JP2008197404A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus, wherein even if the edges of a cleaning blade are worn with the lapse of time and the contact area of the same with an image carrier is widened, blade curling is hardly caused and stable quality can be maintained over a long period, at a low cost. <P>SOLUTION: The image forming apparatus has a plurality of image carriers 1, a lubricant application device A7 provided at the first image carrier Al installed on the upstream side viewed from the transferring direction of a developer, and a cleaning blade A61 installed in a counter system at each image carrier A1 on and after the second one installed on the downstream side, wherein the lubricant application region is wider than the effective cleaning region A63 in the cleaning blade A61. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus that includes a lubricant application device that applies a lubricant to an image carrier, and includes a counter type cleaning blade on the image carrier.

In recent years, there has been an increasing demand for higher image quality in image forming apparatuses, and in particular, in order to realize high-definition color image formation, toner particle diameters and spheroidization have been promoted. The dot reproducibility is improved by reducing the particle size, and the developability and transferability can be improved by making the particles spherical. Since it is very difficult to produce such a small particle size and spherical toner by the conventional kneading and pulverization method, the polymerization produced by suspension polymerization method, emulsion polymerization method, dispersion polymerization method, etc. Toner is being adopted. However, when a toner having a small particle size and a spherical shape is used, it is difficult to clean residual toner on an image carrier such as a photosensitive member or an intermediate transfer member by a generally used blade cleaning method. For this reason, a method for applying a lubricant such as zinc stearate directly or indirectly onto the image carrier has been proposed as one of the solutions.
For example, in Patent Document 1 and Patent Document 2, a lubricant is applied to a photoconductor or an intermediate transfer body to improve the cleaning property of polymerized toner or improve image quality.

In contrast, for example, in Patent Document 1, an image carrier that carries a toner image on a surface that moves endlessly, and a toner on the image carrier that has a surface that moves endlessly and is opposed to the image carrier. In an image forming apparatus having an intermediate transfer member that carries the toner image by primary transfer of the image, and secondarily transferring the toner image carried on the intermediate transfer member to a transfer material, the image carrier and Lubricant application means for applying a lubricant to a toner image non-carrying region before carrying a toner image on at least one surface of the intermediate transfer member, and a surface of a member to be coated before the lubricant is applied There is disclosed an image forming apparatus provided with a cleaning means for cleaning the toner and a lubricant leveling means for uniformly leveling the lubricant applied by the lubricant applying means on the surface to be coated. As a result, in an intermediate transfer type image forming apparatus, by applying a lubricant to the surface of a member to be coated after cleaning, and smoothing the lubricant, it is possible to obtain an excellent image free of abnormal images such as worm erosion, image blur, and blurring. A transfer image can be obtained.
Further, in Patent Document 2, a lubricant film is formed in which a solid lubricant is brought into contact with a rotating brush, the lubricant adhered to the brush is applied to an image carrier, and a film made of the lubricant is formed on the surface of the image carrier. Forming means and image data counting means for counting image data to be imaged on the image carrier, and applying the lubricant on the surface of the image carrier based on the information of the image data counting means An image forming apparatus for controlling the above is disclosed. As a result, by optimizing the amount of solid lubricant applied to the surface of the photoconductor drum, a highly reliable image forming apparatus that does not cause poor cleaning, fusing, increase in driving torque, etc. throughout its endurance life. Obtainable.

In an image forming apparatus using an electrophotographic process, a counter system in which a cleaning blade made of an elastic material such as rubber is pressed against the moving direction of the image carrier in a direction opposite to the moving direction of the image carrier is the mainstream. It is. However, the counter type cleaning blade is unstable with respect to the movement of the surface of the image carrier, and when the blade is brought into contact with the image carrier, the tip of the blade is caught in the movement of the image carrier. In other words, so-called blade turning occurs. On the other hand, since the sufficient cleaning function is not exhibited if it is laid too much, setting the contact angle of the blade is a very difficult task.
Further, the edge of the cleaning blade wears with time, and the contact area with the image carrier increases and the frictional force increases, so that the blade is more likely to turn over with time.
Another trend in recent years is that the replacement unit has been prolonging its life, but for the above reasons, it is very difficult to make a stable design so that the blade does not turn over for a long period of time.
One way to solve this is to apply a lubricant to the second and subsequent image carriers to reduce the frictional force with the blade and make it difficult to turn the blade. The provision of the agent application device (consisting of a solid lubricant, a holding member for holding the lubricant, an application member, a pressing member, and the like) goes against the trend of the times in terms of cost and space.

