JP5656601B2 - Developer carrier, process cartridge, and electrophotographic apparatus - Google Patents

Description

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

  In an electrophotographic apparatus, an electrostatic latent image formed on an electrophotographic photosensitive member (hereinafter also referred to as “photosensitive member”) is developed by bringing a developer carrying member carrying a developer and a photosensitive member close to each other. There is a method. As the developer carrying member used in such a developing method, for example, a developing roller is used in which a surface layer is provided around a metal core member with or without an elastic layer. Such a developer carrying member has a function of charging the developer by friction.

Therefore, various charge imparting agents are contained in the surface layer of the developer carrying member in order to control the charge amount of the developer. Patent Document 1 discloses a developer carrier having a surface coating layer containing a copolymer of a methyl methacrylate monomer and a nitrogen-containing vinyl monomer. Patent Document 2 discloses a developing roller containing a positive charge imparting resin obtained by copolymerizing a (meth) acrylic acid ester monomer and an amino group-containing monomer. Further, Patent Document 3 discloses a developing sleeve containing a copolymer comprising an amino group-containing monomer, a fluorine-containing monomer, and a vinyl group-containing coupling agent component.

Japanese Patent Laid-Open No. 11-125966 JP 2005-031657 A Japanese Patent Laid-Open No. 10-055109

  In the future, as the performance of electrophotographic devices increases, the performance required for the developer carrier will become higher, and it will be necessary to provide stable chargeability in a harsh usage environment or sustainability of chargeability. Is done. According to the study by the present inventors, in Patent Documents 1 to 3, an increase in the charge amount of the developer was recognized by adding a random copolymer containing a nitrogen-containing monomer component to the developer carrier. . However, it has been recognized that these developer carriers may not achieve the level required in the future in terms of charge imparting property and sustainability in a high temperature and high humidity environment.

  Accordingly, an object of the present invention is to provide a high-quality developer carrying member that has a high charge imparting property even in a high-temperature and high-humidity environment, and can stably impart a high charge amount to the developer even when many sheets are used. An object of the present invention is to provide a process cartridge and an electrophotographic apparatus using a developer carrier.

The inventors of the present invention have made extensive studies and studies in order to provide a developer carrying member that meets the above-mentioned purpose, and have arrived at the present invention. That is, the present invention provides a first polymer block comprising at least one structural unit selected from the group consisting of structural units represented by the following structural formulas (1) and (2);
A second polymer block comprising at least one structural unit selected from the group consisting of structural units represented by the following structural formulas (3) and (4);
A third polymer block consisting of at least one structural unit selected from the group consisting of structural units represented by the following structural formulas (1) and (2), and the second polymer block A developer carrier comprising a surface layer containing a block copolymer sandwiched between one polymer block and the third polymer block.

［Ｒ ^１ は水素原子もしくはメチル基、Ｒ ^２ は炭素数１以上１３以下の直鎖または分岐を有するアルキル基またはシクロアルキル基を表す。］

[ R ¹ represents a hydrogen atom or a methyl group, and R ² represents a linear or branched alkyl or cycloalkyl group having 1 to 13 carbon atoms. ]

［Ｒ ^３ は水素原子もしくはメチル基、Ｒ ^４ は炭素数１あるいは２のアルキレン基、Ｒ ^５ は炭素数１以上８以下のパーフルオロアルキル基を表す。］

[ R ³ represents a hydrogen atom or a methyl group, R ⁴ represents an alkylene group having 1 or 2 carbon atoms, and R ⁵ represents a perfluoroalkyl group having 1 to 8 carbon atoms. ]

［Ｒ ^６ は水素原子もしくはメチル基、Ｒ ^７ ，Ｒ ^８ は各々独立して炭素数１以上１２以下のアルキル基を表す。］

[ R ⁶ represents a hydrogen atom or a methyl group, and R ⁷ and R ⁸ each independently represents an alkyl group having 1 to 12 carbon atoms. ]

［Ｒ ^９ は水素原子もしくはメチル基、Ｒ ¹⁰ ，Ｒ ¹¹ ，Ｒ ¹² は各々独立して炭素数１以上１２以下のアルキル基、Ｘ ^- はハロゲンイオンあるいはパラトルエンスルホン酸イオンを表す。］

[ R ⁹ represents a hydrogen atom or a methyl group, R ¹⁰ , R ¹¹ , and R ¹² each independently represents an alkyl group having 1 to 12 carbon atoms, and X ⁻ represents a halogen ion or a paratoluenesulfonic acid ion. ]

The present invention also relates to a process cartridge having at least a developer carrying member attached thereto and detachable from an electrophotographic apparatus, wherein the developer carrying member is the developer carrying member described above.
The present invention further includes a developer carrying member that carries a developer in a state of being opposed to the photosensitive member carrying the latent image, and the developer carrying member imparts the developer to the photosensitive member to thereby form the latent image. An electrophotographic apparatus for development, comprising the developer carrying member according to claim 1.

  According to the present invention, the surface layer of the developer-carrying member contains a triblock copolymer and a resin having a specific structure, so that it has a good charge imparting property even after the endurance use of a large number of sheets from the beginning. A high-quality developer carrying member capable of maintaining good charge imparting properties can be obtained. Further, a high-quality process cartridge and an electrophotographic apparatus can be obtained by using the developer carrier.

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

As shown in FIG. 1, the developer carrier of the present invention has a columnar or hollow cylindrical shaft core 2 and a surface layer 4. When the shaft core body 2 is cylindrical, the elastic layer 3 is provided between the guide shaft core body 2 and the surface layer 4 as shown in FIG. In particular, in a non-magnetic one-component contact development system process, a developer carrier having an elastic layer 3 is preferably used.
<Shaft core>
The shaft core 2 functions as an electrode and a support member of the developer carrier 1, and is made of a metal or alloy such as aluminum, copper alloy, stainless steel, or iron plated with chromium or nickel. It is composed of a conductive material.

