JP2005257824A - Fixing device, image forming apparatus and toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing device in which temperature rising of a fixing belt of the fixing apparatus is increased to satisfy fixing property to fix toner on a recording medium and uneven temperature distribution on the fixing belt is eliminated to suppress melt-sticking of the toner, to provide an image forming apparatus using the fixing apparatus, and to provide toner. <P>SOLUTION: In the fixing device 9 having a fixing belt 93 stretched over a plurality of rollers 91, 92 and a pressure roller 95 disposed opposing to the fixing belt 93 to fix toner on a recording medium P passing, the device is equipped with a controlling mechanism 16 to control the contact range of the fixing belt 93 to the roller 92 having a heat source in the plurality of rollers 91, 92. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fixing device for fixing toner on a recording member by a fixing belt in image formation by an electrostatic copying process such as a copying machine, a facsimile machine, a printer, etc., and an image forming apparatus using this fixing device, The present invention relates to a toner suitable for an image forming apparatus.

  In the image forming apparatus, a toner image on a recording medium transferred from a photosensitive member as a latent image carrier is fixed on the recording medium. This is an indispensable process, for example, in which the toner is infiltrated into a transfer paper, a resin sheet, or the like as a recording medium in a state where the toner is melted by heating and pressurizing and is fused. As a method for fixing, there are a contact fixing method in which a heat source side member and a toner as an object to be fixed are in direct contact and a non-contact method using atmosphere heating by infrared rays or induction heating. Typical examples of the contact fixing method include a heat roller fixing method and a belt fixing method. In any type of fixing device, a nip is formed at a position where the roller and / or the belt contact, and the recording medium is transported and heated and pressurized at the nip to fix the toner onto the recording medium. In this heating and pressurization, a fixing roller having a heat source such as a halogen lamp or nichrome wire or a heated belt is directly brought into contact with the toner for fixing. In this fixing device, the heat source is maintained and managed so that the surface temperature becomes a predetermined temperature by a temperature sensor provided on the surface of the roller or the belt, thereby supplying the sheet to the sheet passing through the nip portion. The amount of heat is stabilized.

  In recent years, there has been a demand for energy saving and shortening of standby time. However, if the temperature during standby is lowered, the time until the fixing device is raised to a temperature at which fixing can be performed, so-called warm-up time, becomes longer, and fixing efficiency becomes worse. For this reason, in order to reduce the heat capacity of the fixing device, the fixing belt is used rather than the fixing roller to meet this requirement. By using the fixing belt, the temperature of the fixing device rises quickly, and the warm-up time is shortened, which is useful for energy saving measures. In the fixing device including the fixing belt, the fixing belt is undulated, an adjustment roller for applying belt tension to prevent fluctuations in the moving speed, and a release agent such as silicone oil for improving the releasing property of the fixing belt. An application roller for applying the agent, a cleaning roller for cleaning the fixing belt, and the like are provided.

  When a recording medium of a small size passes through the nip portion of this fixing device, heat is consumed in the area through which the recording medium passes, so the temperature of the fixing belt, adjustment roller, and cleaning roller decreases. In the area that has not passed, the fixing belt and the adjustment roller are in direct contact with each other, so that the temperature rises because no heat is consumed by the recording medium. FIG. 16 is a diagram schematically illustrating the temperature distribution of the adjustment roller when a small-size recording medium passes through a fixing device including a fixing belt. The fixing belt 93, the adjustment roller 16d, and the cleaning roller 97 that have passed through a recording medium having a small size do not have a uniform temperature distribution in the width direction. In particular, when the heating roller 91 having a heating member and the fixing belt 93 sensitive to temperature are heated to immediately return the temperature to the set temperature, the adjusting roller 16d and the cleaning roller 97, which have not decreased in temperature, are heated. Rises. In particular, the toner adhering to the fixing belt 93, the adjustment roller 16d, and the cleaning roller 97 as stains is excessively melted due to a decrease in viscoelasticity due to an increase in temperature, and the toner is deposited on the surface of a large-sized recording medium. There is a problem that a so-called melt-out phenomenon occurs in which the recording medium is stained by reverse transition.

For example, in Patent Document 1 and Patent Document 2, in an image forming apparatus provided with a fixing device that fixes and fixes an unfixed image by nipping and conveying a recording material on which an unfixed image has been formed by heating means. Each means has a plurality of heating sources having different light distributions, and during the preparatory operation for causing the heating unit to reach a predetermined temperature, all of the plurality of heating sources are successively and sequentially performed in a single preparatory operation. An image forming apparatus that performs a heating operation is disclosed. However, this image forming apparatus is inadequate as a countermeasure against the uneven temperature distribution in the longitudinal direction of the fixing roller, and has a problem that it is complicated including control.
In Patent Document 3, an endless fixing belt having a release layer is stretched between the fixing roller and the heating roller, and recording is performed at a position below the fixing belt between the heating roller and the nip portion. There is disclosed an image fixing apparatus having a control means for providing a material support and forming a substantially linear heating path between the support and the fixing belt and controlling the surface temperature of the recording material support on the fixing belt. However, in this image fixing apparatus, temperature control in the width direction of the fixing belt is insufficient, and it is difficult to prevent the melting phenomenon.
Further, in Patent Document 4, a belt wound around a plurality of rollers and a pressure roller facing one of the rollers are provided, and the toner is held while the sheet is nipped and conveyed by one of the rollers and the pressure roller. A fixing device is disclosed that uses a roller other than a roller that is heated / pressurized and has a belt wound thereon, other than the roller facing the sheet, as a means for uniformizing temperature distribution in the entire width direction of the sheet. However, since the belt temperature changes rapidly, it is difficult to prevent the melting phenomenon.

JP-A-8-220932 JP-A-11-167307 JP-A-9-212031 JP 2003-84597 A

  Therefore, the present invention has been made in view of the above-mentioned problems, and the problem is that the fixing temperature for fixing the toner on the recording medium is satisfied by increasing the temperature of the fixing belt in the fixing device faster. Another object of the present invention is to provide a fixing device, an image forming apparatus using the same, and a toner that suppress the occurrence of a toner melting phenomenon by eliminating uneven temperature in the fixing belt.

The features of the present invention, which is a means for solving the above problems, are listed below.
1. The fixing device of the present invention is a fixing device for fixing toner on a recording medium passing therethrough by a fixing belt stretched between a plurality of rollers and a pressure roller disposed opposite to the fixing belt. And an adjustment mechanism for adjusting a contact range of the fixing belt to a roller having a heat source among the plurality of rollers, and a fixing belt that is provided at both ends or one end of the detent member for preventing Features.
2. The fixing device according to the present invention further detects the temperature of at least one of the fixing belt, the plurality of rollers that stretch the fixing belt, and the pressure roller, and the adjustment mechanism is configured to generate a heat source among the plurality of rollers. The contact range of the fixing belt with respect to the roller having the above is adjusted.
3. In the fixing device of the present invention, the size of the recording medium passing therethrough is further detected, and the adjusting mechanism adjusts a range in which the fixing belt contacts a roller having a heat source among the plurality of rollers. And
4). Further, the fixing device of the present invention further detects a passing amount of the recording medium per unit time,
The adjusting mechanism adjusts a contact range of the fixing belt with a roller having a heat source among the plurality of rollers.
5). The fixing device of the present invention is further characterized in that the adjustment mechanism is adjusted by an eccentric cam or a gear.
6). The fixing device of the present invention is further characterized in that the adjustment mechanism is provided with an adjustment roller.

7). The fixing device of the present invention is further characterized in that the difference between the end of the fixing member of the fixing belt and the end of the adjusting roller is 1 mm or more.
8). The fixing device according to the present invention is further characterized in that a difference between the end of the fixing member of the fixing belt and the end of the recording member passing therethrough is 10 mm or more.
9. The fixing device of the present invention further includes a plurality of adjustment rollers that apply pressure to the fixing belt.
10. The fixing device of the present invention is further characterized in that the length of the adjusting roller in the axial direction is different.
11. The fixing device of the present invention is further characterized in that the adjustment roller of the adjustment mechanism has a counter drum shape.
12 Further, in the fixing device of the present invention, when the detent members are provided at both ends of at least one of the plurality of rollers, at least one of the hardness, width, and thickness of the detent members at both ends is different. It is characterized by that.
13. Further, the fixing device of the present invention is characterized in that the stopper member has a hardness in a range of 20 to 80 Hs.
14 The fixing device of the present invention is further characterized in that the detent member has a width of 0.5 mm or more.
15. The fixing device of the present invention is further characterized in that the stopper member has a thickness of 0.5 mm or more.

