Fixing apparatus and image forming apparatus

Abstract

To provide a fixing device that offers high release properties for the heating belt and suppresses the occurrence of image gloss unevenness caused by wrinkles in the surface layer of the heating belt. [Solution] A heating belt having a metal layer and a surface layer provided on the metal layer, a pressure roll that contacts the heating belt and pressurizes the heating belt, and a heating device that heats the heating belt in areas other than the contact area between the heating belt and the pressure roll, wherein the surface layer of the heating belt is made of the formula:[R 1 SiO 3 / 2 ] m The unit T is expressed as (where R is used in the formula). 1 is an organic group, m is an integer greater than or equal to 2, and there is at least one R in the T unit. 1 A fixing device comprising a polysiloxane compound having a group that includes at least one alkyl group or aryl group.

Description

[Technical Field]

[0001] The present invention relates to a fixing apparatus and an image forming apparatus. [Background technology]

[0002] In image forming devices using the electrophotographic method (such as photocopiers, facsimile machines, and printers), a toner image formed on the surface of an image holder is transferred to the surface of a recording medium and fixed onto the recording medium to form an image.

[0003] For example, Patent Document 1 discloses "a fixing device including a heating member having a conductive layer, a pressurizing member that forms a fixing nip portion by being pressed against the heating member, and a heating means for inductively heating the heating member via the conductive layer."

[0004] Patent Document 2 discloses "a fixing device comprising a fixing member, a heat source, a pressurizing member, a nip forming member that forms a nip on the inner circumference side of the fixing member facing the pressurizing member, and a shielding member that is disposed between the fixing member and the heat source to shield the heat source." [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 4635783 [Patent Document 2] Patent No. 6131707 [Overview of the project] [Problems that the invention aims to solve]

[0006] A known fixing device comprises a heating belt having a metal layer and a surface layer provided on the metal layer, a pressure roll that contacts the heating belt and pressurizes it, and a heating device that heats the heating belt in areas other than the contact area between the heating belt and the pressure roll. Hereinafter, this fixing device will also be referred to as a "specific fixing device." The object of the present invention is to provide a fixing device that, in a specific fixing device, has better mold release properties for the heating belt compared to a case where the surface layer of the heating belt is a fluororesin layer, and suppresses the occurrence of uneven image gloss caused by wrinkles in the surface layer of the heating belt. [Means for solving the problem]

[0007] The means for solving the above problems include the following embodiments. <1> A heating belt having a metal layer and a surface layer provided on the metal layer, A pressure roll that contacts the heating belt and pressurizes the heating belt, A heating device that heats the heating belt in a location other than the contact area between the heating belt and the pressure roll, Equipped with, The surface layer of the heating belt is given by formula:[R 1 SiO 3 / 2 ] m The unit T is expressed as (where R is used in the formula). 1 is an organic group, m is an integer greater than or equal to 2, and there is at least one R in the T unit. 1 A fixing device comprising a polysiloxane compound having a group that includes at least one alkyl group or aryl group. <2> At least one R in the aforementioned T unit 1 is a group containing an alkyl group <1> The fixing device described above. <3> The group containing the alkyl group is a methyl group. <2> The fixing device described above. <4> The linear thermal expansion coefficient of the surface layer of the heating belt at 150°C is 130 ppm / °C or less. <1> ~ <3> A fixing device as described in any one of the items. <5> The linear thermal expansion coefficient of the surface layer of the heating belt at 150°C is 120 ppm / °C or less. <4> The fixing device described above. <6> The heating belt is a belt having, in this order, a metal substrate layer, an elastic layer, and a surface layer as the metal layer. The heating device is a heating device that emits radiant heat. <1> ~ <5> A fixing device as described in any one of the items. <7> The heating belt is a belt having, in this order, a base layer, a metal heating layer as the metal layer, an elastic layer, and a surface layer. The heating device is an electromagnetic induction heating device that generates heat in the metal heating layer by electromagnetic induction. <1> ~ <5> A fixing device as described in any one of the items. <8> Before the fixing process begins, the heating belt, which is separated from the pressure roll, is rotated, and the electromagnetic induction heating device is used to heat the metal heating layer. Then, the heating belt and the pressure roll are brought into contact, and the fixing process begins. <7> The fixing device described above. <9> The operation of bringing the heating belt and the pressure roll into contact is performed after the surface temperature T1 of the heating belt reaches 120°C or higher, and fixing is started after the surface temperature T2 of the heating belt reaches 130°C or higher. <8> The fixing device described above. <10> Image holder and, A charging device for charging the surface of the image holder, An electrostatic latent image forming apparatus for forming an electrostatic latent image on the surface of the charged image holder, A developing apparatus that contains a developer containing toner, and develops an electrostatic latent image formed on the surface of the image holder with the developer to form a toner image, A transfer device for transferring the toner image onto the surface of a recording medium, The toner image is fixed to the surface of the recording medium. <1> ~ <9> A fixing device as described in any one of the items, An image forming apparatus equipped with the following features. [Effects of the Invention]

[0008] <1> According to the invention, a fixing device is provided that, in a specific fixing device, has higher release properties for the heating belt compared to a case where the surface layer of the heating belt is a fluororesin layer, and suppresses the occurrence of uneven image gloss caused by wrinkles in the surface layer of the heating belt. <2> According to the invention relating to this invention, at least one R in the T unit 1 Compared to cases where the group contains an aryl group, this fixing device provides superior release properties for the heating belt and suppresses the occurrence of uneven image gloss caused by wrinkles in the surface layer of the heating belt. <3> According to the invention, compared to cases where the group containing the alkyl group has two or more carbon atoms, a fixing device is provided which has higher release properties for the heating belt and suppresses the occurrence of uneven image gloss caused by wrinkles in the surface layer of the heating belt. <4> According to the invention, compared to the case where the linear thermal expansion coefficient of the heating belt's surface layer exceeds 130 ppm / °C at 150°C, a fixing device is provided that offers improved mold release properties for the heating belt and suppresses the occurrence of uneven image gloss caused by wrinkles in the heating belt's surface layer. <5> According to the invention, compared to the case where the linear thermal expansion coefficient of the heating belt's surface layer exceeds 120 ppm / °C at 150°C, a fixing device is provided that offers improved mold release properties for the heating belt and suppresses the occurrence of uneven image gloss caused by wrinkles in the heating belt's surface layer. <6> According to the invention, compared to a specific fixing device in which the surface layer of the heating belt is a fluororesin layer, a fixing device is provided that uses a direct heat method, has high release properties for the heating belt, and suppresses the occurrence of uneven image gloss caused by wrinkles in the surface layer of the heating belt. <7> According to the invention, compared to a specific fixing device in which the surface layer of the heating belt is a fluororesin layer, an electromagnetic induction heating type fixing device is provided which has high release properties of the heating belt and suppresses the occurrence of uneven image gloss caused by wrinkles in the surface layer of the heating belt.

[0009] <8> According to the invention, even when the fixing device is not in operation, the release properties of the heating belt are higher compared to when the heating belt and the pressure roll are in contact, and a fixing device is provided that suppresses the occurrence of uneven image gloss caused by wrinkles in the surface layer of the heating belt. <9> According to the invention, compared to the case where the operation of bringing the heating belt and the pressure roll into contact is performed when the surface temperature T1 of the fixing belt is less than 120°C, or when fixing is started when the surface temperature T2 of the fixing belt is less than 130°C, a fixing device is provided that has higher mold release properties for the heating belt and suppresses the occurrence of uneven image gloss caused by wrinkles in the surface layer of the heating belt. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram showing an example of a fixing device according to the first embodiment, in which the pressure rolls are located at a separated position. [Figure 2] This is a schematic diagram showing an example of a fixing device according to the first embodiment, specifically an example of a fixing device in which the pressure roll is in the pressure position. [Figure 3] This is a schematic diagram showing an example of a fixing device according to the second embodiment. [Figure 4] This is a schematic diagram showing an example of an image forming apparatus according to this embodiment. [Figure 5] This is a schematic diagram showing an example of the control system of the image forming apparatus according to this embodiment. [Modes for carrying out the invention]

[0011] The following describes an embodiment that is an example of the present invention. These descriptions and examples are illustrative of embodiments and do not limit the scope of the embodiments.

[0012] In the numerical ranges described in stages within this embodiment, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Furthermore, in the numerical ranges described within this embodiment, the upper or lower limit of that range may be replaced with the values ​​shown in the examples. In this embodiment, the term "process" includes not only independent processes but also any process that cannot be clearly distinguished from other processes, as long as its intended purpose is achieved. When describing an embodiment with reference to the drawings in this embodiment, the configuration of the embodiment is not limited to the configuration shown in the drawings. Also, the sizes of members in each drawing are conceptual, and the relative relationships of the sizes between members are not limited thereto. In this embodiment, each component may contain a plurality of corresponding substances. When referring to the amount of each component in the composition in this embodiment, when there are a plurality of substances corresponding to each component in the composition, unless otherwise specified, it means the total amount of the plurality of substances present in the composition.

