JP2009134084A - Lubricant applicator, transfer device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricant applicator for satisfactorily removing deposits on a surface to be applied eith a lubricant and suppressing occurrence of abnormal images, and to provide a transfer device and an image forming apparatus equipped with the lubricant applicator. <P>SOLUTION: The lubricant applicator 19 includes: a lubricant applying means 21 applying a lubricant on the surface of an application object plane 40 the surface of which is traveling; a first blade member 20 in contact with the surface of the application object plane 40 in an upstream side along the surface traveling direction of the object plane 40 than the lubricant applying means 21 and removing a depositing substance on the surface of the application object 40; and a second blade member 53 in contact with the surface of the application object plane 40 in a downstream side along the surface traveling direction of the application object plane 40 than the lubricant applying means 21 and leveling the lubricant applied on the surface of the application object plane 40. The first blade member 20 and the second blade member 53 are in contact with the application object plane 40 in a counter direction against the surface traveling direction of the object plane. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lubricant application device that applies a lubricant to a surface to which a lubricant is applied, such as an image carrier, in an image forming apparatus such as a copying machine, a facsimile machine, and a printer, and an image forming apparatus that includes the lubricant application device. Is.

  In an image forming apparatus using an electrophotographic process, an electrostatic latent image is formed on a photosensitive member, and the formed electrostatic latent image is developed and visualized as a toner image. The toner image formed on the photosensitive member is transferred directly or via an intermediate transfer member to a recording sheet as a recording member, and the transferred toner image is fixed on the recording sheet to obtain an image. In such an image forming apparatus, toner that has not been transferred remains on a toner image carrier such as a photosensitive member or an intermediate transfer member after the toner image is transferred. For this reason, a cleaning blade that contacts the surface of the toner image carrier so as to be in a counter direction and removes residual toner is often used (Patent Document 1, etc.).

  In general, the contact pressure can be increased by bringing the cleaning blade into contact with the surface movement direction of the toner image carrier in the counter direction, rather than in contact with the trailing direction. Therefore, there is an advantage that the removal performance is higher in the case of contact in the counter direction than in the case of contact in the trailing direction.

  However, if the cleaning blade is brought into contact with the toner image carrier in the counter direction, the frictional force between the cleaning blade and the image carrier increases, so that the amount of wear of the toner image carrier increases and the life may be shortened. was there.

  In the image forming apparatus described in Patent Document 2, a lubricant is applied to the surface of the toner image carrier after being cleaned by a cleaning blade brought into contact with the toner image carrier in the counter direction by a lubricant application unit. ing. Thus, by applying the lubricant to the toner image carrier, the frictional force between the cleaning blade and the toner image carrier can be reduced, and the life of the toner image carrier can be extended. Further, by applying a lubricant, the friction coefficient on the surface of the toner image carrier can be reduced, and the toner can be easily removed from the toner image carrier by the cleaning blade.

  However, a uniform lubricant layer cannot be formed simply by applying the lubricant to the surface of the toner image carrier because the amount of application by the lubricant application means is uneven. If the uniform lubricant layer cannot be formed, the coefficient of friction on the surface of the toner image carrier becomes non-uniform, so that the transfer of the toner image is not performed well, and abnormal images such as worm erosion, image blur and blurring occur.

For this reason, in the image forming apparatus described in Patent Document 2, a lubricant leveling blade for leveling the applied lubricant is disposed on the toner image bearing member on the downstream side in the moving direction of the toner image bearing member with respect to the toner image bearing member. Abutting in the trailing direction. Thus, after cleaning the residual toner, applying a lubricant and leveling the lubricant, a uniform lubricant layer can be obtained, and the friction coefficient of the toner image carrier surface becomes uniform, and Occurrence can be suppressed.

JP 2002-333805 A JP 2006-251751 A

  Further, as described above, a uniform lubricant layer is formed on the toner image carrier and the friction coefficient of the toner image carrier surface is made uniform, so that the friction generated at the contact point between the cleaning blade and the toner image carrier is obtained. The force can be stabilized. By stabilizing the frictional force generated at the contact point in this way, the frictional force generated at the contact point becomes unstable, so that the toner is not removed by the cleaning brush and passes through the contact point. Can be suppressed.

