JP2012181367A - Developer carrier, electrophotographic process cartridge, and electrophotographic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high quality developer carrier which has an excellent charge imparting property in a high temperature and high humidity environment and can reduce occurrence of a ghost image after being left in the high temperature and high humidity environment, and to provide a high quality electrophotographic process cartridge and an electrophotographic apparatus by using the developer carrier.SOLUTION: The developer carrier includes a surface layer containing a copolymer which contains a pyridinium group and a tertiary amino group, and polyurethane.

Description

  The present invention relates to a developer carrier incorporated in an electrophotographic apparatus, an electrophotographic process cartridge, and an electrophotographic apparatus.

  In an electrophotographic image forming apparatus (hereinafter referred to as “electrophotographic apparatus”), a developer is charged by rubbing against a developer carrier or a carrier. Since the charging of the developer greatly affects the image quality and image stability, a technique for controlling the charging of the developer is required. As a means for that, a technique has been proposed in which a charge imparting agent is used for a carrier or a developer carrying member to control the charge imparting property to the developer. Patent Document 1 discloses a developer carrying member containing a copolymer of vinylpyridine and styrene, acrylate or butadiene in the surface layer. Patent Document 2 discloses a carrier coated with vinylpyridine and a copolymer of styrene and methyl methacrylate.

JP 61-254969 A JP-A-1-140168

With the diversification of usage environment of electrophotographic devices in recent years, there is a need for a developer carrier that exhibits stable charging performance even in environments where it is generally difficult to stably charge the developer, such as high-temperature and high-humidity environments. It has been.
The developer-carrying member containing a vinylpyridine copolymer disclosed in Patent Document 1 has a high charge imparting property in a normal temperature and high humidity environment. Patent Document 2 also proposes a carrier containing a vinylpyridine copolymer, and it is known that such a copolymer has a stable charge imparting property even after endurance use. ing. However, the developer carriers according to Patent Documents 1 and 2 still have room for improvement in the stability of the charge imparting performance in a high temperature and high humidity environment.

Further, in the developer carrying bodies of Patent Documents 1 and 2, the copolymer as the charge imparting agent exudes to the surface of the developer carrying body due to active molecular motion when left for a long time in a high temperature and high humidity environment. (Bleed).
SUMMARY OF THE INVENTION An object of the present invention is to provide a developer carrying member that exhibits stable charge imparting performance even in a high-temperature and high-humidity environment and is less likely to cause bleeding.
Another object of the present invention is to provide an electrophotographic process cartridge and an electrophotographic apparatus that contribute to the stable formation of high-quality electrophotographic images.

  The developer carrier according to the present invention is a developer carrier having a shaft core and a surface layer, and the surface layer is a structural unit represented by the following structural formula (1) and the following structural formula (2). A copolymer having one or both selected from the above and a structural unit represented by the following structural formula (3), and polyurethane.

［Ｒ_１は炭素数1以上13以下のアルキル基を、Ｘ_１ ^―はハロゲンイオンまたはパラトルエンスルホン酸イオンを表す。］

[R ₁ represents an alkyl group having 1 to 13 carbon atoms, and X ₁ ^— represents a halogen ion or a paratoluenesulfonic acid ion. ]

［Ｒ_２は炭素数1以上13以下のアルキル基を、Ｘ_２ ^―はハロゲンイオンまたはパラトルエンスルホン酸イオンを表す。］

[R ₂ represents an alkyl group having 1 to 13 carbon atoms, and X ₂ ⁻ represents a halogen ion or a paratoluenesulfonic acid ion. ]

［Ｒ_３は水素原子またはメチル基、Ｒ_４は炭素数2以上4以下のアルキレン基、Ｒ_５及びＲ_６はそれぞれ独立して炭素数1あるいは2のアルキル基を表す。］

[R ₃ represents a hydrogen atom or a methyl group, R ₄ represents an alkylene group having 2 to ₄ carbon atoms, and R ₅ and R ₆ each independently represents an alkyl group having 1 or 2 carbon atoms. ]

The present invention also provides an electrophotographic process cartridge having at least a developer carrying member attached thereto and detachable from a main body of an electrophotographic apparatus, wherein the developer carrying member is the developer carrying member described above. The present invention relates to an electrophotographic process cartridge.
Furthermore, the present invention provides an electrophotographic apparatus comprising a developer carrying member facing a photoconductor that forms a latent image, and the developer carrying body developing the latent image by applying a developer to the photoconductor. The present invention relates to an electrophotographic apparatus comprising the developer carrying member.

According to the present invention, it is possible to obtain a developer carrying member that has good charge imparting property in a high temperature and high humidity environment and is less likely to bleed after being left in a high temperature and high humidity environment. In addition, according to the present invention, an electrophotographic process cartridge and an electrophotographic apparatus that contribute to stable formation of high-quality electrophotographic images can be obtained.

It is a conceptual diagram which shows an example of the developing agent carrier of this invention. It is a conceptual diagram which shows an example of the developing agent carrier of this invention. 1 is a schematic configuration diagram illustrating an example of an electrophotographic process cartridge of the present invention. 1 is a schematic configuration diagram illustrating an example of an electrophotographic apparatus of the present invention.