JP 2001-305907 A JP2002-244485

  The present invention has been made in view of the above problems, and even if the edge of the cleaning blade wears out over time and the contact area with the image carrier increases, the blade does not easily wobble and has a stable quality over a long period of time. It is to provide an image forming apparatus that can maintain the image quality at an inexpensive price.

The features of the present invention, which is a means for solving the above problems, are listed below.
In order to solve the above-described problems, the lubricant application region applied to the first image carrier is made wider than the effective cleaning region of the cleaning blade installed on the second and subsequent image carriers. That is, in the image forming apparatus of the present invention, a plurality of types of image carriers are provided, the first image carrier installed upstream from the transfer direction of the developer is provided with a lubricant application device, and installed downstream. In the image forming apparatus provided with a cleaning blade installed in a counter manner in the second and subsequent image carriers, the lubricant application area is wider than the effective cleaning area of the cleaning blade.

  As described above, in the image forming apparatus of the present invention, the lubricant applied to the image carrier moves in a small amount to the downstream image carrier through the contact point, and the friction coefficient of the downstream image carrier. Lower. Since the lubricant application area is wider than the effective cleaning area of the cleaning blade, the friction coefficient of the image carrier is uniformly reduced in the effective cleaning area, and the blade is less likely to be caught.

FIG. 1 will be described from the overall configuration of the image forming apparatus employed in the present application.
An image forming unit (A) is disposed substantially at the center of the in-body discharge type image forming apparatus, and a sheet feeding unit (B) is disposed immediately below the image forming unit (A). If necessary, another sheet feeding device can be added at the bottom. Above the image forming unit (A), a reading unit (C) that reads a document through a paper discharge storage unit (D) is disposed. A recording medium (hereinafter referred to as paper) on which an image has been formed is discharged and stored in the discharge storage section (D). The arrows in FIG. 1 indicate the sheet passing path.
In the image forming unit (A), a charging device (A2) for charging the surface of the photoconductor (A1) around the drum-shaped photoconductor (A1), and image information is irradiated to the surface of the photoconductor with laser light. An exposure device (A10), a developing device (A3) for visualizing an electrostatic latent image formed by exposure on the surface of the photoconductor (A1), and a toner image developed on each of the plurality of photoconductors (A1). Intermediate transfer device (A4) for superimposing, transfer device (A5) for transferring to paper, cleaning device (A6) for removing and collecting toner remaining on the surface of the photoconductor after transfer, surface of the image carrier such as photoconductor (A1), etc. A lubricant application device (A7) for lowering the friction coefficient and a fixing device (A8) for fixing the toner on the paper on which the toner image has been obtained are arranged downstream in the paper conveyance path. In order to facilitate maintenance, the photoconductor (A1), charging device (A2), developing device (A3), cleaning device (A6), etc. can be incorporated into a single unit as a process cartridge (PC) and detachable from the main unit. It was. For the same reason, the cleaning device (A6) and the lubricant application device (A7) are housed in one unit and are detachable from the intermediate transfer device (A4). Further, the cleaning device (A6), the lubricant application device (A7), and the transfer member (A51) are integrally accommodated, and can be attached to and detached from the main body device. The paper that has passed through the fixing device passes through a paper discharge roller (A9) and is discharged and stored in a paper discharge storage section (D).

  In the paper feed unit (B), unused paper is stored, and the uppermost paper is fed out from the paper feed cassette by the rotation of the paper feed roller (B1) and conveyed to the registration roller (A11). The registration roller (A11) is controlled to start rotation at a timing so that the conveyance of the paper is temporarily stopped and the positional relationship between the toner image on the surface of the photosensitive member and the leading edge of the paper becomes a predetermined position. In the reading unit (C), a reading traveling body (C1) including a light source for document illumination and a mirror reciprocates in order to perform reading scanning of a document (not shown) placed on the contact glass (C2). Image information scanned by the reading traveling body (C1) is read as an image signal into the CCD (C4) installed behind the lens (C3). The read image signal is digitized and subjected to image processing. Based on the image-processed signal, an electrostatic latent image is formed on the surface of the photoreceptor (A1) by light emission of a laser diode (not shown) of the exposure apparatus (A10). The optical signal from the laser diode reaches the photosensitive member via a known polygon mirror or lens.

