JP2006030654A - Toner and image forming apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus in which both anti-filming property and cleanability of an image carrier are ensured. <P>SOLUTION: A technique for measuring the sticking strength of a metal oxide external additive such as large-particle-diameter silica to toner and the free amount is established. Under evaluation by this system, a metal oxide whose number average particle diameter is in a range of 100-300 nm is used as an external additive and the amount of free external additive to the toner is regulated to 0.1-1.0 part, whereby in the image forming apparatus of the invention, filming is suppressed and cleanability is improved, therefore it is made possible to stably provide good images. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a toner for developing an electrostatic latent image used for image formation by an electrostatic copying process such as a copying machine, a facsimile machine, and a printer, and an image forming apparatus using the toner.

  In an image forming method such as electrophotography, electrostatic recording, and electrostatic printing, in the development process, for example, toner contained in a developer is temporarily attached to an image carrier such as a photosensitive member on which an electrostatic image is formed. Then, after the toner is transferred from the photoreceptor to a transfer medium such as transfer paper in the transfer process, the toner is fixed on the paper surface in the fixing process. The developer is classified into a one-component development method and a two-component development method, and a two-component developer composed of a magnetic carrier and a toner, and a one-component developer that does not require a magnetic carrier (magnetic toner, Non-magnetic toners are known.

Conventionally, as a toner, a dry toner of a kneading and pulverizing method, which is produced by melting and kneading a toner binder such as a styrene resin or a polyester resin together with a colorant or the like and finely pulverizing the toner binder, is used. However, in recent years, there has been an increasing demand for higher image quality, and in order to realize particularly high-definition color image formation, toner particles are being made smaller and spherical. The reproducibility of dots is improved by reducing the particle size, and the developability and transferability can be improved by making the particles spherical.
The toner composed of this resin has a volume average particle diameter of about 10 μm, and externally added inorganic / organic fine particles imparting fluidity to supplement transportability and mixing properties. As a method for adding inorganic fine particles or the like to a toner, a method of adhering inorganic fine particles such as silica, alumina, titanium oxide or the like together with the toner by dry mixing and stirring with a mixer or the like is common.

However, the inorganic fine particles externally added to the toner for imparting fluidity are immediately embedded in the toner due to stress with the member in contact with the toner during use, and the fluidity is impaired, so that toner replenishment property, developability, Chargeability deteriorated. In addition, when the toner is not sufficiently mixed, the toner is separated from the toner particles and floats in the image forming apparatus to contaminate the inside of the apparatus. There is a problem that filming of the additive occurs.
Furthermore, in recent years, in order to achieve particularly high-definition color image formation, a polymerization method produced by suspension polymerization, emulsion polymerization, dispersion polymerization, etc., for the purpose of reducing the toner particle size and spheroidizing. Many methods for producing toner particles by granulating toner particles in a liquid have been studied. In particular, the spherical toner has a problem that it easily rolls on the image carrier and easily passes through an elastomeric cleaning blade, resulting in poor cleaning.

Therefore, for this reason, in Patent Document 1, a hydrophobic structure is formed by alkylalkoxysilane and silicone oil, which does not substantially form a structure structure, and the degree of hydrophobicity by methanol titration is 40 to 90%. A toner containing hydrophobic silica fine powder in which the absorption band of isolated silanol groups in the vicinity of a wave number of 3750 cm ⁻¹ in FT-IR analysis has disappeared is disclosed. In Patent Document 2, spherical silica powder having a BET specific surface area of 10 to 50 m ² / g is hydrophobized with hexamethyldisilazane, and the degree of hydrophobicity by methanol titration is 65% or more. A toner containing a highly dispersed, highly hydrophobic spherical silica fine powder characterized by a loose bulk density of 0.25 g / cm ³ or less is disclosed.
Further, in Patent Document 3, the average circularity of toner particles is 0.960 or more, at least titanium oxide fine particles and silica fine particles are externally added, and the number free rate (Yt) of titanium oxide fine particles on the surface is 1. There is disclosed a toner in which the number release rate (Ys) of silica fine particles is 0.01 to 4.00% and Yt> Ys.
Patent Document 4 discloses a toner containing a sol-gel silica having an average primary particle diameter of 80 to 300 nm whose surface is hydrophobized, a water content of 3 to 15%, and a volume resistivity of 1 × 10 ¹³ Ωcm or more. It is disclosed.
Further, Patent Document 5 discloses an image forming apparatus using a toner to which silica-based particles and inorganic fine particles having a weight average particle diameter (D50) of 100 to 1000 nm are added as external additives.

Regarding filming of the image carrier due to the release of the additive, there have been many cases where the additive release rate has been calculated with a party analyzer device (for example, Patent Document 6). However, there is a problem that the detection accuracy is not sufficient to detect a slight difference between the additive adhesion rate and the free amount. Further, in the conventional evaluation method, the optimum control range could not be designed particularly in a system that does not easily adhere to toner particles having a large particle size.
Further, additive processing methods using an ultrasonic homogenizer are conventionally known (Patent Document 7 and Patent Document 8), both of which evaluate toner charging stability or photoreceptor contamination (filming). It is a method established for the purpose, and the measurement conditions are the optimum conditions for evaluating it. On the other hand, when considering both filming and cleaning, it is not always possible to determine the superiority or inferiority of the toner under these conditions, and the development of new measurement method conditions has been desired.

JP 2003-149855 A JP 2004-67475 A JP 2002-72544 A JP 2002-91061 A JP 2003-215836 A JP 2002-244314 A Japanese Patent No. 3129074 JP 2000-122336 A

  The present invention has been made in view of the above problems, and an object thereof is to provide an image forming apparatus that achieves both filming properties and cleaning properties of an image carrier.

As means for solving the above problems, the present invention has the following features.
The image forming apparatus according to claim 1, a latent image carrier that carries a latent image, a charging device that uniformly charges the surface of the latent image carrier, and an electrostatic latent image on the surface of the charged latent image carrier. An exposure device for writing an image, a developing device for supplying toner to the electrostatic latent image formed on the surface of the latent image carrier and making it visible, and a visible image on the surface of the latent image carrier transferred to the transfer target In the image forming apparatus, the charging device is applied with at least AC voltage, and the toner contains an external additive. In addition, the amount of the external additive released with respect to 100 parts of the toner is 0.1 to 1.0 part.
The image forming apparatus according to claim 2, wherein the external additive is a metal oxide having a number average particle diameter in the range of 100 to 300 nm.
The image forming apparatus according to claim 3, wherein the external additive is a metal oxide having a number average particle diameter in the range of 8 to 80 nm.
The image forming apparatus according to claim 4, wherein the toner has an additive amount in the range of 0.5 to 2.0 parts with respect to 100 parts of the toner.

The image forming apparatus according to claim 5 is further characterized in that the toner is obtained by dry mixing using a mixed medium.
The image forming apparatus according to claim 6, wherein the toner is obtained by wet mixing.
The image forming apparatus according to claim 7 is characterized in that the charging device charges a roller-shaped charging member in proximity to or in contact with the latent image carrier.
The image forming apparatus according to claim 8, further comprising an application member that applies a metal stearate.

The image forming apparatus according to claim 9, further characterized in that the toner has an average circularity of 0.94 or more.
The image forming apparatus according to claim 10, wherein the toner has a volume average particle diameter of 3.0 to 8.0 μm, and a ratio of a volume average particle diameter (Dv) to a number average particle diameter (Dn) ( Dv / Dn) is in the range of 1.00 to 1.40.
The image forming apparatus according to an eleventh aspect is further characterized in that the toner has SF-1 in the range of 100 to 180 and SF-2 in the range of 100 to 180.
The image forming apparatus according to claim 12, wherein the toner has a substantially spherical appearance and a ratio of the minor axis to the major axis (r2 / r1) in the range of 0.5 to 1.0. The ratio between the thickness and the minor axis (r3 / r2) is in the range of 0.7 to 1.0, and the relationship of major axis r1 ≧ minor axis r2 ≧ thickness r3 is satisfied.
14. The image forming apparatus according to claim 13, further comprising: an aqueous toner composition comprising at least a polymer having a site capable of reacting with a compound having an active hydrogen group, polyester, a colorant, and a release agent. The crosslinking and / or extension reaction is carried out in the presence of resin fine particles in a medium.

15. The image forming apparatus according to claim 14, further comprising a process cartridge that integrally supports the latent image carrier and at least the developing unit, and is detachable from the main body of the image forming apparatus. .
In the toner according to claim 15, the latent image carrier that carries the latent image, a charging device that applies at least an AC voltage to the surface of the latent image carrier and uniformly charges the surface, and a surface of the charged latent image carrier that is electrostatically charged. The toner is supplied to the electrostatic latent image formed on the surface of the latent image carrier and the exposure device for writing the electrostatic latent image, and the visible image on the surface of the latent image carrier is transferred to the transfer target body. In a toner used in an image forming apparatus including a transfer device that performs fixing and a fixing device that fixes a visible image on a transfer target, the toner includes an external additive, and the toner includes 100 parts of the toner. The amount of liberated external additive is 0.1 to 1.0 part.
The toner according to claim 16 is further characterized in that the toner is used in the image forming apparatus according to any one of claims 2 to 14.

  As described above, by the means for solving the above problem, the image forming apparatus of the present invention can stably provide a good image by suppressing the occurrence of filming and improving the cleaning property. It becomes possible.

The best mode for carrying out the present invention will be described below with reference to the drawings. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. The following description is an example of the best mode of the present invention, and does not limit the scope of the claims.
In the present invention, the ratio of the external additive released from the toner in the external additive of the toner is defined. As described above, the conventional external additive processing method and release rate are not sufficient as a toner superiority / inferiority determination method when considering both filming and cleaning. Developed and used for evaluation judgment.
[Method for evaluating additive release and adhesion strength]
The toner is dispersed in water, the additive is released by ultrasonic energy, and the adhesion strength and release amount are calculated from the residual rate. Examining the conditions to reduce the variation by the measurer and the environment, the following method was adopted.
Measurement method 1) Add 4 g of toner to a mixture of 0.5 ml of dry well (surfactant) and 100 ml of isotone (electrolyte), mix well by hand shaking 50 times, and let stand for 1 hour or more.
2) After stirring with 30 shakes, disperse for 1 minute at 20 W using an ultrasonic homogenizer.
3) The dispersion station solution is suction filtered through a 1 μmφ filter to remove the free additive, and then the toner is dried.
4) The amount of the toner additive before and after the removal of the additive is quantified by the fluorescent X-ray method, and the additive residual rate is evaluated as the adhesion strength.
Ultrasonic condition 1) Vibration time: 60 seconds continuous, 2) Amplitude 20 W (39%), 3) Vibration start speed: 23 ± 1.5 ° C.

  When the amount of the free external additive is measured by this evaluation method, if the amount of the free external additive is less than 0.1 part with respect to 100 parts of the toner, the cleaning property is poor, and conversely 1.0 part. If it is larger, the filming property becomes poor (refer to the evaluation of Example 3, Comparative Example 2 and Comparative Example 3 in Tables 1 and 2). Here, 100 parts of toner refers to parts by weight in which toner particles contain inorganic fine particles and other external additives such as a charge control agent.

  In addition, when a DC power source is used as the charging device, the discharge product on the surface of the photoconductor is unlikely to be generated unlike the case of the AC power source, so the amount of external additive attached to the surface of the photoconductor is reduced. It is considered that the toner cleaning property due to the dam effect tends to deteriorate (refer to the evaluation of Comparative Example 1 in Tables 1 and 2).

