JP2006267244A - Semiconductive composition for electrophotographic equipment and semiconductive member for electrophotographic equipment obtained by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductive composition for electrophotographic equipment excellent in dispersibility, ensuring small variation of electric resistance in a semiconductive region, and excellent in control of conductivity. <P>SOLUTION: The semiconductive composition for electrophotographic equipment contains as essential components (A) a binder polymer having an ionic functional group, (B) metal nanoparticles and (C) at least one high-molecular-weight pigment dispersant selected from the group consisting of (C1) a polymer of a comb structure having a pigment-affinitive group in at least one of a backbone and a plurality of side chains and having a plurality of side chains constituting a solvation moiety, wherein a number average molecular weight of the polymer is within the range of 2,000-1,000,000, (C2) a polymer having a plurality of pigment-affinitive moieties comprising a pigment-affinitive group in a backbone, wherein a number average molecular weight of the polymer is within the range of 2,000-1,000,000, and (C3) a straight chain polymer having a pigment-affinitive moiety comprising a pigment-affinitive group at one end of a backbone, wherein a number average molecular weight of the polymer is within the range of 1,000-1,000,000. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

  In general, in order to use a conductive composition used for a semiconductive member for an electrophotographic apparatus such as a developing roll, it is essential to control electric resistance. Therefore, conventionally, the electrical resistance is controlled by blending an ion conductive agent such as a quaternary ammonium salt or an electronic conductive agent such as carbon black into a binder polymer such as resin or rubber.

  Among the above conductive agents, this ionic conductive agent dissolves in the binder polymer when it is combined with the binder polymer, so that the variation in conductivity is small, and the variation in electrical resistance when the voltage is changed is small. There is an advantage that the voltage dependency of the resistance is small. However, this ionic conductive agent is easily affected by moisture and the like, and under high temperature and high humidity and low temperature and low humidity conditions, the electrical resistance fluctuates by two orders of magnitude or more. There are many restrictions on the use as a device member. On the other hand, the electronic conductive agent such as carbon black is less susceptible to moisture when compounded with a binder polymer, and the variation in electrical resistance under high and high humidity and low and low humidity conditions is small. There is an advantage that environmental dependency is small. However, since this electronic conductive agent is generally highly cohesive, it is difficult to uniformly disperse in the binder polymer. Therefore, the electrical resistance varies greatly, and the electrical conductivity is difficult to control. In addition, even when dispersed relatively uniformly, the mechanism of conductivity development is due to the tunnel effect or hopping phenomenon in which electrons are transmitted between the carbons in the binder polymer by a high voltage. There is a drawback that the fluctuation of the electric resistance is large and the voltage dependence of the electric resistance is large.

Therefore, “including a colloidal particle of noble metal or copper and a high molecular weight pigment dispersant, the high molecular weight pigment dispersant has a pigment affinity group in the main chain and / or a plurality of side chains, and has a solvation part. Comb-shaped polymer having a plurality of side chains constituting the polymer, or a polymer having a plurality of pigment-affinity moieties composed of pigment-affinity groups in the main chain, and the polymer having a comb-shaped structure having the plurality of side chains Is a paint composition comprising a noble metal or copper solid sol having a number average molecular weight of 2000 to 1000000 and the polymer having a plurality of pigment-affinity moieties having a number average molecular weight of 2000 to 1000000. Articles and resin compositions have been proposed (see, for example, Patent Document 1).
JP 2004-217940 A

  In the solid sol of noble metal or copper described in Patent Document 1, since the high molecular weight pigment dispersant functions as a protective colloid for colloidal particles of noble metal or copper, it is possible to suppress aggregation of the colloidal particles of noble metal or copper. it can. However, in a coating composition comprising a combination of this noble metal or copper solid sol and a binder polymer, the dispersibility of the noble metal or copper colloidal particles protected by the high molecular weight pigment dispersant in the binder polymer is low. Since it is bad, there is a problem that variation in electric resistance in the semiconductive region is large.

  The present invention has been made in view of such circumstances, and has excellent dispersibility, small variation in electrical resistance in the semiconductive region, and excellent semiconductive composition for electrophotographic equipment. Another object is to provide a semiconductive member for an electrophotographic apparatus using the same.

In order to achieve the above object, the present invention has a semiconductive composition for electrophotographic equipment having the following (A) to (C) as essential components as a first gist, and this semiconductive composition for electrophotographic equipment. A second aspect of the present invention is a semiconductive member for an electrophotographic apparatus, wherein the conductive composition is used for at least a part of the semiconductive member.
(A) A binder polymer having an ionic functional group.
(B) Metal nanoparticles.
(C) At least one high molecular weight pigment dispersant selected from the group consisting of the following (C1) to (C3).
(C1) A polymer having a comb-like structure having a pigment affinity group in at least one of the main chain and a plurality of side chains and having a plurality of side chains constituting a solvation part, and having a number average molecular weight of 2,000 Within the range of ~ 1,000,000.
(C2) A polymer having a plurality of pigment-affinity moieties composed of pigment-affinity groups in the main chain and having a number average molecular weight in the range of 2,000 to 1,000,000.
(C3) A linear polymer having a pigment affinity part composed of a pigment affinity group at one end of the main chain and having a number average molecular weight in the range of 1,000 to 1,000,000.

  That is, the present inventors have conducted extensive research to obtain a semiconductive composition for electrophotographic equipment that has excellent dispersibility, small variation in electrical resistance in the semiconductive region, and excellent conductivity control. . Then, it is recalled that a binder polymer having an ionic functional group such as a sulfonic acid group is used as a binder polymer, and this is combined with metal nanoparticles and the specific high molecular weight pigment dispersant (component C). It has been found that the intended purpose can be achieved when used, and the present invention has been achieved. That is, the specific high molecular weight pigment dispersant (component C) serves as a surfactant to suppress the aggregation of the metal nanoparticles, and also due to the ionic functional group in the binder polymer. Aggregation is suppressed. Further, since the metal nanoparticles are considered to be finely dispersed in the binder polymer having the ionic functional group in a state protected by the specific high molecular weight pigment dispersant (component C), the dispersibility is excellent. The variation in electric resistance in the semiconductive region (medium resistance region) is small, and the conductivity control is excellent.