16. An image forming apparatus according to the present invention includes an image carrier that forms a latent image, a charging device that uniformly charges the surface of the image carrier, and the surface of the charged image carrier is exposed based on image data to form a latent image. An image forming apparatus comprising: a writing exposure device; a developing device that supplies toner to a latent image formed on a surface of an image carrier to visualize the image; and a cleaning device that cleans the surface of the image carrier. In an image forming apparatus in which a transfer device that transfers a visible image on a surface of a carrier directly or onto an intermediate transfer member and then transferred to a recording medium and a fixing device that fixes a toner image on the recording medium are arranged between a plurality of rollers A fixing device for fixing toner on a recording medium passing therethrough by a fixing belt stretched between the fixing belt and a pressure roller disposed opposite to the fixing belt, and a detent member for preventing detent is provided at both ends. Or one end Characterized by disposing a fixing belt provided outside the fixing device comprising an adjustment mechanism for adjusting the range of contact of the fixing belt against roller having a heat source of the plurality of rollers.
17. The image forming apparatus according to the present invention further includes the fixing device according to any one of claims 2 to 15.

18. In the image forming apparatus of the present invention, the weight average particle diameter is 10 μm or less, and the ratio (dispersity) between the weight average particle diameter and the number average particle diameter is in the range of 1.00 to 1.40. It is characterized by using toner.
19. The image forming apparatus of the present invention is further characterized in that the image forming apparatus uses a toner having an average circularity in the range of 0.93 to 1.00.
20. In addition, the image forming apparatus of the present invention further has a substantially spherical appearance, a ratio of the major axis to the minor axis (r2 / r1) in the range of 0.5 to 1.0, and a diameter and a shortness. A toner having a ratio (r3 / r2) to an axis in a range of 0.7 to 1.0 and satisfying a relationship of major axis r1 ≧ minor axis r2 ≧ diameter r3 is used.
21. The image forming apparatus of the present invention further comprises a toner composition containing at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent in an aqueous medium in the presence of resin fine particles. It is characterized by using a toner that undergoes crosslinking and / or elongation reaction.
22. The image forming apparatus of the present invention further includes a process cartridge in which a latent image carrier, at least one unit selected from a charging unit, a developing unit, and a cleaning unit are integrated. .

23. The toner of the present invention includes an image carrier that forms a latent image, a charging device that uniformly charges the surface of the image carrier, and exposure that writes the latent image by exposing the charged image carrier surface based on image data. An image forming apparatus comprising: a developing device that supplies toner to a latent image formed on a surface of an image carrier and visualizes the image; and a cleaning device that cleans the surface of the image carrier. A fixing device that fixes toner on a recording medium passing therethrough by a fixing belt stretched between rollers and a pressure roller disposed opposite to the fixing belt, and includes a detent member that prevents misalignment. An image forming apparatus in which a fixing belt that is provided at both ends or one end and provided outside and a fixing device that includes an adjustment mechanism that adjusts a contact range of the fixing belt with a roller having a heat source among the plurality of rollers The toner used in the invention is characterized in that the average circularity is in the range of 0.93 to 1.00.
24. Further, the toner of the present invention has a substantially spherical appearance, and the ratio of the major axis to the minor axis (r2 / r1) is in the range of 0.5 to 1.0. The ratio (r3 / r2) is in the range of 0.7 to 1.0, and the relationship of long axis r1 ≧ short axis r2 ≧ diameter r3 is satisfied.
25. Further, the toner of the present invention further comprises a cross-linking of a toner composition containing at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent in the presence of resin fine particles in an aqueous medium. And / or an extension reaction.

According to the present invention, there is provided a fixing device capable of preventing the occurrence of an abnormal image having a stain on an image by suppressing the toner from being discharged from the cleaning roller of the fixing belt by means for solving the above-described problem. it can.
Also, the toner can be prevented from being melted from the fixing belt cleaning roller to prevent the occurrence of an abnormal image having a stain on the image, and a high-definition monochrome / full-color high-quality image can be obtained. A forming apparatus can be provided.
In addition, it is possible to provide a toner capable of obtaining a high-quality image with high precision fine line reproducibility, a large number of color reproduction colors, and no background fog.

  The best mode for carrying out the present invention will be described below with reference to the drawings. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. The following description is an example of the best mode of the present invention, and does not limit the scope of the claims.

FIG. 1 is a schematic diagram illustrating a configuration of an image forming apparatus according to the present invention, FIG. 1A is an overall view of the image forming apparatus, and FIG. 1B is a schematic diagram illustrating a configuration of an image forming unit. .
In the image forming apparatus 1, image forming units 2A, 2B, 2C, and 2D each having four photoconductors as image carriers are detachably attached to the image forming apparatus 1, respectively. A transfer device 3 in which a transfer belt 3a is rotatably mounted in a direction indicated by an arrow A between a plurality of rollers is disposed at a substantially central portion of the image forming apparatus 1. The photosensitive member 5 provided in each of the image forming units 2A, 2B, 2C, and 2D is disposed so as to contact the upper surface of the transfer conveyance belt 3. In correspondence with the image forming units 2A, 2B, 2C, and 2D, developing devices 10A, 10B, 10C, and 10D having different toner colors are arranged. The image forming units 2A, 2B, 2C, and 2D are units having the same configuration, the image forming unit 2A forms an image corresponding to magenta, and the image forming unit 2B forms an image corresponding to cyan. The image forming unit 2C forms an image corresponding to the yellow color, and the image forming unit 2D forms an image corresponding to the black color.

A writing unit 6 is disposed above the image forming units 2A, 2B, 2C, and 2D, and a duplex unit 7 is disposed below the transfer belt 3a. This small printer is equipped with a reversing unit 8 on the left side of the image forming apparatus 1 for reversing and ejecting the recording medium P after image formation or transporting it to the duplex unit 7. The writing unit 6 is arranged in four laser diode (LD) light sources prepared for each color, a set of polygon scanners composed of six polygon mirrors and a polygon motor, and the route of each light source. It is composed of a lens such as an fθ lens or a long cylindrical lens, or a mirror. Laser light emitted from the laser diode is deflected and scanned by a polygon scanner and irradiated onto the photosensitive member 5. The duplex unit 7 includes a pair of conveyance guide plates 45a and 45b and a pair of (four sets in this example) conveyance rollers 46. In the double-sided image formation mode in which images are formed on both sides of the recording medium P The recording medium P on which an image is formed on one side and conveyed to the reversal conveyance path 54 of the reversing unit 8 and switched back is received and conveyed toward the paper feeding unit. The reversing unit 8 includes a plurality of paired transport rollers 46 and a plurality of paired transport guide plates 45. As described above, the reversing unit 8 reverses the recording medium P when double-sided image formation is performed, so that the duplex unit 7 is reversed. And the recording medium P after image formation is discharged out of the apparatus in the same direction, or is reversed and discharged out of the apparatus. Separating sheet feeding units 55 and 56 for separating and feeding the recording medium P one by one are provided in the sheet feeding unit provided with the sheet feeding cassettes 11 and 12, respectively. Between the transfer belt 3a and the reversing unit 8, a fixing device 9 for fixing the image of the recording medium P on which the image has been transferred is provided. A reverse discharge path 20 is formed on the downstream side of the fixing device 9 in the recording medium conveyance direction, and the recording medium P conveyed there can be discharged onto a discharge tray 26 by a pair of discharge rollers 25. Yes.
Further, in the lower part of the image forming apparatus 1, paper feed cassettes 11 and 12 that can store recording media P of different sizes are arranged in two upper and lower stages, respectively. Further, a manual feed tray 13 is provided on the right side surface of the image forming apparatus 1 so as to be openable and closable in the direction indicated by the arrow B, and the manual feed tray 13 is opened so that manual feeding can be performed therefrom.

FIG. 2 is a schematic diagram showing the configuration of the fixing device of the present invention.
As shown in FIG. 2, the fixing device 9 of the present invention is stretched between a heating roller 91, a fixing roller 92, a pressure roller 95 in pressure contact with the fixing roller 92, and the heating roller 91 and the fixing roller 92. The fixing belt 93 includes an adjustment mechanism 16 that includes an adjustment roller that applies belt tension to the fixing belt 93. Further, a heating member 98 is provided on at least one of the heating roller 91, the fixing roller 92, and the pressure roller 95 that stretches the fixing belt 93.
Further, in order to improve the releasability of the fixing belt 93 with the toner and prevent the occurrence of offset, an application roller 96 for applying an oil such as silicone oil for improving the releasability, and the toner attached to the fixing belt 93 A cleaning roller 97a for cleaning the paper dust is provided. Further, since the toner adheres to the pressure roller 95 from the fixing belt 93 that contacts when the paper dust is not recorded, the pressure roller 95 may be provided with a cleaning roller 97c. Further, in order to control the heaters of the members in the fixing device 9 such as the fixing belt 93, the heating roller 91, the fixing roller 92, and the pressure roller 95, a temperature sensor that detects the temperature of each member is provided.