The developer carrier of the present invention has a cylindrical core as shown in FIG. 1 or a hollow cylindrical shaft core 2 and a surface layer 4 as shown in FIG. Further, when the shaft core body 2 has a cylindrical shape as shown in FIG. 1, it is preferable to have the elastic layer 3 between the shaft core body 2 and the surface layer 4. In particular, in a non-magnetic one-component contact development system process, a developer carrier having an elastic layer 3 is preferably used.
The shaft core body 2 functions as an electrode and a support member of the developer carrier 1 and is made of a conductive material such as a metal or alloy such as aluminum, copper alloy, stainless steel, or iron plated with chromium or nickel. Consists of materials. The outer diameter of the shaft core 2 is set by the electrophotographic apparatus used, but is usually in the range of 4 to 10 mm.

<Shaft core>
In the case where the shaft core body 2 has a hollow cylindrical shape, a non-magnetic metal or alloy such as aluminum, stainless steel, or brass is formed into a cylindrical shape and subjected to processing such as polishing or grinding is preferably used.

<Elastic layer>
For the elastic layer 3, various rubber materials conventionally used for conductive rubber rollers can be used. As rubbers used for the rubber material, ethylene-propylene-diene copolymer rubber (EPDM), acrylonitrile-butadiene rubber (NBR), chloroprene rubber (CR), natural rubber (NR), isoprene rubber (IR), styrene- Examples include butadiene rubber (SBR), fluorine rubber, silicone rubber, epichlorohydrin rubber, hydride of NBR, and urethane rubber. These can be used alone or in admixture of two or more. Among these, silicone rubber having a small compressive stress strain is preferable. Examples of the silicone rubber include polydimethylsiloxane, polymethyltrifluoropropylsiloxane, polymethylvinylsiloxane, polyphenylvinylsiloxane, and copolymers of these siloxanes.

  In the elastic layer 3, the electroconductivity can be suitably adjusted by mix | blending electroconductivity imparting agents, such as an electronic electroconductivity substance and an ion electroconductivity substance.

<Surface layer>
The surface layer 4 is a copolymer having one or both selected from structural units represented by the following structural formula (1) and the following structural formula (2), and a structural unit represented by the following structural formula (3). And polyurethane.

［Ｒ_１は炭素数1以上13以下のアルキル基を、Ｘ_１ ^―はハロゲンイオンまたはパラトルエンスルホン酸イオンを表す。］

[R ₁ represents an alkyl group having 1 to 13 carbon atoms, and X ₁ ^— represents a halogen ion or a paratoluenesulfonic acid ion. ]

［Ｒ_２は炭素数1以上13以下のアルキル基を、Ｘ_２ ^―はハロゲンイオンまたはパラトルエンスルホン酸イオンを表す。］

[R ₂ represents an alkyl group having 1 to 13 carbon atoms, and X ₂ ⁻ represents a halogen ion or a paratoluenesulfonic acid ion. ]

［Ｒ_３は水素原子またはメチル基、Ｒ_４は炭素数2以上4以下のアルキレン基、Ｒ_５及びＲ_６はそれぞれ独立して炭素数1または2のアルキル基を表す。］

[R ₃ represents a hydrogen atom or a methyl group, R ₄ represents an alkylene group having 2 to ₄ carbon atoms, and R ₅ and R ₆ each independently represents an alkyl group having 1 or 2 carbon atoms. ]

  As shown in Patent Documents 1 and 2, the charge imparting property of the developer carrier can be improved by the pyridine group-containing copolymer, but the charge imparting property in a high temperature and high humidity environment is insufficient. In addition, the pyridine group-containing copolymers disclosed in Patent Documents 1 and 2 tend to bleed on the surface when left for a long time in a high temperature and high humidity environment.

The present inventors carry a developer carrying a surface layer containing a copolymer having a structural unit containing a pyridinium group represented by the structural formula (1) or (2) instead of a pyridine group as a charge imparting agent. Examine the body. As a result, it was found that the charge imparting property in a high temperature and high humidity environment is excellent. However, bleeding of the developer-carrying member on the surface of the copolymer was observed when the developer-carrying member was allowed to stand for a long time in a high temperature and high humidity environment.
Therefore, the inventors of the present invention provide a co-polymer having at least one structural unit selected from the structural formulas (1) and (2) and a structural unit having a tertiary amino group represented by the structural formula (3). When the coalescence is contained in the surface layer together with polyurethane, a developer carrying body that is less likely to bleed even when left in a high-temperature and high-humidity environment for a long period of time and has excellent charge imparting performance in a high-temperature and high-humidity environment. Found that can be obtained.

