Endless belt, intermediate transfer belt, transfer device, and image forming apparatus

Abstract

To provide an endless belt that contains less air bubbles and has a reduced peeling force on its surface.SOLUTION: An endless belt includes a binder resin, at least one modified silicone oil of modified silicone oil having a benzene ring and polyether-modified silicone oil, and an epoxide derivative.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an endless belt, an intermediate transfer belt, a transfer device, and an image forming apparatus. [Background technology]

[0002] In an image forming apparatus (such as a copier, facsimile, or printer) using an electrophotographic method, a toner image formed on the surface of an image carrier is transferred to the surface of a recording medium and fixed on the recording medium to form an image.

[0003] For example, Patent Document 1 discloses "a charging member having a conductive elastic layer, and a conductive surface layer provided on the conductive elastic layer and in contact with an image carrier, the conductive surface layer containing a resin, porous resin particles having a content of 3 parts by mass or more and 25 parts by mass or less relative to 100 parts by mass of the resin, and silicone oil having a content of 0.1 parts by mass or more and 10 parts by mass or less relative to 100 parts by mass of the resin."

[0004] Furthermore, Patent Document 2 discloses "a coating film having a coating layer formed by applying and curing a coating composition comprising an active energy ray-curable compound, silica nanoparticles having an average particle size of 2 to 300 nm, organic fine particles, and a leveling agent, wherein the content of the silica nanoparticles is 10 to 280 parts by mass relative to 100 parts by mass of the active energy ray-curable compound, the content of the organic fine particles is 0.1 to 2 parts by mass relative to 100 parts by mass of the active energy ray-curable compound, and the content of the leveling agent is 0.007 to 0.5 parts by mass relative to 100 parts by mass of the total amount of the active energy ray-curable compound and the silica nanoparticles."

[0005] Furthermore, Patent Document 3 discloses "an endless belt characterized by comprising a resin layer containing a polyamideimide resin and a silicone surfactant, and having on its outer surface a resin layer with which a cleaning blade is pressed." [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-090454 [Patent Document 2] Japanese Patent Application Publication No. 2017-061701 [Patent Document 3] Japanese Patent Application Laid-Open No. 2012-068558 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide an endless belt that has fewer bubbles and a reduced surface peel force compared to an endless belt that contains a binder resin, a modified silicone oil that is at least one of a modified silicone oil having a benzene ring and a polyether-modified silicone oil, and a methacrylic-modified silicone oil as an antifoaming agent. [Means for solving the problem]

[0008] Means for solving the above problems include the following aspects. <1> The endless belt comprises a binder resin, at least one modified silicone oil selected from the group consisting of a modified silicone oil having a benzene ring and a polyether-modified silicone oil, and an epoxide derivative. <2> The content of the modified silicone oil relative to 100 parts by mass of the binder resin is 0.5 parts by mass or more and 6.0 parts by mass or less. <1> 2. The endless belt according to claim 1. <3> The content of the modified silicone oil relative to 100 parts by mass of the binder resin is 1.0 part by mass or more and 4.0 parts by mass or less. <2> 2. The endless belt according to claim 1. <4> The content of the epoxide derivative relative to the modified silicone oil is 3% by mass or more and 20% by mass or less. <1> ~ <3> 10. The endless belt according to claim 9, <5> The content of the epoxide derivative relative to the modified silicone oil is 5% by mass or more and 15% by mass or less. <4> 2. The endless belt according to claim 1. <6> The epoxide derivative is an epoxy-modified silicone oil. <1> ~ <5> 10. The endless belt according to claim 9, <7> Polyester resin particles with a volume average particle diameter of 4.7 μm are applied to the outer surface under a load of 0 g / cm 2 and then, when air is blown onto the outer peripheral surface from above while increasing the blowing pressure, all of the polyester resin particles adhered to the outer peripheral surface are separated from the outer peripheral surface when the blowing pressure is within 16 kPa. <1> ~ <6> 10. The endless belt according to claim 9, <8> <1> ~ <7> 10. An intermediate transfer belt comprising the endless belt according to any one of claims 1 to 9. <9> An intermediate transfer belt having an outer peripheral surface onto which a toner image is transferred, <1> ~ <7> an intermediate transfer belt having the endless belt according to any one of the above items; a primary transfer device having a primary transfer member that primarily transfers a toner image formed on the surface of an image carrier onto the outer peripheral surface of the intermediate transfer belt; a secondary transfer device that is disposed in contact with the outer peripheral surface of the intermediate transfer belt and has a secondary transfer member that secondarily transfers the toner image transferred onto the outer peripheral surface of the intermediate transfer belt onto a surface of a recording medium; A transfer device comprising: <10> a toner image forming device having an image carrier and forming a toner image on a surface of the image carrier; a transfer device that transfers the toner image formed on the surface of the image carrier to a surface of a recording medium, <9> a transfer device according to the above; An image forming apparatus comprising: [Effects of the Invention]

[0009] <1> According to the invention, an endless belt is provided which has fewer bubbles and a reduced surface peel force compared to an endless belt which contains a binder resin, at least one modified silicone oil selected from modified silicone oil having a benzene ring and polyether-modified silicone oil, and methacrylic-modified silicone oil as an antifoaming agent.

[0010] <2> According to the invention, an endless belt is provided which has fewer bubbles and a reduced surface peel force compared to when the content of modified silicone oil per 100 parts by mass of binder resin is less than 0.5 parts by mass or more than 6.0 parts by mass. <3> According to the invention, an endless belt is provided which has fewer bubbles and a reduced surface peel force compared to when the content of modified silicone oil per 100 parts by mass of binder resin is less than 1.0 part by mass or more than 4.0 parts by mass.

[0011] <4> According to the invention, an endless belt is provided which has fewer bubbles and a reduced surface peeling force, compared to when the content of the epoxide derivative relative to the modified silicone oil is less than 3% by mass or more than 20% by mass. <5> According to the invention, an endless belt is provided which has fewer bubbles and a reduced surface peeling force compared to when the content of the epoxide derivative relative to the modified silicone oil is less than 5% by mass or more than 15% by mass.

[0012] <6> According to the invention, there is provided an endless belt which contains an epoxy-modified silicone oil as an epoxide derivative, has fewer bubbles, and has a reduced surface peeling force, compared to an endless belt which contains a binder resin, at least one modified silicone oil selected from modified silicone oil having a benzene ring and polyether-modified silicone oil, and a methacrylic-modified silicone oil as an antifoaming agent. <7> According to the invention, an endless belt is provided which has fewer bubbles and a reduced surface peeling force compared to when the spray pressure exceeds 6 kPa and all of the polyester resin particles adhering to the outer peripheral surface are separated from the outer peripheral surface.

[0013] <8> , <9> , or <10> According to the invention, there is provided an intermediate transfer belt which produces fewer bubbles and has excellent transferability compared to an endless belt containing a binder resin, at least one modified silicone oil selected from modified silicone oil having a benzene ring and polyether-modified silicone oil, and methacrylic-modified silicone oil as an antifoaming agent, or a transfer device or image forming device equipped with the intermediate transfer belt. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention. [Figure 2] FIG. 10 is a schematic configuration diagram showing the periphery of a secondary transfer unit in another example of an image forming apparatus according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present embodiment, which is an example of the present invention, will be described below. These descriptions and examples are for illustrating the embodiment, and do not limit the scope of the embodiment.

[0016] In the numerical ranges described in this embodiment in stages, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this embodiment, the upper or lower limit value of the numerical range may be replaced with the value shown in the examples. In this embodiment, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes as long as the intended purpose of the process is achieved. When the present embodiment is described with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. Furthermore, the sizes of the components in each drawing are conceptual, and the relative size relationships between the components are not limited to these. In this embodiment, each component may contain multiple types of corresponding substances. When referring to the amount of each component in the composition in this embodiment, if multiple types of substances corresponding to each component are present in the composition, the amount refers to the total amount of the multiple types of substances present in the composition, unless otherwise specified.

