JP6510936B2 - Electrophotographic apparatus members - Google Patents

Description

  The present invention relates to a member for an electrophotographic apparatus.

  2. Description of the Related Art Conventionally, electrophotographic apparatuses such as electrophotographic copying machines, printers, and printers are known. In the electrophotographic apparatus, various members for electrophotographic apparatus such as a developing member such as a developing roll, a charging member such as a charging roll, and a transfer member such as an intermediate transfer belt are incorporated.

  As a member for an electrophotographic apparatus, for example, Patent Document 1 discloses, in a molecule, a first polymerized unit based on a (meth) acrylate having a silicone group and a second polymerized unit based on a (meth) acrylate having a fluorine-containing group. There is disclosed a member for an electrophotographic apparatus which includes in the surface layer a surface modifying agent composed of a copolymer including the above.

International Publication WO 2014/084225

  However, although the conventional electrophotographic apparatus member can achieve both the slipperiness of the surface layer and the toner releasability, it has room for improvement in the following points. That is, in general, in an electrophotographic apparatus, charged toner is moved to each member by providing a constant potential difference between the members, and an image is finally formed on a medium such as paper. This type of electrophotographic apparatus is expected to be used in various environments. At this time, when the charge amount of the toner changes, the movement amount and movement state of the toner to each member change, which adversely affects the formed image. As the reason why the charge amount of the toner changes, the change of the molecular mobility of the surface layer material in each member with which the toner comes in contact, the influence of humidity and the like can be considered.

  In this regard, conventional electrophotographic apparatus members have a high temperature and high temperature of 32.5 ° C. × 85% RH from the above low temperature and low humidity environment as a result of the toner being overcharged under the low temperature and low humidity environment of 10 ° C. × 10% RH There is a problem that it is difficult to suppress the environmental dependency of the toner charge amount in the use environment up to the wet environment.

  The present invention has been made in view of the above background, and is capable of achieving both the slipperiness of the surface layer and the toner releasability, and from a low temperature and low humidity environment of 10 ° C. × 10% RH, 32.5 ° C. × An object of the present invention is to provide a member for an electrophotographic apparatus capable of suppressing the environmental dependency of the toner charge amount in a use environment up to a high temperature and high humidity environment of 85% RH.

One embodiment of the present invention is a member for an electrophotographic apparatus having a surface layer,
The surface layer has a matrix polymer which forms a skeleton of the surface layer, and a surface modifier contained in the matrix polymer,
The surface modifier is
A first polymerized unit derived from a (meth) acrylate having a silicone group,
A second polymerized unit derived from a (meth) acrylate having a fluorine-containing group,
It is composed of a copolymer containing in its molecule a third polymerized unit derived from (meth) acrylate,
The (meth) acrylate in the third polymerized unit is 2-phenoxyethyl acrylate, lauryl acrylate, 2-hydroxypropyl acrylate, 2-ethylhexyl methacrylate, tetrahydrofurfuryl acrylate, phenoxy polyethylene glycol acrylate, tridecyl methacrylate, isodecyl methacrylate, One or more selected from isoamyl acrylate, caprolactone acrylate, isooctyl acrylate, isodecyl acrylate, and n-lauryl methacrylate,
The member for an electrophotographic apparatus, wherein the glass transition temperature Tg of the homopolymer of (meth) acrylate in the third polymerized unit is less than 10 ° C.

  When both a silicone-based surface modifier and a fluorine-based surface modifier are added to the surface layer, the two surface modifiers are poorly compatible with each other and are therefore difficult to mix with each other, and the surface modifier that appears on the surface layer Can be prioritized. That is, in this case, it is difficult to cause both surface modifiers to coexist on the surface layer, and only the effect of either one of the surface modifiers can be obtained. In some cases, the effects of each surface modifier may not be sufficiently obtained.

  On the other hand, the member for an electrophotographic apparatus contains a surface modifier made of a copolymer including the first and second polymerized units in the matrix polymer forming the skeleton of the surface layer. Therefore, the member for an electrophotographic apparatus can force the silicone group of the first polymerized unit and the fluorine-containing group of the second polymerized unit to be present on the surface layer. Therefore, the electrophotographic apparatus member can achieve both the slipperiness of the surface layer and the toner releasability.

  Furthermore, in the member for an electrophotographic apparatus, the copolymer constituting the surface modifier contains the third polymerized unit derived from (meth) acrylate in the molecule, and the (meth) acrylate in the third polymerized unit The glass transition temperature Tg of the homopolymer is below 10 ° C. Therefore, the member for an electrophotographic apparatus is unlikely to cause overcharging of the toner in a low temperature and low humidity environment of 10 ° C. × 10% RH. This is considered to be because, by adopting the above configuration, the molecular mobility of the surface layer material in contact with the toner is improved and the charge is easily moved even under the low temperature and low humidity environment. Be Therefore, the member for an electrophotographic apparatus described above has environmental dependency of toner charge amount in a use environment from a low temperature low humidity environment of 10 ° C. × 10% RH to a high temperature high humidity environment of 32.5 ° C. × 85% RH. It becomes possible to suppress.

FIG. 2 is a view schematically showing a member for an electrophotographic apparatus of Example 1; It is the figure which showed the II-II cross section in FIG. FIG. 7 is a view schematically showing a member for an electrophotographic apparatus of Example 2. It is the figure which showed the IV-IV cross section in FIG. It is explanatory drawing for demonstrating the measuring method of glass transition temperature Tg by differential scanning calorimetry (DSC).

