Image forming device

Abstract

To provide a mechanism capable of replenishing a developer with a simplified configuration or a more easily usable mechanism capable of replenishing the developer.SOLUTION: An attachment port to / from which a developer supply bottle sealed with the developer can be attached / detached is provided in an image forming apparatus and in such a state that a cover is opened, the developer supply bottle can be attached to the attachment port. In the image forming apparatus, when the developer supply bottle is attached to the attachment port, the developer in the developing supply bottle is moved into a developing storage part by self-weight.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus, such as a laser printer, a copying machine, or a facsimile machine, which obtains a recorded image by transferring a toner image formed on an image carrier using an electrophotographic method or the like onto a transfer material. [Background technology]

[0002] Generally, electrophotographic image forming devices form images by transferring a developer image (toner image) formed on the surface of a photosensitive drum, which serves as an image carrier, to a transfer material, which serves as a transfer medium. A variety of developer replenishment methods have been proposed. A typical example is the process cartridge. In this process cartridge system, the photosensitive drum and developer container are integrated, and when the developer runs out, the process cartridge can be replaced with a new one. This system has the advantage of allowing users to easily perform maintenance themselves.

[0003] On the other hand, there is also a known toner supply system in which new toner is supplied to the developing device when the toner runs out. For example, Patent Document 1 discloses a system in which a detachable toner supply container is provided in an image forming apparatus, and when the toner supply container is attached to the image forming apparatus, toner is transported from the toner supply container to the developing container via a toner transport path provided with a transport screw. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 8-30084 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the conventional toner supplying method has the following problem: it is necessary to provide a toner transport path including a transport screw, which leads to a complicated and large-sized device.

[0006] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a mechanism that can replenish developer with a simpler configuration, or a mechanism that can replenish developer with greater ease of use. [Means for solving the problem]

[0007] an image forming apparatus to which a developer supply container containing a developer can be attached, the image forming apparatus comprising: an image carrier; an exposure means for exposing the image carrier; a developer carrier that carries a developer and develops an electrostatic latent image formed on the image carrier by the exposure means with the developer; and a frame unit that supports the developer carrier and constitutes a developer storage chamber that stores the developer carried on the developer carrier, the frame unit having an attachment opening that allows the developer supply container to be attached and detached and that communicates with the developer storage chamber; a developer supply body provided in the developer storage chamber and rotatable to supply developer to the developer carrier; an agitating member provided in the developer storage chamber and rotatable around a rotation axis extending in the longitudinal direction of the developer carrier so as to agitate the developer in the developer storage chamber, the agitating member having a sheet-like member extending along the direction of the rotation axis, and conveying the developer towards the developer carrier in a direction intersecting with the rotation axis as a result of the sheet-like member rotating around the rotation axis; and a cover rotatable between a first position that covers the attachment opening and a second position that opens the attachment opening, the stirring member is a rotationally movable member disposed closest to the attachment opening in the developer accommodating chamber, and is capable of directly supplying the developer to the developer supply body by the sheet-like member; When the cover is in the second position, the developer supply container is attached to the mounting port, and the interior of the developer supply container is connected to the developer storage chamber, the developer in the developer supply container can move to the developer storage chamber, and the cover is configured such that when the developer supply container that has finished supplying developer to the developer storage chamber is attached to the mounting port, the developer supply container prevents the cover from moving from the second position to the first position, and when the developer supply container is removed from the mounting port, the cover is movable from the second position to the first position. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a mechanism for replenishment of developer with a simpler configuration, or a mechanism for replenishment of developer that is easier to use. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view showing an image forming apparatus and a toner bottle according to an embodiment of the present invention; [Figure 2] FIG. 1 is a diagram showing a developing device and a toner bottle as viewed from a direction perpendicular to the longitudinal direction of a developing roller in an embodiment. [Figure 3] FIG. 10 shows a cap for an opening in an embodiment. [Figure 4] FIG. 10 is a diagram showing a developing device having an opening of another type in the embodiment; [Figure 5] FIG. 1 is a diagram showing a development current detection system in an embodiment. [Figure 6] FIG. 1 shows the structure of a Faraday cage in an embodiment. [Figure 7] Flowchart for determining a decrease in toner triboelectricity in an embodiment [Figure 8] An example of a schematic diagram of toner DETAILED DESCRIPTION OF THE INVENTION

[0010] The following describes embodiments of the present invention with reference to the drawings. Note that the following embodiments do not limit the scope of the invention as claimed, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention. [Example]

[0011] [Overall configuration of image forming device] FIG. 1(a) shows a schematic configuration of an image forming apparatus such as a monochrome printer.

[0012] The image forming apparatus in this embodiment is provided with a cylindrical photosensitive member serving as an image carrier, i.e., a photosensitive drum 1. A charging roller 2 serving as a charging means and a developing device 3 serving as a developing means are provided around the photosensitive drum 1. In addition, in relation to the downward direction in the figure, an exposure device 4 serving as an exposure means is provided between the charging roller 2 and the developing device 3. A transfer roller 5 is pressed against the photosensitive drum 1.

[0013] Toner is stored in the developer storage chamber 37 of the developing device 3. In this embodiment, the toner used has a particle size of 6 μm and a normal negative charge polarity.

[0014] In this embodiment, the photosensitive drum 1 is a negatively charged organic photosensitive member. This photosensitive drum 1 has a photosensitive layer on a drum-shaped aluminum substrate, and is driven to rotate at a predetermined process speed in the direction indicated by the arrow in the figure (clockwise) by a drive device (not shown). In this embodiment, the process speed corresponds to the peripheral speed (surface movement speed) of the photosensitive drum 1.

[0015] The charging roller 2 contacts the photosensitive drum 1 with a predetermined pressure to form a charging portion. A desired charging voltage is applied by a charging high-voltage power supply (not shown) as a charging voltage supply means, and the surface of the photosensitive drum 1 is uniformly charged to a predetermined potential. In this embodiment, the photosensitive drum 1 is negatively charged by the charging roller 2.

[0016] In this embodiment, the exposure device 4 is a laser scanner device that outputs laser light corresponding to image information input from an external device such as a host computer, and scans and exposes the surface of the photosensitive drum 1. This exposure forms an electrostatic latent image (electrostatic image) corresponding to the image information on the surface of the photosensitive drum 1. Note that the exposure device 4 is not limited to a laser scanner device, and may be, for example, an LED array in which a plurality of LEDs are arranged along the longitudinal direction of the photosensitive drum 1.

[0017] In this embodiment, the developing device 3 employs a contact development system. The developing device 3 supports a developing roller 31 as a developer carrier within a frame (housing) that defines a developer chamber 37 for containing toner. The developing device 3 also supports a toner supply roller 32 as a developer supply means. The electrostatic latent image formed on the photosensitive drum 1 is developed into a toner image by the toner conveyed by the developing roller 31 at the portion (development nip) where the developing roller 31 and the photosensitive drum 1 face each other. At this time, a developing voltage is applied to the developing roller 31 by a high-voltage developing power supply (103 in FIG. 5) that serves as a developing voltage application means. In this embodiment, the electrostatic latent image is developed using a reversal development system. That is, the electrostatic latent image is developed into a toner image by attaching toner charged with the same polarity as the photosensitive drum 1 to the portion of the photosensitive drum 1 after charging, where the charge has decayed due to exposure.

[0018] A toner supply roller 32 that supplies toner is rotatably in contact with the developing roller 31. Although a one-component non-magnetic contact development method is used in this embodiment, a two-component non-magnetic contact / non-contact development method may also be used. Furthermore, a one-component magnetic contact / non-contact development method or a two-component magnetic contact / non-contact development method may also be used as the development method. Furthermore, as an example, a polymerized toner produced by a polymerization method is used as the developer in this embodiment.

[0019] The developer storage chamber 37 further includes an agitating blade 33 as an agitating member. The agitating blade 33 receives a driving force from a drive unit (not shown) and rotates around a rotation axis 33a in cross section, thereby feeding toner toward the developing roller 31 and the toner supply roller 32. The agitating blade 33 may receive the driving force from the drive unit directly through the agitating blade 33 or via a drive gear. The agitating blade 33 rotates clockwise around the rotation axis 33a as shown in the figure. More specifically, the toner within the rotation radius of the agitating blade 33 is pushed and moved by the agitating blade, and some of the moved toner is sent to the developing roller 31 and the toner supply roller 32. The agitating blade 33 is, for example, a sheet-like member extending along the longitudinal direction of the developing roller 31. In this case, the sheet pushes and moves the toner within the rotation radius in cross section. Some of the moved toner is then sent toward the developing roller 31 and the toner supply roller 32. As shown in the figure, the agitating blade 33 has a shape that extends in a direction that intersects with the direction of rotation. Only one agitating blade 33 (agitating member) is disposed in a space downstream of the supply port of the toner bottle 12 attached to the attachment port (opening 34) in terms of the direction of movement of the toner due to its own weight, and upstream of the photosensitive drum 1. "Only one agitating blade 33 (agitating member)" means that there is only one agitating blade 33 (agitating member) that has the function of sending toner toward the developing roller 31 and the toner supply roller 32.

[0020] The agitating blade 33 also circulates the toner that has not been used for development and has been scraped off from the developing roller 31, thereby leveling the degree of deterioration of the toner in the developer storage chamber 37. The agitating blade 33 also has the function of leveling the surface of the toner that has fallen from the toner bottle 12 under its own weight and moved to the developer storage chamber 37. By leveling the toner surface after replenishment by the agitating blade 33, the remaining toner amount can also be accurately detected.

[0021] The transfer roller 5 can be suitably made of an elastic material such as polyurethane rubber, EPDM (ethylene propylene diene rubber), NBR (nitrile butadiene rubber), or other sponge rubber.

[0022] The transfer roller 5 is pressed against the photosensitive drum 1, forming a transfer section where the photosensitive drum 1 and the transfer roller 5 are in pressure contact. A transfer high-voltage power supply (not shown) is connected to the transfer roller 5 as a transfer voltage application means, and a predetermined voltage is applied at a predetermined timing.

[0023] A transfer material S stored in a cassette 6 is fed by a paper feed unit 7 in time with the toner image formed on the photosensitive drum 1 reaching the transfer section, and is transported to the transfer section via a pair of registration rollers 8. The toner image formed on the photosensitive drum 1 is transferred onto the transfer material S by a transfer roller 5 to which a predetermined transfer voltage is applied by a transfer high-voltage power supply.

[0024] After the toner image has been transferred, the transfer material S is conveyed to a fixing device 9. The fixing device 9 is a film heating type fixing device that includes a fixing film 91 incorporating a fixing heater (not shown) and a thermistor (not shown) that measures the temperature of the fixing heater, and a pressure roller 92 that presses against the fixing film 91. The transfer material S is heated and pressurized to fix the toner image, and is then passed through a pair of paper discharge rollers 10 and discharged outside the machine.

[0025] In addition, a pre-exposure device 11 is provided downstream of the transfer unit and upstream of the charging unit in the rotation direction of the photosensitive drum 1 as a discharge means for discharging the photosensitive drum 1. The pre-exposure device 11 discharges the surface potential of the photosensitive drum 1 before it enters the charging unit in order to generate stable discharge at the charging unit.

[0026] Residual toner remaining on the photosensitive drum 1 without being transferred to the transfer material S is removed in the following process. The residual toner includes a mixture of positively charged toner and negatively charged toner that lacks sufficient charge. The pre-exposure device 11 neutralizes the photosensitive drum 1 after transfer, generating a uniform discharge during charging, thereby re-charging the residual toner to a negative polarity. The residual toner, once negatively charged in the charging section, reaches the developing section as the photosensitive drum 1 rotates. The behavior of the residual toner that reaches the developing section will be explained separately for the exposed and non-exposed sections of the photosensitive drum 1. The residual toner adhering to the non-exposed sections of the photosensitive drum 1 is transferred to the developing roller 31 in the developing section due to the potential difference between the non-exposed section potential of the photosensitive drum 1 and the developing voltage, and is then collected in the developer storage chamber 37. The toner collected in the developer storage chamber 37 is reused for image formation. In addition, the residual toner adhering to the exposed portion of the photosensitive drum 1 is not transferred from the photosensitive drum 1 to the developing roller 31 in the developing section, but is moved to the transfer section together with the developed toner from the developing roller 31, where it is transferred to the transfer material S and removed from the photosensitive drum 1.

[0027] In this embodiment, the transfer residual toner is collected in the developing device 3 and reused, but the effect of this embodiment is not affected even if a conventionally known configuration is used in which the transfer residual toner is not collected and reused using a cleaning blade that contacts the photosensitive drum 1. However, it goes without saying that the configuration of this embodiment eliminates the need for a storage container for temporarily storing the collected transfer residual toner, preventing the device from becoming larger. Furthermore, since the transfer residual toner is reused, printing costs can be reduced.