[0017] [Endless belt] The endless belt according to the present embodiment contains a binder resin, a modified silicone oil selected from the group consisting of a modified silicone oil having a benzene ring and a polyether-modified silicone oil, and an epoxide derivative.

[0018] The endless belt according to this embodiment has the above-described structure, and is an endless belt with few bubbles and reduced peeling force on the surface. The reasons for this are presumed to be as follows.

[0019] Conventionally, there is a technique for using modified silicone oils having benzene rings or polyether-modified silicone oils as silicone oils in order to reduce the peeling force of the surface of an endless belt. The more of these silicone oils used, the more they exhibit the function of reducing the peeling force of the surface of the endless belt. However, air bubbles may be generated during the production of the endless belt (that is, during film formation), making it difficult to sufficiently reduce the peeling force on the surface of the endless belt.

[0020] Therefore, in the endless belt according to the present embodiment, a modified silicone oil, either a modified silicone oil having a benzene ring or a polyether-modified silicone oil, is used in combination with an epoxide derivative, which makes it difficult for bubbles to be generated during the production of the endless belt (i.e., during film formation), and can sufficiently reduce the peeling force on the surface of the endless belt. This is thought to be because the epoxy groups in the epoxide derivatives function to reduce the interfacial tension at the interface between the binder resin and the modified silicone oil in the coating liquid, thereby suppressing the formation of bubbles, while the methyl groups in the silicone side chains of the modified silicone oil sufficiently reduce the surface energy.

[0021] Therefore, it is presumed that the endless belt according to this embodiment has few bubbles and has a reduced peeling force on the surface. The endless belt according to the present embodiment has a reduced surface peeling force, so that toner adhesion is low, and when used as a member of an image forming apparatus, the endless belt has a high toner cleaning ability. In particular, when the endless belt according to the present embodiment is used as an intermediate transfer belt, the intermediate transfer belt has excellent transferability.

[0022] The endless belt according to this embodiment will be described in detail below. (composition) The endless belt according to the present embodiment contains a binder resin, a modified silicone oil, and an epoxide derivative. Specifically, for example, the endless belt is made of a single layer of a resin layer containing the modified silicone oil and the epoxide derivative. In particular, the endless belt (the resin layer constituting the endless belt) may contain conductive particles and other known components as necessary.

[0023] -Binder resin- Examples of binder resins include polyimide resins (PI resins), polyamideimide resins (PAI resins), aromatic polyether ketone resins (e.g., aromatic polyether ether ketone resins), polyphenylene sulfide resins (PPS resins), polyetherimide resins (PEI resins), polyester resins, polyamide resins, and polycarbonate resins. From the viewpoint of improving flex resistance, the binder resin is preferably a polyimide resin (that is, a resin containing a structural unit having an imide bond), more preferably a polyimide resin or a polyamideimide resin, and most preferably a polyimide resin.

[0024] Examples of polyimide resins include imidized products of polyamic acids (precursors of polyimide resins), which are polymers of tetracarboxylic dianhydrides and diamine compounds. An example of the polyimide resin is a resin having a structural unit represented by the following general formula (I).

[0025] [ka]

[0026] In general formula (I), R 1 represents a tetravalent organic group, and R 2 represents a divalent organic group. R 1 Examples of the tetravalent organic group represented by the formula (1) include an aromatic group, an aliphatic group, a cyclic aliphatic group, a group in which an aromatic group and an aliphatic group are combined, and groups in which these groups are substituted. Specific examples of the tetravalent organic group include residues of tetracarboxylic dianhydrides, which will be described later. R 2 Examples of the divalent organic group represented by the formula (I) include an aromatic group, an aliphatic group, a cyclic aliphatic group, a group combining an aromatic group and an aliphatic group, and a group obtained by substituting any of these. Specific examples of the divalent organic group include residues of diamine compounds described below.

[0027] Specific examples of tetracarboxylic dianhydrides used as raw materials for polyimide resins include pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4-biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2'-bis(3,4-dicarboxyphenyl)sulfonic dianhydride, perylene-3,4,9,10-tetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, and ethylenetetracarboxylic dianhydride.

[0028] Specific examples of diamine compounds used as raw materials for polyimide resins include 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,3'-dichlorobenzidine, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 1,5-diaminonaphthalene, m-phenylenediamine, p-phenylenediamine, 3,3'-dimethyl 4,4'-biphenyldiamine, benzidine, and 3,3'-dimethyl Benzidine, 3,3'-dimethoxybenzidine, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenylpropane, 2,4-bis(β-amino-tert-butyl)toluene, bis(p-β-amino-tert-butylphenyl)ether, bis(p-β-methyl-δ-aminophenyl)benzene, bis-p-(1,1-dimethyl-5-amino-pentyl)benzene, 1-isopropyl-2,4-m-phenylenediamine, m-xylylenediamine, p-xylylenediamine, di(p -aminocyclohexyl)methane, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, diaminopropyltetradiamine, 3-methylheptamethylenediamine, 4,4-dimethylheptamethylenediamine, 2,11-diaminododecane, 1,2-bis-3-aminopropoxyethane, 2,2-dimethylpropylenediamine, 3-methoxyhexamethylenediamine, 2,5-dimethylheptamethylenediamine, Examples include 3-methylheptamethylenediamine, 5-methylnonamethylenediamine, 2,17-diaminoeicosadecane, 1,4-diaminocyclohexane, 1,10-diamino-1,10-dimethyldecane, 12-diaminooctadecane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, piperazine, HN(CH)O(CH)O(CH)NH, HN(CH)S(CH)NH, and HN(CH)N(CH)(CH)NH.

[0029] The polyamide-imide resin may be a resin having an imide bond and an amide bond in the repeating unit. More specifically, the polyamide-imide resin may be a polymer of a trivalent carboxylic acid compound (also called tricarboxylic acid) having an acid anhydride group and a diisocyanate compound or a diamine compound.

[0030] As the tricarboxylic acid, trimellitic anhydride and its derivatives are preferred. In addition to the tricarboxylic acid, tetracarboxylic dianhydride, aliphatic dicarboxylic acid, aromatic dicarboxylic acid, etc. may be used in combination.

[0031] Examples of the diisocyanate compound include 3,3'-dimethylbiphenyl-4,4'-diisocyanate, 2,2'-dimethylbiphenyl-4,4'-diisocyanate, biphenyl-4,4'-diisocyanate, biphenyl-3,3'-diisocyanate, biphenyl-3,4'-diisocyanate, 3,3'-diethylbiphenyl-4,4'-diisocyanate, 2,2'-diethylbiphenyl-4,4'-diisocyanate, 3,3'-dimethoxybiphenyl-4,4'-diisocyanate, 2,2'-dimethoxybiphenyl-4,4'-diisocyanate, naphthalene-1,5-diisocyanate, and naphthalene-2,6-diisocyanate. The diamine compound may be a compound having a structure similar to that of the above-mentioned isocyanate, but having an amino group instead of the isocyanato group.

[0032] Here, the resin content of the endless belt (the resin layer constituting it) is preferably 60% by mass or more and 95% by mass or less, more preferably 70% by mass or more and 95% by mass or less, and even more preferably 75% by mass or more and 90% by mass or less.

[0033] -Modified silicone oil- As the modified silicone oil, at least one of a modified silicone oil having a benzene ring and a polyether modified silicone oil is used.

[0034] Examples of modified silicone oils having a benzene ring include aralkyl-modified silicone oils having an aralkyl group on at least one of the side chains and terminals of the polysiloxane chain. The alkyl group in the aralkyl group may be, for example, a straight-chain or branched-chain alkyl group having 1 to 4 carbon atoms. The aryl group in the aralkyl group includes a phenyl group. Examples of the aralkyl group include a benzyl group, a 1-phenylethyl group, a 2-phenylethyl group, and a 2-methyl-2-phenylethyl group.

[0035] The polyether-modified silicone oil may be a silicone oil having a polyoxyalkylene group on at least one of the side chain and the end of the polysiloxane chain.