  The member for an electrophotographic apparatus is used for an electrophotographic apparatus. Specific examples of the electrophotographic apparatus include an electrophotographic copying machine using a charged image, an image forming apparatus such as a printer, a facsimile machine, a multifunction machine, and an on-demand printing machine.

  Specifically, the electrophotographic apparatus member can be a developing member, a charging member, a transfer member, or a cleaning member. As the transfer member, specifically, an intermediate transfer member can be exemplified. The intermediate transfer member is for primarily transferring the toner image carried on the photosensitive member to the member, and secondarily transferring the toner image from the member to a transfer material such as paper.

  Specifically, the member for an electrophotographic apparatus is, for example, (1) a shaft, an elastic layer formed along the outer peripheral surface of the shaft, and a surface layer formed along the outer peripheral surface of the elastic layer (2) the shaft, and the surface layer formed along the outer periphery of the shaft, (3) the cylindrical base layer, and the surface layer formed along the outer peripheral surface of the base layer And (4) a structure having a cylindrical base layer, an elastic layer formed along the outer peripheral surface of the base layer, and a surface layer formed along the outer peripheral surface of the elastic layer, (5 ) A structure having a cylindrically formed surface layer, (6) A structure having a blade body, a surface layer covering a part or all of the surface of the blade body, and a holding portion for holding the blade body, (7) Blade shape It can be set as the structure etc. which have the surface layer formed in, and the holding part holding a surface layer. The configurations (1) and (2) are suitable as a developing member and a charging member, the configurations (3) to (5) are suitable as a transfer member, and the configurations (6) and (7) as a cleaning member.

  Here, the surface layer of the member for an electrophotographic apparatus has a matrix polymer forming a skeleton of the surface layer and a surface modifier contained in the matrix polymer.

  The matrix polymer plays an important role as a polymer component that forms the basic skeleton of the surface layer. The matrix polymer is not particularly limited as long as it can play the above-mentioned role, and various resins and rubbers (the rubber is also included in the elastomer, hereinafter abbreviated) can be used. These can be used alone or in combination of two or more, and an optimum material can be selected according to the application of the member for an electrophotographic apparatus.

  As said resin, various thermoplastic resins, the mixed polymer of a thermoplastic resin and a thermosetting resin, etc. can be used, for example. As the above-mentioned resin, specifically, for example, urethane resin; urethane silicone resin; urethane fluorine resin; polyamide resin; polyimide resin; (meth) acrylic resin; (meth) acrylic silicone resin; (meth) acrylic fluorine resin; Resin; Acetal resin; Alkyd resin; Polyester resin; Polyether resin; Carbonate resin; Phenolic resin; Epoxy resin; Polyvinyl alcohol; Polyvinyl pyrrolidone; Cellulose resin such as carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose; Polyacrylamide; Polyethylene glycol; Polypropylene glycol; Polyvinyl methyl ether; Polyamine; Polyethyleneimine; Casein, gelatin, starch and These copolymers; olefin resins such as copolymer resins with polyethylene, polypropylene and other olefin monomers; vinyl chloride resins; styrene resins such as polystyrene and acrylonitrile-styrene copolymer resins; vinyl chloride Polyvinyl acetate copolymer resins; polyvinyl acetal resins such as polyvinyl butyral resins and derivatives or modified products thereof; polyisobutylene; polytetrahydrofuran; polyaniline; acrylonitrile-butadiene-styrene copolymer (ABS resin); polyisoprene; Polydienes; Polysiloxanes such as polydimethylsiloxane; polysulfones; polyimines; polyacetic anhydrides; polyureas; polysulfides; polyphosphazens; polyketones; polyphenylenes B olefins and derivatives thereof; and the like can be exemplified a melamine resin. Among these, preferably, a urethane resin, a urethane silicone resin, a urethane fluorine resin or the like can be used from the viewpoint of improving the flexibility of the surface layer, the abrasion resistance and the like.

  Further, as the rubber, specifically, for example, acrylonitrile-butadiene rubber (NBR), butadiene rubber (BR), styrene-butadiene rubber (SBR), butyl rubber (IIR), chloroprene rubber (CR), hydrin rubber (ECO) , CO), isoprene rubber (IR), urethane rubber (U), silicone rubber (Q), ethylene-propylene-diene rubber (EPDM), natural rubber (NR), their modified products, and the like. Among these, acrylonitrile-butadiene rubber (NBR), urethane rubber (U), their modified products, and the like can be preferably used from the viewpoints of improving the flexibility of the surface layer, improving the abrasion resistance, and the like.

  On the other hand, the surface modifier contained in the matrix polymer plays an important role as a component present on the surface layer to modify the surface layer. The surface modifier comprises a first polymerized unit derived from a (meth) acrylate having a silicone group, a second polymerized unit derived from a (meth) acrylate having a fluorine-containing group, and a third derived from (meth) acrylate It is comprised from the copolymer which contains a polymerization unit in a molecule | numerator. In the present specification, (meth) acrylate is meant to include both acrylate and methacrylate. Likewise, (meth) acrylic is meant to encompass both acrylic and methacrylic (hereinafter omitted). Moreover, a "fluorine-containing group" means group containing a fluorine atom, and contains -F.

  The surface modifier can include one or more first polymerization units, one or more second polymerization units, and one or more third polymerization units. The surface modifier can be used alone or in combination of two or more. The surface modifier may be a random copolymer or a block copolymer. The surface modifier may preferably be a random copolymer. In this case, the silicone group of the first polymerized unit and the fluorine-containing group of the second polymerized unit are easily present at random on the surface layer surface. Therefore, there is an advantage that unevenness in slipperiness and toner releasability on the surface layer surface does not easily occur. In addition, since the third polymerized units are also easily present randomly on the surface layer surface, the environmental dependency of the toner charge amount in the use environment is easily suppressed. It is considered that this is because the molecular mobility on the surface of the surface where the toner comes in contact is uniformly improved, and the situation in which the charge tends to move is easily maintained. The surface modifier can have, for example, a linear, branched, etc. polymer structure.