  FIG. 2 is a diagram in which the present invention is applied to a process cartridge (PC). The charging device (A2) mainly includes a charging member (A21) and an urging member (A22) that pressurizes the charging member (A21) with a predetermined pressure. The charging member (A21) has a conductive elastic layer around a conductive shaft. A predetermined voltage is applied to the gap between the conductive elastic layer and the photoconductor (A1) via a conductive shaft by a voltage application device (not shown), thereby applying a charge to the surface of the photoconductor. In the developing device (A3), the developer is sufficiently stirred by the stirring screw (A33) and is magnetically attached to the developing roller (A31). The attached developer is thinned on the developing roller (A31) by the developing doctor (A32). The electrostatic latent image on the photoreceptor (A1) is visualized with the thinned developer. The visualized toner image is electrically attached on the intermediate transfer belt (A41) by the transfer bias roller (A42). Residual toner that has not been transferred onto the intermediate transfer belt (A41) is removed from the photoreceptor (A1) by the cleaning device (A6). The lubricant application member (A71) is formed in a roller shape by winding a brush around a metal shaft. The solid lubricant (A72) is urged to the lubricant application member (71) by its own weight, and by rotating the lubricant application member (A71), the solid lubricant (A72) is scraped off into a fine powder, and the photosensitive member ( Apply a lubricant to the surface of A1). At this time, the lubricant application area to which the lubricant is applied is substantially the entire surface of the photoreceptor A1, and is wider than the effective cleaning area A63 shown below. This is because the effective cleaning area A63 is determined by the cleaning property or the like, but it is necessary to apply the lubricant to the entire surface in contact with the cleaning blade.

  FIG. 3 shows the transfer cartridge. The lubricant application device (A7) and the cleaning device (A6) are integrally provided in the housing to form a transfer cartridge. The solid lubricant (A72) is urged at a predetermined pressure by the urging member (A73) to the lubricant application member (A71) composed of a brush roller. The solid lubricant (A72) is scraped off by the rotation of the lubricant application member (A71) and applied to the surface of the intermediate transfer device (A4). A cleaning device (A6) is installed upstream of the cleaning device, and includes a cleaning brush roller (A62) and a cleaning blade (A61). The brush roller (A62) rotates in the same direction as the rotation direction of the transfer device (A4), and diffuses foreign matter on the surface. The cleaning blade (A61) is in contact with the intermediate transfer device (A4) at a predetermined angle and pressure, and removes residual toner on the intermediate transfer device (A4).

FIG. 4 is a view showing another transfer cartridge. The cleaning device (A6) and the transfer member (A51) are integrally provided in the housing to form a transfer cartridge. As shown in the figure, a cleaning device (A6) is installed to remove residual toner on the transfer member (A51).
FIG. 5 is a view showing the front and side surfaces of the cleaning blade (A61). The cleaning blade (A61) is composed of a rubber sheet (A65) portion mainly made of rubber such as urethane, and a support plate (A66) for supporting it. Further, when viewed in the longitudinal direction, it can be divided into an effective cleaning area (A63) at the center and reduced pressure areas (A64) at both ends. The effective cleaning area (A63) is the part that is responsible for cleaning the image carrier. In the decompression regions (A64) at both ends, the support plate (A66) is cut obliquely, and the rubber sheet (A65) portion protruding from the support plate (A66) (so-called protruding amount) is elongated toward the end portion. This is a portion where the contact pressure with the image carrier is decreased. Since the end portion of the rubber sheet (A65) is free, self-excited vibration is likely to occur due to sliding friction with the image carrier 1, and abnormal noise and banding images are likely to occur. As a countermeasure, the contact pressure is reduced. At this time, the lubricant application area to which the lubricant is applied is substantially the entire surface of the photoreceptor A1, and is wider than the effective cleaning area A63 shown below. In other words, the lubricant application area includes both the central effective cleaning area (A63) and the decompression areas (A64) at both ends. As a result, the generation of abnormal noise and banding images due to sliding friction of the cleaning blade can be suppressed.

