JP2005091798A - Cleaning device, process cartridge, image forming apparatus, and toner used for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning device which improves cleaning performance without increasing the rotational driving load of an image carrier etc., maintains the good cleaning performance for a long period of time even in the case of using a polymerized toner and in which the margin of layout is improved. <P>SOLUTION: The cleaning device for cleaning the surface of the image carrier for carrying a toner image has an electrostatic cleaning member for at least electrostatically removing the toner on the surface of the image carrier and the electrostatic cleaning member consists of a belt supported and stretched by and between a plurality of supporting members. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cleaning device mounted on an image forming apparatus using an electrophotographic process such as a copying machine, a printer, and a facsimile, and more particularly to a cleaning device in an image forming apparatus that provides toner with a high degree of circularity for development.

Currently, in order to improve the image quality, the toner is reduced in particle size and increased in circularity. Since toners manufactured by the pulverization method have limitations in these characteristics, polymerized toners manufactured by a suspension polymerization method, an emulsion polymerization method, a dispersion polymerization method, etc. capable of reducing the particle size and increasing the circularity are available. It is being adopted.
In general, it is known that toner having a high degree of circularity has poor cleaning properties. This is due to the fact that in a conventional rubber blade that has been used as a cleaning means when pulverized toner is used, the toner rolls without being caught by the blade edge, and thus the blade is easy to slip through. In particular, some toners produced by the polymerization method are close to true spheres (average circularity of 0.98 or more), and are difficult to clean by the above blade cleaning method.

  The following proposals have been made as cleaning methods when using toner with a high degree of circularity. In this method, a bias having a polarity opposite to the charging polarity of the toner is applied to the brush roller to electrostatically remove the toner from the image bearing member (see, for example, Patent Document 1). However, even if the toner remaining on the image bearing member can be electrostatically transferred to the brush roller, it is difficult to remove all of the toner, including the toner interposed between the fibers of the brush roller. Therefore, there is a problem that the brush roller is gradually soiled with toner and the ability to remove it from the image carrier is reduced.

  As another proposal, there is a method of removing toner by bringing a roller into contact with an image carrier (see Patent Document 2). By using a roller as the removing means, there is no toner intervening between the fibers like the brush roller. For example, if the scraper is brought into contact with the roller surface and the removal performance of the toner adhering to the roller surface is maintained, In particular, it can be expected that the removal capability does not decrease. However, when trying to obtain the nip width of the roller to the image carrier, the amount of the roller biting into the image carrier may have to be increased due to the outer diameter of the image carrier and the outer diameter of the roller. In this case, there is a problem that the rotational driving load of the image carrier and the roller is significantly increased.

JP-A-8-248849 JP 2002-23421 A

  In view of the above problems, the present invention improves the cleaning performance without increasing the rotational driving load of the image carrier and the like, and can maintain good cleaning performance over a long period of time even when polymerized toner is used. It is an object of the present invention to provide a cleaning device having an improved layout margin. In addition, a process cartridge and an image forming apparatus including the cleaning device are provided. Furthermore, the present invention provides toner that is suitably used in the process cartridge and the image forming apparatus.

In order to solve the above problems, the present invention is characterized by the following.
1. The present invention is a cleaning device for cleaning the surface of an image carrier that carries a toner image, and has an electrostatic cleaning member that at least electrostatically removes toner on the surface of the image carrier, In this cleaning device, the target cleaning member comprises a belt supported and stretched by a plurality of support members.
2. The belt includes a first pressing member on the back side of the belt so that the belt can be pressed against the surface of the image carrier to form a nip.
3. The first pressing member has a rotatable roller shape.
4). The first pressing member is conductive and is biased.

5). The belt is driven to rotate so as to move in the forward direction with respect to the moving direction of the image carrier on the surface facing the image carrier.
6). The linear velocity of the belt is substantially the same as the linear velocity of the image carrier.

7). The belt includes a removing member that removes toner adhering to the belt surface.
8). The removal member is a hard blade.
9. The belt includes a second pressing member on the back side of the belt so as to face the removing member.
10. The second pressing member has a rotatable roller shape.
11. The second pressing member is an elastic roller.
12 The elastic roller has an Asker C hardness of 20 to 60 °.
13. The second pressing member is conductive and is connected to ground.

