Image forming apparatus

Abstract

To prevent the occurrence of turn-up of a cleaning blade that cleans a surface of an intermediate transfer body after secondary transfer.SOLUTION: An image forming apparatus executes an image forming operation of primarily transferring a toner image on a surface of a latent image carrier 1 supplied with lubricant including zinc stearate to an intermediate transfer body 15 and subsequently secondarily transferring the toner image from the intermediate transfer body onto recording paper P, and performs cleaning, with a cleaning blade 31, the surface of the intermediate transfer body after the secondary transfer including an adhesion area to which the lubricant on the latent image carrier is adhered. When the difference spectrum between an ATR infrared absorption spectrum of an unused intermediate transfer body and an ATR infrared absorption spectrum of the intermediate transfer body after use is taken for at least an outside area of an A4 lateral paper feed width on the intermediate transfer body, the ratio of the peak area derived from zinc stearate to the peak area derived from the intermediate transfer body is 0.892 or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to an image forming apparatus. [Background technology]

[0002] Conventionally, an image forming apparatus is known that performs an image forming operation in which a toner image on the surface of a latent image carrier supplied with lubricant is first transferred to an intermediate transfer body, and then secondarily transferred from the intermediate transfer body to recording paper, and the surface of the intermediate transfer body after the second transfer is cleaned with a cleaning blade.

[0003] Patent Document 1 discloses an image forming apparatus in which a protective agent (lubricant) containing zinc stearate is rubbed with a brush or the like to form a powder, which is then applied to a photoreceptor (latent image carrier). In this image forming apparatus, toner particles remaining on the intermediate transfer belt (intermediate transfer body) after secondary transfer are cleaned by a cleaning member of a belt cleaning device. [Overview of the project] [Problems that the invention aims to solve]

[0004] However, with conventional image forming apparatuses, when cleaning the surface of the intermediate transfer body after secondary transfer with a cleaning blade, the cleaning blade sometimes peeled off. [Means for solving the problem]

[0005] To solve the above-mentioned problems, the present invention provides an image forming apparatus that performs an image forming operation in which a toner image on the surface of a latent image carrier supplied with a lubricant containing zinc stearate is first transferred to an intermediate transfer body, and then secondarily transferred from the intermediate transfer body to recording paper, and cleans the surface of the intermediate transfer body after the second transfer, including the adhesion region where the lubricant on the surface of the latent image carrier adheres, with a cleaning blade, wherein the intermediate transfer body has an infrared absorption spectrum of 1718 [cm²] derived from the carbonyl group in the ATR method. -1When a difference spectrum is taken between the ATR infrared absorption spectrum of an unused intermediate transfer and the ATR infrared absorption spectrum of a used intermediate transfer after at least 10,000 sheets of A4 paper have been fed, with respect to the region outside the width of A4 landscape paper on the intermediate transfer, The base wavenumber range is 1690.301 to 1760.690 cm⁻¹. -1 Furthermore, the peak wavenumber region is 1707.657~1732.728 cm⁻¹. -1 It is calculated as follows 1718 [cm] derived from the carbonyl group -1 For peak area with a peak near ] The base wavenumber range is 2879.201 to 2988.159 cm⁻¹. -1 Furthermore, the peak wavenumber region is 2910.057~2925.484 cm⁻¹. -1 It is calculated as follows The ratio of peak area derived from zinc stearate 、 It is characterized by being 0.892 or less. [Effects of the Invention]

[0006] According to the present invention, the occurrence of peeling of the cleaning blade used to clean the surface of the intermediate transfer body after secondary transfer is suppressed. [Brief explanation of the drawing]

[0007] [Figure 1] A schematic diagram of the printer according to the embodiment. [Figure 2] A schematic diagram showing another example of the same printer. [Figure 3] A schematic diagram showing an example of a process unit in an embodiment. [Figure 4] (a) to (d) are explanatory diagrams showing the outer adhesion region in the embodiment. [Figure 5] (a) is a graph showing the results of measuring the ATR infrared absorption spectrum of the outer attachment region of an unused intermediate transfer belt. (b) is a graph showing the results of measuring the ATR infrared absorption spectrum of the outer attachment region of a used intermediate transfer belt. [Figure 6] This graph shows the difference spectrum obtained by taking the difference between the ATR infrared absorption spectrum of an unused intermediate transfer belt and the ATR infrared absorption spectrum of an intermediate transfer belt after use. [Figure 7] An explanatory diagram showing an example of a full-color running chart used in an evaluation test for evaluating the relationship between the amount of filming substance adhered and the occurrence of blade curling. [Figure 8] An explanatory diagram showing an example of a monochrome running chart used in the same evaluation test.

Embodiments for Carrying Out the Invention

[0008] Hereinafter, an embodiment in which the present invention is applied to a color laser printer (hereinafter simply referred to as a printer), which is an image forming apparatus, will be described.

[0009] FIG. 1 is a schematic configuration diagram of the printer of this embodiment. In the printer shown in FIG. 1, four process units 10Bk, 10Y, 10M, and 10C that are detachably attached to the printer main body 100 are provided at the center of the printer main body 100. Each of the process units 10Bk, 10Y, 10M, and 10C has the same configuration except that it contains developers of different colors, black (Bk), yellow (Y), magenta (M), and cyan (C), corresponding to the color separation components of the color image. Therefore, when not particularly distinguishing colors, the descriptions of Bk, Y, M, C, etc. are omitted after the reference numerals of each member.

[0010] Each process unit 10 includes a photoreceptor 1 that is a latent image carrier, a charging roller 2 that charges the surface of the photoreceptor, a developing device 4, a cleaning device 7 that cleans the surface of the photoreceptor, and the like. The photoreceptor 1 is a cylindrical drum.

[0011] The cleaning device 7 has a cleaning blade 6 that counter-abuts against the photoreceptor 1. Cleaning is performed by scraping off the transfer residual toner on the photoreceptor 1 with the cleaning blade 6. Note that an electrostatic method such as an electrostatic brush method or an electrostatic roller method can also be mounted instead of the blade cleaning method.

[0012] Above each process unit 10, an exposure device 3, which is a latent image forming means for exposing the surface of each photoreceptor 1, is provided. The exposure device 3 has a light source, a polygon mirror, an f-θ lens, a reflection mirror, etc., and irradiates the surface of each photoreceptor 1 with laser light L based on image data.

[0013] Below each process unit 10, an intermediate transfer belt 15, which is an intermediate transfer member, is provided. The intermediate transfer belt 15 is an endless belt and is stretched by a secondary transfer opposing roller 21, a cleaning backup roller 16, and a tension roller 20.

[0014] Examples of the material used for the intermediate transfer belt 15 include PVDF (polyvinylidene fluoride), ETFE (ethylene-tetrafluoroethylene copolymer), PI (polyimide), PC (polycarbonate), TPE (thermoplastic elastomer), etc. A resin film-shaped endless belt in which a conductive material such as carbon black is dispersed in these materials can be used as the intermediate transfer belt.

