JP2014081520A - Glossing apparatus and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus configured to stably convey a sheet in a glossing apparatus to be used in forming a photographic image partially.SOLUTION: A glossing apparatus includes an endless belt 30, heating means 36 for heating the endless belt; pressure means 40 for applying pressure to the heating means via the endless belt; and cooling means 42 for cooling the endless belt. A recording medium with a toner image carried thereon is introduced to a nip part formed between the heating means and the pressure means via the endless belt, heated, pressured, and cooled in contact with the endless belt by the cooling means, to gloss the toner image. The glossing apparatus includes first charging means 43 for charging the recording medium which has not been introduced to the glossing apparatus, and second charging means 44 for charging the endless belt with a polarity opposite to a polarity with which the recording medium is charged.

Description

  The present invention relates to a gloss applying device provided in a copying machine, a facsimile, a printer, a printing machine, or an ink jet recording apparatus. Furthermore, the present invention relates to an image forming apparatus formed by combining at least one of these.

  In recent years, color laser printers handle special color toners such as intermediate colors in addition to CMYK (cyan (C), magenta (M), yellow (Y), black (K)) process color image forming color toners. Things are increasing. In addition, those that handle transparent clear toner (special color toner for glossiness adjustment) for giving gloss to printed matter have come to be used. By effectively using these toners, the user can generate a printed output with high added value.

  For example, there has been proposed a printing apparatus that performs gloss adjustment by coating clear toner on a color printed material (entire surface or part) (overall coat or partial coat).

  The entire surface coating using clear toner can give glossiness to the entire surface of the paper as shown in the photo by coating the entire surface of the paper after color printing with the clear toner. It can prevent color transfer due to friction and protect images.

  Also, the partial coat using clear toner can give a part of paper glossy like a photograph by coating a part of paper after color printing with clear toner. The difference in gloss on the top is large and can be differentiated compared to normal printing.

  Here, when this clear toner is overlapped and normal heat and pressure fixing is performed, the glossiness is limited to 70% at Gs (60 °). In order to further increase the added value as a photographic image, the glossiness of the silver salt photographic print surface is required to be 64% or more in Gs (20 °).

  In order to satisfy the above-described requirements, for example, an image forming apparatus disclosed in Patent Document 1 is known.

  It is already known that it is important to increase the productivity of photographic glossy images by directly transferring (in-line connection) paper from the electrophotographic image forming system to the gloss applying device.

  In the image forming apparatus described in Patent Document 1, the clear toner remelting temperature is lower than the color toner remelting temperature, so that only the clear toner is melted by the gloss applying device and is closely adhered to the belt having high smoothness. High gloss can be obtained.

  However, since only the clear toner is melted and brought into close contact with the belt, when the photographic image is partially created or when the region to be made into the photographic image is narrow, the contact region with the belt having high smoothness becomes narrow. Therefore, the sheet falls due to its own weight and the like, and the sheet cannot be stably conveyed, and there is a possibility that the productivity of the photo-like glossy image is lowered.

  SUMMARY OF THE INVENTION An object of the present invention is to stably transport a sheet with a glossing device used when partially creating a photographic image.

In order to solve the above-described problem, the gloss imparting device according to claim 1 of the present invention provides:
An endless belt,
Heating means for heating the endless belt;
A pressurizing unit that press-contacts the heating unit via the endless belt;
Cooling means capable of cooling the endless belt,
The recording medium carrying a toner image is introduced into a nip formed between the heating means and the pressurizing means via the endless belt and is heated and pressed, and then comes into contact with the endless belt. In the gloss imparting device that is cooled by the cooling means in a state and imparts gloss to the toner image,
First charging means for charging the recording medium before being introduced into the gloss applying device;
And a second charging means for charging the endless belt to a polarity opposite to the charging polarity of the recording medium.

  According to the present invention, it is possible to stably convey a sheet when partially creating a photographic image.

1 is a configuration diagram schematically illustrating an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a gloss imparting device of the image forming apparatus shown in FIG. 1. FIG. 2 is an explanatory diagram showing an image ratio of a sheet to be introduced into the gloss providing device of the image forming apparatus shown in FIG. FIG. 2 is an explanatory diagram illustrating a relationship between an image ratio of a sheet to be introduced into the gloss applying device of the image forming apparatus illustrated in FIG. 1 and an applied voltage.

  Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram schematically showing an image forming apparatus according to an embodiment of the present invention. The image forming apparatus of the present embodiment is a color printer (hereinafter referred to as “printer”) capable of forming a full-color image adopting an electrophotographic tandem method. The image forming apparatus is not limited to the printer shown in FIG. 1, and may be a copying machine, a facsimile, a printing machine, an ink jet recording apparatus, or the like.

  In FIG. 1, reference numeral 1 denotes an apparatus main body of a tandem color copier as an image forming apparatus, 2 denotes a writing unit that emits laser light based on input image information, and 3 denotes a document D to a document reading unit 4. 4 is a document reading unit that reads image information of the document D, 7 is a paper feeding unit that accommodates a recording medium (paper) P such as transfer paper, and 9 is a registration roller that adjusts the conveyance timing of the paper P. (Timing adjustment roller).

  Further, 11BK, 11C, 11M, 11Y, and 11CL are photosensitive drums on which toner images of respective colors (black, cyan, magenta, yellow, and clear) are formed, and 12 is each photosensitive drum 11BK, 11C, 11M, 11Y, and 11CL. A charging unit that charges the upper side, 13 is a developing unit that develops an electrostatic latent image formed on each of the photoconductive drums 11BK, 11C, 11M, 11Y, and 11CL, and 14 is a photoconductive drum 11BK, 11C, 11M, and 11Y. , A transfer bias roller for transferring the toner image formed on 11CL over the paper P, and 15 a cleaning unit for collecting untransferred toner on each of the photosensitive drums 11BK, 11C, 11M, 11Y, and 11CL. .

  Reference numeral 16 denotes a transfer belt cleaning unit that cleans the transfer belt 17, reference numeral 17 denotes a transfer belt that conveys the paper P such that toner images of a plurality of colors are carried on the paper P, and reference numeral 19 denotes a toner image on the paper P. 1 shows an electromagnetic induction heating type fixing device (heating device) for fixing (unfixed image).

  Hereinafter, an operation at the time of image formation in the image forming apparatus according to the present embodiment will be described with reference to FIG.

  The document D placed on the document table is transported from the document table in the direction of the arrow in the drawing by the transport rollers of the document transport unit 3 and placed on the contact glass 5 of the document reading unit 4. Then, the document reading unit 4 optically reads the image information of the document D placed on the contact glass 5. Then, an image forming process (charging process, exposure process, developing process, transfer process, cleaning process) is performed on the photoreceptor 11, and a desired toner image is formed on the photoreceptor 11.

  Specifically, the document reading unit 4 scans the image of the document D on the contact glass 5 while irradiating light emitted from an illumination lamp (not shown). Then, the light reflected by the document D is imaged on a color sensor (not shown) via a mirror group (not shown) and a lens (not shown). The color image information of the document D is read for each RGB (red, green, blue) color separation light by the color sensor, and then converted into an electrical image signal. Further, color conversion processing, color correction processing, spatial frequency correction processing, and the like are performed by an image processing unit (not shown) based on RGB color separation image signals, and yellow, magenta, cyan, and black colors are processed. Get image information.

  On the other hand, a control unit (not shown) obtains transparent image information in the image processing unit by a control signal for the clear toner (gloss imparting toner) layer corresponding to the region designation by the user. In the present embodiment, the clear toner layer region is designated by the user, but it is needless to say that the present invention is not limited to this mode.

  Then, the image information of each color of black, cyan, magenta, yellow, and clear is transmitted to the writing unit 2. The writing unit 2 emits laser light (exposure light) based on the image information of each color toward the corresponding photosensitive drums 11BK, 11C, 11M, 11Y, and 11CL.

  On the other hand, the five photosensitive drums 11BK, 11C, 11M, 11Y, and 11CL rotate in the clockwise direction of FIG. The surfaces of the photosensitive drums 11BK, 11C, 11M, 11Y, and 11CL are uniformly charged at a portion facing the charging unit 12 (referred to as a “charging process”). Thus, a charged potential is formed on the photosensitive drums 11BK, 11C, 11M, 11Y, and 11CL.

