JP5489780B2 - Development method - Google Patents

Description

  The present invention relates to a developing method used in a recording method using an electrophotographic method, an electrostatic recording method, a magnetic recording method, or the like. More specifically, the present invention relates to a developing method used for an image recording apparatus that can be used for a copying machine, a printer, a facsimile, and the like.

  In recent years, the technological trend of printers has been progressing in the direction of machine miniaturization, high speed, high image quality, and long life (stable images can be obtained over a long period of use). -It has come to be used in the usage environment.

  Under the circumstances, there is a need for a developing method capable of providing a stable image when used for a long period of time even in various environments ranging from a high temperature and high humidity environment to a low temperature and low humidity environment.

  Under such circumstances, improving the characteristics of the toner carrier is one means for achieving high durability with little deterioration in image quality under various usage environments.

  The properties required for the toner carrier generally include (1) uniform and high charge imparting property to the toner and (2) uniform toner transportability.

  In order to improve these characteristics, it is effective to have an elastic layer on the outer periphery of the shaft core of the toner carrier, further have a resin surface layer on the outer periphery, and disperse resin fine particles in the resin surface layer. It is known that

  By using resin particles to which inorganic fine powder is fixed, the dispersibility of the resin particles in the toner carrier is remarkably improved. As a result, the durability under various environments is improved, and the concentration is lowered during long-term use. A method for suppressing a change in charging performance has been reported (for example, Patent Document 1).

  However, when the toner carrier is applied to a high-speed and long-life printer in a harsher environment that is currently required, the toner and the toner carrier may still have problems after long-term use that places a significant load on the toner and toner carrier. all right.

  In other words, when external stress due to long-term use in further high-speed printing is applied, the resin particles to which the inorganic fine powder is fixed are peeled off from the surface layer of the toner carrier, so that the toner chargeability and toner transportability stable over a long period of time. Tended to be difficult to get.

  In addition, recent toners are required to have low-temperature fixing performance, and when the peripheral frictional heat and external stress of the toner regulating member and the toner carrier are applied to the toner due to long-term use in further high-speed printing, the toner regulation is performed. Toner fusion may occur on the member or toner carrier.

  In particular, in a high-temperature and high-humidity environment, the temperature of the toner is significantly increased due to circumferential rubbing between the toner regulating member and the toner carrier, and the above-described phenomenon tends to be noticeable.

  In order to solve these problems, it has been difficult to achieve the required performance only by improving the development carrier and the toner.

  In other words, the fact is that it is required to achieve stable image quality over a long period of time even in a wider variety of environments even with higher-speed printing.

Japanese Patent Registration No. 03087944

An object of the present invention is to solve the above problems.
That is, an object of the present invention is to provide a developing method capable of obtaining a stable image when used for a long time even in high-speed printing under various environments.

  As a result of intensive studies, the present inventors have found that the above problem can be solved by the following configuration, and have completed the present invention.

That is, the present invention includes at least a step of regulating the toner on the toner carrier with the toner regulating member, and a step of developing the electrostatic latent image on the electrostatic latent image carrier using the toner on the toner carrier. A development method,
The toner carrier includes a shaft core, an elastic layer provided on an outer periphery of the shaft core, and resin particles provided on the outer periphery of the elastic layer for forming a convex portion on the surface of the toner carrier. And a surface layer that
The surface layer is mainly composed of urethane resin or acrylic resin,
i) When the surface layer is mainly composed of a urethane resin, the resin particles are urethane resin particles,
ii) When the surface layer is mainly composed of an acrylic resin, the resin particles are acrylic resin particles,
The resin particles have a surface coated with inorganic fine particles, and the coverage of the resin particles with the inorganic fine particles is 10 to 90%,
The toner is a toner obtained by externally adding at least silica fine powder to toner particles. The following formula A = (surface silica amount (g) with respect to 1.00 g of toner particles) / (theoretical specific surface area (m ² / g of toner) ))
The developing method is characterized in that the surface silica index A defined by is 1.5 × 10 ^{−2 to} 6.0 × 10 ⁻² .

  According to the present invention, it is possible to obtain a developing method capable of providing a stable image even when used for a long time in high-speed printing in an environment of high temperature and high humidity or low temperature and low humidity.

  That is, it is possible to obtain a developing method capable of obtaining a stable image without the toner being fused to the toner regulating member or the toner carrier even in high-speed printing over a long period of time in a high temperature and high humidity environment.

1 shows an example of a surface treatment apparatus (schematic cross-sectional view) used in a toner surface treatment process. FIG. 2 is a schematic cross-sectional view of a toner supply port and an airflow ejection member of the surface treatment apparatus shown in FIG. 1.

  Hereinafter, the present invention will be described in detail with reference to embodiments of the present invention.

  By fixing inorganic fine particles to the resin particles on the toner carrier surface layer, it becomes possible to improve the dispersibility of the resin particles during the production of the toner carrier, and more uniformly disperse the resin particles in the surface layer. Can do. As a result, more uniform toner conveyance becomes possible.

  On the other hand, in resin particles simply fixed with inorganic fine particles, the load applied to the toner carrier is large in the current high-speed and long-life printer, and when printing a large number of sheets, the resin particles are more than the surface layer. Image defects due to peeling off tend to occur.

  As a result of intensive studies, the present inventors have found that it is possible to achieve both dispersibility of the resin particles and suppression of peeling off by controlling the composition of the resin particles and the surface layer and the coverage of the resin particles.

  In order to achieve the present invention, it is essential that the coverage of the resin particles with the inorganic fine particles is 10 to 90%, more preferably 30 to 80%. When the coverage is less than 10%, the effect of the inorganic fine particle coating cannot be sufficiently obtained. Moreover, when the coverage is larger than 90%, image defects are likely to occur due to the resin particles peeling off. As a result, the toner carrying of the toner carrier becomes uneven and halftone image unevenness occurs.

  However, as a result of the study by the present inventors, it has been found that the resin particle dispersibility and the peeling-off suppression are not sufficient only when the coverage of the resin particles by the inorganic fine particles satisfies 10 to 90%.

  In the present invention, the surface layer of the toner carrier has a urethane resin or an acrylic resin as a main component. When the binder resin has a urethane resin as a main component, the resin particles are urethane resin particles. When the adhesion resin is mainly composed of an acrylic resin, it is important that the resin particles are acrylic resin particles.

  Although the specific mechanism is not clear, it is considered that when the surface layer and the resin particles are in such a combination, the adhesion at the interface between the surface resin and the resin particles in the toner carrier is improved. The reason for this seems to be that chemical bonding occurs or that the affinity is high. Therefore, it is considered that the resin particles are prevented from peeling off even in a high-speed and long-life printer with a large load applied to the toner carrier.

  Further investigations revealed that using a toner with a controlled surface silica amount in combination with the toner carrier used in the present invention can achieve an unprecedented level of image stability. . In particular, streak-like image damage that occurs during long-term use in high-temperature and high-humidity environments during high-speed printing, which was difficult to solve with conventional toner carrier and development methods using toner, can be greatly reduced. all right.

  The streak-like image damage is caused when the toner regulating member and the toner carried on the toner carrying member are rubbed against the toner regulating member when printing at high speed in a hot and humid environment. It is considered that this occurs by fusing to a member or toner carrier.

  In particular, in the conventional toner carrier, the toner accumulates in the concave portion where the resin particles have been peeled off, and continues to be rubbed, or the resin particles are exposed on the surface of the toner carrier, so that the toner on the toner carrier There was a tendency for fusion to occur easily.

  Although the specific mechanism is not known, it is presumed as follows that the toner fusion during high-speed printing in a high temperature and high humidity environment can be suppressed in the present invention. In the toner carrier of the present invention, not only the resin particles are prevented from peeling off, but even if the resin particles are exposed, it is considered that the inorganic fine particles cover the surface of the resin particles to some extent. Resin particles coated with inorganic fine particles suppress the direct contact between the resin particle matrix and the toner, even if the resin particles are exposed due to the stress of long-term use. We think that there is effect to suppress.

  Further, the toner of the present invention is characterized by a large surface silica index. The surface silica index is an index indicating the amount of silica present on the toner surface, and is not determined only by the amount of silica externally added in a simple external addition process.

