JP2007178551A - Toner kit, developer, process cartridge, image forming method and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner kit and so on capable of eliminating a color difference between in a high temperature and high humidity environment and in a low temperature and low humidity environment, avoiding density irregularity in a full-color image, suppressing a charge-up phenomenon and forming a preferable image free from problems of charging such as contamination on the base and decrease in image density. <P>SOLUTION: The toner kit comprises at least a black toner, a yellow toner, a magenta toner and a cyan toner, wherein each toner contains at least a binder resin, a colorant and a charge control agent. The charge control agent has a molecular structure containing K<SP>+</SP>as a counter ion. The K<SP>+</SP>intensity Kk detected by fluorescent X-rays on the surface of the black toner, the K<SP>+</SP>intensity Ky detected by fluorescent X-rays on the surface of the yellow toner, the K<SP>+</SP>intensity Km detected by fluorescent X-rays on the surface of the magenta toner, and the K<SP>+</SP>intensity Kc detected by fluorescent X-rays on the surface of the cyan toner satisfy Kk<Ky, Kk<Km and Kk<Kc. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a toner kit used in a copying machine, a printer, or the like to which electrophotographic technology is applied, and a developer, a process cartridge, an image forming method, and an image forming apparatus using the toner kit.

  Conventionally, in electrophotography, the surface of a photosensitive member (hereinafter also referred to as “image carrier”, “electrostatic latent image carrier”, or “electrophotographic photosensitive member”) is charged and exposed to light. The electrostatic latent image is developed with toner to form a toner image, the toner image is transferred to a recording medium such as transfer paper, and fixed by a heat roll or the like to form an image.

  Dry development methods employed in electrophotography, electrostatic recording, and the like include a method using a two-component developer composed of a toner and a carrier and a method using a one-component developer not containing a carrier. The method using a two-component developer can obtain a good image relatively stably, but has a drawback that the apparatus configuration becomes large. On the other hand, in the method using a one-component developer, the toner (developer) is usually conveyed by at least one toner conveying member, and the electrostatic latent image formed on the image carrier by the conveyed toner is visualized. Means to make it. At that time, the layer thickness of the toner transported on the surface of the toner transport member must be made as thin as possible. In particular, when a toner having a high electrical resistance is used, it is necessary to charge the toner by a developing device. Therefore, the toner layer thickness must be extremely thin. This is because if the toner layer is thick, only the vicinity of the surface of the toner layer is charged, and the entire toner layer is difficult to be uniformly charged.

  In response to this demand, various methods have been proposed as means for regulating the toner layer thickness on the toner conveying member (toner layer thickness regulating means). As a typical example, there is a type in which a regulating blade is used, the regulating blade is placed against a toner conveying member, and the toner conveyed on the surface of the toner conveying member is pressed by the regulating blade to control the toner layer thickness. . In addition, a type that obtains the same effect by bringing a roller into contact with the surface of the toner conveying member instead of the regulating blade has been proposed.

  Here, since the black toner uses a material having a low electric resistance such as carbon black or magnetic powder as a colorant, the charge holding ability and generation ability are lower than those of the color toner. For this reason, if the charge control is the same for black toner and color toner, there will be a difference in charging characteristics, and the density transition in a high-temperature, high-humidity environment or low-temperature, low-humidity environment will differ, resulting in uneven density in a full-color image. The development control of the image becomes complicated.

If the developing roller is made of metal and the regulating blade is made of resin, the use of toners having different charging characteristics requires that the developing member, particularly the regulating blade member and the development settings, be individually changed. At the same time, it leads to cost increase.
On the other hand, when the developing roller is made of resin and the regulating blade is made of metal, the developing member, in particular the developing roller member, and the development setting must be individually changed, which increases the complexity and increases the cost. is there.

In order to solve the above-mentioned problem, for example, Patent Document 1 uses a benzylboron-based charge control agent for black toner, but when used in a full-color image forming method used in combination with a color toner. However, it does not have satisfactory performance.
In Patent Document 2, a benzyl boron-based charge control agent is used in black toner and color toner. However, in this proposal, since the state of presence of the charge control agent is not controlled, there is a difference in charging characteristics between the black toner and the color toner, and the concentration transition is different in the high temperature and high humidity environment and in the low temperature and low humidity environment. Therefore, there is a problem that development control of a full-color image becomes complicated.

JP-A-10-246987 JP 2004-117551 A

  An object of the present invention is to solve various problems in the prior art and achieve the following objects. That is, the present invention eliminates the color difference between the high temperature and high humidity environment and the low temperature and low humidity environment by controlling the amount of the charge control agent present on the surface of the black toner and the color toner, and density unevenness in the full color image is eliminated. Toner kit capable of suppressing charge-up and forming good images free from defects due to charging such as background smearing and density reduction, and developer, process cartridge, image forming method, and image formation using the toner kit An object is to provide an apparatus.

Means for solving the problems are as follows. That is,
<1> A toner kit having at least black toner, yellow toner, magenta toner, and cyan toner,
The black toner, the yellow toner, the magenta toner, and the cyan toner all contain at least a binder resin, a colorant, and a charge control agent.
The black toner colorant contains at least one of carbon black and magnetic powder,
The charge control agent has a molecular structure containing K ⁺ as a counter ion,
Wherein Kk the K ⁺ intensity detected by the X-ray fluorescence of the black toner surface, the K ⁺ intensity detected by the X-ray fluorescence of the yellow toner surface Ky, is detected by X-ray fluorescence of the magenta toner surface K ⁺ A toner kit characterized by satisfying the following formulas: Km <Ky, Kk <Km, Kk <Kc, where Km is the intensity and K ⁺ intensity detected by fluorescent X-rays on the cyan toner surface is Kc. .
<2> The ratio between Kk and Ky (Kk / Ky), the ratio between Kk and Km (Kk / Km), and the ratio between Kk and Kc (Kk / Kc) are all 0.3 to 0.6. The toner kit according to <1>, wherein
<3> If the volume resistance of the black toner is Rk, the volume resistance of the yellow toner is Ry, the volume resistance of the magenta toner is Rm, and the volume resistance of the cyan toner is Rc, the following equations are given: Rk <Ry, Rk <Rm, Rk The toner kit according to any one of <1> to <2>, wherein <Rc> is satisfied.
<4> The toner kit according to <3>, wherein the volume resistance Rk of the black toner is 0.9 × 10 ^{9 to} 5 × 10 ⁹ Ω.
<5> The toner kit according to any one of <1> to <4>, wherein the charge control agent is a benzyl boron compound represented by the following structural formula.
<6> The toner kit according to any one of <1> to <5>, wherein a content of the charge control agent in each toner is 0.5 to 3 parts by mass with respect to 100 parts by mass of the binder resin.
<7> Black toner used for full color image formation using at least black toner, yellow toner, magenta toner, and cyan toner,
The black toner, the yellow toner, the magenta toner, and the cyan toner all contain at least a binder resin, a colorant, and a charge control agent.
The black toner colorant contains at least one of carbon black and magnetic powder,
The charge control agent has a molecular structure containing K ⁺ as a counter ion,
K ⁺ intensity detected by fluorescent X-rays on the black toner surface is Kk, K ⁺ intensity detected by fluorescent X-rays on the yellow toner surface is Ky, and K ⁺ intensity detected by fluorescent X-rays on the magenta toner surface A black toner characterized by satisfying the following equations: Kk <Ky, Kk <Km, Kk <Kc, where Km is Km and K ⁺ intensity detected by fluorescent X-rays on the cyan toner surface.
<8> The ratio between Kk and Ky (Kk / Ky), the ratio between Kk and Km (Kk / Km), and the ratio between Kk and Kc (Kk / Kc) are all 0.3 to 0.6. The black toner according to <7>, wherein
<9> The black toner according to any one of <7> to <8>, wherein the K ⁺ intensity (Kk) detected by fluorescent X-rays on the black toner surface is 0.1 to 1.
<10> The black toner according to any one of <7> to <9>, wherein the charge control agent is a benzyl boron compound represented by the following structural formula.
<11> The black toner according to any one of <7> to <10>, wherein a content of the charge control agent in the toner is 0.5 to 3 parts by mass with respect to 100 parts by mass of the binder resin.
<12> A developer that is a non-magnetic one-component developer composed of each toner in the toner kit according to any one of <1> to <6>.
<13> An electrostatic latent image carrier, and a developing unit that develops the electrostatic latent image formed on the electrostatic latent image carrier using the developer according to <12> to form a visible image. Is a process cartridge characterized by having at least.
<14> An electrostatic latent image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, and the developer described in <12> above At least developing means for forming a visible image by developing the toner, transfer means for transferring the visible image to a recording medium, and fixing means for fixing the transferred image transferred to the recording medium. An image forming apparatus.
<15> The developing means carries the developer on the peripheral surface, rotates in contact with the electrostatic latent image carrier, and applies the developer to the electrostatic latent image formed on the electrostatic latent image carrier. The image forming apparatus according to <14>, further comprising: a developing roller that supplies and develops; and a thin layer forming member that contacts the peripheral surface of the developing roller and thins the developer on the developing roller. is there.
<16> An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image with the developer described in <12> to form a visible image The image forming method includes at least a developing step for forming the image, a transfer step for transferring the visible image to a recording medium, and a fixing step for fixing the transferred image transferred to the recording medium.