FIG. 6 is a diagram for explaining the contact angle θ between the image carrier and the cleaning blade (A61). The tip of the blade is in contact with the moving direction of the surface of the image carrier so as to face in the opposite direction. The contact angle θ is defined as an angle formed by a tangent line between the image carrier and the contact point between the image carrier and the cleaning blade (A61) and a receiving surface of the remaining toner on the cleaning blade (A61).
FIG. 7 is a graph showing the relationship between the travel distance D and the blade contact angle θ. The edge of the cleaning blade (A61) is worn by sliding friction with the image carrier over time, and the contact area with the image carrier increases. As the contact area increases, the sliding friction also increases, so that the blade is likely to turn up. An area where the blade is not turned over is shown in the graph as an “OK area”, and an area where the blade is likely to occur is shown as an “NG area”. The boundary line shows a downward trend over time. It can be seen that the boundary line of the present invention is shifted upward as compared with the boundary line in the conventional design, and the margin is improved. When the blade contact angle θ is actually set, the middle vicinity of this region is selected in consideration of the dimensional tolerances and mounting tolerances of the parts, but when the same blade contact angle is selected, It can be seen that blades are less likely to turn over and are stable over a long period of time.

  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, and palmitic acid, zinc cobalt palmitate, copper palmitate, palmitate Magnesium acid, aluminum palmitate, and 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.

In the image forming apparatus of the present invention, the toner used in the developing device 10 has a volume average particle diameter of 3 to 8 μm, and 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.
By using a toner having a small particle diameter, the toner can be densely attached to the latent image. However, when the volume average particle size is smaller than the range of the present invention, in the case of a two-component developer, the toner is fused to the surface of the magnetic carrier during a long period of stirring in the developing device, and the charging ability of the magnetic carrier is reduced. When used as a developer, toner filming on the developing roller and toner fusion to a member such as a blade for thinning the toner are likely to occur. On the contrary, when the volume average particle diameter of the toner is larger than the range of the present invention, it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the developer is performed. In many cases, the variation in toner particle size becomes large.
Further, by narrowing the particle size distribution, the toner charge amount distribution becomes uniform, a high-quality image with little background fogging can be obtained, and the transfer rate can be increased. However, it is not preferable that Dv / Dn exceeds 1.40 because the charge amount distribution becomes wide and the resolving power decreases.
The average particle size and particle size distribution of the toner can be measured using a Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter). In the present invention, a Coulter counter TA-II type was used, connected to an interface (manufactured by Nikka Giken) and a personal computer (PC9801: manufactured by NEC) to output the number distribution and volume distribution.

The image forming apparatus that can achieve the effect of mounting the cleaning blade 33 or 43 of the present invention is a case where the toner used in the developing device 10 is a toner having a high degree of circularity with an average circularity of 0.93 or more. . Toner with a high degree of circularity enters the gap between the image carrier and the cleaning blade in blade-type cleaning, and easily slips through. When the contact pressure of the cleaning blade 33 or 43 against the image carrier is increased, the damage to the image carrier increases. Also, in the method of electrostatically collecting toner by applying a bias reverse to the charging polarity of the toner to the brush roller, it is difficult to remove the toner from the brush roller. There is a tendency that the toner removing ability is lowered.
However, even when the above-described toner having a high average circularity is used by the cleaning blade 33 or 43 of the present invention, the surface of the image carrier can be efficiently cleaned as follows.
The average circularity of the toner is a value obtained by dividing particles by the circumference of an equivalent circle having the same projected area after optically detecting particles. Specifically, the measurement is performed using a flow type particle image analyzer (FPIA-2000; manufactured by Sysmex Corporation). In a predetermined container, 100 to 150 mL of water from which impure solids are removed in advance is added, 0.1 to 0.5 mL of a surfactant is added as a dispersant, and about 0.1 to 9.5 g of a measurement sample is further added. The suspension in which the sample is dispersed is subjected to dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the concentration and dispersion of the dispersion are set to 3,000 to 10,000 / μL, and the shape and distribution of the toner are measured.