<Elastic layer>
For the elastic layer 3, various rubber materials conventionally used for conductive rubber rollers can be used. Examples of the rubber used for the rubber material include the following. Ethylene-propylene-diene copolymer rubber (EPDM), acrylonitrile-butadiene rubber (NBR), chloroprene rubber (CR), natural rubber (NR), isoprene rubber (IR), styrene-butadiene rubber (SBR), fluorine rubber, Silicone rubber, epichlorohydrin rubber, hydride of NBR, urethane rubber. These can be used alone or in admixture of two or more. Among these, silicone rubber is particularly preferable from the viewpoint of set performance. Examples of the silicone rubber include polydimethylsiloxane, polymethyltrifluoropropylsiloxane, polymethylvinylsiloxane, polyphenylvinylsiloxane, and copolymers of these siloxanes.

  In the elastic layer 3, various additives such as a conductivity imparting agent, a non-conductive filler, and a catalyst are appropriately blended. As the conductivity-imparting agent, fine particles of conductive metal such as aluminum or copper, fine particles of conductive metal oxide such as zinc oxide, tin oxide or titanium oxide, or carbon black can be used. Of these, carbon black is particularly preferred because it is relatively easy to obtain and provides good conductivity. When carbon black is used as the conductivity-imparting agent, 10 to 80 parts by mass is blended with 100 parts by mass of rubber in the rubber material. Non-conductive fillers include silica, quartz powder, titanium oxide, zinc oxide or calcium carbonate. Examples of the crosslinking agent include di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, and dicumyl peroxide.

<Surface layer>
The surface layer 4 includes a first polymer block composed of at least one structural unit selected from the group consisting of structural units represented by structural formulas (1) and (2), and structural formulas (3) and (4). A second polymer block comprising at least one constituent unit selected from the group consisting of the constituent units represented, and at least one constituent selected from the group consisting of the constituent units represented by structural formulas (1) and (2) A block copolymer having a third polymer block composed of units, and the second polymer block sandwiched between the first polymer block and the third polymer block.

［Ｒ ^１ は水素原子もしくはメチル基、Ｒ ^２ は炭素数１以上１３以下の直鎖または分岐を有するアルキル基またはシクロアルキル基を表す。］、

[ R ¹ represents a hydrogen atom or a methyl group, and R ² represents a linear or branched alkyl or cycloalkyl group having 1 to 13 carbon atoms. ],

［Ｒ ^３ は水素原子もしくはメチル基、Ｒ ^４ は炭素数１あるいは２のアルキレン基、Ｒ ^５ は炭素数１以上８以下のパーフルオロアルキル基を表す。］、

[ R ³ represents a hydrogen atom or a methyl group, R ⁴ represents an alkylene group having 1 or 2 carbon atoms, and R ⁵ represents a perfluoroalkyl group having 1 to 8 carbon atoms. ],

［Ｒ ^６ は水素原子もしくはメチル基、Ｒ ^７ ，Ｒ ^８ は各々独立して炭素数１以上１２以下のアルキル基を表す。］、

[ R ⁶ represents a hydrogen atom or a methyl group, and R ⁷ and R ⁸ each independently represents an alkyl group having 1 to 12 carbon atoms. ],

［Ｒ ^９ は水素原子もしくはメチル基、Ｒ ¹⁰ ，Ｒ ¹¹ ，Ｒ ¹² は各々独立して炭素数１以上１２以下のアルキル基、Ｘ ^- はハロゲンイオンあるいはパラトルエンスルホン酸イオンを表す。］。

[ R ⁹ represents a hydrogen atom or a methyl group, R ¹⁰ , R ¹¹ , and R ¹² each independently represents an alkyl group having 1 to 12 carbon atoms, and X ⁻ represents a halogen ion or a paratoluenesulfonic acid ion. ].

  Usually, charging of the developer by the developer carrier is performed by frictional charging on the surface of the developer carrier. For this reason, it is important to localize the charge imparting agent added to the developer carrier on the surface of the developer carrier. Examples of the method of localizing on the surface include a method of utilizing a polarity difference with the binder resin. That is, when the polarity of the charge imparting agent to be added is low relative to the binder resin having a high polarity, the charge imparting agent tends to be localized on the surface.

  In general, many charge imparting agents used in electrophotographic apparatuses have nitrogen in the structure. Although the detailed mechanism of the charge control of the developer by adding the charge imparting agent is not clear, it is considered that the positive charge tendency of the nitrogen atom contributes. Examples of the structure containing nitrogen include a tertiary amino group and a quaternary ammonium base. Since these structures have high polarity, their tendency to localize on the surface is very weak. As a method for improving the localization on the surface, a method of reducing the polarity by using a copolymer of a monomer containing a tertiary amino group or a quaternary ammonium base and an alkyl ester monomer can be considered. However, in the case of a random copolymer, it is difficult to achieve both the localization on the surface and the charge imparting property, and sufficient charge imparting property may not be obtained. In the case of the AB type diblock copolymer, the presence of the low polarity block enables the molecules to be localized on the surface of the developer carrying member. However, there are cases where a highly polar block containing an amino group or quaternary ammonium base having a charge-imparting property is buried in the binder during durable use of a large number of sheets, and sufficient chargeability cannot be obtained after durable use.

The block copolymer contained in the surface layer of the developer-carrying member of the present invention has high charge-providing properties, and the reason for maintaining good charge-providing properties even after the use of a large number of sheets is not clear, but is as follows. Presumed.
The block copolymer has a low-polarity block composed of a fluorine-containing (meth) acrylic acid ester monomer or a (meth) acrylic acid alkyl ester monomer at both ends. Furthermore, it has a charge-providing block composed of a tertiary amino group or quaternary ammonium base-containing (meth) acrylic ester monomer sandwiched between these blocks. Since the charge imparting block has a high polarity, the charge imparting block tends to be easily oriented inside, but there are low polarity blocks at both ends that tend to be directed toward the surface. The block is raised to the surface. For this reason, the block copolymer is localized on the surface, and the charge-providing block can be present in the vicinity of the surface without being buried inside. Therefore, the block copolymer has a high charge imparting property.
In addition, low polarity blocks at both ends serve as anchors, limiting molecular mobility. For this reason, it is considered that the stagnation of the charge imparting block in the durable use is suppressed, and the charge imparting property is maintained even in the durable use of a large number of sheets.