A relatively small particle size external additive is considered to play an important role in dam formation in the dam effect, and even when the amount of free additive is equivalent to that of a large particle size external additive, The presence of the property that the filming property is relatively difficult to deteriorate is considered to be advantageous for the compatibility between the cleaning property and the filming property.

  Further, when the amount of the external additive is in the range of 0.5 to 2.0 parts with respect to 100 parts of the toner, both the cleaning property and the filming property are good, but the amount is less than 0.5 parts. The cleaning property deteriorates. This is presumably because the amount of free external additive adhering to the surface of the photoreceptor is not sufficient to exert the dam effect. On the other hand, in the case of 2.0 parts or more, the filming property tends to deteriorate, and charging stability and fogging problems occur.

In addition, the toner obtained by wet-mixing the external additive has a reduced amount of free external additive and good filming properties as compared with the dry-mixed external additive toner of the same amount treatment (Table 1, Refer to Example 5 in Table 2).
The charging device of the image forming apparatus using the toner of the present invention performs charging by bringing a roller-shaped charging member close to or in contact with the image carrier as will be described later. This is for the purpose of avoiding the discharge-type charging because a discharge product is generated on the surface of the photosensitive member and becomes a base point of filming.
Further, the lubricant application device of the image forming apparatus using the toner of the present invention includes an application member for applying a metal stearate salt as will be described later.

  Further, since the toner having a smaller volume average particle diameter Dv can improve the reproducibility of fine lines, a toner having a particle size of 10 μm or less is used. However, since the developing property and the cleaning property are lowered when the particle size is small, at least 3 μm is preferable. Further, if the particle diameter is less than 3 μm, the toner having a small particle diameter that is difficult to be developed on the surface of the carrier or the developing roller 5a increases. This is not preferable because an abnormal image such as a ground cover is formed.

  The particle size distribution represented by the ratio (Dv / Dn) of the volume average particle size Dv to the number average particle size Dn is preferably in the range of 1.00 to 1.40. By sharpening the particle size distribution, the toner charge amount distribution can be made uniform. When Dv / Dn exceeds 1.40, the toner charge amount distribution is wide and the amount of the reversely charged toner T1 increases, making it difficult to obtain a high-quality image. If Dv / Dn is less than 1.00, it is difficult to produce and it is not practical. The particle size of the toner is 50,000 by using a Coulter Counter Multisizer (manufactured by Coulter Co., Ltd.) and selecting an aperture having a measurement hole size of 50 μm corresponding to the particle size of the toner to be measured. It is obtained by measuring the average particle size of the particles.

  The toner of the present invention has an average circularity in the range of 0.93 to 1.00. This degree of circularity is thermally or mechanically spheroidized with toner produced by dry grinding. Thermally, for example, the spheroidizing treatment can be performed by spraying toner particles together with a hot air stream on an atomizer or the like. In addition, a spheroidizing treatment can be performed by mechanically putting the mixture in a mixing machine such as a ball mill together with a mixed medium such as glass having a low specific gravity and stirring. However, in the thermal spheronization process, toner particles that are aggregated and have a large particle size or in the mechanical spheronization process, fine powder is generated, so that a classification process is required again. In addition, in a toner manufactured in an aqueous solvent, the shape can be controlled by applying strong stirring in the process of removing the solvent.

The circularity is defined as circularity SR = (peripheral length of a circle having the same area as the particle projection area / perimeter length of the particle projection image) × 100%. The closer the toner is to a true sphere, the closer to 100%. The toner having a high degree of circularity is easily affected by the electric force lines on the carrier or the developing sleeve 5a, and is faithfully developed along the electric force lines of the electrostatic latent image. When reproducing minute latent image dots, fine line reproducibility is enhanced because it is easy to obtain a dense and uniform toner arrangement. In addition, a toner with a high degree of circularity has a smooth surface and a suitable fluidity, so it is easily affected by the lines of electric force and easily transfers faithfully along the lines of electric force. A quality image can be obtained.
However, if the average circularity of the toner is less than 0.93, a satisfactory transferability and a high-quality image free from dust may not be obtained. This is because the toner surface is irregularly shaped, so that the toner surface is non-uniformly charged, and the center of gravity and the center of charge are shifted, making it difficult to move faithfully to the electric field.
The average circularity is measured by, for example, an optical detection band method in which a suspension containing toner particles is passed through an image area detection band on a flat plate, and a particle image is optically detected and analyzed by a CCD camera. For example, it can be measured using a flow type particle image analyzer FPIA-2100 (manufactured by Sysmex Corporation).

The toner preferably has a shape factor SF-1 in the range of 100 or more and 180 or less and a shape factor SF-2 in the range of 100 or more and 180 or less in the circularity. The shape factor SF-1 indicates the ratio of the roundness of the toner shape and is represented by the following formula (1). This is a value obtained by dividing the square of the maximum length MXLNG of the shape formed by projecting the toner on a two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-1 = {(MXLNG) ² / AREA} × (100π / 4) (1)
When the value of SF-1 is 100, the shape of the toner becomes a true sphere, and becomes larger as the value of SF-1 increases.

The shape factor SF-2 indicates the ratio of the unevenness of the toner shape, and is represented by the following formula (2). A value obtained by dividing the square of the perimeter PERI of the figure formed by projecting the toner 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.
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 sphere, the contact with the toner becomes a point contact, so that the attractive force between the toners is weakened. As a result, the fluidity is increased, and the attractive force between the toner and the photoreceptor 1 is increased. It becomes weaker, the transfer rate becomes higher, and the residual toner on the photoreceptor 1 can be easily cleaned.
The shape factors SF-1 and SF-2 of the toner are preferably 100 or more. Further, when SF-1 and SF-2 are increased, the shape becomes indeterminate, the toner charge amount distribution becomes wide, development is not faithful to the latent image, and transfer is not faithful to the transfer electric field. Image quality deteriorates. Furthermore, the transfer rate is reduced, the amount of toner remaining after transfer is increased, and a large cleaning device 7 is required, which is disadvantageous in designing the image forming apparatus 100. For this reason, SF-1 preferably does not exceed 180, and SF-2 preferably does not exceed 180.

Further, the toner used in the image forming apparatus 100 may be substantially spherical. FIG. 1 is a schematic view showing an outer shape of a toner, FIG. 1A is an appearance of the toner, and FIGS. 1B and 1C are sectional views of the toner. In FIG. 1A, the X axis represents the longest axis r1 of the longest axis of the toner, the Y axis represents the shortest axis r2 of the next longest axis, and the Z axis represents the thickness r3 of the shortest axis. ≧ Short axis r2 ≧ Thickness r3
This toner has a minor axis / major axis ratio (r2 / r1) of 0.5 to 1.0 and a thickness / minor axis ratio (r3 / r2) of 0.7 to 1.0. It has a substantially spherical shape. When the ratio of the minor axis to the major axis (r2 / r1) is less than 0.5, the charge amount distribution becomes wide because it approaches an indefinite shape.
When the ratio of the thickness to the short axis (r3 / r2) is less than 0.7, the charge amount distribution becomes wide because the shape approaches an indefinite shape. In particular, when the ratio of the thickness to the short axis (r3 / r2) is 1.0, the charge amount distribution becomes narrow due to the substantially spherical shape.
The size of the toner so far was measured with a scanning electron microscope (SEM) while changing the field angle and observing in situ.

  The shape of the toner can be controlled by the manufacturing method. For example, the toner by the dry pulverization method has an irregular shape in which the toner surface is uneven and the toner shape is not constant. Even this dry pulverized toner can be made into a nearly spherical toner by applying mechanical or thermal treatment. In many cases, a toner produced by forming droplets by a suspension polymerization method or an emulsion polymerization method has a smooth surface and a nearly spherical shape. Moreover, it can be made into an ellipse by stirring in the middle of the reaction in a solvent and applying a shearing force.

The toner of the present invention contains a release agent that is previously coated with a colorant. In order to coat the release agent surface with the colorant, the release agent particles are mixed with the colorant and fixed to the release agent surface by mechanical impact or thermal action.
Conventionally, in the case of a wet polymerization toner that is polymerized in a solvent, it is difficult to apply a force to the release agent and it is difficult to finely and uniformly disperse the toner. Therefore, by previously coating the surface with a colorant and changing the compatibility with the solvent and the binder resin, the colorant can be uniformly dispersed and the release agent can be uniformly dispersed in the binder resin.
As the release agent, known ones can be used, for example, polyolefin wax (polyethylene wax, polypropylene wax, etc.), long chain hydrocarbon (paraffin wax, sazol wax, etc.); carbonyl group-containing wax, etc. It is done. Of these, carbonyl group-containing waxes are preferred. Examples of the carbonyl group-containing wax include polyhydric alcohol carboxylates (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1 , 18-octadecanediol distearate, etc.); polyvalent carboxylic esters (tristearyl trimellitic acid, distearyl maleate, etc.); polyvalent amine carboxylic acid amides (ethylenediamine dibehenyl amide, etc.); polyvalent carboxylic acid amides (tri Meritic acid tristearyl amide, etc.); and dialkyl ketones (distearyl ketone, etc.). Among these carbonyl group-containing waxes, polyhydric alcohol carboxylic acid esters such as pentaerythritol tetrabehenate are preferable.

  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 Russianine green, anthraquinone green, titanium oxide, zinc white, and mixtures thereof can be used.

A mixer such as a hybridizer or an attritor is used as an apparatus for fixing the colorant to the surface of the release agent. The hybridizer fixes the colorant to the surface of the release agent with a blade rotating at high speed without using a dispersion medium. The crushed material of the dispersion medium is not mixed. Also, a release agent having a colorant coated on the surface is obtained by dissolving or dispersing the release agent in an organic solvent to form a spherical shape, adding a colorant thereto, and spraying it by a spray drying method. be able to.
The diameter of the release agent is preferably in the range of 0.05 to 1.5 μm. When the diameter of the release agent is less than 0.05 μm, the release phenomenon that melts when subjected to heat and pressure by the fixing device is small, and the offset phenomenon cannot be suppressed. If it exceeds 1.5 μm, the occurrence of the offset phenomenon can be suppressed, but the heat-resistant storage stability is lowered, the amount of transfer to the carrier is increased, and the life of the developer is reduced.

The volume average particle diameter of the colorant is preferably in the range of 10 to 300 nm. By setting it as this range, the release agent surface which has the above-mentioned particle size can be coat | covered uniformly and uniformly. When the particle size of the colorant is less than 10 nm, the transparency is increased but the coloring power is decreased, and the image density of the color toner single color image cannot be increased. If it exceeds 300 nm, the graininess in the image is lowered, and the image quality is lowered in a rough image. Furthermore, the color reproducibility at the time of color mixing is lowered.
At this time, the amount of the colorant is set to a range of 20 to 500% with respect to the weight of the release agent. By setting it within this range, the surface of the release agent can be uniformly and uniformly coated. If the amount of the colorant is less than 20%, the surface of the release agent cannot be uniformly coated. If the amount of the colorant exceeds 500%, the colorant cannot be fixed to the surface of the release agent, and a colorant that is detached from the surface of the release agent during production and floats. When this becomes toner, it shifts to a carrier or the like, and the developer life is reduced.