  However, in recent image forming apparatuses, a toner having a small particle diameter and a spherical shape, particularly a polymerized toner is often used. When such a toner is used, even if a uniform lubricant layer is formed on the toner image bearing member and the toner is easily removed from the toner image bearing member by the cleaning blade, a small amount of toner may be in contact with the toner image bearing member. There are times when it passes through. For this reason, the toner on the toner image carrier cannot be completely removed by the cleaning blade, and the toner remains on the toner image carrier, and a new toner image is formed on the toner image carrier on which the toner remains. A problem occurs.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a lubricant coating apparatus that can satisfactorily remove deposits adhering to the coated surface and suppress the occurrence of abnormal images. It is another object of the present invention to provide a transfer device and an image forming apparatus provided with the lubricant application device.

In order to achieve the above object, the invention of claim 1 includes a lubricant applying means for applying a lubricant to a surface to be coated and a surface moving in the upstream direction of the surface to be coated with respect to the lubricant applying means. A first blade member that abuts on the surface to be coated and removes deposits adhering to the surface to be coated, and abuts on the surface to be coated on the coated surface surface movement direction downstream from the lubricant coating means; In a lubricant application device comprising a second blade member for leveling the lubricant applied to the surface to be coated, the surface movement of the surface to be coated is moved between the first blade member and the second blade member. It arrange | positions so that it may contact | abut with a counter direction with respect to a direction.
According to a second aspect of the present invention, in the lubricant applicator according to the first aspect, the first blade member and the second blade member have elasticity, and the rebound resilience of the first blade member. When the rate is A% and the rebound resilience of the second blade member is B%, the relationship of A ≧ B is satisfied.
According to a third aspect of the present invention, in the lubricant application device of the first or second aspect, the material of the first blade member and the second blade member is urethane rubber.
According to a fourth aspect of the present invention, there is provided a first image carrier that carries a toner image on a surface that moves endlessly, and a first image carrier that has a surface that moves endlessly and is opposed to the first image carrier. The upper toner image is primarily transferred by a primary transfer means, whereby a second image carrier that carries the toner image, and a secondary that secondarily transfers the toner image carried on the second image carrier to a transfer material. A transfer device including a transfer unit, the transfer unit including a lubricant application unit that applies a lubricant to at least one surface of the first image carrier and the second image carrier; The lubricant application device according to claim 1, 2 or 3 is used.
According to a fifth aspect of the present invention, there is provided a latent image bearing member for carrying a latent image, developing means for developing the latent image with toner, and a toner image on the latent image bearing member directly or on an intermediate transfer member. An image forming apparatus provided with a transfer means for transferring via a transfer means uses the transfer apparatus according to claim 4 as the transfer means.
According to a sixth aspect of the present invention, in the image forming apparatus of the fifth aspect, the toner has a volume average particle diameter of 3 to 8 μm, and a ratio between the 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 the fifth or sixth 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. It is characterized by being.
The invention according to claim 8 is the image forming apparatus according to claim 5, 6 or 7, wherein the toner comprises at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant and a release agent. The toner material liquid dispersed in a solvent is obtained by carrying out at least one of crosslinking and elongation reaction in an aqueous medium.
According to a ninth aspect of the present invention, in the image forming apparatus according to the fifth, sixth, seventh or eighth aspect, the toner has a substantially spherical shape.
According to a tenth aspect of the present invention, in the image forming apparatus according to the tenth 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 of the major axis r1 to the minor axis r2 (r2 / r1) is in the range of 0.5 to 1.0, and the ratio of the thickness r3 to the minor axis r2 (r3 / r2) is 0.7 to It is characterized by being in the range of 1.0.

  Here, in the configuration in which the lubricant leveling blade is provided on the downstream side of the moving direction of the toner image carrier from the cleaning blade as in the image forming apparatus described in Patent Document 2, the toner that has passed through the cleaning blade is removed by the lubricant leveling. It is thought that it can be removed with a blade. However, in the configuration in which the lubricant leveling blade is in contact with the toner image carrier in the trailing direction as in the image forming apparatus described in Patent Document 2, the toner leveling performance of the lubricant leveling blade is insufficient and the toner There is a risk that the removal of the material will not be performed well.