[0015] In this embodiment, by rotationally driving the secondary transfer opposing roller 21 by a belt drive motor, the intermediate transfer belt 15 rotates in the direction indicated by the arrow in the figure. Also, both axial ends of the tension roller 20 are pressed by springs, and the tension roller 20 applies tension to the intermediate transfer belt 15. Note that the drive source of the process unit that drives the photoreceptor 1, etc., and the drive source that rotationally drives the secondary transfer opposing roller 21 can be either independent or common. However, it is common to turn on / off at the same time at least the drive of the process unit for black and the secondary transfer opposing roller 21. Therefore, in order to reduce the size and cost of the main body, it is desirable to make the drive source of the process unit for black common with the drive source of the secondary transfer opposing roller 21.

[0016] The four primary transfer rollers 5 are either conductive sponge rollers or metal rollers (aluminum, SUS), and each roller sandwiches an intermediate transfer belt 15 between itself and each photoreceptor 1 to form a primary transfer nip. A primary transfer high-voltage power supply is connected to each primary transfer roller 5, and a primary transfer bias is applied from this high-voltage power supply to form a transfer field. When conductive sponge rollers are used for the primary transfer rollers 5, ion-conductive rollers (urethane + carbon dispersion, NBR, hydrin rubber) or electronically conductive rollers (EPDM) are used.

[0017] The secondary transfer roller 25 sandwiches the intermediate transfer belt 15 between itself and the secondary transfer opposing roller 21 to form a secondary transfer nip. Similar to the primary transfer roller 5, the secondary transfer roller 25 is connected to a secondary transfer high-voltage power supply, and a predetermined secondary transfer bias is applied from this high-voltage power supply to form a transfer electric field.

[0018] There are two methods for secondary transfer bias: attractive transfer and repulsive transfer. In the attractive transfer method, a positive bias is applied to the secondary transfer roller 25 and the secondary transfer opposing roller 21 is grounded to form a secondary transfer electric field. In the repulsive transfer method, a negative bias is applied to the secondary transfer opposing roller 21 and the secondary transfer roller 25 is grounded to form a secondary transfer electric field.

[0019] The secondary transfer roller 25 is a sponge roller, and ion-conductive rollers (urethane + carbon dispersion, NBR, hydrin rubber) or electronically conductive rollers (EPDM) are used. A secondary transfer cleaning unit may also be provided to remove toner and other deposits adhering to the surface of the secondary transfer roller 25.

[0020] Alternatively, the secondary transfer unit that transfers the toner image from the intermediate transfer belt to the recording paper P, which is used as the recording material, may be a belt system using a secondary transfer belt. The secondary transfer belt is stretched between a drive roller and a tension roller that are opposite the intermediate transfer belt, with the secondary transfer belt in between. A secondary transfer bias is applied to the drive roller.

[0021] The belt cleaning device 32 has an intermediate transfer cleaning blade 31 that makes counter-contact with the intermediate transfer belt 15. Cleaning is performed by scraping off the remaining toner on the intermediate transfer belt 15 with the intermediate transfer cleaning blade 31. Note that electrostatic methods such as electrostatic brush or electrostatic roller methods can also be installed instead of the blade cleaning method. However, in the case of electrostatic methods, a cleaning brush / roller to which bias is applied is placed instead of the intermediate transfer cleaning blade 31. As a result, depending on the usage of the image forming apparatus, it may be necessary to pre-charge the remaining toner, which has disadvantages such as increasing the size of the cleaning unit itself, requiring the addition of one or two high-voltage power supplies, and requiring extra operation for bias cleaning. Therefore, from the viewpoint of miniaturization, cost reduction, and ease of cleaning, the blade cleaning method is adopted in this embodiment.

[0022] On the other hand, the lower part of the printer body 100 is provided with a paper feed tray 22 that holds the recording paper P, and a paper feed roller 23 that discharges the recording paper P from the paper feed tray 22. Here, the recording paper P includes not only plain paper, but also cardboard, postcards, envelopes, thin paper, coated paper (such as coated paper and art paper), tracing paper, OHP sheets, and other recording materials (including those made of materials other than paper) that can be used to form an image. It also has a manual feed slot 42 through which recording paper set in the manual feed tray is transported.

[0023] The printer body 100 is equipped with a transport path for transporting recording paper P from the paper feed tray 22 or manual feed tray through a secondary transfer nip to the outside of the device. In this configuration, the paper feed follows a vertical path. In the transport path, upstream of the secondary transfer roller 25 in the direction of recording paper transport, a pair of registration rollers 24 is provided as a transport means for transporting the recording paper P to the secondary transfer nip.

[0024] Furthermore, a fixing device 40 for fixing the unfixed image transferred to the recording paper P is located downstream of the secondary transfer roller 25 in the recording paper transport direction.

[0025] The basic operation of an image forming apparatus with the above configuration is as follows: When the image forming operation starts, each photoreceptor 1 in each process unit 10 is driven to rotate clockwise in the figure by a drive device. A roller-shaped charging roller 2 is pressed against the surface of each photoreceptor 1, and the charging roller 2 rotates in accordance with the rotation of the photoreceptor 1. Then, by applying a DC voltage or a bias consisting of a DC voltage superimposed on an AC voltage to the charging roller 2 from a high-voltage power supply, the surface of the photoreceptor 1 is uniformly charged to a predetermined polarity by the charging roller 2.

[0026] Each charged photoreceptor 1 is illuminated with writing light from the exposure device 3, forming an electrostatic latent image on the surface of each photoreceptor 1. At this time, the image information exposed to each photoreceptor 1 is monochrome image information obtained by decomposing a desired full-color image into yellow, magenta, cyan, and black color information. This exposure process is performed using a laser beam scanner with a laser diode or an LED.

[0027] In this way, the electrostatic latent image formed on each photoreceptor 1 is exposed (made visible) as a toner image when toner, supported on the developing roller, is supplied by each developing device 4. During this developing process, a predetermined developing bias is applied to the developing roller of the developing device 4 from a high-voltage power supply.

[0028] Furthermore, when the image forming operation begins, the secondary transfer opposing roller 21 rotates counterclockwise in the figure, causing the intermediate transfer belt 15 to travel in a circular motion in the direction indicated by the arrow in the figure. Then, a predetermined transfer bias controlled by a constant voltage or constant current with the opposite polarity to the charging polarity of the toner is applied to each primary transfer roller 5. As a result, a transfer electric field is formed at the primary transfer nip between each primary transfer roller 5 and each photoreceptor 1.

[0029] Subsequently, as each photoreceptor 1 rotates, when the toner images of each color on the photoreceptor 1 reach the primary transfer nip, the transfer electric field formed at the primary transfer nip causes the toner images on each photoreceptor 1 to be sequentially superimposed and transferred onto the intermediate transfer belt 15. In this way, a full-color toner image is carried on the surface of the intermediate transfer belt 15.

[0030] Furthermore, any toner on each photoreceptor 1 that could not be transferred to the intermediate transfer belt 15 is removed by the cleaning device 7. Subsequently, lubricant is supplied by the lubricant supply unit 8, and the surface of each photoreceptor 1 is discharged by the static elimination device, thereby resetting its surface potential.

[0031] At the bottom of the printer body 100, the paper feed roller 23 starts rotating, and the recording paper P is fed from the paper feed tray 22 onto the transport path. The recording paper P fed onto the transport path is then sent to the secondary transfer nip by the registration roller pair 24 so as to coincide with the timing when the leading edge of the toner image on the surface of the intermediate transfer belt 15 reaches the secondary transfer nip between the secondary transfer roller 25 and the secondary transfer opposing roller 21. At this time, the secondary transfer roller 25 is subjected to a transfer bias with the opposite polarity to the toner charge polarity of the toner image on the intermediate transfer belt 15, thereby forming a transfer electric field at the secondary transfer nip.

