JP2007156281A - Transfer device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transfer device for use in an intermediate transfer system which prevents false detection due to a blemish and stain on a belt surface, and also to provide an image forming apparatus using the same. <P>SOLUTION: Patterns comprising toners of respective colors for position adjustment are transferred from photoreceptors in toner image forming sections onto a transfer conveyance belt 60, light is illuminated from a sensor Sr onto the patterns of the respective colors transferred onto the belt 60, and the patterns of the respective colors are detected by the reflected light. In order to make any corrections to the respective colors, the position of the belt 60 is stored, the surface condition of the belt is checked, and when the presence of noise (abnormal place) on the belt 60 is detected by the surface check, corrected patterns are formed, while the abnormal place is avoided. The abnormal place is judged to be abnormal only when it is periodic. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus capable of forming a color image and a transfer device used therefor.

  Representative methods of color image formation include a direct transfer method in which toner images of different colors formed on a plurality of photoconductors are transferred while being superimposed directly on a transfer sheet, and toners of different colors formed on a plurality of photoconductors. There is an intermediate transfer method in which an image is transferred while being superimposed on an intermediate transfer member, and then transferred onto a transfer sheet at once. Since a plurality of photoconductors are arranged side by side facing the transfer paper or intermediate transfer body, this is called a tandem method, and yellow (Y), magenta (M), cyan (C), and black (K) for each photoconductor. For each color, an electrophotographic process such as formation and development of an electrostatic latent image is performed, and the image is transferred onto a running transfer sheet in the direct transfer method, or onto a running intermediate transfer member in the intermediate transfer method.

In the tandem color image forming apparatus using each of these methods, the direct transfer method receives an endless belt that runs while supporting transfer paper, and the intermediate transfer method receives an image from a photoconductor. Generally, an endless belt to be carried is employed. Then, an image forming unit including four photoconductors is installed side by side on one running side of the belt.
Japanese Patent Laid-Open No. 10-073981 JP 2004-33409 A Japanese Unexamined Patent Publication No. 08-085235 Japanese Patent Laid-Open No. 2001-109220

  In the tandem color image forming apparatus, it is important to prevent occurrence of color misregistration by accurately superimposing toner images of respective colors. As one of the means, most products use the automatic alignment correction function. In this case, the pattern position is corrected by detecting the output of the reflective sensor. If a scratch or dirt is erroneously detected, the alignment correction accuracy deteriorates or results in an error.

  In view of the above-described conventional problems, an object of the present invention is to provide a transfer device capable of preventing erroneous detection due to scratches and dirt on the belt surface as much as possible, and an image forming apparatus using the transfer device.

  The transfer apparatus according to the first aspect of the present invention directly transfers a pattern of each color toner from a plurality of image carriers onto a transfer belt or an intermediate transfer belt, and transfers each color transferred onto the belt. A transfer device that irradiates a pattern with light from a sensor, detects a pattern of each color using the reflected light, and performs some correction on each color, and checks the belt surface state and means for storing the position of the belt In the transfer device having the surface check means and the control means for controlling the operation of the apparatus, the control means detects the presence of noise (abnormal part) on the belt by the surface check means. It is characterized in that the corrected pattern is created while avoiding abnormal portions.

  According to the second aspect of the present invention, in the transfer apparatus according to the first aspect, the determination of the abnormal part by the control means is an abnormal part only when it is periodic.

  According to the third aspect of the present invention, in the transfer apparatus according to the first or second aspect, when there are a plurality of the abnormal portions and the interval is La, the control means is configured to perform the alignment correction. If the length L is L> La, the alignment correction is not executed, and if L <La, the alignment correction is executed within the interval of the abnormal part.

  According to a fourth aspect of the present invention, in the transfer apparatus according to the first or second aspect, when the plurality of abnormal portions are present and the interval thereof is L1, the control means is configured to perform the alignment correction. Is set to L1 or less, and alignment correction is performed between the abnormal portions.

  According to the fifth aspect of the present invention, in the transfer device according to any one of the first to fourth aspects, when there are a plurality of the abnormal portions and the distance between the abnormal portions is shorter than the corrected pattern length, the correction is performed. Is not carried out.

  According to a sixth aspect of the present invention, in the transfer apparatus according to the fifth aspect, means for notifying abnormality is provided.