  The monomers constituting the first polymer block and the third polymer block have a structure represented by structural formula (1) or (2). Specific monomers include 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- (P Etc. perfluorooctyl) ethyl (meth) acrylate. "(Meth) acrylate" means methacrylate or acrylate (hereinafter the same).

The monomer constituting the second polymer block has a structure represented by structural formula (3) or (4). Specifically, 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-dimethylaminobutyl (meth) acrylate, N, N-dibutylaminoethyl (meth) acrylate, N, N-dodecylmethylaminoethyl (meth) acrylate, ( (Meth) acrylic acid trimethylaminoethyl cation, (meth) acrylic acid trimethylaminomethyl cation, (meth) acrylic acid dimethylbutylaminoethyl cation, (meth) acrylic acid triethylaminoethyl cation (meth) acrylic acid dimethyloctylaminoethyl cation Examples include bromides such as thione, diethyl octylaminoethyl cation of (meth) acrylate, dimethyllaurylaminoethyl cation of (meth) acrylate, tributylaminoethyl cation of (meth) acrylate, chloride, paratoluenesulfonate, and the like. .
In addition, when the first polymer block and the third polymer block have the structure represented by the structural formula (5) and the second polymer block has the structure represented by the structural formula (6), each polymer block is The balance of polarity is excellent, and it has particularly suitable charge imparting properties.

［Ｒ ¹³ は水素原子あるいはメチル基、Ｒ ¹⁴ は炭素数１以上４以下の直鎖または分岐を有するアルキル基またはシクロアルキル基を表す。］

[R ¹³ is a hydrogen atom or a methyl group, R ¹⁴ represents an alkyl group or a cycloalkyl group having a straight-chain or branched having 1 to 4 carbon atoms. ]

［Ｒ ¹⁵ は水素原子あるいはメチル基、Ｒ ¹⁶ ，Ｒ ¹⁷ ，Ｒ ¹⁸ は各々独立して炭素数１以上１２以下のアルキル基、Ｘ ^- はハロゲンイオンあるいはパラトルエンスルホン酸イオンを表す。］

[ R ¹⁵ represents a hydrogen atom or a methyl group, R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represents an alkyl group having 1 to 12 carbon atoms, and X ⁻ represents a halogen ion or a paratoluenesulfonic acid ion. ]

In the present invention, in the block copolymer, the first polymer block is formed by repeating the structural unit n times, and the second polymer block is formed by repeating the structural unit m times. It is particularly preferable that the third polymer block is formed by repeating the structural unit 1 times, and the ratio of (n + 1) to m satisfies the relationship shown below.
5/95 ≦ (n + 1) / m ≦ 50/50
When the ratio of (n + 1) to m is 5/95 ≦ (n + 1) / m ≦ 50/50, the balance between the local action on the surface by the low polarity block and the charge imparting action by the charge imparting block Is good and has higher charge imparting performance.

The weight average molecular weight (Mw) of the block copolymer is preferably 10,000 or more and 100,000 or less. When Mw is 10,000 or more, the effect of suppressing bleeding out 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 block 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 the binder resin solid content 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 it is 10 parts by mass or less, the harmful effect is excellent.

  In the present invention, the binder resin component contained in the surface layer 4 is a polyol component consisting of at least one selected from polyether, polyester, polycarbonate, polybutadiene, polyisoprene, and acryl, and is crosslinked with polyisocyanate and / or melamine. It is particularly preferable that the resin is a reinforced resin or a phenol resin.

  As described above, in the present invention, it is considered that the above-mentioned block copolymer is held near the surface of the developer carrying member, thereby exhibiting high charge imparting properties and sustaining effects. The reason why the charge imparting block is present in the vicinity of the surface is considered to be because, as described above, the low polarity blocks present at both ends have a property toward the surface. If the polarity of the binder resin component is low, the affinity with the low polarity blocks at both ends of the block copolymer is increased, so that the tendency of pulling up the block copolymer molecules to the surface of the developer carrier is likely to be weak. Therefore, the charge imparting property of the block copolymer is further improved by using a binder resin component that produces an appropriate polarity difference with the block copolymer. Therefore, by using the binder resin component having a relatively high polarity as described above, higher charge imparting properties are given.

  Among the binder resin components as described above, in particular, when a polyether-based polyurethane and / or an aliphatic polyester polyurethane resin is used, there are particularly few deposits derived from the developer, and the effect of the addition of the block copolymer is prolonged over a long period of time. It is preferable because it lasts. Specifically, examples of the polyether polyol include polypropylene glycol and polytetramethylene glycol. Polyester polyols include 1,4-butanediol, 3-methyl-1,5-pentanediol, diol components such as neopentyl glycol, triol components such as trimethylolpropane, adipic acid, glutaric acid, sebacic acid, etc. Aliphatic polyester polyols obtained by condensation reaction with dicarboxylic acids. These polyol components may be prepolymers that are chain-extended with an isocyanate such as 2,4-tolylene diisocyanate (TDI), 1,4 diphenylmethane diisocyanate (MDI), or isophorone diisocyanate (IPDI) as required. The isocyanate compound to be reacted with these polyol components is not particularly limited, but aliphatic polyisocyanates such as ethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), cyclohexane 1, 3-diisocyanates, cycloaliphatic polyisocyanates such as cyclohexane 1,4-diisocyanate, aromatic isocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI) and these A copolymer or its block body can be used.

  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 of conductive 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 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 substrate 2 and then dried, solidified or cured. Can be formed. 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 substrate 2, known methods such as a dipping method, a spray method, and a roll coating method can be applied.