[0032] Subsequently, as the intermediate transfer belt 15 rotates, when the toner image on the intermediate transfer belt 15 reaches the secondary transfer nip, the toner image on the intermediate transfer belt 15 is transferred all at once onto the recording paper P by the transfer electric field formed at the secondary transfer nip.

[0033] At this time, any residual toner on the intermediate transfer belt 15 that could not be transferred to the recording paper P is removed by the belt cleaning device 32. The removed toner is transported through the toner transport path to the waste toner container 33 located between the intermediate transfer belt 15 and the paper feed tray 22, where it is collected.

[0034] The recording paper P is separated from the intermediate transfer belt 15 by the curvature of the secondary transfer opposing roller 21 and transported to the fixing device 40, where the toner image on the recording paper P is fixed to the recording paper P by heat and pressure in the fixing device 40. The recording paper P is then discharged from the device through the discharge port 41. In this way, the series of image forming processes in the printer according to this embodiment are completed.

[0035] Furthermore, the printer of this embodiment has a belt contact / separation mechanism that moves the intermediate transfer belt 15 toward and away from the photoreceptor 1 of process units other than the Bk color process unit. When forming a full-color image, the belt contact / separation mechanism is controlled so that the intermediate transfer belt 15 comes into contact with each photoreceptor 1. When forming a monochrome image, the belt contact / separation mechanism is controlled so that the intermediate transfer belt 15 moves away from the photoreceptor 1 of process units other than the Bk color process unit.

[0036] Note that the arrangement of the process unit 10 and the intermediate transfer belt is not limited to the arrangement shown in Figure 1. As shown in Figure 2, the intermediate transfer belt 15, which is an intermediate transfer body, may be provided above each process unit 10.

[0037] Figure 3 is a schematic diagram showing an example of the process unit 10 in this embodiment. As shown in Figure 3, the process unit 10 of this embodiment has a lubricant supply unit 8 as a lubricant supply means. The lubricant supply unit 8 mainly consists of a lubricant supply member 8a made of a foam roller, a solid lubricant 8b, a pressing force application mechanism 8c, a lubricant layer forming mechanism 8d, and the like.

[0038] The solid lubricant 8b comes into contact with the lubricant supply member 8a due to the pressing force from the pressing force application mechanism 8c. The lubricant supply member 8a is rotationally driven and supplies the powdered lubricant, which is scraped off by friction from the solid lubricant 8b, to the surface of the photoreceptor 1 by coating. The lubricant supply member 8a rotates and rubs against the photoreceptor 1 with a difference in linear velocity, and in the process, the powdered lubricant held on the surface of the lubricant supply member 8a is supplied to the surface of the photoreceptor.

[0039] Since partially degraded lubricant and toner remain on the surface of the photoreceptor 1 after the transfer process, the cleaning blade 6 cleans the surface residue, removing residual toner and degraded lubricant from the photoreceptor surface. As a result, lubricant is supplied from the lubricant supply member 8a to the cleaned photoreceptor surface, and the lubricant layer forming mechanism 8d levels it out, creating a thin layer of powdered lubricant, thereby forming a lubricating layer on the photoreceptor surface.

[0040] Next, the solid lubricant 8b in this embodiment will be described. In this embodiment, the use of a lubricant to improve the cleanability of the photoreceptor surface is assumed. The solid lubricant 8b in this embodiment consists of or contains a lubricant and has an elongated block shape along the rotation axis of the photoreceptor 1.

[0041] The material for the solid lubricant 8b is preferably one that spreads uniformly and quickly across the surface of the photoreceptor, coating the surface of the photoreceptor while simultaneously providing lubrication to protect the cleaning blade 6. Specifically, examples include inorganic lubricants, fatty acid metal salts, waxes, oils, and fluororesins. In this embodiment, the solid lubricant 8b contains a fatty acid metal salt (A) and an inorganic lubricant (B), and the fatty acid metal salt (A) and the inorganic lubricant (B) are mixed and used.

[0042] In this embodiment, the solid lubricant 8b is molded into a block shape because it allows for easy adjustment of the supply amount and enables miniaturization of the device. The solid lubricant 8b in this embodiment may also be referred to as a lubricant bar, lubricant block, etc.

[0043] The molding method for the solid lubricant 8b can be appropriately selected. For example, known methods such as melt molding, in which the material is melted and poured into a mold before cooling and solidifying, and compression molding, in which the powder material is compressed as is to obtain a molded product, can be used. In this embodiment, compression molding is preferred because it allows for easy adjustment of hardness, enabling grinding with less force and allowing it to be supplied onto the photoreceptor.

[0044] Examples of fatty acid metal salts (A) include barium stearate, lead stearate, iron stearate, nickel stearate, cobalt stearate, copper stearate, strontium stearate, calcium stearate, cadmium stearate, magnesium stearate, zinc stearate, zinc oleate, magnesium oleate, iron oleate, cobalt oleate, copper oleate, lead oleate, manganese oleate, zinc palmitate, cobalt palmitate, lead palmitate, magnesium palmitate, aluminum palmitate, calcium palmitate, lead caprylate, lead caprate, zinc linolenate, cobalt linolenate, calcium linolenate, zinc ricinoleate, cadmium ricinoleate, barium laurate, lithium laurate, calcium laurate, and zinc laurate. Mixtures of these may also be used.

[0045] In particular, zinc stearate exhibits excellent film-forming properties on the photoreceptor 1, and therefore, in this embodiment, it is used as the main component of the lubricant. In this embodiment, "main component" means that its weight ratio in the total lubricant is greater than 50%.

[0046] On the other hand, while zinc stearate excels in uniform film formation, it is susceptible to degradation due to electrostatic stress. In typical imaging processes, a blade cleaning method is used to remove residual toner from the photoreceptor after transfer. However, when zinc stearate is used, the zinc stearate tends to degrade when subjected to electrostatic hazards, reducing its lubricity and making it easier for toner to slip off the blade.

[0047] When toner passes through the cleaning blade, it can result in the toner directly appearing in the image or accelerating the contamination of charged components. This toner passing through becomes more pronounced as the toner particle size decreases and the charging hazard increases. At the same time, excessive toner passing through can cause wear on the cleaning blade, shortening the lifespan of the process unit 10.

[0048] Considering the above, in this embodiment, a mixture of fatty acid metal salt (A) and inorganic lubricant (B) is used. In this embodiment, inorganic lubricant (B) refers to an inorganic compound that lubricates by cleavage or causes internal sliding. In this embodiment, when zinc stearate is used as fatty acid metal salt (A), there are no particular limitations on inorganic lubricant (B).

[0049] In this embodiment, the inorganic lubricant (B) can be, for example, talc, mica, boron nitride, molybdenum disulfide, tungsten disulfide, kaolin, smectite, hydrotalcite compounds, calcium fluoride, graphite, plate-like alumina, sericite, synthetic mica, etc.