The toner kit of the present invention comprises at least black toner, yellow toner, magenta toner, and cyan toner,
The black toner, the yellow toner, the magenta toner, and the cyan toner all contain at least a binder resin, a colorant, and a charge control agent.
The black toner colorant contains at least one of carbon black and magnetic powder,
The charge control agent has a molecular structure containing K ⁺ as a counter ion,
K ⁺ intensity detected by fluorescent X-rays on the black toner surface is Kk, K ⁺ intensity detected by fluorescent X-rays on the yellow toner surface is Ky, and K ⁺ intensity detected by fluorescent X-rays on the magenta toner surface Is Km, and K ⁺ intensity detected by fluorescent X-rays on the cyan toner surface is Kc, the following equations are satisfied: Kk <Ky, Kk <Km, Kk <Kc. When used, by controlling the amount of the charge control agent present on the surface of the black toner and the color toner, there is no color difference under each environment, there is no density unevenness in the full color image, and simple density control is possible. .

  Since the developer of the present invention is a non-magnetic one-component developer composed of each toner in the toner kit of the present invention, in particular, it suppresses the charge-up normally seen as a problem of non-magnetic one-component color toner, It is possible to obtain a good image free from problems due to charging such as reduction.

  The process cartridge of the present invention comprises an electrostatic latent image carrier and developing means for developing a latent image formed on the electrostatic latent image carrier using the developer of the present invention to form a visible image. And at least. The process cartridge is attachable to and detachable from the image forming apparatus, is excellent in convenience, and uses the developer of the present invention, thereby eliminating a color difference between a high temperature and high humidity environment and a low temperature and low humidity environment, thereby providing a full color There is no density unevenness in the image, charge-up can be suppressed, and a good image free from problems due to charging such as background smearing and density reduction can be formed.

  The image forming apparatus of the present invention uses an electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image using a developer. And developing means for forming a visible image by developing, transfer means for transferring the visible image to a recording medium, and fixing means for fixing the transfer image transferred to the recording medium, Since the developer of the present invention is used as a developer, there is no color difference between a high-temperature and high-humidity environment and a low-temperature and low-humidity environment, there is no density unevenness in a full-color image, charging is suppressed, A good image free from defects due to charging such as density reduction can be obtained.

  The image forming method of the present invention includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, and developing the electrostatic latent image using a developer to form a visible image. A developing step for transferring the visible image to a recording medium, and a fixing step for fixing the transferred image transferred to the recording medium, wherein the developer of the present invention is used as the developer. As it is used, there is no color difference between high-temperature and high-humidity environment and low-temperature and low-humidity environment. An image can be formed.

  According to the present invention, the conventional problems can be solved, and the color difference between the high temperature and high humidity environment and the low temperature and low humidity environment is eliminated by controlling the amount of the charge control agent present on the surface of the black toner and the color toner. , A toner kit that is free from density unevenness in a full-color image, suppresses charge-up, and can form a good image free from defects due to charging such as background contamination and density reduction, and a developer and process using the toner kit A cartridge, an image forming method, and an image forming apparatus can be provided.

(Toner kit)
The toner kit of the present invention comprises at least black toner, yellow toner, magenta toner, and cyan toner,
Each of the black toner, the yellow toner, the magenta toner, and the cyan toner contains at least a binder resin, a colorant, and a charge control agent, and further contains other components as necessary. It becomes.
As a colorant for black toner in the toner kit, either carbon black or magnetic powder is used.

<Charge control agent>
The charge control agent is not particularly limited as long as it has a molecular structure containing K ⁺ as a counter ion, and can be appropriately selected according to the purpose. For example, a benzyl boron-based compound represented by the following structural formula The compound has K ⁺ as a counter ion, and measuring the K ⁺ ion concentration is particularly preferable because the presence state of the charge control agent on the toner surface can be easily measured.

  Further, the benzyl boron compound as the charge control agent is excellent in charge rising characteristics and is white, so it is suitable not only for black toner but also for color toner. However, the charge control agent causes problems such as a decrease in charge amount and an increase in charge amount when a durability test and a high-temperature and high-humidity environment test are performed when the toner surface is not optimized.

In the present invention, the Kk the K ⁺ intensity detected by the X-ray fluorescence of the black toner surface, the K ⁺ intensity detected by the X-ray fluorescence of the yellow toner surface Ky, the magenta toner surface fluorescence When K ⁺ intensity detected by X-rays is Km and K ⁺ intensity detected by fluorescent X-rays on the cyan toner surface is Kc, the following expressions are satisfied: Kk <Ky, Kk <Km, Kk <Kc Is. By satisfying such a relationship, the electrical resistance is lower than that of yellow, magenta, and cyan toners, so that the charging characteristics of black toner, which tends to decrease the charge amount, and yellow, magenta, and cyan toners are equalized, and charging failure is caused. Can solve the problem.

In this case, the ratio of Kk to Ky (Kk / Ky), the ratio of Kk to Km (Kk / Km), and the ratio of Kk to Kc (Kk / Kc) are all 0.3 to It is preferable that it is 0.6. If the ratio is less than 0.3, the black toner may become charged more than the other three colors and cause a decrease in density. If the ratio exceeds 0.6, the black toner may be in the other three colors. The charging becomes lower, which may be a cause of background stains and image unevenness.
The K ⁺ intensity (Kk) detected by fluorescent X-rays on the black toner surface is preferably 0.1-1.

Here, the measurement of the K ⁺ intensity on the toner surface can be detected by fluorescent X-rays. Specifically, 0.5 g of toner was dissolved in 20 ml of ethanol. 5 ml of this solution is put into a polyethylene container having an outer diameter of 32 mm, an inner diameter of 25 mm, and a height of 23 mm, and this is potassium using a bottom-illuminated fluorescent X-ray measuring apparatus (manufactured by Rigaku Corporation) under the conditions of 50 kV, 60 mA, 40 s in vacuum. The X-ray intensity was measured, and the net intensity obtained by subtracting the background was defined as the potassium intensity existing on the toner surface.

In the present invention, in addition to the benzyl boron compound, other charge control agents conventionally used in full-color toners may be used in combination. Examples of the other charge control agents include nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified quaternary ammonium salts). Salt), alkylamides, phosphorus simple substance or compound, tungsten simple substance or compound, fluorine-based activator, salicylic acid metal salt, metal salt of salicylic acid derivative, and the like.
Specifically, Bontron 03 of nigrosine dye, Bontron P-51 of quaternary ammonium salt, Bontron S-34 of metal-containing azo dye, E-82 of oxynaphthoic acid metal complex, E- of salicylic acid metal complex 81, E-84, phenolic condensate E-89 (above, manufactured by Orient Chemical Co., Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, manufactured by Hodogaya Chemical Co., Ltd.) Quaternary ammonium salt copy charge PSY VP2038, triphenylmethane derivative copy blue PR, quaternary ammonium salt copy charge NEG VP2036, copy charge NX VP434 (from Hoechst), LRA-901, copper phthalocyanine, perylene , Quinacridone, azo pigments, other sulfonic acid groups, Bokishiru group include polymer compounds having a functional group such as quaternary ammonium salts. Among these, a substance that controls the toner to have a negative polarity is particularly preferably used.

  The addition amount of the charge control agent is determined by the toner production method including the type of the binder resin, the presence / absence of the additive used as necessary, and the dispersion method, and is not uniquely limited. Although it is not, 0.5-3 mass parts is preferable with respect to 100 mass parts of the binder resin, and 0.5-2.5 mass parts is more preferable. If the amount is less than 0.5 parts by mass, desired charge rising characteristics cannot be obtained. If the amount is more than 3 parts by mass, the reduction in charge becomes large, and it is difficult to obtain the effect of the present invention.