  The process cartridge and the electrophotographic apparatus of the present invention are not limited to a copying machine, a facsimile machine, or a printer as long as they have the developer carrying member of the present invention. As an example of the process cartridge and the electrophotographic apparatus of the present invention on which the developer carrying member of the present invention is mounted, a non-magnetic one-component developing type printer will be described below. As shown in FIG. 2, the process cartridge includes a developing device 10, a photoreceptor 5, a charging member 12, a cleaning device 13, and the like. The developing device 10 includes a developing container that contains a non-magnetic developer 8 as a one-component developer, a developing roller 1 that is positioned in an opening extending in the longitudinal direction inside the developing container, and that is opposed to the photosensitive member 5. The electrostatic latent image on the photoconductor 5 is developed to form an image. The process cartridge is configured to be detachable from the electrophotographic apparatus.

  As shown in FIG. 3, in the printer, a charging member 12 that charges the surface of the photoconductor 5 to a predetermined polarity / potential is disposed around the photoconductor 5 rotated by a rotation mechanism (not shown). Further, an image exposure device (not shown) is provided that forms an electrostatic latent image by irradiating the surface of the charged photoreceptor 5 with the image exposure light 11. Further, a developing device 10 having a developer carrier 1 of the present invention for developing a developer on the formed electrostatic latent image is disposed around the photoreceptor 5. Further, a cleaning device 13 for cleaning the top of the photoconductor 5 after the developer image is transferred to the paper 22 is provided. A fixing device 15 that fixes the transferred developer image on the paper 22 is disposed on the conveyance path of the paper 22.

Known methods can be used for the synthesis of the triblock type block copolymer of the present invention. Synthesis examples are shown below as reference for block copolymer synthesis.
As a comparative example, a synthesis example of a random copolymer and a diblock type block copolymer is also shown.

Synthesis of triblock type block copolymer (Synthesis Example 1) Synthesis of methyl methacrylate / dimethylmethylaminoethyl methacrylate / methyl methacrylate block copolymer (A1 to A11);
Under an argon atmosphere, 6.4 g of methyl methacrylate and 1.0 g of benzoyl peroxide were dissolved in 80 g of methyl ethyl ketone, reacted at 80 ° C. for 4 hours, and then rapidly cooled to room temperature. Subsequently, 45.2 g of dimethylaminoethyl methacrylate was added to the reaction solution, reacted at 80 ° C. for 10 hours, and then rapidly cooled to room temperature. Further, 6.4 g of methyl methacrylate was added and reacted at 80 ° C. for 6 hours, and then diluted with methyl ethyl ketone to obtain a block copolymer A1 solution having a solid content concentration of 50%. The weight average molecular weight of the block copolymer A1 thus obtained was 9100.
Using the same method, block copolymers A2 to A11 shown in Table 1 were synthesized.

Synthesis Example 2 Synthesis of methyl methacrylate / dimethylaminoethyl octyl bromide methacrylate salt / methyl methacrylate block copolymer (A12 to A25);
Under an argon atmosphere, 6.4 g of methyl methacrylate and 1.0 g of benzoyl peroxide were dissolved in 80 g of ethanol, reacted at 80 ° C. for 4 hours, and then rapidly cooled to room temperature. Subsequently, 100.5 g of dimethylaminoethyl octyl bromide methacrylate was added to the reaction solution, reacted at 80 ° C. for 10 hours, and then rapidly cooled to room temperature. Further, 6.4 g of methyl methacrylate was added and reacted at 80 ° C. for 6 hours, and then diluted with ethanol to obtain a block copolymer A12 solution having a solid content concentration of 50%. The weight average molecular weight of the block copolymer A12 thus obtained was 17500.
Using the same method, block copolymers A13 to A25 shown in Table 1 were synthesized.

Synthesis Example 3 Synthesis of 2,2,2-trifluoroethyl methacrylate / dimethylmethylaminoethyl methacrylate / 2,2,2-trifluoroethyl methacrylate block copolymer (A26 to A33);
Under an argon atmosphere, 10.8 g of 2,2,2-trifluoroethyl methacrylate and 1.0 g of benzoyl peroxide were dissolved in 80 g of methyl ethyl ketone, reacted at 80 ° C. for 4 hours, and then rapidly cooled to room temperature. Subsequently, 45.2 g of dimethylaminoethyl methacrylate was added to the reaction solution, reacted at 80 ° C. for 10 hours, and then rapidly cooled to room temperature. Further, 10.8 g of 2,2,2-trifluoroethyl methacrylate was added and reacted at 80 ° C. for 6 hours, and then diluted with methyl ethyl ketone to obtain a block copolymer A26 solution having a solid concentration of 50%. The weight average molecular weight of the block copolymer A26 thus obtained was 10800.
Using the same method, block copolymers A27 to A33 shown in Table 1 were synthesized.

(Synthesis Example 4) Synthesis of 2,2,2-trifluoroethyl methacrylate / dimethylaminoethyl octyl bromide methacrylate salt / 2,2,2-trifluoroethyl methacrylate block copolymer (A34 to A39);
Under an argon atmosphere, 10.8 g of 2,2,2-trifluoroethyl methacrylate and 1.0 g of benzoyl peroxide were dissolved in 80 g of ethanol, reacted at 80 ° C. for 4 hours, and then rapidly cooled to room temperature. Subsequently, 100.5 g of dimethylaminoethyl octyl bromide methacrylate was added to the reaction solution, reacted at 80 ° C. for 10 hours, and then rapidly cooled to room temperature. Further, 10.8 g of 2,2,2-trifluoroethyl methacrylate was added and reacted at 80 ° C. for 6 hours, and then diluted with ethanol to obtain a block copolymer A34 solution having a solid content concentration of 50%. The weight average molecular weight of the block copolymer A34 thus obtained was 19100.
Using the same method, block copolymers A35 to A39 shown in Table 1 were synthesized.
The triblock type block copolymer obtained by the above method is shown in Table 1.

※表中のＲ ^１ 〜Ｒ ¹² 及びＸ ^- は、前記構造式（１）〜（４）中の記号に対応する。

* R ¹ to R ¹² and X ⁻ in the table correspond to the symbols in the structural formulas (1) to (4).