The reason why bleed can be suppressed by the developer-carrying member according to the above configuration even when left for a long time in a high-temperature and high-humidity environment is that the tertiary amino group in the structural unit represented by the formula (3) interacts with polyurethane. This is considered to be because the exudation of the pyridinium group-containing copolymer is suppressed.
In the N—H bond of the urethane group in polyurethane, a hydrogen atom bonded to a nitrogen atom having a high electronegativity has a weak positive charge. The tertiary amino group has an unshared electron pair. For this reason, it is considered that a hydrogen bond is formed between the urethane group and the tertiary amino group. It is considered that molecular movement is restricted by this hydrogen bond, and as a result, the exudation of the pyridinium group-containing copolymer is suppressed.

  A well-known polymerization method can be used for manufacture of the copolymer in this invention. Specifically, a bulk polymerization method, a solution polymerization method, an emulsion polymerization method, a suspension polymerization method, or the like can be used. Among these, the solution polymerization method is preferable because the reaction can be easily controlled. Examples of the solvent used for the solution polymerization include xylene, toluene, ethyl acetate, isobutyl acetate, isopropyl alcohol, methanol, ethanol, methyl ethyl ketone, methyl isobutyl ketone, N, N-dimethylformamide, and dimethylformamide.

The example of the polymerization initiator used for manufacture of the copolymer based on this invention is given to the following.
t-butylperoxy-2-ethylhexanoate, cumyl perpivalate, t-butylperoxylaurate, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, di-t-butyl peroxide. t-butylcumyl peroxide, dicumyl peroxide, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,4- Dimethylvaleronitrile). 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), dimethyl 2,2′-azobis (2-methylpropionate) and the like.
Said polymerization initiator can be used 1 type or in combination of 2 or more types.

In the structural formulas (1) and (2), R ₁ and R ₂ each independently represents an alkyl group having 1 to 13 carbon atoms. Specific examples of such alkyl groups are given below. Methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group and the like.
X ₁ ⁻ and X ₂ ⁻ each independently represents a chloride ion, a bromide ion, a fluoride ion, an iodide ion or a paratoluenesulfonic acid ion.
The structural units represented by the structural formulas (1) and (2) can be introduced into the copolymer by using a vinyl monomer having a pyridinium group.
Specific examples of the vinyl monomer having a pyridinium group are given below.
1-methyl-2-vinylpyridinium haloid, 1-ethyl-2-vinylpyridinium haloid, 1-propyl-2-vinylpyridinium haloid, 1-butyl-2-vinylpyridinium haloid, 1-pentyl-2- Vinylpyridinium haloid, 1-hexyl-2-vinylpyridinium haloid, 1-heptyl-2-vinylpyridinium haloid, 1-octyl-2-vinylpyridinium haloid, 1-nonyl-2-vinylpyridinium haloid, 1 -Decyl-2-vinylpyridinium haloid, 1-dodecyl-2-vinylpyridinium haloid, 1-tridecyl-2-vinylpyridinium haloid, 1-methyl-2-vinylpyridinium paratoluenesulfonate, 1-ethyl- 2-vinylpyridinium p-toluenesulfonate, 1 Propyl-2-vinylpyridinium p-toluenesulfonate, 1-butyl-2-vinylpyridinium p-toluenesulfonate, 1-pentyl-2-vinylpyridinium p-toluenesulfonate, 1-hexyl-2-vinylpyridinium p-toluene Sulfonate, 1-heptyl-2-vinylpyridinium paratoluenesulfonate, 1-octyl-2-vinylpyridinium paratoluenesulfonate, 1-nonyl-2-vinylpyridinium paratoluenesulfonate, 1-decyl- 2-vinylpyridinium p-toluenesulfonate, 1-dodecyl-2-vinylpyridinium p-toluenesulfonate, 1-tridecyl-2-vinylpyridinium p-toluenesulfonate, and the like.

In the structural formula (3), R ₃ represents a hydrogen atom or a methyl group, R ₄ represents an ethylene group, a propylene group, or a butylene group, and R ₅ and R ₆ represent a methyl group or an ethyl group.
The structural unit represented by the structural formula (3) can be introduced into the copolymer by using a (meth) acrylate monomer having a tertiary amino group.
Specific examples of such (meth) acrylate monomers are given below.
N, N-dimethylaminomethyl (meth) acrylate, N, N-diethylaminomethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N- Dimethylaminopropyl (meth) acrylate, N, N-diethylaminopropyl (meth) acrylate, N, N-dimethylaminobutyl (meth) acrylate, N, N-diethylaminobutyl (meth) acrylate and the like. “(Meth) acrylate” means methacrylate or acrylate (hereinafter the same).

The copolymer shown in the present invention may be copolymerized with another monomer in addition to the above-mentioned pyridinium group-containing monomer and tertiary amino group-containing monomer. Specific examples of other monomers are listed below.
Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, tert-butyl (meth) acrylate, iso-butyl (meth) acrylate, n-amyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, iso-octyl (meth) acrylate, n-nonyl (meth) acrylate, n-lauryl ( (Meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2- (perfluorobutyl) ethyl (meth) acrylate, 2- (perfluorohexyl) ethyl (meth) acrylate, 2- (perfluorooctyl) )ethyl Meth) such as acrylate (meth) methacrylate alkyl esters such as acrylic acid alkyl ester. These monomers can be appropriately used for adjusting the polarity of the copolymer.