  The method for producing the toner base in each toner constituting the toner kit of the present invention is not particularly limited and can be appropriately selected according to the purpose. For example, (1) In the thermoplastic resin serving as the binder resin component In addition, a toner base (pulverized toner) obtained by melting and uniformly dispersing a colorant, a charge control agent, a release agent and the like to obtain a composition, and then grinding and classifying the composition, 2) In a water-based dispersion medium containing a dispersion stabilizer after dissolving or suspending a colorant, a charge control agent, a release agent, etc. in a polymerizable monomer as a binder resin raw material, and adding a polymerization initiator And the suspension is heated to a predetermined temperature to start suspension polymerization, and after completion of the polymerization, a toner base obtained by filtration, washing, dehydration and drying, and (3) a binder containing a polar group obtained by emulsion polymerization. The primary particles of the resin, the colorant and A toner base obtained by agglomerating secondary particles by adding an electric control agent into secondary particles, and further filtering and drying the aggregated particles that are agitated at a temperature higher than the glass transition temperature of the binder resin; (4) A phase inversion emulsification method in which a hydrophilic group-containing resin is used as a binder resin, a coloring agent is added thereto and dissolved in an organic solvent, and then the resin is neutralized to perform phase inversion and then dried to obtain colored particles. Examples thereof include a toner base, and any of these methods can be used.

Hereinafter, the description will be made using a pulverized toner, but the present invention is not limited to this.
The pulverization method is, for example, a method of obtaining the toner base particles by melting and kneading a toner material containing at least a binder resin, a charge control agent, and a colorant, and pulverizing and classifying the toner material. In the case of the pulverization method, for the purpose of increasing the average circularity of the toner, the shape may be controlled by applying a mechanical impact force to the obtained toner base particles. In this case, the mechanical impact force can be applied to the toner base particles using a device such as a hybridizer or mechanofusion.

  First, toner materials are mixed, and the mixture is charged into a melt kneader and melt kneaded. As the melt kneader, for example, a uniaxial or biaxial continuous kneader or a batch kneader using a roll mill can be used. For example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type extruder manufactured by Toshiba Machine Co., Ltd., twin screw extruder manufactured by Casey Kay Co., Ltd., PCM type twin screw extruder manufactured by Ikekai Tekko Co., Ltd. Preferably used. This melt-kneading is preferably performed under appropriate conditions so as not to cause the molecular chains of the binder resin to be broken.

  In the pulverization, the kneaded product obtained by the kneading is pulverized. In this pulverization, it is preferable that the kneaded material is first coarsely pulverized and then finely pulverized. At this time, a method of pulverizing by colliding with a collision plate in a jet stream, pulverizing particles by colliding with each other in a jet stream, or pulverizing with a narrow gap between a mechanically rotating rotor and a stator is preferably used.

In the classification, the pulverized product obtained by the pulverization is classified and adjusted to particles having a predetermined particle diameter. The classification can be performed by removing the fine particle portion by, for example, a cyclone, a decanter, centrifugation, or the like.
After the pulverization and classification are completed, the pulverized product is classified in an air current by centrifugal force or the like to produce a toner having a predetermined particle size.

  Further, in order to improve the fluidity, storage stability, developability and transferability of the toner, inorganic fine particles such as hydrophobic silica fine powder may be further added to and mixed with the toner base particles produced as described above. For mixing the additives, a general powder mixer is used, but it is preferable to equip a jacket or the like to adjust the internal temperature. In order to change the load history applied to the additive, the additive may be added midway or gradually. In this case, you may change the rotation speed, rolling speed, time, temperature, etc. of a mixer. Alternatively, a strong load may be applied first, then a relatively weak load, or vice versa. Examples of the mixing equipment that can be used include a V-type mixer, a rocking mixer, a Ladige mixer, a Nauter mixer, and a Henschel mixer. Next, the toner is obtained by passing through a sieve of 250 mesh or more to remove coarse particles and aggregated particles.

  Here, the toner material contains at least a binder resin, a colorant, and a charge control agent, and further contains a wax and, if necessary, other components.

-Binder resin-
The binder resin is not particularly limited and may be appropriately selected depending on the intended purpose. However, binder resins known in the field of full-color toners such as polyester resins, (meth) acrylic resins, styrene- ( (Meth) acrylic copolymer resin, epoxy resin, COC (cyclic olefin resin (for example, TOPAS-COC, manufactured by Ticona)) and the like. From the viewpoint of stress resistance in the developing unit, polyester resin Is preferably used. You may use these in combination of 2 or more types as needed.

As the polyester-based resin, a polyester resin obtained by polycondensation of a polyhydric alcohol component and a polyvalent carboxylic acid component can be used.
Among the polyhydric alcohol components, examples of the dihydric alcohol component include polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3,3) -2,2 -Bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) Bisphenol A alkylene oxide adducts such as propane; ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol 1,5-pentanediol, 1,6-hexanediol, , 4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polytetramethylene glycol, bisphenol A, hydrogenated bisphenol A, and the like.
Among the polyhydric alcohol components, trihydric or higher alcohol components include, for example, sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, , 2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3, 5-trihydroxymethylbenzene and the like can be mentioned.

Among the polyvalent carboxylic acid components, examples of the divalent carboxylic acid component include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, Adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n-octenyl succinic acid, isooctenyl succinic acid, n-octyl succinic acid, Examples include isooctyl succinic acid, anhydrides or lower alkyl esters of these acids.
Among the polyvalent carboxylic acid components, trivalent or higher carboxylic acid components include, for example, 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,5-benzenetricarboxylic acid, 2,5,7. -Naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxy Propane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empole trimer acid, anhydrides of these acids, And lower alkyl esters.

  The polyester resin is a polycondensation reaction in which a polyester resin is obtained in the same container using a mixture of a polyester resin raw material monomer, a vinyl resin raw material monomer, and a monomer that reacts with both resin raw material monomers. In addition, a resin obtained by performing a radical polymerization reaction for obtaining a vinyl resin in parallel (hereinafter sometimes simply referred to as “vinyl polyester resin”) can also be suitably used. In addition, the monomer which reacts with the raw material monomer of both resin is a monomer which can be used for both reaction of a condensation polymerization reaction and a radical polymerization reaction in other words. That is, it is a monomer having a carboxy group that can undergo a condensation polymerization reaction and a vinyl group that can undergo a radical polymerization reaction, and examples thereof include fumaric acid, maleic acid, acrylic acid, and methacrylic acid.

  Examples of the raw material monomer for the polyester resin include the polyhydric alcohol component and the polyvalent carboxylic acid component described above. Examples of the raw material monomer for the vinyl resin include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, p-ethyl styrene, 2,4-dimethyl styrene, p-tert- Styrene or styrene derivatives such as butyl styrene and p-chlorostyrene; Ethylene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; methyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate , Isobutyl methacrylate, t-butyl methacrylate, n-pentyl methacrylate, isopentyl methacrylate, neopentyl methacrylate, 3- (methyl) butyl methacrylate, hexyl methacrylate, octyl methacrylate, nonyl methacrylate, meta Methacrylic acid alkyl esters such as decyl crylate, undecyl methacrylate, dodecyl methacrylate; methyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, acrylic Alkyl acrylates such as n-pentyl acid, isopentyl acrylate, neopentyl acrylate, 3- (methyl) butyl acrylate, hexyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, and dodecyl acrylate Esters; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid; acrylonitrile, maleic acid ester, itaconic acid ester, vinyl chloride, vinyl acetate, vinyl benzoate, vinylmethylethyl Ton, vinyl hexyl ketone, vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether.

  As a polymerization initiator when polymerizing the raw material monomer of the vinyl resin, for example, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1 Azo or diazo polymerization initiators such as' -azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile; benzoyl peroxide, dicumyl peroxide, And peroxide polymerization initiators such as methyl ethyl ketone peroxide, isopropyl peroxycarbonate, lauroyl peroxide, and the like.

As the binder resin, various polyester resins as described above are preferably used. Among these, from the viewpoint of further improving the separability and offset resistance as an oilless fixing toner, the followings are described. More preferably, the first binder resin and the second binder resin are used.
As the first binder resin, a polyester resin obtained by polycondensation of the above-described polyhydric alcohol component and polyvalent carboxylic acid component, in particular, a bisphenol A alkylene oxide adduct is used as the polyhydric alcohol component. A polyester resin obtained using terephthalic acid and fumaric acid as the divalent carboxylic acid component is preferably used.
As the second binder resin, vinyl polyester resin, in particular, bisphenol A alkylene oxide adduct, terephthalic acid, trimellitic acid, succinic acid is used as a raw material monomer for polyester resin, and styrene and vinyl monomer raw material monomers are used. A vinyl-based polyester resin obtained by using butyl acrylate and fumaric acid as an amphoteric monomer is preferably used.

  During the synthesis of the first binder resin, it is preferable that a hydrocarbon wax is internally added. As described above, the hydrocarbon wax is internally added to the first binder resin in advance, when the first binder resin is synthesized, the hydrocarbon wax is added to the monomer for synthesizing the first binder resin. What is necessary is just to synthesize | combine 1st binder resin in the state added. For example, the polycondensation reaction may be performed in a state where a hydrocarbon wax is added to an acid monomer and an alcohol monomer constituting the polyester resin as the first binder resin. When the first binder resin is a vinyl-based polyester resin, the vinyl-based resin raw material monomer is dropped into the polyester resin raw-material monomer while stirring and heating the hydrocarbon-based wax. Then, a polycondensation reaction and a radical polymerization reaction may be performed.