[0036] Examples of the oxyalkylene unit in the polyoxyalkylene group include oxyethylene, oxypropylene, etc. The number of repetitions of the oxyalkylene unit is preferably 6 or more and 20 or less, and more preferably 10 or more and 16 or less.

[0037] From the viewpoint of reducing the peeling force, the HLB of the modified silicone oil is preferably 2 or more and 14 or less, and more preferably 4 or more and 10 or less. HLB stands for hydrophilic / hydrophobic balance, and is a value calculated by the following formula defined by the Griffin method: Formula: HLB = 20 × (total formula weight of hydrophilic moieties / molecular weight)

[0038] The content of the modified silicone oil relative to 100 parts by mass of the binder resin is 0.3 to 8.0 parts by mass, preferably 0.5 to 6.0 parts by mass, and more preferably 1.0 to 4.0 parts by mass. When the content of the modified silicone oil is 0.5 parts by mass or more, the peeling force of the endless belt surface can be sufficiently reduced. When the content of the modified silicone oil is 6.0 parts by mass or less, the generation of bubbles can be particularly suppressed.

[0039] -Epoxide derivatives- The epoxide derivative is a compound having a three-membered oxacyclopropane ring in its structure. As the epoxide derivative, an epoxy-modified silicone oil is preferred from the viewpoint of suppressing the generation of bubbles and reducing the peeling force on the surface of the endless belt. The epoxy-modified silicone oil may be a silicone oil having an -RX group on at least one of the side chain and the end of the polysiloxane chain. Here, R represents an alkyl group and X represents an epoxy group. Examples of the alkyl group include alkyl groups having from 1 to 12 carbon atoms. The alkyl group may be substituted with a substituent such as a hydroxyl group or a carboxyl group, or may have an ether bond having an oxygen atom interposed between the carbon-carbon bond. The epoxy group also includes an alicyclic epoxy group. An example of the alicyclic epoxy group is a group in which an epoxy group is formed by two carbon atoms and an oxygen atom that constitute an alicyclic hydrocarbon skeleton of a 5- to 8-membered ring. Specific examples of the alicyclic epoxy group include an epoxycyclohexyl group.

[0040] In addition to epoxy-modified silicone oil, the epoxide derivatives may also include 1,2-butylene oxide, 1,2-octylene oxide, cyclooctene oxide, 1,2-epoxypropane, butyl glycidyl ether, diglycidyl ether, epoxy acrylate, and the like.

[0041] The content of the epoxide derivative relative to the modified silicone oil is, for example, 1% by mass or more and 25% by mass or less, preferably 3% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less. When the content of the epoxide derivative is within the above range, the generation of bubbles can be particularly suppressed.

[0042] -Conductive particles- The conductive particles are conductive (for example, a volume resistivity of 10 7 Ω·cm or less, and so on below) or semi-conductive (e.g., volume resistivity 10 7 Ω cm or more 10 13 Examples include powders with a resistivity of Ω·cm or less, and the same applies below. Specifically, examples of the conductive particles include conductive carbon particles and metal oxide particles.

[0043] An example of the conductive carbon particles is carbon black. Examples of carbon black include ketjen black, oil furnace black, channel black, acetylene black, etc. Surface-treated carbon black (hereinafter also referred to as "surface-treated carbon black") may also be used as the carbon black. Surface-treated carbon black can be obtained by adding, for example, a carboxy group, a quinone group, a lactone group, a hydroxy group, etc. to its surface. Examples of surface treatment methods include an air oxidation method in which the carbon black is reacted with air in a high-temperature atmosphere, a method in which the carbon black is reacted with nitrogen oxides or ozone at room temperature (e.g., 22°C), and a method in which the carbon black is oxidized with air in a high-temperature atmosphere and then oxidized with ozone at a low temperature.

[0044] Examples of the metal oxide particles include tin oxide particles, titanium oxide particles, zinc oxide particles, and zirconium oxide particles.

[0045] Examples of conductive particles include metal particles (e.g., aluminum particles, nickel particles, etc.), ion-conductive particles (e.g., potassium titanate particles, LiCl particles, etc.), etc.

[0046] Among these, carbon black is preferred as the conductive particles from the viewpoint of improving electrical properties.

[0047] The average primary particle size of the conductive particles is preferably 2 nm or more and 40 nm or less, more preferably 8 nm or more and 20 nm or less, and even more preferably 10 nm or more and 15 nm or less.

[0048] The method for measuring the average primary particle size of the conductive particles is as follows. First, a measurement sample with a thickness of 100 nm is taken from the endless belt (the resin layer that constitutes it) using a microtome, and this measurement sample is observed using a TEM (transmission electron microscope).The diameter of a circle equal to the projected area of ​​each of 50 primary particles of the conductive particles (i.e., the equivalent circle diameter) is taken as the particle size, and the average value of these is taken as the average primary particle size of the conductive particles.

[0049] The content of the conductive particles is preferably 10% by mass or more and 50% by mass or less, more preferably 12% by mass or more and 40% by mass or less, and more preferably 15% by mass or more and 30% by mass or less, of the endless belt (the resin layer that constitutes it).

[0050] -Other ingredients- Examples of other components include fillers for improving mechanical strength, antioxidants for preventing thermal deterioration of the belt, surfactants for improving fluidity, and heat-resistant anti-aging agents. When other components are contained, the content of the other components is preferably more than 0% by mass and not more than 10% by mass, more preferably more than 0% by mass and not more than 5% by mass, and even more preferably more than 0% by mass and not more than 1% by mass, relative to the endless belt (the resin layer constituting the endless belt).

[0051] (thickness of endless belt) The thickness of the endless belt (the resin layer constituting the endless belt) according to this embodiment is, for example, preferably 60 μm or more and 120 μm or less, and more preferably 60 μm or more and 110 μm or less.

[0052] The thickness of the endless belt is measured as follows. That is, the cross section of the endless belt in the thickness direction is observed with an optical microscope or a scanning electron microscope, the thickness of the endless belt to be measured is measured at 10 points, and the average value is taken as the thickness.

[0053] (Adhesion characteristics of endless belts) The endless belt according to this embodiment is formed by disposing polyester resin particles having a volume average particle diameter of 4.7 μm on the outer circumferential surface under a load of 0 g / cm 2 After the polyester resin particles are adhered to the outer peripheral surface, when air is blown onto the outer peripheral surface from above while increasing the blowing pressure, it is preferable that the polyester resin particles have the property that all of the polyester resin particles adhered to the outer peripheral surface are separated from the outer peripheral surface at a blowing pressure of 16 kPa or less (hereinafter, this requirement is referred to as "adhesion property").

[0054] When the spray pressure in the adhesive force characteristics is 16 kPa or less, the peeling force on the surface of the endless belt is sufficiently reduced. From the viewpoint of reducing the peeling force, the spray pressure is more preferably 12 kPa or less, and even more preferably 10 kPa or less.

[0055] Whether or not the adhesive properties are satisfied is determined as follows. First, a sample piece measuring 3 cm x 4 cm is taken from the target endless belt. Next, in an environment of 22°C and 15% RH, polyester resin particles were scattered on the surface of the sample piece corresponding to the outer surface of the endless belt from above at a height of 15 cm, in a state where a voltage of 10 kV was applied horizontally to the surface corresponding to the outer surface of the endless belt, and 3 g / cm 2 The polyester resin particles are scattered so that they fall naturally under their own weight from a height of 10 cm or less above the surface corresponding to the outer circumferential surface of the endless belt, and the surface corresponding to the outer circumferential surface of the endless belt is applied with a load of 0 g / cm. 2 Attach it with. The polyester resin particles used here are a polycondensation product of dimethyl fumarate, which is a dicarboxylic acid, and propylene glycol, which is a dialcohol, and have a weight-average molecular weight of 25,000 and a volume-average particle size of 4.7 μm. The polyester resin particles used are those that are substantially free from frictional contact with each other or with other members (such as a carrier) and are substantially free from triboelectric charging. Specifically, the polyester resin particles used are those that have been stored for six months after production in an environment of 10°C to 22°C and 10% RH to 55% RH.