[0050] Among the inorganic lubricants (B), boron nitride is preferred, and in this embodiment, boron nitride is used. Boron nitride has a hexagonal network of tightly packed atoms that overlap at wide intervals, and the only force acting between the layers is a weak van der Waals force, so it cleaves and lubricates easily. Furthermore, using boron nitride enhances the cleaning effect on the photoreceptor. The inorganic lubricant (B) may be surface-treated as needed for purposes such as imparting hydrophobicity. In this embodiment, when boron nitride is used as the inorganic lubricant (B), there are no particular limitations on the fatty acid metal salt (A), and it may be something other than zinc stearate.

[0051] These lubricants are applied to the surface of the photoreceptor, but it has been found that small amounts of them are transferred from the photoreceptor surface to the intermediate transfer belt during the imaging process. As a result, it has been found that this increases the filming of the intermediate transfer belt 15 over time.

[0052] This filming phenomenon is particularly pronounced in the outer adhesion regions at both ends of the intermediate transfer belt 15. This is because, while the paper in the paper-feeding region helps to remove the lubricant, this effect is not obtained in the outer adhesion regions. If filming on the intermediate transfer belt 15 deteriorates, the frictional force between the intermediate transfer cleaning blade 31 and the intermediate transfer belt 15 increases, causing the intermediate transfer cleaning blade 31 to curl up (blade curling).

[0053] The inventors have found that by limiting the amount of zinc stearate and boron nitride adhering to the outer adhesion region (at least the outer region of the A4 landscape paper width) within the width of the adhesion region on the intermediate transfer belt 15 to which the lubricant from the photoreceptor 1 adheres, the occurrence of blade curling can be suppressed to a predetermined amount or less.

[0054] Here, to determine the amount of zinc stearate or boron nitride deposited, we use the ATR (Attenuated Total Reflection) infrared absorption spectrum. The ATR method is one of the methods for measuring infrared absorption spectra, utilizing total internal reflection. An ATR prism with a high refractive index is placed in close contact with the sample, infrared light is shone onto the sample through the ATR prism, and the light emitted from the ATR prism is spectrally analyzed. Due to the relationship between the refractive index of the ATR prism and the sample, when infrared light is incident on the prism at an angle greater than a certain value, the infrared light does not exit the ATR prism and undergoes total internal reflection at the contact surface between the ATR prism and the sample. At that time, the infrared light leaks out a short distance towards the sample, so if the sample absorbs infrared light, the reflected light is attenuated, and the absorption spectrum of the sample can be obtained.

[0055] The ATR method has the advantage of being able to measure the absorption spectrum of a very thin sample portion in contact with an ATR prism, meaning that even thick or low-transparency samples can be measured as long as they are in close contact with the ATR prism. Furthermore, because the functional group can be identified from the wavenumber at which infrared light absorption occurs using the ATR method, it is often used for qualitative analysis. However, because the peak intensity of the absorption spectrum changes depending on the pressure applied to the sample, it has not been generally used for quantitative analysis. Nevertheless, it has been discovered that the relative amount of lubricant deposited can be calculated using the ratio of peak areas obtained by the ATR method as an indicator, making it possible to determine the amount of lubricant deposited on the intermediate transfer belt 15.

[0056] For details, the difference spectrum is taken between the ATR infrared absorption spectrum of an unused intermediate transfer belt 15 and the ATR infrared absorption spectrum of a used intermediate transfer belt. When obtaining the amount of zinc stearate deposited, the ratio of the peak area derived from zinc stearate to the peak area derived from the intermediate transfer belt in this difference spectrum is used as an index value indicating the amount of zinc stearate deposited (hereinafter referred to as the "ZnST index"). When obtaining the amount of boron nitride deposited, the ratio of the peak area derived from boron nitride to the peak area derived from the intermediate transfer belt in this difference spectrum is used as an index value indicating the amount of boron nitride deposited (hereinafter referred to as the "BN index").

[0057] In this embodiment, by using these ZnST and BN indices, the index values ​​(ZnST index and BN index) of zinc stearate and boron nitride in the outer adhesion region on the intermediate transfer belt 15 are kept below a predetermined amount, thereby suppressing the occurrence of blade peeling.

[0058] Figures 4(a) to 4(d) are explanatory diagrams showing the outer adhesion region in this embodiment. In this embodiment, the width of the lubricant supply area on the photoreceptor 1 to which lubricant is supplied from the lubricant supply unit 8 is wider than the width of the intermediate transfer belt 15, and the entire width of the intermediate transfer belt 15 is included within the width of the lubricant supply area on the photoreceptor 1. Therefore, in this embodiment, the lubricant from the photoreceptor 1 adheres to the entire outer adhesion area on the intermediate transfer belt 15.

[0059] Figure 4(a) illustrates the relationship between the maximum paper feed width (A3+ width = 329 mm) usable by the printer of this embodiment and the belt width of the intermediate transfer belt 15. In the example in Figure 4(a), since it is the maximum paper feed width, the outer adhesion region shown in Figure 4(a) is a region that does not come into contact with any size of recording paper P, and is therefore the region where filming is most likely to deteriorate and blade curling is most likely to occur. Therefore, in order to prevent curling of the intermediate transfer cleaning blade 31, it is effective to suppress the deterioration of filming in the outer adhesion region at the maximum paper feed width, and it is important to keep the ZnST index and BN index of this outer adhesion region below predetermined values.

[0060] Figure 4(b) illustrates the relationship between the paper feeding area width (=297 mm) and the belt width of the intermediate transfer belt 15 in the case of commonly used A4 size paper feeding in landscape orientation. In the example in Figure 4(b), the outer adhesion area is the area outside the paper feeding area in the width direction of the paper passing through when A4 size paper is fed in landscape orientation. Generally, in addition to A4 size paper feeding, image formation is also performed on recording paper P of other sizes such as A3. Therefore, in the outer adhesion area when A4 size paper is fed in landscape orientation, the portion inside the maximum paper feeding width can have the lubricant removed by feeding wider size recording paper P. However, in usage situations where A4 size paper is fed in landscape orientation, the lubricant cannot be sufficiently removed by occasionally feeding wider size recording paper P. Therefore, the outer adhesion area when A4 size paper is fed in landscape orientation is also prone to filming deterioration and is an area where blade curling is likely to occur. In particular, the outer adhesion area when feeding A4 size paper horizontally is wider than the outer adhesion area when the maximum paper width is used, so the frictional force between the intermediate transfer belt 15 and the intermediate transfer cleaning blade 31 tends to increase when filming deteriorates. Therefore, in order to prevent the intermediate transfer cleaning blade 31 from curling, it is important to suppress the deterioration of filming in the outer adhesion area when feeding A4 size paper horizontally, and it is important to keep the ZnST index and BN index of this outer adhesion area below predetermined values.

[0061] Figure 4(c) illustrates the relationship between the paper feeding area width (=210 mm) and the belt width of the intermediate transfer belt 15 when A4 size paper is fed vertically. Figure 4(d) illustrates the relationship between the paper feeding area width (=148 mm) and the belt width of the intermediate transfer belt 15 in the case of feeding postcards. In the examples shown in Figures 4(c) and 4(d), as with the example in Figure 4(b), if image formation is performed using only paper of each respective width, the outer adhesion region is also prone to filming deterioration and blade peeling. In particular, the outer adhesion region in the examples in Figures 4(c) and 4(d) is wider than that at the maximum paper width, and even wider than that in the example in Figure 4(b), so the frictional force between the intermediate transfer belt 15 and the intermediate transfer cleaning blade 31 tends to increase when filming deteriorates. Therefore, in order to prevent peeling of the intermediate transfer cleaning blade 31, it is important to suppress the deterioration of filming in the outer adhesion region in the examples in Figures 4(c) and (d), and it is important to keep the ZnST index and BN index of the outer adhesion region below predetermined values.

