JP2005121760A - Cleaning device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning device which can efficiently and stably apply a lubricant over time to realize a long life of a photoreceptor and a cleaning blade and which can stabilize the cleaning quality over time even when a polymerization toner is used, to provide a process cartridge and an image forming apparatus using the above device, and to provide toner to be used therefor. <P>SOLUTION: The cleaning device works to remove a developer remaining on the surface of an image carrier and is equipped with a mechanism of rubbing a solid lubricant 312 with a brush 311 and touching and applying the lubricant onto the image carrier so as to decrease the coefficient of friction on the surface of the image carrier. The brush 311 rotates in the same direction as that of the image carrier at the contact point with the image carrier. The cleaning device is equipped with a blade 314 in the downstream side along the rotation direction of the image carrier from the contact point between the brush 311 and the image carrier. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cleaning device in an electrophotographic process such as an electrostatic copying machine and a printer, a process cartridge using the same, an image forming apparatus, and a toner used in these.

  In general, a photoreceptor, which is an electrophotographic image carrier, undergoes repeated processes of charging, exposure, development, transfer, cleaning, and charge removal (or charge removal and cleaning) in an image forming process. The electrostatic latent image formed by charging and exposure is visualized by a developer containing toner and becomes a toner image. Further, the toner image is transferred onto a transfer material such as paper by a transfer unit, but not all the toner is transferred, and a part of the toner image remains on the photoreceptor. If this residual toner is not removed, a high-quality image free from stains cannot be obtained in the repeated process. Therefore, it is necessary to clean the residual toner. As the cleaning means, those using a fur brush, a magnetic brush, a blade, and the like are typical, but blade cleaning is mainly employed from the viewpoint of cleaning accuracy and apparatus configuration.

The blade cleaning will be described with reference to a specific example in FIG. As shown in FIG. 5, the blade has a structure in which an elastic member made of a material such as a plate-like polyurethane is attached to a support, and is brought into pressure contact with the surface of the photoreceptor. Further, the blades are brought into contact with the photosensitive member in the forward direction as shown in FIG. 5 (b) under the counter direction as shown in FIG. 5 (a) with respect to the rotational direction of the photosensitive member. There is. There are many apparatuses that employ the former contact form in the counter direction because of the accuracy of cleaning.
Mechanical rubbing on the surface of the photoreceptor such as a cleaning blade leads to wear on the surface of the photoreceptor. When the surface of the photoconductor is worn, the photosensitivity deteriorates and adversely affects the formation of an appropriate electrostatic latent image.
Further, it is considered that the increase in the frictional force leads to the occurrence of toner fusing due to local edge chipping of the cleaning blade and an increase in the amount of heat generation.
Further, in order to cope with recent rapid colorization and high image quality associated therewith, small diameter and narrow particle size distribution and spheroidization (true sphere) using polymerized toner are becoming mainstream.
The distribution of toner with a small diameter and a narrow particle diameter is advantageous for high-resolution development, and the spheroidization (true sphere) is advantageous for transfer efficiency, and thereby the image quality such as the sharpness of the toner image is remarkably improved.
However, reducing the particle size of the toner increases the specific surface area and increases the adhesion force of the toner per unit weight to the surface of the photoconductor, which makes it difficult to clean the surface of the photoconductor. Further, the reduction in the toner particle size deteriorates the fluidity of the toner and requires a larger amount of additive, which easily causes chipping or abrasion of the cleaning blade, local streak scratches on the surface of the photoreceptor, and the like. It is known.
In addition, when the sphericity of the toner is increased, the above-described blade counter contact method generally used in the related art increases the amount of toner passing through the blade, so that it is necessary to increase the contact pressure more than before. Increasing the pressure reduces the margin against edge chipping due to the local shearing force of the blade.