  The copolymerization ratio of these monomers is not particularly limited, and can be set as necessary. The copolymerization ratio can be set by adjusting the amount of monomer used in the reaction in the polymerization method. That is, if it is necessary to further improve the charge imparting property, the amount of the pyridinium group-containing monomer is increased and the copolymerization ratio is increased. Further, if it is necessary to further reduce the exudation due to leaving in a high-temperature and high-humidity environment, the amount of the tertiary amino group-containing monomer is increased, and the copolymerization ratio is increased. Preferably, the polymerization ratio of the pyridinium group-containing monomer is 20 mol% or more and 80 mol% or less, and the polymerization degree ratio of the tertiary amino group-containing monomer is 20 mol% or less. When the polymerization ratio of the pyridinium group-containing monomer is 20 mol% or more, the charge imparting property is improved, and when it is 80 mol% or less, the compatibility with the binder resin is good. Further, when the degree of polymerization of the tertiary amino group-containing monomer is 20 mol% or less, the balance between charge imparting property and exudation reduction is good.

The weight average molecular weight (Mw) of the copolymer according to the present invention is preferably 10,000 or more and 100,000 or less. When Mw is 10,000 or more, the effect of suppressing bleeding of the copolymer from the surface layer 4 is excellent, and when it is 100,000 or less, the compatibility with the binder resin contained in the surface layer 4 is excellent.
The content of the copolymer is preferably 0.2 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of polyurethane contained in the surface layer 4. When the content is 0.2 parts by mass or more, the charge imparting effect is excellent, and when the content is 10 parts by mass or less, the compatibility with the binder resin is excellent.

In the present invention, the surface layer 4 includes polyurethane obtained by crosslinking a polyol component with an isocyanate compound as a binder resin component.
Specific examples of the polyol component are listed below.
Polyether polyol, polyester polyol, polycarbonate polyol, polybutadiene polyol, polyisoprene polyol, acrylic polyol and the like.
Specific examples of the isocyanate compound are listed below.
Aliphatic polyisocyanate: ethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), etc.
Alicyclic polyisocyanate: isophorone diisocyanate (IPDI), cyclohexane 1,3-diisocyanate, cyclohexane 1,4-diisocyanate and the like.
Aromatic isocyanate: 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI) and the like.

  When the copolymer in the present invention further has a structural unit represented by the following structural formula (4), ghost generation after leaving in a high temperature and high humidity environment is further reduced. As described above, the generation of the ghost after being left in a high temperature and high humidity environment is considered to be caused by the exudation of the charge imparting agent due to the molecular motion of the binder resin and the charge imparting agent. The copolymer has a bulky structure including a cyclic structure such as the following structural formula (4), so that the degree of freedom of molecular motion is limited, and leaching after being left in a high-temperature and high-humidity environment can be reduced. it can. As a result, it is considered that the generation of ghosts can be further reduced.

［Ｒ_７は水素原子またはメチル基、Ｒ_８はシクロヘキシル基、アダマンチル基、ジシクロペンタニル基、ジシクロペンテニル基のいずれかを表す。］

[R ₇ represents a hydrogen atom or a methyl group, and R ₈ represents any one of a cyclohexyl group, an adamantyl group, a dicyclopentanyl group, and a dicyclopentenyl group. ]

  In the present invention, the surface layer 4 can contain conductive fine particles. Carbon black is preferred as the conductive fine particles. As the properties of the conductive fine particles, carbon black having a primary particle size of 18 nm or more and 25 nm or less and a DBP oil absorption of 50 ml / 100 g or more and 160 ml / 100 g or less is preferable because the balance between conductivity and dispersibility is good. As for the content rate of electroconductive fine particles, 10 to 30 mass parts is preferable with respect to 100 mass parts of resin solid content which forms a surface layer.

  When surface roughness is required for the developer carrier, fine particles for controlling the roughness may be added to the surface layer 4. The fine particles for roughness control preferably have a volume average particle size of 3 to 20 μm. Moreover, it is preferable that the particle addition amount added to the surface layer 4 is 1 to 50 parts by mass with respect to 100 parts by mass of the resin solid content of the surface layer 4. As the fine particles for roughness control, polyurethane resin, polyether resin, polyamide resin, acrylic resin, polycarbonate resin, or the like can be used.

  The method for forming the surface layer 4 is not particularly limited. For example, each component of the surface layer 4 is dispersed and mixed in a solvent to form a paint, which is applied onto the shaft core 2 or the elastic layer 3. It can be formed by drying, solidifying or curing. For dispersion mixing, a known dispersion apparatus using beads such as a sand mill, a paint shaker, a dyno mill, and a pearl mill can be suitably used. In addition, as a method for applying the obtained paint to the shaft core 2 or the elastic layer 3, known methods such as a dipping method, a spray method, and a roll coating method can be applied.