  Thereafter, the surfaces of the charged photosensitive drums 11BK, 11C, 11M, 11Y, and 11CL reach the irradiation positions of the respective laser beams. Then, in the writing unit 2, laser light corresponding to the image signal is emitted from the four light sources corresponding to each color. Each laser beam passes through a different optical path for each of black, cyan, magenta, yellow, and clear color components (referred to as an “exposure process”). The laser beam corresponding to the black component is applied to the surface of the fifth photosensitive drum 11BK from the left side in FIG. At this time, the black component laser light is scanned in the rotation axis direction (main scanning direction) of the photosensitive drum 11BK by a polygon mirror that rotates at high speed. Thus, an electrostatic latent image corresponding to the black component is formed on the photosensitive drum 11BK charged by the charging unit 12.

  Similarly, the laser beam corresponding to the cyan component is irradiated on the surface of the fourth photosensitive drum 11C from the left side in FIG. 1, and an electrostatic latent image corresponding to the cyan component is formed. Further, the magenta component laser light is applied to the surface of the third photosensitive drum 11M from the left side in FIG. 1 to form an electrostatic latent image of the magenta component. Further, the yellow component laser light is applied to the surface of the second photosensitive drum 11Y from the left side in FIG. 1 to form a yellow component electrostatic latent image. Finally, the clear component laser light is applied to the surface of the first photosensitive drum 11CL from the left side in FIG. 1 to form an electrostatic latent image of the clear component.

  The surfaces of the photosensitive drums 11BK, 11C, 11M, 11Y, and 11CL on which the electrostatic latent images of the respective colors are formed reach the positions facing the developing unit 13, respectively. Then, the respective color toners are supplied from the developing units 13 onto the photosensitive drums 11BK, 11C, 11M, 11Y, and 11CL, and the latent images on the photosensitive drums 11BK, 11C, 11M, 11Y, and 11CL are developed ( "Development process").

  Then, the surfaces of the photosensitive drums 11BK, 11C, 11M, 11Y, and 11CL after the development process reach the facing portions of the transfer belt 17, respectively. Here, a transfer bias roller 14 is installed at each facing portion so as to contact the inner peripheral surface of the transfer belt 17. The toner images of the respective colors formed on the photosensitive drums 11BK, 11C, 11M, 11Y, and 11CL are sequentially superimposed and transferred onto the paper P on the transfer belt 17 at the position of the transfer bias roller 14 (“ "Transfer process"). Note that the order of the colors in the development process and the transfer process is not limited to this mode, and may be in another order. Further, the transfer process is not limited to this mode, and may be a type in which the transfer process is performed on a recording medium via an intermediate transfer belt.

  Then, the surfaces of the photosensitive drums 11BK, 11C, 11M, 11Y, and 11CL after the transfer process reach positions facing the cleaning unit 15, respectively. Then, the untransferred toner remaining on the photosensitive drums 11BK, 11C, 11M, 11Y, and 11CL is collected by the cleaning unit 15 (referred to as “cleaning process”).

  Thereafter, the surfaces of the photoconductive drums 11BK, 11C, 11M, 11Y, and 11CL pass through a neutralization unit (not shown), and a series of image forming processes on the photoconductive drums 11BK, 11C, 11M, 11Y, and 11CL is completed.

  On the other hand, the sheet P on which the toners of the respective colors on the photosensitive drums 11BK, 11C, 11M, 11Y, and 11CL are transferred (carrying) overlaps with each other and travels in the direction of the arrow in FIG. To reach. Then, the charge accumulated on the sheet P is neutralized at a position facing the separation charger 18, and the sheet P is separated from the transfer belt 17 without causing toner dust or the like.

  Thereafter, the surface of the transfer belt 17 reaches the position of the transfer belt cleaning unit 16. Then, the deposit adhered on the transfer belt 17 is collected by the transfer belt cleaning unit 16.

  Here, the paper P transported onto the transfer belt 17 is transported from the paper supply unit 7 via the registration rollers 9 and the like.

  Specifically, the paper P fed by the paper feed roller 8 from the paper feed unit 7 that stores the paper P passes through a conveyance guide (not shown) and is guided to the registration roller 9. The paper P that has reached the registration roller 9 is conveyed toward the transfer belt 17 in time.

  The paper P on which the full-color image has been transferred is guided to the fixing device 19 after being separated from the transfer belt 17. In the fixing device 19, the color image (toner) is fixed on the paper P at the nip between the fixing roller and the pressure roller.