[0013] <Fixing device> The fixing device according to this embodiment includes a heating belt, a pressure roll, and a heating device. The heating belt is a belt having a metal layer and a surface layer provided on the metal layer. The pressure roll is a roll that contacts the heating belt and presses the heating belt. The heating device is a device that heats the heating belt except at the contact portion between the heating belt and the pressure roll. And the surface layer of the heating belt contains a polysiloxane compound having a T unit represented by the formula: [R 1 SiO 3 / 2 m However, in the formula, R 1 is an organic group, m represents an integer of 2 or more, and at least one R 1 in the T unit contains at least one of an alkyl group or an aryl group. This polysiloxane compound is also referred to as "polysiloxane compound SQ" hereinafter.

[0014] The fixing device according to this embodiment has the above configuration, and has high releasability of the heating belt and suppresses the occurrence of image gloss unevenness caused by wrinkles on the surface layer of the heating belt. The reason is presumed as follows.

[0015] Conventionally, in order to improve energy-saving performance, a belt-type fixing device using a heating belt has been adopted. On the other hand, a fluororesin is used for the surface layer of the heating belt in order to enhance the releasability.​

[0016] In this case, because the heating belt has a small heat capacity, the temperature difference between the area through which the recording medium passes (hereinafter referred to as the "paper-passing area") and the area through which the recording medium does not pass (hereinafter referred to as the "non-paper-passing area") tends to be large. When this temperature difference becomes large, in a heating belt with a layer structure consisting of a metal layer and a surface layer containing fluororesin, large stresses are repeatedly applied to the surface layer of the heating belt, causing wrinkle deformation (i.e., permanent elongation) of the surface layer. As a result, large wrinkles with significant irregularities appear on the surface layer. In particular, in fixing devices that employ a heating device to heat the heating belt at locations other than the contact area between the heating belt and the pressure roll, the above temperature difference is maintained for a long time up to the contact area. As a result, wrinkle deformation (i.e., permanent elongation) of the surface layer is likely to remain. Furthermore, when wrinkle deformation (i.e., permanent stretching) occurs in the surface layer, it appears in the image as uneven gloss.

[0017] In contrast, in the fixing device according to this embodiment, polysiloxane compound SQ is applied to the surface layer of the heating belt. Polysiloxane compound SQ has high release properties as a heat-resistant release material. In addition, compared to fluororesin, polysiloxane compound SQ does not easily cause a large difference in thermal expansion coefficient between the paper-feeding portion and the non-paper-feeding portion. Therefore, wrinkle deformation at the boundary between the paper-feeding portion and the non-paper-feeding portion of the heating belt is suppressed. As a result, the occurrence of image defects caused by wrinkle deformation of the heating belt is suppressed in the fixed image. Therefore, due to the fixing process, even if a temperature difference occurs between the paper-feeding and non-paper-feeding sections of the heated component, wrinkles are less likely to form in the surface layer due to differences in thermal expansion coefficients. As a result, uneven image gloss caused by wrinkles in the surface layer is less likely to occur.

[0018] From the above, it is presumed that the fixing device according to this embodiment has high release properties for the heating belt and suppresses the occurrence of uneven image gloss caused by wrinkles in the surface layer of the heating belt.

[0019] The details of the fixing device according to this embodiment will be described below.

[0020] <First Embodiment> As a fixing device according to the first embodiment, an electromagnetic induction heating type fixing device will be described with reference to Figures 1 and 2.

[0021] (Configuration of the fixing device) As shown in Figures 1 and 2, the fixing device 60 according to the first embodiment includes a heating belt 61 (an example of a heating belt), a pressure roll 62 (an example of a pressure roll), an electromagnetic induction heating device 63 (an example of a heating device), a latch mechanism 64, and a temperature sensor 68. Figure 1 shows an example of the state in which the pressure roll 62 has been moved to a separated position, away from the heating belt 61. Figure 2 shows an example of the state in which the pressure roll 62 has been moved to a pressurized position, in contact with the heating belt 61 and pressurizing the heating belt 61.

[0022] The heating belt 61 has a base layer, a metal heating layer, an elastic layer, and a surface layer in this order. The pressure roll 62 has a base layer, an elastic layer, and a surface layer in this order. Further details regarding the heating belt 61 and the pressure roll 62 will be described later.

[0023] Inside the heating belt 61 are a sliding sheet 65, a pressing pad 66, and a support member 67. The sliding sheet 65 is provided between the pressure pad 66 and the heating belt 61. The sliding sheet 65 reduces the sliding resistance between the heating belt 61 and the pressure pad 66. The pressure pad 66 is positioned to press against the pressure roll 62 via the heating belt 61 when it is moved to a pressurizing position that pressurizes the heating belt 61. The support member 67 is provided to support the pressure pad 66.

[0024] The electromagnetic induction heating device is a device that heats the metal heating layer of the heating belt 61 by electromagnetic induction. The electromagnetic induction heating device 63 is equipped with multiple excitation coils 63A that generate a magnetic field by supplying power from a fixing power supply. The electromagnetic induction heating device 63 modifies the magnetic field generated from the excitation coil 63A using an excitation circuit. This generates eddy currents in the metal heating layer of the heating belt 61. These eddy currents are converted into Joule heat by the electrical resistance of the metal heating layer, causing the metal heating layer to heat up. As a result, the heating belt 61 is heated.

[0025] The latch mechanism 64 is a mechanism that allows the pressure roll 62 to move between a separated position (i.e., the position in Figure 2) and a pressurized position (i.e., the position in Figure 3).

[0026] When the pressure rolls 62 are in a separated position, the target of the drive device (motor, etc.) (not shown) is switched to the heating belt 61. The heating belt 61 is then rotated by the drive device. On the other hand, when the pressure roll 62 is moved to the pressurized position by the latch mechanism 64, the target of the drive device (motor, etc.) (not shown) is switched to the pressure roll 62, and the pressure roll 62 is rotated by the drive device. At this time, the heating belt 61 is also driven to rotate along with the rotation of the pressure roll 62.

[0027] The temperature sensor 68 is located around the heating belt 61. The temperature sensor 68 measures the surface temperature of the heating belt.

[0028] In the fixing device 60, for example, before the start of fixing, the heating belt 61, which is separated from the pressure roll 62, is rotated, and the electromagnetic induction heating device 63 is used to heat the metal heating layer of the heating belt 61. Then, the heating belt 61 and the pressure roll 62 are brought into contact, and fixing begins.

[0029] Specifically, for example, in the fixing device 60, when image formation is started, the heating belt 61 is rotated while the pressure roll 62 is in a separated position before fixing begins. Here, the rotation speed of the heating belt 61 is lower than the rotation speed during fixing. Next, a magnetic field is generated from the excitation coil 63A of the electromagnetic induction heating device 63, causing the metal heating layer of the heating belt 61 to heat up. This heats the heating belt 61. Next, the latch mechanism 64 moves the pressure roll 62 to the pressurized position, and the pressure roll 62 is pressed against the pressure pad 66 via the heating belt 61 and sliding sheet 65. Then, with the heating belt 61 and the pressure roll 62 under pressure, the paper P (an example of a recording medium) on which the toner image has been transferred is transported to the contact area between the heating belt 61 and the pressure roll 62. This fixes the toner image onto the paper P. After the fixing operation is complete, the latch mechanism 64 moves the pressure roll 62 to the separated position. The program that performs the above operations is called the "fixing operation program."

[0030] In the fixing device 60, the heating belt 61 and the pressure roll 62 are separated during non-fixing operations, and only during fixing operations do the heating belt 61 and the pressure roll 62 come into contact and become pressurized. As a result, the surface layer of the heating belt 61 is deformed for a shorter period of time due to mechanical load. Consequently, wrinkles are less likely to occur in the surface layer of the heating belt 61, and the resulting unevenness in image gloss is more easily suppressed.

[0031] In this case, the operation of bringing the heating belt 61 into contact with the pressure roll 62 is preferably performed after the surface temperature T1 of the heating belt 61 reaches 120°C or higher (preferably 120°C to 150°C). It is preferable to start fixing after the surface temperature T2 of the heating belt 61 reaches 130°C or higher (preferably 130°C to 170°C). By performing the contact operation between the heating belt 61 and the pressure roll 62, and initiating the fixing process under the above temperature conditions, wrinkles in the surface layer of the heating belt 61 are less likely to occur due to the difference in the coefficient of linear expansion between the metal substrate layer and the surface layer. As a result, unevenness in image gloss is less likely to occur.

[0032] The following describes the details of the heating belt 61 and pressure roll 62 applied to the fixing device 60 according to the first embodiment.

[0033] (Heating belt) The heating belt 61 has a base layer, a metal heating layer, an elastic layer, and a surface layer in this order. The elastic layer is provided as needed. Specifically, for example, the heating belt 61 is constructed by laminating a base layer, an underlayment metal layer, a metal heating layer, a metal protective layer, an elastic layer, and a surface layer in this order.

[0034] -Base material layer- Examples of base material layers include resin base material layers made of heat-resistant resin belts. Examples of heat-resistant resin belts include those made from polyimide, polyamide-imide, polyphenylene sulfide, polyetheretherketone, and polybenzimidazole. Furthermore, the heat-resistant resin belt may have conductive powder or the like added and dispersed to control its volume resistivity. Specifically, an example of a heat-resistant resin belt is a polyimide resin belt to which carbon black has been added and dispersed. Another example of a heat-resistant resin belt is one in which both ends of a long polyimide sheet are assembled in a puzzle-like manner and heat-sealed together using a heat-sealing member to form a belt. Heat resistance refers to the property of not melting or decomposing even when the temperature of the fixing device is reached (for example, the fixing temperature).