  In the first polymerized unit, the (meth) acrylate having a silicone group can have one or more silicone groups. The silicone groups can specifically include, for example, a polydimethylsiloxane backbone composed of repeating dimethylsiloxane units. In this case, since the molecular weight of the silicone group can be increased by the polydimethylsiloxane skeleton having a relatively simple molecular structure, the slipperiness of the surface layer can be easily secured.

  The polydimethylsiloxane skeleton can have a weight average molecular weight of preferably 275 or more, more preferably 350 or more, and still more preferably 420 or more, from the viewpoint of improving the slipperiness of the surface layer. In addition, the polydimethylsiloxane skeleton preferably has a weight average molecular weight of 20000 or less, from the viewpoint of the reactivity during synthesis such as the reactivity of (meth) acrylic group, the solubility of the surface layer forming material in the solvent, etc. Preferably, it can be 15000 or less, and even more preferably 12000 or less. The weight average molecular weight can be measured by gel permeation chromatography (GPC).

  In the second polymerized unit, the (meth) acrylate having a fluorine-containing group can have one or more fluorine-containing groups. Specifically, the fluorine-containing group can be composed of, for example, a fluoroalkyl group, a fluoroalkyl alkylene oxide group, a fluoroalkenyl group, -F and the like.

  As the fluorine-containing group, a fluoroalkyl group, preferably a fluoroalkyl group having about 4 to 12 carbon atoms, is preferably used from the viewpoint of toner releasability, availability of a (meth) acrylate having a fluorine-containing group, and the like. Can. In the fluoroalkyl group, all hydrogen atoms of the alkyl group may be fluorinated, or a partially non-fluorinated site may be included. The former is perfluorinated and the latter is partially fluorinated. Particularly preferably, the fluoroalkyl group is a perfluoroalkyl group. Since the perfluoroalkyl group has high structural stability, it is difficult to keep the toner close to it, and it is easy to improve the toner releasability of the surface layer.

  Specific examples of the fluoroalkyl group include, for example, trifluoromethyl, trifluoroethyl, trifluorobutyl, pentafluoropropyl, perfluorobutyl, perfluorohexyl, perfluorooctyl, perfluorodecyl, perfluoro-3- Methyl butyl, perfluoro-5-methylhexyl, perfluoro-7-methyloctyl, octafluoropentyl, dodecafluoroheptyl, hexadecafluorononyl and the like can be exemplified.

  As the (meth) acrylate of the third polymerized unit, one having a glass transition temperature Tg of a homopolymer of the (meth) acrylate of 5 ° C. or less is used. In addition, the (meth) acrylate in a 3rd polymerization unit can be confirmed by analysis by TOF-SIMS (time-of-flight type secondary ion mass spectrometry) or thermal decomposition GC-MS analysis. Further, as the glass transition temperature Tg, a value measured by differential scanning calorimetry (DSC) is used. The details will be described later in experimental examples. The reason for defining the glass transition temperature Tg of the homopolymer of (meth) acrylate in the third polymerized unit is that it is difficult to measure the glass transition temperature of the (meth) acrylate monomer.

  When the glass transition temperature Tg is 10 ° C. or higher, the glass transition temperature Tg exists in a working environment from a low temperature low humidity environment of 10 ° C. × 10% RH to a high temperature high humidity environment of 32.5 ° C. × 85% RH Therefore, the state change of the surface of the surface layer is likely to occur, the toner is likely to be overcharged under a low temperature and low humidity environment, and it becomes difficult to suppress the environmental dependence of the toner charge amount in the above use environment. This is because, when the glass transition temperature Tg exists in the use environment, when the use environment temperature is lower than the Tg, the molecules of the surface layer material become difficult to move and the charge becomes difficult to escape, while the use is made more than the Tg When the environmental temperature is high, the molecules of the surface layer material move easily and the charge is easily released. As a result, the charge amount of the toner tends to be different depending on the use environment.

  The glass transition temperature Tg can be preferably 5 ° C. or less, more preferably 0 ° C. or less, still more preferably −10 ° C. or less, and still more preferably −20 ° C. or less. The lower limit of the glass transition temperature Tg is preferably −70 ° C. or more, more preferably from the viewpoint of the availability of the (meth) acrylate constituting the third polymerized unit and the balance with the toner releasability of the surface layer. Can be set to −68 ° C. or higher, more preferably −65 ° C. or higher.

(Meth) acrylate bets in the third polymerization unit is specifically 2 - phenoxyethyl acrylate (Tg of homopolymer: 5 ° C.), lauryl acrylate (Tg of homopolymer: -3 ° C.), 2-hydroxy Propyl acrylate (Tg of homopolymer: -7 ° C), 2-ethylhexyl methacrylate (Tg of homopolymer: -10 ° C), tetrahydrofurfuryl acrylate (Tg of homopolymer: -15 ° C), phenoxy polyethylene glycol acrylate (Tg of homopolymer: -25 ° C), Tridecyl methacrylate (Tg of homopolymer: -40 ° C), isodecyl methacrylate (Tg of homopolymer: -41 ° C), isoamyl acrylate (Tg of homopolymer : -45 ° C), caprolactone acrylate (Tg of homopolymer: -53 ° C), iso Octyl acrylate (Tg of homopolymer: -54 ° C.), isodecyl acrylate (Tg of homopolymer: -60 ° C.), and, n- lauryl methacrylate (Tg of homopolymer: -65 ° C.) is selected from One or two or more.