  The fixing belt 93 is made of an endless belt-like substrate made of heat-resistant resin or metal. Examples of the material of the heat resistant resin include polyimide, polyamideimide, polyether ether ketone, and examples of the material of the metal belt include nickel, aluminum, and stainless steel. A resin and a multilayer may be formed. In particular, a belt obtained by electroforming nickel on a polyimide resin is preferable because it has strength and elasticity and is durable. The thickness is preferably 100 μm or less. Since the recording medium P such as recording paper or OHP is in pressure contact with the toner, the fixing belt 93 has an elastic layer made of high-release silicone rubber or the like and a heat-resistant release layer made of a fluorine resin having a small friction coefficient. It has become. The fluororesin is applied to the surface of the substrate by spraying or the like, and is heat-sealed to form a surface release layer. The high release silicone rubber layer has a rubber hardness (JIS A hardness meter) of 25 to 65 degrees and a thickness in the range of 100 to 300 μm is desirable as a condition for obtaining good fixability and thermal responsiveness.

FIG. 3 is a schematic view showing a configuration of a fixing belt provided with a detent member provided in the fixing device of the present invention. As shown in FIG. 3, the fixing belt 93 is provided with a detent member 93 a on both sides of the fixing belt 93, which prevents the fixing belt 93 from being skewed and one side is shifted. This offset stopper member is brought into contact with the end surface of the fixing roller 92 or the like, thereby restricting the deflection of the intermediate transfer belt in the width direction. Although the detent member 93a is provided on both sides, the fixing belt 93 is shown in FIG. 3, but the detent member 93a may be only on one side of the fixing belt 93. By preventing the fixing 93 belt from being twisted on one side, skewing and shifting of the fixing belt 93 can be suppressed.
Furthermore, by providing the shift stop member 93a, an elastic force, which is a force generated by the elasticity of the fixing belt 93, can be increased, and the skew / shift of the fixing belt 93 can be suppressed.
On the other hand, the fixing belt 93 cannot be thickened to reduce the heat capacity. Therefore, by providing the fixing belt 93 with a detent member 93a, the elastic force can be increased. Due to the elastic force, the fixing belt 93 itself tends to move away from the heating roller 91 depending on the magnitude of the belt tension by the adjusting mechanism 16, so that the contact range can be easily adjusted.
The material of the detent member 93a is a heat-resistant and elastic elastomer such as silicone rubber, urethane rubber, urethane foam, etc., and can prevent deterioration during heating and follow belt deformation during driving.

The heating roller 91 is a member that stretches and heats the fixing belt 93 that is wound around. Therefore, a heating member 98 such as a halogen lamp or nichrome wire is provided inside the heating roller 91. The heating roller 91 is a thin roller of a hollow metal cylinder such as aluminum, carbon steel, stainless steel, etc., but an aluminum cylinder having a thickness of 1 to 4 mm with good thermal conductivity is used, so that The temperature distribution can be reduced. Further, the surface of the heating roller 91 is subjected to an alumite treatment in order to prevent abrasion with the fixing belt 93.
Further, the fixing roller 92 forms a nip portion with the pressure roller 95 facing the fixing belt 93 and sandwiches and conveys the recording medium P at the nip portion, and heats and pressurizes the toner on the recording medium P. For this reason, the fixing roller 92 is provided with an elastic layer of silicone rubber or the like on the surface of the core metal so as to have a thickness of 100 to 500 μm, preferably 400 μm. A good resin surface layer is formed. The resin surface layer is composed of a PFA tube or the like as a fluororesin, and its thickness is preferably about 10 to 50 μm in consideration of mechanical deterioration. The core of the fixing roller 92 is made of a metal cylinder such as stainless steel, and a heating member 98 such as a halogen lamp is provided at the center of the roller shaft.

  The pressure roller 95 is made of a metal cylinder such as stainless steel, an elastic layer made of silicone rubber having a thickness of 2 mm, and a fluororesin such as tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA) or polytetrafluoroethylene (PTFE) on the surface thereof. The heating member 98 is arranged in the cylinder with the same configuration as that in the fixing roller 92. The pressure roller 95 is pressed by a pressure member such as a spring (not shown) toward the fixing roller 92 with the fixing belt 93 interposed therebetween, and is elastically deformed with a rubber layer to be fixed with the fixing roller 92 for a certain period of time. A nip portion that can pressurize and heat the toner is formed. The pressure roller 95 is provided with a cleaning roller for preventing the toner transferred from the fixing belt 93 when the recording medium does not pass through and the toner when the image is formed on both sides of the recording medium from being attached and contaminating the image. 97c is provided.

  FIG. 4 is a schematic view showing the arrangement of the adjusting mechanism for adjustment provided in the fixing device of the present invention. (A) is a schematic diagram showing a configuration in which the adjustment mechanism 16 is provided on the heating roller 91 that stretches the fixing belt 93, and (b) is a schematic diagram showing a configuration in which the adjustment mechanism 16 is provided inside the fixing belt 93. (C) is a schematic diagram showing a configuration in which the adjusting mechanism 16 is provided inside the fixing belt 93. Here, the adjustment mechanism 16 adjusts the range in which the fixing belt 93 is wound around and contacts a roller having a heat source. The adjusting mechanism 16 can adjust the range in which the fixing belt 93 is brought into contact with the belt by applying belt tension.

FIG. 5 is a schematic diagram illustrating the configuration of the adjustment mechanism.
This adjustment mechanism 16 adjusts with an eccentric cam or a gear. Further, an adjustment roller 16d is provided. The fixing roller 93 includes an adjustment roller 16d that is a pressure member that applies belt tension, a drive member that moves the adjustment roller 16d, and a transmission member that transmits a force from the drive member. An elastic member such as a spring or an elastomer may be disposed between the driving member and the adjustment roller 16d in order to avoid abrupt transmission of belt tension. Further, an adjustment member that presses the fixing belt 93 may be provided. The adjusting member to be pressed may have an arc shape or a roller shape so as not to damage the fixing belt 93.
As shown in (a), the adjusting means 16 can also adjust the belt tension by fixing a roller-like adjusting roller 16d with a support 16b member and moving it up and down by rotation of the gear 16a. The gear 16a may be driven by a stepping motor (not shown) or the like according to a signal from the control unit of the main body of the image forming apparatus 1. Further, as shown in (b), the belt tension can be adjusted by using the cam 16a as a drive member and changing the angle by rotation of the drive shaft. Similarly, the cam 16a may be driven by a stepping motor or the like (not shown) according to a signal from a control unit of the main body of the image forming apparatus 1. Further, the adjusting roller 16 d is separated from the fixing belt 93 by these adjusting means 16. When belt tension is applied to the high-temperature fixing belt 93, the fixing belt 93 is prevented from extending or wavy. Further, it is possible to prevent the toner, paper dust, and the like from being transferred from the fixing belt 93 to the adjustment roller 16d, and to prevent the toner from melting out from the adjustment roller 16d.

FIG. 6 is a schematic diagram for explaining the state of the contact range due to the elastic force of the fixing belt and the belt tension by the adjusting mechanism. As indicated by the hatched portion in (a), the contact range can be increased by applying a large belt tension to the heating roller 91. Further, as indicated by the hatched portion in (b), the contact range can be reduced by applying a small belt tension to the heating roller 91.
As described above, when the fixing belt 93 is made of a material such as polyimide resin or electroformed nickel and is manufactured in an endless shape, the fixing belt 93 can have a certain elastic force that tends to be round and cylindrical. Further, in order to stabilize the movement of the fixing belt 93, belt tension is applied by the adjusting mechanism 16. The adjusting mechanism 16 can adjust the belt tension, and thereby adjust the range in which the fixing belt 93 contacts the heating roller 91. By adjusting the contact range, the amount of heat transmitted from the heating roller 91 can be adjusted, and the temperature can be raised or maintained. Furthermore, the temperature of the fixing belt 93 can be lowered by simultaneously adjusting the area that radiates heat into the air. By providing such an adjusting mechanism 16, the temperature of the fixing belt 93 is adjusted by the fixing device 9 having the fixing belt 93.

