JP2001064487A - Semiconductive composition, its production, electrophotographic functional member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a semiconductive composition not only having a specified electrical resistance but also both highly stable and uniform in the electrical resistance, slight in the dependency of the electrical resistance on applied voltage, and slight in the fluctuation of the electrical resistance when continuously used, and to obtain a electrophotographic functional member having the above composition. SOLUTION: This semiconductive composition is formed of a blend prepared by compounding a polymeric compound solution or emulsion and a dispersion made by dispersing polypyrrole-contg. microparticles in a dispersion medium; wherein, the following requirements are met; that is: after the compounding, the polypyrrole-contg. microparticles are homogeneously dispersed by mechanical shearing force, the respective sizes of the polypyrrole-contg. microparticles are 0.01-2.0 μm, and the volume resistivity of this composition is 1×104 to 1×1012 Ω.cm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductive composition, a method for producing the same, and a functional member for electrophotography.

[0002]

2. Description of the Related Art In recent years, with the advance of electrophotographic technology, there has been an increasing demand for semiconductive compositions used in electrophotographic processes. In particular, elastic rolls used in processes such as charging, developing or transferring have attracted attention. Have been. In the semiconductive composition used for such applications, not only a predetermined electric resistance value, but also a high uniformity of the electric resistance value, a small dependence of the electric resistance value on the applied voltage, and a low to low temperature to high temperature It is necessary that the fluctuation range of the electric resistance value until the time of high humidity is small and the fluctuation range of the electric resistance value when used continuously for a long time is small.

[0003] The semiconductive composition used for such an application is a mixture of a polymer material such as a polymer elastomer or a polymer foam with a conductive material. The conductive materials are roughly classified into powder / filler-like substances and soluble (water-soluble) substances.

[0004] When a powder or filler such as carbon black powder or metal powder is used among these conductive materials, the mechanism of the appearance of the conductivity depends on the distance between the conductive materials. Therefore, the state of dispersion of the conductive material in the thermoplastic resin is particularly important, and the electrical resistance value tends to greatly change due to a slight difference in processing conditions and a difference in the amount. Furthermore, even in the same molded product, it is difficult to obtain a molded product exhibiting stable semiconductivity with good reproducibility, such as a large variation in electric resistance depending on the position. In general, in a powder / filler-type additive system, 1 ×
In the semiconductive region in the range of 10 ⁴ to 1 × 10 ¹² Ωcm, the above phenomenon is particularly likely to occur, and it is difficult to control the electric resistance value. In addition, there is a problem that the distance between these powdery / filler-like substances changes with time or with physical pressure such as compression and bending, and the electric resistance value changes. As described above, the powder / filler conductive material has a problem due to uniformity and stability of dispersion.

On the other hand, as soluble substances, inorganic ionic substances such as lithium perchlorate, sodium perchlorate and calcium perchlorate, lauryltrimethylammonium chloride, stearyltrimethylammonium chloride, octadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, hexadecane Cationic surfactants such as decyltrimethylammonium chloride, modified aliphatic dimethylethylammonium ethosulfate, lauryl betaine, stearyl betaine,
Conductive agents composed of organic ionic substances such as zwitterionic surfactants such as dimethylalkyl lauryl betaine, quaternary ammonium salts such as tetraethylammonium perchlorate, tetrabutylammonium perchlorate, and tetrabutylammonium borofluoride; A polymer composition in which an antistatic agent such as ether or polyester is mixed with a polymer substance such as a polymer elastomer or a polymer foam to adjust the resistance to a predetermined value is also known. The material has a problem that the fluctuation range of the electric resistance value from low temperature and low humidity to high temperature and high humidity is large (environmental stability is poor).

The polypyrroles used in the present invention are already known as conductive materials, and have already been industrialized. Its conductivity is provided through protonated or oxidized doping. Polypyrroles have excellent chemical stability, relatively high electrical conductivity, and environmental stability, and have already been studied for charging members and the like. However, examinations so far have not found properties superior to conventional conductive materials. Polypyrroles are generally insoluble and infusible because the main chain has a rigid structure and the interaction between polymer chains is large.
There was a difficulty that molding and processing were difficult. In order to introduce polypyrrole into a polymer substance, it is necessary to pulverize it into a powder / filler and use it. There was a problem to do.

As a means for improving the processability of polypyrrole, a method of dispersing fine-particle polypyrrole in a dispersion medium has been studied. For example, Japanese Patent Publication No. 7-07811
No. 6 discloses that, when producing a uniform aqueous dispersion in which polypyrroles are dispersed in water, one or two types of pyrroles are selected from polyvinyl alcohol or polyvinyl alcohol and a nonionic surfactant or an anionic surfactant. A production method of polymerizing in the presence of the above surfactant is described.