[0028] [Replenishing developer from the developer supply bottle to the developer storage chamber by gravity] The developing device 3 installed in the device has an opening 34, which is an attachment port for a toner bottle (developer supply bottle). This opening 34 is located inside the device body rather than on the exterior of the device body, and toner can be replenished through this opening. The supply port of the toner bottle 12 and the opening 34 are configured so that the toner bottle can be attached and detached to the opening 34. In addition, a stirring blade 33 is disposed as a moving member located closest to the opening 34 within the frame that forms the developer storage chamber 37. This quickly levels the surface of the replenished toner in the longitudinal direction of the developing roller, allowing for a rapid transition to printing operations after toner replenishment. Other rotatable members within the frame of the developer storage chamber 37 include a developing roller 31 and a toner supply roller 32.

[0029] In the following explanations, we will use the term toner bottle, but this toner bottle only needs to be able to be attached to the device and have the minimum function of containing developer (toner) to be replenished or supplied to the developing device, and can also be called a developer container, developer supply container, etc.

[0030] Here, to explain in detail the term "mounted" in this embodiment, this refers to a state in which the supply opening of the toner bottle 12 is positioned horizontally and vertically relative to the opening 34, as will be described later with reference to Figures 1 and 4. In Figure 1, the tip of the toner bottle 12 fits into and abuts the developer storage chamber 37, and in Figure 4(b), the toner bottle 12 is positioned by a partial surface of the toner bottle abutting the developer storage chamber 37. Note that the mechanism for mounting the toner bottle 12 to the main body is not limited to this form. Various mechanisms can be used to position the supply opening of the toner bottle 12 relative to the opening 34.

[0031] Furthermore, while the developer storage compartment of a toner bottle detachable from an image forming apparatus is generally made of resin, the resin may be thinned to a flexible sheet that can be easily deformed by the user's grip. The thickness of the flexible sheet is expected to be, for example, approximately 0.03 to 1 mm, and by thinning the sheet, a developer supply container with a bag-shaped developer storage chamber can be provided. Furthermore, by using paper as the flexible sheet that forms the developer storage chamber, an environmentally friendly developer supply container can be provided. Furthermore, while the supply port of the toner bottle 12 may be made of resin, it may also be made of strong cardboard or other materials for environmental reasons.

[0032] When a user installs the toner bottle 12 in an image forming apparatus, the user moves the cover 38 from a first position to a second position to open it and allow external access to the opening 34, which serves as the installation port. The cover 38 is movable between the first position (shown in FIG. 1( a) ), which covers the interior of the apparatus (the installation port) and corresponds to the position during image formation, and the second position (also referred to as the open position) (shown in FIG. 1( b) ), which allows external access to the interior of the image forming apparatus. When the cover 38 is in the second position, the user can access the interior of the apparatus (the installation port) and install or remove the toner bottle 12 from the opening 34. If a cap 35 is attached to the opening 34, the user removes the cap 35 from the opening 34. Figure 3 shows several examples of caps 35 for the opening 34. The cap 35 can be of various shapes and forms as long as it is a member capable of sealing the opening 34 to prevent toner from leaking from the developer storage chamber 37 to the outside.

[0033] In addition, in the drawing, the cover 38 as an opening / closing member rotates around a hinge on the left side of the cover to cover or expose the inside of the device, but is not limited to this configuration. For example, it may be a sliding door. It may also be a double-door (double door) with hinges on each side of the opening in the image forming device body formed when the cover is opened. Various opening / closing configurations are applicable to the cover 38.

[0034] 1(b), when the toner bottle 12 is attached to the opening 34 with the cover 38 moved to the open position (second position), the toner moves from the toner bottle 12 to the developer storage chamber 37 under its own weight, and the toner is replenished. More specifically, when the toner bottle 12 is attached to the opening 34, the developer storage chamber 37 communicates with the internal space of the toner bottle 12, and the toner sealed in the toner bottle 12 moves into the developer storage chamber 37 under its own weight. When all of the toner (developer) stored in the toner bottle 12, or a predetermined amount determined for one replenishment, is supplied to the storage chamber 37 from the state in which toner replenishment is prompted, the surface of the toner 21 is positioned above the rotation axis 33a in the direction of gravity. In other words, the rotation axis 33a is positioned below the surface of the toner 21 after replenishment in the direction of gravity. Here, after the developer is replenished, the height position of the developer surface in the direction of gravity in the developer storage chamber 37 is not exactly the same when viewed along the longitudinal direction of the developing roller 31. The position of the developer surface here refers to the average position of the developer surface in the developer storage chamber 37 in the direction of gravity.

[0035] In this manner, in this embodiment, toner is moved from the toner bottle 12 to the developer storage chamber 37 by gravity. For example, as another toner replenishment method, it is possible to supply toner from a toner replenishment bottle to a toner replenishment path equipped with a transport screw separate from the developer storage chamber 37, and then transport toner from that toner replenishment path to the developer storage chamber 37 using the transport screw. However, in this case, the device would become larger due to the toner replenishment path. In comparison, the toner replenishment system of this embodiment allows for a more compact device. Furthermore, when replenishment toner is supplied to the toner transport path as just described, it takes time for toner transport in the toner transport path to be completed, forcing the user to wait until printing resumes. This point has also been improved in this embodiment.

[0036] 1(b), when the toner bottle 12 is attached to the opening 34, the upper portion of the toner bottle 12 in the direction of gravity protrudes outward (upward in the direction of gravity) above the exterior of the device body. This eliminates the need to house the entire toner bottle 12 within the image forming device, allowing for a more compact image forming device. During replenishment, the toner bottle 12 protrudes outward in the direction of gravity, so that the cover 38 can be moved to the first position, which is the closed position, when the toner bottle 12 is removed from the opening 34 and taken out of the device. The closed position refers to the position of the cover 38 that corresponds to the time of image formation, and in which the cover 38 covers the opening 34 or the interior of the image forming device.

[0037] 1(a), the agitating blade 33 may be stopped in an inclined position, and when toner is replenished, the agitating blade may guide the replenished toner to the developing roller 31 and the supply roller 32. In this way, by using the agitating blade 33 as a toner guide member, toner can be replenished to the developing roller 31 more quickly.

[0038] The shapes of the supply port of the toner bottle 12 and the opening 34 are not limited to those shown in FIG. 1, as long as the supply port of the toner bottle 12 and the opening 34 are configured to be detachable from each other. For example, in FIG. 4(a), the opening 34 has a shape that protrudes from the surface of the developer storage chamber 37. The inner wall of the protrusion extends into the interior of the developer storage chamber 37, and the surface (outer circumferential surface) of the supply port of the toner bottle 12 is guided by this inner wall and moves downward, positioning the toner bottle 12 in the developer storage chamber 37. In other words, a portion of the side surface of the toner bottle 12 abuts against the edge of the opening 34, restricting downward movement of the toner bottle 12. The side wall that extends inward is indicated by a dashed line in FIG. 4(a).

[0039] 4(b), the toner bottle 12 may have a toner bottle surface (portion) that abuts against the surface of the developer storage chamber 37, and the abutment of these surfaces may restrict downward movement of the toner bottle 12. The abutment of these surfaces also determines the lateral positioning of the toner bottle 12.

[0040] [Developer filling amount in toner bottle] The amount of developer (toner) filled in the toner bottle 12 will now be described. While the amount of toner filled in the toner bottle 12 can be selected as appropriate, in this embodiment, the amount of toner filled in the toner bottle 12 is preferably between A [g] and B [g]. Here, A [g] is the amount of toner (developer amount) contained in the developer storage chamber 37 below (below) the horizontal plane including the highest point (top point) of the developing roller 31 when the developing device 3 is in the position during image formation. In other words, even if toner is replenished when the toner in the developer storage chamber 37 is empty, the amount of toner replenished can be sufficient to cover the developing roller 31. When the toner 21 sealed in the toner bottle 12 shown in FIG. 1(a) is supplied to the developer storage chamber 37 shown in FIG. 1(a), all of the toner 21 in the toner bottle 12 is supplied to the developer storage chamber 37 as shown in FIG. 1(b).

[0041] 2 shows the relationship between the developing device 3 and the toner bottle 12 when viewed from a direction perpendicular to the longitudinal direction of the developing roller 31. The developer storage chamber 37 extends in the longitudinal direction and has a volume sufficient to store all of the toner 21 sealed in the toner bottle 12.

[0042] Furthermore, B[g] is the difference between the maximum amount of toner that can be filled into the developer storage chamber 37 and the threshold remaining toner amount contained in the developer storage chamber 37 when the system begins to prompt the user to replenish toner. FIG. 2(b) shows a configuration for detecting whether the remaining amount of developer stored in the developer storage chamber 37 has fallen below a predetermined amount. Reference numeral 22 denotes a light receiving unit that receives light emitted from a light emitting unit 23. When there is a sufficient amount of toner stored in the developer storage chamber 37, the toner blocks the light from the light emitting unit 23, and the light receiving unit 22 does not receive the light. On the other hand, when the remaining amount of toner falls below a predetermined amount (predetermined volume), the light receiving unit 22 receives light from the light emitting unit 23, and the control unit 101 detects that the remaining amount of toner has fallen below the predetermined amount. The control unit 101 recognizes the output signal from the light receiving unit 22, which is input via a signal line (not shown), and detects that the remaining amount of toner has fallen below the predetermined amount. Furthermore, when the remaining toner amount is detected while the agitating blade 33 installed in the developer storage chamber 37 is rotating, the light blocking time due to the agitated toner changes depending on the remaining toner amount. The control unit 101 may estimate the remaining toner amount based on the length of the light blocking time or the length of the light receiving time.

[0043] When the control unit 101 detects that the light receiving unit 22 has received light, it outputs an output to an external device via an output I / F (not shown) to urge the user to replenish toner. That is, when the control unit 101 detects that the remaining amount of toner has fallen below a predetermined amount, it functions as an output device that outputs an output urging the user to replenish toner. Examples of the external device include a display device, a speaker, or a data transmission device. The output I / F may be wired or wireless.

[0044] Note that A[g] may be defined as the difference between the amount of toner that covers the developing roller 31 when the developer storage chamber 37 is empty and the amount of toner remaining in the developer storage chamber 37 when toner replenishment is prompted, as in B[g]. Also, B[g] may be defined as the maximum amount of toner that can be filled into the developer storage chamber 37 when the developer storage chamber 37 is empty, as in A[g].

[0045] There are various settings for the above A[g] and B[g].

[0046] As described above, when a user replenishes toner after being prompted to do so, even if all of the developer contained in the unopened toner bottle 12 is replenished into the developer storage chamber 37, the amount of developer that can be accommodated in the developer storage chamber 37 will not reach the maximum amount of developer that can be accommodated in the developer storage chamber 37. This has the advantage of preventing toner from spilling outside when the user removes the toner bottle 12 from the image forming apparatus after toner replenishment. Furthermore, after the toner bottle is removed from the image forming apparatus after toner replenishment, a cap 35 such as that shown in FIG. 3 is attached to the opening 34 of the developer storage chamber 37. If it is assumed that the toner bottle is empty, the configuration of the cap 35 can be simplified.

[0047] [Device operation remains stopped] The image forming apparatus includes an optical sensor or mechanical sensor (not shown) for detecting whether the cover 38 is open. When the control unit 101 receives a signal indicating the cover is open, it does not permit image formation. Even if a print command is input from an external device, it does not permit image formation by driving the process means, such as the photosensitive drum 1. Instead of detecting whether the cover is open, the image forming apparatus may detect whether the toner bottle 12 is installed. That is, when a sensor (not shown) detects that the toner bottle 12 is installed in the opening 34, the control unit 101 similarly does not permit image formation by driving the process means, such as the optical drum 1. To detect whether the toner bottle 12 is installed, the image forming apparatus may detect that the toner bottle 12 has pressed a mechanical sensor provided in the apparatus body. If the toner bottle 12 is equipped with a memory unit (including at least a memory element and electrical contacts), a memory reader is provided in the apparatus body. In this case, the image forming apparatus may determine whether the memory reading device is able to perform predetermined communication with the memory unit of the toner bottle 12, and determine whether the toner bottle 12 is attached based on the result.

[0048] As described above, according to this embodiment, a developer replenishment system can be constructed with a simpler configuration in which toner is moved from the toner bottle 12 to the developer storage chamber 37 by gravity. This also makes toner replenishment more user-friendly. For example, after toner replenishment, image formation can be resumed quickly, reducing downtime. Furthermore, since a complex toner transport path is not required, the image forming apparatus can be made smaller, leading to cost reductions. Furthermore, since toner replenishment is performed by attaching and detaching the toner bottle 12 to the opening 34 disposed within the image forming apparatus, problems that often occur in image forming apparatuses that use a toner replenishment method, such as toner scattering, can be prevented. [Example]

[0049] The configuration of the image forming apparatus in this embodiment is the same as that in embodiment 1, and detailed description thereof will be omitted. In this embodiment, image problems that occur when toner is replenished and countermeasures for those problems will be described below.

[0050] The purpose of this embodiment is to provide a toner supply system that suppresses the occurrence of supply fogging. First, we will explain the so-called supply fogging that occurs when toner is replenished, which is caused by the difference in characteristics between new toner that is replenished and old toner that remains in the developing device 3.

[0051] [Supply Cover] The mechanism by which replenishment fogging occurs will be explained below. New toner, whose surface layer is not worn away, easily retains charge, so the amount of charge that the toner has per unit weight (hereafter referred to as toner tribo) is large. Conversely, toner that has been subjected to repeated pressure in the developing unit, etc., has its surface worn away, causing external additives such as silica to become embedded in or become free from the toner matrix (toner particles), reducing the toner's chargeability. Toner with reduced chargeability has difficulty retaining charge, and the toner tribo becomes smaller.