  In the present invention, since the second blade member is brought into contact with the surface to be coated in the counter direction with respect to the surface movement direction of the surface to be coated, it is brought into contact with the surface movement direction in the trailing direction. The removal performance of the deposits can be made higher than the case. As a result, the second blade member removes deposits adhered to the coated surface better than the configuration in which the second blade member is brought into contact with the coated surface in the trailing direction with respect to the surface movement direction. can do. Therefore, it is possible to satisfactorily remove the deposits that have passed through the contact portion between the first blade member and the surface to be coated by the second blade member that smoothes out the lubricant.

  As described above, according to the present invention, there is an excellent effect that it is possible to satisfactorily remove the adhered matter adhering to the coated surface and to suppress the occurrence of an abnormal image.

Hereinafter, an image forming apparatus to which the present invention is applied will be described.
FIG. 2 shows an example of the image forming apparatus. The image forming apparatus mainly includes an apparatus main body 100, a paper feed table 200 on which the apparatus main body is mounted, a scanner 300 mounted on the apparatus main body, and an automatic document feeder (ADF) 400 mounted thereon.

  The apparatus main body 100 is provided with a belt device including an intermediate transfer belt 40 formed of an endless belt. In FIG. 2, the intermediate transfer belt 40 is stretched around a drive roller 31, support rollers 32 and 33, and a curved roller 35, and is driven to rotate clockwise in the drawing. Further, the residual toner remaining on the intermediate transfer belt 40 is removed by the cleaning blade 20 brought into contact with the intermediate transfer belt 40 in the counter direction after the secondary transfer, and the lubricant is removed on the intermediate transfer belt 40 from which the toner has been removed. A lubricant applying device 19 is provided for applying the. The apparatus main body 100 forms a toner image of each color of yellow (Y), magenta (M), cyan (C), and black (Bk) along the outer peripheral surface of the intermediate transfer belt 40. 1, image forming units 10Y, 10M, 10C, and 10B including a developing device 2, a photoreceptor cleaning device 3, and a charging device 4 are arranged side by side. An exposure device 13 is provided on each of these image forming units 10. A fixing device 6 is disposed below the belt device. Further, below the fixing device 6, a sheet reversing device 22 that reverses the transfer paper 18 to record images on both sides of the transfer paper 18 is provided.

  In order to form an image using this image forming apparatus, a document is set on the document table of the automatic document feeder 400. Alternatively, the automatic document feeder 400 is opened, a document is set on the contact glass of the scanner 300, and the automatic document feeder 400 is closed and pressed. Next, a start switch (not shown) is pressed. As a result, when a document is set on the automatic document feeder 400, the document is conveyed onto the contact glass. When a document is set on the contact glass, the scanner 300 is immediately driven to read the document image.

  On the other hand, when the start switch is pressed, the drive roller 31 is rotated by a drive motor (not shown). As a result, the intermediate transfer belt 40 is driven and rotated in a predetermined direction. At the same time, black, yellow, magenta, and cyan single color toner images are formed on the respective photoreceptors 1 of the individual image forming units 10. Then, with the rotation of the intermediate transfer belt 40, these single color toner images are sequentially primary-transferred onto the intermediate transfer belt 40. As a result, a full-color composite toner image is formed on the intermediate transfer belt 40.

  When the start switch is pressed, one of the paper feed rollers 23 of the paper feed table 200 is selected and rotated. As a result, the transfer paper 18 is fed out from the corresponding one paper feed cassette 24. The transfer paper 18 is separated and conveyed one by one, and waits while being abutted against the registration roller 25. The transfer paper 18 is fed between the intermediate transfer belt 40 and the secondary transfer roller 17 by rotating the registration roller 25 in synchronization with the composite color image on the intermediate transfer belt 40. As a result, a color image is recorded on the transfer paper 18.

