypyrrole formed by electroconductivity with the said dopant ((alpha)), you may use a binder polymer together.

  As said binder polymer, what is excellent in compatibility with specific electroconductive polypyrrole (A component) is preferable, for example, an acrylic polymer, a urethane type polymer, a thermoplastic resin, a thermosetting resin, a rubber-type polymer, thermoplasticity Examples thereof include elastomers. These may be used alone or in combination of two or more. Among these, acrylic polymers and urethane polymers are preferably used in terms of physical properties (wearability and strength).

  Examples of the acrylic polymer include polymethyl methacrylate (PMMA), polyethyl methacrylate, polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, polyhydroxy methacrylate, acrylic silicone resin, acrylic fluorine resin, and the like. These may be used alone or in combination of two or more.

  The urethane polymer is not particularly limited as long as it is a polymer having a urethane bond in its molecular structure, for example, ether-based, ester-based, carbonate-based, acrylic-based, aliphatic-based urethane, Examples thereof include those obtained by copolymerizing silicone polyol or fluorine polyol. These may be used alone or in combination of two or more.

  Examples of the thermoplastic resin include polyester, polycarbonate, polyvinyl chloride (PVC), vinyl acetate, polyimide, polyethersulfone, polyvinylidene fluoride (PVDF), and vinylidene fluoride-tetrafluoroethylene copolymer. And vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene copolymer. These may be used alone or in combination of two or more.

  Examples of the thermosetting resin include epoxy resins, urethane resins, urea resins, polyimide resins, and the like. These may be used alone or in combination of two or more.

  Examples of the rubber polymer include natural rubber (NR), butadiene rubber (BR), acrylonitrile butadiene rubber (NBR), hydrogenated NBR (H-NBR), styrene butadiene rubber (SBR), and isoprene rubber (IR). ), Urethane rubber, chloroprene rubber (CR), chlorinated polyethylene (Cl-PE), epichlorohydrin rubber (ECO, CO), butyl rubber (IIR), ethylene propylene diene polymer (EPDM), fluorine rubber and the like. These may be used alone or in combination of two or more.

  Examples of the thermoplastic elastomer include styrene thermoplastic elastomers such as styrene-butadiene block copolymer (SBS) and styrene-ethylene-butylene-styrene block copolymer (SEBS), and urethane thermoplastic elastomer (TPU). Olefin-based thermoplastic elastomer (TPO), polyester-based thermoplastic elastomer (TPEE), polyamide-based thermoplastic elastomer, fluorine-based thermoplastic elastomer, vinyl chloride-based thermoplastic elastomer, and the like. These may be used alone or in combination of two or more.

  The binder polymer may have a sulfonic acid functional group of at least one of a sulfonic acid group and a sulfonic acid group. Examples of the sulfonic acid functional group include a sulfonic acid group, a sulfonic acid group (a sulfonic acid metal base such as a sodium sulfonate base and a potassium sulfonate base, an ammonium sulfonate base, and a pyridium sulfonate base). .

  The amount of the sulfonic acid functional group in the binder polymer is preferably in the range of 0.2 to 0.75 mmol / g, particularly preferably in the range of 0.25 to 0.5 mmol / g, from the viewpoint of solubility. .

  The measurement of the amount of the sulfonic acid functional group can be obtained, for example, by burning the binder polymer in a flask, obtaining the amount of sulfur element by ion chromatography, and converting this as the amount of sulfonic acid functional group. .

  The binder polymer is preferably one that dissolves in an aromatic solvent such as toluene or a ketone solvent such as methyl ethyl ketone (MEK) because the drying speed can be controlled and the coating property is improved.

  Here, the mixing ratio of the specific conductive polypyrrole (component A) and the binder polymer is a weight mixing ratio, and component A / binder polymer = 0.01 / 0.99 to 0.80 / 0.20. Is particularly preferable, and component A / binder polymer = 0.05 / 0.95 to 0.50 / 0.50 is particularly preferable. That is, when the weight mixing ratio of the A component is less than 0.01, there is a tendency that the conductivity for use in the product cannot be satisfied, and conversely, when the weight mixing ratio of the A component exceeds 0.80, This is because the simple substance tends to be hard and brittle, and the physical properties for use in products are not satisfactory.