In addition, the materials used here will be described.
As the binder resin, known monomers are preferably used. Specifically, styrene monomers such as styrene, o- (m-, p-) methylstyrene, m- (p-) ethylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, ( Meth) propyl acrylate, butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (Meth) acrylic acid ester monomers such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate; monomers such as butadiene, isoprene, cyclohexene, (meth) acrylonitrile, and acrylamide are preferred Used.

Here, a method for producing the toner of the present invention will be described. In the toner of the present invention, a binder resin, which is a constituent material of the toner, a release agent coated with a colorant (hereinafter simply referred to as “colorant-coated release agent”), and the like in an organic solvent. Alternatively, a polymerizable monomer composition is prepared by dissolving or dispersing in a polymerizable monomer in an organic solvent, and the polymerizable monomer composition is dispersed in an aqueous medium containing a dispersion stabilizer. A toner is obtained by producing particles of a polymerizable monomer composition therein and polymerizing the polymerizable monomer in the particles. Examples of such a polymerization method include a suspension polymerization method and a solution polymerization method, and any polymerization method may be used.
At this time, in the present invention, the method for dispersing or dissolving the colorant-coated release agent is not particularly limited as long as it is generally marketed as a stirrer / or a disperser. An organic solvent or a polymerizable monomer, a resin, and the like are placed in a container, and stirred using a stirring device such as a homomixer to be dispersed or dissolved.
Preferable specific examples include a stirrer having a 1-10 stage paddle stirrer, a helical ribbon stirrer, a max blend stirrer and the like. Of these, a helical ribbon stirrer and a max blend stirrer are more preferable.
Other stirrers or dispersers can also be used. Commercially available product names include, for example, a homogenizer (manufactured by IKA), polytron (manufactured by Kinematica), and TK auto homomixer (manufactured by Kokika Kogyo Co., Ltd.). Batch type dispersers such as Ebara Milder (manufactured by Aihara Seisakusho Co., Ltd.), TK Fillmix, TK Pipeline Homo Mixer (manufactured by Special Machine Industries Co., Ltd.), Colloid Mill (manufactured by Shinko Pantech Co., Ltd.), Thrasher, Trigonal Wet Fine Continuous dispersers such as pulverizer (Mitsui Miike Kako Co., Ltd.), Captron (Eurotech Co., Ltd.) and Fine Flow Mill (Pacific Kiko Co., Ltd.); Microfluidizer (Mizuho Kogyo Co., Ltd.) ) And APV Gaurin (manufactured by Gaurin), etc .; Kisa (Hiyaka Kogyo) vibrating dispersing machine such as a; and an ultrasonic dispersing machine such as an ultrasonic homogenizer (manufactured by Branson Co., Ltd.).
Of these, APV Gaurin, homogenizer, TK auto homomixer, Ebara milder, TK fill mix and TK pipeline homomixer are preferred, and TK auto homomixer, Ebara milder, TK fill mix and TK pipeline are more preferred. Homomixers, particularly preferably TK auto homomixers, TK fill mixes and TK pipeline homomixers.
The temperature at which the colorant-coated release agent is dispersed is not particularly limited, but is preferably 0 to 60 ° C., more preferably 5 to 50 ° C., particularly 10 to 40 ° C. from the viewpoint of preventing coalescence of the release agent particles. It is.

  As organic solvents, methyl alcohol, ethyl alcohol, modified ethyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, sec-butyl alcohol, tert-amyl alcohol, 3-pentanol, octyl alcohol, benzyl alcohol , Alcohols such as cyclohexanol; ether alcohols such as methyl cellosolve, cellosolve, isopropyl cellosolve, butyl cellosolve, diethylene glycol monobutyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone; ethyl acetate, butyl acetate, ethyl propionate, cellosolve acetate, etc. Esters: hexane, octane, petroleum ether, cyclohexane, benzene, tolue Hydrocarbons such as xylene; halogenated hydrocarbons such as carbon tetrachloride, trichloroethylene and tetrabromoethane; ethers such as ethyl ether, dimethyl glycol and trioxane tetrahydrofuran; acetals such as methylal and diethyl acetal; formic acid, acetic acid and propionic acid Organic acids: Sulfur-containing organic compounds such as nitropropene, nitrobenzene, dimethylamine, monoethanolamine, pyridine, dimethyl sulfoxide, dimethylformamide or nitrogen-containing organic compounds. Further, two or more kinds of these solvents can be mixed and used. Ethyl acetate is preferred from the standpoints of solubility of the release agent and other additives, and handling such as volatilization of the organic solvent itself.

  Further, known dispersion stabilizers in organic solvents can be used. Specifically, as inorganic compounds, calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, hydroxide Examples include calcium, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, and alumina. Examples of the organic compound include polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, polyacrylic acid and its salt, and starch.

  As the polymerization initiator using the polymerization method, known ones can be used. Specifically, 2,2-azobisisobutyronitrile, 2,2-azobis (2,4-dimethylvaleronitrile), 2,2 -Azobis (2-methylbutyronitrile), 1,1-azobis (cyclohexane-1-carbonitrile), dimethyl-2,2-azobisisobutyrate, 4,4-azobis-4-cyanovaleronitrile, 2 And azo compounds such as 2-azobis (4-methoxy-2,4-dimethylvaleronitrile), and peroxides such as benzoyl peroxide and methyl ethyl ketone peroxide.

  When the toner is produced by a polymerization method, known additives can be used such as a crosslinking agent, a chain transfer agent, and a polymerization inhibitor in order to control the degree of polymerization. The toner of the present invention is mixed with these polymerizable monomers, a colorant-coated release agent, a polymerization initiator, and other additives, and then dispersed in an aqueous dispersion medium to polymerize the toner. Obtainable.

At this time, in the toner of the present invention, the difference in solubility parameter (hereinafter simply referred to as “SP value”) between the release agent and the organic solvent is in the range of 0.3 to 1.5. Moreover, it is preferable that the difference of SP value of a mold release agent and the monomer which forms binder resin exists in the range of 0.3-1.5.
The SP value is an index indicating the polarity of a substance and can indicate affinity. The closer this SP value is, the better the compatibility is. The colorant-coated release agent is preferably present in the toner in the vicinity of the toner surface and in a state where a 0.2 to 1.5 μm domain is formed and dispersed in the toner. In the conventional pulverization system, the viscoelasticity of the binder resin due to the temperature at the time of melt kneading could be adjusted by the tenacity of the kneading apparatus, but in the polymerization method, the dispersion of the release agent is adjusted by the tenacity. I can't. Therefore, when dissolved or dispersed in an organic solvent, the difference in SP value from the organic solvent is set to a range of 0.3 to 1.5. By setting it within this range, the release agent can be easily dispersed in an organic solvent. When the difference in SP value between the colorant-coated release agent and the organic solvent is less than 0.3, the particle size of the release agent particles formed in the organic solvent becomes small. The domain diameter becomes small, and in an actual fixing device, hot offset of toner often occurs. In addition, the release agent forms oil droplets in an organic solvent, and some of the release agent does not enter the monomer oil droplets. When the difference in SP value exceeds 1.5, the particle size of the release agent particles formed in the organic solvent becomes large. When the toner is used, the release agent has a large domain diameter, Although hot offset can be suppressed, the amount of the release agent and colorant that migrates to the carrier increases and the life of the developer is reduced.

  Furthermore, since the SP value of water is as large as 20 or more, and the monomer and the release agent are about 8 to 12, oil droplets are formed without affinity in the aqueous medium. Therefore, the difference in SP value between the colorant-coated mold release agent and the monomer in which the dispersant or the like is dissolved or dispersed is set in the range of 0.3 to 1.5. By setting it within this range, the dispersion of the release agent between the aqueous solvent and the monomer can be controlled. When the difference in SP value between the mold release agent and the monomer is less than 0.3, the affinity is high, so the mold release agent is finely and uniformly in a small domain of several tens of nm in the monomer. Due to the dispersion, the amount existing in the vicinity of the toner surface when it becomes toner is reduced, the lower limit fixing temperature is increased, and the hot fix may be caused. When the difference in SP value exceeds 1.5, a large amount appears on the surface of the oil droplet, and when it becomes toner, the hot offset can be reduced, but the amount transferred to the carrier increases, and the developer The service life is reduced.

Here, as a release agent, polypropylene and polyethylene have an SP value of 8.0 to 8.3, paraffin wax has an SP value of 8.3, carnauba wax has an SP value of 8.6, and montan wax has an SP value of 8. .9. As an organic solvent, SP value of toluene is 8.9, SP value of ethyl acetate is 9.1, SP value of methyl ethyl ketone is 9.3, SP value of acetone is 9.9, SP value of ethanol is 12.7, The SP value of methanol is 14.5. Further, the SP value of xylene as a monomer is 8.8, the styrene and acrylic have an SP value of 9.3 to 9.5, the SP value of polyester is in the range of 10.5 to 11.5, and 8 to 14 You can select by range.
Here, when a styrene and / or acrylic monomer having an SP value of 9.4 is used as a polymerized toner, a release toner having an SP value of 7.9 to 9.1 or 9.7 to 10.9 is used. Use a mold. Therefore, polyethylene, paraffin wax, carnauba wax, and montan wax are used. As the organic solvent, toluene, ethyl acetate, and acetone are used.
For polyesters having an SP value of 10.8, 9.1 to 10.5 or 11.2 to 12.3 release agents and organic solvents are used.
Further, in particular, between the colorant-coated release agent, the aqueous solvent, and the monomer, | colorant-coated release agent SP value−monomer SP value | <| colorant-coated release agent SP value -It is preferable that the relationship of the aqueous solvent SP value | Thus, the release agent increases the affinity for the monomer and the affinity for the aqueous medium, so that when the toner particles are formed in the aqueous medium, the release agent is inside the toner and near the toner surface. Can exist.

The SP value calculation method will be described. The SP value (solubility parameter: δ) in the present invention is defined by the formula δ = (ΔEv / V) ^1/2 in the Hildebrand-Scatchard solution theory. Here, ΔEv represents evaporation energy, V represents molecular volume, and ΔEv / V represents cohesive energy density. There are various methods for obtaining the SP value (solubility parameter). In the present invention, the value obtained by calculation using the method of Fedor et al. Mainly from the monomer composition was used.
SP value = (ΣΔei / ΣΔvi) ^1/2
Here, Δei is the evaporation energy of atoms or atomic groups, and Δvi is the molar volume of atoms or atomic groups.

A toner containing at least a binder resin, a colorant, and a release agent, and particles are formed in an aqueous medium by dissolving or dispersing the binder resin and the release agent in an organic solvent or a polymerizable monomer. It is preferable to use a release agent that has been previously coated with a colorant in the production method for producing the toner. When a part of the binder resin is crosslinked and / or extended in an aqueous medium in an aqueous medium, the toner is formed at a low temperature, so that the wax is swollen by raising the temperature and reaggregated by removing the pigment. By reducing the amount, uniform dispersibility of the release agent and the pigment can be maintained.
The constituent materials and manufacturing methods will be described below.

(polyester)
The polyester is obtained by a polycondensation reaction between a polyhydric alcohol compound and a polycarboxylic acid compound.
Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable. Examples of the dihydric alcohol (DIO) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide bisphenol (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyhydric alcohol (TO) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

  Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). (DIC) alone and (DIC) with a small amount of (TC) Mixtures are preferred. Divalent carboxylic acids (DIC) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polyvalent carboxylic acid (TC) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polyhydric carboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.).