Synthesis of random copolymer (Synthesis Example 5) Synthesis of methyl methacrylate / dimethylaminoethyl methacrylate random copolymer (B1 to B4 );
Under an argon atmosphere, 25.6 g of dodecyl methacrylate, 40.2 g of dimethylaminoethyl methacrylate, and 1.0 g of benzoyl oxide were dissolved in 85 g of ethanol and reacted at 80 ° C. for 4 hours. Thereafter, the solution was rapidly cooled to room temperature and diluted with ethanol to obtain a random copolymer B1 solution having a solid content concentration of 50%. The random copolymer B1 thus obtained had a weight average molecular weight of 10,200.

  Thereafter, random copolymers B2 to B4 were obtained in the same procedure. The resulting random copolymer is shown in Table 2. The value of x / y in the table is based on the monomer xmol selected from the structural formula (1) and the structural formula (2) among the monomers constituting each random copolymer, the structural formula (3), and the structural formula (4). The ratio of monomer ymol selected, the value of x / y.

※表中のＲ ^１ 〜Ｒ ¹² 及びＸ ^- は、前記構造式（１）〜（４）中の記号に対応する。

* R ¹ to R ¹² and X ⁻ in the table correspond to the symbols in the structural formulas (1) to (4).

Synthesis of diblock type block copolymer (Synthesis Example 6) Synthesis of methyl methacrylate / dimethylaminoethyl methacrylate diblock copolymer (B5 to B8);
Under an argon atmosphere, 25.6 g of methyl methacrylate and 1.0 g of benzoyl peroxide were dissolved in 100 g of ethanol, reacted at 80 ° C. for 5 hours, and then rapidly cooled to room temperature. Subsequently, 40.2 g of dimethylaminoethyl methacrylate was added to this reaction solution and reacted at 80 ° C. for 8 hours, then rapidly cooled to room temperature and diluted with ethanol to obtain a diblock copolymer B5 solution having a solid content concentration of 50%. Obtained. The weight average molecular weight of the thus obtained diblock copolymer B5 was 10,000.

  Thereafter, diblock copolymers B6 to B8 were obtained in the same procedure. The obtained diblock type block copolymer is shown in Table 3. The value of x ′ / y ′ in the table is the monomer x′mol selected from structural formula (1) and structural formula (2) among the monomers constituting each diblock type block copolymer, and structural formula (3). Represents the ratio of the monomer y′mol selected from the structural formula (4) and the value of x ′ / y ′.

※表中のＲ ^１ 〜Ｒ ¹² 及びＸ ^- は、前記構造式（１）〜（４）中の記号に対応する。

* R ¹ to R ¹² and X ⁻ in the table correspond to the symbols in the structural formulas (1) to (4).

Specific examples and comparative examples according to the present invention will be described below.
Example 1
-Preparation of shaft core 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).

-Preparation 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 4 were mixed was poured into a cavity formed in the mold.

続いて、金型を加熱してシリコーンゴムを１５０℃で１５分間加硫硬化し、脱型した後、さらに１８０℃で１時間加熱し硬化反応を完結させ、軸芯体２の外周に直径１２ｍｍの弾性層３を設けた。

Subsequently, the mold was heated and the silicone rubber was vulcanized and cured at 150 ° C. for 15 minutes. After demolding, the silicone rubber was further heated at 180 ° C. for 1 hour to complete the curing reaction. The elastic layer 3 was provided.

-Preparation of surface layer 4-
As materials for the surface layer 4, the materials listed in Table 5 were mixed with stirring, dissolved and mixed in toluene so that the total solid content ratio was 30% by mass, and then uniformly dispersed in a sand mill.

  Furthermore, 1.80 parts by mass of the block copolymer A8 solution shown in Table 1 was gradually added while stirring with a stirring motor, and further mixed and stirred for 20 minutes with a stirring motor to obtain a coating material for forming a surface layer. Further, the surface layer-forming coating material is diluted with methyl ethyl ketone so as to have a viscosity of 10 to 13 cps, then dip-coated on the elastic layer, dried, and heat-treated at a temperature of 150 ° C. for 1 hour to obtain an outer periphery of the elastic layer. A developer layer of Example 1 was obtained by providing a surface layer having a thickness of about 20 μm.

(Examples 2 to 4)
Developer carriers of Examples 2 to 4 were obtained in the same manner as in Example 1 except that the block copolymer A8 was changed to the block copolymers A17, A30 and A37.

(Example 5)
A shaft core body 2 was prepared in the same procedure as in Example 1, and an elastic layer 3 was provided on the outer periphery thereof.
Next, as the material of the surface layer 4, the materials listed in Table 6 were mixed with stirring, dissolved and mixed in methyl ethyl ketone so that the total solid content ratio was 30% by mass, and then uniformly dispersed in a sand mill.

  Further, 3.90 parts by mass of the block copolymer A8 solution shown in Table 1 was gradually added with stirring by a stirring motor, and further mixed and stirred by a stirring motor for 20 minutes to obtain a coating material for forming a surface layer. Further, the surface layer-forming coating material is diluted with methyl ethyl ketone so as to have a viscosity of 10 to 13 cps, then dip-coated on the elastic layer, dried, and heat-treated at a temperature of 150 ° C. for 1 hour to obtain an outer periphery of the elastic layer. A developer layer of Example 5 was obtained by providing a surface layer having a film thickness of about 20 μm.

(Examples 6 to 8)
Developer carriers of Examples 6 to 8 were obtained in the same manner as Example 5 except that the block copolymer A8 was changed to block copolymers A17, A30 and A37.

Example 9
A shaft core body 2 was prepared in the same procedure as in Example 1, and an elastic layer 3 was provided on the outer periphery thereof. The materials listed in Table 7 were mixed as a material for the surface layer 4.