[0035] The thickness of the heat-resistant resin belt is preferably, for example, 20 μm to 200 μm, more preferably 30 μm to 150 μm, and even more preferably 40 μm to 130 μm.

[0036] -Underlayment metal layer- The base metal layer is a layer that is formed in advance on the outer surface of the base material layer in order to form a metal heating layer by electroplating. Examples of the base metal layer include electroless nickel plating layers and electroless copper plating layers. Note that "nickel plating layer" refers to a plating layer containing Ni (e.g., a nickel layer, a nickel alloy layer, etc.), and "copper plating layer" refers to a plating layer containing Cu (e.g., a copper layer, a copper alloy layer, etc.).

[0037] -Metal heating layer- A metal heating layer is a heating layer that generates heat through eddy currents that occur within the layer when a magnetic field is applied, and is composed of a metal that exhibits electromagnetic induction. Examples of metals that exhibit electromagnetic induction include single metals such as nickel, iron, copper, gold, silver, aluminum, chromium, tin, and zinc, or alloys containing two or more types of metals.

[0038] -Metal protective layer- The metal protective layer is designed to improve the film strength of the metal heating layer, suppress cracking due to repeated deformation and oxidative degradation due to prolonged repeated heating, and maintain the heating characteristics. The metal protective layer is provided in contact with the metal heating layer. The metal protective layer should be a thin film with high tensile strength, durability, and oxidation resistance, and preferably made of an oxide-resistant metal. Specifically, it is often composed of copper or nickel, and in particular, it is preferable to include nickel (or a nickel alloy), which is an oxide-resistant metal, in order to suppress the occurrence of cracks due to repeated deformation and oxidative degradation due to repeated heating.

[0039] -Elastic layer- The elastic layer is, for example, an elastic layer that returns to its original shape even when deformed by an external force of 100 Pa. The elastic layer should preferably be a layer that mainly contains a heat-resistant elastic material. Furthermore, a layer containing heat-resistant elastic material as its main component is defined as a layer in which heat-resistant elastic material is the most abundant component among the components that make up the elastic layer. Heat resistance refers to the property of not melting or decomposing even when the temperature of the fixing device is reached (for example, the fixing temperature).

[0040] Suitable heat-resistant elastic materials include, for example, silicone rubber, from the viewpoint of heat resistance, thermal conductivity, and insulation. Examples of silicone rubber include RTV silicone rubber, HTV silicone rubber, and liquid silicone rubber. Specifically, examples include polydimethyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ), methylphenyl silicone rubber (PMQ), and fluorosilicone rubber (FVMQ). Examples of commercially available silicone rubber include Dow Corning's liquid silicone rubber SE6744.

[0041] As for the silicone rubber, those with an addition reaction type as the crosslinking mechanism are preferred. Furthermore, various types of functional groups are known for silicone rubber, and dimethyl silicone rubber having methyl groups, methylphenyl silicone rubber having methyl and phenyl groups, and vinyl silicone rubber having vinyl groups (vinyl group-containing silicone rubber) are preferred. More preferably, vinyl silicone rubber having vinyl groups is preferred, and even more preferably, silicone rubber having an organopolysiloxane structure having vinyl groups and a hydrogen organopolysiloxane structure having hydrogen atoms (SiH) bonded to silicon atoms is preferred.

[0042] The elastic layer preferably contains a heat-resistant elastic material, with silicone rubber as the main component (i.e., 50% by mass or more relative to the elastic layer). More preferably, the silicone rubber content is 90% by mass or more, and even more preferably 99% by mass or more.

[0043] The elastic layer may contain not only a heat-resistant elastic material but also inorganic fillers for purposes such as reinforcement, heat resistance, and heat transfer. Examples of known inorganic fillers include, for example, fuzzy silica, crystalline silica, iron oxide, alumina, and metallic silicon.

[0044] The content of the inorganic filler can be determined by the required thermal conductivity, mechanical strength, etc. For example, it can be 1% to 20% by mass relative to the elastic layer, preferably 3% to 15% by mass, and more preferably 5% to 10% by mass.

[0045] The elastic layer may contain additives such as softeners (paraffin-based, etc.), processing aids (stearic acid, etc.), antioxidants (amine-based, etc.), vulcanizing agents (sulfur, metal oxides, peroxides, etc.), and functional fillers (alumina, etc.).

[0046] The thickness of the elastic layer is preferably, for example, 30 μm to 600 μm, and more preferably 100 μm to 500 μm.

[0047] -Surface layer- The surface layer is given by formula:[R 1 SiO 3 / 2 ] m The unit T is expressed as (where R is used in the formula). 1 is an organic group, m is an integer greater than or equal to 2, and there is at least one R in the T unit. 1 The polysiloxane compound SQ comprises a group that includes at least one alkyl group or aryl group.

[0048] The surface layer may be a surface layer containing polysiloxane compound SQ as the main component (for example, as a matrix material that acts as a binder), or it may be a surface layer containing polysiloxane compound SQ as an additive. The surface layer may also contain other additives. Here, the surface layer containing polysiloxane compound SQ as the main component (for example, as a matrix material acting as a binder) refers to the surface layer with the highest amount (volume %) of polysiloxane compound.

[0049] --Polysiloxane compound SQ-- Polysiloxane compound SQ is given by formula:[R 1 SiO 3 / 2 ] m The unit T is expressed as (where R is used in the formula). 1 R represents an organic group, m is an integer greater than or equal to 2, and there are multiple R groups in a T unit.1 Of these, at least one R 1 The polysiloxane compound has a group that includes at least one of an alkyl group and an aryl group. Polysiloxane compound SQ is given by formula:[R 1 SiO 3 / 2 ] m Along with the T units represented by the formula: (R 2 R 3 SiO 2 / 2 ) n The D unit is expressed as (however, in the formula, R 2 and R 3 The compound may be a polysiloxane compound having an organic group, where n is an integer of 2 or more. The inclusion of D units is preferable because it allows the surface layer to stretch appropriately, making it less likely for wrinkles to form in the surface layer. Note that there are multiple R units within the D unit. 2 and R 3 Of these, at least one R 2 and R 3 Preferably, the group is one that includes at least one of an alkyl group and an aryl group.

[0050] In units T and D, R in the formula 1 , R 2 and R 3 The organic groups include, for example, hydroxyl groups, siloxy groups, hydrocarbon groups, hydrocarbon groups in which one or more methylene groups are replaced by carbonyl groups, hydrocarbon groups in which one or more carbon atoms are replaced by heteroatoms (oxygen atoms, nitrogen atoms, or sulfur atoms), or groups that combine these.

[0051] R 1 , R 2 and R 3 Examples of siloxy groups represented by the organic group described include monoalkylsiloxy groups, dialkylsiloxy groups, and trialkylsiloxy groups, with dialkylsiloxy groups and trialkylsiloxy groups being preferred, and trialkylsiloxy groups being more preferred.

[0052] R 1 , R 2 and R3 Examples of hydrocarbon groups described using the organic group represented by include aliphatic hydrocarbon groups and aromatic hydrocarbon groups.

[0053] Examples of aliphatic hydrocarbon groups include linear, branched, or alicyclic saturated aliphatic hydrocarbon groups, and linear, branched, or alicyclic unsaturated aliphatic hydrocarbon groups. As the aliphatic hydrocarbon group, a hydrocarbon group having 1 to 20 carbon atoms is preferred, and a hydrocarbon group having 1 to 15 carbon atoms is more preferred. Aliphatic hydrocarbon groups may be substituted with substituents such as halogen atoms, hydroxyl groups, amino groups, or aryl groups.

[0054] Aromatic hydrocarbon groups include hydrocarbon groups having 6 to 18 carbon atoms (preferably 6 to 14 carbon atoms). Examples of aromatic hydrocarbon groups include phenyl groups, naphthyl groups, and anthracenyl groups. Aromatic hydrocarbon groups may be substituted with substituents such as halogen atoms, hydroxyl groups, amino groups, alkyl groups, and alkoxy groups.

[0055] R 1 , R 2 and R 3 The organic group represented by may have a reactive group. Examples of reactive groups include vinyl groups, allyl groups, styryl groups, maleimide groups, epoxy groups, and (meth)acryloyl groups. In other words, the siloxane compound may be a cured product obtained by the reaction of the above reactive groups.

[0056] Multiple R units exist within the T and D units. 1 , R 2 and R 3 These may be the same organic group or different organic groups. However, each of the multiple R units within the T unit 1 , R 2 and R 3 Of these, at least one R 1 , R 2 and R 3 Each of these groups is a group containing at least one of an alkyl group and an aryl group. Furthermore, each of the multiple R units present within the D unit 1 , R 2 and R 3 Of these, at least one R 1 , R 2 and R 3 Preferably, each of these groups contains at least one of an alkyl group and an aryl group. In other words, there are multiple R units within a T unit. 1 Of these, at least one R 1 This group is a group that includes at least one of an alkyl group and an aryl group. Multiple R units exist within the D unit. 2 Of these, at least one R 2 Each of these groups is a group containing at least one of an alkyl group and an aryl group. Multiple R units exist within the D unit. 3 Of these, at least one R 3 Preferably, the group is one that includes at least one of an alkyl group and an aryl group. Here, from the viewpoint of improving release properties, the alkyl group is preferably an alkyl group itself or a siloxy group containing an alkyl group. In other words, at least one of the multiple R groups in structure A is preferably an alkyl group or a siloxy group containing an alkyl group. From the viewpoint of improving release properties, the alkyl group is preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and more preferably an alkyl group having 1 carbon atom (i.e., a methyl group).