The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.
The polycondensation reaction between a polyhydric alcohol (PO) and a polycarboxylic acid (PC) is carried out in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide, and heated to 150 to 280 ° C. while reducing the pressure as necessary. The produced water is distilled off to obtain a polyester having a hydroxyl group. The hydroxyl value of the polyester is preferably 5 or more, and the acid value of the polyester is usually 1 to 30, preferably 5 to 20. By giving an acid value, it tends to be negatively charged, and furthermore, when fixing to a recording paper, the affinity between the recording paper and the toner is good and the low-temperature fixability is improved. However, when the acid value exceeds 30, there is a tendency to deteriorate with respect to the stability of charging, particularly environmental fluctuation.
The weight average molecular weight is 10,000 to 400,000, preferably 20,000 to 200,000. A weight average molecular weight of less than 10,000 is not preferable because offset resistance deteriorates. On the other hand, if it exceeds 400,000, the low-temperature fixability is deteriorated.

(Polyester prepolymer)
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, etc .; 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. In addition, polyester modified by chemical bonds other than urea bonds may be included.
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.
Further, since the urea-modified polyester is likely to be present on the surface of the obtained toner 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.

(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 limited to a specific one. 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.

  Moreover, although the colorant covering mold release agent mentioned above is used, in addition to this, you may use a mold release agent and a colorant each independently. The content of the colorant with respect to the toner must be adjusted depending on the color, and the content of the release agent with respect to the toner must be adjusted depending on the type of the binder resin. If it cannot be adjusted by itself, each may be contained alone.

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-coated release agent, unmodified polyester, and a polyester prepolymer having an isocyanate group 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 particle formation. 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. Even if an organic solvent is contained as an aqueous medium, the amount of water is large, and the SP value of water is large compared with other organic solvents. Does not affect the value relationship.
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), Florad FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M), Unidyne DS-101. DS-102 (manufactured by Daikin Industries, Ltd.), MegaFuck F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

  Further, as the cationic surfactant, aliphatic quaternary ammonium salts such as aliphatic primary, secondary or secondary amine acids having a fluoroalkyl group, and perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salts. , Benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (Asahi Glass Co., Ltd.), Florad FC-135 (Sumitomo 3M Co., Ltd.), Unidyne DS-202 (Daikin Industries) Manufactured), MegaFuck F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products), Footgent F-300 (Neos), and the like.

  As the resin fine particles, the aforementioned substances can be used. 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 Nitrogen compounds such as pyrrolidone, vinylimidazole, ethyleneimine, or homopolymers or copolymers such as those having a heterocyclic ring thereof, polyoxyethylene Polyoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, poly Polyoxyethylenes such as oxyethylene 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 particles.
In order to remove the organic solvent, spindle-shaped toner particles can be produced by gradually raising the temperature of the entire system in a laminar stirring state, giving strong stirring in a certain temperature range, and then removing the solvent. In addition, 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 particles by a method such as washing with water after dissolving the calcium phosphate salt with an acid such as hydrochloric acid. Remove. It can also be removed by operations such as enzymatic degradation.

  Either before or after the washing and solvent-removing steps, a step can be provided in which the emulsified dispersion is allowed to stand at a certain temperature for a certain period of time and the produced toner particles are aged. Thereby, toner particles having a desired particle diameter can be produced. The temperature of the aging step is preferably 25 to 50 ° C., and the time is preferably 10 minutes to 23 hours.

5) A charge control agent is injected into the toner 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.

When the toner produced as described above is used for a two-component developer, it may be used by mixing with a magnetic carrier. As the magnetic carrier, a divalent metal such as iron, magnetite, Mn, Zn, or Cu is used. a ferrite containing, weight average particle diameter _D 4 20 to 100 [mu] m is preferred. When 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.
It can also be used as a one-component magnetic toner that does not use a magnetic carrier, or as a non-magnetic toner.
The toner of the present invention is preferably used as a color toner. It is excellent in reproducibility of fine lines and fine dots, is excellent in toner granularity, and is excellent in reproducibility of intermediate colors, so that it is more suitable for use as a color toner for forming a color image.

The present invention also relates to an image forming apparatus including at least a charging device that uniformly charges the surface of the image carrier, and a charging device that applies charging by applying an alternating electric field and the developer described above. An image forming apparatus including a developing device to be used. FIG. 2 is a schematic diagram showing the configuration of the image forming apparatus of the present invention.
[Image forming equipment]
Hereinafter, an image forming apparatus using the electrophotographic toner of the present invention or a two-component developer composed of the toner and a carrier will be described.

-Intermediate transfer member-
One embodiment of the intermediate transfer member of the transfer system in the present invention will be described with reference to FIG. Around a photosensitive drum (hereinafter referred to as a photosensitive member) 10 as an image carrier, a charging roller 20 as a charging device, an exposure device 30, a cleaning device 60 having a cleaning blade, a static elimination lamp 70 as a static elimination device, and development. An apparatus 40 and an intermediate transfer member 50 as an intermediate transfer member are provided. The intermediate transfer member 50 is suspended by a plurality of suspension rollers 51 and is configured to run endlessly in the direction of the arrow by a driving unit such as a motor (not shown). A part of the suspension roller 51 also serves as a transfer bias roller for supplying a transfer bias to the intermediate transfer member, and a predetermined transfer bias voltage is applied from a power source (not shown). A cleaning device 90 having a cleaning blade for the intermediate transfer member 50 is also provided. Further, a transfer roller 80 is provided as a transfer means for transferring the developed image onto the transfer paper 100 as the final transfer material, facing the intermediate transfer body 50, and the transfer roller 80 is transferred by a power supply device (not shown). Supplied. A corona charger 52 is provided around the intermediate transfer member 50 as charge applying means.

The developing device 40 includes a developing belt 41 as a developer carrier, a black (hereinafter referred to as “Bk”) developing unit 45K, a yellow (hereinafter referred to as “Y”) developing unit 45Y, The developing unit 45M is hereinafter referred to as magenta and the cyan (hereinafter referred to as C) developing unit 45C. Further, the developing belt 41 is stretched between a plurality of belt rollers, and is configured to run endlessly in a direction indicated by an arrow by a driving unit such as a motor (not shown). Moves at approximately the same speed as 10.
Since the structure of each developing unit is common, the following description will be given only for the Bk developing unit 45K, and the other developing units 45Y, 45M, and 45C will be described in the parts corresponding to those in the Bk developing unit 45K in the drawing. Y, M, and C are added after the numbers given to the units, and the description is omitted. The developing unit 45K is disposed so as to immerse the developing tank 42K containing a high-viscosity, high-concentration liquid developer containing toner particles and a carrier liquid component, and the lower part in the liquid developer in the developing tank 42K. And a coating roller 44K for thinning the developer pumped from the pumping roller 43K and applying it to the developing belt 41. The application roller 44K has conductivity, and a predetermined bias is applied from a power source (not shown).
In addition to the apparatus configuration shown in FIG. 2, the image forming apparatus according to the present embodiment has a development unit for each color arranged around one photoconductor 40 as shown in FIG. 3. It may be a device configuration.

Next, the operation of the image forming apparatus according to the present embodiment will be described. In FIG. 2, the photosensitive member 10 is uniformly charged by the charging roller 20 while being driven to rotate in the direction of the arrow, and then the reflected light from the original is imaged and projected by an optical system (not shown) by the exposure device 30 on the photosensitive member 10. An electrostatic charge image is formed on the surface. This electrostatic charge image is developed by the developing device 40 to form a toner image as a visible image. The developer thin layer on the developing belt 41 is peeled off from the belt 41 in a thin layer state by contact with the photosensitive member in the developing region, and moves to a portion where a latent image is formed on the photosensitive member 10. The toner image developed by the developing device 40 is transferred to the surface of the intermediate transfer member 50 at the contact portion (primary transfer region) between the photosensitive member 10 and the intermediate transfer member 50 moving at a constant speed (primary transfer). Transcription). When transferring three or four colors to be superimposed, this process is repeated for each color to form a color image on the intermediate transfer member 50.
The corona charger 52 for applying an electric charge to the superimposed toner image on the intermediate transfer member is provided at a contact facing portion between the photosensitive member 10 and the intermediate transfer member 50 in the rotation direction of the intermediate transfer member 50. It is installed on the downstream side and on the upstream side of the contact facing portion between the intermediate transfer member 50 and the transfer paper 100. The corona charger 52 gives the toner image a true charge having the same polarity as the charge polarity of the toner particles forming the toner image, and is sufficient for good transfer to the transfer paper 100. Charge is applied to the toner image. The toner image is charged by the corona charger 52 and then transferred to the transfer paper 100 conveyed in the direction of the arrow from a paper supply unit (not shown) by a transfer bias from the transfer roller 80 (two). Next transfer). Thereafter, the transfer paper 100 onto which the toner image has been transferred is separated from the photoconductor 10 by a separation device (not shown), and after a fixing process is performed by a fixing device (not shown), the transfer paper 100 is discharged from the device. On the other hand, after the transfer, the untransferred toner is collected and removed by the cleaning device 60, and the residual charge is discharged by the discharging lamp 70 in preparation for the next charging.

As described above, the static friction coefficient of the intermediate transfer member is preferably 0.1 to 0.6, and more preferably 0.3 to 0.5. The volume resistance of the intermediate transfer member is preferably from several Ωcm to 10 ³ Ωcm. When the volume resistance is set to several Ωcm or more and 10 ³ Ωcm or less, the intermediate transfer member itself is prevented from being charged, and the charge imparted by the charge imparting means hardly remains on the intermediate transfer member. Transfer unevenness can be prevented. Further, it is possible to easily apply a transfer bias at the time of secondary transfer.
The material of the intermediate transfer member is not particularly limited, and all known materials can be used. An example is shown below. (1) A material having a high Young's modulus (tensile modulus) is used as a single-layer belt. PC (polycarbonate), PVDF (polyvinylidene fluoride), PAT (polyalkylene terephthalate), PC (polycarbonate) / PAT ( Polyalkylene terephthalate) blend material, ETFE (ethylene tetrafluoroethylene copolymer) / PC, ETFE / PAT, PC / PAT blend material, carbon black dispersed thermosetting polyimide, and the like. These single-layer belts with a high Young's modulus have the advantage that the amount of deformation with respect to stress during image formation is small, and in particular, there is little misregistration during color image formation. (2) A belt having a two- to three-layer structure in which a belt having a high Young's modulus is used as a base layer and a surface layer or an intermediate layer is provided on the outer periphery thereof. Therefore, the line image can be prevented from being lost due to the height. (3) Belts having a relatively low Young's modulus using rubber and elastomer, and these belts have the advantage that line images are hardly lost due to their softness. In addition, the width of the belt is made larger than that of the drive roll and the tension roll, and the elasticity of the belt ear protruding from the roll is used to prevent meandering, so that low cost can be realized without the need for ribs or meandering prevention devices. .
Conventionally, fluororesin, polycarbonate resin, polyimide resin, and the like have been used for the intermediate transfer belt, but in recent years, an elastic belt in which the entire belt layer or a part of the belt is an elastic member has been used. The transfer of a color image using a resin belt has the following problems.

