JP2018072583A - Endless belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endless belt in which an electric characteristic of a base layer can be stabilized for a long period of time.SOLUTION: An endless belt 1 is used for an electrophotographic apparatus. The endless belt 1 comprises a cylindrical base layer 10. The base layer 10 includes a base layer polymer 101 and an ion conductive polymer 102 and the ion conductive polymer 102 is unevenly distributed on the outer peripheral surface side of the base layer. The ion conductive polymer 102 has a polymerization unit derived from a modified monomer or a modified oligomer that is modified with an organic compound having a cationic site and an anion site.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an endless belt.

  Conventionally, electrophotographic apparatuses such as electrophotographic copying machines, printers, and printing machines are known. In these electrophotographic apparatuses, for example, endless belts such as an intermediate transfer belt, a fixing belt, and a conveyance belt are incorporated. This type of endless belt has a cylindrical base layer. A conductive agent is added to the base layer for the purpose of imparting conductivity. As the conductive agent, electronic conductive agents such as carbon black and ionic conductive agents such as quaternary ammonium salts are known.

  Prior Patent Document 1 discloses a transfer material for the purpose of stabilizing electronic conductivity in a resin by using two types of carbon black (CB) having different particle diameters in combination with a thermoplastic resin. An endless belt for use in conveyance is disclosed.

  Prior Patent Document 2 includes at least a thermoplastic resin having a vinylidene difluoride structure and a conductive filler, and is selected from the group consisting of a conductive polymer material made of a wax material and an ionic conductive material. An intermediate transfer belt containing the resulting material on a smooth surface is disclosed.

Japanese Patent No. 4764052 JP 2016-126063 A

  However, the prior art has problems in the following points. That is, the endless belt used in the electrophotographic apparatus receives a high load external force such as rotating in a tensioned state or interfering with other members. Therefore, the base layer of the endless belt is required to have a strength that can withstand the external force as described above, and generally a hard polymer material is often used. However, since it is difficult for ions to move in a hard polymer material, it is difficult to use an ionic conductive agent, and an electronic conductive agent is usually added. However, in a base layer formed by adding an electronic conductive agent to a hard polymer material, the electronic conductive path made of the electronic conductive agent is broken or the polymer is microscopically broken due to deformation caused by an external force applied over a long period of time. As a result, the electrical characteristics change at the destruction site, and image defects are likely to occur when the electrophotographic apparatus is used for a long time.

  The present invention has been made in view of the above background, and an object of the present invention is to provide an endless belt capable of stabilizing the electrical characteristics of a base layer over a long period of time.

One aspect of the present invention is an endless belt for electrophotographic equipment,
Has a cylindrical base layer,
The base layer includes a base layer polymer and an ion conductive polymer, and the ion conductive polymer is unevenly distributed on the outer peripheral surface side of the base layer,
The ion conductive polymer is in an endless belt having a polymer unit derived from a modified monomer or modified oligomer modified with an organic compound having a cation moiety and an anion moiety.

  The endless belt has the above configuration. Therefore, regardless of the material of the base layer polymer, the endless belt can have the hardness on the outer peripheral surface side of the base layer smaller than the inside of the base layer by the ion conductive polymer. Further, the endless belt can exhibit ionic conduction by the ionic conductive polymer on the outer peripheral surface side of the base layer having a low hardness. Therefore, the endless belt can stabilize the surface resistance on the outer peripheral surface side of the base layer even when used in a state where an external force is applied over a long period of time. Therefore, the endless belt can stabilize the electric characteristics of the base layer over a long period of time. Therefore, by incorporating the endless belt into an electrophotographic apparatus, it is possible to obtain an electrophotographic apparatus that can easily suppress image defects caused by belt deformation due to external force.

It is explanatory drawing which showed the endless belt of Example 1 typically. It is II-II sectional drawing of FIG. It is explanatory drawing which expanded and showed typically a part of II-II sectional drawing of FIG.

  The endless belt (seamless belt) is used in electrophotographic equipment. 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 endless belt can be used as an intermediate transfer belt, for example. The intermediate transfer belt is an image forming apparatus for primarily transferring the toner image carried on the latent image carrier onto the belt surface and then secondarily transferring the toner image from the belt surface to a print medium such as paper. It is an endless belt that is built in. In this case, since the electrical characteristics of the base layer can be stabilized over a long period of time, an intermediate transfer belt is obtained in which the transferability of the toner is difficult to change and image defects due to poor toner transfer are unlikely to occur even during durability.