  The required fixing temperature of the paper P onto which the toner of the fixing device 19 is transferred is the yellow, cyan, magenta, and black color from the maximum glass transition temperature of yellow, cyan, magenta, and black color toners. From the temperature range up to the minimum value of the melting point (melting temperature) of the toner, there is no offset phenomenon (a phenomenon in which a part of the toner image is removed from the fixing belt) in both the colored toner layer and the clear toner layer. This is the optimum temperature for fixing.

  The toner that has reached the fixing temperature is in a rubbery physical state, and by applying pressure to the toner in the rubbery physical state and the paper P, the toner adheres to the paper P and the paper P Fixes to paper by entering between fibers (anchor effect). Further, since the glass transition point temperature of the clear toner is set lower than the glass transition point temperatures of the colored toners of yellow, cyan, magenta, and black, the clear toner is also fixed on the paper.

  The paper P after the fixing process is given a gloss by the gloss applicator 301. Then, the glossy paper P is discharged as an output image outside the apparatus main body 1 by a paper discharge roller (not shown), and a series of image forming processes is completed.

  A configuration of a gloss imparting device, which is a characteristic configuration of an image forming apparatus according to an embodiment of the present invention, will be described with reference to FIG.

  As shown in FIG. 1, the gloss applying device 301 is close to the downstream side of the fixing device. The gloss applying device is not limited to this mode, and may be located outside the image forming apparatus, for example.

  As shown in FIG. 2, the gloss imparting belt (endless belt) 30 is made of a heat-resistant resin having a thickness of 10 to 200 μm, or a metal such as nickel or SUS, and has an outer diameter of 80 to 300 mm. It has become. The surface layer may have an elastic layer made of silicone rubber with a thickness of 5 to 50 μm in order to improve adhesion to the conveyed image surface. Further, the outermost layer may have a release layer coated with a silicone-based or fluorine-based resin in order to ensure release during separation.

  The heating roller (heating means) 36 has an outer diameter of φ30 to 90 mm and is made of Al, SUS, or Fe. In order to form a wide nip with the pressure roller 40, an elastic layer such as silicone rubber may be provided on the roller surface with a thickness of 0.5 to 5 mm.

  The separation roller (separation means) 37 has an outer diameter of φ10 to φ30 mm and is made of Fe, Al, or SUS.

  The pressure roller (pressure means) 40 has a diameter of 30 to 90 mm, and an elastic layer such as 1 to 50 mm of fluorine rubber or silicone rubber is formed on a core metal such as Fe, Al, or SUS, and is further formed on the outermost layer. Is composed of a release layer made of a fluorine compound or the like with a thickness of 5 to 50 μm.

  Further, the pressure roller 40 can be operated so as to be in contact with and away from the gloss imparting belt 30 using a cam (not shown), and the nip width and the load can be adjusted by changing the distance between the shafts with the heating roller 36. Variable control is possible. Further, the heating roller 36, the gloss imparting belt 30, and the separation roller 37 are driven to rotate by being connected to a motor (not shown) and driven to rotate.

  Inside the gloss imparting belt 30, an internal cooling fan (cooling means) 42 is disposed as an internal cooling device. The cooling means 42 is not limited to this mode, and the gloss imparting belt 30 may be cooled by providing a cooling device such as a heat sink, a fan, a heat pipe, or a Peltier element.

  Here, in the gloss imparting device 301, only the nip of the gloss imparting device 301 has a required processing temperature at which only the surface layer portion of the clear toner can be transformed into a rubbery physical state, and is below the glass transition temperature of the clear toner. The surface temperature of the gloss imparting belt 30 is gradually lowered toward the conveyance downstream side. The processing temperature of the clear toner described above is equal to or higher than the glass transition temperature of the clear toner and lower than the glass transition temperature of the colored toner.

  The operation of the gloss providing device, which is a characteristic configuration of the image forming apparatus according to the embodiment of the present invention, will be described with reference to FIG.

  The printing signal is inputted as a printing operation, and the paper P on which the toner T made in the image forming unit is placed passes through the fixing device, and then in a fixing state, the heating roller 36 via the gloss applying belt 30 It passes through a nip formed by the pressure roller 40. While pressure is applied at the nip portion, heat is applied from the gloss imparting belt 30.