  In addition, when using conductive polypyrrole (A component) made conductive by the dopant (β), since the dopant (β) itself has the properties of a binder polymer, the binder polymer component is not essential.

  In the semiconductive composition of the present invention, a conductive agent, a cross-linking agent, a cross-linking accelerator, an anti-aging agent and the like may be appropriately blended with the specific conductive polypyrrole (component A) as necessary. .

The conductive agent is not particularly limited, and examples thereof include carbon black, c-ZnO (conductive zinc oxide), c-TiO ₂ (conductive titanium oxide), c-SnO ₂ (conductive tin oxide), graphite, and the like. And an ionic conductive agent such as a compound dissolved in a polymer such as lithium perchlorate, quaternary ammonium salt and borate. These may be used alone or in combination of two or more.

  The blending ratio of the electronic conductive agent is preferably in the range of 5 to 80 parts, particularly preferably 8 to 100 parts by weight (hereinafter abbreviated as “part”) of the specific conductive polypyrrole (component A). Within 20 parts.

  The blending ratio of the ionic conductive agent is preferably in the range of 0.01 to 5 parts, particularly preferably in the range of 0.5 to 2 parts, with respect to 100 parts of the specific conductive polypyrrole (component A). Is within.

  Examples of the crosslinking agent include urea resins such as sulfur, isocyanate, blocked isocyanate, and melamine, epoxy curing agents, polyamine curing agents, hydrosilyl curing agents, and peroxides. A photoinitiator that generates radicals by energy such as ultraviolet rays or electron beams may be used in combination with the crosslinking agent.

  The blending ratio of the cross-linking agent is preferably in the range of 1 to 30 parts, particularly preferably 3 to 100 parts with respect to 100 parts of the specific conductive polypyrrole (component A) from the viewpoint of physical properties, adhesion, and liquid storage property. Within 10 parts.

  Examples of the crosslinking accelerator include known ones such as a sulfenamide-based crosslinking accelerator, a platinum compound, an amine catalyst, and a dithiocarbamate-based crosslinking accelerator.

  The semiconductive composition of the present invention can be produced, for example, as follows. That is, first, a specific conductive polypyrrole (component A) is produced according to the method described above. Next, a binder polymer, a solvent, etc. are mix | blended with this specific electroconductive polypyrrole (A component) as needed. And by kneading these using a kneading machine such as a roll, kneader, Banbury mixer or the like without dissolving them in a solvent, or by dissolving them in a solvent and dispersing them using a bead mill or three rolls, A semiconductive composition can be obtained.

  Examples of the solvent include organic solvents such as m-cresol, methanol, methyl ethyl ketone (MEK), toluene, tetrahydrofuran (THF), acetone, ethyl acetate, dimethylformamide (DMF), and N-methyl-2-pyrrolidone (NMP). Etc.

  Next, a semiconductive member for electrophotographic equipment using the semiconductive composition of the present invention will be described.

  The semiconductive member for an electrophotographic apparatus of the present invention can be obtained by using the above semiconductive composition for at least a part (all or a part) of the semiconductive member. Examples of the semiconductive member for electrophotographic equipment include conductive rolls such as developing rolls, charging rolls, transfer rolls, and toner supply rolls, and conductive belts such as intermediate transfer belts and paper feed belts. It is used for at least a part of the constituent layers. That is, when the semiconductive composition of the present invention is used for at least a part of a constituent layer of a semiconductive member for an electrophotographic apparatus, the voltage dependence of the electrical resistance of the constituent layer formed using this semiconductive composition. Since the electric current and the environmental dependency are reduced and the current flows through the semiconductor composition layer to other constituent layers, the electric resistance is less affected by the voltage dependency and the environmental dependency. As a result, the voltage dependency and the environment dependency of the electrical resistance as a whole semiconductive member for electrophotographic equipment are reduced, so that the density unevenness is reduced and good image quality with little fluctuation is obtained. As a result, an improvement in performance can be realized.