  The transfer paper 18 after the secondary transfer is sent to the fixing device 6. Then, the secondary transfer toner image is fixed on the transfer paper 18 by being heated and pressurized by the fixing device 6. The transfer paper 18 on which the secondary transfer toner image is fixed is discharged out of the apparatus main body and stacked on the paper discharge tray 26. When images are formed on both surfaces of the transfer paper 18, after the image is formed on the surface as described above, the switching claw 27 is switched and the transfer paper 18 is guided to the sheet reversing device 22. With this sheet reversing device 22, the image forming surface of the transfer paper 18 is reversed, and the transfer paper 18 is again guided to the secondary transfer portion. After the image is also recorded and fixed on the back surface of the transfer paper 18, the transfer paper 18 is discharged out of the apparatus main body and stacked on the paper discharge tray 26. On the other hand, the residual toner remaining on the outer peripheral surface of the intermediate transfer belt 40 after the secondary transfer is removed by the lubricant application device 19 having the cleaning blade 20.

  Here, the toner used in this image forming apparatus is a small diameter, narrow particle size distribution and spheroidization (sphericalization) with a polymerized toner in order to cope with recent rapid colorization and accompanying high image quality. ) Is 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 image carrier such as the photoreceptor 1 or the intermediate transfer belt, thereby cleaning the surface of the image carrier. The direction becomes difficult. Further, the reduction in the toner particle size deteriorates the fluidity of the toner and requires a larger amount of additive, which may cause chipping or abrasion of the cleaning blade, local streak scratches on the surface of the image carrier, and the like. It is known to be.

  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.

  Next, toner that is preferably used in the image forming apparatus according to the present exemplary embodiment 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. 3 is a diagram schematically showing the shape of the toner in order to explain the shape factor SF-1 and the shape factor SF-2. The shape factor SF-1 indicates the ratio of the roundness of the toner shape and is expressed 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.

  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 expressed 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.

  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 photosensitive member 1 becomes a point contact, so that the adsorbing force between the toners becomes weak and the fluidity becomes high. The attracting force with the body 1 is also weakened, and the transfer rate is increased. 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) and the polycarboxylic acid (PC) is usually 2/1 to 1/1 as an equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Preferably it is 1.5 / 1-1/1, More preferably, it is 1.3 / 1-1.02 / 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.

<Colorant>
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 salt or compound, tungsten simple substance or compound, fluorine activator, salicylic acid metal salt, metal salt of salicylic acid derivative, and the like. 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 PSYVP2038, 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 (manufactured by Nippon Carlit) ), Copper phthalocyanine, perylene, quinacridone, azo face And other polymeric compounds having functional groups such as sulfonic acid groups, carboxyl groups, and quaternary ammonium salts. Of these, substances that control the negative polarity of the toner are particularly preferably used.

  The amount of charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the developer fluidity is lowered, and the image density is lowered. Invite.

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

  The charge control agent and the release agent can be melt-kneaded together with the master batch and the binder resin, and of course, they may be added when dissolved and dispersed in the organic solvent.

<External additive>
Inorganic fine particles are preferably used as an external additive for assisting the fluidity, developability and chargeability of the toner particles. The primary particle diameter of the inorganic fine particles is preferably 5 × ¹⁰ -3 ~2μm, it is particularly preferably 5 × ¹⁰ -3 ~0.5μm. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The use ratio of the inorganic fine particles is preferably 0.01 to 5 wt% of the toner, and particularly preferably 0.01 to 2.0 wt%.

Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, as the fluidity imparting agent, it is preferable to use hydrophobic silica fine particles and hydrophobic titanium oxide fine particles in combination. In particular, when stirring and mixing are performed using particles having an average particle diameter of 5 × 10 ⁻² μm or less, the electrostatic force and van der Waals force with the toner are remarkably improved. Even when stirring and mixing inside the developing device 2 is performed to obtain a good image quality that does not cause the release of the fluidity imparting agent from the toner and does not generate fireflies, and further reduces the residual toner. Figured.

  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 (manufactured by Asahi Glass), Florard FC-135 (manufactured by Sumitomo 3M), 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 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 embodiment has a substantially spherical shape and can be represented by the following shape rule.