  Thus, the semiconductive composition for electrophotographic equipment of the present invention is used in combination of metal nanoparticles, the specific high molecular weight pigment dispersant (component C), and a binder polymer having an ionic functional group. It was. Therefore, the specific high molecular weight pigment dispersant (component C) plays a role of a surfactant to suppress aggregation of the metal nanoparticles, and the ionic functional group in the binder polymer also causes the Aggregation is suppressed. Further, since the metal nanoparticles are considered to be finely dispersed in the binder polymer having the ionic functional group in a state protected by the specific high molecular weight pigment dispersant (component C), the dispersibility is excellent. The variation in electrical resistance in the semiconductive region (medium resistance region) is small, and the effect of excellent conductivity control is obtained.

Here, in the present invention, the semiconductive region refers to a medium resistance region, and specifically refers to an electric resistance in the range of 1 × 10 ⁵ to 1 × 10 ¹¹ Ω · cm.

  When the number of pigment affinity groups of the polymers (C1) to (C3) is within a specific range, the dispersibility is further improved, and the effect of less variation in electrical resistance can be obtained.

  Further, when the semiconductive composition for an electrophotographic device is used for at least a part of the semiconductive member, the voltage dependency and the environment dependency of the electrical resistance as the entire semiconductive member for an electrophotographic device are reduced. For this reason, it is possible to realize improvement in performance required for the electrophotographic apparatus such that density unevenness is reduced and a good image quality with little fluctuation is obtained.

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

  The semiconductive composition for electrophotographic equipment of the present invention comprises a binder polymer having an ionic functional group (component A), metal nanoparticles (component B), and a specific high molecular weight pigment dispersant (component C). Can be obtained.

  In the present invention, the binder polymer (component A) means a polymer that can be used as an electrophotographic apparatus and serves as a binder for elastomers and resin materials that provide functions with elasticity, flexibility, strength, wear resistance, and surface characteristics. To do. For example, polymers that give flexibility include natural rubber, synthetic rubber, thermoplastic elastomer, and the like, and polymers that give strength and wear resistance include thermosetting resins such as polyurethane and polyimide, engineering plastics, and the like. can give.

  The specific binder polymer (component A) needs to have an ionic functional group from the viewpoint of dispersibility, for example, an ionic functional group such as a sulfonic acid group, a sulfonate group, an ammonium group, or a carboxyl group. Can be given.

  Examples of the sulfonate group include metal sulfonate groups such as sodium sulfonate group and potassium sulfonate group, ammonium sulfonate group, pyridium sulfonate group, and the like.

  The amount of ionic functional groups such as the amount of sulfonic acid functional groups in the specific binder polymer (component A) is preferably in the range of 0.001 to 0.75 mmol / g, particularly preferably from the viewpoint of dispersibility. Is in the range of 0.02 to 0.5 mmol / g. That is, when the amount of the ionic functional group is less than 0.001 mmol / g, the dispersibility tends to be inferior and aggregation tends to increase. Conversely, when it exceeds 0.75 mmol / g, it is easily affected by water. This is because the environmental dependency of electric resistance tends to increase.

  The amount of the sulfonic acid functional group is measured, for example, by burning the specific binder polymer (component A) in a flask, obtaining the amount of sulfur element by ion chromatography, and converting this as the amount of sulfonic acid functional group. Can be obtained.

  As the specific binder polymer (component A), for example, acrylic polymers, urethane polymers, thermoplastic resins, thermosetting resins, rubber polymers, and thermoplastic elastomers having the ionic functional group are preferable. These may be used alone or in combination of two or more.

  Examples of the acrylic polymer having an ionic 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 ionic functional groups such as sulfonic acid groups, amino groups, and carboxyl groups are introduced into the molecular structure. These may be used alone or in combination of two or more.

  Examples of the ionic functional group for the acrylic polymer include vinyl monomers having a sulfonic acid group or a sulfonate group such as 2-acrylamido-2-methylpropanesulfonic acid (AMPS), or dimethylaminoethyl methacrylate. Such as a method of copolymerizing a vinyl monomer having an amino group such as a vinyl monomer having a carboxyl group such as acrylic acid and a radical, anion or cation, a diol monomer having a sulfonic acid group, an amino group or a carboxyl group , Urethane reaction, transesterification and the like.

  The urethane polymer having an ionic functional group is not particularly limited as long as it is a resin having a urethane bond in the molecular structure, for example, an ether polymer, an ester polymer, an acrylic polymer, an aliphatic polymer, etc. And those obtained by copolymerizing a silicone-based polyol or a fluorine-based polyol with an ionic functional group such as a sulfonic acid group, amino group, or carboxyl group introduced into the molecular structure. These may be used alone or in combination of two or more. The urethane polymer may have a urea bond or an imide bond in the molecular structure.

  Examples of the thermoplastic resin having an ionic functional group include polyester, polycarbonate, polyvinyl chloride (PVC), vinyl acetate, polyimide, polyethersulfone, polyvinylidene fluoride (PVDF), and vinylidene fluoride-tetrafluoride. Ethylene copolymers, vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene copolymers, etc., in which ionic functional groups such as sulfonic acid groups, amino groups, carboxyl groups are introduced into the molecular structure Things can be raised. These may be used alone or in combination of two or more.

  Examples of the thermosetting resin having an ionic functional group include epoxy resins, urethane resins, urea resins, polyimide resins, etc., and ions such as sulfonic acid functional groups, amino groups, carboxyl groups in the molecular structure. And a functional group introduced therein. These may be used alone or in combination of two or more.

  Examples of the rubber-based polymer having an ionic 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, an ionic functional group such as a sulfonic acid group, an amino group, or a carboxyl group is introduced. These may be used alone or in combination of two or more.

