JP2017049282A - Member for electrophotographic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a member for electrophotographic apparatus which can achieve slidability of the surface of a surface layer and toner releasability, and can suppress environmental dependency of a toner charge amount in use environment from low-temperature and low-humidity environment of 10°C×10%RH and high-temperature and high-humidity environment of 32.5°C×85%RH.SOLUTION: A member R for electrophotographic apparatus has a matrix polymer, and a surface layer 1 having a surface modifier contained in the matrix polymer. The surface modifier is composed of a copolymer containing a first polymer unit derived from (meth)acrylate having a silicone group, a second polymer unit derived from (meth)acrylate having a fluorine-containing group, and a third polymer unit derived from (meth)acrylate, in the molecule. A glass transition temperature Tg of a single polymer of the (meth)acrylate in the third polymer unit is lower than 10°C.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a member for electrophotographic equipment.

  Conventionally, electrophotographic apparatuses such as electrophotographic copying machines, printers, and printing machines are known. Various members for electrophotographic equipment 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 in the electrophotographic equipment.

  As a member for an electrophotographic apparatus, for example, in Patent Document 1, a first polymer unit based on (meth) acrylate having a silicone group and a second polymer unit based on (meth) acrylate having a fluorine-containing group are contained in the molecule. A member for an electrophotographic apparatus is disclosed that includes a surface modifying agent composed of a copolymer containing the surface modifying agent.

International Publication No. WO2014 / 084225

  However, although conventional electrophotographic apparatus members can achieve both surface slipperiness and toner separation properties, there is room for improvement in the following respects. That is, in general, in an electrophotographic apparatus, by providing a constant potential difference between each member, the charged toner is moved to each member, and finally an image is formed on a medium such as paper. This type of electrophotographic apparatus is expected to be used in various environments. At that time, if the charge amount of the toner changes, the amount and state of movement of the toner to each member change, which adversely affects the formed image. The reason for the change in the toner charge amount may be the change in the molecular mobility of the surface layer material in each member in contact with the toner or the influence of humidity.

  In this regard, the conventional member for an electrophotographic apparatus causes overcharging of the toner in a low temperature and low humidity environment of 10 ° C. × 10% RH. As a result, the high temperature and high temperature of 32.5 ° C. × 85% RH from the low temperature and low humidity environment. There is a problem that it is difficult to suppress the environmental dependency of the toner charge amount in a use environment up to a wet environment.

  The present invention has been made in view of the background described above, and can achieve both the slipperiness of the surface of the surface layer and the toner releasability, and can be used in a low temperature and low humidity environment of 10 ° C. × 10% RH at 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 aspect of the present invention is a member for an electrophotographic apparatus having a surface layer,
The surface layer has a matrix polymer that forms a skeleton of the surface layer, and a surface modifier contained in the matrix polymer,
The surface modifier is
A first polymer unit derived from a (meth) acrylate having a silicone group;
A second polymer unit derived from a (meth) acrylate having a fluorine-containing group;
It is comprised from the copolymer which contains the 3rd polymerization unit derived from (meth) acrylate in a molecule | numerator,
The glass transition temperature Tg of the (meth) acrylate homopolymer in the third polymer unit is in a member for electrophotographic equipment having a temperature of less than 10 ° C.

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

  On the other hand, the member for an electrophotographic apparatus contains a surface modifier made of a copolymer containing a first polymer unit and a second polymer unit in a matrix polymer that forms the skeleton of the surface layer. Therefore, the member for an electrophotographic apparatus can force the silicone group of the first polymer unit and the fluorine-containing group of the second polymer unit to exist on the surface of the surface layer. Therefore, the member for an electrophotographic apparatus can achieve both the slipperiness of the surface layer surface and the toner separation property.