  The surface modifier may contain 0.01 to 60 mol% of the first polymerized unit and 0.01 to 60 mol% of the second polymerized unit. In this case, it is possible to ensure both the slipperiness of the surface layer and the toner releasability. The proportions of the first and second polymerization units are selected such that the total proportion including the first, second and other polymerization units is 100 mol%.

  The proportion of the first polymerization unit can be preferably 0.05 mol% or more, more preferably 0.1 mol% or more, and still more preferably 0.3 mol% or more from the viewpoint of obtaining sufficient slipperiness. The ratio of the first polymerization unit can be preferably 50 mol% or less, more preferably 35 mol% or less, and still more preferably 10 mol% or less from the viewpoint of solubility in the matrix polymer and the dilution solvent. The ratio of the second polymerized units can be preferably 0.05 mol% or more, more preferably 0.1 mol% or more, and still more preferably 0.3 mol% or more from the viewpoint of obtaining sufficient toner releasability. The ratio of the second polymerization unit can be preferably 50 mol% or less, more preferably 45 mol% or less, and still more preferably 30 mol% or less, from the viewpoint of solubility in the matrix polymer and the dilution solvent. In addition, the ratio of the said polymerization unit can be measured by thermal decomposition GC-MS analysis, NMR analysis, etc.

  The surface modifier can contain 10 to 70% by mass of the third polymerized unit. In this case, it is possible to reliably suppress the environmental dependency of the toner charge amount in the use environment. The ratio of the third polymerized unit is the ratio of the mass of the third polymerized unit to the mass of the entire surface modifier.

  The ratio of the third polymerization unit is preferably 13% by mass or more, more preferably 15% by mass or more, and further preferably from the viewpoint of making it difficult to cause overcharging of the toner in a low temperature and low humidity environment of 10 ° C. × 10% RH. Can be 20% by mass or more. The ratio of the third polymerized units can be preferably 68% by mass or less, more preferably 65% by mass or less, and still more preferably 63% by mass or less, from the viewpoint of balance with toner releasability and the like. In addition, the ratio of the said polymerization unit can be measured by thermal decomposition GC-MS analysis, NMR analysis, etc.

  The surface modifier preferably contains one or more polymerization units derived from other (meth) acrylates, in addition to the first polymerization unit, the second polymerization unit, and the third polymerization unit. Can.

  The surface modifier can include, for example, a fourth polymerized unit derived from a (meth) acrylate having a hydroxyl group in the molecule. In addition, a surface modifier can contain 1 type, or 2 or more types of 4th polymerization unit.

  In this case, the hydroxyl group of the fourth polymerized unit can improve the compatibility between the matrix polymer and the surface modifier. Therefore, in this case, there is an advantage that the surface modifying agent can easily be relatively uniformly present on the surface layer surface, and unevenness in the slipperiness and toner releasability on the surface layer surface hardly occurs. Especially when the matrix polymer contains a urethane bond, the above effect is enhanced.

  Specific examples of the (meth) acrylate having a hydroxyl group include 2-hydroxyethyl methacrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate and ethylene oxide modified (meth) Acrylate, hydroxyethyl (meth) acrylamide and the like can be exemplified.

  The said surface modifier can contain 0-95 mol% of a 4th polymerization unit. The proportion of the fourth polymerized unit can be preferably 10 mol% or more, more preferably 30 mol% or more, and still more preferably 50 mol% or more, from the viewpoint of easily ensuring the compatibility with the matrix polymer. Further, the proportion of the fourth polymerized unit is preferably 94 mol% or less, more preferably 93 mol%, from the viewpoint of securing the first, second and third polymerized units necessary for exhibiting the effect. Hereinafter, more preferably, it can be 90 mol% or less.

  The surface modifier can include in the molecule a fifth polymerized unit derived from a (meth) acrylate having a functional group different from the silicone group and the fluorine-containing group.

  In this case, in addition to the slipperiness and the toner releasability, it is possible to impart to the surface the function derived from the above-mentioned functional group, and it is possible to improve the functionality of the surface of the surface. The (meth) acrylate having a functional group different from the silicone group and the fluorine-containing group can include one or more functional groups. Also, in this case, the surface modifier can include one or more fifth polymerization units.

  Specifically, the functional group is, for example, one or more selected from an ester group, an ether group, an amide group, an amino group, a carboxylic acid group, a sulfonic acid group, and a phenyl group. Can.

  Among the above functional groups, for example, an amido group and an amino group can impart chargeability to the surface layer. Therefore, in this case, the surface layer can have the toner chargeability to the negatively charged toner in addition to the slipperiness and the toner releasability. Further, among the above functional groups, for example, a carboxylic acid group and a sulfonic acid group can also impart chargeability to the surface layer surface. Therefore, in this case, the surface layer surface can have toner chargeability to positively charged toner. Further, among the above functional groups, for example, an ether group, an ester group and the like have an effect of reducing the electric resistance.

  The surface modifier can also include in the molecule a sixth polymerized unit derived from (meth) acrylate in which an ion conductive agent such as a quaternary ammonium salt is incorporated in the molecule. In this case, it is advantageous to impart chargeability to the surface layer.

  More specifically, the surface modifier includes a first polymerized unit derived from a (meth) acrylate having a silicone group containing a polydimethylsiloxane skeleton and a (meth) acrylate having a fluoroalkyl group as a fluorine-containing group. It can be composed of a copolymer containing in its molecule a second polymerized unit derived from the above and a third polymerized unit derived from the (meth) acrylate described above whose homopolymer has a glass transition temperature Tg of 5 ° C. or less . In this case, coexistence of the slipperiness on the surface of the surface layer and the toner releasability, and the suppression of the environmental dependence of the toner charge amount in the use environment can be made more reliable.