Further, JP-A-7-10973 discloses that
Oxidative polymerization of monomers such as aniline and pyrrole in the presence of a specific compound and a polymer compound soluble in the polymerization solvent allows π-conjugated conductive polymers such as polyaniline and polypyrrole to be in a colloidal state or emulsion. A production method for obtaining a polymerization liquid having excellent dispersion stability such as a state is described.

Further, JP-A-7-118370 discloses that 100 parts by weight of a pyrrole compound, 5 to 40 parts by weight of a water-soluble polymer containing an amide bond, and an oxidizing agent as a polymerization catalyst are reacted in an aqueous solvent. The average particle size is 0.2 to 10 μm, and the geometric standard deviation is 1.1 to 1.8.
A method for producing pyrrole-based polymer fine particles is described.

Japanese Patent Application Laid-Open No. 8-337725 discloses that
Containing a conductive polymer fine particle having an average particle diameter of 0.01 to 2 μm comprising a π-conjugated conductive polymer containing a low molecular protonic acid as a dopant and a water-soluble polymer compound having a molecular weight of 10,000 to 100,000 as a dispersant, And the surface tension is 40-72m
Aqueous dispersions with N / m and methods for their preparation are described.

According to any of the inventions, a film containing polypyrroles can be obtained by preparing a dispersion in which polypyrroles-containing fine particles are dispersed in a dispersion medium, and drying and removing the solvent. Also, by blending a dispersion of polypyrroles-containing fine particles dispersed in a dispersion medium with another polymer compound solution or polymer compound emulsion, it can be molded by a casting method, or a molded article of any shape, for example, Polypyrrole film, that is, a conductive coating can be formed on a molded article of a complicated shape such as coating a surface of a plastic film, paper, etc. with a coater, or spray coating a molded article molded of plastic, metal ceramic, etc. A wide range of applications to semiconductive compositions is possible.

However, in any of the inventions, although mentioning the simplicity of the moldability, a specific method for uniformly dispersing the polypyrrole fine particles in the semiconductive composition and the obtained semiconductive No uniformity of the polypyrrole fine particles in the hydrophilic composition is described. In addition, the present inventors have found that even if a dispersion obtained by dispersing polypyrrole-containing fine particles in a dispersion medium is directly mixed with another polymer compound, it is difficult to uniformly disperse the dispersion without mechanical shearing force. Thus, it was difficult to obtain a semiconductive composition having a uniform electric resistance value.

JP-A-5-85506 discloses that polypyrrole or polyaniline polymerized into fine particles can be used as the conductive material used for the charging member. According to the patent publication, the particle size of polypyrrole or polyaniline is set to 100 μm or less in order to achieve uniform charging.
It is also described that it is particularly preferable to carry out the polymerization at 10 μm or less, more preferably at 1 μm or less. In the patent publication,
Since powdery polypyrrole fine particles are used, there is no description about specific dispersibility of the polypyrrole fine particles in the charging member.

The present inventors have found that even when polypyrrole fine particles having a particle size of 1 μm or less are used, it is difficult to uniformly disperse them when mixed with other polymer materials in powder form. It was found that it was difficult to obtain a semiconductive composition having a uniform electric resistance value in which the particle diameter of the polypyrrole fine particles was 2 μm or less.

As described above, it is difficult to obtain a semiconductive composition which satisfies all of dispersion uniformity, dispersion stability, and environmental stability with known conductive materials. The present inventors have conducted intensive studies on a semiconductive composition that can solve these problems, and as a result, disperse polypyrrole-containing fine particles in a dispersion medium, and apply mechanical shearing to a polymer compound solution or polymer compound emulsion. It has been found that a semiconductive composition that satisfies all of dispersion uniformity, dispersion stability, and environmental stability can be provided by uniformly blending with force and then forming a semiconductive composition.

[0016]

SUMMARY OF THE INVENTION Therefore, the present invention provides not only a predetermined electric resistance value but also high stability and uniformity of the electric resistance value, little dependence of the electric resistance value on the applied voltage, and low temperature. Developed a conductive composition that has a small fluctuation range of electric resistance from low humidity to high temperature and high humidity, and has a small fluctuation width of electric resistance when used continuously, and a functional member for electrophotography having the same. The challenge is to do.