The toner used in the image forming apparatus of the present invention preferably 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. FIG. 8 is a diagram schematically showing the shape of the toner for explaining the shape factor SF-1 and the shape factor SF-2. The shape factor SF-1 indicates the ratio of the roundness of the toner shape and is represented by the following formula (1). This is a value obtained by dividing the square of the maximum length MXLNG of the shape formed by projecting the toner on a two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-1 = {(MXLNG) 2 / AREA} × (100π / 4) Formula (1)
When the value of SF-1 is 100, the shape of the toner becomes a true sphere, and becomes larger as the value of SF-1 increases.
The shape factor SF-2 indicates the ratio of the unevenness of the toner shape, and is represented by the following formula (2). A value obtained by dividing the square of the perimeter PERI of the figure formed by projecting the toner onto the two-dimensional plane by the figure area AREA and multiplying by 100 / 4π.
SF-2 = {(PERI) 2 / AREA} × (100 / 4π) (2)
When the value of SF-2 is 100, there is no unevenness on the toner surface, and as the value of SF-2 increases, the unevenness of the toner surface becomes more prominent.
When the shape of the toner is close to a sphere, the contact between the toner and the toner or the toner and the image carrier is close to 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. On the other hand, since spherical toner tends to enter the gap between the cleaning blade 8a and the photoreceptor 1, the toner shape factor SF-1 or SF-2 is preferably large to some extent. Further, when SF-1 and SF-2 are increased, toner is scattered on the image and the image quality is lowered. For this reason, it is preferable that SF-1 and SF-2 do not exceed 180.
Specifically, the shape factor is measured by taking a photograph of the toner with a scanning electron microscope (S-800: manufactured by Hitachi, Ltd.) and introducing it into an image analyzer (LUSEX 3: manufactured by Nireco) for analysis. And calculated.

The toner suitably used in the image forming apparatus of the present invention is, for example, 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. Is a toner obtained by crosslinking and / or elongation reaction in an aqueous solvent. Hereinafter, examples of the constituent material and the manufacturing method of the toner will be described.
(Modified polyester)
The toner according to the present invention contains a modified polyester (i) as a binder resin. The modified polyester (i) refers to a state in which a bonding group other than an ester bond is present in the polyester resin, or resin components having different configurations are bonded to the polyester resin by a covalent bond, an ionic bond, or the like. Specifically, the polyester terminal is modified by introducing a functional group such as a carboxylic acid group or an isocyanate group that reacts with a hydroxyl group into the polyester terminal and further reacting with an active hydrogen-containing compound.
Examples of the modified polyester (i) include urea-modified polyester obtained by a reaction between a polyester prepolymer (A) having an isocyanate group and amines (B). As the polyester prepolymer (A) having an isocyanate group, a polyester having a polycondensate of a polyhydric alcohol (PO) and a polyvalent carboxylic acid (PC) and having an active hydrogen group is further added to a polyvalent isocyanate compound (PIC). And those reacted with. Examples of the active hydrogen group possessed by the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, and the like. Among these, an alcoholic hydroxyl group is preferable.

The urea-modified polyester is produced as follows.
Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable. Dihydric alcohol (DIO) includes 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.) adducts; alkylene oxides of the above bisphenols (ethylene oxide) De, propylene oxide, and the like butylene oxide, etc.) adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyhydric alcohol (TO) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). (DIC) alone and (DIC) with a small amount of (TC) Mixtures are preferred. Divalent carboxylic acids (DIC) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polyvalent carboxylic acid (TC) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polyhydric carboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.).
The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; Those blocked with caprolactam or the like; and combinations of two or more of these.
The ratio of the polyvalent isocyanate compound (PIC) is usually 5/1 to 1/1, preferably as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1, when a urea-modified polyester is used, the urea content in the ester is lowered and hot offset resistance is deteriorated.

The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.
The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

Next, as amines (B) to be reacted with the polyester prepolymer (A), a divalent amine compound (B1), a trivalent or higher polyvalent amine compound (B2), an amino alcohol (B3), an amino mercaptan (B4) ), Amino acid (B5), and amino acid block of B1 to B5 (B6).
Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like. Examples of the trivalent or higher polyvalent amine compound (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of the compound (B6) obtained by blocking the amino group of B1 to B5 include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.
The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is more than 2 or less than 1/2, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance is deteriorated.