  At this time, since the glass transition point of the clear toner is lower than the glass transition point of the colored toner, only the clear toner is melted by the gloss applying device, and the glass is brought into close contact with the belt having high smoothness to obtain high gloss. Then, the remelted clear toner adheres to the gloss imparting belt 30. And it is conveyed with the paper P in the state which contact | adhered. At this time, the paper P and the gloss imparting belt 30 are charged with different polarities by the charging means 43 and 44. In this embodiment, as shown in FIG. 2, the sheet P to be conveyed is adsorbed and conveyed by the lower surface of the glossing belt 30 in the horizontal state in the mounted state in the image forming apparatus. Needless to say, the present invention can also be applied to a state in which a situation occurs in which the sheet falls off the gloss imparting belt due to its own weight, for example, an inclined gloss impart belt.

  When the sheet P enters the nip portion, the external cooling fan 41 is driven. Therefore, the air flow from the external cooling fan 41 strikes the back side of the paper P, and the paper P is rapidly cooled. The gloss imparted by the gloss imparting device basically depends on the surface roughness corresponding to the surface roughness of the gloss imparting belt 30. For this reason, the gloss imparting belt 30 is also cooled by the internal cooling fan 42, and the surface of the fixed image portion where the molten toner image is solidified is smoothed in accordance with the gloss imparting belt surface to impart glossiness. Then, the paper P on which the toner image is placed is further conveyed while being in close contact with the gloss imparting belt 30, and is separated by the separation roller 37 and discharged.

  Then, after the paper P is separated from the gloss imparting belt 30, the gloss imparting belt 30 is neutralized by a neutralizing means (not shown).

  Next, the charging means which is a characteristic configuration of the present invention will be described below with reference to FIG. In the present invention, when an image having a partially photographic tone is formed, a voltage is applied to the paper P by the corona charger (first charging unit) 43 before the paper P is introduced into the gloss imparting device 301. Further, the gloss imparting belt 30 having high smoothness is applied to the polarity opposite to the charging polarity of the paper P by the corona charger (second charging means) 44. Since the paper P and the gloss imparting belt 30 are electrically charged with opposite polarities, an electrostatic attraction force acts and the paper P can be adsorbed to the gloss imparting belt 30. The gloss imparting belt 30 may be a substance having a property of holding electric charge, and includes, for example, polyimide.

  Therefore, when the clear toner is only partially present, no paper conveyance failure occurs because the gloss imparting belt 30 and the paper P cannot be completely adhered, and the paper P can be stably conveyed. Further, according to the present invention, it is possible to stably transport the paper regardless of the paper size.

  It is possible to apply clear toner outside the print area of the paper so that the paper does not fall even when the print area only partially has clear toner. There is a problem such as having to be larger. However, the above-described problem does not occur by having the charging mechanism which is a characteristic configuration of the present invention.

Next, the relationship between the applied voltage and the paper weight will be described below with reference to FIGS. The plain paper here refers to 63 to 163 g / m ² , the heavy paper refers to 163 to 350 g / m ² , and the light paper refers to 52 to 63 g / m ² . The image ratio (image area ratio) in the main scanning direction here is the integrated value of the laser lighting time with respect to the scanning time of the entire writing width in the main scanning direction when writing laser light from the writing unit 2 to the photosensitive drum 11. This is a value obtained by calculating a ratio.

  For example, when there is no photographic tone area, that is, when the toner on the paper and the gloss imparting belt 30 are not in close contact with each other, the applied voltage required to attract the plain paper to the gloss imparting belt 30 is 5 kV. Suppose there is. Then, as shown in FIG. 3, when the gloss is partially applied, specifically, the area where the photographic tone is desired (the gloss is desired) is half of the width of the paper P in the main scanning direction (50%). ), The toner on the paper and the gloss imparting belt 30 are in close contact with each other over a wide range, and the applied voltage can be 2.5 kV.

  Specifically, when the region to be photographic-like is larger than the width of the paper P in the main scanning direction, the toner on the paper and the gloss imparting belt 30 are in close contact with each other over a wide range. With the generated suction force, the paper P and the gloss imparting belt 30 are in close contact with each other, and energy saving can be achieved.

  Further, as shown by a dotted line in FIG. 4, when the image ratio in the main scanning direction is 50% and the paper P having a predetermined size is light, the applied voltage can be set to, for example, 2.0 kV.

  Specifically, when the paper P is a light paper, even if the applied voltage is lowered, the weight of the paper P is reduced. The application belt 30 is in close contact with each other, and energy saving can be achieved. In addition, for thin paper and light paper, it is possible to carry the paper if the image ratio in the main scanning direction is to some extent.