  Specifically, the endless belt can be used as, for example, a fixing belt. The fixing belt is an endless belt used for forming an image by melting and fixing the toner transferred to a transfer material (paper) by heating. In this case, since the electric characteristics of the base layer can be stabilized over a long period of time, it is possible to obtain a fixing belt that is less likely to cause image defects due to poor fixing at the time of toner melting and fixing even during durability.

  Specifically, the endless belt can also be used as a transport belt, for example. The conveyance belt is an endless belt that is used to directly place and convey paper on the belt, and to transfer the toner directly to the paper from each color photosensitive drum. In this case, since the electrical characteristics of the base layer can be stabilized over a long period of time, it is possible to obtain a conveyor belt that is less likely to cause image defects due to poor toner transfer even during durability.

  The endless belt has a base layer having a cylindrical shape. The base layer includes a base layer polymer and an ion conductive polymer. The base polymer is a polymer that forms the base layer. Examples of the base layer polymer include polyamideimide, polyimide, polycarbonate, polyethersulfone, polyarylate, and acrylic resin. These can be used alone or in combination of two or more. The base polymer is preferably polyamideimide or polyimide. According to this configuration, the base layer hardness is increased by increasing the elastic modulus of the base layer, and it is easy to secure a belt strength that can withstand a high load of external force, and it is possible to stabilize the electrical characteristics of the base layer by the ion conductive polymer. A possible endless belt is obtained.

  The ion conductive polymer has polymerized units derived from a modified monomer or modified oligomer modified with an organic compound having a cation moiety and an anion moiety (hereinafter, this may be referred to as “first polymerized unit”). It is a polymer.

  In the ion conductive polymer, specific examples of the cation moiety include, for example, quaternary ammonium cation, imidazolium cation, pyridazinium cation, pyridinium cation, phosphonium cation, thiazolium cation, piperidinium cation. Pyrrolidinium cation, triazolium cation, pyridazinium cation, sulfonium cation and the like. Specific examples of anion sites include chlorine anion, perchlorate anion, sulfate anion, heavy carbon anion, bromine anion, thiocyanate anion, bis (fluoroalkanesulfonyl) imide anion, bis (fluorosulfonyl). Examples thereof include an imide anion, a trifluoroacetate anion, a tetrafluoroborate anion, and a hexafluorophosphate anion. In addition, each cation site | part and each anion site | part mentioned above can be combined arbitrarily. The ion conductive polymer may be modified with one or more organic compounds.

  In the ion conductive polymer, the organic compound may be a quaternary ammonium salt. The quaternary ammonium salt has a cation moiety composed of a quaternary ammonium cation. According to this configuration, the quaternary ammonium salt changes the compatibility with the base layer polymer because the modification of the hydrogen moiety to alkyl or the like is easy, and the ion conductive polymer on the outer peripheral surface of the base layer is changed. There is an advantage that the orientation can be easily adjusted. More specifically, examples of the quaternary ammonium cation include a cation represented by the following formula 1.

However, in the above formula 1, R1 is, H or a _CH 3, X is, NH, or, O or,, OR'NHCOO (R 'is an alkyl group having 1 to 10 carbon atoms, an aralkyl group, or aryl Group), R2 is an alkyl group having 1 to 10 carbon atoms, an aralkyl group (for example, benzyl group, phenethyl group, etc.), or an aryl group (for example, phenyl group, etc.), R3, R4, R5, It is a C1-C10 alkyl group, an aralkyl group (for example, a benzyl group, a phenethyl group, etc.), or an aryl group (for example, a phenyl group etc.).

  In the ion conductive polymer, the modified monomer and the modified oligomer may have one or more functional groups such as an acrylic group and a methacryl group. According to this structure, it becomes easy to make the hardness of the outer peripheral surface side of the base layer smaller than the inside of the base layer by the ion conductive polymer. Therefore, according to this structure, it becomes easy to express the ionic conduction by an ion conductive polymer, and it becomes easy to aim at stabilization of the surface resistance of the base layer outer peripheral surface side. Moreover, according to this structure, since the modified monomer and modified oligomer are rich in reactivity during polymerization, the degree of freedom in polymerization when synthesizing the ion conductive polymer is improved. The ion conductive polymer is preferably a modified monomer from the viewpoint of good reactivity during polymerization.