The urea-modified polyester may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.
The modified polyester (i) used in the present invention is produced by a one-shot method or a prepolymer method. The weight average molecular weight of the modified polyester (i) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000. The peak molecular weight at this time is preferably 1000 to 10000. When the molecular weight is less than 1000, the elongation reaction hardly occurs, the elasticity of the toner is small, and as a result, the resistance to hot offset deteriorates. On the other hand, when it exceeds 10,000, the problem in production becomes high in the deterioration of fixability, particle formation and pulverization. The number average molecular weight of the modified polyester (i) is not particularly limited when the unmodified polyester (ii) described later is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. (I) When used alone, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color device are deteriorated. In the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B) to obtain the modified polyester (i), a reaction terminator is used as necessary to adjust the molecular weight of the resulting urea-modified polyester. be able to. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds). The molecular weight of the polymer produced can be measured using gel permeation chromatography (GPC) with THF as a solvent.

(Unmodified polyester)
In the present invention, not only the modified polyester (i) is used alone, but also the unmodified polyester (ii) can be contained as a binder resin component together with the (i). By using (ii) in combination, the low-temperature fixability and the gloss when used in a full-color device are improved, which is preferable to single use. Examples of (ii) include polycondensates of polyhydric alcohol (PO) and polyvalent carboxylic acid (PC) similar to the polyester component of (i), and preferred ones are also the same as (i). . (Ii) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, and may be modified with a urethane bond, for example. It is preferable that (i) and (ii) are at least partially compatible in terms of low-temperature fixability and hot offset resistance. Accordingly, the polyester component (i) and (ii) preferably have similar compositions. When (ii) is contained, the weight ratio of (i) to (ii) is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, Particularly preferred is 7/93 to 20/80. When the weight ratio of (i) is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

The peak molecular weight of (ii) is usually 1000 to 10,000, preferably 2000 to 8000, and more preferably 2000 to 5000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. The hydroxyl value of (ii) is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. The acid value of (ii) is preferably 1 to 5, more preferably 2 to 4. Since a high acid value wax is used as the wax, the low acid value binder leads to electrification and high volume resistance, so that it is easy to match the toner used for the two-component developer.
The glass transition point (Tg) of the binder resin is usually 35 to 70 ° C, preferably 55 to 65 ° C. If the temperature is lower than 35 ° C., the heat-resistant storage stability of the toner deteriorates, and if it exceeds 70 ° C., the low-temperature fixability becomes insufficient. Since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the toner of the present invention tends to have good heat storage stability even when the glass transition point is low, as compared with known polyester-based toners. Show.
The glass transition point (Tg) can be measured with a differential scanning calorimeter (DSC).

(Coloring agent)
As the colorant, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher , Yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sayred, Parachlor Ortonito Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmin Min BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R , Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thio Indigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Lid Russian nin green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

  The colorant can also be used as a master batch combined with a resin. As a binder resin to be kneaded with the production of the master batch or the master batch, a polymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyl toluene or the like, or a copolymer of these and a vinyl compound, Polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, fat Aromatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like can be mentioned, and these can be used alone or in combination.

(Charge control agent)
Known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salts or compounds, tungsten simple substances or compounds, fluorine activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenolic condensate E-89 (above, Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSY VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit) Manufactured), copper phthalocyanine, perylene, quinacridone, azo series Fee, a sulfonic acid group, a carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts. Of these, substances that control the negative polarity of the toner are particularly preferably used.
The amount of charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the flowability of the developer is lowered, and the image density is lowered. Invite.