[0017]

The present invention for solving the above-mentioned problems comprises a dispersion of polypyrrole-containing fine particles dispersed in a dispersion medium and a polymer compound solution or polymer compound emulsion. In the semiconductive composition, the particle diameter of the polypyrrole-containing fine particles in the composition is in the range of 0.01 to 2.0 μm, and
The composition has a volume resistivity of 1 × 10 ⁴ to 1 × 10 ^12.
The semiconductive composition is within the range of Ωcm, and the polypyrrole-containing fine particles are uniformly dispersed by mechanical shearing force after compounding the compounding components, and a method for producing the same. Furthermore, it is an electrophotographic functional member comprising the semiconductive composition.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The semiconductive composition of the present invention (hereinafter referred to as composition A)
Is a dispersion in which polypyrroles-containing fine particles as a conductive material are dispersed in a dispersion medium (hereinafter, referred to as dispersion B), and a polymer compound solution as a polymer material (hereinafter, referred to as solution C). Alternatively, it is formed from a compound (hereinafter, referred to as compound E) containing a polymer compound emulsion (hereinafter, referred to as emulsion D). Furthermore, the functional member for electrophotography of the present invention (hereinafter, referred to as a functional member F) is composed of the composition A.

Composition A is formed from Formulation E. Formulation E is obtained by blending Dispersion B and Solution C or Emulsion D and then uniformly dispersing the polypyrrole-containing fine particles with mechanical shearing force. If no mechanical shearing force is used, it is difficult to uniformly disperse the polypyrrole-containing fine particles.

The mechanical shearing force is not particularly limited, and a disperser or the like used for dispersing pigments may be used. Specific examples include a ball mill, an attritor, a sand mill, an ultrasonic disperser, and a shaker.

The dispersion by the mechanical shearing force is performed by using the dispersion B
And after mixing the solution C or the emulsion D. When the dispersion B or the emulsion D is blended after being dispersed by mechanical shearing force, the polypyrrole or the polymer compound emulsion in the blend E aggregates,
As a result, the particle diameter of the polypyrrole-containing fine particles in the composition A may not be in a desired range.

The particle diameter of the polypyrrole-containing fine particles in the composition A is 0.01 to 2.0 μm. Particle size 0.01μm
Although there is no practical problem even if the following fine particles are present, the particle diameter of the polypyrrole-containing fine particles in the dispersion B is 0.01 to 0.01.
μm or more, the particle size in the composition A is 0.01 μm
That is all. On the other hand, if the particle size exceeds 2.0 μm due to agglomeration, the manifestation of conductivity and the uniformity of resistance will be insufficient, and the performance of the functional member F using the same will decrease.

The method for measuring the particle size of the polypyrrole-containing fine particles in the composition A is not particularly limited, but a method for measuring the conductivity distribution by simultaneous current measurement with a probe microscope, and a method for measuring the element distribution with an electron microscope And a method in which the composition A is processed into a thin film and observed with an optical microscope.

The composition A has a volume resistivity of 1 × 10 ⁴ or more.
1 × 10 ¹² Ωcm. The volume resistivity value is controlled by the amount of the added polypyrrole-containing fine particles. The measuring method is not particularly limited, and can be usually measured by a method of measuring a medium resistance region.

The particle diameter of the polypyrrole-containing fine particles in the formulation E is preferably from 0.01 to 2.0 μm. Although there is no practical problem at all even if fine particles having a particle size of less than 0.01 μm are present, the particle size of the polypyrrole-containing fine particles in the dispersion B is not less than 0.01 μm, so that Is also 0.01 μm or more. On the other hand, when the particle size exceeds 2.0 μm due to aggregation, the particle size of the polypyrrole-containing fine particles in the composition A exceeds 2.0 μm, and the performance of the functional member F using the same decreases.

The method for measuring the particle size of the polypyrrole-containing fine particles in the composition E is not particularly limited, but a method of applying the composition E in a thin film form and measuring it with an optical microscope or the like can be used. No. A method of measuring the mixture E as it is or by diluting the mixture and measuring it with a particle size distribution analyzer may be mentioned, but when a polymer compound emulsion is blended, the particle size of the aggregate of the polypyrrole-containing fine particles and the polymer compound emulsion is observed. There is a possibility that it will be done.

In the dispersion B, the particle diameter of the polypyrrole-containing fine particles is preferably from 0.01 to 2.0 μm. Although there is no practical problem at all even if polypyrrole-containing fine particles having a particle size of less than 0.01 μm are present, there is a problem in the purification step by centrifugation or filtration, and it is practically difficult to obtain them. On the other hand, if the particle size exceeds 2.0 μm, the dispersion becomes unstable, and as a result, the particle size of the polypyrrole-containing fine particles in the formulation E or the composition A cannot be reduced to 2.0 μm or less.