  That is, the applied voltage can be changed depending on the size of the region desired to be photographed, the thickness and the weight of the paper, and an appropriate voltage can be applied to the paper to be given gloss. Therefore, the paper P can be transported efficiently and stably without causing a shortage or excess of applied voltage.

  A method for producing a dry two-component toner containing clear toner will be described below.

  In this description, the Ricoh polymerized toner is taken as an example, but the present invention is not limited to this manufacturing method. It is obtained by crosslinking and / or extending in a water-based solvent 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 are dispersed in an organic solvent. Toner. First, the constituent material and manufacturing method of the toner will be described.

  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 a dihydric alcohol (DIO) and a 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 diol (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenol (bisphenol A, bisphenol F) Bisphenol S, etc .; alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adducts of the above alicyclic diols; Alkylene oxide Le ethers (ethylene oxide, propylene oxide, butylene oxide, etc.) adducts. Among these, 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) and 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) , Naphthalenedicarboxylic acid, etc.). 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 polyvalent carboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polycarboxylic 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 the polyhydric alcohol (PO) and the polycarboxylic acid (PC) is carried out in the presence of a known esterification catalyst such as tetrabutoxy titanate, dibutyltin oxide, and the like, while heating to 150 to 280 ° C., and if necessary, reducing the pressure. 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 further, when fixing to a recording paper, the affinity between the recording paper and the toner is good and the low-temperature fixability is improved. However, when the acid value exceeds 30, there is a tendency to deteriorate with respect to the stability of charging, particularly environmental fluctuation.

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

  In addition to the unmodified polyester obtained by the above polycondensation reaction, the polyester preferably contains a urea-modified polyester. The urea-modified polyester is obtained by reacting a terminal carboxyl group or hydroxyl group of the polyester obtained by the above polycondensation reaction with a polyvalent isocyanate compound (PIC) to obtain a polyester prepolymer (A) having an isocyanate group, This is obtained by cross-linking and / or extending the molecular chain by the reaction of 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; phenol derivatives, oximes, polyisocyanates; Those blocked with caprolactam and 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 polyisocyanate 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 B1 to B5 amino group blocked (B6) 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.

  Further, the urea-modified polyester may contain a urethane bond as well as 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 tetrabutoxy titanate, 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 elongation reaction between the polyester prepolymer (A) and the amines (B), a reaction terminator may 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, the number average molecular weight is usually 2000 to 15000, preferably 2000 to 10,000, 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.

  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, 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 the temperature is lower than 45 ° C., the heat resistance of the toner is deteriorated.

  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.

  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 , Lead yellow, 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 ortho nitro Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, 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, Thioindigo Red B, thioindigo maroon, oil red, quinacridone red, pyrazolone red, port Azo 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, Phthalo Ani down Green, anthraquinone green, titanium oxide, zinc white, lithopone 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 the 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 resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax and the like can be mentioned, and these can be used alone or in combination. Note that when the clear toner is prepared, it is only necessary to remove the colorant.

  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). Quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine-based activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Bontron 03 of nigrosine dye, Bontron P-51 of quaternary ammonium salt, Bontron S-34 of metal-containing azo dye, E-82 of oxynaphthoic acid metal complex, E- of salicylic acid metal complex 84, E-89 of phenol-based condensate (above, manufactured by Orient Chemical Co., Ltd.), TP-302, TP-415 of quaternary ammonium salt molybdenum complex (made of Hodogaya Chemical Co., Ltd.), quaternary ammonium salt Copy charge PSY VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEGVP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit) Manufactured), copper phthalocyanine, perylene, quinacridone, a System pigment, 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. A 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.

  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. 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 petrolatum. And petroleum wax. 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 masterbatch and the binder resin, or may be added when dissolved and dispersed in an organic solvent.

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 the residual toner is further reduced. .

  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 addition 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.

  1) A toner material solution is prepared by dispersing a colorant, unmodified polyester, a polyester prepolymer having an isocyanate group, and a release agent in an organic solvent. The organic solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal after toner base particle formation. Specifically, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, Methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform and carbon tetrachloride are preferred. The usage-amount of an organic solvent is 0-300 weight part normally with respect to 100 weight part of polyester prepolymers, Preferably it is 0-100 weight part, More preferably, it is 25-70 weight part.

  2) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles. The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.