[0062] Next, we will explain the method for quantifying the filming substance (the method for calculating the index value). Our research has revealed that the main filming materials on the intermediate transfer belt 15 that worsen blade curling are zinc stearate and boron nitride. Therefore, in this embodiment, zinc stearate and boron nitride on the intermediate transfer belt 15 are quantified by the following quantification method. Then, using the quantified index values ​​(ZnST index, BN index), the amount of filming material adhering to the outer adhesion region (at least the outer region of the A4 horizontal paper width) on the intermediate transfer belt 15 is suppressed to a predetermined amount or less in order to prevent blade curling.

[0063] Figure 5(a) is a graph showing the results of measuring the ATR infrared absorption spectrum of the outer attachment region for an unused intermediate transfer belt 15. Figure 5(b) is a graph showing the results of measuring the ATR infrared absorption spectrum of the outer adhesion region of the intermediate transfer belt 15 after use.

[0064] The measurement of the ATR method infrared absorption spectrum was performed using an FT / IR-6100 (manufactured by JASCO Corporation). The measurement was performed non-destructively in a state where the intermediate transfer belt was removed from the intermediate transfer unit without cutting the intermediate transfer belt into sample pieces. The measurement location on the intermediate transfer belt was pressed against the measurement unit of the FT / IR-6100 with a force of approximately 3 kgf for measurement. As a result of performing ATR method IR analysis on each of the unused and used intermediate transfer belts, the obtained IR spectra (absorbance spectra) are shown in FIGS. 5(a) and (b).

[0065] In each of the spectra of FIGS. 5(a) and (b), a peak a derived from a carbonate bond contained in the intermediate transfer belt 15 (i.e., peak a derived from the intermediate transfer belt) was found at 1718.93 cm -1 In addition, in the spectrum after use in FIG. 5(b), a peak b derived from zinc stearate was found at 2918 cm -1 and a peak c derived from boron nitride was found at 1370 cm -1 In the spectrum after use in FIG. 5(b), the peak b of zinc stearate and the peak c derived from boron nitride did not overlap with the peak (such as peak a) derived from the intermediate transfer belt.

[0066] FIG. 6 is a graph showing a difference spectrum obtained by taking the difference between the ATR method infrared absorption spectrum of the unused intermediate transfer belt 15 and the ATR method infrared absorption spectrum of the used intermediate transfer belt 15. Once the difference spectrum shown in FIG. 6 is obtained, from this difference spectrum, the peak area Sa for the peak a derived from the intermediate transfer belt is calculated using the base wavenumber region and the peak wavenumber region. At this time, the base wavenumber region is 1690.301 to 1760.690 cm -1 and the peak wavenumber region is 1707.657 to 1732.728 cm -1 is.

[0067] Also, from the difference spectrum shown in FIG. 6, the peak area Sb for the peak b derived from zinc stearate is calculated using the base wavenumber region and the peak wavenumber region. At this time, the base wavenumber region is 2879.201 to 2988.159 cm-1 The peak wavenumber region is 2910.057–2925.484 cm⁻¹. -1 That is the case.

[0068] Furthermore, the peak area Sc for the boron nitride-derived peak c is calculated from the difference spectrum shown in Figure 6, using the base wavenumber region and the peak wavenumber region. In this case, the base wavenumber region is 1336.428 to 1430.922 cm². -1 The peak wavenumber region is 1367.283–1381.747 cm⁻¹. -1 That is the case.

[0069] Then, as the ZnST index, which is an indicator value showing the amount of zinc stearate deposited, the ratio of the peak area Sb derived from zinc stearate to the peak area Sa derived from the intermediate transfer belt (=Sb / Sa) is calculated. In addition, as the BN index, which is an indicator value showing the amount of boron nitride deposited, the ratio of the peak area Sc derived from boron nitride to the peak area Sa derived from the intermediate transfer belt (=Sc / Sa) is calculated.

[0070] Next, we present an evaluation test that assessed the relationship between the amount of filming material adhering to the blade and the occurrence of blade peeling. In this evaluation test, blade peeling was evaluated for intermediate transfer belts prepared under conditions 1 to 7, each with a different amount of filming material in the outer adhesion region.

[0071] This section explains how to create the intermediate transfer belts for conditions 1 through 7. The intermediate transfer belt was created using a Ricoh MP C5503 copier under the following conditions. • Evaluation environment: 23℃ 50% • Running chart: Full-color vertical band 2% chart (Figure 7), A4 landscape. • Continuous paper feeding, double-sided Under the above conditions, intermediate transfer belts were created by changing the amount of filming material in the outer adhesion region by varying the number of sheets printed (10,000 sheets, 20,000 sheets, etc.) in increments of 10,000 sheets.

[0072] Table 1 shows the ZnST index and the presence or absence of blade peeling for each of the conditions 1 to 7. Table 2 shows the BN index and the presence or absence of blade peeling for each of the conditions 1 to 7.

[0073] [Table 1]

[0074] [Table 2]

[0075] The ZnST and BN indices in Tables 1 and 2 were measured on the intermediate transfer belt after a run, in the area outside the A4 landscape paper width and without toner input, using the ATR infrared absorption spectrum measurement method described above.

[0076] Furthermore, the evaluation of blade peeling was performed using a Ricoh MP C5503 copier with the intermediate transfer belt replaced according to conditions 1-7 above. Each time the intermediate transfer belt was replaced, the cleaning blade was also replaced with a new one, and the presence or absence of blade peeling was evaluated under the following conditions. • Evaluation environment: 32℃ 54% • Cleaning blade: New • Cleaning blade linear pressure: 28 N / m • Running chart: Full-color vertical band 2% chart (Figure 7), A4 landscape. • Continuous paper feeding, double-sided Under the above conditions, the machine was operated so that the temperature near the intermediate transfer belt cleaning blade reached 40°C or higher. After the temperature near the intermediate transfer belt cleaning blade reached 40°C or higher, 500 sheets of the single-color black horizontal band chart (A4 landscape) shown in Figure 8 were fed through the machine in continuous, double-sided printing to check for any occurrence of blade peeling.

[0077] As shown in Table 1, it was found that blade peeling does not occur when the ZnST index is 0.892 or less. Furthermore, as shown in Table 2, it was found that blade curling does not occur when the BN index is 1.152 or less.

[0078] Next, in this embodiment, a method for setting the ZnST index to 0.892 or less, or the BN index to 1.152 or less, in the outer adhesion region of the intermediate transfer belt 15 will be described.

[0079] One example of the method in this embodiment is a method in which toner is attached to the outer adhesion area of ​​the intermediate transfer belt 15 at a predetermined filming removal timing. For example, a toner pattern for filming removal can be created on the photoreceptor corresponding to the outer adhesion area, and this toner pattern can be transferred onto the intermediate transfer belt 15. At this time, a toner pattern may also be created in the area corresponding to the paper feeding area. It is preferable that the toner pattern transferred to the intermediate transfer belt 15 is not secondarily transferred onto the recording paper P, but instead passes directly through the secondary transfer area to reach the intermediate transfer cleaning blade 31.