  The surface modifier preferably has a glass transition temperature Tg of 5 ° C. or less of the surface modifier itself. In this case, it is possible to reliably suppress the environmental dependency of the toner charge amount in the use environment. The glass transition temperature Tg of the surface modifier is a value measured by differential scanning calorimetry (DSC). The details will be described later in experimental examples.

  The glass transition temperature Tg of the surface modifier is preferably 3 ° C. or less, more preferably 0 ° C. or less, still more preferably −2 ° C. or less, and still more preferably, from the viewpoint of making the above effects more reliable. It can be set to −5 ° C. or less. The lower limit of the glass transition temperature Tg of the surface modifier is preferably −70 ° C. or more, more preferably −68, from the viewpoint of the synthesis ease of the surface modifier, the balance with the toner releasability of the surface layer, etc. It can be made into ° C or more, more preferably -65 ° C or more.

  The surface layer can contain 0.01 to 20 parts by mass of a surface modifier with respect to 100 parts by mass of the matrix polymer. In this case, coexistence of the slipperiness on the surface of the surface layer and the toner releasability, and the suppression of the environmental dependence of the toner charge amount in the use environment can be ensured. Further, by adjusting the content of the surface modifier within the above range, it is possible to balance the slipperiness of the surface layer, the toner removability, and the suppression of the environmental dependence of the toner charge amount.

  The content of the surface modifier is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and still more preferably 0.5 parts by mass or more from the viewpoint of obtaining a sufficient effect by the addition, etc. can do. The content of the surface modifier is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and further preferably 10 from the viewpoint of compatibility with the matrix polymer, suppression of bleeding from the matrix polymer, cost and the like. It can be made into parts by mass or less, more preferably 7 parts by mass or less, still more preferably 5 parts by mass or less. In addition, after content extraction of the surface modifier, the extract is subjected to pyrolysis GC-MS analysis and NMR analysis to identify the structure of the above surface modifier, and then the entire material is pyrolyzed GC-MS It can measure by analyzing etc.

The surface layer may further contain a conductive agent in the matrix polymer. As a conductive agent, an electronic conductive agent, an ion conductive agent, a conductive polymer etc. can be illustrated, for example. Examples of the electron conductive agent can include carbon-based conductive materials, conductive metal oxides, metal nanoparticles, and the like. As a carbon type conductive material, carbon black, a carbon nanotube, a graphite etc. can be illustrated, for example. As the conductive metal oxide, for example, can be exemplified barium _{titanate, c-TiO 2, c-} ZnO, c-SnO 2 (c- means conductive.) And the like. As an ion conductive agent, a quaternary ammonium salt, a borate, a perchlorate, an ionic liquid etc. can be illustrated, for example. As a conductive polymer, polyaniline, polypyrrole, etc. can be illustrated, for example.

  In the surface layer, in the matrix polymer, if necessary, a reaction catalyst, a filler (inorganic type, organic type), a coupling agent, a dispersing agent, a leveling agent, a crosslinking agent, a crosslinking aid, a plasticizer, Various additives such as a flame retardant, an antifoaming agent, and particles for roughness formation can be contained. These can be used alone or in combination of two or more.

  The thickness of the surface layer is not particularly limited, and can be optimized in consideration of wear resistance, flexibility, and the like. The thickness of the surface layer can be, for example, about 1 to 100 μm.

  In addition, each structure mentioned above can be combined arbitrarily as needed, in order to acquire each effect mentioned above etc., etc. FIG.

  Hereinafter, the member for electrophotographic apparatus of an Example is demonstrated using drawing.

Example 1
The member for electrophotographic apparatus of Example 1 will be described with reference to FIG. 1 and FIG. As shown in FIGS. 1 and 2, the member R for an electrophotographic apparatus of this example is used for an electrophotographic apparatus. Specifically, the electrophotographic apparatus member R of this example is a roll-shaped conductive member incorporated in an electrophotographic image forming apparatus, and is used as a developing roll as a developing member or a charging roll as a charging member. Be

  The electrophotographic apparatus member R has a surface layer 1. Specifically, the electrophotographic apparatus member R of this embodiment further includes a shaft 2 and an elastic layer 3 formed of a conductive rubber elastic body formed along the outer peripheral surface of the shaft 2. ing. However, both end portions of the shaft 2 are in a state of protruding from both end surfaces of the elastic layer 3. The surface layer 1 is formed along the outer peripheral surface of the elastic layer 3. When the electrophotographic apparatus member R is used as a developing member, for example, a state in which a blade member for charging the toner by rubbing or forming a toner of a certain thickness is brought into contact with the surface layer 1 Can be used in When the electrophotographic apparatus member R is used as a charging member, for example, a blade member for removing the toner remaining on the surface after the fixing step of fixing the toner image on the sheet is the surface layer 1 surface. It can be used in a contact state.

  The surface layer 1 has a matrix polymer which forms a skeleton of the surface layer 1 and a surface modifier contained in the matrix polymer. In this example, the matrix polymer is specifically a mixed polymer of thermoplastic polyurethane and thermosetting polyurethane.