14 According to another aspect of the present invention, there is provided a process cartridge that is integrally supported and includes at least an image carrier that carries a latent image and a cleaning unit that cleans the surface of the image carrier, and is detachably formed on the main body of the image forming apparatus. The cleaning means is a process cartridge which is any one of the cleaning devices.

15. The present invention also provides an image carrier that carries a latent image, a charging unit that uniformly charges the surface of the image carrier, and the surface of the charged image carrier that is exposed based on image data to obtain a latent image. An exposure means for writing, a developing means for supplying toner to the latent image formed on the surface of the image carrier to make it visible, and a transfer means for transferring the visible image on the surface of the image carrier to a transfer medium; The image forming apparatus includes a cleaning unit that cleans the surface of the image carrier after the transfer. The cleaning unit is an image forming apparatus that is any one of the cleaning devices.

16. The toner used in the developing means is composed of at least a colorant and a binder resin, and has an average circularity of 0.93 or more.
17. The toner used in the developing unit has a volume average particle diameter of 3 to 8 μm and a ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) of 1.00 to 1.n. It is characterized by being in the range of 40.
18. 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.

19. The toner used in the developing means includes a toner material liquid in which at least a polyester prepolymer having a functional group containing a nitrogen atom, polyester, a colorant, and a release agent is dispersed in an organic solvent in an aqueous medium. It is a toner obtained by crosslinking and / or elongation reaction.
20. The toner used in the developing unit has a substantially spherical shape.
21. The shape of the toner used in the developing unit is defined by the major axis r1, the minor axis r2, and the thickness r3 (where r1 ≧ r2 ≧ r3), and 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 (r3 / r2) of the thickness r3 to the minor axis r2 is in the range of 0.7 to 1.0. .

22. The present invention also provides a toner used in a development process of an electrophotographic process, the toner being used in the image forming apparatus, comprising at least a colorant and a binder resin, and having an average circularity. Is a toner whose toner is 0.93 or more.
23. The toner 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.
24. The toner has a volume average particle diameter of 3 to 8 μm and a ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is in the range of 1.00 to 1.40. It is characterized by.
25. In the toner, a toner material liquid in which at least a polyester prepolymer having a functional group containing a nitrogen atom, polyester, a colorant, and a release agent is dispersed in an organic solvent is crosslinked and / or extended in an aqueous medium. It is characterized by being obtained.

  According to the present invention, it is possible to provide a cleaning device that can improve cleaning performance and maintain good cleaning performance over a long period of time even when polymerized toner is used. In addition, the layout margin in the apparatus is improved. Furthermore, by providing the cleaning device of the present invention, it is possible to provide a process cartridge and an image forming apparatus that do not generate an abnormal image due to poor cleaning of the image carrier.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of an image forming apparatus according to the present invention. Here, a full-color copying machine will be described as an example.
The image forming apparatus 100 includes an image forming unit 300, a paper feeding unit 200, a document reading unit 400, and a document conveying unit 500. The image forming unit 300 includes an image forming unit 10, an exposure unit 3, a transfer unit 5, and a fixing unit 7.
The image forming unit 10 includes four units in parallel for forming four color toner images of black (K), cyan (C), magenta (M), and yellow (Y). Photosensitive members 1K, 1C, 1M, and 1Y are provided at the center of each image forming unit 10, and a charging unit, a developing unit, and a cleaning unit are provided around it.
The exposure unit 3 converts data read by the document reading unit 400 or an image signal sent from the outside such as a personal computer (not shown), scans the laser beam with a polygon motor, and based on the image signal read through the mirror. An electrostatic latent image is formed on the photoreceptor 1.
The transfer unit 5 includes an intermediate transfer belt 50 that sequentially superimposes and holds toner images formed on the respective photoreceptors 1. The color toner image formed on the intermediate transfer belt 50 is recorded on the recording paper. It is configured to transfer to. In addition, the recording paper may be conveyed by a transfer conveyance belt, and the toner image formed on each photoconductor 1 may be directly transferred to the recording paper.
The fixing unit 7 includes a belt stretched around a roller having a halogen heater and the like, and a pressure roller. The fixing unit 7 applies heat and pressure to the toner on the recording paper at a nip formed by both. Fix the toner image. In addition, a pair of rollers or a pair of belts may be used.
In addition to this, the image forming apparatus 100 includes a double-sided reversing unit 9, a paper discharge tray 8, and the like.