  Further, in the electrophotographic apparatus member, the copolymer constituting the surface modifier contains a third polymer unit derived from (meth) acrylate in the molecule, and the (meth) acrylate of the third polymer unit is The glass transition temperature Tg of the homopolymer is less than 10 ° C. Therefore, the above-mentioned member for an electrophotographic apparatus is unlikely to overcharge the toner in a low temperature and low humidity environment of 10 ° C. × 10% RH. This is considered to be because the molecular mobility of the surface layer material in contact with the toner is improved and the state in which the charge easily moves is maintained by adopting the above configuration even in the low temperature and low humidity environment. It is done. Therefore, the above-mentioned member for electrophotographic equipment has an environmental dependency of the toner charge amount in a 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. It becomes possible to suppress.

1 is a diagram schematically showing a member for electrophotographic equipment of Example 1. FIG. It is the figure which showed the II-II cross section in FIG. 6 is a diagram schematically showing a member for an electrophotographic apparatus of Example 2. FIG. It is the figure which showed the IV-IV cross section in FIG. It is explanatory drawing for demonstrating the measuring method of the 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 image forming apparatuses such as an electrophotographic copying machine using a charged image, 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 primary transfer of the toner image carried on the photosensitive member to the member, and then secondary transfer of the toner image from the member to a transfer material such as paper.

  Specifically, the electrophotographic apparatus member includes, 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) A structure having a shaft body and a surface layer formed along the outer periphery of the shaft body, (3) A base layer formed in a cylindrical shape, and a surface layer formed along the outer peripheral surface of the base layer (4) A configuration 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 ) Configuration having a surface layer formed in a cylindrical shape, (6) Configuration having a blade body, a surface layer covering a part or all of the blade body surface, and a holding portion for holding the blade body, (7) Blade shape And the like, and a structure having a holding portion for holding the surface layer. Configurations (1) and (2) are suitable as developing members and charging members, configurations (3) to (5) are suitable as transfer members, and configurations (6) and (7) are suitable as cleaning members.

  Here, the surface layer in the member for an electrophotographic apparatus has a matrix polymer that forms 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 role, and various types of resins and rubbers (rubbers include elastomers and are omitted below) 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 use of the member for an electrophotographic apparatus.

  Examples of the resin include various thermoplastic resins and mixed polymers of thermoplastic resins and thermosetting resins. Specific examples of the resin include urethane resin; urethane silicone resin; urethane fluororesin; polyamide resin; polyimide resin; (meth) acrylic resin; (meth) acrylic silicone resin; (meth) acrylic fluororesin; Resin; Acetal resin; Alkyd resin; Polyester resin; Polyether resin; Carbonate resin; Phenol resin; Epoxy resin; Polyvinyl alcohol; Polyvinylpyrrolidone; Cellulosic resin such as carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose; Polyethylene glycol; polypropylene glycol; polyvinyl methyl ether; polyamine; polyethylene imine; casein, gelatin, starch and These copolymers; Olefin resins such as copolymers of polyethylene, polypropylene and other olefin monomers; Vinyl chloride resins; Styrene resins such as polystyrene and acrylonitrile-styrene copolymer resins; Vinyl chloride Polyvinyl acetate copolymer resin; polyvinyl acetal resins such as polyvinyl butyral resin and derivatives or modified products thereof; polyisobutylene; polytetrahydrofuran; polyaniline; acrylonitrile-butadiene-styrene copolymer (ABS resin); polyisoprene; Polysiloxanes such as polydimethylsiloxane; polysulfones; polyimines; polyacetic anhydrides; polyureas; polysulfides; polyphosphazenes; polyketones; B olefins and derivatives thereof; and the like can be exemplified a melamine resin. Of these, urethane resin, urethane silicone resin, urethane fluororesin, and the like can be preferably used from the viewpoint of improving the flexibility of the surface layer and improving wear resistance.

  Specific examples of the rubber include acrylonitrile-butadiene rubber (NBR), butadiene rubber (BR), styrene-butadiene rubber (SBR), butyl rubber (IIR), chloroprene rubber (CR), and hydrin rubber (ECO). , CO), isoprene rubber (IR), urethane rubber (U), silicone rubber (Q), ethylene-propylene-diene rubber (EPDM), natural rubber (NR), modified products thereof, and the like. Of these, acrylonitrile-butadiene rubber (NBR), urethane rubber (U), modified products thereof and the like can be preferably used from the viewpoint of improving the flexibility of the surface layer and improving the wear resistance.