[0056] Next, air is sprayed onto the center of the polyester resin particle-adhered surface of the sample piece from an air nozzle with a diameter of 0.7 mm located 3 cm above the surface at a spray pressure of 0.1 kPa, and the spray pressure is increased at a rate of 0.5 kPa / sec. When the spray pressure reaches 16 kPa, if all of the polyester resin particles are separated from the sample piece, it is determined that the adhesive force characteristics are satisfied. On the other hand, if polyester resin particles remain on the sample piece even when the spray pressure exceeds 16 kPa, it is determined that the adhesive force characteristics are not satisfied.

[0057] The weight-average molecular weight of the polyester resin particles is measured by gel permeation chromatography (GPC). Molecular weight measurements by GPC are performed using a Tosoh GPC HLC-8120GPC measuring device, a Tosoh TSKgel SuperHM-M (15 cm) column, and THF solvent. The weight-average molecular weight and number-average molecular weight are calculated from the measurement results using a molecular weight calibration curve created with monodisperse polystyrene standard samples. The volume average particle size of the polyester resin particles is measured using a Coulter Multisizer II (manufactured by Beckman Coulter), and the volume average particle size of the electrolyte is measured using an ISOTON-II (manufactured by Beckman Coulter). For the measurement, 0.5 mg to 50 mg of the sample to be measured is added to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant, and this is then added to 100 ml to 150 ml of the electrolyte. The electrolyte solution containing the suspended sample is dispersed for 1 minute using an ultrasonic disperser, and the particle size distribution of particles with diameters ranging from 2 μm to 60 μm is measured using a Coulter Multisizer II with an aperture diameter of 100 μm. The number of particles sampled is 4,000. Based on the particle size distribution measured, a cumulative distribution is drawn for each particle size range (channel) from the smallest diameter side, and the particle diameter at which the cumulative 50% is reached is defined as the volume average particle diameter D50v.

[0058] (Manufacturing method of endless belt) A method for producing an endless belt according to the present embodiment includes, for example, a step of applying a resin solution containing a resin or a precursor thereof, a modified silicone oil, and an epoxide derivative onto a surface of a mold to form a coating film; a step of heating and drying the coating film, and optionally reacting the precursor (e.g., imidizing in the case of a polyimide resin precursor) to form a resin film; A step of releasing the resin film from the mold; It has. Then, the resin film is removed from the mold to form an endless belt.

[0059] Here, the mold is not particularly limited, but a cylindrical mold is preferably used. The substrate may be a metal substrate. Furthermore, instead of a metal mold, a mold made of other materials such as resin, glass, or ceramic may be used. Furthermore, the surface of the mold may be provided with a glass coat, a ceramic coat, or the like, or may be coated with a release agent such as a silicone-based or fluorine-based release agent.

[0060] Examples of methods for applying the resin solution include ordinary methods such as blade coating, wire bar coating, spray coating, dip coating, bead coating, air knife coating, and curtain coating.

[0061] (Endless belt applications) The endless belt according to the present embodiment can be used, for example, as an endless belt for an electrophotographic image forming apparatus. Examples of the endless belt for an electrophotographic image forming apparatus include an intermediate transfer belt, a transfer belt (i.e., a recording medium transport belt), a fixing belt (e.g., a heating belt, a pressure belt), and a transport belt (i.e., a recording medium transport belt). The endless belt according to the present embodiment can be used not only as an endless belt for an image forming apparatus, but also as a belt-like member such as a conveyor belt, a drive belt, a laminate belt, an electrical insulating material, a pipe covering material, an electromagnetic wave insulating material, a heat source insulator, and an electromagnetic wave absorbing film. The endless belt according to the present embodiment may have a functional layer on the inner peripheral surface thereof depending on the application. However, it is preferable that the functional layer be applied as a layer constituting the outer peripheral surface of the endless belt according to the present embodiment.

[0062] [Transfer device] The transfer device according to this embodiment includes an intermediate transfer belt onto whose outer peripheral surface a toner image is transferred, a primary transfer device having a primary transfer member that performs primary transfer of the toner image formed on the surface of an image carrier onto the outer peripheral surface of the intermediate transfer belt, and a secondary transfer device that is arranged in contact with the outer peripheral surface of the intermediate transfer belt and has a secondary transfer member that performs secondary transfer of the toner image transferred onto the outer peripheral surface of the intermediate transfer belt onto the surface of a recording medium. As the intermediate transfer belt, an intermediate transfer belt having the endless belt according to the present embodiment is applied. The transfer device according to this embodiment may include a known device such as a cleaning device having a cleaning member that cleans the outer peripheral surface of the intermediate transfer belt.

[0063] (Intermediate transfer belt) The intermediate transfer belt has the endless belt according to the present embodiment. The intermediate transfer belt may be a single layer endless belt, or may be a laminate in which an endless belt is provided as a release layer on a base layer.

[0064] -Volume resistivity of intermediate transfer belt- The common logarithm of the volume resistivity of the intermediate transfer belt when a voltage of 100 V is applied for 10 seconds is preferably 8.0 (log Ω·cm) or more and 13.5 (log Ω·cm) or less, and more preferably 8.5 (log Ω·cm) or more and 13.2 (log Ω·cm) or less. The volume resistivity of the intermediate transfer belt when a voltage of 500 V is applied for 10 seconds is measured by the following method. A microcurrent meter (Advantest R8430A) is used as the resistance measuring device, and a UR probe (Mitsubishi Chemical Analytech Co., Ltd.) is used as the probe. The volume resistivity (log Ω cm) is measured at 18 points in total (6 points at equal intervals around the circumference of the intermediate transfer belt, and 3 points at the center and both ends in the width direction) at a voltage of 500 V, an application time of 10 seconds, and a pressure of 1 kgf, and the average value is calculated. The measurements are also performed in an environment with a temperature of 22°C and a humidity of 55% RH.

[0065] (Surface resistivity of intermediate transfer belt) The common logarithm of the surface resistivity when a voltage of 100 V is applied to the outer peripheral surface of the intermediate transfer belt for 10 seconds is preferably 9.5 (log Ω / suq.) or more and 15.0 (log Ω / suq.) or less, more preferably 10.5 (log Ω / suq.) or more and 14.0 (log Ω / suq.) or less, and particularly preferably 11.0 (log Ω / suq.) or more and 13.5 (log Ω / suq.) or less. The unit of surface resistivity, log Ω / suq., is a logarithmic value of the resistance per unit area, and is also expressed as log(Ω / suq.), log Ω / suquare, log Ω / □, etc. The surface resistivity when a voltage of 100 V is applied to the outer peripheral surface of the intermediate transfer belt for 10 seconds is measured by the following method. Using a microcurrent meter (Advantest R8430A) as the resistance measuring device and a UR probe (Mitsubishi Chemical Analytech Co., Ltd.) as the probe, the surface resistivity (log Ω / suq.) of the outer surface of the endless belt is measured at 18 points in total (6 points equally spaced circumferentially and 3 points at the center and both ends in the width direction) at a voltage of 500 V for 10 seconds and a pressure of 1 kgf, and the average value is calculated. The measurements are also performed in an environment of 22°C temperature and 55% RH humidity.

[0066] (Primary transfer device) In the primary transfer device, the primary transfer member is disposed opposite to the image carrier with the intermediate transfer belt sandwiched therebetween, and the toner image is primarily transferred onto the outer peripheral surface of the intermediate transfer belt by applying a voltage of a polarity opposite to the charge polarity of the toner to the intermediate transfer belt by the primary transfer member.

[0067] (Secondary transfer device) In the secondary transfer device, the secondary transfer member is disposed on the toner image bearing side of the intermediate transfer belt. The secondary transfer device includes, for example, a backing member disposed on the opposite side of the intermediate transfer belt from the toner image bearing side, along with the secondary transfer member. In the secondary transfer device, the intermediate transfer belt and recording medium are sandwiched between the secondary transfer member and the backing member to form a transfer electric field, thereby secondarily transferring the toner image on the intermediate transfer belt to the recording medium. The secondary transfer member may be a secondary transfer roll or a secondary transfer belt. The backing member may be, for example, a backing roll.