  Further, as shown in FIG. 2, a fixing belt 93, rollers 91, 92, and 95, and a temperature detection sensor 99 such as a thermistor and a thermocouple are arranged to detect the temperature, and if the temperature reaches or exceeds the set value, the adjustment is performed. The mechanism 16 separates the adjustment roller 16d from the fixing belt 93 to reduce the contact range of the fixing belt 93 with the fixing roller 92 and the like, thereby preventing the fixing belt 93 from being heated. When the temperature is lower than the set temperature during standby or fixing, the adjustment mechanism 16 strongly presses the adjustment roller 16d against the fixing belt 93 to increase the contact range of the fixing belt 93 with the fixing roller 92 and the like. Increase the temperature of 93. The temperature detection sensor 99 is preferably provided at least on the fixing belt 93. A plurality of fixing belts 93 may be provided in the width direction of the fixing belt 93 and in the axial direction of the fixing roller 92 and the like. In particular, since the heat capacity of the fixing belt 93 is small, heat from the heating roller 91 is easily transmitted. For this reason, the temperature of the fixing belt 93 heated by the heating roller 91 at the time of fixing rapidly rises in a portion where heat is not absorbed by the recording medium. For this purpose, the temperature is controlled in consideration of the contact range between the fixing belt 93 and the heating roller 91 by the belt tension of the adjusting roller 16d.

  The set temperature at the time of fixing is controlled in the range of 155 to 165 ° C. for the fixing belt 93, 155 to 165 ° C. for the fixing roller 92, 155 to 165 ° C. for the heating roller 91, and 140 to 150 ° C. for the pressure roller 95. When the temperature of the heating roller 91 or the like exceeds the set range, the temperature of the fixing belt 93 rises, a hot offset occurs during fixing, resulting in a dirty image and image quality is lowered. In addition, the set temperature during standby is controlled to a range of 165 to 175 ° C. for the fixing belt 93, 165 to 175 ° C. for the fixing roller 92, 165 to 175 ° C. for the heating roller 91, and 145 to 155 ° C. for the pressure roller 95. . By setting the temperature to the set temperature range during standby, wasteful power consumption can be suppressed and the running cost of the image forming apparatus 1 can be suppressed. In addition, the start of the image forming operation can be accelerated and the first print time can be shortened.

  Further, the amount of recording medium passing through the fixing device 9 per unit time is detected, and the adjusting mechanism 16 adjusts the belt tension against the adjusting belt 16d against the fixing belt 93. The passing amount of the recording medium per unit time is detected by an image forming instruction signal for the image forming apparatus 1 or by measuring the amount of paper fed from the paper feeding unit. There is a correlation between the amount of the recording medium passing through the fixing device 9 and the amount of heat supplied from the fixing device 9 including the fixing belt 93. Therefore, the amount of heat supplied from the heating member 98 can be determined by detecting the passing amount of the recording medium. Similarly, there is a correlation between the passing amount of the recording medium and the temperature decrease amount of the fixing belt 93, and further, there is a correlation between the amount of heat supplied depending on the range where the heating roller 91 and the fixing belt 93 are in contact with each other. The temperature of the fixing belt 93 is controlled by adjusting the belt tension of the adjusting roller 16d that presses against the fixing belt 93 by detecting the passing amount of the recording medium. The fixing belt 93 at the time of fixing can be prevented from exceeding the set temperature, and the occurrence of contamination due to hot offset on the recording medium can be suppressed.

  Further, the size of the recording medium passing through the fixing device 9 is detected, and the adjusting roller 16d is separated from the fixing belt 93 by the adjusting mechanism 16, so that the contact range of the fixing belt 93 with the fixing roller 92 and the like is reduced. Thus, the fixing belt 93 is prevented from being overheated to prevent the occurrence of hot offset during fixing. The size of the recording medium can be detected by the main body of the image forming apparatus 1. When the recording medium passes through the fixing device 9 and is fixed, the fixing belt 93 and the pressure roller 95 of the fixing device 9 are deprived of heat by the recording medium, so that the temperature of the fixing belt 93 and the like decreases. In addition, since the fixing belt 93, the roller, and the like have a constant thermal conductivity, the temperature of the portion in contact with the recording medium is lower than the temperature of the portion not in contact. When a recording medium of the same size is conveyed in this state, since the temperature of the fixing belt 93 is low, the fixing belt 93 is heated by the heating member 98 to keep the fixing belt 93 within a set temperature range in which fixing is possible. Thus, occurrence of fixing failure or hot offset can be suppressed.

FIG. 7 is a schematic view showing the configuration of the adjustment roller and the detent member of the fixing device of the present invention. The detent member 93 a and the adjustment roller 16 d are provided on the same surface side of the fixing belt 93. As a result, the fixing belt 93 is not deviated by the end face of the heating roller 91 or the like, and the fixing belt 93 can be deviated by the adjusting roller 16d. The stopper member 93a may be deformed by heat when a rubber member such as an elastomer is used. Therefore, the lifespan of the stopper member 93a and the fixing belt 93 can be extended by stopping by the adjusting roller 16d without a heat source.
At this time, the distance between the adjustment roller 16d and the detent member 93a is set to 1 mm or more. When the fixing belt 93 is skewed, when the fixing belt 93 is skewed, the fixing member 93a is separated from the fixing belt 93 so that the fixing belt 93 is wrinkled. The fixing belt 93 may be damaged due to occurrence or overlapping movement.
FIG. 8 is a schematic view showing the configuration of the detent member and the recording medium P of the fixing device of the present invention. The detent member 93 a is provided on the outside with a distance of 10 mm or more from the end of the recording medium P passing through the fixing belt 93. The longer distance is because the recording medium P passes through the nip of the fixing belt 93 without being affected by the detent member 93a even if the fixing belt 93 moves obliquely.

  FIG. 9 is a schematic diagram illustrating a configuration in which the fixing device of the present invention includes a plurality of adjustment mechanisms. A plurality of adjusting rollers 16d each having adjusting means 16 for adjusting the belt tension is provided. As a result, the adhesion with the heating roller 91 or the fixing roller 92 can be enhanced. As a result, vibration during movement of the fixing belt 93 can be suppressed, and the time from the standby temperature of the fixing belt 93 to the fixing temperature can be shortened. Further, by providing a plurality of adjusting rollers 16d, heat transfer can be accelerated and the temperature distribution of the fixing belt 93 and the cleaning roller 97 can be reduced. As a result, the area of the adjusting roller 16d or the like where the toner melting phenomenon occurs can be narrowed.

  FIG. 10 is a schematic diagram showing a configuration of a fixing device having a plurality of adjusting rollers having different lengths in the axial direction. As shown in FIG. 10, the adjustment roller 16d close to the fixing roller 92 is shortened, but the reverse may be possible. Since the fixing belt 93 passes through the central portion of the fixing belt 93 regardless of the size of the recording medium, the heat of the fixing belt 93 is deprived and the temperature is greatly reduced. Therefore, the adjusting means 16 is shorter than the width of the fixing belt 93. The belt tension to the adjusting roller 16d is increased to improve the adhesion between the center portion of the fixing belt 93 and the heating roller 91, etc., and the temperature is prevented from being lowered during fixing to satisfy the fixing property. The other adjusting means 16 reduces the belt tension to the adjusting roller 16d longer than the width of the fixing belt 93 to reduce the adhesion between the end of the fixing belt 93 and the heating roller 91 and the like, thereby preventing overheating of the end. This suppresses the toner melting phenomenon. Even when the paper size is changed from a small recording medium to a large recording medium, the belt tension by the adjusting means 16 is increased to increase the belt tension of both the long adjusting roller 16d and the short adjusting roller 16d, thereby fixing at the end of the fixing belt 93. Increase the temperature to satisfy the fixability.

  FIG. 11 is a diagram illustrating a configuration of a fixing device having an adjustment roller that contacts both ends of the fixing belt. As shown in FIG. 11, by individually adjusting the belt tension at the center and both ends of the fixing belt 93, the fixing property of the fixing belt 93 is satisfied, and at both ends of the fixing belt 93 and the adjusting roller 16d. Prevents toner melting by preventing temperature rise. When fixing a recording medium of a small size, the adjusting means 16 increases the belt tension of the adjusting roller 16d in the center to increase the adhesion of the fixing belt 93 to the heating roller 91 and the like, and the other adjusting means 16 fixes it. The belt tension of the adjustment roller 16d with respect to the end portion of the belt 93 is lowered to lower the adhesion, and an excessive temperature rise at the end portion of the fixing belt 93 is suppressed. As a result, the temperature distribution between the central portion and the end portion can be reduced. Next, when fixing a large-sized recording medium, the toner melting phenomenon is suppressed by preventing an excessive temperature rise, and the belt tension of the adjusting roller 16d is increased by another adjusting means 16 to secure the fixing property. To do.