その後、総固形分比が３０質量％になるようにメチルエチルケトンに溶解、混合した後、サンドミルにて均一に分散した。ブロックコポリマーＡ８溶液、３．３５質量部を撹拌モーターにより撹拌しながら徐々に加え、さらに撹拌モーターにより２０分間混合撹拌して表面層形成用塗料を得た。更に、この表面層形成用塗料を粘度１０〜１３ｃｐｓになるようメチルエチルケトンで希釈後、前記弾性層の上に図４に示す液循環型浸漬塗工装置を用いて浸漬塗工した後に乾燥させた。その後、温度１５０℃にて１時間加熱処理することで弾性層外周に膜厚約２０μmの表面層を設け、実施例９の現像剤担持体を得た。

Thereafter, the mixture was dissolved and mixed in methyl ethyl ketone so that the total solid content ratio was 30% by mass, and then uniformly dispersed in a sand mill. The block copolymer A8 solution, 3.35 parts by mass, was gradually added while stirring with a stirring motor, and further mixed and stirred for 20 minutes with a stirring motor 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 using a liquid circulation type dip coating apparatus shown in FIG. 4, 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 9.

(Examples 10 to 12)
Developer carriers of Examples 10 to 12 were obtained in the same manner as in Example 9, except that the block copolymer A8 was changed to block copolymers A17, A30 and A37.

(Example 13)
A shaft core body 2 was prepared in the same procedure as in Example 1, and an elastic layer 3 was provided on the outer periphery thereof.
Next, as the material of the surface layer 4, the materials shown in Table 8 were mixed with stirring, dissolved and mixed in methyl ethyl ketone so that the total solid content ratio was 30% by mass, and then uniformly dispersed in a sand mill.

  Further, 7.30 parts by mass of the block copolymer A8 solution shown in Table 1 was gradually added while stirring with a stirring motor, and further mixed and stirred for 20 minutes with a stirring motor to obtain a coating material for forming a surface layer. Further, the surface layer-forming coating material is diluted with methyl ethyl ketone so as to have a viscosity of 10 to 13 cps, then dip-coated on the elastic layer, dried, and heat-treated at a temperature of 150 ° C. for 1 hour to obtain an outer periphery of the elastic layer. A developer layer of Example 13 was obtained by providing a surface layer having a film thickness of about 20 μm.

(Examples 14 to 16)
Developer carriers of Examples 14 to 16 were obtained in the same manner as in Example 13 except that the block copolymer A8 was changed to block copolymers A17, A30 and A37.

(Example 17)
A shaft core body 2 was prepared in the same procedure as in Example 1, and an elastic layer 3 was provided on the outer periphery thereof.
Next, as the material of the surface layer 4, the materials shown in Table 9 were mixed with stirring, dissolved and mixed in toluene so that the total solid content ratio was 30% by mass, and then uniformly dispersed in a sand mill.

  Further, 6.70 parts by mass of the block copolymer A8 solution shown in Table 1 was gradually added while stirring with a stirring motor, and further mixed and stirred for 20 minutes with a stirring motor to obtain a coating material for forming a surface layer. Further, the surface layer-forming coating material is diluted with methyl ethyl ketone so as to have a viscosity of 10 to 13 cps, then dip-coated on the elastic layer, dried, and heat-treated at a temperature of 150 ° C. for 1 hour to obtain an outer periphery of the elastic layer. A developer layer of Example 17 was obtained by providing a surface layer having a thickness of about 20 μm.

(Examples 18 to 20)
Developer carriers of Examples 18 to 20 were obtained in the same manner as in Example 17 except that the block copolymer A8 was changed to block copolymers A17, A30 and A37.

(Example 21)
A shaft core body 2 was prepared in the same procedure as in Example 1, and an elastic layer 3 was provided on the outer periphery thereof.
Next, the materials listed in Table 10 were stirred and mixed as the material of the surface layer 4, dissolved and mixed in toluene so that the total solid content ratio was 30% by mass, and then uniformly dispersed in a sand mill.

  Further, 7.07 parts by mass of the block copolymer A8 solution shown in Table 1 was gradually added while stirring with a stirring motor, and further mixed and stirred for 20 minutes with a stirring motor to obtain a coating material for forming a surface layer. Further, the surface layer-forming coating material is diluted with methyl ethyl ketone so as to have a viscosity of 10 to 13 cps, then dip-coated on the elastic layer, dried, and heat-treated at a temperature of 150 ° C. for 1 hour to obtain an outer periphery of the elastic layer. A developer layer of Example 21 was obtained by providing a surface layer having a thickness of about 20 μm.

(Examples 22 to 24)
Developer carriers of Examples 22 to 24 were obtained in the same manner as in Example 21 except that the block copolymer A8 was changed to block copolymers A17, A30 and A37.

(Example 25)
A shaft core body 2 was prepared in the same procedure as in Example 1, and an elastic layer 3 was provided on the outer periphery thereof.
Next, as the material of the surface layer 4, the materials listed in Table 11 were mixed with stirring, dissolved and mixed in methyl ethyl ketone so that the total solid content ratio was 30% by mass, and then uniformly dispersed in a sand mill.

  Further, 7.8 parts by mass of block copolymer A28 shown in Table 1 was gradually added while stirring with a stirring motor, and further mixed and stirred for 20 minutes with a stirring motor to obtain a coating material for forming a surface layer. Further, the surface layer-forming coating material is diluted with methyl ethyl ketone so as to have a viscosity of 10 to 13 cps, then dip-coated on the elastic layer, dried, and heat-treated at a temperature of 150 ° C. for 1 hour to obtain an outer periphery of the elastic layer. A developer layer of Example 25 was obtained by providing a surface layer having a thickness of about 20 μm.

(Examples 26 to 28)
Developer carriers of Examples 26 to 28 were obtained in the same manner as in Example 25 except that the block copolymer A8 was changed to block copolymers A17, A30 and A37.

(Example 29)
A shaft core body 2 was prepared in the same procedure as in Example 1, and an elastic layer 3 was provided on the outer periphery thereof.
Next, as the material of the surface layer 4, the materials shown in Table 12 were mixed with stirring, dissolved and mixed in toluene so that the total solid content ratio was 30% by mass, and then uniformly dispersed in a sand mill.