  On the other hand, the surface modifier contained in the matrix polymer plays an important role as a component that exists on the surface of the surface layer and modifies the surface of the surface layer. The surface modifier is a first polymer unit derived from (meth) acrylate having a silicone group, a second polymer unit derived from (meth) acrylate having a fluorine-containing group, and a third polymer unit derived from (meth) acrylate. It is comprised from the copolymer which contains a polymerization unit in a molecule | numerator. In this specification, (meth) acrylate is meant to include both acrylate and methacrylate. Similarly, (meth) acryl is meant to include both acryl and methacryl (hereinafter omitted). The “fluorine-containing group” refers to a group containing a fluorine atom, and includes —F.

  The surface modifier may include one or more kinds of first polymerized units, one kind or two or more kinds of second polymerized units, one kind or two or more kinds of third polymerized units. One or two or more surface modifiers can be used in combination. The surface modifier may be a random copolymer or a block copolymer. The surface modifier can preferably be a random copolymer. In this case, the silicone group of the first polymer unit and the fluorine-containing group of the second polymer unit are likely to be randomly present on the surface of the surface layer. Therefore, there is an advantage that unevenness of slipperiness and toner separation property on the surface of the surface layer is less likely to occur. In addition, since the third polymerization unit is likely to be present randomly on the surface of the surface layer, it is easy to suppress the environmental dependency of the toner charge amount in the use environment. This is presumably because the molecular mobility on the surface of the surface layer in contact with the toner is improved evenly, and it is easy to maintain a state in which charges easily move. The surface modifier can have, for example, a linear or branched polymer structure.

  In the first polymer unit, the (meth) acrylate having a silicone group can have one kind or two or more kinds of silicone groups. Specifically, the silicone group can include, for example, a polydimethylsiloxane skeleton composed of repeating dimethylsiloxane units. In this case, since the molecular weight of the silicone group can be increased by a polydimethylsiloxane skeleton having a relatively simple molecular structure, it becomes easy to ensure the slipperiness of the surface layer surface.

  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 of the surface layer. In addition, the polydimethylsiloxane skeleton has a weight average molecular weight of preferably 20000 or less, from the viewpoint of reactivity during synthesis such as reactivity of (meth) acrylic groups, solubility of the surface layer forming material in a solvent, and the like. Preferably it is 15000 or less, More preferably, it can be 12000 or less. The weight average molecular weight can be measured by gel permeation chromatography (GPC).

  In the second polymer unit, the (meth) acrylate having a fluorine-containing group can have one kind or two or more kinds of fluorine-containing groups. Specifically, the fluorine-containing group can be composed of, for example, a fluoroalkyl group, a fluoroalkylalkylene 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 do. In the fluoroalkyl group, all hydrogen atoms of the alkyl group may be fluorinated, or a part of the alkyl group that is not fluorinated may be included. The former is total fluorination and the latter is partial fluorination. Particularly preferably, the fluoroalkyl group may be a perfluoroalkyl group. This is because the perfluoroalkyl group has high structural stability, so that it is difficult to keep the toner close to the surface, and it is easy to improve the toner separation property on the surface of the surface layer.

  Specific examples of the fluoroalkyl group include trifluoromethyl, trifluoroethyl, trifluorobutyl, pentafluoropropyl, perfluorobutyl, perfluorohexyl, perfluorooctyl, perfluorodecyl, perfluoro-3- Examples thereof include methylbutyl, perfluoro-5-methylhexyl, perfluoro-7-methyloctyl, octafluoropentyl, dodecafluoroheptyl, hexadecafluorononyl and the like.