  The ion conductive polymer can be configured to have at least one of a silicone group and a fluorine-containing group in the molecule. According to this configuration, since compatibility with the base layer polymer can be easily adjusted, the ion conductive polymer is easily unevenly distributed on the outer peripheral surface side of the base layer. Further, when the ion conductive polymer has a silicone group, the outer peripheral surface of the base layer can be reduced in friction, so that the slipperiness of the outer peripheral surface of the base layer can be improved. Further, when the ion conductive polymer has a fluorine-containing group, it is possible to improve the toner separation property on the outer peripheral surface of the base layer, and thus it is possible to improve the toner adhesion resistance on the outer peripheral surface of the base layer.

  Specifically, the silicone group can include, for example, a polydimethylsiloxane skeleton composed of repeating dimethylsiloxane units. According to this configuration, 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 outer peripheral surface of the base layer can be easily improved.

  The fluorine-containing group refers to a group containing a fluorine atom, and includes -F. 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 can be preferably used from the viewpoint of toner adhesion resistance and the like. 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 in close contact, and it is easy to improve the toner adhesion resistance on the outer peripheral surface of the base 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.

  The modified monomer and modified oligomer may have the various functional groups described above for the monomer and oligomer before being modified with the organic compound, or the organic compound may have the various functional groups described above. Also good.

  Specific examples of the monomer and oligomer before being modified with the organic compound include (meth) acrylate having an alkyl group. The (meth) acrylate having an alkyl group can have one or more alkyl groups. According to this structure, it becomes easy to adjust the molecular weight of an ion conductive polymer by selecting an alkyl group. Moreover, it becomes easy to adjust the compatibility between the base layer polymer and the ion conductive polymer, and it becomes easy to obtain a configuration in which the ion conductive polymer is unevenly distributed on the outer peripheral surface side of the base layer when the base layer is manufactured. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group from the viewpoint of polymerization reactivity between resins. be able to. Among these, the alkyl group is preferably a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group or an octyl group from the viewpoint of the molecular mobility of the resin. The (meth) acrylate mentioned above includes both acrylate and methacrylate.

  The ion conductive polymer may be a homopolymer based on the first polymer unit described above, or a copolymer containing one or more other polymer units in the molecule in addition to the first polymer unit described above. It may be a coalescence. In the latter case, regardless of the constitution of the first polymer unit, the molecular weight of the ion conductive polymer is adjusted by other polymer units, the compatibility with the base polymer is adjusted, the slipperiness of the outer peripheral surface of the base layer and the toner adhesion It becomes easier to carry out sex adjustment. Therefore, in the latter case, it is possible to improve the functionality of the base layer while ensuring the above-described effects.

  Specific examples of the other polymerized units include the following second polymerized units and third polymerized units. These polymerized units can be arbitrarily combined with the first polymerized unit as necessary.

  Specifically, the second polymer unit can be a polymer unit derived from the above-described (meth) acrylate having a silicone group. The (meth) acrylate having a silicone group can have one type or two or more types of silicone groups. According to this configuration, even when the first polymer unit does not contain a silicone group, it becomes easy to ensure the slipperiness of the outer peripheral surface of the base layer.

  Specifically, the third polymer unit can be a polymer unit derived from the above-described (meth) acrylate having a fluorine-containing group. The (meth) acrylate having a fluorine-containing group can have one kind or two or more kinds of fluorine-containing groups. According to this configuration, even when the first polymerization unit does not contain a fluorine-containing group, it becomes easy to ensure toner adhesion resistance on the outer peripheral surface of the base layer.

  More specifically, the ion conductive polymer includes a copolymer containing the first polymer unit and the second polymer unit, a copolymer containing the first polymer unit and the third polymer unit, and the first polymer. It can be comprised from the copolymer containing a unit, a 2nd polymerization unit, and a 3rd polymerization unit.

  The ionic conductive polymer can exhibit ionic conductivity when the cation site or the anion site in the first polymer unit moves as an ion. The ionic conductive polymer may be either an anionic site in which the anion site moves as an ion or an anion in which the cation site moves as an ion. When the ion conductive polymer is cationic, it is difficult to reduce the charge of the toner when the negatively charged toner is used in an electrophotographic apparatus. On the other hand, when the ion conductive polymer is anionic, it is difficult to reduce the charge of the toner when the positively charged toner is used in an electrophotographic apparatus. In electrophotographic equipment on the market, negatively charged toner is often used. Therefore, when the ion conductive polymer is cationic, an endless belt applicable to a wider range of electrophotographic apparatuses can be obtained.