[0057] The preferred group containing the aryl group is either the aryl group itself or an aralkyl group. Examples of aryl groups include phenyl groups and naphthyl groups. The alkyl group in the aralkyl group can be, for example, a linear or branched alkyl group having 1 to 4 carbon atoms. The aryl group in the aralkyl group can be a phenyl group, a naphthyl group, etc. Examples of aralkyl groups include a benzyl group, a 1-phenylethyl group, a 2-phenylethyl group, and a 2-methyl-2-phenylethyl group. From the viewpoint of improving release properties, a phenyl group is preferred as the group containing the aryl group.

[0058] From the viewpoint of improving release properties, a higher proportion of groups containing at least one alkyl group and an aryl group is preferable.

[0059] In the T and D units, m and n in the formula represent integers of 2 or more, but from the viewpoint of improving release properties, it is preferable that they represent integers of 8 or more, and more preferably that they represent integers between 8 and 10,000.

[0060] In T and D units, the lower limit of the ratio of m to n in the formula, m / n, is preferably 100 / 0 or greater, and more preferably 100 / 1 or greater. The upper limit of m / n is preferably 10 / 90 or less, more preferably 20 / 80 or less, and even more preferably 25 / 75 or less. The ratio m / n, that is, the ratio of units in T and D, is measured as follows: Solid 29 The result is calculated using Si NMR, based on the peak ratio between D units (high ppm side) and T units (low ppm side).

[0061] From the viewpoint of improving release properties, the content of polysiloxane compound SQ is preferably 10% by volume or more, more preferably 30% by volume or more, and even more preferably 50% by volume or more relative to the surface layer. The upper limit for the content of polysiloxane compound SQ is 100% by volume.

[0062] The polysiloxane compound SQ may be in particulate form. The volume-average particle size of the particulate polysiloxane compound SQ is preferably 0.01 μm or more and 10 μm or less, more preferably 0.01 μm or more and 5 μm or less, and even more preferably 0.01 μm or more and 2.5 μm or less. In particular, the volume-average particle size of the particulate polysiloxane compound SQ is preferably 2.5 μm or less, and more preferably 1 μm or less. When the volume-average particle size of the particulate polysiloxane compound SQ is within the above range, the release properties tend to improve.

[0063] The volume-average particle size of particulate polysiloxane compound SQ is measured as follows: A sample is taken from the surface layer. The sample should have a cross-section aligned with the thickness direction of the surface layer as the observation surface. The observation surface of the sample is observed using a scanning electron microscope, and an image is captured. In the image, the area of ​​each primary particle of polysiloxane compound SQ is measured by image analysis, and the equivalent circle diameter is calculated from this area value. This calculation of the equivalent circle diameter is performed for 100 particles of polysiloxane compound SQ. The 50th percentile diameter (D50v) at the volume-based cumulative frequency of the obtained equivalent circle diameters is then defined as the volume-average particle size of polysiloxane compound SQ.

[0064] Polysiloxane compounds (SQ) can be exemplified by high-molecular-weight compounds called silsesquioxanes (SQ), which can take on various skeletal structures. The polysiloxane compound SQ may have any of the following skeletal structures: a cage structure (complete cage structure or cage structure), a ladder structure, or a random structure.

[0065] --Polysiloxane compounds containing D units-- The surface layer, in addition to the above polysiloxane compound SQ, contains formula:[R 1 SiO 3 / 2 ] m Along with the T units represented by the formula: (R 2 R 3 SiO 2 / 2 ) n The D unit is expressed as (however, in the formula, R 2 and R 3 The material may also contain a polysiloxane compound PS having an organic group, where n is an integer of 2 or more. The inclusion of a polysiloxane compound PS is more preferable because it allows the surface layer to stretch appropriately, making it less likely for wrinkles to form in the surface layer. R in the formula 2 、 R 3 , and n are the "R" units of the D unit as described in the polysiloxane compound SQ above. 2 、 R 3 This is synonymous with ", and n".

[0066] Examples of polysiloxane compounds (PS) include dimethylorganopolysiloxane, diphenylorganopolysiloxane, and methylphenylorganopolysiloxane. Polysiloxane compounds (PS) may contain hydroxyl groups, vinyl groups, etc., at the ends or side chains of the molecule.

[0067] The ratio of polysiloxane compound PS to polysiloxane compound SQ is preferably 0% to 80% by volume, more preferably 5% to 75% by volume, and even more preferably 5% to 70% by volume.

[0068] --Binding material-- The surface layer may contain a binder for immobilizing the polysiloxane compound SQ. Examples of binding agents include heat-resistant release agents. Examples of heat-resistant release materials include silicone resin, silicone rubber, polyimide resin, polyetheretherketone (PEEK) resin, polyphenylene sulfide (PPS) resin, and polymethylpentene (PMP) resin. Among these, silicone resin and silicone rubber are preferred as heat-resistant release materials. Heat resistance refers to the property of not melting or decomposing even when the temperature of the fixing device is reached (for example, the fixing temperature).

[0069] Examples of silicone resins include methyl-based straight silicone resins, methylphenyl-based straight silicone resins, acrylic resin-modified silicone resins, ester resin-modified silicone resins, epoxy resin-modified silicone resins, and alkyd resin-modified silicone resins. Examples of silicone rubbers include RTV (Room Temperature Vulcanizing) silicone rubber, HTV (High Temperature Vulcanizing) silicone rubber, and liquid silicone rubber. Specifically, examples include polydimethyl silicone rubber, methyl vinyl silicone rubber, methylphenyl silicone rubber, and fluorosilicone rubber.

[0070] --Other Additives-- Other additives may be incorporated into the surface layer. Examples of additives include fillers (inorganic particles, etc.), softeners (paraffin-based, etc.), processing aids (stearic acid, etc.), and antioxidants (amine-based, etc.).

[0071] The thickness of the surface layer is preferably 5 μm to 100 μm, and more preferably 10 μm to 30 μm.

[0072] --Linear thermal expansion coefficient-- The linear thermal expansion coefficient of the surface layer at 150°C is preferably 130 ppm / °C or less, and more preferably 120 ppm / °C or less. If the linear thermal expansion coefficient of the surface layer at 150°C is within the above range, wrinkles are less likely to form on the surface layer, and unevenness in image gloss is more easily suppressed.

[0073] The linear thermal expansion coefficient of the surface layer at 150°C was measured using a thermomechanical analyzer (TMA-60, manufactured by Shimadzu Corporation) according to the method described in JIS K 7197:2012.

[0074] (Pressure Roll) The pressure roll 62 has a base layer, an elastic layer, and a surface layer in this order. The pressure roll 62 may be a roll having a base layer and an elastic layer in that order, or a roll having a base layer and a surface layer in that order.

[0075] In the pressure roll 62, the base material, elastic layer, and surface layer may have a similar configuration to those of the base material, elastic layer, and surface layer in the heating belt 61. However, the surface layer does not necessarily have to contain the polysiloxane compound SQ having T units. For example, the surface layer may be a layer containing the heat-resistant release material mentioned above.

[0076] <Second Embodiment> As a fixing device according to the second embodiment, a direct heat type fixing device will be described with reference to Figure 3.

[0077] As shown in Figure 3, the fixing device 70 according to the second embodiment includes a heating belt 71 (an example of a heating belt), a pressure roll 72 (an example of a pressure roll), and a heating device 73 (an example of a heating device).

[0078] The heating belt 71 has a metal substrate layer, an elastic layer, and a surface layer in that order. Further details of the heating belt 71 will be described later. Inside the heating belt 71 are a sliding sheet 74, a pressing pad 75, a support member 76, and a reflective sheet 78. The sliding sheet 74 is provided between the pressure pad 75 and the heating belt 71. The sliding sheet 74 reduces the sliding resistance between the heating belt 71 and the pressure pad 75. The support member 76 is provided to support the pressure pad 75. The reflective sheet 78 is a component that reflects radiant heat emitted from the heating device 73. The reflective sheet 78 is positioned opposite the inner circumferential surface of the heating belt 71 via the heating device 73, and in a position where the radiant heat emitted from the heating device 73 does not reach the sandwiched area N.

[0079] The pressure roll 72 has a base layer, an elastic layer, and a surface layer in that order. Further details of the pressure roll 72 will be described later. The pressure roll 72 is positioned opposite the heating belt 71. The pressure roll 72 is positioned in a pressed state against the pressure pad 75 via the heating belt 71 and the sliding sheet 74. As a result, in the clamping region N, the pressure roll 72 is positioned in pressure against the heating belt 71. The pressure roll 72 is connected to a drive device (not shown) via gears or the like (not shown). The drive device rotates the pressure roll 72 in the direction of the arrow. The heating belt 71 rotates in response to the rotation of the pressure roll 72.