  As the (meth) acrylate of the third polymerization 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 the analysis by TOF-SIMS (time-of-flight type secondary ion mass spectrometry) or thermal decomposition GC-MS analysis. The glass transition temperature Tg is a value measured by differential scanning calorimetry (DSC). Details will be described later in an experimental example. The reason why the glass transition temperature Tg of the (meth) acrylate homopolymer in the third polymer unit is defined 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 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. As a result, the state of the surface of the surface layer is likely to change, the toner is likely to be overcharged in a low-temperature and low-humidity environment, and it becomes difficult to suppress the environmental dependency of the toner charge amount in the use environment. This is because when the glass transition temperature Tg exists in the above-mentioned use environment, when the use environment temperature is lower than the Tg, the molecules of the surface layer material are difficult to move and the charge is difficult to escape, but the use is more than the Tg. This is because when the environmental temperature is high, the molecules of the surface layer material easily move and the electric charge easily escapes. As a result, the charge amount of the toner is likely to vary depending on the use environment.

  The glass transition temperature Tg is preferably 5 ° C. or lower, more preferably 0 ° C. or lower, further preferably −10 ° C. or lower, and even more preferably −20 ° C. or lower. The lower limit of the glass transition temperature Tg is preferably −70 ° C. or more, more preferably from the viewpoint of the balance between the availability of the (meth) acrylate constituting the third polymerization unit and the toner separation on the surface of the surface layer. Can be −68 ° C. or higher, more preferably −65 ° C. or higher.

  Specific examples of the (meth) acrylate in the third polymer unit include, for example, 2-phenoxyethyl acrylate (Tg of homopolymer: 5 ° C.), lauryl acrylate (Tg of homopolymer: −3 ° C.), 2 -Hydroxypropyl acrylate (Tg of homopolymer: -7 ° C), 2-ethylhexyl methacrylate (Tg of homopolymer: -10 ° C), tetrahydrofurfuryl acrylate (Tg of homopolymer: -15 ° C), phenoxypolyethylene Glycol acrylate (Tg of homopolymer: −25 ° C.), tridecyl methacrylate (Tg of homopolymer: −40 ° C.), isodecyl methacrylate (Tg of homopolymer: −41 ° C.), isoamyl acrylate (homopolymer) Tg of -45 ° C), caprolactone acrylate (Tg of homopolymer:- 3 ° C), isooctyl acrylate (Tg of homopolymer: -54 ° C), isodecyl acrylate (Tg of homopolymer: -60 ° C), and n-lauryl methacrylate (Tg of homopolymer: -65 ° C) ) And the like. These can be used alone or in combination of two or more.

  The surface modifier may include 0.01 to 60 mol% of the first polymerization unit and 0.01 to 60 mol% of the second polymerization unit. In this case, both the slipperiness of the surface layer surface and the toner separation property can be ensured. The ratio of the first polymerization unit and the second polymerization unit is selected so that the total ratio including the first polymerization unit, the second polymerization unit, and other polymerization units is 100 mol%.

  The proportion of the first polymer unit is preferably 0.05 mol% or more, more preferably 0.1 mol% or more, and further preferably 0.3 mol% or more, from the viewpoint of obtaining sufficient slipperiness. Further, the ratio of the first polymer unit is 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 a matrix polymer or a diluent solvent. The proportion of the second polymerization unit is preferably 0.05 mol% or more, more preferably 0.1 mol% or more, and further preferably 0.3 mol% or more, from the viewpoint of obtaining sufficient toner releasability. Further, the proportion of the second polymerization unit is preferably 50 mol% or less, more preferably 45 mol% or less, and further preferably 30 mol% or less, from the viewpoint of solubility in a matrix polymer or a diluent solvent. In addition, the ratio of the said polymer unit can be measured by pyrolysis GC-MS analysis, NMR analysis, etc.

  The surface modifier may contain 10 to 70% by mass of the third polymerization unit. In this case, it is possible to reliably suppress the environmental dependency of the toner charge amount in the use environment. In addition, the ratio of a 3rd polymerization unit is a ratio of the mass of a 3rd polymerization unit with respect to the mass of the whole surface modifier.

  The proportion of the third polymer unit is preferably 13% by mass or more, more preferably 15% by mass or more, and still more 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 mass% or more. In addition, the proportion of the third polymerization unit is 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. In addition, the ratio of the said polymer unit can be measured by pyrolysis GC-MS analysis, NMR analysis, etc.

  In addition to the first polymer unit, the second polymer unit, and the third polymer unit, the surface modifier contains one or more polymer units derived from other (meth) acrylates as necessary. Can do.