  The amount of the aqueous medium used relative to 100 parts by weight of the toner material liquid is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner material liquid is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical. Further, in order to improve the dispersion in the aqueous medium, a dispersant such as a surfactant and resin fine particles is appropriately added.

  As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium 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 .

  Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-Hydroxyethyl) Perful Olooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned.

  Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

  In addition, as the cationic surfactant, aliphatic quaternary ammonium such as aliphatic primary, secondary or secondary amic acid, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, which is right on the fluoroalkyl group. Salt, 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) Smoke), Megafuck F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products Co., Ltd.), Footgent F-300 (Neos Co., Ltd.) and the like.

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

  As a dispersant that can be used in combination with the above resin fine particles and inorganic compound dispersant, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid, maleic anhydride, and other acids or hydroxyl group-containing (meth) acrylic monomers 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 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, etc., or esters of compounds containing vinyl alcohol and a carboxyl group 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 imidazole, Nitrogen compounds such as ethyleneimine, or homopolymers or copolymers such as those having a heterocyclic ring thereof, polyoxyethylene, polyoxypropylene, Reoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonylphenyl Polyoxyethylenes such as esters, 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 type, a high-speed shear type, a friction type, a high-pressure jet type, 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 washing with water after dissolving the calcium phosphate salt with an acid such as hydrochloric acid. Remove. It can also be removed by an operation such as degradation with an enzyme.

  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 applying strong agitation in the process of removing the organic solvent, the shape between the 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.

  Next, the operation of the image forming apparatus according to this embodiment will be described.

  First charging means for charging the paper P before being introduced into the gloss imparting apparatus 301, and second charging means for charging the gloss imparting belt 30 of the gloss imparting apparatus 301 to a polarity opposite to that of the paper P. The sheet P and the gloss imparting belt 30 are electrostatically charged with mutually different signs of charges, so that a suction force is generated between the gloss imparting belt 30 and the sheet P, and the clear toner is only partially applied. Even with no image, it can be stably conveyed. As a result, the paper P can be stably conveyed, and the productivity of photographic glossy images is not reduced.

  Further, since the glass transition point of the clear toner is lower than the glass transition point of the colored toner, only the clear toner can be remelted to give the paper P gloss. As a result, a part of the paper can be given a glossy feeling like a photograph, and the difference in gloss on the image is large so that it can be differentiated compared to normal printing.

  Since the corona charger 43 charges the paper P, the paper P can be easily charged with a simple configuration. As a result, the paper P can be stably conveyed, and the productivity of photographic glossy images is not reduced.

  On the other hand, when the paper P is charged with a roller instead of charging the paper P with the corona charger 43, the paper P can be easily charged with a simple configuration. As a result, the paper P can be stably conveyed, and the productivity of photographic glossy images is not reduced.

  Since the corona charger 44 charges the gloss imparting belt 30, the paper P can be easily charged with a simple configuration. As a result, the paper P can be stably conveyed, and the productivity of photographic glossy images is not reduced.

  On the other hand, when the corona charger 44 charges the gloss imparting belt 30 by a mechanism for charging the paper P with a roller instead of charging the gloss imparting belt 30, the gloss imparting belt 30 can be easily charged with a simple configuration. As a result, the paper P can be stably conveyed, and the productivity of photographic glossy images is not reduced.

  By separating the gloss imparting belt 30 by the neutralization mechanism after separating the paper P from the gloss imparting belt 30, the charge can be stably charged when the gloss imparting belt 30 is charged again. As a result, the paper P can be stably conveyed, and the productivity of photographic glossy images is not reduced.

  By changing the applied voltage applied to the paper P by the first charging unit and the applied voltage applied to the gloss applying belt 30 by the second charging unit according to the weight of the paper P, the paper P and the gloss applying belt 30 are changed. The amount of charge applied can be changed. Therefore, it is possible to apply a charge depending on the weight of the paper P and generate an appropriate suction force. As a result, the paper P can be stably conveyed, and the productivity of photographic glossy images is not reduced.

  As the paper P is heavier than plain paper, the applied voltage applied to the paper P by the first charging unit and the applied voltage applied to the gloss applying belt 30 by the second charging unit are increased, so that the paper P and the gloss are applied. The amount of charge applied to the belt 30 can be increased. Therefore, it is possible to apply a charge depending on the weight of the paper P and generate an appropriate suction force. As a result, the paper P can be stably conveyed, and the productivity of photographic glossy images is not reduced.