From the above viewpoint, it is known that reducing the coefficient of friction on the surface of the photoconductor is effective in preventing the photoconductor from being worn, and it has been conventionally practiced to apply and supply a lubricant to the surface of the photoconductor. ing.
The lubricant applying means will be described with specific examples. A solid lubricant is provided in the casing of the cleaning device, and a brush roller is provided between the photosensitive member and the lubricant. The lubricant is scraped off by this brush roller and applied and transferred onto the photosensitive member. A method of applying a solid lubricant in direct contact with the surface of the photoreceptor is also known, but a means for applying via a brush or the like is preferable from the viewpoint of adjusting the coating amount and stability.
Conventionally, the above-described lubricant application brush has a function of collecting toner together with an application function. For this reason, as described in Patent Documents 1, 2, and 3, in terms of the function of collecting and removing toner from the photoconductor, it is preferable that the brush is in rotational contact with the photoconductor in the counter direction. This is because when the photoreceptor is viewed as brush flicker, the toner that peels off from the brush due to flickering is upstream in the rotational direction of the photoreceptor as viewed from the contact position between the photoreceptor and the brush in the case of contact in the counter direction. However, in the case of forward contact, the toner is blown to the downstream side in the rotation direction of the photosensitive member, which is not suitable for the function of collecting and removing toner.
Since the brush cleaning performance deteriorates unless the toner collected and removed by the cleaning brush is peeled off from the brush, flicker or the like is usually provided as means for peeling the toner from the brush.

However, when handling a toner having a small particle diameter, as described above, the adhesion of the toner to the surface of the photoconductor is increased, so that the cleaning performance of the surface of the photoconductor is reduced. Will decline. On the other hand, even when the toner can be collected and removed by the brush, it becomes difficult to efficiently remove the toner with a peeling means such as flicker, and the toner tends to accumulate in the brush over time.
In the conventional mechanism in which the cleaning brush is provided with a lubricant application function, the accumulated toner acts as an abrasive, which increases the amount of brush scraping off the solid lubricant described above, and further accumulates in the brush. When the toner and the lubricant are bonded, the application function to the photoreceptor is lowered. While trying to remove the lubricant and toner with the brush flicker described above, the efficiency of applying the lubricant to the photoreceptor is reduced, so the application efficiency with respect to the amount of lubricant consumed is reduced, and the lubrication is more than ever. It is necessary to prepare a large amount of the agent in the apparatus, and it becomes difficult to reduce the size and extend the life of the apparatus. Further, a lot of lubricant is mixed in the waste toner removed by the brush flicker, and the fluidity is extremely deteriorated, so that the waste toner is easily clogged.

Japanese Utility Model 07-073355 JP 2001-324907 A JP 2000-284526 A

  In view of the above problems, the present invention enables stable and efficient application of a lubricant over time, extends the life of a photoreceptor and a cleaning blade, and even when using polymerized toner, the quality of cleaning over time. It is an object of the present invention to provide a cleaning device capable of stabilizing the toner, a process cartridge using the same, an image forming apparatus, and a toner used in these.

In order to solve the above-mentioned problems, in the present invention, regarding the application of the lubricant, if the photosensitive member is considered as a flicker of the brush, the fine powder lubricant that peels off from the brush by the flicking is in order of contact between the photosensitive member and the brush. Because of the directional contact, the lubricant is blown to the downstream side in the rotation direction of the photosensitive member, and the application efficiency of the lubricant is remarkably increased as compared with the counter direction contact.
In addition, the toner attached to the brush is easily peeled off from the brush due to the effect of flicking, and due to the relationship between the amount of lubricant consumed and the amount applied, the contamination of the lubricant with the waste toner is reduced, and the toner is clogged due to the conveyance of the waste toner. The occurrence of quality problems over time such as the above can also be suppressed.
In recent years, it is difficult to produce a toner having a small particle size and a narrow particle size distribution by a pulverization method, and a polymerization method is usually employed. By this polymerization method, the toner is spheroidized (true sphere), so that the transfer efficiency from the photosensitive member to the transfer member can be remarkably improved. Therefore, the cleaning of the small-diameter, spherical toner to the transfer residual needs to collect a small amount of the transfer residual toner that is difficult to peel off, and therefore, a combination of a means for efficiently reducing the photoreceptor surface friction coefficient and blade cleaning is suitable.