-Wax-
Generally, the lower the polarity of the wax, the better the releasability from the fixing member roller, and therefore, a hydrocarbon wax having a low polarity is preferably used.
The hydrocarbon wax is a wax composed of only carbon atoms and hydrogen atoms, and does not contain an ester group, an alcohol group, an amide group, etc. Examples of the hydrocarbon wax include polyethylene, polypropylene, and ethylene. Polyolefin waxes such as copolymers of propylene; petroleum waxes such as paraffin wax and microcrystalline wax; synthetic waxes such as Fischer-Tropsch wax. Among these, polyethylene wax, paraffin wax, and Fischer-Tropsch wax are preferable, and polyethylene wax and paraffin wax are particularly preferable.

  The melting point of the wax is represented by the endothermic peak of the wax at the time of temperature rise measured by a differential scanning calorimeter (DSC), and is preferably in the range of 70 to 90 ° C. If the melting point exceeds 90 ° C., the wax may not be sufficiently melted in the fixing process, and separation from the fixing member may not be ensured. If the melting point is less than 70 ° C., the toner particles may be used in a high temperature and high humidity environment. Problems may arise in storage stability, such as fusion between the two. In order to provide a sufficient fixing separation property at a low temperature, the melting point of the wax is more preferably 70 to 85 ° C, and further preferably 70 to 80 ° C.

  Moreover, it is preferable that the half value width of the wax endothermic peak at the time of temperature rise measured by a differential scanning calorimeter (DSC) is 7 ° C. or less. Since the melting point of the wax is relatively low, a wax that has a broad endothermic peak, that is, melts from a low temperature range, adversely affects the storage stability of the toner.

  The content of the wax in the toner is preferably 3 to 10% by mass, more preferably 4 to 8% by mass, and still more preferably 4 to 6.5% by mass. When the content is less than 3% by mass, the amount of wax that exudes between the molten toner and the fixing member in the fixing process is insufficient, and the adhesive force between the molten toner and the fixing member does not decrease. The member does not leave the fixing member. On the other hand, if the wax content exceeds 10% by mass, the amount of wax exposed on the toner surface increases, and the transfer efficiency from the developing unit to the photoconductor and from the photoconductor to the recording member increases due to the deterioration of the fluidity of the toner particles. In addition to a significant reduction in image quality, the wax may be detached from the toner surface, which may cause contamination of the developing member and the photoreceptor.

The content ratio (first binder resin: second binder resin) of the first binder resin (including the mass of the internally added wax) and the second binder resin in the toner particles is 20:80. ~ 45: 55 is preferable, and 30:70 to 40:60 is more preferable. If the amount of the first binder resin is too small, the separability and the high temperature offset resistance may be lowered. If the amount of the first binder resin is too much, the glossiness and the heat-resistant storage property may be lowered.
Further, the softening point of the binder resin composed of the first binder resin and the second binder resin used at the above mass ratio is preferably 100 to 125 ° C, and more preferably 105 to 125 ° C. In the present invention, the softening point of the binder resin composed of the first binder resin and the second binder resin into which wax is internally added may be within the above range.

The acid value of the wax-added first binder resin is preferably 5 to 50 KOHmg / g, and more preferably 10 to 40 KOHmg / g.
The acid value of the second binder resin is preferably 0 to 10 KOHmg / g, and more preferably 1 to 5 KOHmg / g.
In particular, when a polyester-based resin is used, by using a resin having such an acid value, the dispersibility of various colorants and the like can be improved, and a toner having a sufficient charge amount can be obtained.
The first binder resin preferably contains a component insoluble in tetrahydrofuran (THF) from the viewpoint of high temperature offset resistance. The content of the THF-insoluble component in the first wax-added resin is preferably 0.1 to 15 parts by mass, more preferably 0.2 to 10 parts by mass, and still more preferably 0.3 to 5 parts by mass. .

-Colorant-
There is no restriction | limiting in particular as said coloring agent, The well-known pigment and dye conventionally used as a coloring agent of a full color toner can be used. Examples of the colorant include carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, and 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 Rake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimony Zhu, Permanent Red 4R, Para Red, Faise Red, Parachlor Ortho Nitroaniline Red , Risorfa Toscarlet G, Brilliant Fast Scarlet, Brilliant Carmine 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, Thioindigo Red B , Thioindigo maroon, oil red, quinacridone red, pyrazolone red, polyazo red, chrome bar Lion, 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, Bituminous Blue, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chrome Oxide, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Phthalocyanine Green, Anthraki Non-green, titanium oxide, zinc white, lithobon, etc. are mentioned. These may be used alone or in combination of two or more. As the colorant for the black toner, either carbon black or magnetic powder is used.

The content of the colorant in the toner is preferably in the range of 2 to 15 parts by mass with respect to 100 parts by mass of the binder resin.
It is preferable from the viewpoint of dispersibility that the colorant is used in the form of a masterbatch dispersed in a mixed binder resin of the first binder resin and the second binder resin used. The addition amount of the masterbatch may be an amount such that the amount of the colorant contained is within the above range. In addition, 20-40 mass% is suitable for the coloring agent content rate in a masterbatch.

-External additive-
In the present invention, other inorganic fine particles can be used as an external additive for assisting fluidity, developability and chargeability.
Examples of the inorganic fine particles include silicon oxide, zinc oxide, tin oxide, silica sand, titanium oxide, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, and oxide. Examples thereof include aluminum, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, and magnesium silicate.
The total amount of the external additive is preferably 1.0 to 5.0 parts by mass with respect to 100 parts by mass of the toner base particles. When the total amount of the external additive is larger than the above range, fog, developability and fixing separation may be deteriorated. When the total amount of the external additive is smaller than the above range, Property, transferability, and heat-resistant storage property may be deteriorated.

  The toner manufacturing method of the present invention includes, for example, mixing, kneading, pulverizing, and classifying a first binder resin, a second binder resin, and a colorant, into which a hydrocarbon wax is internally added, by a conventionally known method. Then, toner particles (colored resin particles) having a desired particle diameter are prepared. It can be obtained by mixing the toner particles and an external additive.

In the toner kit of the present invention, assuming that the volume resistance of the black toner is Rk, the volume resistance of the yellow toner is Ry, the volume resistance of the magenta toner is Rm, and the volume resistance of the cyan toner is Rc, the following equation is given: Rk <Ry, Rk <Rm and Rk <Rc are preferably satisfied.
The volume resistance Rk of the black toner is preferably 0.9 × 10 ^{9 to} 5 × 10 ⁹ Ω.
Here, the volume resistance of the toner can be measured by, for example, an impedance analyzer manufactured by Solartron.

The mass average particle size of each toner constituting the toner kit is preferably 4 to 10 μm, and more preferably 5 to 10 μm. The ratio of the mass average particle diameter to the number average particle diameter (mass average particle diameter / number average particle diameter) of the toner is preferably 1.00 to 1.40, more preferably 1.10 to 1.25. preferable.
The mass average particle diameter and the ratio of the mass average particle diameter to the number average particle diameter (mass average particle diameter / number average particle diameter) are, for example, a particle size measuring instrument ““ Coulter Counter TAII ”manufactured by Coulter Electronics Co., Ltd. Can be measured.

(Developer)
The developer of the present invention is a nonmagnetic one-component developer composed of each toner in the toner kit of the present invention.
In the one-component developer, after the toner is transported onto the developer carrier, the toner is thinned by the layer thickness regulating member and developed, but the toner and the developer carrier, the layer thickness regulating member, etc. The contact / friction charging time with the friction charging member is very short. Therefore, in order to obtain a toner with a desired charge amount, toner charge control is important. As a result, the toner is not supported on the developing roller and becomes scattered toner, which contaminates the inside of the image forming apparatus, or the toner is developed in a non-image area of the photoreceptor, causing fogging. Is intended to properly control toner charging, and is therefore sufficiently effective in a one-component development system.

  The developer of the present invention can be suitably used for image formation by a non-magnetic one-component development method, and is particularly preferably used for the following toner-containing container, process cartridge, image forming apparatus and image forming method of the present invention. it can.