  The ion conductive polymer is unevenly distributed on the outer peripheral surface side of the base layer. The uneven distribution mentioned above refers to a state in which a relatively large amount of ion conductive polymer is present on the outer peripheral surface side of the base layer rather than the central portion in the base layer thickness direction. Therefore, the base layer has an ion conductive region containing an ion conductive polymer on the outer peripheral surface side of the base layer. The inside of the ion conductive region can be a base layer main body mainly composed of a base polymer. In addition, the base layer main body part may contain an ion conductive polymer that is not unevenly distributed on the base layer outer peripheral surface side at the time of manufacture. Specifically, the base layer can have an inclined structure in which the proportion of the ion conductive polymer decreases from the base layer outer peripheral surface toward the base layer inside on the base layer outer peripheral surface side. In addition, the base layer may have an ion conductive polymer layered on the outer peripheral surface side of the base layer. When the base layer has the above-described inclined structure, the adhesion between the ion conductive polymer and the base layer polymer that are unevenly distributed on the outer peripheral surface side of the base layer is greater than when the base layer is formed by laminating the layers of the ion conductive polymer. There are advantages such as superiority. In addition, the state where the ion conductive polymer is unevenly distributed on the outer peripheral surface side of the base layer is, for example, thinned a cross section perpendicular to the outer peripheral surface of the base layer with a microtome and observed using a TEM (transmission electron microscope) And EDX (Energy Dispersive X-ray Spectroscopy) can be used for elemental analysis, and vertical sections can be analyzed by TOF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometry). .

  The base layer can contain 0.05 parts by mass or more and 5 parts by mass or less of the ion conductive polymer with respect to 100 parts by mass of the base layer polymer. According to this configuration, with a small amount of ion conductive polymer, it is possible to secure ion conductivity near the outer peripheral surface of the base layer and stabilize electrical characteristics. Further, according to this configuration, since the content of the ion conductive polymer is small, it is advantageous for reducing the cost of the endless belt.

  The ion conductive polymer is preferably 0.1 parts by weight or more, more preferably 0.2 parts by weight with respect to 100 parts by weight of the base layer polymer from the viewpoint of ensuring the effect of addition to the base layer. It can be more than mass parts. The ion conductive polymer is preferable with respect to 100 parts by mass of the base layer polymer from the viewpoint of easily suppressing excessive bleeding to the outer peripheral surface of the base material, hardly contaminating the counterpart member, and reducing the cost of the endless belt. Is 5 parts by weight or less, more preferably 3 parts by weight or less, more preferably less than 3 parts by weight, even more preferably 2.5 parts by weight or less, still more preferably 2 parts by weight or less, most preferably Can be 1.5 parts by mass or less.

  The base layer may further include a conductive filler. In this case, the conductivity inside the base layer can be ensured. There are also advantages such as reinforcement of the base layer. In addition, it is preferable that a conductive filler is contained in the base layer main-body part mentioned above from a viewpoint of ensuring the electroconductivity inside a base layer.

  As the conductive filler, an electronic conductive filler can be suitably used. According to this configuration, an electronic conductive path in which the electronic conductive filler is continuous (percolated) can be formed inside the base layer, and the inside of the base layer can be made conductive. In this case, even when the base layer is deformed by an external force applied over a long period of time and the electron conduction path is microscopically broken, the ionic conductivity is expressed by the ion conductive polymer unevenly distributed on the outer peripheral surface side of the base layer. The conductivity can be stabilized. When the ion conductive polymer and the conductive filler that are unevenly distributed on the outer peripheral surface side of the base layer are in a conductive state, the above-described effect can be further ensured.

Specific examples of the electronic conductive filler include carbon-based fillers, conductive metal oxides, and metal nanoparticles. These can be used alone or in combination of two or more. Specific examples of the carbon filler include carbon black, carbon nanotube, carbon nanofiber, 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. As the electronic conductive filler, a carbon-based filler is preferable from the viewpoint of electronic conductivity, ease of dispersion control in the base layer polymer, cost, and the like. These can be used alone or in combination of two or more.

  In addition, the base layer may contain one or more kinds of various additives such as a flame retardant, a crosslinking agent, a leveling agent, a filler, and an antioxidant as necessary.

The endless belt may be configured such that the Martens hardness ratio A / B measured on the outer peripheral surface of the base layer is less than 1. The Martens hardness ratio A / B is measured as follows.
Using a micro hardness tester (Fischer Instruments, “FISCHERSCOPE H100C”, using Vickers indenter), apply a load of 100 mN to the outer peripheral surface of the base layer for 10 seconds at 25 ° C., and then perform unloading by creeping for 10 seconds. . The Martens hardness (N / mm) at each time is calculated from the relationship between the displacement and the load at the time when the load values are 10 mN and 100 mN. The Martens hardness at the load value of 10 mN is A, the Martens hardness at the load value of 100 mN is B, and the Martens hardness ratio A / B is calculated. The Martens hardness A is a physical property value mainly indicating the hardness in the vicinity of the outer peripheral surface of the base layer (ionic conductive region), and the Martens hardness B is a physical property value mainly indicating the hardness inside the base layer (base layer body).