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

  In this case, the compatibility between the matrix polymer and the surface modifier can be improved by the hydroxyl group of the fourth polymer unit. Therefore, in this case, there is an advantage that the surface modifier is likely to be present relatively uniformly on the surface of the surface layer, and unevenness of slipperiness and toner separation property on the surface of the surface layer is less likely to occur. In particular, when the matrix polymer includes a urethane bond, the above effect is increased.

  Specific examples of the (meth) acrylate having a hydroxyl group include, for example, 2-hydroxyethyl methacrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and ethylene oxide modified (meth). Examples thereof include acrylate and hydroxyethyl (meth) acrylamide.

  The surface modifier may include 0 to 95 mol% of the fourth polymerization unit. The proportion of the fourth polymer unit is preferably 10 mol% or more, more preferably 30 mol% or more, and even more preferably 50 mol% or more, from the viewpoint of easily ensuring compatibility with the matrix polymer. The proportion of the fourth polymer unit is preferably 94 mol% or less, more preferably 93 mol%, from the viewpoint of securing the first polymer unit, the second polymer unit and the third polymer unit necessary for the expression of the effect. Hereinafter, it can be more preferably 90 mol% or less.

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

  In this case, in addition to slipperiness and toner releasability, a function attributable to the functional group can be imparted to the surface layer surface, and the functionality of the surface layer surface can be improved. The (meth) acrylate having a functional group different from the silicone group and the fluorine-containing group can contain one type or two or more types of functional groups. Further, in this case, the surface modifier can include one kind or two or more kinds of fifth polymer 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 do.

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

  The surface modifier may also contain in the molecule a sixth polymer unit derived from (meth) acrylate in which an ionic conductive agent such as a quaternary ammonium salt is incorporated in the molecule. In this case, it is advantageous for imparting chargeability to the surface layer.

  More specifically, the surface modifier is a first polymer 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 comprised from the copolymer which contains in the molecule | numerator the 2nd polymerization unit derived from, and the 3rd polymerization unit derived from the (meth) acrylate mentioned above whose glass transition temperature Tg of a homopolymer is 5 degrees C or less. . In this case, it is possible to further ensure the compatibility between the slipperiness of the surface of the surface layer and the toner releasability, and the suppression of the environmental dependency of the toner charge amount in the use environment.

  The surface modifier may have a glass transition temperature Tg of 5 ° C. or lower. In this case, it is possible to reliably suppress the environmental dependency of the toner charge amount in the use environment. As the glass transition temperature Tg of the surface modifier, a value measured by differential scanning calorimetry (DSC) is used. Details will be described later in an experimental example.

  The glass transition temperature Tg of the surface modifier is preferably 3 ° C. or lower, more preferably 0 ° C. or lower, further preferably −2 ° C. or lower, even more preferably, from the viewpoint of ensuring the above effect. It can be -5 degrees 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 ease of synthesis of the surface modifier and the balance with the toner separation property on the surface layer surface. C. or higher, more preferably −65 ° C. or higher.

  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, it is possible to ensure both the slipping property of the surface layer surface and the toner separation property, and the suppression of the environmental dependency of the toner charge amount in the use environment. In addition, by adjusting the content of the surface modifier within the above range, it is possible to achieve a balance between the slipperiness of the surface layer surface, the toner separation property, and the suppression of the environmental dependency 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 further preferably 0.5 parts by mass or more, from the viewpoint of obtaining a sufficient effect by addition. can do. In addition, the content of the surface modifier is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and still more preferably 10 from the viewpoints of compatibility with the matrix polymer, suppression of bleeding from the matrix polymer, cost, and the like. The amount can be not more than part by mass, more preferably not more than 7 parts by mass, and still more preferably not more than 5 parts by mass. The content of the surface modifier is determined by extracting the extract with a solvent, pyrolyzing GC-MS analysis and NMR analysis of the extract, specifying the structure of the surface modifier, and then pyrolyzing the entire material. It can be measured by analyzing.