  The surface modifier comprises a first polymerized unit derived from a (meth) acrylate having a silicone group, a second polymerized unit derived from a (meth) acrylate having a fluorine-containing group, and a third derived from (meth) acrylate It is comprised from the copolymer which contains a polymerization unit in a molecule | numerator. The surface modifier is present more on the surface surface than inside the surface layer. The glass transition temperature Tg of the (meth) acrylate homopolymer in the third polymerized unit is less than 10 ° C. The surface layer 1 contains a surface modifier in the range of 0.01 to 20 parts by mass with respect to 100 parts by mass of the matrix polymer 11. In the present embodiment, an electron conductive agent and an ion conductive agent are added to the surface layer 1 in order to impart conductivity.

(Example 2)
An electrophotographic apparatus member B of Example 2 will be described with reference to FIGS. 3 and 4. As shown in FIGS. 3 and 4, the electrophotographic apparatus member B of this example is used in an electrophotographic apparatus. Specifically, the electrophotographic apparatus member B in this example is an endless belt-like conductive member incorporated in an electrophotographic image forming apparatus, and is used as an intermediate transfer belt as a transfer member.

  The electrophotographic apparatus member B has a surface layer 4. Specifically, the electrophotographic apparatus member B of this example further includes a cylindrical base layer 5 formed of a conductive resin material. The surface layer 4 is formed along the outer peripheral surface of the base layer 5.

  The surface layer 4 contains a surface modifier in the matrix polymer as in Example 1.

  Specifically, the matrix polymer is mainly composed of rubber. Therefore, the surface layer 4 has rubber elasticity. The surface modifier is the same as that of Example 1 and thus the description thereof is omitted. An ion conductive agent is added to the surface layer 4 to impart conductivity.

Hereinafter, a conductive roll sample as a member for an electrophotographic apparatus was produced and evaluated. The experimental example will be described.
(Experimental example)
<Synthesis of surface modifier>
The following materials were prepared for the synthesis of each surface modifier.
-1st polymerization unit-
-Acrylate modified silicone compound (manufactured by Shin-Etsu Chemical Co., Ltd., "X-22-174DX")
-Second polymerized unit-
2- (perfluorohexyl) ethyl acrylate (manufactured by Daikin Industries, "R-1620")
-Third polymerization unit-
-2-phenoxy ethyl acrylate (made by Sakai Kogyo Co., Ltd., "SR339A")
-Lauryl acrylate (manufactured by Kyoeisha Chemical Co., Ltd., "Light acrylate L-A")
-2-hydroxypropyl acrylate (manufactured by Kyoeisha Chemical Co., Ltd., "Light Ester OP-A (N)")
-2-ethylhexyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., "Light Ester EH")
-Tetrahydrofurfuryl acrylate (manufactured by Sakai Kogyo Co., Ltd., "SR 285")
-Phenoxy polyethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., Ltd., "Light acrylate P-200A")
・ Tridecyl methacrylate (manufactured by Sakai Industry Co., Ltd., “SR493D”)
・ Isodecyl methacrylate (manufactured by Sakai Industry Co., Ltd., "SR 242")
・ Isoamyl acrylate (manufactured by Kyoeisha Chemical, "Light acrylate IAA")
・ Caprolactone acrylate (made by Sakai Kogyo Co., Ltd., “SR 495”)
・ Isooctyl acrylate (made by Sakai Kogyo Co., Ltd., "SR440")
・ Isodecyl acrylate (made by Sakai Kogyo Co., Ltd., "SR 395")
・ N-lauryl methacrylate (manufactured by Sakai Kogyo Co., Ltd., “SR313”)
・ Butyl methacrylate (made by Tokyo Chemical Industry Co., Ltd.)
Stearyl acrylate (manufactured by Sakai Industry Co., Ltd., "SR 257")
・ Isobutyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., "Light Ester IB")
・ Methyl methacrylate (manufactured by Junsei Chemical Industry Co., Ltd.)
Among the (meth) acrylates to constitute the third polymerization unit described above, butyl methacrylate, stearyl acrylate, isobutyl methacrylate, and methyl methacrylate all have a Tg of 10 ° C. or more of a homopolymer to be described later. And for comparison.
-Fourth polymerized unit-
・ 2-hydroxyethyl methacrylate (made by Tokyo Chemical Industry Co., Ltd.)
-Polymerization initiator-
-Dimethyl 1,1'-azobis (1-cyclohexanecarboxylate) (manufactured by Wako Pure Chemical Industries, "VE-73")
-Solvent-
・ Methyl isobutyl ketone (MIBK)

-Synthesis of surface modifiers A to T-
Each surface modifier to be added to the surface matrix polymer was prepared as follows. That is, in a 100 mL reaction flask, (meth) acrylate for constituting the first polymerization unit and (meth) acrylate for constituting the second polymerization unit at the compounding ratio shown in Tables 1 to 5 And (meth) acrylate for constituting the third polymerization unit, and, if necessary, (meth) acrylate for constituting the fourth polymerization unit, a polymerization initiator, and an amount such that the total solid content is 55%. The solution for synthesis was charged and bubbling with nitrogen was performed for 5 minutes while stirring, and then polymerization was performed for 7 hours at a temperature of 80 ° C. of the inner liquid. Next, each solution containing 30% of each surface modifier by solid content was obtained by adding a predetermined amount of final dilution solvent shown in Tables 1 to 5.

  Hereinafter, the preparation amounts of the respective polymerization components in the synthesis of the respective surface modifiers and the detailed constitutions of the respective surface modifiers are collectively shown in Tables 1 to 5. The “mass ratio of the third polymerization unit” in Tables 1 to 5 is the mass ratio of the third polymerization unit in the solid content excluding the polymerization initiator and the solvent component in the solution containing the surface modifier ( Mass%).