  FIG. 4 is a diagram schematically showing the shape of the toner of the present invention. In FIG. 4A, 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 The ratio (r2 / r1) to the minor axis (see FIG. 4B) is 0.5 to 1.0, and the ratio of the thickness to the minor axis (r3 / r2) (see FIG. 4C) is 0. Preferably it is in the range of 7 to 1.0. When the ratio of the major axis to the minor axis (r2 / r1) is less than 0.5, the dot reproducibility and transfer efficiency are inferior because of being away from the true spherical shape, and high quality image quality cannot be obtained. On the other hand, if the ratio of thickness to minor axis (r3 / r2) is less than 0.7, the shape is close to a flat shape, and a high transfer rate like a spherical toner cannot be obtained. In particular, when the ratio of the thickness to the minor axis (r3 / r2) is 1.0, the rotating body has a major axis as a rotation axis, and the fluidity of the toner can be improved. Note that r1, r2, and r3 were measured with a scanning electron microscope (SEM) while changing the angle of field of view and taking pictures.

  In this embodiment, a lubricant is applied to the surface of the photoreceptor 1 and the surface of the intermediate transfer belt 40 so that the static friction coefficient μs of both can be maintained at an appropriate value. Here, since the lubricant application to the photosensitive member 1 and the lubricant application to the intermediate transfer belt 40 can be performed with substantially the same configuration, the lubricant application to the intermediate transfer belt 40 will be described below as an example.

  FIG. 1 is a partially enlarged view of the vicinity of the lubricant application device 19 in the present embodiment. The lubricant application device 19 is provided in an intermediate transfer belt cleaning unit, and includes a solid lubricant and an application brush 21 as a brush-like member for applying the solid lubricant to the intermediate transfer belt 40. Yes. The solid lubricant is obtained by dissolving a lubricating oil additive mainly composed of zinc stearate and then cooling and solidifying it, and is molded into a bar shape. The solid lubricant is held by the lubricant holding member, and the solid lubricant is pressed against the application brush 21 side through the lubricant holding member by the pressure spring 54 attached to the intermediate transfer belt cleaning unit housing. The application brush 21 is provided in contact with the intermediate transfer belt 40, and the solid lubricant is scraped to the application brush 21 side by the rotation of the application brush 21, and the lubricant attached to the application brush 21 is separated from the intermediate transfer belt 40. To the surface of the intermediate transfer belt 40 from the contact portion.

  As the solid lubricant, a dry solid hydrophobic lubricant can be used. Besides zinc stearate, barium stearate, lead stearate, iron stearate, nickel stearate, cobalt stearate, Those having a stearic acid group such as copper stearate, strontium stearate, calcium stearate, cadmium stearate and magnesium stearate can be used. In addition, the same fatty acid groups zinc oleate, manganese oleate, iron oleate, cobalt oleate, lead oleate, magnesium oleate, copper oleate, palmitic acid, zinc cobalt palmitate, copper palmitate, palmitic acid Magnesium, aluminum palmitate, or calcium palmitate may be used. In addition, fatty acids such as lead caprylate, lead caproate, zinc linolenate, cobalt linolenate, calcium linolenate and cadmium ricolinolenate, metal salts of fatty acids, and the like can also be used. Further, waxes such as candelilla wax, carnauba wax, rice wax, wax, ooba oil, beeswax, and lanolin can be used.

  Next, the characteristic part of this embodiment is demonstrated. In the present embodiment, a cleaning blade 20 as a cleaning unit is brought into contact with the surface of the intermediate transfer belt 40 on the upstream side in the moving direction with respect to the lubricant application position by the application brush 21, and the lubricant application position is in contact with the lubricant application position. Thus, the leveling blade 53 is brought into contact with the surface of the intermediate transfer belt 40 on the downstream side in the moving direction. The cleaning blade 20 and the leveling blade 53 are both made of rubber which is an elastic body, and for example, urethane rubber can be used.

  In the above configuration, the residual toner remaining on the surface of the intermediate transfer belt 40 after the toner image carried on the surface is secondarily transferred to the transfer paper is first removed by the cleaning blade 20. As a result, the application brush 21 comes into contact with the surface of the intermediate transfer belt 40 in a clean state, and the lubricant is applied. When the applied lubricant passes through the contact position of the leveling blade 53 on the downstream side of the surface of the intermediate transfer belt 40 in the moving direction, the surface is leveled and uniformly spread, so that the lubricant of uniform thickness can be obtained. Become a layer.