In the present invention, in order to increase the efficiency of applying the lubricant by the brush described above, the lubricant is applied by rotating the brush in the forward direction with respect to the photoconductor, thereby enabling stable and efficient application of the lubricant over time. Thus, the life of the photosensitive member and the cleaning blade can be extended, and the cleaning quality over time can be stabilized.
In addition, as a means for applying the adhering lubricant onto the photoconductor, a blade is disposed downstream of the brush contact position in the rotation direction of the photoconductor, thereby filling the unevenness of the photoconductor and covering the photoconductor uniformly. Is obtained.

Accordingly, the present invention described in claim 1 is a cleaning device that removes the developer remaining on the surface of the image carrier, and includes a friction reducing means for reducing the friction coefficient of the surface of the image carrier, In the cleaning device in which the friction reducing means is a mechanism that rubs a solid lubricant with a brush and applies the contact to the image carrier, the brush rotates and rotates the image carrier at the contact position with the image carrier. A cleaning device that rotates in a direction.
According to a second aspect of the present invention, in the cleaning device according to the first aspect, a blade is provided downstream of the contact position between the brush and the image carrier in the image carrier rotation direction. is there.

According to a third aspect of the present invention, an image carrier that carries a latent image and a cleaning unit that cleans the surface of the image carrier after transfer are integrally supported and detachably attached to the main body of the image forming apparatus. In the process cartridge to be formed, the cleaning means is the cleaning device according to claim 1 or 2.
The invention according to claim 4 is an image carrier that carries a latent image, a charging means that uniformly charges the surface of the image carrier, and the surface of the charged image carrier is exposed based on image data, An exposure means for writing a latent image; 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; An image forming apparatus comprising: a cleaning unit that cleans the surface of the image carrier after the transfer. The cleaning unit is the cleaning device according to claim 1 or 2.
The present invention described in claim 5 is 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 is exposed based on image data, An exposure means for writing a latent image; 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; An image forming apparatus comprising the process cartridge according to claim 3, wherein the image forming apparatus includes a cleaning unit that cleans the surface of the image carrier after the transfer.

According to a sixth aspect of the present invention, in the image forming apparatus according to the fourth or fifth aspect, 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 the number average particle diameter (Dn) (Dv / Dn) is in the range of 1.00 to 1.40.
According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the fourth to sixth aspects, the toner used in the developing unit has a shape factor SF-1 in the range of 100 to 180, The image forming apparatus is characterized in that the shape factor SF-2 is in the range of 100 to 180.
According to an eighth aspect of the present invention, in the image forming apparatus according to any one of the fourth to seventh aspects, the toner used in the developing unit is a polyester prepolymer having at least a functional group containing a nitrogen atom, An image forming apparatus characterized by being a toner obtained by crosslinking and / or extending a toner material liquid in which polyester, a colorant, and a release agent are dispersed in an organic solvent in an aqueous medium.
According to a ninth aspect of the present invention, in the image forming apparatus according to any one of the fourth to eighth aspects, the toner used in the developing unit has a substantially spherical shape. is there.
According to a tenth aspect of the present invention, in the image forming apparatus according to the ninth aspect, 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 (r2 / r1) between the major axis r1 and the minor axis r2 is in the range of 0.5 to 1.0, and the ratio (r3 / r2) between the thickness r3 and the minor axis r2 is 0. An image forming apparatus characterized by being in the range of .7 to 1.0.

The present invention described in claim 11 is a toner that is used in a developing step of an electrophotographic process, and is used in the image forming apparatus according to claim 4 or 5, and has a volume average particle diameter of 3 to 8 μm, The toner is characterized in that 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.
According to a twelfth aspect of the present invention, in the toner according to the eleventh aspect, 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. The toner is characterized by the above.
According to a thirteenth aspect of the present invention, in the toner according to the eleventh or twelfth aspect, the toner contains at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent. A toner obtained by cross-linking and / or stretching reaction of a toner material liquid dispersed in a solvent in an aqueous medium.

  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. Further, 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.