[0052] Furthermore, when new toner and old toner are mixed, the difference in the charge series between the toners is a major factor. That is, when new toner and old toner come into contact, the triboelectricity of the new toner becomes higher than when new toner is used alone, and the triboelectricity of the old toner becomes lower than when old toner is used alone. As a result, the triboelectricity of the old toner becomes too low, and it cannot be retained on the developing roller 31 by the electric field, resulting in fogging.

[0053] As explained in the above embodiment, in the configuration of the image forming apparatus of this embodiment, the new replenished toner comes into direct contact with the old toner in the developing device 3, so care must be taken to prevent replenishment fogging.

[0054] [Characteristics of this Example] In this embodiment, to prevent replenishment fogging, it is important to eliminate the difference in triboelectricity between new and old toner when replenishing toner. In other words, new toner must be replenished when the triboelectricity of the old toner is not too low. In this embodiment, the triboelectricity of the toner is indirectly detected, and new toner is replenished when the toner triboelectricity is not too low, thereby suppressing the occurrence of replenishment fogging. More specifically, in this embodiment, the amount of charge on the toner is measured by measuring the current value (developing current) generated when a predetermined amount of toner is developed, and a decision is made as to whether or not to replenish new toner.

[0055] [Developing current] Because the potential difference between the development voltage applied to the development roller 31 and the potential of the exposed portion of the photosensitive drum 1 is generally below the discharge threshold, the current flowing during development is significantly affected by the movement of charge (toner). Therefore, if the weight of toner developed per unit time is assumed, the amount of charge (toner tribo) of the toner per unit weight can be predicted. The weight of toner developed per unit time is calculated from the toner weight per unit area of ​​the development roller surface (hereinafter referred to as M / S) and the area of ​​toner developed per unit time. The area of ​​toner developed per unit time is determined by the longitudinal width of the developed toner, i.e., the longitudinal width of the exposed area of ​​the photosensitive drum 1, and the process speed of the image forming apparatus. Therefore, by performing a dedicated development current detection operation, the area of ​​toner developed per unit time can be kept constant. In other words, the change in M / S of the toner in the image forming apparatus used in this embodiment is small and remains almost constant. Therefore, the current flowing during development can be considered equivalent to the charge amount per given weight of toner. The control unit 101 can also calculate the charge amount per unit weight from the charge amount per predetermined weight. The exposure intensity at this time was set to the maximum exposure amount that the image forming apparatus can output. This is because all of the toner on the developing roller 31 is developed to accurately measure the triboelectric power of the toner. If the toner M / S ratio changes significantly, a conventionally known toner adhesion amount sensor may be used to measure the toner M / S ratio and determine the toner charge amount.

[0056] [Method for measuring development current] 5 shows a detection system that detects the current that flows through the developing roller 31 when a high voltage is applied to the developing roller 31 by a high-voltage power supply for development 103. A current detection circuit 102 in the figure detects the current that flows through the developing roller 31, the photosensitive drum 1, and the ground when a developing voltage (for example, −350 V) is applied to the developing roller 31 by the high-voltage power supply for development 103. A signal indicating the current value detected by the current detection circuit 102 is input to the control unit 101, which then predicts and detects how much current is flowing.

[0057] The timing of developing current measurement can be set as appropriate, but in this embodiment, it is performed when the image forming apparatus is installed, and then every 100 pages printed (every time a predetermined number of sheets are printed). However, this is not limited to this. For example, developing current measurement may be performed every time the image forming apparatus is turned off or started up from a power-saving state.

[0058] When the control unit 101 starts measuring the development current, it first starts driving each component, such as the photosensitive drum 1, the development roller 31, and the charging roller 2. Then, at a predetermined timing, under the instruction of the control unit 101, the exposure device 4 exposes the surface of the photosensitive drum 1, toner is developed on the formed electrostatic latent image, and the development current is measured. In this embodiment, the exposure device 4 exposes a range of 216 mm in the longitudinal direction of the photosensitive drum 1 for one second (corresponding to the length of the surface of the photosensitive drum 1 in the sub-scanning direction), and when the formed electrostatic latent image reaches the development nip, the control unit 101 measures the average current value I for one second based on the input signal.

[0059] [Toner replenishment necessity determination] According to the inventors' investigation, the triboelectric power of new toner was approximately -40 μC / g. Furthermore, when new toner was replenished when the absolute value of the toner triboelectric power was smaller than approximately -20 μC / g due to toner degradation, replenishment fogging occurred. In other words, replenishment fogging occurred when the difference in triboelectric power between new toner and old toner was approximately twice as large.

[0060] In this embodiment, the toner triboelectricity was measured using a Faraday cage 13 shown in the perspective view of Figure 6. The inside (right side of the figure) was depressurized to suck in the toner on the developing roller, and a toner filter 133 was provided to collect the toner. Reference numeral 131 denotes the suction part, and 132 denotes a holder. The charge amount per unit mass, Q / M [μC / g], is calculated from the mass M of the collected toner and the charge Q measured directly with a coulomb meter. In this embodiment, the system is configured to issue a notification urging the user to replenish toner when it is determined that the toner triboelectricity is approaching half the toner triboelectricity of new toner.

[0061] The operation of the image forming apparatus will be described below with reference to the flowchart of FIG.

[0062] (step 1) When the image forming apparatus is installed (when the developer is new), under the instruction of the control unit 101, the exposure device 4 forms an electrostatic latent image of 216 mm in the longitudinal direction x 1 second exposure (corresponding to the length in the sub-scanning direction) on the surface of the photosensitive drum 1 charged by the charging roller 2.

[0063] (step 2) When the image forming apparatus is installed (when the developer is new), the control unit 101 detects a signal from the current detection circuit 102 during the one second that the electrostatic latent image passes through the development nip, measures the development current, and obtains the development current I0 when new toner is used. The control unit 101 samples the signal indicating the development current I0 for one second and averages the obtained multiple data to calculate the development current I0. Note that the method for calculating the development current I0 is not limited to averaging; for example, a median value may be calculated from multiple sampled data and used as the development current I0. The acquired development current I0 is stored in a storage device (not shown) of the control unit 101. Note that the timing for obtaining the development current I0 may be, for example, after the first several dozen sheets have been printed, as long as the developing device 3 can be considered to be in a substantially initial state.

[0064] (step 3-5) Next, when the control unit 101 determines that 100 pages have been printed, it measures the development current again. In step 4, the same processing as in step 1 is performed, and in step 5, the control unit 101 acquires the development current Ii. The method of acquiring / calculating the development current Ii is the same as that of the development current I0, so a detailed explanation will be omitted.

[0065] (step 6) Next, the control unit 101 calculates the ratio between Ii and I0 based on the detection result, and makes the following determination.

[0066] When Ii / I0 is 0.55 or more Since the triboelectric power of the toner is sufficiently high, no notification to replenish the toner is issued (step 3). If Ii / I0 is 0.55 or more, the charge amount of the toner corresponds to 55% or more of the charge amount of the toner initially stored in the developer storage chamber 37.

[0067] When Ii / I0 is less than 0.55 Since the triboelectric charge of the toner is approaching half of that of the new toner, the process proceeds to (step 7) and a notification is issued urging the user to replenish toner. If Ii / I0 is less than 0.55, the toner charge amount corresponds to less than 55% of the charge amount of the toner initially stored in the developer storage chamber 37. As described in the first embodiment, the control unit 101 issues a toner replenishment notification to an external device via an input / output I / F (not shown), such an external device including a display device, a speaker, and a data transmission device. The output may be text, an image, or an audio signal.

[0068] (Exception handling) If an optical sensor (not shown) detects that there is no toner before 100 sheets have been printed, the process proceeds to (step 7) without measuring the development current, and a toner replenishment notification is issued.

[0069] As described above, according to this embodiment, toner triboelectricity can be detected by measuring the development current, so new toner can be replenished before the toner triboelectricity of the old toner becomes too low, thereby preventing the occurrence of replenishment fogging. [Example]

[0070] The configuration of the image forming apparatus in this embodiment is the same as in Embodiment 1, and therefore a detailed description is omitted. As described in Embodiment 2, toner that has been repeatedly subjected to pressure in the developing unit or the like has a reduced chargeability. Such degraded toner (with reduced chargeability) generates a small reflective force and is therefore difficult to support on the developing roller 31. Even if it is supported on the developing roller 31, it is difficult for it to be transferred to the photosensitive drum 1 by electrostatic force. Instead, new, high-triboelectric toner is preferentially used for development and transferred to the photosensitive drum 1. As a result, degraded toner with reduced chargeability accumulates. Furthermore, toner with reduced chargeability is difficult to control by electrostatic force, and is prone to developing toner on the white areas (dark potential areas) on the surface of the photosensitive drum 1, resulting in so-called background fog. However, although it is discharged to the outside as fog, the amount of degraded toner that accumulates is greater. As a result, the amount of degraded toner that accumulates increases with repeated toner replenishment. This situation should be avoided.

[0071] This embodiment describes a developer that can suppress the occurrence of replenishment fogging as described in embodiment 2, and also suppresses the increase in the amount of accumulated degraded toner with reduced chargeability as much as possible. By applying the developer described below to the toner replenishment system shown in Fig. 1, an excellent toner replenishment system with even fewer image defects can be realized.

[0072] [Explanation of improved toner] In this embodiment, the developer is used, which can suppress the change in toner triboelectricity due to printing by improving the toner, and prevents the accumulation of deteriorated toner with reduced charging characteristics and fogging when toner is replenished. More specifically, the toner has toner particles containing a binder resin and a colorant, and has a maximum load of 2.0 × 10 -4The toner to be used has a Martens hardness (hereinafter referred to as the Martens hardness) of 200 MPa or more and 1100 MPa or less when measured under the condition of [N]. This reduces the frequency of or eliminates the need to execute the toner replenishment flowchart described in FIG. 7 of the second embodiment. When the flowchart of FIG. 7 is not executed, the control unit 101 may issue a toner replenishment notification based on the remaining amount result of the remaining amount detection described in FIG. 2(b).

[0073] Maximum load 2.0 x 10 -4 There are no particular limitations on the means for adjusting the Martens hardness to 200 MPa or more and 1100 MPa or less when measured under the N condition. However, because this hardness is significantly higher than the hardness of organic resins used in general toners, it is difficult to achieve this hardness using conventional means for increasing hardness. For example, it is difficult to achieve this hardness using means such as designing a resin with a high glass transition temperature, increasing the molecular weight of the resin, thermal curing, or adding a filler to the surface layer.

[0074] The Martens hardness of organic resins used in general toner is 2.0 x 10 -4 When measured under N conditions, the hardness is about 50 MPa to 80 MPa. Even if the hardness is increased by further increasing the resin design or molecular weight, the hardness is still about 120 MPa or less. Furthermore, even if filler such as magnetic material or silica is filled near the surface and thermally cured, the hardness is still about 180 MPa or less, meaning that the toner of this embodiment is significantly harder than general toner.

[0075] One method for adjusting the hardness to the above-mentioned specific range is, for example, to form a surface layer of the toner using a substance such as an inorganic substance having an appropriate hardness, and then to control the chemical structure and macrostructure of the toner so that it has an appropriate hardness.

[0076] As a specific example, an organosilicon polymer can be cited as a substance that can achieve the above-mentioned specific hardness, and the hardness can be adjusted by selecting the material and adjusting the number of carbon atoms directly bonded to the silicon atoms of the organosilicon polymer, the carbon chain length, etc. It is preferable that the toner particles have a surface layer containing an organosilicon polymer, and that the number of carbon atoms directly bonded to the silicon atoms of the organosilicon polymer is, on average, from 1 to 3 per silicon atom, since this makes it easier to adjust the above-mentioned specific hardness. Furthermore, the number of carbon atoms directly bonded to the silicon atoms of the organosilicon polymer is preferably from 1 to 2 per silicon atom, more preferably 1.

[0077] The Martens hardness can be adjusted by chemical structure by adjusting the chemical structure, such as the crosslinking or polymerization degree of the surface layer material. The Martens hardness can be adjusted by macrostructure by adjusting the uneven shape of the surface layer or the network structure connecting the convexities. When an organosilicon polymer is used as the surface layer, these adjustments can be made by adjusting the pH, concentration, temperature, time, etc. during pretreatment of the organosilicon polymer. Furthermore, the Martens hardness can be adjusted by the timing, shape, concentration, reaction temperature, etc., of applying the organosilicon polymer to the toner core particles as a surface layer.