  According to the seventh aspect of the present invention, in the transfer device according to the first or second aspect, in the case where the abnormal portion is present, the position of the correction pattern and its position coincide with each other. The correction amount calculated and determined for the case is excluded.

  According to the eighth aspect of the present invention, in the transfer device according to the first or second aspect, when the abnormal portion exists, the control unit moves the abnormal portion to a specific position and stops the belt. It is characterized by.

  An image forming apparatus according to claim 9 uses the transfer device according to any one of claims 1 to 8.

  According to a tenth aspect of the present invention, in the image forming apparatus according to the ninth aspect, the toner used in the developing unit has a volume average particle diameter of 3 to 8 μm, a volume average particle diameter (Dv) and a number average particle diameter. The ratio (Dv / Dn) to the diameter (Dn) is in the range of 1.00 to 1.40.

  According to the eleventh aspect, in the image forming apparatus according to the ninth or tenth aspect, the toner used in the developing unit has a shape factor SF-1 in the range of 100 to 180, and the shape factor SF-2. Is in the range of 100-180.

  The image forming apparatus according to any one of claims 9 to 11, wherein the toner used in the developing unit includes at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, It is a toner obtained by crosslinking and / or extending a toner material liquid in which a colorant and a release agent are dispersed in an organic solvent in an aqueous medium.

  According to a thirteenth aspect of the present invention, in the image forming apparatus according to the ninth to twelfth aspects, the toner used in the developing unit has a substantially spherical shape.

  According to the fourteenth aspect of the invention, in the image forming apparatus according to the ninth to thirteenth aspects, the shape of the toner is defined by a major axis r1, a minor axis r2, and a thickness r3 (provided that r1 ≧ r2 ≧ r3), the ratio of the major axis r1 to the minor axis r2 (r2 / r1) is in the range of 0.5 to 1.0, and the ratio of the thickness r3 to the minor axis r2 (r3 / r2) is It exists in the range of 0.7-1.0.

  In the present invention, when noise (abnormal part) exists on the belt surface, a correction pattern is created by avoiding the abnormal part. It is possible to prevent detection, and it is possible to prevent erroneous detection due to scratches or dirt on the belt surface as much as possible.

  The best mode for carrying out the present invention will be described below with reference to the embodiments shown in the drawings. In the following,

  One embodiment in which the present invention is applied to an electrophotographic color laser printer (hereinafter referred to as “laser printer”) as an image forming apparatus will be described with reference to FIGS.

  FIG. 1 is a schematic configuration diagram of a laser printer according to an embodiment of the present invention. This laser printer includes four toner image forming units 1Y, 1M, 1C, 1K (hereinafter referred to as “yellow” (Y), magenta (M), cyan (C), and black (K)). The subscripts Y, M, C, and K of the reference numerals indicate yellow, magenta, cyan, and black members, respectively, and the direction of movement of the transfer paper 100 (the belt 60 along the arrow A in the figure). In the traveling direction) from the upstream side. Each of the toner image forming units 1Y, 1M, 1C, and 1K includes photosensitive drums 11Y, 11M, 11C, and 11K as image carriers and a developing unit. In addition, the arrangement of the toner image forming units 1Y, 1M, 1C, and 1K is set so that the rotation axes of the photosensitive drums are parallel and arranged at a predetermined pitch in the transfer paper moving direction. .

  In addition to toner image formation 1Y, 1M, 1C, and 1K, this laser printer carries an optical writing unit 2, paper feed cassettes 3, 4, a pair of registration rollers 5, and transfer paper 100 to transfer each toner image forming unit. A transfer unit 6 as a belt driving device having a transfer conveyance belt 60 as a transfer conveyance member that conveys the sheet so as to pass through the position, a belt fixing type fixing unit 7, a paper discharge tray 8, and the like are provided. In addition, a manual feed tray MF and a toner supply container TC are provided, and a waste toner bottle, a duplex / reversing unit, a power supply unit, and the like (not shown) are also provided in a space S indicated by a two-dot chain line.

  The optical writing unit 2 includes a light source, a polygon mirror, an f-θ lens, a reflection mirror, and the like, and irradiates the surface of each of the photosensitive drums 11Y, 11M, 11C, and 11K while scanning the laser beam based on image data. To do.