The best mode for carrying out the present invention will be described below with reference to the drawings. The following description is an example of the best mode of the present invention, and it is easy for a person skilled in the art to make other embodiments within the scope of the claims by making changes and modifications within the scope of the claims. However, this does not limit the scope of the claims.
FIG. 1 is a schematic diagram showing the configuration of a full-color image forming apparatus according to the present invention. However, the functions and effects of the cleaning device, which is a feature of the present invention, and the monochrome image forming device are the same as long as the image forming device uses small diameter and spherical toner.
FIG. 2 is an overall schematic configuration diagram of an image forming system in which four image forming units of the image forming apparatus are juxtaposed.
In the image forming apparatus shown in FIG. 2, four image forming units yellow (Y) 1Y, cyan (C) 1C, magenta (M) 1M, and black (Bk) 1K are arranged in parallel, and the four image forming units. On the other hand, one intermediate transfer belt 501 and one paper transfer device 600 are provided.

FIG. 3 is a schematic configuration diagram illustrating a configuration example of the yellow image forming unit 1Y of the image forming apparatus.
When the image forming operation is started, in the yellow image forming unit 1Y shown in FIG. 3, the surface of the photosensitive member 101, which is an electrostatic latent image carrier, is uniformly charged by the charging device 201. An electrostatic latent image of a yellow component image of a full-color original is formed on the charged photoreceptor 101 by exposure from an optical writing device, and the electrostatic latent image is visualized with yellow toner by a yellow developing device 401. . Similar image forming operations are also performed in the cyan image forming unit, the magenta image forming unit, and the black image forming unit with a predetermined time difference, and toner images of cyan, magenta, and black colors are formed on the respective photoreceptors. . This intermediate transfer belt is used to superimpose toner images Y, C, M, and Bk formed on the photosensitive member at the respective image forming portions Y, C, M, and Bk as one full-color image on the intermediate transfer belt 501. A belt transfer roller 507 is disposed on the back surface side of the image forming unit 501 at a position opposed to the photosensitive member of each image forming unit, and a predetermined transfer bias is applied to the belt transfer roller 507 so that the toner images of each image forming unit are sequentially intermediated. The image is transferred onto the transfer belt 501 in a superimposed manner. Then, the toner image on the intermediate transfer belt 501 that has become one full-color image is transferred onto a transfer sheet that is conveyed in time with a sheet transfer roller to which a predetermined bias is applied.
Thereafter, the transfer paper is conveyed to a fixing device 700 shown in FIG. 2, heated and pressurized, and the toner image on the transfer paper is fixed and a full color image is output.

The photoreceptor of each image forming unit after transfer to the intermediate transfer belt is neutralized by the neutralizing device 901, and the residual toner is removed by the cleaning blade of the cleaning device 301 and charged by the above-described charging device. A series of image forming cycles is repeated.
The toner removed by the cleaning device 301 is transported to a waste toner storage tank through a waste toner transport path.

FIG. 4 is a diagram illustrating a configuration of a cleaning device that collects and removes residual toner on a photoconductor as an image carrier. Unless otherwise specified, other cyan image forming units, magenta image forming units, and black image forming units have the same configuration and operation.
As shown in FIGS. 4A and 4B, a cleaning device 301 according to the present invention removes a transfer residual toner and a mechanism constituted by a brush 311 and a lubricant 312 for applying a lubricant to a photoreceptor. And a blade mechanism 314.
In FIG. 4A, the brush roller 311 located upstream of the contact position between the photoconductor 101 and the cleaning blade 314 rotates in contact with the photoconductor 101 in the direction in which the photoconductor 101 rotates. Flicker 313 that sweeps away foreign matters such as toner in the brush fibers and zinc stearate 312 that is a solid lubricant are placed in contact with the brush roller 311, and the brush rubs the lubricant into fine powder. It is scraped off and applied to the photoreceptor. The solid lubricant 312 is uniformly pressed against the brush with a predetermined spring pressure.
The brush roller 311 is formed of a fiber adjusted to reduce resistance by adding a resistance control material such as carbon black to a resin such as nylon or acrylic.
In addition to zinc stearate, solid lubricant 312 is known to use metal salts of fatty acids such as stearic acid, oleic acid, palmitic acid, and linolenic acid.