FIG. 2 is an enlarged view showing the image forming unit 10 of FIG.
The photoconductor 1 can be made of amorphous metal having photoconductivity, amorphous metal such as amorphous selenium, or organic compound such as bisazo pigment or phthalocyanine pigment. In consideration of environmental problems and post-treatment after use, an OPC photoreceptor using an organic compound is preferable.
The charging means 2 may be any one of a corona method, a roller method, a brush method, and a blade method. Here, the roller-type charging device 2 is shown. The charging unit 2 includes a charging roller 2a, a charging roller cleaning member 2b in contact with the charging roller 2a for cleaning, and a power source (not shown) connected to the charging roller 2a. A high voltage is applied to the charging roller 2a to generate corona discharge with the photosensitive member 1 to uniformly charge the surface of the photosensitive member 1.
The developing unit 4 includes a developer carrying member 4a that carries a developer and supplies it to the photosensitive member 1, a toner supply chamber 4b, and the like. The developer carrier 4a includes a hollow cylindrical developer carrier 4a that is rotatably supported, and a magnet roll fixed coaxially with the developer carrier 4a. The developer is magnetically attracted to the outer peripheral surface of the carrier 4a and conveyed. The developer carrier 4a is electrically conductive and is made of a nonmagnetic member, and is connected to a power source (not shown) for applying a developing bias. A voltage is applied from the power source between the developer carrying member 4a and the photoreceptor 1, and an electric field is formed in the developing region.
A primary transfer unit 51 is provided at a position facing the photoreceptor 1 with the intermediate transfer belt 50 interposed therebetween. The primary transfer means 51 is connected to a power source (not shown), and a voltage is applied when transferring the toner image on the photoreceptor 1 to the intermediate transfer belt 50, so that an electric field is generated between the photoreceptor 1 and the intermediate transfer belt 50. The toner image is transferred electrostatically.

  The cleaning device of the present invention will be described with reference to FIG. The cleaning device 6 includes a cleaning blade 61 in contact with the photoconductor 1, and includes an electrostatic cleaning member 67 on the upstream side of the cleaning blade 61 in the rotation direction of the photoconductor 1. The toner remaining on the photoreceptor 1 after the primary transfer is first collected from the photoreceptor 1 by the electrostatic cleaning member 67. Subsequently, lubricant fine particles are supplied onto the photoreceptor 1 by, for example, a lubricant application unit (not shown), and toner, filming, and the like remaining on the photoreceptor 1 are finally scraped off by the cleaning blade 61.

As the electrostatic cleaning member 67, various means such as a rubber blade and a fur brush can be applied. As shown in FIG. 2, the means for efficiently removing the toner without damaging the surface of the photoreceptor 1 is shown. In addition, a conductive belt 67 supported and stretched by a plurality of support members 65, 68 and 69 is used. Support members 68 and 69 provided on the back side of the belt 67 serve to press the belt 67 against the surface of the photoreceptor 1 and form a nip. By arranging the support members 68 and 69 so as to contact the photoreceptor 1 in this way, a nip can be formed without causing the belt 67 as an electrostatic cleaning member to bite the photoreceptor 1 more than necessary. The load torque for rotationally driving the photoreceptor 1 and the belt 67 can be reduced. Further, the use of a flexible member such as the belt 67 can improve the margin of the layout in the apparatus.
Hereinafter, the support member 69 is referred to as an entrance roller, and the support member 68 is referred to as an exit roller.

  In order to efficiently collect the toner from the surface of the photoreceptor 1 to the belt 67, the entrance roller 69 and the exit roller 68 are formed of a conductive material, the entrance roller 69 is grounded, and the exit roller 68 is connected to a power source (not shown). It is preferable that a bias having a polarity opposite to that of the toner is applied. As a result, the toner on the surface of the photoreceptor 1 can be electrostatically collected on the belt 67 without requiring any pressing force. The applied bias is preferably a direct current or a bias in which an alternating current is superimposed on a direct current. Further, the magnitude of the bias is set to be equal to or lower than the discharge start voltage.