  Examples of the thermoplastic elastomer having an ionic 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 an ionic functional group such as a sulfonic acid group, an amino group or a carboxyl group introduced therein. These may be used alone or in combination of two or more.

  Among the above-mentioned specific binder polymers (component A), TPUs and acrylics having an ionic functional group such as sulfonic acid in terms of simplicity of the synthesis process, solubility in solvents, and physical properties (wearability, strength) Polymers, isoprene rubber and the like are 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 order to introduce a sulfonic acid group, 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid, sodium sulfoterephthalic acid in a predetermined range (preferably in a range of 20 to 50 mol%) in the total acid component. It is preferable to copolymerize a sulfonic acid metal salt-containing aromatic dicarboxylic acid such as.

  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, in order to introduce a sulfonic acid group, a sulfonic acid metal salt-containing glycol such as 2-sodium sulfo-1,4-butanediol, 2-sodium sulfo-1,6-hexanediol, etc. within a predetermined range in all glycol components Is preferably copolymerized.

  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 (1) is preferable, for example.

  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 (2) is preferable, for example.

  The specific binder polymer (component A) is preferably not soluble in water but soluble in a ketone solvent such as methyl ethyl ketone (MEK), an aromatic solvent such as toluene, or the like. That is, it becomes possible to control the drying rate of the semiconductive composition for OA members, the dry coating property becomes good, the film thickness can be easily controlled in the coating process, and the ionicity of the protective agent in a humid environment. This is because suppressing the environmental resistance of the electrical resistance can be reduced and the change in physical properties can be suppressed.

  Next, the metal nanoparticles (component B) used together with the specific binder polymer (component A) preferably have an average particle size in the range of 0.5 to 30 nm. It is in the range of 5 to 15 nm. That is, when the average particle size is less than 0.5 nm, the yield in the metal colloid cleaning process is deteriorated. Conversely, when the average particle size exceeds 30 nm, it tends to be affected by dispersion, resulting in variations in electrical characteristics and electrical resistance. This is because the voltage dependence tends to increase.

  Examples of the metal nanoparticles (component B) include metal nanoparticles such as gold, silver, copper, iron, nickel, platinum, ruthenium, rhodium, palladium, osmium and iridium. These may be used alone or in combination of two or more. Among these, silver nanoparticles and copper nanoparticles are preferable in terms of supplyability (cost).

  Moreover, the specific high molecular weight pigment dispersant (C component) used together with the specific binder polymer (component A) and the metal nanoparticles (component B) is selected from the group consisting of the following (C1) to (C3). Is at least one.

  (C1) A polymer having a comb-like structure having a pigment affinity group in at least one of the main chain and a plurality of side chains and having a plurality of side chains constituting a solvation part, and having a number average molecular weight of 2,000 Within the range of ~ 1,000,000.

  (C2) A polymer having a plurality of pigment-affinity moieties composed of pigment-affinity groups in the main chain and having a number average molecular weight in the range of 2,000 to 1,000,000.

  (C3) A linear polymer having a pigment affinity part composed of a pigment affinity group at one end of the main chain and having a number average molecular weight in the range of 1,000 to 1,000,000.

  The pigment affinity group refers to a functional group having a strong adsorptive power to the pigment surface, for example, a tertiary amino group, a quaternary ammonium, a heterocyclic group having a basic nitrogen atom, a hydroxyl group, Examples thereof include a carboxyl group, a phenyl group, a lauryl group, a stearyl group, a dodecyl group, and an oleyl group. Since the pigment affinity group has a strong affinity for metal nanoparticles (component B), the specific high molecular weight pigment dispersant (component C) having the pigment affinity group is metal nanoparticles (component B). Sufficient performance as a protective colloid.

  The specific comb-shaped polymer (C1) has a structure having a pigment affinity group in at least one of the main chain and the plurality of side chains and a plurality of side chains constituting a solvation part, These side chains are connected to the main chain as if they were comb teeth. In the present specification, the above structure is referred to as a comb structure. In the polymer (C1) having the specific comb structure, a plurality of the pigment affinity groups may be present not only at the end of the side chain but also in the middle of the side chain or in the main chain. The solvation part is a part having affinity for a solvent and has a hydrophobic structure, and is composed of, for example, a lipophilic polymer chain.

  The polymer having the specific comb structure (C1) is not particularly limited, and has, for example, one or more poly (carbonyl-C3-C6-alkyleneoxy) chains disclosed in JP-A-5-177123. And each of these chains has 3 to 80 carbonyl-C3-C6-alkyleneoxy groups and is linked to poly (ethyleneimine) by an amide or salt bridging group or its Consisting of an acid salt; comprising a reaction product of a poly (lower alkylene) imine disclosed in JP-A-54-37082 and a polyester having a free carboxylic acid group, and each poly (lower alkylene) imine Having at least two polyester chains bonded to the chain; having an epoxy group at the end as disclosed in JP-B-7-24746 Epoxy compounds of high molecular weight, mention may be made of a pigment dispersing agent obtained by reacting a carboxyl group-containing prepolymer of the amine compound having a number average molecular weight from 300 to 7000 concurrently or in any order.

  The polymer (C1) having the specific comb structure preferably has 2 to 3000 pigment affinity groups in one molecule, and particularly preferably has a range of 25 to 1500. That is, when the pigment affinity group is less than 2 in one molecule, the dispersion stability is not sufficient, and the metal colloid particles are coarsened. Conversely, when it exceeds 3000, the viscosity is too high and handling becomes difficult. In addition, the particle size distribution of the metal colloidal particles becomes wide.

  The specific comb-shaped polymer (C1) preferably has 2 to 1000 side chains constituting the solvation part in one molecule, particularly preferably in the range of 5 to 500. That is, when the side chain constituting the solvation part is less than 2, the dispersion stability is not sufficient. Conversely, when it exceeds 1000, the viscosity is too high to be handled, and the particle size distribution of the metal colloid particles This is because

  The polymer (C1) having the specific comb structure has a number average molecular weight (Mn) in the range of 2,000 to 1,000,000, preferably Mn in the range of 4,000 to 500,000. is there. That is, when the number average molecular weight (Mn) is less than 2,000, the dispersion stability is not sufficient. Conversely, when the number average molecular weight (Mn) exceeds 1,000,000, the viscosity is too high and handling becomes difficult. This is because the particle size distribution of the particles becomes wide.