FIG. 2 is an enlarged view showing a schematic configuration of the transfer unit 6. The transfer conveyance belt 60 used in the transfer unit 6 is a high-resistance endless single-layer belt having a volume resistivity of 10 ⁹ to 10 ¹¹ Ωcm, and the material thereof is PVDF (polyvinylidene fluoride). The transfer / conveying belt 60 is wound around support rollers 61 to 68 so as to pass through the transfer positions that are in contact with and opposed to the photosensitive drums 11M, 11C, 11Y, and 11K of the toner image forming units.

  Among these support rollers, the entrance roller 61 on the upstream side in the transfer sheet moving direction is disposed on the outer peripheral surface of the transfer conveyance belt 60 so that the electrostatic adsorption roller 80 to which a predetermined voltage is applied from the power source 80a is opposed. Yes. The transfer paper 100 that has passed between the two rollers 61 and 65 is electrostatically attracted onto the transfer conveyance belt 60.

  A roller 63 is a drive roller that frictionally drives the transfer conveyance belt 60, and is connected to a drive source (not shown) and rotates in the direction of the arrow.

  As a transfer electric field forming means for forming a transfer electric field at each transfer position, transfer bias applying members 67Y, 67M, 67C, and 67K are provided at positions facing the photosensitive drum 11 so as to contact the back surface of the transfer conveyance belt 60. Provided. These are bias rollers provided with a sponge or the like on the outer periphery, and a transfer bias is applied to the roller core from each transfer bias power source 9Y, 9M, 9C, 9K. Due to the action of the applied transfer bias, a transfer charge is applied to the transfer conveyance belt 60, and a transfer electric field having a predetermined strength is formed between the transfer conveyance belt 60 and the surface of the photosensitive drum at each transfer position. In addition, a backup roller 68 is provided in order to keep the contact between the transfer paper and the photosensitive member appropriately in the transfer area and to obtain the best transfer nip.

  The transfer bias applying members 67Y, 67M, and 67C and the backup roller 68 disposed in the vicinity thereof are integrally held by the swing bracket 93 so as to be rotatable, and can be rotated about a rotation shaft 94. This rotation is clockwise when the cam 96 fixed to the cam shaft 97 is rotated in the direction of the arrow.

  The entrance roller 61 and the suction roller 80 are integrally supported by the entrance roller bracket 90, and can be rotated clockwise from the state of FIG. A hole 95 provided in the swing bracket 93 and a pin 92 fixed to the entrance roller bracket 90 are engaged with each other, and rotate in conjunction with the swing of the swing bracket 93. By the clockwise rotation of the brackets 90 and 93, the bias applying members 67Y, 67M, and 67C and the backup roller 68 disposed in the vicinity thereof are separated from the photoreceptors 11M, 11C, and 11Y, and the entrance roller 61 and the suction roller 80 are separated. Also move downwards. It is possible to avoid contact between the photoconductors 11Y, 11M, and 11C and the transfer conveyance belt 60 when a black-only image is formed.

  On the other hand, the transfer bias applying member 67K and the backup roller 68 adjacent to the transfer bias applying member 67K are rotatably supported by the outlet bracket 98, and are rotatable about a shaft 99 coaxial with the outlet roller 62. When attaching / detaching the transfer unit 6 to / from the main body, the transfer unit 6K is rotated clockwise by operating a handle (not shown), and the transfer bias applying member 67K and the backup roller 68 adjacent thereto are moved from the black image forming photosensitive member 11K. They are separated.

  A cleaning device 85 composed of a brush roller and a cleaning blade is disposed on the outer peripheral surface of the transfer conveyance belt 60 wound around the driving roller 63. The cleaning device 85 removes foreign matters such as toner adhering to the transfer conveyance belt 60.

  A roller 64 is provided downstream of the driving roller 63 in the traveling direction of the transfer / conveying belt 60 in a direction to push the outer peripheral surface of the transfer / conveying belt, and a winding angle around the driving roller 83 is secured. A tension roller 65 that applies tension to the belt with a pressing member (spring) 69 is provided in the loop of the transfer conveyance belt 60 further downstream from the roller 64.

  The one-dot chain line in FIG. 1 shown above indicates the conveyance path of the transfer paper 100. The transfer paper 100 fed from the paper feed cassettes 3 and 4 or the manual feed tray MF is transported by transport rollers while being guided by a transport guide (not shown), and is transported to a temporary stop position where the registration roller pair 5 is provided. The transfer paper 100 delivered at a predetermined timing by the registration roller pair 5 is carried on the transfer conveyance belt 60, conveyed toward the toner image forming units 1Y, 1M, 1C, and 1K, and passes through the transfer nips. .