  According to the said structure, it becomes certain that the ion conductive area | region where hardness is smaller than a base layer main-body part exists in the base layer outer peripheral surface side. Therefore, according to the said structure, the ionic conduction by the ion conductive polymer in the base layer outer peripheral surface side with small hardness can be ensured.

  The Martens hardness ratio A / B is preferably 0.9 or less, more preferably 0.8 or less, and even more preferably 0.7 or less, from the viewpoint of stabilizing the electrical properties of the base layer. it can. The Martens hardness ratio A / B is preferably 0.4 or more from the viewpoint of wear durability of the outer peripheral surface of the base layer.

  The endless belt can be composed of a single base layer. In addition, the endless belt may have a configuration in which a rubber elastic layer, a heat generation layer, a surface layer, and the like are laminated on the outer periphery of the base layer, as required, alone or in combination.

  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 endless belt of the embodiment will be specifically described with reference to the drawings.

Example 1
As shown in FIGS. 1 to 3, the endless belt 1 of this example is used in an electrophotographic apparatus. In this example, the endless belt 1 is used as an intermediate transfer belt in an electrophotographic image forming apparatus.

  The endless belt 1 has a cylindrical base layer 10. The base layer 10 includes a base layer polymer 101 and an ion conductive polymer 102, and the ion conductive polymer 102 is unevenly distributed on the outer peripheral surface side of the base layer. The ion conductive polymer 102 has polymerized units derived from a modified monomer or modified oligomer modified with an organic compound having a cation moiety and an anion moiety. In FIG. 2, the detailed configuration of the base layer 10 is omitted. FIG. 3 shows an example in which the base layer 10 includes a conductive filler 103.

  Hereinafter, a plurality of endless belt samples having different configurations were prepared and evaluated. An experimental example will be described.

(Experimental example)
<Base layer polymer>
The following were prepared as a base layer polymer containing liquid used for the base layer forming coating liquid.
-Polyamideimide (PAI) -containing liquid Diphenylmethane diisocyanate (MDI) (manufactured by Tokyo Chemical Industry Co., Ltd., reagent), Tolidine diisocyanate (TODI) (manufactured by Tokyo Chemical Industry Co., Ltd., reagent), trimellitic anhydride (trimellitic anhydride, TMA ) (Manufactured by Tokyo Chemical Industry Co., Ltd., reagent). Subsequently, in a reaction vessel equipped with a stirrer, a nitrogen introduction tube, a thermometer, and a cooling tube, N-methyl-2-pyrrolidone (NMP) at a mass ratio of MDI: TODI: TMA = 7: 68: 55 The mixture was charged with a solid content of 26%, heated to 160 ° C. over 1 hour with stirring in a nitrogen stream, and allowed to react at 160 ° C. for about 10 hours, after which the reaction was stopped. This prepared the PAI containing liquid (solid content 26 mass%).
Polycarbonate (PC) -containing liquid Polycarbonate (PC) (manufactured by Mitsubishi Gas Chemical Company, "Iupilon S3000") was diluted with NMP to a solid content of 15% to prepare a paint. As a result, a PC-containing liquid was prepared.
・ Polyethersulfone (PES) -containing liquid Polyethersulfone (PES) (manufactured by Sumitomo Chemical Co., Ltd., “SUMICA EXCEL PES 4100G”) was diluted with NMP so that the solid content was 15% by mass, and a paint was prepared. . Thereby, the PES containing liquid was prepared.
-Polyimide (PI) -containing liquid Polyimide varnish ("Upia AT" manufactured by Ube Industries, Ltd.) was directly used as the PI-containing liquid. In the PI-containing liquid, the solvent is NMP and the solid content is 18% by mass.
-Polyarylate (PAR) -containing liquid Polyarylate (PAR) (manufactured by Unitika Ltd., “U polymer U100”) was diluted with NMP so that the solid content was 15% by mass, and was made into a paint. Thereby, a PAR-containing liquid was prepared.
-Acrylic resin-containing liquid Acrylic resin varnish (manufactured by Negami Kogyo Co., Ltd., "Paracron Precoat 200") was used as the acrylic resin-containing liquid. The acrylic resin-containing liquid has a solvent of methyl isobutyl ketone (MIBK) and a solid content of 20% by mass.