FIG. 5 is a diagram illustrating a contact form of the cleaning blade to the photosensitive member. As a form of contact of the blade with the photosensitive member, there is a forward direction as shown in FIG. 5B under the counter direction as shown in FIG. 5A with respect to the rotating direction of the photosensitive member. . There are many apparatuses that employ the former contact form in the counter direction because of the accuracy of cleaning. The present invention also employs a counter system. The cleaning blade includes a blade rubber 316 and a holder metal plate 317. The material of the blade rubber 316 is polyurethane rubber, and is bonded to a metal holder sheet metal 317 such as a galvanized steel plate with an adhesive such as hot melt.
Further, as shown in FIGS. 4A and 4B, the cleaning blade 314 has a waste toner conveyance path 315 in the direction in which the toner scraped from the photosensitive member 101 falls by its own weight, and the waste toner is on the brush. The position configuration is such that does not fall.
A brush flicker 313 is installed between the photosensitive drum contact position of the brush and the lubricant contact position in order to increase the efficiency of the supply amount to the photosensitive body with respect to the amount of wear (consumption) of the lubricant.
In addition, the arrangement is such that waste toner that is flicked away does not reattach to the brush.
Deposits such as toner and paper dust remaining on the surface of the intermediate transfer belt 501 after the transfer of the full-color toner image onto the transfer paper are removed by the cleaning brush roller and the cleaning blade of the intermediate transfer belt cleaning device 520, and the above-described photoreceptor. In the same manner as the waste toner, it is conveyed to a waste toner container.
In FIG. 4B, the lubricant application mechanism is installed downstream of the cleaning blade 314, and the blade 314 for applying the lubricant is installed further downstream. With such an arrangement, it is possible to completely avoid the mixing of toner into the brush, and it is not necessary to install the brush flicker 313, the brush hair falls due to flicker contact, and the amount of biting into the photoreceptor due to it. The concern about the change in coating efficiency due to the decrease can be eliminated.

  The cleaning device 301 of the present invention described above can be a process cartridge that is integrally supported with the photoreceptor 101 and is detachably formed on the main body of the image forming apparatus. In addition to this, the process cartridge may include a charging device 201 as a charging unit and / or a developing device 401 as a developing unit. This process cartridge greatly improves the life of the process cartridge by improving the cleaning property of the photosensitive member 101.

Next, the toner suitably used in the image forming apparatus of the present invention will be described.
In order to reproduce minute 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 and the shape factor SF-2. The shape factor SF-1 indicates the ratio of the roundness of the toner shape and is represented by the following formula (1). This is a value obtained by dividing the square of the maximum length MXLNG of the shape formed by projecting the toner on a two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-1 = {(MXLNG) ² / AREA} × (100π / 4) (1)
When the value of SF-1 is 100, the shape of the toner becomes a true sphere, and becomes larger as the value of SF-1 increases.
The shape factor SF-2 indicates the ratio of the unevenness of the toner shape, and is represented by the following formula (2). A value obtained by dividing the square of the perimeter PERI of the figure formed by projecting the toner on the two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-2 = {(PERI) ² / AREA} × (100π / 4) Expression (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 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 includes a 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 an aqueous 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. 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.
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, it tends to be negatively charged, and furthermore, 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] 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 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, 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 salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride, fatty acid amide derivative, polyhydric alcohol Nonionic surfactants such as derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine And the like.

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

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

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

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

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

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

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

5) A charge control agent is injected into the toner base particles obtained above, and then inorganic fine particles such as silica fine particles and titanium oxide fine particles are externally added to obtain a toner.
The injection of the charge control agent and the external addition of the inorganic fine particles are performed by a known method using a mixer or the like.
Thereby, a toner having a small particle size and a sharp particle size distribution can be easily obtained. Furthermore, by giving strong agitation in the process of removing the organic solvent, the shape between the true spherical shape and the rugby ball shape can be controlled, and the surface morphology is also controlled between the smooth shape and the umeboshi shape. be able to.
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. 7C) 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.