A color image is usually formed with four colored toners. On one color image, toner layers of 1 to 4 layers are formed. The toner layer receives pressure by passing through the primary transfer (transfer from the photoreceptor to the intermediate transfer belt) and the secondary transfer (transfer from the intermediate transfer belt to the sheet), and the cohesive force between the toners increases. When the cohesive force between the toners increases, the phenomenon of missing characters in the characters and missing edges in the solid portion image tends to occur. Since the resin belt has a high hardness and does not deform according to the toner layer, the toner layer is easily compressed, and the character dropout phenomenon is likely to occur.
Recently, there is an increasing demand for forming full-color images on various papers, for example, Japanese paper, intentionally irregularities, and forming images on paper. However, a paper with poor smoothness is liable to generate toner and voids at the time of transfer, and transfer loss is likely to occur. When the transfer pressure at the secondary transfer portion is increased to improve the adhesion, the condensing power of the toner layer is increased, and the above-described character void is generated.

Therefore, the elastic belt is used for the following purposes when transferring to the sheet. The elastic belt is deformed corresponding to the toner layer and the paper having poor smoothness at the transfer portion. In other words, because the elastic belt deforms following local irregularities, the paper does not have excessive flatness and does not excessively increase the transfer pressure with respect to the toner layer. In contrast, a transfer image having excellent uniformity can be obtained.
The elastic belt resin is polycarbonate, fluororesin (ETFE, PVDF), polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer. Styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (for example, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene- Octyl acrylate copolymer and styrene-phenyl acrylate copolymer), styrene-methacrylic acid ester copolymer (for example, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-methacrylic acid). Acid phenyl copolymer, etc.), styrene -Styrenic resins (monopolymer or copolymer containing styrene or styrene-substituted product) such as methyl α-chloroacrylate copolymer, styrene-acrylonitrile-acrylate ester copolymer, methyl methacrylate resin, methacrylic acid Butyl resin, ethyl acrylate resin, butyl acrylate resin, modified acrylic resin (for example, silicone-modified acrylic resin, vinyl chloride resin-modified acrylic resin, acrylic / urethane resin, etc.), vinyl chloride resin, styrene-vinyl acetate copolymer, Vinyl chloride-vinyl acetate copolymer, rosin-modified maleic acid resin, phenol resin, epoxy resin, polyester resin, polyester polyurethane resin, polyethylene, polypropylene, polybutadiene, polyvinylidene chloride, ionomer resin, polyurethane resin, silica One type or a combination of two or more types selected from the group consisting of carbon resins, ketone resins, ethylene-ethyl acrylate copolymers, xylene resins and polyvinyl butyral resins, polyamide resins, modified polyphenylene oxide resins and the like can be used. . However, it is a matter of course that the material is not limited to the above materials.

  Elastic rubber and elastomer include butyl rubber, fluorine rubber, acrylic rubber, EPDM, NBR, acrylonitrile-butadiene-styrene rubber natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, ethylene-propylene rubber, ethylene-propylene ter Polymer, chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, urethane rubber, syndiotactic 1,2-polybutadiene, epichlorohydrin rubber, ricone rubber, fluororubber, polysulfide rubber, polynorbornene rubber, hydrogenated nitrile rubber , Selected from the group consisting of thermoplastic elastomers (for example, polystyrene, polyolefin, polyvinyl chloride, polyurethane, polyamide, polyurea, polyester, fluororesin) It is possible to use one kind or two or more kinds of combinations that. However, it is a matter of course that the material is not limited to the above materials.

There are no particular restrictions on the conductive agent for adjusting the resistance value. For example, carbon black, graphite, metal powder such as aluminum and nickel, tin oxide, titanium oxide, antimony oxide, indium oxide, potassium titanate, antimony oxide-tin oxide composite Conductive metal oxides such as oxide (ATO) and indium oxide-tin oxide composite oxide (ITO), and conductive metal oxides are coated with insulating fine particles such as barium sulfate, magnesium silicate, and calcium carbonate. But you can. Of course, the conductive agent is not limited thereto.
Surface layer materials and surface layers are required to prevent contamination of the photoreceptor by elastic materials, reduce surface friction resistance to the surface of the transfer belt, reduce toner adhesion, and improve cleaning properties and secondary transfer properties. . For example, materials that use one or a combination of two or more of polyurethane, polyester, epoxy resin, etc. to reduce surface energy and increase lubricity, such as fluorine resin, fluorine compound, fluorocarbon, titanium dioxide, silicon carbide, etc. These powders and particles can be used by dispersing one type, two or more types, or a combination of particles having different particle sizes. Further, it is also possible to use a material having a surface energy reduced by forming a fluorine-rich layer on the surface by heat treatment, such as a fluorine-based rubber material.

~ Charging device ~
FIG. 4 is a schematic diagram illustrating a configuration of an image forming apparatus using a contact-type charging device. The photosensitive member 140 serving as a member to be charged and an image carrier is rotationally driven in the direction of the arrow at a predetermined speed (process speed). The charging roller 160, which is a charging member brought into contact with the photosensitive drum, is basically composed of a cored bar and a conductive rubber layer formed concentrically and integrally on the outer periphery of the cored bar. In this case, the charging roller 160 is driven by the rotational drive of the photosensitive member 140, and is pressed against the photosensitive drum by a pressing means (not shown). Rotate. The charging roller 160 is formed to have a diameter of 16 mm by coating a medium resistance rubber layer 522 of about 100,000 Ω · cm on a core metal having a diameter of 9 mm.
The core of charging roller 160 and a power source (not shown) are electrically connected, and a predetermined bias is applied to the charging roller by the power source. As a result, the peripheral surface of the photoreceptor 140 is uniformly charged to a predetermined polarity and potential.
The charging device used in the present invention is not limited to the contact-type charging device as described above, and may be non-contact. However, since an image forming apparatus in which ozone generated from the charging device is reduced is obtained, the contact-type charging device can be obtained. It is preferable to use a charging device.
Further, in the image forming apparatus of the present invention, an alternating electric field is applied to the charging device. In a DC (direct current) electric field, a large number of O ₃ ⁻ and NO ₃ ⁻ are formed in order to charge the photosensitive member to a negative polarity. The ozone and nitrogen oxides adhere to the photoreceptor and deteriorate the surface of the photoreceptor. In particular, the surface of the photoconductor is hardened and wear increases, and the coefficient of friction decreases, so that external additives are likely to adhere and filming often occurs. For this reason, by applying an alternating electric field on which AC (alternating current) is superimposed, generation of ozone and the like can be suppressed and the photosensitive member can be charged uniformly. In particular, by using an alternating electric field, it is possible to suppress deterioration of the photoreceptor with ozone due to generation of H ₃ O ⁺ having a reverse polarity.

  The shape of the charging member used in the present invention may take any form such as a magnetic brush or a fur brush in addition to the roller, and can be selected according to the specifications and form of the image forming apparatus. In the case of using a magnetic brush, the magnetic brush is composed of various ferrite particles such as Zn—Cu ferrite as a charging member, a non-magnetic conductive sleeve for supporting it, and a magnet roll included therein. In addition, when using a fur brush, for example, as a material of the fur brush, a fur treated with carbon, copper sulfide, metal or metal oxide is used, and this is wound around a metal or other conductive core. By charging or pasting, it becomes a charging device.

-Tandem type color image forming device-
FIG. 5 is a schematic diagram showing the configuration of the tandem color image forming apparatus of the present invention.
As shown in FIG. 5, the tandem type image forming apparatus includes a direct transfer system that sequentially transfers an image on each photoconductor 1 to a sheet s conveyed by a sheet conveying belt 3 by a transfer device 2. As shown in FIG. 6, the images on the respective photosensitive members 1 are once transferred sequentially to the intermediate transfer member 4 by the primary transfer device 2, and then the images on the intermediate transfer member 4 are transferred to the sheet s by the secondary transfer device 5. There are indirect transfer systems that perform batch transfer. The transfer device 5 is a transfer conveyance belt, but there are also roller shapes and methods.
Comparing the direct transfer type and the indirect transfer type, the former arranges the paper feeding device 6 on the upstream side of the tandem type image forming apparatus T on which the photoconductors 1 are arranged, and the fixing device 7 on the downstream side. There is a drawback in that the size increases in the sheet conveying direction. On the other hand, the latter can set the secondary transfer position relatively freely. The paper feeding device 6 and the fixing device 7 can be arranged so as to overlap with the tandem image forming apparatus T, and there is an advantage that downsizing is possible.

In the former, in order not to increase the size in the sheet conveyance direction, the fixing device 7 is disposed close to the tandem type image forming apparatus T. For this reason, the fixing device 7 cannot be disposed with a sufficient margin that allows the sheet s to bend, and an impact when the leading edge of the sheet s enters the fixing device 7 (particularly with a thick sheet) or fixing. Due to the speed difference between the sheet conveying speed when passing through the apparatus 7 and the sheet conveying speed by the transfer conveying belt, there is a drawback that the fixing device 7 tends to affect the image formation on the upstream side. On the other hand, in the latter case, the fixing device 7 can be disposed with a sufficient margin that allows the sheet s to bend, so that the fixing device 7 hardly affects the image formation.
Due to the above, recently, an indirect transfer type among tandem type image forming apparatuses has attracted attention. FIG. 6 is a schematic diagram showing a configuration of an image forming apparatus having an intermediate transfer member, which is a tandem color image forming apparatus of the present invention.
In this type of color image forming apparatus, as shown in FIG. 6, the transfer residual toner remaining on the photoconductor 1 after the primary transfer is removed by the photoconductor cleaning device 8 to clean the surface of the photoconductor 1. In preparation for image formation again. Further, the transfer residual toner remaining on the intermediate transfer body 4 after the secondary transfer is removed by the intermediate transfer body cleaning device 9 to clean the surface of the intermediate transfer body 4 to prepare for image formation again.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 7 shows an embodiment of the present invention and is a schematic diagram showing the configuration of a tandem indirect transfer type image forming apparatus. In the figure, reference numeral 100 is a copying apparatus main body, 200 is a paper feed table on which it is placed, 300 is a scanner mounted on the copying apparatus main body 100, and 400 is an automatic document feeder (ADF) further mounted thereon. The copying machine main body 100 is provided with an endless belt-shaped intermediate transfer member 10 at the center.
Then, as shown in FIG. 7, in the illustrated example, it is wound around three support rollers 14, 15, and 16 so as to be able to rotate and convey clockwise in the drawing.
In this illustrated example, an intermediate transfer body cleaning device 17 for removing residual toner remaining on the intermediate transfer body 10 after image transfer is provided on the left of the second support roller 15 among the three.
Further, among the three images, four images of yellow, cyan, magenta, and black are arranged on the intermediate transfer member 10 stretched between the first support roller 14 and the second support roller 15 along the conveyance direction. The tandem image forming apparatus 20 is configured by arranging the forming units 18 side by side.
An exposure device 21 is further provided on the tandem image forming apparatus 20 as shown in FIG. On the other hand, a secondary transfer device 22 is provided on the side opposite to the tandem image forming apparatus 20 with the intermediate transfer body 10 interposed therebetween. In the illustrated example, the secondary transfer device 22 is configured by spanning a secondary transfer belt 24, which is an endless belt, between two rollers 23, and is pressed against the third support roller 16 via the intermediate transfer body 10. The image on the intermediate transfer body 10 is transferred to a sheet.

A fixing device 25 for fixing the transfer image on the sheet is provided beside the secondary transfer device 22. The fixing device 25 is configured by pressing a pressure roller 27 against a fixing belt 26 that is an endless belt.
The secondary transfer device 22 described above is also provided with a sheet transport function for transporting the sheet after image transfer to the fixing device 25. Of course, a transfer roller or a non-contact charger may be arranged as the secondary transfer device 22, and in such a case, it is difficult to provide this sheet conveying function together.
In the illustrated example, under such a secondary transfer device 22 and a fixing device 25, a sheet reversing device 28 for reversing the sheet to record images on both sides of the sheet in parallel with the tandem image forming device 20 described above. Is provided.