  The electrophotographic process cartridge and the electrophotographic apparatus of the present invention are not limited to copying machines, facsimiles, or printers as long as they have the developer carrying member of the present invention. As an example of the electrophotographic process cartridge and the electrophotographic apparatus of the present invention equipped with the developer carrying member of the present invention, a non-magnetic one-component developing type printer will be described below. In FIG. 3, the electrophotographic apparatus includes a developing device 8 containing a nonmagnetic developer 7 as a one-component developer, a developer carrier 1, and a developer supply roller 6. The developer carrying member 1 is located in an opening extending in the longitudinal direction in the developing device and is disposed opposite to the photosensitive member 5. The electrostatic latent image on the photosensitive member 5 is developed to produce an electrophotographic image. Form.

  As shown in FIG. 4, the photoconductor 5 rotated by a rotation mechanism (not shown) is arranged in the printer. Further, around the photoconductor 5, charging that charges the surface of the photoconductor 5 to a predetermined polarity / potential is performed. A member 9 is arranged. Further, an image exposure device (not shown) is arranged for the purpose of performing image exposure on the surface of the charged photoconductor 5 to form an electrostatic latent image. Further, a developing device 8 having a developer carrying member 1 of the present invention for developing a developer on the formed electrostatic latent image is disposed around the photosensitive member 5. A fixing device 10 for fixing the transferred image on the paper 11 is disposed on the transport path of the paper 11.

  A known polymerization method can be used for the synthesis of the copolymer in the present invention. Although the manufacture example of a copolymer is shown below as reference, this invention is not limited to these manufacture examples.

Production example of copolymer solution (Production example of copolymer solution A1)
The materials described in Table 1 were mixed in a four-necked separable flask equipped with a stirrer, a cooler, a thermometer, and a nitrogen introduction tube, and stirred until the system became uniform.

While continuing to stir, the temperature in the reaction system was raised to 70 ° C., and the reaction was carried out for 8 hours in a nitrogen-introduced reflux state. Further, this solution was diluted with ethanol to obtain a copolymer solution A1 having a solid content of 40% by mass. When the weight average molecular weight of the copolymer was measured by the following molecular weight measurement method using the obtained copolymer solution, the weight average molecular weight was 14,000.

[Molecular weight measurement]
Table 2 shows the apparatus and conditions used for the measurement of the weight average molecular weight (Mw).

In addition, the measurement sample used what diluted the copolymer solution with THF and made it the solution of 0.1 mass%. Further, an RI (refractive index) detector was used as a detector for measurement.
As standard samples for preparing calibration curves, TSK standard polystyrene A-1000, A-2500, A-5000, F-1, F-2, F-4, F-10, F-20, F-40, F- A calibration curve was prepared using 80, F-128 (manufactured by Tosoh Corporation). The weight average molecular weight was determined from the retention time of the measurement sample obtained based on this.

(Production example of copolymer solutions A2 to A14)
Copolymer solutions A2 to A14 were obtained in the same manner as in A1 Production Example except that the types and weights (mass parts) of the copolymerization components used were as shown in Table 3. The structure of the copolymer and the weight average molecular weight (Mw) are shown in Table 4.

※PTSA：パラトルエンスルホン酸

* PTSA: p-toluenesulfonic acid

(Production example of copolymer solution B1)
The materials listed in Table 5 were mixed in a four-necked separable flask equipped with a stirrer, a cooler, a thermometer, and a nitrogen introduction tube, and stirred until the system became uniform.

While continuing to stir, the temperature in the reaction system was raised to 70 ° C., and the reaction was carried out for 8 hours in a nitrogen-introduced reflux state. Further, this solution was diluted with ethanol to obtain a copolymer solution B1 having a solid content of 40% by mass. The weight average molecular weight of the obtained copolymer was 17500.

(Production example of copolymer solutions B2 to B13)
Copolymer solutions B2 to B13 were obtained in the same manner as in B1 Production Example except that the types and weights (parts by mass) of the copolymerization components used were as shown in Table 6. Table 7 shows the structure and weight average molecular weight (Mw) of the copolymer.

(Production example of copolymer solution H1)
The materials listed in Table 8 were mixed in a four-necked separable flask equipped with a stirrer, a cooler, a thermometer, and a nitrogen introduction tube, and stirred until the system became uniform.

While continuing to stir, the temperature in the reaction system was raised to 70 ° C., and the reaction was carried out for 8 hours in a nitrogen-introduced reflux state. Further, this solution was diluted with ethanol to obtain a copolymer solution H1 having a solid content of 40% by mass. The weight average molecular weight of the obtained copolymer was 16,500.

(Production example of copolymer solution H2)
A copolymer solution H2 was obtained in the same procedure as the copolymer solution H1, except that n-hexyl-2-vinylpyridinium bromide was changed to n-hexyl-4-vinylpyridinium bromide. The weight average molecular weight of the obtained copolymer was 16,200.

(Example of production of copolymer solution H3)
A copolymer solution H3 was obtained in the same procedure as the copolymer solution H1, except that the copolymer components were changed to those shown in Table 9. The weight average molecular weight of the obtained copolymer was 11700.