[0080] The heating device 73 is a heating device that emits radiant heat. Examples of well-known heating devices for the heating device 73 include halogen lamps, ceramic heaters, and carbon heaters. The heating device 73 is located inside the heating belt 71, between the reflective sheet 78 and the heating belt 71. The heating device 73 heats the heating belt 71 from inside the heating belt 71 by the radiant heat it emits and the radiant heat reflected by the reflective sheet 78.

[0081] In the fixing device 70, the paper P onto which the toner image has been transferred is transported to the clamping area N, where the toner image is heated and pressured by the heating belt 71 and the pressure roll 72, and the toner image is fixed to the paper P. Then, the paper P on which the toner image has been fixed is peeled off from the heating belt 71 by a change in the curvature of the heating belt 71 at the exit region of the sandwiching region N.

[0082] The following describes the details of the heating belt 71 and pressure roll 72 applied to the fixing device 70 according to the second embodiment.

[0083] (Heating belt) The heating belt 71 has a metal base layer, an elastic layer, and a surface layer in that order. The elastic layer is provided as needed.

[0084] -Metal base layer- Examples of metal substrate layers include metal belts made of nickel, aluminum, stainless steel, etc. The thickness of the metal substrate layer is preferably 20 μm to 200 μm, more preferably 30 μm to 150 μm, and even more preferably 40 μm to 130 μm.

[0085] -Elastic layer and surface layer- The elastic layer and surface layer are the same as those described for the heating belt 61 of the fixing device 60 according to the first embodiment. Furthermore, the difference in linear thermal expansion coefficients between the surface layer and the metal substrate layer, and the method for measuring the linear thermal expansion coefficients, are the same as those described for the heating belt 61 of the fixing device 60 according to the first embodiment, and the method for measuring the difference in linear thermal expansion coefficients between the surface layer and the metal heating layer.

[0086] <Image forming apparatus> Next, the image forming apparatus according to this embodiment will be described. The image forming apparatus according to this embodiment is The system comprises an image holder, a charging device for charging the surface of the image holder, an electrostatic latent image forming device for forming an electrostatic latent image on the charged surface of the image holder, a developing device containing a developer including toner and using the developer to develop the electrostatic latent image formed on the surface of the image holder to form a toner image, a transfer device for transferring the toner image to the surface of a recording medium, and a fixing device for fixing the toner image to the surface of a recording medium. The fixing device according to this embodiment is then applied as the fixing device.

[0087] In this embodiment, the fixing device may be a cartridge that can be attached to and detached from the image forming apparatus. In other words, the image forming apparatus according to this embodiment may include the fixing device according to this embodiment as a component of the process cartridge.

[0088] The image forming apparatus according to this embodiment will be described below with reference to the drawings. Figure 4 is a schematic diagram showing the configuration of the image forming apparatus according to this embodiment.

[0089] As shown in Figure 4, the image forming apparatus 100 according to this embodiment is, for example, an intermediate transfer type image forming apparatus generally known as a tandem type. The image forming apparatus 100 comprises a plurality of image forming units 1Y, 1M, 1C, and 1K, an intermediate transfer belt 15, a primary transfer section 10, a secondary transfer section 20, and a fixing device 60. The image forming apparatus 100 also has a control device 40 that controls the operation of each device (or part). Here, image forming units 1Y, 1M, 1C, and 1K are image forming units that form toner images of each color component using an electrophotographic method. The primary transfer unit 10 is a transfer unit that sequentially transfers (primary transfer) the toner images of each color component formed by the image forming units 1Y, 1M, 1C, and 1K to the intermediate transfer belt 15. The secondary transfer unit 20 is a transfer unit that transfers the superimposed toner image transferred onto the intermediate transfer belt 15 to the recording medium, paper K, in one go (secondary transfer). The fixing device 60 is a device that fixes the secondary transferred image onto the paper K.

[0090] Each image forming unit 1Y, 1M, 1C, and 1K of the image forming apparatus 100 is equipped with a photoreceptor 11 that rotates in the direction of arrow A, as an example of an image holder that holds the toner image formed on its surface.

[0091] Around the photoreceptor 11, a charger 12 is provided as an example of a charging device to charge the photoreceptor 11. Around the photoreceptor 11, a laser exposure unit 13 (indicated by the symbol Bm in the figure) is provided as an example of an electrostatic latent image forming device to write an electrostatic latent image onto the photoreceptor 11.

[0092] Surrounding the photoreceptor 11, a developer unit 14 is provided, as an example of a developing device. This unit contains toners for each color component and visualizes the electrostatic latent image on the photoreceptor 11 using the toners. A primary transfer roll 16 is provided around the photoreceptor 11, which transfers the toner images of each color component formed on the photoreceptor 11 to the intermediate transfer belt 15 via the primary transfer unit 10.

[0093] A photoreceptor cleaner 17 is provided around the photoreceptor 11 to remove any residual toner on the photoreceptor 11. Around the photoreceptor 11, electrophotographic devices such as a charger 12, a laser exposure unit 13, a developer unit 14, a primary transfer roll 16, and a photoreceptor cleaner 17 are sequentially arranged along the rotational direction of the photoreceptor 11. These image forming units 1Y, 1M, 1C, and 1K are arranged in a nearly 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).

[0094] The intermediate transfer belt 15 is driven (rotated) by various rolls in the direction of arrow B shown in Figure 4 at a speed appropriate for the purpose. The various rolls include a drive roll 31, a support roll 32, a tensioning roll 33, a back roll 25, and a cleaning back roll 34. The drive roll 31 is a roll that rotates the intermediate transfer belt 15, driven by a motor (not shown) with excellent constant-speed performance. The support roll 32 is a roll that supports the intermediate transfer belt 15, which extends substantially in a straight line along the arrangement direction of each photoreceptor 11. The tension-applying roll 33 is a roll provided in the secondary transfer section 20 that applies tension to the intermediate transfer belt 15 and functions as a corrective roll to prevent the intermediate transfer belt 15 from meandering. The cleaning back roll 34 is a roll provided in the cleaning section that scrapes off residual toner from the intermediate transfer belt 15.

[0095] The primary transfer section 10 consists of a primary transfer roll 16 positioned opposite the photoreceptor 11, with an intermediate transfer belt 15 in between.

[0096] The primary transfer roll 16 is then pressed against the photoreceptor 11 with the intermediate transfer belt 15 in between, and a voltage (primary transfer bias) with the opposite polarity to the charge polarity of the toner (negative polarity; the same applies hereafter) is applied to the primary transfer roll 16. As a result, the toner images on each photoreceptor 11 are sequentially electrostatically attracted to the intermediate transfer belt 15, and superimposed toner images are formed on the intermediate transfer belt 15.

[0097] The secondary transfer section 20 comprises a back roll 25 and a secondary transfer roll 22 positioned on the toner image holding surface side of the intermediate transfer belt 15.

[0098] The secondary transfer roll 22 is then pressed against the back roll 25 with the intermediate transfer belt 15 in between, and the secondary transfer roll 22 is grounded to form a secondary transfer bias between itself and the back roll 25, thereby secondary transferring the toner image onto the paper K that is transported to the secondary transfer section 20.

[0099] Furthermore, an intermediate transfer belt cleaner 35 is provided downstream of the secondary transfer section 20 of the intermediate transfer belt 15 so as to be able to move toward and away from the intermediate transfer belt 15. The intermediate transfer belt cleaner 35 is a cleaner that removes residual toner and paper dust from the intermediate transfer belt 15 after secondary transfer, and cleans the surface of the intermediate transfer belt 15.

[0100] The intermediate transfer belt 15, the primary transfer section 10 (primary transfer roll 16), and the secondary transfer section 20 (secondary transfer roll 22) are examples of a transfer apparatus.

[0101] On the other hand, a reference sensor (home position sensor) 42 is installed upstream of the yellow image forming unit 1Y. The reference sensor 42 is a sensor that generates a reference signal that serves as a reference for determining the image formation timing in each image forming unit 1Y, 1M, 1C, and 1K. The reference sensor 42 recognizes a mark provided on the back of the intermediate transfer belt 15 and generates a reference signal. Based on the recognition of this reference signal, the control device 40 instructs each image forming unit 1Y, 1M, 1C, and 1K to start image formation. A black image forming unit 1K is located downstream of an image density sensor 43 for adjusting image quality.

[0102] The image forming apparatus 100 includes a paper storage section 50, a paper feed roll 51, a transport roll 52, a transport guide 53, a transport belt 55, and a fuser entrance guide 56. The paper storage section 50 is a storage section for storing paper K, which is a transport device for transporting paper K. The paper feed roll 51 is a roll that takes out and transports the paper K accumulated in the paper storage section 50 at predetermined timings. The transport roll 52 is a roll that transports the paper K that has been fed out by the paper feed roll 51. The transport guide 53 is a guide that feeds the paper K, which has been transported by the transport roll 52, to the secondary transfer section 20. The conveyor belt 55 is a belt that conveys the paper K, which has been secondarily transferred by the secondary transfer roll 22, to the fixing device 60. The fuser entrance guide 56 is a guide that leads the paper K to the fuser unit 60.