Now, when making a copy using this color image forming apparatus, the document is set on the document table 30 of the automatic document feeder 400. Alternatively, the automatic document feeder 400 is opened, a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed and pressed by it.
When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the other contact glass 32. At that time, the scanner 300 is immediately driven to travel the first traveling body 33 and the second traveling body 34. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34 and is reflected by the mirror of the second traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.
When a start switch (not shown) is pressed, one of the support rollers 14, 15 and 16 is rotationally driven by a drive motor (not shown), the other two support rollers are driven to rotate, and the intermediate transfer body 10 is rotated and conveyed. To do. At the same time, the individual image forming means 18 rotates the photoconductors 40 to form black, yellow, magenta, and cyan single color images on the photoconductors 40, respectively. Then, along with the conveyance of the intermediate transfer member 10, the single color images are sequentially transferred to form a composite color image on the intermediate transfer member 10.
On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed table 200 is selectively rotated, and the sheet is fed out from one of the paper feed cassettes 44 provided in multiple stages in the paper bank 43, and the separation roller 45. Then, the sheets are separated one by one into the paper feed path 46, transported by the transport roller 47, guided to the paper feed path 48 in the copying machine main body 100, and abutted against the registration roller 49 and stopped.

Alternatively, the sheet feed roller 50 is rotated to feed out the sheets on the manual feed tray 51, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped.
Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer member 10, the sheet is fed between the intermediate transfer member 10 and the secondary transfer device 22, and transferred by the secondary transfer device 22. A color image is recorded on the sheet.
The sheet after the image transfer is conveyed by the secondary transfer device 22 and sent to the fixing device 25, and heat and pressure are applied to the fixing device 25 to fix the transferred image. The paper is discharged at 56 and stacked on the paper discharge tray 57. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided again to the transfer position, and the image is recorded also on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56.

The lubricant application device is installed on the downstream side of the cleaning device for the photoconductor 40, and the zinc stearate, which is a lubricant, is scraped off from the molded lubricant with a brush roller and is attached to the brush. Apply by rubbing on the surface. Next, the lubricant is pressed by the cleaning blade that is in contact with the photoconductor 40 to form a thin film. The toner on the photoreceptor 40 forming the lubricant layer is easily cleaned, and the adhesion with the potential on the surface of the photoreceptor 40 is also reduced, so that the residual toner having a circularity of 0.94 or more. Even it can be cleaned.
Further, the photoreceptor 40 coated with the lubricant is pressed onto the photoreceptor 40 by a cleaning blade of a cleaning device to form a thin film. This thin film reduces the friction coefficient of the photoreceptor 1. At this time, it is preferable that the friction coefficient μ of the photosensitive member 1 is 0.2 or less. The friction coefficient μ can be controlled by setting conditions of the coating apparatus such as the pressure due to the strength of the pressure spring against the molded lubricant, the brush density of the brush roller, the diameter of the brush, the rotation speed of the roller, and the rotation direction.
By making the friction coefficient of the photoreceptor 40 0.2 or less, it is possible to suppress the friction with the cleaning blade from increasing, to prevent deformation or turning of the cleaning blade, and to prevent the toner from slipping through the cleaning blade, Occurrence of cleaning failure can be suppressed.

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto. Hereinafter, a part shows a weight part.
(Evaluation of two-component developer)
When evaluating an image with a two-component developer, a ferrite carrier having an average particle size of 35 μm coated with a silicone resin with an average thickness of 0.5 μm is used as follows. The developer was prepared by uniformly mixing and charging the parts by weight using a tumbler mixer of the type in which the container rolls and stirs.

(Carrier production)
Core material Mn ferrite particles (weight average diameter: 35 μm) 5000 parts Coat material toluene 450 parts Silicone resin SR2400 (made by Toray Dow Corning Silicone, nonvolatile content 50%) 450 parts Aminosilane SH6020 (made by Toray Dow Corning Silicone) ) 10 parts carbon black 10 parts The above coating material is dispersed with a stirrer for 10 minutes to prepare a coating solution, and the coating solution and the core material are formed into a swirling flow provided with a rotary bottom plate disk and stirring blades in a fluidized bed. The coating solution was applied to the core material while being applied to a coating apparatus for coating. The obtained coated material was baked in an electric furnace at 250 ° C. for 2 hours to obtain the carrier.

(External additive manufacturing method)
The external additive used in the present invention was produced as follows.
(External additive 1)
From the center part of the two-fluid nozzle for slurry spraying provided in the center part of the burner, a slurry composed of 50 parts by weight of metal silicon powder (average particle size 6.7 μm) and 50 parts by weight of water is put into the flame (temperature about 1800 ° C.). While jetting at a rate of 22.0 kg / hr, oxygen was supplied from the surrounding area. The produced spherical silica powder was pneumatically transported to a collection line by a blower and collected by a bag filter. After adding 250 g of spherical silica powder to a vibrating fluidized bed and fluidizing it with air circulated by a suction blower, spraying 3.2 g of water and fluidizing and mixing for 5 minutes, HMDS (hexamethyldisilane), which is a silane coupling agent. The external additive 1 was obtained by spraying 5.3 g of silazane and fluidly mixing for 40 minutes.

(External additive 2)
600 parts by mass of methanol, 46 parts by mass of water, and 55 parts by mass of 28% aqueous ammonia were added and mixed. While this solution was adjusted to 35 ° C. and stirred, 1300 parts by mass of tetramethoxysilane and 470 parts by mass of 5.4% ammonia water were simultaneously added, and the former was added dropwise over 7 hours and the latter over 3 hours. Stirring was continued for 0.5 hour after the addition of tetramethoxysilane and hydrolysis was performed to obtain a suspension of silica fine particles. To the resulting suspension, 550 parts by mass of hexamethyldisilazane was added at room temperature, heated to 55 ° C. and reacted for 3 hours to trimethylsilylate the silica fine particles. Thereby, the external additive 2 was obtained.

(External additive 3)
40 parts by mass of metal silicon powder (average particle size 6.7 μm), 10 parts by weight of metal titanium powder (average particle size 5 μm), and 50 parts by mass of water from the center of the two-fluid nozzle for spraying slurry provided in the center of the burner Was sprayed into a flame (temperature of about 1900 ° C.) at a rate of 23.0 kg / hour, and oxygen was supplied from its surroundings. The produced spherical silica / titanium oxide powder was pneumatically transported to a collection line by a blower and collected by a bag filter. 250 g of spherical powder was charged into a vibrating fluidized bed, and 3.2 g of water was sprayed and fluidized and mixed for 5 minutes while fluidizing with air circulated by a suction blower. ) 5.3 g was sprayed and fluid mixed for 40 minutes to obtain external additive 3.

[Example 1]
~ Synthesis of organic fine particle emulsion ~
Production Example 1
In a reaction vessel equipped with a stir bar and a thermometer, 683 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries), 166 parts of methacrylic acid, 110 butyl acrylate Parts and 1 part of ammonium persulfate were added and stirred at 3800 rpm for 30 minutes to obtain a white emulsion. The system was heated to raise the system temperature to 75 ° C. and reacted for 3 hours. Furthermore, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 70 ° C. for 5 hours, and an aqueous dispersion of vinyl resin (methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt copolymer). [Fine particle dispersion 1] was obtained. The volume average particle diameter of the [fine particle dispersion 1] measured by LA-920 was 75 nm. A portion of [Fine Particle Dispersion 1] was dried to isolate the resin component. The Tg of the resin was 60 ° C., and the weight average molecular weight was 110,000.

-Adjustment of aqueous phase-
Production Example 2
990 parts of water, 83 parts of [fine particle dispersion 1], 37 parts of a 48.3% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7: manufactured by Sanyo Chemical Industries) and 90 parts of ethyl acetate are mixed and stirred. A milky white liquid was obtained. This is designated as [Aqueous Phase 1].

~ Synthesis of low molecular weight polyester ~
Production Example 3
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen inlet tube, 229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propylene oxide 3-mole adduct, 208 parts terephthalic acid, 46 parts adipic acid and dibutyl Add 2 parts of tin oxide, react at 230 ° C for 7 hours at normal pressure, and further react for 5 hours at a reduced pressure of 10-15 mmHg, then add 44 parts of trimellitic anhydride to the reaction vessel at 180 ° C at normal pressure. By reacting for 3 hours, [low molecular weight polyester 1] was obtained. [Low molecular polyester 1] had a number average molecular weight of 2,300, a weight average molecular weight of 6,700, Tg of 43 ° C., and an acid value of 25.

~ Synthesis of intermediate polyester ~
Production Example 4
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, trimellitic anhydride 22 And 2 parts of dibutyltin oxide were added, reacted at 230 ° C. at normal pressure for 7 hours, and further reacted at reduced pressure of 10-15 mmHg for 5 hours to obtain [Intermediate Polyester 1]. [Intermediate Polyester 1] had a number average molecular weight of 2200, a weight average molecular weight of 9700, Tg of 54 ° C., an acid value of 0.5, and a hydroxyl value of 52.
Next, 410 parts of [Intermediate polyester 1], 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. Polymer 1] was obtained. [Prepolymer 1] had a free isocyanate weight percentage of 1.53%.

~ Synthesis of ketimine ~
Production Example 5
In a reaction vessel equipped with a stir bar and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 4 and a half hours to obtain [ketimine compound 1]. The amine value of [ketimine compound 1] was 417.

~ Synthesis of master batch (MB) ~
Production Example 6
Add 600 parts of water, Pigment Blue 15: 3 water-containing cake (solid content 50%), 1200 parts of polyester resin, mix with Henschel mixer (Mitsui Mining Co., Ltd.) and knead the mixture at 120 ° C for 45 minutes using two rolls. Thereafter, the product was rolled and cooled, and pulverized with a pulverizer to obtain [Masterbatch 1].

~ Creation of oil phase ~
Production Example 7
In a container equipped with a stir bar and a thermometer, 378 parts of [Low molecular weight polyester 1], 100 parts of Carnauba WAX, and 947 parts of ethyl acetate were charged, heated to 80 ° C. with stirring, and kept at 80 ° C. for 5 hours. It was cooled to 30 ° C at 1 hour. Next, 500 parts of [Masterbatch 1] and 500 parts of ethyl acetate were placed in a container and mixed for 1 hour to obtain [Raw material solution 1].
[Raw Material Solution 1] 1324 parts were transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feed speed of 1 kg / Hr, a disk peripheral speed of 6 m / sec, and 0.5 mm zirconia beads were 80% by volume. The pigment and WAX were dispersed under the conditions of filling and 3 passes. Next, 1324 parts of a 65% ethyl acetate solution of [low molecular weight polyester 1] was added, followed by two passes with a bead mill under the above conditions to obtain [Pigment / WAX Dispersion 1]. The solid content concentration of [Pigment / WAX Dispersion 1] (130 ° C., 30 minutes) was 50%.

~ Emulsification⇒Desolvation ~
Production Example 8
[Pigment / WAX Dispersion 1] 749 parts, [Prepolymer 1] 115 parts, [Ketimine Compound 1] 2.9 parts in a container and TK homomixer (manufactured by Tokushu Kika) at 5,000 rpm for 2 minutes After mixing, 1200 parts of [Aqueous Phase 1] was added to the container, and mixed with a TK homomixer at 13,000 rpm for 25 minutes to obtain [Emulsion Slurry 1].
[Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 8 hours, aging was carried out at 45 ° C. for 7 hours to obtain [Dispersion slurry 1].