  Since silica has a low thermal conductivity, it is believed that if the surface silica index is large, the amount of heat applied to the toner particles during rubbing will be small, and the fusion of the toner to the toner regulating member and the toner carrier will not proceed easily. . Further, since the amount of silica per toner surface area is large, the toner particles are hardly exposed even after long-term use. For this reason, the contact between the toner particle surface and the exposed portion of the resin particle matrix on the surface of the resin particle is also suppressed, and the fusion between the resin of the resin particle and the toner particle that is relatively susceptible to thermal fusion is suppressed. I believe that

  On the other hand, the toner of the present invention has a large surface silica index, and silica is present on the toner surface even after long-term use. For this reason, it is considered that, even in an environment where fluidity such as high temperature and high humidity is difficult to obtain due to the interaction with the inorganic fine powder on the surface of the exposed resin particles, it exhibits excellent fluidity that has never been achieved. As a result, heat generation due to friction is reduced, thermal damage to the toner is reduced, and it is speculated that the toner fusion to the toner regulating member and the toner carrier can be significantly improved even during high-speed printing over a long period of time. . In addition, since the toner flowability can be improved over a long period of time in the configuration of the present invention, the toner flows between the toner carrier and the toner regulating member even after being left in a high temperature and high humidity environment. By doing so, it is considered that the toner is quickly charged. As a result, it is predicted that problems such as so-called fogging in which poorly charged toner is printed on a white background portion of an image can be suppressed.

  As described above, in the present invention, since the toner and the toner carrier are satisfactorily interacted with each other, an image stabilization effect that cannot be obtained by the conventional development method can be obtained even during high-speed printing in a high-temperature and high-humidity environment. I think.

In the toner of the present invention, the surface silica index A is 1.5 × 10 ^{−2 to} 6.0 × 10 ⁻² , preferably 3.0 × 10 ^{−2 to} 5.5 × 10 ⁻² . When the surface silica index A is smaller than 1.5 × 10 ⁻² , the amount of silica on the toner surface is small, and therefore, there is a tendency that appropriate fluidity and appropriate durability cannot be maintained during long-term printing in a high temperature and high humidity environment. is there. In addition, when the surface silica index A is larger than 6.0 × 10 ^−2, it tends to be difficult to sufficiently fix the silica to the toner surface, and image defects are liable to occur during long-term printing. If the surface silica index is within the range of the present invention, the effect of the present invention can be achieved. In order to make the surface silica index within this range, it can be achieved by appropriately changing the number of surface silica parts and the toner surface area. In order to maintain moderate fluidity in the present invention, it is essential to externally add silica fine powder to the toner particles. In order to change the number of surface silica parts, the amount of silica added during external addition can be changed. As a means. However, simply increasing the amount of silica added at the time of external addition does not sufficiently fix the silica fine powder on the surface of the toner particles, so that it tends to be difficult to obtain good image stability over a long period of time.

  A preferable addition amount when silica fine powder is externally added to the toner is 0.05 to 3.00 parts by mass with respect to 100.00 parts by mass of the toner particles. When the amount of silica fine powder added at the time of external addition is less than 0.05 parts by mass, the fluidity of the toner cannot be maintained, and the load on the toner tends to increase. When the amount of silica fine powder added at the time of external addition exceeds 3.00 parts by mass, the silica fine powder is easily released from the toner, and the silica fine powder is fused to the toner carrier and the regulating member, thereby deteriorating the image. May occur.

  In order to achieve the surface silica index satisfying the present invention, means for fixing the silica fine powder to the toner particle surface, such as fixing the silica fine powder to the toner surface, may be used in combination with a simple external addition step. Any known means may be used as the means for fixing. For example, after external addition of silica fine powder (pre-external addition step), heat treatment is performed to fix the silica to the toner particles (heat treatment step), and further silica is externally added (external addition step). There is a means for increasing the surface silica index while achieving silica fixation.

  In addition, addition of silica fine powder to toner particles is one means for increasing the surface silica index. Although it is difficult for all of the added silica to be present on the toner particle surface by this method, a part of the added silica is present on the surface, and as a result, the surface silica index can be increased.

  By utilizing these means, it becomes possible to make the amount of silica more than the amount limited by simple external addition exist on the toner surface.

  The average circularity of the toner is preferably 0.950 or more. If the average circularity is less than 0.950, the proper fluidity cannot be maintained during long-term printing, so that the toner is damaged by the rubbing between the toner regulating member and the toner carrier, and image defects such as toner fusion are caused. Tend to lead to

  It is preferable that the toner has been subjected to a spheronization treatment with heat in a gas phase. By processing with heat, a higher level of average circularity can be achieved, and it is also possible to reduce the roughness of the surface at a minute level that cannot be expressed by average circularity, and moderate flow over a long period of time. It is possible to maintain sex. Further, when the pre-external addition step described above is performed before the thermal spheronization treatment, the silica fine powder can be fixed to the toner particle surface, and the effects of the present invention tend to be easily obtained.

  The developing method of the present invention will be further described.

  In the developing method according to the present invention, the toner carrying member transported onto the electrostatic latent image carrying member while carrying the toner on the surface, and the toner carrying member are brought into contact with the toner carrying member via the toner carried on the surface of the toner carrying member. And a toner regulating member that regulates the amount of toner adhering to the surface of the toner carrying member.

  The pressure of the toner regulating member against the toner carrier is preferably 0.05 to 1.00 N / cm. When the contact pressure is within the above range, better charge can be imparted to the toner, and excessive toner deterioration can be suppressed.

  The toner carrier in the present invention has an elastic layer and a surface layer on the outer periphery of the conductive shaft core.

  The conductive shaft core functions as an electrode and a support member for the toner carrier. Examples of the material include metals or alloys such as aluminum, copper alloy, and stainless steel; iron plated with chromium, nickel, etc .; synthetic resin having conductivity. The outer diameter of the shaft core is usually about 4 to 10 mm.

  Specific examples of the resin base material for the elastic layer include the following. Polyurethane, natural rubber, butyl rubber, nitrile rubber, isoprene rubber, butadiene rubber, silicone rubber, styrene-butadiene rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, chloroprene rubber, acrylic rubber. These can be used alone or in combination of two or more. Among these, a silicone rubber having a moderate elasticity and a small compression set is preferable. Examples of the silicone rubber include polydimethylsiloxane, polymethyltrifluoropropylsiloxane, polymethylvinylsiloxane, polyphenylvinylsiloxane, and copolymers of these polysiloxanes. These 1 type can be used combining these 2 types or more as needed.

  A conductive substance may be added to impart conductivity to the elastic layer. The conductive substance may be any one such as an electronic conductive substance or an ionic conductive substance. Electronic conductive materials include “Ketjen Black EC” (trade name, manufactured by Lion Corporation), conductive carbons such as acetylene black; rubbers such as SAF, ISAF, HAF, FEF, GPF, SRF, FT, and MT. Carbon for color: Carbon for color ink subjected to oxidation treatment can be exemplified. In addition, metals such as copper, silver, germanium, and metal oxides can be given. These conductive materials can be used alone or in combination of two or more thereof. Of these, carbon black such as conductive carbon, carbon for rubber, and carbon for color ink is preferable because the conductivity can be easily controlled with a small amount. Examples of the ion conductive substance include inorganic compounds such as sodium perchlorate, lithium perchlorate, calcium perchlorate, and lithium chloride; and organic compounds such as modified aliphatic dimethyl ammonium etosulphate and stearyl ammonium acetate. These can be used alone or in combination of two or more.

  These conductive materials are used in an amount necessary to make the elastic layer have a desired volume resistivity. The conductive substance can be used, for example, in a range of 0.5 to 50.0 parts by mass with respect to 100.0 parts by mass of the resin base material, and more preferably in a range of 1.0 to 30.0 parts by mass. Can be used.

Further, the electric resistance of the elastic layer is preferably 1 × 10 ³ Ω or more and 1 × 10 ¹³ Ω or less, more preferably 1 × 10 ⁴ Ω or more and 1 × 10 ¹² Ω or less.

  The Asker-C hardness of the elastic layer is preferably 25 ° to 70 °, more preferably 30 ° to 60 °. By setting this range, the contact nip width with the photoreceptor can be stably secured. Asker-C hardness is measured according to a rubber material hardness measurement method. Specifically, an Asker rubber hardness meter (polymer) is used by using a test piece separately prepared according to the standard standard Asker C-type SRIS (Japan Rubber Association Standard) 0101. (Made by Keiki Co., Ltd.).

  The following method is mentioned as a manufacturing method of an elastic layer. An elastic layer is produced on the outer periphery of the conductive shaft core appropriately coated with an adhesive or the like. In the production method of the elastic layer, the composition for forming the elastic layer is injected into the cavity of the molding die provided with the conductive shaft core, and the reaction is cured or solidified by heating, irradiation with active energy rays, etc. There is a method in which the conductive shaft core body is manufactured integrally. In addition, a tube shape having a predetermined shape and size is cut out from a slab or block separately molded using the elastic layer molding composition in advance by cutting or the like, and a conductive shaft core body is press-fitted into this to form a conductive shaft. An elastic layer may be formed on the core. Further, the elastic layer may be adjusted to a predetermined outer diameter by cutting or polishing treatment.

  The surface layer of the toner carrier has a urethane resin or an acrylic resin as a main component and contains resin particles for forming convex portions on the surface.

  The surface layer only needs to have a urethane resin or an acrylic resin as a main component, and other resins are not particularly limited. What is necessary is just to select and use suitably so that the toner charge amount according to the developing system to be used can be obtained. In addition, it is particularly preferable that the urethane resin is a main component in that the effect of the present invention is easily obtained.