  By changing the applied voltage applied to the paper P by the first charging unit and the applied voltage applied to the gloss applying belt 30 by the second charging unit in accordance with the region to which the gloss is partially applied, the paper P and the gloss are applied. The amount of charge applied to the belt 30 can be changed. For this reason, it is possible to apply a charge to the area to which gloss is applied and generate an appropriate suction force. As a result, the paper P can be stably conveyed, and the productivity of photographic glossy images is not reduced.

  The smaller the partial gloss-applying area is relative to the overall size of the paper, the greater the applied voltage applied to the paper P by the first charging means and the applied voltage applied to the gloss applying belt 30 by the second charging means. By doing so, the amount of charge applied to the paper P and the gloss imparting belt 30 can be increased. Therefore, it is possible to apply a charge corresponding to the region to which gloss is applied and generate an appropriate suction force. As a result, the paper P can be stably conveyed, and the productivity of photographic glossy images is not reduced.

  According to the image forming apparatus of the eleventh aspect, it is possible to stably convey the paper P when partially creating a photographic image.

Although one embodiment of the present invention has been described above, the present invention is not limited to this. Further, in the present embodiment, an example in which the gloss generating device is incorporated in the image forming apparatus is illustrated, but the gloss generating device may be provided in the image forming apparatus, and the mode is not particularly limited. In the present embodiment, an image having only a clear toner has been described. However, the present invention is not limited to this mode, and it is needless to say that the present invention can be applied to a belt fixing when an image forming area is small on a sheet. .
Further, the present invention is not limited to a mode in which a toner image is transferred to a sheet on a transfer belt as in the present embodiment, and can be applied to an image forming apparatus that transfers a toner image to a sheet after being transferred to the transfer belt. Needless to say.

  It should be noted that the materials and dimensions of each component introduced in the above-described embodiment are merely examples, and it is needless to say that various materials and dimensions can be selected within a range where the effects of the present invention can be exhibited.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus main body 30 Gloss imparting belt (an example of an endless belt)
36 Heating roller (an example of heating means)
37 Separation roller (an example of separation means)
40 Pressure roller (an example of pressure means)
42 Internal cooling fan (an example of cooling means)
43 Corona charger (example of first charging means)
44 Corona charger (example of second charging means)
301 Gloss imparting device P paper

JP 2011-100106 A JP-A-5-158364 JP 2007-286510 A

Claims (10)

An endless belt,
Heating means for heating the endless belt;
A pressurizing unit that press-contacts the heating unit via the endless belt;
Cooling means capable of cooling the endless belt,
The recording medium carrying a toner image is introduced into a nip formed between the heating means and the pressurizing means via the endless belt and is heated and pressed, and then comes into contact with the endless belt. In the gloss imparting device that is cooled by the cooling means in a state and imparts gloss to the toner image,
First charging means for charging the recording medium before being introduced into the gloss applying device;
A gloss applying device, comprising: a second charging unit that charges the endless belt to a polarity opposite to a charging polarity of the recording medium. The toner image is formed of a colored toner and a gloss imparting toner,
The gloss imparting apparatus according to claim 1, wherein a glass transition point of the gloss imparting toner is lower than a glass transition point of the colored toner.   In accordance with the weight of the recording medium, the applied voltage applied to the previous recording medium by the first charging unit and the applied voltage applied to the endless belt by the second charging unit are changed, whereby the recording medium and the recording medium The gloss applying device according to claim 1 or 2, wherein the amount of electric charge applied to the endless belt is changed.   By changing the applied voltage applied to the preceding recording medium by the first charging unit and the applied voltage applied to the endless belt by the second charging unit in accordance with a region to which the gloss is partially applied, the recording medium is changed. The gloss applying device according to claim 1, wherein the amount of charge applied to the endless belt is changed.   The gloss applying apparatus according to claim 1, wherein the first charging unit is a corona charger.   The gloss applying apparatus according to claim 1, wherein the first charging unit is charged by a roller.   The gloss applying apparatus according to claim 1, wherein the second charging unit is a corona charger.   The gloss applying apparatus according to claim 1, wherein the second charging unit is charged by a roller.   The gloss applying apparatus according to claim 1, further comprising: a discharging unit that discharges the endless belt after the recording medium is separated from the endless belt by the separating unit.   An image forming apparatus comprising the gloss applying device according to claim 1.

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