~ Washing⇒Drying ~
Production Example 9
[Dispersion Slurry 1] After filtering 100 parts under reduced pressure,
(1): 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(2): 1OO parts of 10% aqueous sodium hydroxide solution was added to the filter cake of (1), mixed with a TK homomixer (30 minutes at 12,000 rpm), and filtered under reduced pressure.
(3): 100 parts of 10% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(4): 300 parts of ion-exchanged water is added to the filter cake of (3), mixed with a TK homomixer (10 minutes at 12,000 rpm) and then filtered twice to obtain [filter cake 1]. It was.
[Filter cake 1] was dried at 45 ° C. for 48 hours in a circulating dryer.

Thereafter, in a water solvent soda in which the fluorine compound (2) is dispersed at a concentration of 1 wt%, the toner compound is mixed so that the fluorine compound (2) is 0.1 wt to adhere (bond) the fluorine compound. Thereafter, it was dried at 45 ° C. for 48 hours in a circulating dryer, and further dried on a shelf at 30 ° C. for 10 hours. Thereafter, sieved with a mesh of 75 μm, [toner base particle 1] was obtained.
Thereafter, 100 parts of [toner base particle 1], 1.5 parts of hexamethyldisilazane hydrophobized silica having a primary particle size of 10 nm produced by the combustion method and external additive 1 are added in Table 1 and further hydrophobized titanium oxide. 0.5 part was mixed with a Henschel mixer (FM20C manufactured by Mitsui Mining Co., Ltd.) to obtain a toner. Mixing conditions were set by repeating a set of 30 second rotation and 60 second rotation stop at a peripheral speed of 30 m / sec 12 times. The physical properties of the obtained toner are shown in Table 1, and the evaluation results are shown in Table 2.

[Example 2]
In Example 1, a toner was produced and evaluated in the same manner as in Example 1 except that the mixing conditions of the Henschel mixer during mixing of the external additive were changed as follows, and the formulation was changed as shown in Table 1.
The mixing conditions were a circumferential speed of 35 m / sec, mixing for 12 minutes, stopping rotation for 60 seconds, and then mixing for another 12 minutes. The physical properties of the obtained toner are shown in Table 1, and the evaluation results are shown in Table 2.

[Example 3]
In Example 1, a toner was produced and evaluated in the same manner as in Example 1 except that the mixing conditions of the Henschel mixer during mixing of the external additive were changed as follows, and the formulation was changed as shown in Table 1.
The mixing conditions were a set of 30 seconds rotation and 60 seconds rotation stop at a peripheral speed of 23 m / sec. The physical properties of the obtained toner are shown in Table 1, and the evaluation results are shown in Table 2.

[Example 4]
In Example 1, a toner was produced and evaluated in the same manner as in Example 1 except that the external additive 2 was used instead of the external additive 1 when the external additive was mixed, and the formulation was changed as shown in Table 1. The physical properties of the obtained toner are shown in Table 1, and the evaluation results are shown in Table 2.

[Example 5]
In Example 1, the toner was manufactured and evaluated in the same manner as in Example 1 except that the steps were changed from washing to drying to changing the wet method as described below. The physical properties of the obtained toner are shown in Table 1, and the evaluation results are shown in Table 2.

~ Washing⇒Drying ~
Production Example 9
[Dispersion Slurry 1] After filtering 100 parts under reduced pressure,
(1): 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(2): 100 parts of 10% sodium hydroxide aqueous solution was added to the filter cake of (1), mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure.
(3): 100 parts of 10% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(4): 300 parts of ion-exchanged water is added to the filter cake of (3), mixed with a TK homomixer (10 minutes at 12,000 rpm) and then filtered twice to obtain [filter cake 1]. It was.
[Filter cake 1] was dried at 45 ° C. for 48 hours in a circulating dryer.
Thereafter, the external additive A1 was added at a concentration of 1.2 wt% and dispersed in an aqueous solvent solution in which the fluorine compound (2) was dispersed at a concentration of 1 wt%. Thereafter, the fluorine compound (2) is mixed with the toner particles so as to be 0.1 wt%, and the fluorine compound is adhered (bonded), and at the same time, the amount of the external additive A1 finally adhering to the toner particles is 1 wt%. The mixture was processed at a ratio. Thereafter, it was dried at 45 ° C. for 48 hours by a circulating dryer, and further dried on a shelf at 30 ° C. for 10 hours. Thereafter, sieved with a mesh of 75 μm, [toner base particle 1] was obtained.

Thereafter, 100 parts of [toner base particle 1], 1.5 parts of hexamethyldisilazane hydrophobized silica having a primary particle size of 10 nm produced by a combustion method and 0.5 part of hydrophobized titanium oxide were added to a Henschel mixer (Mitsui Mining Co., Ltd.). A toner was obtained by mixing with FM20C). Mixing conditions were set by repeating a set of 30 second rotation and 60 second rotation stop at a peripheral speed of 30 m / sec 12 times.

[Example 6]
In Example 1, a toner was produced and evaluated in the same manner as in Example 1 except that 0.15 part of zinc stearate was mixed together again after mixing the external additive. The physical properties of the obtained toner are shown in Table 1, and the evaluation results are shown in Table 2.

[Example 7]
A toner was produced and evaluated in exactly the same manner as in Example 1 except that the process of “emulsification → desolvation” was changed to the following. The physical properties of the obtained toner are shown in Table 1, and the evaluation results are shown in Table 2.
~ Emulsification⇒Desolvation ~
[Pigment / WAX Dispersion 1] 749 parts, [Prepolymer 1] 115 parts, [Ketimine Compound 1] 2.9 parts in a container, and TK homomixer (made by Tokushu Kika) at 6,000 rpm for 2 minutes After mixing, 1200 parts of [Aqueous Phase 1] was added to the container and mixed with a TK homomixer at 13,000 rpm for 10 minutes to obtain [Emulsion Slurry 1].
[Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C for 5 hours, aging was carried out at 45 ° C for 4 hours to obtain [Dispersion slurry 1].

[Example 8]
A toner was produced and evaluated in exactly the same manner as in Example 1 except that the process of “emulsification → solvent removal” was changed to the following. The physical properties of the obtained toner are shown in Table 1, and the evaluation results are shown in Table 2.
~ Emulsification⇒Desolvation ~
[Pigment / WAX Dispersion 1] 630 parts, [Prepolymer 1] 120 parts, [Ketimine Compound 1] 3.1 parts in a container, TK homomixer (manufactured by Tokushu Kika) for 2 minutes at 5,000 rpm After mixing, 1200 parts of [Aqueous phase 1] was added to the container, and mixed with a TK homomixer at 11,000 rpm for 50 minutes to obtain [Emulsion slurry 1].
[Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 10 hours, aging was carried out at 45 ° C. for 24 hours to obtain [Dispersion slurry 1].

[Comparative Example 1]
Using the toner used in Example 1, the charging mechanism of the machine used for the evaluation was remodeled and evaluated so that only DC (direct current) charging was applied.
[Comparative Example 2]
In Example 1, a toner was produced and evaluated in the same manner as in Example 1 except that the mixing conditions of the Henschel mixer during mixing of the external additive were changed as follows, and the formulation was changed as shown in Table 1.
The mixing conditions were a peripheral speed of 35 m / sec, mixing for 25 minutes, stopping rotation for 60 seconds, and then mixing for another 25 minutes. The physical properties of the obtained toner are shown in Table 1, and the evaluation results are shown in Table 2.
[Comparative Example 3]
In Example 1, a toner was produced and evaluated in the same manner as in Example 1 except that the mixing conditions of the Henschel mixer during mixing of the external additive were changed as follows, and the formulation was changed as shown in Table 1.
The mixing conditions were a circumferential speed of 23 m / sec, and a set of 30 second rotation and 60 second rotation stop was repeated twice for mixing. The physical properties of the obtained toner are shown in Table 1, and the evaluation results are shown in Table 2.

(Evaluation item)
1) Particle size The particle size of the toner was measured using a particle size measuring device “Coulter Counter TAII” manufactured by Coulter Electronics Co., Ltd., with an aperture diameter of 100 μm. The volume average particle size and the number average particle size were determined by the particle size measuring instrument.
2) Average circularity E
The average circularity E can be measured by a flow type particle image analyzer FPIA-1000 (manufactured by Toa Medical Electronics Co., Ltd.). As a specific measuring method, 0.3 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 120 ml of water from which impure solids have been removed in advance, and about 0.2 g of a measurement sample is further added. Add. The suspension in which the sample is dispersed is obtained by carrying out a dispersion treatment with an ultrasonic disperser for about 2 minutes, and measuring the shape and distribution of the toner with the above apparatus at a dispersion concentration of about 5000 / μl.

3) Fixability RICOH Imagio Neo 450 manufactured by Ricoh is used as a belt fixing system, and a plain image and a cardboard transfer paper (Ricoh type 6200 and NBS Ricoh copy printing paper <135>) with a solid image of 1.0 ± Fixing evaluation was performed with a toner adhesion amount of 0.1 mg / cm ² . The fixing test was performed by changing the temperature of the fixing belt, and the upper limit temperature at which hot offset did not occur on plain paper was defined as the upper limit fixing temperature. Further, the minimum fixing temperature was measured with cardboard. The lower limit fixing temperature was determined as the fixing lower limit temperature at the fixing roll temperature at which the residual ratio of the image density after rubbing the obtained fixed image with a pad was 70% or more. It is desirable that the fixing upper limit temperature is 190 ° C. or higher and the fixing lower limit temperature is 140 ° C. or lower.
4) Cleanability (LL evaluation)
Using an evaluation machine that was tuned by refining Ricoh's IPSiO Color 8100 to an oil-less fixing system, it passed through a cleaning blade after outputting 100 sheets of a 5% image density chart in an LL environment (temperature 10 ° C., humidity 15%). The transfer residual toner on the photoconductor is transferred to a white paper with a scotch tape (manufactured by Sumitomo 3M Co., Ltd.), measured with X-Rite 938 (manufactured by X-Rite), and the difference from the blank is less than 0.005 Was evaluated as ◎, 0.005 to 0.010 as ○, 0.011 to 0.02 as Δ, and more than 0.0 as ×.

5) Cleanability (durability)
Using an evaluation machine modified from an Ricoh IPSiO Color 8100 and tuned to an oil-less fixing system, the transfer residual toner on the photoreceptor after passing through a cleaning process after outputting 40000 5% image density charts is removed from Scotch tape (Sumitomo 3M). Manufactured by Co., Ltd.), measured with X-Rite 938 (manufactured by X-Rite), and those with a difference from the blank less than 0.005 are ◎, 0.005 to 0.010 Was evaluated as ○, 0.011 to 0.02 as Δ, and more than 0.02 as ×.
6) Filming property Using an evaluation machine in which Ricoh IPSiO Color 8100 was remodeled into an oil-less fixing system and tuned, the amount of adhering components adhering to the photoconductor after outputting 5% image density charts was visually evaluated. . The case where no adhesion was observed was evaluated as ◎, the case where a slightly cloudy trace was observed was evaluated as ◯, the case where a cloudy streak could be confirmed was evaluated as Δ, and the case where a cloudy area was large was evaluated as ×.