<Ion conductive polymer>
Each ion conductive polymer was prepared as follows.
・ Ion conductive polymers A to C
As materials for synthesizing the ion conductive polymers A to C, the following were prepared.
..Butyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.)
..Quaternary ammonium salt ((3-acrylamidopropyl) trimethylammonium chloride) (manufactured by Tokyo Chemical Industry Co., Ltd.)
..Acrylate-modified silicone oil (“X-22-174DX” manufactured by Shin-Etsu Chemical Co., Ltd.)
.. 2-Perfluorohexyl ethyl acrylate (Daikin Kasei Sales Co., Ltd., “R-1620”)
..Dimethyl 1,1′-azobis (1-cyclohexanecarboxylate (manufactured by Wako Pure Chemical Industries, “VE-73”)
Using a 100 mL reaction flask, the above materials and the synthesis solvent (MEK) in an amount such that the total solid content is 55% are charged and stirred at a predetermined blending ratio shown in Table 1 below. After bubbling with nitrogen for 5 minutes, polymerization was performed at an internal liquid temperature of 80 ° C. for 7 hours. Next, by adding a predetermined amount of the final dilution solvent (MEK) shown in Table 1, each solution A to C containing 30% of each ion conductive polymer A to C in solid content was obtained.

  The obtained ion conductive polymers A to C all have a first polymer unit derived from a modified monomer modified with a quaternary ammonium salt (the monomer before modification is butyl methacrylate). Moreover, the ion conductive polymer A has a fluorine-containing group in a molecule | numerator by having the 2nd polymerization unit derived from the (meth) acrylate which has a fluorine-containing group. Moreover, the ion conductive polymer B has a silicone group in a molecule | numerator by having the 3rd polymerization unit derived from the (meth) acrylate which has a silicone group. Moreover, the ion conductive polymer C has neither a silicone group nor a fluorine-containing group in the molecule. In addition, the ion conductive polymers A to C are all cationic.

・ Ion conductive polymer D (Mitsubishi Chemical Co., Ltd., “Saftmer ST2000H”)
The ion conductive polymer D is a cationic acrylic resin.
-Ion conductive polymer E (Mitsubishi Chemical Corporation, "Saftmer ST1000")
The ion conductive polymer E is an amphoteric acrylic resin.

<Conductive filler>
The following were prepared as conductive fillers.
・ Carbon black (manufactured by Showa Cabot, "Shblack N220")

<Others>
For comparison, the following additives were prepared.
・ Butyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.)
・ Quaternary ammonium salt ((3-acrylamidopropyl) trimethylammonium chloride) (manufactured by Tokyo Chemical Industry Co., Ltd.)

<Preparation of base layer forming coating solution>
As shown in Table 2, the predetermined base layer polymer-containing liquid prepared above is mixed with a predetermined part by mass of a conductive filler as necessary, and mixed by blade stirring at room temperature (25 ° C.). To be dispersed. The solid content at the time of dispersion was adjusted to be the initial solid content in the base layer polymer-containing liquid. Thereafter, a predetermined part by mass of a predetermined ion conductive polymer shown in Table 2 was blended with each dispersion and mixed by blade stirring. By the above, each base layer forming coating liquid used for preparation of the endless belts of Sample 1 to Sample 13 was prepared.

  Moreover, in preparation of each base layer formation coating liquid used for preparation of the endless belts of Sample 1 to Sample 13, the base layer formation coating liquid used for Sample 1C is the same except that the ion conductive polymer is not blended. Was prepared.

  In addition, in the preparation of each base layer forming coating solution used for the production of the endless belts of Sample 1 to Sample 13, the same applies to Sample 2C, except that a quaternary ammonium salt was blended instead of the ion conductive polymer. A base layer forming coating solution to be used was prepared.

  In addition, in the preparation of each base layer forming coating solution used for the production of endless belts of Sample 1 to Sample 13, in the same manner except that an acrylic resin and a quaternary ammonium salt were blended in place of the ion conductive polymer, A base layer forming coating solution used for Sample 3C was prepared.

  Moreover, in preparation of each base layer formation coating liquid used for preparation of the endless belts of Samples 1 to 13, the point that the quaternary ammonium salt was blended instead of the ion conductive polymer, the conductive filler was not blended. A base layer-forming coating solution used for Sample 4C was prepared in the same manner except for the above.