（共重合体溶液Ｈ４の製造例）

(Production example of copolymer solution H4)

  A copolymer solution H4 was obtained in the same procedure as the copolymer solution H1, except that the copolymer components were changed to those shown in Table 10. The weight average molecular weight of the obtained copolymer was 10100. Table 11 shows the structures and weight average molecular weights (Mw) of the copolymers of H1 to H4.

※下記に示す構造式（５）

* Structural formula shown below (5)

以上の製造例で示した共重合体溶液を用いた実施例を以下に示すが、本発明は以下の実施例に限定されるものではない。

Examples using the copolymer solution shown in the above production examples are shown below, but the present invention is not limited to the following examples.

Example 1
<Manufacture of shaft core body 2>
As the shaft core body 2, a SUS304 core metal having a diameter of 6 mm was prepared by applying and baking a primer (trade name: DY35-051; manufactured by Toray Dow Corning).

<Manufacture of elastic layer 3>
Next, the shaft core 2 was placed in a mold, and an addition-type silicone rubber composition in which the materials shown in Table 12 were mixed was injected into a cavity formed in the mold.

Subsequently, the mold is heated to cure and cure the silicone rubber at 150 ° C. for 15 minutes, and after demolding, the silicone rubber is further heated at 180 ° C. for 1 hour to complete the curing reaction. A 3 mm elastic layer 3 was provided.

<Manufacture of surface layer 4>
As a binder resin material for the surface layer 4, 100.0 parts by mass of polyether polyol (trade name: PTG2000, manufactured by Hodogaya Chemical Co., Ltd.) and MDI-based polyisocyanate (trade name: CORONATE 2521, manufactured by Nippon Polyurethane Industry Co., Ltd.) 124.9 Mass parts were mixed. Furthermore, 36.0 parts by mass of carbon black (trade name: MA230, manufactured by Mitsubishi Chemical Corporation) was added as conductive fine particles and mixed with stirring. Thereafter, the mixture was dissolved in methyl ethyl ketone so as to have a total solid content ratio of 30% by mass, mixed and then uniformly dispersed by a sand mill. 11.7 parts by mass of copolymer solution A1 was gradually added while stirring with a stirring motor, and further mixed and stirred with a stirring motor for 20 minutes to obtain a coating material for forming a surface layer. Further, the surface layer-forming coating material was diluted with methyl ethyl ketone so as to have a viscosity of 10 to 13 cps, and then applied onto the elastic layer. After the applied coating material was dried, the surface layer 4 having a film thickness of about 20 μm was provided on the outer periphery of the elastic layer by heat treatment at a temperature of 150 ° C. for 1 hour, whereby the developer carrying member of Example 1 was produced.

(Examples 2 to 14)
The developer carrying bodies of Examples 2 to 14 were obtained in the same manner as in Example 1 except that the copolymer solution A1 used in Example 1 was changed to the copolymer solutions A2 to 14.

(Example 15)
A shaft core body 2 was prepared in the same procedure as in Example 1, and an elastic layer 3 was further provided. Next, as a binder resin material for the surface layer 4, 100.0 parts by mass of polyester polyol (trade name: Nipponporan 3027, manufactured by Nippon Polyurethane Industry Co., Ltd.) and MDI polyisocyanate (product name: CORONATE 2521, manufactured by Nippon Polyurethane Industry Co., Ltd. 102) Further, 33.7 parts by mass of carbon black (trade name: MA230, manufactured by Mitsubishi Chemical Corporation) was added and mixed by stirring as conductive fine particles, and then the total solid content ratio was 30% by mass. After dissolving and mixing in methyl ethyl ketone, it was uniformly dispersed in a sand mill.
11.7 parts by mass of copolymer solution A2 was gradually added while stirring with a stirring motor, and further mixed and stirred with a stirring motor for 20 minutes to obtain a coating material for forming a surface layer. Further, the surface layer-forming coating material was diluted with methyl ethyl ketone so as to have a viscosity of 10 to 13 cps, then dip-coated on the elastic layer and then dried. Thereafter, a surface layer having a film thickness of about 20 μm was provided on the outer periphery of the elastic layer by heat treatment at a temperature of 150 ° C. to obtain a developer carrying member of Example 15.

(Examples 16 and 17)
The developer carriers of Examples 16 and 17 were prepared in the same manner as in Example 15 except that the copolymer solution A2 used in Example 15 was changed to the copolymer solution A7 and the copolymer solution A13. Obtained.