  As shown in Tables 6 to 8 described later, 10 parts by mass of a thermoplastic polyurethane (Tosoh Corporation "Nipporan 5196"), and polyether diol (bifunctional polypropylene glycol) (ADEKA Corporation, "Adecapolyether P- 60 parts by mass), 30 parts by mass of polyisocyanate (hexamethylene diisocyanate trimer) (manufactured by Tosoh Corp., "Corronate HX"), and an electronic conductive agent (carbon black) (manufactured by Lion, "Ketchen EC 300 J") ) 3 parts by mass, 0.5 parts by mass of an ion conductive agent (tetramethyl ammonium chloride) (manufactured by Tokyo Chemical Industry Co., Ltd.), and each surface modifier of a predetermined type and a predetermined compounding amount shown in Tables 6 to 8 Were dissolved in MEK to a concentration of 20% by mass, and thoroughly mixed and dispersed using a triple roll. Thereby, each surface formation material used for preparation of conductive roll samples 1-17 and 1C-7C was prepared.

<Measurement of glass transition temperature Tg>
The glass transition temperature Tg of a homopolymer of (meth) acrylate (molecular weight of 10,000 or more) for constituting the third polymerization unit described above, and the glass transition temperature Tg of the synthesized surface modifier are as follows: It was measured.

  About 2 to 3 g of the target material was weighed in a container such as an aluminum cup or petri dish, and the solvent was removed by heat treatment at a temperature at which the contained solvent component was sufficiently vaporized to obtain only solid content. In this example, since MIBK, MEK or the like is mainly used as a solvent, heat treatment was performed at 120 ° C. for 60 minutes. Next, as a process before measurement by differential scanning calorimetry (DSC), the solid content was dried in a vacuum dryer under a normal temperature environment for 16 hours. Next, using a thermal analyzer (“Q200” manufactured by TA Instruments, Inc.), measurement temperature: −100 ° C. to 150 ° C., temperature rising rate: 20 ° C./min, environment: glass transition of sample under conditions of nitrogen atmosphere The temperature Tg was measured. As each sample, one in which about 10 mg of solid content subjected to the treatment before the above measurement was sealed in a closed pan was used. The glass transition temperature Tg is, as shown in FIG. 5, the abscissa: temperature (° C.), the ordinate: baseline BL of the curve drawn as heat flow (mW) and tangent V at the inflection point of the curve It calculated | required as temperature which shows a contact.

<Production of conductive roll sample>
A material for forming an elastic layer was prepared by mixing conductive silicone rubber (Shin-Etsu Chemical Co., Ltd., “X-34-264 A / B, mixing mass ratio A / B = 1/1”) with a static mixer. .

  As a shaft, a solid cylindrical iron rod with a diameter of 6 mm was prepared, and an adhesive was applied to the outer peripheral surface. After this shaft body was set in the hollow space of the roll forming mold, the above-prepared elastic layer forming material was poured into the hollow space, heated at 190 ° C. for 30 minutes to be cured, and demolded. Thus, a roll-shaped elastic layer (3 mm in thickness) made of conductive silicone rubber was formed along the outer peripheral surface of the shaft.

  Next, the surface layer forming materials prepared above were coated on the outer peripheral surface of the elastic layer by roll coating, and then cured by heating at 120 ° C. for 60 minutes to form a surface layer (thickness: 15 μm). Thereby, conductive roll samples 1 to 17 and 1C to 7C of a two-layer structure having a surface layer along the outer peripheral surface of the elastic layer were produced. The surface layer contains each surface modifier shown in Tables 6 to 8 as an additive in a mixed polymer of a thermoplastic polyurethane and a thermosetting polyurethane which forms a skeleton of the surface layer.

<Slipperiness>
Vertical load W50g by contacts (made of steel balls with a diameter of 3 mm) on the surface of a conductive roll sample fixed on the stage of a static / dynamic coefficient of friction measurement device (Kyowa Interface Science Co., Ltd., “Triboster 500”) Was added. In this state, the stage was moved horizontally by 1 cm at a moving speed of 7.5 mm / sec. From the frictional force F generated between the conductive roll sample and the contact, the initial dynamic friction coefficient μk (F / W) on the surface layer surface of the conductive roll sample was calculated.
The case where the dynamic friction coefficient μk was 1.5 or less was designated as “A”, as the slipperiness of the surface layer was excellent. When the dynamic friction coefficient μk is more than 1.5, the friction force on the surface of the surface layer is large, and it is considered as "C" because it is inferior in slipperiness.

<Toner separation property>
Each of the prepared surface layer forming materials was heated and cured under the same conditions as in the formation of the surface layer to prepare sheet-like test pieces (15 μm in thickness). Subsequently, the toner of the cartridge of a digital full color multifunction machine ("Fuji Centre-IV C2260" manufactured by Fuji Xerox Co., Ltd.) adopting an electrophotographic system was quantitatively sprayed on the surface of each test piece. Subsequently, each test piece to which this toner was dispersed was set in a centrifuge, and the remaining amount of toner after the addition of 12000 G was evaluated by image processing. When the residual area of the toner in the image is less than 30%, the toner exfoliation property is excellent as “A”, and when the residual area of the toner in the image is 30% or more and less than 50%, the toner exfoliation property is provided. As “B”, when the remaining area of the toner in the image is more than 50%, it is considered as “C” as having no toner separation property.