  The belt 67 is rotationally driven on the surface facing the photoreceptor 1 so as to move in the forward direction with respect to the moving direction of the photoreceptor 1. The linear velocity of the belt 67 is preferably substantially the same as the linear velocity of the photoreceptor 1. By rotating in this way, damage to the surface of the photoreceptor 1 due to contact between the belt 67 and the photoreceptor 1 can be reduced.

Further, a hard blade 66 is provided in contact with the surface of the belt 67 as a removing member for removing the toner adhering to the belt 67. The support member 65 located on the back side of the belt 67 serves to press the belt 67 against the hard blade 66 while facing the hard blade 66.
The support member 65 is preferably an elastic roller, and an elastic layer made of a rubber material having an Asker C hardness of 20 ° to 60 ° and a volume resistivity of 1 × 10 ³ to 1 × 10 ⁸ Ω · cm is provided around the core metal. Configured. If the hardness is in the above range, the toner adhering to the surface of the belt 67 is easily scraped off by the hard blade 66.

  The hard blade 66 that scrapes off the toner adhering to the surface of the belt 67 is preferably a metal material having high hardness and non-magnetic properties and low electrical resistance, and SUS is particularly preferable. In this embodiment, a SUS plate having a thickness of 0.1 mm, which can cope with a case where the layer thickness of the input toner is large, is used.

  Since the hard blade 66 contacts, the elastic roller 65 preferably has the following configuration. FIG. 3 is a diagram showing the configuration of the elastic roller 65. The elastic roller 65 has a structure in which an elastic layer 65b is provided on a core metal 65a. Since the elastic layer 65b is intended to have an elastic function, a conductive material such as polyurethane rubber, which is a continuous pore porous body, is desirable. Further, when the core metal 65 a is connected to the ground, the charge of the toner is reduced and is easily removed by the hard blade 66.

  On the other hand, since the belt 67 needs to not stretch even when subjected to mechanical stress by the hard blade 66, a material having low stretchability is desirable, and in addition, polyimide or the like is desirable from the viewpoint of wear resistance. Further, a resistance control material such as carbon black may be mixed with these, or a lubricant for reducing the coefficient of friction against the hard blade 66 may be mixed.

  FIG. 4 is an enlarged view showing a contact portion of the belt 67, the elastic roller 65, and the hard blade 66. At the contact portion between the elastic roller 65 and the hard blade 66, the elastic roller 65 is deformed. As a result, no gap is generated even when the hard blade 66 is brought into contact, and since it is the hard blade 66, the blade edge is not deformed and the toner does not slip through. Further, when a SUS plate having a thickness smaller than that of a normally used rubber blade is used as the blade as in this embodiment, the force F with which the toner pushes the blade is also reduced. In addition, since the rigidity of the blade with respect to the force F is higher in the hard blade than in the rubber blade, the toner is more difficult to slip through. As a result, the belt 67 can always be brought into contact with the photoreceptor 1 with the surface thereof being clean, so that the toner recovery capability is not lowered.

  The cleaning device 6 of the present invention described above can be a process cartridge that is integrally supported with the photoreceptor 1 and is detachably formed on the main body of the image forming apparatus. In addition to this, the process cartridge may include a charging unit 2 and / or a developing unit 4. With this process cartridge, even in an image forming process in which the average circularity is high and development using a toner having a small particle diameter is performed, the cleaning on the photoreceptor 1 is improved and the image quality is deteriorated. It is possible to make the process cartridge without any. Further, since the cleaning function can be maintained for a long time, the life of the process cartridge is also improved. Furthermore, the maintenance of the image forming apparatus is improved by integrally forming the plurality of means as described above.

The image forming apparatus that can obtain the effect of mounting the cleaning device 6 of the present invention is a case where the toner used in the developing unit 4 is a toner having a high degree of circularity with an average circularity of 0.93 or more. Toner with a high degree of circularity enters the gap between the photosensitive member 1 and the cleaning blade during blade-type cleaning, and easily slips through. Increasing the contact pressure of the cleaning blade against the photosensitive member 1 increases the damage to the photosensitive member 1. Also, in the method of electrostatically collecting toner by applying a bias reverse to the charging polarity of the toner to the brush roller, it is difficult to remove the toner from the brush roller. There is a tendency that the toner removing ability is lowered.
However, even when the above-described toner having a high average circularity is used, the surface of the photoreceptor 1 can be efficiently cleaned as follows by the cleaning device 6 of the present invention. That is, the residual toner on the photoreceptor 1 is first electrostatically recovered by the belt 67 which is an electrostatic cleaning member, and then the residual toner is finally scraped off and removed by the cleaning blade 61. Cleaning can be performed efficiently without damaging the surface of the photoreceptor 1.