FIG. 12 is a schematic diagram for explaining a contact range by a plurality of adjustment mechanisms.
At this time, as shown in (a), the belt tension is changed by the plurality of adjusting mechanisms 16 in front of and behind the single adjusting roller. As a result, as shown in (b), the belt tension Ff of the adjustment roller 16d on the front side is increased to increase the contact range of the fixing belt 93 with the heating roller 91 and the like. The belt tension Fr of the adjustment roller 16d with respect to the back side is lowered to reduce the contact range, thereby suppressing an excessive temperature rise at the end of the fixing belt 93. As a result, the temperature distribution on both sides of the fixing belt 93 can be reduced. By preventing the temperature rise on the back side of the fixing belt, the toner can be prevented from melting out from the cleaning roller. Next, when fixing a large-sized recording medium, an excessive temperature rise is prevented to suppress the toner melting phenomenon, and the other adjusting mechanism 16 increases the belt tension of the adjusting roller 16d to make a contact range. Can be bigger.
Moreover, FIG. 13 is a figure which shows the structure which made the adjustment roller the drum shape. Thus, by making the adjusting roller 16d into a drum shape, it is difficult for the detent member 93a to get over the adjusting roller 16d even if the fixing belt is skewed or stretched by heat. The fixing belt 93 can be stably run.

Further, the hardness of the stopper members 93a on both sides is in the range of 20 to 80 ° Hs (JIS A). The detent members 93a provided on both sides of the fixing belt 93 are bent by the heating roller 91 and the like, and the lower hardness can correspond to the roller shape. In order to give the fixing belt 93 a certain elastic force, it is preferable that the fixing belt 93 has a high hardness. Accordingly, the hardness is set in the range of 20 to 80 ° Hs. However, if the hardness is less than 20 ° Hs, the hardness is low and the elastic force is small, and if the hardness exceeds 80 ° Hs, the roller may break when stretched between the rollers.
Further, when the paper is conveyed at the center reference, the hardness of the detent members 93a on both sides is made the same. If the paper conveyance is performed on one side, the hardness of the detent member 93a may be different within this range and on both sides of the fixing belt 93. In this case, the rubber hardness of the stopper member 93a on the side where the fixing belt 93 contacts in paper conveyance is made lower than the rubber hardness of the stopper member 93a on the non-contact side. Accordingly, the elastic force on the non-contact side is increased, the range in which the fixing belt 93 and the heating roller 91 are in contact with each other is reduced, and the adjustment of the range in which the heating roller 91 is in contact with the adjustment of the adjusting mechanism 16 is promptly adjusted. be able to.

Further, the detent members 93a on both sides have a width of 0.5 mm or more. This is because the detent members 93a provided on both sides of the fixing belt 93 are bent by the heating roller 91 and the like, and the smaller width can correspond to the roller shape. In order to give the fixing belt 93 a certain elastic force, it is preferable that the fixing belt 93 is wide. Accordingly, the width is at least 0.5 mm or more. However, if the width is less than 0.5 mm, the elastic force / elastic force is small, and the adjustment of the range in contact with the heating roller 91 cannot be immediately adapted to the adjustment of the adjustment mechanism 16.
Further, when the paper conveyance is the center reference, the widths of the detent members 93a on both sides are made the same. When the paper conveyance is performed on one side, the width of the detent member 93a on both sides of the fixing belt 93 may be different within this range. In this case, the width of the stopper member 93a on the side where the fixing belt 93 contacts in paper conveyance is made smaller than the width of the stopper member 93a on the non-contact side. Accordingly, the elastic force on the non-contact side is increased, the range in which the fixing belt 93 and the heating roller 91 are in contact with each other is reduced, and the adjustment of the range in which the heating roller 91 is in contact with the adjustment of the adjusting mechanism 16 is promptly adjusted. be able to.

The detent members 93a on both sides have a thickness of 0.5 mm or more. The detent members 93a provided on both sides of the fixing belt 93 are bent by the heating roller 91 and the like, and the thinner one can correspond to the roller shape. Further, in order to give the fixing belt 93 a certain elastic force, it is preferable that the fixing belt 93 is thick. Therefore, the thickness is at least 0.5 mm or more. However, if the thickness is less than 0.5 mm, the elastic force / elastic force is small, and the adjustment of the range in contact with the heating roller 91 cannot be immediately adapted to the adjustment of the adjustment mechanism 16, and the roller end surface is rubbed. When stopping, the fixing member 93a rides on the roller, and the fixing belt 93 may be biased.
Further, when the paper is conveyed at the center reference, the thicknesses of the detent members 93a on both sides are made the same. When the paper conveyance is performed on one side, the width of the detent member 93a on both sides of the fixing belt 93 may be different within this range. In this case, the thickness of the stopper member 93a on the side where the fixing belt 93 contacts in paper conveyance is made thinner than the thickness of the stopper member 93a on the non-contact side. Accordingly, the elastic force on the non-contact side is increased, the range in which the fixing belt 93 and the heating roller 91 are in contact with each other is reduced, and the adjustment of the range in which the heating roller 91 is in contact with the adjustment of the adjusting mechanism 16 is promptly adjusted. be able to.

Further, at this time, in order to make the elastic forces on both sides of the fixing belt 93 different, the detent member 93a may have the same hardness and the width of the non-reference side detent member 93a may be widened.
When the fixing members 93a, which are thicker and more elastic than the fixing belt 93, are provided on both sides of the fixing belt 93, the left and right shifting members 93a have the same hardness, and the recording medium P and the fixing belt 93 are measured on one side of paper conveyance. By increasing the width of the detent member 93a on the side opposite to the side where the contact is made, the elastic force is increased. As a result, the belt tension by the adjusting mechanism 16 can be promptly adjusted.
Further, the detent member 93a has the same hardness, and the anti-reference side detent member 93a is thickened. As a result, the belt tension by the adjusting mechanism 16 can be promptly adjusted.
Further, the detent member 93a may have the same thickness, and the width of the non-reference side detent member 93a may be increased. Further, the detent member 93a may have the same hardness, and the non-reference side detent member 93a may have a higher hardness. Further, the detent member 93a may have the same width, and the thickness of the non-reference side detent member 93a may be increased. Further, the detent member 93a may have the same width, and the non-reference side detent member 93a may have a higher hardness.

Further, in the image forming apparatus using this fixing device, the volume average particle diameter is 10 μm or less, and the ratio (dispersity) between the volume average particle diameter and the number average particle diameter is in the range of 1.00 to 1.40. Use toner.
By using a toner having a small particle diameter of 10 μm or less, the toner can be densely attached to the latent image. Preferably, it is 8 μm or less. Thereby, it is possible to obtain a high-quality image by obtaining high-precision fine line reproducibility. In addition, it is possible to increase the number of reproduced colors for color reproducibility in a full-color image. The volume average particle size is 3 μm or more. If it is less than 3 μm, it is difficult to perform blade-type cleaning.
Further, by reducing the dispersion degree to within the range of 1.00 to 1.40, the particle size distribution can be narrowed, whereby the charge amount distribution of the toner becomes uniform and high quality with little background fogging. An image can be obtained and the transfer rate can be increased. If the degree of dispersion is less than 1.40, the charge amount distribution becomes wide and a high-quality image cannot be obtained.
The average particle size and particle size distribution of the toner can be measured using a Coulter Counter TA-II and a Coulter Multisizer II (both manufactured by Coulter). In the present invention, a counter-counter type TA-II is used, connected to an interface (manufactured by Nikka Giken) and PC9801 personal computer (manufactured by NEC) that outputs number distribution and volume distribution, and measurement is performed. did.

  In this image forming apparatus, toner having an average circularity in the range of 0.93 to 1.00 is used. When the toner has a circularity of 0.93 or more, the dot reproducibility is excellent and the transferability is also good, so that high image quality can be obtained. When the average circularity is less than 0.93 and the toner is separated from the spherical shape, it is difficult to obtain a high-quality image having sufficient transferability or no dust. The circularity of the toner is a value obtained by optically detecting particles and dividing by the perimeter of an equivalent circle having the same projected area. Specifically, the measurement is performed using a flow type particle image analyzer (FPIA-2000; manufactured by Sysmex Corporation). In a predetermined container, 100 to 150 mL of water from which impure solids are removed in advance is added, 0.1 to 0.5 mL of a surfactant is added as a dispersant, and about 0.1 to 9.5 g of a measurement sample is further added. The suspension in which the sample is dispersed is subjected to dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the shape and distribution of the toner are measured at a dispersion concentration of 3,000 to 10,000 pieces / μL.