  Moreover, in the preparation of each base layer forming coating liquid used for the production of the endless belts of Sample 1 to Sample 13, the same procedure was performed except that the ion conductive polymer was not blended and the conductive filler was not blended. A base layer forming coating solution used for Sample 5C was prepared.

<Production of endless belt>
By applying the prepared base layer-forming coating solution on the outer peripheral surface of the cylindrical mold by a spray coating method, and then performing a predetermined heat treatment according to the type of the base layer polymer contained in the base layer-forming coating solution. A cylindrical base layer was formed.

  When the base layer polymer is polyamideimide (PAI), polycarbonate (PC), polyethersulfone (PES), or polyarylate (PAR), the above heat treatment is performed at room temperature (25 ° C.) to 250 ° C. for 2 hours. The temperature was raised over a period of 1 hour and maintained at 250 ° C. for 1 hour. When the base layer polymer was polyimide (PI), the heat treatment was performed under the condition that the temperature was raised from room temperature (25 ° C.) to 350 ° C. over 2 hours and held at 350 ° C. for 1 hour. When the base layer polymer was an acrylic resin, the heat treatment was performed under the condition that the temperature was raised from room temperature (25 ° C.) to 150 ° C. over 2 hours and held at 150 ° C. for 1 hour.

  As described above, endless belts of Sample 1 to Sample 13 and Sample 1C to Sample 5C composed of a single base layer (thickness of 80 μm) were produced.

  About the cross section perpendicular | vertical with respect to the outer peripheral surface of the base layer in the endless belt of the obtained samples 1 to 13 and samples 2C to 4C, TEM observation, EDX, and analysis by TOF-SIMS were performed from the cross sections. As a result, in Samples 1 to 13, it was confirmed that the ion conductive polymer was unevenly distributed on the outer peripheral surface side of the base layer. This is because the ion conductive polymer added to the base layer forming coating solution naturally came out to the outer peripheral surface of the base layer when the base layer forming coating solution was dried during the heat treatment. On the other hand, in Sample 2C to Sample 4C, the added ionic conductive agent (quaternary ammonium salt) was uniformly dispersed throughout the base layer. In Sample 3C, the added acrylic resin was dispersed throughout the base layer.

<Martens hardness ratio A / B>
According to the measurement method described above, the Martens hardness ratio A / B on the outer peripheral surface of the base layer was measured for each endless belt.

<Measurement of surface resistance on the outer peripheral surface side of the base layer>
When an applied voltage of 500 V is applied to each endless belt using an electrical resistivity meter (measurement range: 10 ⁴ to 10 ¹³ Ω) (manufactured by Mitsubishi Chemical Analytech Co., Ltd., “Hiresta UP”) in accordance with JIS-K6911. The surface resistivity (Ω / □) of the outer peripheral surface of the base layer was measured.

<Measurement of initial surface residual potential and durable surface residual potential on base layer outer peripheral surface>
A corotron core (using a DC power supply) is attached with an endless belt cut out on a metal roll with a diameter of 20 mm and rotated in the circumferential direction at a rotational speed of 10 rpm in an environment of 23 ° C. × 53% RH. The belt surface was charged by applying a corona current of 100 μA (constant current) with a distance of 10 mm from the belt surface. Next, at a position rotated 90 degrees in the rotation direction from the charging position, the distance between the probe of the surface potential meter and the belt surface was set to 1 mm, and the surface potential of the belt surface was measured at one point in the central portion in the metal roll axis direction. This was defined as the surface residual potential on the belt surface. These measurements were performed at the initial stage and after the durability image evaluation described later. In this case, the value of the surface residual potential was set to A if less than 300V, B if 300V or more and less than 450V, and C if 450V or more. When the initial surface residual potential was “A or B” and the durable surface residual potential was “A or B”, it was determined that the electrical characteristics of the base layer could be stabilized over a long period of time. At other times, it was determined that the electrical properties of the base layer could not be stabilized over a long period of time. The reason why this evaluation was conducted in addition to the measurement of the surface resistance on the outer peripheral surface side of the base layer is to confirm the effect of reducing the resistance of the outer peripheral surface portion of the base layer due to the uneven distribution of the ion conductive polymer on the outer peripheral surface side of the base layer. .

<Durable image evaluation>
Each endless belt is incorporated as an intermediate transfer belt of a commercially available multi-function printer (manufactured by Fuji Xerox Co., Ltd., “DocuCentre-IV C2260”) of a color image under an environment of 23.5 ° C. × 52% RH. The process of leaving for 3 days after printing 10,000 sheets was repeated up to a total of 50,000 sheets. After the above 50,000 sheets were printed, the image was marked “A” when no image defects such as missing images or streaks (white, black) were observed, and “C” when image defects were observed.