  The raw material of the urethane resin is composed of a polyol and an isocyanate, and if necessary, a chain extender. The following are mentioned as an example as a polyol which is a raw material of a urethane resin. Polyether polyols, polyester polyols, polycarbonate polyols, polyolefin polyols, acrylic polyols, and mixtures thereof. The following are mentioned as an example as isocyanate which is a raw material of a urethane resin. Tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), naphthalene diisocyanate (NDI), tolidine diisocyanate (TODI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), phenylene diisocyanate (PPDI), xylylene diisocyanate (XDI) , Tetramethylxylylene diisocyanate (TMXDI), cyclohexane diisocyanate, polymeric diphenylmethane diisocyanate and mixtures thereof. Examples of the chain extender that is a raw material of the urethane resin include the following. Bifunctional low molecular diols such as ethylene glycol, 1,4-butanediol, 3-methylpentanediol; trifunctional low molecular triols such as trimethylolpropane, and mixtures thereof.

  Examples of the acrylic resin include the following. Polymethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate, polyisobutyl methacrylate, polybutyl acrylate, styrene-acrylic copolymer resin.

  As the resin particles dispersed in the surface layer and forming the convex portions on the surface, a suitable type of resin particles is selected depending on the type of the main component of the surface layer. That is, when the surface layer is mainly composed of urethane resin, the resin particles are urethane resin particles, and when the surface layer is mainly composed of acrylic resin, the resin particles are acrylic resin particles. Is essential. These resin particles can obtain the effects of the present invention if the resin particles are the main component, but the higher the abundance ratio, the easier it is to obtain the effects of the present invention.

  The urethane resin of the urethane resin particles is not particularly limited as long as it is a urethane resin that can be bonded to the urethane resin of the surface layer, such as polyether urethane, polyester urethane, polycarbonate urethane, and acrylic urethane.

The acrylic resin of the acrylic resin particles is not particularly limited as long as it is an acrylic resin that can be adhered to the acrylic resin of the surface layer such as polyacrylate and polymethacrylate.
The method for producing the resin particles is not particularly limited, and a known production method such as a suspension polymerization method, an emulsion polymerization method, or a pulverization method can be used.

  The average particle diameter of the resin particles can be suitably used in the range of 2 μm to 30 μm. In particular, in order to form convex portions of the surface layer and obtain stable toner transportability, those having an average particle diameter in the range of 5 μm to 18 μm are more preferable. Here, the average particle diameter of the resin particles is a number-based median diameter, and can be measured by a method similar to the measurement of the median diameter of toner particles described later.

Resin particles are present in the surface layer in a state of being coated with inorganic fine particles. Examples of the inorganic fine particles include oxides such as SiO ₂ , Al ₂ O ₃ , TiO ₂ , SrTiO ₃ , CeO ₂ , CrO, ZnO, and MgO; nitrides such as Si ₃ N ₄ ; carbides such as SiC Sulfates such as CaSO ₄ and BaSO ₄ ; carbonates such as CaCO _{3 and} the like. These inorganic fine particles may be subjected to surface treatment such as hydrophobization or hydrophilization as necessary. Among these, SiO ₂ is particularly preferable in that proper fluidity and chargeability can be imparted by the toner even when the resin particles are exposed. These inorganic fine particles may be used alone or in combination.

  The average primary particle diameter of the inorganic fine particles is preferably 5 nm or more and 200 nm or less because the covering property to the resin particles is good. Furthermore, since it can coat effectively by adding a small amount, it is more preferably 5 nm or more and 50 nm or less. Here, the average primary particle diameter of the inorganic fine particles is a number-based average particle diameter, and can be measured using a scanning electron microscope (SEM), a transmission electron microscope (TEM), or the like.

  The amount of inorganic fine particles added is preferably 0.01 to 1.00 parts by mass with respect to 100 parts by mass of the resin particles. If it is said addition amount, sufficient addition effect will be acquired.

  The method for coating the resin particles with the inorganic fine particles is not particularly limited as long as the coverage within the range of the present invention can be achieved, and the method of mixing and adhering the resin particles and the inorganic fine particles. And a method of adding inorganic fine particles during the synthesis of resin particles. Among these, from the viewpoint of efficiently coating the resin particles, it is preferable to adhere the resin particles by mixing the resin particles and the inorganic fine particles. In that case, it is possible to coat using a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, a Nauter mixer, or the like.

  Hereinafter, the toner will be described.

  As the binder resin used for the toner, a known resin can be used. For example, polystyrene; styrene copolymer such as styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer; polyester resin; hybrid resin in which styrene copolymer and polyester resin are chemically bonded Is mentioned. These resins may be used alone or in combination.

  The following are mentioned as a polymerizable monomer used for a styrene-type copolymer. For example, styrene; styrene derivatives such as α-methylstyrene; monoolefins such as ethylene, propylene, butylene and isobutylene; polyenes such as butadiene and isoprene; halogens such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride. Vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate; α-methylene aliphatic monocarboxylic esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate and n-butyl methacrylate Acrylic acid esters such as methyl acrylate, ethyl acrylate, propyl acrylate and n-butyl acrylate; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide. Furthermore, unsaturated dibasic acids such as maleic acid, alkenyl succinic acid and fumaric acid; unsaturated dibasic acid anhydrides such as maleic anhydride and alkenyl succinic anhydride; methyl maleic acid half ester, methyl citraconic acid half ester Unsaturated dibasic acid half-esters such as: Dimethylmaleic acid, unsaturated dibasic acid esters such as dimethylfumaric acid; α, β-unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, and cinnamic acid It is done. Furthermore, monomers having a hydroxy group such as 2-hydroxyethyl acrylate and 4- (1-hydroxy-1-methylbutyl) styrene are exemplified.

  Specifically, the component constituting the polyester resin includes a divalent or higher alcohol monomer component, a divalent or higher carboxylic acid, a divalent or higher carboxylic acid anhydride, and a divalent or higher carboxylic acid ester monomer. Ingredients. Known monomer components can be used as these monomer components.

  For example, the following are mentioned as an alcohol monomer component more than bivalence. As the dihydric alcohol monomer component, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis (4-hydroxyphenyl) Propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2-bis (4- Alkylene oxide adducts of bisphenol A such as hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopenty Glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, hydrogen Additive bisphenol A etc. are mentioned.

  Examples of trivalent or higher alcohol monomer components include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. Can be mentioned. Examples of other monomers include polyhydric alcohols such as oxyalkylene ethers of novolak type phenol resins.

  Examples of the divalent carboxylic acid monomer component include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid or anhydrides thereof; alkyldicarboxylic acids such as succinic acid, adipic acid, sebacic acid and azelaic acid or anhydrides thereof; And succinic acid substituted with an alkyl group or alkenyl group having 6 to 18 carbon atoms or an anhydride thereof; unsaturated dicarboxylic acids such as fumaric acid, maleic acid and citraconic acid or the anhydride thereof; and the like.

  Examples of the trivalent or higher carboxylic acid monomer component include trimellitic acid, pyromellitic acid, polyvalent carboxylic acid such as benzophenone tetracarboxylic acid and its anhydride, and the like.

  When the surface treatment with hot air is performed, the glass transition temperature (Tg) of the binder resin is preferably 40 ° C. or higher and 90 ° C. or lower, which is preferable because the toner can be prevented from coalescing with each other. More preferably, it is 45 degreeC or more and 85 degrees C or less.

  As the wax used for the toner, a known wax can be used. Specifically, the following are exemplified. Oxides of aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, alkylene copolymers, microcrystalline wax, paraffin wax, Fischer-Tropsch wax, and aliphatic hydrocarbon waxes such as oxidized polyethylene wax, or Block copolymers of the above: Deoxidized part or all of fatty acid esters such as carnauba wax, behenic ester behenate wax, montanate ester wax, and deoxygenated carnauba wax thing.

  Particularly preferably used waxes include aliphatic hydrocarbon waxes and esterified products which are esters of fatty acids and alcohols.

  Further, the wax used for the toner has a peak temperature of a maximum endothermic peak existing in a temperature range of 30 ° C. or more and 200 ° C. or less in an endothermic curve at a temperature rise measured by a differential scanning calorimetry (DSC) apparatus. It is preferably in the range of 45 ° C. or higher and 140 ° C. or lower. More preferably, it is the range of 65 degreeC or more and 120 degrees C or less, Most preferably, it is the range of 65 degreeC or more and 100 degrees C or less.

  The wax content is preferably 3.0 parts by mass or more and 20.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin. More preferably, it is 3.0 mass parts or more and 15.0 mass parts or less, More preferably, it is 3.0 mass parts or more and 10.0 mass parts or less.