  The specific polymer (C2) has a plurality of pigment affinity groups arranged along the main chain, and the pigment affinity group is, for example, pendant to the main chain. is there.

  Examples of the specific polymer (C2) include, for example, a polyisocyanate disclosed in JP-A-4-210220, a mixture of a monohydroxy compound and a monohydroxymonocarboxylic acid or monoaminomonocarboxylic acid compound, and A reaction product of a compound having at least one basic ring nitrogen and an isocyanate-reactive group; disclosed in JP-A-60-16631, JP-A-2-612, JP-A-63-241818 A polymer in which a plurality of tertiary amino groups or groups having a basic cyclic nitrogen atom are pendant on the main chain made of polyurethane / polyurea; a water-soluble poly (oxyalkylene) disclosed in JP-A-1-279919 A copolymer comprising a steric stabilizing unit having a chain, a structural unit and an amino group-containing unit; The amine group-containing monomer unit contains a tertiary amino group or a group of an acid addition salt thereof or a quaternary ammonium group, and 0.025 to 0.5 milliequivalent amino group per gram of the copolymer A main chain composed of an addition polymer disclosed in JP-A-6-1000064, and at least one C1-C4 alkoxy polyethylene or polyethylene-copropylene glycol (meth) acrylate. An amphiphilic copolymer consisting of agent units and having a weight average molecular weight of 2500 to 20000, the main chain comprising up to 30% by weight of non-functional structural units and a total of up to 70% by weight A stabilizer unit and a functional unit, wherein the functional unit is a substituted or unsubstituted styrene-containing unit, hydroxyl Containing unit and carboxyl group-containing unit, wherein the ratio of hydroxyl group to carboxyl group, hydroxyl group to styrene group, and hydroxyl group to propyleneoxy group or ethyleneoxy group is 1: 0.10 to 26.1; 1 : Amphiphilic polymer etc. which are: 0.28-25.0; 1: 0.80-66.1.

  The specific polymer (C2) preferably has 2 to 3000 pigment-affinity groups in one molecule, particularly preferably in the range of 25 to 1500. That is, when the pigment affinity group is less than 2 in one molecule, the dispersion stability is not sufficient, and the metal colloid particles are coarsened. Conversely, when it exceeds 3000, the viscosity is too high and handling becomes difficult. In addition, the particle size distribution of the metal colloidal particles becomes wide.

  The specific polymer (C2) has a number average molecular weight (Mn) in the range of 2,000 to 1,000,000, preferably Mn in the range of 4,000 to 500,000. That is, when the number average molecular weight (Mn) is less than 2,000, the dispersion stability is not sufficient. Conversely, when the number average molecular weight (Mn) exceeds 1,000,000, the viscosity is too high and handling becomes difficult. This is because the particle size distribution of the particles becomes wide.

  Further, the specific polymer (C3) has a pigment affinity portion composed of one or more pigment affinity groups only at one end of the main chain.

  The specific polymer (C3) is not particularly limited. For example, an AB block type polymer, one of which is basic disclosed in JP-A-46-7294; US Pat. No. 4,656,226 AB block type polymer in which an aromatic carboxylic acid is introduced into the A block disclosed in the document; AB block type in which one end is a basic functional group as disclosed in US Pat. No. 4,032,698 Polymer: an AB block type polymer having an acidic functional group at one end as disclosed in US Pat. No. 4,070,388; US Pat. No. 4,656,226 disclosed in JP-A-1-204914 And those obtained by improving the weathering yellowing resistance of the AB block type polymer in which an aromatic carboxylic acid is introduced into the A block described in 1).

  The specific polymer (C3) preferably has 2 to 3000 pigment-affinity groups in one molecule, particularly preferably in the range of 25 to 1500. That is, when the pigment affinity group is less than 2 in one molecule, the dispersion stability is not sufficient, and the metal colloid particles are coarsened. Conversely, when it exceeds 3000, the viscosity is too high and handling becomes difficult. In addition, the particle size distribution of the metal colloidal particles becomes wide.

  The specific polymer (C2) has a number average molecular weight (Mn) in the range of 1,000 to 1,000,000, preferably Mn in the range of 2,000 to 500,000. . That is, when the number average molecular weight (Mn) is less than 1,000, the dispersion stability is not sufficient. On the contrary, when the number average molecular weight (Mn) exceeds 1,000,000, the viscosity is too high and handling becomes difficult. This is because the particle size distribution of the particles becomes wide.

  Specific examples of the specific high molecular weight pigment dispersant (component C) include Solsperse 20000, Solsperse 24000, Solsperse 26000, Solsperse 27000, Solsperse 28000 (all manufactured by Zeneca), Dispersic 160, Dispersic 161, Dispersic 162, Dispersic 163, Dispersic 166, Dispersic 170, Dispersic 180, Dispersic 182, Dispersic 184, Dispersic 190 (all manufactured by BYK Chemie), EFKA-46, EFKA-47, EFKA-48, EFKA -49 (all manufactured by EFKA Chemical), polymer 100, polymer 120, polymer 150, polymer 400, polymer 401, polymer 402, polymer 03, Polymer 450, Polymer 451, Polymer 452, Polymer 453 (all manufactured by EFKA Chemical Co., Ltd.), Ajisper PB711, Azisper PA111, Azisper PB811, Azisper PW911 (all manufactured by Ajinomoto Co., Inc.), Florene DOPA-158, Florene DOPA-22 , Floren DOPA-17, Floren TG-730W, Floren G-700, Floren TG-720W (all manufactured by Kyoeisha Chemical Co., Ltd.) and the like. These may be used alone or in combination of two or more.