[0080] According to this method, the toner adhering to the outer adhesion region of the intermediate transfer belt 15 functions as an abrasive, and the filming material (zinc stearate, boron nitride) adhering to the outer adhesion region can be removed. As a result, by appropriately setting the filming removal timing, the ZnST index can be kept below 0.892 and the BN index below 1.152.

[0081] Another example of the method in this embodiment is a method in which the lubricant supply unit 8 supplies less lubricant to the area on the photoreceptor corresponding to the outer adhesion area than supplies less lubricant to the area on the photoreceptor corresponding to the paper feeding area.

[0082] For example, the amount of solid lubricant 8b abraded by the lubricant supply member 8a is set such that the amount of powdered lubricant abraded to the area on the photoreceptor corresponding to the outer adhesion area is less than the amount of powdered lubricant abraded to the area on the photoreceptor corresponding to the paper feeding area. Specifically, for example, the abrasive capacity of the lubricant supply member 8a is made different between these areas, or the hardness (resistance to abrasion by friction) of the solid lubricant 8b is made different between these areas.

[0083] As mentioned above, if the hardness of the solid lubricant 8b is to be varied, for example, the following can be done: Compress and mold the powdered lubricant such that the density of the portion of the lubricant supplied to the region on the photoreceptor corresponding to the paper-feeding region is lower than the density of the portion of the lubricant supplied to the region on the photoreceptor corresponding to the outer adhesion region that is scraped off.

[0084] Furthermore, for example, the content per unit volume of at least one of zinc stearate and boron nitride in the solid lubricant 8b may be as follows: that is, the content of the lubricant supplied to the area on the photoreceptor corresponding to the outer adhesion area is less than the content of the lubricant supplied to the area on the photoreceptor corresponding to the paper feeding area.

[0085] In this embodiment, the lubricant is supplied by a lubricant supply unit 8 that supplies powdered lubricant scraped from solid lubricant 8b to the surface of the photoreceptor, but the method of supplying the lubricant is not limited to this. For example, zinc stearate may be added to the toner and the lubricant may be supplied onto the photoreceptor together with the toner. The predetermined amounts for the ZnST index and BN index described above do not depend on the method of supplying the lubricant.

[0086] The above is just one example; each of the following embodiments produces its own unique effects. [First aspect] The first embodiment is an image forming apparatus that performs an image forming operation in which a toner image on the surface of a latent image carrier (e.g., a photoreceptor 1) supplied with a lubricant containing zinc stearate is first transferred to an intermediate transfer body (e.g., an intermediate transfer belt 15), and then secondarily transferred from the intermediate transfer body to recording paper P, and cleans the surface of the intermediate transfer body after the second transfer, including the adhesion region where the lubricant on the surface of the latent image carrier adheres, with a cleaning blade (e.g., an intermediate transfer cleaning blade 31), characterized in that, when the difference spectrum is taken between the ATR infrared absorption spectrum of an unused intermediate transfer body and the ATR infrared absorption spectrum of the intermediate transfer body after use for the outer adhesion region within the width of the adhesion region on the intermediate transfer body, the ratio Sb / Sa of the peak area Sb derived from zinc stearate to the peak area Sa derived from the intermediate transfer body is 0.892 or less. In image forming apparatuses that perform an image forming operation in which a toner image on the surface of a latent image carrier is first transferred to an intermediate transfer body, and then secondarily transferred from the intermediate transfer body to recording paper, a problem can occur in which the cleaning blade used to clean the surface of the intermediate transfer body after the second transfer peels off. This is because the frictional force between the cleaning blade and the intermediate transfer body increases over time, resulting in the cleaning blade peeling off. Based on our research, the cause of the peeling of the cleaning blade used to clean the intermediate transfer material (hereinafter referred to as "blade peeling") is considered to be as follows. In image forming apparatuses that supply a lubricant containing zinc stearate to the surface of a latent image carrier for purposes such as maintaining the lubricity of the latent image carrier surface over a long period, the lubricant supplied to the latent image carrier surface is transferred to the intermediate transfer body. As a result, the zinc stearate of the lubricant transferred to the surface of the intermediate transfer body causes filming, and if this filming deteriorates, the frictional force between the cleaning blade that cleans the surface of the intermediate transfer body and the intermediate transfer body increases, causing the blade to peel. However, in the paper-feeding area of ​​the surface of the intermediate transfer body, the zinc stearate on the intermediate transfer body is removed by contact with the recording material during the image forming operation, so filming is less likely to deteriorate. In contrast, in the outer adhesion area of ​​the surface of the intermediate transfer body, the zinc stearate on the intermediate transfer body is not removed because it does not come into contact with the recording material during the image forming operation, and filming deteriorates. Since the cleaning blade also comes into contact with this outer adhesion area, the deterioration of filming in the outer adhesion area causes the blade to peel. Furthermore, the inventors have found that by limiting the amount of zinc stearate adhering to the outer adhesion region within the width of the adhesion region on the intermediate transfer body to which the lubricant from the latent image carrier adheres, to a predetermined amount or less, the occurrence of blade peeling can be suppressed. Specifically, the difference spectrum is taken between the ATR infrared absorption spectrum of an unused intermediate transfer and the ATR infrared absorption spectrum of the intermediate transfer after use. The ratio of the peak area derived from zinc stearate to the peak area derived from the intermediate transfer in this difference spectrum is used as an indicator of the amount of zinc stearate attached, and this ratio is kept to 0.892 or less. This suppresses the amount of zinc stearate attached to the outer attachment area to a degree that does not cause filming deterioration to the extent that blade curling occurs, thereby suppressing the occurrence of blade curling.

[0087] [Second aspect] The second embodiment is an image forming apparatus that performs an image forming operation in which a toner image on the surface of a latent image carrier supplied with a lubricant containing boron nitride is first transferred to an intermediate transfer body, and then secondarily transferred from the intermediate transfer body to recording paper, and cleans the surface of the intermediate transfer body after the second transfer, including the adhesion region on the surface of the latent image carrier to which the lubricant adheres, with a cleaning blade, characterized in that when the difference spectrum is taken between the ATR infrared absorption spectrum of an unused intermediate transfer body and the ATR infrared absorption spectrum of the intermediate transfer body after use for the outer adhesion region within the width of the adhesion region on the intermediate transfer body, the ratio of the peak area Sc derived from boron nitride to the peak area Sa derived from the intermediate transfer body Sc / Sa is 1.152 or less. Similar to the zinc stearate mentioned above, boron nitride, a lubricant transferred to the surface of the intermediate transfer material, causes filming. If this filming worsens, the frictional force between the cleaning blade that cleans the surface of the intermediate transfer material and the intermediate transfer material increases, causing the blade to peel. Furthermore, the inventors have found that by limiting the amount of boron nitride deposited in the outer deposition region within the width of the deposition region on the intermediate transfer body to a predetermined amount or less, the occurrence of blade peeling can be suppressed. Specifically, the difference spectrum is taken between the ATR infrared absorption spectrum of an unused intermediate transfer material and the ATR infrared absorption spectrum of the same intermediate transfer material after use. The ratio of the peak area derived from boron nitride to the peak area derived from the intermediate transfer material in this difference spectrum is used as an indicator of the amount of boron nitride deposited, and this ratio is kept to 1.152 or less. This suppresses the amount of boron nitride deposited in the outer deposition area to a degree that does not cause filming deterioration to the extent that blade curling occurs, thereby suppressing the occurrence of blade curling.