1 is a schematic diagram illustrating a configuration of a full-color image forming apparatus according to the present invention. FIG. 2 is an overall schematic configuration diagram of an image forming system in which four image forming units of the image forming apparatus in FIG. 1 are juxtaposed. FIG. 2 is a schematic configuration diagram illustrating a configuration example of a yellow image forming unit 1Y of the image forming apparatus in FIG. 1. It is a figure which shows the structure of the cleaning apparatus which concerns on this invention. It is a figure which shows the contact form to the photoreceptor of a cleaning blade. FIG. 6 is a diagram schematically illustrating the shape of a toner for explaining the shape factor SF-1 and the shape factor SF-2. It is a figure which shows typically the shape of the toner of this invention.

Explanation of symbols

101 Photoconductor 201 Charging Device 301 Cleaning Device 311 Brush (Brush Roller)
312 Solid lubricant (zinc stearate)
313 Flicker 314 Blade 315 Waste toner transport path 316 Rubber blade 317 Holder metal plate 401 Development device 501 Intermediate transfer belt 507 Belt transfer roller 600 Paper transfer device 700 Fixing device 901 Static elimination device

Claims (13)

A cleaning device for removing developer remaining on the surface of an image carrier,
A friction reducing means for reducing the friction coefficient of the image carrier surface;
In the cleaning device in which the friction reducing means is a mechanism that rubs a solid lubricant with a brush and applies it to the image carrier,
The cleaning device according to claim 1, wherein the brush rotates in a forward direction with the rotation of the image carrier at a contact position with the image carrier. The cleaning device according to claim 1,
A cleaning device comprising a blade downstream of the contact position between the brush and the image carrier in the image carrier rotation direction. An image carrier for carrying a latent image;
In a process cartridge that is integrally supported and includes at least a cleaning unit that cleans the surface of the image carrier after transfer, and is detachably formed on the main body of the image forming apparatus.
The process cartridge according to claim 1, wherein the cleaning unit is the cleaning device according to claim 1. An image carrier for carrying a latent image;
Charging means for uniformly charging the surface of the image carrier;
Exposure means for exposing the surface of the charged image carrier based on image data and writing a latent image;
Developing means for supplying a toner to the latent image formed on the surface of the image bearing member to visualize the latent image;
Transfer means for transferring a visible image on the surface of the image carrier to a transfer medium;
In an image forming apparatus comprising a cleaning means for cleaning the surface of the image carrier after transfer,
The image forming apparatus according to claim 1, wherein the cleaning unit is the cleaning apparatus according to claim 1. An image carrier for carrying a latent image;
Charging means for uniformly charging the surface of the image carrier;
Exposure means for exposing the surface of the charged image carrier based on image data and writing a latent image;
Developing means for supplying a toner to the latent image formed on the surface of the image bearing member to visualize the latent image;
Transfer means for transferring a visible image on the surface of the image carrier to a transfer medium;
In an image forming apparatus comprising a cleaning means for cleaning the surface of an image carrier after transfer,
An image forming apparatus comprising the process cartridge according to claim 3. The image forming apparatus according to claim 4 or 5, wherein:
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. An image forming apparatus characterized by being in the range of 40. The image forming apparatus according to any one of claims 4 to 6,
The toner used in the developing means 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. The image forming apparatus according to any one of claims 4 to 7,
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. An image forming apparatus comprising a toner obtained by a crosslinking and / or elongation reaction. The image forming apparatus according to any one of claims 4 to 8,
An image forming apparatus, wherein the toner used in the developing unit has a substantially spherical shape. The image forming apparatus according to claim 9.
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 ratio (r2 / r1) between the major axis r1 and the minor axis r2 is set. An image forming apparatus, characterized in that it 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. A toner used in a developing step of an electrophotographic process, which is used in the image forming apparatus according to claim 4 or 5 and has a volume average particle diameter of 3 to 8 μm, a volume average particle diameter (Dv) and a number average. A toner having a ratio (Dv / Dn) to a particle diameter (Dn) in the range of 1.00 to 1.40. The toner according to claim 11.
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. The toner according to claim 11 or 12,
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. A toner characterized by being obtained.

Images