Furthermore, 7.8 parts by mass of the block copolymer A8 solution shown in Table 1 was gradually added while stirring with a stirring motor, and further mixed and stirred for 20 minutes with a stirring motor to obtain a coating material for forming a surface layer.
Further, the surface layer-forming coating material is diluted with methyl ethyl ketone so as to have a viscosity of 10 to 13 cps, then dip-coated on the elastic layer, dried, and heat-treated at a temperature of 150 ° C. for 1 hour to obtain an outer periphery of the elastic layer. A developer layer of Example 29 was obtained by providing a surface layer having a thickness of about 20 μm.

(Examples 30 to 32)
Developer carriers of Examples 30 to 32 were obtained in the same manner as in Example 29 except that the block copolymer A8 was changed to block copolymers A17, A30 and A37.

(Example 33)
A shaft core body 2 was prepared in the same procedure as in Example 1, and an elastic layer 3 was provided on the outer periphery thereof. Next, the materials listed in Table 13 were stirred and mixed as the material of the surface layer 4, dissolved and mixed in methanol so that the total solid content ratio was 30% by mass, and then uniformly dispersed in a sand mill.

  Further, 3.6 parts by mass of the block copolymer A8 solution shown in Table 1 was gradually added while stirring with a stirring motor, and further mixed and stirred for 20 minutes with a stirring motor to obtain a coating material for forming a surface layer. Further, the surface layer-forming coating material is diluted with methyl ethyl ketone so as to have a viscosity of 10 to 13 cps, then dip-coated on the elastic layer, dried, and heat-treated at a temperature of 150 ° C. for 1 hour to obtain an outer periphery of the elastic layer. A developer layer of Example 33 was obtained by providing a surface layer having a thickness of about 20 μm.

(Examples 34 to 36)
Developer carriers of Examples 34 to 36 were obtained in the same manner as in Example 33 except that the block copolymer A8 was changed to block copolymers A17, A30 and A37.

(Example 37)
A shaft core body 2 was prepared in the same procedure as in Example 1, and an elastic layer 3 was provided on the outer periphery thereof. Next, the materials listed in Table 14 as materials for the surface layer 4 were stirred and mixed, dissolved and mixed in methyl ethyl ketone so that the total solid content ratio was 30% by mass, and then uniformly dispersed in a sand mill.

  Furthermore, 8.74 parts by mass of the block copolymer A1 solution shown in Table 1 was gradually added while stirring with a stirring motor, and further mixed and stirred for 20 minutes with a stirring motor to obtain a coating material for forming a surface layer. Further, the surface layer-forming coating material is diluted with methyl ethyl ketone so as to have a viscosity of 10 to 13 cps, then dip-coated on the elastic layer, dried, and heat-treated at a temperature of 150 ° C. for 1 hour to obtain an outer periphery of the elastic layer. A developer layer of Example 37 was obtained by providing a surface layer having a thickness of about 20 μm.

(Examples 38 to 75)
Developer carriers of Examples 38 to 75 were obtained in the same manner as in Example 37 except that the block copolymer A1 was changed to block copolymers A2 to A39.

(Example 76)
A shaft core body 2 was prepared in the same procedure as in Example 1, and an elastic layer 3 was provided on the outer periphery thereof.
Next, as the material of the surface layer 4, the materials shown in Table 15 were mixed with stirring, dissolved and mixed in methyl ethyl ketone so that the total solid content ratio was 30% by mass, and then uniformly dispersed in a sand mill.

  Further, 9.18 parts by weight of the block copolymer A1 solution shown in Table 1 was gradually added while stirring with a stirring motor, and further mixed and stirred for 20 minutes with a stirring motor to obtain a coating material for forming a surface layer. Further, the surface layer-forming coating material is diluted with methyl ethyl ketone so as to have a viscosity of 10 to 13 cps, then dip-coated on the elastic layer, dried, and heat-treated at a temperature of 150 ° C. for 1 hour to obtain an outer periphery of the elastic layer. A developer layer of Example 76 was obtained by providing a surface layer having a thickness of about 20 μm.

(Examples 77 to 114)
Developer carriers of Examples 77 to 114 were obtained in the same manner as in Example 76 except that the block copolymer A1 was changed to the block copolymers A2 to A39.

(Comparative Example 1)
A developer carrier of Comparative Example 1 was obtained in the same manner as in Example 1 except that the block copolymer A1 was not added to the surface layer forming coating material of Example 1.
(Comparative Examples 2-9)
Developer carriers of Comparative Examples 2 to 9 were obtained in the same manner as in Example 1 except that the block copolymer A1 was changed to random copolymers B1 to B4 and diblock copolymers B5 to 8.

The following items were evaluated for the developer carriers of Examples 1-114 and Comparative Examples 1-9 obtained as described above.

[Molecular weight measurement]
Table 16 shows the apparatus and conditions used for the measurement of the number average molecular weight (Mn) and the weight average molecular weight (Mw) in this example.

なお測定サンプルは、０．１質量％のＴＨＦとした。更に検出器としてはＲＩ（屈折率）検出器を用いて測定を行った。
検量線作成用の標準試料として、ＴＳＫ標準ポリスチレンＡ−１０００、Ａ−２５００、Ａ−５０００、Ｆ−１、Ｆ−２、Ｆ−４、Ｆ−１０、Ｆ−２０、Ｆ−４０、Ｆ−８０、Ｆ−１２８（東ソー社製）を用いて検量線の作成を行い、これをもとに得られた測定サンプルの保持時間から重量平均分子量を求めた。

The measurement sample was 0.1% by mass of THF. 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), and the weight average molecular weight was determined from the retention time of the measurement sample obtained based on this.