(Toner container)
The toner container contains the toner or developer of the present invention in a container.
There is no restriction | limiting in particular as said container, It can select suitably from well-known things, For example, what has a toner container main body and a cap etc. are mentioned suitably.
The size, shape, structure, material and the like of the toner container body are not particularly limited and can be appropriately selected according to the purpose. For example, the shape is preferably a cylindrical shape, A spiral unevenness is formed on the surface, the toner as the contents can be transferred to the discharge port side by rotating, and a part or all of the spiral part has a bellows function, etc. Particularly preferred.
The material of the toner container main body is not particularly limited, and those having good dimensional accuracy are preferable. For example, a resin is preferable. Among them, for example, a polyester resin, a polyethylene resin, a polypropylene resin, a polystyrene resin, a polychlorinated resin is preferable. Preferred examples include vinyl resin, polyacrylic acid, polycarbonate resin, ABS resin, polyacetal resin, and the like.
The toner-containing container of the present invention is easy to store and transport, has excellent handleability, and is preferably used for replenishing toner by being detachably attached to the process cartridge and image forming apparatus of the present invention described later. Can do.

(Process cartridge)
The process cartridge of the present invention develops an electrostatic latent image carrier carrying an electrostatic latent image and the electrostatic latent image carried on the electrostatic latent image carrier using the developer of the present invention. And a developing means for forming a visible image, and further having other means such as a charging means, a developing means, a transfer means, a cleaning means, and a static elimination means, which are appropriately selected as necessary. Become.
The developing means includes a developer container that contains the toner or developer of the present invention, and a developer carrier that carries and transports the toner or developer contained in the developer container. And a layer thickness regulating member for regulating the thickness of the toner layer to be carried.
The process cartridge of the present invention can be detachably mounted on various electrophotographic apparatuses, facsimiles, and printers, and is preferably detachably mounted on the image forming apparatus of the present invention described later.

Here, for example, as shown in FIG. 1, the process cartridge includes a photosensitive member 201, and includes a charging unit 202, a developing unit 204, a transfer unit 208, and a cleaning unit 207, and other units as required. It has. In FIG. 1, reference numeral 203 denotes exposure by exposure means, and 205 denotes a recording medium.
As the photosensitive member 201, the same one as an image forming apparatus described later can be used. An arbitrary charging member is used for the charging means 202.
Next, the image forming process using the process cartridge shown in FIG. 1 will be described. The photoconductor 201 is rotated on the surface by charging by the charging means 202 and exposure 203 by the exposure means (not shown) while rotating in the direction of the arrow. An electrostatic latent image corresponding to the exposure image is formed. The electrostatic latent image is developed with toner by the developing unit 204, and the toner development is transferred to the recording medium 205 by the transfer unit 208 and printed out. Next, the surface of the photoconductor after the image transfer is cleaned by the cleaning unit 207, further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.

  The image forming apparatus of the present invention is constructed by integrally combining the electrostatic latent image carrier and the components such as a developing device and a cleaning device as a process cartridge, and this unit can be attached to and detached from the apparatus main body. It may be configured. Further, at least one of a charger, an image exposure device, a developing device, a transfer or separation device, and a cleaning device is integrally supported together with an electrostatic latent image carrier to form a process cartridge, and is detachably attached to the apparatus main body. One unit may be detachable using guide means such as a rail of the apparatus main body.

(Image forming apparatus and image forming method)
The image forming apparatus of the present invention includes at least an electrostatic latent image carrier, an electrostatic latent image forming unit, a developing unit, a transfer unit, and a fixing unit, and further appropriately selected as necessary. It has other means, for example, static elimination means, cleaning means, recycling means, control means and the like.
The image forming method of the present invention includes at least an electrostatic latent image forming step, a developing step, a transfer step, and a fixing step, and other steps appropriately selected as necessary, for example, a static elimination step, a cleaning step. A recycling process, a control process, and the like.

  The image forming method of the present invention can be preferably carried out by the image forming apparatus of the present invention, the electrostatic latent image forming step can be performed by the electrostatic latent image forming means, and the developing step is the developing The transfer step can be performed by the transfer unit, the fixing step can be performed by the fixing unit, and the other steps can be performed by the other unit.

-Electrostatic latent image forming step and electrostatic latent image forming means-
The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrostatic latent image carrier.
The material, shape, structure, size, etc. of the electrostatic latent image carrier (photosensitive member) are not particularly limited, and can be appropriately selected from known ones. Preferred examples of the material include an inorganic photoreceptor such as amorphous silicon and selenium, and an organic photoreceptor such as polysilane and phthalopolymethine. Among these, amorphous silicon and the like are preferable in terms of long life.

  As the amorphous silicon photoreceptor, for example, a support is heated to 50 to 400 ° C., and a vacuum deposition method, a sputtering method, an ion plating method, a thermal CVD method, a photo CVD method, a plasma CVD method, or the like is applied on the support. A photoconductor having a photoconductive layer made of a-Si (hereinafter sometimes referred to as “a-Si-based photoconductor”) can be used. Among these, a plasma CVD method, that is, a method in which a source gas is decomposed by direct current, high frequency or microwave glow discharge to form an a-Si deposited film on a support is preferable.

The electrostatic latent image can be formed, for example, by charging the surface of the electrostatic latent image carrier and then exposing it like an image, and by the electrostatic latent image forming means. .
The electrostatic latent image forming unit includes, for example, at least a charger that charges the surface of the electrostatic latent image carrier and an exposure device that exposes the surface of the electrostatic latent image carrier imagewise.

The charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charger.
The charger is not particularly limited and may be appropriately selected depending on the purpose. For example, the charger includes a conductive or semiconductive roller, a brush, a film, a rubber blade, or the like, which is a publicly known contact. Examples thereof include a charger, a non-contact charger using corona discharge such as corotron and scorotron.

The shape of the charging member 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 electrophotographic 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. Or, when using a 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 or attached to a metal or other conductive core. To make a charger.
The charger is not limited to the contact charger as described above. However, since an image forming apparatus in which ozone generated from the charger is reduced is obtained, a contact charger is used. preferable.

The exposure can be performed, for example, by exposing the surface of the latent electrostatic image bearing member imagewise using the exposure device.
The exposure device is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charger so as to form an image to be formed, and is appropriately selected according to the purpose. For example, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system can be used.
In the present invention, a back light system in which imagewise exposure is performed from the back side of the electrostatic latent image carrier may be employed.

-Development process and development means-
The developing step is a step of developing the electrostatic latent image using the toner or the developer of the present invention to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the toner or the developer of the present invention, and can be performed by the developing unit.
The developing means is not particularly limited as long as it can be developed using, for example, the toner or developer of the present invention, and can be appropriately selected from known ones. For example, the toner of the present invention Preferably, a developer containing at least a developer and having at least a developing unit capable of contacting or non-contacting the toner or the developer with the electrostatic latent image is provided, and includes the toner container according to the present invention. More preferred is a developing device.
As the developing means, a toner is carried on the peripheral surface, rotated in contact with the electrostatic latent image carrier, and supplied to the electrostatic latent image formed on the electrostatic latent image carrier. An embodiment having a developing roller that performs development and a thin layer forming member that contacts the peripheral surface of the developing roller and thins the toner on the developing roller is preferable.

  The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multi-color developing unit. For example, a toner having a stirrer for charging the toner or the developer by frictional stirring and a rotatable magnet roller is preferable.

  In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrostatic latent image carrier (photoconductor), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted. It moves to the surface of the electrostatic latent image carrier (photoconductor) by force. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrostatic latent image carrier (photoconductor).

  The developer accommodated in the developing device is a developer containing the toner of the present invention, and a one-component developer is used as the developer.

As the developing roller, either a metal roller or an elastic roller is preferably used.
There is no restriction | limiting in particular as said metal roller, Although it can select suitably according to the objective, For example, an aluminum roller etc. are mentioned. By performing blasting on the metal roller, a developing roller having an arbitrary surface friction coefficient can be produced relatively easily. Specifically, by treating the aluminum roller with glass bead blasting, the roller surface can be roughened, and an appropriate toner adhesion amount can be obtained on the developing roller.

As the elastic roller, a roller coated with an elastic rubber layer is used, and a surface coat layer made of a material that is easily charged to a polarity opposite to that of the toner is provided on the surface. The elastic rubber layer is set to a hardness of 60 degrees or less according to JIS-A in order to prevent toner deterioration due to pressure concentration at the contact portion with the layer regulating member. The surface roughness (Ra) is set to 0.3 to 2.0 μm, and a necessary amount of toner is held on the surface. Further, since the developing roller is applied with a developing bias for forming an electric field between the developing roller and the photosensitive member, the elastic rubber layer is set to have a resistance value of 10 ³ to 10 ¹⁰ Ω. The developing roller rotates in the clockwise direction, and conveys the toner held on the surface to a position facing the layer regulating member and the photoconductor.

  The layer regulating member is provided at a position lower than the contact position between the supply roller and the developing roller. The layer regulating member is made of a metal leaf spring material such as stainless steel (SUS) or phosphor bronze. The free end is brought into contact with the surface of the developing roller with a pressing force of 10 to 40 N / m and passes under the pressure. The toner is thinned and charged by triboelectric charging. Further, a regulation bias having a value offset in the same direction as the toner charging polarity with respect to the developing bias is applied to the layer regulating member in order to assist frictional charging.