  The toner images developed on the photosensitive drums 11Y, 11M, 11C, and 11K of the toner image forming units 1Y, 1M, 1C, and 1K are superimposed on the transfer paper 100 at the transfer nips, and the transfer electric field and nip It is transferred onto the transfer paper 100 under the action of pressure. By this superposition transfer, a full-color toner image is formed on the transfer paper 100.

  The surfaces of the photosensitive drums 11Y, 11M, 11C, and 11K after the toner image transfer are cleaned by a cleaning device, and are further discharged to prepare for the formation of the next electrostatic latent image.

  On the other hand, the transfer paper 100 on which the full-color toner image is formed is fixed in the first paper discharge direction B or the second in accordance with the rotation posture of the switching guide G after the full-color toner image is fixed by the fixing unit 7. In the paper discharge direction C. When the paper is discharged from the first paper discharge direction B onto the paper discharge tray 8, it is stacked in a so-called face-down state with the image surface down. On the other hand, when the paper is discharged in the second paper discharge direction C, it is conveyed toward another post-processing device (such as a sorter or a binding device) (not shown), or is registered again for double-sided printing via a switchback unit. It is conveyed to the roller pair 5.

  In the embodiment described above, the present invention is applied to the transfer unit 6 in the tandem printer in which a plurality of the photosensitive drums 11Y, 11M, 11C, and 11K are arranged on the transfer conveyance belt 60. The printer and the belt driving device to which can be applied are not limited to this configuration. In a full-color printer having a belt driving device that rotationally drives an endless belt stretched between a plurality of rollers by at least one of the rollers, a pattern is formed directly on the transfer belt, and an alignment correction mode Any belt driving (transfer) device having the above can be applied.

  The present invention has an alignment function for creating a toner image pattern between colors and correcting the position thereof, and is particularly effective when correcting a shift amount between colors using a light receiving waveform of a reflective sensor or the like.

  In the case of a high-accuracy color image forming apparatus, the color superposition accuracy of each color needs to be maintained at 50 μm to 150 μm or less, but it is very difficult to maintain only by the accuracy and adjustment of each component for image formation. . Even if it becomes possible, the adjustment is necessary again when a change in dimensions due to the environment of the member, slip due to deterioration with time, replacement of a part due to a failure, or the like occurs, so that maintenance by the user is virtually impossible.

  Therefore, in order to automatically correct the positional accuracy for superimposing the respective color components, after the toner patterns for alignment of the respective color components are formed on the photosensitive drums 11Y, 11M, 11C, and 11K, the transfer conveyance belt is formed. 60, and the position of the toner image pattern is read by an optical sensor or the like, the amount of deviation or inclination in the main scanning direction and sub-scanning direction at each image station is detected, and the amount of deviation is automatically corrected. Many devices have been proposed and commercialized.

  The outline of automatic correction is as follows. As described above, a resin such as PVDF is used for the transfer conveyance belt 60 to which each color pattern for alignment is transferred, and the light transmittance of the belt itself is high. Therefore, in this embodiment, a member having a high light reflectance, that is, a so-called mirror-like surface is used on the back side of the transfer belt of the sensor facing portion, and in the state where there is no toner image, the sensor side receives reflected light that is almost 100%. When the toner image exists, a method of recognizing the position of the pattern by using reflected light is used. At this time, the mirror-like member used for the sensor facing portion is preferably a rotating body. The reason for this is that in the case of a fixed member, the scraped surface on the back surface of the belt is soiled by rubbing against the transfer conveyance belt, and the surface of the facing member may be stained, leading to a possibility that the reflected light will not return sufficiently and an increase in belt driving torque. Because. (A schematic configuration diagram is shown in FIG. 3) Of course, it is possible to directly recognize the reflected light from the belt surface without adopting such a configuration. In FIG. 3, the sensor is indicated by reference numeral Sr, and the roller 62 around which the transfer / conveying belt 60 is wound is used as the sensor facing member. However, other rollers that are suitable in terms of space, arrangement, and the like can be used. .

  However, in the case of the reading method using sensor reflected light, if the scratch or dirt on the belt surface is erroneously detected and falls into a state indistinguishable from the actual toner pattern, the alignment correction amount is not appropriate or the correction itself is impossible. turn into.