  The specific high molecular weight pigment dispersant (component C) preferably has a softening temperature of 30 ° C. or higher, particularly preferably 40 ° C. or higher. That is, when the softening temperature is less than 30 ° C., the obtained metal sol tends to block during storage.

  The compounding amount of the specific high molecular weight pigment dispersant (component C) is preferably in the range of 20 to 1000 parts, particularly preferably 50 to 650 parts, relative to 100 parts by weight of the metal (hereinafter abbreviated as “parts”). Is within the range. That is, when the blending amount of the specific high molecular weight pigment dispersant (component C) is less than 20 parts, the dispersibility of the metal colloid particles is insufficient, and conversely when the blending amount exceeds 1000 parts, the specific binder polymer This is because the blending amount of the specific high molecular weight pigment dispersant (C component) with respect to (Component A) increases, and there is a tendency for defects in physical properties and the like.

  Here, the said metal nanoparticle (B component) can be prepared as follows, for example using the said specific high molecular weight pigment dispersant (C component). That is, metal colloidal particles in which a metal compound is dissolved in a solvent, a specific high molecular weight pigment dispersant (C component) is added, then reduced to a metal and protected with the specific high molecular weight pigment dispersant (C component) Then, the solvent is removed to obtain a solid sol. Next, by dissolving the solid sol in a solvent such as tetrahydrofuran (THF) or methyl ethyl ketone (MEK), a solution of metal nanoparticles (component B) protected with the specific high molecular weight pigment dispersant (component C). Can be obtained.

  Examples of the metal compound include chloroauric acid, silver nitrate, silver acetate, silver perchlorate, chloroplatinic acid, potassium chloroplatinate, copper (II), copper (II) acetate, and copper (II) sulfate. can give. The solvent is not particularly limited as long as it can dissolve the metal compound and the binder polymer (component A) having an ionic functional group. For example, ketone solvents such as acetone and MEK, toluene Aromatic solvents such as xylene, ester solvents such as ethyl acetate and butyl acetate, ether solvents such as THF, and the like. These may be used alone or in combination of two or more.

  The specific high molecular weight pigment dispersant (component C) is preferably water-insoluble. That is, when it is water-soluble, it is difficult to deposit metal colloidal particles when a water-soluble organic solvent is removed to obtain a solid sol. Examples of the water-insoluble high molecular weight pigment dispersant (component C) include Dispersic 161, Dispersic 166 (all manufactured by BYK Chemie), Solsperse 24000, Solsperse 28000 (all manufactured by Geneca), and the like. it can.

  The method for reducing the metal is not particularly limited, and examples thereof include a method in which a compound is added and chemically reduced, a method in which the metal is reduced by light irradiation using a high-pressure mercury lamp, and the like.

  The above compound is not particularly limited, and for example, alkali metal borohydride salts such as sodium borohydride conventionally used as a reducing agent, hydrazine compounds, citric acid or salts thereof, succinic acid or salts thereof are used. can do. In the present invention, an amine may be used in addition to the reducing agent.

  The amine is not usually used as a reducing agent, but metal ions and the like can be reduced to a metal at around room temperature by adding the amine to the solution of the metal compound and stirring and mixing. Therefore, it is not necessary to use a reducing agent that is highly hazardous or harmful, and without using a heating or special light irradiation device, at a reaction temperature of about 5 to 100 ° C., preferably about 20 to 80 ° C., Metal compounds can be reduced.

  The amine is not particularly limited, and examples thereof include propylamine, butylamine, hexylamine, diethylamine, dipropylamine, dimethylethylamine, diethylmethylamine, triethylamine, ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine. , 1,3-diaminopropane, N, N, N ′, N′-tetramethyl-1,3-diaminopropane, aliphatic amines such as triethylenetetramine, tetraethylenepentamine; piperidine, N-methylpiperidine, piperazine , N, N'-dimethylpiperazine, pyrrolidine, N-methylpyrrolidine, morpholine, and other alicyclic amines; aniline, N-methylaniline, N, N-dimethylaniline, toluidine, anisidine, phenetidine, and other aromatic amines; , N- methylbenzylamine, N, N- dimethylbenzylamine, phenethylamine, xylylenediamine, N, N, N ', and an aralkyl amine such as N'- tetramethyl xylylene diamine. Examples of the amine include methylaminoethanol, dimethylaminoethanol, triethanolamine, ethanolamine, diethanolamine, methyldiethanolamine, propanolamine, 2- (3-aminopropylamino) ethanol, butanolamine, hexanolamine, dimethylamino. An alkanolamine such as propanol can also be mentioned. Of these, alkanolamines are preferred.

  The addition amount of the amine is preferably in the range of 1 to 50 mol, particularly preferably in the range of 2 to 8 mol, with respect to 1 mol of the metal compound. That is, when the amount is less than 1 mol, the reduction is not sufficiently performed. Conversely, when the amount exceeds 50 mol, the aggregation stability of the generated metal colloid particles may be lowered.

  In addition, when using the sodium borohydride as the reducing agent, the sodium borohydride is expensive and should be handled with care, but can be reduced at room temperature. It is not necessary to use a simple light irradiation device.

  The addition amount of the sodium borohydride is preferably in the range of 1 to 50 mol, particularly preferably in the range of 1.5 to 10 mol, with respect to 1 mol of the metal compound. That is, when the amount is less than 1 mol, the reduction is not sufficiently performed. Conversely, when the amount exceeds 50 mol, the aggregation stability of the generated metal colloid particles may be lowered.

  Further, when citric acid or a salt thereof is used as the reducing agent, metal ions and the like can be reduced by heating to reflux in the presence of alcohol. The citric acid or a salt thereof has an advantage that it is very inexpensive and easily available. For example, sodium citrate is preferably used as the citric acid or a salt thereof.

  The addition amount of the citric acid or a salt thereof is preferably in the range of 1 to 50 mol, particularly preferably in the range of 1.5 to 10 mol, with respect to 1 mol of the metal compound. That is, if the amount is less than 1 mol, the reduction is not sufficiently performed. Conversely, if the amount exceeds 50 mol, the aggregation stability of the generated colloidal particles may be lowered.