  As described above, after cleaning the residual toner, the lubricant is applied, and the lubricant is further formed into a uniform layer so that the intermediate transfer belt 40 is cleaned only after the lubricant is applied. Both of the above-mentioned problems occurring in the case of post-cleaning application in which a lubricant is applied after cleaning can be prevented. That is, the application amount of the lubricant is biased by the cleaning after the application, and the surface static friction coefficient is uneven, or the uniform lubricant layer cannot be formed on the surface of the intermediate transfer belt 40 by the application after the cleaning. It is possible to prevent the occurrence of abnormal images such as worm eaters, image blurring, and blurring caused by this, and to maintain the application function of the application brush 21 for a long period of time.

  In addition, as described above, the toner used has a small diameter, narrow particle size distribution and spheroidization (true sphere) due to the polymerized toner, and along with this, it becomes difficult to clean the surface of the image carrier. Further, chipping and abrasion of the cleaning blade, local streak scratches on the surface of the image carrier, etc. are likely to occur. Further, since the toner passes through the blade more, it is necessary to increase the contact pressure more than before, and by increasing the pressure, the margin is reduced against edge chipping due to the local shearing force of the blade.

  Therefore, even if the cleaning blade 20 is chipped or wear is increased, the leveling blade 53 can back up even if the cleaning performance cannot be maintained.

  In the present embodiment, the leveling blade 53 disposed downstream of the cleaning blade 20 in the moving direction of the intermediate transfer belt scrapes off excess lubricant applied to the intermediate transfer belt 40 or uniformly on the belt. In addition to the role of spreading the lubricant and making it easy to form a lubricant film by pressing the lubricant against the belt with a blade, in order to have the following role, in the surface movement direction of the intermediate transfer belt 40 On the other hand, it is installed in the counter direction. In other words, when the transfer residual toner slips through the cleaning blade because the cleaning blade 20 wears with time and the cleaning ability decreases, for example, this cleaning residual toner is scraped off to have a role of cleaning. is there.

  Further, when the leveling blade 53 is brought into contact with the surface of the intermediate transfer belt 40 in the counter direction with respect to the surface movement direction of the intermediate transfer belt 40, and is brought into contact with the surface movement direction in the trailing direction. Therefore, the toner removal performance can be improved.

  Further, when the rebound resilience (rate) of the cleaning blade 20 is A% and the rebound resilience (rate) of the blade 53 is B%, it is preferable that A ≧ B. The reason for setting the rebound resilience in this way is as follows.

  Generally, the greater the resilience of the blade material, the better the cleaning property (especially the cleaning property in a low temperature environment). On the other hand, however, the wear amount of the blade edge with time increases. As described above, one of the purposes of the leveling blade 53 is to back up with the leveling blade 53 even if the cleaning blade 20 is chipped or wear becomes large and cleaning performance cannot be maintained. It is. Accordingly, the cleaning blade 20 has the basic cleaning ability. If the cleaning blade 20 passes through the cleaning blade 20, it only needs to have a cleaning ability enough to clean a small amount of toner. Can be small. Therefore, the rebound resilience of the leveling blade 53 may be set smaller than that of the cleaning blade 20. In addition, since the lifetime is longer than that of the cleaning blade 20, it is desirable to suppress the wear amount with time. This is another reason for setting the rebound resilience of the leveling blade 53 smaller than that of the cleaning blade 20. For example, the rebound resilience of the cleaning blade 20 is set to 44%, the rebound resilience of the leveling blade 53 is set to 17%, and the like.

  In addition, as described above, cleaning is performed with a cleaning blade on the upstream side in the direction of movement of the surface to be coated with respect to the coating brush for applying the lubricant, and the surface to be coated with the leveling blade on the downstream side in the direction of surface movement. The configuration in which the applied lubricant is made uniform can be applied not only to the intermediate transfer belt 40 but also to the photosensitive member 1. An effect can be obtained.