  Next, examples will be described together with comparative examples. However, the present invention is not limited to these examples.

  First, prior to Examples and Comparative Examples, materials shown below were prepared and prepared.

[Polypyrrole]
64.88 g (0.4 mol) of anhydrous iron (III) chloride was dissolved in 1000 ml of ether, and 16.50 g (0.1 mol) of a pyrrole monomer having the structural unit represented by the general formulas (1a) and (1b) was added. Added with stirring. Since an exothermic reaction occurred and the reaction solution turned black and polypyrrole was precipitated, the reaction temperature was kept at 22 ° C. for 1 hour. After the reaction, the solution was filtered, washed with a large amount of water, washed with 500 ml of 1N hydrochloric acid, and further washed with water until the washing filtrate became neutral. Subsequently, it was washed with ethanol and ether and dried under reduced pressure at 65 ° C. for 4 hours to obtain 21.15 g of powdered polypyrrole. The number average molecular weight (Mn) of the obtained polypyrrole was 20,000.

[Dopant a]
Dodecylbenzenesulfonic acid

[Dopant b]
Pentadecylbenzenesulfonic acid

[Dopant c]
A mixture of sodium alkylbenzene sulfonate having two pentyl groups and one hexyl group, sodium alkylbenzene sulfonate having one pentyl group and two hexyl groups, and sodium alkylbenzene sulfonate having three hexyl groups ( Mn: 440)

[Dopant d]
Sodium dodecylphenylbutadecylphenylethersulfonate (molecular weight: 636)

[Dopant e]
To a reactor equipped with a thermometer, stirrer and partial reflux condenser, 178 parts of 5-sodium sulfoisophthalic acid, 155.8 parts of 1,6-hexanediol, and 321.7 parts of neopentyl glycol were added, The transesterification was carried out for 5 hours. Subsequently, 480.8 parts of adipic acid was added and reacted at 200 ° C. for 10 hours, and then the reaction system was depressurized to 200 mmHg over 3 hours, and further subjected to polycondensation reaction at 5 to 20 mmHg and 210 ° C. for 2 hours. A polyester diol (Mn: 2000) was obtained. Next, 100 parts of this polyester diol was dissolved in MEK so as to have a solid content of 30% by weight, 0.02 part of dibutyltin dilaurate was added as a catalyst, and the mixture was kept at 80 ° C. while stirring, while 4,4 ′ -12.5 parts of diphenylmethane diisocyanate was added to obtain a urethane elastomer having a sodium sulfonate group (Mn: 20,000, sodium sulfonate group amount: 0.5 mmol / g).

[Dopant f]
In a reactor equipped with a thermometer, a stirrer and a partial reflux condenser, 40 parts of methyl methacrylate (MMA), 10.4 parts of 2-acrylamido-2-methylpropanesulfonic acid (AMPS), 6 parts of hydroxyethyl methacrylate (HEMA) 6 .5 parts, 64.1 parts of butyl acrylate (BA) and 200 parts of methyl isobutyl ketone (MIBK) are added, and 2 parts of azobisisobutyronitrile (AIBN) are added at 120 ° C. with stirring. Then, an acrylic elastomer having a sulfonic acid group (Mn: 12,000, sulfonic acid group amount: 0.4 mmol / g) was obtained.

[Dopant g]
While stirring 36.5 parts of sodium 2-methyl-1,3-butadiene-1-sulfonate (MBSN) and 664 parts of isoprene in water, potassium persulfate was added and polymerization was carried out at 70 ° C. for 5 hours. An isoprene-based elastomer having a sodium sulfonate group (Mn: 50,000, sodium sulfonate group amount: 0.35 mmol / g) was obtained.

[Dopant h]
2,3,6,7-tetracyano-1,4,5,8-tetraazanaphthalene (TCNA)

[Binder polymer a]
Sodium TPU sulfonate (Nipporan 3312, manufactured by Nippon Polyurethane Industry Co., Ltd.)