  As shown in the example of the sensor output waveform shown in FIG. 5, for example, when a pattern group of toner images L1 in FIG. 4 passes through the sensor unit having the above-described configuration, four output drops (valleys) are detected. The This is an output waveform that usually must be detected. However, if dirt or scratches are present on the surface of the transfer / conveying belt 60 at the sensor facing portion, the sensor output waveform may appear in the belt cycle at one location, for example. Of course, not all scratches and dirt affect the reflected light, but depend on the degree of dirt and the degree of scratches. Therefore, it is considered that the probability of an output waveform that is erroneously detected as an actual toner image pattern is very low. However, in the case where the waveform is detected as shown in FIG. 5, if the timing is exactly the same as the position in the pattern group, there is a possibility that a side effect is exerted on the alignment correction (false detection or error).

  Therefore, in the present invention, a mode for checking whether there is any scratch or dirt on the surface of the transfer conveyance belt 60 that affects the sensor output is provided so as not to have a side effect on the automatic alignment correction. In the check mode, the toner image is not placed on the belt, and the belt is rotated for at least one rotation of the belt. If the number of rotations is increased, a more reliable check can be performed. At that time, a sensor dedicated to checking may be provided, but if the sensor for alignment is also used, both the configuration and cost are advantageous.

  It should be noted that it is desirable to perform the check mode at a time that does not affect print productivity by performing it other than during non-image formation (print operation). For example, it is good when the power is turned on (using the time until the fixing temperature rises) or after the end of the printing operation. Further, if it is performed immediately before the alignment correction is performed, it is possible to prevent useless machine operations such as not performing the alignment correction when noise due to scratches or dirt is detected on the belt surface.

  An example of general alignment correction will be described. When a group of patterns of toner images of each color is used as a pattern group (for example, L1 or L2 or L in FIG. 4 is referred to as such), it is assumed here that L1 is the pattern group length. Then, the interval between each color in the pattern group is measured, and the exposure timing is changed so as to return to the ideal length, or the rotational speed of the photoconductor is slightly changed to perform correction. Further, in order to reduce the measurement variation by averaging, a plurality of pattern groups can be measured and corrected.

  If noise due to scratches or dirt is placed on the transfer / conveying belt 60, the error is not judged immediately, but if there is a plurality of noises, there is a means for storing the intervals. This makes it possible to correct the alignment. Therefore, in the present invention, the transfer conveyance belt 60 has a home position detection mark and a sensor for detecting the mark.

Therefore, first, the belt surface condition is checked to check whether there is any abnormality. Therefore, if there is no abnormality, the alignment correction is executed as it is. If there is a periodic abnormality there, the following operation is performed.
<Operation example 1>
1. 1. Calculate the distance between abnormal points. 2. Store the location of the abnormal part Judgment whether the interval La of the abnormal part is larger or smaller than the alignment correction pattern group interval L 4-1. If large: Alignment correction is performed between the abnormal portions with the pattern length L as it is. 4-2. 4. If small: Change the pattern group length to La or less (L1 or L2) and execute correction between abnormal parts. If the distance between the abnormal parts is too short (La <L1 or L2), the process ends as abnormal.
<Operation example 2>
1. Memorize the location of the abnormal part. 2. Determine whether an abnormal part is mixed in the alignment correction pattern group. When mixed, the correction amount in the pattern group is ignored.

  In this embodiment, the alignment correction pattern is described as an example. However, the same effect can be obtained in various correction operations performed by transferring the toner image onto the transfer conveyance belt 60. It is.

Next, the toner suitably used in the image forming apparatus of the present invention will be described.
In order to reproduce fine dots of 600 dpi or more, the toner preferably has a volume average particle diameter of 3 to 8 μm. The ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is preferably in the range of 1.00 to 1.40. The closer (Dv / Dn) is to 1.00, the sharper the particle size distribution. With such a toner having a small particle size and a narrow particle size distribution, the toner charge amount distribution is uniform, a high-quality image with little background fogging can be obtained, and the electrostatic transfer method has a high transfer rate. can do.