The rubber elastic body constituting the surface of the developing roller is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include styrene-butadiene copolymer rubber and acrylonitrile-butadiene copolymer rubber. Acrylic rubber, epichlorohydrin rubber, urethane rubber, silicone rubber, or a blend of two or more thereof. Among these, a blend rubber of epichlorohydrin rubber and acrylonitrile-butadiene copolymer rubber is particularly preferable.
The developing roller is manufactured, for example, by covering the outer periphery of a conductive shaft with a rubber elastic body. The conductive shaft is made of a metal such as stainless steel (SUS).

  Here, FIG. 2 is a cross-sectional view showing an example of a one-component developing type developing apparatus to which the present invention is applied together with the vicinity of the photoreceptor 101. In the developing device 100, the toner in the toner hopper 102 is supplied onto the developing roller 104 by the replenishing roller 103. The toner supplied onto the developing roller 104 is charged by friction between the developing roller 104 and the thin layer forming member. The toner that has not been consumed for development is peeled off from the developing roller 104 by the replenishing roller 103 and returned to the toner hopper 102. Further, the inside of the hopper is agitated by the agitator 105, and the toner is kept in a uniform state. In FIG. 1, reference numeral 106 denotes a cleaning means.

-Transfer process and transfer means-
The transfer step is a step of transferring the visible image onto a recording medium. After the primary transfer of the visible image onto the intermediate transfer member using an intermediate transfer member, the visible image is transferred onto the recording medium. A primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate transfer body using two or more colors, preferably full color toner as the toner, and a composite transfer image; A mode including a secondary transfer step of transferring the transfer image onto the recording medium is more preferable.
The transfer can be performed, for example, by charging the latent electrostatic image bearing member (photoconductor) of the visible image using a transfer charger, and can be performed by the transfer unit. The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Embodiments are preferred.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.

The transfer means (the primary transfer means and the secondary transfer means) is a transfer for peeling and charging the visible image formed on the electrostatic latent image carrier (photoconductor) to the recording medium side. It is preferable to have at least a vessel. The number of the transfer means may be one, or two or more.
Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is typically plain paper, but is not particularly limited as long as it can transfer an unfixed image after development, and can be appropriately selected according to the purpose. PET for OHP A base or the like can also be used.

-Fixing Step and Fixing Unit The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing device, and may be performed each time the toner of each color is transferred to the recording medium. Alternatively, the toners of the respective colors may be simultaneously formed in a state where they are laminated.
There is no restriction | limiting in particular as said fixing device, Although it can select suitably according to the objective, A well-known heating-pressing means is suitable. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt.
The heating in the heating and pressing means is usually preferably 80 to 200 ° C.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing step and the fixing unit depending on the purpose.

The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrostatic latent image carrier, and can be suitably performed by a neutralization unit.
The neutralization means is not particularly limited, and may be appropriately selected from known neutralizers as long as it can apply a neutralization bias to the electrostatic latent image carrier. Preferably mentioned.

The cleaning step is a step of removing the electrophotographic toner remaining on the electrostatic latent image carrier, and can be suitably performed by a cleaning unit.
The cleaning means is not particularly limited as long as it can remove the electrophotographic toner remaining on the electrostatic latent image carrier, and can be appropriately selected from known cleaners. Suitable examples include brush cleaners, electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners, and the like.

The recycling step is a step of recycling the electrophotographic toner removed by the cleaning step to the developing unit, and can be suitably performed by the recycling unit.
There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

The control means is a process for controlling the respective steps, and can be suitably performed by the control means.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

  Here, FIG. 3 is a schematic view showing an example of the image forming apparatus of the present invention. In FIG. 3, the image forming apparatus includes a photosensitive body 2 that is driven to rotate in a clockwise direction in FIG. 3 in a main body housing (not shown), and a charging unit 3 around the photosensitive body 2. , A writing unit 4, a developing unit 5, a transfer unit 7, a paper separating unit, a cleaning unit 13, a photoreceptor charge eliminating unit 8, a control device 15, and a voltage applying unit 16.

  The image forming apparatus includes a paper feeding cassette (not shown) that stores a plurality of recording papers. The recording paper in the paper feeding cassette is formed by a pair of registration rollers (not shown) one by one by a paper feeding roller (not shown). After the timing adjustment, the paper is transferred between the paper transfer unit 7 and the photosensitive member 2.

  The image forming apparatus rotates the photosensitive member 2 in the clockwise direction in FIG. 3, uniformly charges the photosensitive member 2 with the charging unit 3, and then irradiates a laser modulated with image data by the writing unit 4. An electrostatic latent image is formed on the photosensitive member 2, and toner is attached to the photosensitive member 2 on which the electrostatic latent image is formed by the developing unit 5 and developed. In the image forming apparatus, the photosensitive member 2 on which the toner image is formed by attaching the toner in the developing unit 5 is transferred to the recording paper conveyed between the photosensitive member 2 and the paper transfer unit 7 by the paper transfer unit 7. Then, the recording paper on which the toner image is transferred is conveyed to the fixing unit.

  The fixing unit includes a fixing roller that is heated to a predetermined fixing temperature by a built-in heater and a pressure roller that is pressed against the fixing roller with a predetermined pressure, and heats and applies the recording paper conveyed from the paper transfer unit 7. After the toner image on the recording paper is fixed to the recording paper, the paper is discharged onto a paper discharge tray (not shown).

  On the other hand, the image forming apparatus further rotates the photosensitive member 2 on which the toner image is transferred to the recording paper by the paper transfer unit 7, and scrapes and removes the toner remaining on the surface of the photosensitive member by the cleaning unit 13 with a blade. The photosensitive member neutralizing unit 8 neutralizes the charge. In the image forming apparatus, after the photosensitive member 2 that has been neutralized by the photosensitive member neutralizing unit 8 is uniformly charged by the charging unit 3, the next image formation is performed in the same manner as described above. The cleaning unit 13 is not limited to the one that scrapes the residual toner on the photoconductor 2 with a blade, and may be one that scrapes the residual toner on the photoconductor 2 with a fur brush 502, for example.

FIG. 4 is a schematic diagram showing an example of an image forming apparatus to which the present invention is applied. FIG. 4 shows a tandem type full-color image forming apparatus.
In FIG. 4, the image forming apparatus stores an electrostatic latent image carrier 2 that is driven to rotate clockwise in FIG. 4 in a main body housing (not shown). A charging unit 3, a writing unit 4, a developing unit 5, an intermediate transfer unit 6, a paper transfer unit 7 and the like are arranged.
Although not shown, the image forming apparatus includes a paper feeding cassette that stores a plurality of recording papers. The recording paper P in the paper feeding cassette is timed by a pair of registration rollers (not shown) one by one by a paper feeding roller (not shown). After the adjustment, the sheet is sent out between the intermediate transfer unit 6 and the electrostatic latent image carrier 2.
The image forming apparatus rotates the electrostatic latent image carrier 2 in the clockwise direction in FIG. 4 to uniformly charge the electrostatic latent image carrier 2 with the charging unit 3, and then writes the image data with the writing unit 4. An electrostatic latent image is formed on the electrostatic latent image carrier 2 by irradiating the modulated laser, and the developing unit 5 attaches toner to the electrostatic latent image carrier 2 on which the electrostatic latent image has been formed. To do. In the image forming apparatus, toner is attached by the developing unit 5 and the toner image is transferred from the electrostatic latent image carrier 2 to the intermediate transfer member by the intermediate transfer unit 6. This is performed for each of four colors of cyan (C), magenta (M), yellow (Y), and black (K) to form a full-color toner image.

  Next, FIG. 5 is a schematic diagram illustrating an example of a revolver type full-color image forming apparatus. In this image forming apparatus, a plurality of colors of toner are sequentially developed on one electrostatic latent image carrier by switching the operation of the developing device. Then, the color toner image on the intermediate transfer member is transferred to the recording paper P by the paper transfer unit 7, and the recording paper P on which the toner image is transferred is conveyed to the fixing unit 10 to obtain a fixed image.

  On the other hand, the image forming apparatus further rotates the electrostatic latent image carrier 2 on which the toner image is transferred to the recording paper by the intermediate transfer unit 6, and removes the toner remaining on the surface of the electrostatic latent image carrier by the cleaning unit 13. Then, the charge is removed by the charge removing unit 8. The image forming apparatus uniformly charges the electrostatic latent image carrier 2 neutralized by the neutralization unit 8 by the charging unit 3, and then performs the next image formation as described above. The cleaning unit 13 is not limited to scraping off the residual toner on the electrostatic latent image carrier 2 with a blade. For example, the cleaning unit 13 scrapes off residual toner on the electrostatic latent image carrier 2 with a fur brush. There may be.