<Toner chargeability under low temperature and low humidity environment and high temperature and high humidity environment>
Each conductive roll sample is incorporated as a developing roll into a commercially available color printer ("Color Laser Jet Pro 400 Color M 451 dn" manufactured by Hewlett-Packard Japan) under a low temperature and low humidity environment of 10 ° C × 10% RH and 32.5 Solid images were output under a high temperature and high humidity environment of ° C × 85% RH. After output under each environment was finished, the toner on the surface was sucked and collected using a metal cylindrical tube and a cylindrical filter, and at that time, the charge amount Q (-μC) stored in the condenser through the metal cylindrical tube was suctioned and collected The total mass M (g) of the toner was measured. Then, the toner charge amount Q / M (−μC / g) per unit mass under each environment was calculated. Further, the difference between the toner charge amount Q / M (−μC / g) under the low temperature and low humidity environment and the toner charge amount Q / M (−μC / g) under the high temperature and high humidity environment It calculated | required as / M (-micro C / g).

  Hereinafter, detailed configurations and evaluation results of each conductive roll sample are collectively shown in Tables 6 to 8.

According to Tables 6 to 8, the following can be understood.
The conductive rolls of Samples 1C to 4C all use a surface modifier in which the glass transition temperature Tg of the homopolymer of (meth) acrylate in the third polymerized unit is less than 10 ° C. Therefore, in the conductive rolls of Samples 1C to 4C, the toner was easily overcharged under a low temperature and low humidity environment of 10 ° C. × 10% RH, and ΔQ / M became large. Therefore, the conductive rolls of Samples 1C to 4C have difficulty in suppressing the environmental dependence of the toner charge amount.

  The conductive roll of Sample 5C uses a fluorine-based surface modifier S which does not contain a first polymerized unit derived from a (meth) acrylate having a silicone group. Therefore, in the conductive roll of sample 5C, the dynamic friction coefficient of the surface layer surface was extremely large, and the slipperiness of the surface layer surface was inferior.

  The conductive roll of Sample 6C uses a silicone-based surface modifier T which does not contain a second polymerized unit derived from a (meth) acrylate having a fluorine-containing group. Therefore, in the conductive roll of sample 6C, the toner attached to the surface layer is difficult to separate, and the toner separation property is inferior.

  The conductive roll of sample 7C is an example in which the fluorine-based surface modifier S and the silicone-based surface modifier T are combined and contained in the matrix polymer. However, even if both surface modifiers are combined, the effects of the surface modifiers can not be sufficiently exhibited, and it can be said that it is difficult to achieve both the slipperiness of the surface layer and the toner releasability.

  On the other hand, the conductive roll of samples 1-17 contains the surface modifier which consists of a copolymer which contains a 1st polymeric unit and a 2nd polymeric unit in the matrix polymer which forms frame | skeleton of surface layer. Therefore, the conductive roll can force the silicone group of the first polymerized unit and the fluorine-containing group of the second polymerized unit to be present on the surface layer. Therefore, the conductive roll can achieve both the slipperiness of the surface layer and the toner releasability.

  Furthermore, in the conductive roll, the copolymer constituting the surface modifier contains the third polymerized unit derived from (meth) acrylate in the molecule, and the single weight of (meth) acrylate in the third polymerized unit The glass transition temperature Tg of the combination is less than 10 ° C. Therefore, the conductive roll is unlikely to cause overcharging of the toner in a low temperature and low humidity environment of 10 ° C. × 10% RH. This is considered to be because, by adopting the above configuration, the molecular mobility of the surface layer material in contact with the toner is improved and the charge is easily moved even under the low temperature and low humidity environment. Be Therefore, the conductive roll suppresses the environmental dependency of the toner charge amount in the use environment from a low temperature and low humidity environment of 10 ° C. × 10% RH to a high temperature and high humidity environment of 32.5 ° C. × 85% RH. I was able to.

  As mentioned above, although the Example of this invention was described in detail, this invention is not limited to the said Example, A various change is possible within the range which does not impair the meaning of this invention.

R, B Electrophotographic Equipment 1 Surface

Claims (6)

A member for an electrophotographic apparatus having a surface layer,
The surface layer has a matrix polymer which forms a skeleton of the surface layer, and a surface modifier contained in the matrix polymer,
The surface modifier is
A first polymerized unit derived from a (meth) acrylate having a silicone group,
A second polymerized unit derived from a (meth) acrylate having a fluorine-containing group,
It is composed of a copolymer containing in its molecule a third polymerized unit derived from (meth) acrylate,
The (meth) acrylate in the third polymerized unit is 2-phenoxyethyl acrylate, lauryl acrylate, 2-hydroxypropyl acrylate, 2-ethylhexyl methacrylate, tetrahydrofurfuryl acrylate, phenoxy polyethylene glycol acrylate, tridecyl methacrylate, isodecyl methacrylate, One or more selected from isoamyl acrylate, caprolactone acrylate, isooctyl acrylate, isodecyl acrylate, and n-lauryl methacrylate,
The member for electrophotographic equipment whose glass transition temperature Tg of the homopolymer of (meth) acrylate in the said 3rd polymerization unit is less than 10 degreeC.   The member for electrophotographic apparatus according to claim 1, wherein the glass transition temperature Tg of the surface modifier is 5 ° C or less.   The member for electrophotographic equipment according to claim 1, wherein the surface modifier contains 10 to 70% by mass of the third polymerized unit. The member for electrophotographic equipment according to any one of claims 1 to 3 , wherein the surface layer contains 0.01 to 20 parts by mass of the surface modifier with respect to 100 parts by mass of the matrix polymer. The member for electrophotographic equipment according to any one of claims 1 to 4 , wherein the surface modifier further contains, in the molecule, a fourth polymerized unit derived from a (meth) acrylate having a hydroxyl group. The member for an electrophotographic apparatus according to any one of claims 1 to 5 , which is a developing member, a charging member, a transfer member, or a cleaning member.

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