[0078] In this embodiment, the following method is particularly preferred. First, toner core particles containing a binder resin and a colorant are produced and dispersed in an aqueous medium to obtain a core particle dispersion. The core particles are preferably dispersed at a concentration such that the solids content of the core particles is 10% by mass or more and 40% by mass or less relative to the total amount of the core particle dispersion. The temperature of the core particle dispersion is preferably adjusted to 35°C or higher. The pH of the core particle dispersion is preferably adjusted to a pH that inhibits condensation of the organosilicon compound. The pH at which condensation of the organosilicon polymer inhibits condensation varies depending on the substance, so it is preferably adjusted within ±0.5 of the pH at which the reaction most inhibits. Meanwhile, it is preferable to use an organosilicon compound that has been hydrolyzed. For example, the organosilicon compound is pretreated by hydrolysis in a separate vessel. The concentration of water used for hydrolysis is preferably 40 to 500 parts by mass of deionized water, such as ion-exchanged water or RO water, based on 100 parts by mass of the organosilicon compound, more preferably 100 to 400 parts by mass of water. The hydrolysis conditions are preferably a pH of 2 to 7, a temperature of 15 to 80° C., and a time of 30 to 600 minutes.

[0079] The resulting hydrolysis solution is mixed with the core particle dispersion and adjusted to a pH suitable for condensation (preferably 6 to 12, or 1 to 3, more preferably 8 to 12), allowing the organosilicon compound to condense while forming a surface layer on the toner core particle surface. The condensation and surface layer formation are preferably carried out at 35°C or higher for 60 minutes or more. The surface macrostructure can be adjusted by adjusting the time for which the mixture is kept at 35°C or higher before adjusting the pH to a suitable pH for condensation, but a time of 3 minutes to 120 minutes is preferred to make it easier to obtain a specific Martens hardness.

[0080] The above-mentioned measures can reduce the amount of reaction residue, form irregularities on the surface layer, and further form a network structure between the protrusions, making it easier to obtain a toner with the above-mentioned specific Martens hardness. An example of a toner is shown in Figure 8 as 46. In the figure, a surface layer 46b covers a toner core particle 46a from the outside, and the surface layer 46b has an irregular shape.

[0081] When using a surface layer containing an organosilicon polymer, the adhesion rate of the organosilicon polymer is preferably 90% or more and 100% or less, and more preferably 95% or more. If the adhesion rate is within this range, the change in Martens hardness over time is small, and charging can be maintained. The method for measuring the adhesion rate of the organosilicon polymer will be described later.

[0082] [About the surface] When toner particles have a surface layer, the surface layer is a layer that covers the toner core particle and exists on the outermost surface of the toner particle. A surface layer containing an organosilicon polymer is much harder than conventional toner particles. Therefore, from the viewpoint of fixability, it is also preferable to provide a portion of the toner particle surface where no surface layer is formed.

[0083] However, it is preferable that the percentage of the number of segmented axes with a surface layer containing an organosilicon polymer having a thickness of 2.5 nm or less (hereinafter also referred to as the percentage of surface layer thicknesses of 2.5 nm or less) be 20.0% or less. This condition approximates the situation where at least 80.0% of the surface of the toner particle is composed of a surface layer containing an organosilicon polymer having a thickness of 2.5 nm or more. In other words, if this condition is met, the surface layer containing the organosilicon polymer will sufficiently cover the core surface. More preferably, it is 10.0% or less. This can be determined by cross-sectional observation using a transmission electron microscope (TEM), as will be described in detail below.

[0084] [Surface layer containing organosilicon polymer] When the toner particles have a surface layer containing an organosilicon polymer, it is preferred that the surface layer have a partial structure represented by formula (1). R-SiO 3 / 2 Formula (1) (R represents a hydrocarbon group having 1 to 6 carbon atoms.)

[0085] In an organosilicon polymer having the structure of formula (1), one of the four valences of the Si atom is bonded to R, and the remaining three are bonded to O atoms. The O atom has two valences bonded to Si, forming a siloxane bond (Si-O-Si). Considering the Si atom and O atom as an organosilicon polymer, two Si atoms have three O atoms, so -SiO 3 / 2 The -SiO of this organosilicon polymer is expressed as follows: 3 / 2 The structure is thought to have properties similar to silica (SiO2), which is composed of many siloxane bonds. Therefore, compared to toners with a surface layer made of conventional organic resins, the structure is closer to that of inorganic materials, and it is thought that it is possible to increase the Martens hardness.

[0086] Furthermore, the tetrahydrofuran (THF) insoluble fraction of the toner particles 29 In the chart obtained by Si-NMR measurement, it is preferable that the ratio of the peak area attributable to the structure of formula (1) to the total peak area of ​​the organosilicon polymer is 20% or more. The detailed measurement method will be described later, but this is because the R-SiO 3 / 2 This approximates that the partial structure represented by the formula (I) is 20% or more.

[0087] As mentioned above, three of the four valences of a Si atom are bonded to oxygen atoms, and these oxygen atoms are then bonded to other Si atoms, forming the -SiO 3 / 2 If one of the oxygen atoms is a silanol group, the partial structure of the organosilicon polymer is R-SiO 2 / 2 Furthermore, if two oxygen atoms are silanol groups, the partial structure is R-SiO 1 / 2 (-OH)2. Comparing these structures, the one with more oxygen atoms forming bridge structures with Si atoms is closer to the silica structure represented by SiO2. Therefore, -SiO 3 / 2 The more skeletons there are, the lower the surface free energy of the toner particle surface can be, which has excellent effects on environmental stability and resistance to member contamination.

[0088] Furthermore, the durability provided by the partial structure represented by formula (1) and the hydrophobicity and electrostatic chargeability of R in formula (1) suppress bleeding of low-molecular-weight resins (Mw 1000 or less), low-Tg resins (40°C or less), and in some cases mold release agents, which are present in the inner part of the film and tend to bleed out.

[0089] The peak area ratio of the partial structure represented by formula (1) can be controlled by the type and amount of organosilicon compound used to form the organosilicon polymer, as well as the reaction temperature, reaction time, reaction solvent, and pH of the hydrolysis, addition polymerization, and condensation polymerization reactions that occur during organosilicon polymer formation.

[0090] In the partial structure represented by formula (1), R is preferably a hydrocarbon group having 1 to 6 carbon atoms. This makes it easier to stabilize the charge amount. In particular, an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a phenyl group, which are excellent in environmental stability, is preferred.

[0091] In this embodiment, it is more preferable for R to be an aliphatic hydrocarbon group having 1 to 3 carbon atoms in order to further improve the chargeability and prevent fogging. Good chargeability results in good transferability and less residual toner, which improves contamination of the drum, charging member, and transfer member.

[0092] Preferred examples of the aliphatic hydrocarbon group having 1 to 3 carbon atoms include a methyl group, an ethyl group, a propyl group, and a vinyl group. From the viewpoints of environmental stability and storage stability, R is more preferably a methyl group.

[0093] A preferred example of the production of organosilicon polymers is the sol-gel process. The sol-gel process uses liquid starting materials as starting materials, undergoes hydrolysis and condensation polymerization, and then gels after passing through a sol state. This process is used to synthesize glass, ceramics, organic-inorganic hybrids, and nanocomposites. This production method allows functional materials in various shapes, such as surface layers, fibers, bulk materials, and microparticles, to be produced from the liquid phase at low temperatures.

[0094] Specifically, the organosilicon polymer present on the surface layer of the toner particles is preferably produced by hydrolysis and condensation polymerization of a silicon compound, typically an alkoxysilane.

[0095] By providing a surface layer containing this organosilicon polymer on toner particles, environmental stability is improved, and the toner performance is less likely to deteriorate over long-term use, resulting in a toner with excellent storage stability.

[0096] Furthermore, because the sol-gel method starts with a liquid and forms a material by gelling the liquid, it is possible to create a variety of microstructures and shapes. In particular, when toner particles are produced in an aqueous medium, the hydrophilic properties of the organosilicon compound, such as the silanol groups, facilitate precipitation on the surface of the toner particles. The microstructure and shape can be adjusted by adjusting the reaction temperature, reaction time, reaction solvent, pH, and the type and amount of organosilicon compound.

[0097] The organosilicon polymer in the surface layer of the toner particles is preferably a condensation polymer of an organosilicon compound having a structure represented by the following formula (Z).

[0098] [ka]

[0099] (In formula (Z), R1 represents a hydrocarbon group having from 1 to 6 carbon atoms, and R2, R3, and R4 each independently represent a halogen atom, a hydroxy group, an acetoxy group, or an alkoxy group.)

[0100] The hydrocarbon group (preferably an alkyl group) of R1 can improve hydrophobicity, resulting in toner particles with excellent environmental stability. Alternatively, an aromatic hydrocarbon group, such as an aryl group, for example, a phenyl group, can be used as the hydrocarbon group. Since high hydrophobicity of R1 tends to increase fluctuations in charge amount in various environments, in consideration of environmental stability, R1 is preferably an aliphatic hydrocarbon group having 1 to 3 carbon atoms, more preferably a methyl group. R2, R3, and R4 are each independently a halogen atom, a hydroxy group, an acetoxy group, or an alkoxy group (hereinafter also referred to as reactive groups). These reactive groups undergo hydrolysis, addition polymerization, and condensation polymerization to form a crosslinked structure, resulting in a toner with excellent resistance to component contamination and development durability. From the viewpoints of mild hydrolysis at room temperature and deposition and coating properties on the surface of toner particles, an alkoxy group having 1 to 3 carbon atoms is preferred, and a methoxy group or an ethoxy group is more preferred. Furthermore, the hydrolysis, addition polymerization, and condensation polymerization of R2, R3, and R4 can be controlled by the reaction temperature, reaction time, reaction solvent, and pH. To obtain the organosilicon polymer used in this example, it is advisable to use one or a combination of several organosilicon compounds (hereinafter also referred to as trifunctional silanes) that have three reactive groups (R2, R3, and R4) in one molecule, excluding R1 in the formula (Z) shown above.

[0101] Examples of the compound represented by the above formula (Z) include the following.

[0102] Trifunctional methylsilanes such as methyltrimethoxysilane, methyltriethoxysilane, methyldiethoxymethoxysilane, methylethoxydimethoxysilane, methyltrichlorosilane, methylmethoxydichlorosilane, methylethoxydichlorosilane, methyldimethoxychlorosilane, methylmethoxyethoxychlorosilane, methyldiethoxychlorosilane, methyltriacetoxysilane, methyldiacetoxymethoxysilane, methyldiacetoxyethoxysilane, methylacetoxydimethoxysilane, methylacetoxymethoxyethoxysilane, methylacetoxydiethoxysilane, methyltrihydroxysilane, methylmethoxydihydroxysilane, methylethoxydihydroxysilane, methyldimethoxyhydroxysilane, methylethoxymethoxyhydroxysilane, and methyldiethoxyhydroxysilane.

[0103] Trifunctional silanes such as ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrichlorosilane, ethyltriacetoxysilane, ethyltrihydroxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltrichlorosilane, propyltriacetoxysilane, propyltrihydroxysilane, butyltrimethoxysilane, butyltriethoxysilane, butyltrichlorosilane, butyltriacetoxysilane, butyltrihydroxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, hexyltrichlorosilane, hexyltriacetoxysilane, and hexyltrihydroxysilane.

[0104] Trifunctional phenylsilanes such as phenyltrimethoxysilane, phenyltriethoxysilane, phenyltrichlorosilane, phenyltriacetoxysilane, and phenyltrihydroxysilane.

[0105] Furthermore, organosilicon polymers obtained by combining the organosilicon compound having the structure represented by formula (Z) with the following may also be used to the extent that the effects of this embodiment are not impaired: organosilicon compounds having four reactive groups per molecule (tetrafunctional silanes), organosilicon compounds having two reactive groups per molecule (bifunctional silanes), or organosilicon compounds having one reactive group (monofunctional silanes). Examples include the following:

[0106] Trifunctional vinyl silanes such as dimethyldiethoxysilane, tetraethoxysilane, hexamethyldisilazane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, vinyltriisocyanatesilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyldiethoxymethoxysilane, vinylethoxydimethoxysilane, vinylethoxydihydroxysilane, vinyldimethoxyhydroxysilane, vinylethoxymethoxyhydroxysilane, and vinyldiethoxyhydroxysilane.

[0107] Furthermore, the content of the organosilicon polymer in the toner particles is preferably 0.5% by weight or more and 10.5% by weight or less.

[0108] By ensuring that the organosilicon polymer content is 0.5% by mass or more, the surface free energy of the surface layer can be further reduced, improving fluidity and suppressing component contamination and fogging. By ensuring that the content is 10.5% by mass or less, charge-up is less likely to occur. The organosilicon polymer content can be controlled by the type and amount of organosilicon compound used to form the organosilicon polymer, the method for producing the toner particles when forming the organosilicon polymer, the reaction temperature, reaction time, reaction solvent, and pH.

[0109] It is preferable that the surface layer containing the organosilicon polymer and the toner core particle are in contact with each other without any gaps. This suppresses bleeding of the resin components and release agents inside the toner particle rather than the surface layer, resulting in a toner with excellent storage stability, environmental stability, and development durability. In addition to the organosilicon polymer, the surface layer may contain resins such as styrene-acrylic copolymer resins, polyester resins, and urethane resins, as well as various additives.

[0110] [About binder resin] The toner particles contain a binder resin. The binder resin is not particularly limited, and conventionally known binder resins can be used. Vinyl resins, polyester resins, and the like are preferred. Examples of the vinyl resins, polyester resins, and other binder resins include the following resins or polymers.