The toner shape factor SF-1 is preferably in the range of 100 to 180, and the shape factor SF-2 is preferably in the range of 100 to 180. FIG. 6 is a diagram schematically showing the shape of the toner for explaining the shape factor SF-1 (FIG. 6A) and the shape factor SF-2 (FIG. 6B). The shape factor SF-1 indicates the ratio of the roundness of the toner shape.
SF-1 = {(MXLNG) 2 / AREA} × (100π / 4)
It is represented by That is, a value obtained by dividing the square of the maximum length MXLNG of the shape formed by projecting the toner onto a two-dimensional plane by the figure area AREA and multiplying by 100π / 4. 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.
SF-2 = {(PERI) 2 / AREA} × (100π / 4)
It is represented by 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. 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.

  When the shape of the toner is close to a spherical shape, the contact state between the toner and the toner or the toner and the photoconductor becomes a point contact, so that the adsorbing force between the toners becomes weak and the fluidity increases, and the toner and the photoconductor The attraction force becomes weaker and the transfer rate becomes higher. If either of the shape factors SF-1 and SF-2 exceeds 180, the transfer rate is lowered, which is not preferable.

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

(polyester)
The polyester is obtained by a polycondensation reaction between a polyhydric alcohol compound and a polycarboxylic acid compound. 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. As trihydric or higher polyhydric alcohol (TO), 3 to 8 or higher polyhydric aliphatic alcohol (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. The polycondensation reaction between a polyhydric alcohol (PO) and a polycarboxylic acid (PC) is carried out in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide, and heated to 150 to 280 ° C. while reducing the pressure as necessary. The produced water is distilled off to obtain a polyester having a hydroxyl group. The hydroxyl value of the polyester is preferably 5 or more, and the acid value of the polyester is usually 1 to 30, preferably 5 to 20. By giving an acid value, the toner tends to be negatively charged, and further, when fixing to a recording paper, the affinity between the recording paper and the toner is good and the low-temperature fixability is improved. However, when the acid value exceeds 30, there is a tendency to deteriorate with respect to the stability of charging, particularly environmental fluctuation.

  The weight average molecular weight is 10,000 to 400,000, preferably 20,000 to 200,000. A weight average molecular weight of less than 10,000 is not preferable because offset resistance deteriorates. On the other hand, if it exceeds 400,000, the low-temperature fixability is deteriorated.

  In addition to the unmodified polyester obtained by the above polycondensation reaction, the polyester preferably contains a urea-modified polyester. The urea-modified polyester is obtained by reacting a terminal carboxyl group or hydroxyl group of the polyester obtained by the above polycondensation reaction with a polyvalent isocyanate compound (PIC) to obtain a polyester prepolymer (A) having an isocyanate group. It is obtained by cross-linking and / or extending the molecular chain by the reaction of the amine with amines.

  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] exceeds 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 urea-modified polyester is produced by a one-shot method or the like. Polyhydric alcohol (PO) and polyvalent carboxylic acid (PC) are heated to 150-280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate, dibutyltin oxide, etc., and water generated while reducing the pressure as necessary. Distill off to obtain a polyester having a hydroxyl group. Subsequently, at 40-140 degreeC, this is made to react with polyvalent isocyanate (PIC), and the polyester prepolymer (A) which has an isocyanate group is obtained. Further, this (A) is reacted with amines (B) at 0 to 140 ° C. to obtain a urea-modified polyester.

  When reacting (PIC) and when reacting (A) and (B), a solvent may be used if necessary. Usable solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And those inert to isocyanates (PIC), such as tetrahydrofuran (such as tetrahydrofuran).

  In addition, in the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B), a reaction terminator can be used as necessary to adjust the molecular weight of the resulting urea-modified polyester. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).

  The weight average molecular weight of the urea-modified polyester is usually 10,000 or more, preferably 20,000 to 10,000,000, and more preferably 30,000 to 1,000,000. If it is less than 10,000, the hot offset resistance deteriorates. The number average molecular weight of the urea-modified polyester or the like is not particularly limited when the above-mentioned unmodified polyester is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. When the urea-modified polyester is used alone, its number average molecular weight is usually 2000-15000, preferably 2000-10000, more preferably 2000-8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color apparatus are deteriorated.

  By using the unmodified polyester and the urea-modified polyester in combination, the low-temperature fixability and the gloss when used in the full-color image forming apparatus 100 are improved. Therefore, it is preferable to use the urea-modified polyester alone. The unmodified polyester may include a polyester modified with a chemical bond other than a urea bond.