As described above, according to the present embodiment, the application brush 21 that is a lubricant application unit that applies a lubricant to the surface of the intermediate transfer belt 40 that is the surface to be applied, and the intermediate transfer belt 40 that is more than the application brush 21. The cleaning blade 20, which is a first blade member that contacts the surface of the intermediate transfer belt 40 on the upstream side in the surface movement direction and removes toner that is attached to the surface of the intermediate transfer belt 40, and the application brush 21. A leveling blade 53 that is a second blade member that contacts the surface of the intermediate transfer belt 40 on the downstream side of the surface movement direction of the intermediate transfer belt 40 and leveles the lubricant applied to the surface of the intermediate transfer belt 40 is provided. In the lubricant application device 19, the cleaning blade 20 and the leveling blade 53 are brought into contact with the surface movement direction of the intermediate transfer belt 40 in the counter direction. It is arranged so. In this way, the leveling blade 53 is brought into contact with the surface of the intermediate transfer belt 40 in the counter direction with respect to the surface movement direction of the intermediate transfer belt 40, so that it is leveled in the trailing direction with respect to the surface movement direction. The toner removal performance can be made higher than when the blade 53 is brought into contact. Therefore, the deposits that have passed through the cleaning blade 20 can be better removed by the leveling blade 53 than in the configuration in which the leveling blade 53 contacts the surface moving direction in the trailing direction.
Further, according to the present embodiment, the cleaning blade 20 and the leveling blade 53 have elasticity, the rebound resilience of the cleaning blade 20 is A%, and the rebound resilience of the leveling blade 53 is B%. When the relationship of A ≧ B is satisfied, the wear amount of the leveling blade 53 can be made smaller than the wear amount of the cleaning blade 20 over time as described above. Therefore, the life of the leveling blade 53 can be made longer than that of the cleaning blade 20.
Further, according to the present embodiment, the cleaning blade 20 and the leveling blade 53 are made of urethane rubber, so that the cleaning capability and the lubricant leveling capability can be sufficiently exhibited.
Further, according to the present embodiment, the photosensitive member 1 that is the first image carrier that carries the toner image on the surface that moves endlessly, and the surface of the photosensitive member 1 that is opposed to the photosensitive member 1 that has the surface that moves endlessly. An intermediate transfer belt 40 that is a second image carrier that carries the toner image by primary transfer of the toner image by primary transfer means, and a toner image that is carried on the intermediate transfer belt 40 is transferred onto a transfer sheet that is a transfer material. The transfer apparatus having a secondary transfer means for secondary transfer has a lubricant application means for applying a lubricant to at least one surface of the photoreceptor 1 and the intermediate transfer belt 40, and the lubricant application By using the lubricant application device 19 of the present invention as a means, the toner image can be transferred satisfactorily.
Further, according to the present embodiment, the photosensitive member 1 that is a latent image carrier that carries a latent image, the developing device 2 that is a developing unit that develops the latent image with toner, and the toner image on the photosensitive member 1 are transferred. In an image forming apparatus provided with transfer means for transferring directly onto paper or via an intermediate transfer belt 40, an abnormal image is generated by using a transfer apparatus provided with the lubricant applying device 19 of the present invention as the transfer means. Generation | occurrence | production can be suppressed.
According to the exemplary embodiment, the toner has a volume average particle diameter of 3 to 8 μm and a ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is 1.00. It is in the range of ~ 1.40. As a result, the toner charge amount distribution becomes uniform, and a high-quality image with little background fogging can be obtained. Further, the transfer rate can be increased in the electrostatic transfer system.
Further, according to the present embodiment, the toner has a shape factor SF-1 in the range of 100 to 180, and the shape factor SF-2 in the range of 100 to 180, so that the toner has a nearly spherical shape. Therefore, since the contact state between the toner and the toner or the toner and the photoreceptor 1 is point contact, the attractive force between the toners becomes weak and the fluidity becomes high, or the attractive force between the toner and the photosensitive member 1 becomes weak. The transfer rate can be increased. Note that if either of the shape factor SF-1 or the shape factor SF-2 exceeds 180, the transfer rate is lowered, which is not preferable.
Further, according to the present embodiment, 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 is dispersed in an organic solvent is used. By obtaining a crosslink and / or elongation reaction in an aqueous medium, a toner having the above-described characteristics can be obtained.
Further, according to the present embodiment, the toner to be used has a substantially spherical shape, so that the transfer rate can be increased.
Further, according to the present embodiment, the shape of the toner to be used is defined by the major axis r1, the minor axis r2, and the thickness r3 (provided that r1 ≧ r2 ≧ r3), and the shape of the major axis r1 and the minor axis r2 is determined. The ratio (r2 / r1) is in the range of 0.5 to 1.0, and the ratio (r3 / r2) of the thickness r3 to the minor axis r2 is in the range of 0.7 to 1.0. 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.