[0103] Next, the basic image formation process of the image forming apparatus 100 according to this embodiment will be described. In the image forming apparatus 100 according to this embodiment, image data output from an image reading device (not shown) or a personal computer (PC) (not shown) is processed by an image processing device (not shown), and then image formation is performed by image forming units 1Y, 1M, 1C, and 1K.

[0104] The image processing device performs various image processing operations on the input image data, including shading correction, positional shift correction, brightness / color space conversion, gamma correction, frame removal, color editing, and movement editing. The processed image data is converted into four-color chromatic data (Y, M, C, K) and output to the laser exposure unit 13.

[0105] In the laser exposure unit 13, according to the input color tone data, an exposure beam Bm emitted from, for example, a semiconductor laser is irradiated onto each of the photoreceptors 11 of the image forming units 1Y, 1M, 1C, and 1K. After the surface of each photoreceptor 11 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 unit 13, and an electrostatic latent image is formed. The formed electrostatic latent image is then developed as toner images of the respective colors Y, M, C, and K by the respective image forming units 1Y, 1M, 1C, and 1K.

[0106] The toner images formed on the photoreceptors 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 photoreceptor 11 comes into contact with the intermediate transfer belt 15. More specifically, in the primary transfer section 10, a primary transfer roll 16 applies a voltage (primary transfer bias) with the opposite polarity to the toner's charge polarity (negative polarity) to the substrate of the intermediate transfer belt 15, and the toner images are sequentially superimposed on the surface of the intermediate transfer belt 15 to perform primary transfer.

[0107] After the toner image is sequentially transferred to the surface of the intermediate transfer belt 15, the intermediate transfer belt 15 moves and the toner image is transported to the secondary transfer section 20. When the toner image is transported to the secondary transfer section 20, the transport device rotates the paper feed roll 51 in time with the transport of the toner image to the secondary transfer section 20, and paper K of the desired size is supplied from the paper storage section 50. The paper K supplied by the paper feed roll 51 is transported by the transport roll 52 and reaches the secondary transfer section 20 via the transport guide 53. Before reaching the secondary transfer section 20, the paper K is temporarily stopped, and the position of the paper K and the position of the toner image are aligned by rotating the alignment roll (not shown) in time with the movement of the intermediate transfer belt 15 holding the toner image.

[0108] In the secondary transfer section 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 transported in sync with the timing, is sandwiched between the intermediate transfer belt 15 and the secondary transfer roll 22. When a voltage (secondary transfer bias) with 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 image held on the intermediate transfer belt 15 is electrostatically transferred all at once onto the paper K in the secondary transfer section 20, which is pressed by the secondary transfer roll 22 and the back roll 25.

[0109] Subsequently, the paper K on which the toner image has been electrostatically transferred is peeled off the intermediate transfer belt 15 by the secondary transfer roll 22 and transported as is. The paper K is transported to a transport belt 55 located downstream of the secondary transfer roll 22 in the paper transport direction. The transport belt 55 transports the paper K to the fuser 60 at an optimal transport speed for the fuser 60. The unfixed toner image on the paper K transported to the fuser 60 is fixed to the paper K by the fuser 60 through a fixing process using heat and pressure. The paper K with the fixed image formed is then transported to a paper discharge and storage section (not shown) located in the discharge section of the image forming apparatus 100.

[0110] Meanwhile, after the transfer to paper K is complete, any residual toner remaining on the intermediate transfer belt 15 is transported to the cleaning section as the intermediate transfer belt 15 rotates. The residual toner is removed from the intermediate transfer belt 15 by the cleaning back roll 34 and the intermediate transfer belt cleaner 35.

[0111] Here, as described above, the image forming apparatus 100 has a control device 40 that controls the operation of each device (each part). The control unit 40 is configured as a computer that controls the entire device and performs various calculations. Specifically, as shown in Figure 5, the control unit 40 includes a CPU (Central Processing Unit) 400A, which is an example of a processor; a ROM (Read Only Memory) 400B that stores various programs; a RAM (Random Access Memory) 400C used as a work area when programs are executed; a storage device 400D that stores various information; and an input / output interface (I / O) 400E. The CPU 400A, ROM 400B, RAM 400C, storage device 400D, and I / O 400E are each connected via a bus 400F.

[0112] The CPU400A is the central processing unit, which executes various programs and controls various components. Specifically, the CPU400A reads programs from ROM400B or storage400D and executes them using RAM40AC as the working area. The CPU400A controls the above components and performs various calculations according to the programs recorded in ROM400B or storage400D. ROM400B stores various programs and data. RAM400C temporarily stores programs or data as a working area. The Storage 400D consists of an HDD (Hard Disk Drive) or SSD (Solid State Drive) and stores various programs, including the operating system, and various data. ROM400B or storage 400D stores various programs for the "fixing operation program" in addition to the "image forming operation program".

[0113] Furthermore, the image forming apparatus 100 includes, in addition to the control device 40, an operation display unit 402, an image processing unit 404, an image memory 406, an image forming unit 408, a storage unit 410, and a communication unit 412. Each of the operation display unit 402, image processing unit 404, image memory 406, image forming unit 408, storage unit 410, and communication unit 412 is connected to the I / O 400E of the control device 40. The control device 40 exchanges information with each of the operation display unit 402, image processing unit 404, image memory 406, image forming unit 408, storage unit 410, and communication unit 412 to control each of these units.

[0114] The operation display unit 402 includes various buttons such as a start button and a numeric keypad, as well as a touch panel for displaying various screens such as warning screens and setting screens. With the above configuration, the operation display unit 402 accepts operations from the user and displays various information to the user.

[0115] The image processing unit 404 performs predetermined image processing on image information acquired from the external device 414 via the communication unit 412 to generate image information for output to the image forming unit 408. For example, it unpacks PDL data described in a page description language and converts it into raster data (RGB data) unpacked into each RGB color, then performs color conversion processing on the RGB data to generate YMCK data, etc., expressed in colors that can be reproduced by the image forming apparatus. Furthermore, screen processing and gamma correction processing may also be performed.

[0116] The image memory 406 stores various types of image information acquired by the image forming apparatus 10, such as image information acquired from an external device 414 and image information generated by the image processing unit 404. For example, the image memory 406 stores at least image information after image processing by the image processing unit 404, that is, image information to be output to the image forming unit 408.

[0117] The image forming unit 408 is described as a main component of the image forming apparatus 10. The image forming unit 408 includes, for example, image forming units 1Y, 1M, 1C, 1K, and a fixing device 60. Each of these units is connected to the control device 40. The control device 40 controls each of these units by exchanging information with them.

[0118] The input unit 410 includes a pointing device such as a mouse and a keyboard, and is used for various types of input. The communication unit 412 is an interface for communicating with an external device 414 via a wired or wireless communication line, and standards such as Ethernet®, FDDI, and Wi-Fi® are used. For example, the communication unit 412 acquires image formation information from the external device 414 along with image formation instructions or image information of an electronic document. The image formation information includes parameters that represent attributes such as the type of paper K (size, etc.), the paper feeding direction of the paper K, the number of copies, and the color mode.

[0119] In the control device 40, a CPU 400A, which is an example of a processor, executes the above-mentioned "fusing operation program" and operates the fixing device 60.

[0120] Note that the term "processor" refers to a broad category of processors, including general-purpose processors (e.g., CPU: Central Processing Unit, etc.) and specialized processors (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.).

[0121] The operation of a processor may not be performed by a single processor, but may also be performed by multiple processors located in physically separate locations working together. Alternatively, some or all of the operations performed by specific multiple processors in each of the above embodiments may be integrated and performed by a single processor. Furthermore, the order of the operations of the processor is not limited to the order described in each of the above embodiments, and may be changed as appropriate.

[0122] The program for operating the image forming apparatus 100 may be provided on a computer-readable recording medium such as a USB (Universal Serial Bus) memory, a flexible disk, or a CD-ROM (Compact Disc Read Only Memory), or it may be provided online via a network such as the Internet. In this case, the program recorded on the computer-readable recording medium is usually transferred to and stored in memory or storage. Furthermore, this program may be provided, for example, as a standalone application software, or it may be incorporated into the software of each device as a function of the image forming apparatus 100.

[0123] Although this embodiment has been described above, it is not intended to be interpreted as being limited to the above embodiment, and various modifications, changes, and improvements are possible. [Examples]

[0124] [Example A] <Fabrication of heating belt A1> (Formation of resin substrate layer) An N-methyl-2-pyrrolidone (NMP) solution (solid content concentration 18% by mass) of polyimide precursor (polyimide varnish "U Varnish-S", manufactured by UBE Co., Ltd.) was spirally coated onto a mold with a diameter of φ30 mm to a film thickness of 60 μm, and fired to 380°C by the following step heating procedure. The step heating procedure involved raising the temperature from 25°C to 120°C, maintaining it at 120°C for 1 hour, raising the temperature from 120°C to 250°C, maintaining it at 250°C for 1 hour, raising the temperature from 250°C to 380°C, maintaining it at 380°C for 1 hour, and then cooling it down from 380°C to 25°C. This resulted in a tubular polyimide resin belt (hereinafter referred to as PI substrate) consisting of a single layer of polyimide resin with an outer diameter of 30 mm, a film thickness of 60 μm, and a width of 400 mm. This was used as the resin substrate layer.