[0111] Homopolymers of styrene and its substituted derivatives such as polystyrene and polyvinyltoluene; styrene-based copolymers such as styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, and styrene-maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyamide resin, epoxy resin, polyacrylic resin, rosin, modified rosin, terpene resin, phenolic resin, aliphatic or alicyclic hydrocarbon resin, and aromatic petroleum resin. These binder resins can be used alone or in combination.

[0112] From the viewpoint of electrostatic chargeability, it is preferable that the binder resin contains a carboxy group, and it is preferable that the binder resin is produced using a polymerizable monomer containing a carboxy group. For example, acrylic acid; derivatives of α-alkyl unsaturated carboxylic acids such as methacrylic acid, α-ethylacrylic acid, and crotonic acid, or derivatives of β-alkyl unsaturated carboxylic acids; unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, and itaconic acid; unsaturated dicarboxylic acid monoester derivatives such as succinic acid monoacryloyloxyethyl ester, succinic acid monoacryloyloxyethylene ester, phthalic acid monoacryloyloxyethyl ester, and phthalic acid monomethacryloyloxyethyl ester.

[0113] The polyester resin may be a condensation polymerization product of the following carboxylic acid component and alcohol component. Examples of the carboxylic acid component include terephthalic acid, isophthalic acid, phthalic acid, fumaric acid, maleic acid, cyclohexanedicarboxylic acid, and trimellitic acid. Examples of the alcohol component include bisphenol A, hydrogenated bisphenol, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, glycerin, trimethylolpropane, and pentaerythritol.

[0114] The polyester resin may also be a polyester resin containing a urea group. It is preferred that the carboxyl groups at the terminals of the polyester resin are not capped.

[0115] The binder resin may have a polymerizable functional group for the purpose of improving the viscosity change of the toner at high temperatures. Examples of the polymerizable functional group include a vinyl group, an isocyanate group, an epoxy group, an amino group, a carboxy group, and a hydroxy group.

[0116] [Crosslinking agent] In order to control the molecular weight of the binder resin, a crosslinking agent may be added during polymerization of the polymerizable monomer.

[0117] For example, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, divinylbenzene, bis(4-acryloxypolyethoxyphenyl)propane, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol #200, #400, and #600 diacrylates, dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyester diacrylate (MANDA Nippon Kayaku), and those in which the above acrylates have been replaced with methacrylates.

[0118] The amount of the crosslinking agent added is preferably 0.001 parts by mass or more and 15,000 parts by mass or less per 100 parts by mass of the polymerizable monomer.

[0119] [About release agents] The toner particles preferably contain a release agent. Examples of release agents that can be used in the toner particles include petroleum waxes and derivatives thereof, such as paraffin wax, microcrystalline wax, and petrolatum, montan wax and derivatives thereof, hydrocarbon waxes produced by the Fischer-Tropsch process and derivatives thereof, polyolefin waxes such as polyethylene and polypropylene and derivatives thereof, natural waxes such as carnauba wax and candelilla wax and derivatives thereof, higher aliphatic alcohols, fatty acids such as stearic acid and palmitic acid, or their acid amides, esters, and ketones, hydrogenated castor oil and derivatives thereof, vegetable waxes, animal waxes, and silicone resins. Derivatives include oxides, block copolymers with vinyl monomers, and graft-modified products.

[0120] The content of the release agent is preferably 5.0 parts by mass or more and 20.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin or polymerizable monomer.

[0121] [About colorants] The toner particles contain a colorant. The colorant is not particularly limited, and the following known colorants can be used, for example.

[0122] Examples of black pigments include carbon black, aniline black, non-magnetic ferrite, magnetite, and those toned to black using the above-mentioned yellow colorants, red colorants, and blue colorants. These colorants can be used alone or in combination, or in the form of a solid solution.

[0123] Examples of colorants include the following: Yellow pigments include condensed azo compounds such as yellow iron oxide, Nabels Yellow, Naphthol Yellow S, Hansa Yellow G, Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, and Tartrazine Lake, as well as isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specific examples include the following: CI Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 155, 168, 180.

[0124] Orange pigments include the following: Permanent Orange GTR, Pyrazolone Orange, Balkan Orange, Benzidine Orange G, Induthrene Brilliant Orange RK, Induthrene Brilliant Orange GK.

[0125] Examples of red pigments include condensed azo compounds such as red iron oxide, permanent red 4R, lithol red, pyrazolone red, watching red calcium salt, lake red C, lake red D, brilliant carmine 6B, brilliant carmine 3B, eosin lake, rhodamine lake B, and alizarin lake, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specific examples include the following: CI Pigment Red 2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, 254.

[0126] Examples of blue pigments include copper phthalocyanine compounds and their derivatives such as alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partial chloride, fast sky blue, and indanthrene blue BG, anthraquinone compounds, and basic dye lake compounds. Specific examples include the following: CI Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, 66.

[0127] Purple pigments include Fast Violet B and Methyl Violet Lake.

[0128] Green pigments include Pigment Green B, Malachite Green Lake, and Final Yellow Green G. White pigments include zinc white, titanium oxide, antimony white, and zinc sulfide.

[0129] If necessary, the colorant may be surface-treated with a substance that does not inhibit polymerization.

[0130] The content of the colorant is preferably 3.0 parts by mass or more and 15.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin or polymerizable monomer.

[0131] [About the manufacturing method of toner particles] Toner particles can be produced by known methods, such as a kneading and pulverization method or a wet production method. From the viewpoint of uniform particle size and shape controllability, a wet production method is preferably used. Further, examples of the wet production method include a suspension polymerization method, a solution suspension method, an emulsion polymerization aggregation method, and an emulsion aggregation method.

[0132] Here, the suspension polymerization method will be described. First, a polymerizable monomer composition is prepared by uniformly dissolving or dispersing a polymerizable monomer for producing a binder resin, a colorant, and other additives as needed, using a disperser such as a ball mill or an ultrasonic disperser. (Preparation process of polymerizable monomer composition) At this time, if needed, a multifunctional monomer, a chain transfer agent, a wax as a mold release agent, a charge control agent, a plasticizer, and the like can be appropriately added. Suitable examples of polymerizable monomers in the suspension polymerization method include the vinyl polymerizable monomers shown below.

[0133] Styrene; styrene derivatives such as α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, and p-phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, and dibutyl phosphate. acrylic polymerizable monomers such as ethyl acrylate and 2-benzoyloxyethyl acrylate; methacrylic polymerizable monomers such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, diethyl phosphate ethyl methacrylate, and dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, and vinyl formate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether; vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropyl ketone.

[0134] Next, the polymerizable monomer composition is poured into a previously prepared aqueous medium, and droplets of the polymerizable monomer composition are formed into the desired toner particle size using a stirrer or disperser with high shear force (granulation process).

[0135] It is preferable that the aqueous medium used in the granulation process contains a dispersion stabilizer in order to control the particle size of the toner particles, sharpen the particle size distribution, and prevent the coalescence of toner particles during the manufacturing process. Dispersion stabilizers are generally broadly classified into polymers that exhibit repulsive forces due to steric hindrance and poorly water-soluble inorganic compounds that stabilize dispersion by electrostatic repulsive forces. Fine particles of poorly water-soluble inorganic compounds are preferably used because they dissolve in acid or alkali and can be easily removed by washing with acid or alkali after polymerization.

[0136] As the dispersion stabilizer of the poorly water-soluble inorganic compound, one containing any of magnesium, calcium, barium, zinc, aluminum, and phosphorus is preferably used. More preferably, one containing any of magnesium, calcium, aluminum, and phosphorus is desired. Specific examples include the following. Examples of the dispersion stabilizer include magnesium phosphate, tricalcium phosphate, aluminum phosphate, zinc phosphate, magnesium carbonate, calcium carbonate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, and hydroxyapatide. The dispersion stabilizers may be used in combination with organic compounds such as polyvinyl alcohol, gelatin, methyl cellulose, methylhydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, and starch. These dispersion stabilizers are preferably used in an amount of 0.01 to 2.00 parts by mass per 100 parts by mass of the polymerizable monomer.

[0137] Furthermore, to refine the dispersion stabilizer, a surfactant may be used in an amount of 0.001 to 0.1 parts by mass per 100 parts by mass of the polymerizable monomer. Specifically, commercially available nonionic, anionic, and cationic surfactants can be used. For example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, and calcium oleate are preferably used.

[0138] After the granulation step, or while the granulation step is being carried out, the temperature is preferably set to 50°C or higher and 90°C or lower to polymerize the polymerizable monomers contained in the polymerizable monomer composition, thereby obtaining a toner particle dispersion (polymerization step).

[0139] In the polymerization step, stirring is preferably performed so as to achieve a uniform temperature distribution in the vessel. When adding a polymerization initiator, this can be done at any timing and for any required time. The temperature may be raised in the latter half of the polymerization reaction to obtain a desired molecular weight distribution. Furthermore, in order to remove unreacted polymerizable monomers, by-products, etc. from the system, a portion of the aqueous medium may be distilled off in the latter half of the reaction or after completion of the reaction. The distillation can be performed under normal pressure or reduced pressure.

[0140] In the suspension polymerization method, an oil-soluble initiator is generally used, for example, the following: azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), and 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile; and peroxide initiators such as acetylcyclohexylsulfonyl peroxide, diisopropyl peroxycarbonate, decanoyl peroxide, lauroyl peroxide, stearoyl peroxide, propionyl peroxide, acetyl peroxide, tert-butyl peroxy-2-ethylhexanoate, benzoyl peroxide, tert-butyl peroxyisobutyrate, cyclohexanone peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, tert-butyl peroxypivalate, and cumene hydroperoxide.

[0141] The polymerization initiator may be used in combination with a water-soluble initiator as needed, and examples thereof include ammonium persulfate, potassium persulfate, 2,2'-azobis(N,N'-dimethyleneisobutyromidine) hydrochloride, 2,2'-azobis(2-amidinopropane) hydrochloride, azobis(isobutylamidine) hydrochloride, sodium 2,2'-azobisisobutyronitrile sulfonate, ferrous sulfate, and hydrogen peroxide.

[0142] These polymerization initiators can be used alone or in combination, and a chain transfer agent, a polymerization inhibitor, etc. can also be added to control the degree of polymerization of the polymerizable monomer.

[0143] The weight average particle size of the toner particles is preferably 3.0 μm or more and 10.0 μm or less from the viewpoint of obtaining high-definition, high-resolution images. The weight average particle size of the toner can be measured by the pore electrical resistance method. For example, it can be measured using a Coulter Counter Multisizer 3 (manufactured by Beckman Coulter, Inc.). The toner particle dispersion thus obtained is sent to a filtration process for solid-liquid separation of the toner particles and the aqueous medium.

[0144] Solid-liquid separation to obtain toner particles from the resulting toner particle dispersion can be performed by a general filtration method, and then, in order to remove any foreign matter that has not been completely removed from the toner particle surface, further washing is preferably performed by reslurrying or washing with washing water. After sufficient washing, solid-liquid separation is again performed to obtain a toner cake. Thereafter, the toner cake is dried by a known drying means, and if necessary, particle groups having particle sizes other than the specified particle size are separated by classification to obtain toner particles. The particle groups having particle sizes other than the specified particle size separated at this time may be reused to improve the final yield.

[0145] When forming a surface layer having an organosilicon polymer, or when forming toner particles in an aqueous medium, the hydrolysis solution of the organosilicon compound can be added as described above while performing a polymerization step or the like in the aqueous medium to form the surface layer. A dispersion of toner particles after polymerization may be used as a core particle dispersion, and the hydrolysis solution of the organosilicon compound may be added to form the surface layer. Further, in cases other than an aqueous medium such as the kneading and grinding method, the obtained toner particles are dispersed in an aqueous medium and used as a core particle dispersion, and the hydrolysis solution of the organosilicon compound is added as described above to form the surface layer.

[0146] [Method for Measuring Physical Properties of Toner] <Method for Separating THF-Insoluble Portion of Toner Particles for NMR Measurement> The tetrahydrofuran (THF)-insoluble portion of toner particles can be obtained as follows. Weigh 10.0 g of toner particles, put them in a cylindrical filter paper (No. 86R manufactured by Toyo Roshi Kaisha, Ltd.), and place them in a Soxhlet extractor. Extract for 20 hours using 200 mL of THF as a solvent, and the residue in the cylindrical filter paper obtained by performing vacuum drying at 40 °C for several hours is taken as the THF-insoluble portion of the toner particles for NMR measurement.

[0147] When the surface of the toner particles is treated with an external additive or the like, the external additive is removed by the following method to obtain toner particles.

[0148] Add 160 g of sucrose (manufactured by Kishida Chemical Co., Ltd.) to 100 mL of ion-exchanged water, dissolve it while stirring, and prepare a thick sucrose solution. Put 31 g of the above thick sucrose solution and 6 mL of Contaminon N (a 10% by mass aqueous solution of a neutral detergent for precision measuring instrument cleaning with pH 7 composed of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) into a centrifuge tube (capacity 50 mL) to prepare a dispersion. Add 1.0 g of toner to this dispersion, and loosen the toner lumps with a spatula or the like.