(Release agent)
As a release agent, a low melting point wax having a melting point of 50 to 120 ° C. works more effectively as a release agent in the dispersion with the binder resin between the fixing roller and the toner interface. The effect on high temperature offset is exhibited without applying a release agent such as oil. Examples of such a wax component include the following. Examples of waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, 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 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 diameter of 5 × 10-2 μm or less, the electrostatic force and van der Waals force with the toner are remarkably improved. Even when stirring and mixing inside the developing device is performed, 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 added amount of the hydrophobic silica fine particles and the hydrophobic titanium oxide fine particles is in the range of 0.3 to 1.5 wt%, the charge rising characteristics are not greatly impaired, and the desired charge rising characteristics can be obtained, that is, repeated copying. Stable image quality can be obtained even if

Next, a toner manufacturing method will be described. Here, although a preferable manufacturing method is shown, it is not limited to this.
(Toner production method)
1) A toner material solution is prepared by dispersing a colorant, unmodified polyester, a polyester prepolymer having an isocyanate group, and a release agent in an organic solvent.
The organic solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal after toner base particle formation. Specifically, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, Methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable. The usage-amount of an organic solvent is 0-300 weight part normally with respect to 100 weight part of polyester prepolymers, Preferably it is 0-100 weight part, More preferably, it is 25-70 weight part.

2) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles.
The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.
The amount of the aqueous medium used relative to 100 parts by weight of the toner material liquid is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner material liquid is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical.
Further, in order to improve the dispersion in the aqueous medium, a dispersant such as a surfactant and resin fine particles is appropriately added.
As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride, fatty acid amide derivative, polyhydric alcohol Nonionic surfactants such as derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine And the like.

Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-Hydroxyethyl) Perful Olooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned.
Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).
Moreover, as the cationic surfactant, aliphatic quaternary ammonium such as aliphatic primary, secondary or secondary amic acid, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt which has a right fluoroalkyl group is used. Salt, benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (Asahi Glass Co., Ltd.), Florard FC-135 (Sumitomo 3M Co., Ltd.), Unidyne DS-202 (Daikin Industries) Smoke), Megafac F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products), Footage F-300 (Neos), and the like.

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

As a dispersant that can be used in combination with the above resin fine particles and inorganic compound dispersant, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as acrylic acid-β-hydroxyethyl, methacrylic acid-β-hydroxyethyl, acrylic acid-β-hydroxypropyl, methacrylic acid-β-hydroxypropyl, acrylic acid-γ-hydroxypropyl, methacrylic acid-γ-hydroxy Propyl, acrylic acid-3-chloro-2-hydroxypropyl, methacrylic acid-3-chloro-2-hydroxypropyl, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate Luric acid esters, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or compounds containing vinyl alcohol and a carboxyl group Esters such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl Nitrogen compounds such as imidazole and ethyleneimine, or homopolymers or copolymers such as those having a heterocyclic ring thereof, polyoxyethylene, poly Xoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxy Polyoxyethylenes such as ethylene nonylphenyl ester, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.
The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. Among these, the high-speed shearing method is preferable in order to make the particle size of the dispersion 2 to 20 μm. When a high-speed shearing disperser is used, the number of rotations 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 of the isocyanate group structure of the polyester prepolymer (A) with 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.

Further, the toner according to the present invention has a substantially spherical shape and can be represented by the following shape rule.
FIG. 9 is a diagram schematically showing the shape of the toner according to the present invention. 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 ratio of the minor axis to the major axis (r2). / R1) (see (b)) is 0.5 to 1.0 and the ratio of thickness to minor axis (r3 / r2) (see (c)) is in the range of 0.7 to 1.0. Is preferred. If the ratio of the minor axis to the major axis (r2 / r1) is less than 0.5, the distance from the true spherical shape is inferior, so that dot reproducibility and transfer efficiency are inferior, and high quality image quality cannot be obtained. On the other hand, if the ratio of thickness to minor axis (r3 / r2) is less than 0.7, the shape is close to a flat shape, and a high transfer rate like a spherical toner cannot be obtained. In particular, when the ratio of the thickness to the minor axis (r3 / r2) is 1.0, the rotating body has a major axis as a rotation axis, and the fluidity of the toner can be improved.
Note that r1, r2, and r3 were measured with a scanning electron microscope (SEM) while changing the angle of field of view and taking pictures.