  The average circularity of the toner is a value obtained by dividing particles by the circumference of an equivalent circle having the same projected area after optically detecting particles. 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 concentration and dispersion of the dispersion are set to 3,000 to 10,000 / μL, and the shape and distribution of the toner are measured.

The toner is also suitable for cleaning toner having a nearly spherical shape. The spherical toner can be defined by the values of the following shape factors SF-1 and SF-2. The toner used in the image forming apparatus is a toner having a shape factor SF-1 of 100 to 180 and a shape factor SF-2 of 100 to 180.
FIG. 5 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) Formula (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} × (100π / 4) (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.
When the shape of the toner is close to a spherical shape, the contact between the toner and the toner or the toner and the photoreceptor 1 is close to a point contact, so that the adsorbing force between the toners is weakened and the fluidity is increased. The attracting force with the body 1 is also weakened, and the transfer rate is increased. On the other hand, as described above, the spherical toner is liable to cause a cleaning failure in the blade-type cleaning, but can be satisfactorily cleaned by the cleaning device 6 of the present invention.
If SF-1 and SF-2 are increased, toner is scattered on the image and the image quality is lowered. Therefore, it is preferable that SF-1 and SF-2 do not exceed 180.

  The volume average particle diameter of the toner is 3 to 8 μm, and the ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is in the range of 1.00 to 1.40. Even when a toner having a small particle size and a narrow particle size distribution is used, good cleaning properties can be obtained. By narrowing the particle size distribution of the toner, the charge amount distribution becomes uniform, a high-quality image with little background fogging can be obtained, and the transfer rate can be increased. It is difficult to clean such a small particle size toner by overcoming the adhesion force with the photoreceptor 1 by the conventional blade type cleaning. However, with the cleaning device 6 of the present invention, the remaining toner on the surface of the photoreceptor 1 can be recovered electrostatically and efficiently by the belt 67, and the cleaning performance can be maintained for a long time.

  The toner used in the image forming apparatus of the present invention is preferably 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 dispersed in an organic solvent. It is a toner obtained by crosslinking and / or extending the liquid in an aqueous solvent. Hereinafter, preferable constituent materials and manufacturing methods of the toner will be described.

(Modified polyester)
The toner of 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 to 2 μm, and particularly preferably 5 × 10 −3 to 0.5 μm. 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 size 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, a fluidity-imparting agent is not detached from the toner, a good image quality that does not cause fireflies and the like is obtained, and a reduction in residual toner is further achieved. .
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 salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride, fatty acid amide derivatives, polyhydric alcohols 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).

  Further, as the cationic surfactant, 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), Footgent 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 spherical shape and the spindle shape can be controlled, and the surface morphology is also controlled between the smooth shape and the umeboshi shape. Can do.

The toner according to the present invention has a substantially spherical shape and can be represented by the following shape rule.
FIG. 6 is a diagram schematically showing the shape of the toner of the present invention. In FIG. 6, 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. 6B) is 0.5 to 1.0, and the ratio of thickness to minor axis (r3 / r2) (see FIG. 6C) 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.

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.
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, A volume average particle size of 20 to 100 μm is preferred. 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 its high saturation magnetization, but can be appropriately selected according to the process of the image forming apparatus 100. 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.

1 is a diagram illustrating a schematic configuration of an image forming apparatus according to the present invention. FIG. 2 is an enlarged view showing an image forming unit in FIG. 1. It is a figure which shows the structure of the toner removal member with which the cleaning apparatus was equipped. It is a figure which expands and shows the contact part of a hard blade. 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 a toner shape.