[0068] (cleaning device) In the cleaning device, the cleaning member is disposed on the toner image bearing side of the intermediate transfer belt. The cleaning device further includes, for example, the cleaning member and a backing member disposed on the opposite side of the intermediate transfer belt from the toner image bearing side. In the cleaning device, for example, the cleaning member cleans the outer peripheral surface of the intermediate transfer belt while sandwiching the intermediate transfer belt between the cleaning member and the backing member. Examples of the cleaning member include a cleaning blade and a cleaning brush.

[0069] The transfer device according to the present embodiment may be a transfer device that transfers a toner image onto the surface of a recording medium via multiple intermediate transfer bodies. That is, the transfer device may be, for example, a transfer device that performs primary transfer of a toner image from an image carrier to a first intermediate transfer body, secondary transfer of the toner image from the first intermediate transfer body to a second intermediate transfer body, and then tertiary transfer of the toner image from the second intermediate transfer body to a recording medium. The transfer device applies an intermediate transfer belt having the endless belt according to the present embodiment to at least one of a plurality of intermediate transfer bodies.

[0070] [Image forming equipment] The image forming apparatus according to the present embodiment includes a toner image forming device that forms a toner image on the surface of an image carrier, and a transfer device that transfers the toner image formed on the surface of the image carrier onto the surface of a recording medium. The transfer device according to the present embodiment is applied to the transfer device.

[0071] An example of a toner image forming device is a device that includes an image carrier, a charging device that charges the surface of the image carrier, an electrostatic latent image forming device that forms an electrostatic latent image on the surface of the charged image carrier, and a developing device that develops the electrostatic latent image formed on the surface of the image carrier using a developer containing toner to form a toner image.

[0072] The image forming apparatus according to this embodiment may be any known image forming apparatus, such as an apparatus equipped with a fixing device that fixes a toner image transferred onto the surface of a recording medium; an apparatus equipped with a cleaning device that cleans the surface of an image carrier after the toner image is transferred and before the image carrier is charged; an apparatus equipped with a static elimination device that irradiates the surface of an image carrier with static elimination light to eliminate static electricity after the toner image is transferred and before the image carrier is charged; or an apparatus equipped with an image carrier heating member that increases the temperature of the image carrier and reduces the relative temperature.

[0073] The image forming apparatus according to this embodiment may be either a dry development type image forming apparatus or a wet development type image forming apparatus (a development type using a liquid developer).

[0074] In the image forming apparatus according to the present embodiment, for example, the portion including the image carrier may have a cartridge structure (process cartridge) that is detachably attached to the image forming apparatus. As the process cartridge, for example, a process cartridge including a toner image forming device and a transfer device is preferably used.

[0075] An example of an image forming apparatus according to the present embodiment will be described below with reference to the drawings. However, the image forming apparatus according to the present embodiment is not limited to this. Note that only the main parts shown in the drawings will be described, and descriptions of other parts will be omitted.

[0076] (Image forming device) FIG. 1 is a schematic diagram showing the configuration of an image forming apparatus according to this embodiment.

[0077] 1, image forming apparatus 100 according to this embodiment is, for example, an intermediate transfer type image forming apparatus generally called a tandem type, and includes a plurality of image forming units 1Y, 1M, 1C, and 1K (an example of a toner image forming device) that form toner images of each color component by electrophotography, a primary transfer unit 10 that sequentially transfers (primary transfer) the toner images of each color component formed by each image forming unit 1Y, 1M, 1C, and 1K onto an intermediate transfer belt 15, a secondary transfer unit 20 that collectively transfers (secondary transfer) the superimposed toner images transferred onto intermediate transfer belt 15 onto paper K, which is a recording medium, and a fixing device 60 that fixes the secondarily transferred images onto paper K. Image forming apparatus 100 also has a control unit 40 that controls the operation of each device (each unit).

[0078] Each of the image forming units 1Y, 1M, 1C, and 1K of the image forming apparatus 100 includes a photoconductor 11 (an example of an image carrier) that rotates in the direction of arrow A and carries a toner image formed on its surface.

[0079] Around the photosensitive member 11, there is provided a charger 12 as an example of a charging means for charging the photosensitive member 11, and there is provided a laser exposure device 13 (the exposure beam is indicated by the symbol Bm in the figure) as an example of an electrostatic latent image forming device for writing an electrostatic latent image on the photosensitive member 11.

[0080] In addition, around the photosensitive member 11, there is provided a developing device 14 as an example of a developing means, which contains toner of each color component and makes the electrostatic latent image on the photosensitive member 11 visible using the toner, and there is provided a primary transfer roll 16 which transfers the toner image of each color component formed on the photosensitive member 11 to an intermediate transfer belt 15 at the primary transfer section 10.

[0081] Furthermore, a photoreceptor cleaner 17 is provided around the photoreceptor 11 to remove residual toner from the photoreceptor 11, and electrophotographic devices including a charger 12, a laser exposure device 13, a developing device 14, a primary transfer roll 16, and the photoreceptor cleaner 17 are arranged in this order along the rotation direction of the photoreceptor 11. These image forming units 1Y, 1M, 1C, and 1K are arranged in a substantially linear fashion from the upstream side of the intermediate transfer belt 15 in the order of yellow (Y), magenta (M), cyan (C), and black (K).

[0082] The intermediate transfer belt 15 is driven (rotated) in a circular manner by various rolls at a speed suited to the purpose in the direction of arrow B shown in Fig. 1. These rolls include a drive roll 31 driven by a motor (not shown) with excellent constant speed characteristics to rotate the intermediate transfer belt 15, a support roll 32 that supports the intermediate transfer belt 15 that extends in a substantially straight line along the arrangement direction of the photoconductors 11, a tensioning roll 33 that applies tension to the intermediate transfer belt 15 and functions as a correction roll that prevents the intermediate transfer belt 15 from meandering, a backing roll 25 provided in the secondary transfer unit 20, and a cleaning backing roll 34 provided in a cleaning unit that scrapes off residual toner on the intermediate transfer belt 15.

[0083] The primary transfer unit 10 is composed of a primary transfer roll 16 disposed opposite the photoconductor 11 with the intermediate transfer belt 15 sandwiched therebetween. The primary transfer roll 16 is disposed in pressure contact with the photoconductor 11 with the intermediate transfer belt 15 sandwiched therebetween, and a voltage (primary transfer bias) of the opposite polarity to the charge polarity of the toner (negative polarity; the same applies below) is applied to the primary transfer roll 16. As a result, the toner images on the photoconductors 11 are electrostatically attracted to the intermediate transfer belt 15 in sequence, and superimposed toner images are formed on the intermediate transfer belt 15.

[0084] The secondary transfer unit 20 is configured to include a back roll 25 and a secondary transfer roll 22 that is disposed on the toner image bearing surface side of the intermediate transfer belt 15 .

[0085] The back roll 25 has a surface resistivity of 1 x 10 7 Ω / □ or more 1×10 10 The hardness is set to, for example, 70° (Asker C, manufactured by Kobunshi Keiki Co., Ltd.; the same applies hereinafter.) The back roll 25 is disposed on the back side of the intermediate transfer belt 15 and constitutes an opposing electrode of the secondary transfer roll 22, and is in contact with a metal power supply roll 26 to which a secondary transfer bias is stably applied.

[0086] On the other hand, the secondary transfer roll 22 has a volume resistivity of 10 7.5 Ωcm or more 10 8.5 The secondary transfer roll 22 is a cylindrical roll of Ωcm or less. The secondary transfer roll 22 is arranged in pressure contact with the back roll 25 with the intermediate transfer belt 15 sandwiched therebetween, and the secondary transfer roll 22 is grounded to form a secondary transfer bias between the secondary transfer roll 22 and the back roll 25, thereby performing a second transfer of the toner image onto the paper K being transported to the secondary transfer unit 20.