The surface layer can contain a conductive agent in addition to the matrix polymer. Examples of the conductive agent include an electronic conductive agent, an ionic conductive agent, and a conductive polymer. Examples of the electronic conductive agent include carbon-based conductive materials, conductive metal oxides, and metal nanoparticles. Examples of the carbon-based conductive material include carbon black, carbon nanotube, and graphite. 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. Examples of the ionic conductive agent include quaternary ammonium salts, borates, perchlorates, ionic liquids, and the like. Examples of the conductive polymer include polyaniline and polypyrrole.

  In addition to the matrix polymer, the surface layer can be used in addition to the reaction catalyst, filler (inorganic or organic), coupling agent, dispersant, leveling agent, crosslinking agent, crosslinking aid, plasticizer, Various additives such as a flame retardant, an antifoaming agent, and particles for forming roughness 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 set to an optimum thickness 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 arbitrarily combined as needed, in order to acquire each effect etc. which were mentioned above.

  Hereinafter, the member for an electrophotographic apparatus of the example will be described with reference to the drawings.

Example 1
The electrophotographic apparatus member of Example 1 will be described with reference to FIGS. 1 and 2. As shown in FIGS. 1 and 2, the electrophotographic apparatus member R of this example is used for an electrophotographic apparatus. The electrophotographic apparatus member R in this example is specifically a roll-like 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. It is done.

  The electrophotographic apparatus member R has a surface layer 1. Specifically, the member R for electrophotographic equipment of this example further includes a shaft body 2 and an elastic layer 3 made of a conductive rubber elastic body formed along the outer peripheral surface of the shaft body 2. ing. However, both end portions of the shaft body 2 are projected from both end surfaces of the elastic layer 3. A 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 toner by rubbing or forming a toner having a certain thickness is in contact with the surface of the surface layer 1 Can be used in. In addition, when the electrophotographic apparatus member R is used as a charging member, for example, a blade member for removing toner remaining on the surface after a fixing step for fixing a toner image on a sheet is provided on the surface of the surface layer 1. Can be used in contact.

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

(Example 2)
The electrophotographic apparatus member B of Example 2 will be described with reference to FIGS. As shown in FIGS. 3 and 4, the electrophotographic apparatus member B of this example is used for an electrophotographic apparatus. Specifically, the electrophotographic apparatus member B of 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. A surface layer 4 is formed along the outer peripheral surface of the base layer 5.

  Similar to Example 1, the surface layer 4 contains a surface modifier in the matrix polymer.

  Specifically, the matrix polymer contains rubber as a main component. Therefore, the surface layer 4 has rubber elasticity. Since the surface modifier has the same configuration as that of Example 1, the description thereof is omitted. Note that an ionic conductive agent is added to the surface layer 4 in order to impart conductivity.