  The glass transition temperature (Tg) of the toner is preferably 40 ° C. or higher and 90 ° C. or lower, and the softening temperature (Tm) is 80 ° C. or higher and 150 ° C. or lower in order to achieve both storage stability, low-temperature fixability, and high-temperature offset resistance. Is preferable. In addition, when surface treatment with hot air is performed, it is possible to efficiently form a spheroid and to prevent toner from being coalesced.

  Moreover, as a coloring agent, the following can be used, for example. When a colorant is used, the pigment may be used alone, but it is preferable from the viewpoint of the image quality of a full-color image to improve the sharpness by using a dye and a pigment together.

  Examples of the black colorant include carbon black; a magnetic material; a black colorant prepared using a yellow colorant, a magenta colorant, and a cyan colorant.

  Examples of the color pigment for magenta toner include the following. Examples include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Examples of the magenta toner dye include known oil-soluble dyes and basic dyes.

  Examples of the color pigment for cyan toner include the following. C. I. Pigment Blue 1, 2, 3, 7, 15: 2, 15: 3, 15: 4, 16, 17, 60, 62, 66; I. Bat Blue 6, C.I. I. Acid Blue 45, a copper phthalocyanine pigment in which 1 to 5 phthalimidomethyls are substituted on the phthalocyanine skeleton.

  Examples of the color pigment for yellow include the following. Condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal compounds, methine compounds, allylamide compounds. In addition, C.I. I. Direct Green 6, C.I. I. Basic Green 4, C.I. I. Dyes such as Basic Green 6 and Solvent Yellow 162 can also be used.

  The amount of the colorant used is preferably 0.1 parts by mass or more and 30.0 parts by mass or less, more preferably 0.5 parts by mass or more and 20.0 parts by mass with respect to 100.0 parts by mass of the binder resin. Or less, more preferably 3.0 parts by mass or more and 15.0 parts by mass or less.

  In order to stabilize the chargeability of the toner, a known charge control agent can be added to the toner particles either internally or externally. The charge control agent varies depending on the type of charge control agent and the physical properties of other toner constituent materials, but in the case of internal addition, 0.1 to 10.0 parts by mass per 100.0 parts by mass of resin in the toner. It is preferable that it is 0.1-5.0 mass parts or less.

  Examples of the negatively chargeable charge control agent include salicylic acid metal compounds, naphthoic acid metal compounds, dicarboxylic acid metal compounds, polymer compounds having sulfonic acid or carboxylic acid in the side chain, boron compounds, urea compounds, silicon compounds, An example is calix arene. On the other hand, examples of the positively chargeable charge control agent include quaternary ammonium salts, polymer compounds having a quaternary ammonium salt in the side chain, guanidine compounds, and imidazole compounds.

  For the purpose of improving the fluidity, transferability, and charging stability of the toner, it is possible to use the toner particles mixed with an external additive by a mixer such as a Henschel mixer.

  Known external additives such as silica fine powder can be used.

  Examples of the silica fine powder include dry silica or fumed silica produced by vapor phase oxidation of silicon halide, and wet silica produced from water glass.

  The dry silica may be a composite fine powder of silica and another metal oxide by using a metal halogen compound such as aluminum chloride or titanium chloride together with a silicon halogen compound in the production process.

The silica fine powder preferably has a BET specific surface area of 30 to 400 m ² / g. If the BET specific surface area is within the above range, good fluidity can be obtained even after durability.

  By hydrophobizing the silica fine powder, it is possible to adjust the charge amount of the toner, improve the environmental stability, and improve the characteristics in a high-humidity environment. It is preferable to use it. Non-modified silicone varnishes, various modified silicone varnishes, unmodified silicone oils, various modified silicone oils, silane compounds, silane coupling agents, other organosilicon compounds, and organotitanium compounds are used as hydrophobic treatment agents for inorganic fine powders. Can be mentioned. These treatment agents may be used alone or in combination. Among these, inorganic fine powder treated with silicone oil is preferable. More preferably, when the inorganic fine powder is hydrophobized with a coupling agent, or after the hydrophobization treatment, the hydrophobized inorganic fine powder treated with silicone oil maintains a high charge amount of toner particles even in a high humidity environment, and is stable. The point which can provide the done image is good.

  In addition to the silica fine powder, the following fine powder can be preferably used. For example, fluorine resin powder such as vinylidene fluoride fine powder, polytetrafluoroethylene fine powder; titanium oxide fine powder, alumina fine powder; surface treatment with silane compound, organosilicon compound, titanium coupling agent, silicone oil The thing which gave. If the titanium oxide fine powder is used, the sulfuric acid method, chlorine method, titanium oxide fine powder obtained by low-temperature oxidation (thermal decomposition, hydrolysis) of volatile titanium compounds such as titanium alkoxide, titanium halide, titanium acetylacetonate is used. It is done. As the crystal system, any of anatase type, rutile type, mixed crystal type thereof, and amorphous type can be used. If it is the above-mentioned alumina fine powder, buyer method, improved buyer method, ethylene chlorohydrin method, underwater spark discharge method, organoaluminum hydrolysis method, aluminum alum pyrolysis method, ammonium aluminum carbonate pyrolysis method, aluminum chloride flame Alumina fine powder obtained by a decomposition method is used.

  The surface of the fine powder is more preferably hydrophobized with a coupling agent or silicone oil. The method of hydrophobizing the surface of the fine powder is a method of chemically or physically treating with an organosilicon compound that reacts or physically adsorbs with the fine powder.

The external additive has a specific surface area by nitrogen adsorption measured by BET method of 30 m ² / g or more, preferably 50 m ² / g or more from the viewpoint of imparting characteristics. The amount of the external additive added is preferably 0.02 parts by mass or more and 8.00 parts by mass or less, more preferably 0.05 parts by mass or more and 4.00 parts by mass or less with respect to 100.00 parts by mass of the toner particles. .

  Next, a procedure for manufacturing toner will be described.

  The toner production method is not particularly limited as long as the characteristics can be achieved, and a known production method can be used.

  An example of a general pulverization method as a toner manufacturing method will be described below. In the toner production method of the pulverization method, the binder resin, the wax, and an arbitrary material are melt-kneaded, cooled and pulverized, and the pulverized product is spheroidized, surface-treated, and classified as necessary. It is possible to manufacture by mixing an external additive.

  As said surface treatment, the surface treatment apparatus which performs surface treatment with the hot air represented, for example by FIG. 1 can be used. The classification step may be before or after the surface treatment.

  Further, as described above, after the silica fine powder and the external additive are mixed in advance, the surface treatment may be performed with hot air.

  An outline of the surface treatment apparatus will be described with reference to FIGS.

  FIG. 1 is a cross-sectional view showing an example of a surface treatment apparatus, and FIG. 2 is a cross-sectional view showing an example of an airflow injection member.

The toner 114 supplied from the toner supply port 100 is accelerated by the injection air ejected from the air supply nozzle 115 and travels toward the airflow ejecting member 102 below the air. As shown in FIG. 2, diffused air 110 is ejected from the airflow ejecting member 102, and the diffused air 110 diffuses the toner upward and outward. At this time, the toner diffusion state can be controlled by adjusting the flow rate of the injection air and the flow rate of the diffusion air. Further, a cooling jacket 106 is provided on the outer periphery of the toner supply port 100, the outer periphery of the surface treatment apparatus, and the outer periphery of the transfer pipe 116 for the purpose of preventing toner fusion. In addition, it is preferable to pass cooling water (preferably antifreeze such as ethylene glycol) through the cooling jacket. Further, the surface of the toner diffused by the diffusion air is treated with hot air supplied from the hot air supply port 101. At this time, the temperature C in the hot air supply port is preferably 100 ° C. or higher and 450 ° C. or lower. If it is said temperature range, it can process to a nearly uniform state and can suppress the coalescence of particle | grains. The toner surface-treated with hot air is cooled by cold air supplied from a cold air supply port 103 provided on the outer periphery of the upper part of the apparatus. At this time, cold air may be introduced from the second cold air supply port 104 provided on the side surface of the main body of the apparatus for the purpose of managing the temperature distribution in the apparatus and controlling the surface state of the toner. The outlet of the second cold air supply port 104 can use a slit shape, a louver shape, a perforated plate shape, a mesh shape, etc., and the introduction direction can be selected according to the purpose, horizontal to the center direction and along the device wall surface It is. At this time, the temperature E (° C.) in the cold air supply port and the second cold air supply port is preferably −50 ° C. or more and 10 ° C. or less. The cold air is preferably dehumidified cold air. Specifically, the absolute water content is preferably 5 g / m ³ or less.