[0149] The centrifuge tube is shaken in a shaker at 350 strokes per minute (spm) for 20 minutes. After shaking, the solution is transferred to a glass tube for a swing rotor (50 mL capacity) and separated in a centrifuge (H-9R, manufactured by Kokusan Co., Ltd.) at 3500 rpm for 30 minutes. This operation separates the toner particles from the detached external additives. Visually confirm that the toner and aqueous solution have been sufficiently separated, and collect the toner that has separated to the top layer with a spatula or similar. The collected toner is filtered using a vacuum filter and then dried in a dryer for at least 1 hour to obtain toner particles. This operation is repeated multiple times to ensure the required amount.

[0150] <Method for confirming the partial structure represented by formula (1)> The partial structure represented by formula (1) in the organosilicon polymer contained in the toner particles is confirmed by the following method. The hydrocarbon group represented by R in formula (1) is 13 Confirmed by C-NMR. ( 13 C-NMR (solid state) measurement conditions Equipment: JEOL RESONANCE JNM-ECX500II Sample tube: 3.2 mm diameter Sample: 150 mg of tetrahydrofuran-insoluble toner particles for NMR measurement Measurement temperature: room temperature Pulse mode: CP / MAS Measurement nuclear frequency: 123.25MHz ( 13 C) Reference substance: Adamantane (external standard: 29.5ppm) Sample rotation speed: 20kHz Contact time: 2ms Delay time: 2 seconds Number of times accumulated: 1024

[0151] In this method, methyl groups (Si-CH3), ethyl groups (Si-C2H5), propyl groups (Si-C3H7), butyl groups (Si-C4H9), pentyl groups (Si-C5H 11 ), hexyl group (Si-CH 13The hydrocarbon group represented by R in formula (1) is identified based on the presence or absence of signals due to a phenyl group (Si-C6H5) or the like.

[0152] <Method for calculating the proportion of the peak area attributable to the structure of formula (1) in the organosilicon polymer contained in the toner particles> THF insoluble fraction of toner particles 29 Si-NMR (solid state) measurement is carried out under the following measurement conditions. ( 29 Si-NMR (solid state) measurement conditions Equipment: JEOL RESONANCE JNM-ECX500II Sample tube: 3.2 mm diameter Sample: 150 mg of tetrahydrofuran-insoluble toner particles for NMR measurement Measurement temperature: room temperature Pulse mode: CP / MAS Measured nuclear frequency: 97.38MHz ( 29 Si) Reference material: DSS (external standard: 1.534ppm) Sample rotation speed: 10kHz Contact time: 10ms Delay time: 2 seconds Accumulation times: 2000 to 8000 times

[0153] After the above measurement, the peaks of a plurality of silane components having different substituents and bonding groups in the tetrahydrofuran-insoluble portion of the toner particles are separated into the following X1 structure, X2 structure, X3 structure, and X4 structure by curve fitting, and the peak area of ​​each is calculated. X1 structure: (Ri)(Rj)(Rk)SiO 1 / 2 Formula (2) X2 structure: (Rg)(Rh)Si(O 1 / 2 )2 Formula (3)X3 Structure: RmSi(O 1 / 2 )3 formula (4) X4 structure: Si(O 1 / 2 )4 formula (5)

[0154] [ka]

[0155] [ka]

[0156] [ka]

[0157] [ka]

[0158] (In formulas (2), (3), and (4), Ri, Rj, Rk, Rg, Rh, and Rm represent silicon-bonded organic groups such as hydrocarbon groups having 1 to 6 carbon atoms, halogen atoms, hydroxy groups, acetoxy groups, or alkoxy groups.)

[0159] In this embodiment, the THF-insoluble portion of the toner particles 29 In the chart obtained by Si-NMR measurement, the ratio of the peak area attributable to the structure of formula (1) to the total peak area of ​​the organosilicon polymer is preferably 20% or more.

[0160] If it is necessary to confirm the partial structure represented by the above formula (1) in more detail, 13 C-NMR and 29 Along with the Si-NMR measurement results 1 It may also be identified by the results of H-NMR measurement.

[0161] <Method for measuring the proportion of surface layers containing organosilicon polymers with a thickness of 2.5 nm or less, as measured by observing the cross section of toner particles using a transmission electron microscope (TEM)> In this embodiment, the cross section of the toner particle is observed by the following method.

[0162] A specific method for observing the cross-section of a toner particle involves thoroughly dispersing toner particles in a room-temperature curing epoxy resin, then curing the resin in an atmosphere at 40°C for two days. A thin sample is cut from the resulting cured product using a microtome equipped with a diamond blade. This sample is then magnified at 10,000 to 100,000 times using a transmission electron microscope (TEM) (JEOL JEM-2800), and the cross-section of the toner particle is observed.

[0163] This can be confirmed by taking advantage of the difference in atomic weight between the binder resin and the surface material, where the larger the atomic weight, the brighter the contrast. Ruthenium tetroxide staining and osmium tetroxide staining methods are used to create contrast between the materials.

[0164] The particles used in this measurement have their equivalent circle diameter Dtem determined from the cross section of the toner particles obtained from the TEM micrograph, and this value is considered to be within ±10% of the weight average particle diameter D4 of the toner particles determined by the method described below.

[0165] As mentioned above, a dark-field image of the cross section of a toner particle is obtained using a JEOL JEM-2800 at an accelerating voltage of 200 kV. Next, a mapping image is obtained using a Gatan EELS detector GIF Quantam by the Three Window method to confirm the surface layer.

[0166] Next, for one toner particle whose circle-equivalent diameter Dtem is within ±10% of the weight-average particle diameter D4 of the toner particles, the cross section of the toner particle is equally divided into 16 parts centered on the intersection of the major axis L of the toner particle cross section and an axis L90 that passes through the center of and is perpendicular to the major axis L. Next, the division axes extending from the center toward the surface layer of the toner particle are designated An (n=1 to 32), the length of the division axis is designated RAn, and the thickness of the surface layer is designated FRAn.

[0167] The ratio of the number of segments on each of the 32 segments where the thickness of the surface layer containing the organosilicon polymer is 2.5 nm or less is then determined. For averaging purposes, measurements are taken on 10 toner particles and the average value per toner particle is calculated.

[0168] [Circle equivalent diameter (Dtem) obtained from the cross section of a toner particle taken from a transmission electron microscope (TEM) photograph] The equivalent circle diameter (Dtem) obtained from the cross section of a toner particle obtained from a TEM photograph is determined by the following method: First, for one toner particle, the equivalent circle diameter Dtem obtained from the cross section of the toner particle obtained from a TEM photograph is determined according to the following formula. [Circle equivalent diameter (Dtem) obtained from the cross section of a toner particle obtained from a TEM photograph] = (RA1 + RA2 + RA3 + RA4 + RA5 + RA6 + RA7 + RA8 + RA9 + RA10 + RA11 + RA12 + RA13 + RA14 + RA15 + RA16 + RA17 + RA18 + RA19 + RA20 + RA21 + RA22 + RA23 + RA24 + RA25 + RA26 + RA27 + RA28 + RA29 + RA30 + RA31 + RA32) / 16

[0169] The circle-equivalent diameters of 10 toner particles are determined, and the average value per particle is calculated to obtain the circle-equivalent diameter (Dtem) determined from the cross section of the toner particle. [Proportion of surface layer containing organosilicon polymer with a thickness of 2.5 nm or less] [Percentage of surface layers containing organosilicon polymers with a thickness (FRAn) of 2.5 nm or less] = [{Number of divided axes with a surface layer containing organosilicon polymers with a thickness (FRAn) of 2.5 nm or less} / 32] x 100

[0170] This calculation was performed on 10 toner particles, and the average of the percentage of the 10 particles with a surface layer thickness (FRAn) of 2.5 nm or less was calculated, which was taken as the percentage of toner particles with a surface layer thickness (FRAn) of 2.5 nm or less.

[0171] <Measurement of organosilicon polymer content in toner particles> The organosilicon polymer content was measured using a wavelength-dispersive X-ray fluorescence analyzer "Axios" (PANalytical) and the accompanying dedicated software "SuperQ ver. 4.0F" (PANalytical) for setting measurement conditions and analyzing measurement data. Rh was used as the anode of the X-ray tube, the measurement atmosphere was vacuum, the measurement diameter (collimator mask diameter) was 27 mm, and the measurement time was 10 seconds. Light elements were detected using a proportional counter (PC), and heavy elements were detected using a scintillation counter (SC).

[0172] The measurement sample was prepared by placing 4 g of toner particles in a special aluminum ring for pressing, flattening it, and then pressing it at 20 MPa for 60 seconds using a tablet molding compressor "BRE-32" (manufactured by Maekawa Testing Machinery Manufacturing Co., Ltd.) to form a pellet with a thickness of 2 mm and a diameter of 39 mm.

[0173] 0.5 parts by weight of silica (SiO2) fine powder is added to 100 parts by weight of toner particles that do not contain organosilicon polymer, and the mixture is thoroughly mixed using a coffee mill. Similarly, 5.0 parts by weight and 10.0 parts by weight of silica fine powder are mixed to 100 parts by weight of toner particles, and these are used as samples for the calibration curve.

[0174] For each sample, pellets for the calibration curve were prepared using a tablet press as described above, and the count rate (units: cps) of the Si-Kα ray observed at a diffraction angle (2θ) of 109.08° when PET was used as the analyzing crystal was measured. The acceleration voltage and current of the X-ray generator were set to 24 kV and 100 mA, respectively. A linear calibration curve was obtained by plotting the obtained X-ray count rate on the vertical axis and the amount of SiO2 added in each calibration curve sample on the horizontal axis. Next, the toner particles to be analyzed were pelletized using a tablet press as described above, and the count rate of the Si-Kα ray was measured. The organosilicon polymer content in the toner particles was then determined from the calibration curve.

[0175] <Method for measuring adhesion rate of organosilicon polymer> Add 160 g of sucrose (Kishida Chemical) to 100 mL of ion-exchanged water and dissolve in a hot water bath to prepare a concentrated sucrose solution. Place 31 g of the above concentrated sucrose solution and 6 mL of Contaminon N (a 10% by weight aqueous solution of a pH 7 neutral detergent for cleaning precision measuring instruments, consisting of a nonionic surfactant, anionic surfactant, and organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) in a 50 mL centrifuge tube to prepare a dispersion. Add 1.0 g of toner to this dispersion and break up any clumps of toner with a spatula or similar.

[0176] The centrifuge tube is shaken in a shaker at 350 strokes per minute (spm) for 20 minutes. After shaking, the solution is transferred to a glass tube for a swing-out rotor (50 mL capacity) and separated in a centrifuge (H-9R, manufactured by Kokusan Co., Ltd.) at 3500 rpm for 30 minutes. Visually confirm that the toner and aqueous solution have been sufficiently separated, and collect the toner that has separated to the top layer with a spatula. The collected aqueous solution containing the toner is filtered through a vacuum filter and then dried in a dryer for at least 1 hour. The dried product is crushed with a spatula, and the amount of silicon is measured using fluorescent X-rays. The adhesion rate (%) is calculated from the ratio of the amount of the measured element between the toner after washing and the initial toner.

[0177] The measurement of fluorescent X-rays for each element conforms to JIS K 0119-1969, and specifically is as follows.

[0178] The measurement equipment used was a wavelength dispersive X-ray fluorescence analyzer "Axios" (PANalytical) and the accompanying dedicated software "SuperQver.4.0F" (PANalytical) for setting measurement conditions and analyzing measurement data. Rh was used as the anode of the X-ray tube, the measurement atmosphere was vacuum, the measurement diameter (collimator mask diameter) was 10 mm, and the measurement time was 10 seconds. Light elements were detected using a proportional counter (PC), and heavy elements were detected using a scintillation counter (SC).

[0179] The measurement sample is prepared by placing approximately 1 g of washed toner and the initial toner in a dedicated aluminum ring with a diameter of 10 mm, flattening it, and then pressing it at 20 MPa for 60 seconds using a tablet press to form pellets with a thickness of approximately 2 mm.The tablet press used is the "BRE-32" (manufactured by Mayekawa Testing Machinery Co., Ltd.).

[0180] Measurements are carried out under the above conditions, and elements are identified based on the peak positions of the obtained X-rays. Their concentrations are then calculated from the counting rate (unit: cps), which is the number of X-ray photons per unit time.

[0181] To quantify the amount of silicon in a toner, for example, 0.5 parts by mass of silica (SiO2) fine powder is added to 100 parts by mass of toner particles and thoroughly mixed using a coffee mill. Similarly, 2.0 parts by mass and 5.0 parts by mass of silica fine powder are mixed with the toner particles, respectively, and these are used as samples for the calibration curve.

[0182] For each sample, pellets for the calibration curve were prepared using a tablet press as described above, and the count rate (unit: cps) of the Si-Kα ray observed at a diffraction angle (2θ) of 109.08° when PET was used as the analyzing crystal was measured. The acceleration voltage and current of the X-ray generator were set to 24 kV and 100 mA, respectively. A linear calibration curve was obtained with the obtained X-ray count rate on the vertical axis and the amount of SiO2 added in each calibration curve sample on the horizontal axis. Next, the toner to be analyzed was pelletized using a tablet press as described above, and the count rate of the Si-Kα ray was measured. The content of the organosilicon polymer in the toner was then determined from the calibration curve. The ratio of the elemental amounts of the toner after washing to the elemental amounts of the initial toner calculated using the above method was calculated and used as the adhesion rate (%).