  In addition, the present invention is not limited to the above-described embodiment, and can be applied to all apparatuses that use the technical idea of the present invention. The photoreceptor 1 and the intermediate transfer member may be any of a belt shape, a drum shape, and a roller shape.

FIG. 3 is an enlarged schematic configuration diagram in the vicinity of a lubricant application device that is a feature of the present invention. 1 is a schematic configuration diagram of a copier according to an embodiment. (A) The figure which showed the shape of the toner typically in order to demonstrate shape factor SF-1. (B) The figure which showed the shape of the toner typically in order to demonstrate shape factor SF-2. (A) Schematic diagram showing the shape of toner used in the copying machine of the present embodiment. (B) A schematic diagram showing the shape of the toner viewed from the z-axis direction. (C) A schematic diagram showing the shape of the toner viewed from the x-axis direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Developing device 3 Photoconductor cleaning device 4 Charging device 6 Fixing device 10 Image forming unit 13 Exposure device 17 Secondary transfer roller 18 Transfer paper 19 Lubricant application device 20 Cleaning blade 21 Application brush 24 Paper feed cassette 25 Lubrication Agent 31 Drive roller 32 Support roller (separation roller)
33 Support roller 35 Curved roller 40 Intermediate transfer belt 50 Opposing member 51 Opposing member 53 Leveling blade 54 Pressure spring 100 Apparatus main body 200 Feeding table 300 Scanner 400 Automatic document feeder

Claims (10)

Lubricant application means for applying a lubricant to the surface to be applied that moves,
A first blade member that comes into contact with the surface to be coated on the upstream side in the moving direction of the surface to be coated with respect to the lubricant coating means, and removes deposits attached to the surface to be coated;
Lubricant coating apparatus comprising: a second blade member that abuts the coated surface downstream of the lubricant coating means in the moving direction of the coated surface and smoothes the lubricant coated on the coated surface In
A lubricant coating apparatus, wherein the first blade member and the second blade member are arranged so as to contact each other in a counter direction with respect to a surface movement direction of the coated surface. The lubricant application device according to claim 1, wherein
The first blade member and the second blade member have elasticity,
A lubricant application device satisfying a relation of A ≧ B, where the rebound resilience of the first blade member is A% and the rebound resilience of the second blade member is B%. The lubricant application device according to claim 1 or 2,
The lubricant applying device, wherein the material of the first blade member and the second blade member is urethane rubber. A first image carrier that carries a toner image on an endlessly moving surface;
A second image carrier having a surface that moves endlessly and carrying the toner image by primary transfer of the toner image on the first image carrier by primary transfer means at a position facing the first image carrier. When,
In a transfer apparatus comprising secondary transfer means for secondary transfer of a toner image carried on the second image carrier to a transfer material,
4. A lubricant applying means for applying a lubricant to at least one surface of the first image carrier and the second image carrier, wherein the lubricant according to claim 1, 2 or 3 is used as the lubricant application means. A transfer device using a coating device. A latent image carrier for carrying the latent image, and developing means for developing the latent image with toner;
In an image forming apparatus comprising: a transfer unit that transfers a toner image on the latent image carrier onto a transfer material directly or via an intermediate transfer member;
An image forming apparatus using the transfer device according to claim 4 as the transfer means. The image forming apparatus according to claim 5.
The toner has a volume average particle diameter of 3 to 8 μm and a ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is in the range of 1.00 to 1.40. An image forming apparatus. The image forming apparatus according to claim 5 or 6,
The image forming apparatus, wherein the toner has a shape factor SF-1 in the range of 100 to 180 and a shape factor SF-2 in the range of 100 to 180. The image forming apparatus according to claim 5, 6 or 7.
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 subjected to at least crosslinking and elongation reaction in an aqueous medium. An image forming apparatus obtained by performing one of the steps. The image forming apparatus according to claim 5, 6, 7, or 8.
The image forming apparatus, wherein the toner has a substantially spherical shape. The image forming apparatus according to claim 10.
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 having a thickness in the range of 0.5 to 1.0 and a ratio (r3 / r2) of the thickness r3 to the minor axis r2 in the range of 0.7 to 1.0.

Images