The method for measuring the particle size of the polypyrrole-containing fine particles in the dispersion B is not particularly limited, but the dispersion in which the polypyrrole-containing fine particles are dispersed in a dispersion medium may be used as it is or diluted to obtain a particle size distribution. How to measure with a meter,
Or isolating polypyrrole-containing fine particles from Dispersion B,
A method of drying and observing with an electron microscope may be used. However, the former and latter measurements may not match. In the present invention, the measurement is performed by the former method.

Dispersion B is a dispersion in which polypyrrole fine particles are dispersed in water or an organic solvent. The method for producing the dispersion B is not particularly limited.
No. 078116, JP-A-7-10973, JP-A-7-118370 and the like, that is, a method of polymerizing pyrroles with an oxidation catalyst in the presence of a water-soluble polymer under oxidizing conditions, and the like. Can be mentioned.

The pyrroles used in the production of the dispersion B are not particularly limited, and even if unsubstituted pyrroles, the carbon atom or the nitrogen atom at the 3-, 3-, or 4-position is substituted. You may. Specifically, for example, pyrrole, N-methylpyrrole, N-ethylpyrrole, N-
n-propylpyrrole, Nn-butylpyrrole, N-
Phenylpyrrole, N-naphthylpyrrole, N-methyl-3methylpyrrole, N-methyl-3ethylpyrrole,
N-phenyl-3-methylpyrrole, N-phenyl-3-ethylpyrrole, 3-methylpyrrole, 3-ethylpyrrole, 3,4-dimethylpyrrole, 3-n-propylpyrrole, 3-iso-propylpyrrole, 3-n -Butylpyrrole, 3-methoxypyrrole, 3,4-dimethoxypyrrole, 3-ethoxypyrrole, 3-n-propoxypyrrole, 3-n-butoxypyrrole, 3-phenylpyrrole, 3-toluylpyrrole, 3-naphthylpyrrole, 3-phenoxypyrrole, 3-methylphenoxypyrrole, 3-naphthoxythiophene, 3-aminopyrrole, 3-dimethylaminopyrrole, 3-diethylaminopyrrole, 3-diphenylaminopyrrole, 3-methylphenylaminopyrrole, 3-phenylnaphthyl Such as aminopyrrole Mixtures thereof. A small amount of a monomer that can be polymerized under the polymerization conditions of the present invention, for example, furan, thiophene, aniline, or the like, may be mixed with the pyrrole-based compound and copolymerized.

The water-soluble polymer compound used for the production of the dispersion B is not particularly limited, but specific examples thereof include polyvinyl pyrrolidone, polyvinyl alcohol, polyethylene imine, polyethylene oxide, poly (meth) acrylic acid, and poly (meth) acrylic acid. (Meth) acrylate, fatty acid-modified polyester, polyethylene glycol, polypropylene glycol, alginic acid, polystyrene sulfonic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, polyvinyl sulfate, dimethylaminomethylethyl poly (meth) acrylate, polyvinylpyrrolidone, poly -2-oxazoline, poly-2-methyl-2-oxazoline, poly-2-ethyl-2-oxazoline, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, dextran, Cellulose such as Ruran, gelatin, collagen, can be mentioned casein. In addition, in order to realize chemical bonding to pyrroles,
Langmuir, vol. 11, p. 4222 (1995) and the like can also be used.

The oxidation catalyst used in the production of the dispersion B is not particularly limited, but examples thereof include metal halides such as ferric chloride, boron trifluoride and aluminum chloride, hydrogen peroxide, and organic peroxides. Oxides, peroxides such as ozone, persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate; perhalic acids such as periodic acid, potassium perchlorate, and ammonium perchlorate, or salts thereof; Examples thereof include transition metal compounds such as potassium manganate, potassium dichromate, and ammonium bichromate, or ferric hydroxide and oxygen.

When synthesizing the dispersion B, an external dopant is added as required. The addition of external dopants
Determined according to the oxidizing agent. That is, when a metal halide such as ferric chloride is used, an anion generated from an oxidizing agent coordinates to polypyrrole as a dopant, so that an external dopant is unnecessary. On the other hand, when a peroxide, iron hydroxide, or the like is used, an external dopant is required. The external dopant may be any anion of a protonic acid. Examples of anions of the protonic acid include chloride, bromide, iodine, nitrate, sulfate, phosphate, borofluoride, perchlorate, thiocyanate, acetate, propionate, and p-toluene. 1 such as sulfonic acid ion, trifluoroacetic acid ion, trifluoromethanesulfonic acid ion, etc.
There is a trivalent anion, preferably a divalent anion.

As a dispersion medium used for producing the dispersion B,
Usually, water is used, but if necessary, a mixture of an organic compound such as acetonitrile, methanol, acetone or the like with water may be used.