[0087] In addition, an intermediate transfer belt cleaning member 35 is provided downstream of the secondary transfer section 20 of the intermediate transfer belt 15 so as to be freely movable toward and away from the intermediate transfer belt 15, and removes residual toner and paper dust from the intermediate transfer belt 15 after the secondary transfer and cleans the outer surface of the intermediate transfer belt 15. Further, downstream of the secondary transfer unit 20 of the secondary transfer roll 22, a secondary transfer roll cleaning member 22A is provided to remove residual toner and paper dust from the secondary transfer roll 22 after secondary transfer and clean the outer peripheral surface of the intermediate transfer belt 15. The secondary transfer roll cleaning member 22A is exemplified by a cleaning blade, but may also be a cleaning roll.

[0088] The intermediate transfer belt 15, the primary transfer roll 16, the secondary transfer roll 22, and the intermediate transfer belt cleaning member 35 correspond to an example of a transfer device. Here, the image forming apparatus 100 may be configured to include a secondary transfer belt (an example of a secondary transfer member) instead of the secondary transfer roll 22. Specifically, as shown in Fig. 2, the image forming apparatus 100 may include a secondary transfer device including a secondary transfer belt 23, a drive roll 23A disposed opposite to a back roll 25 with the intermediate transfer belt 15 and the secondary transfer belt 23 interposed therebetween, and an idler roll 23B that stretches the secondary transfer belt 23 together with the drive roll 23A.

[0089] Meanwhile, a reference sensor (home position sensor) 42 is disposed upstream of the yellow image forming unit 1Y, generating a reference signal that serves as a reference for timing image formation in each of the image forming units 1Y, 1M, 1C, and 1K. An image density sensor 43 for adjusting image quality is disposed downstream of the black image forming unit 1K. This reference sensor 42 generates a reference signal by recognizing a mark provided on the back side of the intermediate transfer belt 15, and each of the image forming units 1Y, 1M, 1C, and 1K is configured to start image formation in response to an instruction from the control unit 40 based on the recognition of this reference signal.

[0090] Furthermore, the image forming apparatus according to this embodiment is equipped with a transport means for transporting paper K, which includes a paper storage section 50 for storing paper K, a paper feed roll 51 for taking out and transporting paper K accumulated in the paper storage section 50 at a predetermined timing, a transport roll 52 for transporting paper K unwound by the paper feed roll 51, a transport guide 53 for sending paper K transported by the transport roll 52 to the secondary transfer section 20, a transport belt 55 for transporting paper K transported after secondary transfer by the secondary transfer roll 22 to the fixing device 60, and a fixing entrance guide 56 for guiding paper K to the fixing device 60.

[0091] Next, the basic image forming process of the image forming apparatus according to this embodiment will be described. In the image forming apparatus according to this embodiment, image data output from an image reading device (not shown) or a personal computer (PC) (not shown) is subjected to image processing by an image processing device (not shown), and then image formation is performed by image forming units 1Y, 1M, 1C, and 1K.

[0092] The image processing device performs image processing on the input image data, such as shading correction, positional deviation correction, brightness / color space conversion, gamma correction, and various image editing operations such as frame erasure, color editing, and movement editing. The image data that has undergone image processing is converted into color material gradation data for four colors, Y, M, C, and K, and is output to the laser exposure device 13.

[0093] In accordance with the input color material gradation data, the laser exposure device 13 irradiates the photoconductor 11 of each of the image forming units 1Y, 1M, 1C, and 1K with an exposure beam Bm emitted from, for example, a semiconductor laser. After the surface of the photoconductor 11 of each of the image forming units 1Y, 1M, 1C, and 1K is charged by the charger 12, the surface is scanned and exposed by the laser exposure device 13 to form an electrostatic latent image. The formed electrostatic latent image is developed into a toner image of each color of Y, M, C, and K by each of the image forming units 1Y, 1M, 1C, and 1K.

[0094] The toner images formed on the photoconductors 11 of the image forming units 1Y, 1M, 1C, and 1K are transferred onto the intermediate transfer belt 15 in the primary transfer section 10 where each photoconductor 11 comes into contact with the intermediate transfer belt 15. More specifically, in the primary transfer section 10, a voltage (primary transfer bias) of the opposite polarity to the charge polarity (negative polarity) of the toner is applied to the base material of the intermediate transfer belt 15 by the primary transfer roll 16, and the toner images are sequentially superimposed on the outer peripheral surface of the intermediate transfer belt 15 to perform the primary transfer.

[0095] After the toner images are sequentially primarily transferred onto the outer peripheral surface of the intermediate transfer belt 15, the intermediate transfer belt 15 moves, and the toner images are transported to the secondary transfer unit 20. When the toner images are transported to the secondary transfer unit 20, the transport means rotates the paper feed roll 51 in synchronization with the timing at which the toner images are transported to the secondary transfer unit 20, and paper K of the desired size is supplied from the paper storage unit 50. The paper K supplied by the paper feed roll 51 is transported by the transport roll 52 and reaches the secondary transfer unit 20 via the transport guide 53. Before reaching the secondary transfer unit 20, the paper K is temporarily stopped, and a positioning roll (not shown) rotates in synchronization with the movement of the intermediate transfer belt 15 on which the toner images are held, thereby aligning the position of the paper K with the position of the toner image.

[0096] In the secondary transfer unit 20, the secondary transfer roll 22 is pressed against the back roll 25 via the intermediate transfer belt 15. At this time, the paper K, which has been conveyed in time, is sandwiched between the intermediate transfer belt 15 and the secondary transfer roll 22. At this time, when a voltage (secondary transfer bias) of the same polarity as the charge polarity (negative polarity) of the toner is applied from the power supply roll 26, a transfer electric field is formed between the secondary transfer roll 22 and the back roll 25. Then, the unfixed toner images held on the intermediate transfer belt 15 are electrostatically transferred onto the paper K all at once in the secondary transfer unit 20, which is pressed by the secondary transfer roll 22 and the back roll 25.

[0097] Thereafter, the paper sheet K onto which the toner image has been electrostatically transferred is transported as is after being peeled off from the intermediate transfer belt 15 by the secondary transfer roll 22, and is transported to a transport belt 55 provided downstream of the secondary transfer roll 22 in the paper transport direction. The transport belt 55 transports the paper sheet K to the fixing device 60 at an optimal transport speed for the fixing device 60. The unfixed toner image on the paper sheet K transported to the fixing device 60 is fixed onto the paper sheet K by being subjected to a fixing process using heat and pressure by the fixing device 60. The paper sheet K on which the fixed image has been formed is then transported to an ejected paper storage unit (not shown) provided in the ejection unit of the image forming apparatus.

[0098] On the other hand, after the transfer to the paper K is completed, the residual toner remaining on the intermediate transfer belt 15 is transported to the cleaning section as the intermediate transfer belt 15 rotates, and is removed from the intermediate transfer belt 15 by the cleaning back roll 34 and the intermediate transfer belt cleaning member 35.

[0099] Although the present embodiment has been described above, it should not be construed as being limited to the above embodiment, and various modifications, changes, and improvements are possible. [Example]

[0100] Examples of the present invention will be described below, but the present invention is not limited to the following examples. In the following description, unless otherwise specified, all "parts" and "%" are based on mass.

[0101] <Preparation of polyamic acid solution> (Preparation of polyamic acid solution DA-A1) 83.48 g (416.9 mmol) of 4,4'-diaminodiphenyl ether (hereinafter abbreviated as "ODA") as a diamine compound was added to 800 g of N-methyl-2-pyrrolidone (hereinafter abbreviated as "NMP") and dissolved with stirring at room temperature (25°C). Next, 116.52 g (396.0 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (hereinafter abbreviated as "BPDA") was gradually added as a tetracarboxylic dianhydride. After the tetracarboxylic dianhydride was added and dissolved, the temperature of the reaction solution was heated to 60°C, and then the polymerization reaction was carried out for 20 hours while maintaining the reaction solution temperature, thereby obtaining a reaction solution containing polyamic acid DA-A1 and NMP.