7) Using an evaluation machine that has been tuned by modifying the IPSiO Color 8100 made by Ricoh with the HH image blur Ricoh into an oil-less fixing system, output the 2000% 5% image density chart to the HH environment (temperature 90 ° C, humidity 80%). Installed, output image, and confirmed whether image blur occurred. A good one with no blur was marked with ◎, a little blurred but almost unobservable was marked with ◯, a slightly blurred one was marked with Δ, and a clearly blurred one was marked with ×.
8) Charging stability Using an evaluation machine in which Ricoh's IPSiO Color 8100 was remodeled into an oil-less fixing system and tuned, an image area ratio 5% chart continuous 100,000 sheet output durability test was carried out. Changes in charge amount were evaluated. 1 g of developer was weighed and the change in charge amount was determined by the blow-off method. When the change in the charge amount was 5 μc / g or less, it was evaluated as ◯, when it was 10 μc / g or less, Δ when it exceeded 10 μc / g.

9) Image density After remodeling Ricoh's imgio Neo 450 as a belt fixing method, after outputting a solid image at an adhesion amount of 0.4 ± 0.1 mg / cm ^{2 on} a plain paper transfer paper (type 6200 made by Ricoh), The image density was measured by X-Rite 938 (manufactured by X-Rite). An image density of 1.4 or higher was evaluated as ◯, and an image density lower than that as X.
10) Image granularity and sharpness Using an evaluation machine that was tuned by refining Ricoh's IPSiO Color 8100 to an oilless fixing system, a photographic image was output in a single color, and the degree of granularity and sharpness was visually evaluated. . Evaluations were made from GOOD, ◎, ○, Δ, and ×.並 is equivalent to offset printing, ◯ is slightly worse than offset printing, Δ is much worse than offset printing, and × is very bad compared to conventional electrophotographic images.

11) Fog In an environment with a temperature of 10 ° C. and a humidity of 15%, using an evaluation machine that has been tuned by modifying the Ricoh IPSiO Color 8100 to an oil-less fixing system, each toner outputs an image area ratio of 5% and a continuous output of 100,000 sheets. The degree of toner contamination on the transfer paper upper surface after the durability test was visually evaluated (loupe). Evaluations were made from GOOD, ◎, ○, Δ, and ×. ◎ indicates that the toner stains are not observed at all and is in a good state, ○ indicates that only a slight amount of stains are observed, △ indicates a slight amount of stains, and × indicates very dirty outside the allowable range. There is a problem.
12) Toner scattering In an environment with a temperature of 40 ° C. and a humidity of 90%, an evaluation machine tuned by remodeling Ricoh's IPSiO Color 8100 into an oil-less fixing system, and using each toner, an image area ratio 5% chart continuous 100,000 sheets The toner contamination state in the copying machine after the output durability test was visually evaluated. ◎ indicates that the toner is not observed at all and is in a good condition, ○ indicates that the slight contamination is observed, which is not a problem, △ indicates that the contamination is slightly observed, and × indicates that the contamination is not within the allowable range. There is a problem.

13) Weigh 10g of environmentally storable toner, put it in a 20ml glass container, tap the glass bottle 100 times, leave it in a constant temperature bath set at a temperature of 55 ° C and a humidity of 80% for 24 hours. The penetration was measured with The toner stored in a low-temperature and low-humidity (10 ° C., 15%) environment was similarly evaluated for penetration, and the value with the smaller penetration was evaluated in a high-temperature and high-humidity and low-temperature and low-humidity environment. From the favorable ones, ◎: 20 mm or more, ◯: 15 mm or more and less than 20 mm, Δ: 10 mm or more to less than 15 mm, x: less than 10 mm.
14) Using an evaluation machine remodeled and tuned to a transferable oil-less fixing system, the developing machine was agitated without outputting paper for 60 minutes to give development stress. Thereafter, the electrostatic image developed with an adhesion amount of 0.4 mg / cm ² on the photoconductor is transferred to paper (Type 6200, manufactured by Ricoh Co., Ltd.) at a transfer current of 15 μA, and the transfer residual toner on the photoconductor is removed. Transfer to white paper with Scotch tape (manufactured by Sumitomo 3M Co., Ltd.) and measure it with X-Rite 938 (manufactured by X-Rite). The evaluation was evaluated as ○ for 0.015, Δ for 0.016 to 0.02, and × for those exceeding 0.02.

15) Using an evaluation machine remodeled and tuned to an image-bottled oilless fixing system, the developing machine was stirred for 60 minutes without applying paper and development stress was applied. Thereafter, an electrostatic image developed with an adhesion amount of 0.4 mg / cm ² on the photosensitive member is transferred to paper (Type 6200, manufactured by Ricoh Co., Ltd.) at a transfer current of 15 μA, and the transfer residual toner on the photosensitive member is removed. The paper was transferred to white paper with Scotch tape (manufactured by Sumitomo 3M). Observe the transfer residual image visually, ◎ if the degree of blurring is good, no blurry feeling ◎, slightly blurry but almost inconspicuous ○, slightly blurry △, very blurry The unacceptable level was evaluated as x.
16) Charging roller stain Using an evaluation machine that was tuned by remodeling Ricoh's IPSiO Color 8100 into an oil-less fixing system, stains derived from external additives attached to the charging roller after 2000 sheets of 5% image density chart were output were confirmed. did. Good samples with no dirt were marked with ◎, those with slight dirt but no problem were marked with ○, those with slight dirt that could be used were marked with △, and those with bad dirt that could not be used.

17) Circularity SF-1 and SF-2 evaluation 300 toner SEM images obtained by FE-SEM (S-4200) manufactured by Hitachi, Ltd. were randomly sampled, and the image information was sent via the interface. Introduced into an image analysis apparatus (Luzex AP) manufactured by Nireco Co., Ltd.
18) Black solidity Using an evaluation machine that was tuned by modifying the IPSiO Color 8100 made by Ricoh to an oil-less fixing system, charging unevenness when outputting 5% image density chart and outputting 100% image density chart It was evaluated whether or not a spot-like image abnormality caused by the occurrence of the defect occurred. Good results with no occurrence at all were marked with ◎, those with slight cracks but no problem were marked with ◯, those with slight cracks that could be used were marked with △, and those that were severely unusable.

FIG. 3 is a diagram schematically illustrating the shape of a toner according to the present invention. 1 is a schematic diagram illustrating a configuration of an image forming apparatus of the present invention. 1 is a schematic diagram illustrating a configuration of an image forming apparatus of the present invention. 1 is a schematic diagram illustrating a configuration of an image forming apparatus using a contact-type charging device. 1 is a schematic diagram showing a configuration of a tandem color image forming apparatus of the present invention. 1 is a schematic diagram illustrating a configuration of an image forming apparatus having an intermediate transfer member, which is a tandem color image forming apparatus of the present invention. 1 is a schematic diagram showing a configuration of an image forming apparatus of a tandem type indirect transfer system of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Transfer apparatus 3 Sheet conveyance belt 4 Intermediate transfer body 5 Secondary transfer apparatus 6 Paper feed apparatus 7 Fixing apparatus 8 Photoconductor cleaning apparatus 9 Intermediate transfer body cleaning apparatus 10 Intermediate transfer bodies 14, 15, 16 Support roller 17 Intermediate Transfer body cleaning device 18 Image forming means 20 Tandem image forming portion 21 Exposure device 22 Secondary transfer device (transfer roller)
23 Roller 24 Secondary transfer belt 25 Fixing device 26 Fixing belt (fixing film)
27 Pressure roller 28 Sheet reversing device 32 Contact glass 33 First traveling body 34 Second traveling body 35 Imaging lens 36 Reading sensor 40 Photoconductor 41 Development belt 42 Paper feed roller 43 Paper bank 44 Paper feed cassette 45 Separating roller 46, 48 Feeding path 47 Conveying roller 49 Registration roller 50 Feeding roller 51 Manual feed tray 52 Separating roller 53 Manual feed path 55 Switching claw 56 Ejecting roller 57 Ejecting tray 60 Charging device 61 Developing device 62 Primary transfer device 63 Cleaning device 64 Static eliminator (static charge lamp)
DESCRIPTION OF SYMBOLS 100 Copier main body 140 Photoconductor 160 Charging roller 200 Paper feed table 300 Scanner 400 Automatic document feeder

Claims (16)

A latent image carrier for carrying a latent image;
A charging device for uniformly charging the surface of the latent image carrier;
An exposure device for writing an electrostatic latent image on the surface of the charged latent image carrier;
A developing device that supplies toner to the electrostatic latent image formed on the surface of the latent image carrier to visualize it;
A transfer device for transferring the visible image on the surface of the latent image carrier to the transfer target;
In an image forming apparatus including a fixing device that fixes a visible image on a transfer target,
The charging device is applied with at least an AC voltage,
The toner includes an external additive, and the amount of the external additive released to 100 parts of the toner is 0.1 to 1.0 part. The image forming apparatus according to claim 1.
The external additive is a metal oxide having a number average particle diameter in the range of 100 to 300 nm. The image forming apparatus according to claim 1, wherein
The external additive is a metal oxide having a number average particle diameter in the range of 8 to 80 nm. The image forming apparatus according to any one of claims 1 to 3,
The image forming apparatus, wherein the toner has an additive amount in the range of 0.5 to 2.0 parts with respect to 100 parts of toner. The image forming apparatus according to claim 1,
The image forming apparatus, wherein the toner is obtained by dry mixing using a mixed medium. The image forming apparatus according to claim 1,
An image forming apparatus, wherein the toner is obtained by wet mixing. The image forming apparatus according to claim 1,
The image forming apparatus, wherein the charging device charges a roller-shaped charging member in proximity to or in contact with a latent image carrier. The image forming apparatus according to claim 1,
The image forming apparatus includes an application member that applies a stearic acid metal salt. The image forming apparatus according to claim 1,
The image forming apparatus, wherein the toner has an average circularity of 0.94 or more. The image forming apparatus according to claim 1,
The toner has a volume average particle size of 3.0 to 8.0 μm,
A ratio (Dv / Dn) of volume average particle diameter (Dv) to number average particle diameter (Dn) is 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 toner has an SF-1 of 100 to 180 and an SF-2 of 100 to 180. The image forming apparatus according to claim 1,
The toner 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. An image forming apparatus characterized by satisfying a relationship of major axis r1 ≧ minor axis r2 ≧ thickness r3. The image forming apparatus according to claim 1,
In the toner, a toner composition containing at least a polymer having a site capable of reacting with a compound having an active hydrogen group, a polyester, a colorant, and a release agent is crosslinked and / or in the presence of resin fine particles in an aqueous medium. An image forming apparatus characterized by performing an extension reaction. The image forming apparatus according to claim 1,
The image forming apparatus includes a process cartridge that integrally supports the latent image carrier and at least the developing unit and is detachable from the main body of the image forming apparatus. A latent image carrier that carries a latent image, a charging device that uniformly applies at least an AC voltage to the surface of the latent image carrier, an exposure device that writes an electrostatic latent image on the surface of the charged latent image carrier, and a latent device A developing device that supplies toner to the electrostatic latent image formed on the surface of the image carrier and visualizes the image, a transfer device that transfers the visible image on the surface of the latent image carrier to the transfer body, and a surface on the transfer body In a toner used in an image forming apparatus including a fixing device that fixes a visible image,
The toner contains an external additive, and the amount of the external additive released to 100 parts of the toner is 0.1 to 1.0 part. The toner according to claim 15.
The toner used in the image forming apparatus according to claim 2.

Images