[0088] [Third aspect] The third embodiment is an image forming apparatus that performs an image forming operation in which a toner image on the surface of a latent image carrier supplied with a lubricant containing zinc stearate and boron nitride is first transferred to an intermediate transfer body, and then secondarily transferred from the intermediate transfer body to recording paper, and cleans the surface of the intermediate transfer body after the second transfer, including the adhesion region on the surface of the latent image carrier to which the lubricant adheres, with a cleaning blade, characterized in that when the difference spectrum is taken between the ATR infrared absorption spectrum of an unused intermediate transfer body and the ATR infrared absorption spectrum of the intermediate transfer body after use for the outer adhesion region within the width of the adhesion region on the intermediate transfer body, the ratio of the peak area derived from zinc stearate to the peak area derived from the intermediate transfer body is 0.892 or less, and the ratio of the peak area derived from boron nitride to the peak area derived from the intermediate transfer body is 1.152 or less. According to this method, the amount of zinc stearate and boron nitride adhering to the outer adhesion area is suppressed to such an extent that it does not cause filming deterioration to the point of blade peeling, thereby preventing blade peeling.

[0089] [Fourth aspect] The fourth embodiment is characterized in that, in any of the first to third embodiments, the present invention has a lubricant supply means (e.g., a lubricant supply unit 8) that supplies the powdered lubricant scraped from the solid lubricant 8b to the surface of the latent image carrier, wherein the amount of powdered lubricant scraped off by the lubricant supply means to the region on the latent image carrier corresponding to the outer adhesion region is less than the amount of powdered lubricant scraped off by the region on the latent image carrier corresponding to the paper-feeding region. According to this method, the amount of lubricant adhering to the outer adhesion region on the intermediate transfer body is suppressed, so the amount of zinc stearate or boron nitride adhering to the outer adhesion region is suppressed to the extent that it does not cause filming deterioration that would lead to blade curling. Therefore, the occurrence of blade curling is suppressed.

[0090] [Fifth aspect] The fifth embodiment is characterized in that, in the fourth embodiment, the solid lubricant 8b is characterized in that, with respect to the content per unit volume of at least one of the zinc stearate and the boron nitride, the portion of the powdery lubricant supplied to the region on the latent image carrier corresponding to the outer adhesion region that is scraped off is less than the portion of the powdery lubricant supplied to the region on the latent image carrier corresponding to the paper-feeding region that is scraped off. According to this, the amount of zinc stearate or boron nitride, which are the substances that cause blade peeling (filming substances), among the lubricant adhering to the outer adhesion region on the intermediate transfer body is suppressed. Therefore, the amount of zinc stearate or boron nitride adhering to the outer adhesion region is suppressed to the extent that it does not cause deterioration of filming that would cause blade peeling, thereby suppressing the occurrence of blade peeling.

[0091] [Sixth aspect] The sixth embodiment is characterized in that, in the fifth embodiment, the solid lubricant 8b contains both zinc stearate and boron nitride, wherein the content of boron nitride is less in the portion where the powdery lubricant supplied to the region on the latent image carrier corresponding to the outer adhesion region is scraped off than in the portion where the powdery lubricant supplied to the region on the latent image carrier corresponding to the paper-feeding region is scraped off, and the content of zinc stearate is uniform in both portions. According to this method, the lubricating function of zinc stearate can be uniformly applied to both the paper-feeding area and the outer adhesion area, while the amount of boron nitride adhering to the outer adhesion area on the intermediate transfer material is suppressed. Therefore, the amount of boron nitride adhering to the outer adhesion area is suppressed to the extent that it does not cause filming deterioration that would result in blade curling, thereby preventing blade curling.

[0092] [Seventh aspect] The seventh embodiment is characterized in that, in any of the fourth to sixth embodiments, the solid lubricant 8b is made by compression molding a powdered lubricant such that the density of the portion of the powdered lubricant supplied to the region on the latent image carrier corresponding to the paper-feeding region is lower than the density of the portion of the powdered lubricant supplied to the region on the latent image carrier corresponding to the outer adhesion region that is scraped off. According to this method, the amount of lubricant adhering to the outer adhesion region on the intermediate transfer body is suppressed, so the amount of zinc stearate or boron nitride adhering to the outer adhesion region is suppressed to the extent that it does not cause filming deterioration that would lead to blade curling. Therefore, the occurrence of blade curling is suppressed.

[0093] [8th aspect] The eighth aspect is characterized in that, in any of the first to seventh aspects, the lubricant is added to the toner constituting the toner image. Since toner adheres within the paper-feeding area but not to the outer adhesion area, the amount of lubricant adhering to the outer adhesion area on the intermediate transfer body is reduced. Therefore, the amount of zinc stearate or boron nitride adhering to the outer adhesion area is reduced to a degree that does not cause filming deterioration to the extent of blade curling, thereby suppressing the occurrence of blade curling.

[0094] [Ninth aspect] The ninth embodiment is characterized in that, in any of the first to eighth embodiments, toner is attached to an area on the intermediate transfer body corresponding to the outer attachment area at a predetermined filming removal timing. According to this method, zinc stearate or boron nitride adhering to the outer adhesion region of the intermediate transfer body can be removed by utilizing the polishing function of the toner. Therefore, the amount of zinc stearate or boron nitride adhering to the outer adhesion region is suppressed, and the occurrence of blade peeling is inhibited. [Explanation of symbols]

[0095] 1: Photoreceptor 2: Electrostatic roller 3: Exposure equipment 4: Developing equipment 5: Primary transfer roller 7: Cleaning device 8: Lubricant supply unit 8a: Lubricant supply member 8b: Solid lubricant 8c: Pressing force application mechanism 8d: Lubricating layer formation mechanism 10: Process Unit 15: Intermediate transfer belt 16: Cleaning backup roller 20: Tension Roller 21: Secondary transfer opposing roller 22: Paper feed tray 23: Paper feed roller 24: Resistola vs. 25: Secondary transfer roller 31: Intermediate transfer cleaning blade 32: Belt cleaning device 40: Fixing device [Prior art documents] [Patent Documents]

[0096] [Patent Document 1] Patent No. 5555997

Claims

1. An image forming apparatus that performs an image forming operation in which a toner image on the surface of a latent image carrier supplied with a lubricant containing zinc stearate is first transferred to an intermediate transfer body, and then secondarily transferred from the intermediate transfer body to recording paper, and cleans the surface of the intermediate transfer body after the second transfer, including the adhesion area on the surface of the latent image carrier to which the lubricant adheres, with a cleaning blade, The aforementioned intermediate transfer is found to have an infrared absorption spectrum of 1718 [cm²] derived from the carbonyl group in the ATR method. －１ It has a peak near ] When the difference spectrum is taken between the ATR infrared absorption spectrum of an unused intermediate transfer and the ATR infrared absorption spectrum of a used intermediate transfer after at least 10,000 sheets of A4 paper have been fed through, for at least the outer region of the A4 landscape width on the intermediate transfer, the base wavenumber region is set to 1690.301 to 1760.690 cm⁻¹ and the peak wavenumber region is set to 1707.657 to 1732.728 cm⁻¹, resulting in a carbonyl group-derived value of 1718 [cm⁻¹]. －１ An image forming apparatus characterized in that the ratio of the peak area derived from zinc stearate, calculated with a base wavenumber range of 2879.201 to 2988.159 cm⁻¹ and a peak wavenumber range of 2910.057 to 2925.484 cm⁻¹, to the peak area having a peak in the vicinity of 0.892 or less.