[0102] The resulting reaction solution was filtered using a #800 stainless steel mesh and cooled to room temperature (25°C) to obtain a polyamic acid solution DA-A1 having a solution viscosity of 2.0 Pa·s at 25°C. The solution viscosity of the polyamic acid solution was measured using a Toki Sangyo Co., Ltd. E-type rotational viscometer, TV-20H, with a standard rotor (1°34" x R24) at a measurement temperature of 25°C and a rotation speed of 0.5 rpm (100 Pa s or more) or 1 rpm (less than 100 Pa s).

[0103] (Preparation of Polyamic Acid Solution DC-A1) A polyamic acid solution DC-A1 containing polyamic acid DC-A1 and NMP and having a solution viscosity of 6.0 Pa s was obtained in the same manner as in Synthesis Example 1, except that the amount of ODA was 79.57 g (397.4 mmol) and the amount of BPDA was 120.43 g (409.3 mmol).

[0104] Example 1 Polyamic acid solution DA-A1 (solid content concentration: 45% by mass) 88 parts by mass as solid content Polyamic acid solution DC-A1 (solid content concentration: 15% by mass) 12 parts by mass as solid content Carbon black (dry state; conductive carbon particles) 20 parts by mass of Color Black FW200, manufactured by Orion Engineered Carbons, gas black (i.e., channel black), number-average primary particle size: 13 nm, pH: 3.0 (hereinafter abbreviated as "FW200"). 6 parts by mass of aralkyl-modified silicone oil having a benzene ring (KF410, manufactured by Shin-Etsu Chemical Co., Ltd.) as modified silicone oil Epoxy-modified silicone oil (BYK1760, manufactured by BYK Japan) as an epoxide derivative: 1.2 parts by mass (20% by mass of the modified silicone oil) The polyamic acid solutions DA-A1 and DC-A1 having the above compositions were mixed, and FW200, modified silicone oil, and an epoxide derivative were added, followed by dispersion treatment in a ball mill at 30°C for 12 hours to disperse the mixture of polyamic acid solutions. The mixture with FW200 dispersed therein was then filtered through a #800 stainless steel mesh to obtain a coating solution. A cylindrical mold made of stainless steel with an outer diameter of 366 mm and a length of 400 mm was prepared as the material to be coated, and a silicone-based mold release agent (Shin-Etsu Chemical Co., Ltd., product name: Sepacoat SP) was applied to its outer surface, followed by a drying treatment (mold release agent treatment). While a cylindrical mold treated with a mold release agent was rotated in the circumferential direction at a speed of 10 rpm, the above coating solution was dispensed from a dispenser with a 1.0 mm diameter from the end of the cylindrical mold and applied by pressing with uniform pressure using a metal blade installed on the mold. The dispenser unit was moved in the axial direction of the cylindrical mold at a speed of 100 mm / min, thereby applying the coating solution in a spiral onto the cylindrical mold to form a coating film. Next, the coating film was dried in a drying oven for 15 minutes at 140°C in an air atmosphere while rotating at 10 rpm. The integrated average temperature rise rate A / B during the drying process of the coating film was 6.00°C / min. Next, the endless belt was obtained by placing the sheet in an oven for 4 hours at a temperature of 320° C. The total thickness of the endless belt (i.e., the thickness of a single layer) was 80 μm. The endless belt was removed from the mold, stretched over a holder, and cut with a cutter with an adjusted insertion angle to obtain an endless belt with a diameter of 366 mm and a width of 369 mm.

[0105] <Examples A2 to A12, Comparative Examples A1 to A2, Examples B1 to B12, Comparative Examples B1 to B2> An endless belt was obtained in the same manner as in Example 1, except that the composition of the coating liquid was changed according to Tables 1 and 2.

[0106] <Evaluation> The endless belts of the respective examples were evaluated as follows.

[0107] (Bubble generation) The outer peripheral surface of each endless belt was observed with a magnifying glass, and the size and number of bubbles observed on the outer peripheral surface of the endless belt were evaluated according to the following criteria. The observation area of ​​the outer peripheral surface of the endless belt was the entire periphery of the endless belt. S: No bubbles were observed, or the maximum diameter of the bubbles observed was 0.3 mm or less and the number of bubbles was 5 or less A: The maximum diameter of the bubbles observed is 0.3 mm or less, and the number is between 6 and 10. B: The maximum diameter of the observed bubbles is 0.3 mm or less and the number is 11 to 15, or the maximum diameter of the observed bubbles is 0.4 to Φ0.6 mm and the number is 1 to 8 C: The maximum diameter of the observed bubbles is 0.3 mm or less and the number is 16 or more, or the maximum diameter of the observed bubbles is 0.4 mm to 0.6 mm and the number is 9 or more, or the diameter of the observed bubbles is 0.8 mm or more and the number is 1 to 3 D: The maximum diameter of the observed bubbles is 0.3 mm or less and the number is 16 or more, or the maximum diameter of the observed bubbles is 0.4 mm to 0.6 mm and the number is 9 or more, or the maximum diameter of the observed bubbles is 0.8 mm or more and the number is 4 or more

[0108] (adhesion properties) The adhesive force characteristics of each endless belt were measured. The numerical values ​​in the adhesive force characteristics column in the table indicate the air blowing pressure when all the polyester resin particles adhering to the outer peripheral surface of the endless belt were separated from the outer peripheral surface. The adhesive force characteristics were evaluated according to the following criteria. S: Air blowing pressure ≦ 10kPa A: 10kPa<Air blowing pressure≦13kPa B: 13kPa<Air blowing pressure≦16kPa C: 16kPa<Air blowing pressure≦19kPa D: 20kPa<Air blowing pressure

[0109] (Transferability) The endless belt of each example was installed as an intermediate transfer belt in an image forming apparatus for evaluation, "Apeos C7070." Using this image forming apparatus for evaluation, the transferability of the intermediate transfer belt was evaluated as follows. A 100% density cyan solid image was output, and a hard stop was performed at the end of the transfer process. The toner weight on the two intermediate transfer bodies was transferred onto tape, and the weight of the toner attached to the tape was measured. The amount of transferred toner (a) was calculated by averaging after subtracting the tape weight. The amount of toner (b) remaining on the photoreceptor was calculated in the same way. The transfer efficiency was then calculated using the following formula. Formula: Transfer efficiency η (%) = a × 100 / (a + b)

[0110] The evaluation criteria are as follows: S: Transfer efficiency η is 97% or more A: Transfer efficiency η is 95% or more but less than 97% B: Transfer efficiency η is 93% or more but less than 95% C: Transfer efficiency η is 91% or more but less than 93% D: Transfer efficiency η is less than 91%

[0111] The results are shown in Tables 1 and 2. Details such as abbreviations in Table 1 are as follows. CB: Carbon black (dry state; conductive carbon particles) [Color Black FW200, manufactured by Orion Engineered Carbons, gas black (i.e., channel black), number-average primary particle size: 13 nm, pH: 3.0] Modified Si-Oil: Modified silicone oil KF410: Aralkyl-modified silicone oil with a benzene ring (KF410, manufactured by Shin-Etsu Chemical Co., Ltd.) KP126: Polyether-modified silicone oil (KP126, manufactured by Shin-Etsu Chemical Co., Ltd.) BYK1760: Epoxy-modified silicone oil (BYK1760, manufactured by BYK Japan) X-22-1877: Aralkyl-modified silicone oil with a benzene ring (X-22-1877, manufactured by Shin-Etsu Chemical Co., Ltd.) BYK-307: Polyether-modified silicone oil (BYK-307, manufactured by BYK-Chemie Japan) KF101: Epoxy-modified silicone oil (KF101, manufactured by Shin-Etsu Chemical Co., Ltd.) X-22-2426: Methacrylic-modified silicone oil (X-22-2246, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0112] [Table 1]

[0113] [Table 2]

[0114] From the above results, the endless belt of this example generates fewer bubbles than the endless belt of the comparative example, and is superior in both adhesive force characteristics and transferability. This shows that the endless belt of this example has few bubbles and has a reduced peeling force on the surface.