  In addition, in the semiconductive composition for electrophotographic equipment of the present invention, a conductive agent, a cross-linking agent, a cross-linking accelerator, an anti-aging agent and the like may be blended as necessary together with the above-described components A to C.

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 in the range of 8 to 20 parts, with respect to 100 parts of the specific binder polymer (component A).

  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 binder polymer (component A). It is.

  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 crosslinking agent is preferably in the range of 1 to 30 parts, particularly preferably 3 to 10 parts per 100 parts of the specific binder polymer (component A) from the viewpoint of physical properties, adhesion, and liquid storage property. Within the range of the part.

  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.

  Here, the semiconductive composition for electrophotographic equipment of the present invention can be prepared, for example, as follows. That is, in the same manner as described above, metal nanoparticles (component B) protected with the specific high molecular weight pigment dispersant (component C) are prepared. And the said crosslinking agent etc. are suitably mix | blended with this special metal nanoparticle (B component) and the binder polymer (A component) which has the said specific ionic functional group as needed. Then, these are dissolved in a solvent to form a solution, and dispersed by using a bead mill or a three roll, thereby obtaining a target semiconductive composition.

  The compounding amount of the metal nanoparticles (component B) protected with the specific high molecular weight pigment dispersant (component C) is in the range of 10 to 2000 parts with respect to 100 parts of the specific binder polymer (component A). Is preferable, and particularly preferably within the range of 50 to 1000 parts. That is, when the amount of the special metal nanoparticle (component B) is less than 10 parts, there is no effect to produce semiconductivity. Conversely, when the amount exceeds 2000 parts, the specific binder polymer (component A) This is because there is a tendency to deteriorate the physical properties of).

  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.

  The semiconductive composition for an electrophotographic apparatus of the present invention can be formed into a film by coating a coating solution dissolved in a solvent, but is not limited thereto, and is an extrusion molding method, an injection molding method, an inflation molding method. It is also possible to form a film by, for example.

  Next, a semiconductive member for electrophotographic equipment using the semiconductive composition for electrophotographic equipment 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 environment dependency of the electrical resistance as a whole semiconductive member for electrophotographic equipment are reduced, so that density unevenness and the like can be reduced, and good image quality with little fluctuation can be obtained. The performance required for the device can be improved.

  Next, examples will be described together with comparative examples.

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

[Preparation of silver nanoparticle solution]
After taking 10 ml of 1000 mM silver nitrate aqueous solution in a beaker and diluting with 90 ml of acetone, the above-described high molecular weight pigment dispersant (Dispvic 161, manufactured by BYK Chemie, softening temperature: 100 ° C., Mn : 2000) was dissolved. After the high molecular weight pigment dispersant was completely dissolved, 5 ml of dimethylaminoethanol was added to obtain a bright and thick yellow colloidal silver solution. The obtained silver colloid solution was put into a large amount of hexane. Since this high molecular weight pigment dispersant (manufactured by Big Chemie, Dispersic 161) is insoluble in hexane, silver colloid protected with the high molecular weight pigment dispersant was precipitated and precipitated. The precipitate was separated by filtration, further washed with hexane, and then completely dried to obtain a silver solid sol. The concentration of the obtained silver solid sol was 11 mol per kg of the high molecular weight pigment dispersant. 3 g of this solid sol was dissolved in 10 ml of tetrahydrofuran (THF), and a solution of silver nanoparticles (average particle diameter of 8 nm) protected with a bright and dark yellow high molecular weight pigment dispersant (containing the above silver nanoparticles) Amount: 20% by weight) was obtained.

(Preparation of copper nanoparticle solution)
After taking 10 ml of 100 mM copper chloride (II) aqueous solution in a beaker and diluting with 90 ml of acetone, the high molecular weight pigment dispersant (Zeneca Corp., Solsperse 28000, softening temperature: 0) 1 g of Mn: 100,000 or less was dissolved. After the high molecular weight pigment dispersant was completely dissolved, 10 ml of a 2M aqueous sodium borohydride solution was added as a reducing agent to obtain a bright and dense red copper colloid solution. The obtained copper colloid solution was heated under reduced pressure to remove acetone. Since this high molecular weight pigment dispersant (manufactured by Zeneca, Solsperse 28000) is insoluble in water, the copper colloid protected with the high molecular weight pigment dispersant was precipitated and settled as the amount of acetone decreased. The supernatant aqueous layer was removed by decantation, and the precipitate was washed with ion-exchanged water and then completely dried to obtain a solid sol of copper. The concentration of the obtained solid sol of copper was 1 mol per 1 kg of the high molecular weight pigment dispersant. 3 g of this solid sol was dissolved in 10 ml of methyl ethyl ketone (MEK), and a solution of copper nanoparticles (average particle size of 15 nm) protected with a high-molecular weight pigment dispersant with a bright and rich red color (containing the above copper nanoparticles) Amount: 20% by weight) was obtained.

[Sulfonated urethane elastomer A (component A)]
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, after adding 480.8 parts of adipic acid and reacting at 200 ° C. for 10 hours, the reaction system was depressurized to 20 mmHg over 3 hours, and further subjected to polycondensation reaction at 5-20 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 sulfonated urethane elastomer (Mn: 20,000, sodium sulfonate group amount: 0.5 mmol / g).

[Sulfonated urethane elastomer B (component A)]
To a reactor equipped with a thermometer, a stirrer and a partial reflux condenser, 0.8 parts of 5-sodium sulfoisophthalic acid, 155.8 parts of 1,6-hexanediol, and 321.7 parts of neopentyl glycol are added, The transesterification was carried out at 200 ° C. for 5 hours. Subsequently, 334.7 parts of adipic acid and 274.1 parts of terephthalic acid were added and reacted at 200 ° C. for 10 hours. Then, the reaction system was depressurized to 20 mmHg over 3 hours, and further 5-20 mmHg at 210 ° C. for 2 hours. A time polycondensation reaction was performed to obtain a polyester diol (Mn: 2000). Next, 90 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 ′ -After adding 12.5 parts of diphenylmethane diisocyanate, 0.59 parts of 1,6-hexanediol was added, and sulfonated urethane elastomer (Mn: 70,000, sodium sulfonate group amount: 0.002 mmol / g) Got.