The production of the dispersion B is generally carried out by mixing a pyrrole and an oxidizing agent with an aqueous solution of a water-soluble polymer compound. The mixing method is not particularly limited, and examples thereof include a method of preparing a mixed solution of an aqueous solution of a water-soluble polymer compound and an oxidizing agent and dropping pyrroles. After the reaction, polypyrrole-containing fine particles are isolated from the reaction mixture by a method such as centrifugation or filtration. By redispersing the obtained polypyrrole-containing fine particles in a dispersion medium, it can be handled as a dispersion. The dispersion medium is not particularly limited, but water is particularly preferable from the viewpoint of environmental preservation and measures against dangerous substances.

The solvent of the solution C and the dispersion medium of the emulsion D are not particularly limited, but water is particularly preferable from the viewpoint of environmental preservation and measures against dangerous substances. Therefore, the solution C is preferably an aqueous solution of a water-soluble polymer compound, and the emulsion D is preferably a polymer compound which forms an aqueous emulsion.

Specific examples of the water-soluble polymer compound include polyvinyl alcohols such as polyvinyl alcohol, polyvinyl formal and polyvinyl butyral, polyacrylamide, poly (Nt-butylacrylamide),
Polyacrylamides such as polyacrylamide methylpropanesulfonic acid, polyvinylpyrrolidone, water-soluble alkyd resin, water-soluble amide resin, water-soluble melamine resin, water-soluble urea resin, water-soluble phenol resin, water-soluble epoxy resin, water-soluble polybutadiene resin , Water-soluble acrylic resin, water-soluble urethane resin, water-soluble acrylic / styrene copolymer resin, water-soluble vinyl acetate / acryl copolymer resin, water-soluble polyester resin, water-soluble styrene / maleic acid copolymer resin, water-soluble fluororesin and These copolymers are exemplified.

Specific examples of the polymer compound that forms an emulsion in an aqueous system include an aqueous alkyd resin, an aqueous amide resin, an aqueous melamine resin, an aqueous urea resin, an aqueous phenol resin, an aqueous epoxy resin, an aqueous polybutadiene resin, an aqueous acrylic resin, Water-based urethane resin, water-based acrylic / styrene copolymer resin, water-based vinyl acetate resin, water-based vinyl acetate / acrylic copolymer resin, water-based polyester resin, water-based styrene / maleic acid copolymer resin, water-based acrylic / silica resin, water-based fluororesin and these And the like.

Each of these polymer compounds may be used alone, or two or more of them may be used in a mixture at an arbitrary ratio.

The proportion of the dispersion B, the solution C or the emulsion D, the solvent or the dispersion medium in the formulation E is not particularly limited, but if the amount of the solution C or the emulsion D is too small, the film-forming properties, moldability, strength and abrasion resistance are reduced. And the adhesiveness to the substrate is deteriorated. Solution C or emulsion D
If the content is too large, the conductivity will deteriorate. Also, if the solvent or the dispersion medium is too large, the ratio of the solid content will decrease,
When used as a coating liquid, it is difficult to control the film thickness, and the coating property is deteriorated.

Usually, the composition A is formed by applying the compound E to the surface of a substrate by a method used for general coating. For example, coating methods such as gravure coater, roll coater, curtain flow coater, spin coater, bar coater, reverse coater, kiss coater, fountain coater, rod coater, air doctor coater, knife coater, blade coater, cast coating, screen coating, etc. A spraying method such as spray coating and a dipping method such as dip are used, but are not limited thereto.

After the composition A is formed on the substrate, a heat treatment may be performed. As the heat treatment, 250 ° C. or less,
Preferably, heating in the range of 40 to 200C is preferred. 2
If the temperature is higher than 50 ° C., the conductivity may decrease due to deterioration of the conductive material.

The functional member F has the composition A and is used in an electrophotographic process. Specifically, it is used for an elastic roll or the like used in processes such as charging, development, and transfer.
The method of processing the composition A into an electrophotographic member is not particularly limited. For example, a method of directly applying and drying the compound E on another member, or forming the composition A on another substrate by film formation After that, a method of combining with another member can be cited.

The composition A of the present invention is superior in dispersion stability and dispersion uniformity of a conductive material as compared with a semiconductive composition using a powder or filler substance such as carbon black. The state of dispersion of the powdery or filler-like substance such as carbon black in the resin is particularly important, and the electric resistance value tends to greatly change due to a slight difference in processing conditions or a difference in the amount of the compound. It was also difficult to achieve a high degree of dispersion uniformity. Further, the composition A of the present invention is more excellent in environmental stability of electric resistance value than the soluble substance.