  In the image forming method and the image forming apparatus of the present invention, since the developer of the present invention is used as the developer, the color difference between the high temperature and high humidity environment and the low temperature and low humidity environment is eliminated, and the density within the full color image is eliminated. There is no unevenness, charge-up is suppressed, and a good image free from problems due to charging such as background contamination and density reduction can be obtained.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Production Example 1)
<Preparation of Cyan Toner 1>
-Synthesis of first binder resin H1-
First, 600 g of styrene as a vinyl monomer, 110 g of butyl acrylate, 30 g of acrylic acid, and 30 g of dicumyl peroxide as a polymerization initiator were charged into a dropping funnel.
Next, in a 5-liter four-necked flask equipped with a thermometer, a stainless steel stirrer, a flow-down condenser, and a nitrogen inlet tube, among the polyester monomers, polyoxypropylene (2.2)- 1,230 g of 2,2-bis (4-hydroxyphenyl) propane, 290 g of polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 250 g of isododecenyl succinic anhydride, 310 g of terephthalic acid, 180 g of 2,4-benzenetricarboxylic acid, 7 g of dibutyltin oxide as an esterification catalyst, and paraffin wax as a wax (melting point: 73.3 ° C., the half-value width of the endothermic peak at the time of temperature rise measured by a differential scanning calorimeter is 4 340 g (11.0 parts by mass with respect to 100 parts by mass of charged monomer).
Next, the liquid mixture of the vinyl monomer resin and the polymerization initiator was dropped from the dropping funnel over 1 hour while stirring at a temperature of 160 ° C. in a mantle heater in a nitrogen atmosphere. Next, the addition polymerization reaction was aged for 2 hours while maintaining the temperature at 160 ° C., and then the temperature was raised to 230 ° C. to perform the condensation polymerization reaction. The degree of polymerization was tracked by the softening point measured using a constant load extrusion type capillary rheometer, and when the desired softening point was reached, the reaction was terminated to synthesize the first binder resin H1. The softening point of the obtained first binder resin H1 measured as follows was 130 ° C.

-Synthesis of the second binder resin L1-
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane as a polyol in a 5-liter four-necked flask equipped with a thermometer, a stainless steel stirrer, a falling condenser, and a nitrogen introduction tube 2210 g, 850 g of terephthalic acid, 120 g of 1,2,4-benzenetricarboxylic anhydride, and 0.5 g of dibutyltin oxide as an esterification catalyst were charged. Subsequently, the temperature was raised to 230 ° C. under a nitrogen atmosphere in a mantle heater to perform a condensation polymerization reaction. The degree of polymerization was tracked by the softening point measured using a constant load extrusion capillary rheometer, and when the desired softening point was reached, the reaction was terminated to synthesize the second binder resin L1. The obtained second binder resin L1 had a softening point of 115 ° C. measured as follows.

<Measurement of softening point (Tm)>
Using a flow tester (CFT-500, manufactured by Shimadzu Corporation), 1.5 g of a measurement sample is weighed, using a die having a height of 1.0 mm and a diameter of 1.0 mm, a heating rate of 3.0 ° C./min, preheating Measurement was performed under the conditions of a time of 180 seconds, a load of 30 kg, and a measurement temperature range of 80 to 140 ° C., and the temperature at which the above sample flowed out 1/2 was defined as the softening point (Tm).

-Production of toner particles-
With respect to 100 parts by mass (including the mass of the internally added wax) of the obtained first binder resin H1 and second binder resin L1, the binder resin having a mixing mass ratio (H1: L1 = 5: 5) Pigment C.I. I. A master batch corresponding to 4 parts by mass of Pigment Blue 15: 3 and 2 parts by mass of a benzyl boron compound (LR-147, manufactured by Nippon Carlit) as a charge control agent were added to make a total amount of 3 kg. Next, after mixing for 5 minutes at a peripheral speed of 20 m / s with a 20 liter Henschel mixer, melt kneading was performed using the one from which the discharge part of the biaxial extrusion kneader (PCM-30, manufactured by Ikekai Tekko Co., Ltd.) was removed. did.
The obtained kneaded product was rolled to a thickness of 2 mm with a cooling press roller, cooled with a cooling belt, and then roughly pulverized with a feather mill. Then, it grind | pulverized until it became an average particle diameter of 10-12 micrometers with the mechanical grinder (KTM, Kawasaki Heavy Industries, Ltd. make). Subsequently, after pulverizing with coarse powder classification with a jet pulverizer (IDS, manufactured by Nippon Pneumatic Industry Co., Ltd.), the fine powder classification is performed using a rotor type classifier (teaplex type classifier type, 100 ATP, manufactured by Hosokawa Micron Corporation). Classification was performed to obtain colored resin particles. The mass average particle diameter of the colored resin particles obtained was 7.9 μm as measured as follows.
1 part by mass of silica (RX200, manufactured by Nippon Aerosil Co., Ltd.) is added to 100 parts by mass of the obtained colored resin particles, and mixed with a Henschel mixer at a peripheral speed of 40 m / sec for 60 seconds. Cyan toner 1 was produced.
The volume resistance of the obtained cyan toner 1 was measured as follows and found to be 8.4 × 10 ⁹ Ω.

<Measurement of toner weight average particle diameter>
The particle size distribution of the toner particles was measured by the Coulter Counter method using a Coulter Counter TA-II or Coulter Multisizer II (both manufactured by Coulter, Inc.) as follows.
First, 0.1 to 5 ml of a surfactant (alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution. Here, as the electrolytic solution, ISOTON-II (manufactured by Coulter, Inc.) prepared by preparing an approximately 1% NaCl aqueous solution using primary sodium chloride can be used. Here, 2 to 20 mg of the measurement sample is further added as a solid content. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the measurement device is used to measure the volume and number of toner particles or toner using a 100 μm aperture as an aperture. Volume distribution and number distribution are calculated.
From the obtained distribution, the mass average particle diameter (Dv) and the number average particle diameter (Dp) of the toner can be obtained. As a channel, it is 2.00 micrometers or more and less than 2.52 micrometers; 2.52 micrometers or more and less than 3.17 micrometers; 3.17 micrometers or more and less than 4.00 micrometers; 4.00 micrometers or more and less than 5.04 micrometers; 5.04 micrometers or more and less than 6.35 micrometers; .35 μm or more and less than 8.00 μm; 8.00 μm or more and less than 10.08 μm; 10.08 μm or more and less than 12.70 μm; 12.70 μm or more and less than 16.00 μm; 16.00 μm or more and less than 20.20 μm; Less than 40 μm; 25.40 μm or more and less than 32.00 μm; 3 channels of 32.00 μm or more and less than 40.30 μm are used, and particles having a particle size of 2.00 μm or more and less than 40.30 μm are targeted.

<Measurement of toner volume resistance>
3 g of toner was pressed at 5 MPa for 1 minute to produce pellets, which were then sandwiched between electrodes with a diameter of 30 mm, and measured with an impedance analyzer 1260 manufactured by Solartron at a frequency of 1 kHz and an applied voltage of 0.1 V.

(Production Example 2)
-Preparation of magenta toner 1-
In Production Example 1, pigment C.I. I. A master batch corresponding to 4 parts by mass of Pigment Blue 15: 3 was added to Pigment C.I. I. Magenta toner 1 was produced in the same manner as in Production Example 1, except that Pigment Red 269 was changed to a master batch corresponding to 5 parts by mass. The obtained magenta toner 1 had a volume resistance of 9.5 × 10 ⁹ Ω.

(Production Example 3)
-Preparation of Yellow Toner 1-
In Production Example 1, pigment C.I. I. A master batch corresponding to 4 parts by mass of Pigment Blue 15: 3 was added to Pigment C.I. I. A yellow toner 1 was produced in the same manner as in Production Example 1 except that Pigment Yellow 180 was changed to a master batch equivalent to 6 parts by mass. The volume resistance of the obtained yellow toner 1 was 9.6 × 10 ⁹ Ω.

(Production Example 4)
-Preparation of black toner 1-
In Production Example 1, pigment C.I. I. A master batch corresponding to 4 parts by mass of Pigment Blue 15: 3 was used as 6 parts by mass of carbon black, and 1 part by mass of a benzylboron compound (LR-147, manufactured by Nippon Carlit) was used as a charge control agent. A black toner 1 was produced in the same manner as in Production Example 1. The resulting black toner 1 had a volume resistance of 3.7 × 10 ⁹ Ω.