The toner used in the constant developing device 10 is preferably a toner that can be defined by the values of the following shape factors SF-1 and SF-2. FIG. 14 is a diagram schematically illustrating the shape of the toner in order to explain the shape factor SF-1 and the shape factor SF-2.
The shape factor SF-1 indicates the ratio of the roundness of the toner shape and is represented by the following formula (1). This is a value obtained by dividing the square of the maximum length MXLNG of the shape formed by projecting the toner on a two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-1 = {(MXLNG) ² / AREA} × (100π / 4) (1)
When the value of SF-1 is 100, the shape of the toner becomes a true sphere, and becomes larger as the value of SF-1 increases.
The shape factor SF-2 indicates the ratio of the unevenness of the toner shape, and is represented by the following formula (2). A value obtained by dividing the square of the perimeter PERI of the figure formed by projecting the toner on the two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-2 = {(PERI) ² / AREA} × (100 / 4π) (2)
When the value of SF-2 is 100, there is no unevenness on the toner surface, and as the value of SF-2 increases, the unevenness of the toner surface becomes more prominent.
Specifically, the shape factor is measured by taking a photograph of the toner with a scanning electron microscope (S-800: manufactured by Hitachi, Ltd.), introducing it into an image analyzer (LUSEX 3: manufactured by Nireco) and analyzing it. Calculated.

  The toner is a toner having SF-1 in the range of 100 to 180 and SF-2 in the range of 100 to 180. When the shape of the toner is close to a sphere, the contact between the toner and the toner or the toner and the photosensitive member 1 becomes a point contact, so that the adsorbing force between the toners becomes weak and the fluidity becomes high, and the toner and the photosensitive member. The adhesion with 5 is weakened and the transfer rate is increased. On the other hand, since the true spherical toner tends to enter the gap between the cleaning blade 15a and the photoreceptor 5, it is preferable that the toner shape factors SF-1 and SF-2 be large to some extent. Will be scattered and image quality will deteriorate. For this reason, it is preferable that SF-1 and SF-2 do not exceed 180.

  The toner suitably used in the image forming apparatus 1 of the present invention is a toner material in which at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent are dissolved or dispersed in an organic solvent. It is a toner obtained by crosslinking and / or extending the liquid in an aqueous solvent. Hereinafter, the constituent material and the manufacturing method of the toner will be described.

(Modified polyester)
The toner according to the present invention contains a modified polyester (i) as a binder resin. The modified polyester (i) refers to a state in which a bonding group other than an ester bond is present in the polyester resin, or resin components having different configurations are bonded to the polyester resin by a covalent bond, an ionic bond, or the like. Specifically, the polyester terminal is modified by introducing a functional group such as a carboxylic acid group or an isocyanate group that reacts with a hydroxyl group into the polyester terminal and further reacting with an active hydrogen-containing compound.

  Examples of the modified polyester (i) include urea-modified polyester obtained by a reaction between a polyester prepolymer (A) having an isocyanate group and amines (B). As the polyester prepolymer (A) having an isocyanate group, a polyester having a polycondensate of a polyhydric alcohol (PO) and a polyvalent carboxylic acid (PC) and having an active hydrogen group is further added to a polyvalent isocyanate compound (PIC). And those reacted with. Examples of the active hydrogen group possessed by the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, and the like. Among these, an alcoholic hydroxyl group is preferable.

The urea-modified polyester is produced as follows.
Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable. Examples of the dihydric alcohol (DIO) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide bisphenol (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyhydric alcohol (TO) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

  Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). (DIC) alone and (DIC) with a small amount of (TC) Mixtures are preferred. Divalent carboxylic acids (DIC) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polyvalent carboxylic acid (TC) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polyhydric carboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.).

  The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

  Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; Those blocked with caprolactam or the like; and combinations of two or more of these.

  The ratio of the polyvalent isocyanate compound (PIC) is usually 5/1 to 1/1, preferably as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1, when a urea-modified polyester is used, the urea content in the ester is lowered and hot offset resistance is deteriorated.

The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.
The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

Next, as amines (B) to be reacted with the polyester prepolymer (A), a divalent amine compound (B1), a trivalent or higher polyvalent amine compound (B2), an amino alcohol (B3), an amino mercaptan (B4) ), Amino acid (B5), and amino acid block of B1 to B5 (B6).
Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like. Examples of the trivalent or higher polyvalent amine compound (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of the compound (B6) obtained by blocking the amino group of B1 to B5 include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is more than 2 or less than 1/2, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance is deteriorated.
The urea-modified polyester may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

The modified polyester (i) used in the present invention is produced by a one-shot method or a prepolymer method. The weight average molecular weight of the modified polyester (i) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000. The peak molecular weight at this time is preferably 1000 to 10000. When the molecular weight is less than 1000, the elongation reaction hardly occurs, the elasticity of the toner is small, and as a result, the resistance to hot offset deteriorates. On the other hand, when it exceeds 10,000, the problem in production becomes high in the deterioration of fixability, particle formation and pulverization. The number average molecular weight of the modified polyester (i) is not particularly limited when the unmodified polyester (ii) described later is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. (I) When used alone, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color device are deteriorated.
In the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B) to obtain the modified polyester (i), a reaction terminator is used as necessary to adjust the molecular weight of the resulting urea-modified polyester. be able to. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).

(Unmodified polyester)
In the present invention, not only the modified polyester (i) is used alone, but also the unmodified polyester (ii) can be contained as a binder resin component together with the (i). By using (ii) in combination, the low-temperature fixability and the gloss when used in a full-color device are improved, which is preferable to single use. Examples of (ii) include polycondensates of polyhydric alcohol (PO) and polyvalent carboxylic acid (PC) similar to the polyester component of (i), and preferred ones are also the same as (i). . (Ii) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, and may be modified with a urethane bond, for example. It is preferable that (i) and (ii) are at least partially compatible in terms of low-temperature fixability and hot offset resistance. Accordingly, the polyester component (i) and (ii) preferably have similar compositions. When (ii) is contained, the weight ratio of (i) to (ii) is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, Particularly preferred is 7/93 to 20/80. When the weight ratio of (i) is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

  The peak molecular weight of (ii) is usually 1000 to 10,000, preferably 2000 to 8000, and more preferably 2000 to 5000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. The hydroxyl value of (ii) is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. The acid value of (ii) is preferably 1 to 5, more preferably 2 to 4. Since a high acid value wax is used as the wax, the low acid value binder leads to electrification and high volume resistance, so that it is easy to match the toner used for the two-component developer.

  The glass transition point (Tg) of the binder resin is usually 35 to 70 ° C, preferably 55 to 65 ° C. If the temperature is lower than 35 ° C., the heat-resistant storage stability of the toner deteriorates, and if it exceeds 70 ° C., the low-temperature fixability becomes insufficient. Since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the toner of the present invention tends to have good heat storage stability even when the glass transition point is low, as compared with known polyester-based toners. Show.

(Coloring agent)
As the colorant, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher , Yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sayred, Parachlor Ortonito Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmin Min BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R , Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thio Indigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Lid Russian nin green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

  The colorant can also be used as a master batch combined with a resin. As a binder resin to be kneaded with the production of the master batch or the master batch, a polymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyl toluene or the like, or a copolymer of these and a vinyl compound, Polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, fat Aromatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like can be mentioned, and these can be used alone or in combination.

(Charge control agent)
Known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salts or compounds, tungsten simple substances or compounds, fluorine activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenolic condensate E-89 (above, Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSY VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit) Manufactured), copper phthalocyanine, perylene, quinacridone, azo series Fee, a sulfonic acid group, a carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts. Of these, substances that control the negative polarity of the toner are particularly preferably used.
The amount of the charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the flowability of the developer is lowered, and the image density is lowered. Invite.

(Release agent)
As a release agent, a low melting point wax having a melting point of 50 to 120 ° C. works more effectively as a release agent in the dispersion with the binder resin between the fixing roller and the toner interface. The effect on high temperature offset is exhibited without applying a release agent such as oil. Examples of such a wax component include the following. Examples of waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, and paraffin, microcrystalline, And petroleum waxes such as petrolatum. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, and synthetic waxes such as esters, ketones, and ethers can be used. Furthermore, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbon, and low molecular weight crystalline polymer resin, poly-n-stearyl methacrylate, poly-n- A crystalline polymer having a long alkyl group in the side chain such as a homopolymer or copolymer of polyacrylate such as lauryl methacrylate (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.) can also be used. .
The charge control agent and the release agent can be melt-kneaded together with the master batch and the binder resin, and of course, they may be added when dissolved and dispersed in the organic solvent.