[H / H fogging evaluation]
The evaluation of fogging in a high temperature and high humidity environment is carried out by loading the developer carrier of this example and the comparative example into a laser printer (trade name: LBP5300; manufactured by Canon Inc.) having the configuration as shown in FIG. I went there.
The printer was stopped during the output of a solid white image under an environment (hereinafter referred to as H / H) of an air temperature of 30 ° C. and a relative humidity of 80% RH. At this time, the toner (developer) adhering to the photoreceptor is peeled off with a tape, and the amount of decrease in the reflectance with respect to the reference is measured with a reflection densitometer (trade name: TC-6DS / A; manufactured by Tokyo Denshoku Co., Ltd.). (%) Was measured and used as the initial fogging value. Further, after continuously printing 12,000 sheets with a black toner at a printing rate of 2%, the value measured by the same method was used as the fog value after durability. Based on these fog values, the following evaluations were made.
A: Less than 3% B: 3% or more and less than 5% C: 5% or more

[Measurement of triboelectric charge (Q / M) of toner on developer carrier]
In an environment with an air temperature of 30 ° C. and a relative humidity of 80% RH (hereinafter referred to as “H / H”), the toner carried on the developer carrying member is sucked and collected by a metal cylindrical tube and a cylindrical filter. The charge amount Q stored in the condenser through the tube and the weight M of the sucked toner were measured. From these values, the charge amount Q / M (μC / g) per unit area was calculated.
The above results are shown in Table 17 to Table 20 below.

In each of Examples 1 to 8, since the surface layer 4 contains the block copolymer of the present invention, the surface layer 4 has high chargeability, and the decrease in chargeability due to durable use is also suppressed. Further, since it has a high charge imparting property, fogging is also suppressed.
As a binder resin component, any of acrylic polyurethane, polyether polyurethane, polyester polyurethane, polycarbonate polyurethane, polybutadiene polyurethane, isoprene polyurethane, phenol resin, polyester melamine resin, isoprene melamine resin is contained. In Examples 9 to 114, the charge imparting property and the sustainability of the effect are good.
Among them, Examples 42 to 46, Examples 51 to 55, Examples 64 to 68, Examples 71 to 75, Examples 81 to 85, Examples 90 to 94, Examples 103 to 107, and Examples 110 to 114 were used. When compared, the composition ratio of the polymer block is in the range of 5/95 ≦ (n + 1) / m ≦ 50/50, and the charge imparting property is good.

  Further, a developer carrier containing block copolymers A12 to 14, A16 to 18, and A20 to 23 having the structures shown in Structural Formula 5 and Structural Formula 6 as monomers constituting the block copolymer, that is, Example 10, Example 14, Example 18, Example 22, Example 26, Example 30, Example 34, Example 48-50, Example 52-54, Example 56-59, Example 87-89, Example 91-93 and Examples 95-98 have higher charge imparting properties, and the charge imparting properties are maintained at a high level even after durable use.

In particular, a developer carrier containing a polyether polyurethane resin and / or an aliphatic polyester polyurethane resin as the binder resin component of the surface layer 4, that is, Examples 48 to 50, Examples 52 to 54, and Examples 56 to 59. Examples 87 to 89, Examples 91 to 93, and Examples 95 to 98 have high charge imparting properties, and are maintained at a high level even after durable use.
On the other hand, Comparative Example 1 not containing the block copolymer of the present invention and Comparative Examples 2 to 5 containing the random copolymer had a low initial charge amount, a decrease in the charge amount after durable use, and fogging was also observed. In Comparative Examples 6 to 9 containing a diblock type block copolymer, a decrease in the charge amount after endurance use was observed, and the deterioration of fog accompanying this was recognized.

1: Developer carrier 2: Conductive shaft core 3: Elastic layer 4: Surface layer

Claims (7)

A first polymer block comprising at least one structural unit selected from the group consisting of structural units represented by the following structural formulas (1) and (2);
A second polymer block comprising at least one structural unit selected from the group consisting of structural units represented by the following structural formulas (3) and (4);
A third polymer block consisting of at least one structural unit selected from the group consisting of structural units represented by the following structural formulas (1) and (2), and
The developer carrier, wherein the second polymer block has a surface layer containing a block copolymer sandwiched between the first polymer block and the third polymer block:

[ R ¹ represents a hydrogen atom or a methyl group, and R ² represents a linear or branched alkyl or cycloalkyl group having 1 to 13 carbon atoms. ],

[ R ³ represents a hydrogen atom or a methyl group, R ⁴ represents an alkylene group having 1 or 2 carbon atoms, and R ⁵ represents a perfluoroalkyl group having 1 to 8 carbon atoms. ],

[ R ⁶ represents a hydrogen atom or a methyl group, and R ⁷ and R ⁸ each independently represents an alkyl group having 1 to 12 carbon atoms. ],

[ R ⁹ represents a hydrogen atom or a methyl group, R ¹⁰ , R ¹¹ , and R ¹² each independently represents an alkyl group having 1 to 12 carbon atoms, and X ⁻ represents a halogen ion or a paratoluenesulfonate ion. ]. The surface layer contains a polyol component consisting of at least one selected from polyether, polyester, polycarbonate, polybutadiene, polyisoprene, and acrylic, a resin crosslinked with polyisocyanate and / or melamine, or a phenol resin. 2. The developer carrying member according to 1. The first polymer block is formed by repeating the structural unit n times;
The second polymer block is formed by repeating the structural unit m times; and
The third polymer block is formed by repeating the structural unit l times;
The developer carrier according to claim 1, wherein a ratio of (n + 1) to m satisfies a relationship represented by the following formula:
5/95 ≦ (n + 1) / m ≦ 50/50. The first and third polymer blocks are composed of structural units represented by the following formula (5),
The developer carrier according to any one of claims 1 to 3, wherein the second polymer block is composed of a structural unit represented by the following formula (6).

[R ¹³ is a hydrogen atom or a methyl group, R ¹⁴ represents an alkyl group or a cycloalkyl group having a straight-chain or branched having 1 to 4 carbon atoms. ],

[ R ¹⁵ represents a hydrogen atom or a methyl group, R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represents an alkyl group having 1 to 12 carbon atoms, and X ⁻ represents a halogen ion or a paratoluenesulfonic acid ion. ]. The developer carrying member according to any one of claims 1 to 4, wherein the surface layer contains at least one selected from a polyether polyurethane resin and an aliphatic polyester polyurethane resin. A process cartridge configured to be attachable to and detachable from an electrophotographic apparatus, comprising the developer carrying member according to claim 1. An electrophotographic apparatus comprising the developer carrying member according to claim 1.

Images