(Production Example 5)
-Preparation of black toner 2-
In Example 1, Example 2 was used except that 2 parts by mass of a benzyl boron compound (LR-147, manufactured by Nippon Carlit Co., Ltd.) was used as a charge control agent and was mixed for 20 minutes at a peripheral speed of 30 m / s with a Henschel mixer. Similarly, black toner 2 was produced. The resulting black toner 2 had a volume resistance of 1.4 × 10 ⁹ Ω.

(Comparative Production Example 1)
-Preparation of black toner 3-
A black toner 3 was produced in the same manner as in Production Example 4 except that 2 parts by mass of a benzyl boron compound (LR-147, manufactured by Nippon Carlit Co., Ltd.) was used as the charge control agent in Production Example 4. The resulting black toner 3 had a volume resistance of 0.9 × 10 ⁹ Ω.

(Comparative Production Example 2)
-Preparation of black toner 4-
A black toner 4 was produced in the same manner as in Production Example 4 except that the mixing process of each component was carried out for 2 minutes at a peripheral speed of 15 m / s using a Henschel mixer. The resulting black toner 4 had a volume resistance of 0.5 × 10 ⁹ Ω.

Next, for each of the obtained toners, the potassium ion strength on the toner surface was measured as follows. The results are shown in Table 1.
<Measurement of potassium strength on toner surface>
0.5 g of toner was dissolved in 20 ml of ethanol. 5 ml of this solution is put into a polyethylene container having an outer diameter of 32 mm, an inner diameter of 25 mm, and a height of 23 mm, and this is potassium using a bottom-illuminated fluorescent X-ray measuring apparatus (manufactured by Rigaku Corporation) under the conditions of 50 kV, 60 mA, 40 s in vacuum. The X-ray intensity was measured, and the net intensity obtained by subtracting the background was defined as the potassium intensity existing on the toner surface.

(Examples 1-2 and Comparative Examples 1-2)
Next, toner kits of Examples 1-2 and Comparative Examples 1-2 were prepared by combining the obtained toners as shown in Table 2 below.

The lower part of each toner represents the potassium ion strength on the toner surface.

  Next, using the obtained toner and toner kit, various characteristics were evaluated as follows. The results are shown in Tables 3 to 6.

<Evaluation of actual machine>
Using each toner and toner kit, using an image forming apparatus (manufactured by Ricoh Co., Ltd., IPSiO CX2500), changing the configuration of the developing device as shown in Table 3, under an N / N environment (temperature 22 ° C., 55% RH), L / L environment (temperature 10 ° C., 20% RH), and H / H environment (temperature 28 ° C., 80% RH), adhesion on the photoreceptor with the same development bias (−200 V) The quantity was measured and evaluated according to the following criteria. The adhesion amount was measured with a suction type small charge amount measuring device MODEL 210HS manufactured by Trek Japan.
〔Evaluation criteria〕
○: The difference between the toners in the toner kit is good within ± 5%. Δ: The difference between the toners in the toner kit is within ± 10% and there is no problem in actual use. ×: The difference between the toners in the toner kit is ± 10%. Larger, unusable level

<Image quality (image unevenness)>
Print a print pattern with 5 1cm x 1cm solid images shown in Fig. 6 in one A4 size sheet, measure the density difference (ΔOD) of 5 print samples of each toner and toner kit, and use the following criteria. evaluated.
〔Evaluation criteria〕
○: ΔOD ≦ 0.1
Δ: 0.1 <ΔOD ≦ 0.2
×: 0.2 <ΔOD

<Soil dirt>
1000 blank paper images were printed with each toner and toner kit, and the collected toner amount T was measured and evaluated according to the following criteria.
〔Evaluation criteria〕
○: T ≦ 3g
Δ: 3 g <T ≦ 5 g
X: 5 g <T

<Chargeability>
The charge amount Q was measured using a suction type small charge amount measuring device MODEL 210HS manufactured by Trek Japan Co., Ltd., and evaluated according to the following criteria.
[Evaluation of charge amount of each toner]
○: −20 μC / g ≦ Q ≦ −30 μC / g
Δ: −30 μC / g <Q ≦ −35 μC / g, −15 μC / g ≦ Q <−20 μC / g
×: −35 μC / g <Q, Q <−15
[Determination of charge amount difference ΔQ in toner kit]
○: ΔQ ≦ 5 μC / g
Δ: 5 μC / g <ΔQ ≦ 8 μC / g
×: 8 μC / g <ΔQ

* N / N is 22% and 55% RH * L / L is 10 and 20% RH * H / H is 28 and 80% RH

  The toner kit of the present invention eliminates the color difference between the high-temperature and high-humidity environment and the low-temperature and low-humidity environment by controlling the amount of the charge control agent present on the surface of the black toner and the color toner. In addition, it is possible to suppress charge-up and form good images free from defects due to charging such as background contamination and density reduction, so it is widely used in developers, process cartridges, full-color image forming methods, and image forming apparatuses. Used.

FIG. 1 is a schematic view showing an example of the process cartridge of the present invention. FIG. 2 is a schematic view showing an example of a developing device used in the image forming apparatus of the present invention. FIG. 3 is a schematic view showing an example of the image forming apparatus of the present invention. FIG. 4 is a schematic view showing an example of the tandem type full-color image forming apparatus of the present invention. FIG. 5 is a schematic view showing an example of a revolver type full color image forming apparatus of the present invention. FIG. 6 is a diagram illustrating a print pattern used for evaluation of image quality (image unevenness) in the example.

Explanation of symbols

2 Photoconductor (electrostatic latent image carrier)
DESCRIPTION OF SYMBOLS 3 Charging part 4 Writing part 5 Developing part 6 Intermediate transfer part 7 Transfer part 8 Static eliminating part 10 Fixing part 13 Cleaning part 15 Control device 16 Voltage applying part 100 Developing apparatus 101 Photoconductor 102 Toner hopper 103 Supply roller 104 Developing roller 105 Agitator 106 Cleaning means 201 Photoconductor 202 Charging means 203 Exposure means 204 Developing means 205 Recording medium 207 Cleaning means 208 Transfer means P Recording paper

Claims (11)

A toner kit having at least black toner, yellow toner, magenta toner, and cyan toner,
The black toner, the yellow toner, the magenta toner, and the cyan toner all contain at least a binder resin, a colorant, and a charge control agent.
The black toner colorant contains at least one of carbon black and magnetic powder,
The charge control agent has a molecular structure containing K ⁺ as a counter ion,
Wherein Kk the K ⁺ intensity detected by the X-ray fluorescence of the black toner surface, the K ⁺ intensity detected by the X-ray fluorescence of the yellow toner surface Ky, is detected by X-ray fluorescence of the magenta toner surface K ⁺ A toner kit, which satisfies the following expressions: Kk <Ky, Kk <Km, Kk <Kc, where Km is the intensity and Kc is the intensity of K ⁺ detected by fluorescent X-rays on the cyan toner surface.   The ratio of Kk to Ky (Kk / Ky), the ratio of Kk to Km (Kk / Km), and the ratio of Kk to Kc (Kk / Kc) are all 0.3 to 0.6. The toner kit according to 1.   When the volume resistance of the black toner is Rk, the volume resistance of the yellow toner is Ry, the volume resistance of the magenta toner is Rm, and the volume resistance of the cyan toner is Rc, the following expressions are given: Rk <Ry, Rk <Rm, Rk <Rc, The toner kit according to claim 1, wherein: The toner kit according to claim 3, wherein the volume resistance Rk of the black toner is 0.9 × 10 ^{9 to} 5 × 10 ⁹ Ω. The toner kit according to claim 1, wherein the charge control agent is a benzyl boron compound represented by the following structural formula.
  The toner kit according to any one of claims 1 to 5, wherein a content of the charge control agent in each toner is 0.5 to 3 parts by mass with respect to 100 parts by mass of the binder resin.   A developer, which is a non-magnetic one-component developer comprising each toner in the toner kit according to claim 1.   An electrostatic latent image carrier and at least developing means for developing the electrostatic latent image formed on the electrostatic latent image carrier using the developer according to claim 7 to form a visible image. Process cartridge characterized by.   An electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image using the developer according to claim 7. And at least developing means for forming a visible image, transfer means for transferring the visible image to a recording medium, and fixing means for fixing the transferred image transferred to the recording medium. apparatus.   The developing means carries the developer on the peripheral surface, rotates in contact with the electrostatic latent image carrier, and supplies the developer to the electrostatic latent image formed on the electrostatic latent image carrier. The image forming apparatus according to claim 9, further comprising: a developing roller that performs development; and a thin layer forming member that contacts a peripheral surface of the developing roller and thins the developer on the developing roller. An electrostatic latent image forming step for forming an electrostatic latent image on the electrostatic latent image carrier, and development for forming the visible image by developing the electrostatic latent image using the developer according to claim 7. An image forming method comprising: a step, a transfer step of transferring the visible image to a recording medium, and a fixing step of fixing the transferred image transferred to the recording medium.