(External additive)
Inorganic fine particles are preferably used as an external additive for assisting the fluidity, developability and chargeability of the toner particles. The primary particle diameter of the inorganic fine particles is preferably 5 × ¹⁰ -3 ~2μm, it is particularly preferably 5 × ¹⁰ -3 ~0.5μm. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The use ratio of the inorganic fine particles is preferably 0.01 to 5 wt% of the toner, and particularly preferably 0.01 to 2.0 wt%.
Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, as the fluidity imparting agent, it is preferable to use hydrophobic silica fine particles and hydrophobic titanium oxide fine particles in combination. In particular, when stirring and mixing are performed using particles having an average particle diameter of 5 × 10 ⁻² μm or less, the electrostatic force and van der Waals force with the toner are remarkably improved. Even when stirring and mixing inside the developing device is performed to obtain a good image quality that does not cause the release of the fluidity imparting agent from the toner and does not generate firefly, etc., and further reduces the residual toner. It is done.
Titanium oxide fine particles are excellent in environmental stability and image density stability, but have a tendency to deteriorate the charge rise characteristics. Therefore, if the amount of titanium oxide fine particles added is larger than the amount of silica fine particles added, this side effect is affected. It can be considered large. However, when the added amount of the hydrophobic silica fine particles and the hydrophobic titanium oxide fine particles is in the range of 0.3 to 1.5 wt%, the charge rising characteristics are not greatly impaired, and the desired charge rising characteristics can be obtained, that is, repeated copying. Stable image quality can be obtained even if

Next, a toner manufacturing method will be described. Here, although a preferable manufacturing method is shown, it is not limited to this.
(Toner production method)
1) A toner material solution is prepared by dispersing a colorant, unmodified polyester, a polyester prepolymer having an isocyanate group, and a release agent in an organic solvent.
The organic solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal after toner base particle formation. Specifically, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, Methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable. The usage-amount of an organic solvent is 0-300 weight part normally with respect to 100 weight part of polyester prepolymers, Preferably it is 0-100 weight part, More preferably, it is 25-70 weight part.

2) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles.
The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.
The amount of the aqueous medium used relative to 100 parts by weight of the toner material liquid is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner material liquid is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical.

Further, in order to improve the dispersion in the aqueous medium, a dispersant such as a surfactant and resin fine particles is appropriately added.
As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride, fatty acid amide derivative, polyhydric alcohol Nonionic surfactants such as derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine And the like.

Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-Hydroxyethyl) Perful Olooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned.
Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

  Moreover, as the cationic surfactant, aliphatic quaternary ammonium such as aliphatic primary, secondary or secondary amic acid, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt which has a right fluoroalkyl group is used. Salt, benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (Asahi Glass Co., Ltd.), Florard FC-135 (Sumitomo 3M Co., Ltd.), Unidyne DS-202 (Daikin Industries) Smoke), Megafac F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products), Footage F-300 (Neos), and the like.

The resin fine particles are added to stabilize the toner base particles formed in the aqueous medium. For this reason, it is preferable to add so that the coverage existing on the surface of the toner base particles is in the range of 10 to 90%. For example, polymethyl methacrylate fine particles 1 μm and 3 μm, polystyrene fine particles 0.5 μm and 2 μm, poly (styrene-acrylonitrile) fine particles 1 μm, trade names are PB-200H (manufactured by Kao), SGP (manufactured by Soken), Techno Examples include polymer SB (manufactured by Sekisui Chemical Co., Ltd.), SGP-3G (manufactured by Sokensha), and micropearl (manufactured by Sekisui Fine Chemical Co., Ltd.).
In addition, inorganic compound dispersants such as tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite can also be used.

  As a dispersant that can be used in combination with the above resin fine particles and inorganic compound dispersant, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as acrylic acid-β-hydroxyethyl, methacrylic acid-β-hydroxyethyl, acrylic acid-β-hydroxypropyl, methacrylic acid-β-hydroxypropyl, acrylic acid-γ-hydroxypropyl, methacrylic acid-γ-hydroxy Propyl, acrylic acid-3-chloro-2-hydroxypropyl, methacrylic acid-3-chloro-2-hydroxypropyl, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate Luric acid esters, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or compounds containing vinyl alcohol and a carboxyl group Esters such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl Nitrogen compounds such as imidazole and ethyleneimine, or homopolymers or copolymers such as those having a heterocyclic ring thereof, polyoxyethylene, poly Xoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxy Polyoxyethylenes such as ethylene nonylphenyl ester, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

  The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. Among these, the high-speed shearing method is preferable in order to make the particle size of the dispersion 2 to 20 μm. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C.

3) At the same time as the preparation of the emulsion, the amines (B) are added to cause a reaction with the polyester prepolymer (A) having an isocyanate group.
This reaction involves molecular chain crosslinking and / or elongation. The reaction time is selected depending on the reactivity between the isocyanate group structure of the polyester prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

4) After completion of the reaction, the organic solvent is removed from the emulsified dispersion (reactant), washed and dried to obtain toner base particles.
In order to remove the organic solvent, the temperature of the entire system is gradually raised in a laminar stirring state, and after giving strong stirring in a certain temperature range, the solvent base is removed to produce spindle-shaped toner base particles. . Further, when an acid such as calcium phosphate salt or an alkali-soluble material is used as the dispersion stabilizer, the calcium phosphate salt is dissolved from the toner base particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. Remove. It can also be removed by operations such as enzymatic degradation.

5) A charge control agent is injected into the toner base particles obtained above, and then inorganic fine particles such as silica fine particles and titanium oxide fine particles are externally added to obtain a toner.
The injection of the charge control agent and the external addition of the inorganic fine particles are performed by a known method using a mixer or the like.
Thereby, a toner having a small particle size and a sharp particle size distribution can be easily obtained. Furthermore, by giving strong agitation in the process of removing the organic solvent, the shape between the true spherical shape and the rugby ball shape can be controlled, and the surface morphology is also controlled between the smooth shape and the umeboshi shape. be able to.

Further, the toner according to the present invention has a substantially spherical shape and can be represented by the following shape rule.
FIG. 15 is a diagram schematically showing the shape of the toner according to the present invention. In (a), when a substantially spherical toner is defined by a major axis r1, a minor axis r2, and a thickness r3 (where r1 ≧ r2 ≧ r3), the toner of the present invention has a major axis and a minor axis. (R2 / r1) (see (b)) is 0.5 to 1.0, and the ratio of thickness to short axis (r3 / r2) (see (c)) is 0.7 to 1.0. It is preferable that it exists in the range. When the ratio of the major axis to the minor axis (r2 / r1) is less than 0.5, the dot reproducibility and transfer efficiency are inferior because of being away from the true spherical shape, and high-quality image quality cannot be obtained. On the other hand, if the ratio of thickness to minor axis (r3 / r2) is less than 0.7, the shape is close to a flat shape, and a high transfer rate like a spherical toner cannot be obtained. In particular, when the ratio of the thickness to the minor axis (r3 / r2) is 1.0, the rotating body has a major axis as a rotation axis, and the fluidity of the toner can be improved.
Note that r1, r2, and r3 were measured with a scanning electron microscope (SEM) while changing the angle of field of view and taking pictures.

The toner produced as described above can also be used as a one-component magnetic toner that does not use a magnetic carrier or a non-magnetic toner.
Further, when used in a two-component developer, it may be used by mixing with a magnetic carrier, and the magnetic carrier is a ferrite containing a divalent metal such as iron, magnetite, Mn, Zn, Cu, The weight average particle diameter D ₄ is preferably 20 to 100 μm. If the average particle size is less than 20 μm, carrier adhesion is likely to occur on the photoreceptor 1 during development, and if it exceeds 100 μm, the miscibility with the toner is low and the charge amount of the toner is insufficient, resulting in poor charging during continuous use. Cheap. In addition, Cu ferrite containing Zn is preferable because of high saturation magnetization, but can be appropriately selected according to the process of the image forming apparatus. The resin for coating the magnetic carrier is not particularly limited, and examples thereof include silicone resin, styrene-acrylic resin, fluorine-containing resin, and olefin resin. In the manufacturing method, the coating resin may be dissolved in a solvent, sprayed into a fluidized bed and coated on the core, or the resin particles are electrostatically attached to the core particles and then thermally melted for coating. It may be a thing. The resin to be coated has a thickness of 0.05 to 10 μm, preferably 0.3 to 4 μm.

  The image forming apparatus 1 according to the present invention includes a photosensitive member 5 and one or more devices selected from a charging device 14, a developing device 10, a cleaning device 15, and a coating device 17, which are integrally supported to be attached and detached. A possible process cartridge 2 is provided. Accordingly, the developer and the developing device 10 can be easily replaced, and the main body of the image forming apparatus 1 can be used over a long period of time.