Since the functional member F according to the present invention has little variation depending on the position of the electric resistance value, it is suitably used particularly for a member requiring uniform electric resistance value. According to the electrophotographic apparatus using this, an image excellent in solid and halftone images and having no density unevenness can be obtained. The functional member F according to the present invention is easy to handle because the influence of environmental changes due to the conductive material is small.

[0047]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 Polyvinylpyrrolidone (K-30, manufactured by Kishida Chemical Co., Ltd.) in 1,000 ml of ion-exchanged water
10 g were dissolved with stirring. Further, 98 g of ferric chloride hexahydrate (manufactured by Kishida Chemical Co., Ltd.) was added and dissolved.
To this solution was added 10 g of pyrrole (manufactured by Wako Pure Chemical Industries, Ltd.), and the mixture was stirred for 15 hours. The obtained black dispersion was subjected to centrifugation-redispersion operation three times to obtain 1200 g of a polypyrrole dispersion. The particle size of polypyrrole in this dispersion was measured with a Microtrac particle size distribution analyzer UPA (manufactured by Honeywell), and the particle size was 0.0911 to 0.22.
It was 71 μm. A part of the dispersion was weighed, evaporated and dried, and the solid content was measured by re-weighing.
Its solids concentration was 10.8% by weight. The resulting polypyrrole powder is molded under pressure, and the resistivity meter “Loresta H
P "(manufactured by Dia Instruments Co., Ltd.), the volume resistance was measured to be 0.095Ωc.
m.

In the obtained polypyrrole dispersion, an aqueous emulsion acrylic resin [MX-152] was used as a polymer material.
7] (Mitsubishi Rayon Co., Ltd.) was added, and ion-exchanged water was further added. Mixing was performed so that the total solid content was 10% by weight, the solid content was 10 parts by weight of polypyrrole, and the acrylic resin was 90 parts by weight. , The same volume of glass beads was added, and the mixture was stirred with cooling with a sand grinder for 1 hour to obtain a blend. This composition is cast-coated in an aluminum container and dried at 80 ° C.
A 00 μm semiconductive composition was formed.

The following evaluations were performed on the obtained compound and the semiconductive composition, respectively. Table 1 shows the results. Evaluation (1): Particle size of conductive material in formulation The formulation was coated on a slide glass in a thin film form and observed with an optical microscope or the like. Evaluation (2): Volume resistivity value of semiconductive composition The volume resistivity value of the semiconductive composition was measured at 22 ° C. and 55 RH% using a super insulation meter [Toa Denpa Co., Ltd.]. Evaluation (3): Volume resistance value of polymer material The volume resistance value of the polymer material used for blending was measured in the same manner as in Evaluation (2), without adding a conductive material. Evaluation (4): Reduction of volume resistivity due to conductive material Evaluations (2) and (3) were compared, and if the volume resistivity decreased by one digit or more, it was recognized that there was an effect. Evaluation (5): Particle size of conductive material in semiconductive composition For the semiconductive composition, a scanning probe microscope (SP
I3800N: Simultaneous current measurement was performed by Seiko Instruments Inc. A conductive region caused by polypyrrole fine particles having a particle size of 0.1 to 0.5 μm was observed.

Example 2 A particle size of 0.0646 to 0.1681 μm was obtained in the same manner as in Example 1 except that polyvinylpyrrolidone was changed to polyallylamine.
m and a 11.2% by weight dispersion of polypyrrole having a volume resistance value of 0.098 Ωcm. A blend was prepared in the same manner as in Example 1 to form a semiconductive composition. Formulation,
The same evaluation as in Example 1 was performed for the semiconductive composition. Table 1 shows the results.

Example 3 In Example 1, polyvinylpyrrolidone was replaced with polyethylene oxide [Alcox E-
60] (Meiji Chemical Industry Co., Ltd.) except that the particle size was 0.4296 to 0.6852 μm.
m, a 10.6% by weight dispersion of polypyrrole having a volume resistivity of 0.15 Ωcm. A blend was prepared in the same manner as in Example 1 to form a semiconductive composition. The same evaluation as in Example 1 was performed for the compound and the semiconductive composition.
Table 1 shows the results.

Example 4 A blend was prepared in the same manner as in Example 1 except that polyvinyl alcohol [PVA-117] (Kuraray Co., Ltd.) was used as the polymer material, and a semiconductive composition was prepared. Formed. The same evaluation as in Example 1 was performed for the compound and the semiconductive composition. Table 1 shows the results.

Comparative Example 1 Example 1 was used as a conductive material.
A compound was prepared in the same manner as in Example 1 except that the polypyrrole powder used in the measurement of the solid content concentration of the dispersion and the measurement of the volume resistance was used to form a semiconductive composition. The same evaluation as in Example 1 was performed for the compound and the semiconductive composition. Table 1 shows the results.