  Next, the airflow injection unit provided in the surface treatment apparatus will be described with reference to FIG. FIG. 2 is a cross-sectional view showing an example of the airflow injection member. As shown in FIG. 2, the toner supplied from the upper part of the toner supply port 100 by the metering feeder is accelerated by the injection air in the same pipe toward the outlet, and by the diffusion air from the airflow injection member 102 installed in the apparatus. Spreads outward. Note that the lower end of the airflow ejecting member 102 is provided at a position of 5 mm to 150 mm from the toner supply port 100. When the lower end of the airflow injection member is arranged at the above position, high processing capability can be secured and uniform processing can be performed on each particle. Further, on the outer periphery of the toner supply port 100, an air flow supply port 111 for the purpose of preventing condensation may be provided between the toner supply port 100 and the cooling jacket 106. This air flow for preventing condensation may be introduced from diffused air or a supply device common to the cold air and the second cold air, or the outside air may be taken in with the intake port opened. It is also possible to operate the apparatus with the intake port closed as buffer air.

  Further, if necessary, surface treatment and spheronization treatment may be further performed using, for example, a hybridization system manufactured by Nara Machinery Co., Ltd. or a mechano-fusion system manufactured by Hosokawa Micron. In such a case, if necessary, a sieving machine such as a wind-type sieve high voltor (manufactured by Shin Tokyo Machine Co., Ltd.) may be used.

  Furthermore, as a method of externally adding the external additive, a predetermined amount of classified toner and various known external additives are blended, and a high-speed stirrer that gives a shearing force to the powder such as a Henschel mixer or a super mixer is removed. A method of stirring and mixing can be used as an accessory.

  Next, a method for measuring various physical properties in the present invention will be described.

<Calculation of resin particle coverage with inorganic fine powder>
The surface layer of the toner carrier was cut out with a razor blade in the direction perpendicular to the conductive shaft core and embedded with a visible light curable acrylic resin.

Next, using a cryo system (trade name: “REICHERT-NISSEI-FCS”, manufactured by Leica Corporation), trimming / surfaced with an ultramicrotome (trade name: “EM-ULTRACUT · S”, manufactured by Leica Corporation) equipped with a diamond knife, Ultrathin sections were prepared.
Thereafter, observation was performed with a transmission electron microscope (trade name: “JEM-2100”, manufactured by JEOL Ltd.) at an acceleration voltage of 200 kV. Take a picture with the magnification adjusted so that the length of the ridgeline at the interface between the surface layer resin and the resin particles is 2.0 μm or more in one image, and use the image to obtain the coverage as follows. It was.

  From the transmission electron microscope (TEM) image obtained as described above, the length (L) of the ridgeline at the interface between the surface layer resin and the resin particles is measured.

  Next, the sum (l) of the lengths of the ridge portions where inorganic fine particles are present and the surface resin and resin particles are not in direct contact is measured. And a coverage is calculated | required by the following formula.

Coverage (%) = (l / L) × 100 (formula)
By this measurement method, the coverage of 50 portions of an arbitrary surface layer in the image area of the toner carrier is calculated, and the arithmetic average value is used as the coverage in the present invention. The substance present at the interface between the surface resin and the resin particles was subjected to elemental analysis using EDAX (non-dispersive X-ray analyzer).

<Measurement of number of surface silica parts>
In the present invention, the surface silica part is calculated from the difference between the silica part of the whole toner and the silica part of the toner from which the surface silica is removed.

  In order to remove the surface silica, the following procedure is performed. It has been confirmed that only the silica on the toner surface can be sufficiently removed by the following treatment.

  In a glass 200 ml Erlenmeyer flask, 100 ml of 10 mol / l sodium hydroxide aqueous solution and 5 g of toner are put. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. About 0.3 ml of a diluted solution obtained by diluting 3) with ion-exchanged water is added. The toner dispersion is stirred for 1 hour using a magnetic stirrer. Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dissipation System Tetora 150” (manufactured by Nikkei Bios Co., Ltd.) having an electrical output of 120 W is prepared. A predetermined amount of ion-exchanged water is placed in a water tank of an ultrasonic disperser, and about 2 ml of the contamination N is added to the water tank. The Erlenmeyer flask containing the toner dispersion is set on the ultrasonic disperser, and the ultrasonic disperser is operated. Then, the height position of the beaker is adjusted so that the resonance state of the liquid surface of the electrolytic aqueous solution in the Erlenmeyer flask is maximized, and the ultrasonic dispersion treatment is continued for 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower. Further, the toner dispersion is stirred for 4 hours using a magnetic stirrer. The toner dispersion is filtered, and the obtained residue is washed twice with 200 ml of ion-exchanged water. Then, drying is performed at 40 ° C. for 1 day in a vacuum dryer. The number of silica parts on the toner surface can be calculated from the difference in the number of silica parts between the treated product and the toner.

  X-ray fluorescence can be used to calculate the number of silica parts. The measurement of fluorescent X-rays conforms to JIS K 0119-1969, and is specifically as follows.

  As a measuring device, a wavelength dispersion type fluorescent X-ray analyzer “Axios” (manufactured by PANalytical) and attached dedicated software “SuperQ ver. 4.0F” (manufactured by PANalytical) for setting measurement conditions and analyzing measurement data ) Is used. Rh is used as the anode of the X-ray tube, the measurement atmosphere is vacuum, the measurement diameter (collimator mask diameter) is 27 mm, and the measurement time is 10 seconds. Further, when measuring a light element, it is detected by a proportional counter (PC), and when measuring a heavy element, it is detected by a scintillation counter (SC). As a measurement sample, about 4 g of the toner or the above processed product is put in a dedicated aluminum ring for pressing and leveled, and a tablet molding compressor “BRE-32” (manufactured by Maekawa Test Instruments Co., Ltd.) is used. The pellets used were pressed at 20 MPa for 60 seconds and molded to a thickness of about 2 mm and a diameter of about 39 mm. The measurement is performed under the above conditions, the element is identified based on the obtained X-ray peak position, and the concentration is calculated from the count rate (unit: cps) which is the number of X-ray photons per unit time.

  The method for calculating the number of silica parts in the toner will be specifically described below.

Silica (SiO ₂ ) fine powder is added to 0.10 parts by mass with respect to 100.00 parts by mass of the toner particles, and sufficiently mixed using a coffee mill. Similarly, the silica fine powder is mixed with the toner particles so as to be 1.00 parts by mass, 5.00 parts by mass and 10.00 parts by mass, respectively, and these are used as samples for the calibration curve.

  For each sample, a pellet for a calibration curve was prepared as described above using a tablet molding compressor, and the diffraction angle (2θ) was observed at 109.08 ° when PET was used as a spectroscopic crystal. The counting rate (unit: cps) of Si-Kα rays is measured. At this time, the acceleration voltage and current value of the X-ray generator are 24 kV and 100 mA, respectively. A linear function calibration curve is obtained with the X-ray count rate obtained on the vertical axis and the number of silica parts in each calibration curve sample on the horizontal axis.

  Next, the toner to be analyzed is pelletized as described above using a tablet molding compressor, and the counting rate of the Si-Kα rays is measured. Then, the number of silica parts for 1.00 parts by mass of toner particles is determined from the calibration curve.

  From the difference between the number of silica parts of the toner obtained and the number of silica parts of the treated product, the number of silica parts on the toner surface with respect to 1.00 parts by mass of toner particles can be calculated.

<Measurement of Median Diameter D50t Based on Number of Toner Particles>
As a measuring device, a precise particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method equipped with a 100 μm aperture tube is used. For setting the measurement conditions and analyzing the measurement data, the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) is used. The measurement is performed with 25,000 effective measurement channels. As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used. Prior to measurement and analysis, the dedicated software was set as follows. On the “Change Standard Measurement Method (SOM)” screen of the dedicated software, set the total count in the control mode to 50000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter, Inc.) Set the value obtained using By pressing the “Threshold / Noise Level Measurement Button”, the threshold and noise level are automatically set. In addition, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the “aperture tube flush after measurement” is checked. In the “Pulse to particle size conversion setting” screen of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm to 60 μm. The specific measurement method is as follows.

  (1) About 200 ml of the electrolytic solution is placed in a glass 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rpm.

  Then, the dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the dedicated software.

  (2) About 30 ml of the electrolytic aqueous solution is put into a glass 100 ml flat bottom beaker.

  In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. About 0.3 ml of a diluted solution obtained by diluting 3) with ion-exchanged water is added.

  (3) Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dissipation System Tetora 150” (manufactured by Nikki Bios Co., Ltd.) having an electrical output of 120 W is prepared.

  A predetermined amount of ion-exchanged water is placed in a water tank of an ultrasonic disperser, and about 2 ml of the contamination N is added to the water tank.

  (4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.

  (5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.

  (6) To the round bottom beaker of (1) installed in the sample stand, the electrolyte solution of (5) in which the toner is dispersed is dropped using a pipette, and the measurement concentration is adjusted to about 5%. . Measurement is performed until the number of measured particles reaches 50,000.

  (7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the number-based median diameter D50t is calculated. The “average diameter” on the “analysis / number statistical value (arithmetic average)” screen when the graph / number% is set in the dedicated software is the median diameter D50t based on the number of toners.