Explanation of symbols

1 Image carrier (photoreceptor)
2 Charging means 3 Exposure means
DESCRIPTION OF SYMBOLS 4 Developing means 5 Transfer means 50 Intermediate transfer belt 51 Primary transfer means 6 Cleaning device 61 Cleaning blade 65 Elastic roller 65a Core metal 65b Elastic layer 66 Hard blade 67 Electrostatic cleaning member (belt)
69 exit roller 68 entrance roller 7 fixing means 100 image forming apparatus

Claims (25)

  A cleaning device for cleaning the surface of an image carrier that carries a toner image, comprising: an electrostatic cleaning member that at least electrostatically removes toner on the surface of the image carrier, wherein the electrostatic cleaning member A cleaning device comprising a belt supported and stretched by a plurality of support members.   2. The cleaning device according to claim 1, wherein the belt includes a first pressing member on a back surface side of the belt so that the belt can be pressed against the surface of the image carrier and a nip can be formed. apparatus.   The cleaning device according to claim 2, wherein the first pressing member has a rotatable roller shape.   The cleaning apparatus according to claim 3, wherein the first pressing member is conductive, and a bias is applied thereto.   5. The cleaning device according to claim 1, wherein the belt is rotationally driven so as to move in a forward direction with respect to a moving direction of the image carrier on a surface facing the image carrier. Cleaning device to do.   6. The cleaning device according to claim 5, wherein the linear velocity of the belt is substantially the same as the linear velocity of the image carrier.   The cleaning device according to claim 1, wherein the belt includes a removing member that removes toner attached to the belt surface.   8. The cleaning device according to claim 7, wherein the removing member is a hard blade.   9. The cleaning device according to claim 7, wherein the belt includes a second pressing member on a back surface side of the belt so as to face the removing member.   The cleaning device according to claim 9, wherein the second pressing member has a rotatable roller shape.   The cleaning device according to claim 10, wherein the second pressing member is an elastic roller.   12. The cleaning device according to claim 11, wherein the elastic roller has an Asker C hardness of 20 to 60 [deg.].   13. The cleaning device according to claim 9, wherein the second pressing member is conductive and connected to ground.   In a process cartridge that is integrally supported and includes at least an image carrier that carries a latent image and a cleaning unit that cleans the surface of the image carrier and is detachably formed on the image forming apparatus main body, the cleaning unit includes: A process cartridge which is the cleaning device according to claim 1.   An image carrier that carries a latent image; a charging unit that uniformly charges the surface of the image carrier; an exposure unit that exposes the charged surface of the image carrier based on image data and writes the latent image; Developing means for supplying toner to the latent image formed on the surface of the image carrier to make it visible, transfer means for transferring the visible image on the surface of the image carrier to a transfer medium, and the image after transfer 14. An image forming apparatus comprising: a cleaning unit that cleans the surface of the carrier; and the cleaning unit is the cleaning device according to claim 1.   The image forming apparatus according to claim 15, wherein the toner used in the developing unit includes at least a colorant and a binder resin, and has an average circularity of 0.93 or more.   17. The image forming apparatus according to claim 15, wherein the toner used in the developing unit has a volume average particle diameter of 3 to 8 μm and a volume average particle diameter (Dv) and a number average particle diameter (Dn). An image forming apparatus having a ratio (Dv / Dn) in a range of 1.00 to 1.40.   18. The image forming apparatus according to claim 15, 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 characterized by being in a range.   19. The image forming apparatus according to claim 15, wherein the toner used in the developing unit includes 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 an organic solvent in an aqueous medium.   20. The image forming apparatus according to claim 15, wherein the toner used in the developing unit has a substantially spherical shape.   21. The image forming apparatus according to claim 20, wherein the shape of the toner used in the developing unit 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 0.7 to 1. An image forming apparatus in the range of 0.0.   A toner used in a developing step of an electrophotographic process, wherein the toner is used in the image forming apparatus according to claim 15 and includes at least a colorant and a binder resin, and has an average circularity. A toner having a viscosity of 0.93 or more.   23. The toner according to claim 22, wherein the toner 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.   24. The toner according to claim 22, wherein the toner has a volume average particle diameter of 3 to 8 μm and a ratio (Dv / Dn) of volume average particle diameter (Dv) to number average particle diameter (Dn) of 1. A toner in the range of 0.001 to 1.40.   The toner according to any one of claims 22 to 24, wherein the toner is a toner 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 extending a material solution in an aqueous medium.

Images