Hereinafter, a conductive roll sample as a member for an electrophotographic apparatus was produced and evaluated. An experimental example will be described.
(Experimental example)
<Synthesis of surface modifier>
In synthesizing each surface modifier, the following materials were prepared.
-First polymer unit-
Acrylate-modified silicone compound (“X-22-174DX” manufactured by Shin-Etsu Chemical Co., Ltd.)
-Second polymerization unit-
2- (Perfluorohexyl) ethyl acrylate (Daikin Industries, “R-1620”)
-Third polymer unit-
・ 2-phenoxyethyl acrylate (manufactured by Sakai Kogyo Co., Ltd., “SR339A”)
・ Lauryl acrylate (manufactured by Kyoeisha Chemical Co., “Light acrylate LA”)
2-hydroxypropyl acrylate (manufactured by Kyoeisha Chemical Co., Ltd., “Light Ester OP-A (N)”)
2-ethylhexyl methacrylate (Kyoeisha Chemical Co., Ltd., “Light Ester EH”)
Tetrahydrofurfuryl acrylate (manufactured by Sakai Industries, “SR285”)
・ Phenoxypolyethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., Ltd., “Light acrylate P-200A”)
・ Tridecyl methacrylate (manufactured by Sakai Kogyo Co., Ltd., “SR493D”)
・ Isodecyl methacrylate (manufactured by Sakai Kogyo Co., Ltd., “SR242”)
・ Isoamyl acrylate (manufactured by Kyoeisha Chemical Co., Ltd., “Light acrylate IAA”)
・ Caprolactone acrylate (manufactured by Sakai Kogyo Co., Ltd., “SR495”)
・ Isooctyl acrylate (manufactured by Sakai Kogyo Co., Ltd., “SR440”)
・ Isodecyl acrylate (manufactured by Sakai Kogyo Co., Ltd., “SR395”)
N-lauryl methacrylate (manufactured by Sakai Kogyo Co., Ltd., “SR313”)
・ Butyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.)
・ Stearyl acrylate (“SR257” manufactured by Sakai Kogyo Co., Ltd.)
・ Isobutyl methacrylate (Kyoeisha Chemical Co., Ltd., “Light Ester IB”)
・ Methyl methacrylate (made by Pure Chemical Industries)
In addition, among the (meth) acrylates for constituting the above-mentioned third polymerization unit, butyl methacrylate, stearyl acrylate, isobutyl methacrylate, and methyl methacrylate all have a Tg of a homopolymer described later of 10 ° C. or higher. And for comparison.
-Fourth polymer unit-
・ 2-hydroxyethyl methacrylate (manufactured 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 layer matrix polymer was prepared as follows. That is, in a 100 mL reaction flask, (meth) acrylate for constituting the first polymer unit and (meth) acrylate for constituting the second polymer unit at the blending ratios shown in Tables 1 to 5 , (Meth) acrylate for constituting the third polymer unit, (meth) acrylate for constituting the fourth polymer unit, if necessary, polymerization initiator, and an amount of the total solid content of 55% And a bubbling with nitrogen for 5 minutes with stirring, followed by polymerization at an internal liquid temperature of 80 ° C. for 7 hours. Subsequently, each solution containing 30% of each surface modifier in solid content was obtained by adding a predetermined amount of the final dilution solvent shown in Tables 1 to 5.

  Hereinafter, the charged amounts of the respective polymerization components in the synthesis of each surface modifier and the detailed configuration of each surface modifier 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 below, 10 parts by mass of thermoplastic polyurethane (manufactured by Tosoh Corporation, “Nipporan 5196”) and polyether diol (bifunctional polypropylene glycol) (manufactured by ADEKA, “ADEKA Polyether P- 1000 "), 30 parts by mass of polyisocyanate (hexamethylene diisocyanate trimer) (manufactured by Tosoh Corporation," Coronate HX "), and electronic conductive agent (carbon black) (manufactured by Lion Corporation," Ketjen EC300J " ) 3 parts by mass, 0.5 parts by mass of an ionic conductive agent (tetramethylammonium chloride) (manufactured by Tokyo Chemical Industry Co., Ltd.), and each surface modifier of a predetermined type and a predetermined blending amount shown in Tables 6 to 8. Were dissolved in MEK so as to have a concentration of 20% by mass, and sufficiently mixed and dispersed using a three roll. Thereby, each surface layer forming material used for preparation of the conductive roll samples 1-17 and 1C-7C was prepared.

<Measurement of glass transition temperature Tg>
The glass transition temperature Tg of the (meth) acrylate homopolymer (molecular weight 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 into a container such as an aluminum cup or a petri dish, and the solvent was removed by heat treatment at a temperature at which the solvent component contained was sufficiently vaporized, so that only the solid content was obtained. In this example, since MIBK, MEK, etc. are mainly used as a solvent, it heat-processed at 120 degreeC for 60 minutes. Next, as a process before measurement by differential scanning calorimetry (DSC), the solid content was dried for 16 hours in a vacuum dryer under a normal temperature environment. Next, using a thermal analyzer (TA Instruments, “Q200”), the glass transition of the sample under the conditions of measurement temperature: −100 ° C. to 150 ° C., heating rate: 20 ° C./min, environment: nitrogen atmosphere The temperature Tg was measured. In addition, each sample used what enclosed about 10 mg of solid content which performed the process before the said measurement in the airtight type bread | pan. As shown in FIG. 5, the glass transition temperature Tg is a curve between the base line BL of the curve drawn as the horizontal axis: temperature (° C.) and the vertical axis: heat flow (mW), and the tangent V at the inflection point of the curve. It calculated | required as the temperature which shows a contact.