(Example 18)
A shaft core body 2 was prepared in the same procedure as in Example 1, and an elastic layer 3 was further provided. Next, as a binder material for the surface layer 4, polycarbonate polyol (trade name: NIPPOLAN 980R, manufactured by Nippon Polyurethane Industry Co., Ltd.) 100.0 parts by mass and MDI-based polyisocyanate (product name: CORONATE 2521, manufactured by Nippon Polyurethane Industry Co., Ltd.) 122 7 parts by weight were mixed. Furthermore, 35.8 parts by mass of carbon black (trade name: MA230, manufactured by Mitsubishi Chemical Corporation) was added as conductive fine particles, and the mixture was stirred and mixed. Thereafter, the mixture was dissolved in methyl ethyl ketone so as to have a total solid content ratio of 30% by mass, mixed and then uniformly dispersed by a sand mill.
11.7 parts by mass of copolymer solution A2 was gradually added while stirring with a stirring motor, and further mixed and stirred with a stirring motor for 20 minutes to obtain a coating material for forming a surface layer. Further, the surface layer-forming coating material was diluted with methyl ethyl ketone so as to have a viscosity of 10 to 13 cps, then dip-coated on the elastic layer and then dried. Thereafter, a surface layer having a film thickness of about 20 μm was provided on the outer periphery of the elastic layer by heat treatment at a temperature of 150 ° C. to obtain a developer carrying member of Example 18.

(Examples 19 and 20)
The developer carriers of Examples 19 and 20 were prepared in the same manner as in Example 18 except that the copolymer solution A2 used in Example 18 was changed to the copolymer solution A7 and the copolymer solution A13. Obtained.

(Example 21)
A shaft core body 2 was prepared in the same procedure as in Example 1, and an elastic layer 3 was further provided. Next, as a binder material for the surface layer 4, 100.0 parts by mass of polyether polyol (trade name: PTG2000, manufactured by Hodogaya Chemical Co., Ltd.) and TDI-based polyisocyanate (trade name: CORONATE 2232, manufactured by Nippon Polyurethane Industry Co., Ltd.) 101 2 parts by weight were mixed. Furthermore, 29.5 parts by mass of carbon black (trade name: MA230, manufactured by Mitsubishi Chemical Corporation) was added as conductive fine particles and mixed with stirring. Thereafter, the mixture was dissolved in methyl ethyl ketone so as to have a total solid content ratio of 30% by mass, mixed and then uniformly dispersed by a sand mill.
11.7 parts by mass of copolymer solution A2 was gradually added while stirring with a stirring motor, and further mixed and stirred with a stirring motor for 20 minutes to obtain a coating material for forming a surface layer. Further, the surface layer-forming coating material was diluted with methyl ethyl ketone so as to have a viscosity of 10 to 13 cps, then dip-coated on the elastic layer and then dried. Thereafter, a surface layer having a film thickness of about 20 μm was provided on the outer periphery of the elastic layer by heat treatment at a temperature of 150 ° C. to obtain a developer carrying member of Example 21.

(Examples 22 and 23)
The developer carriers of Examples 22 and 23 were obtained in the same manner as in Example 21 except that the copolymer solution A2 used in Example 21 was changed to copolymer solutions A7 and A13.
(Examples 24-36)
Developer carriers of Examples 24-36 were obtained in the same manner as in Example 1 except that the copolymer solution A1 used in Example 1 was changed to copolymer solutions B1-13.
(Examples 37 to 41)
The developer carriers of Examples 37 to 41 were prepared in the same manner as in Example 15 except that the copolymer solution A2 used in Example 15 was changed to copolymer solutions B1, B2, B7, B9, and B12. Obtained.
(Examples 42 to 46)
The developer carriers of Examples 42 to 46 were prepared in the same manner as in Example 18 except that the copolymer solution A2 used in Example 18 was changed to copolymer solutions B1, B2, B7, B9, and B12. Obtained.
(Examples 47 to 51)
The developer carriers of Examples 47 to 51 were prepared in the same manner as in Example 21, except that the copolymer solution A2 used in Example 21 was changed to copolymer solutions B1, B2, B7, B9, and B12. Obtained.

(Comparative Example 1)
A shaft core body 2 was prepared in the same procedure as in Example 1, and an elastic layer 3 was further provided. Next, 100.0 parts by mass of polyether polyol (trade name: PTG2000, manufactured by Hodogaya Chemical Co., Ltd.) and melamine resin (trade name: Cymel 235, manufactured by Nippon Cytec Industry Co., Ltd.) 0 parts by mass were mixed. Furthermore, 19.8 parts by mass of carbon black MA230 (trade name, manufactured by Mitsubishi Chemical Corporation) as conductive fine particles was added and mixed by stirring. The mixture was dissolved in toluene so that the total solid content ratio was 30% by mass. Evenly dispersed.
11.7 parts by mass of copolymer solution A2 was gradually added while stirring with a stirring motor, and further mixed and stirred with a stirring motor for 20 minutes to obtain a coating material for forming a surface layer. Further, the surface layer-forming coating material was diluted with methyl ethyl ketone so as to have a viscosity of 10 to 13 cps, then dip-coated on the elastic layer and then dried. Thereafter, a surface layer having a thickness of about 20 μm was provided on the outer periphery of the elastic layer by heat treatment at a temperature of 150 ° C. to obtain a developer carrying member of Comparative Example 1.

(Comparative Examples 2-6)
A developer carrier of Comparative Examples 2 to 6 was obtained in the same manner as Comparative Example 1, except that the copolymer solution A2 of Comparative Example 1 was changed to the copolymer solutions A7, B1, B2, B9, and B12. .