[Sulfonated urethane elastomer C (component A)]
To a reactor equipped with a thermometer, a stirrer and a partial reflux condenser, 258.5 parts of 5-sodium sulfoisophthalic acid, 155.8 parts of 1,6-hexanediol, and 321.7 parts of neopentyl glycol are added, The transesterification was carried out at 200 ° C. for 5 hours. Subsequently, after adding 437 parts of adipic acid and reacting at 200 ° C. for 10 hours, the reaction system was depressurized to 20 mmHg over 3 hours, and further subjected to polycondensation reaction at 5 to 20 mmHg and 210 ° C. for 2 hours. (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 sulfonated urethane elastomer (Mn: 20,000, sodium sulfonate group amount: 0.75 mmol / g).

[Sulfonated acrylic elastomer (component A)]
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, a sulfonated acrylic elastomer (Mn: 12,000, sulfonic acid group amount: 0.4 mmol / g) was obtained.

[Ammonium-modified acrylic elastomer (component A)]
In 200 g of methyl ethyl ketone, 35 g of methyl methacrylate (MMA), 55 g of butyl acrylate (BA), 5 g of hydroxymethyl methacrylate (HEMA), 5 g of dimethylaminoethyl methacrylate (DMAEMA) are mixed, and 0.1 g of azo initiator (AIBN) is used. Then, radical polymerization was performed. Precipitation with alcohol and redissolving in THF (30%) gave an ammonium-modified acrylic elastomer (Mn: 40,000, ammonium group content: 0.24 mmol / g).

[Sulfonated isoprene elastomer (component A)]
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. Thus, a sulfonated isoprene elastomer (Mn: 50,000, sodium sulfonate group amount: 0.35 mmol / g) was obtained.

[Urethane elastomer]
Carbonate TPU (Nippon Miraclan, E980)

[Acrylic elastomer]
In 200 g of methyl ethyl ketone, 35 g of methyl methacrylate (MMA), 55 g of butyl acrylate (BA) and 5 g of hydroxymethyl methacrylate (HEMA) were mixed, and radical polymerization was performed using 0.1 g of an azo initiator (AIBN). Precipitation with alcohol and redissolving in THF (30%) gave an acrylic elastomer.

[Conductive agent]
Acetylene black (Denka Black HS100, manufactured by Denki Kagaku Kogyo)

[Conductive agent]
Quaternary ammonium salt (Lion Corporation, tetrabutylammonium bromide TBAB)

[Vulcanization accelerator a]
Sulfenamide-based cross-linking accelerator (Ouchi Shinsei Chemical Co., Ltd., Noxeller CZ)

[Vulcanization accelerator b]
Dithiocarbamate-based crosslinking accelerator (Ouchi Shinsei Chemical Co., Ltd., Noxeller BZ)

[Examples 1-9, Comparative Examples 1-5]
The components shown in Table 1 and Table 2 below were blended in the proportions shown in the same table, and kneaded using three rolls to prepare a semiconductive composition (coating liquid). In addition, the compounding quantity of the silver nanoparticle or copper nanoparticle in a table | surface shows the compounding quantity of the silver nanoparticle protected with the high molecular weight pigment dispersant or the copper nanoparticle protected with the high molecular weight pigment dispersant, respectively.

[Electric 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, the electrical resistance when a voltage of 10 V was applied in an environment of 25 ° C. × 50% RH was measured according to SRIS 2304.

[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).

[Controllability of electrical resistance]
Conductive agent (metal nanoparticles) is dispersed in the binder polymer, and under the conditions of an applied voltage of 10 V and 25 ° C. × 50% RH, the compounding amount showing Rv = 1 × 10 ⁷ Ω · cm is the center. The difference between the volume resistance (Rv) when increased by% vol and the volume resistance (Rv) when decreased by 5% vol is expressed in Log (digit).

[Dispersibility]
The dispersibility of the metal nanoparticles or the conductive agent in the binder polymer was evaluated. The evaluation was ○ when the aggregates of 0.05 μm or more did not occur, ○ when the aggregates of 0.05 to 0.1 μm were generated, and Δ when the aggregates exceeding 0.1 μm were generated × It was.

  From the above results, the products of the examples were excellent in dispersibility, were less dependent on the environment of electrical resistance, and had good controllability of electrical resistance.

  On the other hand, since the product of Comparative Example 1 uses a conductive agent (acetylene black) instead of metal nanoparticles, the acetylene black aggregates and the dispersibility is inferior, and the electrical resistance controllability is evaluated. Was inferior. Since the product of Comparative Example 2 used a conductive agent (quaternary ammonium salt) instead of the metal nanoparticles, bloom occurred and the electrical resistance was highly dependent on the environment. Moreover, since the comparative example 3 and 4 products use TPU which is not sulfonated, while dispersibility was inferior, evaluation of the controllability of electrical resistance was inferior. The product of Comparative Example 5 was inferior in dispersibility because it used an acrylic elastomer that was not sulfonated or ammoniumized.

  Next, examples of developing rolls using the semiconductive composition will be described.

Example 10
(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 in the same manner as in Example 1.

(Preparation of developing roll)
The base layer material is poured into an injection mold having a shaft core (diameter 10 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 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 was prepared.

[Comparative Example 6]
(Preparation of surface layer material)
A semiconductive composition was produced in the same manner as in Comparative Example 1.

(Preparation of developing roll)
Two layers formed by forming a base layer (thickness 4 mm) on the outer peripheral surface of the shaft body and forming a surface layer (thickness 20 μm) on the outer peripheral surface in the same manner as in Example 10 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 Table 3 below.

[Electric resistance of products]
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 It measured according to SRIS 2304 on the conditions which applied the voltage of 10V in the environment of 25 degreeC x 50% RH.