<Measurement of theoretical specific surface area of toner>
The theoretical specific surface area (m ² / g) obtained from the particle size distribution of the toner is calculated as follows. As a measuring device, a precise particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method equipped with a 100 μm aperture tube is used. The measurement conditions are set in the same manner as the measurement of the median diameter D50t based on the number of toners described above. The measurement data is analyzed with the dedicated software attached to the apparatus, and the theoretical specific surface area is calculated as described later. First, the following results are calculated on the “analysis / number statistics (arithmetic mean)” screen when graph / number% is set in the dedicated software. In the measurement result of the particle size distribution (number statistic value) of the measured toner sample, it is divided into the following 16 channels and the number% of the particle size within each range is calculated.

CH range DIF% (number%)
1 1.587 to 2.000 μm N ₁
2 2.000 to 2.520 μm N ₂
3 2.520 to 3.175 μm N ₃
4 3.175 to 4.000 μm N ₄
5 4.000 to 5.040 μm N ₅
6 5.040 to 6.350 μm N ₆
7 6.350 to 8.000 μm N ₇
8 8.000 to 10.079 μm N ₈
9 10.079 to 12.699 μm N ₉
10 12.699 to 16.000 μm N ₁₀
11 16.000 to 20.159 μm N ₁₁
12 20.159 to 25.398 μm N ₁₂
13 25.398 to 32.000 μm N ₁₃
14 32.000 to 40.317 μm N ₁₄
15 40.317 to 50.797 μm N ₁₅
16 50.797 to 64.000 μm N ₁₆
Next, it is assumed that the particles in the range of the particle size of each range are true spherical particles having a specific gravity of 1.00 (g / cm ³ ) and having a particle size just in the middle of each range (for example, 1.587 to 2. (All particles in the range of 000 μm are assumed to be 1.7935 μm.) From the surface area per particle of the particles in each range and the number% of particles in each range, the theoretical specific surface area of toner per 1.00 g of toner (m ² / G). In other words, assuming that the radius of an intermediate particle in a certain range is Rn (m) and the number% of the range is Nn (number%), the calculation is performed for all applicable ranges, and the theoretical ratio obtained from the particle size distribution of the toner is calculated. The surface area is calculated from the following formula.

Theoretical specific surface area =
{Σ (4πRn ² × Nn)} / [Σ {(4/3) πRn ³ × Nn × 1.00 × 10 ⁻⁶ }]
(Where n = 1 to 16)
<Measurement of surface silica index>
The surface silica index A is calculated by dividing the aforementioned number of surface silica parts by the theoretical toner surface area per 1.00 g of toner, as shown in the formula (1).

A = (Amount of surface silica with respect to 1.00 g of toner particles (g)) / (theoretical specific surface area of toner (m ² / g)) Formula (1)
<Measurement of average circularity of toner>
The average circularity of the toner particles is measured by a flow type particle image analyzer “FPIA-3000” (manufactured by Sysmex Corporation) under the measurement and analysis conditions during the calibration operation.

  The measurement principle of the flow-type particle image analyzer “FPIA-3000” (manufactured by Sysmex Corporation) is to capture flowing particles as a still image and perform image analysis. The sample added to the sample chamber is fed into the flat sheath flow cell by a sample suction syringe. The sample fed into the flat sheath flow is sandwiched between sheath liquids to form a flat flow. The sample passing through the flat sheath flow cell is irradiated with strobe light at 1/60 second intervals, and the flowing particles can be photographed as a still image. Further, since the flow is flat, the image is taken in a focused state. The particle image is picked up by a CCD camera, and the picked-up image is image-processed with an image processing resolution of 512 × 512 (0.37 μm × 0.37 μm per pixel), the contour of each particle image is extracted, and the particle image The projected area S, the peripheral length L, and the like are measured.

  Next, the equivalent circle diameter and the circularity are obtained using the area S and the peripheral length L. The equivalent circle diameter is the diameter of a circle having the same area as the projected area of the particle image, and the circularity C is a value obtained by dividing the circumference of the circle obtained from the equivalent circle diameter by the circumference of the projected particle image. And is calculated by the following formula.

Circularity C = 2 × (π × S) ^1/2 / L
When the particle image is circular, the degree of circularity is 1, and the degree of unevenness on the outer periphery of the particle image increases, and the degree of circularity decreases. After calculating the circularity of each particle, the range of the circularity of 0.200 to 1.000 is divided into 800, the arithmetic average value of the obtained circularity is calculated, and the value is defined as the average circularity.

  A specific measurement method is as follows. First, about 20 ml of ion-exchanged water from which impure solids are removed in advance is put in a glass container. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. About 0.2 ml of a diluted solution obtained by diluting the solution with ion exchange water about 3 times by mass. Further, about 0.02 g of a measurement sample is added, and dispersion treatment is performed for 2 minutes using an ultrasonic disperser to obtain a dispersion for measurement. In that case, it cools suitably so that the temperature of a dispersion liquid may become 10 to 40 degreeC. As the ultrasonic disperser, a desktop type ultrasonic cleaner disperser (for example, “VS-150” (manufactured by VervoCrea)) having an oscillation frequency of 50 kHz and an electric output of 150 W is used. Ion exchange water is added, and about 2 ml of the above-mentioned Contaminone N is added to this water tank. For the measurement, the above-mentioned flow type particle image analyzer equipped with “UPlanApro” (magnification 10 times, numerical aperture 0.40) as an objective lens is used, and the particle sheath “PSE-900A” (manufactured by Sysmex Corporation) is used as the sheath liquid. It was used. The dispersion prepared in accordance with the above procedure is introduced into the flow type particle image analyzer, and 3000 toner particles are measured in the HPF measurement mode and in the total count mode. Then, the binarization threshold at the time of particle analysis is set to 85%, the analysis particle diameter is limited to the circle equivalent diameter of 1.985 μm or more and less than 39.69 μm, and the average circularity of the toner particles is obtained. In the measurement, automatic focus adjustment is performed using standard latex particles (eg, “RESEARCH AND TEST PARTICLES Latex Microsphere Suspensions 5200A” manufactured by Duke Scientific) diluted with ion-exchanged water before starting the measurement. Thereafter, it is preferable to perform focus adjustment every two hours from the start of measurement. In the examples of the present application, a flow-type particle image analyzer that has been issued a calibration certificate issued by Sysmex Corporation, which has been calibrated by Sysmex Corporation, was used. Measurement was performed under the measurement and analysis conditions when the calibration certificate was received, except that the analysis particle size was limited to a circle equivalent diameter of 1.985 μm or more and less than 39.69 μm.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the examples.

<Production Example of Resin Particle Base (1)>
A 2 L autoclave that had been sufficiently replaced with nitrogen gas and dried in advance was prepared. The autoclave was charged with 700 g of trifunctional polypropylene polyol “MN-400” (trade name, hydroxyl value 235 mg KOH / g, manufactured by Takeda Chemical Polyurethane Co., Ltd.) and 1000 g of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd.). Next, the upper gas was replaced with nitrogen gas, and the mixture was sealed and reacted at 120 ° C. for 20 hours with stirring. Thereafter, unreacted hexamethylene diisocyanate was removed under reduced pressure, and toluene was added to obtain a synthesized product (1) having a nonvolatile content of 90% by mass. NCO% of this synthesized product (1) was 9.1%.

  Next, 900 g of water was charged into a separable flask equipped with a 2 L stirrer, and 32 g of “Metroze 90SH-100” (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) was dissolved therein to prepare a dispersion medium. Then, a suspension obtained by diluting 261 g of the compound (1) with 112 g of toluene was added to the dispersion medium with stirring at 500 rpm to prepare a suspension. The suspension was heated to 60 ° C. with stirring and reacted for 1.5 hours. Thereafter, the mixture was cooled to room temperature, separated into solid and liquid, sufficiently washed with water, and then dried at 70 ° C. for 20 hours to obtain a resin particle matrix (1) which is ether urethane having an average primary particle size of 6.2 μm.

<Production Example of Resin Particle Base (2)>
As an acrylic resin, 100 parts by mass of Delpet 60N manufactured by Asahi Kasei Chemicals Co., Ltd. was sufficiently premixed with a Henschel mixer, and melt kneaded at an arbitrary barrel temperature with a twin screw extruder kneader. After cooling, it was coarsely pulverized using a hammer mill, and as a first stage, it was finely pulverized to a particle size of 10 μm or less with a mechanical pulverizer. Furthermore, as a second stage, the finely pulverized product was further pulverized by a mechanical pulverizer whose pulverization conditions were changed, and the obtained finely pulverized product was subjected to thermal spheronization treatment at an arbitrary temperature using a thermal spheronizer. Thereafter, the obtained finely pulverized product is classified by a multi-division classifier (Elbow Jet Classifier manufactured by Nittetsu Mining Co., Ltd.) using the Coanda effect, and a resin particle matrix which is an acrylic resin particle having an average primary particle size of 6.5 μm. (2) was obtained.