(Comparative Examples 7 to 10)
In Example 1, developer carriers of Comparative Examples 7 to 10 were obtained in the same manner as in Example 1 except that the copolymer solution A1 was changed to the copolymer solutions H1 to H4.

(Image evaluation)
The developer carriers of Example 1-51 and Comparative Example 1-10 produced as described above were evaluated by the following methods. For the evaluation, a laser printer (trade name: LBP5300; manufactured by Canon Inc.) having a configuration as shown in FIG. 4 was used.

[Measurement of triboelectric charge (Q / M) of developer on developer carrier]
In an environment of room temperature 30 ° C. and relative humidity 80% (hereinafter referred to as “H / H environment”), a developer carrier is loaded into the laser printer, and a solid white image is output on the developer carrier. A developer was supported. The developer on the developer carrying member was sucked and collected by a metal cylindrical tube and a cylindrical filter. At that time, the charge amount Q stored in the condenser through the metal cylindrical tube and the weight M by which the developer was sucked were measured. From these values, the charge amount Q / M (μC / g) per unit weight was calculated.

[Ghost evaluation after leaving in high temperature and high humidity environment]
The developer carrier was left in a H / H environment for 1 month, and then loaded into the laser printer, and ghost evaluation was performed by the following method.
In the output image of the printer, solid black images (squares and circles) are arranged at equal intervals on a white background in the area corresponding to one developer carrier at the front of the image, and the rest of the image is halftone What was done was used. Ranking was performed according to how ghost images appear on the halftone. The positive ghost indicates a ghost having a higher image density than the halftone, and the negative ghost indicates a ghost having a lower image density than the halftone.
A: No difference in shading is observed.
B: A slight shading difference can be confirmed depending on the viewing angle.
C: A ghost is clearly confirmed visually.
D: Ghost appears clearly as light and shade. The density difference can be measured with a reflection densitometer.
E: A ghost appears over the circumference of the developer carrier 2 or more.
The above results are summarized in Tables 13 to 15 and shown below.

Examples 1 to 51 are represented by the structural formula (3) and any one or both selected from the structural units represented by the structural formula (1) and the structural formula (2), which are features of the present invention. It contains a copolymer having structural units and polyurethane. From the results of Tables 13 to 15, it can be said that the developer carriers of Examples 1 to 51 all have high Q / M in the H / H environment and thus have high charge imparting properties. The ghost rank was also good.

Each of the developer carriers of Comparative Examples 1 to 6 contains a copolymer having the structural unit represented by the structural formula (1) or (2) and the structural unit represented by the structural formula (3). However, it does not contain polyurethane. For this reason, a copolymer tends to ooze out in H / H environment, and the rank of a ghost is low compared with Examples 1-23.
The developer carriers of Comparative Examples 7 and 8 contain polyurethane, but do not have the structural unit represented by the structural formula (3) in the copolymer. For this reason, a copolymer tends to ooze out in H / H environment, and the rank of a ghost is low compared with Examples 1-23.

The developer carriers of Comparative Examples 9 and 10 have polyurethane and the structural unit represented by the structural formula (3), but the structural unit represented by the structural formula (1) and the structural formula (2). None of them. For this reason, compared with Examples 1-23, Q / M in H / H environment is low, and charge provision property is low.
In addition, in the developer carriers of Examples 24-51 having a bulky structure such as the structural unit represented by the structural formula (4) in the copolymer, Examples having no such structural unit are used. Compared with 1 to 23, the ghost rank was particularly good.

1: developer carrier 2: shaft core 3: elastic layer 4: surface layer 5: photoconductor 6: developer supply roller 7: developer 8: developing device 9: charging member 10: fixing device 11: paper

Claims (4)

A developer carrier having a shaft core and a surface layer,
The surface layer is
A copolymer having any one or both of structural units represented by the following structural formula (1) and structural formula (2) and a structural unit represented by the following structural formula (3), and polyurethane A developer carrier characterized by:

[R ₁ represents an alkyl group having 1 to 13 carbon atoms, and X ₁ ^— represents a halogen ion or a paratoluenesulfonic acid ion. ]

[R ₂ represents an alkyl group having 1 to 13 carbon atoms, and X ₂ ⁻ represents a halogen ion or a paratoluenesulfonic acid ion. ]

[R ₃ represents a hydrogen atom or a methyl group, R ₄ represents an alkylene group having 2 to ₄ carbon atoms, and R ₅ and R ₆ each independently represents an alkyl group having 1 or 2 carbon atoms. ]. The developer carrier according to claim 1, wherein the copolymer further has a structural unit represented by the following structural formula (4):

[R ₇ represents a hydrogen atom or a methyl group, and R ₈ represents any one of a cyclohexyl group, an adamantyl group, a dicyclopentanyl group, and a dicyclopentenyl group. ].   An electrophotographic process cartridge configured to be detachable from a main body of an electrophotographic apparatus, comprising the developer carrying member according to claim 1. An electrophotographic apparatus comprising the developer carrying member according to claim 1.

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