[Binder polymer b]
Polyol obtained by copolymerizing adipic acid / 5-sodium sulfoisophthalic acid = 4/1 (weight ratio) and ethylene glycol [weight average molecular weight (Mw): 2000], and polyethylene adipate polyol (Mw: 2000) Then, a silicone polyol (Mw: 2000) and MDI were reacted to prepare a sulfonated urethane silicone (sodium sulfonate group amount: 0.01 mmol / g, silicone component: 10%, Mw: 80,000).

  Next, a semiconductive composition was prepared using each of the above materials.

[Example 1A]
(Preparation of conductive polypyrrole)
A 5 wt% NMP solution was prepared from the polypyrrole powder synthesized above, and dopant a was blended in the proportion shown in Table 1 below while stirring the solution. Thereafter, a large amount of methanol was added to precipitate conductive polypyrrole, and the precipitated solution was filtered and further washed with methanol. It was dried under reduced pressure at 60 ° C. for 4 hours to produce conductive polypyrrole.

(Preparation of semiconductive composition)
30 parts of the conductive polypyrrole, 70 parts of the binder polymer a, and 500 ml of THF were blended and kneaded using a roll to prepare a semiconductive composition (coating liquid).

[Examples 2A to 16A, Comparative Examples 1A to 3A]
(Preparation of conductive polypyrrole)
Conductive polypyrrole was obtained in the same manner as in Example 1A, except that the amount of polypyrrole and the type or amount of dopant were changed to those shown in Tables 1 to 4 below.

(Preparation of semiconductive composition)
A semiconductive composition (coating liquid) was prepared in the same manner as in Example 1A, except that the type or amount of each component was changed to those shown in Tables 1 to 4 below.

Example 17A
The urethane elastomer having a sodium sulfonate group of the dopant e was diluted with THF, and ion exchange was performed on a sulfonic acid group having a proton using an ion exchange resin. Next, 80 parts of the urethane elastomer subjected to this ion exchange, 20 parts of polypyrrole synthesized above, and 500 ml of THF were mixed to prepare a semiconductive composition (coating liquid).

[Examples 18A and 19A]
A semiconductive composition (coating liquid) was prepared in the same manner as in Example 17A except that the dopant f and the dopant g were used in place of the dopant e.

  Each characteristic was evaluated according to the following reference | standard using the semiconductive composition of the Example and comparative example which were obtained in this way. These results are shown in Tables 1 to 4 above.

[Electrical resistance, voltage dependence of electrical resistance]
Each semiconductive composition (coating liquid) was applied on a SUS304 plate and dried at 120 ° C. for 30 minutes to prepare a conductive coating film having a thickness of 30 μm. Next, with respect to this conductive coating film, an electric resistance (Rv = 1V) when a voltage of 1V is applied in an environment of 25 ° C. × 50% RH, and an electric resistance (Rv = VV) when a voltage of 300V is applied. 300V) was measured according to SRIS 2304, respectively. Then, the voltage dependence of the electrical resistance is displayed in the number of fluctuation digits by Log (Rv = 1V / Rv = 300V).

[Environmental dependence of electrical resistance]
Using each semiconductive composition (coating liquid), a conductive coating film was prepared in the same manner as described above, and this conductive coating film was subjected to low temperature and low humidity (15 ° C. × 10%) under the condition of an applied voltage of 10 V. RH) electrical resistance (Rv = 15 ° C. × 10% RH) and high temperature high humidity (35 ° C. × 85% RH) electrical resistance (Rv = 35 ° C. × 85% RH) according to SRIS 2304 Each was measured. Then, the environmental dependency of the electrical resistance was displayed by the number of fluctuation digits by Log (Rv = 15 ° C. × 10% RH / Rv = 35 ° C. × 85% RH).