  The unmodified polyester and the urea-modified polyester are preferably at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Therefore, it is preferable that the unmodified polyester and the urea-modified polyester have a similar composition.

  The weight ratio of unmodified polyester to urea-modified polyester is usually 20/80 to 95/5, preferably 70/30 to 95/5, more preferably 75/25 to 95/5, and particularly preferably 80 /. 20-93 / 7. When the weight ratio of the urea-modified polyester 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 glass transition point (Tg) of the binder resin containing unmodified polyester and urea-modified polyester is usually 45 to 65 ° C, preferably 45 to 60 ° C. If it is less than 45 ° C., the heat resistance of the toner deteriorates, and if it exceeds 65 ° C., the low-temperature fixability becomes insufficient.

  In addition, since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the heat-resistant storage stability tends to be good even when the glass transition point is low as compared with known polyester-based toners.

(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 together 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 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 developer fluidity 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 and 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 preferred. 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).

  In addition, examples of the cationic surfactant include aliphatic quaternary ammonium salts such as aliphatic primary, secondary or secondary amine acids having a fluoroalkyl group, and perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salts. , Benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (manufactured by Asahi Glass), Florard FC-135 (manufactured by Sumitomo 3M), Unidyne DS-202 (Daikin Industries) Manufactured), MegaFuck F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products Co., Ltd.), Footgent F-300 (Neos Co., Ltd.), 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.

  The toner according to the present invention has a substantially spherical shape and can be represented by the following shape rule. FIG. 7 is a diagram schematically showing the shape of the toner of the present invention. In FIG. 7, 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. Ratio (r2 / r1) (see FIG. 7B) is 0.5 to 1.0, and the ratio of thickness to minor axis (r3 / r2) (see FIG. 9C) is 0.7 to 1.0. It is preferable to be in the range of 1.0. 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.

  In other words, as described above, in order to prevent erroneous detection due to scratches and dirt on the belt surface, the pattern of each color toner for alignment is directly transferred from a plurality of image carriers onto the transfer belt (or intermediate transfer belt). And a means for storing the position of the belt in a transfer device that irradiates light from the sensor to each color pattern transferred onto the belt, detects the pattern of each color by the reflected light, and performs some correction of each color; In a transfer device having means and mode for checking the belt surface condition, if noise (abnormal part) exists on the surface check sensor, the correction pattern is created by avoiding the abnormal part, and the belt is added to the correction pattern group. It is possible to prevent erroneous detection due to mixing of scratches and dirt on the surface.

  In addition, in order to prevent erroneous determination due to sudden false detection, if the abnormal part is determined as an abnormal part only when it is periodic, error determination due to noise can be prevented and abnormal In order to prevent erroneous detection of a location as an alignment correction pattern, if there are a plurality of abnormal locations and the interval is L1, if the alignment correction pattern length L is L> La, alignment correction is performed. If L <La, and if the alignment correction is executed within the interval of the abnormal part, it is possible to reliably prevent erroneous correction due to erroneous detection.

  Furthermore, in order to prevent erroneous detection of an abnormal part as a registration correction pattern, when there are a plurality of abnormal parts and the interval is L1, the correction pattern length is set to L1 or less, and the positions between the abnormal parts are By performing the alignment correction, it is possible to reliably prevent erroneous correction due to erroneous detection. Also, in order to prevent erroneous correction due to erroneous detection, if there are multiple abnormal parts and the distance between abnormal parts is shorter than the correction pattern length, if the correction is not performed, the correction amount will be inappropriate due to erroneous detection. Can be reliably prevented.

  Furthermore, in order to prevent erroneous correction due to erroneous detection, if there is an abnormal location, the correction pattern and its position match, and if the correction amount calculated and determined there is excluded, the correction amount is incorrect. It is possible to reliably prevent improperness due to detection and to perform correction within a possible range. Minimize the time required to start the next printing operation. (To prevent the first print time from being delayed, if there is an abnormal part, you can move the abnormal part to a specific position and stop the belt. No need to change.

  Also, if the output image is strange, if a means for notifying some abnormality is provided, the person who has repaired will be able to grasp the cause immediately.

  If the transfer device as described above is used, an image with good image quality can be formed as a color image forming device, and printing with higher image quality can be achieved by using a transfer device with high alignment accuracy.