<Production Example of Resin Particle (1)>
The following materials were mixed for 5 minutes using a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) at a rotational speed of 4000 rpm to obtain resin particles (1).

Resin particle matrix (1) 100.0 parts by mass Silica 1 (Reorosil MT-10 (average primary particle size 15 nm) manufactured by Tokuyama)
0.30 parts by mass <Preparation of resin particles (2) to (8), (10), (11)>
Resin particles (2) to (8), (10), (11) are produced in the same manner as the production of the resin particles 1 except that the resin particle matrix and inorganic fine particles described in Table 1 are used and the conditions described in Table 2 are used. Got.

  In addition, the following were used as the silica 2, titania and alumina in Table 1.

Silica 2: OX50 (average primary particle size 30 nm) manufactured by Nippon Aerosil Co., Ltd.
Titania: AMT-100 (average primary particle size 6 nm) manufactured by Teika
Alumina: AEROXIDE Alu C (average primary particle size 13 nm) manufactured by Nippon Aerosil Co., Ltd.
<Production Example of Resin Particle (9)>
A resin particle (9) was obtained by adding no inorganic fine particles to the resin particle matrix (1).

<Synthesis Example of Polyol Compound (1)>
79.6 parts by mass of methyl ethyl ketone (MEK) and 100.0 parts by mass of polytetramethylene glycol (trade name: “PTG1000SN”, manufactured by Hodogaya Chemical Co., Ltd.) and 4,4-diphenylmethane diisocyanate (trade name: “Cosmonate PH”), 19.4 parts by mass of Mitsui Chemicals Polyurethane) were mixed stepwise. The mixture was reacted at 75 ° C. for 4.5 hours under a nitrogen atmosphere to obtain a MEK solution of a polyether polyurethane polyol (1) having a weight average molecular weight Mw = 12000 and a hydroxyl value of 22 mgKOH / g.

<Synthesis Example of Polyol Compound (2)>
79.6 parts by mass of methyl ethyl ketone (MEK) and 100.0 parts by mass of polyester polyol (trade name: “P-1010”, manufactured by Kuraray Co., Ltd.) and 4,4-diphenylmethane diisocyanate (trade name: “Cosmonate PH”, Mitsui Chemicals) 19.4 parts by mass of Polyurethane) was mixed stepwise. The mixture was reacted at 75 ° C. for 4.5 hours in a nitrogen atmosphere to obtain a MEK solution of polyester polyurethane polyol (2) having a weight average molecular weight Mw = 11000 and a hydroxyl value of 21 mgKOH / g.

<Synthesis Example of Isocyanate Compound (1)>
Under a nitrogen atmosphere, 100.0 parts by mass of polytetramethylene glycol (trade name: “PTG1000SN”, manufactured by Hodogaya Chemical Co., Ltd.) and polymeric diphenylmethane diisocyanate (trade name: “Millionate MR-200”, manufactured by Nippon Polyurethane Industry Co., Ltd.) 69.6 parts by mass were reacted by heating at 80 ° C. for 2 hours. Thereafter, 72.7 parts by mass of butyl cellosolve was added.

  Furthermore, 25.8 parts by mass of 2-butanone oxime (manufactured by Ardrich) was added dropwise under a reaction temperature of 50 ° C. to obtain a butyl cellosolve solution of the isocyanate compound (1) having a weight average molecular weight Mw = 38000.

<Example of production of conductive shaft core>
As a conductive shaft core, a primer (trade name: “DY35-051”, manufactured by Toray Dow Corning Silicone) was applied to a 6 mm diameter cored bar made of SUS304, and baked at a temperature of 150 ° C. for 30 minutes.

<Example of production of elastic layer>
Next, the conductive shaft core is placed in a mold, and liquid conductive silicone rubber (manufactured by Toray Dow Corning Silicone, ASKER-C hardness 45 degrees, volume resistivity 1 × 10 ⁵ Ω · cm) is placed in the mold. Was injected into the cavity formed. Subsequently, the mold was heated to vulcanize the silicone rubber at 150 ° C. for 15 minutes, removed from the mold, and then heated at 200 ° C. for 2 hours to complete the curing reaction. In this way, an elastic layer having a diameter of 12 mm was provided on the outer periphery of the conductive shaft core.

<Example of production of coating material containing surface layer binder resin (1)>
The following materials are mixed and stirred by a stirring motor, dissolved in MEK so that the total solid content becomes 30% by mass, mixed and then uniformly dispersed by a sand mill, and the surface layer binder resin-containing paint (1) Got.

Polyol compound (1) 62.0 parts by mass (as solid content)
Isocyanate compound (1) 38.0 parts by mass (as solid content)
Carbon black (trade name: “MA100”, manufactured by Mitsubishi Chemical Corporation) 20.0 parts by mass <Preparation Example of Surface Layer Binder Resin-Containing Paint (2)>
The following materials are mixed and stirred by a stirring motor, dissolved in MEK so that the total solid content is 30% by mass, mixed and then uniformly dispersed by a sand mill, and the surface layer binder resin-containing paint (2) Got.

Polyol compound (2) 62.0 parts by mass (as solid content)
Isocyanate compound (1) 38.0 parts by mass (as solid content)
Carbon black (trade name: “MA100”, manufactured by Mitsubishi Chemical Corp.) 20.0 parts by mass <Preparation Example of Surface Layer Binder Resin-Containing Paint (3)>
The following materials are mixed and stirred by a stirring motor, dissolved in MEK so that the total solid content is 30% by mass, mixed and then uniformly dispersed by a sand mill, and the surface layer binder resin-containing paint (3) Got.

Acrylic resin (Hitaroid 3001; Hitachi Chemical Co., Ltd.) 100.0 parts by mass Isocyanate compound (Coronate L; Nippon Polyurethane Co., Ltd.) 12.0 parts by mass Carbon black (trade name: “MA100”, manufactured by Mitsubishi Chemical Corporation) 0 part by mass <Example of preparation of toner carrier (1)>
Surface layer binder resin-containing paint (1) 25 parts by mass of urethane resin particles (1) was added to 100 parts by mass, and after uniformly dispersing with a sand mill, dip coating was performed on the elastic layer. After drying, a surface layer having a film thickness of 6.0 μm was provided on the outer periphery of the elastic layer by heating and curing at a temperature of 140 ° C. for 2 hours. The obtained toner carrier is referred to as “toner carrier (1)”.

<Examples of production of toner carrier (2) to (13)>
Toner carriers (2) to (13) were obtained in the same manner except that the surface layer binder resin-containing paint and resin particles shown in Table 2 were used in Preparation Example (1) of the toner carrier.

<Example of toner particle production (1)>
29 parts by mass of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 31 parts by mass of polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, Put 20.5 parts by mass of terephthalic acid, 3.5 parts by mass of trimellitic anhydride, 26 parts by mass of fumaric acid and dibutyltin oxide into a 4 liter glass four-necked flask and introduce a thermometer, stirring rod, condenser and nitrogen. The tube was attached to a four-necked flask, and this four-necked flask was placed in a mantle heater. The reaction was allowed to proceed for 3.5 hours at 195 ° C. in a nitrogen atmosphere to obtain a polyester resin (1). The peak molecular weight (Mp) obtained by molecular weight distribution measurement using gel permeation chromatography (GPC) of the obtained polyester resin (1) is 6,700, and ASTM D3418-82 is measured using a differential scanning calorimeter. The glass transition temperature (Tg) measured accordingly was 64 ° C.

  Next, a toner for evaluation was produced using the following materials and production method.

-100.00 mass parts of the said polyester resin (1)-C.I. I. Pigment Blue 15: 3 5.00 parts by mass-Negative charge control agent (Orient Chemical Industries, Ltd .: Bontron E88) 0.60 parts by mass-Wax (Nippon Seiwa Wax: HNP-10) 5.00 parts by mass-Silica fine powder Body (RX200 manufactured by AEROSIL) 3.00 parts by mass Divinylbenzene 0.30 parts by mass The above prescription was mixed with a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.), and then the temperature was set to 120 ° C. Kneading with a biaxial kneader (PCM-30 type, manufactured by Ikegai Iron Works Co., Ltd.). The obtained kneaded material was cooled and coarsely pulverized to 1 mm or less with a hammer mill to obtain a coarsely pulverized material. The obtained coarsely crushed material was pulverized with a mechanical pulverizer (T-250, manufactured by Turbo Kogyo Co., Ltd.). Further, the toner particles (1) were obtained by classifying with a multi-division classifier (Elbow Jet classifier manufactured by Nittetsu Mining Co., Ltd.) using the Coanda effect. The number-based median diameter D50t of the obtained toner particles (1) was 7.1 μm.

<Example of toner particle production (2)>
Toner particles (2) were obtained in the same manner as in the toner particle production example (1) except that silica fine powder was not added. The number-based median diameter D50t of the obtained toner particles (2) was 7.5 μm.