1 is a schematic diagram illustrating a configuration of an image forming apparatus of the present invention, (a) an overall view of the image forming apparatus, and (b) a schematic diagram illustrating a configuration of an image forming unit. 1 is a schematic diagram illustrating a configuration of a fixing device of the present invention. FIG. 3 is a schematic diagram illustrating a configuration of a fixing belt provided with a detent member provided in the fixing device of the present invention. FIG. 6 is a schematic diagram illustrating an arrangement of an adjustment mechanism that is provided in the fixing device of the present invention. It is the schematic which shows the structure of an adjustment mechanism. FIG. 6 is a schematic diagram for explaining a state of a contact range due to an elastic force of a fixing belt and belt tension by an adjustment mechanism. FIG. 3 is a schematic diagram illustrating a configuration of an adjustment roller and a detent member of the fixing device of the present invention. FIG. 3 is a schematic diagram illustrating a configuration of a detent member and a recording medium P of the fixing device of the present invention. The fixing device of the present invention is a schematic diagram illustrating a configuration including a plurality of adjustment mechanisms. FIG. 3 is a schematic diagram illustrating a configuration of a fixing device having a plurality of adjustment rollers having different axial lengths. FIG. 3 is a diagram illustrating a configuration of a fixing device having an adjustment roller that contacts both ends of the fixing belt. It is a mimetic diagram for explaining the range which contacts by a plurality of adjustment mechanisms. It is a figure which shows the structure which made the adjustment roller the drum shape. FIG. 6 is a diagram schematically illustrating the shape of a toner in order to explain the shape factor SF-1 and the shape factor SF-2. FIG. 3 is a diagram schematically illustrating the shape of a toner according to the present invention. FIG. 6 is a diagram schematically illustrating a temperature distribution of an adjustment roller when a small-size recording medium passes through a fixing device including a fixing belt.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Image forming unit 3 Transfer apparatus 3a Transfer belt 5 Photoconductor (Image carrier)
6 Writing unit 7 Double-sided unit 8 Reversing unit 9 Fixing device 91 Heating roller 92 Fixing roller 93 Fixing belt 93a Shifting member 95 Pressure roller 96 Application roller 97 Cleaning roller 97a Fixing belt cleaning roller 97b Application roller cleaning roller 97c Pressure roller cleaning Roller 98 Heating member 98a Heating heater 98b Pressure heater 98c Fixing heater 99 Temperature detection sensor 99a Heating roller thermistor 99b Fixing roller thermistor 99c Fixing belt thermistor 99d Pressure roller thermistor 10 Developing device 11, 12 Paper feed cassette 13 Manual tray 14 Charging device 14a Charging roller 15 Cleaning means 16 Adjustment mechanism 16a Drive member 16b Support member 16c Elastic member 16d Adjustment roller 20 Reverse discharge Road 25 rollers 26 discharge tray 45a, 45b conveying guide plate 46 conveying rollers 55 and 56 separating feeding unit 58 the paper attracting roller 59 registration roller pair

Claims (25)

In a fixing device for fixing toner on a passing recording medium with a fixing belt stretched between a plurality of rollers and a pressure roller disposed opposite to the fixing belt,
The fixing device includes a fixing belt that is provided on both sides or one end of a locking member that prevents shifting, and is provided on the outside.
A fixing device comprising: an adjustment mechanism that adjusts a contact range of the fixing belt with a roller having a heat source among the plurality of rollers. The fixing device according to claim 1,
The fixing device detects the temperature of at least one of a fixing belt, a plurality of rollers that stretch the fixing belt, and a pressure roller,
The fixing device adjusts a range in which the fixing belt contacts a roller having a heat source among the plurality of rollers. The fixing device according to claim 1 or 2,
The fixing device detects the size of the recording medium that passes therethrough,
The fixing device adjusts a range in which the fixing belt contacts a roller having a heat source among the plurality of rollers. The fixing device according to any one of claims 1 to 3,
The fixing device detects a passing amount of the recording medium per unit time,
The fixing device adjusts a range in which the fixing belt contacts a roller having a heat source among the plurality of rollers. The fixing device according to claim 1,
The fixing device is characterized in that the adjustment mechanism is adjusted by an eccentric cam or a gear. The fixing device according to any one of claims 1 to 5,
The fixing mechanism includes an adjustment roller. The fixing device according to claim 1,
The fixing device is characterized in that the difference between the end of the fixing member of the fixing belt and the end of the adjusting roller is 1 mm or more. In the fixing device according to any one of claims 1 to 6,
The fixing device is characterized in that a difference between an end portion of the fixing member of the fixing belt and an end portion of the passing recording member is 10 mm or more. The fixing device according to claim 1,
The fixing device includes a plurality of adjustment rollers that apply pressure to the fixing belt. The fixing device according to claim 9.
The fixing device is characterized in that the adjustment rollers have different axial lengths. The fixing device according to claim 1,
In the fixing device, the adjusting roller of the adjusting mechanism has a counter drum shape. The fixing device according to any one of claims 1 to 11,
A fixing device characterized in that when a detent member is provided at both ends of at least one of the plurality of rollers, at least one of hardness, width, and thickness of the detent members at both ends is different. The fixing device according to claim 12,
The fixing member has a hardness in a range of 20 to 80 Hs. The fixing device according to claim 12,
The fixing device is characterized in that the stopper member has a width of 0.5 mm or more. The fixing device according to claim 12,
The fixing device is characterized in that the stopper member has a thickness of 0.5 mm or more. An image carrier that forms a latent image, a charging device that uniformly charges the surface of the image carrier, an exposure device that exposes the charged image carrier surface based on image data and writes the latent image, and an image carrier An image forming apparatus comprising: a developing device that supplies toner to a latent image formed on a surface thereof to visualize the latent image; and a cleaning device that cleans the surface of the image carrier. In an image forming apparatus in which a transfer device for transferring to a recording medium directly or after transferring to an intermediate transfer member and a fixing device for fixing a toner image on the recording medium are arranged,
The image forming apparatus is a fixing device that fixes toner on a recording medium passing therethrough with a fixing belt stretched between a plurality of rollers and a pressure roller disposed opposite to the fixing belt,
A detent member for preventing detent is provided at both ends or one end of the fixing belt, and an adjustment mechanism for adjusting a contact range of the fixing belt with a roller having a heat source among the plurality of rollers. An image forming apparatus comprising a fixing device. The image forming apparatus according to claim 16.
An image forming apparatus using the fixing device according to claim 2. The image forming apparatus according to claim 16 or 17,
The image forming apparatus uses a toner having a weight average particle diameter of 10 μm or less and a ratio (dispersity) of the weight average particle diameter to the number average particle diameter in the range of 1.00 to 1.40. Image forming apparatus. The image forming apparatus according to any one of claims 16 to 18,
An image forming apparatus using toner having an average circularity in a range of 0.93 to 1.00. The image forming apparatus according to any one of claims 16 to 19,
The image forming apparatus has an almost spherical appearance,
The ratio of the major axis to the minor axis (r2 / r1) is in the range of 0.5 to 1.0, and the ratio of the diameter to the minor axis (r3 / r2) is in the range of 0.7 to 1.0. An image forming apparatus using a toner satisfying a relationship of major axis r1 ≧ minor axis r2 ≧ diameter r3. 21. The image forming apparatus according to claim 16, wherein
An image forming apparatus crosslinks and / or extends a toner composition containing at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent in an aqueous medium in the presence of resin fine particles. An image forming apparatus using toner. The image forming apparatus according to any one of claims 16 to 21, wherein
An image forming apparatus comprising: a process cartridge in which a latent image carrier, at least one unit selected from a charging unit, a developing unit, and a cleaning unit are integrated. An image carrier that forms a latent image, a charging device that uniformly charges the surface of the image carrier, an exposure device that exposes the charged image carrier surface based on image data and writes the latent image, and an image carrier An image forming apparatus in which a developing device that supplies toner to a latent image formed on a surface to visualize the latent image and a cleaning device that cleans the surface of the image carrier are arranged between a plurality of rollers. A fixing device for fixing toner on a recording medium passing therethrough by a fixing belt and a pressure roller disposed opposite to the fixing belt, wherein the fixing device includes a detent member for preventing detent. Image formation in which a fixing belt provided at both ends or one end and provided outside and a fixing device having an adjustment mechanism for adjusting a contact range of the fixing belt with a roller having a heat source among the plurality of rollers is arranged The toner used in the location,
The toner has an average circularity in a range of 0.93 to 1.00. The toner according to claim 23.
The appearance of the toner is almost spherical,
The ratio of the major axis to the minor axis (r2 / r1) is in the range of 0.5 to 1.0, and the ratio of the diameter to the minor axis (r3 / r2) is in the range of 0.7 to 1.0. And a toner satisfying the relationship of major axis r1 ≧ minor axis r2 ≧ diameter r3. The toner according to claim 23 or 24, wherein:
The toner is prepared by subjecting a toner composition containing at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent to a crosslinking and / or elongation reaction in the presence of resin fine particles in an aqueous medium. Features toner.

Images