[Electric resistance after wet heat, number of fluctuations after wet heat]
Using each semiconductive composition (coating liquid), a conductive coating film was prepared in the same manner as described above. The conductive coating film had an electrical resistance before standing (Rv = 0 days) and 50 ° C. The electrical resistance (Rv = January) after standing for 1 month (wet heat) in an environment of × 95% RH was measured according to SRIS 2304 under the conditions of 25 ° C. × 50% RH and 10 V application. And the number of fluctuation digits after wet heat was calculated | required by Log (Rv = January / Rv = 0 day).

  From the results shown in Tables 1 to 4, all of the products according to the examples had low voltage dependency and environmental dependency of the electrical resistance, and small fluctuation digits after wet heat, and were excellent in controllability of the electrical resistance.

  On the other hand, since the product of Comparative Example 1A uses TCNA as a dopant, it has poor solubility in a general-purpose organic solvent such as THF, and is soluble only in a high boiling point solvent (boiling point 200 ° C. or higher) such as NMP. . Therefore, as will be described later, in the product of Comparative Example 1B in which the surface layer of the developing roll is formed using this, repelling, uneven coating, etc. occur during coating. Moreover, since the comparative examples 2A and 3A products use TCNA as a dopant, the voltage dependency of the electrical resistance, the environment dependency, and the moist heat fluctuation are large, and the controllability of the electrical resistance is inferior.

  Next, a developing roll was prepared using each of the semiconductive compositions.

[Example 1B]
(Preparation of base layer material)
Silicone rubber (manufactured by Shin-Etsu Chemical Co., Ltd., KE1350AB) in which carbon black was dispersed was prepared.

(Preparation of surface layer material)
A semiconductive composition was prepared according to Example 1A, and a surface layer material (coating solution) was prepared using the semiconductive composition.

(Preparation of developing roll)
The base layer material is cast into an injection mold having a shaft core (diameter 8 mm, made of SUS304), heated at 150 ° C. for 45 minutes, and then removed from the mold. A base layer was formed along the outer peripheral surface of the shaft body. Next, the base layer (thickness 4 mm) is formed on the outer peripheral surface of the shaft body by applying (coating) the surface layer material to the outer peripheral surface of the base layer to form the surface layer. A developing roll having a two-layer structure in which a surface layer (thickness: 5 μm) was formed was produced.

[Examples 2B to 19B, Comparative Examples 1B to 3B]
(Preparation of surface layer material)
A surface layer material was produced in the same manner as in Example 1B, except that the type of the semiconductive composition used for the surface layer material was changed to those shown in Tables 5 to 8 below.

(Preparation of developing roll)
Two layers in which a base layer (thickness 4 mm) is formed on the outer peripheral surface of the shaft body and a surface layer (thickness 5 μm) is formed on the outer peripheral surface in the same manner as in Example 1B, except that the surface layer material is used. A developing roll having a structure was prepared.

  Using the developing rolls of Examples and Comparative Examples thus obtained, each characteristic was evaluated according to the following criteria. These results are also shown in Tables 5 to 8 above.

[Electrical resistance, voltage dependence of electrical resistance]
With the surface of the developing roll pressed against the SUS plate, a load of 1 kg is applied to both ends of the developing roll, and the electrical resistance between the core of the developing roll and the surface of the developing roll pressed against the SUS plate is Measured according to SRIS 2304. The electrical resistance is the electrical resistance when a voltage of 1V is applied in an environment of 25 ° C. × 50% RH (Rv = 1V) and the electrical resistance when a voltage of 300V is applied (Rv = 300V), respectively. It was measured. Then, the voltage dependence of the electrical resistance is displayed in the number of fluctuation digits by Log (Rv = 1V / Rv = 300V).

[Environmental dependence of electrical resistance]
According to the evaluation of the electrical resistance, the electrical resistance (Rv = 15 ° C. × 10% RH) at the low temperature and low humidity (15 ° C. × 10% RH) and the high temperature and high humidity (35 ° C. × 35 ° C.) The electrical resistance (Rv = 35 ° C. × 85% RH) at 85% RH was measured according to SRIS 2304. Then, the environmental dependency of the electrical resistance was displayed by the number of fluctuation digits by Log (Rv = 15 ° C. × 10% RH / Rv = 35 ° C. × 85% RH).