<Production Example of Toner Particles (3)>
Toner particles (3) were obtained in the same manner as in the toner particle production example (1) except that the pulverization conditions and classification conditions with a mechanical pulverizer (T-250, manufactured by Turbo Industry Co., Ltd.) were changed. The number-based median diameter D50t of the obtained toner particles (3) was 9.7 μm.

<Toner Production Example (1)>
The toner particles (1) were heat-treated in the surface treatment apparatus shown in FIG. The operating condition was a feed amount = 5 kg / hr. Also, hot air temperature C = 260 ° C., hot air flow rate = 6 m ³ / min, cold air (absolute water content: 2 g / m ³ ), second cold air temperature E = 5 ° C., cold air flow rate = 5 m ³ / min, second The cold air flow rate = 1 m ³ / min, the blower air flow rate = 20 m ³ / min, the injection air flow rate = 1 m ³ / min, and the diffusion air = 0.4 m ³ / min. Further, the particles were classified by a multi-division classifier using the Coanda effect (elbow jet classifier manufactured by Nippon Steel Mining Co., Ltd.) to obtain particles having an average circularity of 0.985.

  To 100.0 parts by mass of the obtained particles, 2.5 parts by mass of silica fine powder (RX200 manufactured by AEROSIL, Japan) is added, and a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) is used for 5 minutes at a rotational speed of 4000 rpm. A mixing step was performed to obtain toner (1).

<Example of toner production (2)>
To 100.0 parts by mass of toner particles (2), 2.5 parts by mass of silica fine powder (RX200 manufactured by AEROSIL, Japan) is added, and 5 rpm under the condition of a rotational speed of 4000 rpm using a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.). A mixing step was performed for a minute.

  Next, the obtained particles were subjected to heat treatment using the surface treatment apparatus shown in FIG.

The operating condition was a feed amount = 5 kg / hr. Also, hot air temperature C = 260 ° C., hot air flow rate = 6 m ³ / min, cold air (absolute water content: 2 g / m ³ ), second cold air temperature E = 5 ° C., cold air flow rate = 5 m ³ / min, second The cold air flow rate = 1 m ³ / min, the blower air flow rate = 20 m ³ / min, the injection air flow rate = 1 m ³ / min, and the diffusion air = 0.4 m ³ / min. Further, the particles were classified by a multi-division classifier using the Coanda effect (elbow jet classifier manufactured by Nittetsu Mining Co., Ltd.) to obtain particles having an average circularity of 0.981.

  To 100.0 parts by mass of the obtained particles, 3.0 parts by mass of silica fine powder (RX200, manufactured by AEROSIL, Japan) is added, and using a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) for 5 minutes at a rotational speed of 4000 rpm. A mixing step was performed to obtain a toner (2).

<Examples of toner production (3), (9)>
Toners (3) and (9) were obtained in the same manner as in Toner Production Example (1) except that the toner was prepared with the number of silica addition parts shown in Table 3. Table 3 shows the physical properties of the obtained toner.

<Examples of toner production (4), (10)>
Toners (4) and (10) were obtained in the same manner as in Toner Production Example (2) except that the toner was prepared with the number of silica addition parts shown in Table 3. Table 3 shows the physical properties of the obtained toner.

<Example of toner production (5)>
The toner (5) was prepared in the same manner as in the toner production example (1) except that the toner particles (3) were used instead of the toner particles (1) and the toner was prepared with the number of silica additions shown in Table 3. Obtained. Table 3 shows the physical properties of the obtained toner.

<Examples of toner production (6), (8)>
Toners (6) and (8) were obtained in the same manner as in Toner Production Example (2) except that the hot air temperature during the heat treatment was changed. Table 3 shows the physical properties of the obtained toner.

<Example of toner production (7)>
Toner particles (2) were subjected to spheroidization and fine powder removal using a surface modification device faculty (manufactured by Hosokawa Micron Corporation) twice to obtain particles having an average circularity of 0.951.

  To 100.0 parts by mass of the obtained particles, 2.5 parts by mass of silica fine powder (RX200 manufactured by AEROSIL, Japan) is added, and a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) is used for 5 minutes at a rotational speed of 4000 rpm. A mixing step was performed to obtain a toner (7).

<Example 1>
As an image forming apparatus, a commercially available laser printer LBP-3700 (manufactured by HP) was remodeled (process speed was 250 mm / s, and the toner regulating member was remodeled so that a blade bias of −200 V was applied to the developing bias. Used). In the evaluation, the toner carrier of the image output cartridge was replaced with the toner carrier (1), and a toner charged with 170 g of the toner (1) as a toner was attached to the cyan station, and image evaluation was performed. In addition to the cyan station, evaluation was performed by mounting a cartridge of a normal product. The evaluation environment includes a normal temperature and normal humidity environment (N / N: temperature 23.5 ° C., humidity 60.0% RH) and a high temperature and high humidity environment (H / H: temperature 32.5 ° C., humidity 80.0% RH). ) Was evaluated.

The image evaluation items are as follows, and the image evaluation was performed after printing 20,000 images with a printing rate of 1% on the paper at the initial stage. During printing, a pause period of 7 seconds was provided every time two sheets were printed.
Further, LETTER size XEROX 4200 paper (manufactured by XEROX, 75 g / m ² ) was used as evaluation paper. The obtained evaluation results are shown in Table 5.

<Striped image effects>
The streak-like image damage was evaluated using a halftone (30H) image. The 30H image is a value obtained by displaying 256 gradations in hexadecimal, and is a halftone image when 00H is solid white and FFH is solid black.

  Rank A: No streak-like harmful effect is seen on the image.

  Rank B: There are 3 or less streak-like image defects on the image.

  Rank C: There are four or more streaky image defects on the image.

<Fog after leaving>
Under each environment, after the initial printing and 20000 printing, the cartridge was placed in a machine that was turned off in a high temperature and high humidity environment and left for 2 days. Thereafter, an entire white image was output to a LETTER size HP Photo Paper (HP, 220 g / m ² ) at a process speed of 30 mm / s. The reflectivity (%) of the five places on the paper that has not been imaged is measured by a reflectometer (“REFLECTOMETER MODEL TC-6DS” manufactured by Tokyo Denshoku Co., Ltd.) equipped with an amber filter, and these average values are calculated. The average reflectance of the paper. Next, the reflectances (%) at five locations of the entire white image are measured, and these average values are taken as the average reflectance of the entire white image. The fog density (%) was calculated from the difference between the average reflectance of the entire white image and the average reflectance of the paper, and the image fog was evaluated based on the following criteria. Since this phenomenon occurs due to charging failure, the evaluation was performed in a high-temperature and high-humidity environment where the charge amount is the lowest and this phenomenon easily occurs.

Rank A: fog density of less than 1.0% Rank B: fog density of 1.0% or more and less than 3.0% Rank C: fog density of 3.0% or more <Halftone uniformity>
A halftone (30H) image was formed after the initial printing and after 20000 printing, and this image was visually observed, and the dot reproducibility of the image was evaluated based on the following criteria.

Rank A: Image with very good image uniformity and very clear image Rank B: Image with excellent image uniformity and good image Rank C: Image quality with no practical problems <Examples 2 to 15 and Comparative Example 1 To 7>
The above-described image evaluation was performed in the same manner as in Example 1 except that the toner and the toner carrier were changed as shown in Table 4. The evaluation results are shown in Table 5.

DESCRIPTION OF SYMBOLS 1 Toner carrier 2 Conductive shaft core 3 Elastic layer 4 Surface layer 100 Toner supply port 101 Hot-air supply port 102 Airflow injection member 103 Cold-air supply port 104 Second cold-air supply port 106 Cooling jacket 110 Diffusion air 111 The purpose of preventing condensation Airflow supply port 112 Diffusion member having a plurality of holes 114 Toner 115 Air supply nozzle 116 Transfer piping

Claims (1)

A development method comprising at least a step of regulating toner on a toner carrier with a toner regulating member, and a step of developing an electrostatic latent image on an electrostatic latent image carrier using toner on the toner carrier,
The toner carrier includes a shaft core, an elastic layer provided on an outer periphery of the shaft core, and resin particles provided on the outer periphery of the elastic layer for forming a convex portion on the surface of the toner carrier. And a surface layer that
The surface layer is mainly composed of urethane resin or acrylic resin,
i) When the surface layer is mainly composed of a urethane resin, the resin particles are urethane resin particles,
ii) When the surface layer is mainly composed of an acrylic resin, the resin particles are acrylic resin particles,
The resin particles have a surface coated with inorganic fine particles, and the coverage of the resin particles with the inorganic fine particles is 10 to 90%,
The toner is a toner obtained by externally adding at least silica fine powder to toner particles, and the surface silica index A defined by the following formula is 1.5 × 10 ^{−2 to} 6.0 × 10 ^−2. Development method characterized.
A = (Amount of surface silica with respect to 1.00 g of toner particles (g)) / (theoretical specific surface area of toner (m ² / g))

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