[0115] The following additional notes are provided regarding the above-described embodiments. (((1))) The endless belt comprises a binder resin, at least one modified silicone oil selected from the group consisting of a modified silicone oil having a benzene ring and a polyether-modified silicone oil, and an epoxide derivative. (((2))) The endless belt according to (((1))), wherein the content of the modified silicone oil relative to 100 parts by mass of the binder resin is 0.5 parts by mass or more and 6.0 parts by mass or less. (((3))) The endless belt according to (((2))), wherein the content of the modified silicone oil relative to 100 parts by mass of the binder resin is 1.0 part by mass or more and 4.0 parts by mass or less. (((4))) The endless belt according to any one of (((1))) to (((3))), wherein the content of the epoxide derivative relative to the modified silicone oil is 3% by mass or more and 20% by mass or less. (((5))) The endless belt according to (((4))), wherein the content of the epoxide derivative relative to the modified silicone oil is 5% by mass or more and 15% by mass or less. (((6))) The endless belt according to any one of (((1))) to (((5))), wherein the epoxide derivative is an epoxy-modified silicone oil. (((7))) Polyester resin particles with a volume average particle diameter of 4.7 μm are applied to the outer surface under a load of 0 g / cm 2and then, when air is blown onto the outer peripheral surface from above while increasing the blowing pressure, all of the polyester resin particles adhered to the outer peripheral surface are separated from the outer peripheral surface at a blowing pressure of 16 kPa or less. (((8))) An intermediate transfer belt having the endless belt according to any one of (((1))) to (((7))). (((9))) an intermediate transfer belt having an outer peripheral surface onto which a toner image is transferred, the intermediate transfer belt having the endless belt according to any one of (((1))) to (((7))); a primary transfer device having a primary transfer member that primarily transfers a toner image formed on the surface of an image carrier onto the outer peripheral surface of the intermediate transfer belt; a secondary transfer device that is disposed in contact with the outer peripheral surface of the intermediate transfer belt and has a secondary transfer member that secondarily transfers the toner image transferred onto the outer peripheral surface of the intermediate transfer belt onto a surface of a recording medium; A transfer device comprising: (((10))) a toner image forming device having an image carrier and forming a toner image on a surface of the image carrier; a transfer device that transfers the toner image formed on the surface of the image carrier to a surface of a recording medium, the transfer device being described in (((9))); An image forming apparatus comprising:

[0116] The effects of the above addition are as follows. According to the invention (((1))), an endless belt is provided which has fewer bubbles and a reduced surface peel force compared to an endless belt which contains a binder resin, a modified silicone oil which is at least one of a modified silicone oil having a benzene ring and a polyether-modified silicone oil, and a methacrylic-modified silicone oil as an antifoaming agent.

[0117] According to the invention related to (((2))), an endless belt is provided which has fewer bubbles and a reduced surface peel force, compared to when the content of modified silicone oil relative to 100 parts by mass of binder resin is less than 0.5 parts by mass or more than 6.0 parts by mass. According to the invention related to (((3))), an endless belt is provided which has fewer bubbles and a reduced peeling force on the surface, compared to when the content of the modified silicone oil relative to 100 parts by mass of the binder resin is less than 1.0 part by mass or more than 4.0 parts by mass.

[0118] According to the invention related to (((4))), an endless belt is provided which has fewer bubbles and a reduced surface peeling force, compared to when the content of the epoxide derivative relative to the modified silicone oil is less than 3% by mass or more than 20% by mass. According to the invention related to (((5))), an endless belt is provided which has fewer bubbles and a reduced surface peeling force, compared to when the content of the epoxide derivative relative to the modified silicone oil is less than 5% by mass or more than 15% by mass.

[0119] According to the invention of (((6))), there is provided an endless belt which contains an epoxy-modified silicone oil as an epoxide derivative, has fewer bubbles, and has a reduced surface peeling force, compared to an endless belt which contains a binder resin, at least one modified silicone oil selected from modified silicone oil having a benzene ring and polyether-modified silicone oil, and a methacrylic-modified silicone oil as an antifoaming agent. According to the invention (((7))), an endless belt is provided which has fewer bubbles and a reduced surface peeling force compared to when the spray pressure exceeds 6 kPa and all of the polyester resin particles adhering to the outer peripheral surface are separated from the outer peripheral surface.

[0120] According to the inventions of (((8))), (((9))), or (((10))), there is provided an intermediate transfer belt which produces fewer bubbles and has excellent transferability, as compared to an endless belt containing a binder resin, a modified silicone oil which is at least one of a modified silicone oil having a benzene ring and a polyether-modified silicone oil, and a methacrylic-modified silicone oil as an antifoaming agent, or a transfer device or image forming device including the same. [Explanation of symbols]

[0121] 1Y, 1M, 1C, 1K Image forming units 10 Primary transfer unit 11 Photoreceptor 12 Charger 13 Laser exposure device 14 Developer 15 Intermediate transfer belt 16 Primary transfer roll 17 Photoconductor cleaner 20 Secondary transfer unit 22 Secondary transfer roll 22A Secondary transfer roll cleaning member 25 Back Roll 26 Power supply roll 31 Drive Roll 32 Support Roll 33 Tensioning roll 34 Cleaning back roll 35 Intermediate transfer belt cleaning member 40 Control Unit 42 Reference Sensor 43 Image density sensor 50 Paper storage section 51 Paper feed roll 52 Transport roll 53 Transport guide 55 Conveyor belt 56 Fixing entrance guide 60 Fixing device 100 Image forming device

Claims

1. The endless belt comprises a binder resin, a modified silicone oil selected from the group consisting of a modified silicone oil having a benzene ring and a polyether-modified silicone oil, and an epoxide derivative.

2. 2. The endless belt according to claim 1, wherein the content of the modified silicone oil relative to 100 parts by mass of the binder resin is 0.5 parts by mass or more and 6.0 parts by mass or less.

3. 3. The endless belt according to claim 2, wherein the content of the modified silicone oil relative to 100 parts by mass of the binder resin is 1.0 part by mass or more and 4.0 parts by mass or less.

4. 2. The endless belt according to claim 1, wherein a content of the epoxide derivative relative to the modified silicone oil is 3% by mass or more and 20% by mass or less.

5. 5. The endless belt according to claim 4, wherein a content of the epoxide derivative relative to the modified silicone oil is 5% by mass or more and 15% by mass or less.

6. 2. The endless belt according to claim 1, wherein the epoxide derivative is an epoxy-modified silicone oil.

7. Polyester resin particles with a volume average particle diameter of 4.7 μm are applied to the outer periphery of the device under a load of 0 g / cm ２ 2. The endless belt according to claim 1, wherein when air is blown onto the outer peripheral surface from above the outer peripheral surface while increasing the blowing pressure after the polyester resin particles are adhered to the outer peripheral surface, all of the polyester resin particles adhered to the outer peripheral surface are separated from the outer peripheral surface at a blowing pressure of 16 kPa or less.

8. An intermediate transfer belt comprising the endless belt according to any one of claims 1 to 7.

9. an intermediate transfer belt having an outer peripheral surface onto which a toner image is transferred, the intermediate transfer belt including the endless belt according to any one of claims 1 to 7; a primary transfer device having a primary transfer member that primarily transfers a toner image formed on the surface of an image carrier onto the outer peripheral surface of the intermediate transfer belt; a secondary transfer device that is disposed in contact with the outer peripheral surface of the intermediate transfer belt and has a secondary transfer member that secondarily transfers the toner image transferred onto the outer peripheral surface of the intermediate transfer belt onto a surface of a recording medium; A transfer device comprising:

10. a toner image forming device having an image carrier and forming a toner image on a surface of the image carrier; A transfer device that transfers the toner image formed on the surface of the image carrier to a surface of a recording medium, comprising: the transfer device according to claim 9; An image forming apparatus comprising:

Images