2. An image forming apparatus that performs an image forming operation in which a toner image on the surface of a latent image carrier supplied with a lubricant containing boron nitride is first transferred to an intermediate transfer body, and then secondarily transferred from the intermediate transfer body to recording paper, and cleans the surface of the intermediate transfer body after the second transfer, including the adhesion area where the lubricant on the surface of the latent image carrier adheres, with a cleaning blade, The aforementioned intermediate transfer is found to have an infrared absorption spectrum of 1718 [cm²] derived from the carbonyl group in the ATR method. －１ It has a peak near ] When the difference spectrum is taken between the ATR infrared absorption spectrum of an unused intermediate transfer and the ATR infrared absorption spectrum of a used intermediate transfer after at least 10,000 sheets of A4 paper have been fed through, for at least the outer region of the A4 landscape width on the intermediate transfer, the base wavenumber region is set to 1690.301 to 1760.690 cm⁻¹ and the peak wavenumber region is set to 1707.657 to 1732.728 cm⁻¹, resulting in a carbonyl group-derived value of 1718 [cm⁻¹]. －１ An image forming apparatus characterized in that the ratio of the peak area derived from boron nitride, calculated with a base wavenumber region of 1336.428 to 1430.922 cm⁻¹ and a peak wavenumber region of 1367.283 to 1381.747 cm⁻¹, to the peak area having a peak in the vicinity of 1,152 or less, is 1.152 or less.

3. An image forming apparatus that performs an image forming operation in which a toner image on the surface of a latent image carrier supplied with a lubricant containing zinc stearate and boron nitride is first transferred to an intermediate transfer body, and then secondarily transferred from the intermediate transfer body to recording paper, and cleans the surface of the intermediate transfer body after the second transfer, including the adhesion area where the lubricant on the surface of the latent image carrier adheres, with a cleaning blade, The aforementioned intermediate transfer is found to have an infrared absorption spectrum of 1718 [cm²] derived from the carbonyl group in the ATR method. －１ It has a peak near ] When the difference spectrum is taken between the ATR infrared absorption spectrum of an unused intermediate transfer and the ATR infrared absorption spectrum of a used intermediate transfer after at least 10,000 sheets of A4 paper have been fed through, for at least the outer region of the A4 landscape width on the intermediate transfer, the base wavenumber region is set to 1690.301 to 1760.690 cm⁻¹ and the peak wavenumber region is set to 1707.657 to 1732.728 cm⁻¹, resulting in a carbonyl group-derived value of 1718 [cm⁻¹]. －１ The ratio of the peak area derived from zinc stearate to the peak area with a peak in the vicinity of 1718 [cm²] is calculated with a base wavenumber range of 2879.201 to 2988.159 cm² - 1 and a peak wavenumber range of 2910.057 to 2925.484 cm² - 1, and the ratio of the peak area derived from the carbonyl group is 0.892 or less, and the ratio of the peak area derived from the carbonyl group is 1718 [cm²] －１ An image forming apparatus characterized in that the ratio of the peak area derived from boron nitride, calculated with a base wavenumber region of 1336.428 to 1430.922 cm⁻¹ and a peak wavenumber region of 1367.283 to 1381.747 cm⁻¹, to the peak area having a peak in the vicinity of 1,152 or less, is 1.152 or less.

4. In the image forming apparatus according to any one of claims 1 to 3, The aforementioned intermediate transfer material is derived from carbonate bonds, with a value of 1718 [cm]. －１ It has a peak near ] The peak area having a peak around 1718 [cm －１ derived from the carbonyl group is the peak area having a peak around 1718 [cm －１ derived from the carbonate bond, and the image forming apparatus is characterized by this.

5. In the image forming apparatus according to any one of claims 1 to 3, The device has a lubricant supply means for supplying the powdered lubricant, which has been scraped off from the solid lubricant, to the surface of the latent image carrier, The image forming apparatus is characterized in that the amount of powdery lubricant scraped off from the region on the latent image carrier corresponding to the outer region of at least the width of A4 landscape paper is less than the amount of powdery lubricant scraped off from the region on the latent image carrier corresponding to the paper feeding region.

6. In the image forming apparatus according to claim 1 or 3, The device has a lubricant supply means for supplying the powdered lubricant, which has been scraped off from the solid lubricant, to the surface of the latent image carrier, The lubricant supply means ensures that the amount of powdered lubricant scraped off from the region on the latent image carrier corresponding to at least the outer region of the A4 landscape paper feed width is less than the amount of powdered lubricant scraped off from the region on the latent image carrier corresponding to the paper feed region. The image forming apparatus is characterized in that, with respect to the content of zinc stearate per unit volume of the solid lubricant, the portion of the powdered lubricant supplied to the region on the latent image carrier corresponding to at least the outer region of the A4 landscape paper feed width that is scraped off is less than the portion of the powdered lubricant supplied to the region on the latent image carrier corresponding to the paper feed region that is scraped off.

7. In the image forming apparatus according to claim 2 or 3, The device has a lubricant supply means for supplying the powdered lubricant, which has been scraped off from the solid lubricant, to the surface of the latent image carrier, The lubricant supply means ensures that the amount of powdered lubricant scraped off from the region on the latent image carrier corresponding to at least the outer region of the A4 landscape paper feed width is less than the amount of powdered lubricant scraped off from the region on the latent image carrier corresponding to the paper feed region. The image forming apparatus is characterized in that, with respect to the content of boron nitride per unit volume, the portion of the powdered lubricant supplied to the region on the latent image carrier corresponding to at least the outer region of the A4 landscape paper feed width is scraped off, and the portion of the powdered lubricant supplied to the region on the latent image carrier corresponding to the paper feed region is scraped off.

8. In the image forming apparatus according to claim 7, The solid lubricant contains both zinc stearate and boron nitride. The amount of boron nitride per unit area is such that the portion of the powdered lubricant supplied to the region on the latent image carrier corresponding to at least the outer region of the A4 landscape paper feed width is scraped off, and the portion of the powdered lubricant supplied to the region on the latent image carrier corresponding to the paper feed region is scraped off. The image forming apparatus is characterized in that the content of zinc stearate per unit area is uniform throughout the entire area.

9. In the image forming apparatus according to any one of claims 5 to 8, The image forming apparatus is characterized in that the solid lubricant is made by compressing and molding a powdered lubricant such that the density of the portion of the powdered lubricant supplied to the region on the latent image carrier corresponding to the paper feeding region is lower than the density of the portion of the powdered lubricant supplied to the region on the latent image carrier corresponding to the paper feeding region from which the powdered lubricant supplied is scraped off.

10. In the image forming apparatus according to any one of claims 1 to 9, An image forming apparatus characterized in that the lubricant is added to the toner that constitutes the toner image.

11. In the image forming apparatus according to any one of claims 1 to 10, An image forming apparatus characterized by depositing toner onto an area on an intermediate transfer body corresponding to at least the outer area of ​​the A4 landscape paper width at a predetermined filming removal timing.

Images