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

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

  Next, each of the prepared surface layer forming materials was applied to the outer peripheral surface of the elastic layer by a roll coating method, and then heated and cured 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 having 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 thermoplastic polyurethane and thermosetting polyurethane that forms the skeleton of the surface layer.

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

<Toner separation>
Each of the prepared surface layer forming materials was heated and cured under the same conditions as those for forming the surface layer, to prepare sheet-like test pieces (thickness 15 μm). Next, the toner of the cartridge of a digital full-color multifunction peripheral (“Fuji Xerox Co., Ltd.,“ DocuCentre-IV C2260 ”) employing an electrophotographic method was quantitatively dispersed on the surface of each test piece. Next, each test piece sprayed with this toner was set in a centrifuge, and the remaining amount of toner after adding 12000 G was evaluated by image processing. If the remaining area of the toner in the image is less than 30%, the toner separation property is “A”. If the remaining area of the toner in the image is 30% or more and less than 50%, the toner separation property is obtained. "B", and the case where the remaining area of the toner in the image was more than 50% was designated as "C" as having no toner separation property.

<Toner chargeability in 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 M451dn” 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 in a high-temperature and high-humidity environment of ° C x 85% RH. After the output under each environment, the toner on the surface layer was collected by suction using a metal cylindrical tube and a cylindrical filter. At that time, the charge amount Q (-μC) stored in the capacitor was collected by suction through the metal cylindrical tube. 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) in the low temperature and low humidity environment and the toner charge amount Q / M (−μC / g) in the high temperature and high humidity environment is represented by the change amount ΔQ of the toner charge amount. / M (−μC / g).

  Hereafter, the detailed structure and evaluation result of each electroconductive roll sample are put together in Table 6-Table 8, and are shown.

According to Tables 6 to 8, the following can be understood.
Each of the conductive rolls of Samples 1C to 4C uses a surface modifier having a glass transition temperature Tg of a (meth) acrylate homopolymer in the third polymerization unit of less than 10 ° C. Therefore, in the conductive rolls of Samples 1C to 4C, toner was easily overcharged in a low temperature and low humidity environment of 10 ° C. × 10% RH, and ΔQ / M was increased. Therefore, it was difficult for the conductive rolls of Samples 1C to 4C to suppress the environmental dependence of the toner charge amount.

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

  The conductive roll of Sample 6C uses a silicone-based surface modifier T that does not contain a second polymerization 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 of the surface layer was difficult to separate and the toner separating property was 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 a matrix polymer. However, even when both surface modifiers are combined, the effects of the respective surface modifiers cannot be sufficiently exhibited, and it can be said that it is difficult to achieve both slipperiness on the surface of the surface layer and toner separation properties.

  On the other hand, the conductive rolls of Samples 1 to 17 contain a surface modifier made of a copolymer containing the first polymer unit and the second polymer unit in the matrix polymer that forms the skeleton of the surface layer. Therefore, the conductive roll can force the silicone group of the first polymer unit and the fluorine-containing group of the second polymer unit to exist on the surface of the surface layer. Therefore, the conductive roll can achieve both slipperiness on the surface of the surface layer and toner separation.

  Further, in the conductive roll, the copolymer constituting the surface modifier contains a third polymer unit derived from (meth) acrylate in the molecule, and the single weight of (meth) acrylate in the third polymer unit is The glass transition temperature Tg of the coalescence is less than 10 ° C. Therefore, the conductive roll is unlikely to overcharge the toner in a low temperature and low humidity environment of 10 ° C. × 10% RH. This is considered to be because the molecular mobility of the surface layer material in contact with the toner is improved and the state in which the charge easily moves is maintained by adopting the above configuration even in the low temperature and low humidity environment. It is done. Therefore, the conductive roll suppresses the environmental dependency of the toner charge amount in a 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 members 1 Surface layer

Claims (7)

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

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