[Environmental dependence of electrical resistance]
According to the evaluation of the electrical resistance of the product, the electrical resistance (Rv = 15 ° C. × 10% RH) at low temperature and low humidity (15 ° C. × 10% RH) and high temperature and high humidity (35 The electrical resistance (Rv = 35 ° C. × 85% RH) at the time of (° C. × 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).

[Variation of electrical resistance]
A product and a metal roll (diameter 20 mm) are contacted in parallel, a load of 1 kg is applied, 30 V is rotated and applied at 10 V in a stationary state, and the electrical resistance between the metal roll and the metal core of the product is measured. did. Then, the difference between the maximum value and the minimum value of the electrical resistance was displayed in the number of digits.

[Hardness (JIS A)]
The hardness of the outermost surface of each developing roll was measured according to JIS K 6253.

(Compression set)
The compression set of each developing roll was measured according to JIS K 6262 under conditions of a temperature of 70 ° C., a test time of 22 hours, and a compression rate of 25%.

(Development roll characteristics)
(Image unevenness)
Each developing roll was incorporated into a commercially available color printer, and images were taken out in an environment of 20 ° C. × 50% RH. In the evaluation, a case where there was no density unevenness in a halftone image and no thin line breaks or color misregistration was given as ◯, and a case where it was not, was given as x.

(Changes in image quality due to the environment)
Image quality depending on the environment when each developing roll is incorporated in a commercially available color printer and images are output in an environment of 15 ° C. × 10% RH and when images are output in an environment of 35 ° C. × 85% RH We evaluated the fluctuations. 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.

[Concentration fluctuation due to charge-up]
Each developing roll was incorporated into a commercially available color printer, and 10,000 sheets of images were taken out in an environment of 25 ° C. × 50% RH. In the evaluation, a case where there was no density difference in a halftone image (less than 0.1 with a Macbeth densitometer) was evaluated as ◯, and a case where a density difference occurred (0.1 or more with a Macbeth densitometer) was evaluated as x.

  From the above results, the product of Example 10 was excellent in all characteristics and excellent in developing roll characteristics. On the other hand, the product of Comparative Example 6 had a large variation in electrical resistance, and the evaluation of image unevenness was poor.

  Next, examples of the charging roll using the semiconductive composition will be described.

Example 11
(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 in the same manner as in Example 6.

(Preparation of charging roll)
The base layer material is poured into an injection mold having a shaft core (diameter 10 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 3 mm) is formed on the outer peripheral surface of the shaft body by applying the surface layer material to the outer peripheral surface of the base layer to form the surface layer. A charging roll having a two-layer structure was prepared.

[Comparative Example 7]
(Preparation of surface layer material)
A semiconductive composition was produced in the same manner as in Comparative Example 2.

(Preparation of charging roll)
Two layers formed by forming a base layer (thickness 4 mm) on the outer peripheral surface of the shaft body and forming a surface layer (thickness 20 μm) on the outer peripheral surface in the same manner as in Example 11 except that the surface layer material is used. A charging roll having a structure was prepared.

  Using the charging rolls of Examples and Comparative Examples thus obtained, each characteristic was evaluated according to the evaluation criteria for the developing roll. These results are also shown in Table 4 below.

  From the above results, the product of Example 11 was excellent in all characteristics and excellent in charging roll characteristics. On the other hand, the product of Comparative Example 7 had a large environmental dependency of electrical resistance, a large compression set, a poor evaluation of image quality variation due to the environment, and a poor evaluation of density variation due to charge-up.

  The semiconductive composition for electrophotographic equipment of the present invention can be suitably used for electrophotographic equipment such as a semiconductive member for electrophotographic equipment such as a charging roll, a developing roll, a transfer roll, and an intermediate transfer belt.

Claims (8)

A semiconductive composition for an electrophotographic apparatus comprising the following (A) to (C) as essential components.
(A) A binder polymer having an ionic functional group.
(B) Metal nanoparticles.
(C) At least one high molecular weight pigment dispersant selected from the group consisting of the following (C1) to (C3).
(C1) A polymer having a comb-like structure having a pigment affinity group in at least one of the main chain and a plurality of side chains and having a plurality of side chains constituting a solvation part, and having a number average molecular weight of 2,000 Within the range of ~ 1,000,000.
(C2) A polymer having a plurality of pigment-affinity moieties composed of pigment-affinity groups in the main chain and having a number average molecular weight in the range of 2,000 to 1,000,000.
(C3) A linear polymer having a pigment affinity part composed of a pigment affinity group at one end of the main chain and having a number average molecular weight in the range of 1,000 to 1,000,000.   2. The semiconductive composition for electrophotographic equipment according to claim 1, wherein the ionic functional group of the component (A) is at least one selected from the group consisting of a sulfonic acid group, a sulfonic acid group, an ammonium group and a carboxyl group. object.   The semiconductive composition for electrophotographic equipment according to claim 1 or 2, wherein the amount of the ionic functional group of the component (A) is in the range of 0.001 to 0.75 mmol / g.   The semiconducting material for electrophotographic equipment according to any one of claims 1 to 3, wherein the polymer (C1) to (C3) has 2 to 3000 pigment affinity groups in one molecule. Composition. The semiconductive composition for an electrophotographic apparatus according to any one of claims 1 to 4, wherein the electric resistance is in the range of 1 x 10 ⁵ to 1 x 10 ¹¹ Ω · cm.   The semiconductive composition for electrophotographic equipment according to any one of claims 1 to 5, wherein the metal nanoparticles of the component (B) are protected by the high molecular weight pigment dispersant of the component (C).   A semiconductive member for electrophotographic equipment, wherein the semiconductive composition for electrophotographic equipment according to any one of claims 1 to 6 is used for at least a part of the semiconductive member.   The semiconductive member for electrophotographic equipment according to claim 7, wherein the semiconductive composition for electrophotographic equipment is used for at least a part of a developing roll, a charging roll, a transfer roll and a transfer belt.