[0183] Detailed Examples The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, the "parts" and "%" of each material in the examples and comparative examples are all based on mass.

[0184] Detailed Example 1 <Step of preparing aqueous medium 1> To 1000.0 parts of ion-exchanged water in a reaction vessel, 14.0 parts of sodium phosphate (12-hydrate) (manufactured by Rasa Kogyo Co., Ltd.) were added, and the mixture was kept at 65°C for 1.0 hour while being purged with nitrogen.

[0185] Aqueous medium containing a dispersion stabilizer was prepared by adding an aqueous calcium chloride solution prepared by dissolving 9.2 parts of calcium chloride (dihydrate) in 10.0 parts of ion-exchanged water all at once while stirring at 12,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) Further, 10% by mass of hydrochloric acid was added to the aqueous medium to adjust the pH to 5.0, thereby obtaining aqueous medium 1.

[0186] <Hydrolysis process of the organosilicon compound for the surface layer> 60.0 parts of ion-exchanged water was weighed into a reaction vessel equipped with a stirrer and a thermometer, and the pH was adjusted to 3.0 using 10% by mass of hydrochloric acid. This was heated with stirring until the temperature reached 70°C. 40.0 parts of methyltriethoxysilane, an organosilicon compound for the surface layer, was then added and stirred for 2 hours or more to carry out hydrolysis. The end point of the hydrolysis was confirmed by visual inspection when the oil and water were not separated and a single layer was formed, and the mixture was cooled to obtain a hydrolyzed solution of the organosilicon compound for the surface layer.

[0187] <Preparation step of polymerizable monomer composition> Styrene: 50.0 parts Carbon black (Nipex 35 [Orion Engineered Carbon]): 7.0 parts

[0188] The materials were placed in an attritor (manufactured by Mitsui Miike Chemical Engineering Co., Ltd.), and further dispersed using zirconia particles with a diameter of 1.7 mm at 220 rpm for 5.0 hours to prepare a pigment dispersion. The following materials were added to the pigment dispersion. Styrene: 20.0 parts n-Butyl acrylate: 30.0 parts Crosslinking agent (divinylbenzene): 0.3 parts Saturated polyester resin: 5.0 parts (Polycondensation polymer of propylene oxide-modified bisphenol A (2-mol adduct) and terephthalic acid (molar ratio 10:12), glass transition temperature Tg = 68°C, weight average molecular weight Mw = 10,000, molecular weight distribution Mw / Mn = 5.12) Fischer-Tropsch wax (melting point 78°C): 7.0 parts

[0189] The mixture was kept at 65°C and uniformly dissolved and dispersed at 500 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare a polymerizable monomer composition.

[0190] <Granulation process> While maintaining the temperature of the aqueous medium 1 at 70°C and the rotation speed of the TK homomixer at 12,000 rpm, the polymerizable monomer composition was charged into the aqueous medium 1, and 9.0 parts of t-butyl peroxypivalate as a polymerization initiator was added. Granulation was continued for 10 minutes while maintaining the stirring speed at 12,000 rpm with the stirring device.

[0191] <Polymerization process> After the granulation process, the agitator was replaced with a propeller agitator and stirred at 150 rpm. Polymerization was carried out at 70°C for 5.0 hours, then the temperature was raised to 85°C and heated for 2.0 hours to complete the polymerization reaction and obtain core particles. The temperature of the slurry containing the core particles was cooled to 55°C and the pH was measured, which was found to be 5.0. While continuing to stir at 55°C, 20.0 parts of a hydrolyzed solution of an organosilicon compound for the surface layer was added to initiate the formation of the toner surface layer. After holding for 30 minutes, the slurry was adjusted to pH 9.0 using aqueous sodium hydroxide to complete the condensation, and then held for an additional 300 minutes to form the surface layer.

[0192] <Cleaning and drying process> After the polymerization process was completed, the toner particle slurry was cooled, and hydrochloric acid was added to the toner particle slurry to adjust the pH to 1.5 or less. The mixture was then stirred for 1 hour and then subjected to solid-liquid separation using a pressure filter to obtain a toner cake. This was then reslurried with ion-exchanged water to form a dispersion again, and then subjected to solid-liquid separation using the aforementioned filter. The reslurrying and solid-liquid separation were repeated until the electrical conductivity of the filtrate reached 5.0 μS / cm or less, after which solid-liquid separation was finally performed to obtain a toner cake.

[0193] The obtained toner cake was dried in a flash jet dryer (manufactured by Seishin Enterprises), and further fine and coarse particles were removed using a multi-division classifier utilizing the Coanda effect to obtain toner particles 1. The drying conditions were an inlet temperature of 90°C, a dryer outlet temperature of 40°C, and the toner cake supply rate was adjusted according to the moisture content of the toner cake so that the outlet temperature did not deviate from 40°C.

[0194] Silicon mapping was performed in cross-sectional TEM observation of toner particle 1, and it was confirmed that silicon atoms were present in the surface layer, and that the proportion of the number of dividing axes with a surface layer thickness of 2.5 nm or less for toner particles containing an organosilicon polymer was 20.0% or less. In the following examples, similar silicon mapping was performed on the surface layer containing an organosilicon polymer to confirm that silicon atoms were present in the surface layer, and that the proportion of the number of dividing axes with a surface layer thickness of 2.5 nm or less was 20.0% or less. In these examples, the obtained toner particle 1 was used as toner 1 without any external additions.

[0195] The evaluation method for Toner 1 is described below.

[0196] <Measurement of Martens hardness> Hardness is one of the mechanical properties of the surface or near the surface of an object, and refers to the resistance of the object to deformation or scratching when a foreign object tries to deform or scratch it. There are various measurement methods and definitions. For example, the measurement method used depends on the size of the measurement area; for example, the Vickers method is used for measurement areas of 10 μm or more, the nanoindentation method for measurement areas of 10 μm or less, and the AFM method for measurement areas of 1 μm or less. For definitions, for example, Brinell hardness and Vickers hardness are used for indentation hardness, Martens hardness for scratch hardness, and Shore hardness for rebound hardness.

[0197] When measuring toner, the nanoindentation method is a preferred measurement method because the typical particle size is 3 μm to 10 μm. According to the inventors' investigations, the Martens hardness, which indicates scratch hardness, was found to be appropriate as the definition of hardness for achieving the effects of this embodiment. This is because scratch hardness can indicate the resistance of toner to being scratched by hard materials such as metals and external additives inside the developing machine.

[0198] The Martens hardness of toner can be measured by nanoindentation using a commercially available device conforming to ISO 14577-1, and calculated from the obtained load-displacement curve according to the indentation test procedure specified in ISO 14577-1. In this example, an ultra-microindentation hardness tester "ENT-1100b" (manufactured by Elionix Co., Ltd.) was used as the device conforming to the ISO standard. The measurement method is described in the "ENT1100 Operation Manual" that comes with the device, and the specific measurement method is as follows.

[0199] The measurement environment was maintained at 30.0°C inside the shield case using the attached temperature control device. Maintaining a constant ambient temperature is effective in reducing variations in measurement data due to factors such as thermal expansion and drift. The set temperature was set to 30.0°C, which simulates the temperature near the developing machine where the toner is rubbed. The standard sample stage attached to the device was used as the sample stage, and after applying the toner, a gentle blast of air was applied to disperse the toner. The sample stage was then set in the device and held for at least one hour before measurements were taken.

[0200] Measurements were performed using a flat indenter (titanium indenter with a diamond tip) attached to the device, with a 20 μm square flat tip. For small, spherical objects like toner, objects with external additives attached, or objects with uneven surfaces, a flat indenter is used because using a sharp indenter would have a significant effect on measurement accuracy. The maximum load for the test was 2.0 × 10 -4 The test load is set to N. By setting this test load, it is possible to measure the hardness without damaging the surface layer of the toner under conditions equivalent to the stress that a single toner particle experiences in the developing section. In this embodiment, since abrasion resistance is important, it is important to measure the hardness while maintaining the surface layer without damaging it.

[0201] The particles to be measured are selected as toner particles present alone on the measurement screen (field of view: 160 μm wide, 120 μm long) of the microscope attached to the device. However, to minimize errors in the amount of displacement, particles with a particle diameter (D) within ±0.5 μm of the number average particle diameter (D1) (D1 - 0.5 μm ≦ D ≦ D1 + 0.5 μm) are selected. The particle diameter of the particles to be measured is measured using the software attached to the device, and the particle diameter D (μm) is calculated as [(long diameter + short diameter) / 2]. The number average particle diameter is measured using a Coulter Counter Multisizer 3 (manufactured by Beckman Coulter, Inc.) using the method described below.

[0202] For the measurement, 100 randomly selected toner particles whose particle diameter D (μm) satisfies the above conditions are measured. The conditions to be input for the measurement are as follows: Test mode: Load-unload test Test load: 20,000 mgf (= 2.0 × 10 -4 N) Number of divisions: 1000 steps Step interval: 10msec

[0203] When the analysis menu "Data Analysis (ISO)" is selected and measurement is performed, the Martens hardness is analyzed and output by the software attached to the device after the measurement. The above measurement was performed on 100 toner particles, and the arithmetic mean value was used as the Martens hardness in this example.

[0204] <Method for measuring adhesion rate> Measurements were carried out using the methods described in [Methods for measuring physical properties of toner].

[0205] <Printout evaluation> A modified Canon LBP7600C laser beam printer was used. The modification involved changing the evaluation machine itself and software to set the rotation speed of the developing roller to 1.8 times the peripheral speed. Specifically, the rotation speed of the developing roller before modification was 200 mm / sec, but after modification it was changed to 360 mm / sec.

[0206] 40 g of toner was loaded into the toner cartridge of the LBP7600C. Then, the toner cartridge was left in an environment of normal temperature and humidity NN (25°C / 50%RH) for 24 hours. After leaving the toner cartridge in this environment for 24 hours, it was installed in the LBP7600C.

[0207] The evaluation of charge buildup was carried out in an NN environment after printing out up to 4,000 sheets of A4 paper in landscape orientation with a print ratio of 35.0%. The evaluation of charge buildup was also carried out initially.

[0208] <Evaluation of development streaks> Letter size XEROX4200 paper (XEROX, 75 g / m 2 ) and halftone (toner amount: 0.2 mg / cm 2The image was printed out and the development streaks were evaluated. A grade of C or better was judged to be good.

[0209] (Evaluation criteria) A: No vertical lines in the paper ejection direction are visible on the developing roller or on the image. B: Five or fewer thin circumferential lines are visible on both ends of the developing roller, or very slight vertical lines are visible on the image in the paper ejection direction. C: 6 to 20 fine circumferential lines are visible on both ends of the developing roller, or 5 or fewer fine lines are visible on the image. D: 21 or more lines are visible on the developing roller, or one or more prominent lines or six or more fine lines are visible on the image.

[0210] <Ghost evaluation> An image consisting of a 3cm wide solid vertical line and a solid white vertical line was printed on 10 consecutive sheets, and then a halftone image was printed, and the history of the previous image remaining on the image was visually determined. The image density of the halftone image was measured using a Macbeth densitometer (manufactured by Macbeth) with an SPI filter and adjusted to a reflection density of 0.4. A: No ghosting occurs. B: Minor traces of previous images can be visually confirmed in some areas. C: The history of the previous image can be visually confirmed in some areas. D: The history of the previous image can be visually confirmed overall.

[0211] <Evaluation of cleaning ability> Toner loading is 0.2mg / cm 2 Five halftone images were printed and evaluated. A: No defective images and no stains on the charging roller. B: No cleaning defects, charging roller dirty. C: A slight cleaning defect can be seen on the halftone image. D: Poor cleaning is noticeable on halftone images.

[0212] <Evaluation of charging start-up> Ten solid images were printed. The machine was forcibly stopped during the printing of the tenth sheet, and the toner charge on the developing roller was measured immediately after passing the regulating blade. The charge on the developing roller was measured using a Faraday cage, as shown in the perspective view of Figure 6. The inside (right side of the figure) was depressurized to suck in the toner on the developing roller, and a toner filter 33 was installed to collect the toner. 31 is the suction part, and 32 is the holder. The charge per unit mass, Q / M (μC / g), was calculated from the mass M of the collected toner and the charge Q measured directly with a coulomb meter, and the toner charge (Q / M) was ranked as follows: A: Less than -40μC / g B: -40μC / g or more and less than -30μC / g C: -30μC / g or more and less than -20μC / g D: -20μC / g or more

[0213] [Detailed Examples 2 to 12] A toner was produced in the same manner as in Example 1, except that the conditions for adding the hydrolyzed liquid in the "polymerization step" and the retention time after addition were changed as shown in Table 1. The pH of the slurry was adjusted with hydrochloric acid and an aqueous solution of sodium hydroxide. The obtained toner was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

[0214] [Detailed Examples 13 to 18] A toner was produced in the same manner as in Example 1, except that the surface layer organosilicon compound used in the "hydrolysis step of the surface layer organosilicon compound" was changed as shown in Table 1. The obtained toner was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

[0215] [Detailed Examples 19 to 23] A toner was produced in the same manner as in Example 1, except that the conditions for adding the hydrolysis liquid in the "polymerization step" were changed as shown in Table 1. The obtained toner was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

[0216] [Comparative Example 1 and Comparative Example 2] A toner was produced in the same manner as in Example 1, except that the conditions for adding the hydrolyzed liquid in the "polymerization step" and the retention time after addition were changed as shown in Table 1. The obtained toner was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

[0217] Comparative Example 3 The "hydrolysis step of the surface layer organosilicon compound" was not carried out. Instead, 8 parts of methyltriethoxysilane, an organosilicon compound for the surface layer, was added as a monomer in the "polymerizable monomer composition preparation step."