[0125] Using a liquid honing apparatus (LH-8TTHiS, manufactured by Fuji Seiki Co., Ltd.), the surface of the PI substrate was roughened to a surface roughness of Ra = 0.5 μm to 1.0 μm. The honing conditions were abrasive grain #320, spray pressure 0.3 MPa, spray distance 100 mm, and processing time 1.5 minutes. After the abrasive grains on the roughened surface of the PI substrate were washed off with deionized water, the moisture on the surface of the PI substrate was removed with compressed air.

[0126] (Formation of each metal layer) Next, the PI substrate was assembled into a plating jig, and an electroless nickel plating layer with a thickness of 0.5 μm (i.e., a metal underlayer) was formed by electroless plating. Next, after forming an electroless copper plating layer (metal base layer), electrodes were set at both ends of the plating jig, and electroplating was performed using copper sulfate plating solution to form an electroplated copper layer (i.e., a metal heating layer) with a thickness of 10 μm. Next, electrodes were set at both ends of the plating jig, and electrolytic nickel plating was performed using an electrolytic plating solution to form an electrolytic nickel plating layer (i.e., a metal protective layer) with a thickness of 10 μm.

[0127] (Formation of an elastic layer) Next, a solution was prepared by mixing equal amounts of solution A and solution B of PRIMER-NO.32 (two-component silicone rubber primer, manufactured by Shin-Etsu Chemical Co., Ltd.), and this solution was applied to the surface of the electrolytic nickel plating layer using a spiral coating apparatus. The mixture was then air-dried at room temperature for 30 minutes and baked at 170°C for 20 minutes to form an adhesive layer with a thickness of 0.2 μm.

[0128] Next, silicone rubber (X34-1053-A / B, manufactured by Shin-Etsu Chemical Co., Ltd.) was diluted with butyl acetate to a solid content concentration of 85% by mass to obtain a coating solution for forming an elastic layer. The coating solution for forming an elastic layer was applied to the surface (i.e., the outer surface) of the adhesive layer to a thickness of 200 μm using a spiral coating apparatus to form a coating film. Next, the formed coating film was subjected to a self-smoothing treatment (30°C for 5 minutes) and primary vulcanization (120°C for 20 minutes) to form an elastic layer.

[0129] (Formation of the surface layer) Next, a coating solution with the following composition was applied to the surface of the elastic layer by a spiral coating method, dried at 120°C for 10 minutes, and then heated at 170°C for 10 minutes to form a 30 μm surface layer. The composition of the coating solution is as follows: • Polysiloxane compound SQ1: Konishi Chemical Co., Ltd. "SR-13H", formula: [R 1 SiO 3 / 2 ] m The unit T is expressed as (in the formula, R 1 Polysiloxane compounds having only methyl groups: the amount shown in Table 1 as "volume % (relative to surface layer)". • Solvent: Butyl acetate: An amount that makes up 10% by mass of the coating solution (i.e., an amount that makes up 90% by mass of the solids content)

[0130] A heating belt was obtained through the above operations.

[0131] <Fabrication of heating belts A2-A6 and AC2> A heating belt was obtained in the same manner as heating belt A1, except that the following items were changed according to Table 1. However, in some examples, polysiloxane compound SP was used in combination with polysiloxane compound SQ. In heating belt AC2, only polysiloxane compound SP was used as the polysiloxane compound. • Type and amount of polysiloxane compound SQ (amount is the content relative to the surface layer) • Type and amount of polysiloxane compound SP (amount is the content relative to the surface layer)

[0132] <Heating belt AC1> The resin substrate layer and elastic layer were formed in the same manner as with heating belt A1. Next, a 35 μm thick tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) tube (manufactured by Gunze Corporation) was placed on top of the elastic layer and heated at 200°C for 120 minutes to form a surface layer made of fluororesin tube.

[0133] <Examples A1-A10, Comparative Examples A1-A2> For the fixing method, we prepared an image forming apparatus (Fujifilm Business Innovation Co., Ltd. "Apeos C5570") equipped with a fixing device using the electromagnetic induction heating method (indicated as "IH method" in the table). The heating belts obtained above were mounted as heating belts in the fixing device of this image forming apparatus. The resulting image forming apparatus was designated as the image forming apparatus for each example. The following evaluation was then performed. In this example, the fixing apparatus of the image forming apparatus is a device that, before the start of fixing, rotates the heating belt which is separated from the heating belt and pressure roll, and then performs an operation to heat the metal heating layer using an electromagnetic induction heating device, and then performs an operation to bring the heating belt and pressure roll into contact, thereby starting the fixing process. The surface temperature T1 of the heating belt when the heating belt and the pressure roll come into contact, and the surface temperature T2 of the heating belt when fixing begins, were set to the temperatures shown in Table 1.

[0134] <Rating> (Toner offset) The toner offset was evaluated using the image forming apparatus in each example as follows. A solid black image was formed on Mirror Coat Platinum 256gsm paper (manufactured by Fujifilm Business Innovation Co., Ltd.), and evaluated by visual observation. The evaluation criteria are as follows: A+: No image defects due to toner offset are visible in the image. A: No image defects due to toner offset are visible in the image, but gloss unevenness is visible in the image, though it is within an acceptable range. B: Slight image defects due to toner offset are visible in the image, but they are within acceptable limits. C: Clear toner offset defects are visible in the image.

[0135] (Image gloss unevenness) The image gloss unevenness was evaluated using the image forming apparatus in each example as follows. While outputting an image with a black halftone density of 10% in the SEF (short edge feed) direction on A4 paper, a solid black image was output on A3 paper every 100,000 image outputs. This evaluation was carried out until 1,000,000 image outputs were reached, after which the image quality and the deformation state (i.e., wrinkles) of the surface layer of the heating belt were checked. The results are shown in Table 1. The evaluation criteria are as follows. A+: No wrinkles were observed on the surface layer of the heating belt, and no unevenness in gloss was visible in the image. A: Slight wrinkles are visible on the surface layer of the heating belt, and slight gloss unevenness is visible in the image, but these are within acceptable limits. B: Wrinkles are visible on the surface layer of the heating belt, and uneven gloss is visible in the image, but these are within acceptable limits. C: Clear wrinkles are visible on the surface layer of the heating belt, and clear unevenness in gloss is visible in the image.

[0136] [Example B] <Fabrication of heating belt B1> (Preparation of the metal substrate layer) A nickel metal belt with an outer diameter of 30 mm, a film thickness of 40 μm, and a width of 400 mm was prepared, and its inner surface was blackened. This was used as the metal base material layer.

[0137] (Formation of the elastic layer) In the same manner as the heating belt A1, an adhesive layer and an elastic layer were sequentially formed.

[0138] (Formation of the surface layer) Next, a coating solution with the following composition was applied to the surface of the elastic layer by the spiral coating method, dried at 120 °C for 10 minutes, and then heated at 170 °C for 10 minutes to form a 30-μm surface layer. The composition of the coating solution is as follows. · Polysiloxane compound SQ1: Shin-Etsu Chemical Co., Ltd. "SR-13H", formula: [R 1 SiO 3 / 2 m Polysiloxane compound having only T units (wherein, R 1 = methyl group) represented by the formula: the amount to be "volume% (with respect to the surface layer)" shown in Table 1 · Solvent: butyl acetate: the amount to be 10% by mass of the coating solution (that is, the amount to make the solid content 90% by mass)

[0139] After the above operations, the heating belt was adjusted to a width of 360 mm to obtain a heating belt.

[0140] <Production of heating belts B2 to B6 and BC2> According to Table 2, heating belts were obtained in the same manner as heating belt B1, except that the following items were changed. However, in some examples, polysiloxane compound SP was used in combination with polysiloxane compound SQ. Note that in heating belt BC2, only polysiloxane compound SP was used as the polysiloxane compound. · Type and amount of polysiloxane compound SQ (the amount is the content with respect to the surface layer) · Type and amount of polysiloxane compound SP (the amount is the content with respect to the surface layer)

[0141] <Heating belt BC1> In the same manner as heating belt B1, the metal base material layer to the elastic layer was formed. ​Next, a tube made of tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) with a film thickness of 35 μm (manufactured by Gunze, Ltd.) was placed over the elastic layer and heated at 200 °C for 120 minutes to form a surface layer made of a fluororesin tube.

[0142] <Examples B1 to B6, Comparative Examples B1 to B2> An image forming apparatus (Ricoh Co., Ltd. "MPC6003") equipped with a fixing device using the direct heat method (denoted as "DH method" in the table) was prepared. Each of the obtained heating belts was mounted as the heating belt of the fixing device of this image forming apparatus. The obtained image forming apparatus was used as the image forming apparatus for each example. Then, in the same manner as in Example A1, evaluation of toner offset and image gloss unevenness was performed.

[0143] <00008​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​Polysiloxane compounds (i.e., dimethylorganosiloxanes) that have only methyl groups.

[0145] [Table 1]

[0146] [Table 2]

[0147] From the above results, it can be seen that in this embodiment, compared to the comparative example, toner offset and image gloss unevenness are suppressed in both the electromagnetic induction heating method and the direct heat method of the fixing device. This demonstrates that both electromagnetic induction heating and direct heat fixing devices exhibit high release properties for the heating belt and suppress image gloss unevenness.