Comparative Example 2 A compound was prepared in the same manner as in Example 1 except that glass beads were added and the mixture was not stirred with a sand grinder to form a semiconductive composition. The same evaluation as in Example 1 was performed for the compound and the semiconductive composition.
Table 1 shows the results.

Comparative Example 3 The same procedure as in Example 1 was carried out except that carbon black [FW1] (manufactured by Degussa Japan KK) was used as the conductive material and cooling and stirring were performed with a sand grinder for 20 minutes. Prepare the formulation,
A semiconductive composition was formed. The same evaluation as in Example 1 was performed for the compound and the semiconductive composition. Table 1 shows the results.

Comparative Example 4 A blend was prepared in the same manner as in Comparative Example 3 except that cooling and stirring was performed by a sand grinder for 1 hour to form a semiconductive composition. The same evaluation as in Example 1 was performed for the compound and the semiconductive composition. Table 1 shows the results.

[0058]

[Table 1] In Examples 1 to 4, where a polypyrrole dispersion having a particle size of 1.0 μm or less was used as the conductive material and the particle size of the polypyrrole fine particles in the mixture was dispersed to 2.0 μm or less by mechanical shearing after compounding, polypyrrole was added. , The particle diameter of the polypyrrole fine particles in the semiconductive composition was 2.0 μm or less. On the other hand, Comparative Example 1 using polypyrrole powder, although polypyrrole fine particles having a particle size of 1.0 μm or less were used as the conductive material.
In addition, in Comparative Example 2 in which dispersion was not performed by mechanical shearing force after compounding using a polypyrrole dispersion, no decrease in volume resistance due to addition of a conductive material was observed, and polypyrrole fine particles in the semiconductive composition were not observed. Had a particle size of more than 2.0 μm. In Comparative Examples 3 and 4, in which carbon black was used as the conductive material, it was not possible to achieve both a reduction in volume resistance due to the addition of the conductive material and a dispersion of the conductive material in the semiconductive composition.

Example 5 100 parts of a millable silicone rubber compound (SE4637: manufactured by Tore Dow Corning) containing about 30% by weight of carbon black as a conductive material and a peroxide-containing vulcanizing agent paste (RC) -450 PFD: manufactured by Toray Dow Corning)
1.5 parts were kneaded with an open roll for 10 minutes to prepare a silicone rubber kneaded product in which carbon black was uniformly dispersed. Next, SUM22B having an outer diameter of 6 mm and KN plating of 3 to 6 μm, which had been previously subjected to a primer treatment, were concentrically inserted into and supported by a cylindrical mold having an inner diameter of 12 mm. The rubber kneaded material is filled into the cavity of the mold by an injection molding method.
It was vulcanized by heating at 70 ° C. for 3 minutes. In this manner, a roll having a carbon black-containing silicone rubber molded product having an outer diameter of 11.8 mm (thickness of 2.9 mm) as a conductive rubber layer was formed. Using the roll obtained as described above as a base layer, the following surface layer was formed thereon to manufacture a charging roll.

The composition obtained in Example 1 was applied to the outer peripheral surface of the conductive rubber layer prepared previously by a dip coating method at a pulling rate of 300 mm / min. After air-drying, it was cured by heating in an oven at 130 ° C. for 30 minutes.
A μm surface layer was formed.

Using the apparatus shown in FIG. 1, the obtained charging roll was subjected to L / L (15 ° C./10%) and N / N (23 ° C./60%).
%) And H / H (32.5 ° C./80%) in three environments.

Further, these charging rolls were attached to a primary charging position of a cartridge used for a laser beam printer (manufactured by LaserJet 4000 Hewlett-Packard), and a DC voltage of -620 V;
A constant current, frequency; superimposed application at 600 Hz, L / L,
Under three environments of N / N and H / H, solid black, solid white, and halftone (a pattern for printing two intersecting dots out of a total of 6 dots in 2 × 3 rows) are imaged, and ( a) density, (b) fog, (c) halftone uniformity,
(D) An abnormal image due to a leak was evaluated. In an N / N environment, an endurance test was performed, and the current value and the image after the endurance were compared with those at the initial stage. The obtained results are shown in Table 2 below together with the layer structure and current value of each charging roll.

Example 6 A conductive roll was used in the same manner as in Example 5, and the surface layer was replaced with the composition obtained in Example 2.
A charging roll was manufactured. The thickness of the surface layer was 10 μm. In the same manner as in Example 5, current values were measured after endurance tests in three environments of L / L, N / N, and H / H, and in an N / N environment, and solid and halftone images were formed. The image quality was evaluated. Table 2 shows the results.