  The toner produced as described above can also be used as a one-component magnetic toner that does not use a magnetic carrier or a non-magnetic toner. When used in a two-component developer, it may be used by mixing with a magnetic carrier, and the magnetic carrier is a ferrite containing a divalent metal such as iron, magnetite, Mn, Zn, Cu, A volume average particle size of 20 to 100 μm is preferred. If the average particle size is less than 20 μm, carrier adhesion is likely to occur on the photoreceptor 1 during development. Cheap. In addition, Cu ferrite containing Zn is preferable because of high saturation magnetization, but can be appropriately selected according to the process of the image forming apparatus. The resin for coating the magnetic carrier is not particularly limited, and examples thereof include silicone resin, styrene-acrylic resin, fluorine-containing resin, and olefin resin. In the manufacturing method, the coating resin may be dissolved in a solvent, sprayed into a fluidized bed and coated on the core, or the resin particles are electrostatically attached to the core particles and then thermally melted for coating. It may be a thing. The resin to be coated has a thickness of 0.05 to 10 μm, preferably 0.3 to 4 μm.

1 is a diagram illustrating a configuration of an image forming apparatus using the present invention. It is explanatory drawing of a process cartridge. It is explanatory drawing of a transfer cartridge. It is explanatory drawing of another transfer cartridge. It is explanatory drawing of a cleaning blade. It is explanatory drawing of contact angle (theta). It is the graph which showed the comparison with the past and this invention. FIG. 4 is a diagram schematically illustrating the shape of a toner for explaining the shape factor SF-1 and the shape factor SF-2. FIG. 3 is a diagram schematically illustrating the shape of a toner according to the present invention.

Explanation of symbols

A Image forming unit A1 Photoconductor A2 Charging device A21 Charging member A22 Biasing member



A3 Developing device A31 Developing roller A32 Developing sleeve A33 Stirring screw A4 Intermediate transfer device A41 Intermediate transfer belt A42 Transfer bias roller A5 Transfer device A51 Transfer member

A6 Cleaning device A61 Cleaning blade A62 Cleaning brush roller A63 Effective cleaning region A64 Depressurization region A65 Rubber sheet A66 Support plate A7 Lubricant coating device A71 Lubricant coating member A72 Solid lubricant

A8 Fixing device A9 Paper discharge roller A10 Exposure device A11 Registration roller B Paper feed part B1 Paper feed roller C Reading part C1 Reading traveling body C2 Contact glass C3 Lens C4 CCD
D Paper storage compartment PC Process cartridge

Claims (9)

A plurality of types of image carriers, a first image carrier disposed upstream from the transfer direction of the developer is provided with a lubricant application device, and second and subsequent image carriers disposed downstream are provided. Is an image forming apparatus equipped with a cleaning blade installed in a counter manner,
An image forming apparatus, wherein a lubricant application area is wider than an effective cleaning area of the cleaning blade. The image forming apparatus according to claim 1, wherein the support plate that supports the cleaning blade is cut obliquely so as to gradually become smaller from the effective cleaning area of the cleaning blade toward the end. The lubricant is a fatty acid metal salt,
The metal of the fatty acid metal salt is a metal selected from zinc, iron, calcium, aluminum, lithium, magnesium, strontium, barium, cerium, titanium, zirconium, lead, manganese,
The image formation according to claim 1 or 2, wherein the fatty acid of the fatty acid metal salt is at least one fatty acid selected from lauric acid, stearic acid, palmitic acid, mysteric acid, and oleic acid. apparatus. The image forming apparatus according to claim 1, wherein the lubricant is made of a fatty acid salt metal having a lamellar crystal structure. The image forming apparatus uses a toner having a volume average particle diameter of 10 μm or less and a ratio (dispersity) of the volume average particle diameter to the number average particle diameter in the range of 1.00 to 1.40. The image forming apparatus according to claim 1. The image forming apparatus according to claim 1, wherein the image forming apparatus uses toner having an average circularity in a range of 0.93 to 1.00. The image forming apparatus according to any one of claims 1 to 6, wherein the image forming apparatus uses toner having SF-1 of 100 to 180 and SF-2 of 100 to 180. . The image forming apparatus has a substantially spherical appearance.
The ratio of the minor axis to the major axis (r2 / r1) is in the range of 0.5 to 1.0, and the ratio of the thickness to the minor axis (r3 / r2) is in the range of 0.7 to 1.0. The image forming apparatus according to claim 1, wherein toner satisfying a relationship of major axis r 1 ≧ minor axis r 2 ≧ thickness r 3 is used. In the toner, a toner composition containing at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent is crosslinked and / or extended in an aqueous medium in the presence of resin fine particles. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.

Images