  Tables 2 and 3 collectively show the detailed configuration and evaluation results of each endless belt sample.

  According to Tables 1 to 3, the following can be understood. The endless belt of Sample 5C has a high surface resistance of the base layer, and it is difficult to control the electric charge on the outer peripheral surface of the base layer. Therefore, the endless belt of the sample 5C is not suitable as an endless belt for an electrophotographic apparatus.

  The endless belt of Sample 1C contains electronically conductive carbon black. However, Sample 1C was unable to stabilize the electrical characteristics of the base layer during durability, and image defects occurred in durability image evaluation. This is considered to be caused by the destruction of the electron conduction path or the microscopic destruction of the polymer caused by the carbon black due to the deformation caused by the external force applied over a long period of time.

  The endless belt of Sample 4C contains a quaternary ammonium salt as an ionic conductive agent. However, Sample 4C was unable to stabilize the electrical characteristics of the base layer during durability, and image defects occurred in durability image evaluation. This is because the elastic modulus of the base layer polymer used was as hard as 2000 MPa or more, so that ions due to the quaternary ammonium salt dispersed in the base layer polymer were difficult to move in the base layer.

  The endless belts of Sample 2C and Sample 3C contain an electron conductive carbon black and an ion conductive quaternary ammonium salt in the base layer. However, even if such a configuration is adopted, an image defect occurs in the durability image evaluation that can stabilize the electrical characteristics of the base layer during the durability.

  On the other hand, in the endless belts of Sample 1 to Sample 13, the base layer includes the base layer polymer and the ion conductive polymer, and the ion conductive polymer is unevenly distributed on the outer peripheral surface side of the base layer. The ion conductive polymer has a polymer unit derived from a modified monomer modified with an organic compound having a cation moiety and an anion moiety.

  Therefore, the endless belts of Sample 1 to Sample 13 can be made harder on the outer peripheral surface side of the base layer than the inside of the base layer by the ion conductive polymer regardless of the material of the base layer polymer. Further, the endless belt can exhibit ionic conduction by the ionic conductive polymer on the outer peripheral surface side of the base layer having a low hardness. Therefore, the endless belt can stabilize the surface resistance on the outer peripheral surface side of the base layer even when used in a state where an external force is applied for a long period of time. Therefore, it was confirmed that the endless belt can stabilize the electric characteristics of the base layer over a long period of time. It was also confirmed that by incorporating the endless belt into an electrophotographic apparatus, an electrophotographic apparatus that can easily suppress image defects caused by belt deformation due to external force can be obtained.

  As mentioned above, although the Example of this invention and the experiment example were demonstrated in detail, this invention is not limited to the said Example and experiment example, A various change is possible within the range which does not impair the meaning of this invention. is there. For example, in the above experimental example, an example in which the ion conductive polymer has a polymer unit derived from a specific modified monomer is shown, but the ion conductive polymer is a polymer derived from a specific modified oligomer. You may have a unit.

DESCRIPTION OF SYMBOLS 1 Endless belt 10 Base layer 101 Base layer polymer 102 Ion conductive polymer

Claims (8)

An endless belt for electrophotographic equipment,
Has a cylindrical base layer,
The base layer includes a base layer polymer and an ion conductive polymer, and the ion conductive polymer is unevenly distributed on the outer peripheral surface side of the base layer,
The ion conductive polymer is an endless belt having a polymer unit derived from a modified monomer or modified oligomer modified with an organic compound having a cation moiety and an anion moiety.   The endless belt according to claim 1, wherein the modified monomer and the modified oligomer have at least one of an acryl group and a methacryl group.   The endless belt according to claim 1 or 2, wherein the base layer comprises 0.05 parts by mass or more and 5 parts by mass or less of the ion conductive polymer with respect to 100 parts by mass of the base layer polymer.   The endless belt according to any one of claims 1 to 3, wherein the base layer polymer is polyamideimide or polyimide.   The endless belt according to claim 1, wherein the base layer further includes a conductive filler.   The endless belt according to claim 1, wherein the ion conductive polymer is cationic.   The endless belt according to any one of claims 1 to 6, wherein the organic compound is a quaternary ammonium salt.   The endless belt according to any one of claims 1 to 7, wherein the ion conductive polymer has at least one of a silicone group and a fluorine-containing group in a molecule.

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