Example 7 A conductive roll was used in the same manner as in Example 5, and the surface layer was replaced with the composition obtained in Example 4.
A charging roll was manufactured. The thickness of the surface layer was 10 μm. In the same manner as in Example 5, current values were measured after endurance tests in three environments of L / L, N / N, and H / H, and in an N / N environment, and solid and halftone images were formed. The image quality was evaluated. Table 2 shows the results.

Comparative Example 5 A conductive roll was used in the same manner as in Example 5, and the surface layer was replaced with the composition obtained in Comparative Example 3.
A charging roll was manufactured. The thickness of the surface layer was 10 μm. In the same manner as in Example 5, current values were measured after endurance tests in three environments of L / L, N / N, and H / H, and in an N / N environment, and solid and halftone images were formed. The image quality was evaluated. Table 2 shows the results.

Comparative Example 6 A composition was prepared in the same manner as in Comparative Example 2, except that the polypyrrole dispersion liquid was replaced by lithium perchlorate (Kishida Chemical Co., Ltd.). This solution was used to produce a charging roll in the same manner as in Example 5. The thickness of the surface layer was 10 μm. As in Example 5, L /
After endurance tests in three environments of L, N / N, H / H and in an N / N environment, current values were measured, and solid and halftone images were evaluated to evaluate image quality. Table 2 shows the results.

[0067]

[Table 2] The electrophotographic functional member of the example using the polypyrrole dispersion as the conductive material of the surface layer of the charging roll has extremely excellent solid and halftone images and a higher density than the comparative example 5 using carbon black. It provides an image with no unevenness, and provides an advanced and stable image even during durability. In addition, the coating obtained by adding a polypyrrole dispersion to a polymer material has the advantage that the influence of the environmental change of the semiconductive member due to the addition of the conductive agent is smaller than that of an ionic conductive agent such as lithium perchlorate. And provide excellent electrophotographic images in any environment.

[0068]

According to the present invention described above, it is possible to provide a semiconductive composition having desired electric characteristics in which the electric resistance can be easily adjusted by the amount of addition. In addition, since there is little variation due to the position of the electrical characteristics, an electrophotographic apparatus using the present semiconductive composition can provide solid and halftone images with extremely excellent density non-uniformity, and have high image quality even in endurance. And a stable image can be obtained. In addition, a dispersion in which polypyrroles-containing fine particles are dispersed in a dispersion medium has the advantage that the influence of the environmental fluctuation of the semiconductive composition due to the addition of a conductive agent such as that found in an ionic conductive agent such as lithium perchlorate is small. And an electrophotographic functional member using the same can provide an excellent electrophotographic image in any environment.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a charging roll current measuring device. Applied voltage AC: 500 Vp-p, 300 MHz, DC:
200V

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G03G 15/08 501 G03G 15/08 501D 15/16 103 15/16 103 F term (reference) 2H003 BB11 BB13 BB16 CC05 2H032 AA05 2H077 AD06 FA00 FA25 3J103 AA02 AA51 BA41 FA01 FA30 GA02 GA52 HA04 HA12 HA20 HA41 HA54 4J002 AA00X BE02X BJ00X CE00W CH02X FD11W FD31X HA06

Claims (4)

[Claims] 1. A method for dispersing polypyrrole-containing fine particles into a dispersion medium.
Dispersed dispersion, polymer solution or polymer compound
Of semi-conductive composition containing compound emulsion
The particles of the polypyrrole-containing fine particles in the composition
The diameter is in the range of 0.01 to 2.0 μm, and
The composition has a volume resistivity of 1 × 10 ^Four~ 1 × 10¹²
Within the range of Ωcm, before and after the compounding
The particles containing polypyrroles are evened out by mechanical shearing force.
A semiconductive composition characterized by being dispersed in one. 2. The composition has a particle size of 0.01 to 2.0.
2. The semiconductive composition according to claim 1, wherein the semiconductive composition is formed by blending a dispersion in which polypyrrole-containing fine particles having a particle diameter of μm are dispersed in a dispersion medium, and a polymer compound solution or a polymer compound emulsion. . 3. Mixing a polymer compound solution or a polymer compound emulsion with a dispersion liquid in which polypyrrole-containing fine particles are dispersed in a dispersion medium, and then uniformly dispersing the polypyrrole-containing fine particles by mechanical shearing force. The particle size of the polypyrrole-containing fine particles is 0.01
A method for producing a semiconductive composition, wherein the semi-conductive composition has a volume resistivity in the range of 1 to 10 μm and a volume resistivity of 1 × 10 ⁴ to 1 × 10 ¹² Ωcm. 4. A functional member for electrophotography, wherein the semiconductive composition according to claim 1 is used as a semiconductive member in an electrophotographic process.