[0218] In the "polymerization step," the mixture was cooled to 70°C and the pH was measured, but no hydrolysis liquid was added. With stirring continued at 70°C, the slurry was adjusted to pH 9.0 using an aqueous sodium hydroxide solution to complete the condensation, and the mixture was maintained for a further 300 minutes to form a surface layer.

[0219] Other than that, a toner was produced in the same manner as in Example 1. The obtained toner was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

[0220] Comparative Example 4 In Comparative Example 3, the amount of methyltriethoxysilane added in the "polymerizable monomer composition preparation step" was changed to 15 parts.

[0221] Other than that, a toner was produced in the same manner as in Comparative Example 3. The obtained toner was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

[0222] Comparative Example 5 In Comparative Example 3, the amount of methyltriethoxysilane added in the "polymerizable monomer composition preparation step" was changed to 30 parts.

[0223] Other than that, a toner was produced in the same manner as in Comparative Example 3. The obtained toner was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

[0224] Comparative Example 6 <Production example of binder resin 1> Terephthalic acid 25.0mol% Adipic acid 13.0mol% Trimellitic acid 8.0mol% Propylene oxide modified bisphenol A (2.5 mol adduct) 33.0 mol% A four-neck flask was charged with 100 parts of ethylene oxide-modified bisphenol A (2.5 mol adduct) (21.0 mol%), a total of the acid component and alcohol component shown above, and 0.02 parts of tin 2-ethylhexanoate as an esterification catalyst, and the flask was equipped with a pressure reducing device, a water separator, a nitrogen gas introducing device, a temperature measuring device, and a stirrer. The reaction was carried out by heating to 230°C under a nitrogen atmosphere. After completion of the reaction, the product was removed from the vessel, cooled, and pulverized to obtain binder resin 1.

[0225] <Production example of binder resin 2> Binder resin 2 was prepared in the same manner as binder resin 1, except that the monomer composition ratio and reaction temperature were changed as follows. Terephthalic acid 50.0mol% Trimellitic acid 3.0mol% Propylene oxide modified bisphenol A (2.5 mol adduct) 47.0 mol% Reaction temperature: 190℃

[0226] <Production Example of Comparative Toner 6> Binder resin 1:70.0 parts Binder resin 2: 30.0 parts Magnetic iron oxide particles: 90.0 parts (Number average particle size 0.14μm, Hc=11.5kA / m, σs=84.0Am 2 / kg, σr=16.0Am 2 / kg) Fischer-Tropsch wax (melting point 105°C): 2.0 parts Charge control agent 1 (structural formula below): 2.0 parts Charge control agent 1

[0227] [ka]

[0228] In the formula, tBu represents a tert-butyl group.

[0229] The above materials were premixed in a Henschel mixer and then melt-kneaded in a twin-screw extruder with three kneading sections and a screw section. The first kneading section (closest to the feed port) was heated to 110°C, the second kneading section to 130°C, and the third kneading section to 150°C, with a paddle rotation speed of 200 rpm. The resulting kneaded mixture was then cooled. The mixture was then coarsely pulverized in a hammer mill and pulverized in a fine pulverizer using a jet stream. The resulting finely pulverized powder was classified using a multi-division classifier utilizing the Coanda effect to obtain toner particles with a weight-average particle size of 7.0 μm.

[0230] For 100 parts of toner particles, hydrophobic silica fine powder (BET140m 2 / g, 1.0 parts of silane coupling treatment and silicone oil treatment, hydrophobicity 78%), and 3.0 parts of strontium titanate (D50; 1.2 μm) were externally added and mixed, and sieved through a mesh with 150 μm openings to obtain comparative toner 6. The obtained toner was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

[0231] Comparative Example 7 Magnetic toner particles 1 were prepared as described in the examples of JP 2015-45860 A. A magnetic material was present as a filler in a binder, and the surface was heat-treated. The obtained toner was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

[0232] [Table 1]

[0233] [Table 2]

[0234] [Toner effect] As shown in the table above, by adjusting the Martens hardness to between 200 and 1100 MPa, the wear resistance of the toner in the developing section is significantly improved compared to conventional toner, and changes in toner triboelectricity due to printing can be suppressed compared to conventional toners. This makes it possible to minimize the accumulation of degraded toner with reduced charging properties. In addition, the occurrence of replenishment fogging can be suppressed, and image improvements can be confirmed in terms of development streaks and ghosts.

[0235] When the change in toner triboelectricity is reduced and replenishment fogging is suppressed, complex operations such as measuring the development current and downtime are not required. Furthermore, even in an image forming apparatus configured as in this embodiment, where old toner in the developing device and new toner being replenished immediately come into contact with each other during replenishment, replenishment fogging does not occur and downtime during toner replenishment can be significantly reduced.

[0236] It can also be seen from the table that when the Martens hardness is lower than 200 [MPa], the effect of this embodiment cannot be obtained satisfactorily.

[0237] [External additives] The toner particles can be used as a toner without adding any external additives. However, in order to further improve the fluidity, chargeability, cleaning properties, etc., so-called external additives such as a fluidizing agent and a cleaning aid may be added to the toner.

[0238] Examples of external additives include inorganic oxide fine particles such as silica fine particles, alumina fine particles, and titanium oxide fine particles, inorganic stearic acid compound fine particles such as aluminum stearate fine particles and zinc stearate fine particles, and inorganic titanic acid compound fine particles such as strontium titanate and zinc titanate. These may be used alone or in combination of two or more.

[0239] The total amount of these various external additives added is preferably 0.05 parts by mass or more and 5 parts by mass or less, and more preferably 0.1 parts by mass or more and 3 parts by mass or less, relative to 100 parts by mass of toner particles. Also, various external additives may be used in combination.

[0240] The toner preferably has positively charged particles on the surface of the toner particles. The number average particle size of the positively charged particles is preferably 0.10 μm or more and 1.00 μm or less, and more preferably 0.20 μm or more and 0.80 μm or less.

[0241] It has been revealed that the presence of such positively charged particles results in good transfer efficiency throughout long-term use. It is believed that the positively charged particles of this particle size allow the particles to roll on the surface of the toner particles, and friction between the photosensitive drum and the transfer belt promotes negative charging of the toner, thereby suppressing positive charging due to the application of a transfer bias. The toner of this embodiment is characterized by a hard surface, and the positively charged particles are less likely to adhere to or be embedded in the surface of the toner particles, thereby maintaining high transfer efficiency. Preferred types of positively charged particles include hydrotalcite, titanium oxide, and melamine resin. Of these, hydrotalcite is particularly preferred.

[0242] It is also preferable that the toner particles have boron nitride on their surfaces. There are no particular limitations on the means for providing boron nitride on the toner particle surfaces, but a method of providing it by external addition is preferred. It has been found that if the toner has a Martens hardness within the range of this example, boron nitride can be provided uniformly on the toner particle surfaces with a high adhesion rate, and furthermore, there is little decrease in the adhesion rate over long-term use.

[0243] [Variations] Although this has the disadvantage of increasing the size of the device compared to the cases described in the above embodiments, the toner bottle 12 may be housed inside the device without protruding above the exterior of the device when attached to the opening 34. Even in this case, developer can be replenished using a simplified configuration in which toner is moved from the toner bottle 12 to the developer storage chamber 38 by its own weight. Furthermore, by using the toner described in the third embodiment, a synergistic effect can be achieved in that replenishment fogging and an increase in the amount of accumulated degraded toner can be further suppressed even if toner is continuously replenished using a new toner bottle 12 each time the toner runs out. It is assumed that other process means, such as the photosensitive drum 1 and the developing device 3, are not subject to replacement when replenishment is performed using a new toner bottle. [Explanation of symbols]

[0244] 1 Photosensitive drum 2 Charging roller 3. Developing device 31 Developing roller 32 Supply roller 33 Stirring blade 34 Opening 35 Cap 36 Shutter 37 Developer chamber 38 Cover 4 Exposure equipment 5 Transfer roller 6 cassettes 7 Paper feed unit 8 Registration Roller Pair 9 Fixing device 91 Fixing film 92 Pressure roller 10 Paper ejection roller pair 11 Pre-exposure device 12 Toner bottle 13 Faraday Cage

Claims

1. An image forming apparatus to which a developer supply container containing a developer can be attached, an image carrier; an exposure unit for exposing the image carrier to light; a developer carrier that carries a developer and develops the electrostatic latent image formed on the image carrier by the exposure means with the developer; a frame unit that supports the developer carrier and that constitutes a developer accommodating chamber that accommodates the developer carried on the developer carrier, the frame unit having an attachment opening that allows the developer supply container to be attached and detached and that communicates with the developer accommodating chamber; a developer supply body provided in the developer storage chamber and rotatable to supply developer to the developer carrier; a stirring member provided in the developer storage chamber, rotatable about a rotation axis extending in the longitudinal direction of the developer carrier so as to stir the developer in the developer storage chamber, the stirring member having a sheet-like member extending along the direction of the rotation axis, and conveying the developer toward the developer carrier in a direction intersecting with the rotation axis as the sheet-like member rotates about the rotation axis; a cover that is rotatable between a first position that covers the mounting opening and a second position that opens the mounting opening; and the stirring member is a rotationally movable member disposed closest to the attachment opening in the developer accommodating chamber, and is capable of directly supplying the developer to the developer supply body by the sheet-like member; the cover is in the second position, and the developer supply container is attached to the attachment opening; When the inside of the developer supply container and the developer accommodating chamber are in communication with each other, the developer in the developer supply container can move to the developer accommodating chamber, The cover is a developer supply container that has finished supplying the developer to the developer accommodating chamber and is attached to the attachment opening is configured to be prevented from moving from the second position to the first position by the developer supply container; an image forming apparatus, the image forming apparatus being movable from the second position to the first position in a state where the developer supply container is detached from the attachment opening;

2. The developer supply body has a rotation center located below the rotation center of the stirring member, 2. The image forming apparatus according to claim 1, wherein after the developer is supplied from the developer supply container to the developer storage chamber and before an image is formed, the developer surface in the developer storage chamber is located above the center of rotation of the stirring member in the direction of gravity.

3. 2. The image forming apparatus according to claim 1, wherein only one stirring member is arranged in a space downstream of the developer supply port of the developer supply container attached to the mounting port in terms of the direction of developer movement when toner is supplied, and upstream of the image carrier.

4. 4. The image forming apparatus according to claim 1, wherein the stirring member is rotated by a driving force from an external driving device.

5. a control unit that detects a state in which the cover is in the second position or a state in which the developer supply container is attached to the attachment opening, 2. The image forming apparatus according to claim 1, wherein the control unit keeps the operation of the image forming apparatus stopped based on the detection.

6. 6. The image forming apparatus according to claim 1, wherein the developer storage chamber has a maximum capacity for storing developer that is greater than an initial amount of developer contained in the developer supply container.

7. 7. The image forming apparatus according to claim 1, wherein the amount of developer contained in the developer storage chamber when a notification prompting the user to replenish developer is issued is greater than the initial amount of developer contained in the developer supply container.

8. 8. The image forming apparatus according to claim 1, wherein, in the attitude of the developer storage chamber during image formation, the amount of developer that can be stored in the developer storage chamber below a plane passing through the highest point of the developer carrier, minus the amount of developer contained in the developer storage chamber when issuing a notification to prompt the user to replenish the developer, is less than the initial amount of developer contained in the developer supply container.

9. 9. The image forming apparatus according to claim 1, wherein the charge amount of the developer when the notification prompting the replenishment of the developer is less than 55% of the charge amount of the developer initially stored in the developer storage chamber.

10. 10. The image forming apparatus according to claim 9, further comprising a current detection means for detecting a current generated as the developer moves, and determining based on the detection result of the current detection means that the charge of the developer stored in the developer storage chamber is less than 55% of the initial charge amount.

11. 11. The image forming apparatus according to claim 1, wherein the frame unit is provided with only one mounting opening.

12. 12. The image forming apparatus according to claim 1, wherein the rotation axis of the cover about which the cover rotates between the first position and the second position is parallel to the rotation axis of the developer carrier.

13. 13. The image forming apparatus according to claim 1, wherein the attachment opening is disposed so that the developer supply container attached to the attachment opening is exposed to the outside of the image forming apparatus.

14. 14. The image forming apparatus according to claim 13, wherein the attachment opening is provided on a protruding portion that protrudes upward from the frame unit.

15. 3. The image forming apparatus according to claim 2, wherein the center of rotation of said developer supply body is located below the center of rotation of said developer carrier.

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