[Number of fluctuation digits after wet heat]
The electrical resistance (Rv = June) after standing for 6 months in an environment of 50 ° C. × 95% RH and the electrical resistance before standing (Rv = 0 day) are the conditions of 25 ° C. × 50% RH, 10V application Below, it measured according to SRIS 2304, respectively. Then, the number of fluctuation digits after wet heat was determined by Log (Rv = June / Rv = 0 day).

[Coating properties]
When the surface layer material was coated, the coating property was evaluated with x indicating that repelling or uneven coating occurred, and ○ indicating that no repelling or uneven coating occurred.

[Physical properties]
Each developing roll was incorporated into a commercially available color printer (LBP2510), and the surface state of the developing roll was observed after 8000 sheets were printed in an environment of 35 ° C. × 85% RH. In the evaluation, ○ indicates that there is no peeling, cracks, or scratches, and × indicates that there is peeling, cracks, scratches, or the like.

[Image unevenness]
Each developing roll was incorporated into a commercially available color printer (LBP2510), and images were taken out in an environment of 20 ° C. × 50% RH. The evaluation was ○ when there was no density unevenness in the halftone image and there was no fine line break or color unevenness, Δ when density unevenness was less than 2% in the entire image, and 2% or more in the entire image In the case where the unevenness of the density occurred, x was marked.

[Image density stability depending on the environment]
When each developing roll was incorporated into a commercially available color printer (LBP2510) and imaged in an environment of 15 ° C. × 10% RH and when imaged in an environment of 35 ° C. × 85% RH, The stability of image quality density due to the environment was evaluated. In the evaluation, a solid black image was printed, and when the change was 0.1 or less with a Macbeth densitometer, ○, and when it exceeded 0.1, x.

  From the results of Tables 5 to 8, all of the examples had good physical properties, image unevenness, and image density stability depending on the environment.

  On the other hand, the product of Comparative Example 1B was inferior in image density stability due to coating properties, physical properties and environment, and was slightly inferior in image unevenness. The product of Comparative Example 2B had large electrical resistance voltage dependency, environmental dependency, and wet heat fluctuation, and was inferior in coating properties, physical properties, image unevenness, and image density stability due to the environment. The product of Comparative Example 3B had large electrical resistance voltage dependency, environmental dependency, and wet heat fluctuation, and was slightly inferior in image unevenness and inferior in image density stability due to the environment.

  The semiconductive composition of the present invention can be used for an electrophotographic apparatus member such as a developing roll, and specifically, can be suitably used as a material for a coat layer (surface layer) such as a developing roll.

Claims (7)

A semiconductive composition for electrophotographic equipment, comprising the following (A) as an essential component.
(A) Conductive polypyrrole obtained by conducting polypyrrole having a structural unit represented by the following general formula (1) with a dopant having a sulfonic acid group or sulfonate structure.

  The semiconductive composition for an electrophotographic apparatus according to claim 1, wherein the dopant has a number average molecular weight of 300 or more. The semiconductive composition for electrophotographic equipment according to claim 1 or 2, wherein the dopant is the following (α).
(Α) benzenesulfonic acid or a salt thereof having at least one selected from the group consisting of an alkyl group, an alkoxy group and a phenyl ether group in the molecular structure. The semiconductive composition for electrophotographic equipment according to claim 1 or 2, wherein the dopant is the following (β).
(Β) A non-conjugated polymer having a sulfonic acid group or sulfonate structure.   The semiconductive composition for an electrophotographic apparatus according to claim 3, comprising a binder polymer together with the dopant (α).   The semiconductive composition for an electrophotographic apparatus according to claim 5, wherein the binder polymer is dissolved in a solvent.   A semiconductive member for an electrophotographic apparatus, wherein the semiconductive composition according to any one of claims 1 to 6 is used for at least a part of the semiconductive member.