[0148] This embodiment includes the following aspects. (((1))) A heating belt having a metal layer and a surface layer provided on the metal layer, A pressure roll that contacts the heating belt and pressurizes the heating belt, A heating device that heats the heating belt in a location other than the contact area between the heating belt and the pressure roll, Equipped with, The surface layer of the heating belt is given by formula:[R 1 SiO 3 / 2 ] m The unit T is expressed as (where R is used in the formula). 1 is an organic group, m is an integer greater than or equal to 2, and there is at least one R in the T unit. 1 A fixing device comprising a polysiloxane compound having a group that includes at least one alkyl group or aryl group. (((2))) At least one R in the aforementioned T unit 1 The fixing apparatus according to (((1))), wherein the group contains an alkyl group. (((3))) The fixing apparatus according to (((2))), wherein the group containing the alkyl group is a methyl group. (((4))) The fixing device according to any one of (((1))) to (((3))), wherein the linear thermal expansion coefficient of the surface layer of the heating belt at 150°C is 130 ppm / °C or less. (((5))) The fixing device according to ((4)), wherein the linear thermal expansion coefficient of the surface layer of the heating belt at 150°C is 120 ppm / °C or less. (((6))) The heating belt is a belt having, in this order, a metal substrate layer, an elastic layer, and a surface layer as the metal layer. The fixing device according to any one of items (((1))) to (((5))), wherein the heating device is a heating device that emits radiant heat. (((7))) The heating belt is a belt having, in this order, a base layer, a metal heating layer as the metal layer, an elastic layer, and a surface layer. The fixing device according to any one of (((1))) to (((5))), wherein the heating device is an electromagnetic induction heating device that generates heat in the metal heating layer by electromagnetic induction. (((8))) The fixing apparatus according to (((7))), wherein, before the start of fixing, the heating belt is rotated while it is separated from the pressure roll, and the operation to heat the metal heating layer is performed using the electromagnetic induction heating device, and then the operation to bring the heating belt and the pressure roll into contact is performed to start fixing. (((9))) The fixing apparatus according to (((8))), wherein the operation of bringing the heating belt and the pressure roll into contact is performed after the surface temperature T1 of the heating belt reaches 120°C or higher, and fixing is started after the surface temperature T2 of the heating belt reaches 130°C or higher. (((10))) Image holder and, A charging device for charging the surface of the image holder, An electrostatic latent image forming apparatus for forming an electrostatic latent image on the surface of the charged image holder, A developing apparatus that contains a developer containing toner, and develops an electrostatic latent image formed on the surface of the image holder with the developer to form a toner image, A transfer device for transferring the toner image onto the surface of a recording medium, A fixing device according to any one of items (((1))) to (((9))) for fixing the toner image onto the surface of a recording medium, An image forming apparatus equipped with the following features.

[0149] The effects of the above embodiment are as follows: According to the invention of (((1))), a fixing device is provided that, in a specific fixing device, has higher mold release properties for the heating belt compared to a case where the surface layer of the heating belt is a fluororesin layer, and suppresses the occurrence of uneven image gloss caused by wrinkles in the surface layer of the heating belt. According to the invention of (((2))), at least one R in the T unit 1 Compared to cases where the group contains an aryl group, this fixing device provides superior release properties for the heating belt and suppresses the occurrence of uneven image gloss caused by wrinkles in the surface layer of the heating belt. According to the invention of (((3))), compared to the case where the group containing the alkyl group has two or more carbon atoms, a fixing device is provided which has higher release properties for the heating belt and suppresses the occurrence of uneven image gloss caused by wrinkles in the surface layer of the heating belt. The heating belt has high release properties. According to the invention of (((4))), compared to the case where the linear thermal expansion coefficient of the heating belt's surface layer exceeds 130 ppm / °C at 150°C, a fixing device is provided that offers improved release properties of the heating belt and suppresses the occurrence of uneven image gloss caused by wrinkles in the heating belt's surface layer. According to the invention of (((5))), compared to the case where the linear thermal expansion coefficient of the heating belt's surface layer exceeds 120 ppm / °C at 150°C, a fixing device is provided that offers improved mold release properties for the heating belt and suppresses the occurrence of uneven image gloss caused by wrinkles in the heating belt's surface layer. According to the invention according to ((6)), in a specific fixing device, compared with the case where the surface layer of the heating belt is a fluororesin layer, there is provided a fixing device of the direct heat type, having high releasability of the heating belt and suppressing the occurrence of image gloss unevenness caused by wrinkles in the surface layer of the heating belt. According to the invention according to ((7)), in a specific fixing device, compared with the case where the surface layer of the heating belt is a fluororesin layer, there is provided a fixing device of the electromagnetic induction heating type, having high releasability of the heating belt and suppressing the occurrence of image gloss unevenness caused by wrinkles in the surface layer of the heating belt.

[0150] According to the invention according to ((8)), there is provided a fixing device having high releasability of the heating belt and suppressing the occurrence of image gloss unevenness caused by wrinkles in the surface layer of the heating belt, compared with the case where the heating belt and the pressure roll are in contact even when the fixing device is not operating. According to the invention according to ((9)), there is provided a fixing device having high releasability of the heating belt and suppressing the occurrence of image gloss unevenness caused by wrinkles in the surface layer of the heating belt, compared with the case where the operation of bringing the heating belt and the pressure roll into contact is performed when the surface temperature T1 of the fixing belt is less than 120°C or fixing is started when the surface temperature T2 of the fixing belt is less than 130°C.

Explanation of Reference Numerals

[0151] 100 Image forming apparatus 1Y, 1M, 1C, 1K Image forming units 10 Primary transfer section 11 Photoconductor 12 Charger 13 Laser exposure device 14 Developing device 15 Intermediate transfer belt 16 Primary transfer roll [[ID=DB32]] 17 Photoconductor cleaner 20 Secondary transfer section 22 Secondary transfer roll 25 Back roll 26 Feed roll 31 Driving roll 32 Support roll 33 Tension-imparting roll 34 Cleaning back roll 35 Intermediate transfer belt cleaner 40 Control device 42 Reference sensor 43 Image density sensor 50 Paper storage unit 51 Paper feed roll 52 Conveyor roll 53 Conveyor guide [[ID=***]]55 Conveyor belt 56 Fixing entrance guide 60 Fixing device 61 Heating belt 62 Pressing roll 63 Electromagnetic induction heating device 63A Excitation coil 64 Latch mechanism 65 Sliding sheet 66 Pressing pad 66 Pressing sheet 67 Support member 68 Temperature sensor 70 Fixing device 71 Heating belt 72 Pressing roll 73 Heating device 74 Sliding sheet 75 Pressing pad 76 Support member 78 Reflective sheet

Claims

1. A heating belt having a metal layer and a surface layer provided on the metal layer, A pressure roll that contacts the heating belt and pressurizes the heating belt, A heating device that heats the heating belt in a location other than the contact area between the heating belt and the pressure roll, Equipped with, The surface layer of the heating belt is given by formula: [R １ SiO ３／２ ] ｍ The unit T is expressed as (where R is used in the formula). １ is an organic group, m is an integer greater than or equal to 2, and at least one R in the T unit １ A fixing device comprising a polysiloxane compound having a group that includes at least one alkyl group or aryl group.

2. At least one R in the T unit １ The fixing apparatus according to claim 1, wherein the group contains an alkyl group.

3. The fixing apparatus according to claim 2, wherein the group containing the alkyl group is a methyl group.

4. The fixing device according to claim 1, wherein the linear thermal expansion coefficient of the surface layer of the heating belt at 150°C is 130 ppm / °C or less.

5. The fixing device according to claim 4, wherein the linear thermal expansion coefficient of the surface layer of the heating belt at 150°C is 120 ppm / °C or less.

6. The heating belt is a belt having a metal substrate layer, an elastic layer, and a surface layer in that order as the metal layer. The fixing device according to claim 1, wherein the heating device is a heating device that emits radiant heat.

7. The heating belt is a belt having, in this order, a base layer, a metal heating layer as the metal layer, an elastic layer, and a surface layer. The fixing apparatus according to claim 1, wherein the heating device is an electromagnetic induction heating device that generates heat in the metal heating layer by electromagnetic induction.

8. The fixing apparatus according to claim 7, wherein, before the start of fixing, the heating belt is rotated while it is separated from the pressure roll, and after performing an operation to heat the metal heating layer using the electromagnetic induction heating device, the heating belt and the pressure roll are brought into contact, and fixing is started.

9. The fixing apparatus according to claim 8, wherein the operation of bringing the heating belt and the pressure roll into contact is performed after the surface temperature T1 of the heating belt reaches 120°C or higher, and fixing is started after the surface temperature T2 of the heating belt reaches 130°C or higher.

10. Image holder and, A charging device for charging the surface of the image holder, An electrostatic latent image forming apparatus for forming an electrostatic latent image on the surface of the charged image holder, A developing apparatus that contains a developer containing toner, and uses the developer to develop an electrostatic latent image formed on the surface of the image holder to form a toner image, A transfer device for transferring the toner image onto the surface of a recording medium, A fixing apparatus according to any one of claims 1 to 9, for fixing the toner image onto the surface of a recording medium, An image forming apparatus equipped with the following features.

Images