1 is a schematic configuration diagram of a laser printer according to an embodiment of the present invention. 1 is an enlarged view showing a schematic configuration of a transfer unit of the apparatus of FIG. Schematic of sensor and sensor facing part in the apparatus of FIG. The figure which shows an example of the pattern group for position correction Diagram showing an example of sensor output waveform The figure which represented the shape of the toner typically in order to explain shape factor SF-1 and shape factor SF-2 The figure which shows the shape of the toner of this invention typically

Explanation of symbols

1Y, 1M, 1C, 1K: toner image forming unit 2: optical writing unit 3, 4: paper feeding cassette 5: registration roller pair 6: transfer unit 7: fixing unit 8: paper discharge tray 9: transfer bias power supply 10: photosensitive Body units 11Y, 11M, 11C, 11K: photosensitive drum 60: transfer conveyor belts 61-68: support roller 80: electrostatic adsorption roller 80a: power supply 90: entrance roller bracket 91: shaft 92: pin 93: swing bracket 94 : Rotating shaft 95: hole 96: cam 97: cam shaft 98: outlet bracket 99: shaft 100: transfer paper A: belt running direction B: first paper discharge direction C: second paper discharge direction S: space MF : Manual feed tray G: Switching guide Sr: Sensor

Claims (14)

A pattern of toner of each color for alignment is directly transferred from a plurality of image carriers onto a transfer belt or an intermediate transfer belt, light is irradiated from the sensor to the pattern of each color transferred onto the belt, and the reflected light A transfer device that detects a pattern of each color and performs some correction on each color, the means for storing the position of the belt, the surface check means for checking the surface condition of the belt, and the control for controlling the operation of the apparatus A transfer device comprising:
When the surface check means detects that noise (abnormal part) exists on the belt, the control means avoids the abnormal part and creates the corrected pattern. . 2. The transfer apparatus according to claim 1, wherein the determination of the abnormal part by the control means is an abnormal part only when it is periodic. 3. The transfer device according to claim 1, wherein when there are a plurality of the abnormal portions and the interval is La, the control unit is configured such that the length L of the pattern for alignment correction satisfies L> La. If there is no alignment correction, if there is L <La, the alignment correction is executed within the interval of the abnormal part. 3. The transfer device according to claim 1, wherein when there are a plurality of the abnormal portions and the interval is L <b> 1, the control unit sets the length of the pattern for alignment correction to L <b> 1 or less, and A transfer apparatus that performs alignment correction between the abnormal portions. 5. The transfer device according to claim 1, wherein the correction is not performed when there are a plurality of the abnormal portions and a distance between the abnormal portions is shorter than the corrected pattern length. 6. Transfer device. 6. The transfer apparatus according to claim 5, wherein means for notifying abnormality is provided. 3. The transfer device according to claim 1, wherein when the abnormal portion exists, the correction pattern is calculated and determined by the control unit when the position of the correction pattern coincides with the position thereof. Is a transfer device characterized in that it is excluded. 3. The transfer device according to claim 1, wherein, when the abnormal portion exists, the control unit moves the abnormal portion to a specific position and stops the belt. 4. An image forming apparatus using the transfer device according to claim 1. 10. The image forming apparatus according to claim 9, wherein the toner used in the developing unit has a volume average particle diameter of 3 to 8 μm, and a ratio (Dv) of the volume average particle diameter (Dv) to the number average particle diameter (Dn). / Dn) is in the range of 1.00 to 1.40. 11. The image forming apparatus according to claim 9, wherein the toner used in the developing unit has a shape factor SF-1 in the range of 100 to 180 and a shape factor SF-2 in the range of 100 to 180. An image forming apparatus. 12. The image forming apparatus according to claim 9, wherein the toner used in the developing unit contains at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent. An image forming apparatus, which is a toner obtained by crosslinking and / or stretching reaction of a toner material liquid dispersed in a solvent in an aqueous medium. 13. The image forming apparatus according to claim 9, wherein the toner used in the developing unit has a substantially spherical shape. 14. The image forming apparatus according to claim 9, wherein the shape of the toner is defined by a major axis r1, a minor axis r2, and a thickness r3 (where r1 ≧ r2 ≧ r3), and a major axis r1. And the ratio (r2 / r1) of the minor axis r2 is in the range of 0.5 to 1.0, and the ratio of the thickness r3 to the minor axis r2 (r3 / r2) is in the range of 0.7 to 1.0. And an image forming apparatus.